ARHGAP4 regulates the cell migration and invasion of pancreatic cancer by the HDAC2/β-catenin signaling pathway

Novel prognostic biomarkers in nasopharyngeal carcinoma unveiled by mega-data bioinformatics analysis

Nasopharyngeal carcinoma (NPC) is commonly diagnosed at an advanced stage with a high incidence rate in Southeast Asia and Southeast China. However, the limited availability of NPC patient survival data in public databases has resulted in less rigorous studies examining the prediction of NPC survival through construction of Kaplan-Meier curves. These studies have primarily relied on small samples of NPC patients with progression-free survival (PFS) information or data from head and neck squamous cell carcinoma (HNSCC) studies almost without NPC patients. Thus, we coanalyzed RNA expression profiles in eleven datasets (46 normal (control) vs 160 tumor (NPC)) downloaded from the Gene Expression Omnibus (GEO) database and survival data provided by Jun Ma from Sun Yat-sen University. Then, differential analysis, gene ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and network analysis were performed using STRING database. After that, 2142 upregulated differentially expressed genes (DEGs) and 3857 downregulated DEGs were screened. Twenty-five of them were identified as hub genes, which were enriched in several pathways (cilium movement, extracellular matrix structural constituent, homologous recombination and cell cycle). Utilizing the comprehensive dataset we amassed from GEO database, we conducted a survival analysis of DEGs and subsequently constructed survival models. Seven DEGs (RASGRP2, MOCOS, TTC9, ARHGAP4, DPM3, CD37, and CD72) were identified and closely related to the survival prognosis of NPC. Finally, qRT-PCR, WB and IHC were performed to confirm the elevated expression of RASGRP2 and the decreased expression of TTC9, CD37, DPM3 and ARHGAP4, consistent with the DEG analysis. Conclusively, our findings provide insights into the novel prognostic biomarkers of NPC by mega-data bioinformatics analysis, which suggests that they may serve special targets in the treatment of NPC.

Hydroxytyrosol ameliorates stress-induced liver injury through activating autophagy via HDAC1/2 inhibition

Hydroxytyrosol (HT), a phenolic extra-virgin olive oil compound used as a food supplement, has been recognized to protect liver function and alleviate stress-induced depressive-like behaviors. However, its protective effects against stress-induced liver injury (SLI) remain unknown. Here, the anti-SLI effect of HT was evaluated in mice with chronic unpredictable mild stress-induced SLI. Network pharmacology combined with molecular docking was used to clarify the underlying mechanism of action of HT against SLI, followed by experimental verification. The results showed that accompanying with the alleviation of HT on stress-induced depressive-like behaviors, HT was confirmed to exert the protective effects against SLI, as represented by reduced serum corticosterone (CORT), aspartate aminotransferase and alanine aminotransferase activities, as well as repair of liver structure, inhibition of oxidative homeostasis collapse, and inflammation reaction in the liver. Furthermore, core genes including histone deacetylase 1 and 2 (HDAC1/2), were identified as potential targets of HT in SLI based on bioinformatic screening and simulation. Consistently, HT significantly inhibited HDAC1/2 expression to maintain mitochondrial dysfunction in an autophagy-dependent manner, which was confirmed in a CORT-induced AML-12 cell injury and SLI mice models combined with small molecule inhibitors. We provide the first evidence that HT inhibits HDAC1/2 to induce autophagy in hepatocytes for maintaining mitochondrial dysfunction, thus preventing inflammation and oxidative stress for exerting an anti-SLI effect. This constitutes a novel therapeutic modality to synchronously prevent stress-induced depression-like behaviors and liver injury, supporting the advantaged therapeutic potential of HT.

miR-939, as an important regulator in various cancers pathogenesis, has diagnostic, prognostic, and therapeutic values: a review

BACKGROUND

MicroRNAs (miRNAs or miRs) are highly conserved non-coding RNAs with a short length (18-24 nucleotides) that directly bind to a complementary sequence within 3'-untranslated regions of their target mRNAs and regulate gene expression, post-transcriptionally. They play crucial roles in diverse biological processes, including cell proliferation, apoptosis, and differentiation. In the context of cancer, miRNAs are key regulators of growth, angiogenesis, metastasis, and drug resistance.

MAIN BODY

This review primarily focuses on miR-939 and its expanding roles and target genes in cancer pathogenesis. It compiles findings from various investigations. MiRNAs, due to their dysregulated expression in tumor environments, hold potential as cancer biomarkers. Several studies have highlighted the dysregulation of miR-939 expression in human cancers.

CONCLUSION

Our study highlights the potential of miR-939 as a valuable target in cancer diagnosis, prognosis, and treatment. The aberrant expression of miR-939, along with other miRNAs, underscores their significance in advancing our understanding of cancer biology and their promise in personalized cancer care.

