Comparison of Tripterygium wilfordii Hook F with methotrexate in the treatment of active rheumatoid arthritis (TRIFRA): a randomised, controlled clinical trial.

OBJECTIVES: To compare the efficacy and safety of Tripterygium wilfordii Hook F (TwHF) with methotrexate (MTX) in the treatment of active rheumatoid arthritis (RA). METHODS: Design: a multicentre, open-label, randomised controlled trial. All patients were assessed by trained investigators who were unaware of the therapeutic regimen. INTERVENTION: 207 patients with active RA were randomly allocated (1:1:1) to treatment with MTX 12.5 mg once a week, or TwHF 20 mg three times a day, or the two in combination. At week 12, if reduction of the 28-joint count Disease Activity Score (DAS28) was <30% in the monotherapy groups, the patient was switched to MTX+TwHF. The primary efficacy point was the proportion of patients achieving an American College of Rheumatology (ACR) 50 response at week 24. RESULTS: 174/207 (84.1%) patients completed 24 weeks of the trial. In an intention-to-treat analysis, the proportion of patients reaching the ACR50 response criteria was 46.4% (32/69), 55.1% (38/69) and 76.8% (53/69), respectively, in the MTX, TwHF and MTX+TwHF groups (TwHF vs MTX monotherapy, p=0.014; MTX+TwHF vs MTX monotherapy, p<0.001). Similar statistically significant patterns at week 24 were found for ACR20, ACR70, clinical Disease Activity Index good responses, EULAR good response, remission rate and low disease activity rate. Significant improvement in the Health Assessment Questionnaire and 36-item Short-Form Health Survey questionnaire scores from baseline to week 24 was seen in each treatment arm (p<0.05), though no significant difference was found among the treatment arms (p>0.05). The result of per-protocol analysis agreed with that seen in the intention-to-treat analysis. Seven, three and five women in the TwHF, MTX and combination groups, respectively, developed irregular menstruation (TwHF vs MTX monotherapy, p=0.216). CONCLUSIONS: TwHF monotherapy was not inferior to, and MTX+TwHF was better than, MTX monotherapy in controlling disease activity in patients with active RA. TRIAL REGISTRATION NUMBER: NCT01613079.

Clinical characteristics of patients with solitary pulmonary mass after radical treatment for primary cancers: pulmonary metastasis or second primary lung cancer?

We identified clinical characteristics of 30 pulmonary metastasis (PM) patients and 29 second primary lung cancer (SPLC) patients with feature of solitary pulmonary mass (SPM) after radical treatment of prior cancers. 6.7% and 44.8% patients presented with centrally located SPM and the median event-free durations were 33 and 72 months in PM and SPLC groups, respectively. PM was more likely to be found in prior cancers with stage III. In conclusion, the location of SPM, the event-free duration and the prior tumor staging were important features for differentiating SPLC from PM among patients with SPM after prior cancers.

Prognostic influence of metformin as first-line chemotherapy for advanced nonsmall cell lung cancer in patients with type 2 diabetes.

BACKGROUND: It has been reported that antidiabetic drugs affect the risk of cancer and the prognosis of patients with diabetes, but few studies have demonstrated the influence of different antidiabetic agents on outcomes after anticancer therapy among patients with cancer. The objective of this study was to evaluate the influence of the antidiabetic drugs metformin and insulin on the prognosis of patients with advanced nonsmall cell lung cancer (NSCLC) plus type 2 diabetes who received first-line chemotherapy. METHODS: Data on patients with NSCLC who had diabetes from 5 hospitals in China during January 2004 to March 2009 were reviewed retrospectively. Ninety-nine patients were included in the final analysis. The influence of metformin and insulin on chemotherapy response rates and survival in these patients was evaluated. RESULTS: Chemotherapy with metformin (Group A) produced superior results compared with insulin (Group B) and compared with drugs other than metformin and insulin (Group C) in terms of both progression-free survival (PFS) (8.4 months vs 4.7 months vs 6.4 months, respectively; P = .002) and overall survival (OS) (20.0 months vs 13.1 months vs 13.0 months, respectively; P = .007). Although no significant differences in the response rate (RR) were observed between these 3 groups, when groups B and C (ie, the nonmetformin group) were combined, there was a tendency for better disease control in Group A than that in nonmetformin group. No significant difference in survival was observed between chemotherapy with insulin (Group B) versus other drugs (Group C). CONCLUSIONS: The current data suggested that metformin may improve chemotherapy outcomes and survival for patients who have NSCLC with diabetes.

