Non-Genomic Action of Androgens is Mediated by Rapid Phosphorylation and Regulation of Androgen Receptor Trafficking.

BACKGROUND: Testosterone is critical for maintaining spermatogenesis and male fertility. The accomplishment of these processes requires the synergistic actions of the classical and non-classical signaling pathways of androgens. METHODS: A murine testicular Sertoli cell line, TM4 cell was used to examine androgen actions in Sertoli cells. Western blot analysis and immunofluorescence assay were employed to study the testosterone-induced Androgen receptor (AR) translocation. Protein phosphorylation antibody array was applied to identify the phosphorylation sites under testosterone treatment, and these findings were verified by Western blot analysis. RESULTS: We found that a physiological dose of testosterone induced fast membrane association of AR. By using a phosphorylation antibody array, several phosphorylation sites, such as MEK1/2 (Ser217/221), Akt (Ser473), and Erk1/2 (Thr202/Tyr204) were rapidly phosphorylated within 5 min of testosterone treatment. Inhibition of the MEK and Akt signaling pathways prevented AR trafficking. Blocking of AR by flutamide eliminated the stimulation effect of testosterone on kinase phosphorylation. Testosterone induced kinase Src phosphorylation, and inhibition of Src restricted AR translocation to the membrane and the nucleus. CONCLUSION: Findings suggested that the membrane association of AR was mediated by the MEK and Akt phosphorylation signaling pathways, which resulted in Src activation and was initiated by testosterone binding to the membrane-localized AR. This study provides new insights into the testosterone signaling pathway in Sertoli cells, which mediate spermatogenesis. In addition, the study can be used in the diagnosis and treatment of male infertility caused by disorders in spermatogenesis.

The Wilms tumor gene, Wt1, is critical for mouse spermatogenesis via regulation of sertoli cell polarity and is associated with non-obstructive azoospermia in humans.

Azoospermia is one of the major reproductive disorders which cause male infertility in humans; however, the etiology of this disease is largely unknown. In the present study, six missense mutations of WT1 gene were detected in 529 human patients with non-obstructive azoospermia (NOA), indicating a strong association between WT1 mutation and NOA. The Wilms tumor gene, Wt1, is specifically expressed in Sertoli cells (SCs) which support spermatogenesis. To examine the functions of this gene in spermatogenesis, Wt1 was deleted in adult testis using Wt1(flox) and Cre-ER(TM) mice strains. We found that inactivation of Wt1 resulted in massive germ cell death and only SCs were present in most of the seminiferous tubules which was very similar to NOA in humans. In investigating the potential mechanism for this, histological studies revealed that the blood-testis barrier (BTB) was disrupted in Wt1 deficient testes. In vitro studies demonstrated that Wt1 was essential for cell polarity maintenance in SCs. Further studies found that the expression of cell polarity associated genes (Par6b and E-cadherin) and Wnt signaling genes (Wnt4, Wnt11) were downregulated in Wt1 deficient SCs, and that the expression of Par6b and E-cadherin was regulated by Wnt4. Our findings suggest that Wt1 is important in spermatogenesis by regulating the polarity of SCs via Wnt signaling pathway and that WT1 mutation is one of the genetic causes of NOA in humans.

Overexpression of cyclooxygenase-1 correlates with poor prognosis in renal cell carcinoma.

The aim of this study was to evaluate expression of COX-1 in renal cell carcinoma (RCC) and its prognostic value. mRNA of COX-1 was detected in 42 paired RCC and adjacent normal tissues with quantitative real- time polymerase chain reaction (qRT-PCR). Expression of COX-1 was also evaluated in 196 RCC sections and 91 adjacent normal tissues with immunohistochemistry. Statistical analysis was performed to assess COX-1 expression in RCC and its prognostic significance. The results of qRT-PCR showed mRNA levels of COX-1 in RCC tissues to be significantly higher than that in adjacent normal tissues (p < 0.001). Immunohistochemical assays also revealed COX-1 to be overexpressed in RCC tissues (p < 0.001). Statistical analysis demonstrated high expression of COX-1 was correlated with tumour size (p = 0.002), pathological stage (p = 0.003), TNM stage (p = 0.003, 0.007, 0.027, respectively), and tumour recurrence (p < 0.001). Survival analysis indicated patients with high expression of COX-1 had shorter survival time (p < 0.001), and COX-1 was an independent predictor. This is the first study to reveal overexpression of COX-1 in RRC and point to use as a prognostic marker in affected patients.

