Overexpression Of Hepatocyte Growth Factor Research Articles

Expression of the hepatocyte growth factor and c-Met in colon cancer: correlation with clinicopathological features and overall survival.

The hepatocyte growth factor (HGF)/c-Met signaling system has been implicated in the development and progression of colon cancer, but the relationship between the expression of HGF or c-MET and clinicopathologic features remains controversial. In the study, we analyzed the expression of HGF and c-Met in colon cancer and assessed the influence of the expression of this growth factor and its receptor on clinical and histological parameters and patient survival. We investigated the mRNA expression of HGF and c-Met with real-time PCR in 90 unselected colon carcinomas and the corresponding normal mucosa. Furthermore, HGF and c-Met protein expression was investigated with immunohistochemistry in all the samples. The mRNA and protein expression levels of HGF and c-Met were significantly higher in colon cancer than in matched normal mucosa. The protein level in most of the cases investigated was correlated with the mRNA level. Overexpression of HGF and c-Met, at both protein and mRNA levels, was correlated with depth of invasion, lymph node metastases and overall AJCC stage. According to univariate analysis, the mean survival time was shorter in the HGF-positive and c-Met-positive groups. Multivariate Cox analysis showed that high M stage and the expression of c-Met independently had a negative impact on overall survival. The HGF/c-Met signaling pathway may be involved in the pathogenesis and progression of colon cancer. C-Met overexpression can be used as a useful parameter to evaluate the prognosis of colon cancer.

Abstract WMP74: Therapeutic Effect of Human Dental Pulp Stem Cells Overexpressing Hepatocyte Growth Factor in Experimental Ischemic Stroke

Objective: Human dental pulp stem cell (DPSC) is an attractive cell source because they can be easily obtained as medical waste without ethical and logistical problems. Transplantation of DPSC decreases tissue injury in the rat brain and enhances motor function recovery after the middle cerebral artery occlusion (MCAO). We aimed increasing therapeutic effects combining DPSC and ex vivo human hepatocyte growth factor (HGF) gene transfer with adeno-associated virus (AAV) vector. Methods: Male Sprague-Dawley rats were subjected to transient 90 minute MCAO, followed by intravenous administration of 1 x 10 6 cells of DPSC, AAV-1/HGF transferred DPSC (DPSC/HGF) or vehicle immediately after reperfusion (each, n=8). Infarct volumes, neurological deficits and immunochemistry were assessed at 24 and 72 h after reperfusion. We also detected concentrations of TNF-α and IL-1β in the brain tissue extracts from the ischemic hemisphere by ELISA. Results: Infarct volumes at 24 h after reperfusion were diminished in both DPSC (155.7 ± 35.6 mm 3 , p < 0.01) and DPSC/HGF (110.2 ± 34.7 mm 3 , p < 0.01) transplantation compared with vehicle (213.1 ± 29.1 mm 3 ). DPSC/HGF transplantation showed more reduction of infarct volume compared with DPSC (110.2 ± 34.7 mm 3 vs 155.7 ± 35.6 mm 3 , p < 0.05). Motor function recovery was also observed at 24 and 72 h by both DPSC and DPSC/HGF transplantation. Furthermore, we determined that DPSC/HGF transplantation significantly suppressed expression of Iba-1 and TNF-α compared with DPSC in the cortical ischemic boundary zone (p < 0.05, p < 0.01). Also, DPSC/HGF markedly decreased brain tissue TNF-α (11.5 ± 4.2 pg/ml) and IL-1β (22.2 ± 4.2 pg/ml) concentrations compared with vehicle (TNF-α, 54.6 ± 9.8 pg/ml, p < 0.01; IL-1β, 95.2 ± 9.8 pg/ml, p < 0.01) and DPSC (TNF-α, 26.8 ± 11.2 pg/ml, p < 0.05; IL-1β, 40.6 ± 11.2 pg/ml, p < 0.05) in the ischemic hemisphere. Both DPSC and DPSC/HGF group improved neuronal degeneration compared with vehicle (p < 0.05, p < 0.01). Conclusions: These findings show that overexpression of HGF by AAV vector would enhance the neuroprotective effects of DPSC transplantation through the modulation of inflammation after acute ischemic stroke.

Treatment of Myocardial Infarction with Gene-modified Mesenchymal Stem Cells in a Small Molecular Hydrogel

The effect of transplanted rat mesenchymal stem cells (MSCs) can be reduced by extracellular microenvironment in myocardial infarction (MI). We tested a novel small-molecular hydrogel (SMH) on whether it could provide a scaffold for hepatocyte growth factor (HGF)-modified MSCs and alleviate ventricular remodeling while preserving cardiac function after MI. Overexpression of HGF in MSCs increased Bcl-2 and reduced Bax and caspase-3 levels in response to hypoxia in vitro. Immunocytochemistry demonstrated that cardiac troponin (cTnT), desmin and connexin 43 expression were significantly enhanced in the 5-azacytidine (5-aza) with SMH group compared with the 5-aza only group in vitro and in vivo. Bioluminescent imaging indicated that retention and survival of transplanted cells was highest when MSCs transfected with adenovirus (ad-HGF) were injected with SMH. Heart function and structure improvement were confirmed by echocardiography and histology in the Ad-HGF-SMHs-MSCs group compared to other groups. Our study showed that: HGF alleviated cell apoptosis and promoted MSC growth. SMHs improved stem cell adhesion, survival and myocardial cell differentiation after MSC transplantation. SMHs combined with modified MSCs significantly decreased the scar area and improved cardiac function.

Hepatocyte Growth Factor/c-Met Signaling in Head and Neck Cancer and Implications for Treatment

Aberrant signaling of the hepatocyte growth factor (HGF)/c-Met pathway has been identified as a promoter of tumorigenesis in several tumor types including head and neck squamous cell carcinoma (HNSCC). Despite a relatively low c-Met mutation frequency, overexpression of HGF and its receptor c-Met has been observed in more than 80% of HNSCC tumors, with preclinical and clinical studies linking overexpression with cellular proliferation, invasion, migration, and poor prognosis. c-Met is activated by HGF through a paracrine mechanism to promote cellular morphogenesis enabling cells to acquire mesenchymal phenotypes in part through the epithelial-mesenchymal transition, contributing to metastasis. The HGF/c-Met pathway may also act as a resistance mechanism against epidermal growth factor receptor (EGFR) inhibition in advanced HNSCC. Furthermore, with the identification of a biologically distinct subset of HNSCC tumors acquired from human papillomavirus (HPV) infection that generally portends a good prognosis, high expression of HGF or c-Met in HPV-negative tumors has been associated with worse prognosis. Dysregulated HGF/c-Met signaling results in an aggressive HNSCC phenotype which has led to clinical investigations for targeted inhibition of this pathway. In this review, HGF/c-Met signaling, pathway alterations, associations with clinical outcomes, and preclinical and clinical therapeutic strategies for targeting HGF/c-Met signaling in HNSCC are discussed.

T Cell Deficits and Overexpression of Hepatocyte Growth Factor in Anti-inflammatory Circulating Monocytes of Middle-Aged Patients with Bipolar Disorder Characterized by a High Prevalence of the Metabolic Syndrome.

We previously reported T cell deficits and pro-inflammatory gene activation in circulating monocytes of two cohorts of bipolar disorder (BD) patients, a cohort of postpartum psychosis patients and in bipolar offspring. Pro-inflammatory gene activation occurred in two clusters of mutually correlating genes, cluster 1 for inflammation-related cytokines/factors, cluster 2 for motility, chemotaxis, and metabolic factors. To verify these cellular immune abnormalities in yet another cohort [the bipolar stress study (BiSS) cohort] of relative old (52 years, median) BD patients and to relate immune abnormalities to hair cortisol levels, measured in this cohort and representing long-term systemic cortisol levels, and to the presence of the metabolic syndrome (MetS), which was prevalent in 29% of the BiSS patients. Monocyte immune gene activation (quantitative polymerase chain reaction) and T cell deficits (fluorescence-activated cell sorting analysis) were determined in 97 well-controlled, largely euthymic BiSS BD patients. Monocyte genes included the cluster 1 and 2 genes, the genes for the glucocorticoid receptor (GR) α and GRβ, and the gene for hepatocyte growth factor [HGF, a marker of monocyte-derived circulating angiogenic cells (CACs)]. CACs serve vessel repair. Abnormal numbers are found in patients with MetS and vascular damage. As compared to healthy controls: (1) the pro-inflammatory cluster 1 genes were downregulated, and the GRα and the HGF gene were upregulated in the monocytes of the BiSS patients and (2) T cell deficits were shown (reduced numbers of lymphocytes in particular of T cells). Within the reduced T cell population, a shift had taken place in the T-helper populations: T-helper 17 and T-helper 2 increased and T regulatory cells decreased. Correlations between hair cortisol, the MetS, monocyte gene activation, and T cell deficits were not found. T cell deficits most likely are a trait phenomenon of BD, since they have also been found in the other cohorts of BD patients and in bipolar offspring. Monocytes of this cohort showed an anti-inflammatory set point, suggesting that pro- and anti-inflammation are state characteristics of BD. The monocyte gene profile indicated an increased CAC activity; the question arises whether this is due to putative vessel damage in these relatively old patients with a high prevalence of the MetS.

Increased HGF Expression Induces Resistance to c-MET Tyrosine Kinase Inhibitors in Gastric Cancer.

Increased expression of hepatocyte growth factor (HGF) and MET proto-oncogene (c-MET) is associated with poor prognosis in various cancer types. Recently, it was reported that the expression of HGF induces resistance to tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor, human epidermal receptor receptor 2, and b-raf proto-oncogene. Here, we investigated the effects of HGF overexpression in gastric cancer cells in the absence or presence of c-MET TKIs. The effects of c-MET TKIs in gastric cancer cells with and without c-MET overexpression were determined in gastric cancer cell lines with various cell biology methods. Compared to the control, cells with induced expression of HGF showed increase in anchorage-independent colony formation (p<0.001). The c-MET TKIs inhibited HGF/c-MET downstream signaling, cell proliferation, migration and invasion, and triggered cell-cycle arrest in Hs746T cells. However, HGF-transfected cells were less affected. c-MET TKIs had inhibitory effects only on cells overexpressing c-MET. Furthermore, overexpression of HGF resulted in resistance to c-MET TKIs through an autocrine manner in gastric cancer cells.

Hepatocyte Growth Factor Prevented High-Fat Diet-Induced Obesity and Improved Insulin Resistance in Mice

Obesity and its associated chronic inflammation in adipose tissue initiate insulin resistance, which is related to several pathologies including hypertension and atherosclerosis. Previous reports demonstrated that circulating hepatocyte growth factor (HGF) level was associated with obesity and type 2 diabetes. However, its precise role in obesity and related-pathology is unclear. In this experiment, cardiac-specific over-expression of human HGF in mice (HGF-Tg mice) which showed 4–5 times higher serum HGF levels than wild-type mice were used. While body weight in wild-type mice fed with high fat diet (HFD) for 14 weeks was significantly increased accompanied with insulin resistance, HGF-Tg mice prevented body weight gain and insulin resistance. The accumulation of macrophages and elevated levels of inflammatory mediators in adipose tissue were significantly inhibited in HGF-Tg mice as compared to wild-type mice. The HFD-induced obesity in wild-type mice treated with HGF-neutralizing antibody showed an exacerbated response to the glucose tolerance test. These gain-of-function and loss-of-function studies demonstrated that the elevated HGF level induced by HFD have protective role against obesity and insulin resistance.

Hepatocyte growth factor is a prognostic marker in patients with colorectal cancer: a meta-analysis.

Hepatocyte growth factor (HGF) is a crucial factor associated with development, progression and metastasis of colorectal cancer (CRC). However, its prognostic value remains unclear. Thus studies referring to the correlation between HGF and CRC patients’ prognosis were included to explore the role of HGF in CRC. At last nine articles were included. The results showed that the over-expression of HGF was associated with a poor prognosis, presented through overall survival (OS, Hazard ratio (HR) = 2.50, 95% confidence interval (CI): 2.12–2.96) and disease-free survival (DFS, HR = 1.99, 95% CI: 1.59–2.50). Subgroup analysis indicated that no significant difference was found between the Asian countries (OS: HR = 2.37; DFS: HR = 2.02) and the non-Asian countries (OS: HR = 3.15; DFS: HR = 1.87), between the studies that used univariate analyses (OS: HR = 2.51; DFS: HR = 2.07) and those that used multivariate analyses (OS: HR = 2.65; DFS: HR = 1.78), and between metastatic CRC (OS: HR = 2.26; DFS: HR = 2.06) and stage I-IV CRC (OS: HR = 3.08; DFS: HR = 0.70). Our meta-analysis has shown that the over-expression of HGF is valuable in CRC prognosis evaluation. This conclusion should be further confirmed by large-sample cohort studies.

Crosstalk between bone marrow-derived myofibroblasts and gastric cancer cells regulates cancer stemness and promotes tumorigenesis.

Bone marrow-derived cells play important roles in cancer development and progression. Our previous studies demonstrated that murine bone marrow-derived myofibroblasts (BMFs) enhanced tumor growth. In this study, we investigated the mechanisms of BMF actions. We found that co-injection of BMFs with gastric cancer cells markedly promoted tumorigenesis. Co-cultured BMFs or BMF-conditioned medium (BMF-CM) induced the formation of spheres, which expressed stem cell signatures and exhibited features of self-renewal, epithelial-to-mesenchymal transition and tumor initiation. Furthermore, CD44+ fractions in spheres were able to initiate tumorigenesis and reestablish tumors in serially passaged xenografts. In co-culture systems, BMFs secreted high levels of murine interleukin-6 (IL-6) and hepatocyte growth factor (HGF), while cancer cells produced high level of transformation growth factor-β1 (TGF-β1). BMF-CM and IL-6 activated BMFs to produce mHGF, which activated signal transducer and activator of transcription 3 (STAT3) and upregulated TGF-β1 in human cancer cells. In return, cancer cell-CM stimulated BMFs to produce IL-6, which was inhibited by anti-TGF-β1 neutralizing antibody. Blockade of HGF/Met, JAK2/STAT3 and TGF-β1 signaling by specific inhibitors inhibited BMF-induced sphere formation. STAT3 knockdown in cancer cells also inhibited BMF-induced sphere formation and tumorigenesis. Moreover, TGF-β1 overexpression in cancer cells was co-related with IL-6 and HGF overexpression in stromal cells in human gastric cancer tissues. Our results demonstrate that BMF-derived IL-6/HGF and cancer cell-derived TGF-β1 mediate the interactions between BMFs and gastric cancer cells, which regulate cancer stemness and promote tumorigenesis. Targeting inhibition of the interactions between BMFs and cancer cells may be a new strategy for cancer therapy.

Enhanced cell survival and paracrine effects of mesenchymal stem cells overexpressing hepatocyte growth factor promote cardioprotection in myocardial infarction

Poor cell survival post transplantation compromises the therapeutic benefits of mesenchymal stem cells (MSCs) in myocardial infarction (MI). Hepatocyte growth factor (HGF) is an important cytokine for angiogenesis, anti-inflammation and anti-apoptosis. This study aimed to evaluate the cardioprotective effects of MSCs overexpressing HGF in a mouse model of MI. The apoptosis of umbilical cord-derived MSCs (UC-MSCs) and HGF-UC-MSCs under normoxic and hypoxic conditions was detected. The conditioned medium (CdM) of UC-MSCs and HGF-UC-MSCs under a hypoxic condition was harvested and its protective effect on neonatal cardiomyocytes (NCMs) exposed to a hypoxic challenge was examined. UC-MSCs and HGF-UC-MSCs were transplanted into the peri-infarct region in mice following MI and heart function assessed 4 weeks post transplantation. The apoptosis of HGF-UC-MSCs under hypoxic conditions was markedly decreased compared with that of UC-MSCs. NCMs treated with HGF-UC-MSC hypoxic CdM (HGF-UC-MSCs-hy-CdM) exhibited less cell apoptosis in response to hypoxic challenge than those treated with UC-MSC hypoxic CdM (UC-MSCs-hy-CdM). HGF-UC-MSCs-hy-CdM released the inhibited p-Akt and lowered the enhanced ratio of Bax/Bcl-2 induced by hypoxia in the NCMs. HGF-UC-MSCs-hy-CdM expressed higher levels of HGF, EGF, bFGF and VEGF than UC-MSCs-hy-CdM. Transplantation of HGF-UC-MSCs or UC-MSCs greatly improved heart function in the mouse model of MI. Compared with UC-MSCs, transplantation of HGF-UC-MSCs was associated with less cardiomyocyte apoptosis, enhanced angiogenesis and increased proliferation of cardiomyocytes. This study may provide a novel therapeutic strategy for MSC-based therapy in cardiovascular disease.

Therapeutic Potential of HGF-Expressing Human Umbilical Cord Mesenchymal Stem Cells in Mice with Acute Liver Failure.

Human umbilical cord-derived mesenchymal stem cells (UCMSCs) are particularly attractive cells for cellular and gene therapy in acute liver failure (ALF). However, the efficacy of this cell therapy in animal studies needs to be significantly improved before it can be translated into clinics. In this study, we investigated the therapeutic potential of UCMSCs that overexpress hepatocyte growth factor (HGF) in an acetaminophen-induced acute liver failure mouse model. We found that the HGF-UCMSC cell therapy protected animals from acute liver failure by reducing liver damage and prolonging animal survival. The therapeutic effect of HGF-UCMSCs was associated with the increment in serum glutathione (GSH) and hepatic enzymes that maintain redox homeostasis, including γ-glutamylcysteine synthetase (γ-GCS), superoxide dismutase (SOD), and catalase (CAT). Immunohistochemical staining confirmed that HGF-UCMSCs were mobilized to the injured areas of the liver. Additionally, HGF-UCMSCs modulated apoptosis by upregulating the antiapoptotic Bcl2 and downregulating proapoptotic genes, including Bax and TNFα. Taken together, these data suggest that ectopic expression of HGF in UCMSCs protects animals from acetaminophen-induced acute liver failure through antiapoptosis and antioxidation mechanisms.

Abstract 13742: PDE3 Inhibitor, Cilostazol, Ameliorates Ischemic Hindlimb Through cAMP and PPARγ Activation

Peripheral arterial disease (PAD) is highly prevalent in the elderly and subjects with atherosclerotic risk factors. Approximately 2-4% of those affected with PAD commonly complain of intermittent claudication (IC) that is a strong indicator for the development of systemic atherosclerosis. Cilostazol (CSZ) has been shown to be of benefit in improving pain-free walking distance and quality of life in patients with IC. CSZ may be the most clinically effective pharmacologic option for IC. However, the underlying mechanism for amelioration of IC by CSZ remains largely unclear. Here, we demonstrate that CSZ increases expression of hepatocyte growth factor (HGF) in vascular smooth muscle cells (SMCs) via two distinct pathways, PPAR γ and cAMP pathway. Activation of PPAR γ and cAMP activates HGF promoter leading to increase in capillary density and improvement of perfusion in mouse ischemic hind limb model. Enhancement of angiogenesis by CSZ involves Akt/eNOS activation in endothelial cells by HGF secreted from SMCs. However, this process was essentially absent in aspirin treatment group and CSZ with HGF neutralizing antibody treatment group. As CSZ also increases HGF protein production in interstitial area of skeletal muscle where satellite cells reside, we postulated that CSZ stimulates myogenesis. To proof this hypothesis, BrdU was injected every day for 7days in mouse hind limb model, and animals were sacrificed at day 7 and 28. Embryonic form of myocyte heavy chain (eMHC), BrdU positive myocyte, and nuclear centralization was measured. As predicted, CSZ increases the number of newly formed myocyte in ischemic leg compared to control and Aspirin treated mouse. This beneficial effect of CSZ was blunted by the administration of HGF neutralizing antibody. Additionally, Heart specific HGF overexpression mouse in which serum level of HGF is 4-5 times higher than wild type mouse were generated to proof the role of HGF in angiogenesis and myogenesis. Similar to the data obtained from CSZ treated mouse, HGF Tg mouse ameliorates ischemic hind limb via both angiogenesis and myogenesis. Altogether, our date demonstrates that CSZ improves ischemic hind limb via angiogenesis and myogenesis. This results may account for the beneficial effect of CSZ in PAD patients with IC.

Overexpression of hepatocyte growth factor in SBMA model mice has an additive effect on combination therapy with castration

Spinal and bulbar muscular atrophy (SBMA) is an inherited motor neuron disease caused by the expansion of a polyglutamine (polyQ)-encoding tract within the androgen receptor (AR) gene. The pathologic features of SBMA are motor neuron loss in the spinal cord and brainstem and diffuse nuclear accumulation and nuclear inclusions of mutant AR in residual motor neurons and certain visceral organs. Hepatocyte growth factor (HGF) is a polypeptide growth factor which has neuroprotective properties. To investigate whether HGF overexpression can affect disease progression in a mouse model of SBMA, we crossed SBMA transgenic model mice expressing an AR gene with an expanded CAG repeat with mice overexpressing HGF. Here, we report that high expression of HGF induces Akt phosphorylation and modestly ameliorated motor symptoms in an SBMA transgenic mouse model treated with or without castration. These findings suggest that HGF overexpression can provide a potential therapeutic avenue as a combination therapy with disease-modifying therapies in SBMA.

Targeted delivery of HGF to the skeletal muscle improves glucose homeostasis in diet-induced obese mice.

Hepatocyte growth factor (HGF) is a cytokine that increases glucose transport ex vivo in skeletal muscle. The aim of this work was to decipher the impact of whether conditional overexpression of HGF in vivo could improve glucose homeostasis and insulin sensitivity in mouse skeletal muscle. Following tetracyclin administration, muscle HGF levels were augmented threefold in transgenic mice (SK-HGF) compared to control mice without altering plasma HGF levels. In conditions of normal diet, SK-HGF mice showed no differences in body weight, plasma triglycerides, blood glucose, plasma insulin and glucose tolerance compared to control mice. Importantly, obese SK-HGF mice exhibited improved whole-body glucose tolerance independently of changes in body weight or plasma triglyceride levels compared to control mice. This effect on glucose homeostasis was associated with significantly higher (∼80%) levels of phosphorylated protein kinase B in muscles from SK-HGF mice compared to control mice. In conclusion, muscle expression of HGF counteracts obesity-mediated muscle insulin resistance and improves glucose tolerance in mice.

HGF and NRG1 protein expression are not poor prognostic markers in surgically resected lung adenocarcinoma.

PurposeAlthough over-expression of hepatocyte growth factor (HGF) and neuregulin-1 (NRG1) are important mechanisms involved in acquired drug-resistance in many cancers, few reports have evaluated their clinicopathologic features and prognostic significance. The aim of our study was to investigate protein expressions of HGF and NRG1 in lung adenocarcinomas and their association with clinicopathologic parameters, oncogenic mutations, and the prognosis.MethodsHGF and NRG1 protein tumor/stroma expressions were evaluated by immunohistochemistry (IHC) in 115 surgically resected lung adenocarcinomas and were correlated with clinicopathologic and molecular variables including tumor size, tumor node metastasis stage, differentiation, oncogenic mutations (EGFR, KRAS, HER2, BRAF) and ALK fusions, relapse-free survival, and overall survival.ResultsPositive IHC HGF tumor and stroma staining were found in 49 (42.61%) and 12 (10.43%) cases, respectively, while positive IHC NRG1 tumor and stroma staining were found in 56 (48.70%) and eleven (9.57%) cases, respectively. Dual positive IHC HGF and NRG1 tumor staining was 12.17%. EML4-ALK fusion more significantly existed in HGF-tumor positive samples (P=0.03), positive NRG1 protein stroma expression was significantly associated with male sex (P=0.04), while HGF and NRG1 dual tumor-positive mainly existed in the tumor size >3 cm group (P=0.0231). No significant clinically prognostic difference was found between patients with HGF/NRG1-positive expression and those with HGF/NRG1-negative expression.ConclusionThis study represents the first comprehensive analysis of HGF and NRG1 tumor and stroma expressions in patients with surgically resected lung adenocarcinomas. Our molecular data, in conjunction with clinical and pathological features, as well as their effects on survival indicated to us that patients with HGF- and NRG1-negative expression tended to have better survival, but these results probably did not warrant these markers to be indicators of poor prognosis.

Hepatocyte Growth Factor Gene-Modified Mesenchymal Stem Cells Augment Sinonasal Wound Healing.

This study was designed to investigate the effects of hepatocyte growth factor (HGF) transgenic mesenchymal stem cells (HGF-MSCs) on wound healing in the sinonasal mucosa and nasal epithelial cells (NECs). We also sought to determine whether HGF-MSCs and MSCs can migrate into the injured mucosa and differentiate into ciliated cells. Human HGF-overexpressing umbilical cord MSCs (hHGF-UCMSCs) were established, and upregulation of hHGF expression was confirmed by real-time PCR (RT-PCR) and enzyme-linked immunosorbant assay (ELISA). To investigate the paracrine effect of human MSCs (hMSCs) on nasal epithelial repair, hMSC- and HGF-MSC-conditioned media (CM) were used in NEC proliferation assays and in an in vitro scratch-wound repair model. The in vivo sinonasal wound-healing model was established, and all enrolled rabbits were randomly assigned to four groups: the GFP-MSC group, the HGF-MSC group, the Ad-HGF group, and the surgery control group. The average decreased diameter was recorded, and the medial wall of the maxillary sinus was removed for histological analysis and scanning electron microscopy. Collagen deposition in the wound tissue was detected via Masson trichrome (M&T) staining. The distribution of MSCs and HGF-MSCs was observed by immunofluorescence. MSCs improved nasal wound healing both in vivo and in vitro. HGF overexpression in MSCs augmented the curative effects. Reduced collagen deposition and transforming growth factor beta1 (TGF-β1) expression were detected in the HGF-MSC group compared with the MSC-, Ad-HGF-, and phosphate-buffered saline-treated groups based on M&T staining and ELISA. The enhanced therapeutic effects of HGF-MSCs were accompanied by decreased level of the fibrogenic cytokine TGF-β1. In addition, both HGF-MSCs and MSCs can migrate to the injured mucosa and epithelial layer.

