The mammalian testis and epididymis are responsible for spermatozoa production and maturation, which contributes to male fertility. Predominantly expressed proteins in the testis and epididymis were suggested to be involved in the key functions or pathways in spermatogenesis and sperm maturation. To further investigate these proteins and their associations with sperm, large protein profiles of human testis and epididymis were mapped. Predominantly‑expressed testicular (173) and epididymal (244) secreted proteins were further screened and functionally characterized. Differential expression levels of solute carrier family 2 (facilitated glucose transporter), member 3, solute carrier family 25 (carnitine/acylcarnitine translocase), member 20, WAP‑type four‑disulfide core domain protein 8 and prostate and testis expressed 1 were validated using western blot and immunohistochemical analyses. The results may provide novel insight into the understanding of testicular and epididymal physiology and function, and facilitate sperm maturation research.

The aim of the present study was to investigate the genetic etiology of patients with nonsyndromic hearing impairment through gene analysis, and provide accurate genetic counseling and prenatal diagnosis for deaf patients and families with deaf children. Previous molecular etiological studies have demonstrated that the most common molecular changes in Chinese patients with nonsyndromic hearing loss (NSHL) involved gap junction protein β 2, solute carrier family 26, member 4 (SLC26A4), and mitochondrial DNA 12S rRNA. A total of 117 unrelated NSHL patients were included. Mutation screening was performed by Sanger sequencing in GJB2, 12S rRNA, and the hot‑spot regions of SLC26A4. In addition, patients with a single mutation of SLC26A4 in the hot‑spot regions underwent complete exon sequencing to identify a mutation in the other allele. A total of 36 of the 117 deaf patients were confirmed to have two pathogenic mutations, which included 4 deaf couples, husband or wife in 11 deaf couples and 17 deaf individuals. In addition, prenatal diagnoses was performed in 7 pregnant women at 18‑21 weeks gestation who had previously given birth to a deaf child, and the results showed that two fetal genotypes were the same as the proband's genotypes, four fetuses carried one pathogenic gene from their parents, and one fetus was identified to have no mutations. Taken together, the genetic testing of deaf patients can provide reasonable guidance to deaf patients and families with deaf children.

Abnormal expression of solute carrier family 34 (sodium phosphate), member 2 (SLC34A2) in the lung may induce abnormal alveolar type II (AT II) cells to transform into lung adenocarcinoma cells, and may also be important in biological process of lung adenocarcinoma. However, at present, the effects and molecular mechanisms of SLC34A2 in the initiation and progression of lung cancer remain to be elucidated. To the best of our knowledge, the present study revealed for the first time that the expression levels of SLC34A2 were downregulated in the A549 and H1299 lung adenocarcinoma cell lines. Further investigation demonstrated that the elevated expression of SLC34A2 in A549 cells was able to significantly inhibit cell viability and invasion in vitro. In addition, 10 upregulated genes between the A549‑P‑S cell line stably expressing SLC34A2 and the control cell line A549‑P were identified by microarray analysis and quantitative polymerase chain reaction, including seven tumor suppressor genes and three complement genes. Furthermore, the upregulation of complement gene C3 and complement 4B preproprotein (C4b) in A549‑P‑S cells was confirmed by ELISA analysis and was identified to be correlated with recovering Pi absorption in A549 cells by the phosphomolybdic acid method by enhancing the expression of SLC34A2. Therefore, it was hypothesized that the mechanisms underlying the effect of SLC34A2 on A549 cells might be associated with the activation of the complement alternative pathway (C3 and C4b) and upregulation of the expression of selenium binding protein 1, thioredoxin‑interacting protein, PDZK1‑interacting protein 1 and dual specificity protein phosphatase 6. Downregulation of SLC34A2 may primarily cause abnormal AT II cells to escape from complement‑associated immunosurveillance and abnormally express certain tumor‑suppressor genes inducing AT II cells to develop into lung adenocarcinoma. The present study further elucidated the effects and mechanisms of SLC34A2 in the generation and development of lung cancer.