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We identified a novel gene ST13 from a subtractive cDNA library of normal intestinal mucosa in 1993, more studies showed that ST13 was a co-chaperone of Hsp70s. Recently we detected the ST13 gene expression in tumor tissue and adjacent normal tissue of the same colorectal cancer patient and investigated if the ST13 gene expression might have any prognostic value. Analysis was performed at molecular level by reverse transcription-PCR using real-time detection method. We measured two genes simultaneously, ST13 as the target gene and glyceraldehydes-3-phosphate dehydrogenase as a reference gene, in primary colorectal tumor specimens and tumor-adjacent normal mucosa specimens from 50 colorectal cancer patients. The expression levels of the ST13 gene were significantly decreased in primary tumors compared with adjacent mucosa (P<0.05). But there were no significant differences in the expression of ST13 as compared with different Dukes' stage, tumor differentiation grade, invasion depth, lymph node metastasis and disease-specific survival.

Objective: To study the base sequence of an enhancer in up-stream 5'-flank near regulation region (from -595 to +74) of human colorectal cancer related gene ST13., Methods: Several deletion PCR primers were designed. Amplified DNA fragments of ST13 gene 5'-flank near region were cloned with pGEMT-EASY vector and sequenced; then subcloned into several pGL2 report vectors respectively. Equal quantitative recombined DNA was transfected into SW620 cell lines and the luciferase activity was checked., Results: Several amplified base sequence fragments (669 bp,263 bp,163 bp) in pGL2-Basic all enhanced and promoted luciferase gene expression strongly. The 47 bp and 101 bp fragments didn't promote luciferase gene expression. 101 bp fragment recombined with pGL2-Promoter enhanced luciferase gene expression distinctly (P<0.01), but the effect was less strong than the positive pGL2-Control(P<0.05)., Conclusion: The base sequence 101 bp (from -595 to -494) in up-stream 5'-flank near regulation region of colorectal cancer related gene ST13 is an enhancer regulating gene transcript.