| 1. |
- Braekeveldt, Noémie, et al.
(författare)
-
Neuroblastoma patient-derived orthotopic xenografts reflect the microenvironmental hallmarks of aggressive patient tumours
- 2016
-
Ingår i: Cancer Letters. - : Elsevier BV. - 1872-7980 .- 0304-3835. ; 375:2, s. 384-389
-
Tidskriftsartikel (refereegranskat)abstract
- Treatment of high-risk childhood neuroblastoma is a clinical challenge hampered by a lack of reliable neuroblastoma mouse models for preclinical drug testing. We have previously established invasive and metastasising patient-derived orthotopic xenografts (PDXs) from high-risk neuroblastomas that retained the genotypes and phenotypes of patient tumours. Given the important role of the tumour microenvironment in tumour progression, metastasis, and treatment responses, here we analysed the tumour microenvironment of five neuroblastoma PDXs in detail. The PDXs resembled their parent tumours and retained important stromal hallmarks of aggressive lesions including rich blood and lymphatic vascularisation, pericyte coverage, high numbers of cancer-associated fibroblasts, tumour-associated macrophages, and extracellular matrix components. Patient-derived tumour endothelial cells occasionally formed blood vessels in PDXs; however, tumour stroma was, overall, of murine origin. Lymphoid cells and lymphatic endothelial cells were found in athymic nude mice but not in NSG mice; thus, the choice of mouse strain dictates tumour microenvironmental components. The murine tumour microenvironment of orthotopic neuroblastoma PDXs reflects important hallmarks of aggressive and metastatic clinical neuroblastomas. Neuroblastoma PDXs are clinically relevant models for preclinical drug testing.
|
|
| 2. |
- Ekberg, Jenny, et al.
(författare)
-
Expression of cyclin A1 and cell cycle proteins in hematopoietic cells and acute myeloid leukemia and links to patient outcome
- 2005
-
Ingår i: European Journal of Haematology. - : Wiley-Blackwell Publishing Inc.. - 0902-4441 .- 1600-0609. ; 75:2, s. 106-115
-
Tidskriftsartikel (refereegranskat)abstract
- Abnormal expression of several key regulators essential for G1/S transitions has been implicated in tumorigenesis. A critical role of cyclin A1 in the development of acute myeloid leukemia (AML) has previously been demonstrated in transgenic mice. Our present study focused on the expression and prognostic significance of cyclin A1 and a panel of cell cycle regulatory proteins including cyclin A2, cyclin B1, cyclin E, CDK1, CDK2, p21 and p27 in bone marrow samples from 40 patients with AML. Freshly isolated CD34+ hematopoietic cells and bone marrow samples from 10 healthy donors were also assessed for cell type- and subcellular-specific expression of the cell cycle regulatory proteins. The level of cyclin A1 expression was the only factor that showed a significant correlation with patient outcome. In log-rank test stratified by levels of cyclin A1 expression, patients with high levels of cyclin A1 had significantly worse overall survival (OS) (P = 0.012) compared to those with low levels. Further, patients with high levels of cyclin A1 had significantly lower disease-free survival (DFS) (P = 0.028). Multivariate analysis indicated that cyclin A1 protein expression was an independent prognostic factor for predicting DFS (P = 0.035) and OS (P = 0.045). No correlation between cyclin A1 expression and age was found. However, expression of cyclin A2, cyclin B1, cyclin E, CDK1, CDK2, p21 and p27 did not show prognostic significance in these AML patients.
|
|
| 3. |
- Ekberg, Jenny, et al.
(författare)
-
Regulation of the cyclin A1 protein is associated with its differential subcellular localization in hematopoietic and leukemic cells
- 2004
-
Ingår i: Oncogene. - : Nature Publishing Group. - 0950-9232 .- 1476-5594. ; 23:56, s. 9082-9089
-
Tidskriftsartikel (refereegranskat)abstract
- An important role of the cell cycle regulatory protein cyclin A1 in the development of acute myeloid leukemia (AML) was previously demonstrated in a transgenic mouse model. We have now turned our attention to study specific aspects of the activity and subcellular distribution of cyclin A1 using bone marrow samples from normal donors and patients with AML, as well as leukemic cell lines. We show that the localization of cyclin A1 in normal hematopoietic cells is nuclear, whereas in leukemic cells from AML patients and cell lines, it is predominantly cytoplasmic. In leukemic cell lines treated with all-trans retinoic acid (ATRA), cyclin A1 localized to the nucleus. Further, there was a direct interaction between cyclin A1 and cyclin-dependent kinase 1, as well as a major ATRA receptor, RARalpha, in ATRA-treated cells but not in untreated leukemic cells. Our results indicate that the altered intracellular distribution of cyclin A1 in leukemic cells correlates with the status of the leukemic phenotype.
|
|
| 4. |
- Holm, Caroline, et al.
(författare)
-
Cyclin A1 expression and associations with disease characteristics in childhood acute lymphoblastic leukemia
- 2006
-
Ingår i: Leukemia Research. - : Elsevier. - 0145-2126 .- 1873-5835. ; 30:3, s. 254-261
-
Tidskriftsartikel (refereegranskat)abstract
- A critical cell cycle regulatory protein, cyclin A1, has been implicated in the development of acute myeloid leukemia (AML). Here, we have examined the expression and clinical significance of cyclin A1 in childhood acute lymphoblastic leukemia (ALL). Cyclin A1 was highly expressed in lymphoblastic leukemic cell lines and in 22 of 30 ALL patients (73%). Cyclin A1 expression correlated with patient age (P=0.006), but not with cytogenetic abnormalities. Patients with high levels of cyclin A1 had poorer event-free survival (57.9%) compared to patients with lower levels (75%).
|
|
| 5. |
- Kok, Marleen, et al.
