Snail promotes cell migration through PI3K/AKT-dependent Rac1 activation as well as PI3K/AKT-independent pathways during prostate cancer progression

TGFβ1-TNFα regulated secretion of neutrophil chemokines is independent of epithelial-mesenchymal transitions in breast tumor cells

Neutrophils have tumor-promoting roles in breast cancer and are detected in higher numbers in aggressive breast tumors. How aggressive breast tumors recruit neutrophils remains undefined. Here, we investigated the roles of TGF-β1 and TNF-α in the regulation of neutrophil recruitment by breast cancer cells. TGF-β1 and TNF-α are pro-inflammatory factors upregulated in breast tumors and induce epithelial to mesenchymal transitions (EMT), a process linked to cancer cell aggressiveness. We report that, as expected, dual treatment with TGF-β1 and TNF-α induces EMT signatures in premalignant M2 cells, which are part of the MCF10A breast cancer progression model. Conditioned media (CM) harvested from M2 cells treated with TGF-β1/TNF-α gives rise to amplified neutrophil chemotaxis compared to CM from control M2 cells. This response correlates with higher levels of the neutrophil chemokines CXCL1, CXCL2, and CXCL8 and is significantly attenuated in the presence of a CXCL8-neutralizing antibody. Furthermore, we found that secretion of CXCL1 and CXCL8 from treated M2 cells depends on p38MAPK activity. By combining gene editing, immunological and biochemical approaches, we show that the regulation of neutrophil recruitment and EMT signatures are not mechanistically linked in treated M2 cells. Finally, analysis of publicly available cancer cell line transcriptomic databases revealed a significant correlation between CXCL8 and TGF-β1/TNF-α-regulated or effector genes in breast cancer. Together, our findings establish a novel role for the TGF-β1/TNF-α/p38 MAPK signaling axis in regulating neutrophil recruitment in breast cancer, independent of TGF-β1/TNF-α regulated EMT.

In silico analysis of the interaction of de novo peptides derived from Salvia hispanica with anticancer targetsEvaluation of the anticancer potential of de novo peptides derived from Salvia hispanica through molecular docking

Cancer is one of the leading causes of death worldwide. Conventional cancer therapies are not selective to cancer cells resulting in serious side effects on patients. Thus, the need for complementary treatments that improve the patient's response to cancer therapy is highly important. To predict and evaluate the physicochemical characteristics and potential anticancer activity of the peptides identified from S. hispanica protein fraction <1 kDa through the use of in silico tools. Peptides derived from Salvia hispanica's protein fraction <1 kDa were identified and analyzed for the prediction of their physicochemical properties. The characterized peptide sequences were then submitted to a multi-criteria decision analysis to identify the peptides that possess the characteristics to potentially exert anticancer activity. Through molecular docking analysis, the potential anticancer activity of the Potentially Anticancer Peptide (PAP)-1, PAP-2, PAP-3, PAP-4, and PAP-5 was estimated by their binding interactions with cancer and apoptosis-related molecules. All five evaluated PAPs exhibited strong binding interactions (< -100 kcal/mol). However, PAP-3 showed the lowest binding free energies with several of the targets. Thus, PAP-3 shows potential to be used as a nutraceutical or ingredient for functional foods that adjuvate in cancer treatment. Conclusions: Through the molecular docking studies, the binding of the PAPs to target molecules of interest for cancer treatment was successfully simulated, from which PAP-3 exhibited the lowest binding free energies. Further in vitro and in vivo studies are required to validate the predictions obtained by the in silico analysis.Communicated by Ramaswamy H. Sarma.

Lipid metabolism, amino acid metabolism, and prostate cancer: a crucial metabolic journey

Prostate cancer (PCa) is one of the most common malignancies in males worldwide, and its development and progression involve the regulation of multiple metabolic pathways. Alterations in lipid metabolism affect the proliferation and metastatic capabilities of PCa cells. Cancer cells increase lipid synthesis and regulate fatty acid oxidation to meet their growth and energy demands. Similarly, changes occur in amino acid metabolism in PCa. Cancer cells exhibit an increased demand for specific amino acids, and they regulate amino acid transport and metabolic pathways to fulfill their proliferation and survival requirements. These changes are closely associated with disease progression and treatment response in PCa cells. Therefore, a comprehensive investigation of the metabolic characteristics of PCa is expected to offer novel insights and approaches for the early diagnosis and treatment of this disease.

CHST2-mediated sulfation of MECA79 antigens is critical for breast cancer cell migration and metastasis

Snail is a denoted transcriptional repressor that plays key roles in epithelial-mesenchymal transition (EMT) and metastasis. Lately, a plethora of genes can be induced by stable expression of Snail in multiple cell lines. However, the biological roles of these upregulated genes are largely elusive. Here, we report identification of a gene encoding the key GlcNAc sulfation enzyme CHST2 is induced by Snail in multiple breast cancer cells. Biologically, CHST2 depletion results in inhibition of breast cancer cell migration and metastasis, while overexpression of CHST2 promotes cell migration and lung metastasis in nude mice. In addition, the expression level of MECA79 antigen is elevated and blocking the cell surface MECA79 antigen with specific antibodies can override cell migration mediated by CHST2 upregulation. Moreover, the sulfation inhibitor sodium chlorate effectively inhibits the cell migration induced by CHST2. Collectively, these data provide novel insights into the biology of Snail/CHST2/MECA79 axis in breast cancer progression and metastasis as well as potential therapeutic strategy for the diagnosis and treatment of breast cancer metastasis.

A20 interacts with mTORC2 to inhibit the mTORC2/Akt/Rac1 signaling axis in hepatocellular carcinoma cells

A20 acts as a tumor suppressor in hepatocellular carcinoma, especially inhibiting metastasis of the malignant cells. However, the mechanisms whereby A20 plays the inhibitory roles are not understood completely. Rac1 signaling is essential for cell migration in hepatocellular carcinoma metastasis. Nevertheless, it is not known whether and how A20 inhibits Rac1 signaling to suppress the migration of hepatocellular carcinoma cell. Thereby, we analyzed the relationship between A20 and Rac1 activation, as well as the activity of Akt and mTORC2, two signaling components upstream of Rac1, using gain and loss of function experiments. We found that the overexpression of A20 repressed, while the knockdown or knockout of A20 promoted, the activation of Rac1, Akt and mTORC2 in hepatocellular carcinoma cells. Moreover, the inhibitory effect of A20 on the mTORC2/Akt/Rac1 signaling axis was due to the interaction between A20 and mTORC2 complex. The binding of A20 to mTORC2 was mediated by the ZnF7 domain of A20 and M1 ubiquitin chain in the mTORC2 complex. Furthermore, A20 inhibited metastasis of hepatocellular carcinoma cells via restraining mTORC2 in a hepatocellular carcinoma xenograft mouse model. These findings revealed the relationship between A20 and mTORC2, and explained the molecular mechanisms of A20 in inhibition of hepatocellular carcinoma metastasis.

Epithelial–Mesenchymal Transition of Breast Cancer Cells Induced by Activation of the Transcription Factor Snail1

Cancer cells use the program of epithelial-mesenchymal transition (EMT) for initiation of the invasion-metastasis cascade. Using confocal and video-microscopy, reorganization of the cytoskeleton was studied in the MCF-7 breast cancer cells undergoing Snail1-induced EMT. We used the line of MCF-7 cells stably expressing tetOff SNAI1 construct (MCF-7-SNAI1 cells). After tetracycline washout and Snail1 activation MCF-7-SNAI1 cells underwent EMT and acquired a migratory phenotype while retaining expression of E-cadherin. We identified five variants of the mesenchymal phenotype, differing in cell morphology and migration velocity. Migrating cells had high degree of plasticity, which allowed them to quickly change both the phenotype and migration velocity. The changes of the phenotype of MCF-7-SNAI1 cells are based on the Arp2/3-mediated branched actin network polymerization in lamellipodia, myosin-based contractility in the zone behind the nucleus, redistribution of adhesive proteins from cell-cell contacts to the leading edge, and reorganization of intermediate keratin filaments.

Network-based approach for targeting human kinases commonly associated with amyotrophic lateral sclerosis and cancer

Background

Amyotrophic Lateral Sclerosis (ALS) is a rare progressive and chronic motor neuron degenerative disease for which at present no cure is available. In recent years, multiple genes encode kinases and other causative agents for ALS have been identified. Kinases are enzymes that show pleiotropic nature and regulate different signal transduction processes and pathways. The dysregulation of kinase activity results in dramatic changes in processes and causes many other human diseases including cancers.

