Discs large homolog 5 decreases formation and function of invadopodia in human hepatocellular carcinoma via Girdin and Tks5

Comprehensive Analysis of MICALL2 Reveals Its Potential Roles in EGFR Stabilization and Ovarian Cancer Cell Invasion

Molecules interacting with CasL (MICALs) are critical mediators of cell motility that act by cytoskeleton rearrangement. However, the molecular mechanisms underlying the regulation of cancer cell invasion remain elusive. The aim of this study was to investigate the potential role of one member of MICALs, i.e., MICALL2, in the invasion and function of ovarian cancer cells. We showed by bioinformatics analysis that MICALL2 expression was significantly higher in tissues of advanced-stage ovarian cancer and associated with poor overall survival of patients. MICALL2 was strongly correlated with the infiltration of multiple types of immune cells and T-cell exhaustion markers. Moreover, enrichment analyses showed that MICALL2 was involved in the tumor-related matrix degradation pathway. Mechanistically, MMP9 was identified as the target gene of MICALL2 for the regulation of invadopodium formation and SKOV3, HO-8910PM cell invasion. In addition, EGFR-AKT-mTOR signaling was identified as the downstream pathway of MICALL2 in the regulation of MMP9 expression. Furthermore, MICALL2 silencing promoted EGFR degradation; however, this effect was abrogated by treatment with the autophagy inhibitors acadesine and chloroquine diphosphate. Silencing of MICALL2 resulted in a suppressive activity of Rac1 while suppressing Rac1 activation attenuated the pro-EGFR, pro-MMP9, and proinvasive effects induced by the overexpression of MICALL2. Collectively, our results indicated that MICALL2 participated in the process of immune infiltration and invasion by ovarian cancer cells. Moreover, MICALL2 prevented EGFR degradation in a Rac1-dependent manner, consequently leading to EGFR-AKT-mTOR-MMP9 signaling activation and invadopodia-mediated matrix degradation.

DAB2IP suppresses invadopodia formation through destabilizing ALK by interacting with USP10 in breast cancer

Invadopodia, being actin-rich membrane protrusions, play a vital role in tumor cell invasion and metastasis. Our previous studies have revealed some functions of the DOC-2/DAB2 interacting protein (DAB2IP) as a tumor suppressor. Nevertheless, the specific role and mechanism of DAB2IP in invadopodia formation remain unclear. Here, we find that DAB2IP effectively suppresses invadopodia formation and metastasis in breast cancer, both in vitro and in vivo. Additionally, DAB2IP could downregulate anaplastic lymphoma kinase (ALK), resulting in the inhibition of tyrosine phosphorylation of Cortactin and the prevention of invadopodia formation. DAB2IP competitively antagonizes the interaction between the deubiquitinating enzyme Ubiquitin-specific peptidase 10 (USP10) and ALK, leading to a decrease in the abundance of ALK protein. In summary, DAB2IP impairs the stability of ALK through USP10-dependent deubiquitination, suppressing Cortactin phosphorylation, thereby inhibiting invadopodia formation and metastasis of breast cancer cells. Furthermore, this study suggests a potential therapeutic strategy for breast cancer treatment.

A double-edged sword: DLG5 in diseases

Discs large homolog 5 (DLG5), a key member of the membrane-associated guanylate kinase (MAGUKs) family, is a scaffold molecule for signal transduction complexes and is responsible for assembling receptors and adapters. This scaffold protein stabilizes adhesion and tight bonding complexes in many organs and tissues, and is involved of maintaining epithelial polarity. Although DLG5 plays a role in normal development in mice, it has also been linked to the onset and development of several diseases, particularly Crohn's disease and various malignancies. DLG5 has been shown to impact the progression of cancer through direct or indirect interactions with H-catenin, E-cadherin, Vimentin, p53, P21, Cyclin D1, TGF-β1, AKT, Hippo, and classic G protein signaling pathways. DLG5 and DLG5 variants has been found to have a dual role in human diseases. Although it is overexpressed in pancreatic adenocarcinoma, its expression is reduced in lung, liver, breast, prostate, and bladder cancers. However, two independent studies on glioblastoma (GBM) have shown the opposite effects of DLG5. Our study evaluates the existing literature on the role of DLG5 and DLG5 variants in disease processes, and summarizes the available data on the role of DLG5 in disease based on cell experiments, clinical samples, and animal models, while highlighting its future potential in disease treatment.

LINC00589-dominated ceRNA networks regulate multiple chemoresistance and cancer stem cell-like properties in HER2+ breast cancer

Resistance to human epidermal growth factor receptor 2 (HER2)-targeted therapy (trastuzumab), cancer stem cell (CSC)-like properties and multiple chemoresistance often concur and intersect in breast cancer, but molecular links that may serve as effective therapeutic targets remain largely unknown. Here, we identified the long noncoding RNA, LINC00589 as a key regulatory node for concurrent intervention of these processes in breast cancer cells in vitro and in vivo. We demonstrated that the expression of LINC00589 is clinically valuable as an independent prognostic factor for discriminating trastuzumab responders. Mechanistically, LINC00589 serves as a ceRNA platform that simultaneously sponges miR-100 and miR-452 and relieves their repression of tumor suppressors, including discs large homolog 5 (DLG5) and PR/SET domain 16 (PRDM16, a transcription suppressor of mucin4), thereby exerting multiple cancer inhibitory functions and counteracting drug resistance. Collectively, our results disclose two LINC00589-initiated ceRNA networks, the LINC00589-miR-100-DLG5 and LINC00589-miR-452-PRDM16- mucin4 axes, which regulate trastuzumab resistance, CSC-like properties and multiple chemoresistance of breast cancer, thus providing potential diagnostic and prognostic markers and therapeutic targets for HER2-positive breast cancer.

