| 1. |
- Azimi, Alireza, et al.
(författare)
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Targeting CDK2 overcomes melanoma resistance against BRAF and Hsp90 inhibitors
- 2018
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Ingår i: Molecular Systems Biology. - : EMBO. - 1744-4292. ; 14:3
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Tidskriftsartikel (refereegranskat)abstract
- Novel therapies are undergoing clinical trials, for example, the Hsp90 inhibitor, XL888, in combination with BRAF inhibitors for the treatment of therapy-resistant melanomas. Unfortunately, our data show that this combination elicits a heterogeneous response in a panel of melanoma cell lines including PDX-derived models. We sought to understand the mechanisms underlying the differential responses and suggest a patient stratification strategy. Thermal proteome profiling (TPP) identified the protein targets of XL888 in a pair of sensitive and unresponsive cell lines. Unbiased proteomics and phosphoproteomics analyses identified CDK2 as a driver of resistance to both BRAF and Hsp90 inhibitors and its expression is regulated by the transcription factor MITF upon XL888 treatment. The CDK2 inhibitor, dinaciclib, attenuated resistance to both classes of inhibitors and combinations thereof. Notably, we found that MITF expression correlates with CDK2 upregulation in patients; thus, dinaciclib would warrant consideration for treatment of patients unresponsive to BRAF-MEK and/or Hsp90 inhibitors and/or harboring MITF amplification/overexpression.
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| 4. |
- Das, Ishani, et al.
(författare)
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Inhibiting insulin and mTOR signaling by afatinib and crizotinib combination fosters broad cytotoxic effects in cutaneous malignant melanoma
- 2020
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Ingår i: Cell Death and Disease. - : Springer Nature. - 2041-4889. ; 11:10
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Tidskriftsartikel (refereegranskat)abstract
- Current treatment modalities for disseminated cutaneous malignant melanoma (CMM) improve survival, however disease progression commonly ensues. In a previous study we identified afatinib and crizotinib in combination as a novel potential therapy for CMM independent of BRAF/NRAS mutation status. Herein, we elucidate the underlying mechanisms of the combination treatment effect to find biomarkers and novel targets for development of therapy that may provide clinical benefit by proteomic analysis of CMM cell lines and xenografts using mass spectrometry based analysis and reverse phase protein array. Identified candidates were validated using immunoblotting or immunofluorescence. Our analysis revealed that mTOR/Insulin signaling pathways were significantly decreased by the afatinib and crizotinib combination treatment. Both in vitro and in vivo analyses showed that the combination treatment downregulated pRPS6KB1 and pRPS6, downstream of mTOR signaling, and IRS-1 in the insulin signaling pathway, specifically ablating IRS-1 nuclear signal. Silencing of RPS6 and IRS-1 alone had a similar effect on cell death, which was further induced when IRS-1 and RPS6 were concomitantly silenced in the CMM cell lines. Silencing of IRS-1 and RPS6 resulted in reduced sensitivity towards combination treatment. Additionally, we found that IRS-1 and RPS6KB1 expression levels were increased in advanced stages of CMM clinical samples. We could demonstrate that induced resistance towards combination treatment was reversible by a drug holiday. CD171/L1CAM, mTOR and PI3K-p85 were induced in the combination resistant cells whereas AXL and EPHA2, previously identified mediators of resistance to MAPK inhibitor therapy in CMM were downregulated. We also found that CD171/L1CAM and mTOR were increased at progression in tumor biopsies from two matched cases of patients receiving targeted therapy with BRAFi. Overall, these findings provide insights into the molecular mechanisms behind the afatinib and crizotinib combination treatment effect and leverages a platform for discovering novel biomarkers and therapy regimes for CMM treatment.
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| 6. |
- Edlundh-Rose, Esther, et al.
