Breast cancer is one of the most prominent causes of illness and death in humans and there is little information available on etiology of this disease. Breast cancer is a malignant proliferation of epithelial cells that cover ducts or lobules of breast. Breast epithelial malignancies are the most common causes of cancer in women (except skin cancer), which accounts for about 1/3 of all cancers in women. Risk factors such as premenstrual meningitis, premature menopause, infertility or age at the time of first birth may be responsible for another one-third of other cases of breast cancer. With the improvement in treatment and early detection, the mortality rate of breast cancer in United States is significantly decreasing(1). “Metastasis” refers to the spread of cancer cells. In breast cancer, most of the cells that belong to the glands or the ducts grow abnormally so that over time, they gradually bump into the fat and surrounding tissues(2, 3). By leaving even one cell outside the original tissue, the cell begins to grow, divide and multiply, and the invasive tumor of the breast is formed. The most common metastasis of breast cancer is the involvement of the lymph nodes through the lymphatic pathway. Breast cancer may also spread to other organs such as bones, lungs, liver and brain(4-9).Breast cancer is a complex and multifactorial process, and a large number of epidemiological studies have been conducted to identify several risk factors for breast cancer that include multiple factors (10).Previous genomic research has provided evidence to support single-nucleotide polymorphisms and genomic talent (SNP) in several genes along with the breast cancer risk and the contribution of carcinogenic agents to breast cancer (11, 12).Of the total 301 SNPs identified by 2013 for cancer, only 12 (3.3%) were associated with a change in the amino acid sequence of the protein, and a large proportion of them were located in the introns of the protein coding genes (40%) Or in the non-genic regions (44%) (13).This highly questionable observation led to a wide range of research into the discovery of the function of these non-coding sites and their role in the development of cancer. These studies have led to the identification of lncRNAs that are transcribed from non-coding sites for cancer, in which SNPs present in them are susceptible to cancer. For example, there is an SNP in the form of rs944289 in the region 3.14q13, which has a high association with papillary thyroid carcinoma (PTC), and affects the function of a tumor suppressor lncRNA (13).Similar to the protein coding genes, the lncRNA encoding genes can also act as tumorous tumor angiomas or tumor suppressor genes. Some of the highly preserved lncRNA encoding genes (UCEs-T) are abundantly found in fragile sites and carcinoma-related genomic regions (CAGRs), including very small areas that are proliferated in canceror Loss of heterozygosity occurs in them. Also, some of these elements have similar sequences with transcription enhancer elements and are increasingly called to another part of the DNA sequence. Sometimes the transcripts of these genes act as antisense agents and turn off the tumor suppressor genes. It is worth noting that the selective connection of some of these transcripts to protein assemblies involved in epigenetic processes and changes in chromatin state significantly affects the expression of the gene (14, 15).The H19 gene is a maternal expression tool that expresses the transcription of a long-coded non-coding RNA that has been reported previously and is involved in the tumor and progression of the cancer.In Wilms’ tumors, which are childhood neoplasms and often present in the syndrome overgrowh or excessive growth syndrome, H19 is extinguished on both chromosomes,and IGF2 is expressed as a duality (16).Long-term non-coding RNAs (lncRNAs) are defined as the transcription factor of RNA molecules, which are <200 nucleotides, which are not readily readable in their structure and are without having a protein encoding capacity (17, 18).Several cancer-related lncRNAs have been reported, including breast cancer .LncRNA of a handful of those misplaced in various cancers indicate that they contribute to carcinogens and provide their function in controlling the cell cycle and apoptosis, invasion and migration. Single-nucleotide polymorphism (SNPs) has been shown to have profound effects on gene expression and function, and participation in cancer.Recently, applied and extended studies have been done on the effects of SNPs on lncRNAs. For example, HOTAIR has been widely recognized for its role in tumor pathogenesis as a promoter in colon cancer. HOTAIR with polymorphic rs7958904 CC, is less likely to develop colon cancer than GG.HOTAIR with genotype rs920778 carrying TT increases the risk of gastric cancer.The risk of breast cancer with the rs12325489 CC and CT lincRNA-ENST00000515084 genotypes is higher than rs12325489TT genotype.lincRNA-uc003opf.1 in Exon rs11752942 AG + GGsignificantly decreases the risk of esophageal squamous cell carcinoma (19).Another lncRNA that may play an important role in cancer is H19. LncRNA H19 is a carcinogenic gene located at p15.5 of human chromosome 11 which is abnormally expressed in some tumors and its function is as a tumor suppressor or an oncogene. An increase in evidence suggests that genetic diversity of H19 plays an important role in cancer development(20-24)The false expression of H19 is associated with increased cell proliferation, while its silencing by siRNA molecules contributes to the induction of apoptosis. Subsequently, the H19 levels induced by hypoxia in hepatocellular and bladder cancers are accompanied by an increase in the expression of angiogenic induction genes, cell proliferation and survival. Against, a 675-miR coded from the H19 site is a tumor suppressor that inhibits cell proliferation in response to stress and reduction of the receptor IGF1 (25).According to our latest knowledge, no research has been conducted on the H19 polymorphism and the risk of breast cancer. Based on the above, we assume that the function of SNP in H19 may be related to the risk of breast cancer.However, the relationship between H19 polymorphism and breast cancer (BC) was unclear. The purpose of this study was to examine the association between the labeled H19 haplotypes (rs3741219 T> C, rs217727 C> T) and the risk of breast cancer.
Our study includes 150 breast cancer patients and 100 healthy cancer control women in East Azerbaijan.The genotypes rs3741219 and rs217727 polymorphisms were measured by PCR-RFLP polymerase chain reaction.
materials and methods
150 women with cancer and 100 women without cancer were studied. All of the patients were from Tabriz International Hospital. All women who were recently diagnosed with breast cancer were studied. We then selected 100 healthy women without any diseases that lacked any disease, especially chronic diseases, from over 2,000 people. A questionnaire was prepared for women’s data .
5 ml peripheral blood samples from 150 healthy individuals and 100 patients with breast cancer (according to entry and exit criteria) were collected in tubes containing anticoagulant EDTA after obtaining a satisfactory form from patients who referred to the International Hospital. All specimens were stored at -80 ° C to 0 ° C prior to DNA extraction.Primers were designed using the primer software 6 below.