Low-dose paclitaxel enhances the anti-tumor efficacy of GM-CSF surface-modified whole-tumor-cell vaccine in mouse model of prostate cancer.

Chemotherapy combined with a tumor vaccine is an attractive approach in cancer therapy. This study was designed to investigate the optimal schedule and mechanisms of action of a novel GM-CSF (granulocyte-macrophage colony-stimulating factor) surface-modified tumor-cell vaccine in combination with paclitaxel in the treatment of mouse RM-1 prostate cancer. First, the anti-tumor efficiencies of various dosage of paclitaxel (4, 20, 40 mg/kg) in combination with the vaccine in different administration sequences were examined in the mouse RM-1 prostate cancer model. Then, the in vivo and in vitro effects of various dosage of paclitaxel on RM-1 cells, T cells, and DCs (dendritic cells) were evaluated. The results showed that: (a) the GM-CSF-surface-modified tumor-cell vaccine was more potent at inducing the uptake of tumor antigens by DCs than irradiated tumor cells plus free GM-CSF; (b) 4 mg/kg paclitaxel combined with the GM-CSF-surface-modified tumor-cell vaccine was the most effective at enhancing tumor regression in RM-1 prostate cancer mice when the vaccine was administrated 2 days after paclitaxel; and (c) administration of 4 mg/kg paclitaxel followed by the vaccine induced the highest degree of CD8(+) T-cell infiltration in tumor tissue, suggesting that the induction of tumor-specific immune response had occurred. These findings suggested that the GM-CSF-surface-modified tumor-cell vaccine may have potential clinical benefit for patients with prostate cancer when it is combined with paclitaxel. Furthermore, the effect of immunochemotherapy depends on careful selection of paclitaxel dosage and the sequence of paclitaxel/vaccine administration.

Combined perioperative EOX chemotherapy and postoperative chemoradiotherapy for locally advanced gastric cancer.

Currently, adjunctive therapy for gastric cancer is not standardized worldwide and the most effective combination of different modalities has not been clearly determined. The aim of the present study was to retrospectively analyze the efficacy and toxicity of the combination of perioperative epirubicin, capecitabine and oxaliplatin (EOX) chemotherapy and postoperative concurrent chemoradiotherapy in the treatment of locally advanced gastric cancer. A total of 41 patients with locally advanced gastric cancer who had undergone perioperative EOX chemotherapy and surgical resection followed by chemoradiotherapy, were assessed. The perioperative EOX regimen consisted of 50 mg/m2 epirubicin and 130 mg/m2 oxaliplatin on day 1, with 625 mg/m2 capecitabine administered twice daily on days 1-21. The perioperative regimen was repeated 2-3 times every 3 weeks. After complete resection following the perioperative EOX regimen, concurrent chemoradiotherapy with capecitabine (4,500 cGy in daily fractions of 180 cGy administered 5 days per week for 5 weeks, with 625 mg/m2 capecitabine twice daily during radiotherapy) and 2 cycles of the EOX regimen 4 weeks after radiotherapy, were performed. In total, 30/41 patients (73.2%) completed all the planned treatments, including perioperative chemotherapy, surgical resection and chemoradiotherapy. The effective rate of preoperative chemotherapy (partial and complete response) was 56.1%; 30/41 patients received R0 resection, and the overall 3-year survival rate was 57.7%. Grade 3/4 gastrointestinal toxicity (nausea/vomiting) occurred in 22% of the patients, while 18 patients (43.9%) developed grade 3/4 hematological toxicity (granulocytopenia). The results of the present study indicated that the combination of perioperative EOX chemotherapy and postoperative concurrent chemoradiotherapy is feasible and effective for locally advanced gastric cancer.

[Combined chemotherapy with domestic gemcitabine plus carboplatin in the treatment of advanced non-small cell lung cancer].

