SPANX-A/D protein subfamily plays a key role in nuclear organisation, metabolism and flagellar motility of human spermatozoa

The Price of Human Evolution: Cancer-Testis Antigens, the Decline in Male Fertility and the Increase in Cancer

The increasing frequency of general and particularly male cancer coupled with the reduction in male fertility seen worldwide motivated us to seek a potential evolutionary link between these two phenomena, concerning the reproductive transcriptional modules observed in cancer and the expression of cancer-testis antigens (CTA). The phylostratigraphy analysis of the human genome allowed us to link the early evolutionary origin of cancer via the reproductive life cycles of the unicellulars and early multicellulars, potentially driving soma-germ transition, female meiosis, and the parthenogenesis of polyploid giant cancer cells (PGCCs), with the expansion of the CTA multi-families, very late during their evolution. CTA adaptation was aided by retrovirus domestication in the unstable genomes of mammals, for protecting male fertility in stress conditions, particularly that of humans, as compensation for the energy consumption of a large complex brain which also exploited retrotransposition. We found that the early and late evolutionary branches of human cancer are united by the immunity-proto-placental network, which evolved in the Cambrian and shares stress regulators with the finely-tuned sex determination system. We further propose that social stress and endocrine disruption caused by environmental pollution with organic materials, which alter sex determination in male foetuses and further spermatogenesis in adults, bias the development of PGCC-parthenogenetic cancer by default.

Auto-immunoproteomics analysis of COVID-19 ICU patients revealed increased levels of autoantibodies related to the male reproductive system

Background: Coronavirus disease (COVID-19) manifests many clinical symptoms, including an exacerbated immune response and cytokine storm. Autoantibodies in COVID-19 may have severe prodromal effects that are poorly understood. The interaction between these autoantibodies and self-antigens can result in systemic inflammation and organ dysfunction. However, the role of autoantibodies in COVID-19 complications has yet to be fully understood. Methods: The current investigation screened two independent cohorts of 97 COVID-19 patients [discovery (Disc) cohort from Qatar (case = 49 vs. control = 48) and replication (Rep) cohort from New York (case = 48 vs. control = 28)] utilizing high-throughput KoRectly Expressed (KREX) Immunome protein-array technology. Total IgG autoantibody responses were evaluated against 1,318 correctly folded and full-length human proteins. Samples were randomly applied on the precoated microarray slides for 2 h. Cy3-labeled secondary antibodies were used to detect IgG autoantibody response. Slides were scanned at a fixed gain setting using the Agilent fluorescence microarray scanner, generating a 16-bit TIFF file. Group comparisons were performed using a linear model and Fisher's exact test. Differentially expressed proteins were used for KEGG and WIKIpathway annotation to determine pathways in which the proteins of interest were significantly over-represented. Results and conclusion: Autoantibody responses to 57 proteins were significantly altered in the COVID-19 Disc cohort compared to healthy controls (p ≤ 0.05). The Rep cohort had altered autoantibody responses against 26 proteins compared to non-COVID-19 ICU patients who served as controls. Both cohorts showed substantial similarities (r 2 = 0.73) and exhibited higher autoantibody responses to numerous transcription factors, immunomodulatory proteins, and human disease markers. Analysis of the combined cohorts revealed elevated autoantibody responses against SPANXN4, STK25, ATF4, PRKD2, and CHMP3 proteins in COVID-19 patients. The sequences for SPANXN4 and STK25 were cross-validated using sequence alignment tools. ELISA and Western blot further verified the autoantigen-autoantibody response of SPANXN4. SPANXN4 is essential for spermiogenesis and male fertility, which may predict a potential role for this protein in COVID-19-associated male reproductive tract complications, and warrants further research.

Mapping the human sperm proteome - novel insights into reproductive research

INTRODUCTION

Spermatozoa are highly specialized cells with unique morphology. In addition, spermatozoa lose a considerable amount of cytoplasm during spermiogenesis, when they also compact their DNA, resulting in a transcriptionally quiescent cell. Throughout the male reproductive tract, sperm will acquire proteins that enable them to interact with the female reproductive tract. After ejaculation, proteins undergo post-translational modifications for sperm to capacitate, hyperactivate and fertilize the oocyte. Many proteins have been identified as predictors of male infertility, and also investigated in diseases that compromise reproductive potential.