(författare)
-
PKA-induced phosphorylation of ER alpha at serine 305 and high PAK1 levels is associated with sensitivity to tamoxifen in ER-positive breast cancer
- 2011
-
Ingår i: Breast Cancer Research and Treatment. - : Springer Science and Business Media LLC. - 1573-7217 .- 0167-6806. ; 125:1, s. 1-12
-
Tidskriftsartikel (refereegranskat)abstract
- Phosphorylation of estrogen receptor alpha at serine 305 (ER alpha S305-P) by protein kinase A (PKA) or p21-activated kinase 1 (PAK1) has experimentally been associated with tamoxifen sensitivity. Here, we investigated the clinical application of this knowledge to predict tamoxifen resistance in ER-positive breast cancer patients. Using immunohistochemistry, a score including PAK1 and co-expression of PKA and ER alpha S305-P (PKA/ER alpha S305-P) was developed on a training set consisting of 103 patients treated with tamoxifen for metastatic disease, and validated on 231 patients randomized between adjuvant tamoxifen or no treatment. In the training set, PAK1 levels were associated with tumor progression after tamoxifen (HR 1.57, 95% CI 0.99-2.48), as was co-expression of PKA and ER alpha S305-P (HR 2.00, 95% CI 1.14-3.52). In the validation set, a significant tamoxifen benefit was found among the 73% patients negative for PAK1 and PKA/ER alpha S305-P (HR 0.54, 95% CI 0.34-0.87), while others (27%) were likely to have no benefit from tamoxifen (HR 0.88, 95% 0.42-1.82). The test for interaction showed a significant difference in recurrence-free survival between groups defined by PAK1 and PKA/ER alpha S305-P (P = 0.037). Elevated PAK1 and PKA/ER alpha S305-P appeared to influence tamoxifen sensitivity. Both PAK1 and PKA/ER alpha S305-P levels were associated with sensitivity to tamoxifen in breast tumors and the combination of these variables should be considered in predicting tamoxifen benefit.
|
|
| 6. |
- Wigerup, Caroline, et al.
(författare)
-
Association between Pak1 expression and subcellular localization and tamoxifen resistance in breast cancer patients.
- 2006
-
Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 1460-2105 .- 0027-8874. ; 98:10, s. 671-680
-
Tidskriftsartikel (refereegranskat)abstract
- Background: p21-activated kinase 1 (Pak1) phosphorylates many proteins in both normal and transformed cells. Its ability to phosphorylate and thereby activate the estrogen receptor alpha (ER alpha) potentially limits the effectiveness of antiestrogen treatment in breast cancer. Here we studied associations between Pak1 expression and subcellular localization in tumor cells and tamoxifen resistance. Methods: Pak1 protein expression was evaluated in 403 primary breast tumors from premenopausal patients who had been randomly assigned to 2 years of adjuvant tamoxifen or no treatment. Tamoxifen response was evaluated by comparing recurrence-free survival in relation to Pak1 and ER alpha expression in untreated versus tamoxifen-treated patients. Tamoxifen responsiveness of human MCF-7 breast cancer cells that inducibly expressed constitutively active Pak1 or that transiently overexpressed wild-type Pak1 (Wt-Pak1) or Pak1 that lacked functional nuclear localization signals (Pak1 Delta NLS) was evaluated by analyzing cyclin D1 promoter activation and protein levels as markers for ER alpha activation. The response to tamoxifen in relation to Pak1 expression was analyzed in naturally tamoxifen-resistant Ishikawa human endometrial cancer cells. All statistical tests were two-sided. Results: Among patients who had ER alpha-positive tumors with low Pak1 expression, those treated with tamoxifen had better recurrence-free survival than those who received no treatment (hazard ratio [HR] = 0.502, 95% confidence interval [CI] = 0.331 to 0.762; P = .001) whereas there was no difference in recurrence-free survival between treatment groups for patients whose tumors had high cytoplasmic (HR = 0.893, 95% CI = 0.420 to 1.901; P = .769) or any nuclear Pak1 expression (HR = 0.955, 95% CI = 0.405 to 2.250; P = .916). In MCF-7 cells, overexpression of Wt-Pak1, but not of Pak1 Delta NLS, compromised tamoxifen response by stimulating cyclin D1 expression. Treatment of Ishikawa cells with tamoxifen led to an increase in the amount of nuclear Pak1 and Pak1 kinase activity, suggesting that tamoxifen, to some extent, regulates Pak1 expression. Conclusions: Our data support a role for Pak1, particular Pak1 localized to the nucleus, in ER alpha signaling and in tamoxifen resistance.
|
|
| 7. |
- Aaltonen, Kristina, et al.
(författare)
-
Laser capture microdissection (LCM) and whole genome amplification (WGA) of DNA from normal breast tissue - optimization for genome wide array analyses.
- 2011
-
Ingår i: BMC Research Notes. - : Springer Science and Business Media LLC. - 1756-0500. ; 4, s. 69-69
-
Tidskriftsartikel (refereegranskat)abstract
- Background Laser capture microdissection (LCM) can be applied to tissues where cells of interest are distinguishable from surrounding cell populations. Here, we have optimized LCM for fresh frozen normal breast tissue where large amounts of fat can cause problems during microdissection. Since the amount of DNA needed for genome wide analyses, such as single nucleotide polymorphism (SNP) arrays, is often greater than what can be obtained from the dissected tissue, we have compared three different whole genome amplification (WGA) kits for amplification of DNA from LCM material. In addition, the genome wide profiling methods commonly used today require extremely high DNA quality compared to PCR based techniques and DNA quality is thus critical for successful downstream analyses. Findings We found that by using FrameSlides without glass backing for LCM and treating the slides with acetone after staining, the problems caused by excessive fat could be significantly decreased. The amount of DNA obtained after extraction from LCM tissue was not sufficient for direct SNP array analysis in our material. However, the two WGA kits based on Phi29 polymerase technology (Repli-g® (Qiagen) and GenomiPhi (GE Healthcare)) gave relatively long amplification products, and amplified DNA from Repli-g® gave call rates in the subsequent SNP analysis close to those from non-amplified DNA. Furthermore, the quality of the input DNA for WGA was found to be essential for successful SNP array results and initial DNA fragmentation problems could be reduced by switching from a regular halogen lamp to a VIS-LED lamp during LCM. Conclusions LCM must be optimized to work satisfactorily in difficult tissues. We describe a work flow for fresh frozen normal breast tissue where fat is inclined to cause problems if sample treatment is not adapted to this tissue. We also show that the Phi29-based Repli-g® WGA kit (Qiagen) is a feasible approach to amplify DNA of high quality prior to genome wide analyses such as SNP profiling.
|
|
| 8. |
- Alam, Muhammad Wasi, et al.
