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

Transforming growth factor-β (TGF-β) signaling pathway-related genes in predicting the prognosis of colon cancer and guiding immunotherapy

Background

Colon cancer is a malignant tumor with high malignancy and a low survival rate whose heterogeneity limits systemic immunotherapy. Transforming growth factor-β (TGF-β) signaling pathway-related genes are associated with multiple tumors, but their role in prognosis prediction and tumor microenvironment (TME) regulation in colon cancer is poorly understood. Using bioinformatics, this study aimed to construct a risk prediction signature for colon cancer, which may provide a means for developing new effective treatment strategies.

Methods

Using consensus clustering, patients in The Cancer Genome Atlas (TCGA) with colon adenocarcinoma were classified into several subtypes based on the expression of TGF-β signaling pathway-related genes, and differences in survival, molecular, and immunological TME characteristics and drug sensitivity were examined in each subtype. Ten genes that make up a TGF-β-related predictive signature were found by least absolute shrinkage and selector operation (LASSO) regression using colon cancer data from the TCGA database and confirmed using a Gene Expression Omnibus (GEO) dataset. A nomogram incorporating risk scores and clinicopathologic factors was developed to stratify the prognosis of patients with colon cancer for accurate clinical diagnosis and therapy.

Results

Two TGF-β subtypes were identified, with the TGF-β-high subtype being associated with a poorer prognosis and superior sensitivity to immunotherapy. Mutation analyses showed a high incidence of gene mutations in the TGF-β-high subtype. After completing signature construction, patients with colon cancer were categorized into high- and low-risk subgroups based on the median risk score of the TGF-β-related predictive signature. The risk score exhibited superior predictive performance relative to age, gender, and stage, as evidenced by its AUC of 0.686. Patients in the high-risk subgroup had higher levels of immunosuppressive cell infiltration and immune checkpoints in the TME, suggesting that these patients had better responses to immunotherapy.

Conclusions

Patients with colon cancer were divided into two subtypes with different survival and immune characteristics using consensus clustering analysis based on TGF-β signaling pathway-related genes. The constructed risk prediction signature may show promise as a biomarker for evaluating the prognosis of colon cancer, with potential utility for screening individuals for immunotherapy.

Inhibin subunit beta B (INHBB): an emerging role in tumor progression

The gene inhibin subunit beta B (INHBB) encodes the inhibin βB subunit, which is involved in forming protein members of the transforming growth factor-β (TGF-β) superfamily. The TGF-β superfamily is extensively involved in cell proliferation, differentiation, adhesion, movement, metabolism, communication, and death. Activins and inhibins, which belong to the TGF-β superfamily, were first discovered in ovarian follicular fluid. They were initially described as regulators of pituitary follicle-stimulating hormone (FSH) secretion both in vivo and in vitro. Later studies found that INHBB is expressed not only in reproductive organs such as the ovary, uterus, and testis but also in numerous other organs, including the brain, spinal cord, liver, kidneys, and adrenal glands. This wide distribution implies its involvement in the normal physiological functions of various organs; however, the mechanisms underlying these functions have not yet been fully elucidated. Recent studies suggest that INHBB plays a significant, yet complex role in tumorigenesis. It appears to have dual effects, promoting tumor progression in some contexts while inhibiting it in others, although these roles are not yet fully understood. In this paper, we review the different expression patterns, functions, and mechanisms of INHBB in normal and tumor tissues to illustrate the research prospects of INHBB in tumor progression.

Evolving roles of activins and inhibins in ovarian cancer pathophysiology

Activins and inhibins are unique members of the transforming growth factor-β (TGFβ) family of growth factors, with the ability to exert autocrine, endocrine, and paracrine effects in a wide range of complex physiologic and pathologic processes. Although first isolated within the pituitary, emerging evidence suggests broader influence beyond reproductive development and function. Known roles of activin and inhibin in angiogenesis and immunity along with correlations between gene expression and cancer prognosis suggest potential roles in tumorigenesis. Here, we present a review of the current understanding of the biological role of activins and inhibins as it relates to ovarian cancers, summarizing the underlying signaling mechanisms and physiologic influence, followed by detailing their roles in cancer progression, diagnosis, and treatment.

