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Fenretinide (N-[4-Hydroxyphenyl]retinamide; 4HPR) is a semisynthetic retinoid that induces apoptosis in a variety of malignancies. Fenretinide has been examined in clinical trials as a cancer chemopreventive and chemotherapeutic agent. Oxidative stress induced by fenretinide has been shown to mediate apoptosis through a mitochondrial pathway by the induction of a transcription factor CCAAT/enhancer binding protein homologous protein (CHOP) and Bak. In this study, we report that fenretinide induces death receptor 5 (DR5)/TRAIL-R2 up-regulation via the induction of the transcription factor CHOP in colon cancer cell lines. Fenretinide induced DR5 expression at protein and mRNA levels. Furthermore, fenretinide increased DR5 promoter activity and the enhanced activity decreased by mutation of the CHOP binding site. CHOP was also up-regulated by fenretinide at the promoter level. We also showed that combined treatment with fenretinide and TRAIL induced synergistic apoptosis in colon cancer cell lines. The synergistic apoptosis was markedly blocked by DR5/Fc chimeric protein. Fenretinide and TRAIL cooperatively activated caspase-3, -8, -10 and -9 and cleavage of Bid and PARP, and this activation was also blocked in the presence of DR5/Fc chimeric protein. These results indicate that fenretinide-induced apoptosis is sensitized by TRAIL. Therefore, combined treatment with fenretinide and TRAIL might be a promising model for the treatment of colorectal cancer.

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.

Three-field lymph node dissection has been widely used to treat thoracic esophageal cancer, but is very invasive and can cause serious complications. Whether cervical lymph node dissection should be performed in all patients with thoracic esophageal cancer remains controversial. We pathologically examined the recurrent nerve lymph nodes during surgery in patients with thoracic esophageal cancer to determine the presence or absence of lymph node involvement. In patients without recurrent nerve nodal involvement, cervical lymph node dissection was not performed. Treatment outcomes were analyzed to evaluate whether intraoperative pathological investigation was a useful procedure. Among 71 patients with thoracic esophageal cancer who underwent 3-field lymph node dissection, the rate of cervical lymph node metastasis was 40.9% in patients with recurrent nerve nodal metastasis on intraoperative pathological investigation, as compared with 10.2% in patients without recurrent nerve nodal metastasis (p=0.007). Multiple logistic-regression analysis showed that recurrent nerve nodal metastasis was a strong predictor of cervical lymph node metastasis (odds ratio, 2.98; 95% confidence interval, 1.139-7.775; p = 0.03). Among 41 patients who underwent intraoperative pathological investigation, 10 had recurrent nerve nodal metastasis and underwent cervical lymph node dissection. Two of these patients had histological evidence of cervical lymph node metastasis. The remaining 31 patients had no recurrent nerve nodal metastasis on intraoperative pathological examination and therefore did not receive cervical lymph node dissection. None of these patients had cervical lymph node recurrence on follow-up. We compared patients who underwent intraoperative pathological investigation with those who underwent conventional 3-field lymph node dissection (without performing intraoperative pathological investigation). The rates of cervical lymph node recurrence were similar among the groups (2.6% vs. 6.7%), but the 3-year survival rate was significantly higher in the patients who underwent intraoperative pathological dissection (83.3%) than in those who underwent 3-field dissection (57.2%; p

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.

To evaluate the efficacy of long-term postoperative adjuvant chemotherapy with low-dose cisplatin (CDDP) plus 5-fluorouracil (5-FU) (CDDP/5-FU), we retrospectively examined 167 patients with squamous cell carcinoma of the esophagus who received the treatment after curative surgery (R0 resection). We classified the patients into the following three groups according to their postoperative therapies and analyzed their outcomes: a) low-dose CDDP (10 mg body(-1) day(-1) x 5 days) plus 5-FU (250-500 mg body(-1) day(-1) x 5 days) repeated every 6 months for 3 years, with an oral fluoropyrimidine (5-FU 150-200 mg body(-1) day(-1) or UFT 300-400 mg body(-1) day(-1)) administered between each treatment cycle (low-dose CDDP/5-FU group, 98 patients); b) high-dose CDDP (80 mg body(-1) day(-1) x 1 day) plus 5-FU (750-1,000 mg body(-1) day(-1) x 5 days) administered once only, followed by treatment with an oral fluoropyrimidine (5-FU 150-200 mg body(-1) day(-1) or UFT 300-400 mg body(-1) day(-1)) for 3 years (high-dose CDDP/5-FU group, 17 patients); or c) surgery alone (surgery alone group, 52 patients). The 3-year survival rates were 83.7% in the low-dose CDDP/5-FU group, 61.4% in the high-dose CDDP/5-FU group, and 62.2% in the surgery alone group; the difference between the low-dose CDDP/5-FU group and surgery alone group was significant (log-rank, p

The EAP combination of etoposide (ETP), doxorubicin (ADM) and cisplatin (CDDP) has been reported to be highly active for advanced gastric cancer. However, it is associated with severe myelotoxicity, and its use has declined. We examined whether peripheral blood stem cells (PBSCs) could be mobilized during hematopoietic recovery after EAP, and assessed the possibility of using multimodal cell therapy with PBSCs for the treatment of advanced gastric cancer. Five men with advanced gastric adenocarcinoma were enrolled. All patients were chemotherapy-naïve. EAP (ETP, 360 mg/m2; ADM, 40 mg/m2; CDDP, 80 mg/m2) was given to each patient, and myelotoxicity was carefully monitored. Granulocyte colony-stimulating factor was administered after the neutrophil nadir, and PBSCs were collected by leukapheresis during hematopoietic recovery. The median nadir of the neutrophil count after EAP was 225/ml, occurring between day 17 and 20. Sufficient numbers of PBSCs [CD34(+) cells, CFU-GM] could be mobilized in 4/5 patients. A 45-year-old patient with extended lymph node metastasis received high-dose EAP with peripheral blood stem cell transplantation (PBSCT), followed by cancer vaccine therapy with dendritic cells (DCs), induced from cryopreserved PBSCs. Both high-dose EAP with PBSCT and DC-based immunotherapy was safely performed for the first time against gastric cancer. Although associated with severe myelotoxicity, EAP can mobilize sufficient numbers of PBSCs during hematopoietic recovery. Multimodal cell therapy combining high-dose chemotherapy with PBSCT and DC-based immunotherapy is feasible and can be a reasonable approach in advanced gastric cancer.

A multi-institutional study was performed to evaluate the appropriate duration of oral administration of Carmofur (1-hexylcarbamoyl-5-fluorouracil, HCFU), a 5-fluorouracil (5-FU) derivative, for postoperative adjuvant chemotherapy in patients with colorectal cancer undergoing curative operation. Patients were divided into two: i) short duration group receiving 6 months of HCFU administration and ii) long duration group receiving 1 year of the administration, using a centralized registration system. Among 364 patients entered in this study, 293 evaluable cases were analyzed to investigate the appropriate duration of adjuvant oral chemotherapy. No statistical differences were found in the cumulative 5-year disease-free or survival rates between the groups. However, the actual duration of oral HCFU administration differed in the patients of short and long duration groups from the protocol. Namely, more than 70% of the patients received a different duration of oral adjuvant chemotherapy in each of the groups. Therefore, apart from this division of two groups, correlation between the actual duration of oral HCFU administration and the prognosis was examined in these patients. As a result, it was suggested that oral adjuvant chemotherapy with HCFU would be effective in colon cancer patients when the duration of administration exceeded 330 days. In rectal cancer patients, however, adjuvant chemotherapy with HCFU alone was considered to be not sufficient to affect the prognosis.