HGF and c-Met interaction promotes migration in human chondrosarcoma cells

Functional interaction between receptor tyrosine kinase MET and ETS transcription factors promotes prostate cancer progression

Prostate cancer, the most common malignancy in men, has a relatively favourable prognosis. However, when it spreads to the bone, the survival rate drops dramatically. The development of bone metastases leaves patients with aggressive prostate cancer, the leading cause of death in men. Moreover, bone metastases are incurable and very painful. Hepatocyte growth factor receptor (MET) and fusion of genes encoding E26 transformation-specific (ETS) transcription factors are both involved in the progression of the disease. ETS gene fusions, in particular, have the ability to induce the migratory and invasive properties of prostate cancer cells, whereas MET receptor, through its signalling cascades, is able to activate transcription factor expression. MET signalling and ETS gene fusions are intimately linked to high-grade prostate cancer. However, the collaboration of these factors in prostate cancer progression has not yet been investigated. Here, we show, using cell models of advanced prostate cancer, that ETS translocation variant 1 (ETV1) and transcriptional regulator ERG (ERG) transcription factors (members of the ETS family) promote tumour properties, and that activation of MET signalling enhances these effects. By using a specific MET tyrosine kinase inhibitor in a humanised hepatocyte growth factor (HGF) mouse model, we also establish that MET activity is required for ETV1/ERG-mediated tumour growth. Finally, by performing a comparative transcriptomic analysis, we identify target genes that could play a relevant role in these cellular processes. Thus, our results demonstrate for the first time in prostate cancer models a functional interaction between ETS transcription factors (ETV1 and ERG) and MET signalling that confers more aggressive properties and highlight a molecular signature characteristic of this combined action.

Transcriptomic data integration and analysis revealing potential mechanisms of doxorubicin resistance in chondrosarcoma cells

Chondrosarcoma is a type of bone cancer that originates from cartilage cells. In clinical practice, surgical resection is the primary treatment for chondrosarcoma, but chemotherapy becomes essential for patients with metastasis or tumors in surgically inaccessible sites. However, drug resistance often leads to treatment failure. Tumor microenvironment proteins modulate intercellular communication, contributing to drug resistance. Doxorubicin (Dox) is a common chemotherapeutic agent. The present study aimed to establish Dox-resistant chondrosarcoma cells and compare their secretome with parental cells using antibody arrays. Results showed significantly heightened secretion of hepatocyte growth factor (HGF). Knockdown of both HGF and its receptor MET increased Dox sensitivity in chondrosarcoma cells. Treatment of chondrosarcoma cells with conditioned media (CM) from cells secreting high levels of HGF resulted in MET activation. Additionally, the expression levels of HGF and MET were significantly elevated in chondrosarcoma tissues compared to normal cartilage tissues, as confirmed by analysis of GEO database. RNA sequencing and Gene Set Enrichment Analysis (GSEA) elucidated the mechanism involving HGF. Additionally, genes with log fold change > 1 underwent bioinformatics analysis using the ShinyGO web server. The results from both GSEA and ShinyGO analyses corroborate each other, indicating the significance of HGF in cellular signal transduction, regulation of cell motility, developmental processes, immune-inflammatory responses, and functions related to blood and neural systems. In summary, highly secreted HGF can activate signaling pathways through its receptor MET, particularly Ras and Akt activation, enhancing drug resistance in chondrosarcoma cells. The present study may guide the development of novel therapeutic strategies targeting HGF, ultimately improving treatment outcomes and prognosis for malignant chondrosarcoma patients.

Fabricating Composite Cell Sheets for Wound Healing: Cell Sheets Based on the Communication Between BMSCs and HFSCs Facilitate Full-Thickness Cutaneous Wound Healing

BACKGROUND

Insufficient angiogenesis and the lack of skin appendages are critical challenges in cutaneous wound healing. Stem cell-fabricated cell sheets have become a promising strategy, but cell sheets constructed by a single cell type are inadequate to provide a comprehensive proregenerative microenvironment for wound tissue.

METHODS

Based on the communication between cells, in this study, bone marrow mesenchymal stem cells (BMSCs) and hair follicle stem cells (HFSCs) were cocultured to fabricate a composite cell sheet (H/M-CS) for the treatment of full-thickness skin wounds in mice.

RESULTS

Experiments confirmed that there is cell-cell communication between BMSCs and HFSCs, which enhances the cell proliferation and migration abilities of both cell types. Cell-cell talk also upregulates the gene expression of pro-angiogenic-related cytokines in BMSCs and pro-hair follicle-related cytokines in HFSCs, as well as causing changes in the properties of secreted extracellular matrix components.

CONCLUSIONS

Therefore, the composite cell sheet is more conducive for cutaneous wound healing and promoting the regeneration of blood vessels and hair follicles.

Increased collective migration correlates with germline stem cell competition in a basal chordate

Cell competition is a process that compares the relative fitness of progenitor cells, resulting in winners, which contribute further to development, and losers, which are excluded, and is likely a universal quality control process that contributes to the fitness of an individual. Cell competition also has pathological consequences, and can create super-competitor cells responsible for tumor progression. We are studying cell competition during germline regeneration in the colonial ascidian, Botryllus schlosseri. Germline regeneration is due to the presence of germline stem cells (GSCs) which have a unique property: a competitive phenotype. When GSCs from one individual are transplanted into another, the donor and recipient cells compete for germline development. Often the donor GSCs win, and completely replace the gametes of the recipient- a process called germ cell parasitism (gcp). gcp is a heritable trait, and winner and loser genotypes can be found in nature and reared in the lab. However, the molecular and cellular mechanisms underlying gcp are unknown. Using an ex vivo migration assay, we show that GSCs isolated from winner genotypes migrate faster and in larger clusters than losers, and that cluster size correlates with expression of the Notch ligand, Jagged. Both cluster size and jagged expression can be manipulated simultaneously in a genotype dependent manner: treatment of loser GSCs with hepatocyte growth factor increases both jagged expression and cluster size, while inhibitors of the MAPK pathway decrease jagged expression and cluster size in winner GSCs. Live imaging in individuals transplanted with labeled winner and loser GSCs reveal that they migrate to the niche, some as small clusters, with the winners having a slight advantage in niche occupancy. Together, this suggests that the basis of GSC competition resides in a combination in homing ability and niche occupancy, and may be controlled by differential utilization of the Notch pathway.