Methods

In this study, we have adopted a network-based system biology approach to investigate the kinase-based molecular interplay between ALS and other human disorders. A list of 62 ALS-associated-kinases was first identified and then we identified the disease associated with them by scanning multiple disease-gene interaction databases to understand the link between the ALS-associated kinases and other disorders.

Results

An interaction network with 36 kinases and 381 different disorders associated with them was prepared, which represents the complexity and the comorbidity associated with the kinases. Further, we have identified 5 miRNAs targeting the majority of the kinases in the disease-causing network. The gene ontology and pathways enrichment analysis of those miRNAs were performed to understand their biological and molecular functions along with to identify the important pathways. We also identified 3 drug molecules that can perturb the disease-causing network by drug repurposing.

Conclusion

This network-based study presented hereby contributes to a better knowledge of the molecular underpinning of comorbidities associated with the kinases associated with the ALS disease and provides the potential therapeutic targets to disrupt the highly complex disease-causing network.

Distinct Dynamics of Migratory Response to PD-1 and CTLA-4 Blockade Reveals New Mechanistic Insights for Potential T-Cell Reinvigoration following Immune Checkpoint Blockade

Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1), two clinically relevant targets for the immunotherapy of cancer, are negative regulators of T-cell activation and migration. Optimizing the therapeutic response to CTLA-4 and PD-1 blockade calls for a more comprehensive insight into the coordinated function of these immune regulators. Mathematical modeling can be used to elucidate nonlinear tumor-immune interactions and highlight the underlying mechanisms to tackle the problem. Here, we investigated and statistically characterized the dynamics of T-cell migration as a measure of the functional response to these pathways. We used a previously developed three-dimensional organotypic culture of patient-derived tumor spheroids treated with anti-CTLA-4 and anti-PD-1 antibodies for this purpose. Experiment-based dynamical modeling revealed the delayed kinetics of PD-1 activation, which originates from the distinct characteristics of PD-1 and CTLA-4 regulation, and followed through with the modification of their contributions to immune modulation. The simulation results show good agreement with the tumor cell reduction and active immune cell count in each experiment. Our findings demonstrate that while PD-1 activation provokes a more exhaustive intracellular cascade within a mature tumor environment, the time-delayed kinetics of PD-1 activation outweighs its preeminence at the individual cell level and consequently confers a functional dominance to the CTLA-4 checkpoint. The proposed model explains the distinct immunostimulatory pattern of PD-1 and CTLA-4 blockade based on mechanisms involved in the regulation of their expression and may be useful for planning effective treatment schemes targeting PD-1 and CTLA-4 functions.

Combinatorial approaches of nanotherapeutics for inflammatory pathway targeted therapy of prostate cancer

Prostate cancer (PC) is the most prevalent male urogenital cancer worldwide. PC patients presenting an advanced or metastatic cancer succumb to the disease, even after therapeutic interventions including radiotherapy, surgery, androgen deprivation therapy (ADT), and chemotherapy. One of the hallmarks of PC is evading immune surveillance and chronic inflammation, which is a major challenge towards designing effective therapeutic formulations against PC. Chronic inflammation in PC is often characterized by tumor microenvironment alterations, epithelial-mesenchymal transition and extracellular matrix modifications. The inflammatory events are modulated by reactive nitrogen and oxygen species, inflammatory cytokines and chemokines. Major signaling pathways in PC includes androgen receptor, PI3K and NF-κB pathways and targeting these inter-linked pathways poses a major therapeutic challenge. Notably, many conventional treatments are clinically unsuccessful, due to lack of targetability and poor bioavailability of the therapeutics, untoward toxicity and multidrug resistance. The past decade witnessed an advancement of nanotechnology as an excellent therapeutic paradigm for PC therapy. Modern nanovectorization strategies such as stimuli-responsive and active PC targeting carriers offer controlled release patterns and superior anti-cancer effects. The current review initially describes the classification, inflammatory triggers and major inflammatory pathways of PC, various PC treatment strategies and their limitations. Subsequently, recent advancement in combinatorial nanotherapeutic approaches, which target PC inflammatory pathways, and the mechanism of action are discussed. Besides, the current clinical status and prospects of PC homing nanovectorization, and major challenges to be addressed towards the advancement PC therapy are also addressed.

Nectin-4 promotes osteosarcoma progression and metastasis through activating PI3K/AKT/NF-κB signaling by down-regulation of miR-520c-3p

PURPOSE

Nectin-4 is specifically up-regulated in various tumors, exert crucial effects on tumor occurrence and development. Nevertheless, the role and molecular mechanism of Nectin-4 in osteosarcoma (OS) are rarely studied.

METHODS

The expression of Nectin-4 and its relationship with clinical characteristics of OS were investigated using OS clinical tissues, tissue microarrays, TCGA, and GEO databases. Moreover, the effect of Nectin-4 on cell growth and mobility was detected by CCK-8, colony formation, transwell, and wound-healing assays. The RT-qPCR, Western blotting, and luciferase reporter assays were performed to explore molecular mechanisms through which Nectin-4 mediates the expression of miR-520c-3p, thus modulating PI3K/AKT/NF-κB signaling. In vivo mice models constructed by subcutaneous transplantation and tail vein injection were used to validate the functional roles of Nectin-4 and miR-520c-3p.

RESULTS

Nectin-4 displayed a higher expression in OS tumor tissues compared with normal tissues, and its overexpression was positively associated with tumor stage and metastasis in OS patients. Functionally, Nectin-4 enhanced OS cells growth and mobility in vitro. Mechanistically, Nectin-4 down-regulated the levels of miR-520c-3p that directly targeted AKT-1 and P65, thus leading to the stimulation of PI3K/AKT/NF-κB signaling. In addition, the expression of miR-520c-3p was apparently lower in OS tissues than in normal tissues, and its low expression was significantly related to tumor metastasis. Furthermore, ectopic expression of miR-520c-3p markedly blocked the effect of Nectin-4 on OS cell growth and mobility. Knockdown of Nectin-4 could suppress the tumorigenesis and metastasis in vivo, which could be remarkably reversed by miR-520c-3p silencing.

CONCLUSIONS

Nectin-4 as an oncogene can promote OS progression and metastasis by activating PI3K/AKT/NF-κB signaling via down-regulation of miR-520c-3p, which could represent a novel avenue for identifying a potential therapeutic target for improving patient outcomes.

Role of ELMO1 in inflammation and cancer-clinical implications

BACKGROUND

Engulfment and cell motility protein 1 (ELMO1) is a key protein for innate immunity since it is required for the clearance of apoptotic cells and pathogenic bacteria as well as for the control of inflammatory responses. ELMO1, through binding with Dock180 and activation of the Rac1 signaling pathway, plays a significant role in cellular shaping and motility. Rac-mediated actin cytoskeletal rearrangement is essential for bacterial phagocytosis, but also plays a crucial role in processes such as cancer cell invasion and metastasis. While the role of ELMO1 in bacterial infection and inflammatory responses is well established, its implication in cancer is not widely explored yet. Molecular changes or epigenetic alterations such as DNA methylation, which ultimately leads to alterations in gene expression and deregulation of cellular signaling, has been reported for ELMO1 in different cancer types.

CONCLUSIONS

In this review, we provide an updated and comprehensive summary of the roles of ELMO1 in infection, inflammatory diseases and cancer. We highlight the possible mechanisms regulated by ELMO1 that are relevant for cancer development and progression and provide insight into the possible use of ELMO1 as a diagnostic biomarker and therapeutic target.

EGF/EGFR Promotes Salivary Adenoid Cystic Carcinoma Cell Malignant Neural Invasion via Activation of PI3K/AKT and MEK/ERK Signaling

BACKGROUND

Salivary adenoid cystic carcinoma (SACC) is one of the most common malignant cancers of the salivary gland, and 32.4-72.0% of SACC cases exhibit neural invasion (NI), however, the molecular mechanism underlying the high invasion potential of SACC remains unclear.

METHODS

The present study investigated the role of epidermal growth factor receptor (EGFR) in the AKT inhibition- or mitogen-activated protein kinase kinase (MEK)-induced NI and epithelial-mesenchymal transition (EMT) in SACC cells using EGFR, PI3K and MEK inhibitors. SACC 83 cell viability was assessed using an MTT assay, and a wound healing assay was performed to evaluate cell migration. Immunohistochemical staining with streptavidin peroxidase was used to detect the positive expression rate of EMT, AKT, phosphorylated (p)-AKT, ERK and p-ERK proteins. The impact of EGFR, PI3K and MEK inhibitors on tumor growth and NI was examined in a xenograft model in nude mice.