(författare)
-
HIF2α contributes to antiestrogen resistance via positive bilateral crosstalk with EGFR in breast cancer cells.
- 2016
-
Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:10, s. 50-11238
-
Tidskriftsartikel (refereegranskat)abstract
- The majority of breast cancers express estrogen receptor α (ERα), and most patients with ERα-positive breast cancer benefit from antiestrogen therapy. The ERα-modulator tamoxifen and ERα-downregulator fulvestrant are commonly employed antiestrogens. Antiestrogen resistance remains a clinical challenge, with few effective treatments available for patients with antiestrogen-resistant breast cancer. Hypoxia, which is intrinsic to most tumors, promotes aggressive disease, with the hypoxia-inducible transcription factors HIF1 and HIF2 regulating cellular responses to hypoxia. Here, we show that the ERα-expressing breast cancer cells MCF-7, CAMA-1, and T47D are less sensitive to antiestrogens when hypoxic. Furthermore, protein and mRNA levels of HIF2α/HIF2A were increased in a panel of antiestrogen-resistant cells, and antiestrogen-exposure further increased HIF2α expression. Ectopic expression of HIF2α in MCF-7 cells significantly decreased sensitivity to antiestrogens, further implicating HIF2α in antiestrogen resistance. EGFR is known to contribute to antiestrogen resistance: we further show that HIF2α drives hypoxic induction of EGFR and that EGFR induces HIF2α expression. Downregulation or inhibition of EGFR led to decreased HIF2α levels. This positive and bilateral HIF2-EGFR regulatory crosstalk promotes antiestrogen resistance and, where intrinsic hypoxic resistance exists, therapy itself may exacerbate the problem. Finally, inhibition of HIFs by FM19G11 restores antiestrogen sensitivity in resistant cells. Targeting HIF2 may be useful for counteracting antiestrogen resistance in the clinic.
|
|
| 9. |
|
|
| 10. |
- Borgquist, Signe, et al.
(författare)
-
Oestrogen receptors alpha and beta show different associations to clinicopathological parameters and their co-expression might predict a better response to endocrine treatment in breast cancer.
- 2008
-
Ingår i: Journal of Clinical Pathology. - : BMJ. - 1472-4146 .- 0021-9746. ; 61:2, s. 197-202
-
Tidskriftsartikel (refereegranskat)abstract
- AIMS: The majority of all breast cancers are hormone responsive, traditionally defined by the expression of oestrogen receptor (ER) alpha and/or progesterone receptors. In contrast to ERalpha, the clinical significance of the relatively recently identified ERbeta is still unclear. This study aimed to define the relationship between ERbeta and clinicopathological parameters in a mixed cohort of breast cancer and, furthermore, to investigate the impact of ERbeta expression on disease outcome. METHODS: The immunohistochemical expression of ERalpha and ERbeta was analysed in tissue microarrays containing a total number of 512 tumours with all incident breast cancers diagnosed at the Malmö University Hospital between 1988 and 1992. RESULTS: 78% of the tumours were ERalpha positive and 50% were ERbeta positive. ERbeta correlated positively with ERalpha (p = 0.001). In contrast to ERalpha, ERbeta was not associated with any important clinicopathological variables. Furthermore, no overall prognostic significance could be demonstrated for ERbeta. In the ERalpha-positive subgroup, however, a low expression of ERbeta correlated with a decreased disease-free survival in patients receiving endocrine treatment (p = 0.003). CONCLUSIONS: Although interrelated, ERalpha and ERbeta seem to be differentially associated to clinicopathological parameters, and this would support the fact that they might have different functions in vivo. Furthermore, ERbeta might be a predictive marker of response to endocrine therapy, although this needs to be confirmed in additional studies, preferably randomised trials.
|
|
| 11. |
- Braekeveldt, Noémie, et al.
(författare)
-
Neuroblastoma Patient-Derived Orthotopic Xenografts Retain Metastatic Patterns and Geno- and Phenotypes of Patient Tumours.
- 2015
-
Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 136:5, s. 252-261
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is a childhood tumour with heterogeneous characteristics and children with metastatic disease often have a poor outcome. Here we describe the establishment of neuroblastoma patient-derived xenografts (PDXs) by orthotopic implantation of viably cryopreserved or fresh tumour explants of patients with high risk neuroblastoma into immunodeficient mice. In vivo tumour growth was monitored by magnetic resonance imaging and fluorodeoxyglucose - positron emission tomography. Neuroblastoma PDXs retained the undifferentiated histology and proliferative capacity of their corresponding patient tumours. The PDXs expressed neuroblastoma markers NCAM, chromogranin A, synaptophysin and tyrosine hydroxylase. Whole genome genotyping array analyses demonstrated that PDXs retained patient-specific chromosomal aberrations such as MYCN amplification, deletion of 1p, and gain of chromosome 17q. Thus, neuroblastoma PDXs recapitulate the hallmarks of high-risk neuroblastoma in patients. PDX-derived cells were cultured in serum-free medium where they formed free-floating neurospheres, expressed neuroblastoma gene markers MYCN, CHGA, TH, SYP and NPY, and retained tumour-initiating and metastatic capacity in vivo. PDXs showed much higher degree of infiltrative growth and distant metastasis as compared to neuroblastoma SK-N-BE(2)c cell line-derived orthotopic tumours. Importantly, the PDXs presented with bone marrow involvement, a clinical feature of aggressive neuroblastoma. Thus, neuroblastoma PDXs serve as clinically relevant models for studying and targeting high-risk metastatic neuroblastoma. © 2014 Wiley Periodicals, Inc.
|
|
| 12. |
- Claeys, Shana, et al.
