Expression of B7S1 related with immune infiltration in colorectal cancer

Abstract

Objective To investigate the expression of B7S1 mRNA which is encoded by VTCN1 and protein levels in colorectal cancer(CRC) with the analysis of relation to clinicopathological characteristics, immune cell infiltration, and prognosis for the evaluation as a immunotherapeutic target in CRC. Methods Both Oncomine and TIMER databases were used to review the expression of VTCN1 in a variety of human solid tumors. The relationship between the expression of VTCN1 and the clinicopathological characteristics of CRC was analyzed using UALCAN and LinkedOmics databases. The expression of VTCN1 which is related with immune infiltration and clinical prognosis was evaluated using Human Protein Atlas database, Kaplan-Meier Plotter and TIMER database. A total of 24 patients with CRC in Ruijin Hospital (North) were collected and the expression of B7S1 protein in both CRC and normal intestinal tissues was detected by immunofluorescence staining. Results It was found in database that VTCN1 was expressed in many human solid tumors. VTCN1 was highly expressed in various subtypes of CRC when compared with that in normal intestinal tissues. The up-regulated VTCN1 was related to tumor stage, lymph node metastasis, distant metastasis, mismatch repair and overall survival rate. VTCN1 was also related to the immune cell infiltration. Immunofluorescence analysis showed that the protein of B7S1 was up-regulated in CRC when compared with that in normal intestinal tissues, and it was expressed in CD45- cells and CD45+ cells. Conclusions As co-inhibitory immune checkpoint molecule, B7S1 may be a potential prognostic factor and might become the target of immunotherapy for CRC.

Keywords

• |colorectal cancer|b7s1|immune checkpoint|immune microenvironment|tumor-infiltrating lymphocyte