Arsenic (As) is an environmental metalloid. Previous studies have demonstrated that As exposure resulted in decline of sperm quality. This study aimed to investigate the impact of exposure to As on blood-testis barrier (BTB) in a mouse model. Four-week-old male mice were exposed to NaAsO₂ (1 or 15 mg/L) for 6 weeks. Our results found that NaAsO₂ exposure disrupted the BTB and reduced sperm counts in adult mice. NaAsO₂ activated the integrated stress response (ISR) and downregulated barrier junction protein in mouse testes and Sertoli cells. Ribosome profiling sequencing (Ribo-seq) and Ribosome-nascent chain complex-bound mRNA qPCR (RNC-qPCR) showed that translational efficiency of N-cadherin and ZO-1, two key barrier junction proteins, was reduced in NaAsO₂-treated Sertoli cells. Mechanistically, NaAsO₂ exposure reduced SIRT3 protein via proteasomal degradation, thereby resulting in mitochondrial dysfunction and excess mitochondrial ROS (mtROS) generation in Sertoli cells. Melatonin alleviated NaAsO₂-induced mitochondrial dysfunction and mtROS upregulation via reducing SOD2 acetylation in Sertoli cells. Moreover, melatonin antagonized NaAsO₂-induced ISR, barrier junction proteins downregulation and barrier function impairment in Sertoli cells. Accordingly, melatonin attenuated NaAsO₂-evoked BTB disruption and sperm count reduction in adult mice. These results suggest that mitochondrial dysfunction-associated translational inhibition of barrier junction proteins is involved in As-mediated BTB disruption and sperm quality decline.

Background: Cuproptosis plays a crucial role in cancer, and different subtypes of cuproptosis have different immune profiles in prostate adenocarcinoma (PRAD). This study aimed to investigate immune genes associated with cuproptosis and develop a risk model to predict prognostic characteristics and chemotherapy/immunotherapy responses of patients with PRAD.Methods: The CIBERSORT algorithm was used to evaluate the immune and stromal scores of patients with PRAD in The Cancer Genome Atlas (TCGA) cohort. Validation of differentially expressed genes DLAT and DLD in benign and malignant tissues by immunohistochemistry, and the immune-related genes of DLAT and DLD were further screened. Univariable Cox regression were performed to select key genes. Least absolute shrinkage and selection operator (LASSO)–Cox regression analyse was used to develop a risk model based on the selected genes. The model was validated in the TCGA, Memorial Sloan-Kettering Cancer Center (MSKCC) and Gene Expression Omnibus (GEO) datasets, as well as in this study unit cohort. The genes were examined via functional enrichment analysis, and the tumor immune features, tumor mutation features and copy number variations (CNVs) of patients with different risk scores were analysed. The response of patients to multiple chemotherapeutic/targeted drugs was assessed using the pRRophetic algorithm, and immunotherapy was inferred by the Tumor Immune Dysfunction and Exclusion (TIDE) and immunophenoscore (IPS).Results: Cuproptosis-related immune risk scores (CRIRSs) were developed based on PRLR, DES and LECT2. High CRIRSs indicated poor overall survival (OS), disease-free survival (DFS) in the TCGA-PRAD, MSKCC and GEO datasets and higher T stage and Gleason scores in TCGA-PRAD. Similarly, in the sample collected by the study unit, patients with high CRIRS had higher T-stage and Gleason scores. Additionally, higher CRIRSs were negatively correlated with the abundance of activated B cells, activated CD8⁺ T cells and other stromal or immune cells. The expression of some immune checkpoints was negatively correlated with CRIRSs. Tumor mutational burden (TMB), mutant-allele tumor heterogeneity (MATH) and copy number variation (CNV) scores were all higher in the high-CRIRS group. Multiple chemotherapeutic/targeted drugs and immunotherapy had better responsiveness in the low-CRIRS group.Conclusion: Overall, lower CRIRS indicated better response to treatment strategies and better prognostic outcomes.

