Yajin Chen

Cabozantinib suppresses tumor growth and metastasis in hepatocellular carcinoma by a dual blockade of VEGFR2 and MET

Purpose: MET signaling has been suggested a potential role in hepatocellular carcinoma (HCC) and associated with prometastasis during antiangiogenesis therapy. We investigated the potential association between MET expression and therapeutic response to sorafenib in patients with HCC. Antitumor effects of cabozantinib, a dual inhibitor of MET and VEGFR2, were examined in cultured HCC cells as well as in vivo models. Experimental Design: Total MET and phosphorylated MET (p-MET) were measured in 29 resected HCC specimens, and correlated with response to sorafenib as postoperative adjuvant therapy. In the second set of experiments using cultured HCC cells, and mouse xenograft and metastatic models, effects of cabozantinib were examined. Results: High level of p-MET in resected HCC specimens was associated with resistance to adjuvant sorafenib therapy. In cultured HCC cells that expressed p-MET, cabozantinib inhibited the activity of MET and its downstream effectors, leading to G1-phase arrest. Cabozantinib inhibited tumor growth in p-MET–positive and p-MET–negative HCC by decreasing angiogenesis, inhibiting proliferation, and promoting apoptosis, but it exhibited more profound efficacy in p-MET–positive HCC xenografts. Cabozantinib blocked the hepatocyte growth factor (HGF)–stimulated MET pathway and inhibited the migration and invasion of the HCC cells. Notably, cabozantinib reduced the number of metastatic lesions in the lung and liver in the experimental metastatic mouse model. Conclusions: Patients with HCC with high level of p-MET are associated with resistance to adjuvant sorafenib treatment. The dual blockade of VEGFR2 and MET by cabozantinib has significant antitumor activities in HCC, and the activation of MET in HCC may be a promising efficacy-predicting biomarker. Clin Cancer Res; 20(11); 2959–70. ©2014 AACR.

Cabozantinib reverses multidrug resistance of human hepatoma HepG2/ adr cells by modulating the function of P-glycoprotein

Cabozantinib, a small‐molecule multitargeted tyrosine kinase inhibitor, has entered into a phase III clinical trial for the treatment of hepatocellular carcinoma (HCC). This study assessed the mechanistic effect of cabozantinib on the reversal of P‐glycoprotein (P‐gp)‐mediated multidrug resistance (MDR).

Selective enrichment of hepatocytes from mouse embryonic stem cells with a culture system containing cholestatic serum

AbstractAim:There is increasing evidence indicating that embryonic stem (ES) cells are capable of differentiating into hepatocyte-like cells in vitro. However, it is necessary to improve the differentiation efficiency so as to promote the clinical application. Here, we report an efficient culture system to support hepatocyte differentiation from ES cells by utilizing cholestatic serum.Methods:One week after the induction of E14 mouse ES cells into hepatocytes with sodium butyrate, cholestatic serum was added into the culture system at various concentrations and hepatocyte-like cells were induced to proliferate. The morphological and phenotypic markers of hepatocytes were characterized using light microscopy, immunocytochemistry, and RT-PCR, respectively. The function of glycogen storage of the differentiated cells was detected by Periodic acid-Schiff (PAS) reaction, and the ratio of hepatic differentiation was determined by counting the albumin and PAS-positive cells.Results:In the presence of conditional selective medium containing cholestatic serum, numerous epithelial cells resembling hepatocytes were observed. The RT-PCR analysis showed that undifferentiated ES cells did not express any hepatic-specific markers; however, in the presence of sodium butyrate and conditional selective medium containing cholestatic serum, hepatic differentiation markers were detected. Immunofluorescence staining showed that those ES-derived hepatocytes were α-fetoprotein, albumin, and cytokeratin 18 positive, with the ability of storing glycogen. Further determination of the hepatic differentiation ratio showed that the application of cholestatic serum efficiently enriched ES-derived hepatocyte-like cells by inducing lineage differentiation and enhancing lineage proliferation.Conclusion:The conditional selective medium containing cholestatic serum is optimal to selectively enrich hepatocyte-like cells from mixed differentiated ES cells, which may provide a novel method to improve the hepatic differentiation ratio of ES cells.

