Daam1 activates RhoA to regulate Wnt5a‑induced glioblastoma cell invasion

Identification of epigenetic silencing of the SFRP2 gene in colorectal cancer as a clinical biomarker and molecular significance

BACKGROUND

Several studies have suggested secreted frizzled-related protein 2 (SFRP2) gene as a potential clinical biomarker in colorectal cancer (CRC). However, its diagnostic role remains unclear. In this study, we aimed to investigate the significance of SFRP2 methylation levels in a large cohort of biological specimens (including blood, adipose and colonic tissues) from patients with CRC, thereby potentially identifying new biomarker utility.

METHODS

We examined the expression (by qPCR) and methylation status (by 450 K DNA array and DNA pyrosequencing) of the SFRP2 gene in healthy participants (N = 110, aged as 53.7 (14.2), 48/62 males/females) and patients with CRC (N = 85, aged 67.7 (10.5), 61/24 males/females), across different biological tissues, and assessing its potential as a biomarker for CRC. Additionally, we investigated the effect of recombinant human SFRP2 (rhSFRP2) as a therapeutic target, on cell proliferation, migration, and the expression of key genes related to carcinogenesis and the Wnt pathway.

RESULTS

Our findings revealed that SFRP2 promoter methylation in whole blood could predict cancer stage (I + II vs. III + IV) (AUC = 0.653), lymph node invasion (AUC = 0.692), and CRC recurrence (AUC = 0.699) in patients with CRC (all with p < 0.05). Furthermore, we observed a global hypomethylation of SFRP2 in tumors compared to the adjacent area (p < 0.001). This observation was validated in the TCGA-COAD and TCGA-READ cohorts, demonstrating overall hypermethylation (both with p < 0.001) and low expression (p < 0.001), as shown in publicly available scRNA-Seq data. Notably, neoadjuvant-treated CRC patients exhibited lower SFRP2 methylation levels compared to untreated patients (p < 0.05) and low promoter SFRP2 methylation in untreated patients was associated with poor overall survival (p < 0.05), when compared to high methylation. Finally, treatment with 5 µg of rhSFRP2 treatment in CRC cells (HCT116 cells) inhibited cell proliferation (p < 0.001) and migration (p < 0.05), and downregulated the expression of AXIN2 (p < 0.01), a gene involved in Wnt signaling pathway.

CONCLUSIONS

These findings establish promoter methylation of the SFRP2 gene as a prognostic candidate in CRC when assessed in blood, and as a therapeutic prognostic candidate in tumors, potentially valuable in clinical practice. SFRP2 also emerges as a therapeutic option, providing new clinical and therapeutical avenues.

Single-nucleus and spatial landscape of the sub-ventricular zone in human glioblastoma

The sub-ventricular zone (SVZ) is the most well-characterized neurogenic area in the mammalian brain. We previously showed that in 65% of patients with glioblastoma (GBM), the SVZ is a reservoir of cancer stem-like cells that contribute to treatment resistance and emergence of recurrence. Here, we built a single-nucleus RNA-sequencing-based microenvironment landscape of the tumor mass (T_Mass) and the SVZ (T_SVZ) of 15 GBM patients and 2 histologically normal SVZ (N_SVZ) samples as controls. We identified a mesenchymal signature in the T_SVZ of GBM patients: tumor cells from the T_SVZ relied on the ZEB1 regulatory network, whereas tumor cells in the T_Mass relied on the TEAD1 regulatory network. Moreover, the T_SVZ microenvironment was predominantly characterized by tumor-supportive microglia, which spatially co-exist and establish heterotypic interactions with tumor cells. Lastly, differential gene expression analyses, predictions of ligand-receptor and incoming/outgoing interactions, and functional assays revealed that the IL-1β/IL-1RAcP and Wnt-5a/Frizzled-3 pathways are therapeutic targets in the T_SVZ microenvironment. Our data provide insights into the biology of the SVZ in GBM patients and identify specific targets of this microenvironment.

