Testis-specific protein on Y chromosome (TSPY) represses the activity of the androgen receptor in androgen-dependent testicular germ-cell tumors

In Silico Molecular Docking Analysis of α-Pinene: An Antioxidant and Anticancer Drug Obtained from Myrtus communis

Background: Testis-specific protein on Y chromosome (TSPY) is the output of a tandem gene cluster. TSPY expression has been observed in gonadoblastoma and numerous distinct kinds of germ cell tumors, such as carcinoma in situ/intratubular germ cell neoplasia, seminoma, and extragonadal intracranial germ cell tumors (GCT). Myrtus communis extract rich in α-pinene showed high antioxidant and anticancer activity against a TSPY. Methods: The molecular weight and theoretical isoelectric of the TSPY proteins were calculated, using the ExPASSY ProtParam tools. Some software like mega 6, BioEdit, NEB cutter (New England Biolabs), and CAP3 were used to analyze clustering and find restriction enzymes on the TSPY sequence. To evaluate the nucleotide diversity of all sequences, the number of diverse situations and Tajima’s and Watterson’s estimators of theta were assessed. Nucleotide polymorphism can be measured by several parameters, such as haplotypes diversity, nucleotide diversity, theta using Dnasp software. To find interaction networks of protein-protein search tool for the retrieval of interacting genes/proteins (STRING) tools and to predict 3D structure, SWISS-MODEL was used; however, for docking protein-peptide based on interaction, Swiss Dock, Galaxy web, and CABS-dock software were employed. Results: We report a high (0.91) dN/dS index, positive Tajima's D, Fu, and Li’s tests, and a non-significant D test suggesting the occurrence of old modifications or a decrease of newborn mutations in the TSPY gene family. Interestingly, several hub proteins produced a strong chain or an operative module within their protein groups, such as nucleosome assembly protein (1NAP1L), RBMXL2, TBL1Y, and AMELY, which are all associated with the same cellular appliance elements and/or genetic uses. The docking of the TSPY target with α-pinene using docking revealed that the computationally-prognosticated lowest energy networks of TSPY are established by intermolecular hydrogen bonds and stacking interactions. Conclusions: The results of this study demonstrated that α-pinene interacts with the TSPY protein target and could be developed as a promising candidate for the new anticancer agent.

Hypermethylation of genes in testicular embryonal carcinomas

BACKGROUND

Testicular embryonal carcinoma (EC) is a major subtype of non-seminomatous germ cell tumours in males. Embryonal carcinomas are pluripotent, undifferentiated germ cell tumours believed to originate from primordial germ cells. Epigenetic changes during testicular EC tumorigenesis require better elucidation.

METHODS

To identify epigenetic changes during testicular neoplastic transformation, we profiled DNA methylation of six ECs. These samples represent different stages (stage I and stage III) of divergent invasiveness. Non-cancerous testicular tissues were included. Expression of a number of hypermethylated genes were examined by quantitative RT-PCR and immunohistochemistry (IHC).

RESULTS

A total of 1167 tumour-hypermethylated differentially methylated regions (DMRs) were identified across the genome. Among them, 40 genes/ncRNAs were found to have hypermethylated promoters. Quantitative RT-PCR confirmed downregulation of 8 out of 9 of the genes. Among the confirmed genes, five were sex-linked genes, including X-linked genes STAG2, SPANXD/E and MIR1184, and Y-linked genes RBMY1A1/1B/1D and FAM197Y2P. RBMY1A is a testis-specific gene for spermatogenesis. RNF168 and USP13 are potential tumour suppressors. Expression of RBMY1A was lost in EC and seminoma as documented in the Protein Atlas. We confirmed downregulation of USP13 in EC by IHC.

CONCLUSIONS

Our genome-wide analysis of testicular EC identified methylation changes in several previously unknown genes. This may provide insight of crosstalk between normal germ cell development and carcinogenesis.

Ubiquitin Specific Protease 26 (USP26) expression analysis in human testicular and extragonadal tissues indicates diverse action of USP26 in cell differentiation and tumorigenesis

Ubiquitin specific protease 26 (USP26), a deubiquitinating enzyme, is highly expressed early during murine spermatogenesis, in round spermatids, and at the blood-testis barrier. USP26 has also been recognized as a regulator of androgen receptor (AR) hormone-induced action involved in spermatogenesis and steroid production in in vitro studies. Prior mutation screening of USP26 demonstrated an association with human male infertility and low testosterone production, but protein localization and expression in the human testis has not been characterized previously. USP26 expression analysis of mRNA and protein was completed using murine and human testis tissue and human tissue arrays. USP26 and AR mRNA levels in human testis were quantitated using multiplex qRT-PCR. Immunofluorescence colocalization studies were performed with formalin-fixed/paraffin-embedded and frozen tissues using primary and secondary antibodies to detect USP26 and AR protein expression. Human microarray dot blots were used to identify protein expression in extra-gonadal tissues. For the first time, expression of USP26 and colocalization of USP26 with androgen receptor in human testis has been confirmed predominantly in Leydig cell nuclei, with less in Leydig cell cytoplasm, spermatogonia, primary spermatocytes, round spermatids, and Sertoli cells. USP26 likely affects regulatory proteins of early spermatogenesis, including androgen receptor with additional activity in round spermatids. This X-linked gene is not testis-specific, with USP26 mRNA and protein expression identified in multiple other human organ tissues (benign and malignant) including androgen-dependent tissues such as breast (myoepithelial cells and secretory luminal cells) and thyroid tissue (follicular cells). USP26/AR expression and interaction in spermatogenesis and androgen-dependent cancer warrants additional study and may prove useful in diagnosis and management of male infertility.

