| 61. |
- Higgins, Geoff S, et al.
(författare)
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A small interfering RNA screen of genes involved in DNA repair identifies tumor-specific radiosensitization by POLQ knockdown.
- 2010
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 70:7, s. 2984-93
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Tidskriftsartikel (refereegranskat)abstract
- The effectiveness of radiotherapy treatment could be significantly improved if tumor cells could be rendered more sensitive to ionizing radiation (IR) without altering the sensitivity of normal tissues. However, many of the key therapeutically exploitable mechanisms that determine intrinsic tumor radiosensitivity are largely unknown. We have conducted a small interfering RNA (siRNA) screen of 200 genes involved in DNA damage repair aimed at identifying genes whose knockdown increased tumor radiosensitivity. Parallel siRNA screens were conducted in irradiated and unirradiated tumor cells (SQ20B) and irradiated normal tissue cells (MRC5). Using gammaH2AX foci at 24 hours after IR, we identified several genes, such as BRCA2, Lig IV, and XRCC5, whose knockdown is known to cause increased cell radiosensitivity, thereby validating the primary screening end point. In addition, we identified POLQ (DNA polymerase ) as a potential tumor-specific target. Subsequent investigations showed that POLQ knockdown resulted in radiosensitization of a panel of tumor cell lines from different primary sites while having little or no effect on normal tissue cell lines. These findings raise the possibility that POLQ inhibition might be used clinically to cause tumor-specific radiosensitization.
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| 62. |
- Hilvo, Mika, et al.
(författare)
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Novel theranostic opportunities offered by characterization of altered membrane lipid metabolism in breast cancer progression
- 2011
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Ingår i: Cancer Research. - Philadelphia, PA, USA : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 71:9, s. 3236-45
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Tidskriftsartikel (refereegranskat)abstract
- Activation of lipid metabolism is an early event in carcinogenesis and a central hallmark of many cancers. However, the precise molecular composition of lipids in tumors remains generally poorly characterized. The aim of the present study was to analyze the global lipid profiles of breast cancer, integrate the results to protein expression, and validate the findings by functional experiments. Comprehensive lipidomics was conducted in 267 human breast tissues using ultraperformance liquid chromatography/ mass spectrometry. The products of de novo fatty acid synthesis incorporated into membrane phospholipids, such as palmitate-containing phosphatidylcholines, were increased in tumors as compared with normal breast tissues. These lipids were associated with cancer progression and patient survival, as their concentration was highest in estrogen receptor-negative and grade 3 tumors. In silico transcriptomics database was utilized in investigating the expression of lipid metabolism related genes in breast cancer, and on the basis of these results, the expression of specific proteins was studied by immunohistochemistry. Immunohistochemical analyses showed that several genes regulating lipid metabolism were highly expressed in clinical breast cancer samples and supported also the lipidomics results. Gene silencing experiments with seven genes [ACACA (acetyl-CoA carboxylase α), ELOVL1 (elongation of very long chain fatty acid-like 1), FASN (fatty acid synthase), INSIG1 (insulin-induced gene 1), SCAP (sterol regulatory element-binding protein cleavage-activating protein), SCD (stearoyl-CoA desaturase), and THRSP (thyroid hormone-responsive protein)] indicated that silencing of multiple lipid metabolism-regulating genes reduced the lipidomic profiles and viability of the breast cancer cells. Taken together, our results imply that phospholipids may have diagnostic potential as well as that modulation of their metabolism may provide therapeutic opportunities in breast cancer treatment.
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| 63. |
- Issaeva, Natalia, et al.
