ABSTRACT
The development of human neoplasms can be provoked by exposure to one of several viruses. Burkitt lymphoma, cervical carcinoma, and hepatocellular carcinoma are associated with Epstein-Barr, human papilloma, and hepatitis B virus infections, respectively. Over the past three decades, many studies have attempted to establish an association between colorectal cancer and viruses, with debatable results. The aim of the present research was to assess the presence of BK polyomavirus (BKV) DNA and protein in colorectal cancer samples from patients in the Western Province of Saudi Arabia. DNA extracted from archival samples of colorectal cancer tissues was analyzed for BKV sequences using polymerase chain reaction (PCR)-based techniques. In addition, expression of a BKV protein was assessed using immunohistochemical staining. None of the tumor and control samples examined tested positive for BKV DNA in PCR assays. Furthermore, immunohistochemical staining failed to detect viral proteins in both cancer and control specimens. These results may indicate that BKV is not associated with the development of colorectal adenocarcinoma in patients in the Western Province of Saudi Arabia.
Subject(s)
Adenocarcinoma/virology , BK Virus/isolation & purification , Colorectal Neoplasms/virology , Adenocarcinoma/pathology , Adult , Aged , Aged, 80 and over , BK Virus/genetics , Case-Control Studies , Colorectal Neoplasms/pathology , DNA, Viral/genetics , Female , Humans , Male , Middle Aged , Saudi Arabia , Viral Proteins/genetics , Viral Proteins/metabolismABSTRACT
The enzyme glutathione S-transferase Mu 1 (GSTM1) is encoded by the GSTM1 gene. Polymorphisms in GSTM1 affect the detoxifying function of the enzyme variants. This forms the basis of the debate about the impact of the GSTM1 null/present genotype on colorectal carcinoma risk. We tested the potential influence of GSTM1 polymorphisms on the development of colorectal cancer. DNA extracted from 83 samples taken from patients that were previously diagnosed as having colorectal carcinoma and from 35 control subjects who did not have colorectal carcinoma were amplified. GSTM1 genotypes were determined by DNA sequencing. The current study revealed that the majority (69/83, 83%) of colorectal cancer cases harbored the null genotype (GSTM1*0/*0), and the remaining 14 (17%) cases harbored either the GSTM1wt/wt or the GSTM1wt/*0 genotype. In contrast, among the control cases, 23 (65%) had the null genotype (GSTM1*0/*0) and 12 (35%) had either the GSTM1wt/wt or the GSTM1wt/*0 genotype. The current report emphasizes the impact of the GSTM1 null genotype on the increased risk of colorectal carcinoma in Saudi Arabia.