Cancer invasion and metastasis: Insights from murine pubertal mammary gland morphogenesis

Cancer invasion and metastasis accounts for the majority of cancer related mortality. A better understanding of the players that drive the aberrant invasion and migration of tumors cells will provide critical targets to inhibit metastasis. Postnatal pubertal mammary gland morphogenesis is characterized by highly proliferative, invasive, and migratory normal epithelial cells. Identifying the molecular regulators of pubertal gland development is a promising strategy since tumorigenesis and metastasis is postulated to be a consequence of aberrant reactivation of developmental stages. In this review, we summarize the pubertal morphogenesis regulators that are involved in cancer metastasis and revisit pubertal mammary gland transcriptome profiling to uncover both known and unknown metastasis genes. Our updated list of pubertal morphogenesis regulators shows that most are implicated in invasion and metastasis. This review highlights molecular linkages between development and metastasis and provides a guide for exploring novel metastatic drivers.

Expression and Prognostic Evaluation of the Receptor Tyrosine Kinase MET in Canine Malignant Melanoma

The overexpression and activation of the MET receptor tyrosine kinase has been identified in many human malignancies, but its role in canine cancer has only been minimally investigated. In this study we evaluated the expression of MET in two canine malignant melanoma (CMM) cell lines as well as in 30 CMM tissue samples that were collected from the clinical service at our institution. We were able to confirm the expression of the MET protein in both melanoma cell lines, and we demonstrated MET activation by its ligand, HGF, through phosphorylation, in Western blot analysis. We were also able to demonstrate, by immunohistochemistry, the expression of MET in 63% of the tumor tissue samples analyzed, with the majority demonstrating a relatively low expression profile. We then evaluated the association of MET expression scores with histologic parameters, metastasis, and survival. While statistically significant associations were not found across these parameters, an inverse relationship between MET expression levels and time to lymph node versus distant metastasis was suggested in our cohort. These findings may require assessment in a larger group of specimens to further evaluate the role of MET expression in the homing of metastasis in lymph nodes versus that in distant organs.

Generation of Stable Epithelial-Mesenchymal Hybrid Cancer Cells with Tumorigenic Potential

PURPOSE

Cancer progression, invasiveness, and metastatic potential have been associated with the activation of the cellular development program known as epithelial-to-mesenchymal transition (EMT). This process is known to yield not only mesenchymal cells, but instead an array of cells with different degrees of epithelial and mesenchymal phenotypes with high plasticity, usually referred to as E/M hybrid cells. The characteristics of E/M hybrid cells, their importance in tumor progression, and the key regulators in the tumor microenvironment that support this phenotype are still poorly understood.

METHODS

In this study, we established an in vitro model of EMT and characterized the different stages of differentiation, allowing us to identify the main genomic signature associated with the E/M hybrid state.

RESULTS

We report that once the cells enter the E/M hybrid state, they acquire stable anoikis resistance, invasive capacity, and tumorigenic potential. We identified the hepatocyte growth factor (HGF)/c-MET pathway as a major driver that pushes cells in the E/M hybrid state.

CONCLUSIONS

Herein, we provide a detailed characterization of the signaling pathway(s) promoting and the genes associated with the E/M hybrid state.

EZH2/hSULF1 axis mediates receptor tyrosine kinase signaling to shape cartilage tumor progression

Chondrosarcomas are primary cancers of cartilaginous tissue and capable of alteration to highly aggressive, metastatic, and treatment-refractory states, leading to a poor prognosis with a five-year survival rate at 11 months for dedifferentiated subtype. At present, the surgical resection of chondrosarcoma is the only effective treatment, and no other treatment options including targeted therapies, conventional chemotherapies, or immunotherapies are available for these patients. Here, we identify a signal pathway way involving EZH2/SULF1/cMET axis that contributes to malignancy of chondrosarcoma and provides a potential therapeutic option for the disease. A non-biased chromatin immunoprecipitation sequence, cDNA microarray analysis, and validation of chondrosarcoma cell lines identified sulfatase 1 (SULF1) as the top EZH2-targeted gene to regulate chondrosarcoma progression. Overexpressed EZH2 resulted in downregulation of SULF1 in chondrosarcoma cell lines, which in turn activated cMET pathway. Pharmaceutical inhibition of cMET or genetically silenced cMET pathway significantly retards the chondrosarcoma growth and extends mice survival. The regulation of EZH2/SULF1/cMET axis were further validated in patient samples with chondrosarcoma. The results not only established a signal pathway promoting malignancy of chondrosarcoma but also provided a therapeutic potential for further development of effective target therapy to treat chondrosarcoma.

Visfatin Promotes the Metastatic Potential of Chondrosarcoma Cells by Stimulating AP-1-Dependent MMP-2 Production in the MAPK Pathway

Chondrosarcoma is a malignant bone tumor that is characterized by high metastatic potential and marked resistance to radiation and chemotherapy. The knowledge that adipokines facilitate the initiation, progression, metastasis, and treatment resistance of various tumors has driven several in vitro and in vivo investigations into the effects of adipokines resistin, leptin, and adiponectin upon the development and progression of chondrosarcomas. Another adipokine, visfatin, is known to regulate tumor progression and metastasis, although how this molecule may affect chondrosarcoma metastasis is unclear. Here, we found that visfatin facilitated cellular migration via matrix metalloproteinase-2 (MMP-2) production in human chondrosarcoma cells and overexpression of visfatin enhanced lung metastasis in a mouse model of chondrosarcoma. Visfatin-induced stimulation of MMP-2 synthesis and activation of the AP-1 transcription factor facilitated chondrosarcoma cell migration via the ERK, p38, and JNK signaling pathways. This evidence suggests that visfatin is worth targeting in the treatment of metastatic chondrosarcoma.

