Microbial Antigen-Presenting Extracellular Vesicles Derived from Genetically Modified Tumor Cells Promote Antitumor Activity of Dendritic Cells.

Tumor-derived extracellular vesicles (EVs), as tumor vaccines, carry tumor-associated antigens (TAAs), and were expected to transfer TAAs to antigen-presenting cells. However, treatment with tumor-derived EVs exhibited no obvious antitumor effect on the established tumors, likely due to their immuno-suppressive functions, and also to the poor immunogenicity of TAAs. In order to improve the immune stimulating properties, EVs expressing a highly immunogenic bacterial antigen, 6 kDa early secretory antigenic target (ESAT-6), from Mycobacterium tuberculosis were prepared by genetically modifying the parent tumor cells with a plasmid coding for ESAT-6. Cultured B16 tumor cells were transfected with a ternary complex system consisting of pDNA, polyethylenimine (PEI), and chondroitin sulfate. The cells that were transfected with the ternary complex secreted EVs with a higher number of ESAT-6 epitopes than those transfected by a conventional DNA/PEI binary complex, due to the low cytotoxicity, and durable high expression efficiency of the ternary complex systems. The EVs presenting the ESAT-6 epitope (ESAT-EV) were collected and explored as immune modulatory agents. Dendritic cells (DCs) were differentiated from mouse bone marrow cells and incubated with ESAT-EV. After incubating with the EVs for one day, the DCs expressed a significantly higher level of DC maturation marker, CD86. The DCs treated with ESAT-EV showed a significantly improved antitumor activity in tumor-bearing mice.

Tumor Growth Suppression With Novel Intra-arterial Chemotherapy Using Epirubicin-entrapped Water-in-oil-in-water Emulsion In Vivo.

BACKGROUND/AIM: A mixture of anticancer agents and iodized poppy seed oil (IPSO) has been widely used for intra-arterial chemotherapy of hepatocellular carcinoma. However, the anticancer agents can easily separate from IPSO, so the therapeutic potential is limited. We developed epirubicin-entrapped water-in-oil-in-water emulsion (WOW-Epi) using a double-membrane emulsification technique. MATERIALS AND METHODS: We delivered WOW-Epi through a hepatic arterial injection to VX2 hepatic tumor rabbit model (1.2 mg/kg). RESULTS: VX2 tumor growth was selectively suppressed in the WOW-Epi-treated group compared with the control treated groups. The accumulation of WOW in nearby cancer cells was confirmed via electron-microscopy. Endocytosis seemed to be the mechanism underlying the uptake of WOW. CONCLUSION: WOW-Epi led to tumour growth suppression in vivo. WOW does not cause toxicity to arterial vessels. WOW-Epi will be hopefully used for repeated intra-arterial chemotherapy to HCC patients in the near future.

Bioadhesive and biodissolvable hydrogels consisting of water-swellable poly(acrylic acid)/poly(vinylpyrrolidone) complexes.

Films that can form bioadhesive hydrogels on wet biotissues absorbing blood or body fluids are useful for medical devices such as hemostats, adhesion barriers, wound dressings, and drug release devices. We focused on a hydrogen-bonding polymer complex consisting of poly(acrylic acid) (PAA) and poly(vinylpyrrolidone) (PVP). PAA is known as a tissue-adhesive polymer. However, simple mixing of aqueous PAA and PVP solutions resulted in the formation of an insoluble nonadhesive precipitate. We developed a novel solid/solution interface complexation method to afford a PAA/PVP complex that forms a strongly bioadhesive hydrogel with low cytotoxicity. The complex hydrogel can be slowly dissociated and dissolved in the body. The formation of the complexes as well as their swelling and degradation behavior depended strongly on the molecular weights and cross-linking densities of the component polymers. When the complex film was applied to a clipped incised jugular vein of a rat, it immediately formed a hydrogel and closed the incision. After removal of the clip, blood flowed through the vessel without any leakage. Application of the complex film to the surface of an incised mouse liver resulted in firm adhesion and the hemorrhage was effectively stopped. Such bioadhesive and biodissolvable materials consisting of low-toxicity synthetic polymers have high potential for implantable medical devices.

