Relationship between the expression of human telomerase reverse transcriptase gene and cell cycle regulators in gastric cancer and its significance

AIM To investigate the expression of human telomerasereverse transcriptase gene(hTRT)in gastric cancer(GC)and its relevance with cell cycle regulators including P16INK4,cyclin and P53.METHODS:In situ hybridization(ISH)for hTRT mRNA wasperformed in 53 cases of gastric cancer and adjacentcancerous tissues.Immunohistochemical staining(S-Pmethod)for hTRT protein,P16INK4,cyclinD1 and P53 wasperformed in 53 cases of GC and adjacent cancerous tissues.RESULTS:Of 53 cases of GC,the expression of hTRT mRNAand hTRT protein was significantly higher than the expressionof hTRT mRNA and hTRT protein in adjacent canerous tissues(P<0.01),the positive rates of hTRTmRNA and hTRT proteinwere 79.2 % and 88.6 %.There was a stastical differenceof the expression of hTRT protein among well differentiatedadenocarcinoma,poorly differentiated adenocarcinoma andmucoid carcinoma.And there was a highly significant positivecorrelation between the expression of hTRT mRNA and hTRTprotein(r=0.625,P<0.01).However,the expression of hTRTmRNA and its protein in GC were not related with otherclinicopathological parameters including gender,age,locationand size of neoplasm,invasion depth,lymph node metastasisand clinical stage.There was a significant positive correlationbetween the expression of hTRT mRNA and cyclinD1 protein(r=0.350,P<0.01).There was a significant positivecorrelation between the expression of cyclinD1 protein andhTRT protein(r=0.549,P<0.01),so was between P53 andhTRT protein(r=0.319,P<0.05)CONCLUSION: The expression of TRT gene is correlated significantly to the specific defects of cell cycle on G1/S check point ; telomerase activity may depend on cell cycle in gastric cancer and it is available to clarify the molecular mechanism of telomerase activity regulation. The expression of hTRT mRNA and hTRT protein in GC is significantly different from the expression of hTRT mRNA and hTRT protein in adjacent cancerous tissue which indicates that these targets are correlated closely to the occurrence of GC and can provide important morphologic index for diagnosis of GC.