RESULTS

EGF and EGFR are effective in increasing cell viability, migration and invasion. SACC metastasis is affected by the PI3K/AKT and MEK/ERK pathways, both of which are initiated by EGF/EGFR. The EMT and NI are regulated by the EGF/EGFR, PI3K/AKT and MEK/ERK pathways. The present findings demonstrate the importance of suppressed EGFR/AKT/MEK signaling in NI in SACC by neural-tumor co-culture in vitro. Furthermore, our preclinical experiment provides solid evidence that injection of EGFR, PI3K and MEK inhibitors obviously suppressed the tumor growth and NI of SACC cells in nude mice.

CONCLUSION

It was identified that inhibitors of EGFR, PI3K/AKT or MEK/ERK suppressed the proliferation, migration and NI of SACC-83 cells via downregulation of the PI3K/AKT or MEK/ERK pathways. It was also demonstrated that inhibition of EGFR abolishes EMT in SACC by inhibiting the signaling of PI3K/AKT and MEK/ERK. The present results suggest the potential effectiveness of targeting multiple oncogenes associated with downstream pathways of EGF/EGFR, as well as potential therapeutic targets to limit NI in SACC by PI3K/AKT or MEK/ERK inhibition.

Risk-Related Genes and Associated Signaling Pathways of Gastrointestinal Stromal Tumors

Purpose

Knowledge on the potential association between differential gene expression and risk of gastrointestinal stromal tumors (GISTs) is currently limited. We used bioinformatics tools to identify differentially expressed genes in GIST samples and the related signaling pathways of these genes.

Patients and Methods

The GSE136755 dataset was obtained from the GEO database and differentially expressed genes (CENPA, CDK1, TPX2, CCNB1, CCNA2, BUB1, AURKA, KIF11, NDC80) were screened using String and Cytoscape bioinformatics tools. Then, three groups of eight patients at high, intermediate and low risk of GIST were selected from patients diagnosed with GIST by immunohistochemistry in our hospital from October 2020 to March 2021. Differential expression of CDK1 and BUB1 was verified by comparing the amount of expressed p21-Activated kinase 4 (PAK4) protein in pathological sections.

Results

SPSS26.0 analysis showed that the expression level of PAK4 in GISTs was significantly higher than in normal tissues and paratumoral tissues and there was significant difference among the three groups of patients (P < 0.01). PAK4 levels in paratumoral and normal tissues were negligible with no significant difference between the tissues.

Conclusion

CENPA, CDK1, TPX2, CCNB1, CCNA2, BUB1, AURKA, KIF11 and NDC80 gene expression can be used as biomarkers to assess the risk of gastrointestinal stromal tumors whereby expression increases gradually with the increased risk of GIST formation. The genes encode proteins that regulate the division, proliferation and apoptosis of gastrointestinal stromal tumors mainly through PI3K/AKT, MARK, P53, WNT and other signaling pathways.

Isoforms of autophagy-related proteins: role in glioma progression and therapy resistance

Autophagy is the process of recycling and utilization of degraded organelles and macromolecules in the cell compartments formed during the fusion of autophagosomes with lysosomes. During autophagy induction the healthy and tumor cells adapt themselves to harsh conditions such as cellular stress or insufficient supply of nutrients in the cell environment to maintain their homeostasis. Autophagy is currently seen as a form of programmed cell death along with apoptosis and necroptosis. In recent years multiple studies have considered the autophagy as a potential mechanism of anticancer therapy in malignant glioma. Although, subsequent steps in autophagy development are known and well-described, on molecular level the mechanism of autophagosome initiation and maturation using autophagy-related proteins is under investigation. This article reviews current state about the mechanism of autophagy, its molecular pathways and the most recent studies on roles of autophagy-related proteins and their isoforms in glioma progression and its treatment.

Long non-coding RNA ncRuPAR regulates gastric cancer cell proliferation and apoptosis via phosphoinositide 3-kinase/protein kinase B signaling

Objective: To determine the effect and mechanism of the long non-coding RNA (lncRNA) ncRuPAR (non-protein coding RNA, upstream of coagulation factor II thrombin receptor [F2R]/protease-activated receptor-1 [PAR-1]) in human gastric cancer. Methods: HGC-27-ncRuPAR overexpression and MGC-803-ncRuPAR-RNAi knockdown gastric cancer cell lines were established. We assessed the effect of ncRuPAR on cell proliferation, apoptosis, migration, and invasion using Cell Counting Kit 8, flow cytometry, scratch and transwell assays, respectively. Differentially expressed genes in HGC-27-ncRuPAR overexpression and HGC-27-empty vector cell lines were identified using Affymetrix GeneChip microarray analysis. Ingenuity Pathway Analysis (IPA) of the microarray results was subsequently conducted to identify ncRuPAR-enriched pathways, followed by validation using real time-quantitative PCR (RT-qPCR). As one of the top enriched pathways, phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was further examined by western blotting to determine its role in ncRuPAR-mediated regulation of gastric cancer pathogenesis. Results: ncRuPAR inhibited human gastric cancer cell proliferation and induced G1/S phase arrest and apoptosis, but did not affect migration or invasion in vitro. Overexpression of ncRuPAR in vitro was found to inhibit its known target PAR-1, as well as PI3K/Akt signaling. The downstream targets of PI3K/Akt, cyclin D1 was downregulated, but there was no change in expression level of B-cell lymphoma 2 (Bcl-2). Conclusions: We showed that lncRNA-ncRuPAR could inhibit tumor cell proliferation and promote apoptosis of human gastric cancer cells, potentially by inhibiting PAR-1, PI3K/Akt signaling, and cyclin D1. The results suggest a potential role for lncRNAs as key regulatory hubs in GC progression.

The Transcription Factors Zeb1 and Snail Induce Cell Malignancy and Cancer Stem Cell Phenotype in Prostate Cells, Increasing Androgen Synthesis Capacity and Therapy Resistance

Prostate cancer (PCa) incidence has increased during the last decades, becoming one of the leading causes of death by cancer in men worldwide. During an extended period of prostate cancer, malignant cells are androgen-sensitive being testosterone the main responsible for tumor growth. Accordingly, treatments blocking production and action of testosterone are mostly used. However, during disease progression, PCa cells become androgen insensitive producing a castration-resistant stage with a worse prognosis. Overcoming castration-resistant prostate cancer (CRPC) has become a great challenge in the management of this disease. In the search for molecular pathways leading to therapy resistance, the epithelial-mesenchymal transition (EMT), and particularly the transcription factors zinc finger E-box-binding homeobox 1 (Zeb1) and zinc finger protein SNAI1 (Snail), master genes of the EMT, have shown to have pivotal roles. Also, the discovery that cancer stem cells (CSCs) can be generated de novo from their non-CSCs counterpart has led to the question whereas these EMT transcription factors could be implicated in this dynamic conversion between non-CSC and CSC. In this review, we analyze evidence supporting the idea that Zeb1 and Snail induce cell malignancy and cancer stem cell phenotype in prostate cells, increasing androgen synthesis capacity and therapy resistance.

CMAHP promotes metastasis by reducing ubiquitination of Snail and inducing angiogenesis via GM-CSF overexpression in gastric cancer

Pseudogenes are generally considered "junk" DNA or "genomic fossils" generated during the evolution process that lack biological activity. However, accumulating reports indicate that pseudogenes have biological functions critical for cancer development. Experiments from the current study showed marked overexpression of the cytidine monophospho-N-acetylneuraminic acid hydroxylase pseudogene (CMAHP) in gastric cancer, which was associated with poor overall survival. However, the mechanisms underlying the activity of CMAHP in tumor development are largely unknown. Gene Set Enrichment Analysis (GSEA) revealed that CMAHP-correlated genes are significantly involved in epithelial-mesenchymal transition (EMT) and angiogenesis. Functional studies further confirmed that CMAHP mediates metastasis and angiogenesis in vitro and in vivo. Furthermore, CMAHP promoted cancer cell migration, invasion, and metastasis through Snail overexpression, which decreased ubiquitination mediated by NF-κB signaling. Angiogenesis is known to be induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulation. CMAHP increased GM-CSF transactivation via promoting direct binding of c-Jun to the -1981/-1975 region of the GM-CSF promoter. Notably, CMAHP interacts with Histone H1.4 promoting histone acetylation to enhance c-Jun and RelA (p65) expression. Our collective findings provide novel evidence that CMAHP contributes to tumor progression and modulates metastasis and angiogenesis in gastric cancer.