BTB domain and CNC homolog 1 promotes glioma invasion mainly through regulating extracellular matrix and increases ferroptosis sensitivity

BTB Domain and CNC Homolog 1 (Bach1) has been implicated in cancer progression, particularly in invasion, but little is unknown about its effect on glioma. Here, we confirmed that highly expressed Bach1 prominently promoted glioma invasion. Similar to the reported mechanisms in other tumors, Bach1 upregulation was also correlated with epithelial mesenchymal transition (EMT) in glioma cells. More importantly, proteomic analysis indicated that the main mechanism of Bach1 promoting invasion in glioma involved extracellular matrix (ECM). We further found thatBach1 upregulation was associated with the multiple mechanisms of ECM remodeling in glioma, including increasing the expression and deposition of ECM components, activating TGFBR2-smad2/3 signaling, promoting invadopodia formation and inducing the expression and secretion of MMP2. Meanwhile, Bach1 overexpression increased ferroptosis sensitivity in glioma cells. The ferroptosis inducer (sulfasalazine) obviously suppressed the gliomas with Bach1 upregulation in vitro and in vivo. Overall, Bach1 has a two-faced role in glioma. Highly expressed Bach1 promotes glioma invasion. Conversely, Bach1 upregulation is also a potential indicator of the sensitivity of ferroptosis inducers.

PLXDC2 enhances invadopodium formation to promote invasion and metastasis of gastric cancer cells via interacting with PTP1B

Plexin-domain containing 2 (PLXDC2) has been reported as an oncoprotein in several human malignancies. However, its expression and roles in gastric cancer remain largely unclear. In this study, we found that PLXDC2 was highly expressed in gastric cancer tissues, and the expression levels were positively correlated with clinicopathological features, but negatively with the patients’ outcome. Cox regression analysis identified PLXDC2 as an independent prognostic indicator for the patients. Knockdown of PLXDC2 markedly suppressed the in vitro invasion and in vivo metastasis of gastric cancer cells, while overexpression of PLXDC2 resulted in opposite effects. Mechanistically, PLXDC2 enhanced the level of phosphorylated Cortactin (p-Cortactin) by physically interacting with protein tyrosine phosphatase 1B (PTP1B), an important dephosphorylase, to prevent its dephosphorylating of p-Cortactin, thereby promoting the formation of invadopodia. Collectively, our results indicate that PLXDC2 contributes to the invasion and metastasis of gastric cancer by inhibiting PTP1B to facilitate the invadopodium formation, and may serve as a potential prognostic biomarker and a therapeutic target for this disease.

miR-103 Derived from Bone Marrow Mesenchymal Stem Cell (BMSC) Retards the Chemo-Resistance Through Targeted-Regulation of TP53 Regulated Inhibitor of Apoptosis 1 (TRIAP1) in Breast Cancer

The chemo-resistance was one of the major reasons for the treatment failure for breast cancer. Our study aimed to discuss the action of miR-103 derived from BMSC on retarding the chemo-resistance through targeted-regulating TRIAP1 in breast cancer. The cisplatin-resistant breast cancer cells were cultivated and transfected with si-RNA targeting miR-103 followed by analysis of cell invasion, migration and apoptosis by Transwell. MiR-103 target gene was analyzed with bioinformatics method and dual-luciferase reporter assay. TRIAP1 expression was measured by Western Blot. The cell apoptosis was reduced when miR-103 expression was restrained along with enhanced cell proliferation. The co-cultivation with BMSC in vitro could upregulate TRIAP1 expression in breast cancer cells. In cells transfected with si-miR-103, the expression of TRIAP1 was reduced, cell apoptosis was increased and invasion was decreased. In conclusion, the chemo-resistance is induced and the malignant invasion of breast cancer cells is retarded by co-cultivation with mikR-103 derived from BMSC which might be through regulating the expression of TRIAP.

Long non-coding RNA TPTEP1 exerts inhibitory effects on hepatocellular carcinoma by impairing microRNA-454-3p-mediated DLG5 downregulation

BACKGROUND

Hepatocellular carcinoma (HCC) is usually diagnosed at late stages, making it the second cause of malignancy-related death across the world. Long noncoding RNAs (lncRNAs) are of significance to tumorigenesis, highly suggestive of their functional roles as novel biomarkers for cancer therapy. The current study investigated the specific role of lncRNA TPTE pseudogene 1 (TPTEP1) in HCC.