Selective boron delivery by intra-arterial injection of BSH-WOW emulsion in hepatic cancer model for neutron capture therapy.

OBJECTIVE: Boron neutron-capture therapy (BNCT) has been used to inhibit the growth of various types of cancers. In this study, we developed a 10BSH-entrapped water-in-oil-in-water (WOW) emulsion, evaluated it as a selective boron carrier for the possible application of BNCT in hepatocellular carcinoma treatment. METHODS: We prepared the 10BSH-entrapped WOW emulsion using double emulsification technique and then evaluated the delivery efficacy by performing biodistribution experiment on VX-2 rabbit hepatic tumour model with comparison to iodized poppy-seed oil mix conventional emulsion. Neutron irradiation was carried out at Kyoto University Research Reactor with an average thermal neutron fluence of 5 × 1012 n cm-2. Morphological and pathological analyses were performed on Day 14 after neutron irradiation. RESULTS: Biodistribution results have revealed that 10B atoms delivery with WOW emulsion was superior compared with those using iodized poppy-seed oil conventional emulsion. There was no dissemination in abdomen or lung metastasis observed after neutron irradiation in the groups treated with 10BSH-entrapped WOW emulsion, whereas many tumour nodules were recognized in the liver, abdominal cavity, peritoneum and bilateral lobes of the lung in the non-injected group. CONCLUSION: Tumour growth suppression and cancer-cell-killing effect was observed from the morphological and pathological analyses of the 10BSH-entrapped WOW emulsion-injected group, indicating its feasibility to be applied as a novel intra-arterial boron carrier for BNCT. Advances in knowledge: The results of the current study have shown that entrapped 10BSH has the potential to increase the range of therapies available for hepatocellular carcinoma which is considered to be one of the most difficult tumours to cure.

Exosomes derived from tumor cells genetically modified to express Mycobacterium tuberculosis antigen: a novel vaccine for cancer therapy.

OBJECTIVES: To examine the potential of exosomes derived from the tumor cells, which had been genetically modified to express a Mycobacterium tuberculosis antigen, as a cancer vaccine aimed at overcoming the weak immunogenicity of tumor antigens. RESULTS: We transfected B16 melanoma cells with a plasmid encoding the M. tuberculosis antigen, early secretory antigenic target-6 (ESAT-6). The secreted exosomes bearing both tumor-associated antigens and the pathogenic antigen (or their epitopes) were collected. When the exosomes were injected into foot pads of mice, they significantly (p < 0.05) evoked cellular immunity against both ESAT-6, and B16 tumor cells. Intra-tumoral injection of the exosomes significantly suppressed (p < 0.001) tumor growth in syngeneic B16 tumor-bearing mice, while the exosomes derived from the non-transfected B16 cells showed no effect on tumor growth, although both exosomes should have similar tumor antigens. CONCLUSIONS: Exosomes bearing both tumor antigens and the M. tuberculosis antigen (or their epitopes) have a high potential as a candidate for cancer vaccine to overcome the immune escape by tumor cells.

Pilot clinical study of boron neutron capture therapy for recurrent hepatic cancer involving the intra-arterial injection of a (10)BSH-containing WOW emulsion.

A 63-year-old man with multiple HCC in his left liver lobe was enrolled as the first patient in a pilot study of boron neutron capture therapy (BNCT) involving the selective intra-arterial infusion of a (10)BSH-containing water-in-oil-in-water emulsion ((10)BSH-WOW). The size of the tumorous region remained stable during the 3 months after the BNCT. No adverse effects of the BNCT were observed. The present results show that (10)BSH-WOW can be used as novel intra-arterial boron carriers during BNCT for HCC.

