Jia Hu

Improved tumor-targeting drug delivery and therapeutic efficacy by cationic liposome modified with truncated bFGF peptide

Fibroblast growth factor receptors (FGFRs), overexpressed on the surface of a variety of tumor cells and on tumor neovasculature in situ, are potential targets for tumor- and vascular-targeting therapy. This study aimed to develop a FGFR-mediated drug delivery system to target chemotherapeutic agents to FGFR-overexpressed tumor cells and tumor neovasculature endothelial cells in vitro and in vivo. Here we designed a truncated human basic fibroblast growth factor peptide (tbFGF), which was attached to the surface of cationic liposomal doxorubicin (LPs-DOX) and paclitaxel (LPs-PTX) via electrostatic force. Then we characterized the tbFGF-modified liposome (tbFGF-LPs) and examined internalization of doxorubicin in tumor cells (TRAMP-C1, B16) and HUVEC cells in vitro. In vivo, we evaluated the biodistribution and antitumor efficacy of tbFGF-LPs-DOX and tbFGF-LPs-PTX in C57BL/6J mice bearing TRAMP-C1 prostate carcinoma and B16 melanoma, respectively. The tbFGF-LPs-DOX significantly improved the uptake of doxorubicin in TRAMP-C1, B16 and HUVEC cells, respectively. Biodistribution study in B16 tumor-bearing mice showed that tbFGF-LPs-PTX achieved 7.1-fold (72.827+/-7.321mgh/L vs 10.292+/-0.775mgh/L, mean+/-SD, P<0.01) accumulation of paclitaxel in tumor tissue than those of free paclitaxel. More importantly, treatment of tumor-bearing mice with tbFGF-LPs-DOX and tbFGF-LPs-PTX showed the significant inhibition in tumor growth and improvement in survival rate as compared with mice treated with free and liposomal drugs in TRAMP-C1 and B16 tumor models, respectively. Furthermore, repeated intravenous administration of tbFGF-LPs-DOX/PTX did not induce anti-bFGF antibodies. These results suggested that this FGFR-mediated drug delivery system may provide a new treatment strategy for tumors which overexpress FGFRs.

Millepachine, a novel chalcone, induces G2/M arrest by inhibiting CDK1 activity and causing apoptosis via ROS-mitochondrial apoptotic pathway in human hepatocarcinoma cells in vitro and in vivo

In this study, we reported millepachine (MIL), a novel chalcone compound for the first time isolated from Millettia pachycarpa Benth (Leguminosae), induced cell cycle arrest and apoptosis in human hepatocarcinoma cells in vitro and in vivo. In in vitro screening experiments, MIL showed strong antiproliferation activity in several human cancer cell lines, especially in HepG2 cells with an IC50 of 1.51 µM. Therefore, we chose HepG2 and SK-HEP-1 cells to study MILs antitumor mechanism. Flow cytometry showed that MIL induced a G2/M arrest and apoptosis in a dose-dependent manner. Western blot demonstrated that MIL-induced G2/M arrest was correlated with the inhibition of cyclin-dependent kinase 1 activity, including a remarkable decrease in cell division cycle (cdc) 2 synthesis, the accumulation of phosphorylated-Thr14 and decrease of phosphorylation at Thr161 of cdc2. This effect was associated with the downregulation of cdc25C and upmodulation of checkpoint kinase 2 in response to DNA damage. MIL also activated caspase 9 and caspase 3, and significantly increased the ratio of Bax/Bcl-2 and stimulated the release of cytochrome c into cytosol, suggesting MIL induced apoptosis via mitochondrial apoptotic pathway. Associated with those effects, MIL also induced the generation of reactive oxygen species. In HepG2 tumor-bearing mice models, MIL remarkably and dose dependently inhibited tumor growth. Treatment of mice with MIL (20mg/kg intravenous [i.v.]) caused more than 65% tumor inhibition without cardiac damage compared with 47.57% tumor reduction by 5mg/kg i.v. doxorubicin with significant cardiac damage. These effects suggested that MIL and its easily modified structural derivative might be a potential lead compound for antitumor drug.