BACKGROUND: Chemotherapy is very important in the treatment of advanced non-small cell lung cancer (NSCLC). The aim of this study is to evaluate the efficacy, clinical benefit and toxicity of combined chemotherapy with domestic gemcitabine (ZEFEI) plus carboplatin in the treatment of advanced NSCLC. METHODS: Thirty-four previously untreated patients with advanced NSCLC (stage III-IV) received domestic gemcitabine of 1000mg/m² on days 1, 8, and carboplatin of AUC 5 on day 1, with 21 days as a cycle. Each patient received at least three cycles. RESULTS: The total clinical response rate (complete and partial response) was 44% (15/34). Overall clinical benefit rate was 53% (18/34). The main toxicities were hematological toxicities. The rate of grade III-IV leukopenia and thrombocytopenia was 47% and 24% respectively. CONCLUSIONS: Combined chemotherapy with domestic gemcitabine plus carboplatin is an effective and feasible regimen for advanced NSCLC.

Niclosamide suppresses renal cell carcinoma by inhibiting Wnt/ß-catenin and inducing mitochondrial dysfunctions.

PURPOSE: To investigate the effects of anthelminthic drug niclosamide in renal cell carcinoma (RCC) and the underlying mechanisms of its action. METHODS: The effects of niclosamide on the proliferation and apoptosis of RCC cells were examined in vitro and in vivo by using MTS, colony formation assay, flow cytometry and xenograft cancer mouse model. Mechanism studies were performed by analyzing Wnt/ß-catenin signaling and mitochondrial functions in a panel of RCC cell lines. RESULTS: We show that niclosamide effectively targets two RCC cell lines through inhibiting proliferation and anchorage-independent colony formation, and inducing apoptosis. It also enhances the inhibitory effects of chemotherapeutic drug cisplatin in two independent in vivo RCC xenograft mouse models. Mechanistically, niclosamide decreases ß-catenin levels and therefore suppresses Wnt/ß-catenin activities. Overexpression of ß-catenin partially reverses the inhibitory effects of niclosamide in RCC cells, demonstrating that besides ß-catenin, other mechanisms are involved in niclosamide's anti-cancer activity. Indeed, we further show that niclosamide induces mitochondrial dysfunctions as shown by the decreased level of mitochondrial membrane potential and respiration, resulting in decreased ATP levels and increased reactive oxygen species (ROS) levels. CONCLUSIONS: Our findings support the inhibitory effects of niclosamide in cancer and provide better understanding on its underlying mechanism. Our data suggests that niclosamide is a useful addition to the treatment armamentarium for RCC.

[Eukaryotic expression and bioactivity determination of the fusion protein sTNFRII-gAD consisting of soluble tumor necrosis factor receptor II and globular domain of adiponectin].

In order to get soluble TNF receptor (sTNFR) II with good neutralizing activity against TNFalpha, we constructed the fusion gene sTNFRII-gAD, which encoded human sTNFR II and the globular domain of adiponectin (gAD), and then expressed it in mammalian cells and analyzed its anti-TNFalpha activity. First, sTNFRII cDNA was obtained by RT-PCR from the total RNA of human peripheral blood lymphocytes, and fused in frame with gAD gene. Then, the fusion gene sTNFRII-gAD was cloned into the expression vector pAAV2neo to result in the plasmid pAAV2neo-sTNFRII-gAD. By immunofluorescent staining with monoclonal antibody either against TNFRII or against adiponectin, we demonstrated that the pAAV2neo-s7NFRII-gAD-transiently-transfected BHK-21S cells were positive. To obtain G418-resistant BHK-21S/pAAV2neo-sTNFRII-gAD cells, we cultured the transfected BHK-21S cells above in 10% FBS containing DMEM media with 800 microg/mL G418 for 15 days, and changed the serum-containing culture media to a serum-free chemically defined media so as to change the cells culturing style from adhesion to suspension. 24 hours later, we harvested the supernatant of the culture for sTNFRII-gAD fusion protein characterization and anti-TNFalpha activity analysis. With monoclonal antibody either against TNFRII or against adiponectin, the Western blotting analysis showed that the sTNFRII-gAD fusion protein was expressed and existed as monomer, trimer and multimer forms in the supernatant. The bioactivity assay demonstrated that the sTNFRII-gAD fusion protein had the ability to neutralize TNFalpha so as to inhibit the cytotoxicity of TNFalpha on L929 cells. Put together, this study has laid the groundwork for large-scale preparation of sTNFRII-gAD fusion protein.

