Inhibin ßA is an independent prognostic factor that promotes invasion via Hippo signaling in non­small cell lung cancer.

Inhibin ßA (INHBA) serves a prognostic and tumor­promoting role in numerous types of cancer. The present study aimed to determine the clinical significance of INHBA in non­small cell lung cancer (NSCLC) and the mechanisms underlying its potential tumor­promoting effect. INHBA expression was detected in clinical NSCLC samples using immunohistochemistry. In vivo loss­ and gain­of­function studies were performed to determine the effects of INHBA on NSCLC invasion. In addition, protein and mRNA expression levels of INHBA, yes­associated protein (YAP), large tumor suppressor 1/2 kinase (LATS1/2), connective tissue growth factor, cysteine rich angiogenic inducer 61 and Merlin were assessed using western blotting and reverse transcription­quantitative PCR, respectively, to investigate the mechanism by which INHBA may affect the invasion of NSCLC. The present study revealed that INHBA was significantly upregulated in 238 clinical NSCLC samples compared with its expression levels in paired adjacent non­cancerous tissues, and in metastatic nodules compared with in primary tumors. Notably, high INHBA expression was statistically associated with clinicopathological features, including poor differentiation and advanced tumor stage. INHBA positivity was statistically related to decreased 5­year overall survival, for which INHBA was an independent prognostic factor. Furthermore, INHBA promoted NSCLC invasion in vitro. In NSCLC, INHBA expression was associated with the nuclear levels of YAP and INHBA overexpression enhanced the invasive abilities of NSCLC cells via inhibiting the Hippo pathway. Mechanistically, INHBA inhibited l LATS1/2 phosphorylation and induced YAP nuclear translocation by downregulating the protein expression levels of Merlin. In conclusion, INHBA may negatively regulate the Hippo pathway to act as a tumor promotor, and could represent a marker of prognosis in NSCLC.

Elevated expression of inhibin α gene in sterile allotriploid crucian carp.

Inhibin and Activin, belong to the transforming growth factor ß superfamily (TGF-ß), which associate with the regulation of the reproductive process by the modulation of the hypothalamic-pituitary-gonad (HPG) axis. In this study, we reported the molecular cloning and tissue expression of inhibin α in allotriploid crucian carp and its parent- diploid red crucian carp. The full-length cDNA of inhibin α were respectively 1632 bp and 1642 bp in allotriploids and diploids, which both consisted of a 1044 bp open reading frame (ORF) encoding 347 amino acids. Real-time quantitative PCR (RT-qPCR) showed that allotriploids and diploids had significant expression of inhibin α in testis and ovary, and the expression of inhibin α in the gonads of allotriploids was higher than that of diploids. The immunohistochemistry indicated that the ovarian development of allotriploids was abnormal, and the expression of Inhibin α in the ovary of allotriploids was higher than that of diploids. Results of co-immunoprecitation (co-IP) demonstrated that the Inhibin α and Activin ßA, Inhibin α and Activin ßB can form dimers. These findings suggested that the elevated expression of inhibin α and the competitive binding of Inhibin α subunit with Activin ß subunits in allotriploids may be releted to the sterility of allotriploids. Furthermore, these results will facilitate the investigation of reproduction characteristics in allotriploids and provide theoretical basis for the study of polyploid breeding in the future.

Testicular immune cell populations and macrophage polarisation in adult male mice and the influence of altered activin A levels.