METHODS

Expression of lncRNA TPTEP1, microRNA-454-3p (miR-454-3p) and discs large homolog 5 (DLG5) was determined in tissues samples from the recruited patients with HCC. Cell proliferation, migration and invasion assays were performed to determine effects of lncRNA TPTEP1, miR-454-3p and DLG5 on the malignant phenotype of tumor cells. Finally, the mouse HCC model was also established to disclose the tumor suppressor effects of lncRNA TPTEP1 in vivo.

RESULTS

LncRNA TPTEP1 was downregulated both in HCC cells and tissues, and played a negative regulatory role in HCC cell proliferation, migration and invasion. Mechanistically, lncRNA TPTEP1 competitively bound to miR-454-3p, thereby upregulating its endogenous target DLG5. Moreover, lncRNA TPTEP1 hindered activation of the protein kinase B signaling pathway, causing inhibited malignant phenotypes of HCC cells. Also, lncRNA TPTEP1 suppressed tumor growth and extrahepatic metastasis (lung) via miR-454-3p/DLG5 axis.

CONCLUSION

Taken together, this research revealed a concrete mechanism of lncRNA TPTEP1 in HCC.

Meta-analysis: The efficacy of metformin and other anti-hyperglycemic agents in prolonging the survival of hepatocellular carcinoma patients with type 2 diabetes

INTRODUCTION

This study aimed to compare the therapeutic efficacy of metformin and other anti-hyperglycemic agents in hepatocellular carcinoma (HCC) patients with type 2 diabetes (T2D).

MATERIALS

A systematic electronic search on keywords including HCC and different anti-hyperglycemic agents was performed through electronic databases including Medline and EMBASE. The primary outcome was the overall survival (OS). The secondary outcomes were the recurrence-free survival (RFS) and progression-free survival (PFS).

RESULTS

Six retrospective cohort studies were included for analysis: Four studies with curative treatment for HCC (618 patients with metformin and 532 patients with other anti-hyperglycemic agents) and two studies with non-curative treatment for HCC (92 patients with metformin and 57 patients with other anti-hyperglycemic agents). Treatment with metformin was associated with significantly longer OS (OR_1yr=2.62, 95%CI: 1.76-3.90; OR_3yr=3.14, 95%CI: 2.33-4.24; OR_5yr=3.31, 95%CI: 2.39-4.59, all P<0.00001) and RFS (OR_1yr=2.52, 95%CI: 1.84-3.44; OR_3yr=2.87, 95%CI: 2.15-3.84; all P<0.00001; and OR_5yr=2.26, 95%CI: 0.94-5.45, P=0.07) rates vs. those of other anti-hyperglycemic agents after curative therapies for HCC. However, both of the two studies reported that following non-curative HCC treatment, there were no significant differences in the OS and PFS rates between the metformin and non-metformin groups (I²>50%).

CONCLUSIONS

Metformin significantly prolonged the survival of HCC patients with T2D after the curative treatment of HCC. However, the efficacy of metformin needs to be further determined after non-curative therapies for HCC patients with T2D.

Decreased expression of Dlg5 is associated with a poor prognosis and epithelial-mesenchymal transition in squamous cell lung cancer

Background

Discs large homolog 5 (Dlg5) is a newly discovered member of the membrane-associated guanylate kinase superfamily (MAGUK) that is involved in several important processes, including the maintenance of epithelial cell polarity, cell proliferation control, and cell migration and invasion. Decreased expression of Dlg5 has been reported in malignancies arising from different organs. In the present study, we analyzed Dlg5 expression and its prognostic value in squamous cell lung cancer (SqCLC).

Methods

Tumor tissue and adjacent normal tissue sections were collected from 98 patients with SqCLC. The expression levels of Dlg5 and epithelial-mesenchymal transition (EMT) biomarkers in the tissue sections were examined by immunohistochemistry and western blot.

Results

There were 80 males and 18 females in the study cohort. Patients at pathological stages I and IIIA accounted for 64.3% and 35.7% of the cohort, respectively. Western blot showed that Dlg5 expression differed between SqCLC and healthy tissues. Western blot also revealed low Dlg5 expression to be associated with low E-cadherin expression and high vimentin expression, which was consistent with the findings of immunohistochemical staining. Dlg5 expression was significantly correlated with lymph node (LN) metastasis (P=0.001) and disease recurrence (P<0.001), as well as with E-cadherin and vimentin expression (P=0.025 and P=0.001, respectively). Univariate analysis showed that overall survival was significantly correlated with the tumor-node-metastasis (P<0.001) and T (P=0.001) stages, LN metastasis (P<0.001), Dig5 expression (P<0.001), β-catenin expression (P=0.004), and vimentin expression (P=0.002). Patients with overexpression of Dlg5 and β-catenin had a more favorable prognosis than those without. Multivariate analysis revealed that tumor-node-metastasis stage [hazard ratio (HR) =2.124; 95% confidence interval (CI), 1.195–3.777; P=0.010], Dlg5 expression (HR =0.548; 95% CI, 0.313–0.959; P=0.035), β-catenin expression (HR =0.545; 95% CI, 0.312–0.953; P=0.033), and vimentin expression (HR =1.850; 95% CI, 1.050–3.258; P=0.033) could all independently predict the overall survival of patients with SqCLC.

