Preliminary Research On The Regulating Effect Of ADP-ribosyltransferase Diphtheria Toxin-like 10 On Colorectalcarcinoma And The Mechanism

Background: ADP ribosylation is a posttranslational modification and is known to play an important role in many physiological and pathological processes such as cell death,cell cycle and DNA repair.ARTD10(ADP-ribosyltransferase diphtheria toxin-like 10)is intracellular mono-ADP ribosyltransferase which has been found recently.The relationship between ARTD10 and various tumor diseases is unclear till now.The effect of ARTD10 on the biological behaviors of colorectal carcinoma and the cell signal pathway role in the relationship between ARTD10 and colorectal carcinoma is also unclear.Methods : The expression of ARTD10 in human colorectal carcinoma tissues and colorectal carcinoma cell lines with different degree of differentiation(Lo Vo cells,SW480 cells and CT26 cells)were detected by immunohistochemistry assay and immunofluorescence assay,respectively.ARTD10 specific inhibitor was used to treat mouse colorectal carcinoma CT26 cells and the proliferation ability of CT 26 cells was monitered with cell counting kit-8 assay.Subcutaneous transplanted carcinoma in Balb/c mice was established to investigate the effect of ARTD10 on CT26 cells in vivo.Further more,nuclear transfer factor ?-catenin and it's down stream protein AXIN2 and c-MYB were determined with Western blot analysis.Results: ARTD10 positive staining exists both in colorectal carcinoma tissues and adjacent normal colorectal mucosae.ARTD10 expresses predominantly in cytoplasm,occasionally in nucleus.A significant difference of ARTD10 positive rate has been observed between colorectal carcinoma tissues and adjacent normal colorectal mucosae(p<0.05).The positive of ARTD10 has a significant difference between different degrees of colorectal carcinoma(p<0.05).Moreover,the positive degree of ARTD10 is positive correlated to the degrees of the neoplasm(p<0.05).As to ARTD10 expression in different colorectal carcinoma cell lines,ARTD10 expression is weak in SW480 cells,while in CT26 cells and Lo Vo cells is strong.The proliferation of CT26 cells is decreased when enzyme activity of ARTD10 is inhibit in vitro with specific ARTD10 inhibitor.With the increasing of ARTD10 inhibitor concentration,the inhibit effect increased and showing a significant dosage-dependent relationship(P< 0.05).The inhibitting effect of ATRD10 is most obvious at the concentration of 0.5?M.Moreover,there is statistical difference on proliferation of CT26 cells between treatment group and control group at all concentrations except0.1?M(P<0.05).CT26 cells were also cultured with 0.5?M ARTD10 inhibitor for 24 h,48h,72 h,96h and 120 h,respectively.The maximum inhibit effect has been got at 72 h.The volume and weight of Balb/c mouse axillary CT26 cell transplant tumor also decreased when ARTD10 is specifically inhibited.The expression of ?-catenin in CT26 cells and in cell nucleus of CT26 cells is reduced when ARTD10 is inhibited(P<0.05),meanwhile the expression of down stream proteins of ?-catenin,c-MYB is distinctly reduced(P<0.05)and the expression of AXIN2 is obviously increased(P<0.05).Conclusions: ARTD10 is highly expressed in colorectal carcinoma tissues compared with adjacent normal colorectal mucosae and predominantly located in cytoplasm.The expression of ARTD10 is related to malignant of colorectal carcinoma.ARTD10 promotes the proliferation of CT26 cells,and the possible mechanism maybe ARTD10 promotes the expression and nuclear translocation of ?-catenin and subsequent c-MYB expression,meanwhile decreases AXIN2 expression in colorectal carcinoma CT26 cells,indicating that ?-catenin may play a role in the regulating effect of ARTD10 on proliferation of CT26 cells.But the precise mechanisms remain to be researched.The results of this present study could provid some experimental datas and theoretical supports for developing ARTD10 as a potential target of colorectal carcinoma treatment.