Introduction Pigment epithelium-derived factor (PEDF) is a 50kDa, secreted glycoprotein that has been identified as a member of the serpin gene family and has been shown to exhibit neurotrophic, neuroprotective, anti-angiogenic and anti-tumourigenic effects. The aims of our study were to determine the expression profile of PEDF in a range of colorectal cell lines and its association with clinical and pathological data.
Method Six human cell lines (RKO and HT115 are colonic adenocarcinoma, HRT-18 is rectal adenocarcinoma, COLO-201 is metastatic adenocarcinoma (originating from ascites), LS174T is a mucinous adenocarcinoma, and CCD-33C0 is a normal colorectal fibroblast cell line) were analysed using polymerase chain reaction (PCR) and quantitative transcript analysis (qPCR). Primary colorectal cancer tissue was collected at operation and analysed using qPCR.
Results PEDF transcript was positive in RKO, HRT-18, LS174T and CCD-33C0 cell lines but negative in HT115 and COLO-201. On qPCR, PEDF expression was highly positive in CCD-33C0. PEDF expression was significantly higher in tissue from mucinous tumours compared to adenocarcinoma (p = 0.0421). PEDF expression was lower in colorectal tissue from palliative resections compared to radical resections, with a trend towards significance (p = 0.097).
Conclusion PEDF expression was higher in the normal colorectal cell line when compared to colorectal cancer cell lines. There was a trend towards decreased expression in colorectal cancer tissue from palliative resections suggesting a possible tumour suppressor role and may indicate a potential role in primary tumour growth. Further work is proposed to investigate the effect of PEDF expression on cell function.
Disclosure of interest None Declared.