Platelet-derived circRNAs signature in patients with gastroenteropancreatic neuroendocrine tumors

BACKGROUND

Neuroendocrine tumors (NETs) early diagnosis is a clinical challenge that require a deep understanding of molecular and genetic features of this heterogeneous group of neoplasms. However, few biomarkers exist to aid diagnosis and to predict prognosis and treatment response. In the oncological field, tumor-educated platelets (TEPs) have been implicated as central players in the systemic and local responses to tumor growth, thereby altering tumor specific RNA profile. Although TEPs have been found to be enriched in RNAs, few studies have investigated the potential of a type of RNA, circular RNAs (circRNA), as platelet-derived biomarkers for cancer. In this proof-of-concept study, we aim to demonstrate whether the circRNAs signature of tumor educated platelets can be used as a liquid biopsy biomarker for the detection of gastroenteropancreatic (GEP)-NETs and the prediction of the early response to treatment.

METHODS

We performed a 24-months, prospective proof-of-concept study in men and women with histologically proven well-differentiated G1-G2 GEP-NET, aged 18-80 years, naïve to treatment. We performed a RNAseq analysis of circRNAs obtained from TEPs samples of 10 GEP-NETs patients at baseline and after 3 months from therapy (somatostatin analogs or surgery) and from 5 patients affected by non-malignant endocrinological diseases enrolled as a control group.

RESULTS

Statistical analysis based on p < 0.05 resulted in the identification of 252 circRNAs differentially expressed between GEP-NET and controls of which 109 were up-regulated and 143 were down-regulated in NET patients. Further analysis based on an FDR value ≤ 0.05 resulted in the selection of 5 circRNAs all highly significant downregulated. The same analysis on GEP-NETs at baseline and after therapy in 5 patients revealed an average of 4983 remarkably differentially expressed circRNAs between follow-up and baseline samples of which 2648 up-regulated and 2334 down-regulated, respectively. Applying p ≤ 0.05 and FDR ≤ 0.05 filters, only 3/5 comparisons gave statistically significant results.

CONCLUSIONS

Our findings identified for the first time a circRNAs signature from TEPs as potential diagnostic and predictive biomarkers for GEP-NETs.

Inference of glioblastoma migration and proliferation rates using single time-point images

Cancer cell migration is a driving mechanism of invasion in solid malignant tumors. Anti-migratory treatments provide an alternative approach for managing disease progression. However, we currently lack scalable screening methods for identifying novel anti-migratory drugs. To this end, we develop a method that can estimate cell motility from single end-point images in vitro by estimating differences in the spatial distribution of cells and inferring proliferation and diffusion parameters using agent-based modeling and approximate Bayesian computation. To test the power of our method, we use it to investigate drug responses in a collection of 41 patient-derived glioblastoma cell cultures, identifying migration-associated pathways and drugs with potent anti-migratory effects. We validate our method and result in both in silico and in vitro using time-lapse imaging. Our proposed method applies to standard drug screen experiments, with no change needed, and emerges as a scalable approach to screen for anti-migratory drugs.

The Novel Small Molecule BTB Inhibits Pro-Fibrotic Fibroblast Behavior though Inhibition of RhoA Activity

Idiopathic pulmonary fibrosis (IPF) is a progressive, chronic, interstitial lung disease with a poor prognosis. Although specific anti-fibrotic medications are now available, the median survival time following diagnosis remains very low, and new therapies are urgently needed. To uncover novel therapeutic targets, we examined how biochemical properties of the fibrotic lung are different from the healthy lung. Previous work identified lactate as a metabolite that is upregulated in IPF lung tissue. Importantly, inhibition of the enzyme responsible for lactate production prevents fibrosis in vivo. Further studies revealed that fibrotic lesions of the lung experience a significant decline in tissue pH, likely due to the overproduction of lactate. It is not entirely clear how cells in the lung respond to changes in extracellular pH, but a family of proton sensing G-protein coupled receptors has been shown to be activated by reductions in extracellular pH. This work examines the expression profiles of proton sensing GPCRs in non-fibrotic and IPF-derived primary human lung fibroblasts. We identify TDAG8 as a proton sensing GPCR that is upregulated in IPF fibroblasts and that knockdown of TDAG8 dampens myofibroblast differentiation. To our surprise, BTB, a proposed positive allosteric modulator of TDAG8, inhibits myofibroblast differentiation. Our data suggest that BTB does not require TDAG8 to inhibit myofibroblast differentiation, but rather inhibits myofibroblast differentiation through suppression of RhoA mediated signaling. Our work highlights the therapeutic potential of BTB as an anti-fibrotic treatment and expands upon the importance of RhoA-mediated signaling pathways in the context of myofibroblast differentiation. Furthermore, this works also suggests that TDAG8 inhibition may have therapeutic relevance in the treatment of IPF.

