Evaluation of Bax and BCL ۲ Genes Polymorphisms in Iraqi Women with Breast Cancer

The present study aimed to examine the polymorphism -۹۳۸C > A of BCL-۲ gene and promoter -۲۴۸G>A in the Bax gene, as well as their relationship with specific clinical-pathological characteristics, in patients with breast cancer. Blood samples were obtained from ۷۰ patients who had been diagnosed with breast cancer and ۳۴ healthy women as the control group. Polymorphic analysis was performed using the polymerase chain reaction-restriction fragment length polymorphism assay. Anthropometric data were assessed. Estrogen receptor (ER), human epidermal growth factor receptor ۲ (Her-۲), and progesterone receptor (PR) were measured by immunohistochemistry. The data of age and body mass index (BMI) demonstrated no significant variations between the two groups (P>۰.۰۵). The results of HER-۲ revealed that ۴۲.۸۶% of breast cancer patients reflected positively for Her-۲/neu expression, while ۲۴.۲۹% reflected negative results of Her-۲/neu. Moreover, the results of ER revealed that ۴۲.۸۶% and ۲۸.۵۷% of subjects were positive and negative ER, respectively; moreover, the missing data was ۲۸.۵۷%. In addition, the results of PR indicated that ۳۵.۷۱% of patients (۲۵/۷۰) were positive for PR, while ۲۸.۵۷% reflected negative results, and the missing results were ۳۵.۷۱%. The genotype and allele frequencies of BCL-۲(-۹۳۸C>A) were not statistically significant in women with breast cancer and the control group (P=۰.۵۷۴, P=۰.۵۳۳) for heterozygous and recessive models, respectively. The genotype of BCL-۲(-۹۳۸C>A) in control and patients in codominant, dominant, recessive, and additive models demonstrated no significant variations of all genotypes in all groups. Genotypes and allele frequencies for Bax (-۲۴۸G>A) in patients with breast cancer and control indicated that the frequencies of GG, AG, and AA genotypes in cases were ۱۶.۶۷%, ۳.۳۳%, and ۸۰ %, while in controls, these values were ۳.۲۳ %, ۵۸.۰۶ %, and ۳.۲۳ %, respectively. The heterozygous genotype (AG) in the codominant model was OR=۳۶.۰۰ (۹۵% CI: ۴.۵۶۰۸ - ۲۸۴.۱۶۰۸; P=۰.۰۰۰۷). In comparison with the wild type (GG), there was a ۳۶-fold increase in the risk of breast cancer. Furthermore, the findings of this study revealed a significant correlation between Bax (-۲۴۸G>A) polymorphism and breast cancer risk under the dominant and overdominant (OR=۶.۳۳; ۹۵% CI: ۲.۲۶۰۴ -۱۷.۷۴۵۲; P=۰.۰۰۰۴, and OR=۴۰.۱۵۴; ۹۵% CI: ۵.۱۳۶۵ - ۳۱۳.۸۹۴۹; P=۰.۰۰۰۴, respectively. The recessive model revealed that there was a decreased risk of breast cancer (OR= ۰.۱۶۷; ۹۵% CI: ۰.۰۳۰۳ to ۰.۹۱۶۸; P=۰.۰۳۹). Based on the results, it can be concluded that there were no significant variations in BCL-۲ (-۹۳۸C>A) polymorphism of all genotypes models when breast cancer women are compared with healthy ones. In a similar vein, there was no significant association between the BCL-۲ (-۹۳۸C>A) polymorphism and breast cancer risk under dominant, codominant, or recessive models.

Keywords:

Bax gene , BCL-۲ gene , Breast cancer , ۲۴۸G>A polymorphism , -۹۳۸C > -۹۷h۵۲۶A polymorphism , Iraq