Ovarian sex cord-stromal tumors: an update on clinical features, molecular changes, and management

Sex cord stromal-tumors are rare tumors of the ovary that include numerous tumor subtypes of variable histological features and biological behavior. Surgery is the main therapeutic modality for the management of these tumors, while chemotherapy and hormonal therapy may be used in some patients with progressive and recurrent tumors. Several studies investigated molecular changes in the different tumor types. Understanding molecular changes underlying the development and progression of sex cord-stromal tumors provides valuable information for diagnostic and prognostic biomarkers and potential therapeutic targets for these tumors. In this review, we provide an update on the clinical presentation, molecular changes, and management of sex cord-stromal tumors.

Inhibin B suppresses anoikis resistance and migration through the transforming growth factor-β signaling pathway in nasopharyngeal carcinoma

Inhibin B (INHBB), a heterodimer of a common α‐subunit and a βB‐subunit, is a glycoprotein belonging to the transforming growth factor‐β (TGF‐β) family. In this study, we observed INHBB expression was reduced in nasopharyngeal carcinoma (NPC) tissues compared to non‐tumor nasopharyngeal epithelium tissues, and INHBB was associated with lymph node metastasis, stage of disease, and clinical progress. Positive expression of INHBB in NPC predicted a better prognosis (overall survival, P = 0.038). However, the molecular mechanisms of INHBB have not been addressed in NPC. We induced anoikis‐resistant cells in NPC cell lines under anchorage‐independent conditions, then found epithelial‐mesenchymal transition markers changed, cell apoptosis decreased, cell cycle was modified, and invasion strengthened in anoikis‐resistant NPC cells. These anoikis‐resistant NPC cells showed decreased expression of INHBB compared with adhesion cells. Furthermore, INHBB was found to influence the above‐mentioned changes. In the anoikis‐resistant NPC cells with INHBB overexpression, apoptotic cells increased, S phase cells weakened, vimentin, matrix metallopeptidase‐9, and vascular endothelial growth factor A expression were downregulated, and E‐cadherin expression was upregulated, and vice versa in knockdown of INHBB (INHBB shRNA) anoikis‐resistant NPC cells. Diminished INHBB expression could activate the TGF‐β pathway to phosphorylate Smad2/3 and form complexes in the nucleus, which resulted in the above changes. Thus, our results revealed for the first time that INHBB could suppress anoikis resistance and migration of NPC cells by the TGF‐β signaling pathway, decrease p53 overexpression, and could serve as a potential biomarker for NPC metastasis and prognosis as well as a therapeutic application.

Activin B promotes endometrial cancer cell migration by down-regulating E-cadherin via SMAD-independent MEK-ERK1/2-SNAIL signaling

High-risk type II endometrial cancers account for ~30% of cases but ~75% of deaths due, in part, to their tendency to metastasize. Histopathological studies of type II endometrial cancers (non-endometrioid, mostly serous) suggest overproduction of activin B and down-regulation of E-cadherin, both of which are associated with reduced survival. Our previous studies have shown that activin B increases the migration of type II endometrial cancer cell lines. However, little is known about the relationship between activin B signaling and E-cadherin in endometrial cancer. We now demonstrate that activin B treatment significantly decreases E-cadherin expression in both a time- and concentration-dependent manner in KLE and HEC-50 cell lines. Interestingly, these effects were not inhibited by knockdown of SMAD2, SMAD3 or SMAD4. Rather, the suppressive effects of activin B on E-cadherin were mediated by MEK-ERK1/2-induced production of the transcription factor SNAIL. Importantly, activin B-induced cell migration was inhibited by forced-expression of E-cadherin or pre-treatment with the activin/TGF-β type I receptor inhibitor SB431542 or the MEK inhibitor U0126. We have identified a novel SMAD-independent pathway linking enhanced activin B signaling to reduced E-cadherin expression and increased migration in type II endometrial cancer.

Activin B induces human endometrial cancer cell adhesion, migration and invasion by up-regulating integrin β3 via SMAD2/3 signaling

Endometrial cancer is the fourth most common female cancer and the most common gynecological malignancy. Although it comprises only ~10% of all endometrial cancers, the serous histological subtype accounts for ~40% of deaths due to its aggressive behavior and propensity to metastasize. Histopathological studies suggest that elevated expression of activin/inhibin βB subunit is associated with reduced survival in non-endometrioid endometrial cancers (type II, mostly serous). However, little is known about the specific roles and mechanisms of activin (βB dimer) in serous endometrial cancer growth and progression. In the present study, we examined the biological functions of activin B in type II endometrial cancer cell lines, HEC-1B and KLE. Our results demonstrate that treatment with activin B increases cell migration, invasion and adhesion to vitronectin, but does not affect cell viability. Moreover, we show that activin B treatment increases integrin β3 mRNA and protein levels via SMAD2/3-SMAD4 signaling. Importantly, siRNA knockdown studies revealed that integrin β3 is required for basal and activin B-induced cell migration, invasion and adhesion. Our results suggest that activin B-SMAD2/3-integrin β3 signaling could contribute to poor patient survival by promoting the invasion and/or metastasis of type II endometrial cancers.

