[1391] microRNA Profiling of Follicular Lymphoma and Tumor Infiltrating T-Cells.

Weixin Wang, Ryan Plyler, John E Janik, Elaine S Jaffe, Katherine R Calvo. NIH Clinical Center, Bethesda, MD; National Cancer Institute, Besthesda, MD

Background: Follicular lymphoma (FL) is the second most common non-Hodgkin lymphoma and comprises over 20% of all lymphomas in the adult population. MicroRNA represents a novel post-transcriptional gene regulation mechanism that has been shown to play a role in development, differentiation, disease, and tumorigenesis. To understand the biology of FL and mechanisms of lymphomagenesis, microRNA and gene expression profiling were conducted in sorted FL B-cells and in tumor infiltrating T-cells in this study.
Design: B-cells and T-cells from 19 FL and 4 control follicular hyperplasia (FH) from tonsils were separated with Human CD3 Positive Selection kit (Stemcell). RNA was isolated with miRNeasy Mini Kit (Qiagen). microRNA (miR) profiling was performed on Agilent human microRNA array (v.2, Rel.12) with 851 human miRs represented on the array. Gene expression profiling was conducted on NanoString nCounter system with custom-compiled gene probes (199 genes) related to lymphoma and tumor development.
Results: From microRNA profiling, 476 of miRs in FL B-cells and 77 miRs in FL T-cells were found changed 2-fold or more compared with those in B- and T-cells of FH controls. Among them, hsa-miR-15b, 16, 20b, 26b, 34a, 374a, 374b, 454 and 1274a were found significantly increased in FL B- and T-cells. The results of gene expression profiling of 199 genes related to lymphoma and tumor development indicated that the expression of 43 genes in FL B-cells and 25 genes in FL T-cells were changed 2-fold or more compared with that in control FH B- and T-cells. Among these, ERBB3, GADD45B, IL-4, ING1, IRF4, LEF1 and SMAD4 transcripts were found decreased in FL B- and T-cells. BCL2, IL-8, MYB and PTEN transcripts were increased only in FL B-cells; while CAV1, CCND1, FASLG and FOXP3 were increased only in FL T-cells. Interestingly, transcripts of the majority of these genes were predicted to be potential targets of miRs with significant altered expression in FL B-cells and T-cells.
Conclusions: We found significantly altered microRNA and gene expression profiles in FL tumor cells and in tumor infiltrating T lymphocytes. Many of the microRNAs and predicted gene targets are critically related to proliferation, cell survival and B-cell and T-cell development/differentiation, such as BLIMP1, CDKN1A (p21Cip1/Waf1), CHEK1, IL4, IL-8, IRF4, NBKB1(p50/p105), RAD51, SMAD4, Cyclin D1, and FOXP3. The findings suggest that the alteration of microRNA expression may play a role in altered gene expression and in the biology of FL.
Category: Hematopathology

Monday, February 28, 2011 11:00 AM

Platform Session: Section B, Monday Morning


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