Expression of Lysophosphatidylinositol Signaling-relevant Molecules in Colorectal Cancer

Abstract

Background/Aim: Lysophosphatidylinositol (LPI) is a subspecies of the lysophospholipid mediators produced when phospholipase hydrolyzes membrane phosphatidylinositol. Previously, we used mass spectrometry-based lipidomics to demonstrate that LPI is selectively elevated in colorectal cancer (CRC) tissues. Here, we hypothesized that the expression levels of the LPI biosynthetic enzyme and LPI receptor - DDHD domain containing 1 (DDHD1) and G protein-coupled receptor 55 (GPR55), respectively - may be correlated with malignant potential, and we evaluated their roles in the context of CRC. Materials and Methods: Colorectal specimens from 92 CRC patients underwent DDHD1 and GPR55 immunolabeling. Correlation between protein expression levels and clinicopathological variables was examined. Results: Depth of tumor invasion was positively correlated with DDHD1 expression. Regardless of the degree of invasion depth, GPR55 was highly expressed in CRC tissues. Neither DDHD1 nor GPR55 expression levels were associated with disease-free survival. Conclusion: DDHD1 expression is associated with depth of tumor invasion in CRC tissues and may be involved in tumor progression.