title: Tumor-suppressive effects of CDK8 in endometrial cancer cells.
abstract: CDK8 is either amplified or mutated in a variety of human cancers, and CDK8 functions as an oncoprotein in melanoma and colorectal cancers. Previously, we reported that loss or reduction of CDK8 results in aberrant fat accumulation in Drosophila and mammals, suggesting that CDK8 plays an important role in inhibiting lipogenesis. Epidemiological studies have identified obesity and overweight as the major risk factors of endometrial cancer, thus we examined whether CDK8 regulates endometrial cancer cell growth by using several endometrial cancer cell lines, including KLE, which express low levels of CDK8, as well as AN3 CA and HEC-1A cells, which have high levels of endogenous CDK8. We observed that ectopic expression of CDK8 in KLE cells inhibited cell proliferation and potently blocked tumor growth in an in vivo mouse model. In addition, gain of CDK8 in KLE cells blocked cell migration and invasion in transwell, wound healing and persistence of migratory directionality assays. Conversely, we observed the opposite effects in all of the aforementioned assays when CDK8 was depleted in AN3 CA cells. Similar to AN3 CA cells, depletion of CDK8 in HEC-1A cells strongly enhanced cell migration in transwell assays, while overexpression of CDK8 in HEC-1A cells blocked cell migration. Furthermore, gene profiling of KLE cells overexpressing CDK8 revealed genes whose protein products are involved in lipid metabolism, cell cycle and cell movement pathways. Finally, depletion of CDK8 increased the expression of lipogenic genes in endometrial cancer cells. Taken together, these results show a reverse correlation between CDK8 levels and several key features of the endometrial cancer cells, including cell proliferation, migration and invasion as well as tumor formation in vivo. Therefore, in contrast to the oncogenic effects of CDK8 in melanoma and colorectal cancers, our results suggest that CDK8 plays a tumor-suppressive role in endometrial cancers.
authors: Department of Obstetrics and Gynecology, Qilu Hospital, Shandong University, Jinan, Shandong, China.
authors: Weiting
authors: W
authors: Gu
authors: Chenguang
authors: C
authors: Wang
authors: Weihua
authors: W
authors: Li
authors: Fu-Ning
authors: FN
authors: Hsu
authors: Lifeng
authors: L
authors: Tian
authors: Jie
authors: J
authors: Zhou
authors: Cunzhong
authors: C
authors: Yuan
authors: Xiao-Jun
authors: XJ
authors: Xie
authors: Tao
authors: T
authors: Jiang
authors: Sankar
authors: S
authors: Addya
authors: Yanhong
authors: Y
authors: Tai
authors: Beihua
authors: B
authors: Kong
authors: Jun-Yuan
authors: JY
authors: Ji
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics; D056850:Cyclin-Dependent Kinase 8 / Q000235:genetics / Q000378:metabolism*; D016889:Endometrial Neoplasms / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D051379:Mice; D009361:Neoplasm Invasiveness; D014945:Wound Healing / Q000235:genetics
chemical_list: C095686:CDK8 protein, human; D056850:Cyclin-Dependent Kinase 8
keywords: cell growth; cell migration; cyclin-dependent kinae 8 (CDK8); endometrial cancer; tumorigenesis