Inhibition of miR‑21 promotes cell apoptosis in oral squamous cell carcinoma by upregulating PTEN

Abstract

MicroRNA‑21 (miR‑21) has been identified as an oncogene and confirmed to serve an important role in carcinogenesis in various types of cancer. However, the effect and mechanism of miR‑21 in oral squamous cell carcinoma (OSCC) has not been fully elucidated. In the present study, miR‑21 inhibitor and empty vector were transfected into OSCC cells, and non‑transfected cells were used as a blank control. The results indicated that when compared with the control and scramble groups, miR‑21 inhibitor suppressed the expression of miR‑21. Conversely, phosphatase and tensin homolog deletion on chromosome 10 (PTEN) was markedly upregulated, and a dual luciferase reporter assay revealed PTEN to be a target gene of miR‑21. Furthermore, miR‑21 inhibitor decreased the proliferation and invasion and enhanced the apoptosis of OSCC cells. There was no significant difference in cell proliferation, invasion and apoptosis between the control and scramble groups. The present data suggested that there may be a regulatory loop between miR‑21 and PTEN, and that miR‑21 inhibition affected the proliferative, invasive and apoptotic abilities of OSCC cells. These findings indicate that miR‑21 may be a possible novel target in the treatment of OSCC.

Prognostic Value of MiR-21: An Updated Meta-Analysis in Head and Neck Squamous Cell Carcinoma (HNSCC)

“…The oncogenic potential of miR-21 in oral squamous cell carcinoma (OSCC) cell lines was underlined in relation with PTEN protein levels. Specifically, the induced underexpression of miR-21 correlated with the upregulation of PTEN gene expression and inhibition of cell growth, with these results showing miR-21 to be a potential therapeutic target in OSCC [33]. MiR-21 was also reported as a regulator of the immune response in tongue cancer, playing a role in expressly activating the nuclear factor NF-κB pathway in CAL27 cell line exosomes [34].…”

Identification and profiling of microRNAs expressed in oral buccal mucosa squamous cell carcinoma of Chinese hamster

“…In addition, Zheng, Y et al . reported that miR-21 acts as a regulator factor in many signaling pathways such as Wnt/β-catenin and PI3K/Akt 34 . Meanwhile, PTEN is a direct target in downstream of the PI3K/Akt pathway and is associated with apoptosis and tumor growth 35 .…”

MicroRNAs: The Link between the Metabolic Syndrome and Oncogenesis

“…MiR-21 is implicated in the pathogenesis of oral squamous cell carcinoma (OSCC) through its target gene, PTEN. Additionally, the expression of miR-21 and PTEN were associated with the tumors' grade [114]. Tongue squamous cell carcinoma oncomir-21 increased tumors' aggressiveness by inhibiting DKK and consequently activating the Wnt/β-Catenin pathway [115].…”

“…The aforementioned findings shed some light on the implication of miR-21 and its pathogenic pathways implicated in both MetS and cancer. Thus, miR-21 PTEN-induced deregulation is implicated in CRC [103], NSCLC [108], gastric cancer [110], OSCC [114], and cervical cancer [117], being closely correlated with the tumor aggressiveness [110], grade [114], and invasiveness [108]. Additionally, the miR-21/PTEN/PI3K/Akt pathway is implicated in the glucose metabolism and insulin homeostasis [91].…”