Detailed morphological characterization of testicular leukocytes in the adult CX3CR1 gfp/+ transgenic mouse identified two distinct CX3CR1 + mononuclear phagocyte (macrophage and dendritic cell) populations: stellate/dendriform cells opposed to the seminiferous tubules (peritubular), and polygonal cells associated with Leydig cells (interstitial). Using confocal microscopy combined with stereological enumeration of CX3CR1gfp/+ cells established that there were twice as many interstitial cells (68%) as peritubular cells (32%). Flow cytometric analyses of interstitial cells from mechanically-dissociated testes identified multiple mononuclear phagocyte subsets based on surface marker expression (CX3CR1, F4/80, CD11c). These cells comprised 80% of total intratesticular leukocytes, as identified by CD45 expression. The remaining leukocytes were CD3+ (T lymphocytes) and NK1.1+ (natural killer cells). Functional phenotype assessment using CD206 (an anti-inflammatory/M2 marker) and MHC class II (an activation marker) identified a potentially tolerogenic CD206+MHCII+ sub-population (12% of total CD45+ cells). Rare testicular subsets of CX3CR1 +CD11c+F4/80+ (4.3%) mononuclear phagocytes and CD3+NK1.1+ (3.1%) lymphocytes were also identified for the first time. In order to examine the potential for the immunoregulatory cytokine, activin A to modulate testicular immune cell populations, testes from adult mice with reduced activin A (Inhba+/-) or elevated activin A (Inha+/-) were assessed using flow cytometry. Although the proportion of F4/80+CD11b+ leukocytes (macrophages) was not affected, the frequency of CD206+MHCII+cells was significantly lower and CD206+MHCII- correspondingly higher in Inha+/- testes. This shift in expression of MHCII in CD206+ macrophages indicates that changes in circulating and/or local activin A influence resident macrophage activation and phenotype and, therefore, the immunological environment of the testis.

Immunohistochemical localization of inhibin/activin subunits in adult Asian elephant (Elephas maximus) testes.

Immunolocalization of inhibin-α and inhibin/activin ßA and ßB subunits in the testes of Asian elephant was determined. Testicular sections were immunostained with polyclonal antisera against inhibin subunit-α and inhibin/activin ßA and ßB using the avidin-biotin-peroxidase complex method. Positive immunostaining against inhibin-α subunit was strongly present in Sertoli cells, and positive immunostaining for the inhibin/activin ßA and ßB subunits was observed in both Sertoli and Leydig cells. These results indicated that while Sertoli cells are the predominant source of inhibin and activin secretions in the testes of adult male Asian elephant, Leydig cells are a source of activin but not inhibin.

Regional localization of activin-ßA, activin-ßC, follistatin, proliferation, and apoptosis in adult and developing mouse prostate ducts.

Activins and inhibins, members of the TGF-ß superfamily, are growth and differentiation factors involved in the regulation of several biological processes, including reproduction, development, and fertility. Previous studies have shown that the activin-ßA subunit plays a pivotal role in prostate development. Activin-A inhibits branching morphogenesis in the developing prostate, and its expression is associated with increased apoptosis in the adult prostate. Follistatin, a structurally unrelated protein to activins, is an antagonist of activin-A. A balance between endogenous activin-A and follistatin is required to maintain prostatic branching morphogenesis. Deregulation of this balance leads to branching inhibition or excessive branching and increased maturation of the stroma surrounding the differentiating epithelial ducts. Recent work identified another member of the TGF-ß superfamily, the activin-ßC subunit, as a novel antagonist of activin-A. Over-expression of activin-C (ßC-ßC) alters prostate homeostasis, by interfering with the activin-A signaling. The current study characterized the spatiotemporal localization of activin-A, activin-C and follistatin in the adult and developing mouse prostate using immunohistochemical analysis. Results showed activin-C and follistatin are differentially expressed during prostate development and suggested that the antagonistic property of follistatin is secondary to the action of activin-C. In conclusion, the present study provides evidence to support a role of activin-C in prostate development and provides new insights in the spatiotemporal localization of activins and their antagonists during mouse prostate development.

Expression of Cripto-1 gene protein and Activin-A in human lung adenocarcinoma tissue.

To research the expression in human lung adenocarcinoma tissue of Cripto-1 (teratocarcinoma derived growth factor-1) gene protein and Activin-A gene protein, and explore the relationship and clinical significance between the two gene protein and clinical pathological characteristic of lung adenocarcinoma. This study had applied the immunohistochemical method to detect the 188 cases of lung adenocarcinoma and expression of Cripto-1 protein and Activin-A protein in 100 cases of normal lung tissue. Then, analysis the relationship between these two-gene protein and clinical lung adenocarcinoma histopathological features, and inherent correlation between these two genes. The positive expression rate of Cripto-1 protein in lung adenocarcinoma tissue was significantly higher in normal lung tissue, while, the positive expression rate of Activin-A protein in lung adenocarcinoma tissue was significantly lower than in normal lung tissue. The high expression of Cripto-1 and low expression of Activin-A was closely related (each P<0.05) to the TNM staging of lung adenocarcinoma, lymph node metastasis and the main pathological tissue staging of lung adenocarcinoma. And the correlation analysis showed that it was negative correlation for the expression of Activin-A protein and Cripto-1 protein in lung adenocarcinoma. The over expression of Cripto-1 and the expression lack of Activin-A were correlated with the occurrence, development, metastasis and malignant degree of lung adenocarcinoma.