Conclusions

Dlg5 is an important player in EMT which may have potential predictive value for SqCLC prognosis after surgery.

Prognostic value of SH3PXD2B (Tks4) in human hepatocellular carcinoma: a combined multi-omics and experimental study

Background

Hepatocellular carcinoma (HCC) is one of the most common and fatal cancers worldwide. HCC invasion and metastasis are crucial for its poor prognosis. SH3PXD2B is a scaffold protein and critical for intravascular and extravascular invasion and metastasis of various types of tumors. However, the role of SH3PXD2B in HCC progression remains unclear.

Methods

The levels of SH3PXD2B mRNA transcripts in the TCGA database and SH3PXD2B protein expression in the Human Protein Atlas were analyzed. Furthermore, the levels of SH3PXD2B expression in clinical samples were analyzed by quantitative RT-PCR and immunohistochemistry. The potential association of the levels of SH3PXD2B expression with clinicopathological characteristics, overall survival (OS), and recurrence-free survival (RFS) of HCC patients was analyzed. The impact of SH3PXD2B silencing by shRNA-based lentivirus transduction on the proliferation and invasion of human HCC Hep3B and Huh7 cells was determined.

Results

SH3PXD2B expression was up-regulated in HCC tissues in the TCGA and Human Protein Atlas as well as clinical samples, relative to that of non-tumor liver samples. The levels of SH3PXD2B expression in HCC tissues were significantly associated with higher HBV infection rate, higher HCC grades and TNM stages, higher Ki-67 expression, higher serum α-fetoprotein (AFP), a shorter OS and RFS of HCC patients. Functionally, SH3PXD2B silencing significantly inhibited the formation and function of invadopodia and the invasion of Hep3B and Huh7 cells, but did not affect their proliferation in vitro.

Conclusions

Our data suggest that SH3PXD2B may promote the invasion and metastasis of HCC and be a valuable therapeutic target and biomarker for treatment and prognosis of HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-00963-6.

The relationship among Girdin DNA methylation, its high expression, and immune infiltration in hepatocellular carcinoma: Clues from in silico analysis

Objective: The aim of the present study was to explore the relationship among Girdin DNA methylation, its high expression, and immune infiltration in human hepatocellular carcinoma (HCC).

Materials and methods: The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and International Cancer Genome Consortium (ICGC) databases were used to compare Girdin mRNA expression between HCC tissues and normal tissues, and determine the relationship between Girdin expression and HCC prognosis. TCGA database was also used to analyze the expression of Girdin and its methylation status, as well as the relationship between Girdin DNA methylation and HCC prognosis. The Tumor IMmune Estimation Resource (TIMER) database was used to explore the correlation between Girdin expression and HCC immune infiltration.

Results: Girdin expression was elevated in HCC tissues compared with that in normal tissues. The degree of methylation at cg03188526, a CpG site in the Girdin gene body, was positively correlated with Girdin mRNA expression, while high Girdin expression and cg03188526 hypermethylation were both correlated with poor HCC prognosis. Additionally, HCC tissue with high Girdin expression exhibited abundant immune infiltration, and the high Girdin expression was associated with a worse prognosis in macrophage-enriched HCC specimens.

Conclusion: Our findings indicated that Girdin likely functions as an oncogene in HCC and that hypermethylation at cg03188526 in the Girdin gene body may explain the high Girdin expression levels in HCC tissue. Furthermore, we report for the first time that the adverse effects of high Girdin expression in HCC patients may be partially mediated by tumor macrophage infiltration.

Advances in Understanding TKS4 and TKS5: Molecular Scaffolds Regulating Cellular Processes from Podosome and Invadopodium Formation to Differentiation and Tissue Homeostasis

Scaffold proteins are typically thought of as multi-domain "bridging molecules." They serve as crucial regulators of key signaling events by simultaneously binding multiple participants involved in specific signaling pathways. In the case of epidermal growth factor (EGF)-epidermal growth factor receptor (EGFR) binding, the activated EGFR contacts cytosolic SRC tyrosine-kinase, which then becomes activated. This process leads to the phosphorylation of SRC-substrates, including the tyrosine kinase substrates (TKS) scaffold proteins. The TKS proteins serve as a platform for the recruitment of key players in EGFR signal transduction, promoting cell spreading and migration. The TKS4 and the TKS5 scaffold proteins are tyrosine kinase substrates with four or five SH3 domains, respectively. Their structural features allow them to recruit and bind a variety of signaling proteins and to anchor them to the cytoplasmic surface of the cell membrane. Until recently, TKS4 and TKS5 had been recognized for their involvement in cellular motility, reactive oxygen species-dependent processes, and embryonic development, among others. However, a number of novel functions have been discovered for these molecules in recent years. In this review, we attempt to cover the diverse nature of the TKS molecules by discussing their structure, regulation by SRC kinase, relevant signaling pathways, and interaction partners, as well as their involvement in cellular processes, including migration, invasion, differentiation, and adipose tissue and bone homeostasis. We also describe related pathologies and the established mouse models.

