Orientation Diagnosis System For Early-stagecolorectal Carcinoma With Laser Inducedautoflurescence Under Endoscope

Objective: To investigate the correlation between the expression of collagen type and MMP-2 and TIMP-2 and the difference of autofluorescence in normal and carcinomatous colorectal tissues and its possible mechanism.Methods: Laser-induced autofluorescence analysical system was used to detect the autofluorescence of normal and carcinomatous colorectal tissues in 32 patients.In all the samples, the expression of collage type was detected with immunohistochemical staining and MMP-2 and TIMP-2 were detected with immunohistochemical staining and RT-PCR. The correlations of the results were studied.Results: Autofluorescence peak intensity in 460nm in carcinomatous colorectal tissues was lower than that in normal tissues. The difference of autofluorescence peak intensity between carcinomatous colorectal tissues and corresponding normal tissues increased with the decreasing of the expression of collagen type in carcinomatous colorectal tissues.There was negative correlation in the expression of MMP-2 and collagen type .There was positive correlation in the expression of TIMP-2 and collagen type . Conclusions: 1,There is maked difference in autofluorescence peak intensity in 460nm in carcinomatous colorectal tissues and corresponding normal tissues.2,The degrading of collagen type in carcinomatous colerecatal tissues may be the histological basis of the difference ofautofluorescence in carcinomatous colorectal tissues and normal tissues.3,There different expression of MMP-2 and TIMP-2 in carcinomatous colorectal tissues and normal tissues may be one of the mechanisms of the difference between autofluorescence in carcinomatous colorectal tissues and normal tissues.