Dual inhibition of cMET and EGFR by microRNA-338-5p suppresses metastasis of esophageal squamous cell carcinoma

MicroRNAs, as a group of post-transcriptional regulators, regulate multiple pathological processes including metastasis during tumor development. Here, we demonstrated the metastasis-suppressive function of microRNA (miR)-338-5p in esophageal squamous cell carcinoma (ESCC). Overexpression of miR-338-5p had inhibitory effect on invasive ability of ESCC cells and extracellular matrix degradation, whereas silencing miR-338-5p had opposite effects. Mechanistically, miR-338-5p directly targeted the 3' untranslated regions of hepatocellular growth factor receptor cMet (cMET) and epidermal growth factor receptor (EGFR). As a result, miR-338-5p inhibited the downstream signaling cascades of cMET and EGFR and repressed cMET- and EGFR-mediated ESCC cell invasion. Re-expression of cMET or EGFR in miR-338-5p overexpressing ESCC cells was sufficient to derepress ESCC cell invasion both in vitro and in vivo. We further showed that such manipulation downregulated the expression and secretion of matrix metalloproteinases 2 and 9, which resulted in impaired extracellular matrix degradation and cell invasion. Most importantly, systemic delivery of miR-338-5p mimic significantly inhibited metastasis of ESCC cells in nude mice. Taken together, our results uncovered a previously unknown mechanism through which miR-338-5p suppresses ESCC invasion and metastasis by regulating cMET/EGFR-matrix metalloproteinase 2/9 axis and highlighted the potential significance of miR-338-5p-based therapy in treating patients with metastatic ESCC.

Hepatocyte growth factor and matrix metalloprotease 2 levels in synovial fluid of the knee joint are correlated with clinical outcome of meniscal repair

BACKGROUND

The reoperation rate after primary meniscal repair is about 20%. Thus far, it has remained unclear whether there are distinct individual preconditions that may be associated with a better or worse outcome of this procedure. We therefore analysed typical biochemical mediators in the synovial fluid (SF) of patients with meniscus tear before arthroscopic meniscal refixation and correlated their concentrations to the occurrence of re-rupture after meniscus repair.

METHODS

In this study, 48 patients with meniscus ruptures were included. SF samples were taken intraoperatively prior to arthroscopy. Multiplex enzyme-linked immunosorbent assay (ELISA)-based methods were used to measure hepatocyte growth factor (HGF), interleukin-18 (IL-18), matrix metalloproteinases (MMP) MMP-1, MMP-2, MMP-9 and MMP-13 in the SF. At follow-up, the patients were classified into two groups: surgical success and surgical failure.

RESULTS

Ten out of 48 patients (20.8%) had to undergo revision surgery after meniscal repair (surgical failure). The median HGF in the surgical failure group was 2.4-times higher than in the surgical success group (P = .006), and the median MMP-2 was 1.8 times higher (P = .017). Concentration levels of the other tested proteins were not correlated with the success or failure of the meniscus surgery. There was weak evidence that both markers are indicators of an unsatisfactory healing process for meniscal refixation.

CONCLUSION

These results suggest that HGF and MMP-2 could serve as molecular markers to estimate the chances of healing success of meniscus repair and possibly to individualise therapy in meniscal surgery.

The Role of Kinase Signaling in Resistance to Bevacizumab Therapy for Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is the most malignant primary brain tumor and is characterized by vascular hyperplasia, necrosis, and high cell proliferation. Despite current standard therapies, including surgical resection and chemoradiotherapy, GBM patients survive for only about 15 months after diagnosis. Recently, the U.S. Food and Drug Administration (FDA) has approved an antiangiogenesis medication for recurrent GBM-bevacizumab-which has improved progression-free survival in GBM patients. Although bevacizumab has resulted in significant early clinical benefit, it inescapably predisposes tumor to relapse that can be represented as an infiltrative phenotype. Fundamentally, bevacizumab antagonizes the vascular endothelial growth factor A (VEGF_A), which is consistently released on both endothelial cells (ECs) and GBM cells. Actually, VEGF_A inhibition on the ECs leads to the suppression of vascular progression, permeability, and the vasogenic edema. However, the consequence of the VEGF_A pathway blockage on the GBM cells remains controversial. Nevertheless, a piece of evidence supports the relationship between bevacizumab application and compensatory activation of kinase signaling within GBM cells, leading to a tumor cell invasion known as the main mechanism of bevacizumab-induced tumor resistance. A complete understanding of kinase responses associated with tumor invasion in bevacizumab-resistant GBMs offers new therapeutic opportunities. Thus, this study aimed at presenting a brief overview of preclinical and clinical data of the tumor invasion and resistance induced by bevacizumab administration in GBMs, with a focus on the kinase responses during treatment. The novel therapeutic strategies to overcome this resistance by targeting protein kinases have also been summarized.

Challenges facing antiangiogenesis therapy: The significant role of hypoxia-inducible factor and MET in development of resistance to anti-vascular endothelial growth factor-targeted therapies

It is now fully recognized that along with multiple physiological functions, angiogenesis is also involved in the fundamental process and pathobiology of several disorders including cancer. Recent studies have fully established the role of angiogenesis in cancer progression as well as invasion and metastasis. Consequently, many therapeutic agents such as monoclonal antibodies targeting angiogenesis pathway have been introduced in clinic with the hope for improving the outcomes of cancer therapy. Bevacizumab (Avastin®) was the first anti-vascular endothelial growth factor (VEGF) targeting monoclonal antibody developed with this purpose and soon received its accelerated US Food and Drug Administration (FDA) approval for treatment of patients with metastatic breast cancer in 2008. However, the failure to meet expecting results in different follow-up studies, forced FDA to remove bevacizumab approval for metastatic breast cancer. Investigations have now revealed that while suppressing VEGF pathway initially decreases tumor progression rate and vasculature density, activation of several interrelated pathways and signaling molecules following VEGF blockade compensate the insufficiency of VEGF and initially blocked angiogenesis, explaining in part the failure observed with bevacizumab single therapy. In present review, we introduce some of the main pathways and signaling molecules involved in angiogenesis and then propose how their interconnection may result in development of resistance to bevacizumab.

