Breast cancer is a disease of unknown etiology; however, the major risk factors are genetic alterations. Studies have demonstrated an association between insulin-like growth factor 1 (IGF-1) gene polymorphism and cell proliferation and reduced apoptosis, in addition to its role in breast cancer growth and aggressiveness. Two polymorphic variants of the IGF-1 gene are highlighted in association with breast cancer, rs6220 and rs7136446, although controversy exists as to this relationship. The current study included 137 women (68 breast cancer cases and 69 controls without breast cancer) who had 3 ml of peripheral blood drawn for the study of genomic DNA extracted from leukocytes using the genotyping technique by real-time polymerase chain reaction. The CC genotype (rs7136446) was present in 4 women (5.9%) from the case group and in 2 (3.0%) women from the control group (p = 0.67), while the GG genotype (rs6220) occurred in 8 (11.5%) women from the case group and in 5 (7.2%) women from the control group (p = 0.75). No statistically significant difference was observed between the CC genotype of variant rs7136446 in premenopausal case and control women (p = 0.31), thus as there was also no significant difference between case and control postmenopausal women (p = 1.00). Concerning the GG genotype of rs6220, it occurred in 6 (14.2%) premenopausal case and 4 (8%) control women (p = 0.71) and no difference was found in postmenopausal women (p = 1.00). In the current study, IGF-1 gene polymorphism of SNP variants rs6220 and rs7136446 had no statistically significant association with breast cancer, both in premenopausal and postmenopausal women.

Polymorphism of the calcium-sensing receptor gene (CaSR or CaR) has been associated with an increased risk for breast cancer. This receptor plays an important role in calcium homeostasis, and has also been detected in several tissues that are unrelated to calcium metabolism, such as the skin, brain, and breast. The calcium-sensing receptor on cellular level, it regulates cell differentiation, proliferation, cell death, and gene expression. In breast cancer cells, CaSR seems to stimulate secretion of the parathyroid hormone-related protein (PTHrP), which stimulates cellular proliferation. Likewise, some studies have supported not only an association between calcium receptor gene polymorphism and breast cancer risk, but also a higher aggressiveness and unfavorable outcomes in breast cancer, which led us to make a survey in Pubmed on the subject in the last 10 years. Thus, in the literature there is a paucity of studies on the subject and the aim of this review was to show the role of calcium-sensing receptor and its association with breast cancer risk.

BackgroundMatrix metalloproteinases (MMPs) 2 and 9 may play an important role in cell proliferation and dissemination of cancer. However, few studies have compared the expression of these proteins between breast cancer and fibroadenoma.Material and methodsA randomized, double-blind study was carried out in 66 premenopausal women, aged 20-49 years, who had been diagnosed with fibroadenoma or breast cancer. The patients were divided into two groups: Group A, control (fibroadenoma, n=36) and Group B, study (cancer, n=30). Immunohistochemical analysis was performed using tissue samples of fibroadenoma and breast cancer to assess MMP-2 and MMP-9 antigen expression. Cells were considered positive if exhibiting brown cytoplasmic staining. Fisher’s exact test was used to compare the percentage of cases with cells expressing MMP-2 and MMP-9 in control and study groups (p < 0.05).ResultsLight microscopy showed a higher concentration of cells with positive cytoplasmic staining for MMP-2 and MMP-9 expression in breast cancer than in fibroadenoma. The percentage of cases with cells expressing MMP-2 in the control and study groups was 41.67% and 86.11%, respectively (p < 0.0009), whereas the percentage of cases with cells expressing MMP-9 in groups A and B was 66.67% and 93.33%, respectively (p<0.0138). MMP-2 and MMP-9 positive expression was significantly higher in moderately differentiated tumors compared to well and poorly differentiated tumors, p <0.005 and p<0.001, respectively.ConclusionsThe current study shows that MMP-2 and MMP-9 protein expression was significantly higher in the breast cancer than in the fibroadenoma and also in moderately differentiated breast cancer.

Breast cancer is a disease of unknown etiology, whose major risk factors are genetic alterations. Polymorphism of the calcium-sensing receptor (CaSR) has been a focus of some recent studies, due to a probable association with breast cancer risk and tumor aggressiveness. A relationship between polymorphic rs17251221 variant of the CaSR gene, and allele G (considered a gain-of-function mutation) and breast cancer risk has been stressed, despite the paucity of studies found in the literature. The present study involved 137 women (69 women with breast cancer-case; and 68 controls without breast cancer) who had 3 ml of peripheral blood drawn for DNA study. Genomic DNA was extracted from leukocytes by genotyping technique with real-time polymerase chain reaction. The AG genotype (rs17251221) was present in 13 women (18.84%) from the case group and in 8 (11.76%) women from the control group (p = 0.3434), while the GG genotype (rs17251221) did not occur in any group. In contrast, no statistically significant difference was observed between the AG genotype of variant rs17251221 in premenopausal case and control women (p = 0.71). There was also no statistically significant difference between postmenopausal case and control patients (p = 0.6851). In the current study, CaSR gene polymorphism of SNP variant rs17251221 did not show any statistically significant association with breast cancer, in both premenopausal and postmenopausal women.