Flow rate gradient high-speed counter-current chromatography separation of five diterpenoids from Triperygium wilfordii and scale-up.

In this paper, high-speed counter-current chromatography (HSCCC) instruments with different gravitational forces were applied for the separation of bioactive compounds from Triperygium wilfordii Hook.f. The critical parameters including sample concentration, sample volume and flow rate were first optimized on an analytical Mini-DE HSCCC system, and then scaled up to a preparative TBE 300A HSCCC system. Although this scale-up process was performed using different CCC instruments with different centrifuges and gravitational forces, the same resolutions were obtained and the elution time could be predictable. Five diterpenoid compounds and one unknown compound were separated from Triperygium wilfordii Hook.f. by HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (HEMW) (3:2:3:2, v/v/v/v). This one-step flow gradient separation produced triptonide (25 mg), isoneotriptophenolide (77 mg), hypolide (83 mg), unknown compound (1 mg), triptophenolide (42 mg), triptonoterpene methyl ether VI (37 mg) from 320 mg crude extract with purities of 98.2%, 96.6%, 98.1%, 95.3%, 95.1%, and 96.5%, respectively. Their purities and structures were identified by high-performance liquid chromatography, mass spectrometry and NMR. This paper demonstrates that analytical CCC plays an important role in optimizing parameters and scale-up process when analytical CCC and preparative CCC are supplied by different manufacturers with different gravitational forces, and the scale-up process from analytical CCC to preparative CCC is still predictable.

Synergistic Antitumor Effects of Liposomal Honokiol Combined with Adriamycin in Breast Cancer Models

Honokiol, a novel antitumor agent, could induce apoptosis and inhibit the growth of vascular endothelium in several tumor cell lines and xenograft models. It has been suggested that the antitumor effect of chemotherapy could be increased by combining it with an antiangiogenesis agent in anticancer strategy. The present study explored the potential to increase the antitumor effect of adriamycin by combining it with honokiol in mouse 4T1 breast cancer models, and the underlining mechanism was investigated. Honokiol was encapsulated in liposomes to improve the water insolubility. In vitro, liposomal honokiol inhibited the proliferation of 4T1 cells via apoptosis and significantly enhanced the apoptosis of 4T1 cells induced by adriamycin. In vivo, the systemic administration of liposomal honokiol and adriamycin significantly decreased tumor growth through increased tumor cell apoptosis compared with either treatment alone. Collectively, these findings suggest that liposomal honokiol may augment the induction of apoptosis in 4T1 cells in vitro and in vivo, and this combined treatment has shown synergistic suppression in tumor progression according to the analysis of isobologram. The present study may be important in future exploration of the potential application of the combined approach in the treatment of breast cancer. Copyright

Liposomal honokiol, a potent anti-angiogenesis agent, in combination with radiotherapy produces a synergistic antitumor efficacy without increasing toxicity

Honokiol is an active compound purified from magnolia that has been shown to induce cell differentiation, apoptosis, and anti-angiogenesis effects, as well as an enhancement in tumor growth delay in combination with chemotherapeutic agents in several mouse xenograft models. Our goal was to investigate the radiosensitization effect of honokiol on lung carcinoma. The radiosensitization effect of liposomal honokiol in Lewis lung carcinoma cells (LL/2) was analyzed using an in vitro clonogenic survival assay. For an in vivo study, Lewis lung carcinoma-bearing C57BL/6 mice were treated with either liposomal honokiol at 25 mg/kg or 5 Gy of single tumor radiation, or a combination of both over 12 days of treatment. The tumor growth delay and the survival time were evaluated. In addition, histological analysis of tumor sections was performed to examine changes by detecting the microvessel density and apoptosis in tumor tissues. In the clonogenic survival assay, LL/2 cells treated with IC50 Lipo-HNK for 24 h showed a radiation enhancement ratio of 1.9. After 12 days of combination treatment, the tumor volume decreased 78% and produced an anti-tumor activity 1.3-fold greater than a predicted additive effect of honokiol and radiation alone. This combination treatment also caused an 8.7 day delay in tumor growth. The cell cycle distribution and histological analysis demonstrated that liposomal honokiol has an anti-tumor effect via inducing apoptosis and inhibiting angiogenesis. Liposomal honokiol can enhance tumor cell radiosensitivity in vitro and in vivo, indicating that radiotherapy combined with liposomal honokiol can lead to greater anti-tumor efficacy.