Cancer Mutations Converge on a Collection of Protein Assemblies to Predict Resistance to Replication Stress

Rapid proliferation is a hallmark of cancer associated with sensitivity to therapeutics that cause DNA replication stress (RS). Many tumors exhibit drug resistance, however, via molecular pathways that are incompletely understood. Here, we develop an ensemble of predictive models that elucidate how cancer mutations impact the response to common RS-inducing (RSi) agents. The models implement recent advances in deep learning to facilitate multidrug prediction and mechanistic interpretation. Initial studies in tumor cells identify 41 molecular assemblies that integrate alterations in hundreds of genes for accurate drug response prediction. These cover roles in transcription, repair, cell-cycle checkpoints, and growth signaling, of which 30 are shown by loss-of-function genetic screens to regulate drug sensitivity or replication restart. The model translates to cisplatin-treated cervical cancer patients, highlighting an RTK-JAK-STAT assembly governing resistance. This study defines a compendium of mechanisms by which mutations affect therapeutic responses, with implications for precision medicine.

SIGNIFICANCE

Zhao and colleagues use recent advances in machine learning to study the effects of tumor mutations on the response to common therapeutics that cause RS. The resulting predictive models integrate numerous genetic alterations distributed across a constellation of molecular assemblies, facilitating a quantitative and interpretable assessment of drug response. This article is featured in Selected Articles from This Issue, p. 384.

Cai's prescription inhibits granulosa cell apoptosis through ARHGAP4 on poor ovarian responders

PURPOSE

Poor ovarian response (POR) is a big challenge for in vitro fertilization. The traditional Chinese medicine, Cai's Prescription of Tonifying Kidney and Strengthening Vitals (Cai's Prescription) has yielded satisfactory results for POR treatment clinically, but systematic scientific research of Cai's Prescription is not well reported. This study aimed to investigate the clinical effect of Cai's Prescription on poor ovarian responders and its biological mechanism.

METHODS

Serum was collected from poor ovarian responders, and IL-1β, INFγ, FSH, E2 and AMH levels were analyzed by ELISA. Ovarian antral follicles were identified and counted using transvaginal ultrasound. The embryo quality grading were done on day 3 after retrieval. We used high-throughput sequencing of granulosa cells to investigate the gene transcription patterns of ovarian granulosa cells in poor ovarian responders after Cai's Prescription pretreatment. The expression level of ARHGAP4 was analyzed by quantitative real-time PCR and western blot. The effects of ARHGAP4 for granulosa cells were analyzed by CCK-8 assay, annexin-V and PI staining, ELISA and western blot. The effects of Cai's Prescription on the expression of PI3K-Akt pathway and apoptosis were analyzed by western blot.

RESULTS

In this study, we found that Cai's Prescription pretreatment had the tendency to improve the ovarian reserve function and could increase the number of high quality embryos for poor ovarian responders. Through high-throughput sequencing of mRNA in granulosa cells, we discovered ARHGAP4, which is a member of GTPase-activating proteins (GAPs) may be a candidate target for POR treatment. ARHGAP4 was significantly increased in poor ovarian responders and can be recovered after Cai's Prescription pretreatment. Mechanically, combining the cell line model and clinical tissue samples, we found that ARHGAP4 can accelerate cell apoptosis and inflammation response in granulosa cells via PI3K-Akt signaling pathway. In addition, Cai's Prescription pretreatment for three months significantly reduced the high level of ARHGAP4 in poor ovarian responders.

CONCLUSION

This study shows that the traditional Chinese medicine, Cai's Prescription yielded satisfactory results for poor ovarian responders clinically and ARHGAP4 may be a candidate target for POR treatment.

USP43 impairs cisplatin sensitivity in epithelial ovarian cancer through HDAC2-dependent regulation of Wnt/β-catenin signaling pathway

Epithelial ovarian cancer (EOC) is the leading cause of cancer death all over the world. USP43 functions as a tumor promoter in various malignant cancers. Nevertheless, the biological roles and mechanisms of USP43 in EOC remain unknown. In this study, USP43 was highly expressed in EOC tissues and cells, and high expression of USP43 were associated with a poor prognosis of EOC. USP43 overexpression promoted EOC cell proliferation, enhanced the ability of migration and invasion, decreased cisplatin sensitivity and inhibited apoptosis. Knockdown of USP43 in vitro effectively retarded above malignant progression of EOC. In vivo xenograft tumors, silencing USP43 slowed tumor growth and enhanced cisplatin sensitivity. Mechanistically, USP43 inhibited HDAC2 degradation and enhanced HDAC2 protein stability through its deubiquitylation function. USP43 diminished the sensitivity of EOC cells to cisplatin through activation of the Wnt/β-catenin signaling pathway mediated by HDAC2. Taken together, the data in this study revealed the functions of USP43 in proliferation, migration, invasion, chemoresistance of EOC cells, and the mechanism of HDAC2-mediated Wnt/β-catenin signaling pathway. Thus, USP43 might serve as a potential target for the control of ovarian cancer progression.