Prognostic and predictive value of MET deregulation in non-small cell lung cancer.

Recent progress in cancer biology has led to the discovery of increasing number of oncogene alterations that have dramatically changed the paradigm of lung cancer treatment. MET is a tyrosine kinase receptor for the hepatocyte growth factor (HGF) that is deregulated in several malignancies, including non-small cell lung cancer (NSCLC). Abnormal MET-HGF signaling pathway activation can occur via different mechanisms, including HGF and/or MET overexpression, MET gene amplification, mutations or rearrangements. MET protein overexpression and increased MET gene number have been identified as poor prognostic factors in several series of surgically resected NSCLC making this receptor an attractive target for cancer treatment. Several clinical trials have recently evaluated the activity of a variety of anti-MET strategies in NSCLC patients with or without molecular selection with a variable degree of success, underscoring the need of establishing the best predictive biomarker for the identification of responding patients.

MET gene copy number alterations and expression of MET and hepatocyte growth factor are potential biomarkers in angiosarcomas and undifferentiated pleomorphic sarcomas.

Soft tissue sarcomas are a heterogeneous group of tumors with many different subtypes. In 2014 an estimated 12,020 newly diagnosed cases and 4,740 soft tissue sarcoma related deaths can be expected in the United States. Many soft tissue sarcomas are associated with poor prognosis and therapeutic options are often limited. The evolution of precision medicine has not yet fully reached the clinical treatment of sarcomas since therapeutically tractable genetic changes have not been comprehensively studied so far. We analyzed a total of 484 adult-type malignant mesenchymal tumors by MET fluorescence in situ hybridization and MET and hepatocyte growth factor immunohistochemistry. Eleven different entities were included, among them the most common and clinically relevant subtypes and tumors with specific translocations or complex genetic changes. MET protein expression was observed in 2.6% of the cases, all of which were either undifferentiated pleomorphic sarcomas or angiosarcomas, showing positivity rates of 14% and 17%, respectively. 6% of the tumors showed hepatocyte growth factor overexpression, mainly seen in undifferentiated pleomorphic sarcomas and angiosarcomas, but also in clear cell sarcomas, malignant peripheral nerve sheath tumors, leiomyosarcomas and gastrointestinal stromal tumors. MET and hepatocyte growth factor overexpression were significantly correlated and may suggest an autocrine activation in these tumors. MET FISH amplification and copy number gain were present in 4% of the tumors (15/413). Two samples, both undifferentiated pleomorphic sarcomas, fulfilled the criteria for high level amplification of MET, one undifferentiated pleomorphic sarcoma reached an intermediate level copy number gain, and 12 samples of different subtypes were categorized as low level copy number gains for MET. Our findings indicate that angiosarcomas and undifferentiated pleomorphic sarcomas rather than other frequent adult-type sarcomas should be enrolled in screening programs for clinical trials with MET inhibitors. The screening methods should include both in situ hybridization and immunohistochemistry.

Combining onartuzumab with erlotinib inhibits growth of non-small cell lung cancer with activating EGFR mutations and HGF overexpression.

Erlotinib, a tyrosine kinase inhibitor of the epidermal growth factor receptor (EGFR-TKI), benefits survival of patients with non-small cell lung cancer (NSCLC) who harbor activating EGFR mutations. However, elevated expression of hepatocyte growth factor (HGF), a ligand of the MET receptor tyrosine kinase, causes erlotinib resistance. Because onartuzumab, a monovalent antibody to MET, blocks HGF-induced MET activation, the addition of onartuzumab to erlotinib may improve therapeutic efficacy. We engineered the human NSCLC cell line PC-9 (MET-positive cells harboring an exon 19 deletion of EGFR) to overexpress hHGF and evaluated the effects of an onartuzumab and erlotinib combination in vitro and in vivo in xenograft models. A stable clone of PC-9/hHGF was less sensitive to erlotinib than the parental PC-9, and the addition of onartuzumab to erlotinib suppressed the proliferation of these cells in vitro. In PC-9/hHGF xenograft tumors, onartuzumab or erlotinib alone minimally inhibited tumor growth; however, combining onartuzumab and erlotinib markedly suppressed tumor growth. The total MET protein level was decreased in PC-9/hHGF cells, because MET is constitutively phosphorylated by autocrine HGF, leading to its ubiquitination and degradation. Onartuzumab reduced phospho-MET levels, inhibited MET ubiquitination, and consequently restored MET protein levels. Moreover, in NSCLC clinical specimens harboring activating EGFR mutations, more than 30% of patients expressed high levels of HGF. Our findings raised the possibility that patients with NSCLC with EGFR mutations who express high levels of HGF may benefit from onartuzumab and erlotinib combination therapy, and that HGF can be a novel biomarker for selecting such patients.