[A novel strategy for development of universal tumor vaccine: a DC-targeted adenovirus encoding hTRT].

OBJECTIVE: To explore the feasibility of constructing a dendritic cell targeted adenovirus as a possible universal tumor vaccine. METHODS: The cDNA of human telomerase reverse transcriptase (hTRT) from pBABE-PURO-hTERT was subcloned into pAdTrack-CMV. Recombinant adenovirus for hTRT was constructed in AdEasy system. The confirmed recombinant adenovirus plasmid was transfected into 293 cells to generate the recombinant adenovirus. Later the recombinant adenovirus was multiplied, purified and modified with mannan as a vaccine to immunize mice. RESULTS: An obvious cytopathic effect was observed with the rescue of recombinant adenovirus. The expression of hTRT was confirmed by PCR and Western blot analysis. Mannan modified adenovirus stained positively by periodic acid Schiff stain, and expression of the adenovirus was found mainly restricted in dendritic cells (DC) in spleen of mice. CONCLUSION: A DC-targeted adenovirus was constructed. This might be helpful (or the development of universal tumor vaccine in future.

A recombinant DNA plasmid encoding the human interleukin-5 breaks immunological tolerance and inhibits airway inflammation in a murine model of asthma.

BACKGROUND: Eosinophils play a pivotal role in the generation of asthma inflammation. Interleukin (IL)-5 is the major activator of eosinophils. We hypothesize that modulating IL-5 activity could be an effective strategy for asthma therapy. In this study, we tested whether the plasmid encoding human IL-5 as a xenogeneic DNA vaccine could induce the production of autoantibodies, and be used for asthma treatment. METHODS: A eukaryotic plasmid encoding the human IL-5 was constructed, and used as a DNA vaccine. A mouse model of asthma was established to observe its antiasthma activities. Eosinophils in tissue, blood and the bronchoalveolar lavage were stained and counted. Airway hyperresponsiveness (AHR) was determined by whole body plethysmography. Antibody characters and cytokines were detected with immunological methods. RESULTS: Immunization with a plasmid encoding the human IL-5 as DNA vaccine reduced airway inflammation, reversed Th2 cytokines, and decreased AHR in mice. In addition, this immunization induced the production of polyclonal antibodies that were cross-reactive with native murine IL-5, and IgG1 and IgG2a were the major subclasses. Adoptive transfer of the purified antibodies from the sera of mice immunized with the plasmid encoding the human IL-5 resulted in similar antiasthma effects. CONCLUSIONS: Our results suggest that active vaccination against IL-5 may be a rational therapeutic approach for the treatment of asthma and potentially other eosinophilic disorders.

Active immunogene therapy of cancer with vaccine on the basis of chicken homologous matrix metalloproteinase-2.

Matrix metalloproteinase (MMP) family, in particular MMP-2, may play a key role in angiogenesis and tumor growth. It is conceivable that the breaking of immune tolerance of MMP-2 should be a useful approach to cancer therapy by active immunity. To test this concept, we constructed a plasmid DNA encoding chicken homologous MMP-2 (c-MMP-2) and control vectors. We found that the vaccine based on chicken homologous MMP-2 as a model antigen could induce both protective and therapeutic antitumor immunity. Autoantibodies against MMP-2 in sera of mice immunized with c-MMP-2 could be found by Western blotting analysis and ELISA assay. There was the deposition of autoantibodies within the tumor. IgG1 and IgG2b were substantially increased in response to c-MMP-2 immunization. The elevation of MMP-2 in the sera of tumor-bearing mice was abrogated with the vaccination of c-MMP-2. Transmigration of human endothelial cells and tumor cells through gelatin-coated filters was inhibited with immunoglobulins isolated from mice immunized with c-MMP-2. The gelatinase activity of MMP-2, including both latent MMP-2 (M(r) 72,000) and active MMP-2 (M(r) 66,000) derived from tumor tissues, was apparently inhibited by the vaccination with c-MMP-2. The antitumor activity and the inhibition of angiogenesis were acquired by the adoptive transfer of the purified immunoglobulins. The antitumor activity and production of autoantibodies against MMP-2 could be abrogated by the depletion of CD4(+) T lymphocytes. Angiogenesis was apparently inhibited within tumor, and chick CAMs angiogenesis was also inhibited. Thus, our findings may provide a vaccine strategy for cancer therapy through the induction of an autoimmune response against MMP-2 in a cross-reaction by the immunization with the single xenogeneic homologous MMP-2 gene and may be of importance in the additional exploration of the application of other xenogeneic homologous genes identified in human and other animal genome projects in cancer therapy.

[Inhibition of tumor growth and metastasis via local administration of recombinant human endostatin adenovirus].

OBJECTIVE: The growth and metastasis of solid tumors are dependent on angiogenesis. Endostatin, the C-terminal proteolytic fragment of collagen XVIII, is a potent endogenous angiogenesis inhibitor. The authors designed a topical antiangiogenic gene therapy with recombinant human endostatin adenovirus (Ad-hEndo) and assessed its effects on the inhibition of angiogenesis in vitro, and tumor growth and metastasis in vivo. METHODS: Malignant cells (A549) were infected with Ad-hEndo. The expression of recombinant protein and the inhibition of cultured human umbilical vein endothelial were investigated. Immunodeficient A549 nude mice were treated with intratumoral injection of Ad-hEndo, the empty vector Ad-control or saline (NS). The dose-response, side effects, and serum concentration of endostatin were observed. RESULTS: Recombinant endostatin protein was detected in the infected tumor cells with different MOI Ad-hEndo and its inhibitory effect on endothelial cells growth was shown. In animal study, the volume of tumor and the number of pulmonary metastatic lesions in the Ad-hEndo treatment group were significantly smaller than those in the control groups (P<0.05). CONCLUSION: The present findings provide evidence of the anti-tumor effects of the endostatin and may be important for the further use of it in topical antiangiogenic gene therapy of cancer.

[Constructing the tumor cell vaccine based on homologous matrix metalloproteinase-2 and exploring its effects].

OBJECTIVE: To construct the tumor cell vaccine based on homologous matrix metalloproteinase-2 (MMP-2), and explore its anti-tumor effects. METHODS: The tumor cell vaccine was constructed by transfecting chicken MMP-2 to tumor cells. MTT colorimetric assay was used to evaluate the activation of the transfectants. Then we observed the formative tumor response in vivo and evaluated the effects of the tumour cell vaccine in immunized mice rechallenged with parental cells. RESULTS: Using RT-PCR, we picked out the cell strain with the highest expression level from the transfectants. The MTT colorimetric assay revealed that the transfectants increased the expression of the MMP-2 of tumor cells while they did not change the trend of tumor cells' growth. And in animal experiments the vaccine was preliminarily found to be effective for inhibiting the tumour growth and prolonging the survival time of animals. CONCLUSION: We have constructed the tumor cell vaccine based on homologous matrix metalloproteinase-2. The experiments demonstrated that breaking the immune tolerance of MMP-2 by means of active immunity should be a useful approach to cancer therapy.

[Prokaryotic expression, purification and refolding of extracellular ligand binding domains of chick Tie-2 and its immunogenicity].

OBJECTIVE: To study the prokaryotic expression of extracellular ligand binding domains of chick Tie-2, the purification and refolding conditions of the recombinant protein, and to observe its immunogenicity in mouse. METHODS: A DNA fragment encoding extracellular ligand binding domains of chick Tie-2 was obtained by PCR from a previous constructed plasmid as a template. The amplified fragment was then inserted into prokaryotic expression vector PQE30, and was expressed in E. coli XL-1 blue by adding isopropyl-beta-D-thiogalactoside(IPTG). The recombinant protein in inclusion bodies was purified by nickel-nitrilotriacetic acid (Ni-NTA) affinity chromatography under denatured conditions. Then the refolding of the purified protein was performed with gradient dialysis. The target protein was injected into mouse subcutaneously, and the antiserum of the mouse was analyzed by ELISA and Western blot analysis. RESULTS: The recombinant protein was highly expressed in E. coli XL-1 blue, and in mouse it produced the antibody which could specifically recognize the recombinant protein. CONCLUSION: The protein of extracellular ligand binding domains of chick Tie-2 can be highly expressed in prokaryotic expression system, and the expressed protein can induce immune response in mouse. These findings are very important for the further study of this protein in anti-angiogenesis and immunotherapy research.

Epidermal growth factor receptor (EGFR)-RAS signaling pathway in penile squamous cell carcinoma.

