Expression of WNT14 and WNT14B mRNAs in human cancer, up-regulation of WNT14 by IFNγ and up-regulation of WNT14B by β-estradiol

WNT proteins play key roles in carcinogenesis. We have previously cloned and characterized WNT14 and WNT14B/WNT15. WNT14 and WNT3A genes are clustered on human chromosome 1q42, while WNT14B and WNT3 genes are clustered on human chromosome 17q21. Here, we investigated expression of WNT14 and WNT14B mRNAs in human cancer. WNT14 was significantly up-regulated in 1 out of 9 cases of primary breast cancer. WNT14B was not expressed in primary breast, gastric and colorectal cancers. Among 3 human breast cancer cell lines, WNT14 mRNA was expressed in T-47D cells, and weakly expressed in MCF-7 cells. WNT14 mRNA was also detected in 7 out of 7 pancreatic cancer cell lines, 12 out of 12 esophageal cancer cell lines, 4 out of 4 cervical cancer cell lines, and 5 out of 7 brain tumor cell lines by using cDNA-PCR. These results indicate that WNT14 rather than WNT14B is preferentially expressed in various types of human cancer, such as breast cancer, gastric cancer, and pancreatic cancer. WNT14 mRNA was up-regulated by inferferon γ (IFNγ), but not by tumor necrosis factor α (TNFα), in MKN45 cells derived from gastric cancer, while expression of WNT14B mRNA was not affected by IFNγ and TNFα in MKN45 cells. Although expression of WNT14 mRNA was not affected by β-estradiol in MCF-7 cells, WNT14B mRNA was transiently up-regulated by β-estradiol in MCF-7 cells. These results indicate that WNT14 is a target gene of IFNγ in MKN45 cells, and that WNT14B is a target gene of estrogen in MCF-7 cells.