The clinical frequency of colorectal cancer occurrence increase in adenomas with a predominant villous histopathology: tubular (5%), tubulovillous (22%) and villous (40%). Adenoma may develop throughout the gastrointerestinal tract with coarse lobulations formed by branching tubular glands whose lumens open on the surface which are rare in most patient gastrointerestinal tract areas other than the colorectum. The adenoma-carcinoma sequence is clinically associated in patients with polyposis and ulcerative colitis since their predilection for developing carcinoma in adenomatous epithelium is greatly increased. This study focused on COX, ATPase, rRNA, Cytb and ND genes of the mitochondrial genome that have been associated as modifying risks of cancer. Using PCR-based sequence and High resolution restriction endonuclease, we investigated the potential role of mtDNA alterations in colorectal adenopolyps (Tubular, Tubulovillous, and Villous) and carcinoma. Fifty-eight primary tissues of colorectal adenopolyps, carcinoma and their matched normal controls were used in this study. Twenty-two variants were observed and most of these variants were germline and homoplasmic transitions. Unreported germline variants Cytb-A14782T (90%) and MT-ATPase 8 A9169C (75%) were associated with tubular adenomas. Also, MT-ATPase 6- variant T8994A (85%) was associated with tubulovillous adenomas. Moreover, in the highly conservative region of rRNA, variant T1738C was found in colorectal carcinoma only. Results suggest that some specific mtDNA variants may exert their effects on colorectal adenopolyps to gain a proliferative advantage in patients bearing CRC.

Citation Format: LaShanale M. Wallace, Sharifeh Mehrabi, Xuebiao Yao, Felix O. Aikhionbare. Specific mtDNA variants and colorectal adenopolyps. [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 5262. doi:10.1158/1538-7445.AM2015-5262