Role of Nectin‑4 protein in cancer (Review)

The Nectin cell adhesion molecule (Nectin) family members are Ca2+‑independent immunoglobulin‑like cellular adhesion molecules (including Nectins 1‑4), involved in cell adhesion via homophilic/heterophilic interplay. In addition, the Nectin family plays a significant role in enhancing cellular viability and movement ability. In contrast to enrichment of Nectins 1‑3 in normal tissues, Nectin‑4 is particularly overexpressed in a number of tumor types, including breast, lung, urothelial, colorectal, pancreatic and ovarian cancer. Moreover, the upregulation of Nectin‑4 is an independent biomarker for overall survival in numerous cancer types. A large number of studies have revealed that high expression of Nectin‑4 is closely related to tumor occurrence and development in various cancer types, but the manner in which Nectin‑4 protein contributes to the onset and development of these malignancies is yet unknown. The present review summarizes the molecular mechanisms and functions of Nectin‑4 protein in the biological processes and current advances with regard to its expression and regulation in various cancer types.

p32 promotes melanoma progression and metastasis by targeting EMT markers, Akt/PKB pathway, and tumor microenvironment

Melanoma originates from melanin-producing cells called melanocytes. Melanoma poses a great risk because of its rapid ability to spread and invade new organs. Cellular metastasis involves alteration in the gene expression profile and their transformation from epithelial to mesenchymal state. Despite of several advances, metastatic melanoma being a key cause of therapy failure and mortality remains poorly understood. p32 has been found to be involved in various physiological and pathophysiological conditions. However, the role of p32 in melanoma progression and metastasis remains underexplored. Here, we identify the role of p32 in the malignancy of both murine and human melanoma. p32 knockdown leads to reduced cell proliferation, migration, and invasion in murine and human melanoma cells. Furthermore, p32 promotes in vitro tumorigenesis, inducing oncogenes and EMT markers. Mechanistically, we show p32 regulates tumorigenic and metastatic properties through the Akt/PKB signaling pathway in both murine and human melanoma. Furthermore, p32 silencing attenuates melanoma tumor progression and lung metastasis in vivo, modulating the tumor microenvironment by inhibiting the angiogenesis, infiltration of macrophages, and leukocytes in mice. Taken together, our findings identify that p32 drives melanoma progression, metastasis, and regulates the tumor microenvironment. p32 can be a target of a novel therapeutic approach in the regulation of melanoma progression and metastasis.

Dynamic extracellular matrix stiffening induces a phenotypic transformation and a migratory shift in epithelial cells

Soft tissue tumors, including breast cancer, become stiffer throughout disease progression. This increase in stiffness has been shown to correlate to malignant phenotype and epithelial-to-mesenchymal transition (EMT) in vitro. Unlike current models, utilizing static increases in matrix stiffness, our group has previously created a system that allows for dynamic stiffening of an alginate-matrigel composite hydrogel to mirror the native dynamic process. Here, we utilize this system to evaluate the role of matrix stiffness on EMT and metastasis both in vitro and in vivo. Epithelial cells were seen to lose normal morphology and become protrusive and migratory after stiffening. This shift corresponded to a loss of epithelial markers and gain of mesenchymal markers in both the cell clusters and migrated cells. Furthermore, stiffening in a murine model reduced tumor burden and increased migratory behavior prior to tumor formation. Inhibition of FAK and PI3K in vitro abrogated the morphologic and migratory transformation of epithelial cell clusters. This work demonstrates the key role extracellular matrix stiffening has in tumor progression through integrin signaling and, in particular, its ability to drive EMT-related changes and metastasis.

Anti-Proliferative and Anti-Migratory Activities of Hispidulin on Human Melanoma A2058 Cells

Melanoma represents less than 5% of skin cancers, but is the most lethal, mainly because of its high-metastatic potential and resistance to various therapies. Therefore, it is important to develop effective treatments, especially chemotherapeutic drugs with cytotoxicity, anti-metastaticity, and few side effects. One such natural product is hispidulin, a flavone distributed in plants of the Asteraceae. Previous studies have demonstrated that hispidulin has various pharmacological benefits, such as anti-tumor, anti-inflammation, and anti-allergic effects. This study aims to explore the effects of hispidulin against melanoma in vitro and in vivo. Results revealed that hispidulin selectively decreased the cell viability of A2058 cells in a dose- and time-dependent manner. Hispidulin induced cells accumulated in the sub-G1 phase via activating caspase 8 and 9, increased cleaved caspase 3, and cleaved PARP expression. Hispidulin was able to decrease AKT and ERK phosphorylation, which facilitated cell growth and survival. Moreover, hispidulin promoted reactive oxygen species generation in cells and suppressed cell migration through downregulated matrix metalloproteinase-2 expression. Hispidulin significantly inhibited tumor growth in a xenograft model. Based on these results, hispidulin produces its anti-melanoma effects by inducing cancer cell apoptosis and reducing its migration. Therefore, we suggest hispidulin as a potent therapeutic candidate for melanoma treatment.

NET1 promotes HCC growth and metastasis in vitro and in vivo via activating the Akt signaling pathway

Neuroepithelial cell transforming gene 1 (NET1), a member of the guanine nucleotide exchange factor family, is involved in various cancers, including gastric cancer, breast cancer and glioma. However, the role of NET1 in hepatocellular carcinoma (HCC) remains largely uncovered. In this study, we found that NET1 expression was upregulated in HCC, and that upregulated NET1 expression was closely associated with poor prognosis and some clinical characteristics in HCC patients. Whilst forced expression of NET1 in HCC cells was observed to significantly promote cell growth and metastasis in vitro and in vivo; downregulation of NET1 was shown to exhibit an opposite inhibitory effect. RNA-seq analysis and gene set enrichment analysis demonstrated that knockdown of NET1 significantly suppressed the level of Akt phosphorylation level and the expression of Akt downstream genes in HCC cells. Moreover, MK2206, a potent Akt inhibitor was shown to block the NET1-induced effects in HCC. Taken together, this study demonstrated that, through the Akt signaling pathway, NET1 plays an oncogenic role in HCC progression and metastasis. Hence, NET1 may potentially be used as a potential therapeutic target and prognostic marker of HCC.

Signaling Pathways That Control Apoptosis in Prostate Cancer

Prostate cancer is the second most common malignancy and the fifth leading cancer-caused death in men worldwide. Therapies that target the androgen receptor axis induce apoptosis in normal prostates and provide temporary relief for advanced disease, yet prostate cancer that acquired androgen independence (so called castration-resistant prostate cancer, CRPC) invariably progresses to lethal disease. There is accumulating evidence that androgen receptor signaling do not regulate apoptosis and proliferation in prostate epithelial cells in a cell-autonomous fashion. Instead, androgen receptor activation in stroma compartments induces expression of unknown paracrine factors that maintain homeostasis of the prostate epithelium. This paradigm calls for new studies to identify paracrine factors and signaling pathways that control the survival of normal epithelial cells and to determine which apoptosis regulatory molecules are targeted by these pathways. This review summarizes the recent progress in understanding the mechanism of apoptosis induced by androgen ablation in prostate epithelial cells with emphasis on the roles of BCL-2 family proteins and "druggable" signaling pathways that control these proteins. A summary of the clinical trials of inhibitors of anti-apoptotic signaling pathways is also provided. Evidently, better knowledge of the apoptosis regulation in prostate epithelial cells is needed to understand mechanisms of androgen-independence and implement life-extending therapies for CRPC.

Krill oil extract inhibits the migration of human colorectal cancer cells and down-regulates EGFR signalling and PD-L1 expression

BACKGROUND

The currently available treatments for colorectal cancer (CRC) are often associated with serious side-effects. Therefore, the development of a novel nutraceutical agent may provide an alternative complementary therapy for CRC. Overexpression of the epidermal growth factor receptor (EGFR) associates with a range of cancers while downregulation of EGFR signalling can inhibit cancer growth. Our previous studies have shown that the free fatty acid extract (FFAE) of krill oil exhibits anti-proliferative and pro-apoptotic properties. This study determines the effects of krill oil extract on the migration of human CRC cells, and its potential role in modulating EGFR signalling pathway and the expression of programmed death ligand 1 (PD-L1).