(författare)
-
ALK positively regulates MYCN activity through repression of HBP1 expression
- 2019
-
Ingår i: Oncogene. - : Springer Science and Business Media LLC. - 0950-9232 .- 1476-5594. ; 38:15, s. 2690-2705
-
Tidskriftsartikel (refereegranskat)abstract
- ALK mutations occur in 10% of primary neuroblastomas and represent a major target for precision treatment. In combination with MYCN amplification, ALK mutations infer an ultra-high-risk phenotype resulting in very poor patient prognosis. To open up opportunities for future precision drugging, a deeper understanding of the molecular consequences of constitutive ALK signaling and its relationship to MYCN activity in this aggressive pediatric tumor entity will be essential. We show that mutant ALK downregulates the ‘HMG-box transcription factor 1’ (HBP1) through the PI3K-AKT–FOXO3a signaling axis. HBP1 inhibits both the transcriptional activating and repressing activity of MYCN, the latter being mediated through PRC2 activity. HBP1 itself is under negative control of MYCN through miR-17~92. Combined targeting of HBP1 by PI3K antagonists and MYCN signaling by BET- or HDAC-inhibitors blocks MYCN activity and significantly reduces tumor growth, suggesting a novel targeted therapy option for high-risk neuroblastoma.
|
|
| 13. |
- Emdal, Kristina B., et al.
(författare)
-
Phosphoproteomics of primary AML patient samples reveals rationale for AKT combination therapy and p53 context to overcome selinexor resistance
- 2022
-
Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 40:6
-
Tidskriftsartikel (refereegranskat)abstract
- Acute myeloid leukemia (AML) is a heterogeneous disease with variable patient responses to therapy. Selinexor, an inhibitor of nuclear export, has shown promising clinical activity for AML. To identify the molecular context for monotherapy sensitivity as well as rational drug combinations, we profile selinexor signaling responses using phosphoproteomics in primary AML patient samples and cell lines. Functional phosphosite scoring reveals that p53 function is required for selinexor sensitivity consistent with enhanced efficacy of selinexor in combination with the MDM2 inhibitor nutlin-3a. Moreover, combining selinexor with the AKT inhibitor MK-2206 overcomes dysregulated AKT-FOXO3 signaling in resistant cells, resulting in synergistic anti-proliferative effects. Using high-throughput spatial proteomics to profile subcellular compartments, we measure global proteome and phospho-proteome dynamics, providing direct evidence of nuclear translocation of FOXO3 upon combination treatment. Our data demonstrate the potential of phosphoproteomics and functional phosphorylation site scoring to successfully pinpoint key targetable signaling hubs for rational drug combinations.
|
|
| 14. |
- Gururaj, Anupama E, et al.
(författare)
-
Breast cancer-amplified sequence 3, a target of metastasis-associated protein 1, contributes to tamoxifen resistance in premenopausal patients with breast cancer
- 2006
-
Ingår i: Cell Cycle. - 1551-4005. ; 5:13, s. 1407-1410
-
Tidskriftsartikel (refereegranskat)abstract
- Lysine acetylation occurs in many protein targets, including core histones, transcription factors, and other proteins. Metastasis-associated protein 1 (MTA1) is implicated in the progression and metastasis of various epithelial tumors. Because MTA1 functions as a transcriptional coregulator, much of its role in cancer promoting processes are likely to involve its ability to regulate the transcription of downstream target genes that encode effector proteins. We recently showed that MTA1 could be post-translationally modified by acetylation, which modulates its function as a coregulator molecule. We also defined a chromatin target of MTA1, namely, breast cancer-amplified sequence 3 (BCAS3), in the context of which MTA1 behaves as a transcriptional coactivator in breast cancer cells. Because the phenotypic effect of BCAS3 overexpression in tumors has not been defined, we investigated the consequence of increased expression of BCAS3 in human breast tumors. Here, we report that BCAS3 overexpression in hormone receptor-positive premenopausal breast cancer seemed to be associated with impaired responses to tamoxifen. Our findings have implications for endocrine therapy.
|
|
| 15. |
- Gururaj, AE, et al.
(författare)
-
MTA1, a transcriptional activator of breast cancer amplified sequence 3
- 2006
-
Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 103:17, s. 6670-6675
-
Tidskriftsartikel (refereegranskat)abstract
- Here we define a function of metastasis-associated protein 1 (MTA1), a presumed corepressor of estrogen receptor alpha (ER alpha), as a transcriptional activator of Breast Cancer Amplified Sequence 3 (BCAS3), a gene amplified and overexpressed in breast cancers. We identified BCAS3 as a MTA1 chromatin target in a functional genomic screen. MTA1 stimulation of BCAS3 transcription required ERa and involved a functional ERE half-site in BCAS3. Furthermore, we discovered that MTA1 is acetylated on lysine 626, and that this acetylation is necessary for a productive transcriptional recruitment of RNA polymerase 11 complex to the BCAS3 enhancer sequence. BCAS3 expression was elevated in mammary tumors from MTA1 transgenic mice and 60% of the human breast tumors, and correlated with the coexpression of MTA1 as well as with tumor grade and proliferation of primary breast tumor samples. These findings reveal a previously unrecognized function of MTA1 in stimulating BCAS3 expression and suggest an important role for MTA1-BCAS3 pathway in promoting cancerous phenotypes in breast tumor cells.
|
|
| 16. |
- Holm, C, et al.
(författare)
-
Phosphorylation of the oestrogen receptor alpha at serine 305 and prediction of tamoxifen resistance in breast cancer
- 2009
-
Ingår i: JOURNAL OF PATHOLOGY. - : Wiley. - 0022-3417 .- 1096-9896. ; 217:3, s. 372-379
-
Tidskriftsartikel (refereegranskat)abstract
- Phosphorylation of oestrogen receptor a at serine 305 (ER alpha S305-P) induces tamoxifen resistance in experimental studies, but does not influence response to other endocrine agents, such as fulvestrant. We evaluated ER alpha S305-P using immunohistochemistry in 377 breast carcinomas from premenopausal participants of a randomized trial (n = 248) and patients with advanced disease (n = 129). Among the premenopausal patients, adjuvant tamoxifen improved recurrence-free survival (RFS) for ER alpha S305-P-negative tumours (multivariate HR = 0.53, 95% CI 0.32-0.86, p = 0.010), but not for ER alpha S305-P-positive tumours (multivariate HR = 1.01, 95% CI 0.33-3.05, p = 0.99) (interaction p = 0.131). Notably, ER alpha S305-P was not significantly associated with RFS in patients not treated with tamoxifen (multivariate HR = 0.64, 95% CI 0.30-1.37, p = 0.248), indicating that ER alpha S305-P is a marker for treatment outcome rather than tumour progression. Given the direct experimental link between ER alpha S305-P and tamoxifen resistance and these first clinical data suggesting that premenopausal patients with ER alpha S305-P-positive breast cancer are resistant to adjuvant tamoxifen, further research is encouraged to study whether alternative endocrine treatment should be considered for this subgroup.
|
|
| 17. |
- Johansson, Ida, et al.
