Long non-coding RNA CCAT1 is overexpressed in oral squamous cell carcinomas and predicts poor prognosis

Abstract

Abstract. Oral squamous cell carcinoma (SCC) is the most common malignant tumor in India with 5-year survival rates totaling <50%. Recently, dysregulation of non-coding RNA was reported as a potential hallmark of carcinogenesis. Colon Cancer Associated Transcript 1 (CCAT1), an lncRNA located in chromosome 8q24, close to the c-Myc gene, has been reported to be overexpressed in many human cancers. In the present study, the authors analyzed the expression of CCAT1, c-Myc and the miRNAs miR155-5p, let7b-5p, miR490-3p and miR218-5p sponged by CCAT1 in 60 oral tumor and 8 normal tissue samples by reverse transcription-quantitative polymerase chain reaction. CCAT1 was significantly overexpressed in 27% (16/60) of oral tumors. Interestingly, a high level of c-Myc expression was observed in all CCAT1 overexpressing cases (P=0.0473). Furthermore, CCAT1 overexpression significantly downregulated miR155-5p (P=0.03) and let7b-5p (P<0.0001). Oral cancer cases expressing high level of CCAT1 (P=0.01) presented poor therapeutic outcome. To the best of the authors' knowledge, this is the first study to report the overexpression of the CCAT1 in oral SCCs, and the results suggested that CCAT1 overexpression may sponge miR155-5p and let7b-5p, and may account for poor treatment response.

World Workshop on Oral Medicine VII: Clinical evidence of differential expression of lncRNAs in oral squamous cell carcinoma: A scoping review

“…In a group of 62 OSCCs, underexpression of PTENp1 was observed in all the lesions from buccal mucosa or gingiva, in 71% of lesions from the lip and in 77% of lesions from the tongue (Gao et al, 2017). Arunkumar, Murugan et al (2017) reported that overexpression of CCAT1 was found in only 27% of 60 OSCC cases, but the majority of the CCAT1-overexpressing samples (62.5%) were tumours from buccal mucosa. Moreover, in the presence of tobacco smoking or tobacco chewing/smoking a high expression of CCAT1 was observed.…”

“…The lncRNA colon cancer-associated transcripts CCAT1 and CCAT2 have been reported to behave differently in OSCC; CCAT1 was found to be overexpressed in only 27% of OSCC (Arunkumar, Murugan, et al, 2017), while CCAT2 was found to be significantly overexpressed (Ma et al, 2017;Zhou et al, 2016).…”

“…Arunkumar, Murugan et al. () reported that overexpression of CCAT1 was found in only 27% of 60 OSCC cases, but the majority of the CCAT1‐overexpressing samples (62.5%) were tumours from buccal mucosa. Moreover, in the presence of tobacco smoking or tobacco chewing/smoking a high expression of CCAT1 was observed.…”

Long noncoding RNAs: emerging players in thyroid cancer pathogenesis

“…Nonetheless, the variant rs7763881 in HULC has been found to be associated with a decreased risk of HCC in persistent carriers of HBV . Recently, CCAT1 has been demonstrated to be upregulated and shown to predict poor prognosis in oral squamous cell carcinomas (Arunkumar et al 2017).…”

LncRNAOIP5-AS1is overexpressed in undifferentiated oral tumors and integrated analysis identifies as a downstream effector of stemness-associated transcription factors

“…A few lncRNAs including MEG3, PTENP-AS1, PANDAR and GAS5 functions as tumor suppressors and several other lncRNAs are well established to function as oncogenes in various cancers [12]. HOTAIR, linc-ROR, H19, CCAT1, ZEB1-AS1, NEAT1, MALAT1, UCA1 and CDKN2B-AS1 are well documented to be upregulated in oral cancer [12,14,15]. LncRNAs function by acting as signals, decoys, guides, and scaffolds and as a repressor or activator of gene transcription and translation.…”