Downregulation of MiR-203a Disinhibits Bmi1 and Promotes Growth and Proliferation of Keratinocytes in Cholesteatoma

Abstract

Background: Keratinocytes are the predominant cell type in a cholesteatoma, and microRNA (miR)-203a has been shown to be essential for the growth and differentiation of keratinocytes. The regulatory mechanisms of miR-203a and Bmi1—the predicted target of miR-203a that is associated with cholesteatoma—have not been clarified.Methods: Real-time PCR and western blot were carried out for the detection of miRNAs, mRNAs, and proteins, including miR-203a, Bmi1, and phosphorylated (p-)Akt. Immunohistochemical staining was applied to observe the expression and distribution of Bmi1 and of p-Akt in cholesteatoma and in control retroauricular skin. The dual luciferase reporter assay was used to analyze the relationship between miR-203a and Bmi1. Ectopic miR-203a and Bmi1 were transfected into an immortalized line of human keratinocytes (HaCaT cells), and the roles of these molecules in cell proliferation, apoptosis, and migration were explored.Results: Cholesteatoma tissues were characterized by downregulation of miR-203a and concomitant upregulation of Bmi1. Results of the dual-luciferase reporter assay indicated that Bmi1 was a direct target gene of miR-203a. Silencing of miR-203a increased Bmi1 expression; promoted proliferation, colony formation, and migration of HaCaT cells; and inhibited apoptosis. Moreover, p-Akt was significantly increased in cholesteatoma tissues and was positively correlated with Bmi1. Suppression of Bmi1 reduced p-Akt expression in HaCaT cells; subsequent inhibition of miR-203a reversed this phenomenon.Conclusions: Our results reveal that miR-203a may regulate cholesteatoma growth and proliferation by targeting Bmi1. These findings provide insight for the development of novel nonsurgical options for cholesteatoma.

Effect of lncRNA ANRIL silencing on anoikis and cell cycle in human glioma via microRNA-203a

“…Some reports have shown that lncRNA ANRIL is associated with osteosarcoma and lung cancer; 4 , 5 however, the role of lncRNA ANRIL in glioma has not been fully elucidated. An increased expression of lncRNA ANRIL in glioma correlating with grade and a negative correlation with the anti-oncogene miR-203a has been found; 6 , 7 thus, we considered that there may be a potential relationship between lncRNA ANRIL, the glioma tumorigenesis process, and miR-203a expression. This study aimed to explore the effect of lncRNA ANRIL silencing on induced anoikis and cell cycle arrest in human glioma and the possible mechanism involved.…”

miR-199a Targeting PNRC1 to Promote Keratinocyte Proliferation and Invasion in Cholesteatoma

“…miRNAs have vital functions in regulating cellular activities. Over the past years, substantial studies have confirmed the involvement of miRNA in the pathogenesis of acquired cholesteatoma [ 11 , 14 , 26 ]. Notably, miR-199a has attracted wide attention.…”

“…2020-KY-225) for the whole research, as well as all involved patients' (or their parents') written informed consent, was obtained before the research. Cholesteatoma tissues and matched normal postauricular skin tissues [ 11 , 21 , 22 ] were obtained from cholesteatoma patients conformed by pathologists in the First Affiliated Hospital of Zhengzhou University from March 2020 to June 2020. The collected specimens were sent to the laboratory for immediate surgery.…”

“…MicroRNAs (miRNAs) refer to small and noncoding RNAs able to inhibit the translation of mRNA and/or intervene in the degradation of mRNA to regulate the posttranscriptional expression [ 11 ]. Furthermore, they function significantly to regulate proliferation, differentiation, migration, and apoptosis of cells [ 12 ].…”

“…Furthermore, they function significantly to regulate proliferation, differentiation, migration, and apoptosis of cells [ 12 ]. In previous studies, numerous miRNAs such as miR-let-7a, miR-203a, and miR-21 were determined to be correlated with the pathogenesis of cholesteatoma [ 11 , 13 , 14 ]. However, the role of microRNA-199a (miR-199), an extensively studied cancer-promoting microRNA, in cholesteatoma has not attracted researchers' attention.…”