Oct-1 induces pituitary tumor transforming gene expression in endocrine tumors

Diagnostic and Prognostic Value of Long Noncoding RNAs as Potential Novel Biomarkers in Intrahepatic Cholestasis of Pregnancy

Long noncoding RNAs (lncRNAs) are a class of important regulators participating in various pathological processes. Until now, the role of lncRNAs in the occurrence and development of intrahepatic cholestasis of pregnancy (ICP) has rarely been investigated. The data from microarray screening revealed 58 upregulated and 85 downregulated lncRNAs and 47 upregulated and 71 downregulated mRNAs in ICP patients compared to healthy controls. Bioinformatics analysis revealed biological processes focused on lipid metabolism, apoptosis, cell cycle, cell differentiation, and oxidative stress. Furthermore, the expressions of three lncRNAs (ENST00000505175.1, ASO3480, and ENST00000449605.1) chosen for verification were significantly decreased and showed the diagnostic and prognostic value for ICP based on ROC analysis. This is the first study to report the specific role of lncRNAs in ICP, which may be helpful for the diagnosis and prognosis of ICP clinically.

PTTG1 is involved in TNF-α-related hepatocellular carcinoma via the induction of c-myc

Hepatocellular carcinoma (HCC) is a malignant disease caused by a variety of factors. However, the genomic and molecular aberrations in HCC are largely unknown. Herein, pituitary tumor transforming gene 1 (PTTG1) was discovered as a potential inflammation‐related oncogene in HCC, and its functions and molecular mechanisms were investigated. mRNA expression microarray, real‐time polymerase chain reaction (PCR), immunohistochemistry, and western blotting analyses revealed that PTTG1 is upregulated in HCC. Further in vitro and in vivo studies indicated that the proinflammatory cytokine tumor necrosis factor‐α (TNF‐α) induces PTTG1 expression, and PTTG1 was found to upregulate c‐myc, a well‐known oncogene. Downregulation of PTTG1 reduced c‐myc and proliferating cell nuclear antigen (PCNA) expression and inhibited cell proliferation. Interestingly, inhibition of c‐myc by 10058‐F4 did not affect PTTG1, which suggests that PTTG1 regulates c‐myc expression. Furthermore, PTTG1 expression levels are inversely correlated with HCC patient survival, indicating an independent prognostic biomarker for patients with HCC. Our data demonstrate that PTTG1 is involved in TNF‐α‐related HCC via c‐myc induction and that PTTG1 may be a potential therapeutic target for HCC.

Expression profile and promoter analysis of HEPIS

Human embryo lung cellular protein interacting with severe acute respiratory syndrome-coronavirus nonstructural protein-10 (HEPIS) is a novel transcriptional repressor, the expression profile and promoter activity of which have not been well studied. In the present study, in situ hybridization of RNA was used to study differential HEPIS expression levels in different types of cancer and normal tissues. A total of six truncated lengths of the HEPIS promoter regulatory sequences were cloned into the pGL3-basic vector, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and dual luciferase reporter assays were performed. The results of RT-qPCR demonstrated that HEPIS expression levels differed across four breast cancer cell lines. The results of the dual luciferase reporter assays revealed that the activities of the reporter gene fragments spanning -1334/+373, -1203/+373, -1060/+373 and -899/+373 bp were higher compared with the reporter gene fragments spanning -759/+373 and -279/+373 bp. A search of the transcription factor database TRANSFAC identified numerous octamer transcription factor-1 (OCT-1), nuclear factor (NF)-κB and C-JUN transcription factor binding sites located on the HEPIS promoter (pHEPIS). Furthermore, the results revealed that mutations of the OCT-1 (-1236/-1223 bp), NF-κB (-1186/-1176 bp) and C-JUN (-856/-846 bp) sites on the human pHEPIS resulted in a decrease in luciferase activity. A chromatin immunoprecipitation assay revealed that OCT-1, NF-κB and C-JUN bound to pHEPIS in a site-dependent manner at the basal state. The TRANSFAC database was used to analyze the pHEPIS of multiple species and several activator protein-1, NF-κB and OCT-1 transcription factor binding sites were predicted. In conclusion, the results of the present study suggest that HEPIS is expressed at different levels in multiple organs and breast cancer cell lines. Furthermore, these findings indicate that OCT-1, NF-κB and C-JUN transcription factors are associated with transcriptional regulation of the HEPIS gene.

