A-Kinase Anchor Protein 95 Is Involved in ERK1/2–Elk-1 Signal Transduction in Colon Cancer

Abstract

Objectives. To assess A-kinase anchor protein 95 (AKAP95), B-Raf, extracellular regulated protein kinases 1/2 (ERK1/2), and Elk-1 expression in colon cancer tissue, and characterize AKAP95 associations with B-Raf, ERK1/2, Elk-1, and colon cancer clinicopathological indices. Methods. The immunohistochemistry streptavidin-perosidase (SP) method was used to determine protein expression levels in 64 colon cancer and 32 para-carcinoma tissue specimens. Results. (1) Positive AKAP95 expression rates in colon cancer tissue were higher when compared with para-carcinoma tissue (92.19% vs. 59.38%, $P<0.05$ ). Similar findings were determined for B-Raf (76.56% vs. 25%, $P<0.05$ ), ERK1/2 (90.63% vs. 31.25%, $P<0.05$ ), and Elk-1 levels (92.19% vs. 40.63%, $P<0.05$ ). (2) No significant associations were identified between AKAP95, B-Raf, ERK1/2, and Elk-1 protein expression and degree of differentiation, histological type, and lymph node metastasis in colon cancer samples ( $P>0.05$ ); however, in The Cancer Genome Atlas and Gene Expression Omnibus datasets, AKAP95 was closely related to immune infiltration, and highly expressed AKAP95 was negatively associated with overall survival and relapse free survival rates in colon cancer patients. (3) Correlations were observed between AKAP95 and ERK1/2, AKAP95 and Elk-1, B-Raf and ERK1/2, B-Raf and Elk-1, and ERK1/2 and Elk-1 (all $P<0.05$ ), but no correlation was observed between AKAP95 and B-Raf ( $P>0.05$ ). Conclusions. AKAP95 may affect immune infiltration levels in colon cancer by participating in ERK1/2–Elk-1 signal transduction.