Function and regulation of MTA1 and MTA3 in malignancies of the female reproductive system

The family of metastasis-associated (MTA) genes is a small group of transcriptional co-regulators which are involved in various physiological functions, ranging from lymphopoietic cell differentiation to the development and maintenance of epithelial cell adhesions. By recruiting histone-modifying enzymes to specific promoter sequences, MTA proteins can function both as transcriptional repressors and activators of a number of cancer-relevant proteins, including Snail, E-cadherin, signal transducer and activator of transcriptions (STATs), and the estrogen receptor. Their involvement in the epithelial-mesenchymal transition process and regulatory interactions with estrogen receptor activity has made MTA proteins highly interesting research candidates, especially in the field of hormone-sensitive breast cancer and malignancies of the female reproductive tract. This review focuses on the current knowledge about the function and regulation of MTA1 and MTA3 proteins in gynecological cancer, including ovarian, endometrial, and cervical tumors.

The inhibin-βC subunit is down-regulated, while inhibin-βE is up-regulated by interferon-β1a in Ishikawa carcinoma cell line

INTRODUCTION

Inhibins are important regulators of the female reproductive system. Recently, two new inhibin-subunits βC and βE have been described, although, their function is still quite unclear. Interestingly, there is an association between interferon and TGF-β expression. Therefore, the aim of this study was to determine expression changes of inhibin-βC and -βE subunits in endometrial Ishikawa carcinoma cell line after stimulation with interferon-β1a.

MATERIALS AND METHODS

The Ishikawa cell line was cultured until confluence was observed (after 2 days). After adding interferon-β1a (1,000 IE/ml), Ishikawa cells were analyzed for inhibin-βC and -βE subunits by RT-PCR. The fibroblast cell line BJ6 served as negative control. Experiments were performed in triplicates.

RESULTS

The endometrial adenocarcinoma cell line Ishikawa synthesized the inhibin- βC and -βE subunits. The fibroblast cells BJ6 did not demonstrate an inhibin -βC and -βE mRNA expression, while inhibin-βC subunit is down-regulated and inhibin-βE is up-regulated in Ishikawa carcinoma cell line after stimulation with interferon-β1a in Ishikawa.

DISCUSSION

We demonstrated for the first time a functional relationship between interferon and the novel inhibin-βC and -βE subunits. It might be possible that interferon exerts a possible apoptotic function through the βE-subunit, while, by down-regulating the βC isoform, cell proliferation is inhibited. However, the precise function of the novel βC- and βE-subunits are still not known in human endometrial tissue and a possible association with interferon is still unclear and warrants further research.

New targets for old hormones: inhibins clinical role revisited

Inhibins are gonadal peptide hormones belonging to the transforming growth factor-β (TGF-β) superfamily that regulate the pituitary follicle stimulating hormone (FSH) secretion by negative feedback mechanisms. It is evident that the understanding of inhibins function in the hypothalamic-pituitary-gonadal axis will provide insights into physiology and pathology of the gonadal function. In recent years, a great deal of attention has been focussed on clinical relevance of measuring circulating inhibins in normal and disease state. The past few years also have witnessed the emergence and discovery of extra pituitary action of inhibins that might provide further insights into the underlying diseases like cancer especially in the reproductive axis and various other new endocrine target organs. In this review after systematic analysis of literature, we discuss briefly the known and recent advances in function of these hormones highlighting also its structure, production and mechanisms of signal transduction. Also this review discusses about the physiological relevance of inhibin association in the normal function to the development of reproductive cancers. Finally, we describe evidence from various emerging studies that inhibins make an important contribution to other physiological functions apart from reproduction which reveals new endocrine target organs of inhibins. The emerging view is inhibin participates in multiple ways to regulate the function in different cell types and still complete repertoire of its actions is under investigation.

Evidence of inhibin/activin subunit betaC and betaE synthesis in normal human endometrial tissue

BACKGROUND

Inhibins are important regulators of the female reproductive system. Recently, two new inhibin subunits betaC and betaE have been described, although it is unclear if they are synthesized in normal human endometrium.