(författare)
-
Increased gene copy number of KIT and VEGFR2 at 4q12 in primary breast cancer is related to an aggressive phenotype and impaired prognosis.
- 2012
-
Ingår i: Genes, Chromosomes and Cancer. - : Wiley. - 1045-2257. ; 51:4, s. 375-383
-
Tidskriftsartikel (refereegranskat)abstract
- Triple-negative breast cancer (TNBC) is associated with poor prognosis and no targeted treatments are available for TNBC. Drugs inhibiting tyrosine kinases, such as vascular endothelial growth factor receptor 2 (VEGFR2) and KIT, have shown some promising results for patients with TNBC. The aim of the study was to investigate whether gains and/or amplifications of VEGFR2 and KIT, located at 4q12, occur in TNBC. Fluorescence in situ hybridization (FISH) was used to quantify gene copy numbers of VEGFR2 and KIT in 83 primary human breast cancers including 31 TNBCs. Gains were defined as ≥4 gene copies in >40% of the cancer cells, whereas amplification was defined as CEP >2 in more than 10% of the cancer cells. A tumor was considered FISH positive for KIT and/or VEGFR2 if it displayed copy number gain and/or amplification. Ten (32%) of the TNBCs were VEGFR2 FISH positive and nine (29%) were KIT FISH positive, whereas non-TNBCs were FISH positive for VEGFR2 and KIT in nine (18%) cases for both genes, but no significant difference between TNBCs and non-TNBCs was found. FISH positivity for VEGFR2 and KIT was significantly correlated (χ(2) test, P < 0.001), and significantly related to ER negativity and high Nottingham histological grade (NHG). A significantly worse 5-year breast cancer specific survival (BCSS) was seen for FISH positive cases. Increased copy number of VEGFR2 and KIT thus has the potential of functioning as a novel predictive biomarker for selected targeted therapy particularly in the difficult-to-treat TNBC patient category. © 2011 Wiley Periodicals, Inc.
|
|
| 18. |
- Kok, Marleen, et al.
(författare)
-
Estrogen receptor-alpha phosphorylation at serine-118 and tamoxifen response in breast cancer.
- 2009
-
Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 1460-2105 .- 0027-8874. ; 101:24, s. 1725-9
-
Tidskriftsartikel (refereegranskat)abstract
- Although estrogen receptor-alpha (ER) [corrected] is a marker used to identify breast cancer patients most likely to benefit from endocrine therapy, approximately 50% of ER-positive [corrected] breast carcinomas are resistant to tamoxifen. Preclinical studies have shown that phosphorylation of ER [corrected] at serine-118 (ER alpha S118-P) is required for tamoxifen-mediated inhibition of ER-induced [corrected] gene expression. We evaluated the association between recurrence-free survival after tamoxifen treatment and ER alpha S118-P expression by use of Cox proportional hazards regression. Data were from 239 premenopausal patients with breast cancer who participated in a randomized trial of 2 years of adjuvant tamoxifen treatment vs no systemic treatment. ER alpha S118-P expression was assessed by immunohistochemistry and categorized by use of the Allred score (low expression = score of 0-6; high expression = score of 7-8). All statistical tests were two-sided. Compared with systemically untreated patients, we found evidence of a benefit from adjuvant tamoxifen among patients whose tumors had high ER alpha S118-P expression (23.7 recurrences per 1000 person-years versus 72.2 recurrences per 1000 person-years, hazard ratio [HR] of recurrence = 0.36, 95% confidence interval [CI] = 0.20 to 0.65) but not among patients whose tumors had low expression (51.0 recurrences per 1000 person-years versus 57.0 recurrences per 1000 person-years, HR of recurrence = 0.87, 95% CI = 0.51 to 1.48), a statistically significant difference (P for interaction = .037). ER alpha 118-P was not associated with recurrence-free survival among untreated patients. Thus, ER alpha S118-P expression appears to be associated with response to tamoxifen. [corrected]
|
|
| 19. |
- Kumar, Rakesh, et al.
(författare)
-
Extranuclear Coactivator Signaling Confers Insensitivity to Tamoxifen.
- 2009
-
Ingår i: Clinical Cancer Research. - 1078-0432. ; 15, s. 4123-4130
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Tamoxifen is one of many standard therapeutic options currently available for estrogen receptor-alpha-positive breast cancer patients. Emerging data have suggested that levels of estrogen receptor coregulatory proteins play a significant role in acquiring resistance to antiestrogen action. It has been suggested that high levels of estrogen receptor coactivators and its mislocalization may enhance the estrogen agonist activity of tamoxifen and contribute to tamoxifen resistance.EXPERIMENTAL DESIGN: In an effort to understand the impact of nongenomic signaling and its contribution to hormone resistance in a whole-animal setting, we generated a transgenic mouse expressing a cytoplasmic version of proline-, glutamic acid-, and leucine-rich protein-1 (PELP1) mutant defective in its nuclear translocation (PELP1-cyto) and implanted these mice with tamoxifen pellets to assess its responsiveness.RESULTS: We show that mammary glands from these mice developed widespread hyperplasia with increased cell proliferation and enhanced activation of mitogen-activated protein kinase and AKT as early as 12 weeks of age. Treatment with tamoxifen did not inhibit this hyperplasia; instead, such treatment exaggerated hyperplasia with an enhanced degree of alteration, indicative of hypersensitivity to tamoxifen. Analysis of molecular markers in the transgenic mammary glands from the tamoxifen-treated transgenic mice showed higher levels of proliferation markers proliferating cell nuclear antigen and activated mitogen-activated protein kinase than in untreated PELP1-cyto cell-derived mice. We also found that nude mice with MCF-7/PELP1-cyto cell-derived tumor xenografts did not respond to tamoxifen. Using immunohistochemical analysis, we found that 43% of human breast tumor samples had high levels of cytoplasmic PELP1, which shows a positive correlation between tumor grade and proliferation. Patients whose tumors had high levels of cytoplasmic PELP1 exhibited a tendency to respond poorly to tamoxifen compared with patients whose tumors had low levels of cytoplasmic PELP1.CONCLUSIONS: These findings suggest that PELP1 localization could be used as a determinant of hormone sensitivity or vulnerability. The establishment of the PELP1-cyto transgenic mouse model is expected to facilitate the development of preclinical approaches for effective intervention of breast tumors using cytoplasmic coregulators and active nongenomic signaling.
|
|
| 20. |
- Lundgren, Katja, et al.
