The Relationship between the Expression of Small Heat-Shock Proteins and Suppression of OCT4B1

Background: OCT4B1, a variant of OCT4, is expressed in both cancer cells and tissues. This variant has a main role in the regulation of both apoptotic and stress (heat-shock proteins) pathways. The aim of this study was to investigate the effects of OCT4B1 silencing on the expression of small heat-shock proteins (sHSPs)in three human tumor cell lines. Methods:AGS (gastric adenocarcinoma), 5637 (bladder tumor) and U-87MG (brain tumor) cell lines were transfected with specific OCT4B1 siRNA (test group) and scramble siRNA (control group), using siRNA and Lipofectamine. Real-Time PCR Array technique was applied and the fold changes were calculated using RT2 Profiler PCR Array Data Analysis version 3.5. Results: It was revealed that HSPB1, HSPB6 and HSPE1 were down-regulated in all three studied tumor cell lines and HSPB2, HSPB7 and HSPB8 were down-regulated in two of three studied tumor cell lines (AGS and 5637). It was also revealed that HSPB3 was down-regulated in 5637 cell line and up-regulated in AGS and U87MG cell lines. Conclusion: According to the results, it may be concluded that there is a direct relationship between OCT4B1 and sHSPs gene family expression. Thus, suppression of OCT4B1 may be considered in cancer therapy/research.