Expression of Intermediate Filaments in the Developing Testis and Testicular Germ Cell Cancer

Cytokeratin and desmin expression have been associated with Sertoli cell maturity and the development of testicular germ cell cancer (TGCC). Thus, the present study aimed to characterize the expression of these intermediate filaments in normal testis development and TGCC. Cytokeratin and desmin were determined by immunohistochemistry and immunofluorescence in human fetal, and adult testis and tissue from patients with pre-invasive germ cell neoplasia in-situ (GCNIS) or invasive TGCC. Desmin was expressed in Sertoli cells of the human fetal testis, and the proportion of desmin expressing Sertoli cells was significantly reduced in the second trimester, compared with the first trimester (31.14% vs. 6.74%, p = 0.0016). Additionally, Desmin was expressed in the majority of Sertoli cells in the adult testis and TGCC samples. Cytokeratin was detected in Sertoli cells of human fetal testis but was not expressed in Sertoli cells of human adult testis. In patients with TGCC, cytokeratin was not expressed in Sertoli cells in tubules with active spermatogenesis but was detected in Sertoli cells in tubules containing GCNIS cells in patients with both pre-invasive and invasive TGCC. In conclusion, desmin was not associated with Sertoli cell maturation or progression to TGCC. However, cytokeratin appeared to be an indicator of impaired Sertoli cell maturation

The oncogene Gankyrin is expressed in testicular cancer and contributes to cisplatin sensitivity in embryonal carcinoma cells

BACKGROUND: Testicular germ cell cancer (TGCC) develops from pre-malignant germ neoplasia in situ (GCNIS) cells. GCNIS originates from fetal gonocytes (POU5F1+/MAGE-A4-), which fail to differentiate to pre-spermatogonia (POU5F1-/MAGE-A4+) and undergo malignant transformation. Gankyrin is an oncogene which has been shown to prevent POU5F1 degradation and specifically interact with MAGE-A4 in hepatocellular carcinoma (HCC) cells. We aimed to investigate the role of Gankyrin in progression from gonocyte to pre-invasive GCNIS and subsequent invasive TGCC. METHODS: We determined Gankyrin expression in human fetal testicular tissue (gestational weeks 9-20; n = 38), human adult testicular tissue with active spermatogenesis (n = 9), human testicular tissue with germ cell maturation delay (n = 4), testicular tissue from patients with pre-invasive GCNIS (n = 6), and invasive TGCC including seminoma (n = 6) and teratoma (n = 7). Functional analysis was performed in-vitro by siRNA knock-down of Gankyrin in the NTera2 cells (derived from embryonal carcinoma). RESULTS: Germ cell expression of Gankyrin was restricted to a sub-population of prespermatogonia in human fetal testes. Nuclear Gankyrin was also expressed in GCNIS cells of childhood and adult pre-invasive TGCC patients, and in GCNIS from seminoma and non-seminoma patients. Cytoplasmic expression was observed in seminoma tumour cell

Prolonged exposure to acetaminophen reduces testosterone production by the human fetal testis in a xenograft model

Most common male reproductive disorders are linked to lower testosterone exposure in fetal life, although the factors responsible for suppressing fetal testosterone remain largely unknown. Protracted use of acetaminophen during pregnancy is associated with increased risk of cryptorchidism in sons, but effects on fetal testosterone production have not been demonstrated. We used a validated xenograft model to expose human fetal testes to clinically relevant doses and regimens of acetaminophen. Exposure to a therapeutic dose of acetaminophen for 7 days significantly reduced plasma testosterone (45% reduction; P = 0.025) and seminal vesicle weight (a biomarker of androgen exposure; 18% reduction; P = 0.005) in castrate host mice bearing human fetal testis xenografts, whereas acetaminophen exposure for just 1 day did not alter either parameter. Plasma acetaminophen concentrations (at 1 hour after the final dose) in exposed host mice were substantially below those reported in humans after a therapeutic oral dose. Subsequent in utero exposure studies in rats indicated that the acetaminophen-induced reduction in testosterone likely results from reduced expression of key steroidogenic enzymes (Cyp11a1, Cyp17a1). Our results suggest that protracted use of acetaminophen (1 week) may suppress fetal testosterone production, which could have adverse consequences. Further studies are required to establish the dose-response and treatment-duration relationships to delineate the maximum dose and treatment period without this adverse effect

Intratubular germ cell neoplasia of the human testis:heterogeneous protein expression and relation to invasive potential

Testicular germ cell cancer develops from premalignant intratubular germ cell neoplasia, unclassified cells that are believed to arise from failure of normal maturation of fetal germ cells from gonocytes (OCT4(+)/MAGEA4(-)) into pre-spermatogonia (OCT4(-)/MAGEA4(+)). Intratubular germ cell neoplasia cell subpopulations based on stage of germ cell differentiation have been described, however the importance of these subpopulations in terms of invasive potential has not been reported. We hypothesized that cells expressing an immature (OCT4(+)/MAGEA4(-)) germ cell profile would exhibit an increased proliferation rate compared with those with a mature profile (OCT4(+)/MAGEA4(+)). Therefore, we performed triple immunofluorescence and stereology to quantify the different intratubular germ cell neoplasia cell subpopulations, based on expression of germ cell (OCT4, PLAP, AP2γ, MAGEA4, VASA) and proliferation (Ki67) markers, in testis sections from patients with preinvasive disease, seminoma, and non-seminoma. We compared these subpopulations with normal human fetal testis and with seminoma cells. Heterogeneity of protein expression was demonstrated in intratubular germ cell neoplasia cells with respect to gonocyte and spermatogonial markers. It included an embryonic/fetal germ cell subpopulation lacking expression of the definitive intratubular germ cell neoplasia marker OCT4, that did not correspond to a physiological (fetal) germ cell subpopulation. OCT4(+)/MAGEA4(-) cells showed a significantly increased rate of proliferation compared with the OCT4(+)/MAGEA4(+) population (12.8 versus 3.4%, P<0.0001) irrespective of histological tumor type, reflected in the predominance of OCT4(+)/MAGEA4(-) cells in the invasive tumor component. Surprisingly, OCT4(+)/MAGEA4(-) cells in patients with preinvasive disease showed significantly higher proliferation compared to those with seminoma or non-seminoma (18.1 versus 10.2 versus 7.2%, P<0.05, respectively). In conclusion, this study has demonstrated that OCT4(+)/MAGEA4(-) cells are the most frequent and most proliferative cell population in tubules containing intratubular germ cell neoplasia, which appears to be an important factor in determining invasive potential of intratubular germ cell neoplasia to seminomas