Study Of UbcH10's Roles On ALLN-Susceptibility In Colorectal Cancer

Colon cancer is one of the malignant tumors,which threatens body health of humans and even leads to death.In the world,the morbidity of colon cancer shows a rising trend year by year.Recently,some achievements in cancer-related researches reveal that a variety kind of gene mutations are closely associated with tumorigenesis and carcinoma progression,and these genes are usually involved in the courses of apoptosis,DNA damage and cell cycle.UbcH10 belongs to the family of E2 ubiquitin conjugating enzymes,which fulfill the function of protein ubiquitin modification by assisting E3 ubiquitin ligases.The previous results show that the expression levels of UbcH10 are relatively higher in several tumors including colon cancer than those in normal tissues,elucidating that UbcH 10 is an oncogene,but its detailed functions in cancer cells still need further research..In our study,we observed,using immunohistochemical method and western blot,the expression levels of UbcH10 in the colon cancer tissue samples are much higher than those in normal tissues.We examined some physiological changes caused by the overexpression or knockout of UbcH10 in DLD1 cells,finding that UbcH10 promotes cell proliferation of DLD1 significantly.Besides,reintroduction of UbcH10 into the knockout cell lines rescues the phenotype.Flow cytometry and phosphorylation of histone H3.1 immunofluorescence staining,as well as other experiments,confirmed that knockout of UbcH10 gene in DLD1 results in an increased proportion of cells distributed in the G2/M phase,indicating that blocking cells in the G2/M phase may be one of the key factors by which UbcH10 effects cell proliferation,and the deletion of UbcH10 gene also leads to cell cycle-related proteins' renewal process delay.Upon UbcH10 knockout,DLD1 cells become more sensitive to ALLN,which kills the cells by promoting apoptosis.We subsequently found out that the apoptosis caused by ALLN is much more severe in the UbcH10 knockout cells compared to the wildtype DLD1 cells.In conclusion,UbcH10 promotes DLD1 cell proliferation by regulating cell cycle and helps maintaining stronger resistance to ALLN which causes cell death via triggering apoptosis.Thus,our findings provide an important potential target and references for future clinical treatment of colon cancer.RPRD1B is a transcription-related gene,and it has been reported to function as an oncogene in all kinds of cancers,which accelerates tumorigenesis by regulating cell-cycle-related genes including CDK2,CDK4,CDK6,Cyclin D1,Cyclin E.Our results indicate that overexpression of RPRD1B significantly increases the growth rate of HCT116 cells,while it shows the reverse results when RPRD1B was knocked out.Meanwhile,RPRD1B knockout HCT116 cells are more sensitive to ALLN,leading to enhanced apoptosis.Our research towards the two oncogenes,UbcH10 and RPRD1B,verifies that their loss of function makes cells more sensitive to ALLN stimulation,resulting in an increased apoptosis-induced cell death.In summary,these achievements may help us better understand the mechanism of tumorigenesis and development of cancer as well as pave the way for researchers to find cures for more cancers.