Feasibility evaluation of neutron capture therapy for hepatocellular carcinoma using selective enhancement of boron accumulation in tumour with intra-arterial administration of boron-entrapped water-in-oil-in-water emulsion.

INTRODUCTION: Hepatocellular carcinoma (HCC) is one of the most difficult to cure with surgery, chemotherapy, or other combinational therapies. In the treatment of HCC, only 30% patients can be operated due to complication of liver cirrhosis or multiple intrahepatic tumours. Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between (10)B atoms and thermal neutrons, so it is necessary to accumulate a sufficient quantity of (10)B atoms in tumour cells for effective tumour cell destruction by BNCT. Water-in-oil-in-water (WOW) emulsion has been used as the carrier of anti-cancer agents on intra-arterial injections in clinical. In this study, we prepared (10)BSH entrapped WOW emulsion by double emulsifying technique using iodized poppy-seed oil (IPSO), (10)BSH and surfactant, for selective intra-arterial infusion to HCC, and performed simulations of the irradiation in order to calculate the dose delivered to the patients. MATERIALS AND METHODS: WOW emulsion was administrated with intra-arterial injections via proper hepatic artery on VX-2 rabbit hepatic tumour models. We simulated the irradiation of epithermal neutron and calculated the dose delivered to the tissues with JAEA computational dosimetry system (JCDS) at JRR4 reactor of Japan Atomic Research Institute, using the CT scans of a HCC patient. RESULTS AND DISCUSSIONS: The (10)B concentrations in VX-2 tumour obtained by delivery with WOW emulsion were superior to those by conventional IPSO mix emulsion. According to the rabbit model, the boron concentrations (ppm) in tumour, normal liver tissue, and blood are 61.7, 4.3, and 0.1, respectively. The results of the simulations show that normal liver biologically weighted dose is restricted to 4.9 Gy-Eq (CBE; liver tumour: 2.5, normal liver: 0.94); the maximum, minimum, and mean tumour weighted dose are 43.1, 7.3, and 21.8 Gy-Eq, respectively, in 40 min irradiation. In this study, we show that (10)B entrapped WOW emulsion could be applied to novel intra-arterial boron delivery carrier for BNCT, and we show the possibility to apply BNCT to HCC. We can irradiate tumours as selectively and safety as possible, reducing the effects on neighbouring healthy tissues.

[Chemokine and chemokine receptor related to cancer metastasis].

The relationship has become clear between the expression of chemokine/chemokine receptors on cancer cells and the invasion, metastasis and peritoneal dissemination. Many cancer cells express chemokine receptors which are not expressed on the surface of normal tissues. Recently, it has been reported that overexpression of CXCR4/CXCL12 is related with metastasis to lung, liver, lymph nodes and bone marrow, while the overexpression of CCR7/CCL21 is mainly related with lymph node metastasis. We performed a comparative analysis of differential gene expressions related to chemokines/chemokine receptors, and cytokines in established gastric cancer cell lines by cDNA microarray. Upregulated chemokine genes were CCL21, CCL5, CXCL14, CCL2, CXCL1, CXCL8, CXCL7 and CXCL12, which the downregulated chemokines genes were MIP-1alpha and TECK. The upregulated gene of chemokine receptors was CCR-6. In the cancer microenvironment, cancer cells readily formed edematous and inflammatory conditions, easily metastasizing to other organs with the suppression of dendritic cells. The chemokines/chemokine receptors will hopefully become the new targets for cancer therapies for the regulation of metastasis.

Tumor growth suppression by adenovirus-mediated introduction of a cell-growth-suppressing gene tob in a pancreatic cancer model.

