Identification of Androgen-Regulated Epigenetic Regulatory Enzymes in Prostate Cancer
Project no. 32979 · Status: Kapanmış (Yayın bekleniyor) · 2025
Summary
<p>Prostate cancer (PCa) is a complex disease resulting from the accumulation of genetic and epigenetic alterations. Epigenetic mechanisms are reversible processes that regulate gene expression without altering the deoxyribonucleic acid (DNA) sequence. Alterations in the expression or activity of chromatin-modifying enzymes (CMEs), which regulate epigenetic mechanisms, are known to be associated with the initiation, progression, and therapeutic response of PCa. Since both normal prostate tissue and PCa development are largely androgen-dependent, identifying androgen-induced changes in CMEs is essential for understanding PCa biology. In this study, the androgen-regulated CME profile will be characterized in androgen-sensitive, lymph node metastatic LNCaP PCa cells, and the role of a selected target enzyme in the regulation of androgen-induced matrix metalloproteinase (MMP) expression will be investigated.</p><p>Samples obtained from androgen-treated cells were analyzed using the Human Epigenetic Chromatin Modification Enzymes PCR Array containing 84 CMEs to identify androgen-responsive enzymes. Among the 84 genes analyzed, only four, DAZ interacting zinc finger protein 3 (DZIP3), histone deacetylase 4 (HDAC4), lysine methyltransferase 2A (KMT2A), and p21-activated kinase 1 (PAK1), exhibited significantly reduced expression. Notably, among the 11 HDAC family members included in the PCR Array, only HDAC4 showed significant differential expression. Since its potential role in MMP regulation has not previously been investigated, HDAC4 was selected as the target enzyme for further analyses. The androgen-induced reduction in HDAC4 expression identified by the PCR Array was subsequently confirmed by conventional polymerase chain reaction (PCR).</p><p>To identify the MMP family members for subsequent analyses, the transcriptional expression of 23 MMP genes was evaluated in androgen-treated LNCaP cells. Relative mRNA expression levels of MMP-26 and MMP-28 were significantly increased compared with the control group.</p><p>To investigate the role of HDAC4 in androgen-mediated MMP regulation, LMK-235, a selective HDAC4/5 inhibitor, was used because a commercially available HDAC4-specific inhibitor is unavailable. Following optimization of treatment concentration and duration, changes in HDAC4, MMP-26, and MMP-28 mRNA expression levels were evaluated in cells treated with androgen and/or LMK-235. LMK-235 treatment resulted in a greater increase in the transcriptional expression of MMP-26 than treatment with R1881 alone. Relative MMP-26 mRNA levels were further increased following combined R1881 and LMK-235 treatment compared with either treatment alone. In contrast, although LMK-235 significantly increased MMP-28 expression, the magnitude of this increase remained lower than that induced by R1881 alone.</p><p>In conclusion, androgen stimulation established a selective MMP expression profile in LNCaP PCa cells, accompanied by reduced HDAC4 expression. HDAC4/5 inhibition by LMK-235 regulated MMP expression in a gene-specific manner, exerting a pronounced stimulatory effect on MMP-26, whereas MMP-28 was identified as the most androgen-responsive target. Although MMP-28 exhibited a robust response to androgen stimulation, its expression following combined R1881 and LMK-235 treatment did not exceed that observed with R1881 alone, suggesting that androgen-mediated regulation of MMP-28 may involve more complex, context-dependent mechanisms. These findings indicate a target gene-specific and context-dependent regulatory relationship among androgen signaling, HDAC4/5 activity, and MMP-associated extracellular matrix (ECM) remodeling in PCa.</p>