Detection of Tumor Markers Using Stools with RT-PCR

Lee, Ryung Ah; Lee, Eun Joung; Kang, Bo Young; Kim, Kwang Ho

Abstract

PURPOSE: There is a need for sensitive, specific diagnostic and prognostic molecular markers that can monitor the early patterns of gene expression in non-invasive exfoliated colonocytes shed in stools. It has been estimated that approximately 10(10) normal adult colonic epithelial cells, each having a lifespan of 3~4 days, are shed from the lower two-thirds of colon crypts daily; thus, the development of a screening test using colonocytes is an realistic goal. Due to the characteristics of stools, few studies have been conducted on RNA based detection methods. Herein, a mass RNA analysis, using stools in colorectal cancer, is reported.
METHODS
The study included 15 colorectal cancer patients, and 15 control patients without neoplastic disease. RNA was isolated from routinely collected stool samples using a modified method. The expression levels of survivin, livin, Akt-1, caveolin, histone deacetylase (HDAC)1, matrix metalloproteinases (MMP)-2, MMP-7, MMP-9, MMP-12, hepatoma derived growth factor (HDGF), peptideYY, hypoxia-inducible factor (HIF)-1, epidermal growth factor receptor (EGFR), N-cadherin, catenin-beta, inducible nitric oxide synthase (iNOS), ring-3, enolase-1beta, insulin-like growth factor binding protein (IGFBP)-2, tissue inhibitors of metalloproteinase (TIMP)-1 and EphB2 were determined by reverse transcriptase- polymerase chain reactions (RT-PCR).
RESULTS
The rates of expression of fecal survivin, livin and Akt-1 assays for colorectal cancer were all 93%; whereas, those of the fecal caveolin, HDAC1, MMP-2, HDGF and peptideYY assays for colorectal cancer were 13, 6, 20, 6 and 6%, respectively. The remaining 13 assays did not show any expression in either the colorectal or normal groups. The expression levels of survivin, livin and Akt-1 were higher in the colorectal cancer than normal group in a semiquantitative analysis (P < 0.05).
CONCLUSIONS
These fecal survivin, livin and Akt-1 assays had both high expression rate and levels (colorectal cancer as distinguished from normal group) for detecting colorectal cancer; although, a larger study will be necessary to assess the expression rates and levels.