TOB (transducer of ErbB-2) is a tumor suppressor that interacts with protein-tyrosine kinase receptors, including ErbB-2. Introduction of the tob gene into NIH3T3 cells results in cell growth suppression. In this study, we evaluated the effect of tob expression in pancreatic cell lines (AsPC-1, BxPC-3, SOJ) and discuss the tumor-suppressing effects of adenoviral vector expressing tob cDNA. We first measured the levels of endogenous tob mRNA being expressed in all pancreatic cancer cell lines. Then, we examined the effect of adenoviral vector containing tob cDNA (Ad-tob vector) on cancer cell lines. The viral vector was expanded with transfection in 293 cells. The titer of the vector was 350x10(6) pfu/ml. These cancer cells were able to be transfected with MOI 20 without adenoviral toxicity. The transfection of Ad-tob vector results in growth suppression of SOJ and AsPC-1 cell lines. The magnitude of the expression of the Ad-tob gene in cancer is correlated to tumor suppressive activity. We prepared pancreatic cancer peritonitis models using a peritoneal injection of AsPC-1 cells. In this model, bloody ascites and multiple tumor nodules were seen at the mesentery after 16 days. AdCAtob (50x10(6) pfu/day) was administered from day 5 to day 9 after 4 days of peritoneal injection of 2x10(6) AsPC-1 cells. Tumor growth suppression occurred 10 days after peritoneal injection of AdCAtob compared with the control group. There were no tumor nodules in the abdomen and no bloody ascites. These results suggest that the peritoneal injection of AdCAtob has potential to suppress the formation of pancreatic cancer peritonitis, and can be applied for chemotherapy-resistant cancer peritonitis.

Improvement of sensitivity to platinum compound with siRNA knockdown of upregulated genes in platinum complex-resistant ovarian cancer cells in vitro.

It is known that some cancers show platinum complex resistance and that others show platinum complex sensitivity among ovarian cancers. Oxaliplatin (cis-[oxalato[trans-l-1, 2-diamino-cyclohexane] platinum[II]]; l-OHP), an active anti-cancer agent consisting of platinum, inhibits RNA synthesis and results in cytostatic effects. We investigated the difference between an oxaliplatin-resistant ovarian cancer cell line, KFR, and an oxaliplatin-sensitive ovarian cancer cell line, KF-1, using DNA microarray analysis. The oxaliplatin-resistant cell line, KFR, was established by using KF-1 cells derived from human serous cystadenocarcinoma of the ovary. Acquisition of platinum resistance in human ovarian cancer cells thus appeared to be related mainly to the expression of gamma-glutamylcysteine synthetase (gamma-GCS), topo II and metallothionein (hMT) genes, and partly to that of topo I and glutathione S-transferase--pi (GST-pi) genes, in addition to a decrease in platinum accumulation. KFR cells had 8.5- and 24.7-fold higher mRNA levels of gamma-glutamylcysteine synthetase (gamma-GCS), and topo II genes than KF-1 cells, while KFR had only a slight increase in the glutathione S-transferase--pi (GST-pi) mRNA level as compared with KF-1. In comparison of the gene expressions between KFR and KF-1 ovarian cancer cell lines, tubulin-specific chaperone E (TBCE) and CBP/p300-interacting transactivator (CITED2) were overexpressed in KFR compared to KF-1. These genes are overexpressed in MKN74, an oxaliplatin-resistant gastric cancer cell line, compared to MKN28, an oxaliplatin-sensitive gastric cancer cell line. TBCE is 13-fold increased in KFR cells compared to KF-1 cells. CBP/p300-interacting transactivator is increased 2-fold in KFR cells compared to KF-1 cells. The siRNA directed to the TBCE gene and CBP/p300-interacting transactivator gene enhanced the cytotoxicity of diplatin to the platinum-resistant ovarian cancer cell line KFR. These results show that the TBCE gene and CBP/p300 gene have potential as multidrug-resistant genes. It is necessary to check the effect of siRNA to influx or exflux. It has potential to enhance the effect of anti-cancer agents to resistant cancer cells, so we will proceed to develop an inhibitor of these TBCE and CBP/p300 proteins.

Application of drug delivery system to boron neutron capture therapy for cancer.

