DEF6 expression in ovarian carcinoma correlates with poor patient survival

An EMT-related genes signature as a prognostic biomarker for patients with endometrial cancer

BACKGROUND

The epithelial-mesenchymal transition (EMT) plays an indispensable role in the development and progression of Endometrial cancer (EC). Nevertheless, little evidence is reported to uncover the functionality and application of EMT-related molecules in the prognosis of EC. This study aims to develop novel molecular markers for prognosis prediction in patients with EC.

METHODS

RNA sequencing profiles of EC patients obtained from The Cancer Genome Atlas (TCGA) database were used to screen differential expression genes (DEGs) between tumors and normal tissues. The Cox regression model with the LASSO method was utilized to identify survival-related DEGs and to establish a prognostic signature whose performance was evaluated by Kaplan-Meier curve, receiver operating characteristic (ROC) and calibration curve. Eventually, functional enrichment analysis and cellular experiments were performed to reveal the roles of prognosis-related genes in EC progression.

RESULTS

A total of 540 EMT-related DEGs in EC were screened, and subsequently a four-gene risk signature comprising SIRT2, SIX1, CDKN2A and PGR was established to predict overall survival of EC. This risk signature could serve as a meaningfully independent indicator for EC prognosis via multivariate Cox regression (HR = 2.002, 95%CI = 1.433-2.798; P < 0.001). The nomogram integrating the risk signature and clinical characteristics exhibited robust validity and performance at predicting EC overall survival indicated by ROC and calibration curve. Functional enrichment analysis revealed that the EMT-related genes risk signature was associated with extracellular matrix organization, mesenchymal development and cellular component morphogenesis, suggesting its possible relevance to epithelial-mesenchymal transition and cancer progression. Functionally, we demonstrated that the silencing of SIX1, SIRT2 and CDKN2A expression could accelerate the migratory and invasive capacities of tumor cells, whereas the downregulation of PGR dramatically inhibited cancer cells migration and invasion.

CONCLUSIONS

Altogether, a novel four-EMT-related genes signature was a potential biomarker for EC prognosis. These findings might help to ameliorate the individualized prognostication and therapeutic treatment of EC patients.

DEF6(differentially exprehomolog) exacerbates pathological cardiac hypertrophy via RAC1

Pathological cardiac hypertrophy involves multiple regulators and several signal transduction pathways. Currently, the mechanisms of it are not well understood. Differentially expressed in FDCP 6 homolog (DEF6) was reported to participate in immunity, bone remodeling, and cancers. The effects of DEF6 on pathological cardiac hypertrophy, however, have not yet been fully characterized. We initially determined the expression profile of DEF6 and found that DEF6 was upregulated in hypertrophic hearts and cardiomyocytes. Our in vivo results revealed that DEF6 deficiency in mice alleviated transverse aortic constriction (TAC)-induced cardiac hypertrophy, fibrosis, dilation and dysfunction of left ventricle. Conversely, cardiomyocyte-specific DEF6-overexpression aggravated the hypertrophic phenotype in mice under chronic pressure overload. Similar to the animal experiments, the in vitro data showed that adenovirus-mediated knockdown of DEF6 remarkably inhibited phenylephrine (PE)-induced cardiomyocyte hypertrophy, whereas DEF6 overexpression exerted the opposite effects. Mechanistically, exploration of the signal pathways showed that the mitogen-activated extracellular signal-regulated kinase 1/2 (MEK1/2)-extracellular signal-regulated kinase 1/2 (ERK1/2) cascade might be involved in the prohypertrophic effect of DEF6. Coimmunoprecipitation and GST (glutathione S-transferase) pulldown analyses demonstrated that DEF6 can directly interact with small GTPase Ras-related C3 botulinum toxin substrate 1 (Rac1), and the Rac1 activity assay revealed that the activity of Rac1 is altered with DEF6 expression in TAC-cardiac hypertrophy and PE-triggered cardiomyocyte hypertrophy. In the end, western blot and rescue experiments using Rac1 inhibitor NSC23766 and the constitutively active mutant Rac1(G12V) verified the requirement of Rac1 and MEK1/2-ERK1/2 activation for DEF6-mediated pathological cardiac hypertrophy. Our study substantiates that DEF6 acts as a deleterious regulator of cardiac hypertrophy by activating the Rac1 and MEK1/2-ERK1/2 signaling pathways, and suggests that DEF6 may be a potential treatment target for heart failure.