AREAS COVERED

In this review we proposed to summarize the recent findings about the sperm proteome and how they affect sperm structure, function, and fertility. A literature search was performed using PubMed and Google Scholar databases within the past 5 years until August 2022.

EXPERT OPINION

Sperm function depends on protein abundance, conformation, and PTMs; understanding the sperm proteome may help to identify pathways essential to fertility, even making it possible to unravel the mechanisms involved in idiopathic infertility. In addition, proteomics evaluation offers knowledge regarding alterations that compromise the male reproductive potential.

Three-Dimensional Ultrastructural and Volume Analysis of the Redundant Nuclear Envelope of Developing and Matured Sperm in Mice

The ultrastructure of the nuclear envelope (NE) and redundant NE (RNE) of the spermatozoon cannot be observed in detail using conventional electron microscopy. Thus, this study aimed to employ transmission electron microscopy (TEM) and focused ion beam/scanning electron microscopy (FIB/SEM) tomography to fill this research gap. Male mice aged 13 weeks were deeply anesthetized, and the testes and vas deferens were extracted and processed for electron microscopy. In round spermatids, the acrosomal vesicle compressed the nucleus, and the acrosomal center was depressed. The nucleoli concentrated on the contralateral side of the acrosome formation site. In mature spermatozoa, the RNE accumulated in the neck with the residual bodies. The NE pores exhibited a hexagonal pattern. The body surface area and volume of the nuclei of spermatids and spermatozoa in each maturation phase were analyzed using FIB/SEM tomography. The body surface area and volume of the nuclei decreased during spermatid maturation into spermatozoa. The RNE converged at the sperm neck and possessed a honeycomb structure. The method used revealed that the nuclei of spermatids gradually condense as they mature into spermatozoa. This method may be used to analyze small tissues, such as RNE, and detect morphological abnormalities in microtissues, such as spermatozoa.

Prognostic Biomarkers in Uveal Melanoma: The Status Quo, Recent Advances and Future Directions

Simple Summary

Although rare, uveal melanoma (UM) is the most common cancer that develops inside adult eyes. The prognosis is poor, since 50% of patients will develop lethal metastases in the first decade, especially to the liver. Once metastases are detected, life expectancy is limited, given that the available treatments are mostly unsuccessful. Thus, there is a need to find methods that can accurately predict UM prognosis and also effective therapeutic strategies to treat this cancer. In this manuscript, we initially compile the current knowledge on epidemiological, clinical, pathological and molecular features of UM. Then, we cover the most relevant prognostic factors currently used for the evaluation and follow-up of UM patients. Afterwards, we highlight emerging molecular markers in UM published over the last three years. Finally, we discuss the problems preventing meaningful advances in the treatment and prognostication of UM patients, as well as forecast new roadblocks and paths of UM-related research.

Abstract

Uveal melanoma (UM) is the most common malignant intraocular tumour in the adult population. It is a rare cancer with an incidence of nearly five cases per million inhabitants per year, which develops from the uncontrolled proliferation of melanocytes in the choroid (≈90%), ciliary body (≈6%) or iris (≈4%). Patients initially present either with symptoms like blurred vision or photopsia, or without symptoms, with the tumour being detected in routine eye exams. Over the course of the disease, metastases, which are initially dormant, develop in nearly 50% of patients, preferentially in the liver. Despite decades of intensive research, the only approach proven to mildly control disease spread are early treatments directed to ablate liver metastases, such as surgical excision or chemoembolization. However, most patients have a limited life expectancy once metastases are detected, since there are limited therapeutic approaches for the metastatic disease, including immunotherapy, which unlike in cutaneous melanoma, has been mostly ineffective for UM patients. Therefore, in order to offer the best care possible to these patients, there is an urgent need to find robust models that can accurately predict the prognosis of UM, as well as therapeutic strategies that effectively block and/or limit the spread of the metastatic disease. Here, we initially summarized the current knowledge about UM by compiling the most relevant epidemiological, clinical, pathological and molecular data. Then, we revisited the most important prognostic factors currently used for the evaluation and follow-up of primary UM cases. Afterwards, we addressed emerging prognostic biomarkers in UM, by comprehensively reviewing gene signatures, immunohistochemistry-based markers and proteomic markers resulting from research studies conducted over the past three years. Finally, we discussed the current hurdles in the field and anticipated the future challenges and novel avenues of research in UM.