Rho GTPase-activating protein 4 is upregulated in Kidney Renal Clear Cell Carcinoma and associated with poor prognosis and immune infiltration

BACKGROUND

Kidney Renal Clear Cell Carcinoma (KIRC) is a malignant tumor that seriously threatens human health. Rho GTPase-activating protein 4 (ARHGAP4) plays an important role in the occurrence and development of tumors.

OBJECTIVE

The purpose of this study was to explore the role of ARHGAP4 in the progression of KIRC and its diagnostic and prognostic value.

METHODS

Multiple analytical methods and in vitro cell assays were used to explore the expression of ARHGAP4 and its value in the progression, diagnosis and prognosis of KIRC. The biological function of ARHGAP4 was studied by GO analysis and KEGG pathway analysis, and then the relationship between ARHGAP4 and immune infiltration was analyzed.

RESULTS

The expression of ARHGAP4 was significantly up-regulated in KIRC. We found that the high expression of ARHGAP4 was related to the progression of KIRC and suggested a poor prognosis. Compared with normal tissues, ARHGAP4 had a better diagnostic value in KIRC. The biological function of ARHGAP4 was related to immunity, and its expression was also closely related to tumor immune infiltration and immune checkpoints.

CONCLUSIONS

Our study demonstrated that ARHGAP4 may be a biomarker, which is related to the progression, diagnosis and prognosis of KIRC. Its biological functions are related to tumor immune infiltration.

ARHGAP4 promotes leukemogenesis in acute myeloid leukemia by inhibiting DRAM1 signaling

Rho GTPase-activating protein 4 (ARHGAP4) is an important Rho family GTPase-activating protein that is strongly associated with the onset and progression of some tumors. We found that ARHGAP4 mRNA and protein are overexpressed in human acute myeloid leukemia (AML) patients and are associated with a poor prognosis. ARHGAP4 knockdown significantly impairs viability and colony formation capacity and induces apoptosis in AML cells. Further results demonstrate that ARHGAP4 deletion impairs AML progression in vivo. Interestingly, DRAM1 signaling is significantly activated in AML cells with ARHGAP4 knockdown. Our results also indicated that ARHGAP4 might function in AML cells by binding with p53 to inhibit DRAM1. Moreover, knockdown of DRAM1 rescues the defects of ARHGAP4 in AML cells. This newly described role of the ARHGAP4/DRAM1 axis in regulating AML progression may have important therapeutic implications.

HDAC2 as a Target for developing Anti-cancer Drugs

Histone deacetylases (HDACs) deacetylate histones H3 and H4. An imbalance between histone acetylation and deacetylation can lead to various diseases. HDAC2 is present in the nucleus. It plays a critical role in modifying chromatin structures and regulates the expression of various genes by functioning as a transcriptional regulator. The roles of HDAC2 in tumorigenesis and anti-cancer drug resistance are discussed in this review. Several reports suggested that HDAC2 is a prognostic marker of various cancers. The roles of microRNAs (miRNAs) that directly regulate the expression of HDAC2 in tumorigenesis are also discussed in this review. This review also presents HDAC2 as a valuable target for developing anti-cancer drugs.

Prognosis, immune microenvironment, and personalized treatment prediction in Rho GTPase-activating protein 4-mutant cervical cancer: Computer strategies for precision oncology

AIMS

Cervical cancer with different mutations is associated with specific genomic differences. We developed a new mutation prediction model of the ARHGAP4 gene for cervical cancer.

MAIN METHODS

We conducted a panoramic analysis of CESC mutations based on The Cancer Genome Atlas-Cervical Squamous Cell Carcinoma and Endocervical Adenocarcinoma (TCGA-CESC) database. We made copy number variation analysis and correlation analysis of somatic mutations and tumor mutation load fraction. Then we established a prediction model of ARHGAP4 mutation, screened related genes based on the risk scores, calculated the correlation between the risk score and immune microenvironment, and analyzed drug sensitivity.

KEY FINDINGS

The prediction model of ARHGAP4 mutation based on mRNA expression is closely related to the survival rate of cervical cancer patients and to the effect of immunotherapy. The prediction model is also related to the infiltration of immune cells and human leukocyte antigen family expression in the immune microenvironment. After computational analysis, three drugs (cytarabine, docetaxel, imatinib) were identified as potential agents for the ARHGAP4 mutation high-risk group, and two drugs (erlotinib, methotrexate) were shown to have therapeutic significance for patients in the low-risk group. The expression of ARHGAP4 was higher in cervical cancer tissues. The proliferation ability of HeLa and SiHa cells decreased after ARHGAP4 knockdown.

SIGNIFICANCE

This study provides not only a new approach for the prediction of the response of the cervical cancer patients to targeted drug therapy but also a new strategy for combining risk stratification with precision treatment.

Ras superfamily GTPase activating proteins in cancer: Potential therapeutic targets?

