Expression Status of UBE2Q2 in Colorectal Primary Tumors and Cell Lines

Background: Activation of the ubiquitin-proteasome pathway in various malignancies, including colorectal cancer, is established. This pathway mediates the degradation of damaged proteins and regulates growth and stress response. The novel human gene, UBE2Q2, with a putative ubiquitin-conjugating enzyme activity, is reported to be overexpressed in some malignancies. We sought to investigate the expression levels of the UBE2Q2 gene in colorectal cell lines as well as in cancerous and normal tissues from patients with colorectal cancer. Methods: Levels of UBE2Q2 mRNA in cell lines were assessed by Real-Time PCR. Western blotting was employed to investigate the levels of the UBE2Q2 protein in 8 colorectal cell lines and 43 colorectal tumor samples. Results: Expression of UBE2Q2 was observed at the level of both mRNA and protein in colorectal cell lines, HT29/219, LS180, SW742, Caco2, HTC116, SW48, SW480, and SW1116. Increased levels of UBE2Q2 immunoreactivity was observed in the 65.11% (28 out of 43) of the colorectal carcinoma tissues when compared with their corresponding normal tissues. Difference between the mean intensities of UBE2Q2 bands from cancerous and normal tissues was statistically significant at P<0.001 (paired t test). Conclusion: We showed the expression pattern of the novel human gene, UBE2Q2, in 8 colorectal cell lines. Overexpression of UBE2Q2 in the majority of the colorectal carcinoma samples denotes that it may have implications for the pathogenesis of colorectal cancer.