PBX3 promotes migration and invasion of colorectal cancer cells via activation of MAPK/ERK signaling pathway

AIM:To investigate the role of pre-B-cell leukemia homeobox(PBX)3 in migration and invasion of colorectal cancer(CRC)cells.METHODS:We detected PBX3 expression in five cell lines and surgical specimens from 111 patients with CRC using real-time reverse transcription-polymerase chain reaction.We forced expression of PBX3 in low metastatic HT-29 and SW480 cells and knocked down expression of PBX3 in highly metastatic LOVO and HCT-8 cells.Wound healing and Boyden chamber assays were used to detect cell migration and invasionafter altered expression of PBX3.Western blot was performed to detect the change of signaling molecule ERK1/2 following PBX3 overexpression.RESULTS:High level of PBX3 expression was correlated with the invasive potential of CRC cells,and significantly associated with lymph node invasion(P=0.02),distant metastasis(P=0.04),advanced TNM stage(P=0.03)and poor overall survival of patients(P<0.05).Ectopic expression of PBX3 in low metastatic cells was shown to promote migration and invasion,while inhibited PBX3 expression in highly metastatic cells suppressed migration and invasion.Furthermore,upregulation of phosphorylated extracellular signal-regulated kinase(ERK)1/2 was found to be one of the targeted molecules responsible for PBX3-induced CRC cell migration and invasion.CONCLUSION:PBX3 induces invasion and metastasis of CRC cells partially through activation of the MAPK/ERK signaling pathway.