(författare)
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6-Thioguanine Selectively Kills BRCA2-Defective Tumors and Overcomes PARP Inhibitor Resistance
- 2010
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 70:15, s. 6268-6276
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Tidskriftsartikel (refereegranskat)abstract
- Familial breast and ovarian cancers are often defective in homologous recombination (HR) due to mutations in the BRCA1 or BRCA2 genes. Cisplatin chemotherapy or poly(ADP-ribose) polymerase (PARP) inhibitors were tested for these tumors in clinical trials. In a screen for novel drugs that selectively kill BRCA2-defective cells, we identified 6-thioguanine (6TG), which induces DNA double-strand breaks (DSB) that are repaired by HR. Furthermore, we show that 6TG is as efficient as a PARP inhibitor in selectively killing BRCA2-defective tumors in a xenograft model. Spontaneous BRCA1-defective mammary tumors gain resistance to PARP inhibitors through increased P-glycoprotein expression. Here, we show that 6TG efficiently kills such BRCA1-defective PARP inhibitor-resistant tumors. We also show that 6TG could kill cells and tumors that have gained resistance to PARP inhibitors or cisplatin through genetic reversion of the BRCA2 gene. Although HR is reactivated in PARP inhibitor-resistant BRCA2-defective cells, it is not fully restored for the repair of 6TG-induced lesions. This is likely to be due to several recombinogenic lesions being formed after 6TG. We show that BRCA2 is also required for survival from mismatch repair-independent lesions formed by 6TG, which do not include DSBs. This suggests that HR is involved in the repair of 6TG-induced DSBs as well as mismatch repair-independent 6TG-induced DNA lesion. Altogether, our data show that 6TG efficiently kills BRCA2-defective tumors and suggest that 6TG may be effective in the treatment of advanced tumors that have developed resistance to PARP inhibitors or platinum-based chemotherapy. Cancer Res; 70(15); 6268-76. (C) 2010 AACR.
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| 64. |
- Jackson, Sarah S., et al.
(författare)
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Anthropometric Risk Factors for Cancers of the Biliary Tract in the Biliary Tract Cancers Pooling Project
- 2019
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Ingår i: Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 0008-5472 .- 1538-7445. ; 79:15, s. 3973-3982
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Tidskriftsartikel (refereegranskat)abstract
- Biliary tract cancers are rare but highly fatal with poorly understood etiology. Identifying potentially modifiable risk factors for these cancers is essential for prevention. Here we estimated the relationship between adiposity and cancer across the biliary tract, including cancers of the gallbladder (GBC), intrahepatic bile ducts (IHBDC), extrahepatic bile ducts (EHBDC), and the ampulla of Vater (AVC). We pooled data from 27 prospective cohorts with over 2.7 million adults. Adiposity was measured using baseline body mass index (BMI), waist circumference, hip circumference, waist-to-hip, and waist-to-height ratios. HRs and 95% confidence intervals (95% CI) were estimated using Cox proportional hazards models adjusted for sex, education, race, smoking, and alcohol consumption with age as the time metric and the baseline hazard stratified by study. During 37,883,648 person-years of follow-up, 1,343 GBC cases, 1,194 EHBDC cases, 784 IHBDC cases, and 623 AVC cases occurred. For each 5 kg/m(2) increase in BMI, there were risk increases for GBC (HR = 1.27; 95% CI, 1.19-1.36), IHBDC (HR = 1.32; 95% CI, 1.21-1.45), and EHBDC (HR = 1.13; 95% CI, 1.03-1.23), but not AVC (HR = 0.99; 95% CI, 0.88-1.11). Increasing waist circumference, hip circumference, waist-to-hip ratio, and waist-to-height ratio were associated with GBC and IHBDC but not EHBDC or AVC. These results indicate that adult adiposity is associated with an increased risk of biliary tract cancer, particularly GBC and IHBDC. Moreover, they provide evidence for recommending weight maintenance programs to reduce the risk of developing these cancers. Significance: These findings identify a correlation between adiposity and biliary tract cancers, indicating that weight management programs may help minimize the risk of these diseases.
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| 65. |
- Jerby, Livnat, et al.
(författare)
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Metabolic associations of reduced proliferation and oxidative stress in advanced breast cancer
- 2012
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Ingår i: Cancer Research. - : American Association for Cancer Research. - 0008-5472 .- 1538-7445. ; 72:22, s. 5712-5720
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Tidskriftsartikel (refereegranskat)abstract
- Aberrant metabolism is a hallmark of cancer, but whole metabolomic flux measurements remain scarce. To bridge this gap, we developed a novel metabolic phenotypic analysis (MPA) method that infers metabolic phenotypes based on the integration of transcriptomics or proteomics data within a human genome-scale metabolic model. MPA was applied to conduct the first genome-scale study of breast cancer metabolism based on the gene expression of a large cohort of clinical samples. The modeling correctly predicted cell lines' growth rates, tumor lipid levels, and amino acid biomarkers, outperforming extant metabolic modeling methods. Experimental validation was obtained in vitro. The analysis revealed a subtype-independent "go or grow" dichotomy in breast cancer, where proliferation rates decrease as tumors evolve metastatic capability. MPA also identified a stoichiometric tradeoff that links the observed reduction in proliferation rates to the growing need to detoxify reactive oxygen species. Finally, a fundamental stoichiometric tradeoff between serine and glutamine metabolism was found, presenting a novel hallmark of estrogen receptor (ER)(+) versus ER(-) tumor metabolism. Together, our findings greatly extend insights into core metabolic aberrations and their impact in breast cancer.