(författare)
-
Hypoxia and breast cancer: prognostic and therapeutic implications
- 2007
-
Ingår i: Cellular and Molecular Life Sciences. - : Springer Science and Business Media LLC. - 1420-9071 .- 1420-682X. ; 64:24, s. 3233-3247
-
Forskningsöversikt (refereegranskat)abstract
- Hypoxia affects many important processes in tumour progression and is a key feature in the tumour microenvironment that needs to be taken into account when evaluating prognostics and therapeutic options for cancer patients. Hypoxia-regulating proteins, i.e. hypoxia inducible factors (HIFs), and associated gene products have been linked to certain tumour behaviours and might be useful as prognostic and predictive markers. Recently, hypoxia-driven gene products have been launched as novel cancer treatment targets with the potential to increase tumour-specific effects. Breast cancer consists of a multitude of different diseases with certain common characteristics, but also clearly disparate behaviours and genetic alterations. In this review we will summarise the role of hypoxia in breast cancer and specifically outline the importance of hypoxia and HIF-1alpha regarding prognostic and treatment-specific implications.
|
|
| 21. |
- Mohlin, Sofie, et al.
(författare)
-
Hypoxia, pseudohypoxia and cellular differentiation
- 2017
-
Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 356:2, s. 192-196
-
Tidskriftsartikel (refereegranskat)abstract
- Tumor hypoxia correlates to aggressive disease, and while this is explained by a variety of factors, one clue to understand this phenomena was the finding that hypoxia induces a de-differentiated, stem cell-like phenotype in neuroblastoma and breast tumor cells. The hypoxia inducible transcription factors (HIFs) are regulated at the translational level by fluctuating oxygen concentrations, but emerging data reveal that both HIF-1α and HIF-2α expression can be induced by aberrantly activated growth factor signaling independently of oxygen levels. Furthermore, HIF-2α is regulated by hypoxia also at the transcriptional level in neuroblastoma and glioma cells. In cultured tumor cells, HIF-2α is stabilized at physiological oxygen concentrations followed by induced expression of classical hypoxia-driven genes, resulting in a pseudohypoxic phenotype. In addition, in neuroblastoma and glioma specimens, a small subset of HIF-2α positive, HIF-1α negative, tumor cells is found adjacent to blood vessels, i.e. in areas with presumably adequate oxygenation. These tumor niches are thus pseudohypoxic, and the HIF-2α expressing cells present immature features. We have postulated that this niche in neuroblastomas encompass the tumor stem cells. Oncogenes or tumor suppressor genes associated with pseudohypoxia are frequently mutated or deleted in the germline, implicating that the pseudohypoxic phenotype indeed is tumorigenic. In summary, the hypoxic and pseudohypoxic phenotypes of solid tumors are attractive therapeutic targets.
|
|
| 22. |
- Mohlin, Sofie, et al.
(författare)
-
Neuroblastoma aggressiveness in relation to sympathetic neuronal differentiation stage.
- 2011
-
Ingår i: Seminars in Cancer Biology. - : Elsevier BV. - 1096-3650 .- 1044-579X. ; 21:4, s. 276-282
-
Tidskriftsartikel (refereegranskat)abstract
- Neuroblastoma is a childhood malignancy of the sympathetic neuronal lineage. It is a rare disease, but since it is frequently diagnosed during infancy, neuroblastoma causes life-long medical follow up of those children that survive the disease. It was early recognized that a high tumor cell differentiation stage correlates to favorable clinical stage and positive clinical outcome. Today, highly differentiated tumors are surgically removed and not further treated. Cells of many established human neuroblastoma cell lines have the capacity to differentiate when stimulated properly, and these cell lines have been used as models for studying and understanding central concepts of tumor cell differentiation. One recent aspect of this issue is the observation that tumor cells can dedifferentiate and gain a stem cell-like phenotype during hypoxic conditions, which was first shown in neuroblastoma. Aberrant or blocked differentiation is a central aspect of neuroblastoma genesis. In this review we summarize known genetic and non-genetic events in neuroblastoma that might be coupled to an aberrant sympathetic neuronal differentiation and thereby indirectly influencing tumorigenesis and/or aggressive neuroblastoma behavior.
|
|
| 23. |
- Mohlin, Sofie, et al.
(författare)
-
PI3K-mTORC2 but not PI3K-mTORC1 Regulates Transcription of HIF2A/EPAS1 and Vascularization in Neuroblastoma.
- 2015
-
Ingår i: Cancer Research. - 1538-7445. ; 75:21, s. 4617-4628
-
Tidskriftsartikel (refereegranskat)abstract
- Hypoxia-inducible factor (HIF) is a master regulator of cellular responses to oxygen deprival with a critical role in mediating the angiogenic switch in solid tumors. Differential expression of the HIF subunits HIF1α and HIF2α occurs in many human tumor types, suggesting selective implications to biologic context. For example, high expression of HIF2α that occurs in neuroblastoma is associated with stem cell-like features, disseminated disease, and poor clinical outcomes, suggesting pivotal significance for HIF2 control in neuroblastoma biology. In this study, we provide novel insights into how HIF2α expression is transcriptionally controlled by hypoxia and how this control is abrogated by inhibition of insulin-like growth factor-1R/INSR-driven phosphoinositide 3-kinase (PI3K) signaling. Reducing PI3K activity was sufficient to decrease HIF2α mRNA and protein expression in a manner with smaller and less vascularized tumors in vivo. PI3K-regulated HIF2A mRNA expression was independent of Akt or mTORC1 signaling but relied upon mTORC2 signaling. HIF2A mRNA was induced by hypoxia in neuroblastoma cells isolated from metastatic patient-derived tumor xenografts, where HIF2A levels could be reduced by treatment with PI3K and mTORC2 inhibitors. Our results suggest that targeting PI3K and mTORC2 in aggressive neuroblastomas with an immature phenotype may improve therapeutic efficacy. Cancer Res; 75(21); 1-12. ©2015 AACR.
|
|
| 24. |
|
|
| 25. |
|
|
| 26. |
- Ohshiro, Kazufumi, et al.