Clinical outcomes in patients with stage I non-seminomatous germ cell cancer.

This study assesses the long-term outcomes in Han Chinese patients with clinical stage I non-seminomatous germ cell testicular cancer (CSI NSGCT) treated with surveillance, retroperitoneal lymph node dissection (RPLND) and adjuvant chemotherapy. We retrospectively evaluated 89 patients with a mean age of 26.5 years. After orchiectomy, 37 patients were treated with surveillance, 34 underwent RPLND and 18 were managed with chemotherapy. The overall survival rate, the recurrence-free survival rate and the risk factors were evaluated. The median follow-up length was 92 months (range: 6-149 months). Thirteen of the 89 patients (14.6%) had relapses, and one died by the evaluation date. The overall survival rate was 98.9%. The cumulative 4-year recurrence-free rates were 80.2%, 92.0% and 100% for the surveillance, RPLND and chemotherapy groups, respectively. The disease-free period tended to be briefer in patients with a history of cryptorchidism and those with stage Is. Therefore, surveillance, RPLND and adjuvant chemotherapy might be reliable strategies in compliant patients with CSI NSGCT. Surveillance should be recommended for patients with the lowest recurrence rate, especially those without lymphovascular invasion. This study might aid the establishment of a standard therapy for CSI NSGCT in China.

RALY RNA binding protein-like reduced expression is associated with poor prognosis in clear cell renal cell carcinoma.

The molecular mechanisms involved in the progression of clear cell renal cell carcinomas (ccRCCs) are still unclear. The aim of this study was to analyse the relationships between expression of RALYL and clinical characteristics. In 41 paired samples of ccRCCs and adjacent normal tissues, we used real-time qPCR to evaluate the expression of RALYL mRNA. RALYL protein levels were determined in 146 samples of ccRCC and 37 adjacent normal tissues by immunohistochemistry. Statistical analysis was used to explore the relationships between expression of RALYL and the clinical characteristics (gender, age, tumor size, T stage, N stage, M stage, survival times and survival outcome) in ccRCC. In addition, these patients were follow-up period 64 months (range: 4~116 months) to investigate the influence on prognosis. We found significantly differences between ccRCC tissues and normal tissues (p<0.001, paired-sample t test) in mRNA levels of RALYL. Immunohistochemistry analyses in 146 ccRCC samples and 37 adjacent normal tissues showed significantly lower RALYL protein levels in ccRCC samples (χ2-test, p<0.001), inversely correlating with tumour size (p=0.024), T stage (0.005), N stage (p<0.001) as well as M stage (p=0.019), but not age (p=0.357) and gender (p=0.348). Kaplan-Meier survival analysis demonstrated that people with lower level of RALYL expression had a poorer survival rate than those with a higher level of RALYL expression, significantly different by the log-rank test (p=0.011). Cox regression analysis indicated that RALYL expression (p=0.039), N stage (p=0.008) and distant metastasis (p<0.001) were independent prognosis factors for the overall survival of ccRCC patients. We demonstrated that the expression of RALYL was significantly low in ccRCC and correlated with a poor prognosis in a large number of clinical samples. Our findings showed that RALYL may be a potential therapeutic target as well as a poor prognostic factor.

[Abnormal expression and significance of MIR-184 in human renal carcinoma].

OBJECTIVE: To explore the role of microRNA-184(MIR-184) in the development of renal cell carcinoma(RCC). METHODS: The expressions of MIR-184 in 51 patients with RCC Investigated, normal adjacent tissues (ADTs) matched by fluorescence quantitative PCR technology (RT-qPCR) and the correlations analyzed between MIR-184 expression and the age, gender and clinical stage of RCC patients. RESULTS: The average expression of MIR-184 in RCC was -14.664 6 ± 5.362 4, while that in ADTs was -10.408 7 ± 3.482 7(P<0.01). Bounded with the MIR-184 expression in RCC, patients were divided into lower-expression group and higher-expression group. Meanwhile, the RCC patients were divided into three groups according to the age, gender and clinical stage of the patients. Chi-square statistical analysis showed that the expression level of MIR-184 was not significantly correlated with the patient's age, gender and clinical stage (respectively: P>0.03, P>0.99, P>0.03). CONCLUSION: MIR-184 in RCC was significantly lower than that in ADTs, which may have potential significance in the occurrence and development of RCC.

[The progress of TMPRSS2-ETS gene fusions and their mechanism in prostate cancer].

