Research On Expression Of The Co-stimulation Factor PD-L1 And Its Clinical Significance In Colorectal Carcinoma

Objetive To investigate the expression level of the Co-stimulation Factor PD-L1 incolorectal carcinoma. To study the relationships between the expression level of theCo-stimulation Factor PD-L1 and pathologic and clinical features of colorectalcarcinoma.Methods The mRNA and protein expression levels of PD-L1 in carcinoma andproximal surgical margin tissues which collected from 30 patients with colorectalcarcinoma were assayed by real-time quantitative PCR and immunohistochemical S-Pmethods respectively. The relativity between expression of PD-Lland pathologic andclinical features in colorectal carcinoma was analysed.Results1. Positive PD-L1 expression rates in colorectal carcinoma and proximal surgicalmargin tissues are 53.3%(16/30) and 13.3%(4/30) respectively. The mRNA andprotein expression levels of PD-L1 in colorectal carcinoma are significantlyhigher than that in proximal surgical margin tissues.2. The mRNA and protein expression levels of the PD-L1 in tumor tissue arepositively correlated with the depth of invasion, lymphatic metastasis and Dukesstage of colorectal carcinoma.3. The mRNA and protein expression levels of PD-L1 in colorectal carcinoma arestatistically uncorrelated with tumor histological type and pathological grade. 4. The mRNA expression levels of PD-L1 is positively correlated with proteinexpression in colorectal carcinoma, but they are uncorrelated in proximal surgicalmargin tissues.Conclusion1. The elevation of PD-L1 expression level in colorectal carcinoma suggests thatthe PD-L1 may participate in the immunotolerance in colorectal carcinoma.2. The mRNA and protein expression levels of PD-L1 is positively correlatedwith the depth of invasion, lymphatic metastasis and Dukes stage of colorectalcarcinoma, which suggests that PD-L1 might be involved in the invasiveness andmetastasis of the colorectal carcinoma.3. The elevation of PD-L1 expression level in colorectal carcinoma is resulted fromthe changes of regulatory mechanisms of translation.