Hyper-expression of PAX2 in human metastatic prostate tumors and its role as a cancer promoter in an in vitro invasion model

BACKGROUND

Metastasis is a consequence of many biological events, during which cancer stem cells are shifted into a malignant state. Among these events, invasion of prostate cancer cells into host tissues is possible to be assessed by means of an in vitro invasion model, and is thought to be coupled to altered expression of membrane proteins. Dysregulated functions of the factors regulating organogenesis during embryogenesis are known to facilitate metastasis of many types of cancers. PAX2 (paired box 2) is a member of the PAX transcription factor family, which regulates prostatic ductal growth and branching in organogenesis of mammalian prostates. However, the role of PAX2 in prostate cancer development remains to be determined.

METHODS

PAX2 expression in human prostate cancers and normal prostate epithelium were examined by quantitative RT-PCR and immunohistochemistry. Matrigel invasion assay and a gene array analysis were performed using prostate cancer cell lines transfected with either control or PAX2 siRNA.

RESULTS

In human prostate cancers, PAX2 was hyper-expressed in metastatic cancers, but was expressed at lower levels in non-metastatic cancers. Consistent with this, PAX2 knockdown repressed cell growth and invasion in a Matrigel invasion assay. Gene ontology analysis revealed that many cell membrane proteins were downregulated after PAX2 knockdown.

CONCLUSIONS

Our data suggested that PAX2 hyper-expression promotes the development of the metastatic state in prostate cancer cells, presumably through upregulating the expression of cell membrane proteins.

A significant effect of the TSPY1 copy number on spermatogenesis efficiency and the phenotypic expression of the gr/gr deletion

AZFc deletions cause a significant phenotypic heterogeneity with respect to spermatogenesis; however, the reason for this is poorly understood. Recently, testis-specific protein Y-encoded 1 (TSPY1) copy number variation (CNV) was determined to be a potential genetic modifier of spermatogenesis. We performed a large-scale cohort study to investigate the effect of TSPY1 CNV on spermatogenesis and to elucidate the possible contribution of TSPY1 genetic variation to the phenotypic expression of AZFc deletions. Haplogrouping of the Y-chromosome and quantification of the TSPY1 copy number were performed in 2272 Han Chinese males with different spermatogenic statuses (704 males with the b2/b4 or gr/gr deletion and 1568 non-AZFc-deleted males). Our data revealed that the TSPY1 copy number distributions were significantly different among non-AZFc-deleted males with different spermatogenic phenotypes. Lower sperm production and an elevated risk of spermatogenic failure were observed in males with fewer than 21 TSPY1 copies and in those with more than 55 copies relative to men with 21-35 copies. Similar results were observed in males with the gr/gr deletion. These findings indicate that TSPY1 CNV affects an individual's susceptibility to spermatogenic failure by modulating the efficiency of spermatogenesis and strongly suggest that there is a significant quantity effect of the TSPY1 copy number on the phenotypic expression of the gr/gr deletion. To our knowledge, this CNV is the first independent genetic factor that has been clearly observed to influence the spermatogenic status of gr/gr deletion carriers. A combined genetic analysis of the TSPY1 copy number and the gr/gr deletion could inform the clinical counselling of infertile couples.

A fresh look at the male-specific region of the human Y chromosome

The Chromosome-centric Human Proteome Project (C-HPP) aims to systematically map the entire human proteome with the intent to enhance our understanding of human biology at the cellular level. This project attempts simultaneously to establish a sound basis for the development of diagnostic, prognostic, therapeutic, and preventive medical applications. In Iran, current efforts focus on mapping the proteome of the human Y chromosome. The male-specific region of the Y chromosome (MSY) is unique in many aspects and comprises 95% of the chromosome's length. The MSY continually retains its haploid state and is full of repeated sequences. It is responsible for important biological roles such as sex determination and male fertility. Here, we present the most recent update of MSY protein-encoding genes and their association with various traits and diseases including sex determination and reversal, spermatogenesis and male infertility, cancers such as prostate cancers, sex-specific effects on the brain and behavior, and graft-versus-host disease. We also present information available from RNA sequencing, protein-protein interaction, post-translational modification of MSY protein-coding genes and their implications in biological systems. An overview of Human Y chromosome Proteome Project is presented and a systematic approach is suggested to ensure that at least one of each predicted protein-coding gene's major representative proteins will be characterized in the context of its major anatomical sites of expression, its abundance, and its functional relevance in a biological and/or medical context. There are many technical and biological issues that will need to be overcome in order to accomplish the full scale mapping.

