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As part of our continuing efforts to explore bioactive compounds from natural resources, a new iridoid glycoside, adoxosidic acid-6′-oleuroperic ester (1), together with one known phenylethanoid glycoside (2) and two known flavonoid glycosides (3–4) were isolated from the fruit of Forsythia suspensa. The structure of the new compound (1) was elucidated through 1D and 2D NMR spectroscopic data and HR-ESIMS. Interestingly, compound 1 was a monoterpene ester of one iridoid glycoside. Compounds 2–4 were identified as calceolarioside A (2), kaempferol-3-O-rutinoside (3), kampferol-3-O-robinobioside (4) on the basis of NMR spectroscopic data analyses and comparison with the data reported in the literature. The antiviral activity aganisist influenza A (H5N1) virus of compound 1 was studied as well. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) are critical for tumor initiation/maintenance and recurrence or metastasis, so they may serve as a potential therapeutic target. However, CSC-established multitherapy resistance and immune tolerance render tumors resistant to current tumor-targeted strategies. To address this, renewable multiepitope-integrated spheroids based on placentaderived mesenchymal stem cells (pMSCs) were X-ray-modified, at four different irradiation levels, including 80, 160, 240, and 320 Gy, as pluripotent biologics, to inoculate hosts bearing Lewis lung carcinoma (LL2) and compared with X-ray-modified common LL2 cells as control. We show that the vaccines at the 160/240 Gy irradiation levels could rapidly trigger tumor cells into the apoptosis loop and evidently prolong the tumor-bearing host's survival cycle, in contrast to vaccines irradiated at other levels (P<0.05), with tumor-sustaining stromal cell-derived factor-1/CXCR4 pathway being selectively blockaded. Meanwhile, almost no or minimal toxicity was detected in the vaccinated hosts. Importantly, 160/240 Gy-irradiated vaccines could provoke significantly higher killing of CSCs and non-CSCs, which may provide an access to developing a novel biotherapy against lung carcinoma. [ABSTRACT FROM AUTHOR]

Transient receptor potential channel 1 (TRPC1) is a nonselective cation channel that is required for Ca2+ homeostasis necessary for cellular functions. However, whether TRPC1 is involved in infectious disease remains unknown. Here, we report a novel function for TRPC1 in host defense against Gram-negative bacteria. TRPC1-/- mice exhibited decreased survival, severe lung injury, and systemic bacterial dissemination upon infection. Furthermore, silencing of TRPC1 showed decreased Ca2+ entry, reduced proinflammatory cytokines, and lowered bacterial clearance. Importantly, TRPC1 functioned as an endogenous Ca2+ entry channel critical for proinflammatory cytokine production in both alveolar macrophages and epithelial cells. We further identified that bacterium-mediated activation of TRPC1 was dependent on Toll-like receptor 4 (TLR4), which induced endoplasmic reticulum (ER) store depletion. After activation of phospholipase Cγ (PLC-γ), TRPC1 mediated Ca2+ entry and triggered protein kinase Cα (PKCα) activity to facilitate nuclear translocation of NF-κB/Jun N-terminal protein kinase (JNK) and augment the proinflammatory response, leading to tissue damage and eventually mortality. These findings reveal that TRPC1 is required for host defense against bacterial infections through the TLR4-TRPC1-PKCα signaling circuit. [ABSTRACT FROM AUTHOR]

Background Sunitinib alone exhibits satisfactory efficacy in several mouse homografts and xenografts but unsatisfactory efficacy in many kinds of solid tumors in clinic. Different from animals, receiving a diagnosis of cancer impacts chronic stress on patients. Here, we examine whether norepinephrine (NE), one of the most potent stress related hormones, leads to the difference in the efficacy of sunitinib between clinical and preclinical trials. Methods The influence of NE on mouse melanoma B16F1 cells under sunitinib was evaluated in vitro and in vivo. The β-AR/cAMP/PKA (β-adrenoceptor/cyclic adenosine monophosphate/protein kinase A) signaling pathway was also evaluated in human lung adenocarcinoma cells. Results We found that NE upregulated the expression of VEGF, IL-8 and IL-6 in vitro and stimulated tumor growth in vivo, which was mediated by β-AR/cAMP/PKA signaling pathway and could be inhibited by propranolol, a β-blocker for hypertension for decades. Conclusions This research indicates exogenous norepinephrine attenuates the efficacy of sunitinib, and a combination of sunitinib and propranolol might be suggested as a new strategy in solid tumor in clinic. [ABSTRACT FROM AUTHOR]

Background Vascular endothelial growth factor (VEGF)-D has been shown to promote lymph node metastasis in several cancers. Although generally overexpressed in ovarian carcinoma, its role in nodal dissemination of this cancer is unclear. To clarify the role of VEGF-D and the underlying molecular mechanisms, we investigated the function of VEGF-D using a mouse xenograft model of ovarian cancer. Methods Human ovarian serous adenocarcinoma SKOV3 cells were transfected with VEGF-D recombinant plasmid DNA, or with control vectors. The cells were injected subcutaneously into the footpads of nude mice. Tumor growth was evaluated weekly. Draining lymphatics were observed grossly with Evan's blue lymphangiography. Tumoral lymphatics were delineated with both Evan's blue and LYVE-1 immunostaining. Tumor metastases to lymph nodes were evaluated by H&E and CA125/CD40 staining. Expression of VEGF-D in primary tumors and levels of CA125 in involved lymph nodes were examined by immunohistochemistry. Tumor cell apoptosis was analyzed by Hoechst dyeing. Results Mice bearing VEGF-D overexpressing xenografts showed a significantly higher rate of lymph node metastasis and markedly greater tumor volume compared with the controls. The functional lymphatic vessels were denser and enlarged in marginal and central tumor portions. Additionally, higher CA125 expression was observed in the involved lymph nodes. Mice bearing VEGF-D overexpressing xenografts also exhibited a markedly lower apoptotic index compared with the controls. Conclusions Our data demonstrate the important role of VEGF-D in promoting lymph node metastasis by increasing tumor lymphangiogenesis, stimulating draining lymphatic vessel formation, and enhancing tumor invasiveness. Our findings show that VEGF-D can be a promising therapeutic target for ovarian cancer. [ABSTRACT FROM AUTHOR]

Purpose: Tumor associated macrophages (TAMs) are considered with the capacity to have both negative and positive effects on tumor growth. The prognostic value of TAM for survival in patients with solid tumor remains controversial. Experimental Design: We conducted a meta-analysis of 55 studies (n = 8,692 patients) that evaluated the correlation between TAM (detected by immunohistochemistry) and clinical staging, overall survival (OS) and disease free survival (DFS). The impact of M1 and M2 type TAM (n = 5) on survival was also examined. Results: High density of TAM was significantly associated with late clinical staging in patients with breast cancer [risk ratio (RR) = 1.20 (95% confidence interval (CI), 1.14-1.28)] and bladder cancer [RR = 3.30 (95%CI, 1.56-6.96)] and with early clinical staging in patients with ovarian cancer [RR = 0.52 (95%CI, 0.35-0.77)]. Negative effects of TAM on OS was shown in patients with gastric cancer [RR = 1.64 (95%CI, 1.24-2.16)], breast cancer [RR = 8.62 (95%CI, 3.10-23.95)], bladder cancer [RR = 5.00 (95%CI, 1.98-12.63)], ovarian cancer [RR = 2.55 (95%CI, 1.60-4.06)], oral cancer [RR = 2.03 (95%CI, 1.47-2.80)] and thyroid cancer [RR = 2.72 (95%CI, 1.26-5.86)],and positive effects was displayed in patients with colorectal cancer [RR = 0.64 (95%CI, 0.43-0.96)]. No significant effect was showed between TAM and DFS. There was also no significant effect of two phenotypes of TAM on survival. Conclusions: Although some modest bias cannot be excluded, high density of TAM seems to be associated with worse OS in patients with gastric cancer, urogenital cancer and head and neck cancer, with better OS in patients with colorectal cancer. [ABSTRACT FROM AUTHOR]

Ovarian cancer is the most common cause of death from gynecologic malignancy. Deregulation of p53 and/or p73-associated apoptotic pathways contribute to the platinum-based resistance in ovarian cancer. NOXA, a pro-apoptotic BH3- only protein, is identified as a transcription target of p53 and/or p73. In this study, we found that genetic variants of Bcl-2 proteins exist among cisplatin-sensitive and -resistant ovarian cancer cells, and the responses of NOXA and Bax to cisplatin are regulated mainly by p53. We further evaluated the effect of NOXA on cisplatin. NOXA induced apoptosis and sensitized A2780s and SKOV3 cells to cisplatin in vitro and in vivo. The effects were mediated by elevated Bax expression, enhanced caspase activation, release of Cyt C and Smac into the cytosol. Furthermore, gene silencing of Bax or Smac significantly attenuated NOXA and/or cisplatin-induced apoptosis in chemosensitive A2780s cells, whereas overexpression of Bax or addition of Smac-N7 peptide significantly increased NOXA and/or cisplatin-induced apoptosis in chemoresistant SKOV3 cells. To our knowledge, these data suggest a new mechanism by which NOXA chemosensitized ovarian cancer cells to cisplatin by inducing alterations in the Bax/Smac axis. Taken together, our findings show that NOXA is potentially useful as a chemosensitizer in ovarian cancer therapy. [ABSTRACT FROM AUTHOR]

A series of novel benzothiazole-2-thiol derivatives were synthesized and their structures determined by 1H-NMR, 13C-NMR and HRMS (ESI). The effects of all compounds on a panel of different types of human cancer cell lines were investigated. Among them, pyridinyl-2-amine linked benzothiazole-2-thiol compounds 7d, 7e, 7f and 7i exhibited potent and broad-spectrum inhibitory activities. Compound 7e displayed the most potent anticancer activity on SKRB-3 (IC50 = 1.2 nM), SW620 (IC50 = 4.3 nM), A549 (IC50 = 44 nM) and HepG2 (IC50 = 48 nM) and was found to induce apoptosis in HepG2 cancer cells. [ABSTRACT FROM AUTHOR]

A novel series of 2-(3-fluoro-4-nitrophenoxy)-N-phenylacetamide compounds were designed, synthesized and in vitro assessed for their antitubercular activities by a microdilution method. All the novel derivatives exerted potent or moderate active against M. tuberculosis H37Rv, with MIC values ranging from 4 to 64 μg/mL. The most potent derivative 3m showed an identical MIC value of 4 μg/mL for both M. tuberculosis H37Rv and rifampin-resistant M. tuberculosis 261. It demonstrated no inhibitory effects against six different tumor cell lines by a MTT assay and had a good safety profile in a vero cell line, providing a good lead for subsequent optimization in search of novel affordable antitubercular agents. [ABSTRACT FROM AUTHOR]

Hepatitis represents a ubiquitous human health problem but effective therapies with limited side effects are still lacking. In this study, we investigated the effect and mechanism of TP-58, a novel thienopyridine derivative, on a murine fulminant hepatitis model induced by concanavalin A (ConA). We found TP-58 markedly alleviated ConA-caused liver injury and increased survival ratio of mice injected with a lethal dose of ConA. Oral administration of TP-58 significantly alleviated ConA-caused liver injury in mice by the reduction of serum aminotransferases and liver necrosis.The analysis of proinflammatory cytokines showed that TP-58 decreased both hepatic mRNA expressions and serum protein levels of TNF-α and IL-6. And the result from LPS-stimulated RAW 264.7 cells showed TP-58 suppressed the production of TNF-α, IL-6, and Nitro Oxide (NO) in the supernatant of LPS-stimulated RAW 264.7 cells. The study of activation of nuclear factor-κB (NF- κB) by electrophoretic mobility shift assay (EMSA) showed that TP-58 inhibited the activation of NF-κB both in vivo and in vitro. The inhibitory effect was also accompanied by a parallel reduction of IκB phosphorylation. These results indicate that TP-58 protects against liver injury by inhibition of the NF-κB-mediated inflammation and suggest a potential role of TP-58 against acute liver injury and other inflammatory diseases. [ABSTRACT FROM AUTHOR]

Despite many evidences supporting the concept of ''oncogene addiction'' and many hypotheses rationalizing it, there is still a lack of detailed understanding to the precise molecular mechanism underlying oncogene addiction. In this account, we developed a mathematic model of epidermal growth factor receptor (EGFR) associated signaling network, which involves EGFR-driving proliferation/pro-survival signaling pathways Ras/extracellular-signal-regulated kinase (ERK) and phosphoinositol- 3 kinase (PI3K)/AKT, and pro-apoptotic signaling pathway apoptosis signal-regulating kinase 1 (ASK1)/p38. In the setting of sustained EGFR activation, the simulation results show a persistent high level of proliferation/pro-survival effectors phospho-ERK and phospho-AKT, and a basal level of pro-apoptotic effector phospho-p38. The potential of p38 activation (apoptotic potential) due to the elevated level of reactive oxygen species (ROS) is largely suppressed by the negative crosstalk between PI3K/AKT and ASK1/p38 pathways. Upon acute EGFR inactivation, the survival signals decay rapidly, followed by a fast increase of the apoptotic signal due to the release of apoptotic potential. Overall, our systems biology modeling together with experimental validations reveals that inhibition of survival signals and concomitant release of apoptotic potential jointly contribute to the tumor cell death following the inhibition of addicted oncogene in EGFR addicted cancers. [ABSTRACT FROM AUTHOR]

Twelve novel acenaphthene derivatives have been synthesized. The structures of all compounds were confirmed by 1H-NMR, MS and elemental analysis. Their antitumor activities were evaluated in six human solid tumor cell lines, namely non-small cell lung cancer (H460), human colon adenocarcinoma (SW480), human breast cancer cell (MDA-MB-468 and SKRB-3), human melanoma cell (A375) and human pancreatic cancer (BxPC-3) . Among them, compound 3c shows the best antitumor activity against SKRB-3 cell line, as high as the positive control adriamycin. [ABSTRACT FROM AUTHOR]

Focal adhesion kinase (FAK) is a non-receptor protein tyrosine kinase implicated in cancer cell survival, proliferation, and in various steps in the metastatic cascade. In the present study, we took advantage of a cationic liposome as gene carrier and targeted FAK function through both in vitro and in vivo approaches. We utilized a plasmid-encoded hairpin RNA targeting the human FAK mRNA (pGensil2-shRNA/FAK), as a means to inhibit FAK expression for evaluating its anti-tumor effect in vitro and in vivo. Human MDA-MB-435S breast cancer cells were transfected with pGensil2-shRNA/FAK and examined for apoptosis by propidium iodide staining, DNA ladder, and flow cytometric analysis. For in vivo study, subcutaneous breast carcinomatosis models in nude mice were established to evaluate the therapeutic potential of pGensil2-shRNA/FAK. Assessments of proliferation (Ki-67), apoptosis (TUNEL) and angiogenesis (CD31) were done using immunohistochemical analysis. Transcripts expressed from plasmid both in vitro and in vivo were identified by northern blot analysis. pGensil2-shRNA/FAK effectively down-regulated the expression of FAK as demonstrated in vitro by real time RT-PCR and western blot analysis, whereas by real time RT-PCR and IHC staining of MDA-MB-435S tumors growing subcutaneously. Breast cancer cells lacking FAK expression undergo apoptosis in vitro. Systemic delivery of cationic liposome-complexed plasmids targeting FAK, resulted in the diminishment of subcutaneous tumor growth beyond the effects observed with liposomes carrying a non-specific shRNA. This diminishment in growth was associated with elevated levels of apoptosis (TUNEL staining), decreased cell proliferation (Ki-67 staining) and diminished endothelial cell density (CD31 staining). These results indicate that the systemic delivery of plasmid DNA targeting FAK function using cationic liposome as a gene carrier, represents a promising avenue for breast cancer therapy. [ABSTRACT FROM AUTHOR]

The Pkd2 gene encodes an integral protein (~130 kDa), named polycystin-2 (PC-2). PC-2 is mainly involved in autosomal dominant polycystic kidney disease. Recently, polycystin-1/polycystin-2 complex has been shown to act as an adhesion complex mediating or regulating cell–cell or cell–matrix adhesion, suggesting that PC-2 may play a role in cell–cell/cell–matrix interactions. Here, we knocked down the expression of Pkd2 gene with small interfering RNAs (siRNAs) in the mouse melanoma cells (B16 cells), indicating that the cells transfected with the targeted siRNAs significantly suppressed cell–cell adhesion, but not cell–matrix adhesion, compared to the cells transfected with non-targeted control (NC) siRNA. This study provides the first directly functional evidence that PC-2 mediates cell–cell adhesion. Furthermore, we demonstrated that PC-2 modulated cell–cell adhesion may be, at least partially, associated with E-cadherin. Collectively, these findings for the first time showed that PC-2 may mediate cell–cell adhesion, at least partially, through E-cadherin. [ABSTRACT FROM AUTHOR]

Background: Camptothecin (CPT) has recently attracted increasing attention as a promising anticancer agent for a variety of tumors. But the clinical application is largely hampered by its extreme water insolubility and unpredictable side effect. It is essential to establish an efficient and safe protocol for the administration of CPT versus melanoma. Methods: Camptothecin was encapsulated with N-trimethyl chitosan (CPT-TMC) through microprecipitation and sonication. Its inhibition effect on B16-F10 cell proliferation and induction of apoptosis was evaluated by MTT assay and flow cytometric analysis in vitro. The anti-tumor activity of CPT-TMC was evaluated in C57BL/6 mice bearing B16- F10 melanoma. Tumor volume, tumor weight and survival time were recorded. Assessment of apoptotic cells within tumor tissue was performed by TUNEL assay. Antiangiogenesis and antiproliferation effects of CPT-TMC in vivo were conducted via CD31 and PCNA immunohistochemistry, respectively. Results: CPT-TMC efficiently inhibited B16-F10 cells proliferation and increased apoptosis in vitro. Experiment group showed significant inhibition compared with free CPT-treated group (81.3% vs. 56.9%) in the growth of B16-F10 melanoma xenografts and prolonged the survival time of the treated mice (P < 0.05). Decreased cell proliferation, increased tumor apoptosis as well as a reduction in angiogenesis were observed. Conclusions: Our data suggest that N-trimethyl chitosan-encapsulated camptothecin is superior to free CPT by overcoming its insolubility and finally raises the potential of its application in melanoma therapy. [ABSTRACT FROM AUTHOR]

Background: A high concentration of cisplatin (CDDP) induces apoptosis in many tumor cell lines. CDDP has been administered by infusion to avoid severe toxicity. Recently, it has been reported that changes in survivin expression or function may lead to tumor sensitization to chemical and physical agents. The aim of this study was to determine whether a dominant-negative mouse survivin mutant could enhance the anti-tumor activity of CDDP. Methods: A plasmid encoding the phosphorylation-defective dominant-negative mouse survivin threonine 34Talanine mutant (survivin T34A) complexed to a DOTAP-chol liposome (Lip-mS) was administered with or without CDDP in Lewis Lung Carcinoma (LLC) cells and in mice bearing LLC tumors, and the effects on apoptosis, tumor growth and angiogenesis were assessed. Data were analyzed using one-way analysis of variance(ANOVA), and a value of P < 0.05 was considered to be statistically significant. Results: LLC cells treated with a combination of Lip-mS and CDDP displayed increased apoptosis compared with those treated with Lip-mS or CDDP alone. In mice bearing LLC tumors and treated with intravenous injections of Lip-mS and/ or CDDP, combination treatment significantly reduced the mean tumor volume compared with either treatment alone. Moreover, the antitumor effect of Lip-mS combined with CDDP was greater than their anticipated additive effects. Conclusion: These data suggest that the dominant-negative survivin mutant, survivin T34A, sensitized LLC cells to chemotherapy of CDDP. The synergistic antitumor activity of the combination treatment may in part result from an increase in the apoptosis of tumor cells, inhibition of tumor angiogenesis and induction of a tumor-protective immune response. [ABSTRACT FROM AUTHOR]

Development of small molecular kinase inhibitors has recently been the central focus in drug discovery. And type II kinase inhibitors that target inactive conformation of kinases have attracted particular attention since their potency and selectivity are thought to be easier to achieve compared with their counterpart type I inhibitors that target active conformation of kinases. Although mechanisms underlying the interactions between type II inhibitors and their targeting kinases have been widely studied, there are still some challenging problems, for example, how type II inhibitors associate with or dissociate from their targeting kinases. In this investigation, steered molecular dynamics simulations have been carried out to explore the possible dissociation pathways of typical type II inhibitor imatinib from its targeting protein kinases c-Kit and Abl. The simulation results indicate that the most favorable pathway for imatinib dissociation corresponds to the ATP-channel rather than the relatively wider allosteric-pocket-channel, which is mainly due to the different van der Waals interaction that the ligand suffers during dissociation. Nevertheless, the direct reason comes from the fact that the residues composing the ATP-channel are more flexible than that forming the allosteric-pocket-channel. The present investigation suggests that a bulky hydrophobic head is unfavorable, but a large polar tail is allowed for a potent type II inhibitor. The information obtained here can be used to direct the discovery of type II kinase inhibitors. [ABSTRACT FROM AUTHOR]

PNAS-4, a novel pro-apoptotic gene activated during the early response to DNA damage, can inhibit proliferation via apoptosis when overexpressed in some tumor cells. The objectives of this study were to determine whether PNAS-4 could enhance apoptosis induced by cisplatin besides its induction of apoptosis, and to evaluate the usefulness of combined treatment with mouse PNAS-4 ( mPNAS-4) gene therapy and low-dose cisplatin chemotherapy in the inhibition of tumor growth in colon carcinoma (CT26) and Lewis lung carcinoma (LL/2) murine models. In this study, the in vitro growth-inhibitory and pro-apoptotic effects of PNAS-4 and/or cisplatin on CT26, LL/2, and SKOV3 cancer cells were assessed by MTT assay, flow cytometric analysis, DNA fragmentation, and morphological analysis, respectively. The in vivo antitumor activity of combined treatment with mPNAS-4 gene therapy and low-dose cisplatin were evaluated in the inhibition of tumor growth in colon carcinoma (CT26) and Lewis lung carcinoma (LL/2) murine models. Tumor volume and survival time were observed. Induction of apoptosis was also assessed in tumor tissues. In vitro, PNAS-4 inhibited proliferation of colon carcinoma (CT26), Lewis lung carcinoma (LL/2) and human ovarian cancer (SKOV3) cell lines via apoptosis, and significantly enhanced the apoptosis of CT26, LL/2, and SKOV3 cells induced by cisplatin. In vivo systemic administration of expression plasmid encoding mPNAS-4 (pcDNA3.1-mPS) and cisplatin, significantly decreased tumor growth through increased tumor cell apoptosis compared to treatment with mPNAS-4 or cisplatin alone. Our data suggests that the combined treatment with mPNAS-4 plus cisplatin may augment the induction of apoptosis in tumor cells in vitro and in vivo, and that the augmented antitumor activity in vivo may result from the increased induction of apoptosis. The present study may provide a novel way to augment the antitumor efficacy of cytotoxic chemotherapy. [ABSTRACT FROM AUTHOR]

Malignant pleural effusion (MPE) is a common clinical problem in patients with advanced cancer. Evidence suggests that tumor-mediated angiogenesis and enhanced vascular permeability in the pleural wall are due to high levels of vascular endothelial growth factor (VEGF), which plays an important role in the pathogenesis of MPE. The present study was designed to test whether the recombinant adenovirus-mediated delivery of human endostatin (Ad-hEndo), one of the potent inhibitors of angiogenesis, would inhibit the formation and progression of MPE. We developed a novel mouse model of MPE by injecting Lewis lung carcinoma (LLC) cells directly into pleural cavity of C57BL/6 mice. To evaluate the therapeutic effects of endostatin in this MPE model, we injected the Ad-hEndo into the pleural cavity of MPE-bearing mice three times with the 3-day interval. We found that this treatment resulted in significant reduction in pleural effusion volume, the number of pleural tumor foci, microvessel density, and vascular permeability, while it significantly prolonged the survival time. In addition, VEGF level of MPE in the group administered with the Ad-hEndo was obviously decreased as compared with that in the two control groups administered with null-adenovirus (Ad-null) or normal saline. Our work provides a rationale for future studies toward evaluating the effectiveness of the adenovirus-based endostatin therapy for MPE. [ABSTRACT FROM AUTHOR]

Objective: The phosphatidylinositol 3-kinase (PI3K) pathway plays a critical role in ovarian cancer cell survival and proliferation. The aim of this study was to determine whether the suppression of the PI3K catalytic subunit p110αinhibits the growth of ovarian cancer cells in vitro and in vivo. Methods: The short hairpin RNA (shRNA) was used to knock down the expression of p110α in SKOV3 human ovarian cancer cells. The effects of shRNA on cell viability and apoptosis in vitro were assessed using the MTT assay and flow-cytometric analysis. Furthermore, the growth inhibition capacity of shRNA on ovarian carcinoma xenografts was tested in nude mice. Tumor cell proliferation, apoptosis and angiogenesis were measured by proliferating cell nuclear antigen, TUNEL and CD31 immunohistochemistry, respectively. Results: Using sequence-specific shRNA, we have silenced the expression of p110α in SKOV3 cells. shRNA-mediated knockdown of p110α correlated in vitro with decreased cell viability and increased apoptosis. Furthermore, inhibition of p110α significantly delayed the growth of ovarian carcinoma xenografts, and ultimately resulted in decreased cell proliferation, induction of apoptosis as well as a reduction in microvessel density. Conclusions: Our findings suggest that shRNA-directed targeting of p110αraises the potential of its application in human ovarian cancer therapy. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Barbigerone is a naturally occurring isoflavone with antioxidant activity. In present study, we investigated the antitumor activity of barbigerone against murine lung cancer cells LL/2 and the possible mechanism in vitro. Our results showed that barbigerone inhibited LL/2 cells proliferation in a concentration- and time-dependent manner and caused apoptotic death of LL/2 cells. Barbigerone-induced apoptosis was characterized by enhanced mitochondrial cytochrome c release, activation of caspase-3,-9, but not caspase-8. Exposure of LL/2 cells to barbigerone resulted in upregulation of Bcl-2-associated protein (Bax) and down-regulation of Bcl-2. In addition, proliferation inhibitory effect of barbigerone was associated with decreased level of phosphorylated p42/44 mitogen-activated protein kinase (p42/44 MAPK) and phosphorylated Akt. Moreover, barbigerone exhibit less toxicity to non-cancer cells than tumor cells. In conclusion, our results indicated that barbigerone can inhibit murine lung cancer cell proliferation by inducing apoptosis via mitochondrial apoptotic pathway and by decreasing phosphorylated p42/44 MAPK and Akt. Its potential to be a candidate of anti-cancer agent is worth being further investigated. Copyright © 2009 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Endothelial cell-specific molecules (ECSMs) play a pivotal role in the pathogenesis of many angiogenesis-related diseases. Since its initial discovery, the exact function of human ECSM2 has not been defined. In this study, by database mining, we identified a number of hypothetical proteins across species exhibiting substantial sequence homology to the human ECSM2. We showed that ECSM2 is preferentially expressed in endothelial cells and blood vessels. Their characteristic structures and unique expression patterns suggest that ECSM2 is an evolutionarily conserved gene and may have important functions. We further explored the potential roles of human ECSM2 at the molecular and cellular level. Using a reconstitution mammalian cell system, we demonstrated that ECSM2 mainly resides at the cell membrane, is critically involved in cell-shape changes and actin cytoskeletal rearrangement, and suppresses tyrosine phosphorylation signaling. More importantly, we uncovered that ECSM2 can cross-talk with epidermal growth factor receptor (EGFR) to attenuate the EGF-induced cell migration, possibly via inhibiting the Shc-Ras-ERK (MAP kinase) pathway. Given the importance of growth factor and receptor tyrosine kinase-mediated signaling and cell migration in angiogenesis-related diseases, our findings regarding the inhibitory effects of ECSM2 on EGF-mediated signaling and cell motility may have important therapeutic implications. [ABSTRACT FROM AUTHOR]

AbstractAim:Tumor immunotherapy aims at activating the body's own immune system to fight an existing tumor. Effective antitumor responses require tumor antigens to be presented to lymphocytes. We aimed to test the hypothesis that intratumoral administration of recombinant adenovirus encoding MIP3β would induce antitumor immunity by attracting and facilitating the interaction between lymphocytes and dendritic cells.Methods:A recombinant adenovirus encoding microphage inflammatory protein 3β (AdMIP3β) was constructed. The antitumor activity of AdMIP3β in BALB/c and C57BL/6 mice bearing CT26 colon adenocarcinoma and Lewis lung cancer was evaluated.Results:Immunotherapy with AdMIP3β resulted in significant inhibition of tumor growth and prolonged survival of tumor-bearing mice. Tumor-specific immune responses elicited by AdMIP3β include MHC class I-dependent CD8+ CTL-mediated immune response and IFN-γ response. Immunohistochemical staining demonstrated numerous CD11c+ cells and CD3+ T lymphocytes within tumor tissues of AdMIP3β-treated mice. These findings suggest that the mechanism of specific antitumor immunity induced by AdMIP3β may be involved in the chemoattraction of both T lymphocytes and DCs to the tumor site and thus facilitate the process of antigen capture and mature DC to prime naive T cells.Conclusion:The present study may be important in the exploration of the potential application of AdMIP3β in the treatment of a broad spectrum of tumors.Acta Pharmacologica Sinica (2009) 30: 355–363; doi: 10.1038/aps.2009.4 [ABSTRACT FROM AUTHOR]

Background: Most conventional methods for delivering chemotherapeutic agents fail to achieve therapeutic concentrations of drugs, despite reaching toxic systemic levels. Novel controlled drug delivery systems are designed to deliver drugs at predetermined rates for predefined periods at the target organ and overcome the shortcomings of conventional drug formulations therefore could diminish the side effects and improve the life quality of the patients. Thus, a suitable controlled drug delivery system is extremely important for chemotherapy. Results: A novel biodegradable thermosensitive composite hydrogel, based on poly(ethylene glycol)-poly(∈-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) and Pluronic F127 copolymer, was successfully prepared in this work, which underwent thermosensitive sol-gel-sol transition. And it was flowing sol at ambient temperature but became non-flowing gel at body temperature. By varying the composition, sol-gel-sol transition and in vitro drug release behavior of the composite hydrogel could be adjusted. Cytotoxicity of the composite hydrogel was conducted by cell viability assay using human HEK293 cells. The 293 cell viability of composite hydrogel copolymers were yet higher than 71.4%, even when the input copolymers were 500 µg per well. Vitamin B12 (VB12), honokiol (HK), and bovine serum albumin (BSA) were used as model drugs to investigate the in vitro release behavior of hydrophilic small molecular drug, hydrophobic small molecular drug, and protein drug from the composite hydrogel respectively. All the above-mentioned drugs in this work could be released slowly from composite hydrogel in an extended period. Chemical composition of composite hydrogel, initial drug loading, and hydrogel concentration substantially affected the drug release behavior. The higher Pluronic F127 content, lower initial drug loading amount, or lower hydrogel concentration resulted in higher cumulative release rate. Conclusion: The results showed that composite hydrogel prepared in this paper were biocompatible with low cell cytotoxicity, and the drugs in this work could be released slowly from composite hydrogel in an extended period, which suggested that the composite hydrogel might have great potential applications in biomedical fields. [ABSTRACT FROM AUTHOR]

In this study, 3D-pharmacophore models of Aurora B kinase inhibitors have been developed by using HipHop and HypoGen modules in Catalyst software package. The best pharmacophore model, Hypo1, which has the highest correlation coefficient (0.9911), consists of one hydrogen-bond acceptor, one hydrogen-bond donor, one hydrophobic aliphatic moiety and one ring aromatic feature. Hypo1 was validated by test set and cross-validation methods. And the specificity of Hypo1 to Aurora B inhibitors was examined with the use of selective inhibitors against Aurora B and its paralogue Aurora A. The results clearly indicate that Hypo1 can differentiate selective inhibitors of Aurora B from those of Aurora A, and the ring aromatic feature likely plays some important roles for the specificity of Hypo1. Then Hypo1 was used as a 3D query to screen several databases including Specs, NCI, Maybridge and Chinese Nature Product Database (CNPD) for identifying new inhibitors of Aurora B. The hit compounds were subsequently subjected to filtering by Lipinski’s rule of five and docking studies to refine the retrieved hits, and some compounds selected from the top ranked hits have been suggested for further experimental assay studies. [ABSTRACT FROM AUTHOR]

A biodegradable sponge, composed of chitosan (CS) and sodium alginate (SA), was successfully obtained in this work. The sponge was ethereal and pliable. The chemical structure and morphology of the sponges was characterized by FTIR and SEM. The swelling ability, in vitro drug release and degradation behaviors, and an in vivo animal test were employed to confirm the applicability of this sponge as a wound dressing material. As the chitosan content in the sponge decreased, the swelling ability decreased. All types of the sponges exhibited biodegradable properties. The release of curcumin from the sponges could be controlled by the crosslinking degree. Curcumin could be released from the sponges in an extended period for up to 20 days. An in vivo animal test using SD rat showed that sponge had better effect than cotton gauze, and adding curcumin into the sponge enhanced the therapeutic healing effect. [ABSTRACT FROM AUTHOR]

Background: Antibody-based immuneotherapy has achieved some success for cancer. But the main problem is that only a few tumor-associated antigens or therapeutic targets have been known to us so far. It is essential to identify more immunogenic antigens (especially cellular membrane markers) for tumor diagnosis and therapy. Methods: The membrane proteins of lung adenocarcinoma cell line A549 were used to immunize the BALB/c mice. A monoclonal antibody 4E7 (McAb4E7) was produced with hybridoma technique. MTT cell proliferation assay was carried out to evaluate the inhibitory effect of McAb4E7 on A549 cells. Flow cytometric assay, immunohistochemistry, western blot and proteomic technologies based on 2-DE and mass spectrometry were employed to detect and identify the corresponding antigen of McAb4E7. Results: The monoclonal antibody 4E7 (McAb4E7) specific against A549 cells was produced, which exhibited inhibitory effect on the proliferation of A549 cells. By the proteomic technologies, we identified that ATP synthase beta subunit (ATPB) was the corresponding antigen of McAb4E7. Then, flow cytometric analysis demonstrated the localization of the targeting antigen of McAb4E7 was on the A549 cells surface. Furthermore, immunohistochemstry showed that the antigen of McAb4E7 mainly aberrantly expressed in tumor cellular membrane in non-small cell lung cancer (NSCLC), but not in small cell lung cancer (SCLC). The rate of ectopic expressed ATPB in the cellular membrane in lung adenocarcinoma, squamous carcinoma and their adjacent nontumourous lung tissues was 71.88%, 66.67% and 25.81% respectively. Conclusion: In the present study, we identified that the ectopic ATPB in tumor cellular membrane was the non-small cell lung cancer (NSCLC) associated antigen. ATPB may be a potential biomarker and therapeutic target for the immunotherapy of NSCLC. [ABSTRACT FROM AUTHOR]

This work was initiated with the purpose of purifying and identifying differentially expressed plasma membrane-associated proteins between human liver cancer cell line HepG2 and normal liver cell line L02. The combined strategy of sucrose density gradient centrifugation and subsequent phase partition was applied to obtain high-purity proteins of plasma membrane. Two-dimensional gel electrophoresis revealed the differential protein profile between the two cell lines. A total of 13 plasma membrane-associated proteins containing 10 up-regulated proteins and three down-regulated proteins in HepG2 cells were successfully identified by MALDI-Q-TOF mass spectrometry; they participate in multiple biological functions such as adhesion, proliferation, apoptosis, and signal transduction. The identified proteins could provide helpful reference in clinical investigations on potential candidates for diagnosis and therapy of liver cancer. [ABSTRACT FROM AUTHOR]

Chloroquine is an antimalarial drug that has been used in the treatment and prophylaxis of malaria since the 1950s. The present study was undertaken to examine the effects of chloroquine on Bcap-37 human breast cancer cells’ growth, cell cycle modulation, apoptosis induction, and associated molecular alterations in vitro. The chloroquine treatment decreased the viability of Bcap-37 cells in a concentration- and time-dependent manner, which correlated with G2/M phase cell cycle arrest. The chloroquine-mediated cell cycle arrest was associated with a decrease in protein levels/activity of polo-like kinase 1 (Plk1), phosphorylated cell division cycle 25C (Cdc25C), phosphorylated extracellular signal-regulated kinase 1/2 (ERK1/2), phosphorylated Akt. The chloroquine-treated Bcap-37 cells exhibited a marked decrease in the level of mitochondrial transmembrane potential (ΔΨm), which was accompanied by the activation of caspase-3 and cleaved poly(ADP-ribose) polymerase (PARP). Exposure of Bcap-37 cells to chloroquine also resulted in the induction of spindle abnormalities. In conclusion, the findings in this study suggested that chloroquine might have potential anticancer efficacy, which could be attributed, in part, to its proliferation inhibition and apoptosis induction of cancer cells through modulation of apoptosis and cell cycle-related proteins expressions, down-regulation of mitochondrial transmembrane potential (ΔΨm), and induction of spindle abnormalities. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Honokiol has been receiving attention as an anticancer agent because of its anti-tumor effect. In the current study, we encapsulated honokiol with liposome and tested it on cisplatin-sensitive (A2780s) and -resistant (A2780cp) human ovarian cancer models. The anti-tumor activity of liposomal honokiol (Lipo-HNK) was evaluated in nude mice bearing A2780s and A2780cp s.c. tumors. Mice were treated twice weekly with i.v. administration of Lipo-HNK (10 mg/kg), control liposome (10 mg/kg), 0.9% NaCl solution or weekly with intraperitoneally administered cisplatin (5 mg/kg) for 3 weeks. Tumor volume and survival time were observed. Assessment of apoptotic cells by TUNEL assay was conducted in tumor tissue. Microvessel density within tumor tissue was determined by CD34 immunohistochemistry. For in vitro study, induction of apoptosis by Lipo-HNK was examined by PI staining fluorescence microscopy, DNA fragmentation assay and flow cytometric analysis. Administration of Lipo-HNK resulted in significant inhibition (84–88% maximum inhibition relative to controls) in the growth of A2780s and A2780cp tumor xenografts and prolonged the survival of the treated mice. These anti-tumor responses were associated with marked increases in tumor apoptosis, and reductions in intratumoral microvessel density. The present findings suggest that Lipo-HNK may provide an effective approach to inhibit tumor growth in both cisplatin sensitive and -resistant human ovarian cancer with minimal side effects. [ABSTRACT FROM AUTHOR]

In this paper, honokiol nanoparticles were prepared by emulsion solvent evaporation method. The prepared honokiol nanoparticles were characterized by particle size distribution, morphology, zeta potential and crystallography. Results showed that the obtained honokiol nanoparticles at size of 33 nm might be amorphous, and could be well dispersed in water. Due to the great dispersibility in water, the obtained honokiol nanoparticles might have great potential in medical field. [ABSTRACT FROM AUTHOR]

IFN–inducible protein 10 (IP-10)/CXCL10 (CXC chemokine ligand 10) has been described as an antiangiogenic chemokine and displays a potent antitumor activity in vivo. In the present study, we try to investigate whether the combination therapy of hyperthermia, a physical antiangiogenic modality, with CXCL10 would completely eradicate the established solid tumors. Immunocompetent BALB/c mice bearing Meth A fibrosarcoma were established. Mice were treated with either CXCL10 at 25 μg/kg once a day for 20 days, hyperthermia was given twice (at 42°C for 1 h, on day 6 and 12 after the initiation of CXCL10), or together. Tumor volume and survival time were observed. The microvessel density was determined by CD31 immunofluorescence. Histologic analysis and assessment of apoptotic cells were also conducted in tumor tissues. The results showed that CXCL10 and hyperthermia inhibited the growth of Meth A fibrosarcoma and interestingly, the combination therapy enhanced the antiangiogenic effects and completely eradicated the established solid tumors. Histological examination revealed that CXCL10 + hyperthermia led to increased induction of apoptosis, tumor necrosis, and elevated lymphocyte infiltration compared with the controls. Moreover, the tumor eradicated animals developed a protective T-cell-dependent antitumor memory response against Meth A tumor cells rechallenge. Our finding is that the combination therapy can achieve a synergistic antitumor efficacy, supporting the idea that the combination of two antiangiogenic agents may lead to improved clinical outcome. These findings could open new perspectives in clinical antitumor therapy. [ABSTRACT FROM AUTHOR]

Aurora-A has been identified as one of the most attractive targets for cancer therapy and a considerable number of Aurora-A inhibitors have been reported recently. In order to clarify the essential structure–activity relationship for the known Aurora-A inhibitors as well as identify new lead compounds against Aurora-A, 3D pharmacophore models were developed based on the known inhibitors. The best hypothesis, Hypo1, was used to screen molecular structural databases, including Specs and China Natural Products Database for potential lead compounds. The hit compounds were subsequently subjected to filtering by Lipinski’s rules and docking study to refine the retrieved hits and as a result to reduce the rate of false positive. Finally, 39 compounds were purchased for further in vitro assay against several human tumour cell lines including A549, MCF-7, HepG2 and PC-3, in which Aurora-A is overexpressed. Two compounds show very low micromolar inhibition potency against some of these tumour cells. And they have been selected for further investigation. [ABSTRACT FROM AUTHOR]

Human DRR1 (down-regulated in renal cell carcinoma 1) is widely expressed in normal tissues but dramatically reduced or even undetectable in a number of different cancer cell lines and primary tumour types. DRR1 from Homo sapiens was cloned into the pQE30 vector for fusion-protein expression with six histidine residues in Escherichia coli BL21(DE3). A soluble protein with a molecular mass of approx. 19 kDa on SDS/PAGE that matches the expected rDRR1 (recombinant DRR1) molecular mass (18.7 kDa) was obtained. The soluble and insoluble expression of recombinant protein DRR1 (rDRR1) was temperature-dependent. The expression rDRR1 was in soluble and insoluble forms at 37 °C, and approx. 80% of total rDRR1 was soluble at 37 °C, while rDRR1 was almost exclusively expressing in soluble form at 20 °C. The expressed rDRR1 at 20 °C was affinity-purified on Ni2+-charged resin under native conditions. The purified protein was further identified by ESI–MS (electrospray ionization MS). The purified recombinant protein rDRR1 was further used to raise anti-(human DRR1) polyclonal antibodies, which were suitable for detecting both the recombinant exogenous DRR1 and the endogenous DRR1 from tissues and cells by immunoblotting and immunohistochemistry. The purified rDRR1 and our prepared anti-(human DRR1) polyclonal antibodies may provide useful tools for future biological function studies on DRR1. [ABSTRACT FROM AUTHOR]

Background: Honokiol is a major bioactive compound extracted from Magnolia. The present study was designed to determine whether liposomal honokiol has the antitumor activity against human lung cancer as well as potentiates the antitumor activity of cisplatin in A549 lung cancer xenograft model, if so, to examine the possible mechanism in the phenomenon. Methods: human A549 lung cancer-bearing nude mice were treated with liposomal honokiol, liposomal honokiol plus DDP or with control groups. Apoptotic cells and vessels were evaluated by fluorescent in situ TUNEL assay and by immunohistochemistry with an antibody reactive to CD31 respectively. Results: The present study showed that liposomal honokiol alone resulted in effective suppression of the tumor growth, and that the combined treatment with honokiol plus DDP had the enhanced inhibition of the tumor growth and resulted in a significant increase in life span. The more apparent apoptotic cells in the tumors treated with honokiol plus DDP was found in fluorescent in situ TUNEL assay, compared with the treatment with control groups. In addition, the combination of honokiol and DDP apparently reduced the number of vessels by immunolabeling of CD31 in the tissue sections, compared with control groups. Conclusion: In summary, our data suggest that honokiol alone had the antitumor activity against human lung cancer in A549 lung cancer xenograft model, and that the combination of honokiol with DDP can enhance the antitumor activity, and that the enhanced antitumor efficacy in vivo may in part result from the increased induction of the apoptosis and the enhanced inhibition of angiogenesis in the combined treatment. The present findings may be of importance to the further exploration of the potential application of the honokiol alone or the combined approach in the treatment of lung carcinoma. [ABSTRACT FROM AUTHOR]

Objective: Cancer patients and their families differed in their attitude toward truth telling. The objective is to investigate different attitudes of Chinese patients or families toward whether and how to disclose diagnosis to patients with different stages of cancer and to examine the difference between the two groups. Methods: A questionnaire was delivered to 1023 participants. Results: Three hundred and eighty-two patients and 482 families completed the questionnaire. Cancer patients were more likely than families to believe that patient should be informed of the diagnosis (early-stage, 90.8 vs 69.9%, P<0.001; terminal stage, 60.5 vs 34.4%, P<0.001), and that doctor-in-charge was the appropriate person to disclose the diagnosis. Most participants thought that patient should be disclosed immediately after the diagnosis. Nearly half of participants reported that patient should be disclosed in a quiet and undisturbed room. When the hypothetic diagnosis changed from early-stage cancer to terminal illness, the number of participants, who wanted patient to know the diagnosis, decreased significantly. Conclusion: Our findings indicated that Chinese cancer patients and their families differed in their attitude toward truth telling and the attitudes toward such a disclosure were influenced by disease stage. Physicians should realize this phenomenon and pay more attention to the skills of how to disclose the cancer diagnosis. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

FAM92A1 (named FAM92A1-271) belongs to the family of proteins with conserved DUF1208 domains. Its function remains elusive. We identified two novel transcript variants (FAM92A1-251, FAM92A1-289) of FAM92A1. The presence of these transcripts in cancerous and normal cells, as well as their influence on cell prolifera-tion and apoptosis, were investigated. The subcellular location of FAM92A1 was determined by fluorescence microscopy. We found that FAM92A1-271 and FAM92A1- 289 were highly expressed in both normal and cancerous cells, but FAM92A1-251 was only expressed at a moderate level in both types of cell. Overexpression of FAM92A1-271, FAM92A1-251 and FAM92A1-289 inhibited cell proliferation, caused S-phase arrest and induced apoptosis. Subcellular localization showed that FAM92A1 localizes to the nucleus. Our results show that FAM92A1 has different splicing variants, and that it may take part in regulating cell proliferation and apoptosis. [ABSTRACT FROM AUTHOR]

Density functional theory together with Car-Parrinello ab initio molecular dynamics simulation has been used to investigate the free energy profiles (FEP) of monomer capture in Grubbs- and SHOP-type olefin polymerization catalysts. The FEPs along the reaction coordinates at 300 K were determined directly by a point wise thermodynamic integration technique. Comparison between potential energy profile (PEP) and the FEP has been made. The results show that, for both catalysts, the PEP for the monomer ethylene uptake by the metal center is a typical Morse curve without energy barrier. However, a small barrier (1.8 kcal/mol for Grubbs catalyst and 2.4 kcal/mol for SHOP catalyst) exists on the FEP. The π complexation energy on the FES at 300 K is higher by 10–12 kcal/mol over that on the PES. The differences between FES and PES are due to entropy contribution. Slow growth simulations on the ethylene capture process show that the ethylene attacks the metal center by an asynchronous mode. This indicates that the forming of the π-bonding between the metal and ethylene is initiated by electrophilic attack of the metal to one of the ethylene carbons. © 2006 Wiley Periodicals, Inc. J Comput Chem 28: 513–518, 2007 [ABSTRACT FROM AUTHOR]

The induction of active cellular responses against EGFR should be a promising approach for the treatment of those receptor-positive tumors. However, the immunity against EGFR is presumably difficult to elicit by vaccine based on self or syngeneic EGFR due to the immune tolerance acquired during the development in immune system. We proposed a model to break immune tolerance against self-EGFR through an altered immunogen source based on xenogeneic homologous EGFR. We have previously shown human EGFR as a xenoantigen could induce specific immune responses in mouse and cross-react with mouse EGFR, and resulted in therapeutic benefits for EGFR-positive mouse tumor. Here, we show a recombinant form of extracellular domain of mouse EGFR, in the presence of DCs, could activate human peripheral T cells to proliferate, secret IFN-γ, the induced responses could cross-react with human EGFR and kill autologous EGFR-positive lung cancer cells which could be blocked by anti-CD8 and anti-MHC class I antibody. There is no detectable cytotoxical activity against lung tissue, liver tissue and kidney tissue derived from paracancerous normal tissue. These observations suggest that antitumor immunity induced by the truncated mouse EGFR may be provoked in a cross-reaction between mouse EGFR and self-EGFR, and may provide insight into treatment of EGFR-positive tumors through induction of the autoimmune responses against EGFR. [ABSTRACT FROM AUTHOR]

Vascular endothelial growth factor receptor-2 (VEGFR-2) has been shown to play a major role in inducing the full spectrum of VEGF biological response which is essential for tumor angiogenesis. We have demonstrated that immunotherapy of tumors with a vaccine based on quail homologous VEGFR-2 (qVEGFR) was effective in providing both protective and therapeutic antitumor immunity in several tumor models in mice. The purpose of this study was to determine whether the combination therapy of low-dose gemcitabine with qVEGFR as a vaccine could inhibit tumor growth to a greater extent. To test this concept, H22 hepatoma and Lewis lung carcinoma models were established in BALB/c mice and C57BL/6 mice, respectively. Mice were treated with either qVEGFR as a protein vaccine, gemcitabine, or both agents together. qVEGFR or low-dose chemotherapy treatment individuallyresulted in tumor inhibition to a certain extent.Remarkably, the combination therapy resulted in synergistic antitumor activity. Histological examination revealed that there was endothelial deposition of immunoglobulins within tumor tissues from mice treated with vaccine or combination therapy, especially intratumor angiogenesis was suppressed more significantly for the combination group. Also, ELISPOT analysis showed that mice treated with either qVEGFR alone or in combination with low-dose chemotherapy produced similar amount of anti-VEGFR antibody-producing B cells, which suggested that low-dose gemcitabine did not suppress the host’s immune response, but potentiated the antitumor activity of the qVEGFR vaccine. Furthermore, TUNEL staining demonstrated a significant increase in the number of TUNEL-positive cells in the combination group compared with those of other groups. The observations may provide a new bio-chemotherapeutic approach for cancer. Copyright © 2005 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]