Abstract 1252: RNA-Seq transcriptome analyses of human LNCaP prostate cancer cells treated with a novel bis-aspirinyl selenazolidine AS-10
Authors: Kim Sangyub , Karelia Deepkamal N. , Imamura Yuka , Ramisetti Srinivasa , Jiang Cheng , Amin Shantu , Sharma Arun K. , Lu Junxuan 
Published: August 2018

Purpose: Our goal is to develop novel selenium-containing aspirin compound(s) for the chemoprevention of prostate cancer. Our current studies have shown significant inhibitory effects of bis-aspirinyl selenazolidine AS-10 on androgen receptor (AR) signaling, cell proliferation and survival (apoptosis) of human prostate cancer LNCaP cells in the single micromolar range of continued exposure. Immunoblot analyses of the AS-10 exposed cells showed the upregulation or activation of DNA damage response (DDR) protein p53 and p21Cip1 as well as DNA double strand break marker histone H2A.X associated with the apoptotic metrics. The objectives of the current work were: 1) to cross-validate involvement of transcriptional action of AS-10 to regulate key molecules related to AR signaling, cell cycle arrest, DDR and apoptosis responses, and 2) to discover potential transcriptome signatures and pathway networks induced by AS-10 that help to delineate its mechanisms of action.

Experimental Design: RNA-seq was performed for LNCaP cells that were treated with AS-10 at 5 and 10 μM, with DMSO as a control for 3, 6 or 12 h. The sequencing results were analyzed by Ingenuity Pathway Analysis (IPA) software with several bioinformatic approaches, including functional enrichment analysis, gene-gene interaction network analysis and upstream regulator analysis.

Results: A total of 12055 genes were positively aligned. At AS-10 exposure concentration of 5 and 10 μM, 2535 and 4556 genes were affected by two-fold, respectively (p&lt;0.01). For targeted analyses of mRNA abundance changes of AR and its best known transcriptional target prostate specific antigen (PSA/KLK3), AS-10 decreased them in synchrony with their protein changes.

For un-biased profiling, IPA functional enrichment analysis revealed that many of the differentially expressed genes were associated with cell cycle-associated functions, cell death, and P53 signaling. For gene-gene network interactions, the top ranked networks from all doses and treatment time-points revealed significant links with cancer, organismal injury and abnormalities, cellular development, growth and proliferation, cell death and survival. At AS-10 exposure concentration of 5μM, MYC and PSA were initially targeted, followed by AR and P53. At AS-10 exposure concentration of 10μM, MYC and AR were initially targeted, followed by AR. As expected, higher concentration of AS-10 induced the genes related to cell death earlier than lower level. Consistent with RNA-seq data, our protein assay showed that AS-10 10μM induced cell death at 12 hr.

Conclusions: The RNA-seq data on AR/PSA and p53/p21 identify transcriptional as well as post-transcriptional regulation by AS-10 to affect their protein levels in the LNCaP cells. The transcriptome profiling approaches reveal comprehensive network interactions and cross-talks to contribute to cell cycle arrest and apoptosis.

Citation Format: Sangyub Kim, Deepkamal N. Karelia, Yuka Imamura, Srinivasa Ramisetti, Cheng Jiang, Shantu Amin, Arun K. Sharma, Junxuan Lu. RNA-Seq transcriptome analyses of human LNCaP prostate cancer cells treated with a novel bis-aspirinyl selenazolidine AS-10 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1252.