WNT signaling at the intersection between neurogenesis and brain tumorigenesis

Neurogenesis and tumorigenesis share signaling molecules/pathways involved in cell proliferation, differentiation, migration, and death. Self-renewal of neural stem cells is a tightly regulated process that secures the accuracy of cell division and eliminates cells that undergo mitotic errors. Abnormalities in the molecular mechanisms controlling this process can trigger aneuploidy and genome instability, leading to neoplastic transformation. Mutations that affect cell adhesion, polarity, or migration enhance the invasive potential and favor the progression of tumors. Here, we review recent evidence of the WNT pathway’s involvement in both neurogenesis and tumorigenesis and discuss the experimental progress on therapeutic opportunities targeting components of this pathway.

miR-218 affects the ECM composition and cell biomechanical properties of glioblastoma cells

Glioblastoma (GBM) is the most common malignant brain tumour. GBM cells have the ability to infiltrate into the surrounding brain tissue, which results in a significant decrease in the patient’s survival rate. Infiltration is a consequence of the low adhesion and high migration of the tumour cells, two features being associated with the highly remodelled extracellular matrix (ECM). In this study, we report that ECM composition is partially regulated at the post‐transcriptional level by miRNA. Particularly, we show that miR‐218, a well‐known miRNA suppressor, is involved in the direct regulation of ECM components, tenascin‐C (TN‐C) and syndecan‐2 (SDC‐2). We demonstrated that the overexpression of miR‐218 reduces the mRNA and protein expression levels of TN‐C and SDC‐2, and subsequently influences biomechanical properties of GBM cells. Atomic force microscopy (AFM) and real‐time migration analysis revealed that miR‐218 overexpression impairs the migration potential and enhances the adhesive properties of cells. AFM analysis followed by F‐actin staining demonstrated that the expression level of miR‐218 has an impact on cell stiffness and cytoskeletal reorganization. Global gene expression analysis showed deregulation of a number of genes involved in tumour cell motility and adhesion or ECM remodelling upon miR‐218 treatment, suggesting further indirect interactions between the cells and ECM. The results demonstrated a direct impact of miR‐218 reduction in GBM tumours on the qualitative ECM content, leading to changes in the rigidity of the ECM and GBM cells being conducive to increased invasiveness of GBM.

Roles of the RhoA-ROCK Signaling Pathway in the Endothelial H2S Production and Vasodilation in Rat Cerebral Arteries

Cerebral endothelial H₂S protects against cerebral ischemia-reperfusion injury through vasodilation, but its cerebral vasodilation mechanism and regulation of production are poorly understood. The RhoA-ROCK pathway plays important roles in vascular function. In this study, the roles of this pathway in the endothelial H₂S production and vasodilation in rat cerebral arteries were investigated. Acetylcholine significantly increased H₂S-generating enzyme cystathionine-γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3-MST) protein expressions and H₂S production in rat cerebrovascular endothelial cells (ECs), but the increases were markedly decreased by the M receptor blocker atropine or the CSE inhibitor dl-propargylglycine. Pretreatment with dl-propargylglycine or the 3-MST inhibitor l-aspartic acid markedly reduced the acetylcholine-increased H₂S; CSE protein expression and H₂S levels in the ECs were obviously attenuated by the RhoA agonist U₄₆₆₁₉ but increased by the RhoA inhibitor C3 transferase. U₄₆₆₁₉ also reduced 3-MST protein expression; Acetylcholine markedly inhibited RhoA protein expression and activity, but the inhibition was obviously reversed by atropine, dl-propargylglycine, and l-aspartic acid, respectively; Acetylcholine-induced endothelium-dependent vasodilation in rat cerebral basilar artery was significantly attenuated by pretreatment with dl-propargylglycine or l-aspartic acid or RhoA inhibitor CCG-1423 or ROCK inhibitor KD025, and was further decreased by co-pretreatment with dl-propargylglycine (or l-aspartic acid) and CCG-1423 (or KD025); NaHS significantly relaxed rat cerebral basilar artery vascular smooth muscle cells and inhibited ROCK_1/2 activities, phosphorylated myosin light chain (MLC) protein expression, and KCl-increased [Ca²⁺]_i, but these relaxation and inhibitions were markedly attenuated by pretreatment with C3 transferase or ROCK inhibitor Y27632. Our results demonstrated that endothelial H₂S production is promoted by activation of the M receptor but inhibited by the RhoA-ROCK pathway in rat cerebral arteries; the endothelial H₂S induces cerebral vasodilation by inhibiting this pathway to reduce phosphorylation of MLC and [Ca²⁺]_i in vascular smooth muscle cells.

