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AIM:To explore the activation of signal transduction pathways related with the carcinogenesis of sporadic colon cancers. METHODS:A gene array monitoring the activation of 8 signal transduction pathways (PathwayFinder GEArray) was used to screen the differentially expressed genes between colorectal cancer and normal colon tissues. The differentially expressed genes were further analyzed by RT-PCR, using RNA derived from colorectal cancer and normal colon tissue of 35 patients. RESULTS:The expression of HSF1, HSF27, HSP90 and iNOS was increased in colon cancer tissues compared to normal colon tissue using PathwayFinder GEArray. The RT-PCR results showed that the expression of HSF1 was increased in 86% (30/35) patients and the expression of iNOS was increased in 63% (22/35) patients. CONCLUSION:The induction of HSF1 gene expression is associated with sporadic colon cancer. HSF1 induces heat shock stress signaling pathway, which might play a role in the carcinogenesis of sporadic colorectal cancer.Cen H, Zheng S, Fang YM, Tang XP, Dong Q. Induction of HSF1 expression is associated with sporadic colorectal cancer.

Abbreviations used: FCM -flow cytometry; GFP -green fluorescent protein; HA -haemagglutinin 9 peptide HA epitope; hCMV -human cytomegalovirus; IAP -inhibitor apoptosis protein; PCR -polymerase chain reaction; RT -reverse transcription; UV -ultraviolet Abstract: In our previous study, we demonstrated that azurin could selectively trigger apoptosis in human osteosarcoma cell line U2OS cells. However, the rate of apoptosis (35.8 ± 3.2%) is not very high, and azurin is too expensive to obtain readily. To solve these problems, we constructed a eukaryotic expression plasmid containing the azurin gene with an influenza virus haemagglutinin 9 peptide HA epitope tag, and transfected the recombinant plasmid pcDNA3.1(+)/azurin into U2OS cells. RT-PCR and Western blot analysis validated the successful transfection and the expression of the azurin-HA protein. Conspicuous apoptosis of the transfected cells was detected by flow cytometry (FCM) and the DNA ladder test. The apoptosis rate reached 64.3 ± 13.1%. The transcriptional levels of the Bax and p53 genes increased significantly in U2OS cells transfected with pcDNA3.1(+)/azurin, but the Bcl-2 mRNA level decreased. There was no difference in the levels of Bcl-xl mRNA and Survivin mRNA. We propose that the transfection of the recombinant plasmid pcDNA3.1(+)/azurin can significantly induce apoptosis in U2OS cells. This is closely associated with the up-regulation of the transcriptional level of the Bax and p53 genes, and the down-regulation of that of the Bcl-2 gene.