Expression and regulation of WNT5A and WNT5B in human cancer:: Up-regulation of WNT5A by TNFα in MKN45 cells and up-regulation of WNT5B by β-estradiol in MCF-7 cells

WNT signaling pathway plays key roles in carcinogenesis and embryogenesis, and WNT signaling molecules are potent targets for diagnosis, prevention and treatment of cancer as well as for regenerative medicine or tissue engineering. We have so far cloned and characterized human WNT2B/WNT13, WNT3, WNT3A, WNT5B, WNT6, WNT7B, WNT8A, WNT8B, WNT10A, WNT10B, WNT11, WNT14 and WNT14B/WNT15 using bioinformatics and cDNA-PCR. We have also reported frequent up-regulation of WNT2 and WNT5A in primary gastric cancer, which is probably due to cancer-stromal interaction. Here, expression and regulation of WNT5A and WNT5B in human cancer were investigated. WNT5A was relatively highly expressed in TE6 and TE10 among 12 esophageal cancer cell lines, and WNT5B was expressed in the majority of esophageal cancer cell lines. Among 7 pancreatic cancer cell lines, WNT5A was up-regulated in Hs700T, and WNT5B in PANC-1. WNT5A; but not WNT5B, was up-regulated by TNFalpha in MKN45 cells derived from gastric cancer. WNT5B, but not WNT5A, was up-regulated by beta-estradiol in MCF-7 cells derived from breast cancer. WNT5A and WNT5B were expressed together in 5 embryonal tumor cell lines, and were slightly down-regulated by all-trans retinoic acid in NT2 cells. Up-regulation of WNT5A and WNT5B in several types of human cancer expressing FZD5 might lead to more malignant phenotype through activation of the beta-catenin - TCF pathway.