Cross-Talk between Wnt Signaling and Src Tyrosine Kinase

Src, a non-receptor tyrosine kinase, was first discovered as a prototype oncogene and has been shown to critical for cancer progression for a variety of tissues. Src activity is regulated by a number of post-translational modifications in response to various stimuli. Phosphorylations of Src Tyr419 (human; 416 in chicken) and Src Tyr530 (human; 527 in chicken) have been known to be critical for activation and inactivation of Src, respectively. Wnt signaling regulates a variety of cellular functions including for development and cell proliferation, and has a role in certain diseases such as cancer. Wnt signaling is carried out through two pathways: β-catenin-dependent canonical and β-catenin-independent non-canonical pathways as Wnt ligands bind to their receptors, Frizzled, LRP5/6, and ROR1/2. In addition, many signaling components including Axin, APC, Damm, Dishevelled, JNK kinase and Rho GTPases contribute to these canonical and non-canonical Wnt pathways. However, the communication between Wnt signaling and Src tyrosine kinase has not been well reviewed as Src regulates Wnt signaling through LRP6 tyrosine phosphorylation. GSK-3β phosphorylated by Wnt also regulates Src activity. As Wnt signaling and Src mutually regulate each other, it is noted that aberrant regulation of these components give rise to various diseases including typically cancer, and as such, merit a closer look.

Formins in Human Disease

Almost 25 years have passed since a mutation of a formin gene, DIAPH1, was identified as being responsible for a human inherited disorder: a form of sensorineural hearing loss. Since then, our knowledge of the links between formins and disease has deepened considerably. Mutations of DIAPH1 and six other formin genes (DAAM2, DIAPH2, DIAPH3, FMN2, INF2 and FHOD3) have been identified as the genetic cause of a variety of inherited human disorders, including intellectual disability, renal disease, peripheral neuropathy, thrombocytopenia, primary ovarian insufficiency, hearing loss and cardiomyopathy. In addition, alterations in formin genes have been associated with a variety of pathological conditions, including developmental defects affecting the heart, nervous system and kidney, aging-related diseases, and cancer. This review summarizes the most recent discoveries about the involvement of formin alterations in monogenic disorders and other human pathological conditions, especially cancer, with which they have been associated. In vitro results and experiments in modified animal models are discussed. Finally, we outline the directions for future research in this field.

Daam1 Overexpression Promotes Gastric Cancer Progression and Regulates ERK and AKT Signaling Pathways

Objective

The dishevelled-associated activator of morphogenesis 1 (DAAM1) has been reported to be closely associated with human cancers. However, its involvement in human gastric cancer (GC) remains largely unexplored. This study aimed to investigate the clinical significance and biological roles of Daam1 in human GC.

Methods

Daam1 protein expression was examined in 124 cases of gastric adenocarcinomas using immunohistochemistry. Daam1 plasmid and siRNA transfection were carried out in SGC7901 and AGS cell lines. CCK-8, colony formation, Annexin V/PI, JC-1 staining, and Western blotting were used to explore the biological functions and potential underlying mechanisms of Daam1 in GC cells.

