Abstract LB-428: Upregulation of serum amyloid A1 (SAA 1) gene is associated with ulcerative colitis-related colon cancer

Purpose: Ulcerative colitis (UC)-associated colon cancer is frequently diagnosed in an advanced stage. SAA1 is a secreted protein made in the liver and circulates in low levels in blood. SAA1 gene is expressed in colon carcinomas and is a chemoattractant with induction of migration, adhesion, and tissue infiltration of monocytes and Polymorphnuclear-leucocytes (PMN-L). Methods: Laser capture microdissection of colonic submucosa from UC (n=8), Crohn's colitis (CC) (n=8)), and normal (NL, n=8) samples was performed. The submucosal mRNA was extracted using the PicoPure(TM) RNA Isolation Kit. Comprehensive gene expression analysis of the pooled mRNA from each group was then performed using the Affymetrix GeneChip® Gene 1.0 ST Array System. Statistical comparisons of UC vs. CC and NL as well as CC versus UC and NL were performed (Wilcoxon Rank Test). To detect changes for UC, we compared UC to CC and UC to NL; and for CC, we compared CC to UC and CC to NL. Results: Analysis of all UC vs. CC and NL controls showed 28,869 genes which were represented on the array by 26 probes spread across the full length of each gene. When compared UC vs. CC and NL SAA1 remained the most upregulated gene showing a 56.8-folds and 91.3-folds (p< 0.0001) over expression. Conclusion: Microarray assessments show significantly overexpression of SAA1 in UC specimens. SAA1 has a role in local inflammation in the microenvironment of malignant tissue and is expressed in colon carcinomas. Our finding may potentially facilitate and validate the SAA1 as a new early predictive clinical marker and a unique target for designing novel selective inhibitors for therapeutic intervention of UC-associated CRC. Acknowledgement: 3U54CA091408–09S1 (MMC-VICC partnership) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-428. doi:10.1158/1538-7445.AM2011-LB-428