The gene fusions between transmembrane protease serine 2 (TMPRSS2) and E26 (ETS) transcription factors are present in over 50% of patients with prostate cancer. TMPRSS2-ERG is the most common gene fusion type. The ERG overexpression induced by TMPRSS2-ERG gene fusion contributes to the development of prostate cancer. Both androgen receptor binding and genotoxic stress induce chromosomal proximity and TMPRSS2-ETS gene fusions. TMPRSS2-ERG gene fusion functions as a biomarker for prostate cancer, which can be easily detected in urine. This review focuses on the characteristics, oncogenic and rearranged mechanism, and clinical application of TMPRSS2-ETS gene fusions.

[Advances in the researches of spermatogenic protein, Ropporin].

Ropporin has been identified as a spermatogenic cell-specific protein and may be involved in sperm maturation, motility, capacitation, hyperactivation and acrosome reaction. However, latest studies have shown that Ropporin is expressed weakly in normal non-testis tissues and highly in hematologic malignancies. Its highly conservative expression in mammalians demonstrates its importance to life. This paper updates the characterization, expression and its distribution, and biological function of Ropporin, and the advances in the clinical researches of the protein.

[Expression of amphiregulin in human endometrium during the menstrual cycle].

OBJECTIVE: To investigate the expression of amphiregulin in human endometrium during the menstrual cycle. METHODS: Endometrial tissues were collected from the patients undergoing hysterectomy or endometrial biopsy. Real-time RT-PCR, in situ hybridization and immunohistochemistry were used to detect the expression characteristics of amphiregulin in human endometrium in proliferative and secretory phases. RESULTS: Real-time RT-PCR showed the expression of amphiregulin mRNA in secretory phase was 32 times that in proliferative phase. The results from in situ hybridization and immunohistochemistry showed that amphiregulin was located in the cytoplasm and mainly expressed in the gland of endometrium. The expressions of amphiregulin mRNA in proliferative and secretory phases were 0.54+/-0.22 and 2.96+/-0.47 (P<0.01), and the expressions of amphiregulin protein in proliferative and secretory phases were 0.77+/-0.47 and 2.60+/-0.43 (P<0.01), respectively. The data demonstrated that the amphiregulin expression was significantly increased in secretory phase, which was consistent with the results from RT-PCR. CONCLUSION: The expression of amphiregulin was increased in the secretory phase of human endometrium, which suggests that amphiregulin may play an important role in human implantation.

[Identification of human testicular spermatogenic cells at different stages].

OBJECTIVE: To establish the method to identify human testicular spermatogenic cells. METHODS: Cells were dispersed by mechanic disintegration on testicular biopsy samples of obstructive azoospermic patients. Diff-Quik staining was applied to mixed cell smears. Live cells were observed under inverted microscope equipped with Hoffman modulation contrast optics, and classified according to their morphology. Chromogenic in situ hybridization (CISH) using chromosome 17 centromere probe and anti-c-kit immunocytochemistry staining were applied to classified cell smears. RESULTS: Sertoli cell, primary pachytene spermatocyte (PPS), spermatogonia, round spermatid were the main four round cell groups that can be classified under Hoffman optics. In CISH, Sertoli cell, PPS and spermatogonia displayed 2 centromere signals, while round spermatid and elongated spermatid/sperm displayed 1 centromere signal. In immunocytochemistry staining, PPS and spermatogonia displayed positive staining, while Sertoli cell, round spermatid and sperm displayed negative staining. CONCLUSION: Dispersed human testicular cells displayed different characteristics in live/staining morphology, ploidy analysis, cell surface membrane antigen expression. All of these methods can be chosen to identify human testicular spermatogenic cells at different stages, while cell morphology classifying under Hoffman optics is a simple and effective method for live cell identification.

Low expression of glycoprotein subunit 130 in ejaculated spermatozoa from asthenozoospermic men.

Previous studies showed that interleukin-6 (IL-6) was expressed in human Leydig and Sertoli cells and that it inhibited sperm motility. The aim of this study was to compare the expression of IL-6, IL-6R, and GP130 in ejaculated spermatozoa between normozoospermic and asthenozoospermic men. Human spermatozoa in the semen were purified by Percoll gradient technique to separate the seminal plasma and other round cells. RT-PCR, immunocytochemistry, and Western blot were used to detect the expression of IL-6, IL-6R, and GP130 in spermatozoa. With RT-PCR, only GP130 mRNA but not IL-6 and IL-6R mRNA was expressed in human ejaculated spermatozoa. The expression of GP130 mRNA was significantly lower in asthenozoospermic men than in normozoospermic men. The protein expression of GP130 was further confirmed by both immunocytochemistry and Western blot. Again, GP130 protein levels were significantly lower in asthenozoospermic men than in normozoospermic men. The results suggested that the decreased expression of GP130 in ejaculated spermatozoa could be associated with low sperm motility in asthenozoospermic men.