METHODS

Human CRC cells, DLD-1 and HT-29 were treated with FFAE of KO at 0.03 and 0.12 μL/100 μL for 8 or 24 h. Cell migration was determined by Boyden chamber migration assay. The expression of EGFR, phosphorylated EGFR (pEGFR), protein kinase B (AKT), phosphorylated AKT (pAKT), extracellular signal regulated kinase (ERK1/2), phosphorylated ERK1/2 (pERK1/2) as well as PD-L1 were assessed by western blotting and immunohistochemistry.

RESULTS

The FFAE of krill oil significantly inhibited cell migration compared to ethanol-treated (vehicle control) cells (P < 0.01 to P < 0.001). At the molecular level, krill oil extract reduced the expression of EGFR, pEGFR (P < 0.001 for both) and their downstream signalling, pERK1/2 and pAKT (P < 0.01 to P < 0.001) without altering total ERK 1/2 and AKT levels. In addition, the expression of PD-L1 was reduced by 67 to 72% (P < 0.001) following the treatment with krill oil extract.

CONCLUSION

This study has demonstrated that krill oil may be a potential therapeutic/adjunctive agent for CRC attributed to its anti-migratory effects.. The potential anti-cancer properties of krill oil are likely to be associated with the downregulation of EGFR, pEGFR and their downstream pERK/ERK1/2 and pAKT/AKT signalling pathways along with the downregulation of PD-L1.

Aberrant JmjC domain-containing protein 8 (JMJD8) expression promotes activation of AKT and tumor epithelial-mesenchymal transition

Posttranslational modifications of histone and nonhistone proteins greatly influence numerous molecular events in multiple diseases. Jumonji domain-containing proteins are a family functioning as histone demethylase. Jumonji domain-containing protein 8 (JMJD8) is Jumonji C (JmjC) domain-only member of this family, and its physiological functions remain largely unknown. In this study, we investigated the mechanism by which aberrant JMJD8 stimulates phosphorylation of AKT and activate AKT/GSK3β/β-catenin signaling pathway thereby promotes tumor cell epithelial-mesenchymal transition (EMT). We demonstrated that knockdown of JMJD8 increased the interaction of SETDB1 and phosphoinositide-dependent kinase 1 (PDK1) with AKT1 and resulted in enhanced trimethylation of AKT1 at lysine 142 (K142), which is crucial for cell membrane recruitment, phosphorylation, and activation of AKT. Moreover, the mutation of histidine 200 of JMJD8 (JMJD8-H200Q) disrupted its binding with AKT1 and increased interaction of SETDB1 and PDK1 with AKT1. Furthermore, histone demethylase jumonji domain-containing protein 2B functioned as an adapter to recruit β-catenin to the methylated AKT1 upon JMJD8 depression, which facilitated the phosphorylation of β-catenin at Ser552 and its accumulation in cell nucleus where the activated β-catenin transcriptionally stimulated the expression of genes involved in EMT. In conclusion, our data unraveled a novel role of JMJD8 in regulating the migration and invasion of tumor via modulating AKT methylation and activation. In addition, this study showed that JMJD8 is a potential biomarker and drug design target for tumor EMT.

Inhibition of PI3K/Akt signaling suppresses epithelial-to-mesenchymal transition in hepatocellular carcinoma through the Snail/GSK-3/beta-catenin pathway

Background/Aims

Patients with advanced hepatocellular carcinoma (HCC) have a poor prognosis due to the lack of effective systemic therapies. Epithelial-to-mesenchymal transition (EMT) is a pivotal event in tumor progression, during which cancer cells acquire invasive properties. In this study, we investigated the effects of phosphatidylinositol 3-kinase (PI3K) inhibitors, including LY294002 and idelalisib, on the EMT features of HCC cells in vitro.

Methods

Human HCC cell lines, including Huh-BAT and HepG2, were used in this study. Cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, and cell cycle distributions were evaluated using a flow cytometer by propidium iodide staining. Immunofluorescence staining, quantitative real-time polymerase chain reaction, and immunoblotting were performed to detect EMT-associated changes.

Results

PI3K inhibitors suppressed the proliferation and invasion of HCC cells and deregulated the expression of EMT markers, as indicated by increased expression of E-cadherin, an epithelial marker, and decreased expression of N-cadherin, a mesenchymal marker, and Snail, a transcription factor implicated in EMT regulation. Furthermore, LY294002 and idelalisib inhibited the phosphorylation of GSK-3β and induced the nuclear translocation of GSK-3β, which corresponded to the downregulation of Snail and β-catenin expressions in Huh-BAT and HepG2 cells.

Conclusions

The inhibition of PI3K/Akt signaling decreases Snail expression by enhancing the nuclear translocation of GSK-3β, which suppresses EMT in HCC cells, suggesting the potential clinical application of PI3K inhibitors for HCC treatment.

AKT drives sustained motility following MEK inhibition via promoting SNAIL and AXL in MDA-MB-231 LM2

The adaptive activation of alternative signaling pathways contributes to acquired resistance against targeted cancer therapies. Our previous research has shown that blocking Ras/ERK signaling promotes PI3K/AKT signaling in the lung metastatic derivative of MDA-MB-231 (LM2). Because AKT activation was required to drive sustained cell motility following MEK suppression, we extend our research to elucidate how activation of the PI3K/AKT signaling drives sustained motility following MEK inhibition. Reverse phase protein array (RPPA) revealed that SNAIL (SNAI1) was upregulated in U0126 (MEK inhibitor)-treated LM2 cells. Importantly, LM2 cells simultaneously treated with U0126 and PI3K inhibitor LY294002 exhibited reduced expression of SNAIL. Furthermore, depletion of SNAIL led to reduced cell motility in U0126-treated LM2 cells. In addition, we identified AXL as another downstream effector of AKT. These results suggest that SNAIL and AXL are key factors mediating sustained motility of LM2 cells following MEK suppression. Because AKT mediates motile behavior under MEK suppression, our results suggest that AKT and AXL may be targeted to overcome resistance against drugs targeting the Ras/ERK pathway.

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

FAM46C controls antibody production by the polyadenylation of immunoglobulin mRNAs and inhibits cell migration in multiple myeloma

FAM46C, frequently mutated in multiple myeloma (MM), has recently been shown to encode a non‐canonical poly(A) polymerase (ncPAP). However, its target mRNAs and its role in MM pathogenesis remain mostly unknown. Using CRISPR‐Cas9 technology and gene expression analysis, we found that the inactivation of FAM46C in MM down‐regulates immunoglobulins (Igs) and several mRNAs encoding ER‐resident proteins, including some involved in unfolded protein response and others that affect glycosylation. Interestingly, we show that FAM46C expression is induced during plasma cell (PC) differentiation and that Ig mRNAs encoding heavy and light chains are substrates of the ncPAP, as revealed by poly(A) tail‐length determination assays. The absence of the ncPAP results in Ig mRNA poly(A) tail‐shortening, leading to a reduction in mRNA and protein abundance. On the other hand, loss of FAM46C up‐regulates metastasis‐associated lncRNA MALAT1 and results in a sharp increase in the migration ability. This phenotype depends mainly on the activation of PI3K/Rac1 signalling, which might have significant therapeutic implications. In conclusion, our results identify Ig mRNAs as targets of FAM46C, reveal an important function of this protein during PC maturation to increase antibody production and suggest that its role as a tumour suppressor might be related to the inhibition of myeloma cell migration.

Myo1e modulates the recruitment of activated B cells to inguinal lymph nodes

The inclusion of lymphocytes in high endothelial venules and their migration to the lymph nodes are critical steps in the immune response. Cell migration is regulated by the actin cytoskeleton and myosins. Myo1e is a long-tailed class I myosin and is highly expressed in B cells, which have not been studied in the context of cell migration. By using intravital microscopy in an in vivo model and performing in vitro experiments, we studied the relevance of Myo1e for the adhesion and inclusion of activated B cells in high endothelial venules. We observed reduced expression of integrins and F-actin in the membrane protrusions of B lymphocytes, which might be explained by deficiencies in vesicular trafficking. Interestingly, the lack of Myo1e reduced the phosphorylation of focal adhesion kinase (FAK; also known as PTK2), AKT (also known as AKT1) and RAC-1, disturbing the FAK-PI3K-RAC-1 signaling pathway. Taken together, our results indicate a critical role of Myo1e in the mechanism of B-cell adhesion and migration.

