High vascular endothelial growth factor (VEGF) expression in chemically-induced hepatic microcancers in mice

Polydopamine-modified konjac glucomannan scaffold with sustained release of vascular endothelial growth factor to promote angiogenesis

The fabrication of scaffolds capable of the sustained release of the vascular endothelial growth factor (VEGF) to promote angiogenesis for a long time remains a challenge in tissue engineering. Here, we report a facile approach for effectively fabricating a bioactive scaffold that gradually releases VEGF to promote angiogenesis. The scaffold was fabricated by coating polydopamine (PDA) on a konjac glucomannan (KGM) scaffold, followed by the surface immobilization of VEGF with PDA. The resulting VEGF-PDA/KGM scaffold, with a porous and interconnected microstructure (392 μm pore size with 84.80 porosity), combined the features of long-term biodegradability (10 weeks with 51 % degradation rate), excellent biocompatibility, and sustained VEGF release for up to 21 days. The bioactive VEGF-PDA/KGM scaffold exhibited multiple angiogenic activities over time, as confirmed by in vivo and in vitro experiments. For example, the scaffold significantly promoted the attachment and proliferation of human umbilical vein endothelial cells and the formation of vascular tubes in vitro. Moreover, the in vivo results demonstrated the formation and maturation of blood vessels after subcutaneous implantation in rats for four weeks. This promising strategy is a feasible approach for producing bioactive materials that can induce angiogenesis in vivo. These findings provide a new avenue for designing and fabricating biocompatible and long-term biodegradable scaffolds for sustained VEGF release to facilitate angiogenesis.

Osthole attenuates angiogenesis in an orthotopic mouse model of hepatocellular carcinoma via the downregulation of nuclear factor-κB and vascular endothelial growth factor

Osthole has been demonstrated to have antitumor activity. Previous studies by our group indicated that osthole effectively inhibited tumor growth in hepatocellular carcinoma (HCC) through the induction of apoptosis and enhancement of antitumor immune responses in mice. The importance of angiogenesis in the proliferation, invasion and metastasis of tumor cells in HCC is well established. The present study aimed to investigate the effects of osthole on angiogenesis in an orthotopic mouse model of HCC. Orthotopic HCC in mice was established, and osthole at 61, 122 and 244 mg/kg was administered intraperitoneally once daily to the tumor-bearing mice for 14 consecutive days. Immunohistochemistry was performed to analyze the microvessel density (MVD) of tissues, and the level of vascular endothelial growth factor (VEGF) was measured by ELISA. The protein levels of nuclear factor-κB (NF-κB) p65 and IκB-α were also detected by western blotting. MVD was positively correlated with tumor weight in the orthotopic mouse model of HCC. Osthole administration significantly decreased MVD in tumor and adjacent tissues, and inhibited tumor growth. Furthermore, osthole downregulated the expression of VEGF and NF-κB p65, and upregulated IκB-α expression in tumor and adjacent tissues. To the best of our knowledge, the results of the present study demonstrated for the first time that osthole inhibits angiogenesis in an orthotopic mouse model of HCC, which may be one of the mechanisms underlying the anti-HCC activity of osthole, which in turn may be mediated by the NF-κB/VEGF signaling pathway. Therefore, osthole, a potential angiogenesis inhibitor and immune system enhancer, may be a promising lead compound for the treatment of HCC.

Diethylnitrosamine Increases Proliferation in Early Stages of Hepatic Carcinogenesis in Insulin-Treated Type 1 Diabetic Mice

