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Role of SPDEF gene enhancer and promoter methylation in prostate cancer cell metastasis and therapeutic resistance
Author(s) -
Vatanmakanian Mousa,
Koul Sweaty,
Yousefi Hassan,
Santra Manoranjan,
Alahari Suresh,
Koul Hari
Publication year - 2021
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2021.35.s1.04735
Subject(s) - dna methylation , prostate cancer , epigenetics , cancer research , lncap , bisulfite sequencing , du145 , biology , metastasis , enhancer , prostate , cancer , oncology , medicine , gene expression , gene , genetics
Background Prostate cancer (PCa) is the second most prevalent carcinoma in men which results in over 30,000 deaths annually in the United States, mostly due to the metastatic castration‐resistant (mCRPC) disease. Our previous studies demonstrated that Transcription factor SAM‐pointed domain‐containing Ets‐like factor (SPDEF) inhibits prostate cancer metastasis, in part by promoting luminal differentiation. Decreased SPDEF expression was associated with higher grades of prostate tumors in cell line models and clinical cohorts, with a complete loss of PDEF expression in Neuro‐endocrine form of PCa. In the present study we assessed role of epigenetic mechanisms in SPDEF expression during prostate cancer progression. Methods Differential expression analysis of epigenetic writer enzymes were established by obtaining large scale clinical data published on the TCGA database. We used bisulfite sequencing method from assessing promoter and enhancer methylation from various PCa cells lines (LNCaP, PC3, Du‐145, and LNCaP‐C4‐2B). Samples were treated with sodium bisulfite, regions amplified using PCR technique, cloned into pGEM vector using TA cloning technique, and sequenced using M13 reverse primer. Data were quantified using BiQ Analyzer and QUMA tools. To functionally check the role of DNA methylation, cells were treated with 5‐aza cytidine (a DNA methyl transferase inhibitor) followed by SPDEF gene expression studies. Results Clinical data analysis revealed a significant differential expression of several epigenetic writers including DNMT1, DNMT3a, DNMT3b, as well as EZH2 in a large cohort of prostate cancer patients with various Gleason scores. Our Bisulfite sequencing study also revealed that both enhancer and promoter regions of SPDEF gene undergo significant hypermethylation in aggressive cell models compared to local representatives. Moreover, promoter, but not enhancer, showed a higher methylation level in the androgen insensitive cell models compared to sensitive cells; both suggesting an active role of DNA methylation in metastasis and therapy resistance. Consistently, the aggressive cells with lower SPDEF levels were able to recover SPDEF levels following 5‐aza Cytidine in a dose‐ and time‐dependent manner. Conclusions Our data point to a key role for epigenetic regulation in suppression of SPDEF in metastatic and therapy resistant PCa, suggesting a potential role for targeting epigenetic pathways in preventing metastasis and overcoming therapy resistance in subsets of PCa patients with loss of SPDEF.