METHODS

Samples of human endometrium were obtained from 82 premenopausal, non-pregnant patients undergoing gynecological surgery for benign diseases. Endometrium samples were classified according to anamnestic and histological dating into proliferative (day 1-14, n = 46), early secretory (day 15-22, n = 18) and late secretory phase (day 23-28, n = 18). Immunohistochemical analyses were performed with specific antibodies against inhibin alpha (n = 81) as well as inhibin betaA (n = 82), betaB (n = 82), betaC (n = 74) and betaE (n = 76) subunits. RT-PCR was performed for all inhibin subunits. Correlation was assessed with the Spearman factor to assess the relationship of inhibin-subunits expression within the different endometrial samples.

RESULTS

The novel inhibin betaC and betaE subunits were found in normal human endometrium by immunohistochemical and molecular techniques. Inhibin alpha, betaA, betaB and betaE subunits showed a circadian expression pattern, being more abundant during the late secretory phase than during the proliferative phase. Additionally, a significant correlation between inhibin alpha and all inhibin beta subunits was observed.

CONCLUSIONS

The differential expression pattern of the betaC- and betaE-subunits in normal human endometrial tissue suggests that they function in endometrial maturation and blastocyst implantation. However, the precise role of these novel inhibin/activin subunits in human endometrium is unclear and warrants further investigation.

Inhibin-betaA and -betaB subunits in normal and malignant glandular epithelium of uterine cervix and HeLa cervical cancer cell line

INTRODUCTION

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 tumors. However, it is still unclear if normal and cancerous cervical glandular epithelial cells as well as cervical cancer cell lines of glandular origin express the inhibin-betaA and -betaB subunits.

MATERIALS AND METHODS

Normal cervical tissue samples and a total of 10 specimens of well-differentiated adenocarcinomas of the human cervix were analyzed for inhibin-betaA and -betaB subunit expression by immunohistochemical analysis. Additionally, the cervical carcinoma cell line HeLa was analyzed by immunofluorescence and RT-PCR analysis for the expression of inhibin subunits.

RESULTS

Immunolabeling of normal and malignant glandular epithelium of human cervical tissue revealed a positive staining reaction for the inhibin-betaA and -betaB subunits. Additionally, the cancer cell line HeLa synthesized both inhibin subunits. When compared to the normal cervical glandular epithelium, the expression of the inhibin beta subunits became significantly reduced in cervical adenocarcinoma tissues.

DISCUSSION

In conclusion, we demonstrated a strong, though differential expression pattern of inhibin-betaA and -betaB subunits in normal and malignant glandular epithelial cells of the human uterine cervix. Although the physiological role of inhibins is still quite unclear in cervical tissue, the expression of inhibin-beta-subunits might play an important role in cervical cancer carcinogenesis, since they are significantly down-regulated during pathogenesis in cervical adenocarcinomas.

E-cadherin as a prognostic marker in human serous carcinomas of the ovary: an immunohistochemical analysis

INTRODUCTION

Ovarian cancer is a gynecologic cancer with a high mortality rate, demonstrating the need for effective and reliable tumor markers during the staging and treatment processes.

METHODS

Expression of E-cadherin was immunohistochemically analyzed in 100 ovarian cancer tissue samples.

RESULTS

A significant association of E-cadherin expression with histological grading (p = 0.001) and surgical stage (p = 0.020) could be demonstrated. However, the staining intensity of E-cadherin was not significantly associated with progression-free, cause-specific survival or overall survival in serous ovarian carcinomas.

CONCLUSION

The E-cadherin expression was associated with FIGO surgical staging and histological differentiation in serious ovarian carcinomas, suggesting a substantial role in the carcinogenesis of serous ovarian carcinomas. However, although patients with a strong E-cadherin staining intensity had a better prognosis, no statistical significant differences could be observed. Therefore, E-cadherin might not be a useful prognostic tumor marker in serous ovarian carcinomas.

Inhibin-alpha, -betaA and -betaB subunits in uterine non-endometrioid carcinomas: prognostic significance and clinical implications

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-alpha, -betaA and -betaB subunits in uterine non-endometrioid cancers are still quite unclear. A series of 41 uterine non-endometrioid carcinomas were immunohistochemically analysed with monoclonal antibodies against inhibin-subunits. The staining reactions were correlated with several clinicopathological characteristics and clinical outcome. The inhibin-alpha subunit showed a significant association with age although the loss of this subunit did not affect the survival of patients with non-endometrioid carcinomas and did not constitute an independent prognostic parameter. The inhibin-betaA expression was not associated with any of the analysed clinicopathological parameters and did not affect patients' survival. In contrast, a low betaB-subunit demonstrated a significant better cause-specific survival. Moreover, inhibin-betaB did constitute an independent prognostic parameter in uterine non-endometrioid cancer patients. In contrast to inhibin-alpha and -betaA subunits, the inhibin-betaB subunit seems to have a substantial role in the carcinogenesis and pathology of uterine non-endometrioid carcinomas and might be used as a marker to identify high-risk patients and may aid in the selection of patients for a more aggressive adjuvant therapy.