Inorganic arsenic is a Class I human Carcinogen. However, the role of chronic inorganic arsenic exposure on prostate cancer metastasis still unclear. This study aimed to investigate the effects and mechanism of chronic NaAsO₂ exposure on migration and invasion of prostate cancer cells. DU145 and PC-3 cells were exposed to NaAsO₂ (2 μM) for 25 generations. Wound healing and Transwell assays showed that chronic NaAsO₂ exposure promoted migration and invasion of DU145 and PC-3 cells. In addition, chronic NaAsO₂ exposure induced epithelial-mesenchymal transition (EMT) of DU145 cells by promoting β-catenin/TCF4 transcriptional activity. Mechanically, NaAsO₂ promoted GSK-3β inactivation in the "disruption complex" through Akt- mediated phosphorylation at serine 9, and then inhibited the phosphorylation and ubiquitination degradation of β-catenin, which led to its nuclear translocation. Ly294002, a selective phosphatidylinositol 3-kinase (PI3K)/Akt inhibitor, suppressed the β-catenin/TCF4 complex activation and EMT through blocking Akt-mediated GSK-3β inactivation in the "disruption complex" in chronic NaAsO₂ exposed DU145 and PC-3 cells. Moreover, Ly294002 alleviated chronic NaAsO₂-induced migration and invasion in DU145 and PC-3 cells. These findings provide evidence that chronic arsenic exposure promotes migration and invasion of prostate cancer cells via an EMT mechanism driven by the AKT/GSK-3β/β-catenin/TCF4 signaling axis. Akt is expected to be a potential therapeutic target for chronic arsenic exposure-mediated prostate cancer metastasis.

Human epidermal growth factor receptor 2 (HER2) is one of the most studied tumor-associated antigens for cancer immunotherapy. An engineered anti-HER-2 chimeric A21 antibody (chA21) is a chimeric antibody targeted to subdomain I of the HER2 extracellular domain. Here, we report the anti-tumor activity of the novel engineered monoclonal antibody humanized chA21 (HuA21) that targets HER2 on the basis of chA21, and we describe the underlying mechanisms. Our results reveal that HuA21 markedly inhibits the proliferation and migration of HER2-overexpressing breast cancer cells and causes enhanced antibody-dependent cell-mediated cytotoxicity potency against HER2-overexpressing tumor cells. In particular, HuA21, but not trastuzumab (Tra), markedly suppresses growth and enhances the internalization of the antibody in Tra-resistant BT-474 breast cancer cells. These characteristics are highly associated with the intrinsic ability of HuA21 to down-regulate HER2 activation and inhibit the extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) signaling pathways. Furthermore, the combination of HuA21 with Tra synergistically enhances the anti-tumor effects in vitro and in vivo and inhibits HER2 activation and the ERK1/2 and Akt signaling pathways. Altogether, our results suggest that HuA21 may represent a unique anti-HER2 antibody with potential as a therapeutic candidate alone or in combination with other anti-HER2 reagents in cancer therapy.

Perfluorooctanoic acid (PFOA) is a reproductive toxicant, but its effects on sperm head shaping and acrosome reaction remain unknown. Adult male Bal b/c mice were given 0, 2 or 10 mg/kg/day of PFOA for 6 weeks by gavage. Elevated sperm head malformations and decreased acrosome reaction were observed in PFOA-exposed mice. Transmission electron microscopy (TEM) revealed that PFOA exposure caused ultrastructural changes of endoplasmic reticulum, acrosomal granules, acrosomal membrane and nuclear membrane at different phases of acrosome biogenesis. Additionally, key proteins participated in acrosome biogenesis were downregulated in PFOA-exposed mice testes. Alpha-tubulin immunofluorescence indicated that PFOA impaired the manchette structure in elongating spermatids. Western blotting confirmed that key proteins involved in manchette formation were decreased in PFOA-exposed mice testes. Furthermore, PFOA dose-dependently reduced the proteins participating in perinuclear theca (PT) formation. Intriguingly, PFOA inhibited sperm chromatin condensation. Phosphorylation levels of H2A.X, ATM and ATR, three key biomarkers for DNA strand breakage repair, were significantly increased in PFOA-exposed mice testes. Importantly, levels of 8-OHdG, a classic marker of DNA oxidative damage, was remarkable upregulated in PFOA-exposed mice sperm. Our findings provide new evidence that PFOA decreases acrosome reaction and increases DNA oxidative damage by impairing the sperm head shaping in mice.