miR-200a-3p plays tumor suppressor roles in gastric cancer cells by targeting KLF12
ARTIFICIAL CELLS NANOMEDICINE AND BIOTECHNOLOGY
Authors: Jia, Changhe; Zhang, Yanrui; Xie, Yi; Ren, Ying; Zhang, Haihui; Zhou, Yinglei; Gao, Ning; Ding, Songze; Han, Shuangyin
Abstract
Background: The role of miR-200a-3p in gastric cancer (GC) remain unclear. Materials and methods: miR-200a-3p expression in 65 paired GC and adjacent tissues (AT) were evaluated by quantitative real-time PCR (qRT-PCR) and Western blot. Cell proliferation, cell cycle, and cell migration were assessed by cell growth counting assay, cell cycle analysis, and transwell assay, respectively. The target of miR-200a-3p was analyzed by dual-luciferase reporter assay. Results: miR-200a-3p in GC tissues was significantly reduced compared with AT. miR-200a-3p expression was closely associated with clinicopathological features (P < .05). SGC-7901 cell line demonstrated the lowest level of miR-200a-3p. Cell proliferation and colony formation was significantly inhibited by miR-200a-3p overexpression, but increased by miR-200a-3p knockdown (P < .05). miR-200a-3p upregulation increased the G1/S cell ratio. The 3'-UTR of KLF12 directly interacted with miR-200a-3p. Furthermore, increased levels of KLF12 expression was detected in GC tissues. A correlation analysis suggested a negatively correlation between miR-200a-3p and KLF12 mRNA expressions. Conclusion: miR-200a-3p was down-regulated in GC tissues and was correlated with clinicopathological features. miR-200a-3p overexpression inhibits GC cell proliferation, cell cycle, and cell migration. Furthermore, miR-200a-3p might act as a tumor suppressor in GC by targeting KLF12.
Postnatal expression of KLF12 in the inner medullary collecting ducts of kidney and its trans-activation of UT-A1 urea transporter promoter
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Authors: Suda, S; Rai, T; Sohara, E; Sasaki, S; Uchida, S
Abstract
Maturation of the inner medulla of the kidney Occurs after birth and is vital for mammals to acquire maximal urinary concentrating ability. During this process, expression of several kidney transporters and channels involved in urine concentrating mechanisms is known to be regulated. We previously isolated KLF15 as a transcription factor that regulates the expression of the CIC-K1 chloride channel. We have now found that another KLF transcription factor, KLF12. is expressed in the kidney from around 15 days after birth. To gain insight into its involvement in the maturation process of the inner medulla, we first determined the expression site of KLF12 within the kidney by in situ hybridization. By comparing the AQP2 immunolocalization in sequential sections, KLF12 was found to be expressed in the collecting ducts. Because expression of the urea transporter UT-A1 and amiloride-sensitive epithelial sodium channels ENaC is known to be tightly regulated in the collecting ducts after birth, we tested whether KLF12 has a regulatory role in the promoter activities of these genes. KLF12 is able to increase UT-A1 but not ENaC promoter activity through the binding to CACCC motif. These results suggest that KLF12 is involved in the maturation processes of collecting ducts after birth, and that UT-A1 is a target gene of KLF12. (c) 2006 Elsevier Inc. All rights reserved.