Relationship between Fas ligand expression in colorectal cancer tissues and apo ptosis of tumor-infiltrating lymphocytes / 中华消化杂志

ABSTRACT

Objective To study the relationship between expression of Fas ligand (FasL) in colorectal cancer tissues and apoptosis of tumor-infiltrating lymphocytes (TIL). Methods FasL protein and its mRNA were measured by immunohistochem istry and in situ hybridization in the consecutive tissue slices of 30 colorecta l cancers respectively. Immunohistochemistry and terminal deoxynucleotidyl tra nsferase mediated dUTP nick end labeling assay (TUNEL) were used to detect the cell count of TIL and the count of TIL being apoptosis in both negative and pos i tive regions of FasL in the consecutive tissue slices of cancers respectively. T UN EL method was used to detect apoptosis of tumor cells among different FasL expre ssion regions. Results ①High expression of FasL was examined in 30 cases of colo rectal cancer; there were expressions of FasL in more than 75% tissues in each slice. ②In the consecutive tissue slices, the location of expression of FasL protein corresponded with that of FasL mRNA. ③FasL expression was not eve n in the same or among different tissues. The cell count of TIL was less in FasL positive region than that in FasL negative region in the same tissue, the latt er be ing as 2.88 times as the former. ④ The cell count of TIL being apoptotic in the positive regions was as 2.13 times as that in the negative ones. ⑤ Apoptotic r ate of tumor cells was higher in FasL negative region (81.2%) than that in FasL positive region (47.4%, P