(författare)
-
Acetylation-dependent oncogenic activity of metastasis-associated protein 1 co-regulator.
- 2010
-
Ingår i: EMBO reports. - : EMBO. - 1469-3178 .- 1469-221X. ; 11:9, s. 691-7
-
Tidskriftsartikel (refereegranskat)abstract
- High expression of metastasis-associated protein 1 co-regulator (MTA1), a component of the nuclear remodelling and histone deacetylase complex, has been associated with human tumours. However, the precise role of MTA1 in tumorigenesis remains unknown. In this study, we show that induced levels of MTA1 are sufficient to transform Rat1 fibroblasts and that the transforming potential of MTA1 is dependent on its acetylation at Lys626. Underlying mechanisms of MTA1-mediated transformation include activation of the Ras-Raf pathway by MTA1 but not by acetylation-inactive MTA1; this was due to the repression of Galphai2 transcription, which negatively influences Ras activation. We observed that acetylated MTA1-histone deacetylase (HDAC) interaction was required for the recruitment of the MTA1-HDAC complex to the Galphai2 regulatory element and consequently for the repression of Galphai2 transcription and expression leading to activation of the Ras-Raf pathway. The findings presented in this study provide for the first time--to the best of our knowledge--evidence of acetylation-dependent oncogenic activity of a cancer-relevant gene product.
|
|
| 27. |
- Persson, Camilla U., et al.
(författare)
-
ARNT-dependent HIF-2 transcriptional activity is not sufficient to regulate downstream target genes in neuroblastoma
- 2020
-
Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827. ; 388:2
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Hypoxia-inducible factor (HIF)-2α associates with poor outcome in neuroblastoma and glioblastoma, and gain-of-function mutations in the EPAS1 gene (encoding HIF-2α) have been reported in paragangliomas and pheochromocytomas. Specific targeting of a druggable hydrophobic pocket in the HIF-2α PAS-B domain with PT2385 have demonstrated promising clinical results for clear cell renal cell carcinoma (ccRCC). Here, we investigated the effect of PT2385-mediated inhibition of ARNT dependent HIF-2 activity. Methods: Neuroblastoma patient-derived xenograft (PDX) cells were treated with PT2385 and analyzed for HIF-2-dependent gene expression, HIF activity, HIF-2α protein localization, response to chemotherapy and orthotopic tumor growth in vivo. Two-sided student t-test was used. Results: We detected high levels of HIF-2α protein in perivascular niches in neuroblastoma PDXs in vivo and at oxygenated conditions in PDX-derived cell cultures in vitro, particularly in the cytoplasmic fraction. Nuclear HIF-2α expression was reduced following PT2385 treatment, but surprisingly, virtually no effects on tumor growth in vivo or expression of canonical HIF downstream target genes in vitro were observed. In coherence, RNA sequencing of PT2385-treated PDX cells revealed a virtually unaffected transcriptome. Treatment with PT2385 did not affect cellular response to chemotherapy. In contrast, HIF-2α protein knockdown resulted in profound downregulation of target genes. Conclusions: The lack of effect from PT2385 treatment in combination with high cytoplasmic HIF-2α expression at normoxia suggest that HIF-2α have additional roles than acting as an ARNT dependent transcription factor. It is important to further unravel the conditions at which HIF-2α has transcriptional and non-transcriptional roles in neuroblastoma.
|
|
| 28. |
- Persson, Camilla U., et al.
(författare)
-
Neuroblastoma patient-derived xenograft cells cultured in stem-cell promoting medium retain tumorigenic and metastatic capacities but differentiate in serum
- 2017
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
-
Tidskriftsartikel (refereegranskat)abstract
- Cultured cancer cells serve as important models for preclinical testing of anti-cancer compounds. However, the optimal conditions for retaining original tumor features during in vitro culturing of cancer cells have not been investigated in detail. Here we show that serum-free conditions are critical for maintaining an immature phenotype of neuroblastoma cells isolated from orthotopic patient-derived xenografts (PDXs). PDX cells could be grown either as spheres or adherent on laminin in serum-free conditions with retained patient-specific genomic aberrations as well as tumorigenic and metastatic capabilities. However, addition of serum led to morphological changes, neuronal differentiation and reduced cell proliferation. The epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) were central for PDX cell proliferation and MYCN expression, and also hindered the serum-induced differentiation. Although serum induced a robust expression of neurotrophin receptors, stimulation with their cognate ligands did not induce further sympathetic differentiation, which likely reflects a block in PDX cell differentiation capacity coupled to their tumor genotype. Finally, PDX cells cultured as spheres or adherent on laminin responded similarly to various cytotoxic drugs, suggesting that both conditions are suitable in vitro screening models for neuroblastoma-targeting compounds.
|
|
| 29. |
- Reinbothe, Susann, et al.
(författare)
-
EPO-independent functional EPO receptor in breast cancer enhances estrogen receptor activity and promotes cell proliferation.