Penile Squamous Cell Carcinoma (SCC) is a rare cancer with poor prognosis and limited response to conventional chemotherapy. The genetic and epigenetic alterations of Epidermal Growth Factor Receptor (EGFR)-RAS-RAF signaling in penile SCC are unclear. This study aims to investigate four key members of this pathway in penile SCC. We examined the expression of EGFR and RAS-association domain family 1 A (RASSF1A) as well as the mutation status of K-RAS and BRAF in 150 cases of penile SCC. EGFR and RASSF1A expression was evaluated by immunohistochemistry. KRAS mutations at codons 12 and 13, and the BRAF mutation at codon 600 were analyzed on DNA isolated from formalin fixed paraffin embedded tissues by direct genomic sequencing. EGFR expression was positive in all specimens, and its over-expression rate was 92%. RASSF1A expression rate was only 3.42%. Significant correlation was not found between the expression of EGFR or RASSF1A and tumor grade, pT stage or lymph node metastases. The detection of KRAS and BRAF mutations analysis was performed in 94 and 83 tumor tissues, respectively. We found KRAS mutation in only one sample and found no BRAF V600E point mutation. In summary, we found over-expression of EGFR in the majority cases of penile SCC, but only rare expression of RASSF1A, rare KRAS mutation, and no BRAF mutation in penile SCC. These data suggest that anti-EGFR agents may be potentially considered as therapeutic options in penile SCC.

Prevalence and characteristics of anemia in patients with solid cancers at diagnosis in southwest China.

PURPOSE: Cancer-related anemia is common and may have myriad causes, but the physiological consequences of a low hemoglobin level are similar. Besides chemotherapy-induced anemia, it is also important to understand the anemia in treatment-naive patients, which may represent a consequence of cancer itself and/or cancer complications, and this may help assess anemia risk and facilitate appropriate treatment. The purpose of this study was to analyze the prevalence and characteristics of anemia in solid cancer patients at diagnosis in a Chinese population. METHODS: 1133 patients with newly diagnosed cancers who were admitted to West China Hospital of Sichuan University during January 2010 to May 2011 met the inclusion criteria. Data on age, gender, change of food intake, the diagnosis and the stage of the tumor, bleeding history, the locations of metastasis, and blood cell analysis were searched and analyzed. RESULTS: Prevalence of anemia at diagnosis of cancers was 18.98% in unclassified cancers. Gastric cancers, colorectal cancers, and hepatopancreatobiliary cancers occupied the first three ranks in the cohort. Age, decreased food intake, and bleeding history were identified as independent risk factors for anemia occurrence. Furthermore, decreased food intake was found to be also associated with the severity of anemia. CONCLUSION: Our analysis described the prevalence and risk factors of anemia in new diagnosed solid cancer patients in China. To deal with cancer-related anemia, we suggest that it should be important to improve food intake and nutrition, while controlling bleeding, especially in elderly patients.

Interleukin-15 enhances T-cell responses by stimulation with dendritic cells.

INTRODUCTION: Cytokines play important roles in regulating immune responses. Interleukin-2 (IL-2) has usually been used as an adjuvant to enhance antitumour immune responses. However, its crucial role in activation-induced cell death, inhibition of homeostatic proliferation of CD8+ memory T cells and its notable biological side effects impair its prospect of application. IL-15 has several similar functions to IL-2 and shows potential advantages over IL-2, and is being investigated to enhance antitumour dendritic cell (DC) vaccine strategies in our ongoing studies. OBJECTIVE: In this preliminary study, we evaluated the ability of IL-15, compared with IL-2, to act as an adjuvant to enhance T-cell responses activated by DCs in vitro. MATERIALS AND METHODS: Bone marrow-derived DCs (BMDCs) were pulsed with tumour antigens and used to stimulate lymphocyte responses in the presence of IL-15 or IL-2. The activated T lymphocytes were examined by flow cytometric analysis, and interferon-γ (IFN-γ) enzyme-linked immunospot and cytotoxicity assays. RESULTS: IL-15 was observed to activate lymphocytes with comparable phenotype characteristics of activated/memory CD8+ lymphocytes, compared with IL-2. Both in primary and secondary stimulation with DCs, when using IL-15 as an adjuvant, activated lymphocytes showed higher proportions of IFN-γ-secreting subsets. In secondary stimulation with BMDCs in the presence of IL-15, the activated lymphocytes showed a stronger cytotoxicity to antigen-specific tumour target cells. CONCLUSIONS: Our study suggested that IL-15 might be a prospective adjuvant for a DC vaccine strategy against cancers. The further observation that IL-15 acts as an adjuvant for an antitumour DC vaccine strategy is worth investigating.

Interaction of green tea polyphenol epigallocatechin-3-gallate with sunitinib: potential risk of diminished sunitinib bioavailability.