Why does the fallopian tube fail in ectopic pregnancy? The role of activins, inducible nitric oxide synthase, and MUC1 in ectopic implantation.

OBJECTIVE: To investigate the role of activin-ßA subunit, activin type II receptors, inducible nitric oxide synthase (iNOS), and MUC1 in the pathogenesis of ectopic pregnancy (EP) and their involvement in the determination of the implantation site. DESIGN: Observational study. SETTING: Academic unit of reproductive and developmental medicine. PATIENT(S): Four women at the luteal phase, three pseudopregnant women at the time of hysterectomy for benign disease, and 10 archived cases of EP. We collected 14 Fallopian tubes were collected from four women at the luteal phase and three pseudopregnant women at the time of hysterectomy for benign disease; specimens from implantation site, trophoblast and remote sites from the implantation site were collected from 10 archived cases of EP. INTERVENTION(S): Immunohistochemistry and quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). MAIN OUTCOME MEASURE(S): Comparison of the expression of candidate molecules between the different groups. RESULT(S): The expression of activin-ßA subunit, activin type II receptors, and iNOS was statistically significantly increased and expression of MUC1 statistically significantly decreased in tubes bearing an EP. There was no statistically significant difference in the expression of the candidate molecules between the implantation and remote sites. Candidate molecules were also expressed in the trophoblast. CONCLUSION(S): The pathological expression of candidate molecules by tubes bearing an EP is not involved in the determination of implantation site. Additionally, candidate molecules may play a role in the regulation of trophoblast cells in vivo during early pregnancy.

Evaluation of protein expression pattern of stanniocalcin 2, insulin-like growth factor-binding protein 7, inhibin beta A and four and a half LIM domains 1 in esophageal squamous cell carcinoma.

The pathogenesis of esophageal squamous cell carcinoma (ESCC) involves both genetic and environmental factors. Previously, we have carried out gene and protein expression profiling of ESCC using DNA microarrays and mass spectrometry-based quantitative proteomics, respectively. These studies resulted in identification of several potential biomarkers of ESCC, some with known reports of differential expression in the scientific literature and others that were novel observations from our studies. We report systematic validation of selected markers from our studies on a larger cohort of cancer tissue sections by immunohistochemical labeling of tissue microarrays. We have validated expression of insulin-like growth factor-binding protein 7 (IGFBP7), stanniocalcin 2 (STC2), inhibin beta A (INHBA) and four and a half LIM domains 1 (FHL1). Immunohistochemical labeling with anti-stanniocalcin 2 antibody demonstrated its overexpression in 132/140 (94%) cases, IGFBP7 showed overexpression in 127/140 (91%) cases and overexpression of INHBA was observed in 62/105 (59%) of ESCC cases. In contrast, FHL1 expression was observed only in 12/143 (8%) of ESCC cases suggesting its possible involvement in tumor suppression. These data suggest that IGFBP7, INHBA, STC2 and FHL1 might play an important role in ESCC tumorigenesis, which can be explored in future studies. Overall, our findings open up new avenues for development of novel therapeutics and/or diagnostic approaches in ESCC.

Inhibin beta B: a useful tumor marker in uterine endometrioid adenocarcinomas?