To search more therapeutic strategies for Ras-mutant tumors, regulators of the Ras superfamily involved in the GTP/GDP (guanosine triphosphate/guanosine diphosphate) cycle have been well concerned for their anti-tumor potentials. GTPase activating proteins (GAPs) provide the catalytic group necessary for the hydrolysis of GTPs, which accelerate the switch by cycling between GTP-bound active and GDP-bound inactive forms. Inactivated GAPs lose their function in activating GTPase, leading to the continuous activation of downstream signaling pathways, uncontrolled cell proliferation, and eventually carcinogenesis. A growing number of evidence has shown the close link between GAPs and human tumors, and as a result, GAPs are believed as potential anti-tumor targets. The present review mainly summarizes the critically important role of GAPs in human tumors by introducing the classification, function and regulatory mechanism. Moreover, we comprehensively describe the relationship between dysregulated GAPs and the certain type of tumor. Finally, the current status, research progress, and clinical value of GAPs as therapeutic targets are also discussed, as well as the challenges and future direction in the cancer therapy.

Comprehensive analysis of immune subtypes reveals the prognostic value of cytotoxicity and FAP+ fibroblasts in stomach adenocarcinoma

BACKGROUND

The heterogeneity limits the effective application of immune checkpoint inhibitors for patients with stomach adenocarcinoma (STAD). Precise immunotyping can help select people who may benefit from immunotherapy and guide postoperative management by describing the characteristics of tumor microenvironment.

METHODS

Gene expression profiles and clinical information of patients were collected from ACRG and TCGA-STAD datasets. The immune subtypes (ISs) were identified by consensus clustering analysis. The tumor immune microenvironments (TIME) of each IS were characterized using a series of immunogenomics methods and further confirmed by multiplex immunohistochemistry (mIHC) staining in clinical samples. Two online datasets and one in-house dataset were utilized to construct and validate a prognostic immune-related gene (IRG) signature.

RESULTS

STAD patients were stratified into five reproducible ISs. IS1 (immune deserve subtype) had low immune infiltration and the highest degree of HER2 gene mutation. With abundant CD8⁺ T cells infiltration and activated cytotoxicity reaction, patients in the IS2 (immune-activated subtype) had the best overall survival (OS). IS3 and IS4 subtypes were both in the reactive stroma state and indicated the worst prognosis. However, IS3 (immune-inhibited subtype) was characterized by enrichment of FAP⁺ fibroblasts and upregulated TGF-β signaling pathway, while IS4 (activated stroma subtype) was characterized by enrichment of ACTA2⁺ fibroblasts. In addition, mIHC staining confirmed that TGF-β upregulated FAP⁺ fibroblasts were independent risk factor of OS. IS5 (chronic inflammation subtype) displayed moderate immune cells infiltration and had a relatively good survival. Lastly, we developed a nine-IRG signature model with a robust performance on overall survival prognostication.

CONCLUSIONS

The immunotyping is indicative for characterize the TIME heterogeneity and the prediction of tumor prognosis for STADs, which may provide valuable stratification for the design of future immunotherapy.

Analysis of ARHGAP4 Expression With Colorectal Cancer Clinical Characteristics and Prognosis

Background

This study aims to analyze the correlation between ARHGAP4 in the expression and clinical characteristics of colorectal cancer (CRC), and the influence of ARHGAP4 expression on the prognosis of CRC, and to evaluate whether ARHGAP4 is a potential prognostic oncotarget for CRC.

Methods

ARHGAP4 was identified using the Gene Expression Omnibus database through weighted gene coexpression network analysis. Using the Gene Expression Profiling Interactive Analysis to perform and analyze the expression and prognosis of ARHGAP4 in CRC. The expression of AGRGAP4 and immune cells was analyzed by the Tumor IMmune Estimation Resource online database. Finally, immunohistochemistry was used to analyze the expression difference and prognosis of ARHGAP4 in CRC and adjacent normal tissues, as well as the relationship between AGRGAP4 expression and clinical features of CRC.

Results

We identified ARHGAP4 that is related to the recurrence of CRC from GSE97781 data. ARHGAP4 has not been reported in CRC. The high expression of ARHGAP4 in select colon adenocarcinoma indicates a poor prognosis by database analysis. In our clinical data results, ARHGAP4 is highly expressed in CRC and lowly expressed in normal tissues adjacent to cancer. Compared with the low-expression group, the high-expression group has a significantly poorer prognosis. In colon cancer, the B-cell, macrophage, neutrophil, and dendritic-cell levels are downregulated after ARHGAP4 gene knockout; the levels of CD8⁺ and CD4⁺ T cells, neutrophils, and dendritic cells are upregulated after the amplification of the ARHGAP4 gene. In addition, ARHGAP4 expression is related to N,M staging and clinical staging.

Conclusion

ARHGAP4 is highly expressed in CRC, and the high expression of ARHGAP4 has a poor prognosis. The expression of ARHGAP4 in CRC is related to the immune cells such as B cells, CD8⁺ and CD4⁺ T cells, macrophages, neutrophils, and dendritic cells. ARHGAP4 is correlated with N,M staging and clinical staging in CRC. ARHGAP4 may be a potential biomarker for the prognosis of CRC.

