Background: Pancreatic cancer is highly malignant and characterised by rapid and uncontrolled growth. While some of the important regulatory networks involved in pancreatic cancer have been determined, the cancer relevant genes have not been fully identified.
Methods: We screened genes that may control proliferation in pancreatic cancer in seven pairs of matched pancreatic cancer and normal pancreatic tissue samples. We examined KIF15 expression in pancreatic cancer tissues and the effect of KIF15 on cell proliferation in vitro and in vivo. The mechanisms underlying KIF15 promotion of cell proliferation were investigated.
Results: mRNA microarray and functional analysis identified 22 genes that potentially play an important role in the proliferation of pancreatic cancer. High-content siRNA screening evaluated whether silencing these 22 genes affected proliferation of pancreatic cancer. Notably, silencing KIF15 exhibited the most potent inhibition of proliferation compared with the rest of the 22 genes. KIF15 was upregulated in human pancreatic cancer tissues, and higher KIF15 expression levels correlated with shorter patient survival times. Upregulation KIF15 promoted pancreatic cancer growth. KIF15 upregulated cyclin D1, CDK2, and phospho-RB and also promoted G1/S transition in pancreatic cancer cells. KIF15 upregulation activated MEK-ERK signalling by increasing p-MEK and p-ERK levels. MEK-ERK inhibitors successfully inhibited cell cycle progression, and PD98059 blocked KIF15-mediated pancreatic cancer proliferation in vivo and in vitro.
Conclusions: This study identified KIF15 as a critical regulator that promotes pancreatic cancer proliferation, broadening our understanding of KIF15 function in tumorigenesis.