The Association Between Polymorphisms in the MDR1
The article by Wang et al (2013) published in the cancer cell international journal is a systematic review of the association of multidrug resistance (MDR) 1 gene polymorphisms and the risk of cancer. The researchers conduct a pooled analysis of 52 case-control studies. In addition, the researchers justify the study by citing the presence of conflicting information on MDR 1 gene polymorphism and cancer risk. MDR 1 gene encodes P-glycoprotein, a membrane transporter protein that is hypothesized to play a crucial role in the elimination of carcinogens. Therefore mutation may trigger human malignancies.
An extensive review of relevant existing literature was conducted on various scientific databases that have ample information on this subject. The scope of the study was limited to human studies and this was crucial as there is a lot of information on animal studies. In order to draw a more definite conclusion, the researchers needed to review information on human studies. Each article was evaluated using a set inclusion criteria before acceptance and this further refined the study. However, the researchers should have made effort to access the full text of each relevant article as opposed to solely concentrating on articles that are freely accessible.
The strength of association between MDR1 polymorphisms and cancer risk was measured by ORs with 95% CIs. MDR1 3435C T and 2677G T/A polymorphisms were linked to cancer risk when all studies were pooled together. Overall, the researchers noted that multiple factors including signaling pathways and gene alterations such as polymorphism may cause cancer. In addition, same polymorphisms may act distinct roles in each cancer type, for different genetic backgrounds may contribute to the cancer discrepancy.