- 2014
-
Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 445:1, s. 163-169
-
Tidskriftsartikel (refereegranskat)abstract
- The main function of Erythropoietin (EPO) and its receptor (EPOR) is the stimulation of erythropoiesis. Recombinant human EPO (rhEPO) is therefore used to treat anemia in cancer patients. However, clinical trials have indicated that rhEPO treatment might promote tumor progression and has a negative effect on patient survival. In addition, EPOR expression has been detected in several cancer forms. Using a newly produced anti-EPOR antibody that reliably detects the full-length isoform of the EPOR we show that breast cancer tissue and cells express the EPOR protein. rhEPO stimulation of cultured EPOR expressing breast cancer cells did not result in increased proliferation, overt activation of EPOR (receptor phosphorylation) or a consistent activation of canonical EPOR signaling pathway mediators such as JAK2, STAT3, STAT5, or AKT. However, EPOR knockdown experiments suggested functional EPO receptors in estrogen receptor positive (ERα(+)) breast cancer cells, as reduced EPOR expression resulted in decreased proliferation. This effect on proliferation was not seen in ERα negative cells. EPOR knockdown decreased ERα activity further supports a mechanism by which EPOR affects proliferation via ERα-mediated mechanisms. We show that EPOR protein is expressed in breast cancer cells, where it appears to promote proliferation by an EPO-independent mechanism in ERα expressing breast cancer cells.
|
|
| 30. |
- Stendahl, Maria, et al.
(författare)
-
p27Kip1 is a predictive factor for tamoxifen treatment response but not a prognostic marker in premenopausal breast cancer patients.
- 2010
-
Ingår i: International journal of cancer. Journal international du cancer. - : Wiley. - 1097-0215. ; 127:12, s. 2851-8
-
Tidskriftsartikel (refereegranskat)abstract
- The cell-cycle regulating protein p27(Kip1) (p27) has dual roles by acting as both a cdk inhibitor and as an assembly factor for different cdk complexes. Loss of p27 has been linked to malignant features in tumours; however, the exact role of p27 deregulation in breast cancer regarding prognostic and treatment predictive information has not been fully clarified. We have evaluated p27 expression in 328 primary, Stage II breast cancers from premenopausal patients who had been randomised to either tamoxifen treatment or no adjuvant treatment after surgery. p27 was associated with the oestrogen receptor and cyclin D1, and p27 downregulation was associated with high proliferation. There was no association between recurrence-free survival (RFS) and p27 (HR = 0.800, 95% CI 0.523-1.222, p = 0.300), indicating that p27 is not a prognostic marker. The predictive value of p27 was analysed by comparing RFS in tamoxifen-treated and untreated patients in subgroups of low and high p27 expression (HR = 0.747, 95% CI 0.335-1.664, p = 0.474 and HR = 0.401, 95% CI 0.240-0.670, p < 0.001, respectively). Only patients with p27-high tumours benefited from tamoxifen (multivariate interaction analysis p = 0.034). Our study suggests that p27 downregulation is associated with tamoxifen resistance in premenopausal breast cancer but is not linked to impaired prognosis.
|
|
| 31. |
- Wigerup, Caroline
(författare)
-
Phosphorylation of ERα and HIF-1α in breast cancer with focus on tamoxifen response and links to kinase activation
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Anti-oestrogens are commonly used in adjuvant breast cancer treatment and for a long time tamoxifen has been the main endocrine treatment. Patients who are eligibly for endocrine treatment are selected by the tumour-specific expression of oestrogen receptor (ER) and approximately 70 % of all breast cancer patients are classified as ER positive. However, resistance to tamoxifen is common and several patients will experience tumour relapse and might also die from their disease. This stresses the need for identifying treatment predictive factors that can guide clinicians during treatment decisions. We have identified biomarkers that were associated with tamoxifen response in a material of premenopausal breast tumours. One of the markers is Pak1, a serine/threonine protein kinase, of which high expression and particular nuclear localisation was associated with poor tamoxifen response. Two other biomarkers are different ER phosphorylations at serine 305 and serine 118; ERS305-P and ERS118-P, respectively. Tumours that were positive for ERS305 were associated with poor tamoxifen response while tumours with high expression of ERS-118 were associated with a good response. Furthermore, we have studied associations between the activated kinases responsible for these ER phosphorylations and tamoxifen response. Our observations led us to conclude that ERS118-P and ERS305-P are better tamoxifen predictive factors than their respective phosphorylating kinases, and possibly, using a combination of the phosphorylations might be even more valuable in predicting the response. In addition, we have identified Pak1 as a regulator of the hypoxic response in breast cancer cells. More specifically, we have observed Pak1-mediated phosphorylation of the hypoxia inducible transcription factor 1α (HIF-1α). Silencing of Pak1 led to decreased HIF-1α levels and less transcriptional activity, suggesting that Pak1 phosphorylation stabilises HIF-1α and thereby increases HIF-1α’s ability to induce gene expression during tumour hypoxia.
|
|
| 32. |
- Wigerup, Caroline, et al.
(författare)
-
Therapeutic targeting of hypoxia and hypoxia-inducible factors in cancer
- 2016
-
Ingår i: Pharmacology and Therapeutics. - : Elsevier BV. - 0163-7258. ; 164, s. 152-169
-
Forskningsöversikt (refereegranskat)abstract
- Insufficient tissue oxygenation, or hypoxia, contributes to tumor aggressiveness and has a profound impact on clinical outcomes in cancer patients. At decreased oxygen tensions, hypoxia-inducible factors (HIFs) 1 and 2 are stabilized and mediate a hypoxic response, primarily by acting as transcription factors. HIFs exert differential effects on tumor growth and affect important cancer hallmarks including cell proliferation, apoptosis, differentiation, vascularization/angiogenesis, genetic instability, tumor metabolism, tumor immune responses, and invasion and metastasis. As a consequence, HIFs mediate resistance to chemo- and radiotherapy and are associated with poor prognosis in cancer patients. Intriguingly, perivascular tumor cells can also express HIF-2α, thereby forming a "pseudohypoxic" phenotype that further contributes to tumor aggressiveness. Therefore, therapeutic targeting of HIFs in cancer has the potential to improve treatment efficacy. Different strategies to target hypoxic cancer cells and/or HIFs include hypoxia-activated prodrugs and inhibition of HIF dimerization, mRNA or protein expression, DNA binding capacity, and transcriptional activity. Here we review the functions of HIFs in the progression and treatment of malignant solid tumors. We also highlight how HIFs may be targeted to improve the management of patients with therapy-resistant and metastatic cancer.
|
|