Deguelin—An inhibitor to tumor lymphangiogenesis and lymphatic metastasis by downregulation of vascular endothelial cell growth factor-D in lung tumor model

Deguelin, a rotenoid of the flavonoid family, has been reported to possess antiproliferative and anticarcinogenic activities in several cell lines and tumor models. However, it is still unclear whether deguelin effectively inhibits tumor‐associated lymphangiogenesis and lymphatic metastasis. Since tumor production of vascular endothelial cell growth factor (VEGF)‐D was associated with tumor lymphangiogenesis and lymphatic metastasis, we established the mouse lymphatic metastasis model by transfecting high expression VEGF‐D into LL/2 Lewis lung cells (VEGF‐D‐LL/2) and explored the effects of deguelin on lymphatic metastasis in the immunocompetent C57BL/6 mice. Our results indicated that deguelin inhibited proliferation, migration of VEGF‐D‐LL/2 cells via downregulating AKT and mitogen‐activated protein kinase pathway and interfered tube formation of lymphatic vascular endothelial cells on matrigel at nanomolar concentrations. Deguelin significantly downregulated the expression of VEGF‐D both at mRNA and protein levels in VEGF‐D‐LL/2 cells in a dose‐dependent manner. In the in vivo study, intraperitoneal administration of deguelin (4 mg/kg) remarkably inhibited the tumor‐associated lymphangiogenesis and lymphatic metastasis. The rates of lymph node and lung metastasis in deguelin‐treated mice were 0 and 16.7% compared with 58.3 and 83.3% in control group mice, respectively. Deguelin also resulted in a remarkable delay of tumor growth and prolongation of life span. Immunohistochemical staining with antibodies against VEGF‐D, LYVE‐1 and VEGFR‐3 revealed fewer positive vessel‐like structures in deguelin‐treated mice compared with control group mice. Taken together, we demonstrate for the first time that deguelin suppresses tumor‐associated lymphangiogenesis and lymphatic metastasis by downregulation of VEGF‐D both in vitro and in vivo.

Optimizing high-performance liquid chromatography method for quantification of glucosamine using 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate derivatization in rat plasma: application to a pharmacokinetic study.

A sensitive and reliable HPLC method with fluorescence detection based on the precolumn derivatization of glucosamine with 6-aminoquinolyl-N-hydroxylsuccinimidyl carbamate (AQC) was established for the quantitative determination of glucosamine in rat plasma. The plasma protein was precipitated by acetonitrile, followed by vortex mixing and centrifugation. The supernatant was divided into the organic layer and aqueous layer by adding sodium chloride, and then the aqueous layer was derivatized with AQC in 0.2 M borate buffer of pH 8.8 before the HPLC analysis. An amino acid analysis column (3.9 x 150 mm, 4 microm) was applied, with 140 mM sodium acetate buffer (pH = 5.25) and acetonitrile as mobile phase at a flow rate of 1 mL/min. A linear correlation coefficient of 0.9987 was calculated within the range of 0.1-30 microg/mL of the standard curve for glucosamine. The limit of detection was 30 ng/mL. The intra- and inter-day precisions (as RSD) were less than 7.38 and 12.72%, respectively. The intra- and inter-day accuracy ranged from 91.8 to 110.0%. Extraction recoveries of glucosamine in plasma were more than 90%. The validated method was successfully applied for the quantitative determination of glucosamine in rat plasma and evaluation for pharmacokinetic study of glucosamine. It was also possible to be applied for the quantitative determination of other compounds containing amino group in biological samples.