DEF6 has potential to be a biomarker for cancer prognosis: A pan-cancer analysis

Introduction

DEF6 is a gene associated with the immune system and is thought to play a crucial role in autoimmunity. There are few DEF6-related studies in cancer, and it is assumed that DEF6 is a proto-oncogene. There is currently no pan-cancer analysis of DEF6, and we performed a systematic and comprehensive pan-cancer analysis of DEF6 in an attempt to reveal its role and function in cancer.

Methods

The data were analyzed by mining databases available to the public and by using R software. Moreover, immunohistochemistry was used to validate the results.

Results

Our results revealed that DEF6 is commonly aberrantly expressed in cancer and its expression is strongly correlated with survival prognosis in a variety of cancer types. Through correlation analysis we found that DEF6 was associated with multiple immune genes and was closely related to immune infiltration. In the enrichment analysis, DEF6 may have cross-talk with multiple cancer pathways and exert oncogenic or pro-cancer functions. In addition, we collected pathological samples from colorectal cancer patients for immunohistochemical analysis and found that patients with higher immunohistochemical scores had more lymph node metastases, higher CA199, and bigger tumor size.

Discussion

Overall, DEF6 expression is closely related to cancers and has the potential to act as a cancer biomarker.

A novel immune prognostic model of non-M3 acute myeloid leukemia

Acute myeloid leukemia (AML) is a common hematological malignancy in adults. AML patients exhibit clinical heterogeneity with complications of molecular basis. The leukemogenesis of AML involves immune escape, and the immunosuppression status of the patient might have great impact on AML treatment outcome. In this study, we established an immune prognostic model of AML using bioinformatics tools. With the data in the TCGA and GTEx datasets, we analyzed differentially expressed genes (DEGs) in non-M3 AML and identified 420 immune-related DEGs. Among which, 49 genes' expression was found to be related to AML prognosis based on univariate Cox regression analysis. Next, we established a prognostic model with these 49 genes in AML by LASSO regression and multivariate Cox regression analyses. In our model, the expressions of 5 immune genes, MIF, DEF6, OSM, MPO, AVPR1B, were used to stratify non-M3 AML patients' treatment outcome. A patient's risk score could be calculated as Risk Score=0.40081 × MIF (MIF expression) - 0.15201 × MPO + 0.78073 × DEF6 - 0.45192 × AVPR1B + 0.25912 × OSM. The area under the curve of the risk score signature was 0.8, 0.8, and 0.96 at 1 year, 3 years, and 5 years, respectively. The prognostic model was then validated internally by TCGA data and externally by GEO data. At last, the result of single-sample gene-set enrichment analysis demonstrated that compared with healthy samples, the abundance of non-turmeric immune cells was significantly repressed in AML. To summarize, we presented an immune-related 5-gene signature prognostic model in AML.