Ring finger protein 180 suppresses cell proliferation and energy metabolism of non-small cell lung cancer through downregulating C-myc

Background

Non-small cell lung cancer (NSCLC) causes numerous deaths worldwide. however, biomarkers for NSCLC prognosis are scarce for its heterogeneity. Proteins containing the RING finger domain RING finger protein 180 (RNF180) is a key mediator for ubiquitination, which controls cell cycle and regulates progression in certain human tumors. However, the detailed function of RNF180 in NSCLC remains unclear. In the present study, we aimed to investigate the role of RNF180 and its molecule network in NSCLC.

Methods

Quantitative real-time polymerase chain reaction and immunohistochemical staining were used to analyze RNF180 levels. RNA interference and lentiviral-mediated vector transfections were performed to silence and overexpress RNF180 in NSCLC cells. Furthermore, Cell Counting Kit-8 was used for assessing biological function of RNF180 in cell proliferation and a xenograft model for examining its function in vivo. The activity of glycolysis was determined by examining the level of the extracellular acidification rate (ECAR).

Results

RNF180 expression decreased in NSCLC tissues, and its expression was positively correlated with the survival rate of patients with NSCLC. Moreover, RNF180 overexpression suppressed the proliferation and glycolytic activities in NSCLC cells and restricted its tumorigenicity in vivo. Furthermore, RNF180 silencing promoted the proliferation and glycolysis metabolism of NSCLC cells, whereas C-myc inhibitor disrupted these effects. The underlying anti-oncogene of RNF180 involved in C-myc downregulation via ubiquitin-dependent degradation.

Conclusions

Together, these results firstly indicated the anti-tumor properties of RNF180 and its correlation with NSCLC progression, thereby endorsing the potential role of RNF180 as an efficient prognostic biomarker for tumor recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02599-x.

A Prognostic Model Based on Nine DNA Methylation-Driven Genes Predicts Overall Survival for Colorectal Cancer

Background: Colorectal cancer (CRC) is the third most frequently diagnosed malignancy and the fourth leading cause of cancer-related death among common tumors in the world. We aimed to establish and validate a risk assessment model to predict overall survival (OS) for the CRC patients.

Methods: DNA methylation-driven genes were identified by integrating DNA methylation profile and transcriptome data from The Cancer Genome Atlas (TCGA) CRC cohort. Then, a risk score model was built based on LASSO, univariable Cox and multivariable Cox regression analysis. After analyzing the clinicopathological factors, a nomogram was constructed and assessed. Another cohort from GEO was used for external validation. Afterward, the molecular and immune characteristics in the two risk score groups were analyzed.

Results: In total, 705 methylation-driven genes were identified. Based on the LASSO and Cox regression analyses, nine genes, i.e., LINC01555, GSTM1, HSPA1A, VWDE, MAGEA12, ARHGAP, PTPRD, ABHD12B and TMEM88, were selected for the development of a risk score model. The Kaplan–Meier curve indicated that patients in the low-risk group had considerably better OS (P = 2e-08). The verification performed in subgroups demonstrated the validity of the model. Then, we established an OS-associated nomogram that included the risk score and significant clinicopathological factors. The concordance index of the nomogram was 0.81. A comprehensive molecular and immune characteristics analysis showed that the high-risk group was associated with tumor invasion, infiltration of immune cells executing pro-tumor suppression (such as myeloid-derived suppressor cells, regulatory T cells, immature dendritic cells) and higher expression of common inhibitory checkpoint molecules (ICPs).

Conclusion: Our nine-gene associated risk assessment model is a promising signature to distinguish the prognosis for CRC patients. It is expected to serve as a predictive tool with high sensitivity and specificity for individualized prediction of OS in the patients with CRC.

The interaction of canonical Wnt/β-catenin signaling with protein lysine acetylation

Canonical Wnt/β-catenin signaling is a complex cell-communication mechanism that has a central role in the progression of various cancers. The cellular factors that participate in the regulation of this signaling are still not fully elucidated. Lysine acetylation is a significant protein modification which facilitates reversible regulation of the target protein function dependent on the activity of lysine acetyltransferases (KATs) and the catalytic function of lysine deacetylases (KDACs). Protein lysine acetylation has been classified into histone acetylation and non-histone protein acetylation. Histone acetylation is a kind of epigenetic modification, and it can modulate the transcription of important biological molecules in Wnt/β-catenin signaling. Additionally, as a type of post-translational modification, non-histone acetylation directly alters the function of the core molecules in Wnt/β-catenin signaling. Conversely, this signaling can regulate the expression and function of target molecules based on histone or non-histone protein acetylation. To date, various inhibitors targeting KATs and KDACs have been discovered, and some of these inhibitors exert their anti-tumor activity via blocking Wnt/β-catenin signaling. Here, we discuss the available evidence in understanding the complicated interaction of protein lysine acetylation with Wnt/β-catenin signaling, and lysine acetylation as a new target for cancer therapy via controlling this signaling.

Screening to Identify an Immune Landscape-Based Prognostic Predictor and Therapeutic Target for Prostate Cancer

Objectives

Existing prognostic risk assessment strategies for prostate cancer (PCa) remain unsatisfactory. Similar treatments for patients at the same disease stage can lead to different survival outcomes. Thus, we aimed to explore a novel immune landscape-based prognostic predictor and therapeutic target for PCa patients.

Methods

A total of 490 PCa patients from The Cancer Genome Atlas Project (TCGA) cohort were analyzed to obtain immune landscape-based prognostic features. Then, analyses at different levels were performed to explore the relevant survival mechanisms, prognostic predictors, and therapeutic targets. Finally, experimental verification was performed using a tissue microarray (TMA) from 310 PCa patients. Furthermore, a nomogram was constructed to provide a quantitative approach for predicting the prognosis of patients with PCa.

Results

The immune landscape-based risk score (ILBRS) was obtained. Then, VAV1, which presented a significant positive correlation with Treg infiltration and ILBRS, was screened and identified to be significantly related to the prognosis of PCa. Finally, experimental verification confirmed the prognostic value of VAV1 for PCa prognosis at the protein level.

Conclusions

VAV1 has the potential to be developed as an immune landscape-based PCa prognostic predictor and therapeutic target and will help improve prognosis by enabling the selection of individualized, targeted therapy.

ARHGAP4-SEPT2-SEPT9 complex enables both up- and down-modulation of integrin-mediated focal adhesions, cell migration, and invasion

The Rho family of GTPases are inactivated in a cell context–dependent manner by Rho-GTPase-activating proteins (Rho-GAPs), but their signaling mechanisms are poorly understood. Here we demonstrate that ARHGAP4, one of the Rho-GAPs, forms a complex with SEPT2 and SEPT9 via its Rho-GAP domain and SH3 domain to enable both up- and down-modulation of integrin-mediated focal adhesions (FAs). We show that silencing ARHGAP4 and overexpressing its two mutually independent upstream regulators, SEPT2 and SEPT9, all induce reorganization of FAs to newly express Integrin Beta 1 and also enhance both cell migration and invasion. Interestingly, even if these cell migration/invasion–associated phenotypic changes are induced upon perturbations to the complex, it does not necessarily cause enhanced clustering of FAs. Instead, its extent depends on whether the microenvironment contains ligands suitable for the up-regulated Integrin Beta 1. These results provide novel insights into cell migration, invasion, and microenvironment-dependent phenotypic changes regulated by the newly identified complex.

Histone deacetylase 2 selective inhibitors: A versatile therapeutic strategy as next generation drug target in cancer therapy

Acetylation and deacetylation of histone and several non-histone proteins are the two important processes amongst the different modes of epigenetic modulation that are involved in regulating cancer initiation and development. Abnormal expression of histone deacetylases (HDACs) is often reported in various types of cancers. Few pan HDAC inhibitors have been approved for use as therapeutic interventions for cancer treatment including vorinostat, belinostat and panobinostat. However, not all the HDAC isoforms are abnormally expressed in certain cancers, such as in the case of, ovarian cancer where overexpression of HDAC1-3, lung cancer where overexpression of HDAC 1 and 3 and gastric cancer where overexpression of HDAC2 is seen. Therefore, pan-inhibition of HDAC is not an efficient way to combat cancer via HDAC inhibition. Hence, isoform-selective HDAC inhibition can be one of the best therapeutic strategies in the treatment of cancer. In this context since aberrant expression of HDAC2 largely contributes to cancer progression by silencing pro-apoptotic protein expressions such as NOXA and APAF1 (caspase 9-activating proteins) and inactivation of tumor suppressor p53, HDAC2 specific inhibitors may help to develop not only the direct targets but also indirect targets that are crucial for tumor development. However, to develop a HDAC2 specific and potent inhibitor, extensive knowledge of its structure and specific functions is essential. The present review updates details on the structural features, physiological functions, and roles of HDAC2 in different types of cancer, emphasizing the challenges and status of the development of HDAC2 selective inhibitors against various types of cancer.

Identification of SRGAP2 as a potential oncogene and a prognostic biomarker in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the common malignancies worldwide. Slit-Robo GTPase-activating proteins (SRGAPs) have been shown to regulate the occurrence and development of various tumors. However, their specific roles in HCC remain elusive.

METHODS

The expression pattern, genetic alteration and prognostic value of SRGAPs in HCC are analyzed by bioinformatics tools. The biological functions of SRGAP2 in HCC cells are demonstrated by in vitro experiments. The high-throughput RNA sequencing is conducted to explore the underlying molecular mechanisms of SRGAP2 in HCC cells.

