Further statistical analysis revealed significant associations between increased p21 levels and bladder cancer patients with no exposure to chemicals (p=0.048), as well as with patients with no artificial sweetener intake (p=0.012), and between increased Cyclin D1 levels and study subjects with no artificial sweetener intake (p=0.012).
In the present study, amplification status of CCND1 and expression of CyclinD1 were evaluated by fluorescence in situ hybridization and immunohistochemistry on tissue microarrays from 152 lymph node-positive urothelial bladder cancers (one sample each from the center and invasion front of the primary tumors, two samples per corresponding lymph node metastasis) treated by cystectomy and lymphadenectomy.
Our data from bioinformatic and luciferase reporter gene assays identified that miR-5195-3p targeted the mRNA 3'-UTR of Krüppel-like factor 5 (KLF5), which is a proven proto-oncogene in bladder cancer. miR-5195-3p sharply reduced KLF5 expression and suppressed the expression or activation of its several downstream genes that are kinases improving cell survival or promoting cell cycle regulators, including ERK1/2, VEGFA, and cyclin D1.