BACKGROUND: Tumor cell destruction in boron neutron capture therapy (BNCT) is due to the nuclear reaction between (10)B and thermal neutrons ((10)B + (1)n --> (7)Li + (4)He (alpha) + 2.31 MeV (93.7 %)/2.79 MeV (6.3 %)). The resulting lithium ions and alphaparticles are high linear energy transfer (LET) particles which give a high biological effect. Their short range in tissue (5 - 9 mum) restricts radiation damage to those cells in which boron atoms are located at the time of neutron irradiation. BNCT has been applied clinically for the treatment of malignant brain tumors, malignant melanoma, head and neck cancer and hepatoma. Sodium mercaptoundecahydro-dodecaborate (Na(2)(10)B(12)H(11)SH: BSH) and borono-phenylalanine ((10)BPA) are currently being used in clinical treatments. These low molecule compounds are easily cleared from cancer cells and blood, so high accumulation and selective delivery of boron compounds into tumor tissues and cancer cells are most important to achieve effective BNCT and to avoid damage to adjacent healthy cells. OBJECTIVE: In order to achieve the selective delivery of boron atoms to cancer cells, a drug delivery system (DDS) is an attractive intelligent technology for targeting and controlled release of drugs. METHODS: We performed literature searches related to boron delivery systems in vitro and in vivo. RESULTS: We describe several DDS technologies for boron delivery to cancer tissues and cancer cells from the past to current status. We are convinced that it will be possible to use liposomes, monoclonal antibodies and WOW emulsions as boron delivery systems for BNCT clinically in accordance with the preparation of good commercial product (GCP) grade materials.

Highly efficient in vivo gene transfection by plasmid/PEI complexes coated by anionic PEG derivatives bearing carboxyl groups and RGD peptide.

A new class of an anionic poly (ethylene glycol) derivative, PEG-Suc, bearing 17.7 pairs of carboxylic acid-side chains was synthesized. PEG-Suc deposited onto the DNA/polyethyleneimine complexes without destroying them even at high dose ratio. Coating of the DNA complexes by PEG-Suc recharged their surface to negative, and effectively protected them from the albumin-induced aggregation. Paired carboxyl groups in the side chains showed higher proton sponge effect. Negatively charged surface would diminish the electrostatic binding of the complexes to the cells, and the transfection efficiency on the cultured cells was not high. RGD peptide side chain as a ligand to malignant cell surfaces was then introduced to compensate the reduced electrical adhesion. RGD-PEG-Suc-coated plasmid/PEI complex brought about more than 3 times higher reporter protein activity on the cultured B16 cells. Those bio-compatible DNA complexes with ligand attained very high gene expression in tumor, lung, and liver after injection into mouse tail vein.

Effective anti-tumor activity of oxaliplatin encapsulated in transferrin-PEG-liposome.

Oxaliplatin (trans-L-diaminocyclohexane oxalatoplatinum, L-OHP) is a novel cisplatin derivative that can improve the side effects of cisplatin such as toxicity to the kidneys and peripheral nerve system. However, L-OHP is effective only when combined with 5-Fluorouracil (5-FU) and Leucovorin. The relatively low anti-tumor index of L-OHP alone is because low levels accumulate in tumor tissues due to high partitioning to erythrocytes in vivo. A successful outcome of cancer therapy using L-OHP requires the selective delivery of a relatively high concentration of the drug to tumors. The present study examines tumor-selective delivery of L-OHP using liposomes modified with transferrin-conjugated polyethyleneglycol (TF-PEG-liposomes). Delivery using these liposomes significantly reduced L-OHP partitioning to erythrocytes and improved the circulation time of L-OHP in vivo, resulting in enhanced extravasation of liposomes into tumors. The TF-PEG-liposomes maintained a high L-OHP concentration in tumors for over 72 h after intravenous injection, which was longer than that of the liposomes modified with PEG (PEG-liposomes). Intravenously administered L-OHP encapsulated within TF-PEG-liposomes (L-OHP: 5 mg/kg) suppressed tumor growth more effectively than PEG-liposomes, Bare-liposomes and free L-OHP. Although L-OHP is usually combined with 5-FU and Leucovorin, our results suggest that L-OHP encapsulated within TF-PEG-liposomes has potential for cancer therapy.