RESULTS

The expression levels of SRGAP1 and SRGAP2 are significantly elevated in HCC tissues compared to the normal both in Oncomine and TCGA datasets, and SRGAP2 are dramatically upregulated both in mRNA and protein levels. Moreover, higher SRGAP2 is significantly related to the clinical stages of HCC. Meanwhile, SRGAP2 might be an independent prognostic indicator, as it correlates negatively with the clinical outcomes of HCC patients. Further SRGAP2-silencing experiments imply that SRGAP2 might remarkably promote the migration and invasion of HCC cells in an EMT-independent pattern. Based on the high-throughput RNA sequencing of SRGAP2-knockdown HCC cells, enrichment and network analyses demonstrate that SRGAP2 is closely associated with cellular metabolic signaling.

CONCLUSIONS

Our study firstly illustrates the crucial role of SRGAP2 in the metastasis of HCC and explores its underlying molecular mechanisms. We identify SRGAP2 as a promising prognostic biomarker and a novel therapeutic target for HCC patients.

RNA m6A methylation promotes the formation of vasculogenic mimicry in hepatocellular carcinoma via Hippo pathway

Vasculogenic mimicry (VM) formed by aggressive tumor cells to mimic vasculogenic networks plays an important role in the tumor malignancy of HCC. However, the pathogenesis underlying VM is complex and has not been fully defined. m6A is a common mRNA modification and has many biological effects. However, the relationship between m6A and VM remains unclear. In this research, we found that m6A methyltransferase METTL3 in HCC tissues was positively correlated with VM. The m6A level of mRNA significantly increased in 3D cultured cells treated with VEGFa and was related to VM formation. Transcriptome sequencing analysis of 3D cultured cells with knockdown Mettl3 showed that the Hippo pathway was involved in m6A-mediated VM formation. Further mechanism research indicated that the m6A modification of YAP1 mRNA affected the translation of YAP1 mRNA. In conclusion, m6A methylation plays a key role in VM formation in HCC. METTL3 and YAP1 could be potential therapeutic targets via impairing VM formation in anti-metastatic strategies.

N6-Methyladenosine modification of the TRIM7 positively regulates tumorigenesis and chemoresistance in osteosarcoma through ubiquitination of BRMS1

BACKGROUND

Metastasis is the leading cause of death in patients with osteosarcoma. Some of these patients fail to respond to chemotherapy and die of metastasis within a short period. Therefore, it is important to identify novel biomarkers to improve the diagnosis and treatment of osteosarcoma. TRIM7 is a member of the tripartite motif (TRIM) family protein that is involved in various pathological conditions including cancer; however, its role in osteosarcoma remains elusive.

METHODS

Cell proliferation, invasion and migration were measured by CCK-8 and Transwell. Immunoprecipitation and mass spectrometry analysis were used to identify candidate proteins associated with TRIM7. Immunoprecipitation, immunofluorescence, pull down and ubiquitination assay were performed to examine the regulation between TRIM7 and its candidate protein. m6A modification of TRIM7 was measured by RNA immunoprecipitation.

FINDINGS

TRIM7 expression was upregulated in osteosarcoma tissues and was an independent risk factor in predicting poor prognosis. TRIM7 regulates osteosarcoma cell migration and invasion through ubiquitination of breast cancer metastasis suppressor 1 (BRMS1). Moreover, chemoresistance was readily observed in osteosarcoma cells and in patient-derived xenograft (PDX) mice with higher TRIM7 levels. Loss of TRIM7 m6A modification was observed in osteosarcoma tissues. METTL3 and YTHDF2 were the main factors involved in the aberrant m6A modification of TRIM7.

INTERPRETATION

Overall, our findings show that TRIM7 plays a key role in regulating metastasis and chemoresistance in osteosarcoma through ubiquitination of BRMS1.

FUNDING

This work was financially supported by grants of NSFC (81001192, 81672658 and 81972521) and National Key Research Project of Science and Technology Ministry (2016YFC0106204).

miR-939-5p Contributes to the Migration and Invasion of Pancreatic Cancer by Targeting ARHGAP4

OBJECTIVE

Rho GTPase-activating protein 4 (ARHGAP4) is a GTPase-activating protein for the small GTPases of the Rho family that is involved in tumorigenesis. We recently reported that ARHGAP4 can mediate Warburg effect and malignant phenotype of pancreatic cancer. However, the regulation of ARHGAP4 remains unclear.

METHODS

ARHGAP4 and miR-939-5p expressions in pancreatic cancer tissues and cell lines were measured by real-time PCR or Western blotting. Pancreatic cancer cells were transfected with miR-939-5p inhibitor, miR-939-5p mimic and/or lentivirus expressing ARHGAP4, and the cell viability, invasion and migration were measured by CCK-8 and Transwell assay, respectively. The suppression of ARHGAP4 expression by miR-939-5p was revealed by luciferase reporter assay, real-time PCR or Western blotting.