High expression of the long noncoding RNA SH3PXD2A-AS1 is associated with poor prognosis in patients with esophageal squamous cell carcinoma

Objective

Our objective was to explore the prognostic role of long noncoding RNA (lncRNA) SH3PXD2A-AS1 in esophageal squamous cell carcinoma (ESCC).

Methods

An SH3PXD2A-AS1 expression dataset was retrieved and analyzed from The Cancer Genome Atlas database, and SH3PXD2A-AS1 expression was determined in our cohort of 134 ESCC patients by using quantitative PCR. The clinical significance of SH3PXD2A-AS1 expression was investigated by the Chi square test and its prognostic value was determined by Kaplan–Meier survival curve analysis and Cox proportional hazards analysis. RNA interference and in vitro functional experiments, including cell viability, migration, and invasion, were used to investigate effects of SH3PXD2A-AS1 on cell malignant phenotype.

Results

SH3PXD2A-AS1 expression was increased in ESCC tissues compared with adjacent normal tissues. A high level of SH3PXD2A-AS1 expression was associated with poor tumor differentiation and advanced T, N, and TNM stages, indicating its oncogenic role in ESCC. Moreover, its high expression predicted poor overall survival in patients with ESCC. Inhibition of SH3PXD2A-AS1 expression significantly suppressed cell viability, migration, and invasion of ESCC cells.

Conclusion

High SH3PXD2A-AS1 expression is a poor prognostic factor for patients with ESCC. SH3PXD2A-AS1 might function as an oncogene that can promote malignant biological characteristics of ESCC cells.

GIV/Girdin and Exo70 Collaboratively Regulate the Mammalian Polarized Exocytic Machinery

Polarized exocytosis is a fundamental process by which membranes and cargo proteins are delivered to the cell surface with precise spatial control. Although the need for the octameric exocyst complex is conserved from yeast to humans, what imparts spatial control is known only in yeast, i.e., a polarity scaffold called Bem1p. We demonstrate here that the mammalian scaffold protein, GIV/Girdin, fulfills the key criteria and functions of its yeast counterpart Bem1p; both bind Exo70 proteins via similar short-linear interaction motifs, and each prefers its evolutionary counterpart. Selective disruption of the GIV⋅Exo-70 interaction derails the delivery of the metalloprotease MT1-MMP to invadosomes and impairs collagen degradation and haptotaxis through basement membrane matrix. GIV's interacting partners reveal other components of polarized exocytosis in mammals. Findings expose how the exocytic functions aid GIV's pro-metastatic functions and how signal integration via GIV may represent an evolutionary advancement of the exocytic process in mammals.

PABPC1-induced stabilization of BDNF-AS inhibits malignant progression of glioblastoma cells through STAU1-mediated decay

Glioblastoma is the most common and malignant form of primary central nervous tumor in adults. Long noncoding RNAs (lncRNAs) have been reported to play a pivotal role in modulating gene expression and regulating human tumor’s malignant behaviors. In this study, we confirmed that lncRNA brain-derived neurotrophic factor antisense (BDNF-AS) was downregulated in glioblastoma tissues and cells, interacted and stabilized by polyadenylate-binding protein cytoplasmic 1 (PABPC1). Overexpression of BDNF-AS inhibited the proliferation, migration, and invasion, as well as induced the apoptosis of glioblastoma cells. In the in vivo study, PABPC1 overexpression combined with BDNF-AS overexpression produced the smallest tumor and the longest survival. Moreover, BDNF-AS could elicit retina and anterior neural fold homeobox 2 (RAX2) mRNA decay through STAU1-mediated decay (SMD), and thereby regulated the malignant behaviors glioblastoma cells. Knockdown of RAX2 produced tumor-suppressive function in glioblastoma cells and increased the expression of discs large homolog 5 (DLG5), leading to the activation of the Hippo pathway. In general, this study elucidated that the PABPC1-BDNF-AS-RAX2-DLG5 mechanism may contribute to the anticancer potential of glioma cells and may provide potential therapeutic targets for human glioma.

β-TrCP-mediated ubiquitination and degradation of Dlg5 regulates hepatocellular carcinoma cell proliferation

Background

Discs large homolog 5 (Dlg5) is a member of the membrane-associated guanylate kinase (MAGUK) adaptor family of proteins and its deregulation has been implicated in the malignancy of several cancer types. Dlg5 was down-regulated in hepatocellular carcinoma (HCC) and lower Dlg5 expression was associated with poor survival of HCC patients. However, how to regulate Dlg5 remains largely unknown.

Methods

The co-immunoprecipitation assay was used to determine the interaction between Dlg5 and β-TrCP. The in vivo ubiquitination assay was performed to determine the regulation of Dlg5 by β-TrCP. CCK-8 and colony formation assay were implemented to detect the biological effect of Dlg5 on the growth of HCC cells in vitro. The effect of Dlg5 on HCC tumor growth in vivo was studied in a tumor xenograft model in mice.