Tivantinib induces G2/M arrest and apoptosis by disrupting tubulin polymerization in hepatocellular carcinoma

BackgroundTivantinib has been described as a highly selective inhibitor of MET and is currently in a phase III clinical trial for the treatment of hepatocellular carcinoma (HCC). However, the mechanism of tivantinib anti-tumor effect has been questioned by recent studies.ResultsWe show that tivantinib indiscriminately inhibited MET dependent and independent HCC cells proliferation. In contrast, other MET inhibitors, JNJ-38877605 and PHA-665752, just specifically inhibited the growth of MET dependent HCC cells. Tivantinib neither inhibit constitutive MET phosphorylation nor HGF-induced MET phosphorylation in HCC cells. In the microtubule polymerization analysis, tivantinib affected microtubule dynamics by a mechanism as a microtubule depolymerizer. Interesting, unlike other microtubule-targeting agents, paclitaxel and vincristine, tivantinib showed similar anti-proliferative activity in parental and multidrug-resistant cells. Further studies demonstrated that tivantinib induced a G2/M arrest and promoted apoptosis by both intrinsic and extrinsic pathway. The in vivo efficacy evaluation showed that tivantinib exhibited a good anti-tumor growth activity with anti-proliferative and pro-apoptotic effects.ConclusionsThe potent anti-tumor activity of tivantinib in HCC was achieved by targeting microtubule. Tivantinib treatment for patients with HCC should not be selected based on MET status.

Short-term and long-term outcomes of laparoscopic hepatectomy, microwave ablation, and open hepatectomy for small hepatocellular carcinoma: a 5-year experience in a single center

Laparoscopic hepatectomy (LH), microwave ablation (MWA), and open hepatectomy (OH) are three widely used methods to treat small hepatocellular carcinoma (HCC). However, few studies have compared the short‐ and long‐term outcomes of these three treatments. The aim of this study was to investigate their effectiveness.

Expression of CHODL in hepatocellular carcinoma affects invasion and migration of liver cancer cells

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated death. Due to rapid progression and metastasis, the long-term survival remains poor for most patients. Thus, it is important to discover and develop novel preventive strategies and therapeutic approaches for HCC. Recent data show that chondrolectin (CHODL) is commonly overexpressed in the majority of lung cancers, indicating a possible correlation between CHODL and metastasis of lung cancer cells. Our investigation shows that the expression of CHODL is significantly decreased in HCC clinical samples and in HCC cell lines. Overexpression of CHODL in SMMC7721 cells with a lentiviral vector increased SMMC7721 cell migration and invasion. Our findings establish for the first time an association between human CHODL and HCC metastasis.

Microwave Coagulation Therapy Combined with Laparoscopic Liver Resection for Hepatocellular Carcinoma in Cirrhotic Patients

Objective: Image-guided microwave coagulation therapy as a minimally invasive technique has been widely used for the treatment of small HCC in patients who have high surgical risks. However, tumor residual after thermal albation is still the main reason of HCC recurrence. Laparoscopic resection of the tumor after thermal ablation will take advantage of reducing the risk of tumor residual without increasing the risk of hepatic failure. The aim of this study was to evaluate the feasibility and safety of this technique. Methods: From 2008 to 2010, 18 patients (15 men and 3 women; age range, 35-77 years) with HCC and associated severe liver cirrhosis underwent microwave coagulation therapy combined with laparoscopic liver resection. Inclusion criteria were solitary, peripheral or subcapsular HCC lesions localised to the left or anterior right segments; lesion size less than 4 cm; Child-Pugh grading class B or class C. Mortality, morbidity and recurrence rates were analyzed. Results: A total of 18 patients were included. There was no conversion to open operation. The mean operation time was 105 min (range, 70~155 min) and the mean blood loss during operation was 95 ml (range, 40~160 ml). No patient needed blood transfusion. The complications after operation included: pneumonia in 1 patient and mild transient jaundice in 2 patients (<45 μmol/L). None developed ascites, coagulopathy, or encephalopathy. There were no postoperative bile leaks, hepatic failure, and death. The mean hospital stay was 9.5 d (7~16 d). Complete tumor necrosis was found in 14 patients, while tumor cells were found in the resected specimen of the 4 other patients by pathological examination. The mean resection margin was 8.3 mm (range, 6~11 mm). After a mean follow-up of 13 months (range, 5~28 months), 2 patients (2/18) developed tumor recurrence in the liver. Conclusion: Our study shows that microwave coagulation therapy combined with laparoscopic liver resection for hepatocellular carcinoma in cirrhotic patients is feasible and safe.