RESULTS

ARHGAP4 expression was decreased, while miR-939-5p was increased in pancreatic cancer tissues compared with adjacent-normal pancreatic tissues. Higher miR-939-5p expression was correlated with advanced pathological stages and poor prognosis of pancreatic cancer patients. miR-939-5p directly targeted ARHGAP4. Either miR-939-5p down-regulation or ARHGAP4 overexpression inhibited viability, invasion and migration of pancreatic cancer cells. However, ARHGAP4 overexpression markedly inhibited the increased viability, migration, and invasion induced by miR-939-5p up-regulation in pancreatic cancer cells.

CONCLUSION

These observations suggested that miR-939-5p regulates the malignant phenotype of pancreatic cancer cells by targeting ARHGAP4, establishing miR-939-5p as a novel regulator of ARHGAP4 with a critical role in tumorigenesis in pancreatic cancer.

TRIM27 promotes IL-6-induced proliferation and inflammation factor production by activating STAT3 signaling in HaCaT cells

The IL-6/STAT3 signaling pathway is required for the development of psoriatic lesions, and tripartite motif-containing 27 (TRIM27) is a protein inhibitor of activated STAT3 (PIAS3)-interacting protein that could modulate IL-6-induced STAT3 activation. However, whether TRIM27 is associated with the IL-6/STAT3 signaling pathway in psoriasis remains enigmatic. TRIM27 expression and gene set enrichment analysis in patients with psoriasis were determined using bioinformatics. Human keratinocyte HaCaT cells treated with recombinant protein IL-6 (rh-IL-6) were transduced with lentivirus silencing TRIM27 and/or PIAS3 or, otherwise, transduced with lentivirus expressing TRIM27 and/or lentivirus silencing STAT3, or MG132, a proteasome-specific protease inhibitor. Cell proliferation and inflammation factor production were measured using Cell Counting Kit-8 and ELISA, respectively. TRIM27, proliferation marker protein Ki-67 (Ki67), phospho-STAT3 (p-STAT3), STAT3, and PIAS3 expressions were determined using real-time quantitative PCR, immunofluorescence staining, or Western blot analysis. Coimmunoprecipitation combined with ubiquitination analysis was performed to explore the interaction between TRIM27 and PIAS3. In the present study, TRIM27 expression was increased in psoriatic lesions, associated with the IL-6 signaling pathway, and induced by rh-IL-6 in a time-dependent manner. The increased cell proliferation, inflammation factor production, and expression of Ki67 and of p-STAT3 relative to STAT3 induced by rh-IL-6 and TRIM27 overexpression were significantly inhibited by TRIM27 silencing and STAT3 silencing, respectively. More importantly, TRIM27 interacted with PIAS3, and its overexpression promoted PIAS3 ubiquitination in HaCaT cells. PIAS3 silencing also significantly promoted TRIM27-dependent and IL6-induced STAT3 activation, cell proliferation, and inflammation factor production. In conclusion, our results highlight that TRIM27 expression is significantly increased by IL-6 and suggest a TRIM27/STAT3-dependent mechanism for regulation of inflammation and proliferation-associated development of psoriasis.

ARHGAP4 mediates the Warburg effect in pancreatic cancer through the mTOR and HIF-1α signaling pathways

Objective

The phenomenon that cancer cells avidly exhibit glycolysis with lactate secretion and decrease in mitochondrial activity under aerobic conditions is known historically as the Warburg effect. Rho GTPase-activating protein 4 (ARHGAP4) is an important negative regulator of the Rho signaling pathway that was associated with the tumorigenesis. Our study aims to determine the function of ARHGAP4 in controlling the glycolytic process of pancreatic cancer in vitro and possible molecular mechanism involved.

Methods

ARHGAP4 and PKM2 expressions in pancreatic cancer tissues were measured by immunohistochemistry. Human pancreatic cancer cells transfected with ARHGAP4 expressing lentivirus or siRNA were treated with either mTOR inhibitor (Rapamycin) or HIF-1α inhibitor (YC-1), and the effects were analyzed on cell viability, glucose uptake, lactate release, and the levels of ARHGAP4, p-mTOR, mTOR, PKM2, and HIF-1α expression.

Results

Our findings showed that ARHGAP4 and PKM2 expressions were, respectively, down-regulated and up-regulated in pancreatic cancer tissues. Overexpression of ARHGAP4 significantly inhibited cell viability, glucose uptake, lactate release, PKM2 expression, and activation of mTOR and HIF-1α signaling pathways in pancreatic cancer cells while ARHGAP4 silencing and treatment of Rapamycin or YC-1 showed inverse effects. Additionally, ARHGAP4 downregulation induced cell morphology of pancreatic cancer was inhibited by Rapamycin or YC-1 treatment.

Conclusion

These findings suggest that mTOR and HIF-1α signaling pathways can regulate the ARHGAP4-mediated glycolytic process of pancreatic cancer.