Prevalence of c-KIT mutations in gonadoblastoma and dysgerminomas of patients with disorders of sex development (DSD) and ovarian dysgerminomas

Activating c-KIT mutations (exons 11 and 17) are found in 10–40% of testicular seminomas, the majority being missense point mutations (codon 816). Malignant ovarian dysgerminomas represent ∼3% of all ovarian cancers in Western countries, resembling testicular seminomas, regarding chromosomal aberrations and c-KIT mutations. DSD patients with specific Y-sequences have an increased risk for Type II Germ Cell Tumor/Cancer, with gonadoblastoma as precursor progressing to dysgerminoma. Here we present analysis of c-KIT exon 8, 9, 11, 13 and 17, and PDGFRA exon 12, 14 and 18 by conventional sequencing together with mutational analysis of c-KIT codon 816 by a sensitive and specific LightCycler melting curve analysis, confirmed by sequencing. The results are combined with data on TSPY and OCT3/4 expression in a series of 16 DSD patients presenting with gonadoblastoma and dysgerminoma and 15 patients presenting pure ovarian dysgerminomas without DSD. c-KIT codon 816 mutations were detected in five out of the total of 31 cases (all found in pure ovarian dysgerminomas). A synonymous SNP (rs 5578615) was detected in two patients, one DSD patient (with bilateral disease) and one patient with dysgerminoma. Next to these, three codon N822K mutations were detected in the group of 15 pure ovarian dysgerminomas. In total activating c-KIT mutations were found in 53% of ovarian dysgerminomas without DSD. In the group of 16 DSD cases a N505I and D820E mutation was found in a single tumor of a patient with gonadoblastoma and dysgerminoma. No PDGFRA mutations were found. Positive OCT3/4 staining was present in all gonadoblastomas and dysgerminomas investigated, TSPY expression was only seen in the gonadoblastoma/dysgerminoma lesions of the 16 DSD patients. This data supports the existence of two distinct but parallel pathways in the development of dysgerminoma, in which mutational status of c-KIT might parallel the presence of TSPY.

Testicular germ cell tumors: biology and clinical update

PURPOSE OF REVIEW

This overview discusses several important developments in testicular germ cell tumors in the past year.

RECENT FINDINGS

Genomic studies continue to investigate gene expression as possible markers for disease relapse and chemotherapy resistance. Optimal treatment strategies for early-stage seminomas are evolving toward surveillance versus chemotherapy and away from radiation, and the role of retroperitoneal lymph node dissection in disseminated nonseminomatous cancers in complete remission is becoming less certain.

SUMMARY

Treatment and surveillance paradigms continue to be defined and refined for both early and late-stage disease as research in these areas continues and the data from multiple large studies mature.

Testis-specific protein Y-encoded copy number is correlated to its expression and the field fertility of Canadian Holstein bulls

Testis-specific protein Y-encoded (TSPY) is present in varying copy number in both human (20-76 copies) and cattle (37-200 copies), and some studies have linked this variation to semen quality in men. The purpose of this study was to determine if TSPY copy number is associated with fertility in bulls by using adjusted non-return rates, a commonly used measure of field fertility in Canada. In addition, we investigated the associations between TSPY copy number and its expression as well as specific semen parameters, such as average sperm concentration, sperm count, ejaculate volume, and motility. In 2 independent trials, TSPY copy number was shown to be positively correlated to adjusted non-return rates (trial #1: Spearman r = 0.34, p < 0.05; trial #2: Spearman r = 0.77, p < 0.01). Furthermore, TSPY copy number was inversely correlated to TSPY mRNA expression in the testis (Pearson r = -0.71, p < 0.0001). There were no correlations of TSPY copy number or expression with the semen parameters measured. Therefore, TSPY copy number might represent a potential marker of bull fertility, but its mechanism does not appear to be directly related to the semen characteristics analyzed as part of this study.

Sex, rebellion and decadence: the scandalous evolutionary history of the human Y chromosome

It can be argued that the Y chromosome brings some of the spirit of rock&roll to our genome. Equal parts degenerate and sex-driven, the Y has boldly rebelled against sexual recombination, one of the sacred pillars of evolution. In evolutionary terms this chromosome also seems to have adopted another of rock&roll's mottos: living fast. Yet, it appears to have refused to die young. In this manuscript the Y chromosome will be analyzed from the intersection between structural, evolutionary and functional biology. Such integrative approach will present the Y as a highly specialized product of a series of remarkable evolutionary processes. These led to the establishment of a sex-specific genomic niche that is maintained by a complex balance between selective pressure and the genetic diversity introduced by intrachromosomal recombination. Central to this equilibrium is the "polish or perish" dilemma faced by the male-specific Y genes: either they are polished by the acquisition of male-related functions or they perish via the accumulation of inactivating mutations. Thus, understanding to what extent the idiosyncrasies of Y recombination may impact this chromosome's role in sex determination and male germline functions should be regarded as essential for added clinical insight into several male infertility phenotypes. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure.