Induction of peptide-specific immune response in patients with primary malignant melanoma of the esophagus after immunotherapy using dendritic cells pulsed with MAGE peptides.

Primary malignant melanoma of the esophagus (PMME) is a very rare disease with an extremely poor prognosis. Surgery is currently considered its best treatment, while any other measures are ineffective. We studied the effect of active specific immunotherapy using monocyte-derived dendritic cells (DCs) pulsed with the epitope peptides of melanoma-associated antigens (MAGE-1, MAGE-3) in patients with PMME after surgery, for the first time. The patient received passive immunotherapy with lymphokine-activated killer cells concomitantly. Two HLA-A24-positive patients with PMME were treated. Both patients initially received radical esophagectomy with regional lymphadenectomy, followed by adjuvant chemotherapy with dacarbazine, nimustine, vincristine and interferon-alpha. In the case 1 patient, active specific immunotherapy was used to treat a large abdominal lymph node metastasis that became obvious 21 months after surgery. The disease remained stable for 5 months, and the patient survived for 12 months after the initiation of immunotherapy. In the case 2 patient, immunotherapy was tried as post-operative adjuvant treatment after adjuvant chemotherapy. There was no tumor recurrence for 16 months after the immunotherapy. As of 49 months after esophagectomy, the patient is still alive. In both patients, the ability of peripheral lymphocytes to produce IFN-gamma in vitro in response to peptide stimulation was significantly enhanced and delayed-type hypersensitivity skin test response to MAGE-3 peptide was turned positive after immunotherapy. In conclusion, active specific immunotherapy for PMME with the use of DCs and MAGE peptides was safe and capable of inducing peptide-specific immune responses. This case report warrants further clinical evaluation of this immunotherapy for PMME.

Successful induction of clinically competent dendritic cells from granulocyte colony-stimulating factor-mobilized monocytes for cancer vaccine therapy.

Recent studies have suggested that dendritic cell (DC)-based immunotherapy is one promising approach for the treatment of cancer. We previously studied the clinical toxicity, feasibility, and efficacy of cancer vaccine therapy with peptide-pulsed DCs. In that study, we used granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood monocytes as a cell source of DCs. However, previous investigations have suggested that G-CSF-mobilized peripheral blood monocytes produce reduced levels of proinflammatory cytokines such as interleukin (IL)-12 and tumor necrosis factor (TNF)-alpha. These T helper (Th)-1-type cytokines are thought to promote antitumor immune response. In this study, we assessed the functional abilities of DCs generated from G-CSF-mobilized monocytes obtained from 13 patients with CEA-positive advanced solid cancers. Peripheral blood mononuclear cells were obtained from leukapheresis products collected before and after systemic administration of G-CSF (subcutaneous administration of high-dose [5-10 microg/kg] human recombinant G-CSF for five consecutive days). In vitro cytokine production profiles after stimulation with lipopolysaccharide (LPS) were compared between monocytes with and without G-CSF mobilization. DCs generated from monocytes were also examined with respect to cytokine production and the capacity to induce peptide-specific T cell responses. Administration of G-CSF was found to efficiently mobilize peripheral blood monocytes. Although G-CSF-mobilized monocytes (G/Mo) less effectively produced Th-1-type cytokines than control monocytes (C/Mo), DCs generated from G/Mo restored the same level of IL-12 production as that seen in DCs generated from C/Mo. T cell induction assay using recall antigen peptide and phenotypic analyses also demonstrated that DCs generated from G/Mo retained characteristics identical to those generated from C/Mo. Our results suggest that G-CSF mobilization can be used to collect monocytes as a cell source for the generation of DCs for cancer immunotherapy. DCs generated in this fashion were pulsed with HLA-A24-restricted CEA epitope peptide and administered to patients safely; immunological responses were induced in some patients.

A novel immunotherapeutic modality with direct hemoperfusion targeting transforming growth factor-beta prolongs the survival of tumor-bearing rats.

Immune responses are frequently depressed in patients with cancer. One of the reasons for a poor immune response is the presence of increased levels of immunosuppressive substances associated with tumor growth. Transforming growth factor-beta (TGF-beta), a representative immunosuppressive cytokine, plays various roles in the progression of cancer. To remove immunosuppressive substances from tumor-bearing hosts, we developed an immunosuppressive substance adsorption (ISA) column for direct hemoperfusion (DHP) treatment. It is filled with extra-fine fibers that can adsorb TGF-beta. In this study, we investigated the effects of this DHP treatment on serum levels and activities of TGF-beta, cellular immune responses, and anti-tumor effects in KDH-8 (TGF-beta-producing hepatocellular carcinoma cell line)-bearing rats. We further studied the ability of ISA fibers to adsorb tumor-associated immunosuppressive cytokines [TGF-beta, interleukin (IL)-6 and vascular endothelial growth factor (VEGF)] in samples of body fluids obtained from patients with metastatic cancer. DHP treatment decreased serum levels and activities of TGF-beta in tumor-bearing rats and restored T lymphocyte response to mitogen. Tumor growth in rats treated by DHP was significantly slower than that in untreated rats. The survival time of treated rats was significantly longer than that of untreated rats. The concentrations of TGF-beta, IL-6, and VEGF in the samples of human body fluids were decreased markedly by in vitro treatment with ISA fibers. These results suggest that DHP treatment with an ISA column, which removes TGF-beta and other immunosuppressive substances from the sera of tumor-bearing hosts, is potentially a new immunotherapeutic strategy for cancer.