Results

Our results showed that Daam1 was overexpressed in GC specimens. A high Daam1 level was associated with tumor-node-metastasis (TNM) stage, T status, nodal metastasis, and poor patient survival. Analysis of the Oncomine dataset revealed upregulation of Daam1 mRNA in GC tissues. Western blot showed that Daam1 protein expression was higher in GC cell lines compared to the normal GES-1 cell line. CCK-8 and colony formation assays showed that ectopic Daam1 expression upregulated the cell growth rate and colony number in SGC-7901 cells, while Daam1 siRNA knockdown downregulated the growth rate and colony number in AGS cells. CCK-8 and Annexin V/PI apoptosis assays demonstrated that Daam1 overexpression decreased cisplatin sensitivity and downregulated cisplatin-induced apoptosis. JC1 staining showed that Daam1 overexpression upregulated, while Daam1 depletion downregulated mitochondrial membrane potential. Mechanistically, Daam1 overexpression downregulated p21 and upregulated p-ERK and p-AKT. The increased proliferation rate and decreased cisplatin sensitivity/apoptosis induced by ectopic Daam1 were reversed after treatment with AKT and ERK inhibitors.

Conclusion

Taken together, our results showed that Daam1 overexpression was associated with poor prognosis and promoted malignant activity via regulation of ERK and AKT pathways in GC cells, indicating Daam1 is a malignant biomarker and potential therapeutic target in GC.

YWHAZ interacts with DAAM1 to promote cell migration in breast cancer

Dishevelled-associated activator of morphogenesis 1 (DAAM1) is a critical driver in facilitating metastasis in breast cancer (BrCa). However, molecular mechanisms for the regulation of DAAM1 activation are only partially elucidated. In this research, the expression levels of YWHAZ and DAAM1 were examined by immunohistochemistry (IHC) staining in BrCa tissues. The functional roles of tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ)–DAAM1 axis and their regulator microRNA-613 (miR-613) in BrCa cells and associated molecular mechanisms were demonstrated in vitro. As results, the expression levels of DAAM1 and YWHAZ were significantly upregulated in BrCa tissues compared with normal tissues and remarkably associated with poor prognosis. Besides, DAAM1 and YWHAZ were positively correlated with each other in BrCa tissues. YWHAZ interacted and colocalized with DAAM1 in BrCa cells, which was essential for DAAM1-mediated microfilament remodeling and RhoA activation. Moreover, miR-613 directly targeted both YWHAZ and DAAM1, contributing to inhibiting BrCa cells migration via blocking the complex of YWHAZ–DAAM1. To sum up, these data reveal that YWHAZ regulates DAAM1 activation, and the YWHAZ–DAAM1 complex is directly targeted by the shared post-transcriptional regulator miR-613.

Expression analysis of progesterone‑regulated miRNAs in cells derived from human glioblastoma

Glioblastomas (GBMs) are the most frequent and malignant type of brain tumor. It has been reported that progesterone (P4) regulates the progression of GBMs by modifying the expression of genes that promote cell proliferation, migration and invasion; however, it is not fully understood how these processes are regulated. It is possible that P4 mediates some of these effects through changes in the microRNA (miRNA) expression profile in GBM cells. The present study investigated the effects of P4 on miRNAs expression profile in U-251MG cells derived from a human GBM. U-251MG cells were treated for 6 h with P4, RU486 (an antagonist of the intracellular progesterone receptor), the combined treatment (P4+RU486) and cyclodextrin (vehicle) and then a miRNA microarray analysis conducted. The expression analysis revealed a set of 190 miRNAs with differential expression in the treatments of P4, RU486 and P4+RU486 in respect to the vehicle and P4 in respect to P4+RU486, of which only 16 were exclusively regulated by P4. The possible mRNA targets of the miRNAs regulated by P4 could participate in the regulation of proliferation, cell cycle progression and cell migration of GBMs. The present study provided insight for understanding epigenetic modifications regulated by sex hormones involved in GBM progression, and for identifying potential therapeutic strategies for these brain tumors.

