Activation of the miR-371/372/373 miRNA Cluster Enhances Oncogenicity and Drug Resistance in Oral Carcinoma Cells

Abstract

Oral squamous cell carcinoma (OSCC) is among the leading causes of cancer-associated deaths worldwide. Family members in miR-371/372/373 miRNA cluster, which is localized at human chromosome 19q13.4, are co-expressed in both human stem cells and malignancies. The individual miRNA in this cluster are also involved in modulating the pathogenesis of malignancies as either oncogenes or suppressors. The 19q13 region is frequently gained in head and neck cancers. High expression of miR-372 and miR-373 are survival predictors for OSCC. However, the role of the miR-371/372/373 cluster in oral carcinogenesis remains to be fully investigated. We use the clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9 system to establish OSCC cell subclones that had the miR-371/372/373 cluster deleted. In addition, further subclones were established that had the promoter of this cluster deleted. Concordant silencing in SAS cells of miR-371/372/373 decreased oncogenic potential, increased cisplatin sensitivity, activated p53, and upregulated the expression of Bad and DKK1. We also employed the CRISPR/dCas9 synergistic activation mediator system, which allowed robust transcriptional activation of the whole miR-371/372/373 cistron. Upregulation of endogenous miR-371/372/372 expression increased both oncogenicity and drug resistance. These were accompanied by a slight activation of AKT, β-catenin, and Src. This study identifies the oncogenic role of the miR-371/372/373 cluster in OSCC. Using CRISPR based strategy can be a powerful paradigm that will provide mechanistic insights into miRNA cluster functionality, which will also likely help the development of targeting options for malignancies.

CRISPR/Cas9 gene editing: a new approach for overcoming drug resistance in cancer

“…A recent study on oral carcinoma cells showed that the miR-371/372/373 cluster could be removed using CRISPR/Cas9 technology. The results of this study showed that this deletion significantly enhances the apoptotic effects of cisplatin so that, in deleted subclones, the population of late apoptosis increases significantly after 48 h of treatment with 15 μM cisplatin [143]. One study showed that, using CRISPR/Cas9 technology and lentiviral vector, the expression of miR-21, a well-known oncomiR, in ovarian cancer cells could be inhibited.…”

CmirC: an integrated database of clustered miRNAs co-localized with copy number variations in cancer

“…Researchers have proposed that clustered miRNAs can act more efficiently than a single miRNA, as a cluster contains multiple miRNAs (Wang et al 2016 ). Clustered miRNAs deregulation is more potent and crucial in cancer signaling pathways and is further responsible for clinical complications such as resistance to therapy (Lin et al 2020 ; Becker et al 2012 ). Hence, the role of clustered miRNAs as a biomarker for diagnosis, prognosis, treatment, and improved patient care remains to be fully exploited.…”

Impact of Non-Coding RNAs on Chemotherapeutic Resistance in Oral Cancer

“…The miR-371/372/373 miRNA cluster is located on human chromosome 19q13.4, which is frequently acquired in head and neck cancers [ 122 ]. Additionally, expression of miR-372 and miR-373 is correlated with poor prognosis in OSCC patients.…”