Prolonged MEK inhibition leads to acquired resistance and increased invasiveness in KRAS mutant gastric cancer

Gastric cancer (GC) is one of the most common causes of cancer-associated death. However, traditional therapeutic strategies have failed to significantly improve the survival of patient with advanced GC. While KRAS mutations have been found in some patients with gastric cancer, an effective therapy to treat KRAS-driven gastric cancer has not been established yet. To provide a rationale for clinical application of kinase inhibitors targeting RAS pathways, we first determined the sensitivity of GC cell lines harboring KRAS mutations or amplification to RAS pathway inhibitors. We found that MAPK pathway inhibitors (MEKi and ERKi) were more effective than AKT inhibitor, suggesting that KRAS-driven gastric cancer cells are dependent on MAPK pathway for survival. Further, we established a KRAS mutant GC cell line with acquired resistance to MEK inhibitors in order to mimic clinical situation of kinase inhibitor resistance. A comprehensive analysis of tyrosine phosphorylation in receptor tyrosine kinases in combination with small molecule chemical library screening revealed upregulated c-MET phosphorylation in this resistance cell line with elevated sensitivity to c-MET TKI (crizotinib) and PI3K/mTOR dual inhibitor (BEZ235). We also showed that migration and invasion of resistant cells were promoted, and crizotinib and BEZ235 could inhibit this malignant phenotype. Overall, our results indicate that prolonged MAPK pathway inhibition could result in acquired resistance which is associated with increased malignant phenotype in KRAS mutant GC and pharmacological targeting c-MET and PI3K/mTOR could overcome this problem.

Extracellular vesicles derived from MSCs activates dermal papilla cell in vitro and promotes hair follicle conversion from telogen to anagen in mice

Hair loss is a common medical problem. In this study, we investigated the proliferation, migration, and growth factor expression of human dermal papilla (DP) cells in the presence or absence of treatment with mesenchymal stem cell extracellular vesicles (MSC-EVs). In addition, we tested the efficacy of MSC-EV treatment on hair growth in an animal model. MSC-EV treatment increased DP cell proliferation and migration, and elevated the levels of Bcl-2, phosphorylated Akt and ERK. In addition; DP cells treated with MSC-EVs displayed increased expression and secretion of VEGF and IGF-1. Intradermal injection of MSC-EVs into C57BL/6 mice promoted the conversion from telogen to anagen and increased expression of wnt3a, wnt5a and versican was demonstrated. The first time our results suggest that MSC-EVs have a potential to activate DP cells, prolonged survival, induce growth factor activation in vitro, and promotes hair growth in vivo.

HGF potentiates extracellular matrix-driven migration of human myoblasts: involvement of matrix metalloproteinases and MAPK/ERK pathway

Background

The hepatocyte growth factor (HGF) is required for the activation of muscle progenitor cells called satellite cells (SC), plays a role in the migration of proliferating SC (myoblasts), and is present as a soluble factor during muscle regeneration, along with extracellular matrix (ECM) molecules. In this study, we aimed at determining whether HGF is able to interact with ECM proteins, particularly laminin 111 and fibronectin, and to modulate human myoblast migration.

Methods

We evaluated the expression of the HGF-receptor c-Met, laminin, and fibronectin receptors by immunoblotting, flow cytometry, or immunofluorescence and used Transwell assays to analyze myoblast migration on laminin 111 and fibronectin in the absence or presence of HGF. Zymography was used to check whether HGF could modulate the production of matrix metalloproteinases by human myoblasts, and the activation of MAPK/ERK pathways was evaluated by immunoblotting.

Results

We demonstrated that human myoblasts express c-Met, together with laminin and fibronectin receptors. We observed that human laminin 111 and fibronectin have a chemotactic effect on myoblast migration, and this was synergistically increased when low doses of HGF were added. We detected an increase in MMP-2 activity in myoblasts treated with HGF. Conversely, MMP-2 inhibition decreased the HGF-associated stimulation of cell migration triggered by laminin or fibronectin. HGF treatment also induced in human myoblasts activation of MAPK/ERK pathways, whose specific inhibition decreased the HGF-associated stimulus of cell migration triggered by laminin 111 or fibronectin.

Conclusions

We demonstrate that HGF induces ERK phosphorylation and MMP production, thus stimulating human myoblast migration on ECM molecules. Conceptually, these data state that the mechanisms involved in the migration of human myoblasts comprise both soluble and insoluble moieties. This should be taken into account to optimize the design of therapeutic cell transplantation strategies by improving the migration of donor cells within the host tissue, a main issue regarding this approach.

Electronic supplementary material

The online version of this article (10.1186/s13395-017-0138-6) contains supplementary material, which is available to authorized users.

The Role of Protein Kinase B Signaling Pathway in Anti-Cancer Effect of Rolipram on Glioblastoma Multiforme: An In Vitro Study

Introduction:

The mechanism of putative cytotoxicity of 4-[3-(cyclopentyloxy)-4-methoxyphenyl]-2-pyrrolidone (rolipram), a specific phosphodiesterase-4 (PDE4) inhibitor, on glioblastoma multiforme (GBM) is almost unknown. This study aimed to investigate the role of protein kinase B (Akt) pathway in the cytotoxic effect of rolipram on human GBM U87 MG cell line and Tumor-Initiating Cells (TICs) isolated from patient’s GBM specimen.

Methods:

TICs were characterized by using flow cytometry and quantitative real-time PCR. The cells were treated with rolipram at inhibitory concentration of 50% (IC50) in the presence or absence of SC79 (4μg/mL), a specific AKT activator, for 48 hours. The cell viability and apoptosis were measured by MTT assay and TUNEL staining, respectively. The relative expression of Phospho-Akt (Ser473), matrix metalloproteinase 2 (MMP2), and vascular endothelial growth factor A (VEGFA) were detected using Western blotting.