[Functional expression of adenylyl cyclase and phosphodiesterase in ejaculated human spermatozoa].

OBJECTIVE: To compare the differences of expressions of adenylyl cyclase (AC) and phosphodiesterase (PDE) in ejaculated spermatozoa between healthy volunteers and the patients with asthenospermia. METHODS: Ejaculated spermatozoa were collected from healthy volunteers and the patients with asthenospermia. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect mRNA expression of AC and PDE subtypes in human spermatozoa. The concentrations of cAMP and cGMP in the samples were detected by enzyme-linked immunosorbent assay (ELISA). RESULTS: Compared with healthy volunteers, expression of sAC mRNA and concentration of cAMP were significantly decreased in the patients with asthenospermia (P < 0.01) , while the expression of PDE4C mRNA was significantly increased at the same time (P <0.01). There were no marked differences in the expression of ACIII mRNA and concentration of cGMP between the two groups. CONCLUSION: The sAC down-regulation and PDE4C up-regulation are possible reasons for asthenospermia.

[Hormone regulation of the expression of vascular endothelial growth factor and its receptors in mouse uterus].

OBJECTIVE: To investigate the effects of estrogen and progesterone on the expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR) in mouse uterus. METHODS: 3-week-old immature female mice were randomly divided into 7 groups and treated with corn oil, estradiol (E2) of 1.5, 3.0, 10, 25 ng, progesterone (P) of 100 microg and (E2 10 ng + P 100 microg)/mouse, respectively. After the treatment for 48 h, mouse uterus was collected to isolate total RNA. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expression of mRNA isoforms of VEGF and its receptors in mouse uterus. RESULTS: Compared with control, both E2 and P significantly increased the expression of VEGF164 and VEGF120 mRNA in mouse uterus. The expression of VEGFR2 mRNA, not VEGF1 mRNA, was decreased by E2 treatment in a dose-independent manner. CONCLUSION: Both estradiol and progesterone up-regulated the expression of VEGF, but estradiol down-regulated the expression of VEGFR2 in mouse uterus.

A role for alphavbeta3 integrin during implantation in the rabbit model.

The study of implantation has been facilitated by the identification of specific biomarkers that are associated with uterine receptivity. The alpha(v)beta(3) integrin is a cell surface adhesion receptor, whose expression has been shown to be elevated in the endometrium at the time of implantation in both humans and other mammalian species; however, the distribution of alpha(v)beta(3) in the rabbit model is unknown. The rabbit has been shown to be an excellent model for the study of implantation. As an obligate ovulator, the timing of pregnancy can be precisely established, and embryonic attachment occurs through specialized trophoblast-endometrial structures known as trophoblastic knobs. In the present study, the expression of alpha(v)beta(3) integrin subunit in the rabbit uterus was examined by reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, and in situ hybridization. Expression of the alpha(v)beta(3) integrin was examined in Day 6.5 embryos, flushed from pregnant does. Immunofluorescence demonstrated strong immunostaining on the rabbit blastocyst (Day 6.5). RT-PCR analyses showed higher levels of mRNA for beta(3) subunit at the implantation site, with reduced expression in nonimplantation sites and in nonpregnant adult and immature endometrium. Immunohistochemistry demonstrated little, if any, beta(3) immunoreactivity on the endometrial epithelium. In contrast, in situ hybridization showed expression of the beta(3) integrin subunit mRNA in the uterine myometrium and on the trophoblast. To further determine the functional significance of alpha(v)beta(3) integrin expression during implantation, pregnant female rabbits that underwent ventral laparotomy on the morning of Day 6 received intrauterine injection of the following into the right uterine horn: 1) the monoclonal alpha(v)beta(3) neutralizing antibody (LM609), 2) arg-gly-asp (RGD) hexapeptides (GRGDSP), 3) non-RGD hexapeptides (GRGESP), and 4) IgG isotype matched control antibody. The left horn served as a control and received only saline injections. A significant reduction in the number of implantation sites was observed in the horns receiving anti-alpha(v)beta(3) antibody (P < 0.001) and the RGD peptides (P = 0.03). In the rabbit, the alpha(v)beta(3) integrin is present on the embryo and trophoblast and appears to be involved in early embryo-maternal interaction.