Epigenetic modification-dependent androgen receptor occupancy facilitates the ectopic TSPY1 expression in prostate cancer cells

Testis-specific protein Y-encoded 1 regulates androgen receptor expression through the MAPK/ERK pathway in male hepatocellular carcinoma

OBJECTIVES

To analyze the mechanism of testis-specific protein Y-encoded 1 (TSPY1) in male hepatocellular carcinoma (HCC).

METHODS

This experimental study was carried out at Guangxi Medical University's First Affiliated Hospital, Guangxi, China, between January 2016 and December 2019. The expression of TSPY1, androgen receptor (AR), messenger ribonucleic acids (mRNAs), and proteins were detected by qRT-PCR and Western blotting. The co-localization and interaction of TSPY1 and AR were observed by immunofluorescence assay and co-immunoprecipitation. Hepatocellular carcinoma cells overexpressing and silencing TSPY1 were constructed, and the expression and phosphorylation levels of TSPY1, AR, and mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK) signaling pathway-related key molecules ERK1/2, p38, and JNK were also detected.

RESULTS

The expression levels of TSPY1, AR mRNAs, and proteins were highly positively correlated in HCC cells in different metastatic potentials with a high correlation coefficient of R=0.929 and R=0.884. Testis-specific protein Y-encoded 1 and AR were then co-localized in the nucleus of HCC cells, and TSPY1 and AR can interact with each other. In addition, the expression of AR and phosphorylation of ERK1/2 were enhanced in TSPY1 overexpressed Huh7 cells. They were reduced in HCCLM3 cells with TSPY1 knockdown expression. In addition, in response to blocking MAPK/ERK signaling activity, AR was reduced in expression.

CONCLUSION

These findings suggested that there was a positive correlation between TSPY1 expression and AR in male HCC cells, and high TSPY1 expression stimulates AR expression, MAPK/ERK signaling pathway may be involved in its mechanism.

Y chromosome is moving out of sex determination shadow

Although sex hormones play a key role in sex differences in susceptibility, severity, outcomes, and response to therapy of different diseases, sex chromosomes are also increasingly recognized as an important factor. Studies demonstrated that the Y chromosome is not a 'genetic wasteland' and can be a useful genetic marker for interpreting various male-specific physiological and pathophysiological characteristics. Y chromosome harbors male‑specific genes, which either solely or in cooperation with their X-counterpart, and independent or in conjunction with sex hormones have a considerable impact on basic physiology and disease mechanisms in most or all tissues development. Furthermore, loss of Y chromosome and/or aberrant expression of Y chromosome genes cause sex differences in disease mechanisms. With the launch of the human proteome project (HPP), the association of Y chromosome proteins with pathological conditions has been increasingly explored. In this review, the involvement of Y chromosome genes in male-specific diseases such as prostate cancer and the cases that are more prevalent in men, such as cardiovascular disease, neurological disease, and cancers, has been highlighted. Understanding the molecular mechanisms underlying Y chromosome-related diseases can have a significant impact on the prevention, diagnosis, and treatment of diseases.

Epigenetic modification-dependent androgen receptor occupancy facilitates the ectopic TSPY1 expression in prostate cancer cells

Testis‐specific protein Y‐encoded 1 (TSPY1), a Y chromosome‐linked oncogene, is frequently activated in prostate cancers (PCa) and its expression is correlated with the poor prognosis of PCa. However, the cause of the ectopic transcription of TSPY1 in PCa remains unclear. Here, we observed that the methylation status in the CpG islands (CGI) of the TSPY1 promoter was negatively correlated with its expression level in different human samples. The acetyl‐histone H4 and trimethylated histone H3‐lysine 4, two post–translational modifications of histones occupying the TSPY1 promoter, facilitated the TSPY1 expression in PCa cells. In addition, we found that androgen accelerated the TSPY1 transcription on the condition of hypomethylated of TSPY1‐CGI and promoted PCa cell proliferation. Moreover, the binding of androgen receptor (AR) to the TSPY1 promoter, enhancing TSPY1 transcription, was detected in PCa cells. Taken together, our findings identified the regulation of DNA methylation, acting as a primary mechanism, on TSPY1 expression in PCa, and revealed that TSPY1 is an androgen‐AR axis‐regulated oncogene, suggesting a novel and potential target for PCa therapy.