Results:

The findings showed that rolipram could suppress cell viability in both U87MG and TICs, dose-dependently. Interestingly, the rolipram-induced cytotoxicity was significantly reduced in the presence of SC79. Nevertheless, in rolipram-treated cells, the pretreatment with SC79 significantly led to increase in U87 MG cells and TICs apoptosis and decrease in viability of U87 MG cells but not TICs relative to corresponding control. In U87 MG and TICs, rolipram-induced reduction of Phospho-Akt (Ser473) and MMP2 levels were significantly suppressed by SC79.

Conclusion:

There is a cell type-specific mechanism of anti-proliferative action of rolipram on GBM cells. The reduction of intracellular level of MMP2 but not VEGFA by rolipram is conducted through the inhibition of Akt signal. Rolipram-induced apoptosis is mediated via Akt dependent/independent mechanisms.

Wnt inhibitory factor 1 (WIF1) methylation and its association with clinical prognosis in patients with chondrosarcoma

Chondrosarcoma (CS) is a rare cancer, but it is the second most common primary malignant bone tumor and highly resistant to conventional chemotherapy and radiotherapy. Aberrant DNA methylation in the promoter CpG island of Wnt inhibitory factor 1 (WIF1) has been observed in different cancers. However, no studies have shown the relationship between WIF1 methylation and CS. In this study, we found promoter methylated WIF1 in both CS cell lines (CS-1 and SW1353) and tumor tissues. Western blot analysis confirmed loss WIF1 expression and activation of Wnt pathway proteins (Wnt5a/b, LRP6, and Dvl2). We subsequently examined the correlation between levels of WIF1 methylation and overall survival (OS) and progression-free survival (PFS) in CS patient samples with a follow-up spanning 234 months (mean: 57.6 months). Kaplan-Meier survival curves and log-rank tests revealed that high levels of WIF1 methylation were associated with lower OS and PFS rates (p < 0.05). Multivariate Cox hazard analysis suggested that detection of high level methylation of WIF1 could be an independent prognostic factor in OS and PFS. In conclusion, we found that WIF1 is epigenetically silenced via promoter DNA methylation in CS and propose that WIF1 methylation may serve as a potential prognostic marker for patients with CS.

Tumor-Activated Mesenchymal Stromal Cells Promote Osteosarcoma Stemness and Migratory Potential via IL-6 Secretion

Osteosarcoma (OS) is an aggressive bone malignancy with a high relapse rate despite combined treatment with surgery and multiagent chemotherapy. As for other cancers, OS-associated microenvironment may contribute to tumor initiation, growth, and metastasis. We consider mesenchymal stromal cells (MSC) as a relevant cellular component of OS microenvironment, and have previously found that the interaction between MSC and tumor cells is bidirectional: tumor cells can modulate their peripheral environment that in turn becomes more favorable to tumor growth through metabolic reprogramming. Here, we determined the effects of MSC on OS stemness and migration, two major features associated with recurrence and chemoresistance. The presence of stromal cells enhanced the number of floating spheres enriched in cancer stem cells (CSC) of the OS cell population. Furthermore, the co-culturing with MSC stimulated the migratory capacity of OS via TGFβ1 and IL-6 secretion, and the neutralizing antibody anti-IL-6 impaired this effect. Thus, stromal cells in combination with OS spheres exploit a vicious cycle where the presence of CSC stimulates mesenchymal cytokine secretion, which in turn increases stemness, proliferation, migration, and metastatic potential of CSC, also through the increase of expression of adhesion molecules like ICAM-1. Altogether, our data corroborate the concept that a comprehensive knowledge of the interplay between tumor and stroma that also includes the stem-like fraction of tumor cells is needed to develop novel and effective anti-cancer therapies.

MicroRNA-494 inhibits cell proliferation and invasion of chondrosarcoma cells in vivo and in vitro by directly targeting SOX9

Accumulating evidence indicates that dysregulation of miRNAs could contribute to tumor growth and metastasis of chondrosarcoma by infuencing cell proliferation and invasion. In the current study, we are interested to examine the role of miRNAs in the carcinogenesis and progression of chondrosarcoma. Here, using comparative miRNA profiling of tissues and cells of chondrosarcoma and cartilage, we identified miR-494 as a commonly downregulated miRNA in the tissues of patients with chondrosarcoma and chondrosarcoma cancer cell line, and upregulation of miR-494 could inhibit proliferation and invasion of chondrosarcoma cancer cells in vivo and in vitro. Moreover, our data demonstrated that SOX9, the essential regulator of the process of cartilage differentiation, was the direct target and functional mediator of miR-494 in chondrosarcoma cells. And downregulation of SOX9 could also inhibit migration and invasion of chondrosarcoma cells. In the last, we identified low expression of miR-494 was significantly correlated with poor overall survival and prognosis of chondrosarcoma patients. Thus, miR-494 may be a new common therapeutic target and prognosis biomarker for chondrosarcoma.

Targeting protein kinases to reverse multidrug resistance in sarcoma

Sarcomas are a group of cancers that arise from transformed cells of mesenchymal origin. They can be classified into over 50 subtypes, accounting for approximately 1% of adult and 15% of pediatric cancers. Wide surgical resection, radiotherapy, and chemotherapy are the most common treatments for the majority of sarcomas. Among these therapies, chemotherapy can palliate symptoms and prolong life for some sarcoma patients. However, sarcoma cells can have intrinsic or acquired resistance after treatment with chemotherapeutics drugs, leading to the development of multidrug resistance (MDR). MDR attenuates the efficacy of anticancer drugs and results in treatment failure for sarcomas. Therefore, overcoming MDR is an unmet need for sarcoma therapy. Certain protein kinases demonstrate aberrant expression and/or activity in sarcoma cells, which have been found to be involved in the regulation of sarcoma cell progression, such as cell cycle, apoptosis, and survival. Inhibiting these protein kinases may not only decrease the proliferation and growth of sarcoma cells, but also reverse their resistance to chemotherapeutic drugs to subsequently reduce the doses of anticancer drugs and decrease drug side-effects. The discovery of novel strategies targeting protein kinases opens a door to a new area of sarcoma research and provides insight into the mechanisms of MDR in chemotherapy. This review will focus on the recent studies in targeting protein kinase to reverse chemotherapeutic drug resistance in sarcoma.