Diethylnitrosamine (DEN) induces hepatocarcinogenesis, increasing mitotic hepatocytes and leading to chronic inflammation. In addition, type 1 diabetes mellitus (T1DM) is also characterized by a proinflammatory state and by requiring insulin exogenous treatment. Given the association of diabetes, insulin treatment, and cell proliferation, our specific goal was to determine whether the liver in the diabetic state presents a greater response to DEN-induced cell cycle alteration, which is essential for the malignant transformation. Male C57BL/6 mice (four-week-old) were divided into 4 groups: C, C + DEN, T1DM, and T1DM + DEN. Mice were euthanized ten weeks after DEN injection. DEN per se produced an increase in liver lipid peroxidation levels. Besides, in T1DM + DEN, we found a greater increase in the proliferation index, in comparison with C + DEN. These results are in agreement with the increased expression observed in cell cycle progression markers: cyclin D1 and E1. In addition, a proapoptotic factor, such as activated caspase-3, evidenced a decrease in T1DM + DEN, while the Vascular Endothelial Growth Factor (VEGF) and the protooncogene p53 showed a higher increase with respect to C + DEN. Overall, the results allow us to highlight a major DEN response in T1DM, which may explain in part the greater predisposition to the development of hepatocarcinoma (HCC) during the diabetic state.

The chemopreventive effect of Ginkgo biloba and Silybum marianum extracts on hepatocarcinogenesis in rats

Background/objective

This study was designed to evaluate the potential chemopreventive activities of Ginkgo biloba extract (EGb) and Silybum marianum extract (silymarin) against hepatocarcinogenesis induced by N-nitrosodiethylamine (NDEA) in rats.

Methods

Rats were divided into 6 groups. Group 1 served as normal control rats. Group 2 animals were intragastrically administrated NDEA at a dose of 10 mg/kg five times a week for 12 weeks to induce hepatocellular carcinoma (HCC). Groups 3 and 4 animals were pretreated with silymarin and EGb respectively. Groups 5 and 6 animals were posttreated with silymarin and EGb respectively. The investigated parameters in serum are alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyltransferase (GGT) and vascular endothelial growth factor (VEGF). The investigated parameters in liver tissue are malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and comet assay parameters.

Results

In NDEA group, MDA level was elevated with subsequent decrease in GSH level and SOD, GPx and GR activities. In addition, NDEA group revealed a significant increase in serum ALT, AST and GGT activities and VEGF level. Furthermore, NDEA administrated animals showed a marked increase in comet assay parameters. These biochemical alterations induced by NDEA were confirmed by the histopathological examination of rat livers intoxicated with NDEA that showed an obvious cellular damage and well differentiated HCC.

In contrast, silymarin+NDEA treated groups (3&5) and EGb+NDEA treated groups (4&6) showed a significant decrease in MDA level and a significant increase in GSH content and SOD, GPx and GR activities compared to NDEA group. Silymarin and EGb also beneficially down-regulated the increase in serum ALT, AST, GGT activities and VEGF level induced by NDEA. In addition, silymarin and EGb significantly decreased comet assay parameters. Histopathological examination of rat livers treated with either silymarin or EGb exhibited an improvement in the liver architecture compared to NDEA group.

Conclusions

The obtained findings suggested that silymarin and EGb may have beneficial chemopreventive roles against hepatocarcinogenesis through their antioxidant, antiangiogenic and antigenotoxic activities.

A rodent model of NASH with cirrhosis, oval cell proliferation and hepatocellular carcinoma

BACKGROUND/AIMS

Hepatocellular carcinoma (HCC) is a well recognized complication of advanced NASH (non-alcoholic steatohepatitis). We sought to produce a rat model of NASH, cirrhosis and HCC.

METHODS

Adult Sprague-Dawley rats, weighing 250-300g, were fed a choline-deficient, high trans-fat diet and exposed to DEN in drinking water. After 16 weeks, the animals underwent liver ultrasound (US), sacrifice and assessment by microscopy, immunohistochemistry and transmission electron microscopy (TEM).

RESULTS

US revealed steatosis and focal lesions in 6 of 7. All had steatohepatitis defined as inflammation, advanced fibrosis and ballooning with Mallory-Denk bodies (MDB) with frank cirrhosis in 6. Areas of more severe injury were associated with anti-CK19 positive ductular reaction. HCC, present in all, were macro-trabecullar or solid with polyhedral cells with foci of steatosis and ballooned cells. CK19 was positive in single or solid nests of oval cells and in neoplastic hepatocytes. TEM showed ballooning with small droplet fat, dilated endoplasmic reticulum and MDB in non-neoplastic hepatocytes and small droplet steatosis in some cancer cells.

CONCLUSIONS

This model replicated many features of NASH including steatohepatitis with ballooning, fibrosis, cirrhosis and hepatocellular carcinoma. Oval cell proliferation was evident and the presence anti-CK 19 positivity in the cancer suggests oval cell origin of the malignancy.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) enhances invasiveness of lung cancer cells by up-regulating contactin-1 via the alpha7 nicotinic acetylcholine receptor/ERK signaling pathway

Tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) exhibits potent carcinogenic activity in vitro and in vivo and has been shown to contribute to multiple steps in the tumorigenesis of lung cancer. In this study, we found that NNK up-regulated the expression of contactin-1, a cell adhesion molecule which has been implicated in cell migration, in lowly invasive CL1.0 lung cancer cells in a dose-dependent manner. Reverse transcription-polymerase chain reaction (RT-PCR) analysis and promoter activity assay suggested that NNK directly stimulated contactin-1 gene transcription. Block of alpha7 nicotinic acetylcholine receptor (nAChR) by alpha-bungarotoxin attenuated NNK-induced increase of contactin-1. We also found that NNK activated alpha7 nAChR downstream AKT and extracellular signal-regulated kinase (ERK) signaling pathways in CL1.0 cells. However, only ERK signaling pathway inhibitor PD98059, but not AKT signaling pathway inhibitor LY294002, suppressed the induction of contactin-1 by NNK. Up-regulation of contactin-1 by NNK increased adhesive and invasive abilities of CL1.0 cells which could be effectively inhibited by contactin-1 neutralizing antibody, alpha-bungarotoxin and PD98059. Taken together, we conclude that contactin-1 is a molecule mediator for NNK to promote invasiveness of lung cancer cells.

Antrodia cinnamomea fruiting bodies extract suppresses the invasive potential of human liver cancer cell line PLC/PRF/5 through inhibition of nuclear factor κB pathway

In this study, we first report the anti-invasive effect of ethylacetate extract from Antrodia cinnamomea (EAC) fruiting bodies in the human liver cancer cell line PLC/PRF/5. Treatment with EAC decreased the cancer invasion of PLC/PRF/5 cells in a dose-dependent manner. This effect was strongly associated with a concomitant decrease in either the level or activity of VEGF, MMP-2, MMP-9 and MT1-MMP, and an increase in the expression of TIMP-1 and TIMP-2. EAC inhibited constitutively activated and inducible NF-kappaB in both its DNA-binding activity and transcriptional activity. Furthermore, EAC also inhibited the TNF-alpha-activated NF-kappaB-dependent reporter gene expression of MMP-9 and VEGF, and the invasion of cancer cells. EAC also exhibited an inhibitory effect on angiogenesis in a Matrigel Plug Angiogenesis Assay. Further investigation revealed that EAC's inhibition of cancer cell growth and invasion was also evident in a nude mice model. Our results indicate that EAC inhibits the activation of NF-kappaB, and may provide a molecular basis for drug development using EAC as an anti-invasive agent in the prevention and treatment of cancer.

Metabolic imaging of tissues by infrared fiber-optic spectroscopy: an efficient tool for medical diagnosis

Infrared fingerprints of molecules in biology contain much information on cells metabolism allowing one to distinguish between healthy and altered tissues. Here, to collect infrared signatures, we used evanescent wave spectroscopy based on an original infrared transmitting tapered glass fiber. A strict control of the fiber diameter in the tapered sensing zone allows high sensitivity and wide spectral range exploration from 800 to 3000 cm(-1). Then, merely in depositing the mouse liver biopsies on the fiber, this device has enable us to differentiate between tumorous and healthy tissues.