Fatima Faria, Saleem Saima, Hameed Abdul, Haider Ghulam, Ali Zaidi Syed Aqib, Kanwal Madiha, Zehra Sitwat, Azhar Abid
The Karachi Institute of Biotechnology and Genetic Engineering (KIBGE), University of Karachi, 75270, Karachi, Sindh, Pakistan.
Institute of Biomedical and Genetic Engineering (IB&GE), Islamabad, Pakistan.
Mol Biol Rep. 2019 Apr;46(2):2387-2394. doi: 10.1007/s11033-019-04699-6. Epub 2019 Mar 8.
Chemokine CC receptor type 5 (CCR5) is a cell surface receptor that has high affinity for chemotropic cytokines called chemokines. The CCR5 gene contains a 32 base pairs (bp) deletion (CCR5Δ32). This deletion may result in a malformed and nonfunctional receptor, reported to be responsible for the development and dissemination of different cancers. CCR5Δ32 exists in two allelic forms i.e. deletion (D) and wild type (WT). This study aims to detect the role of CCR5Δ32 in breast cancer development. Blood samples were collected from breast cancer patients (330) and controls of same gender (306). Along with this histopathologically diagnosed malignant tissue samples were also excised from breast lesions of 100 patients. Genetic variations within the blood and tissue samples were examined by PCR then observed through gel electrophoresis and confirmed by direct DNA sequencing. Obtained DNA sequences were aligned and analyzed by MEGA6 software. Genotypic and association analyses were done by SPSS software version 17.0. Deletion of 32 bp in CCR5 gene has been analyzed. Genotypic variations of CCR5Δ32 are; homozygous wild type (WT/WT), heterozygous deletion (WT/D) and homozygous deletion (D/D). Statistical analyses of CCR5Δ32 data revealed that WT/D was significantly higher in blood samples of breast cancer patients (7.27% (24/330)) as compare to controls (1.30% (4/306)). In tumor tissue samples WT/WT being the most frequent genotype (99.00% (99/100)) with 1.00 (1/100) of D/D which suggested that it may be acquired. Hence, association analysis showed that CCR5Δ32 is positively associated with breast cancer in Pakistan (p < 0.001). The risk ratio of CCR5Δ32 was 5.6610 (95% confidence interval: 2.0377 to 15.7267) and odds ratio was calculated to be 6.0335 (95% confidence interval: 2.1288 to 17.0999) which signifies that deletion also increases the risk of breast cancer development. Moreover, association analyses also revealed that clinicopathological features do not have any impact on the CCR5Δ32 genotype of breast cancer. This suggests that deletion of 32 bp in CCR5 gene may be associated with breast cancer. CCR5 signals the activation and migration of immune cells at the site of tumor formation. Because of deletion; deformed CCR5 receptor might be unable to express and function properly which may subdue the immunity against cancer hence, leading to its progression.
趋化因子CC受体5型（CCR5）是一种细胞表面受体，对称为趋化因子的趋化性细胞因子具有高亲和力。CCR5基因包含一个32个碱基对（bp）的缺失（CCR5Δ32）。据报道，这种缺失可能导致受体畸形且无功能，这与不同癌症的发生和扩散有关。CCR5Δ32以两种等位基因形式存在，即缺失型（D）和野生型（WT）。本研究旨在检测CCR5Δ32在乳腺癌发生中的作用。从乳腺癌患者（330例）和同性对照（306例）中采集血样。与此同时，还从100例患者的乳腺病变中切除了经组织病理学诊断的恶性组织样本。通过聚合酶链反应（PCR）检测血样和组织样本中的基因变异，然后通过凝胶电泳观察，并通过直接DNA测序进行确认。获得的DNA序列通过MEGA6软件进行比对和分析。使用SPSS 17.0软件进行基因型和关联性分析。对CCR5基因中32 bp的缺失进行了分析。CCR5Δ32的基因型变异有：纯合野生型（WT/WT）、杂合缺失型（WT/D）和纯合缺失型（D/D）。对CCR5Δ32数据的统计分析显示，与对照组（1.30%（4/306））相比，乳腺癌患者血样中的WT/D显著更高（7.27%（24/330））。在肿瘤组织样本中，WT/WT是最常见的基因型（99.00%（99/100）），D/D为1.00%（1/100），这表明它可能是后天获得的。因此，关联性分析表明，在巴基斯坦CCR5Δ32与乳腺癌呈正相关（p＜0.001）。CCR5Δ32的风险比为5.6610（95%置信区间：2.0377至15.7267），优势比经计算为6.0335（95%置信区间：2.1288至17.0999），这表明缺失也会增加乳腺癌发生的风险。此外，关联性分析还显示临床病理特征对乳腺癌的CCR5Δ32基因型没有任何影响。这表明CCR5基因中32 bp的缺失可能与乳腺癌有关。CCR5在肿瘤形成部位发出免疫细胞激活和迁移的信号。由于缺失，畸形的CCR5受体可能无法正常表达和发挥功能，这可能会削弱对癌症的免疫力，从而导致癌症进展。