Targeting MACC1 by RNA interference inhibits proliferation and invasion of bladder urothelial carcinoma in T24 cells

The purpose of this article is to research on whether MACC1 can serve as a potential target for gene therapy of human bladder urothelial carcinoma (BUC). In this study, the expression of MACC1 gene was knocked down by RNA interference (RNAi) in the T24 cell (human BUC cell). The transcription level of MACC1 was detected by RT-PCR. Activities of MACC1, caspase-3, caspase-8, Bax and Met (mesenchymal-epithelial transition factor) protein were measured by Western blot. The cell proliferation and apoptosis were detected by MTT and flow cytometry. The cell's invasion ability was performed on Matrigel transwell assay. We also detect MMP2 (metalloproteinase-2) proteins by ELISA. The results showed that the level of MACC1 mRNA and protein was significantly reduced after RNAi. MTT assay showed that the proliferation of T24 cell was decreased due to RNA interference. Apoptosis studies also showed that MACC1 gene interference in T24 loses its anti-apoptotic effects. The expression of apoptosis proteins (Caspase-3, Caspase-8 and Bax) increased significantly due to the MACC1 RNAi. The level of Met protein was down-regulated obviously due to RNAi. Transwell assay showed that invasion abilities of T24 cells were reduced obviously due to MACC1 RNAi. Further studies showed that the secretion of MMP-2 was reduced by RNAi. It can conclude that the ability of proliferation and invasion in T24 cells can be inhibited by RNAi-targeting MACC1. As a result, MACC1 can serve as a potential target for gene therapy of human bladder urothelial carcinoma.

The expression of microRNA-34a is inversely correlated with c-MET and CDK6 and has a prognostic significance in lung adenocarcinoma patients

We aimed to establish whether the expression of microRNA-34a (miR-34a) is correlated with that of c-MET and G1 phase regulators such as cyclin dependent kinase (CDK) 4, CDK6, and cyclin D (CCND) 1 in non-small cell lung cancer (NSCLC), and whether a relationship exists between miR-34a expression and both clinicopathologic factors and recurrence-free survival (RFS). For 58 samples archived from NSCLC patients, we measured the expression of miR-34a and c-MET, CDK4/6, and CCND1 by quantitative RT-PCR and assessed the relationship between miR-34a expression, clinicopathological factors, and RFS. The expression of miR-34a was significantly lower in squamous cell tumors (P < 0.001) and in tumors associated with lymphatic invasion (P = 0.001). We found significant inverse correlations between miR-34a and c-MET (R = -0.316, P = 0.028) and CDK6 expression (R = -0.4582, P = 0.004). RFS were longer in adenocarcinoma patients with high miR-34a expression than in those with low miR-34a expression (55.6 vs. 21.6 months; P = 0.020). With univariate analysis, statistically significant prognostic factors for RFS in adenocarcinoma patients were miR-34a expression (Relative risk (RR), 8.14; P = 0.049), TNM stage (RR, 13.55; P = 0.001), LN metastasis (RR, 4.19; P = 0.043), and the presence of lymphatic invasion (RR, 7.05; P = 0.015). In multivariate analysis, only miR-34a was prognostic for RFS (RR, 11.5; P = 0.027). miR-34a expression was inversely correlated with that of c-MET and CDK6 in NSCLC, and had prognostic significance for RFS, especially in adenocarcinoma patients.

Simvastatin induces NFκB/p65 down-regulation and JNK1/c-Jun/ATF-2 activation, leading to matrix metalloproteinase-9 (MMP-9) but not MMP-2 down-regulation in human leukemia cells

The aim of the present study was to explore the signaling pathways associated with the effect of simvastatin on matrix metalloproteinase-2 (MMP-2)/MMP-9 expression in human leukemia K562 cells. In sharp contrast to its insignificant effect on MMP-2, simvastatin down-regulated MMP-9 protein expression and mRNA levels in K562 cells. Simvastatin-induced Pin1 down-regulation evoked NFκB/p65 degradation. Meanwhile, simvastatin induced JNK-mediated c-Jun and ATF-2 activation. Over-expression of Pin1 suppressed simvastatin-induced MMP-9 down-regulation. Treatment with SP600125 (a JNK inhibitor) or knock-down of JNK1 reduced MMP-2 expression in simvastatin-treated cells. Simvastatin enhanced the binding of c-Jun/ATF-2 with the MMP-2 promoter. Down-regulation of c-Jun or ATF-2 by siRNA revealed that c-Jun/ATF-2 activation was crucial for MMP-2 expression. Suppression of p65 activation or knock-down of Pin1 by shRNA reduced MMP-2 and MMP-9 expression in K562 cells. Over-expression of constitutively active JNK1 rescued MMP-2 expression in Pin1 shRNA-transfected cells. Simvastatin treatment also suppressed MMP-9 but not MMP-2 expression in human leukemia U937 and KU812 cells. Taken together, our data indicate that simvastatin-induced p65 instability leads to MMP-9 down-regulation in leukemia cells, while simvastatin-induced JNK1/c-Jun/ATF-2 activation maintains the MMP-2 expression underlying p65 down-regulation.