VIH from the mud crab is specifically expressed in the eyestalk and potentially regulated by transactivator of Sox9/Oct4/Oct1

Vitellogenesis-inhibiting hormone (VIH) is known to regulate ovarian maturation by suppressing the synthesis of vitellogenin (Vtg) in crustaceans, which belongs to a member of crustacean hyperglycemic hormone (CHH) family synthesized and secreted from the X-organ/sinus gland complex of eyestalks. In this study, the cDNA, genomic DNA (gDNA) and the 5'-upstream regulatory (promoter region) sequences of VIH gene were obtained by conventional PCR, genome walker and tail-PCR techniques according to our transcriptomic database of Scylla paramamosain. The full-length cDNA of SpVIH is 634bp including 105bp 5'UTR, 151bp 3'UTR and 378bp ORF that encodes a peptide of 125 amino acids. The full length gDNA of SpVIH is 790bp containing two exons and one intron. The 5'-flanking promoter regions of SpVIH we isolated are 3070bp from the translation initiation (ATG) and 2398bp from the predicted transcription initiation (A), which consists of putative core promoter region and multiple potential transcription factor binding sites. SpVIH was only expressed in eyestalk. The expression level of SpVIH in eyestalk of female crab decreased gradually along with the development of ovary. As there is not cell line of crabs available, we chose the mature transfection system HEK293FT cell lines to explore the mechanism of transcription regulation of SpVIH in crabs. Sequential deletion assays using luciferase reporter gene in HEK293FT cells revealed that the possible promoter activity regions (including positive and negative transcription factors binding sites simultaneously) presented between pSpVIH-4 and pSpVIH-6. In order to further identify the crucial transcription factors binding site in this region, the site-directed mutagenesis of Sox9/Oct4/Oct1 binding site of pSpVIH-4 was created. The results demonstrated that the transcriptional activity of pSpVIH-4△ decreased significantly (p<0.05). Thus, it is reasonable to deduce that the Sox9/Oct4/Oct1 may be the essential positive transcription factors which regulate the expression of SpVIH.

Correlations of pituitary tumor transforming gene expression with human pituitary adenomas: a meta-analysis

OBJECTIVE

Pituitary tumor transforming gene (PTTG) is an important paracrine growth factor involved in early lactotrope transformation and early onset of angiogenesis in pituitary hyperplasia. Emerging evidences have shown that PTTG expression may contribute to the etiology of pituitary adenomas; but individually published studies showed inconclusive results. This meta-analysis aimed to derive a more precise estimation of the correlations of PTTG expression with human pituitary adenomas.

METHODS

A range of electronic databases were searched: MEDLINE (1966∼2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980∼2013), CINAHL (1982∼2013), Web of Science (1945∼2013) and the Chinese Biomedical Database (CBM) (1982∼2013) without language restrictions. Meta-analysis was performed using the STATA 12.0 software. Crude odds ratio (OR) or standard mean difference (SMD) with its corresponding 95% confidence interval (95%CI) were calculated.

RESULTS

Twenty-four clinical cohort studies were included with a total of 1,464 pituitary adenomas patients. The meta-analysis results revealed that patients with invasive pituitary adenomas had higher positive expression of PTTG than those of non-invasive patients (OR  = 6.68, 95%CI  = 3.72-11.99, P<0.001). We also found a significant difference in microvessel density between invasive and non-invasive patients (SMD  = 1.81, 95%CI  = 0.39-3.23, P = 0.013). However, there were no significant difference in PTTG expression between functional and non-functional patients with pituitary adenomas (OR  = 1.11, 95%CI  = 0.58-2.10, P = 0.753). No publication bias was detected in this meta-analysis (all P>0.05).

CONCLUSION

This present meta-analysis suggests that PTTG expression may be associated with tumor invasiveness and microvessel density of pituitary adenomas, while no correlations with functional status was found.

OCT-1 overexpression is associated with poor prognosis in patients with well-differentiated gastric cancer

Octamer transcription factor-1 (OCT-1) is a well-known transcription factor that is reportedly overexpressed in intestinal metaplasia and gastric carcinoma in the intestine. In this study, we investigated OCT-1 overexpression as a prognostic factor for gastric cancer. The association between OCT-1 overexpression (detected using immunohistochemistry) and clinicopathological features including survival was evaluated. In vitro gain-of-function approaches were utilized to assess the function of OCT-1 in malignancy. Analysis of OCT-1 expression in patients with gastric cancer with well-differentiated carcinoma as per the World Health Organization classification showed that OCT-1 overexpression was correlated with advanced tumor invasion (58.8 % of patients with advanced tumor invasion vs. 21.2 % of patients with early tumor invasion; p<0.01), lymph node metastasis (63.9 % of patients with metastasis vs. 24.1 % of those without; p=0.015), and cancer recurrence (83.3 % of patients with recurrence vs. 25.4 % of those without; p<0.01), as well as a lower survival rate (62.8 vs. 87.9 Mo; p<0.01). However, there were no significant differences in the levels of OCT-1 expression in gastric cancer patients with other carcinoma types (p>0.05). Furthermore, we found that the proliferation rate of OCT-1-overexpressing MKN-45 cells was higher than that of the control cells. OCT-1 overexpression may be a marker for poor prognosis in patients with well-differentiated gastric adenocarcinoma.