P-REX1-Independent, Calcium-Dependent RAC1 Hyperactivation in Prostate Cancer

The GTPase Rac1 is a well-established master regulator of cell motility and invasiveness contributing to cancer metastasis. Dysregulation of the Rac1 signaling pathway, resulting in elevated motile and invasive potential, has been reported in multiple cancers. However, there are limited studies on the regulation of Rac1 in prostate cancer. Here, we demonstrate that aggressive androgen-independent prostate cancer cells display marked hyperactivation of Rac1. This hyperactivation is independent of P-Rex1 activity or its direct activators, the PI3K product PIP₃ and Gβγ subunits. Furthermore, we demonstrate that the motility and invasiveness of PC3 prostate cancer cells is independent of P-Rex1, supporting the analysis of publicly available datasets indicating no correlation between high P-Rex1 expression and cancer progression in patients. Rac1 hyperactivation was not related to the presence of activating Rac1 mutations and was insensitive to overexpression of a Rac-GAP or the silencing of specific Rac-GEFs expressed in prostate cancer cells. Interestingly, active Rac1 levels in these cells were markedly reduced by elevations in intracellular calcium or by serum stimulation, suggesting the presence of an alternative means of Rac1 regulation in prostate cancer that does not involve previously established paradigms.

Nakchbandi I. The Rho GTPase RAC1 in Osteoblasts Controls Their Function

The regulation of the differentiation of the bone-forming cells, the osteoblasts, is complex. Many signaling pathways converge on the master regulator of osteoblast differentiation Runx2. The role of molecules that integrate several signaling pathways such as the Rho GTPases need to be better understood. We, therefore, asked at which stage Rac1, one of the Rho GTPase, is needed for osteoblast differentiation and whether it is involved in two pathways, the anabolic response to parathyroid hormone and the stimulatory effect of fibronectin isoforms on integrins. Genetic deletion of Rac1 in preosteoblasts using the osterix promoter diminished osteoblast differentiation in vitro. This effect was however similar to the presence of the promoter by itself. We, therefore, applied a Rac1 inhibitor and confirmed a decrease in differentiation. In vivo, Rac1 deletion using the osterix promoter decreased bone mineral density as well as histomorphometric measures of osteoblast function. In contrast, deleting Rac1 in differentiating osteoblasts using the collagen α1(I) promoter had no effects. We then evaluated whether intermittent parathyroid hormone (PTH) was able to affect bone mineral density in the absence of Rac1 in preosteoblasts. The increase in bone mineral density was similar in control animals and in mice in which Rac1 was deleted using the osterix promoter. Furthermore, stimulation of integrin by integrin isoforms was able to enhance osteoblast differentiation, despite the deletion of Rac1. In summary, Rac1 in preosteoblasts is required for normal osteoblast function and bone density, but it is neither needed for PTH-mediated anabolic effects nor for integrin-mediated enhancement of differentiation.

DEPTOR is an in vivo tumor suppressor that inhibits prostate tumorigenesis via the inactivation of mTORC1/2 signals

The DEPTOR-mTORC1/2 axis has been shown to play an important, but a context dependent role in the regulation of proliferation and the survival of various cancer cells in cell culture settings. The in vivo role of DEPTOR in tumorigenesis remains elusive. Here we showed that the levels of both DEPTOR protein and mRNA were substantially decreased in human prostate cancer tissues, which positively correlated with disease progression. DEPTOR depletion accelerated proliferation and survival, migration, and invasion in human prostate cancer cells. Mechanistically, DEPTOR depletion not only activated both mTORC1 and mTORC2 signals to promote cell proliferation and survival, but also induced an AKT-dependent epithelial–mesenchymal transition (EMT) and β-catenin nuclear translocation to promote cell migration and invasion. Abrogation of mTOR or AKT activation rescued the biological consequences of DEPTOR depletion. Importantly, in a Deptor-KO mouse model, Deptor knockout accelerated prostate tumorigenesis triggered by Pten loss via the activation of mTOR signaling. Collectively, our study demonstrates that DEPTOR is a tumor suppressor in the prostate, and its depletion promotes tumorigenesis via the activation of mTORC1 and mTORC2 signals. Thus, DEPTOR reactivation via a variety of means would have therapeutic potential for the treatment of prostate cancer.

Driver gene alterations and activated signaling pathways toward malignant progression of gastrointestinal stromal tumors

Mutually exclusive KIT and PDGFRA mutations are considered to be the earliest events in gastrointestinal stromal tumors (GIST), but insufficient for their malignant progression. Herein, we aimed to identify driver genes and signaling pathways relevant to GIST progression. We investigated genetic profiles of 707 driver genes, including mutations, gene fusions, copy number gain or loss, and gene expression for 65 clinical specimens of surgically dissected GIST, consisting of six metastatic tumors and 59 primary tumors from stomach, small intestine, rectum, and esophagus. Genetic alterations included oncogenic mutations and amplification‐dependent expression enhancement for oncogenes (OG), and loss of heterozygosity (LOH) and expression reduction for tumor suppressor genes (TSG). We assigned activated OG and inactivated TSG to 27 signaling pathways, the activation of which was compared between malignant GIST (metastasis and high‐risk GIST) and less malignant GIST (low‐ and very low‐risk GIST). Integrative molecular profiling indicated that a greater incidence of genetic alterations of driver genes was detected in malignant GIST (96%, 22 of 23) than in less malignant GIST (73%, 24 of 33). Malignant GIST samples groups showed mutations, LOH, and aberrant expression dominantly in driver genes associated with signaling pathways of PI3K (PIK3CA, AKT1, and PTEN) and the cell cycle (RB1, CDK4, and CDKN1B). Additionally, we identified potential PI3K‐related genes, the expression of which was upregulated (SNAI1 and TPX2) or downregulated (BANK1) in malignant GIST. Based on our observations, we propose that inhibition of PI3K pathway signals might potentially be an effective therapeutic strategy against malignant progression of GIST.

Lactobacillus reuteri extracts promoted wound healing via PI3K/AKT/β-catenin/TGFβ1 pathway

BACKGROUND

The balance of oral microbiomes is crucial to maintain oral health. Microecological imbalance can impair the function of mesenchymal stem cells (MSCs) and lead to delay wound healing. Probiotics is a promising prevention approach for the treatment of oral inflammatory diseases caused by a bacterial infection. However, the effect of probiotics on oral MSCs and wound healing is unclear. In the present study, we used one type of probiotics Lactobacillus reuteri extracts to determine whether bacterial extracts could regulate the functions of gingiva MSCs (GMSCs) and promote wound healing.

METHODS

Lactobacillus reuteri was prepared with bacterial extracts using ultrasonic crushing apparatus. The effects of Lactobacillus reuteri extracts on GMSCs were tested using the cell scratch migration, alkaline phosphatase (ALP) activity, alizarin red staining, cell counting kit-8, real-time PCR, and western blot assays. To investigate the role of Lactobacillus reuteri extracts in the wound in mice, the wound position of bilateral mesial gingival of the maxillary first molar was established, the wound area with a size of 1 mm × 2 mm and the full thickness gingiva was removed. Mice with wound were randomly distributed to two groups: injection of 0.9% NaCl (NS group) or injection of 50 μg/ml bacterial extracts.

RESULTS

We discovered that 50 μg/ml Lactobacillus reuteri extracts increased the capacities of migration, expression of stem cell markers, osteogenic differentiation, and proliferation of GMSCs. In addition, local injection of 50 μg/ml bacterial extracts could promote wound-healing process in mice models. Mechanistically, we found that Lactobacillus reuteri extracts accelerated the process of wound healing via PI3K/AKT/β-catenin/TGFβ1 pathway.

CONCLUSIONS

These data showed that Lactobacillus reuteri extracts could activate the potentials of GMSCs, thus promote wound healing. Our discovery provided the insight of the underlying mechanism activating functions of MSCs and identified Lactobacillus reuteri extracts as a potential therapeutic strategy for accelerating oral wound and potential application in the future dental clinic.

Identification of DNA methylation-regulated differentially-expressed genes and related pathways using Illumina 450K BeadChip and bioinformatic analysis in gastric cancer

In the current research, we aimed to identify and analyze methylation-regulated differentially-expressed genes (MeDEGs) and related pathways using bioinformatic methods. We downloaded RNA-seq, Illumina Human Methylation 450 K BeadChip and clinical information of gastric cancer (GC) from The Cancer Genome Atlas (TCGA) project. Differentially-expressed genes (DEGs) were identified using the edgeR package. Then, we performed Spearman's correlation analysis between DEG expression levels and methylation levels. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed in the DAVID database. We then conducted Kaplan-Meier survival analysis to explore the relationship between methylation, expression and prognosis. The protein-protein interaction networks were further analyzed using the STRING database. A total of 204 down-regulated DEGs and 164 up-regulated DEGs were identified as MeDEGs. GO and KEGG pathway analyses showed that MeDEGs were enriched in multiple cancer-related terms. Kaplan-Meier survival analysis showed that eight up-regulated MeDEGs (CAMKV, COMP, FGF3, FGF19, FOXL2, IGF2BP1, IGFBP1 and NPPB) and five down-regulated MeDEGs (ALDH3B2, CALML3, FLRT1, G6PC and HRASLS2) were associated with prognosis of GC patients. In addition, PPI networks and KEGG pathway analyses further confirmed the critical role of prognosis-related MeDEGs. In conclusion, methylation plays a critical role in GC progression. Multiple MeDEGs are related to prognosis, suggesting that they may be potential targets in tumor treatment.