Evaluation of neutron dosimetry on pancreatic cancer phantom model for application of intraoperative boron neutron-capture therapy.

Pancreatic cancer is one of the most difficult neoplasms to cure and there is a need for new combinated therapy. If sufficient boron compound can be targeted accurate to the tumour, Boron Neutron-Capture Therapy (BNCT) can be applied to pancreatic cancer. We administrated BNCT to a cancer with pancreatic cancer patient using intraoperative irradiation. In this study, we performed preliminary dosimetry of a phantom model of the abdominal cavity. The flux of 8>x10(7)n/cm(2)/s (0.1 ratio) was 4.5 cm in depth from the surface in the case of simple irradiation, and the field of thermal neutrons was spread as 13 cm and 11.5 cm were usage of Void and Void with LiF collimation, respectively in thermal (OO-0011) mode. In the case of epithermal (CO-0000) mode, epithermal and fast components are four times higher at the surface level. In the case of mixed beam (OO-0000) mode, thermal neutron flux was the same as thermal neutron mode at a depth of 10 cm, but the gamma-ray component was two times higher than that of thermal neutron mode. With the use of Void and LiF collimation, thermal neutrons were selectively applied to the tumour combined with the CT-imaging of the cancer patient. This means that we could irradiate the tumour selectively and safely as possible, reducing the effects on neighboring healthy tissues. High resolution whole body dosimetry will be necessary to extend the application of BNCT to pancreatic cancer.

Efficacy of immuno-cell therapy in patients with advanced pancreatic cancer.

BACKGROUND: Patients with advanced pancreatic carcinoma have a risk of relapse after primary therapy, and the prognosis for these patients remains bleak. The effect of immuno-cell therapy in advanced pancreatic carcinoma, with or without other standard therapies, was examined. PATIENTS AND METHODS: Forty-six patients with advanced pancreatic carcinoma, undergoing immuno-cell treatment, were evaluated. RESULTS: Of all the patients, those who received immuno-cell therapy alone accounted for 15.4% of partial response (PR), 23.1% of long-term stable disease (SD), 46.2% of SD and 15.4% of progressive disease (PD), and had a 50% survival time of 14.5 months. The respective values for the 28 patients undergoing immuno-cell therapy with gemcitabine were 10.7% of PR, 10.7% of long-term SD, 32.1% of SD and 46.4% of PD, with a 50% survival time of 15.8 months; for 5 patients undergoing immuno-cell therapy with UFT or TS-1, the values were 0% of PR, 0% of SD, 20.0% of SD and 80.0% of PD, with a 50% survival time of 16.1 months. CONCLUSION: The combination of immuno-cell therapies with standard therapies may be effective in the short-term in patients with advanced pancreatic cancer. Long-term survival depends on the presence of metastases and the duration of coadministration with these standard therapies.

Combined immunocell therapy using activated lymphocytes and monocyte-derived dendritic cells for malignant melanoma.

BACKGROUND: The beneficial effects of immunocell therapy, using either activated lymphocytes (ALs) or dendritic cells (DCs), in the treatment of melanoma has been demonstrated. DCs are professional antigen-presenting cells that induce cytotoxic T lymphocytes against tumor cells. DC therapy may be promising when combined with ALs. PATIENTS AND METHODS: Patients with advanced melanoma, who underwent immunocell therapy with both ALs and DCs, were reviewed. DCs were pulsed with tumor lysates, peptides or both. RESULTS: Side-effects were occasional slight fever and skin erythema. Among 8 of the 14 patients treated with immunocell therapy alone, 1 showed a mixed response (MR) and 1 prolonged stable disease (SD). In the remaining 6 patients treated with immunocell therapy and other conventional therapies, 1 CR, 1 MR and 1 prolonged SD for 24 months were observed. CONCLUSION: Combined immunocell therapy was well tolerated and showed a relatively high tumor response. This treatment may have therapeutic potential for some refractory malignancies.

