Purpose: Angiogenesis is a necessary step in tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is a major mediator of breast cancer angiogenesis. Therefore, we investigated the association of polymorphisms in the VEGF gene with breast cancer risk and prognostic characteristics of the tumors in a large case-control study. Experimental Design: We examined three polymorphisms in the VEGF gene (−2578C/A, −1154G/A, and +936C/T) in 571 familial breast cancer cases from Poland and Germany and −2578C/A, −634G/C, and +936C/T polymorphisms in 974 unselected breast cancer cases from Sweden together with ethnically and geographically selected controls. Results: None of the polymorphisms or any haplotype was significantly associated with either familial or unselected breast cancers. Our study suggests that the +936C/T polymorphism is unlikely to be associated with breast cancer. We also analyzed the unselected cases for genotypes or haplotypes that associated with tumor characteristics. The −634CC genotype and the −2578/−634 CC haplotype were significantly associated with high tumor aggressiveness (large tumor size and high histologic grade, P < 0.01) and the −2578AA genotype and the −2578/−634 AG haplotype with low histologic grade tumors (P = 0.04). The genotypes and haplotypes were not related with other tumor characteristics such as regional or distant metastasis, stage at diagnosis, or estrogen or progesterone receptor status. Conclusions: Although none of the polymorphisms studied in the VEGF gene was found to influence susceptibility to breast cancer significantly, some of the VEGF genotypes and haplotypes may influence tumor growth through an altered expression of VEGF and tumor angiogenesis.
The introduction of microarray techniques to cancer research brought great expectations for finding biomarkers that would improve patients treatment; however, the results of such studies are poorly reproducible, and critical analyses of these methods are rare. In this study we examined gene expression in 97 ovarian cancer samples. Validation of results by quantitative RT-PCR was performed also on 30 additional ovarian cancer samples. We carried out a number of systematic analyses in relation to several defined clinicopathological features. The main goal of our study was to delineate the molecular background of ovarian cancer chemoresistance and find biomarkers suitable for prediction of patients prognosis. Histological tumor type was the major source of variability in genes expression, except for serous and undifferentiated tumors that showed nearly identical profiles. Analysis of clinical endpoints (tumor response to chemotherapy, overall survival, disease-free survival, DFS) brought results that were not confirmed by validation either on the same group or on the independent group of patients. CLASP1 was the only gene that was found as important for DFS in the independent group, while in the preceding experiments it showed associations with other clinical endpoints and with BRCA1 gene mutation; thus, it may be worth of further testing. Our results confirm that histological tumor type is a strong confounding factor and gene expression studies of ovarian carcinomas should be performed on histologically homogeneous groups. Relatively small and unequal patients groups, may be a reason of poor reproducibility of statistical results, as well as the fact that the patients were treated with different chemotherapies. In addition, clinical endpoints may depend on subtle changes in many alternative molecular pathways, and this may be difficult to demonstrate by the methods applied. Also, arbitrarily performed division of samples may not reflect their true biological diversity
Tumor-associated macrophages (TAMs) play a significant role in at least two key processes underlying neoplastic progression: angiogenesis and immune surveillance. TAMs phenotypic changes play important role in tumor vessel abnormalization/ normalization. M2-like TAMs stimulate immunosuppression and formation of defective tumor blood vessels leading to tumor progression. In contrast M1-like TAMs trigger immune response and normalize irregular tumor vascular network which should sensitize cancer cells to chemo- and radiotherapy and lead to tumor growth regression. Here, we demonstrated that combination of endoglin-based DNA vaccine with interleukin 12 repolarizes TAMs from tumor growth-promoting M2-like phenotype to tumor growth-inhibiting M1-like phenotype. Combined therapy enhances tumor infiltration by CD4+, CD8+ lymphocytes and NK cells. Depletion of TAMs as well as CD8+ lymphocytes and NK cells, but not CD4+ lymphocytes, reduces the effect of combined therapy. Furthermore, combined therapy improves tumor vessel maturation, perfusion and reduces hypoxia. It caused that suboptimal doses of doxorubicin reduced the growth of tumors in mice treated with combined therapy. To summarize, combination of antiangiogenic drug and immunostimulatory agent repolarizes TAMs phenotype from M2-like (pro-tumor) into M1-like (anti-tumor) which affects the structure of tumor blood vessels, improves the effect of chemotherapy and leads to tumor growth regression.
Alterations in TGF‐β signaling appear to be associated with an altered risk of developing cancer, including breast cancer. We carried out a case‐control study on 8 polymorphisms, including 5 in the TGF‐β1 gene (G‐800A, C‐509T, Leu10→Pro, Arg25→Pro and Thr263→Ile), a polyalanine polymorphism (9A→6A) in the TGF‐βRI gene and 2 (G‐875A and A‐364G) in the TGF‐βRII gene, using samples from 2 different populations, Polish familial and Finnish unselected breast cancer cases, together with ethnically and geographically matched controls. Additionally, familial breast cancer cases with respective controls from Sweden and Germany were studied in the Leu10→Pro polymorphism, making the total number of familial cases 659. Allele, genotype and haplotype analysis on the TGF‐β1 gene as well as an analysis of the combinations of genotypes of the TGF‐β1 and its receptor genes in each individual were performed. Population differences in the allele and genotype distributions were found from 5 of the polymorphisms and 3 common haplotypes from the TGF‐β1 gene between the Finnish and other populations. However, no statistically significant difference between the breast cancer and healthy control groups was found for any of the 8 polymorphisms nor did the haplotype or genotype combination analysis reach statistical significance. Thus, none of the studied polymorphisms from the TGF‐β1 and its receptor genes was found to influence significantly susceptibility to breast cancer. The possible contribution of 6A/6A homozygosity in the TGF‐βRI gene to breast cancer needs to be confirmed in an independent study.
Pharmacogenetics of toxicity of 5-fluorouracil, doxorubicin and cyclophosphamide chemotherapy in breast cancer patients Pharmacogenetics of toxicity of 5-fluorouracil, doxorubicin and cyclophosphamide chemotherapy in breast cancer patients
The nuclear receptor coactivator 3 (NCOA3, also known as AIB1) is a coactivator of nuclear receptors like the estrogen receptor. NCOA3 is overexpressed in ∼60% of primary human breast tumors, and high levels of NCOA3 expression are associated with tamoxifen resistance and worse survival rate. In contrast, NCOA3 deficiency suppresses v-Ha-ras–induced breast cancer initiation and progression in mice. Here, we analyzed the influence of NCOA3 coding single nucleotide polymorphisms on breast cancer risk by performing a case-control study using a German and a Polish study population and identified an association between NCOA3 polymorphisms and breast cancer. A joint analysis of the German and the Polish study population revealed a significant protective effect for the 1758G>C (Q586H) and 2880A>G (T960T) variants. In addition, haplotype analysis showed a protective effect of the 1758C-2880A and 1758G-2880G haplotypes (odds ratio 0.79; 95% confidence interval, 0.67-0.93; P = 0.004). Because of the impact of NCOA3 in antiestrogen therapy resistance, these polymorphisms might also influence therapy outcome in breast cancer.