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

Activin E is a transforming growth factor β ligand that signals specifically through activin receptor-like kinase 7

Activins are one of the three distinct subclasses within the greater Transforming growth factor β (TGFβ) superfamily. First discovered for their critical roles in reproductive biology, activins have since been shown to alter cellular differentiation and proliferation. At present, members of the activin subclass include activin A (ActA), ActB, ActC, ActE, and the more distant members myostatin and GDF11. While the biological roles and signaling mechanisms of most activins class members have been well-studied, the signaling potential of ActE has remained largely unknown. Here, we characterized the signaling capacity of homodimeric ActE. Molecular modeling of the ligand:receptor complexes showed that ActC and ActE shared high similarity in both the type I and type II receptor binding epitopes. ActE signaled specifically through ALK7, utilized the canonical activin type II receptors, ActRIIA and ActRIIB, and was resistant to the extracellular antagonists follistatin and WFIKKN. In mature murine adipocytes, ActE invoked a SMAD2/3 response via ALK7, like ActC. Collectively, our results establish ActE as a specific signaling ligand which activates the type I receptor, ALK7.

Activin E is a TGFβ ligand that signals specifically through activin receptor-like kinase 7

Activins are one of the three distinct subclasses within the greater Transforming Growth Factor β (TGFβ) superfamily. First discovered for their critical roles in reproductive biology, activins have since been shown to alter cellular differentiation and proliferation. At present, members of the activin subclass include activin A (ActA), ActB, ActC, ActE, and the more distant members myostatin and GDF11. While the biological roles and signaling mechanisms of most activins class members have been well-studied, the signaling potential of ActE has remained largely unknown. Here, we characterized the signaling capacity of homodimeric ActE. Molecular modeling of the ligand:receptor complexes showed that ActC and ActE shared high similarity in both the type I and type II receptor binding epitopes. ActE signaled specifically through ALK7, utilized the canonical activin type II receptors, ActRIIA and ActRIIB, and was resistant to the extracellular antagonists follistatin and WFIKKN. In mature murine adipocytes, ActE invoked a SMAD2/3 response via ALK7, similar to ActC. Collectively, our results establish ActE as an ALK7 ligand, thereby providing a link between genetic and in vivo studies of ActE as a regulator of adipose tissue.

HPV16 E1 dysregulated cellular genes involved in cell proliferation and host DNA damage: A possible role in cervical carcinogenesis

HPV16 is the most prominent cause of cervical cancer. HPV16 E1, a helicase required for HPV replication exhibits increased expression in association with cervical cancer progression, suggesting that E1 has a similar effect on the host as the HPV16 E6 and E7 oncoproteins. This study aimed to determine whether expression of HPV16 E1 correlated with carcinogenesis by modulating cellular pathways involved in cervical cancer. HEK293T cells were transfected with pEGFP, pEGFPE1 or truncated forms of HPV16 E1. Cell proliferation, cell death, and the impact of HPV16 E1 on host gene expression was then evaluated. HPV16 E1 overexpression resulted in a significant reduction of cell viability and cellular proliferation (p-value<0.0001). Moreover, prolonged expression of HPV16 E1 significantly induced both apoptotic and necrotic cell death, which was partially inhibited by QVD-OPH, a broad-spectrum caspase inhibitor. Microarray, real time RT-PCR and kinetic host gene expression analyses revealed that HPV16 E1 overexpression resulted in the downregulation of genes involved in protein synthesis (RPL36A), metabolism (ALDOC), cellular proliferation (CREB5, HIF1A, JMJDIC, FOXO3, NFKB1, PIK3CA, TSC22D3), DNA damage (ATR, BRCA1 and CHEK1) and immune response (ISG20) pathways. How these genetic changes contribute to HPV16 E1-mediated cervical carcinogenesis warrants further studies.

The Significance of INHBE Expression in the Cancer Cells of Clear-Cell Renal Cell Carcinoma

BACKGROUND

Activins and inhibins are structurally related dimeric glycoprotein hormones belonging to the transforming growth factor-β superfamily but whether they are also involved in malignancy is far from clear. No study has reported the expression of INHBE in kidney cancer. The purpose of this study was to examine the expressions of INHBE in the tumor tissue of patients with clear-cell renal cell carcinoma (ccRCC) and to explore the pathologic significance.

METHODS

The INHBE mRNA expression in the tumor tissue of ccRCC patients was analyzed by using RNA sequencing data from the TCGA database. To examine the expression of inhibin βE protein, 241 ccRCC patients were recruited and immunohistochemistry was performed on the tumor tissue of these patients along with 39 normal renal samples. The association between the inhibin βE expression level and patient's clinicopathological indices was evaluated.

RESULTS

In the normal renal tissue, inhibin βE was found to be expressed mainly by renal tubular epithelial cells. In the tumor tissue, inhibin βE was expressed mainly in cancer cells. The expressions of INHBE mRNA and protein in the tumor tissue of ccRCC patients increased significantly compared with those in normal renal samples. There was a significant correlation between the level of inhibin βE in the tumor tissue and tumor grade. Patients with a lower inhibin βE expression in the tumor tissue were found to have a longer overall survival and disease-specific survival.

CONCLUSIONS

INHBE might be involved in the pathogenesis of ccRCC and function as a tumor promoter.