Hepatocyte growth factor regulates the TGF-β1-induced proliferation, differentiation and secretory function of cardiac fibroblasts

Cardiac fibroblast (CF) proliferation and transformation into myofibroblasts play important roles in cardiac fibrosis during pathological myocardial remodeling. In this study, we demonstrate that hepatocyte growth factor (HGF), an antifibrotic factor in the process of pulmonary, renal and liver fibrosis, is a negative regulator of cardiac fibroblast transformation in response to transforming growth factor-β₁ (TGF-β₁). HGF expression levels were significantly reduced in the CFs following treatment with 5 ng/ml TGF-β₁ for 48 h. The overexpression of HGF suppressed the proliferation, transformation and the secretory function of the CFs following treatment with TGF-β₁, as indicated by the attenuated expression levels of α-smooth muscle actin (α-SMA) and collagen I and III, whereas the knockdown of HGF had the opposite effect. Mechanistically, we identified that the phosphorylation of c-Met, Akt and total protein of TGIF was significantly inhibited by the knockdown of HGF, but was significantly enhanced by HGF overexpression. Collectively, these results indicate that HGF activates the c-Met-Akt-TGIF signaling pathway, inhibiting CF proliferation and transformation in response to TGF-β₁ stimulation.

Syk/JNK/AP-1 signaling pathway mediates interleukin-6-promoted cell migration in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) typically migrates and metastasizes. Interleukin-6 (IL-6) is a multifunctional cytokine associated with disease status and cancer outcomes. The effect of IL-6 on human OSCC cells, however, is unknown. Here, we showed that IL-6 increased cell migration and Intercellular adhesion molecule-1 (ICAM-1) expression in OSCC cells. Pretreatment of OSCC cells with IL-6R monoclonal antibody (mAb) significantly abolished IL-6-induced cell migration and ICAM-1 expression. By contrast, IL-6-mediated cell motility and ICAM-1 upregulation were attenuated by the Syk and c-Jun N-terminal kinase (JNK) inhibitors. Stimulation of OSCC cells with IL-6 promoted Syk and JNK phosphorylation. Furthermore, IL-6 enhanced AP-1 activity, and the IL-6R mAb, Syk inhibitor, or JNK inhibitor all reduced IL-6-mediated c-Jun phosphorylation, c-Jun binding to the ICAM-1 promoter, and c-Jun translocation into the nucleus. Our results indicate that IL-6 enhances the migration of OSCC cells by increasing ICAM-1 expression through the IL-6R receptor and the Syk, JNK, and AP-1 signal transduction pathways.

Apoptosis signal-regulating kinase 1 is involved in WISP-1-promoted cell motility in human oral squamous cell carcinoma cells

Oral squamous cell carcinoma (OSCC) has a tendency to migrate and metastasize. WNT1-inducible signaling pathway protein 1 (WISP-1) is a cysteine-rich protein that belongs to the Cyr61, CTGF, Nov (CCN) family of matrix cellular proteins. The effect of WISP-1 on human OSCC cells, however, is unknown. Here, we showed that WISP-1 increased cell migration and intercellular adhesion molecule-1 (ICAM-1) expression in OSCC cells. Pretreatment of cells with integrin αvβ3 monoclonal antibody (mAb) significantly abolished WISP-1–induced cell migration and ICAM-1 expression. On the other hand, WISP-1–mediated cell motility and ICAM-1 upregulation were attenuated by ASK1, JNK, and p38 inhibitor. Furthermore, WISP-1 also enhanced activator protein 1 (AP-1) activation, and the integrin αvβ3 mAb, and ASK1, JNK, and p38 inhibitors reduced WISP-1–mediated AP-1 activation. Moreover, WISP-1 and ICAM-1 expression correlated with the tumor stage of patients with OSCC. Our results indicate that WISP-1 enhances the migration of OSCC cells by increasing ICAM-1 expression through the αvβ3 integrin receptor and the ASK1, JNK/p38, and AP-1 signal transduction pathways.

AMP-activated protein kinase activation mediates CCL3-induced cell migration and matrix metalloproteinase-2 expression in human chondrosarcoma

Chemokine (C-C motif) ligand 3 (CCL3), also known as macrophage inflammatory protein-1α, is a cytokine involved in inflammation and activation of polymorphonuclear leukocytes. CCL3 has been detected in infiltrating cells and tumor cells. Chondrosarcoma is a highly malignant tumor that causes distant metastasis. However, the effect of CCL3 on human chondrosarcoma metastasis is still unknown. Here, we found that CCL3 increased cellular migration and expression of matrix metalloproteinase (MMP)-2 in human chondrosarcoma cells. Pre-treatment of cells with the MMP-2 inhibitor or transfection with MMP-2 specific siRNA abolished CCL3-induced cell migration. CCL3 has been reported to exert its effects through activation of its specific receptor, CC chemokine receptor 5 (CCR5). The CCR5 and AMP-activated protein kinase (AMPK) inhibitor or siRNA also attenuated CCL3-upregulated cell motility and MMP-2 expression. CCL3-induced expression of MMP-2 and migration were also inhibited by specific inhibitors, and inactive mutants of AMPK, p38 mitogen activated protein kinase (p38 or p38-MAPK), and nuclear factor κB (NF-κB) cascades. On the other hand, CCL3 treatment demonstrably activated AMPK, p38, and NF-κB signaling pathways. Furthermore, the expression levels of CCL3, CCR5, and MMP-2 were correlated in human chondrosarcoma specimens. Taken together, our results indicate that CCL3 enhances the migratory ability of human chondrosarcoma cells by increasing MMP-2 expression via the CCR5, AMPK, p38, and NF-κB pathways.