Escherichia coli outer membrane protease OmpT confers resistance to urinary cationic peptides.

Escherichia coli OmpT, located in the outer membrane, has been characterized as a plasminogen activator, with the ability to hydrolyze protamine and block its entry. In this investigation, a complex of low molecular weight cationic peptides purified from human urine by a combination of membrane ultrafiltration and weak cation exchange chromatography was characterized. The impact of OmpT on E. coli resistance to urinary cationic peptides was investigated by testing ompT knockout strains. The ompT mutants were more susceptible to urinary cationic peptides than ompT(+) strains, and this difference was abolished by complementation of the mutants with pUC19 carrying the ompT gene. The urinary protease inhibitor ulinastatin greatly decreased the resistance of the ompT(+) strains. Overall, the data indicate that OmpT may help E. coli persist longer in the urinary tract by enabling it to resist the antimicrobial activity of urinary cationic peptides.

A novel therapeutic vaccine of GM-CSF/TNFalpha surface-modified RM-1 cells against the orthotopic prostatic cancer.

A novel therapeutic vaccine against prostate cancer was developed by simultaneous immobilization of streptavidin-tagged bioactive GM-CSF and TNFalpha on the biotinylated surface of 30% ethanol-fixed RM-1 prostatic cancer cells. This study showed that the GM-CSF/TNFalpha-doubly surface-modified vaccine significantly extended the survival in the orthotopic model of RM-1 prostate cancer, and was superior to single GM-CSF- or TNFalpha-surface-modified vaccine. Moreover, the splenocytes from the GM-CSF/TNFalpha-vaccine-treated mice showed the most potent cytotoxicity on RM-1 cells and the highest production of RM-1-specific IFNgamma. In addition, more CD4+ and CD8+ T cells infiltrated into the tumor sites in the GM-CSF/TNFalpha-vaccine-treated mice than in the GM-CSF- or TNFalpha-vaccine-treated mice. Therefore, our study demonstrated that the efficacy of RM-1 prostate cancer cell vaccine could be improved by conjugating both GM-CSF and TNFalpha simultaneously on the surface of cancer cells, and that this modification thus has a potential translational significance.

[Ex vivo expansion of megakaryocyte progenitor cells from human cord blood in serum-free culture].

Prolonged thrombocytopenia is a puzzling problem following umbilical cord blood (CB) transplantation. It might be the result of inadequate megakaryocyte progenitors and the arrest in the megakaryocyte maturation. It is an important method to solve the problem by transfusing ex-vivo expanded CB megakaryocyte progenitor cells into the patients to shorten the duration of platelet recovery. However, the most optimal condition of expansion has not been established so far. In the study, cord blood mononuclear cells (MNC) were cultured in serum-free medium with TPO, IL-3, SCF and IL-6. The numbers of MNC, CFU-MK and CD41(+) cells were measured at 0, 6, 10 and 14 days, in order to find the best cytokine combination and optimal harvest time point for clinical use. The results showed that the megakaryocyte progenitors most efficiently expanded with the cytokine combination including TPO, IL-3, SCF and IL-6. The time point of maximal CFU-MK growth is day 10. At 10 days, the numbers of CFU-MK and CD41(+) cells expanded by 6.8- and 8.8-fold respectively. In conclusion, in vitro, the cytokine cocktail including TPO, IL-3, SCF and IL-6 was the most optimal cytokine combination which stimulates the ex vivo expansion of megakaryocyte progenitors in CB MNC and serum-free medium. The maximal CFU-MK colonies were harvested at 10 days, that may be an optimal harvest time for clinical transfusion.