CDKs Functional Analysis in Low Proliferating Early-Stage Pancreatic Ductal Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly devastating disease with a poor prognosis and growing incidence. In this study, we explored the potential roles of CDK1, CDK2, CDK4, and CDK6 in the progression of early-stage PDAC. Clinicopathologic and mRNA expression data and treatment information of 140 patients identified with stage I/II PDAC who underwent pancreaticoduodenectomy were obtained from the Cancer Genome Atlas data set. Our bioinformatic analysis showed that higher CDK1, CDK2, CDK4, or CDK6 expression was associated with a shorter median survival of the early-stage PDAC patients. Of note, in the low-proliferating pancreatic cancer group, CDKs expressions were significantly associated with proteins functioning in apoptosis, metastasis, immunity, or stemness. Among the low-proliferating PDAC, higher expression of CDK1 was associated with the shorter survival of patients, suggesting that CDK1 may regulate PDAC progression through cell cycle-independent mechanisms. Our experimental data showed that CDK1 knockdown/inhibition significantly suppressed the expression levels of AHR and POU5F1, two critical proteins functioning in cancer cell metastasis and stemness, in low-proliferating, but not in high-proliferating pancreatic cancer cells. In all, our study suggests that CDKs regulate PDAC progression not only through cell proliferation but also through apoptosis, metastasis, immunity, and stemness.