Knockdown of long non-coding RNA ANRIL inhibits tumorigenesis in human gastric cancer cells via microRNA-99a-mediated down-regulation of BMI1

Abstract

Long non-coding RNA antisense non-coding RNA in the INK4 locus (ANRIL) has been reported to promote tumorigenesis via regulating microRNA (miR)-99a in gastric cancer cells. However, the role of each component involved in it is still not well understood. This study aimed to verify the role of ANRIL in gastric cancer as well as the underlying mechanisms. ANRIL levels in clinical gastric cancer tissues and cell lines were tested by qPCR. Effects of ANRIL silence on cell viability, migration and invasion, apoptosis, and miR-99a expression in MKN-45 and SGC-7901 cells were measured using CCK-8, Transwell assay, flow cytometry, and qPCR assays, respectively. Then, effects of miR-99a inhibition on ANRIL-silenced cells were evaluated. B-lymphoma Mo-MLV insertion region 1 (BMI1) expression, after abnormal expression of ANRIL and miR-99a, was determined. Finally, expression of key proteins in the apoptotic, Notch, and mTOR pathways was assessed. ANRIL level was elevated in gastric cancer tissues and cell lines. Knockdown of ANRIL suppressed cell viability, migration, and invasion, and increased apoptosis through up-regulating miR-99a. Furthermore, ANRIL silence down-regulated BMI1 via up-regulating miR-99a. BMI1 silence down-regulated Bcl-2 and key kinases in the Notch and mTOR pathways and up-regulated p16 and cleaved caspases. We verified the tumor suppressive effects of ANRIL knockdown in gastric cancer cells via crosstalk with miR-99a. Together, we provided a novel regulatory mechanism for ANRIL in gastric cancer, in which ANRIL silence down-regulated BMI1 via miR-99a, along with activation of the apoptotic pathway and inhibition of the Notch and mTOR pathways.

Hyperglycemia Associated Metabolic and Molecular Alterations in Cancer Risk, Progression, Treatment, and Mortality

“…Interestingly, it was overexpressed in streptozotocin (STZ) induced diabetic mice, upregulated in the diabetic mice retinas, in the RF/6A hyperglycemia model, in aqueous humor samples, and the epiretinal fibrovascular membranes (FVM) of diabetic patients [62,63,64]. Another lncRNA, ANRIL, is upregulated under high glucose conditions in normal cells and is correlated with the carcinogenesis of gastric, oral, breast, and cervical cancers [65,66,67,68,69]. Altogether, these evidences demonstrate that hyperglycemia affects cells at transcriptional as well as sub-transcriptional levels, predisposing them to neoplastic transformation.…”

Analysis of association between genetic polymorphism of long non-coding RNA ANRIL and survival of patients with genitourinary cancer

“…CDK6 [14]. Також показано, що ANRIL впливає на ріст злоякісних клітин шляхом пригнічення сигнального шляху TGFβ/Smad [15], хоча конкретні молекулярні механізми взаємодії між днРНК ANRIL і TGFβ1 наразі невідомі.…”

“…Опубліковано низку повідомлень щодо участі днР-НК ANRIL у виникненні злоякісних пухлин різної локалізації. Виявлено, що ANRIL надмірно експресується у клітинах раку шлунка [2], кишечнику [3], молочної залози [4], простати [5] і сечового міхура [6]. Доведено асоціацію генетичного поліморфізму ANRIL із настанням раку легень [7], оптичної гліоми [8], множинної мієломи [9], раку молочної [10] і пе-редміхурової залози [11].…”

Analysis of ANRIL gene polymorphism rs4977574 association with kidney cancer development in Ukrainian population.

“…Today there are a number of reports about relation between ANRIL and development of various oncological pathologies. ANRIL has been found to be overexpressed in gastric cancer [9], esophageal squamous cell carcinoma [12], prostate cancer [15], urinary bladder cancer [11], etc. However, the main molecular mechanism of ANRIL involvement in cancer emergence and progression remains ambiguous.…”

“…ANRIL also influences cell proliferation by regulating target genes in trans. ANRIL has been shown to inhibit the activity of miR-99a/miR-449a in gastric cancer tissues, thereby increasing activity of target genes of these miRNAs -mTOR and CDK6 [9]. On the other hand, in esophageal squamous cell carcinoma ANRIL has been shown to affect cell growth through repression of TGFβ/Smad signaling pathway [12], although the exact molecular mechanisms of interaction between ANRIL and TGFβ1 remain unclear.…”