(författare)
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NRAS and BRAF mutations in melanoma turnours in re ation to clinical characteristics : a study based on mutation screening by pyrosequencing
- 2006
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Ingår i: Melanoma research. - : Ovid Technologies (Wolters Kluwer Health). - 0960-8931 .- 1473-5636. ; 16:6, s. 471-478
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Tidskriftsartikel (refereegranskat)abstract
- We have previously demonstrated the use of pyrosequencing to investigate NRAS [neuroblastoma RAS viral (v-ras) oncogene homolog] mutations in melanoma biopsies. Here, we expanded the analysis to include BRAF (V-raf murine sarcoma viral oncogene homolog 1311), another member of the Ras-Raf-mitogen-activated protein kinase (MAPK) signalling pathway, and analysed a total of 294 melanoma tumours from 219 patients. Mutations in BRAF exons 11 and 15 were identified in 156 (53%) tumours and NRAS exon 2 mutations in 86 (29%) tumours. Overall, mutations in NRAS or BRAF were found in 242 of 294 tumours; (82%) and were found to be mutually exclusive in all but two cases (0.7%). Multiple metastases were analysed in 57 of the cases and mutations were identical in all except three, indicating that BRAF and NRAS mutations occur before metastasis. Association with preexisting nevi was significantly higher in BRAF mutated tumours (P=0.014). In addition, tumours with BRAF mutations showed a significantly more frequent moderate to pronounced infiltration of lymphocytes (P=0.013). NRAS mutations were associated with a significantly higher Clark level of invasion (P=0.022) than BRAF mutations. Age at diagnosis was significantly higher in tumours with NRAS mutations than in those with BRAF mutations (P=0.019). NRAS and BRAF mutations, however, did not influence the overall survival from time of diagnosis (P=0.7). In conclusion, the separate genotypes were associated with differences in several key clinical and pathological parameters, indicating differences in the biology of melanoma tumours with different proto-oncogene mutations.
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| 7. |
- Egyházi, Suzanne
(författare)
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Studies of resistance factors against chloroethylnitrosourea drugs in malignant tumor cells
- 1996
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Drug resistance is a major clinical problem in the chemotherapy of tumor diseases and the identification of factors that make tumor cells resistant to drug treatment is therefore of crucial importance. We have investigated a possible involvement of O6-methylguanine-DNA methyltransferase (MGMT), glutathione transferase (GST) and glutathione (GSH) in the resistance to 1,3- bis(2-chloroethyl)-1-nitrosourea (BCNU) in two human lung cancer cell lines. The non-small cell lung cancer U1810 expresses MGMT while it was undetectable in the small cell lung cancer U1690. Both cell lines possess similar GST activities but they show different GST patterns. GST M3-3, which is detectable in U1810 cells only, is the only one among the tested human GSTs that is capable of inactivating BCNU. U1810 cells were found to be more resistant to BCNU than U1690 cells suggesting that both MGMT and GST M3-3 may contribute to the BCNU resistance in U1810 cells. The contribution of MGMT, GST M3-3 and GSH to BCNU resistance was investigated by inhibition of the activities of MGMT and GST M3-3 and by depletion of cells of GSH. These experiments showed that MGMT and GSH are the predominant resistance factors to BCNU in U1810 cells. The analyses of the MGMT expression and BCNU sensitivity during cell cycle progression in U1810 cells revealed that while the MGMT activity decreased by about 50% in the mid S phase, no significant cell cycle phase-specific alteration in BCNU sensitivity was observed. The measurement of protein and mRNA levels of U1810 cells indicated that the expression of the MGMT gene is regulated at the level of transcription. The content and activity of MGMT in human melanoma metastases were analysed as well. We observed a considerable variation between different melanoma metastases in MGMT content and activity. Heterogeneity occurred frequently between tumors in the same patient and to a lesser extent within individual tumors. Our results underline the importance of analysing MGMT expression at single cell level to obtain correct estimates and accentuate the need for analysis of multiple tumors in each individual before MGMT can be used as a predictive marker for drug resistance.
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| 8. |
- Falkenius, Johan, et al.