Chromosome X-wide Analysis of Positive Selection in Human Populations: Common and Private Signals of Selection and its Impact on Inactivated Genes and Enhancers

The ability of detecting adaptive (positive) selection in the genome has opened the possibility of understanding the genetic basis of population-specific adaptations genome-wide. Here, we present the analysis of recent selective sweeps, specifically in the X chromosome, in human populations from the third phase of the 1,000 Genomes Project using three different haplotype-based statistics. We describe instances of recent positive selection that fit the criteria of hard or soft sweeps, and detect a higher number of events among sub-Saharan Africans than non-Africans (Europe and East Asia). A global enrichment of neural-related processes is observed and numerous genes related to fertility appear among the top candidates, reflecting the importance of reproduction in human evolution. Commonalities with previously reported genes under positive selection are found, while particularly strong new signals are reported in specific populations or shared across different continental groups. We report an enrichment of signals in genes that escape X chromosome inactivation, which may contribute to the differentiation between sexes. We also provide evidence of a widespread presence of soft-sweep-like signatures across the chromosome and a global enrichment of highly scoring regions that overlap potential regulatory elements. Among these, enhancers-like signatures seem to present putative signals of positive selection which might be in concordance with selection in their target genes. Also, particularly strong signals appear in regulatory regions that show differential activities, which might point to population-specific regulatory adaptations.

The multifunctional role of SPANX-A/D protein subfamily in the promotion of pro-tumoural processes in human melanoma

Human sperm protein associated with the nucleus on the X chromosome (SPANX) genes encode a protein family (SPANX-A, -B, -C and -D), whose expression is limited to the testis and spermatozoa in normal tissues and various tumour cells. SPANX-A/D proteins have been detected in metastatic melanoma cells, but their contribution to cancer development and the underlying molecular mechanisms of skin tumourigenesis remain unknown. Combining functional and proteomic approaches, the present work describes the presence of SPANX-A/D in primary and metastatic human melanoma cells and how it promotes pro-tumoural processes such as cell proliferation, motility and migration. We provide insights into the molecular features of skin tumourigenesis, describing for the first time a multifunctional role of the SPANX-A/D protein family in nuclear function, energy metabolism and cell survival, considered key hallmarks of cancer. A better comprehension of the SPANX-A/D protein subfamily and its molecular mechanisms will help to describe new aspects of tumour cell biology and develop new therapeutic targets and tumour-directed pharmacological drugs for skin tumours.

Hypomethylated SPANXA1/A2 promotes the metastasis of head and neck squamous cell carcinoma

The aberrant expression of SPANXA1/A2 (sperm protein associated with the nucleus on the X-chromosome, family members A1/A2) has been observed in multi types of cancers. However, the roles of SPANXA1/A2 in head and neck squamous cell carcinoma (HNSCC) remain largely unknown. The expression of SPANXA1/A2 was evaluated via analyzing UCSC XENA and GEO databases. To dissect the underlying cause of silencing SPANXA1/A2-mediated suppression, cell migration and invasion were detected in SPANXA1/A2 manipulated cell lines. Western blot was performed to evaluate EMT-related factors. The methylation microarray data of SPANXA1/A2 in HNSCC from the UCSC XENA database were used to identify whether aberrant overexpressed SPANXA1/A2 is induced by aberrant DNA methylation. SPANXA1/A2 was highly expressed in tumor tissues and associated with poor survival of patients with HNSCC. Knockdown of SPANXA1/A2 inhibited migration and invasion abilities in both Cal-27 and SCC-9 cells through epithelial-mesenchymal transition (EMT) suppression. The SPANXA1/A2 expression negatively related to its DNA methylation level. SPANXA1/A2 DNA hypomethylation was associated with metastatic stage and poor survival of patients with HNSCC. A dose-dependent increase of SPANXA1/A2 mRNA was observed in both cal-27 and SCC-9 cells after treatment with 5-AZA-2'-deoxycytidine (5-AZA-CdR). We demonstrated that knockdown of SPANXA1/A2 obviously inhibited tumor cell migration and invasion through EMT suppression. DNA hypomethylation might be responsible for the aberrant SPANXA1/A2 overexpressing. SPANXA1/A2 may be used as a diagnosed and independent prognosis indicator of HNSCC, and knockdown of SPANXA1/A2 may present a new gene-based therapy for HNSCC.