Is lymphadenectomy a prognostic marker in endometrioid adenocarcinoma of the human endometrium?

Background

During surgery for endometrial cancer, a pelvic lymphadenectomy with or without para-aortic lymphadenectomy is performed at least in patients with risk factors (stage I, grading 2 and/or histological subtypes with higher risk of lymphatic spread), and is hence recommended by the International Federation of Obstetrics and Gynecology (FIGO). Although lymph node metastases are important prognostic parameters, it has been contentious whether a pelvic lymph node dissection itself has a prognostic impact in the treatment of endometrial cancer, especially in endometrioid adenocarcinoma. Therefore, this study evaluated whether lymphadenectomy has a prognostic impact in patients with endometrioid adenocarcinoma.

Methods

The benefits of lymphadenectomy were examined in 214 patients with a histological diagnosis of endometrial adenocarcinoma. Tumour characteristics were analysed with respect to the surgical and pathological stage.

Results

Of the 214 patients with endometrial adenocarcinoma, 171 (79.9%) were classified as FIGO stage I, 15 (7.0%) FIGO stage II, 21 (9.8%) FIGO stage III and 7 (3.3%) FIGO stage IV. One hundred and thirty four (62.6%) of the patients had a histological grade 1 tumour, while 56 (26.2%) and 24 (11.2%) had a histological grade 2 or grade 3 tumour, respectively. Lymphadenectomy was performed in 151 (70.6%) patients. Only 11 (5.1%) patients showed metastatic disease in the lymph nodes. The performance of a lymphadenectomy resulted in significantly increased cause-specific and overall survival, while progression-free survival was not affected by this operative procedure.

Conclusions

The performance of an operative lymphadenectomy resulted in better survival of patients with endometrioid adenocarcinoma. This increase was significant for cause-specific and overall survival, while there was a tendency only towards increased progression-free survival. Therefore, even in endometrioid adenocarcinoma, a pelvic and/or para-aortic lymphadenectomy should be performed.

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.

Inhibins: from reproductive hormones to tumor suppressors

Inhibins are peptide hormones shown originally to be produced by the gonads to regulate the secretion of follicle stimulating hormone by pituitary gonadotropes. Although gonadotropes have been regarded as the canonical inhibin target cells, in recent years extrapituitary actions of inhibins have come into the spotlight. In particular, disruptions to the local actions of inhibins in peripheral tissues might underlie certain diseases, especially cancers of the reproductive tract. This review focuses on recent advances in the inhibin field, with a particular emphasis on the determinants of inhibin availability, mechanisms of inhibin action, and the physiological relevancy of local inhibin actions in the development and progression of reproductive cancers.

Inhibin/activin-betaE subunit in normal and malignant human cervical tissue and cervical cancer cell lines

Inhibins are dimeric glycoproteins, composed of an alpha-subunit and one of two possible beta-subunits (betaA or betaB), with substantial roles in human reproduction and in endocrine-responsive tumours. Recently a novel beta subunit named betaE was described, although it is still unclear if normal or cancerous cervical epithelial cells as well as cervical cancer cell lines can synthesise the novel inhibin-betaE subunit. About 4 normal cervical tissue samples together with 10 specimens of well-differentiated squamous cervical cancer and adenocarcinoma of the cervix were immunohistochemical analyzed. Additionally, two cervical carcinoma cell lines (HeLa and CaSki) were analyzed by immunofluorescence and RT-PCR for the expression of this novel subunit. We demonstrated for the first time an immunolabelling of the inhibin-betaE subunit in normal and malignant cervical tissue, as well as cervical cancer cells. Although the physiological role is still quite unclear in cervical tissue, inhibin-betaE might play important roles in carcinogenesis. Moreover, the synthesis of this subunit in cervical carcinoma cell lines of squamous and glandular epithelial origins also allows the use of these cell lines in elucidating its functions in cervical cancer pathogenesis. However, since the expression of the inhibin-betaE is minimal in HeLa cells as assessed by immunofluorescence and RT-PCR, the CaSki cell line might be a better model for further functional experiments regarding cervical cancer pathogenesis.