Formin homology domains of Daam1 bind to Fascin and collaboratively promote pseudopodia formation and cell migration in breast cancer

OBJECTIVES

Cancer cell migration to secondary organs remains an essential cause of death among breast cancer (BrCa) patients. Cell motility mainly relies on actin dynamics. Our previous reports verified that dishevelled-associated activator of morphogenesis 1 (Daam1) regulates invadopodia extension and BrCa cell motility. However, how Daam1 is involved in actin filament assembly and promotes pseudopodia formation in BrCa cells remains unclear.

MATERIALS AND METHODS

One hundred human BrCa samples were collected at Women's Hospital of Nanjing Medical University. Immunohistochemistry (IHC) was used to examine Daam1 and Fascin expression. Wound healing and Boyden chamber assays were used to explore cell migration and pseudopodia extension of BrCa cells. Co-IP/pull down and Western blotting were performed to study the physical interaction between Daam1 and Fascin. Immunofluorescence assays were performed to observe whether Daam1 and Fascin were colocalized and mediated actin filament assembly.

RESULTS

Fascin was upregulated in BrCa tissues compared with that in paracarcinoma tissues. The downregulation of Fascin caused a decline in pseudopodia formation and cell motility. Moreover, we found that Daam1 interacted with Fascin via formin homology (FH) domains, especially the FH2 domain. Immunofluorescence assays showed that Daam1 and Fascin partially colocalized to actin filaments, and the knockdown of Daam1 or Fascin failed to colocalize to short and curved actin filaments.

CONCLUSIONS

Daam1 specifically binds to Fascin via FH domains and cooperatively facilitates pseudopodia formation and cell migration by promoting actin filament assembly in BrCa.

Network pharmacology-based analysis of the role of tacrolimus in liver transplantation

Background

Tacrolimus is a powerful immunosuppressant and has been widely used in organ transplantation. In order to further explore the role of tacrolimus in liver transplantation, we conducted network pharmacology analysis.

Methods

GSE100155 was obtained from the GEO database, and the DEGs of liver transplantation were analyzed. The 2D structure of tacrolimus was obtained from the National Library of Medicine, and the pharmacophore model of tacrolimus was predicted using the online tool pharmmapper. Then a network of tacrolimus and target genes was constructed through network pharmacology, and visualization and GO enrichment analysis was performed through Cytoscape. In addition, we also analyzed the correlation between key genes and immune infiltrating cells. The data of GSE84908 was used to verify the changes of key gene expression levels after tacrolimus treatment.

Results

The results of network pharmacological analysis showed that tacrolimus had 43 target genes, and the GO enrichment results showed many potential functions. Further analysis found that there were 5 key target genes in DEGs, and these 5 genes were significantly down-regulated in liver transplant patients. Another important finding was that 5 genes were significantly related to some immune infiltrating cells. The results of the GSE84908 data analysis showed that after tacrolimus treatment, the expression of DAAM1 was significantly increased (p = 0.015).

Conclusion

Tacrolimus may inhibit the human immune response by affecting the expression of DAAM1 in liver transplant patients.

Systematic summarization of the expression profiles and prognostic roles of the dishevelled gene family in hepatocellular carcinoma

Background

Dishevelled (DVL) family members are crucial to Wnt‐induced signaling transduction, and their expression is highly correlated with the progression of multiple malignant cancers. However, the expression profiles and exact prognostic values of DVLs in hepatocellular carcinoma (HCC) have not been explored until now.

Methods

The expression of DVL isoforms was assessed using the Oncomine, HCCDB and UALCAN databases. The prognostic roles of DVLs were further evaluated using the GEPIA database. The relationship between the expression of DVLs and immune infiltration of HCC was investigated using the Timer and ImmuCellAI tools. Furthermore, protein–protein interaction (PPI) networks were built and enrichment analyses were conducted.

Results

We found that the expression levels of DVL2 (OMIM accession number: 602151) and DVL3 (OMIM accession number: 601368) were upregulated in HCC tissues as revealed by the Oncomine and HCCDB databases. Additionally, the expression of DVLs tended to be associated with advanced clinical features in the UALCAN database. Prognostic analysis revealed that the expression levels of DVL1 (OMIM accession number: 601365) and DVL3 were remarkably associated with a poor prognosis in HCC patients. The results also revealed that the DVL expression level was correlated with the infiltration levels of multiple immune cells. By constructing the PPI network and enrichment analyses, the DVL1‐3 gene was identified to interact with 20 key genes and participate in several pathways.