Sunitinib, a novel oral multi-targeted tyrosine kinase inhibitor for patients with metastatic renal cell carcinoma (mRCC) and advanced gastrointestinal stromal tumor, has a good prospect for clinical application and is being investigated for the potential therapy of other tumors. We observed the phenomenon that drinking tea interfered with symptom control in an mRCC patient treated with sunitinib and speculated that green tea or its components might interact with sunitinib. This study was performed to investigate whether epigallocatechin-3-gallate (EGCG), the major constituent of green tea, interacted with sunitinib. The interaction between EGCG and sunitinib was examined in vitro and in vivo. (1)H nuclear magnetic resonance ((1)H-NMR) spectroscopy and mass spectrometry (MS) were used to analyze the interaction between these two molecules and whether a new compound was formed. Solutions of sunitinib and EGCG were intragastrically administered to rats to investigate whether the plasma concentrations of sunitinib were affected by EGCG. In this study, we noticed that a precipitate was formed when the solutions of sunitinib and EGCG were mixed under both neutral and acidic conditions. (1)H-NMR spectra indicated an interaction between EGCG and sunitinib, but no new compound was observed by MS. Sticky semisolid contents were found in the stomachs of sunitinib and EGCG co-administrated mice. The AUC(0-∞) and C (max) of plasma sunitinib were markedly reduced by co-administration of EGCG to rats. Our study firstly showed that EGCG interacted with sunitinib and reduced the bioavailability of sunitinib. This finding has significant practical implications for tea-drinking habit during sunitinib administration.

Synergistic anti-tumor effect of recombinant human endostatin adenovirus combined with gemcitabine.

Endostatin is an important endogenous inhibitor of neovascularization, which has been widely used in anti-angiogenesis therapy for cancer. To fully explore the potential of endostatin, we evaluated the anti-tumor efficacy of the combination of recombinant human endostatin adenovirus and low-dose gemcitabine in nude mice. We injected recombinant human endostatin adenovirus intratumorally plus a low dose of gemcitabine i.p. routinely. The combination treatment produced no side-effects, and resulted in marked suppression in tumor formation and growth of established human lung carcinoma xenografts in nude mice, with decreased microvessel density and increased apoptosis percentage. Our data support the idea of synergistic anti-tumor properties of endostatin plus low-dose chemotherapy against human lung cancer in vivo.

Immunotherapy of tumors with vaccine based on quail homologous vascular endothelial growth factor receptor-2.

The breaking of immune tolerance of "self-antigens" associated with angiogenesis is an attractive approach to cancer therapy by active immunity. We used vascular endothelial growth factor receptor-2 (VEGFR-2) as a model antigen to explore the feasibility of the immunotherapy with a vaccine based on a xenogeneic homologous protein. To test this concept, we prepared a quail homologous VEGFR-2 protein vaccine (qVEGFR) based on quail VEGFR-2. At the same time, a protein vaccine based on the corresponding ligand-binding domain of mouse self-VEGFR-2 (mVEGFR) was also prepared and used as a control. We found that immunotherapy with qVEGFR was effective at protective and therapeutic antitumor immunity in several solid and hematopoietic tumor models in mice. Autoantibodies against mouse VEGFR-2 (Flk-1) were identified by Western blot analysis and enzyme-linked immunosorbent assay (ELISA). Anti-VEGFR antibody-producing B cells were detectable by ELISPOT. Endothelial deposition of immunoglobulins developed within tumor. VEGF-mediated endothelial cell proliferation was inhibited in vitro by immunoglobulins from qVEGFR-immunized mice. Antitumor activity was caused by the adoptive transfer of the purified immunoglobulins. Antitumor activity and production of autoantibodies against Flk-1 could be abrogated by the depletion of CD4+ T lymphocytes. Angiogenesis was apparently inhibited within the tumors, and the vascularization of alginate beads was also reduced. No marked toxicity was found in the immunized mice. The observations may provide a vaccine strategy for cancer therapy through the induction of autoimmunity against the growth factor receptor associated with angiogenesis in a cross-reaction with single xenogeneic homologous protein.

Inhibition of tumor growth with a vaccine based on xenogeneic homologous fibroblast growth factor receptor-1 in mice.