Diallyl disulfide inhibits colon cancer metastasis by suppressing Rac1-mediated epithelial-mesenchymal transition

Background

Prevention of epithelial-mesenchymal transition (EMT) provides a novel treatment strategy for tumor metastasis. Our previous studies have shown that diallyl disulfide (DADS) inhibits Ras related C3 botulinum toxin substrate1 (Rac1) expression, being a potential agent that suppresses migration and invasion of colon cancer cells. The study provides information on the underlying mechanisms.

Methods

The expression of Rac1 and EMT markers (vimentin, N-cadherin and E-cadherin) in colon cancer samples was detected. Colon cancer cell lines treated with or without DADS were used to examine EMT markers, Rac1 and its related molecules. Various cell functions related to metastasis were performed in vitro, and further confirmed in vivo.

Results

Rac1 was highly expressed in colon cancer, and associated with aberrant expression of EMT markers and poor prognosis. Rac1 overexpression induced cell migration and invasion in vitro and metastasis in vivo with down-regulation of E-cadherin and up-regulation of N-cadherin, vimentin, and snail1, whereas inhibition of Rac1 impaired the oncogenic function. DADS suppressed Rac1 expression and activity via inhibition of PI3K/Akt pathway, thus suppressing EMT and invasion and migration of colon cancer cells. The tumor inhibition of DADS was enhanced by knockdown of Rac1, but antagonized by overexpression of Rac1. We further found that DADS blocked EMT via targeting the Rac1-mediated PAK1-LIMK1-Cofilins signaling.

Conclusion

Rac1 is a potential target molecule for the inhibitory effect of DADS on EMT and invasion and metastasis of colon cancer cells.

Loss of BAP1 Results in Growth Inhibition and Enhances Mesenchymal-Epithelial Transition in Kidney Tumor Cells

BRCA1-associated protein 1 (BAP1) is a member of the ubiquitin C-terminal hydrolase family of deubiquitinating enzymes and is implicated in transcriptional regulation. The BAP1 gene is mutated in about 10% of patients with ccRCC, the most common form of renal cancer, suggesting that BAP1 is a tumor suppressor. However, whether BAP1 influences the progression of ccRCC tumors expressing wild-type (WT) BAP1 is unclear. Here, we assessed the expression and function of BAP1 using human ccRCC specimens and cell lines. Analysis of datasets in The Cancer Genome Atlas revealed that lower BAP1 expression is correlated with longer overall survival of ccRCC patients. We established human ccRCC cell lines with stable BAP1 knockout and performed multiomic analysis of BAP1-mediated cellular processes. BAP1 knockout downregulated proteins associated with protein synthesis, resulting in decreased cell growth. Importantly, loss of BAP1 decreased the formation of stress fibers and membrane protrusions and induced migration and invasion defects. BAP1 knockout in ccRCC cells also downregulated the expression of transcriptional repressor protein Snail and decreased the activity of Rho family GTPases, promoting the cells to undergo mesenchymal-epithelial transition. Unexpectedly, quantitative proteomics also showed that BAP1 knockout increased expression of several amino acid transporters and multiple tyrosine kinases, including the epidermal growth factor receptor. Overall, our results suggest that BAP1 regulates multiple cellular processes, and we also uncover a new role for BAP1 in controlling mesenchymal-epithelial transition in ccRCC cells.

microRNA-203 promotes proliferation, differentiation, and migration of osteoblasts by upregulation of Msh homeobox 2

Despite the improvements in fracture healing, about 10% of patients undergo abnormal healing. As a tumor suppressor, upregulation of microRNA (miR)-203 has been observed in osteogenic differentiation. Herein, we aimed to explore the functional role of miR-203 in osteoblasts as well as the underlying mechanisms. The expression of miR-203 in MC3T3-E1 cells that underwent osteogenic differentiation was determined by quantitative reverse transcription PCR (qRT-PCR). The effects of aberrantly expressed miR-203 on cell viability, migration, and expressions of proteins associated with proliferation, migration, and osteogenic differentiation were measured by using a Cell Counting Kit-8 assay, Transwell cell migration assay, and western blot/qRT-PCR, respectively. The possible downstream factor of miR-203 was subsequently studied. Finally, involvements of the mitogen-activated protein kinase (MAPK)/activator of transcription (STAT) pathways were assessed by western blot. We found that the miR-203 level was increased in osteogenic differentiation of MC3T3-E1 cells with increasing duration time (28th day, p < 0.001). After cell transfection, we interestingly found that miR-203 overexpression could increase cell viability (p < 0.05), promote proliferation, migration (p < 0.05), and osteogenic differentiation, and upregulate Msh homeobox 2 (Msx2) expression. Furthermore, Msx2 knockdown was proved to abrogate the effects of miR-203 overexpression on MC3T3-E1 cells. Finally, phosphorylated levels of key kinases in the MAPK/STAT pathways were increased by miR-203 overexpression via upregulating Msx2 expression. In conclusion, miR-203 overexpression promoted proliferation, migration, and osteogenic differentiation of MC3T3-E1 cells through upregulating Msx2 along with activation of the MAPK/STAT pathways.

MicroRNA-4458 suppresses migration and epithelial-mesenchymal transition via targeting HMGA1 in non-small-cell lung cancer cells

Purpose

Increasing studies have shown that microRNA-4458 (miR-4458) is associated with human cancer progression. However, the molecular mechanism of miR-4458 in non-small-cell lung cancer (NSCLC) remains largely unknown. This study aims to reveal the biological function of miR-4458 in NSCLC.

Materials and methods

The expression of miR-4458 in NSCLC cells was evaluated by qRT-PCR. Cell proliferation and migration assay were carried out in vitro after transfection. A luciferase reporter and Western blot assay were performed to identify the functional target of miR-4458.

Results

The study indicated that miR-4458 was markedly downregulated in NSCLC cells. Overexpression of miR-4458 strongly reduced the proliferation and migration in NSCLC cell lines. In addition, miR-4458 inhibited the progression of migration and epithelial–mesenchymal transition (EMT) through the PI3K/AKT pathway. Luciferase report assay demonstrated that HMGA1 was a target gene for miR-4458.

Conclusion

The results indicate that miR-4458 participated in the process of migration and EMT via directly targeting HMGA1 and miR-4458 might be a potential novel therapeutic target in NSCLC.

MiR-3188 Inhibits Non-small Cell Lung Cancer Cell Proliferation Through FOXO1-Mediated mTOR-p-PI3K/AKT-c-JUN Signaling Pathway

This study investigated the role of miR-3188 on the proliferation of non-small cell lung cancer cells and its relationship to FOXO1-modulated feedback loop. Two non-small cell lung cancer (NSCLC) cell lines A549 and H1299 were used. RNA silencing was achieved by lentiviral transfection. Cell proliferation was assessed by immunohistochemical staining of Ki67 and PCNA, Edu incorporation, and colony formation assay. Western blotting was used to examine expression of FOXO1, mTOR, p-mTOR, CCND1, p21, c-JUN, AKT, pAKT, PI3K, p-PI3K, and p27 proteins. It was found that miR-3188 reduced cell proliferation in NSCLC cells. Molecular analyses indicated that the effect of mammalian target of rapamycin (mTOR) was directly mediated by miR-3188, leading to p-PI3K/p-AKT/c-JUN inactivation. The inhibition of this signaling pathway further caused cell-cycle suppression. Moreover, FOXO1 was found to be involved in regulating the interaction of miR-3188 and mTOR through p-PI3K/p-AKT/c-JUN signaling pathway. Taken together, our study demonstrated that miR-3188 interacts with mTOR and FOXO1 to inhibit NSCLC cell proliferation through a mTOR-p-PI3K/AKT-c-JUN signaling pathway. Therefore, miR-3188 might be a potential target for the treatment of NSCLC.