Conclusion

In summary, DVL2 and DVL3 are highly expressed in HCC, and DVL1 and DVL3 are related to a poor prognosis, which might be used as candidate targets for targeted therapy and reliable prognostic biomarkers in HCC.

Inhibitory Effects of Olea europaea Leaf Extract on Mesenchymal Transition Mechanism in Glioblastoma Cells

BACKGROUND

Glioblastoma (GB) is the most aggressive form of brain tumor. Despite the current treatment methods, the survival rate of patients is very low. Therefore, there is a need to develop new therapeutic agents. The migration and invasion capacity of GB cells is related to mesenchymal transition (MT) mechanism.

MATERIALS AND METHODS

The effect of OLE on MT was determined by analysis of the Twist, Snail, Zeb1, N-cadherin and E-cadherin genes in the EMT mechanism. The effect of OLE on cell migration was determined by wound healing test.

RESULTS

2 mg/ml OLE reduced Twist, Snail, Zeb1 and N-cadherin expression and the combination of OLE + TMZ (2 mg/ml OLE + 350 mM TMZ) increased E-cadherin and reduced Twist, Zeb1 and N-cadherin. In addition, co-treatment with OLE increased TMZ-induced anti-invasion properties thought suppressing transcription factors of MT mechanism.

CONCLUSION

OLE can enhance the anti-MT activities of TMZ against GB and provide strong evidence that combined treatment with OLE and TMZ has the potential to be an effective alternative approach in GB therapy.

Tivantinib Hampers the Proliferation of Glioblastoma Cells via PI3K/Akt/Mammalian Target of Rapamycin (mTOR) Signaling

Background

Glioblastoma, the most common and malignant glial tumor, often has poor prognosis. Tivantinib has shown its potential in treating c-Met-high carcinoma. No studies have explored whether tivantinib inhibits the development of glioblastoma.

Material/Methods

The correlation between c-Met expression and clinicopathological characteristics of glioblastoma was investigated. U251 and T98MG glioblastoma cells treated with tivantinib, PI3K inhibitor (LY294002), PI3K activator (740 Y-P), and/or mammalian target of rapamycin (mTOR) inhibitor were subjected to MTT assay or colony formation assay to evaluate cell proliferation. The expression of mTOR signaling and caspase-3 in tivantinib-treated glioblastoma cells was differentially measured by western blotting.

Results

In a group of Chinese patients, expression of c-Met was elevated with the size of glioblastoma, but not with the other clinicopathological characteristics, including gender, age, grade, IDH status, 1p/19q status, and Ki67 status. High dose of tivantinib (1 μmol/L) obviously repressed the proliferation and colony formation of U251 and T98MG glioblastoma cells, but low dose (0.1 μmol/L) of tivantinib failed to retard cell proliferation. Tivantinib blocked PI3K/Akt/mTOR signaling but did not change the expression of cleaved caspase-3. PI3K activator 740 Y-P (20 μmol/L) significantly rescued tivantinib-induced decrease of cell proliferation. Tivantinib (1 μmol/L) in combination with PI3K inhibitor LY294002 (0.5 μmol/L) and mTOR inhibitor rapamycin (0.1 nmol/L) largely inhibited the proliferation of glioblastoma cells.

Conclusions

c-MET inhibitor tivantinib blocks PIKE/Akt/mTOR signaling and hampers the proliferation of glioblastoma cells, which endows the drug a therapeutic effect.

Molecular and Clinical Insights into the Invasive Capacity of Glioblastoma Cells

The invasive capacity of GBM is one of the key tumoral features associated with treatment resistance, recurrence, and poor overall survival. The molecular machinery underlying GBM invasiveness comprises an intricate network of signaling pathways and interactions with the extracellular matrix and host cells. Among them, PI3k/Akt, Wnt, Hedgehog, and NFkB play a crucial role in the cellular processes related to invasion. A better understanding of these pathways could potentially help in developing new therapeutic approaches with better outcomes. Nevertheless, despite significant advances made over the last decade on these molecular and cellular mechanisms, they have not been translated into the clinical practice. Moreover, targeting the infiltrative tumor and its significance regarding outcome is still a major clinical challenge. For instance, the pre- and intraoperative methods used to identify the infiltrative tumor are limited when trying to accurately define the tumor boundaries and the burden of tumor cells in the infiltrated parenchyma. Besides, the impact of treating the infiltrative tumor remains unclear. Here we aim to highlight the molecular and clinical hallmarks of invasion in GBM.