Preparation of antitumor oxaliplatin/cisplatin docking dinuclear platinum complex.

A new dinuclear docking Pt(II) complex, (cis-diammine) (l-1,2-cyclohexanediamine)(mu-dichloro)-diplatinum(II) oxalate was synthesized by reacting oxaliplatin(l-OHP, [Pt(oxalato)(L-dach)]), L-dach = 1R, 2R-cyclohexanediamine), with cisplatin (CDDP). Elemental analysis of the compound indicated that it was 1:1 molar ratio complex of oxaliplatin and cisplatin. A plausible chemical structure has been proposed as Cl(-) bridged dinuclear complex, judged from its yellow coloration and NMR spectral analysis. This complex can be denoted as, i.e. [Pt(2)Cl(2)(NH(3))(2)(L-dach)](COO)(2) (L-OHP/CDDP). The complex showed higher cytotoxicity against L1210 than the parent complexes and low cross-resistance against L1210/CDDP and L1210/DACH. Its antitumor activity was also tested in vivo against murine leukemia L1210 cell lines. The complex showed much higher activity than the mixture(1:1 molar ratio) of oxaliplatin and cisplatin. The antitumor effect against L1210/CDDP was very high, showing collateral sensitivity, being similar to that of oxaliplatin, and against L1210/DACH it showed no cross-resistance.

A report of three patients treated with immunocell therapy with imatinib mesylate.

BACKGROUND: Immunocell therapy has been applied to patients with refractory cancer in clinical trials or as an unconventional cancer therapy, however the efficacy is still limited. To improve this efficacy, a combination therapy may be beneficial. Molecularly-targeted therapy acts directly on neoplasm cells to suppress their growth without causing myelosuppression. CASE REPORT: Recently, we encountered three patients treated by immunocell therapy with imatinib mesylate (Glivec). One patient was diagnosed as having Philadelphia chromosome (Ph) (+) acute lymphoblastic leukemia (ALL) and had a relapse-free survival of more than 24 months. The other two were diagnosed as having GIST; a partial response was observed in one which lasted more than 21 months, while the other's disease has been stabilized for more than 25 months. No side-effects were observed, other than those mentioned in the directions for the use of imatinib. CONCLUSION: Immunocell therapy may have a potent therapeutic effect when used in combination with molecularly-targeted therapy, which has few side-effects.

Phase I study of autologous tumor vaccines transduced with the GM-CSF gene in four patients with stage IV renal cell cancer in Japan: clinical and immunological findings.

We produced lethally irradiated retrovirally GM-CSF-transduced autologous renal tumor cell vaccines (GVAX) from six Japanese patients with stage IV renal cell cancer (RCC). Four patients received GVAX ranging from 1.4 x 10(8) to 3.7 x 10(8) cells on 6-17 occasions. Throughout a total of 48 vaccinations, there were no severe adverse events. After vaccination, DTH skin tests became positive to autologous RCC (auto-RCC) in all patients. The vaccination sites showed significant infiltration by CD4(+) T cells, eosinophils, and HLA-DR-positive cells. The kinetic analyses of cellular immune responses using peripheral blood lymphocytes revealed an enhanced proliferative response against auto-RCC in four patients, and cytotoxicity against auto-RCC was augmented in three patients. T cell receptor beta-chain analysis revealed oligoclonal expansion of T cells in the peripheral blood, skin biopsy specimens from DTH sites, and tumors. Western blot analysis demonstrated the induction of a humoral immune response against auto-RCC. Two of the four patients are currently alive 58 and 40 months after the initial vaccination with low-dose interleukin-2. Our results suggest that GVAX substantially enhanced the antitumor cellular and humoral immune responses, which might have contributed to the relatively long survival times of our patients in the present study.