Tpl2 kinase impacts tumor growth and metastasis of clear cell renal cell carcinoma

Due to the innate high metastatic ability of renal cell carcinoma (RCC), many patients with RCC experience local or systemic relapses after surgical resection. A deeper understanding of the molecular pathogenesis underlying advanced RCC is essential for novel innovative therapeutics. Tumor progression locus 2 (Tpl2), upregulated in various tumor types, has been reported to be associated with oncogenesis and metastatic progression via activation of the MAPK signaling pathway. Herein, the relevance of Tpl2 in tumor growth and metastasis of RCC is explored. Inspection of The Cancer Genome Atlas (TCGA) indicated that Tpl2 overexpression was significantly related to the presence of metastases and poor outcome in clear cell RCC (ccRCC), which is the most aggressive subtype of RCC. Moreover, expression of Tpl2 and CXCR4 showed a positive correlation in ccRCC patients. Depletion of Tpl2 by RNAi or activity by a Tpl2 kinase inhibitor in human ccRCC cells remarkably suppressed MAPK pathways and impaired in vitro cell proliferation, clonogenicity, anoikis resistance, migration, and invasion capabilities. Similarly, orthotopic xenograft growth and lung metastasis were significantly inhibited by Tpl2 silencing. Furthermore, Tpl2 knockdown reduced CXCL12-directed chemotaxis and chemoinvasion accompanied with impaired downstream signaling, indicating potential involvement of Tpl2 in CXCR4-mediated metastasis. Taken together, these data indicate that Tpl2 kinase is associated with and contributes to disease progression of ccRCC.

IMPLICATIONS

Tpl2 kinase activity has prognostic and therapeutic targeting potential in aggressive clear cell renal cell carcinoma.

CCL2 increases αvβ3 integrin expression and subsequently promotes prostate cancer migration

BACKGROUND

Chemokine ligand 2 (CCL2), also known as monocyte chemoattractant protein-1 (MCP-1), belongs to the CC chemokine family which is associated with the disease status and outcomes of cancers. Prostate cancer is the most commonly diagnosed malignancy in men and shows a predilection for metastasis to the bone. However, the effect of CCL2 on human prostate cancer cells is largely unknown. The aim of this study was to examine the role of CCL2 in integrin expression and migratory activity in prostate cancers.

METHODS

Prostate cancer migration was examined using Transwell, wound healing, and invasion assay. The PKCδ and c-Src phosphorylations were examined by using western blotting. The qPCR was used to examine the mRNA expression of integrins. A transient transfection protocol was used to examine AP-1 activity.

RESULTS

Stimulation of prostate cancer cell lines (PC3, DU145, and LNCaP) induced migration and expression of integrin αvβ3. Treatment of cells with αvβ3 antibody or siRNA abolished CCL2-increased cell migration. CCL2-increased migration and integrin expression were diminished by CCR2 but not by CCR4 inhibitors, suggesting that the CCR2 receptor is involved in CCL2-promoted prostate cancer migration. CCL2 activated a signal transduction pathway that includes PKCδ, c-Src, and AP-1. Reagents that inhibit specific components of this pathway each diminished the ability of CCL2 to effect cell migration and integrin expression.

CONCLUSIONS

Interaction between CCL2 and CCR2 enhances migration of prostate cancer cells through an increase in αvβ3 integrin production.

GENERAL SIGNIFICANCE

CCL2 is a critical factor of prostate cancer metastasis.

Determination of peripheral neuropathy prevalence and associated factors in Chinese subjects with diabetes and pre-diabetes - ShangHai Diabetic neuRopathy Epidemiology and Molecular Genetics Study (SH-DREAMS)

OBJECTIVE

This study determined the prevalence and factors associated with peripheral neuropathy (PN) in subjects with diabetes mellitus, impaired glucose regulation (IGR), and normal glucose tolerance (NGT) in a community-based Chinese population.

RESEARCH DESIGN AND METHODS

A total of 2035 subjects in Shanghai were classified as having NGT, IGR, or diabetes. All subjects underwent complete foot examination. PN was assessed according to the neuropathy symptom and neuropathy disability scores. Binary logistic regression was performed to analyze the contributions of factors to PN.

RESULTS

The prevalence of PN was 8.4%, 2.8%, and 1.5% in diabetes mellitus, IGR, and NGT subjects, respectively (P<0.05 for diabetes vs. NGT, and IGR). The subjects with known diabetes had the highest frequency of PN (13.1%). Among the subjects without diabetes, those with PN were older, had a higher waist circumference and 2-h postprandial plasma glucose levels, and were more likely to be hypertensive. Among the IGR subjects, other than age, the 2-h postprandial plasma glucose level was an independent factor significantly associated with PN. Meanwhile, among the subjects with diabetes, PN was associated with fasting plasma glucose, duration of diabetes, and decreased estimated glomerular filtration rate.

CONCLUSIONS

The prevalence of PN is slightly higher in individuals with IGR than that in individuals with NGT, but small fibre damage in IGR as the earliest nerve fibre deficit may be underestimated in our study. As an independent risk factor, postprandial plasma glucose level may be an important target for strategies to prevent or improve PN in IGR subjects.

Underexpression of miR-34a in hepatocellular carcinoma and its contribution towards enhancement of proliferating inhibitory effects of agents targeting c-MET

Aberrant expression of microRNA-34a (miR-34a) has been reported to be involved in the tumorigenesis and progression of various classes of malignancies. However, its role in hepatocellular carcinoma (HCC) has not been completely clarified. In the current study, we have investigated the clinical significance and the in vitro contribution of miR-34a on biological functions of human HCCs. miR-34a expression in eighty-three cases of HCC formalin-fixed paraffin-embedded (FFPE) tissues decreased significantly compared to that in the adjacent liver tissues (P<0.01), as detected by real-time quantitative RT-PCR (RT-qPCR). miR-34a expression in the groups of TNM stage I and II, without metastasis and without portal vein tumor embolus, was significantly higher than that of their corresponding groups (P<0.05). In functional experiments, miR-34a mimic suppressed cell growth, migration and invasion, meanwhile it increased cellular apoptosis and caspase activity in HCC cells. miR-34a mimic also reduced phospho-ERK1/2 and phospho-stat5 signaling. In addition, miR-34a mimic enhanced the effect of cell proliferation inhibition and caspase activity induction of agents targeting c-MET (siRNAs and small molecular inhibitor su11274). In conclusion, miR-34a may act as a tumor suppressor miRNA of HCC. The strategies to increase miR-34a level might be a critical targeted therapy for HCC in future.