Abstract 5267: Effects of polyphenon E treatment on gene expression in DU145 prostate cancer cells

Abstract

Abstract One promising focus of prostate cancer (PCa) research is the chemopreventive effects of Polyphenon E (Poly E), a defined mixture of green tea polyphenols. A previous study utilizing the TRAMP model of human PCa, displayed chemopreventive activity as a result of Poly E oral administration in a dose-dependent pattern. Human clinical trials of Poly E treatment exhibited activity in PCa of those previously diagnosed with atypical small acinar proliferation or high-grade prostate intraepithelial neoplasia. The molecular mechanisms of these Poly E chemopreventive activities against PCa are not well established. Our hypothesis is that Poly E treatment influences expression of genes involved in key cellular signaling pathways. DU145 prostate cancer cells were cultured in complete growth media supplemented with varied Poly E concentrations (100, 200, 300 mg/L) for 24 hrs. RNA was isolated for comparative microarray (0 vs. 200 mg/L Poly E) and qRT-PCR analyses. Microarray data for 54,613 genes were filtered for > 2-fold expression level changes, with 5,272 increased and 6,467 genes decreased. Nine genes, (CASP8, CBLB, CCNB1, HDAC4, MXD1, RGCC, RGS4, TBC1D7, ZNF462) involved in key signaling pathways with >2-fold gene expression changes were selected for subsequent qRT-PCR analyses. Microarray probe set IDs and fold change gene expression values for these nine genes analyzed are listed (Table 1). From qRT-PCR analyses, six of these genes had significant gene expression changes between Poly E treatment levels, MXD1 (14.20-fold; p = 0.0122), RGCC (0.6748-fold; p < 0.0001), TBC1D7(0.2416-fold; p = 0.0037), ZNF462 (0.7030-fold; p = 0.0173), CASP8 (0.4856-fold; p = 0.0136), and CBLB (2.149-fold; p = 0.0036). We conclude that two thirds (6/9) of the genes selected from the microarray data for qRT-PCR analyses had significant Poly E induced gene expression changes. Future experimental directions include cell cycle profiling and annexin V apoptosis analysis, as well as inclusion of other established PCa cell lines. Microarray Data from Poly E-treated DU145 Cells Affymetrix Probe ID Gene Symbol Log2-Fold Changes 207686_s_at CASP8 1.79 213373_s_at CASP8 -1.13 1553306_at CASP8 -2.02 208348_s_at CBLB 7.79 209682_at CBLB 2.27 227900_at CBLB -1.13 228729_at CCNB1 -2.55 214710_s_at CCNB1 -2.70 1554322_a_at HDAC4 -2.06 228813_at HDAC4 -4.74 204225_at HDAC4 -5.43 206877_at MXD1 17.87 228846_at MXD1 8.04 226275_at MXD1 3.80 218723_s_at RGCC 2.54 239827_at RGCC -3.90 204339_s_at RGS4 7.74 204338_s_at RGS4 -1.33 204337_at RGS4 -1.80 1563839_at TBC1D7 47.08 223461_at TBC1D7 1.17 232393_at ZNF462 28.62 226575_at ZNF462 -1.38 244007_at ZNF462 -1.61 Citation Format: Ethan J. Vallebuona, Ashley N. Gannon, Corrine M. Costello, Ricardo Cordova, Ricardo A. Declet-Bauzo, Seung Joon Kim, Nagi Kumar, Jong Y. Park, L. Michael Carastro. Effects of polyphenon E treatment on gene expression in DU145 prostate cancer cells. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5267.