(författare)
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High expression of glycolytic and pigment proteins is associated with worse clinical outcome in stage III melanoma
- 2013
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Ingår i: Melanoma research. - 0960-8931 .- 1473-5636. ; 23:6, s. 452-460
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Tidskriftsartikel (refereegranskat)abstract
- There are insufficient numbers of prognostic factors available for prediction of clinical outcome in patients with stage III malignant cutaneous melanoma, even when known adverse pathological risk factors, such as macrometastasis, number of lymph node metastases, and ulceration are taken into consideration. The aim of this study was therefore to identify additional prognostic factors to better predict patients with a high risk of relapse, thus enabling us to better determine the need for adjuvant treatment in stage III disease. An RNA oligonucleotide microarray study was performed on first regional lymph node metastases in 42 patients with stage III melanoma: 23 patients with short-term survival (13 months) and 19 with long-term survival (60 months), to identify genes associated with clinical outcome. Candidate genes were validated by real-time PCR and immunohistochemical analysis. Several gene ontology (GO) categories were highly significantly differentially expressed including glycolysis (GO: 0006096; P<0.001) and the pigment biosynthetic process (GO: 0046148; P<0.001), in which overexpression was associated with short-disease-specific survival. Three overexpressed glycolytic genes, GAPDHS, GAPDH, and PKM2, and two pigment-related genes, TYRP1 and OCA2, were selected for validation. A significant difference in GAPDHS protein expression between short- and long-term survivors (P=0.021) and a trend for PKM2 (P=0.093) was observed in univariate analysis. Positive expression of at least two of four proteins (GAPDHS, GAPDH, PKM2, TYRP1) in immunohistochemical analysis was found to be an independent adverse prognostic factor for disease-specific survival (P=0.011). Our results indicate that this prognostic panel in combination with established risk factors may contribute to an improved prediction of patients with a high risk of relapse.
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| 9. |
- Foukakis, Theodoros, et al.
(författare)
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Immune gene expression and response to chemotherapy in advanced breast cancer
- 2018
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Ingår i: British Journal of Cancer. - : Springer Science and Business Media LLC. - 0007-0920 .- 1532-1827. ; 118:4, s. 480-488
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Tidskriftsartikel (refereegranskat)abstract
- Background:Transcriptomic profiles have shown promise as predictors of response to neoadjuvant chemotherapy in breast cancer (BC). This study aimed to explore their predictive value in the advanced BC (ABC) setting.Methods:In a Phase 3 trial of first-line chemotherapy in ABC, a fine needle aspiration biopsy (FNAB) was obtained at baseline. Intrinsic molecular subtypes and gene modules related to immune response, proliferation, oestrogen receptor (ER) signalling and recurring genetic alterations were analysed for association with objective response to chemotherapy. Gene-set enrichment analysis (GSEA) of responders vs non-responders was performed independently. Lymphocytes were enumerated in FNAB smears and the absolute abundance of immune cell types was calculated using the Microenvironment Cell Populations counter method.Results:Gene expression data were available for 109 patients. Objective response to chemotherapy was statistically significantly associated with an immune module score (odds ratio (OR)=1.62; 95% confidence interval (CI), 1.03-2.64; P=0.04). Subgroup analysis showed that this association was restricted to patients with ER-positive or luminal tumours (OR=3.54; 95%, 1.43-10.86; P=0.012 and P for interaction=0.04). Gene-set enrichment analysis confirmed that in these subgroups, immune-related gene sets were enriched in responders.Conclusions:Immune-related transcriptional signatures may predict response to chemotherapy in ER-positive and luminal ABC.
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| 10. |
- Georgoudaki, Anna-Maria, et al.
(författare)
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Reprogramming Tumor-Associated Macrophages by Antibody Targeting Inhibits Cancer Progression and Metastasis
- 2016
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 15:9, s. 2000-2011
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Tidskriftsartikel (refereegranskat)abstract
- Tumors are composed of multiple cell types besides the tumor cells themselves, including innate immune cells such as macrophages. Tumor-associated macrophages (TAMs) are a heterogeneous population of myeloid cells present in the tumor microenvironment (TME). Here, they contribute to immunosuppression, enabling the establishment and persistence of solid tumors as well as metastatic dissemination. We have found that the pattern recognition scavenger receptor MARCO defines a subtype of suppressive TAMs and is linked to clinical outcome. An anti-MARCO monoclonal antibody was developed, which induces anti-tumor activity in breast and colon carcinoma, as well as in melanoma models through reprogramming-TAM-populations to a pro-inflammatory phenotype and increasing tumor immunogenicity. This anti-tumor activity is dependent on the inhibitory Fc-receptor, Fc gamma RIIB, and also enhances the efficacy of checkpoint therapy. These results demonstrate that immunotherapies using antibodies designed to modify myeloid cells of the TME represent a promising mode of cancer treatment.
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