Towards the identification of reliable sperm biomarkers for male infertility: A sperm proteomic approach
ANDROLOGIA
Authors: Intasqui, P.; Agarwal, A.; Sharma, R.; Samanta, L.; Bertolla, R. P.
Abstract
Male infertility evaluation is mainly based on semen analysis. Thus, identification of additional diagnostic methods is valuable. The aim of this study was to analyse the sperm proteome of infertile men to identify the underlying mechanisms and reliable diagnostic biomarkers. This cross-sectional study consisted of 16 infertile men and seven proven fertile men. An LC-MS/MS approach was performed in five pooled samples of each group (proven fertile men, primary infertility and secondary infertility). Differentially expressed proteins were used for functional enrichment analyses, and the most central proteins involved in altered functions in both infertile groups and the testis-specific proteins were validated using Western blotting and immunocytochemistry. In total, 1,305 sperm proteins were identified, of which 102 were underexpressed and 15 were overexpressed proteins in both infertile groups. Underexpressed proteins were mostly related to protein post-translational modification and folding, especially BAG6, HSPA2 and SPA17. Validation analysis revealed an underexpression of BAG6 in infertile men, whereas HSPA2 and SPA17 expressions did not differ between the groups. No differences were observed in the sperm localisation of these proteins. An overexpression of HIST1H2BAa testis-specific proteinwas observed in both proteomic approaches. Therefore, BAG6 and HIST1H2BA are potential candidates for male infertility biomarkers.
Cancer-testis antigens as biomarkers for Merkel cell carcinoma: Pitfalls and opportunities
JOURNAL OF CUTANEOUS PATHOLOGY
Authors: Dasgeb, Bahar; Mehregan, Darius; Ring, Christina; Nartker, Nathan; Brownell, Isaac
Abstract
Background The prognosis and treatment options for metastatic Merkel cell carcinoma (MCC) are poor. The immune-privileged status of cancer-testis (CT) antigens imparts tumor specificity, making them ideal candidates for targeted immunotherapy. We investigate the usefulness of the CT antigens SPA17 (sperm protein-17 [SP-17]), IGF2BP3 (insulin-like growth factor-II mRNA-binding protein 3 [IMP-3]), and transmembrane protein with epidermal growth factor (EGF)-like and two follistatin-like domains 1 (TMEFF1) as potential MCC biomarkers and evaluate their possible utility in immunotherapy and molecularly targeted image-guided treatment. Methods The CT antigens SP-17, IMP-3, and TMEFF1 were selected using transcriptome profiling to identify CT antigens expressed in MCC tumors. Antibodies directed against these CT antigens were stained. Twelve normal skin tissue samples were used as a control. The average percentage of positive cells in each tumor was computed. Results Twelve of 14 (86%) MCC cases showed crisp nuclear staining for SP-17, with 2.06% of cells staining positive. IMP-3 showed crisp, perinuclear staining in all 14 MCC cases, with 52.93% MCC cells staining positive. TMEFF1 showed perinuclear staining in all 14 MCC cases, with 96.51% of tumor cells staining positive. Conclusions CT antigens were found to be expressed in both MCC and some control tissues. SP-17 was the most specific yet the least sensitive. IMP-3 and TMEFF1 were both sensitive but not specific. CT antigens may represent valuable treatment targets in MCC.