Perioperative and long-term outcomes of laparoscopic versus open liver resection for hepatocellular carcinoma with well-preserved liver function and cirrhotic background: a propensity score matching study

BackgroundAlthough laparoscopic liver resection (LLR) has advanced into a safe and effective alternative to conventional open liver resection (OLR), it has not been widely accepted by surgeons. This article aimed to investigate the perioperative and long-term benefits of LLR versus OLR for hepatocellular carcinoma (HCC) in selected patients with well-preserved liver function and cirrhotic background.MethodsA retrospective study was conducted on 1085 patients with HCC who underwent liver resection at Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University from July 2010 to July 2015, and 346 patients with well-preserved liver function and cirrhotic background were selected. A 1:1 propensity score matching (PSM), which is the best option to overcome selection bias, was conducted to compare the surgical outcomes and long-term prognosis between LLR and OLR. After PSM, a logistic regression analysis was used to identify the predictive risk factors of posthepatectomy liver failure (PHLF).ResultsBy using PSM, the two groups were well balanced with 86 patients in each group. In the LLR group, only the median operation time was significantly longer than the OLR group, but the hospital stay, overall morbidity, and the incidence of PHLF were significantly decreased compared to OLR. There were no significant differences in the overall survival and disease-free survival rates between the two groups. On multivariate analysis, OLR was identified to be the only independent risk factor for PHLF.ConclusionsIn selected HCC patients with well-preserved liver function and cirrhotic background, LLR could be a better option compared to OLR.

Inhibition of MMP-2 Expression Enhances the Antitumor Effect of Sorafenib in Hepatocellular Carcinoma by Suppressing the PI3K/AKT/mTOR Pathway

Sorafenib has been globally approved as the standard treatment for patients with advanced hepatocellular carcinoma (HCC). However, the response rate of HCC patients to sorafenib is limited because of tumor recurrence and metastasis. Therefore, seeking combined therapeutic strategies with sorafenib is necessary to improve the antitumor efficiency. Here we demonstrated that expression of MMP-2 is positively correlated with the migration ability of HCC cells. Cells with a higher MMP-2 expression (SK-HEP-1 cells) were less sensitive to sorafenib than those with lower MMP-2 expression (HepG2 cells). Cotreatment of cells with SB-3CT and sorafenib more strongly inhibited migration ability than with sorafenib treatment alone in both HCC cells with high and low expression of MMP-2. In vivo cell metastasis experiments confirmed the synergistic effects of sorafenib and SB-3CT in reducing lung metastasis of SK-HEP-1 cells. Mechanistically, we showed that the synergistic antitumor effect may be attributed to inhibition of the PI3K/AKT/mTOR signaling pathway, but not the RAF/MEK/ERK signaling pathway. With these results taken together, the current study demonstrates that inhibiting MMP-2 expression can enhance the antitumor effect of sorafenib in HCC cells with a high MMP-2 expression, which may provide a novel strategy to improve therapeutic efficiency in HCC.

Differentiation of embryonic stem cells into hepatocytes that coexpress coagulation factors VIII and IX

Aim:To establish an efficient culture system to support embryonic stem (ES) cell differentiation into hepatocytes that coexpress F-VIII and F-IX.Methods:Mouse E14 ES cells were cultured in differentiation medium containing sodium butyrate (SB), basic fibroblast growth factor (bFGF), and/or bone morphogenetic protein 4 (BMP4) to induce the differentiation of endoderm cells and hepatic progenitor cells. Hepatocyte growth factor, oncostatin M, and dexamethasone were then used to induce the maturation of ES cell–derived hepatocytes. The mRNA expression levels of endoderm-specific genes and hepatocyte-specific genes, including the levels of F-VIII and F-IX, were detected by RT-PCR and real-time PCR during various stages of differentiation. Protein expression was examined by immunofluorescence and Western blot. At the final stage of differentiation, flow cytometry was performed to determine the percentage of cells coexpressing F-VIII and F-IX, and ELISA was used to detect the levels of F-VIII and F-IX protein secreted into the culture medium.Results:The expression of endoderm-specific and hepatocyte-specific markers was upregulated to highest level in response to the combination of SB, bFGF, and BMP4. Treatment with the three inducers during hepatic progenitor differentiation significantly enhanced the mRNA and protein levels of F-VIII and F-IX in ES cell–derived hepatocytes. More importantly, F-VIII and F-IX were coexpressed with high efficiency at the final stage of differentiation, and they were also secreted into the culture medium.Conclusion:We have established a novel in vitro differentiation protocol for ES-derived hepatocytes that coexpress F-VIII and F-IX that may provide a foundation for stem cell replacement therapy for hemophilia.