5-Formylhonokiol exerts anti-angiogenesis activity via inactivating the ERK signaling pathway

Our previous report has demonstrated that 5-formylhonokiol (FH), a derivative of honokiol (HK), exerts more potent anti-proliferative activities than honokiol in several tumor cell lines. In present study, we first explored the antiangiogenic activities of 5-formylhonokiol on proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) for the first time in vitro. Then we investigated the in vivo antiangiogenic effect of 5-formylhonokiol on zebrafish angiogenesis model. In order to clarify the underlying molecular mechanism of 5-formylhonokiol, we investigated the signaling pathway involved in controlling the angiogenesis process by western blotting assay. Wound-healing results showed that 5-formylhonokiol significantly and dose-dependently inhibited migration of cultured human umbilical vein enthothelial cells. The invasiveness of HUVEC cells was also effectively suppressed at a low concentration of 5-formylhonokiol in the transwell assay. Further F-actin imaging revealed that inhibitory effect of 5-formylhonokiol on invasion may partly contribute to the disruption of assembling stress fiber. Tube formation assay, which is associated with endothelial cells migration, further confirmed the anti-angiogenesis effect of 5-formylhonokiol. In in vivo zebrafish angiogenesis model, we found that 5-formylhonokiol dose-dependently inhibited angiogenesis. Furthermore, western blotting showed that 5-formylhonokiol significantly down-regulated extracellular signal-regulated kinase (ERK) expression and inhibited the phosphorylation of ERK but not affecting the total protein kinase B (Akt) expression and related phosphorylation, suggesting that 5-formylhonokiol might exert anti-angiogenesis capacity via down-regulation of the ERK signal pathway. Taken together, these data suggested that 5-formylhonokiol might be a viable drug candidate in antiangiogenesis and anticancer therapies.

Enrichment and isolation of barbigerone from Millettia pachycarpa Benth. using high-speed counter-current chromatography and preparative HPLC.

Enrichment of the anti-tumor compound barbigerone along with a rotenoid derivative from Millettia pachycarpa Benth. was performed by a two-step high-speed counter-current chromatography (HSCCC) separation process. In the first step, 155.8 mg of target fraction (Fra6) was obtained from 400 mg ethyl acetate extract of M. pachycarpa Benth. with an increase in barbigerone from 5.1 to 13% via HSCCC using a solvent system of n-hexane-ethyl acetate-methanol-water (5:4:5:3, v/v) under normal phase head to tail elution. HSCCC was repeated to eliminate the major contaminant in this initial fraction 6. After a separation time of 65 min, 22.1 mg barbigerone of 87.7% purity was obtained from Fra6 with the ternary solvent system of n-hexane-methanol-water (2:2:1, v/v) under normal phase elution. Finally, preparative HPLC was employed for the further isolation of barbigerone and the rotenoid derivative. The structures were confirmed by ESI-MS, (1)H NMR and (13)C NMR.

Barbigerone inhibits tumor angiogenesis, growth and metastasis in melanoma.

Tumor angiogenesis, growth and metastasis are three closely related processes. We therefore investigated the effects of barbigerone on all three in the B16F10 tumor model established in both zebrafish and mouse models, and explored underlying molecular mechanisms. In vitro, barbigerone inhibited B16F10 cell proliferation, survival, migration and invasion and suppressed human umbilical vascular endothelial cell migration, invasion and tube formation in concentration-dependent manners. In the transgenic zebrafish model, treatment with 10μM barbigerone remarkably inhibited angiogenesis and tumor-associated angiogenesis by reducing blood vessel development more than 90%. In vivo, barbigerone significantly suppressed angiogenesis as measured by H and E staining of matrigel plugs and CD31 staining of B16F10 melanoma tumors in C57BL/6 mice. Furthermore, it exhibited highly potent activity at inhibiting tumor growth and metastasis to the lung of B16F10 melanoma cells injected into C57BL/6 mice. Western blotting revealed that barbigerone inhibited phosphorylation of AKT, FAK and MAPK family members, including ERK, JNK, and p38 MAPKs, in B16F10 cells mainly through the MEK3/6/p38 MAPK signaling pathway. These findings suggested for the first time that barbigerone could inhibit tumor-angiogenesis, tumor growth and lung metastasis via downregulation of the MEK3/6/p38 MAPK signaling pathway. The findings support further investigation of barbigerone as a potential anti-cancer drug.