Inhibins, dimeric peptide hormones composed of an alpha-subunit and one of two possible beta-subunits (betaA or betaB), exhibit substantial roles in human reproduction and in endocrine-responsive tumours. However, the prognostic significance and clinical implications of the inhibin-betaB subunit in uterine endometrioid adenocarcinomas is still not defined yet. A series of 227 uterine endometrioid adenocarcinomas of a previous well-characterized cohort were re-evaluated for the expression of the inhibin-betaB subunit and correlated with several clinicopathological characteristics and the clinical outcome. In this re-analysis, the betaB-subunit expression demonstrated a significant association with the patients' age and cervical involvement. However, inhibin-betaB did not significantly affect the patients survival in this large cohort group. However, patients with a higher intensity of betaB-subunit immunolabelling had a slightly worse survival expectation, although without any significant association, suggesting that this subunit might have a substantial role in the carcinogenesis and pathology of endometrioid adenocarcinomas. Thus, the inhibin-betaB subunit appears not to be a useful prognostic marker regarding endometrioid adenocarcinomas. However, further research is warranted in elucidating the possible implications of inhibin-ßB and endometrial carcinogenesis.

Immunohistochemical labeling of the inhibin/activin betaC subunit in normal human placental tissue and chorionic carcinoma cell lines.

Inhibins and activins are important regulators of the female reproductive system. A novel inhibin subunit, named betaC, has been identified and demonstrated to be expressed in several human tissues. We demonstrate here that inhibin betaC is expressed in human placenta. Expression of the inhibin betaC subunit was demonstrated at the protein level by means of immunohistochemical evaluation and at the transcriptional level by an inhibin betaC-specific RT-PCR analysis. Expression of inhibin betaC was detected in the human chorionic carcinoma cell lines JEG and BeWo. Although the precise role of this novel inhibin subunit in human placenta development and homeostasis is unclear, analogies with other inhibin subunits and the strong expression of betaC in normal human trophoblast cells and chorionic carcinoma cells suggest that betaC may be involved in autocrine/paracrine signaling pathways, angiogenesis, decidualization, and tissue remodeling under normal and malignant conditions. Additionally, JEG and BeWo express betaC and, therefore, can be used as a cell culture model for further functional analysis of this subunit in the human placenta.

Inhibin/activin-betaC and -betaE subunits in the Ishikawa human endometrial adenocarcinoma cell line.

BACKGROUND: Inhibins and activins are important regulators of the female reproductive system. Recently, two novel inhibin subunits, named betaC and betaE, have been identified and shown to be expressed in several human tissues. However, only limited data on the expression of these novel inhibin subunits in normal human endometrial tissue and endometrial adenocarcinoma cell lines exist. MATERIALS AND METHODS: Samples of proliferative and secretory human endometrium were obtained from five premenopausal, non-pregnant patients undergoing gynecological surgery for benign diseases. Normal endometrial tissue and Ishikawa endometrial adenocarcinoma cell lines were analyzed by immunohistochemistry, immunofluorescence and RT-PCR. RESULTS: Expression of the inhibin betaC and betaE subunits could be demonstrated at the protein level by means of immunohistochemical evaluation and at the transcriptional level by establishing a betaC- and betaE-specific RT-PCR analysis in normal human endometrial tissue and the parental Ishikawa cell line. Interestingly, in a highly de-differentiated subclone of the Ishikawa cell line lacking estrogen receptor expression, the expression of the inhibin-betaC subunit appeared strongly reduced. DISCUSSION: Here, we show for the first time that the novel inhibin/activin-betaC and -betaE subunits are expressed in normal human endometrium and the estrogen receptor positive human endometrial carcinoma cell line Ishikawa using RT-PCR and immunohistochemical detection methods. Interestingly, the Ishikawa minus cell line (lacking estrogen receptor expression) demonstrated no to minimal expression of the betaC subunit as observed with immunofluorescence and RT-PCR, suggesting a possible hormone- dependency of this subunit in human endometrial cancer cells. Moreover, because the Ishikawa cell line minus is thought to be a more malignant endometrial cell line than its estrogen receptor positive counterpart, inhibin-betaC subunit might be substantially involved in the pathogenesis and malignant transformation in human endometrium.

Development and characterisation of an antibody for the immunohistochemical detection of inhibin/activin betaE (betaE) in normal human ovarian and placental tissue.

