Enhanced expression and significance of glycosylphosphatidylinositol anchor attachment protein 1 in colorectal cancer.

The aim of this study was to investigate the expression of glycosylphosphatidylinositol anchor attachment protein 1 (GPAA1) and its significance in patients with colorectal cancer. Fifty-two patients with primary colorectal cancer were included in this study. GPAA1 expression was detected by immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blot analysis. A cell invasion assay was performed by the transwell method. The interacting proteins of GPAA1 were detected by co-immunoprecipitation and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/TOF-MS). The expression of GPAA1 mRNA and protein in primary colorectal tumor tissues and liver metastasis tissues was significantly higher than that in normal mucosa tissues (P < 0.01). The number of highly expressing GPAA1 cells penetrating the Matrigel membrane was significantly higher than that of mildly expressing GPAA1 cells (P < 0.05). The results of co-immunoprecipitation and MALDI-TOF/TOF-MS confirmed the identity of the protein. GPAA1 is highly expressed in patients with colorectal cancer, which indicates that it might play an important role in the proliferation, invasion, and metastasis of colorectal cancer.