Abstract 3771: PiR-hsa-4447944 promotes the progression of prostate cancer through NEFH and induces androgen-independent growth
Authors: Peng Qiang , Sun Jingkai , Chiu Peter Ka-Fung , Xie Tingting , Teoh Jeremy Yuen-Chun , Ng Chi-Fai 
Published: April 2023

Abstract
Introduction and Objective: Non-coding RNAs (ncRNAs) represent a diverse family of regulatory transcripts that drive tumorigenesis of prostate cancer (PCa) and various other types of cancers by their hyperactivity or diminished function. PIWI-interacting RNAs (piRNAs) are a class of small ncRNAs mechanistically similar to but much less studied than microRNAs. As the most diversified small ncRNAs, piRNAs are widely involved in the pathogenesis of different types of cancers. Our study aimed to investigate the role of piRNAs in the development of castration-resistant prostate cancer (CRPC).
Methods: Small RNA sequencing was used to explore the CRPC associated piRNAs on a basis of 10 benign prostate tissues, 10 paired hormone-sensitive PCa tissues and CRPC tissues from the same patients. The top 12 upregulated piRNAs were validated through qRT-PCR in a bigger cohort. piR-hsa-4447944 was selected and investigated its biological function by gain of function in vitro. To study its loss of function role, an androgen-independent PCa cell (LNCaP-AI) was established. For mechanistic investigation, high-throughput RNA sequencing was conducted to identify dysregulated genes in PCa cells with control or piR-hsa-4447944 overexpression. Then, potential downstream targets were further predicted by miRanda program and validated by qRT-PCR, western-blot and dual-luciferase reporter assay.
Results: piR-hsa-4447944 demonstrated a relatively higher expression level in both CRPC tissues and CRPC cell lines when compared with PCa tissues and cells. Functionally, overexpression of piR-hsa-4447944 could confer resistance to androgen deprivation and anti-androgen in PCa cells in vitro, whereas anti-sense RNA against the piR-hsa-4447944 could potentiate the sensitivity to androgen deprivation in LNCaP-AI cell. In addition, piR-hsa-4447944 showed the ability in promoting migration and invasion of PCa cells. Mechanistically, mRNA sequencing results identified a panel of downstream target-genes. Among them, neurofilament heavy chain (NEFH) was predicted and validated to have a direct binding relationship with piR-hsa-4447944, and was successfully verified to be negatively regulated by piR-hsa-4447944 in PCa cells.
Conclusions: Our study showed, for the first time, that piR-hsa-4447944 can contribute to androgen insensitivity in CRPC. This sheds a new insight into the regulation of CRPC by a small ncRNA piRNA, which may form the basis of a novel target in the treatment of CRPC.
Citation Format: Qiang Peng, Jingkai Sun, Peter Ka-Fung Chiu, Tingting Xie, Jeremy Yuen-Chun Teoh, Chi-Fai Ng. PiR-hsa-4447944 promotes the progression of prostate cancer through NEFH and induces androgen-independent growth. [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 3771.