Inhibin/activin subunits are homologues to each other and belong to the transforming growth factor-beta (TGF-beta) family of proteins. These proteins have been demonstrated to be disulphide-linked dimers, which have a common alpha-subunit but just one of two beta-subunits, differentiated in inhibin A (alpha-betaA) and in inhibin B (alpha-betaB). Recently, an additional beta-subunit has been identified, determined as betaE and being primarily synthesized in liver tissue. However, since no antibody against the betaE subunit is commercially available, limited data on histological immunodistribution of this inhibin subunit in gynaecological organs exist. Therefore, the aims of the present study were the synthesis and evaluation of a specific antibody against the inhibin-betaE subunit. In this study, we describe the characterisation of a polyclonal antibody against the inhibin-betaE subunit. This antibody demonstrated a specific reaction in both western blot analysis and immunohistochemistry. Moreover, we demonstrated positive immunolabelling in normal human ovary and placenta. The role of this novel subunit is intriguing, especially within the view that the other inhibin/activin subunits might have substantial functions in human reproduction and carcinogenesis. However, the function of this subunit in humans remains still unclear and warrants further research.

Inhibin-alpha subunit is an independent prognostic parameter in human endometrial carcinomas: analysis of inhibin/activin-alpha, -betaA and -betaB subunits in 302 cases.

Inhibins are dimeric glycoproteins, composed of an alpha-subunit (inhibin-alpha) and one of two possible beta-subunits (betaA or betaB), with substantial roles in human reproduction and in endocrine-responsive tumours. The aims of this study were to determine the distribution of inhibin-alpha, -betaA and -betaB subunits in malignant human endometrial tissue and the assessment of an association with specific clinicopathologic tumour features and clinical outcome. A series of 302 endometrial cancer tissue samples were immunohistochemically analysed with monoclonal antibodies against inhibin subunits. The inhibin-alpha subunit showed a significant association with histological grading, surgical staging, lymph node status and diabetes in patients with endometrial cancer. Interestingly, loss of inhibin-alpha expression resulted in a poorer survival of endometrial cancer patients. Additionally, survival analysis demonstrated that inhibin-alpha immunoreactivity was an independent prognostic factor for progression-free survival, cause-specific survival as well as for overall survival. In contrast, although inhibin-betaA- and -betaB subunits showed a significant association between endometrial histological subtypes and histological grading, both subunits were not found to be associated with survival in endometrial cancer patients. Therefore, inhibin-alpha immunostaining might be used as a simple and efficient marker to identify high-risk patients leading to the selection of patients for an aggressive adjuvant therapy.

INHBA overexpression promotes cell proliferation and may be epigenetically regulated in esophageal adenocarcinoma.

INTRODUCTION: The expression, mechanisms of regulation, and functional impact of activin (INHBA) in esophageal adenocarcinoma (EAC) have not been fully defined. METHODS: INHBA expression was examined in 46 esophageal samples (nine Barrett's metaplasia (BM); seven BM/low-grade dysplasia; eight low-grade dysplasia; seven high-grade dysplasia; 15 EAC) using oligonucleotide microarrays and real-time reverse transcription-polymerase chain reaction (RT-PCR) and in 90 tissue samples (79 EAC; 8 dysplastic; 3 BM) using immunohistochemistry (IHC). The proliferation of EAC cell lines FLO and OE-33 was examined after treatment with exogenous activin. The proliferation of OE-33 was also examined after treatment with the activin inhibitor follistatin and INHBA-targeting siRNA. OE-33 and FLO cells were treated with 5-aza-2'deoxycytidine (5-AZA) and trichostatin A to investigate the role of epigenetic regulation in INHBA expression. RESULTS: Primary EACs expressed 5.7-times more INHBA mRNA than BM samples on oligonucleotide microarray. Transcript overexpression in EAC relative to BM was confirmed on real-time RT-PCR. IHC suggested higher INHBA protein expression in EAC (69.6%) than in the dysplastic (37.5%) and BM samples (33.3%). FLO and OE-33 treated with activin demonstrated increased proliferation, and OE-33 cells treated with follistatin and INHBA-targeting siRNA demonstrated reduced proliferation, relative to untreated controls. Treatment of FLO cells with trichostatin A and 5-AZA up-regulated INHBA mRNA and protein production by real time RT-PCR and IHC. CONCLUSIONS: INHBA is overexpressed in EAC relative to dysplastic and BM tissue. INHBA overexpression may promote cell proliferation and may be affected by promoter demethylation and histone acetylation in EAC cell lines.