A supervised network analysis on gene expression profiles of breast tumors predicts a 41-gene prognostic signature of the transcription factor MYB across molecular subtypes

Background. MYB is predicted to be a favorable prognostic predictor in a breast cancer population. We proposed to find the inferred mechanism(s) relevant to the prognostic features of MYB via a supervised network analysis. Methods. Both coefficient of intrinsic dependence (CID) and Galton Pierson's correlation coefficient (GPCC) were combined and designated as CIDUGPCC. It is for the univariate network analysis. Multivariate CID is for the multivariate network analysis. Other analyses using bioinformatic tools and statistical methods are included. Results. ARNT2 is predicted to be the essential gene partner of MYB. We classified four prognostic relevant gene subpools in three breast cancer cohorts as feature types I–IV. Only the probes in feature type II are the potential prognostic feature of MYB. Moreover, we further validated 41 prognosis relevant probes to be the favorable prognostic signature. Surprisingly, two additional family members of MYB are elevated to promote poor prognosis when both levels of MYB and ARNT2 decline. Both MYBL1 and MYBL2 may partially decrease the tumor suppressive activities that are predicted to be up-regulated by MYB and ARNT2. Conclusions. The major prognostic feature of MYB is predicted to be determined by the MYB subnetwork (41 probes) that is relevant across subtypes.

PTTG acts as a STAT3 target gene for colorectal cancer cell growth and motility

Pituitary tumor transforming gene (PTTG), the index mammalian securin, is abundantly expressed in several tumors and regulates tumor growth and progression. Molecular mechanisms elucidating PTTG regulation and actions remain elusive. Here, we provide evidence that PTTG acts as a STAT3 target gene. Total STAT3 and Tyr705 phosphorylated STAT3 were concordantly expressed with PTTG in human colorectal tumors (n=97 and n=95 respectively, P<0.001). STAT3 specifically bound the human PTTG promoter and induced PTTG transcriptional activity (2-fold) as assessed by chromatin immunoprecipitation and luciferase reporter assays. STAT3 transfection increased PTTG mRNA and protein abundance 2-fold in HCT116 human colon cancer cells, and induction was further enhanced (3-fold) by constitutively active STAT3 (STAT3-C), while strongly abrogated by dominant negative STAT3 (STAT3-DN). Attenuating PTTG expression by siRNA in STAT3 HCT116 stable transfectants suppressed cell growth and colony formation in vitro, and PTTG cell knockout also constrained activated STAT3-induced explanted murine tumor growth in vivo. STAT3 increased HCT116 cell migration and invasion up to 5-fold, whereas cell mobility was abolished by STAT3-DN (>85%). Impairing PTTG expression by siRNA also strongly suppressed STAT3-faciliated cell migration and invasion by up to 90%. Knocking out PTTG in STAT3-C HCT116 stable transfectants strongly decreased tumor metastases in nude mice, indicating the requirement of PTTG for STAT3-promoted metastasis. These results elucidate a mechanism for tumor cell PTTG regulation, whereby STAT3 induces PTTG expression to facilitate tumor growth and metastasis; and further support the rationale for targeting PTTG to abrogate colorectal cancer growth.

Pituitary tumor-transforming gene and its binding factor in endocrine cancer

The pituitary tumor-transforming gene (PTTG1) encodes a multifunctional protein (PTTG) that is overexpressed in numerous tumours, including pituitary, thyroid, breast and ovarian carcinomas. PTTG induces cellular transformation in vitro and tumourigenesis in vivo, and several mechanisms by which PTTG contributes to tumourigenesis have been investigated. Also known as the human securin, PTTG is involved in cell cycle regulation, controlling the segregation of sister chromatids during mitosis. This review outlines current information regarding PTTG structure, expression, regulation and function in the pathogenesis of neoplasia. Recent progress concerning the use of PTTG as a prognostic marker or therapeutic target will be considered. In addition, the PTTG binding factor (PBF), identified through its interaction with PTTG, has also been established as a proto-oncogene that is upregulated in several cancers. Current knowledge regarding PBF is outlined and its role both independently and alongside PTTG in endocrine and related cancers is discussed.