Abstract 4935: microRNA profiling of esophageal squamous cell carcinoma patients from formalin-fixed paraffin-embedded (FFPE) specimens

Introduction: microRNA (miRNA) are small non-coding RNAs which target specific mRNA. Recent progression of RNA extraction technology from formalin-fixed paraffin-embedded (FFPE) tissues enables us to access miRNA profiling using world wide stored specimens. Here, we present miRNA profiling of esophageal squamous cell carcinoma (ESCC) patients from FFPE specimens. Method: First, we examined and contrasted the levels of cross-linking caused by formalin and degradation of mRNA and miRNA from daily to yearly time frames. Then, we established the criteria of evaluable RNA from FFPE specimens. The miRNA profiling was obtained from 44 ESCC patients who received operations from 1991 to 2009 using 3D-Gene human miRNA chip (Toray) which contains 904 has-miRNAs. The approval number from Toyama University institutional review board was #19-67. Results: Out of 44 paired samples, 24 pairs (54.5%) were determined evaluable with our criteria. We found that 39 miRNAs (including miR-21, and miR-25) were significantly up-regulated and that 24 miRNAs (including miR-145) were down-regulated in ESCC in comparison to normal esophageal tissue. Of these, miR-15b, miR-200c and miR761 were identified as prognostic factors of ESCC patients. Furthermore, we found 22 miRNAs that have association with the hematogenic recurrence and 9 miRNAs (including miR-103) have association with lymph node metastasis. Conclusion: We have discovered miRNAs that are associated with prognosis, hematogenic recurrence and lymph node metastasis in ESCC patients. miRNA profiling using FFPE specimens is a useful and promising method of evaluation of world wide stored specimens that accompany many valuable clinical data. 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 4935. doi:10.1158/1538-7445.AM2011-4935