Mature dendritic cells generated from patient-derived peripheral blood monocytes in one-step culture using streptococcal preparation OK-432 exert an enhanced antigen-presenting capacity.

Dendritic cells (DCs) have been shown to be potent in inducing cytotoxic T cell (CTL) response leading to the efficient anti-tumor effect in active immunotherapy. Myeloid DCs are conventionally generated from human peripheral blood monocytes in the presence of interleukin (IL)-4 and granulocyte/macrophage colony-stimulating factor (GM-CSF). Streptococcal preparation OK-432, which is known to be a multiple cytokine inducer, has been extensively studied as to its maturation effects on immature DCs using an in vitro culture system. The purpose of this study was to examine whether it could be possible to generate mature DCs directly from peripheral monocytes using OK-432. We specifically focused on the possibility that recombinant cytokines, which are considered to be essential for in vitro DC generation, could be substituted by OK-432. Human peripheral monocytes, which were obtained from patients with advanced cancer, were cultured with IL-4 and OK-432 for 7 days. Cultured cells were compared with DCs generated in the presence of IL-4 and GM-CSF with or without OK-432 with regard to the surface phenotype as well as the antigen-presenting capacity. As a result, the culture of monocytes in the presence of IL-4 followed by the addition of OK-432 on day 4 (IL-4/OK-DC) induced cells with a fully mature DC phenotype. Functional assays also demonstrated that IL-4/OK-DCs had a strong antigen-presenting capacity determined by their enhanced antigen-specific CTL response and exerted a Th1-type T cell response which is critical for the induction of anti-tumor response. In conclusion, human peripheral blood monocytes cultured in the presence of IL-4 and OK-432 without exogenous GM-CSF demonstrated a fully mature DC phenotype and strong antigen-presenting capacity. This one-step culture protocol allows us to generate fully mature DCs directly from monocytes in 7 days and thus, this protocol can be applicable for DC-based anti-tumor immunotherapy.

[The effects of direct hemoperfusion using the filtration column filled with the adsorption fiber for immunosuppressive substances on cell-mediated immunity in tumor-bearing rats].

The patients with advanced cancer often lose their anti-tumor immune responses due to the increase of some immunosuppressive substances in the blood, such as cytokines and proteins derived from cancer cells or immune cells. We developed the adsorption fiber in transforming growth factor (TGF)-beta for the treatment to remove immunosuppressive substances and investigated the effects of direct hemoperfusion using the filtration column filled with this adsorption fiber in tumor-bearing rats. On day 0, KDH-8 tumor cells (1 x 10(6) cells/rat) were implanted subcutaneously into the back of WKAH/Hkm rats. On day 21 after tumor implantation, the rats underwent the direct hemoperfusion with this filtration column for 60 minutes. On day 28, the rats were sacrificed and the natural killer (NK) activities of their spleen cells were examined. As a result, the rats that underwent this treatment showed a significant increase in their NK activities compared with those of rats who underwent direct hemoperfusion with an empty column or had no treatment. Therefore, we indicated the possibility of a new immunotherapy technique against cancer using a direct hemoperfusion column filled with an adsorption fiber for immunosuppressive substances.

[Two case reports of complete regression of liver metastases from colorectal cancer after locoregional immunochemotherapy].

Hepatic arterial infusion (HAI) with pharmacokinetic modulating chemotherapy (PMC) has been well known to be one of the most effective protocols for unresectable liver metastases from colorectal cancer. PMC is a combination of oral UFT and continuous hepatic arterial 5-FU infusion. We present herein the cases of two patients with multiple liver metastases from colorectal cancer in whom complete regression (CR) was achieved by HAI with PMC in combination with Lentinan (immunostimulator). These patients received HAI via an implantable port system with a 4-24-hour continuous perfusion of 5-FU at 1,000 mg/m2 plus Lentinan at 2 mg/body once a week, and oral administration of UFT at 200-300 mg/m2/day everyday. CR of all metastatic lesions in the liver was achieved 4 months after the initiation of the treatment in both patients. One patient maintained CR for 3 months, but he died due to a recurrence of liver metastases and peritoneal dissemination 19 months after the initiation of the treatment. The other patient has been well without recurrence for 21 months. Because the liver is the largest immunologic organ, Lentinan could have activated lymphocytes and macrophages in the liver. Judging from the clinical experience of these two cases, HAI with PMC in combination with Lentinan could be one of the most promising treatment strategies for unresectable liver metastases from colorectal cancer.

Transanal excision of a large rectal polyp assisted by transsacral manipulation of the rectum.

Standard transanal excision of the rectal polyps is curative and is less invasive than transsacral resection or low anterior resction, but it is difficult to resect tumors that are distant from the anal verge. Moreover, in the case of large polyps, the risks of complications, such as hemorrhage or perforation, increase because exposure on the oral side of the tumor is poor. If exposure can be improved, transanal excision can be performed safely and completely when the polyp is large and distant from the anal verge. We used transsacral manual assistance to achieve transanal resection of a large tubulovillous adenoma of the rectum that was hard to be resected using the traditional transanal approach.