Abstract 3700: Role of salivary miRNAs and their target genes in oral cancer patients as a potential diagnostic tool
Authors: Khan Muhammad Jawad , Zahra Andleeb , Rabia Ghulam , Ali Syeda Aba , Sahar Shanza , Bibi Sobia , Fatmi M. Qaiser 
Published: September 2020

Abstract
Oral squamous cell carcinoma (OSCC) is a major cancer type worldwide, ranked in among top ten cancers. However, in South Asia, OSCC is at third position in commonly occurring cancer. Pakistan is ranked at tenth level in world but second in South Asia in OSCC. High ratio of cancer suggests that it is a major reason of death around the globe and is mainly because of the late-stage diagnosis. Metastasis of OSCC depends on many environmental and genetic factors including different genes, proteins and non-coding RNAs i.e. miRNAs. In cancer cells, miRNAs express themselves differentially. This differential expression of miRNAs in cancer cells can be explored and is worth considering as a diagnostic biomarker. On account of these facts, this study was designed to aim at detection of miRNAs and their target genes in OSCC through functional and expression analysis. We already have reported a list of miRNAs and their differentially expressed target genes in OSCC along with their functional and network analysis, in an in silico study. To evaluate the role of miRNAs and their target genes in OSCC patients of Pakistan, we measured the expression of four miRNAs; miR-300, miR-27a-3p, miR-340-5p, miR-205-3p with their corresponding target genes; ALB, CDH1, CACNA1, ARID5B, CDKN1A, BCL2, ABL1 in saliva samples of patients (n=100) and healthy controls (n=100). Total RNA was extracted from saliva samples; cDNA was synthesized and real time quantitative PCR was used to measure the expression. Preliminary results showed that miRNAs were down regulated in saliva samples of patients as compared to healthy controls. Consequently, target genes of each miRNA were dysregulated in patients. miR-300 targets CDH-1 and ALB and there was a direct relationship of miR-300 with ALB. Both of them were down regulated in OSCC patients. We found a down regulation in the expression of miRNA-27a-3p and its target genes CACNA1I and ARID5B in the saliva samples of patients when compared with the healthy controls. This suggests that there is a direct relationship between the miRNA-27a-3p and its target genes CACNA1I and ARID5B. We identified that miRNA-340-5p targets BCL2 and CDKN1A genes; miR-340-5p was down regulated by targeting both genes and also down regulated their expression, which results in OSCC. miRNA-205-3p targets ABL1 gene and there is direct relationship between the two. Both of them were down regulated in OSCC patients and change in expression leads to OSCC. The change in expression pattern of miRNAs and their target genes suggests a potential diagnostic role of these miRNAs in early detection of OSCC by saliva samples at early stages.
Citation Format: Muhammad Jawad Khan, Andleeb Zahra, Ghulam Rabia, Syeda Aba Ali, Shanza Sahar, Sobia Bibi, M. Qaiser Fatmi. Role of salivary miRNAs and their target genes in oral cancer patients as a potential diagnostic tool [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3700.