Results

Here we report that Dlg5 is regulated by the ubiquitin proteasome system and depletion of either Cullin 1 or β-TrCP led to increased levels of Dlg5. β-TrCP regulated Dlg5 protein stability by targeting it for ubiquitination and subsequent destruction in a phosphorylation-dependent manner. We further demonstrated a crucial role of Ser730 in the non-canonical phosphodegron of Dlg5 in governing β-TrCP-mediated Dlg5 degradation. Importantly, failure to degrade Dlg5 significantly inhibited HCC cells proliferation both in vitro and in vivo.

Conclusion

Collectively, our finding provides a novel molecular mechanism for the negative regulation of Dlg5 by β-TRCP in HCC cells. It further suggests that preventing Dlg5 degradation could be a possible novel strategy for clinical treatment of HCC.

A new risk score based on twelve hepatocellular carcinoma-specific gene expression can predict the patients' prognosis

A large panel of molecular biomarkers have been identified to predict the prognosis of hepatocellular carcinoma (HCC), yet with limited clinical application due to difficult extrapolation. We here generated a genetic risk score system comprised of 12 HCC-specific genes to better predict the prognosis of HCC patients. Four genomics profiling datasets (GSE5851, GSE28691, GSE15765 and GSE14323) were searched to seek HCC-specific genes by comparisons between cancer samples and normal liver tissues and between different subtypes of hepatic neoplasms. Univariate survival analysis screened HCC-specific genes associated with overall survival (OS) in the training dataset for next-step risk model construction. The prognostic value of the constructed HCC risk score system was then validated in the TCGA dataset. Stratified analysis indicated this scoring system showed better performance in elderly male patients with HBV infection and preoperative lower levels of creatinine, alpha-fetoprotein and platelet and higher level of albumin. Functional annotation of this risk model in high-risk patients revealed that pathways associated with cell cycle, cell migration and inflammation were significantly enriched. In summary, our constructed HCC-specific gene risk model demonstrated robustness and potentiality in predicting the prognosis of HCC patients, especially among elderly male patients with HBV infection and relatively better general conditions.

CHCHD2 promotes hepatocellular carcinoma and indicates poor prognosis of hepatocellular carcinoma patients

The coiled-coil-helix-coiled-coil-helix domain containing 2 (CHCHD2) is overexpressed in several types of cancer. This study aimed to investigate the role of CHCHD2 in hepatocellular carcinoma (HCC). The expression of CHCHD2 in HCC and non-tumorous tissues was detected by immunohistochemistry and Western blot analysis, and the correlation between CHCHD2 expression and clinicopathological features of HCC was analyzed. Furthermore, the proliferation, apoptosis and migration of HepG2 cells with CHCHD2 knockdown were examined. We found that CHCHD2 was upregulated in HCC tissues, and high CHCHD2 expression was associated with poor differentiation, lymph node metastasis, local tissue invasion, high TNM grade of HCC and poor patient survival. Depletion of CHCHD2 led to significantly reduced cell proliferation, increased apoptosis and diminished migratory capacity in HepG2 cells. In addition, HCC tissues had high expression of CD105, a microvessel marker, and HepG2 cells depleted of CHCHD2 had low CD105 expression. In conclusion, CHCHD2 may play an oncogenic role in HCC via promoting tumor cell growth and migration while preventing apoptosis. CHCHD2 is a potential biomarker for poor outcome of HCC patients.

Bioinformatics analysis of differentially expressed genes in hepatocellular carcinoma cells exposed to Swertiamarin

Aim: To explore gene expression profiling in hepatocellular carcinoma (HCC) cells exposed to swertiamarin.

Methods: Cell viability, apoptosis and invasion were examined in HepG2 cells after swertiamarin treatment. Tumor growth of SK-Hep-1 cells xenografted in nude mice was monitored after swertiamarin treatment. Total RNA was isolated from HepG2 cells treated with swertiamarin for microarray analysis. The data of microarray were analyzed by bioinformatics.

Results: Swertiamarin treatment decreased the viability and invasion while increased the apoptosis of HepG2 cells, and significantly inhibited the growth of SK-Hep-1 cells xenografted in nude mice. Pathway and biological process analysis of differentially expressed genes (DEGs) in swertiamarin treated HepG2 cells showed that PI3k-Akt was the most significant regulated pathway. 47 targets of swertiamarin were predicted by CGBVS while 21 targets were predicted by 3NN. Notably, 8 targets were predicted as the targets of swertiamarin by both programs, including two prominent targets JUN and STAT3. A large range of DEGs induced by swertiamarin could be regulated by JUN and STAT3.

Conclusion: Swertiamarin treatment led to significant changes in the expression of a variety of genes that modulate cell survival, cell cycle progression, apoptosis, and invasion. Moreover, most of these genes can be clustered into pathway networks such as PI3K, JUN, STAT3, which are predicted targets of swertiamarin. Further confirmation of these targets will reveal the anti-tumor mechanisms of swertiamarin and facilitate the development of swertiamarin as a novel agent for cancer prevention and treatment.