Seasonal changes in spermatogenesis and immunolocalization of inhibin/activin subunits in the wild male ground squirrel (Citellus dauricus Brandt).

The objective of this study was to investigate the seasonal changes in spermatogenesis and the immunolocalization of the inhibin alpha and inhibin/activin (betaA and betaB) subunits during the breeding and non-breeding seasons in the wild male ground squirrel. The testicular weight and size and seminiferous tubule diameter were measured, and histological observations of testes were performed. The sections of the testes were immunostained by the avidin-biotin-peroxidase complex method (ABC) using polyclonal antisera raised against porcine inhibin alpha, inhibin/activin betaA and inhibin/activin betaB during the breeding and non-breeding seasons. There were marked variations in testicular weight and size and seminiferous tubule diameter between the breeding and non-breeding seasons, and all types of spermatogenic cells, including spermatozoa, were found in the breeding season. In addition, immunoreactivity was also detected for the inhibin alpha, betaA and betaB subunits in Sertoli and Leydig cells during the breeding season, but immunostaining was only present for the inhibin alpha and inhibin/activin betaB subunits in Sertoli cells during the non-breeding season. These results suggest that seasonal changes in testicular weight and size and seminiferous tubule diameter of wild ground squirrels are correlated with changes in spermatogenesis, and the cellular localization of the inhibin/activin subunits showed season related changes in the breeding and non-breeding seasons.

Activin betaA in term placenta and its correlation with placental inflammation in parturients having epidural or systemic meperidine analgesia: a randomized study.

STUDY OBJECTIVE: To investigate the immunohistochemical localization of betaA subunit of activin A in human term placenta, as a marker for placental infection/inflammation and elevated temperature, in parturients laboring during two analgesic regimens. DESIGN: Prospective, randomized controlled study. SETTING: Delivery room. PATIENTS: 56 healthy, ASA physical status I and II primiparous women in labor. INTERVENTIONS: Parturients were assigned to receive patient-controlled epidural analgesia (PCEA) with 0.2% ropivacaine or patient-controlled intravenous analgesia PCA with meperidine. MEASUREMENTS: Histologic and immunohistochemical placental evaluation for white blood cell infiltration and activin betaA staining were made. Maternal temperature elevation above 37.6 degrees C and leukocytosis above 15,000/microL were recorded. MAIN RESULTS: Temperature was not significantly increased in parturients receiving PCEA over those who received (PCA) with meperidine (31% vs 11%, respectively; P = 0.1). There was also no association between temperature elevation during epidural analgesia and increased white blood cell count (>15,000/microL) or presence of polymorphonuclear and/or lymphocyte aggregation in the placenta. Immunohistochemical staining with antisera against the betaA subunit of activin was present mainly in the placental cytotrophoblast, syncytiotrophoblast, and vascular endothelium, and was not associated with an increase in maternal temperature. No significant difference was noted between the two analgesic techniques with regard to maternal temperature elevation. Intrapartum temperature elevation was not associated with histologic signs of placental inflammation or with expression of activin betaA in the placenta. CONCLUSION: Other mechanisms may be involved in the etiology of temperature elevation during labor.

Expression of activin and inhibin subunits, receptors and binding proteins in human pheochromocytomas: a study based on mRNA analysis and immunohistochemistry.