Insulin as a Potent Stimulator of Akt, ERK and Inhibin-βE Signaling in Osteoblast-Like UMR-106 Cells

Insulin is a peptide hormone of the endocrine pancreas and exerts a wide variety of physiological actions in insulin sensitive tissues, such as regulation of glucose homeostasis, cell growth, differentiation, learning and memory. However, the role of insulin in osteoblast cells remains to be fully characterized. In this study, we demonstrated that the insulin (100 nM) has the ability to stimulate the phosphorylation of protein kinase B (Akt/PKB) and extracellular signal-regulated kinase (ERK) and the levels of inhibin-βE in the osteoblast-like UMR-106 cells. This insulin-stimulated activities were abolished by the PI3K and MEK1 inhibitors LY294002 and PD98059, respectively. This is the first report proving that insulin is a potential candidate that enables the actions of inhibin-βE subunit of the TGF-β family. The current investigation provides a foundation for the realization of insulin as a potential stimulator in survival signaling pathways in osteoblast-like UMR-106 cells.

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.

RNA-sequencing analysis of 5' capped RNAs identifies many new differentially expressed genes in acute hepatitis C virus infection

We describe the first report of RNA sequencing of 5' capped (Pol II) RNAs isolated from acutely hepatitis C virus (HCV) infected Huh 7.5 cells that provides a general approach to identifying differentially expressed annotated and unannotated genes that participate in viral-host interactions. We identified 100, 684, and 1,844 significantly differentially expressed annotated genes in acutely infected proliferative Huh 7.5 cells at 6, 48, and 72 hours, respectively (fold change ≥ 1.5 and Bonferroni adjusted p-values < 0.05). Most of the differentially expressed genes (>80%) and biological pathways (such as adipocytokine, Notch, Hedgehog and NOD-like receptor signaling) were not identified by previous gene array studies. These genes are critical components of host immune, inflammatory and oncogenic pathways and provide new information regarding changes that may benefit the virus or mediate HCV induced pathology. RNAi knockdown studies of newly identified highly upregulated FUT1 and KLHDC7B genes provide evidence that their gene products regulate and facilitate HCV replication in hepatocytes. Our approach also identified novel Pol II unannotated transcripts that were upregulated. Results further identify new pathways that regulate HCV replication in hepatocytes and suggest that our approach will have general applications in studying viral-host interactions in model systems and clinical biospecimens.

Genome-wide screening of indicator genes for assessing the potential carcinogenic risk of Nanjing city drinking water

Effects of all pollutants existing in the Nanjing city drinking water (DWNC) on mouse gene transcription levels were measured to assess the DWNC carcinogenic risks and to identify candidate indicator genes for assessing and early warning the cancer risks. Transcriptional expression levels of 14,000 hepatic genes for the treatment group mice (Mus musculus, ICR) fed with DWNC for 90 days were detected using the GeneChip(®) Mouse Genome 430A 2.0 array. The analysis indicated that the transcriptional levels of 294 genes were up-regulated and 542 ones were down-regulated. Of these genes, 12 ones identified to be involved in at least five different types of cancers were further analyzed. An interrogation by Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that three (including ITGAV, CCND1 and SMAD2) of the 12 genes were mapped to pathway in cancer. Gene Ontology (GO) function annotation also showed that they were associated with the functional categories of cell cycle regulation, adhesion, apoptosis, signal transduction and so on which are closely implicated in tumorigenesis and progression. The correlations between the aberrant expressions of them and the genesis and progression of cancers have been further documented by a number of scientific researches. These results might demonstrate that the potential toxicity and carcinogenic risks were associated with DWNC. Moreover, ITGAV, CCND1 and SMAD2 were identified as the most likely candidate indicator genes for the assessment of the combined carcinogenic risk of all pollutants existing in DWNC.

Evaluation of two commercialised in situ hybridisation assays for detecting HPV-DNA in formalin-fixed, paraffin-embedded tissue

INTRODUCTION

The role of human papilloma virus (HPV) in the pathogenesis of anogenital dysplasia is now conclusive. However, HPV detection in formalin-fixed and paraffin-embedded tissues remains controversial. Therefore, the aim of this study was to evaluate morphological changes directly in tissue specimens using a HPV-DNA detection system involving HPV in situ hybridisation.

MATERIALS AND METHODS

Samples from patients with cervical carcinoma were analysed using the GenPoint HPV DNA Probe Cocktail (Dako, Glostrup, Denmark) and the ZytoFast HPV Screening CISH-Kit (Zytomed, Berlin, Germany). Three cervical carcinoma cell lines with a well-defined HPV copy number per cell (SiHa, HeLa, and CaSki) served as positive controls for sensitivity testing, while two HPV-negative cell lines (AC-1M32, MCF-7) and brain tissue samples served as negative controls. Moreover, to assess the validity of the in situ hybridisation, the expression of HPV-16 DNA in cell lines was demonstrated by HPV-16 E6-specific PCR.

RESULTS

Both HPV-screening assays revealed strong signals of episomal and integrated HPV-DNA at a HPV copy number of more than 50 copies/cell. All cervical carcinoma samples were positive in the Dako assay, which identifies 13 high-risk HPV genotypes, whereas HPV-DNA could be detected in 9/10 cervical carcinoma samples using the Zytofast assay, identifying HPV 16, 18, 31, 33, and 35.

CONCLUSION

HPV in situ hybridisation is a convenient and powerful tool for detecting HPV-DNA in formalin-fixed and paraffin-embedded tissue samples. Therefore, this technique is suitable for analysis of a potential HPV infection using archival pathological slides.

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.