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| 66. |
- Jia, Min, et al.
(författare)
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Estrogen Receptor a Promotes Breast Cancer by Reprogramming Choline Metabolism
- 2016
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Ingår i: Cancer Research. - : AMER ASSOC CANCER RESEARCH. - 0008-5472 .- 1538-7445. ; 76:19, s. 5634-5646
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Tidskriftsartikel (refereegranskat)abstract
- Estrogen receptor alpha (ER alpha) is a key regulator of breast growth and breast cancer development. Here, we report how ER alpha impacts these processes by reprogramming metabolism in malignant breast cells. We employed an integrated approach, combining genome-wide mapping of chromatin-bound ER alpha with estrogeninduced transcript and metabolic profiling, to demonstrate that ER alpha reprograms metabolism upon estrogen stimulation, including changes in aerobic glycolysis, nucleotide and amino acid synthesis, and choline (Cho) metabolism. Cho phosphotransfse CHPT1, identified as a direct era-regulated gene, was required for estrogen- induced effects on Cho metabolism, including increased phosphatidylcholine synthesis. CHPT1 silencing inhibited anchorage- independent growth and cell proliferation, also suppressing early-stage metastasis of tamoxifen-resistant breast cancer cells in a zebrafish xenograft model. Our results showed that era promotes metabolic alterations in breast cancer cells mediated by its target CHPT1, which this study implicates as a candidate therapeutic target. (C) 2016 AACR.
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| 67. |
- Julin, Bettina, et al.
(författare)
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Dietary Cadmium Exposure and Risk of Postmenopausal Breast Cancer : A Population-Based Prospective Cohort Study
- 2012
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 72:6, s. 1459-1466
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Tidskriftsartikel (refereegranskat)abstract
- The ubiquitous food contaminant cadmium has features of an estrogen mimetic that may promote the development of estrogen-dependent malignancies, such as breast cancer. However, no prospective studies of cadmium exposure and breast cancer risk have been reported. , We examined the association between dietary cadmium exposure (at baseline, 1987) and the risk of overall and estrogen receptor (ER)-defined (ER+ or ER-) breast cancer within a population-based prospective cohort of 55,987 postmenopausal women. During an average of 12.2 years of follow-up, 2,112 incident cases of invasive breast cancer were ascertained (1,626 ER+ and 290 ER-). After adjusting for confounders, including consumption of whole grains and vegetables (which account for 40% of the dietary exposure, but also contain putative anticarcinogenic phytochemicals), dietary cadmium intake was positively associated with overall breast cancer tumors, comparing the highest tertile with the lowest [rate ratio (RR), 1.21; 95% confidence interval (CI), 1.07-1.36; P-trend = 0.02]. Among lean and normal weight women, statistically significant associations were observed for all tumors (RR, 1.27; 95% CI, 1.07-1.50) and for ER+ tumors (RR, 125; 95% CI, 1.03-1.52) and similar, but not statistically significant associations were found for ER- tumors (RR, 1.22; 95% CI, 0.76-1.93). The risk of breast cancer increased with increasing cadmium exposure similarly within each textile of whole grain/vegetable consumption and decreased with increasing consumption of whole grain/vegetables within each tertile of cadmium exposure (P-interaction = 0.73). Overall, these results suggest a role for dietary cadmium in postmenopausal breast cancer development.
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| 68. |
- Kharaziha, Pedram, et al.