Identification of a methylomics-associated nomogram for predicting overall survival of stage I-II lung adenocarcinoma

The aim of this paper was to identify DNA methylation based biomarkers for predicting overall survival (OS) of stage I–II lung adenocarcinoma (LUAD) patients. Methylation profile data of patients with stage I–II LUAD from The Cancer Genome Atlas (TCGA) database was used to determine methylation sites-based hallmark for stage I–II LUAD patients’ OS. The patients were separated into training and validation datasets by using median risk score as cutoff. Univariate Cox, least absolute shrinkage and selection operator (LASSO) and multivariate Cox analyses were employed to develop a DNA methylation signature for OS of patients with stage I–II LUAD. As a result, an 11-DNA methylation signature was determined to be critically associated with the OS of patients with stage I–II LUAD. Analysis of receiver operating characteristics (ROC) suggested a high prognostic effectiveness of the 11-DNA methylation signature in patients with stage I–II LUAD (AUC at 1, 3, 5 years in training set were (0.849, 0.879, 0.831, respectively), validation set (0.742, 0.807, 0.904, respectively), entire TCGA dataset (0.747, 0.818, 0.870, respectively). Kaplan–Meier survival analyses exhibited that survival was significantly longer in the low-risk cohort compared to the high-risk cohort in the training dataset (P = 7e − 07), in the validation dataset (P = 1e − 08), and in the all-cohort dataset (P = 6e − 14). In addition, a nomogram was developed based on molecular factor (methylation risk score) as well as clinical factors (age and cancer status) (AUC at 1, 3, 5 years entire TCGA dataset were 0.770, 0.849, 0.979, respectively). The result verified that our methylomics-associated nomogram had a strong robustness for predicting stage I–II LUAD patients’ OS. Furthermore, the nomogram combined clinical and molecular factors to determine an individualized probability of recurrence for patients with stage I–II LUAD, which stood for a major advance in the field of personalized medicine for pulmonary oncology. Collectively, we successfully identified a DNA methylation biomarker and a DNA methylation-based nomogram to predict the OS of patients with stage I–II LUAD.

High expression levels of DEF6 predicts a poor prognosis for patients with clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is one of the most common types of malignant tumors and early detection contributes to a better prognosis. Finding new biomarkers for the diagnosis or treatment remains meaningful. DEF6 guanine nucleotide exchange factor (DEF6) is upregulated in ccRCC compared to normal controls, but the relationship between DEF6 expression and prognosis in ccRCC is unclear. Moreover, the potential biological functions of DEF6 in ccRCC remains unclear. In the present study, the Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), TISIDB and the clinical database of the Peking University First Hospital were used to analyze DEF6 expression in ccRCC. Immunohistochemistry (IHC), western blotting and reverse transcription-quantitative PCR were used to examine the DEF6 protein and mRNA expression levels in cell lines and clinical samples. Subsequently, the Kaplan-Meier method and Cox regression analyses were used to determine the impact of DEF6 expression on the overall survival of patients alongside other clinical variables in both the TCGA database and the present clinical database. The results showed that both DEF6 mRNA and protein expression levels were upregulated in ccRCC compared to normal controls. The Kaplan-Meier survival analysis showed that patients with high DEF6 expression had poor prognoses from both the TCGA database and the present clinical database. Univariate survival analysis and multivariate survival analysis revealed that DEF6 could be an independent prognostic factor for ccRCC. Additionally, bioinformatics analysis indicated that differentially expressed genes related to DEF6 expression influenced ccRCC by regulating the tumor immune microenvironment. In conclusion, overexpression of DEF6 is significantly correlated with a poor prognosis for patients with ccRCC and DEF6 may influence the biological processes involved with ccRCC by regulating the immune microenvironment.

Increased DEF6 expression is correlated with metastasis and poor prognosis in human osteosarcoma