Wnt5a induces ROR1 and ROR2 to activate RhoA in esophageal squamous cell carcinoma cells

Background: Wnt5a is a nontransforming Wnt family member and identified as an oncogenic role on cell motility of breast cancer and glioblastoma. However, Wnt5a signaling in esophageal squamous cell carcinoma (ESCC) progression remains poorly defined.

Materials and methods: Immunohistochemistry assays were used to measure the Wnt5a expression in ESCC sections. We evaluated the role of receptor tyrosine kinase-like orphan receptor (ROR)1/2 and RhoA on the invasion of ESCC cells by using cell invasion assay, immunoprecipitation, immunofluorescence, and Rho activation assay.

Results: Wnt5a was highly expressed in invasive ESCC tissues compared with that in noninvasive and nonmalignant tissues. In vitro assay showed that sfrp2 (Wnt5a antagonist) largely blocked the invasion but not the colony formation of KYSE410 and KYSE520 ESCC cells. Anti-ROR1 mAb and ROR2-shRNA markedly inhibited the disheveled-associated activator of morphogenesis 1 (DAAM1) activity, RhoA activity, microfilament formation and the invasion of ESCC cells. Fluorescent phalloidin staining experiment showed ROR1/ROR2, receptors of Wnt5a signaling, and regulated the reassembly of actin filaments in ESCC cells. Further experiments showed that ROR1 was strongly associated with ROR2 in KYSE410 cells. The activation of RhoA, not Rac1 or Rac2, was involved in ROR1/ROR2 signaling pathway. By using DAAM1 shRNA, we found that RhoA was downstream of DAAM1, which could be rescued by the overexpression of wild-type DAAM1. This could be further proved by a RhoA inhibitor CCG-1423 which could inhibit the invasion of ESCC cells but not DAAM1 activity.

Conclusions: Wnt5a promotes ESCC cell invasion via ROR1 and ROR2 receptors and DAAM1/RhoA signaling pathway.

A DAAM1 3'-UTR SNP mutation regulates breast cancer metastasis through affecting miR-208a-5p-DAAM1-RhoA axis

Background

Dishevelled-associated activator of morphogenesis 1 (DAAM1) is a member of microfilament-related formins and mediates cell motility in breast cancer (BrCa). However, the genetic mutation status of DAAM1 mRNA and its correlation with pathological characteristics are still unclearly. Methods: A patient cohort and BrCa cells were recruited to demonstrate the role of functional SNP in microRNA-208a-5p binding site of DAAM1 3′-UTR and underlying mechanism in BrCa metastasis.

Methods

A patient cohort and BrCa cells were recruited to demonstrate the role of functional SNP in microRNA-208a-5p binding site of DAAM1 3′-UTR and underlying mechanism in BrCa metastasis.

Results

The expression and activation of DAAM1 increased markedly in lymphnode metastatic tissues. A genetic variant (rs79036859 A/G) was validated in the miR-208a-5p binding site of DAAM1 3′-UTR. The G genotype (AG/GG) was a risk genotype for the metastasis of BrCa by reducing binding affinity of miR-208a-5p for the DAAM1 3′-UTR. Furthermore, the miR-208a-5p expression level was significantly suppressed in lymphnode metastatic tissues compared with that in non-lymphnode metastatic tissues. Overexpression of miR-208a-5p inhibited DAAM1/RhoA signaling pathway, thereby leading to the decrease of the migratory ability.

Conclusion

Overall, the rs79036859 G variant of DAAM1 3′-UTR was identified as a relevant role in BrCa metastasis via the diversity of miR-208a-5p binding affinity.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0747-8) contains supplementary material, which is available to authorized users.