Abstract 2578: Serum analysis of obese and diabetic African American colon adenoma patients reveals novel potential miRNA markers of carcinogenesis

We have previously demonstrated that Adiponectin, leptin, TNF-alpha, and IGF-1 were highly prevalent in patients with colon adenomas when compared to healthy individuals. In the present study, we aimed to establish specific miRNA signatures in obese and diabetic African American patients developing colorectal adenomas. Patients & Methods: Serum samples from 72 individuals (18 normal, 18 adenoma-obese, 18 adenoma-diabetic, and 18 adenoma-obese-diabetic) seen at Howard University Hospital were collected. All selected patients were age and gender-matched across the 4 groups. Serum RNA extracts were used for library preparation and sequencing on an Illumina NextSeq 500 using SR75 High Output kit. Sequencing data were processed through the miasma-Seq pipeline. CutAdapt was used to trim Illumina adapters and remove reads that were less than 15 bp long. Reads were aligned to the UCSC hg38 human genome reference sequence using Bowtie2. Annotation data in the form of a GFF file from mirBase was used to count the number of reads falling in each hairpin locus. To estimate differential expression between different groups of samples, the count data were used in the DESeq2 R package and the 4 patient groups comparisons were performed. MiRNAs with statistically significant (p < 0.05) expression difference from normal and log 2 FC > 2 and/or < -2 were selected for functional analysis using Ingenuity Pathway Analysis (IPA). Results: Comparisons to normals revealed that 11 miRNAs [hsa-mir-34a, hsa-mir-133a-1, hsa-mir-127, hsa-mir-99b, hsa-mir-485, hsa-mir-378d-2, hsa-mir-3168, hsa-mir-3679, hsa-mir-378e, hsa-mir-4635, hsa-mir-6509] were down-regulated in Adenoma-Obese; 3 miRNAs were down-regulated [hsa-mir-1228, hsa-mir-3912, hsa-mir-4665] and 3 up-regulated [hsa-mir-455, hsa-mir-219b, hsa-mir-8072 ] in Adenoma-Diabetic patients; and 2 down-regulated [hsa-mir-487b, hsa-mir-6777] and 1 up-regulated miRNA [hsa-mir-4525] in Adenoma-Obese-Diabetic patients. The IPA analysis revealed that many of the altered miRNA have known roles in carcinogenic and metabolic syndrome pathways. Conclusion: From the pairwise comparison, diabetes seems to be associated with more alterations of the miRNA profile in the analyzed samples when compared to patients developing colon adenomas on an obesity background. MiRNA-4525 can be used as a potential serum marker in obese patients while miRNA-455, miRNA-219b, and miRNA-8072 can serve as such in diabetic patients. Except for miRNA-455 that was previously described as a promotor of migration and invasion in breast cancer, the other mi-RNAs are novel and their mechanisms of action need further study. Citation Format: Hassan Brim, Mohammad Daremipouran, Gail Nunlee-Bland, Adeyinka Laiyemo, Hassan Ashktorab. Serum analysis of obese and diabetic African American colon adenoma patients reveals novel potential miRNA markers of carcinogenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2578.