KIFC1 is activated by TCF-4 and promotes hepatocellular carcinoma pathogenesis by regulating HMGA1 transcriptional activity

Background

Kinesins play important roles in the development and progression of many human cancers. The functions and underlying mechanisms of kinesin family member C1 (KIFC1), a member of the kinesin-14 family, in the pathogenesis of hepatocellular carcinoma (HCC) have not been fully elucidated.

Methods

In this study, 168 HCC samples were first analyzed to examine the association between KIFC1 expression and patient clinicopathological features and prognosis. The role of KIFC1 in HCC cell proliferation and metastasis was investigated both in vivo and in vitro. The upstream regulation and downstream targets of KIFC1 were studied by qRT-PCR, western blotting, coimmunoprecipitation, chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays.

Results

KIFC1 was highly expressed in HCC tissues and positively associated with advanced stages and poor prognosis. KIFC1 knockdown suppressed HCC cell proliferation and invasion both in vitro and in vivo. Furthermore, KIFC1 knockdown decreased invadopodia formation and reduced epithelial-mesenchymal transition (EMT). HMGA1, an architectural transcriptional factor, was identified to interact with KIFC1. HMGA1 could bind to the promoters of Stat3, MMP2 and EMT-related genes and promote gene transcription. KIFC1 enhanced HMGA1 transcriptional activity and facilitated HCC proliferation and invasion. Moreover, KIFC1 was activated by TCF-4, and KIFC1 inhibition enhanced HCC cell sensitivity to paclitaxel.

Conclusions

Our findings suggest that KIFC1, activated by TCF-4, functions as an oncogene and promotes HCC pathogenesis through regulating HMGA1 transcriptional activity and that KIFC1 is a potential therapeutic target to enhance the paclitaxel sensitivity of HCC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1331-8) contains supplementary material, which is available to authorized users.

Novel significant stage-specific differentially expressed genes in hepatocellular carcinoma

BACKGROUND

Liver cancer is among top deadly cancers worldwide with a very poor prognosis, and the liver is a vulnerable site for metastases of other cancers. Early diagnosis is crucial for treatment of the predominant liver cancers, namely hepatocellular carcinoma (HCC). Here we developed a novel computational framework for the stage-specific analysis of HCC.

METHODS

Using publicly available clinical and RNA-Seq data of cancer samples and controls and the AJCC staging system, we performed a linear modelling analysis of gene expression across all stages and found significant genome-wide changes in the log fold-change of gene expression in cancer samples relative to control. To identify genes that were stage-specific controlling for confounding differential expression in other stages, we developed a set of six pairwise contrasts between the stages and enforced a p-value threshold (< 0.05) for each such contrast. Genes were specific for a stage if they passed all the significance filters for that stage. The monotonicity of gene expression with cancer progression was analyzed with a linear model using the cancer stage as a numeric variable.

RESULTS

Our analysis yielded two stage-I specific genes (CA9, WNT7B), two stage-II specific genes (APOBEC3B, FAM186A), ten stage-III specific genes including DLG5, PARI, NCAPG2, GNMT and XRCC2, and 35 stage-IV specific genes including GABRD, PGAM2, PECAM1 and CXCR2P1. Overexpression of DLG5 was found to be tumor-promoting contrary to the cancer literature on this gene. Further, GABRD was found to be signifincantly monotonically upregulated across stages. Our work has revealed 1977 genes with significant monotonic patterns of expression across cancer stages. NDUFA4L2, CRHBP and PIGU were top genes with monotonic changes of expression across cancer stages that could represent promising targets for therapy. Comparison with gene signatures from the BCLC staging system identified two genes, HSP90AB1 and ARHGAP42. Gene set enrichment analysis indicated overrepresented pathways specific to each stage, notably viral infection pathways in HCC initiation.

CONCLUSIONS

Our study identified novel significant stage-specific differentially expressed genes which could enhance our understanding of the molecular determinants of hepatocellular carcinoma progression. Our findings could serve as biomarkers that potentially underpin diagnosis as well as pinpoint therapeutic targets.

Recent advances in molecular biomarkers for patients with hepatocellular carcinoma

Introduction: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide and recurrence rate after curative resection remains high. To improve HCC prognosis, novel sensitive biomarkers and targeted molecular therapies are needed. Accumulation of multiple genetic aberrations caused by pathologically derived liver damage results in HCC carcinogenesis. Elucidating the genes associated with tumorigenesis and progression of HCC may lead to the development of early detection and prognosis markers and to the identification of therapeutic targets. Areas covered: We review recently reported (January 2017-March 2019) HCC-associated molecules, including protein-coding genes, microRNAs, long non-coding RNAs, and methylated gene promoters. Expert opinion: The molecules reviewed have the potential to be clinical biomarkers and therapeutic targets for HCC. The accumulation and understanding of genetic and epigenetic data are essential to improve the management of HCC patients.

