Abstract
Purpose: Inflammatory genes and microRNAs have roles in colon carcinogenesis; therefore, they may provide useful biomarkers for colon cancer. This study examines the potential clinical utility of an inflammatory gene expression signature as a prognostic biomarker for colon cancer in addition to previously examined miR-21 expression.
Experimental Design: Quantitative reverse transcriptase-PCR. was used to measure the expression of 23 inflammatory genes in colon adenocarcinomas and adjacent noncancerous tissues from 196 patients. These data were used to develop models for cancer-specific mortality on a training cohort (n = 57), and this model was tested in both a test (n = 56) and a validation (n = 83) cohort. Expression data for miR-21 were available for these patients and were compared and combined with inflammatory gene expression.
Results:PRG1, IL-10, CD68, IL-23a, and IL-12a expression in noncancerous tissue, and PRG1, ANXA1, IL-23a, IL-17a, FOXP3, and HLA-DRA expression in tumor tissues were associated with poor prognosis based on Cox regression (|Z-score| >1.5) and were used to generate the inflammatory risk score (IRS). IRS was associated with cancer-specific mortality in the training, test (P = 0.01), and validation (P = 0.02) cohorts. This association was strong for stage II cases (P = 0.002). Expression of miR-21 was associated with IL-6, IL-8, IL-10, IL-12a, and NOS2a, providing evidence that the function of this microRNA and these inflammatory genes are linked. Both IRS and miR-21 expression were independently associated with cancer-specific mortality, including stage II patients alone.
Conclusion: IRS and miR-21 expression are independent predictors of colon cancer prognosis and may provide a clinically useful tool to identify high-risk patients. (Clin Cancer Res 2009;15(18):5878–87)
- Colon Cancer prognosis
- inflammatory genes
- microRNA-21
Footnotes
Grant support:Intramural Research Program of the National Cancer Institute, Center for Cancer Research, NIH. A.J. Schetter was supported by the Cancer Prevention Fellowship Program, Office of the Director, National Cancer Institute, NIH. G.H. Nguyen and J.E. Hawkes were supported by the Howard Hughes Medical Institute Grant for Graduate Medical Education.
The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
Note: Supplementary data for this article are available at Clinical Cancer Research Online (http://clincancerres.aacrjournals.org/).
- Received March 12, 2009.
- Revision received June 9, 2009.
- Accepted June 9, 2009.
Volume 15, Issue 18
