Abstract 2206: qPCR array of 84 cell cycle genes in oral squamous cell carcinoma reveals differently expressed genes in larger size tumors in relation to small tumors

Abstract

The aim of the study is to investigate if larger oral squamous cell carcinoma (OSCC) tumors show a different transcriptional signature of cell cycle genes in relation to small OSCC tumor samples. To address this issue, 17 fresh OSCC tumor samples were included in the study, including T1(n = 5),T2 (n = 9),T3 (n = 2) and T4 (n = 1) samples. All tumors were either from the tongue or from the floor of the mouth and only two patients were non-smokers. Two samples were from female patients, while the other 15 were from men. Samples were categorized according to clinical tumor size in tumors ≤ 2cm (T1 n = 5) or tumors > 2cm (T2, T3 and T4, n = 12). The median age of both groups was similar (57 and 62, respectively). The group of tumors ≤ 2cm was considered the reference group in the qRT-PCR results interpretation, while the larger tumors were considered the test group. The RNA was extracted and the cDNA was synthesized. A commercially available 84 cell cycle genes PCR array kit was used (PAHS-020, Cell Cycle PCR Array - Human, Qiagen). The results were analyzed according to the formula 2^-deltaCT and differential expressions were considered statistically significant when p<0.05. The target genes expressions were normalized to two housekeeping endogenous genes B2M and HPRT1, considering both, the geometric and arithmetic CT means (that differed less than 1 CT between the reference and test groups). The following genes were downregulated in the test group (larger tumors) compared to the reference group (smaller tumors), showing a minimum fold change of 4: ANAPC4, E2F4, CUL1, PCNA, KNTC1, RPL13A, KPNA2, NBN, CCNG2 and SUMO1. These results need to be further confirmed in a larger cohort of samples. In conclusion, these findings suggest that the transcriptional activity of specific cell cycle genes changes according to the size of the OSCC tumor, which probably reflects tumor molecular evolution.Supported by: FAPEMIG (Fundação de Amparo à Pesquisa de Minas Gerais), CNPq (National Council for Scientific and Technological Development) and CAPES (Coordination for Improvement of Higher Education Personnel), Brazil Note: This abstract was not presented at the meeting. Citation Format: Carolina C. Gomes, Marina G. Diniz, Fabricio T. de Souza, Jeane F. Correia-Silva, Ricardo S. Gomez. qPCR array of 84 cell cycle genes in oral squamous cell carcinoma reveals differently expressed genes in larger size tumors in relation to small tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2206. doi:10.1158/1538-7445.AM2015-2206