Celecoxib suppresses cutaneous squamous-cell carcinoma cell migration via inhibition of SDF1-induced endocytosis of CXCR4

Background

Cutaneous squamous cell carcinoma (CSCC), the main type of non-melanoma skin cancer (NMSC), contributes to 20-30% of the overall number of NMSC cases. Some CSCCs are observed to have metastatic potential induced by solar ultra violet (UV) radiation. Celecoxib, a nonsteroidal anti-inflammatory drug, has been largely associated with prevention of many cancer types. However, the relationship between celecoxib and CSCC cell migration has yet to be determined.

Methods

To determine the association between celecoxib and CSCC, we performed a series of studies in human samples and in vitro models to assess the influence of celecoxib in CSCC cell migration.

Results

In the present study, we found that celecoxib suppresses CSCC cell migration via inhibition of SDF1-induced endocytosis of CXCR4. In addition, ERK/AKT signaling pathways were found to play a key role in this biological process.

Conclusion

Our study provides promising evidence that celecoxib could serve as a potential preventative agent for the metastasis of CSCC cells.

Signaling Pathways Induced by Leptin during Epithelial⁻Mesenchymal Transition in Breast Cancer

Leptin is an adipokine that is overexpressed in obese and overweight people. Interestingly, women with breast cancer present high levels of leptin and of its receptor ObR. Leptin plays an important role in breast cancer progression due to the biological processes it participates in, such as epithelial⁻mesenchymal transition (EMT). EMT consists of a series of orchestrated events in which cell⁻cell and cell⁻extracellular matrix interactions are altered and lead to the release of epithelial cells from the surrounding tissue. The cytoskeleton is also re-arranged, allowing the three-dimensional movement of epithelial cells into the extracellular matrix. This transition provides cells with the ability to migrate and invade adjacent or distal tissues, which is a classic feature of invasive or metastatic carcinoma cells. In recent years, the number of cases of breast cancer has increased, making this disease a public health problem worldwide and the leading cause of death due to cancer in women. In this review, we focus on recent advances that establish: (1) leptin as a risk factor for the development of breast cancer, and (2) leptin as an inducer of EMT, an event that promotes tumor progression.

Downregulating CD26/DPPIV by apigenin modulates the interplay between Akt and Snail/Slug signaling to restrain metastasis of lung cancer with multiple EGFR statuses

BACKGROUND

Metastasis rather than the primary cancer determines the survival of cancer patients. Activation of Akt plays a critical role in the epithelial-to-mesenchymal transition (EMT), the initial step in lung cancer metastasis. Apigenin (API), a flavonoid with a potent Akt-inhibitory effect, shows oncostatic activities in various cancers. However, the effects of API on metastasis of non-small cell lung cancer (NSCLC) remain unclear.

METHODS

NSCLC cell lines with different epidermal growth factor receptor (EGFR) statuses and in vivo orthotopic bioluminescent xenograft model were employed to determine antitumor activity of API. Western blot and genetic knockdown by shRNA or genetic overexpression by DNA plasmids were performed to explore the underlying mechanisms. The Cancer Genome Atlas (TCGA) database was used to investigate the prognosis of API-targeted genes.

RESULTS

API was demonstrated to inhibit the migration/invasion of NSCLC cells harboring different EGFR statuses via suppressing the Snail/Slug-mediated EMT. Mechanistic investigations showed that CD26/dipeptidyl peptidase IV (DPPIV) was downregulated by API following suppressive interplay of Akt and Snail/Slug signaling to modulate the EMT and the invasive ability of NSCLC cells. CD26 expression was positively correlated with the invasive abilities of NSCLC cells and a worse prognosis of lung cancer patients. Furthermore, we observed that patients with CD26^high/Akt^high tumors had the shortest recurrence-free survival times. In vivo, API drastically reduced the growth and metastasis of A549 xenografts through targeting CD26.

CONCLUSIONS

CD26 may be a useful biomarker for predicting NSCLC progression. API effectively suppressed lung cancer progression by targeting the CD26-Akt-Snail/Slug signaling pathway.

Insulin signaling modulates border cell movement in Drosophila oogenesis

As collective cell migration is intimately involved in different aspects of metazoan development, molecular mechanisms underlying this process are being explored in a variety of developmental contexts. Border cell (BC) migration during Drosophila oogenesis has emerged as an excellent genetic model for studying collective cell migration. BCs are of epithelial origin but acquire partial mesenchymal characteristics before migrating as a group towards the oocyte. Here, we report that insulin signaling modulates collective BC movement during Drosophila oogenesis. Supporting the involvement of Insulin pathway, we demonstrate that compromising Insulin-like Receptor (InR) levels in BCs, inhibits their migration. Furthermore, we show that canonical Insulin signaling pathway components participate in this process. Interestingly, visualization of InR-depleted BC clusters, using time-lapse imaging, revealed a delay in detachment of BC clusters from the surrounding anterior follicle cells and altered protrusion dynamics. Lastly, based on genetic interactions between InR, the polarity determinant, par-1 and a regulatory subunit of Drosophila Myosin (spaghetti squash), we propose that Insulin signaling likely influences par-1 activity to engineer border cell detachment and subsequent movement via Drosophila Myosin.

TRPV4 promotes the migration and invasion of glioma cells via AKT/Rac1 signaling

Experimental evidence indicates a critical role of TRPV4 (Transient Receptor Potential Vanilloid 4) in controlling the cell migratory activity of multiple tumors. However, the oncogenic role of TRPV4 in glioma still remains elusive. In this study, we tried to investigate the oncogenic role of TRPV4 in glioma. We found that the expression levels of TRPV4 were upregulated in glioma and the high levels of TRPV4 indicated a worse prognosis in patients with glioma. TRPV4 was critical for glioma migration and invasion: activating TRPV4 by agonist GSK1016790 A enhanced glioma migration and invasion, while, the specific TRPV4 antagonist HC-067047 suppressed glioma migration and invasion. Mechanically, activated TRPV4 promoted the activation of Rac1 (Ras-related C3 botulinum toxin substrate 1) by targeting the AKT for phosphorylation, then enhanced glioma migration and invasion. All these results suggested that TRPV4 accelerates glioma migration and invasion through the AKT/Rac1 signaling, and TRPV4 might be considered as a potential target for glioma therapy.

High expression of Nectin-4 is associated with unfavorable prognosis in gastric cancer

Nectins are Ca²⁺-independent immunoglobulin-like cell adhesion molecules that belong to a family of four members that function in a number of biological cellular activities. Nectin-4 is overexpressed in several types of human cancer; however, the functional and prognostic significance of Nectin-4 in gastric cancer (GC) remains unclear. In the present study, the reverse transcription-quantitative polymerase chain reaction and tissue microarray immunohistochemical analysis were used to investigate the expression of Nectin-4 in GC as well as its function in the prognosis of patients with GC. The results indicated that mRNA and protein expression of Nectin-4 were increased in tumor tissues compared with the matched non-tumor tissues. Expression of Nectin-4 was closely associated with differentiation (P=0.004), primary tumor (P=0.001), lymph node metastasis (P<0.001) and tumor-node-metastasis (TNM) stage (P<0.001). Positive Nectin-4 expression (P=0.001) and advanced TNM stage (P<0.001) were demonstrated to be associated with overall survival time in multivariate analyses. These results suggest that Nectin-4 may serve a significant function in GC and may serve as a novel clinic pathological biomarker and therapeutic target in GC.

New Insights into Protein Kinase B/Akt Signaling: Role of Localized Akt Activation and Compartment-Specific Target Proteins for the Cellular Radiation Response

Genetic alterations driving aberrant activation of the survival kinase Protein Kinase B (Akt) are observed with high frequency during malignant transformation and cancer progression. Oncogenic gene mutations coding for the upstream regulators or Akt, e.g., growth factor receptors, RAS and phosphatidylinositol-3-kinase (PI3K), or for one of the three Akt isoforms as well as loss of the tumor suppressor Phosphatase and Tensin Homolog on Chromosome Ten (PTEN) lead to constitutive activation of Akt. By activating Akt, these genetic alterations not only promote growth, proliferation and malignant behavior of cancer cells by phosphorylation of various downstream signaling molecules and signaling nodes but can also contribute to chemo- and radioresistance in many types of tumors. Here we review current knowledge on the mechanisms dictating Akt’s activation and target selection including the involvement of miRNAs and with focus on compartmentalization of the signaling network. Moreover, we discuss recent advances in the cross-talk with DNA damage response highlighting nuclear Akt target proteins with potential involvement in the regulation of DNA double strand break repair.