Angiogenesis is important for the growth of solid tumors. The breaking of the immune tolerance against the molecule associated with angiogenesis should be a useful approach for cancer therapy. However, the immunity to self-molecules is difficult to elicit by a vaccine based on autologous or syngeneic molecules due to immune tolerance. Basic fibroblast growth factor (bFGF) is a specific and potent angiogenic factor implicated in tumor growth. The biological activity of bFGF is mediated through interaction with its high-affinity receptor, fibroblast growth factor receptor-1 (FGFR-1). In this study, we selected Xenopus FGFR-1 as a model antigen by the breaking of immune tolerance to explore the feasibility of cancer therapy in murine tumor models. We show here that vaccination with Xenopus FGFR-1 (pxFR1) is effective at antitumor immunity in three murine models. FGFR-1-specific autoantibodies in sera of pxFR1-immunized mice could be found in Western blotting analysis. The purified immunoglobulins were effective at the inhibition of endothelial cell proliferation in vitro and at the antitumor activity in vivo. The antitumor activity and production of FGFR-1-specific autoantibodies could be abrogated by depletion of CD4+ T lymphocytes. Histological examination revealed that the autoantibody was deposited on the endothelial cells within tumor tissues from pxFR1-immunized mice, and intratumoral angiogenesis was significantly suppressed. Furthermore, the inhibition of angiogenesis could also be found in alginate-encapsulate tumor cell assay. These observations may provide a new vaccine strategy for cancer therapy through the induction of autoimmunity against FGFR-1 associated with angiogenesis in a cross-reaction.

Immunogene therapy of tumors with a vaccine based on the ligand-binding domain of chicken homologous integrin beta3.

The breaking of immune tolerance against angiogenesis-associated molecules should be a useful approach for cancer therapy by active immunity. We used chicken integrin beta3 as a model antigen to explore the feasibility of immunogene therapy of the tumors with a vaccine based on a single xenogeneic homologous gene, targeting the molecules associated with angiogenesis. To test this concept we constructed a plasmid DNA encoding the ligand-binding domain of chicken integrin beta3 (P-BD-C) and control vectors. We found that immunogene therapy of tumors with a vaccine based on the ligand-binding domain of chicken integrin beta3 (P-BD-C) was effective in both protective and therapeutic anti-tumor immunity in several tumor models in mice. Autoantibodies against integrin beta3 in sera of mice immunized with the ligand-binding domain of chicken integrin beta3 could be found by Western blot analysis and ELISA assay. The purified immunoglobulins were effective in the inhibition of endothelial cell proliferation in vitro, and in anti-tumor activity as well as in the inhibition of angiogenesis by adoptive transfer in vivo. The anti-tumor activity and the production of integrin beta3-specific autoantibodies (manifested by significantly elevated Ig G1 and Ig G2b) could be abrogated by the depletion of CD4+ T lymphocytes. These observations may provide a vaccine strategy for cancer therapy through the induction of the autoimmunity against the molecules associated with tumor growth in a cross-reaction with a single xenogeneic homologous gene and may be of importance in the further exploration of the applications of other xenogeneic homologous genes identified in human and other animal genome sequence projects in cancer therapy.

Induction of apoptosis and tumor regression by vesicular stomatitis virus in the presence of gemcitabine in lung cancer.

Vesicular stomatitis virus (VSV) has been shown to replicate rapidly in vitro and kill selectively a variety of tumor cell lines. The present study was designed to determine whether gemcitabine potentiates the antitumor activity of VSV in vitro and in vivo. A549 human lung adenocarcinoma cells and LLC Lewis lung carcinoma cells were treated with VSV (0.1-10 plaque-forming units per cell) plus gemcitabine (20 nM to 20 microM). Mice bearing A549 or LLC were treated with VSV (5 x 10(4) to 1 x 10(8) plaque-forming units) daily for 5 days plus gemcitabine (5-125 mg/kg/day) once every 3 days for 4 times. Induction of apoptosis and effects on growth inhibition were assessed. The lung cancer cells treated with VSV plus gemcitabine displayed the apparently increased apoptotic cells compared with treatment with VSV or gemcitabine alone. The combined treatment with VSV plus gemcitabine induced the apparent antitumor activity with complete regression of the established lung cancer in both A549 and LLC lung cancer models and augmented the induction of apoptosis in lung cancer cells in vivo as well. This study suggests that the combined treatment with VSV plus gemcitabine may augment the induction of apoptosis in lung cancer cells in vitro and in vivo, and that the augmented antitumor activity in vivo may result from the increased induction of apoptosis in lung cancer cells. The present findings may be of importance to the further exploration of the potential application of this combined approach in the treatment of lung cancer.