OBJECTIVE: Pheochromocytomas are uncommon tumours arising from chromaffin cells of the adrenal medulla and related paraganglia. So far, one of the few reported markers to discriminate malignant from benign tumours is the betaB-subunit of inhibin and activin, members of the transforming growth factor (TGF)-beta superfamily of growth and differentiation factors. DESIGN: We investigated the expression of the mRNAs coding for activin and inhibin subunits, their receptors and binding proteins by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and studied the presence of the inhibin betaB-subunit in human pheochromocytomas by immunohistochemistry. PATIENTS: Samples from resected pheochromocytomas of patients operated between 1973 and 2003 were used for experiments. RESULTS: The immunohistochemical investigations revealed that staining of the inhibin betaB-subunit was positive in 12 of 36 (33%) benign and 5 of 34 (15%) malignant pheochromocytomas (P > 0.05). Therefore, it was not possible to discriminate between benign and malignant tumours solely on the basis of inhibin betaB-subunit immunohistochemistry. Quantitative real-time RT-PCR in nine benign and four malignant tumours showed expression of inhibin alpha-, betaA- and betaB-subunits, the activin receptors Alk-4, ActRIIA, and ActRIIB, and the inhibin- and activin-binding proteins betaglycan and follistatin in all samples. No correlations were detected between individually coupled expression of mRNAs of these activin- and inhibin-related genes in the 13 pheochromocytomas. Only inhibin betaA-subunit expression was different in malignant compared to benign pheochromocytomas (P = 0.020). CONCLUSIONS: No clear role for activin and inhibin was found in discriminating between benign and malignant pheochromocytomas.

The autocrine effect of activin A on human ovarian clear cell adenocarcinoma cells.

The functions of activin, a member of TGF-beta superfamily, in ovarian clear cell adenocarcinoma remain unsolved, although we recently found that inhibin betaA-subunit, activin A, activin receptor type IA, type IB, type IIA, type IIB, Smad2, Smad3 and Smad4 were localized in tumor cells of the ovarian clear cell adenocarcinoma tissue by immunohistochemistry. In the present study, in order to investigate the role of activin concerning cell growth in ovarian clear cell adenocarcinoma cells, we determined the production of activin A and inhibin A, and the expression of activin receptors and Smads using the human ovarian clear cell adenocarcinoma cell line JHOC-5. Moreover, we examined the effects of activin A on the activation of activin signaling pathway and on the proliferation in JHOC-5 cells. We detected a measurable amount of activin A in the culture medium of JHOC-5 cells, although inhibin A was not detected. The expression of activin receptor type IA, IB, IIA, IIB, Smad2, Smad3 and Smad4 was observed in JHOC-5 cells. Activin A induced a significant increase in proliferation of JHOC-5 cells compared with the untreated control. On the other hand, activin A did not affect the growth of JHOC-5 cells and no statistically significant difference was observed in the presence of follistatin which is a specific binding protein of activin. Phosphorylated Smad2, an activated form of Smad2, was detected both in treated JHOC-5 cells and in untreated cells by activin A. Activin A significantly increased the expression of phosphorylated Smad2 in JHOC-5 cells. Therefore, it is possible that activin has autocrine roles in tumor growth of ovarian clear cell adenocarcinoma cells.

Changes in serum inhibin levels and immunolocalization of inhibin/activin subunits during the breeding season in the wild male Japanese black bear (Ursus thibetanus japonicus).

The objective of this study was to investigate the changes in secretion of inhibin and cellular localization of inhibin alpha and inhibin/activin (beta(A) and beta(B)) subunits during the breeding season in the wild male Japanese black bear. Histological observations of testes were performed and seminiferous tubule diameters were measured. The sections of the testes were immunostained by the avidin- biotin-peroxidase complex method (ABC) using polyclonal antisera raised against porcine inhibin alpha, inhibin/ activin beta(A), and inhibin/activin beta(B) during the breeding season. Serum concentrations of immunoreactive (ir-)inhibin, testosterone, and luteinizing hormone (LH) were measured by radioimmunoassay. Higher values of seminiferous tubule diameters and all types of spermatogenic cells including mature-phase spermatozoa were found during the breeding season. There were seasonal changes in serum concentrations of ir-inhibin, testosterone, and LH. Ir-inhibin was positively correlated with testosterone, and LH. In addition, immunoreactivity of inhibin alpha, beta(A), and beta(B) subunits were also detected in Sertoli and Leydig cells during the breeding season. These results suggest that Japanese black bear testes may secrete bioactive inhibins during the breeding season and that the circulating inhibin may be a useful indicator of the testicular function in wild male Japanese black bears.