Abstract A61: Targeting the c-Met signaling pathway by humanized anti-HGF antibody inhibits irinotecan resistance in colorectal cancer.

Abstract Background and Purpose: Preclinical and clinical findings indicate that multiple tumour micro-environmental factors, including growth factors, protect solid tumors from therapeutic interventions. Experimental evidence has clarified some of the resistance mechanisms, which have led to the development of innovative approaches to treat cancer. Irinotecan (CPT-11) is a semi-synthetic derivative of camptothecin, originally isolated from the Chinese/Tibetan ornamental tree Camptothecaacuminata. It is a key component of first- and second-line treatment regimens for metastatic colorectal cancer (CRC). Studies of irinotecan have demonstrated that its efficacy to treat cancer is superior to that of best supportive care. However, de novo or acquired clinical resistance to camptothecins still exists expecting new target. The hepatocyte growth factor (HGF)/c-Met signaling system is known to be implicated in the development and progression of colon cancer, but the relationship between the expressions of HGF or c-MET and clinicopathologic feature remains controversial. Growth Factors derived from the extracellular matrix (ECM) create an environment conducive to tumor growth and invasion. We hypothesized that over-expression of HGF in cancer-associated fibroblast (CAF) is related to tumor metastasis and chemo-resistance. We also hypothesized that HGF deprivation using neutralizing antibody inhibited chemoresistance in colorectal cancer. Results: We measured the levels of mRNA and secreted protein of HGF by real-time PCR and ELISA in fibroblast and CRC cell lines. The mRNA and secreted protein level of HGF were significantly higher in fibroblast than in CRC cell lines. HGF was not detected in conditioned media (CM) from CRC cell cultures established without fibroblasts, but was detected in CM from fibroblast harvested without CRC cells, suggesting that the measured HGF is fibroblast-derived. Fibroblast-derived HGF induced invasion and chemo-resistance of CRC cell lines. We also found elevated levels of HGF in the CM from fibroblast treated with irinotecan. However, anti-HGF antibody removed this resistance to irinitecan. Down regulation of MET expression by a MET-specific siRNA canceled HGF-induced resistance to irinotecan in CRC cells. Fibroblast originated HGF activated c-Met, PI3K/AKT and MAPK signaling in CRC cells. Phosphorylated-MET mediated activation of PI3K/AKT and MAPK rescued HGF effect in CRC cells. Furthermore, fibroblast-derived HGF affected migration and invasion of CRC cells. We further showed that an anti-HGF antibody enhanced anti-tumor activity of irinotecan in vivo, resulting in shrinkage of well-established human colon cancer in mice without enhancing toxicity. Conclusion: We identified HGF as an important determinant of irinotecan resistance and metastasis of CRC. Anti-HGF monoclonal antibody treatment confirmed the importance of this growth factor for chemo-resistance in CRC. These results present new options toward the early diagnosis of chemoresistance and suggest novel combinations of chemotherapy and anti-HGF agents to prevent or significantly delay the onset of therapy resistance. These observations open new avenues toward the diagnosis of chemoresistant tumors and therapies targeting HGF overexpressing cancers. Citation Format: Jong Kyu Woo, Yeong-Su Jang, Ju-Hee Kang, Hwan Mook Kim, Seung-Hyun Oh. Targeting the c-Met signaling pathway by humanized anti-HGF antibody inhibits irinotecan resistance in colorectal cancer.. [abstract]. In: Abstracts: AACR Special Conference on Cellular Heterogeneity in the Tumor Microenvironment; 2014 Feb 26-Mar 1; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(1 Suppl):Abstract nr A61. doi:10.1158/1538-7445.CHTME14-A61