Metastasis is the primary cause of high mortality in patients with osteosarcoma (OS). However, the molecular mechanisms underlying the regulation of metastatic disease are yet to be determined. Differentially expressed in FDCP 6 homolog (DEF6) has been demonstrated to be correlated with the metastatic behavior of several cancers, such as breast, ovarian and colorectal cancers. However, the role of DEF6 in OS remains unknown. Accordingly, the current study aimed to investigate the relationship between DEF6 expression and the malignant behavior of OS. The results revealed that high levels of DEF6 in OS tissues were associated with advanced clinical stage and metastases. Furthermore, immunohistochemistry results predicted a poor prognosis in 58 human OS specimens. Additionally, DEF6 expression was reported to be upregulated in human OS cell lines compared with a normal osteoblast cell line. small interfering RNA transfection, cell proliferation and colony formation assays, wound healing assays and Transwell assays were performed. DEF6 was not identified to be a major driver of OS cell proliferation, but it significantly contributed to metastatic potential in vitro. In addition, bioinformatics, western blotting and immunohistochemistry results indicated that MMP9 expression was positively correlated with DEF6 expression in human OS. To summarize, the results revealed that increased levels of DEF6 were associated with metastasis and poor prognosis in human OS and that DEF6 expression is positively correlated with MMP9 expression. The results indicated that DEF6 may serve as a potential antimetastatic target for OS.

Long non-coding SNHG1 in cancer

OBJECTIVES

Long non-coding RNAs (lncRNAs) consist of a cluster of RNAs having >200 nucleotides lacking protein-coding function. Recent studies indicate that lncRNAs are involved in various cellular processes and their aberrant expression may lead to tumour development and progression. They may also serve as oncogenes or tumour suppressor genes in other diseases. In this review, we emphasize current investigations involving clinical management, tumour progression and the molecular mechanism of SNHG1 in human cancer.

MATERIALS AND METHODS

We investigate and summarize recent studies regarding the biologic functions and mechanisms of lncRNA SNHG1 in tumorigenesis. Related studies were obtained through a systematic search of google scholar, PubMed, Embase and Cochrane Library.

RESULTS

SNHG1 is a novel oncogenic lncRNA aberrantly expressed in different diseases including colorectal, liver, lung, prostate, gastric and esophageal cancers as well as ischemic stroke, nasopharyngeal carcinoma, laryngeal squamous cell carcinoma, neuroblastoma, renal cell carcinoma and osteosarcoma. Upregulation of SNHG1 was significantly associated with advanced tumour stage, tumour size, TNM stage and decreased overall survival. Furthermore, aberrant expression of SNHG1 contributes to cell proliferation, metastasis, migration and invasion of cancer cells.

CONCLUSION

SNHG1 likely acts as a useful tumour biomarker for cancer diagnosis, prognosis and treatment.

Distinct methylation profile of mucinous ovarian carcinoma reveals susceptibility to proteasome inhibitors

Mucinous type of epithelial ovarian cancer (MuOC) is a unique subtype with a poor survival outcome in recurrent and advanced stages. The role of type-specific epigenomics and its clinical significance remains uncertain. We analyzed the methylomic profiles of 6 benign mucinous adenomas, 24 MuOCs, 103 serous type of epithelial ovarian cancers (SeOCs) and 337 nonepithelial ovarian cancers. MuOC and SeOC exhibited distinct DNA methylation profiles comprising 101 genes, 81 of which exhibited low methylation in MuOC and were associated with the response to glucocorticoid, ATP hydrolysis-coupled proton transport, proteolysis involved in the cellular protein catabolic process and ion transmembrane transport. Hierarchical clustering analysis showed that the profiles of MuOC were similar to colorectal adenocarcinoma and stomach adenocarcinoma. Genetic interaction network analysis of differentially methylated genes in MuOC showed a dominant network module is the proteasome subunit beta (PSMB) family. Combined functional module and methylation analysis identified PSMB8 as a candidate marker for MuOC. Immunohistochemical staining of PSMB8 used to validate in 94 samples of ovarian tumors (mucinous adenoma, MuOC or SeOC) and 62 samples of gastrointestinal cancer. PSMB8 was commonly expressed in MuOC and gastrointestinal cancer samples, predominantly as strong cytoplasmic and occasionally weak nuclei staining, but was not expressed in SeOC samples. Carfilzomib, a second-generation proteasome inhibitor, suppressed MuOC cell growth in vitro. This study unveiled a mucinous-type-specific methylation profile and suggests the potential use of a proteasome inhibitor to treat MuOC.