(författare)
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Sorafenib Has Potent Antitumor Activity against Multiple Myeloma In Vitro, Ex Vivo, and In Vivo in the 5T33MM Mouse Model
- 2012
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 72:20, s. 5348-5362
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Tidskriftsartikel (refereegranskat)abstract
- Multiple myeloma (MM) is a B-cell malignancy characterized by the expansion of clonal plasma blasts/plasma cells within the bone marrow that relies on multiple signaling cascades, including tyrosine kinase activated pathways, to proliferate and evade cell death. Despite emerging new treatment strategies, multiple myeloma remains at present incurable. Thus, novel approaches targeting several signaling cascades by using the multi-tyrosine kinase inhibitor (TKI), sorafenib, seem a promising treatment approach for multiple myeloma. Here, we show that sorafenib induces cell death in multiple myeloma cell lines and in CD138(+)-enriched primary multiple myeloma patient samples in a caspase-dependent and -independent manner. Furthermore, sorafenib has a strong antitumoral and -angiogenic activity in the 5T33MM mouse model leading to increased overall survival. Multiple myeloma cells undergo autophagy in response to sorafenib, and inhibition of this cytoprotective pathway potentiated the efficacy of this TKI. Mcl-1, a survival factor in multiple myeloma, is downregulated at the protein level by sorafenib allowing for the execution of cell death, as ectopic overexpression of this protein protects multiple myeloma cells. Concomitant targeting of Mcl-1 by sorafenib and of Bcl-2/Bcl-xL by the antagonist ABT737 improves the efficacy of sorafenib in multiple myeloma cell lines and CD138(+)-enriched primary cells in the presence of bone marrow stromal cells. Altogether, our data support the use of sorafenib as a novel therapeutic modality against human multiple myeloma, and its efficacy may be potentiated in combination with ABT737.
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| 69. |
- Langenkamp, Elise, et al.
(författare)
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Elevated Expression of the C-Type Lectin CD93 in the Glioblastoma Vasculature Regulates Cytoskeletal Rearrangements That Enhance Vessel Function and Reduce Host Survival
- 2015
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 75:21, s. 4504-4516
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Tidskriftsartikel (refereegranskat)abstract
- Glioblastoma is an aggressive brain tumor characterized by an abnormal blood vasculature that is hyperpermeable. Here, we report a novel role for CD93 in regulating angiogenesis in this setting by modulating cell-cell and cell-matrix adhesion of endothelial cells. Tissue microarray analysis demonstrated that vascular expression of CD93 was correlated with poor survival in a clinical cohort of patients with high-grade astrocytic glioma. Similarly, intracranial growth in the GL261 mouse model of glioma was delayed significantly in CD93(-/-) hosts, resulting in improved survival compared with wild-type mice. This effect was associated with increased vascular permeability and decreased vascular perfusion of tumors, indicating reduced vessel functionality in the absence of CD93. RNAi-mediated attenuation of CD93 in endothelial cells diminished VEGF-induced tube formation in a three-dimensional collagen gel. CD93 was required for efficient endothelial cell migration and proper cell polarization in vitro. Further, in endothelial cells where CD93 was attenuated, decreased cell spreading led to a severe reduction in cell adhesion, a lack of proper cell contacts, a loss of VE-cadherin, and aberrant actin stress fiber formation. Our results identify CD93 as a key regulator of glioma angiogenesis and vascular function, acting via cytoskeletal rearrangements required for cell-cell and cell-matrix adhesion.
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| 70. |
- Li, Yihao, et al.
(författare)
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c-Myb Enhances Breast Cancer Invasion and Metastasis through the Wnt/beta-Catenin/Axin2 Pathway
- 2016
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 76:11, s. 3364-3375
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Tidskriftsartikel (refereegranskat)abstract
- The molecular underpinnings of aggressive breast cancers remain mainly obscure. Here we demonstrate that activation of the transcription factor c-Myb is required for the prometastatic character of basal breast cancers. An analysis of breast cancer patients led us to identify c-Myb as an activator of Wnt/beta-catenin signaling. c-Myb interacted with the intracellular Wnt effector beta-catenin and coactivated the Wnt/beta-catenin target genes Cyclin D1 and Axin2. Moreover, c-Myb controlled metastasis in an Axin2-dependent manner. Expression microarray analyses revealed a positive association between Axin2 and c-Myb, a target of the proinflammatory cytokine IL1 beta that was found to be required for IL1 beta-induced breast cancer cell invasion. Overall, our results identified c-Myb as a promoter of breast cancer invasion and metastasis through its ability to activate Wnt/beta-catenin/Axin2 signaling. (C) 2016 AACR.
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