Invadopodia formation: An important step in matrix stiffness-regulated tumor invasion and metastasis

Highly motile and invasive abilities are symbolic features of metastatic tumor cells. Being a critical molecular event for maintaining the highly migratory and invasive capabilities of tumor cells, invadopodia formation undoubtedly determines the progression of tumor invasion and metastasis. Growing numbers of studies suggest that increased matrix stiffness, as a notable property of physical mechanics in solid tumors, participates in the regulation of tumor invasion and metastasis via different molecular mechanisms. However, to date the relevant mechanisms of matrix stiffness-induced invadopodia formation and activity in tumor cells remain largely unclear. This paper is to make a review on the structure and function of invadopodia, the stages and inductive factors of invadopodia formation, the regulatory mechanisms of matrix stiffness-induced invadopodia formation and so on, with an aim to reveal the important roles of invadopodia in matrix stiffness-regulated tumor invasion and metastasis.

The nucleosome binding protein 1 promotes the growth of gastric cancer cells

Nucleosome binding protein 1 (NSBP1) is identified as a new member of HMGN family and is abnormally overexpressed in a variety of tumors. However, it remains unclear whether NSBP1 is overexpressed and promotes gastric cancer. In this study we employed RNAi mediated knockdown of NSBP1 to investigate potential oncogenic role of NSBP1 in gastric cancer. In BGC823 and SGC7901 gastric cancer cell lines, we showed that NSBP1 knockdown decreased cell proliferation while increased apoptosis in vitro. Western blot analysis showed that NSBP1 knockdown decreased the levels of anti-apoptotic protein Bcl-2 while increased the levels of pro-apoptotic protein Bax. In addition, NSBP1 knockdown inhibited the growth and increased the apoptosis of SGC7901 cells xenografted in nude mice. In conclusion, this study provides the first evidence that NSBP1 enhances the proliferation while inhibits the apoptosis of gastric cancer cells, and this is related to the regulation of the expression of apoptosis related proteins by NSBP1. These data suggest that NSBP1 plays oncogenic role in gastric cancer.

Upregulation of eukaryotic translation initiation factor 3 subunit a promotes cell survival in ameloblastoma

OBJECTIVES

This study aimed to detect the expression of eukaryotic translation initiation factor 3 subunit a (eIF3a) in ameloblastoma (AB) tissues compared with normal oral mucosa (NOM) tissues and investigate the roles of eIF3a in the immortalized ameloblastoma cell line (AM-1) cell proliferation and apoptosis.

STUDY DESIGN

We performed immunohistochemistry to determine the expression of eIF3a in AB tissues (n = 83) and NOM tissues (n = 20). Real time-quantitative polymerase chain reaction and Western blot analyses were conducted with AB tissues (n = 30) and NOM tissues (n = 6). The correlation between eIF3a expression and the clinical/pathologic features of patients with AB is also presented. The functional role of eIF3a in AM-1 cells was assessed with lentiviral vector-mediated shRNA (small hairpin RNA).

RESULTS

Our results indicated that eIF3a was significantly upregulated in AB. Additionally, eIF3a knockdown in AM-1 cells significantly inhibited cell proliferation and promoted apoptosis.

CONCLUSIONS

These data indicate that eIF3a facilitates the survival of AB cells and may serve as a promising therapeutic target in AB.

Orthodontic compressive force modulates Ets-1/Tks5 pathway to promote the formation of circumferential invadopodia and the fusion of osteoclast precursors

During orthodontic treatment a mechanical force is applied to the teeth. However, it remains unclear how mechanical force promotes the maturation and fusion of osteoclast precursors into osteoclasts. In this study, we aimed to explore the mechanism by which orthodontic compressive force promotes osteoclast maturation. We used a RAW264.7 macrophage-like cell line derived from Balb/c mice as the experimental model. We found that compressive force promoted the maturation of osteoclasts based on tartrate-resistant acid phosphatase staining and the formation of invadopodia based on immunstaining of Tks5 and F-actin. Moreover, we found that compressive force upregulated the expression of Ets-1 and Tks5 and promoted the activation of Ets-1 in RAW264.7 cells. Furthermore, we identified Tks5 as a transcription target of Ets-1 in RAW264.7 cells and demonstrated that Ets-1 mediates the effects of compressive force on Tks5 upregulation, invadopodia formation and cell fusion in osteoclasts. In conclusion, Ets-1 is upregulated by compressive force and it is essential to transducing the mechanical signal to promote invadopodia formation and osteoclast fusion. Our findings provide novel insight into the mechanism underlying osteoclast maturation and fusion during orthodontic treatment.

Tks adaptor proteins at a glance

Tyrosine kinase substrate (Tks) adaptor proteins are considered important regulators of various physiological and/or pathological processes, particularly cell migration and invasion, and cancer progression. These proteins contain PX and SH3 domains, and act as scaffolds, bringing membrane and cellular components in close proximity in structures known as invadopodia or podosomes. Tks proteins, analogous to the related proteins p47^phox, p40^phox and NoxO1, also facilitate local generation of reactive oxygen species (ROS), which aid in signaling at invadopodia and/or podosomes to promote their activity. As their name suggests, Tks adaptor proteins are substrates for tyrosine kinases, especially Src. In this Cell Science at a Glance article and accompanying poster, we discuss the known structural and functional aspects of Tks adaptor proteins. As the science of Tks proteins is evolving, this article will point out where we stand and what still needs to be explored. We also underscore pathological conditions involving these proteins, providing a basis for future research to develop therapies for treatment of these diseases.