Mitsuo Katano

Vascular endothelial growth factor and platelet-derived growth factor are potential angiogenic and metastatic factors in human breast cancer

BACKGROUND Angiogenesis is a prerequisite for tumor growth and metastasis. Tumor angiogenesis may be mediated by several angiogenic factors such as vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), transforming growth factor-alpha, and basic fibroblast growth factor. METHODS Differential mRNA expressions of VEGF, PDGF (A chain), transforming growth factor-alpha and basic fibroblast growth factor in 32 primary invasive breast tumors were examined by reverse transcriptase-polymerase chain reaction. We analyzed relationships between mRNA expressions of these angiogenic factors and the degree of angiogenesis, tumor size, and metastasis. Quantification of angiogenesis was achieved by the immunohistochemical staining of endothelial cells with antibody to CD31. RESULTS VEGF and PDGF-A mRNAs were expressed more frequently in breast tumors than in nontumor breast tissues, whereas no difference was found in expression frequency of either transforming growth factor-alpha or basic fibroblast growth factor mRNA. Vascular counts in tumors correlated with each expression frequency of VEGF and PDGF-A mRNA. PDGF-A mRNA was expressed more frequently in tumors with lymph node metastasis than in those without metastasis. CONCLUSIONS Expression of VEGF and PDGF mRNAs detected by reverse transcriptase-polymerase chain reaction in breast tumors correlates with tumor-related characteristics of angiogenesis and metastatic potential. Analysis of these mRNAs by reverse transcriptase-polymerase chain reaction may be useful for assessing the biologic behavior of a breast tumor before surgical treatment.

Significant prolongation of disease-free period gained by oral polysaccharide K (PSK) administration after curative surgical operation of colorectal cancer

SummaryTo examine the clinical efficacy and the mechanism of action of polysaccharide K (PSK), a proteinbound polysaccharide extracted from a Basidiomycetes fungus, a randomized double-blind trial was performed by administering PSK to 56 patients and a placebo to another group of 55 patients after surgical operations on their colorectal cancers. The rate of patients in remission (or disease-free) was significantly higher in the PSK group than in the placebo group; the difference between both groups was statistically significant atP <0.05 by the logrank test. The survival rate of patients was also significantly (P <0.05) higher in the PSK group than in the control group. The most significant laboratory finding was that polymorphonuclear leukocytes from PSK-treated patients showed remarkable enhancement in their activities, such as random and/or chemotactic locomotion, and phagocytic activity, when compared with those in the control group. In conclusion, PSK was useful as a maintenance therapy for patients after their curative surgical operations for colorectal cancer. The beneficial effects were probably due to the activation of leukocyte functions as one of the many biological-response-modifying (activities induced by PSK).

Psk-mediated NF-κb inhibition augments docetaxel-induced apoptosis in human pancreatic cancer cells NOR-P1

Docetaxel, a member of the taxane family, has been shown to induce apoptosis in a variety of cancer cells. However, toxicity at therapeutic doses has precluded the use of docetaxel alone for the management of cancer patients. PSK, a protein-bound polysaccharide, is widely used in Japan as an immunopotentiating biological response modifier for cancer patients. Our previous study showed that PSK induced downregulation of several invasion-related factors, suggesting an interaction of PSK with transcriptional factors. In this study, we showed that PSK dose dependently enhanced apoptosis induced by 1 nM of docetaxel in a human pancreatic cancer cell line NOR-P1. Furthermore, PSK inhibited docetaxel-induced nuclear factor kappa B (NF-κB) activation. Moreover, the expression of cellular inhibitor of apoptosis protein (cIAP-1), which is transcriptionally regulated by NF-κB and functions as an antiapoptotic molecule through interrupting the caspase pathway, was also inhibited by treatment with PSK plus docetaxel. As a result, PSK enhanced the docetaxel-induced caspase-3 activation. In addition, treatment by transfection of NF-κB decoy oligodeoxynucleotides (ODNs), but not scramble ones, inhibited the expression of cIAP-1 in NOR-P1 cells and induced a significant increase in docetaxel-induced apoptosis. Our data indicate that PSK suppresses the docetaxel-induced NF-κB activation pathway. Combination of PSK with a low dose of docetaxel may be a new therapeutic strategy to treat patients with pancreatic cancer.

Potentiation of cytotoxicity of mitomycin C bt a polyacetylenic alcohol, panaxytriol

Polyacetylenic alcohol, panaxytriol, which was isolated fromPanax ginseng C. A. Meyer, has antiproliferative activity against several kinds of tumor cells. In this paper, the effect of panaxytriol on the cytotoxicity of mitomycin C (MMC) against a human gastric carcinoma cell line, MK-1, was investigated. The combination of a subthreshold concentration of MMC and panaxytriol produced a significant cytotoxic effect, which indicates that the effects of panaxytriol and MMC are synergistic. A synergistic effect was observed when MK-1 cells were treated with the mixture of MMC and panaxytriol or treated with MMC followed by panaxytriol. In contrast, when MK-1 cells were exposed to panaxytriol and then to MMC, only an additive effect was induced. With the aim of finding a possible mechanism, the effect of panaxytriol on the accumulation of MMC into the MK-1 cells was examined. Cellular concentration of MMC were measured by highperformance liquid chromatography (HPLC). When MK-1 cells were treated with a mixture of panaxytriol and MMC or first with MMC and then with panaxytriol, the cellular level of MMC was significantly higher than that in MK-1 cells treated with MMC alone, but no significantly increased accumulation was found when MK-1 cells were treated with panaxytriol followed by MMC. These results suggest that synergistic effects of panaxytriol and MMC may be induced by acceleration of the effect of MMC on cellular that the enhanced accumulation of MMC in MK-1 cells treated with panaxytriol can probably be attributed to the decreased fluidity of the cell membrane caused by panaxytriol.

Immunosuppressive cytokines (IL‐10, TGF‐β) genes expression in human gastric carcinoma tissues

Contribution of immunosuppressive cytokines to tumor progression in many types of cancers has been suggested. To characterize the in vivo expression of immunosuppressive cytokines in gastric cancer, we analyzed the messenger RNA (mRNA) expression of transforming growth factor‐β (TGF‐β) and interleukin‐10 (IL‐10) in human gastric carcinoma tissues.

Effect of granulocyte colony-stimulating factor (G-CSF) on chemotherapy-induced oral mucositis

In this study, the ability of granulocyte colony-stimulating factor (G-CSF) to treat or prevent chemotherapy-induced oral mucositis in patients with advanced breast cancer was evaluated. A total of 14 patients who received intra-arterial (i.a.) adriamycin (ADM) preoperatively were divided into two groups according to whether or not G-CSF was given. Thus, group A (n=7) was given G-CSF and group B (n=7) was not. G-CSF therapy reduced both the incidence and duration of ADM-induced oral mucositis, and a positive correlation was also seen between the incidence of mucositis and ADM-induced leukopenia (<2,000/mm3). Group A was further divided into two subgroups according to whether G-CSF was given after or before the leukopenia had dropped below 2,000/mm3: group A-1 (n=3) and group A-2 (n=4), respectively. ADM-induced mucositis was observed in two of the three patients in group A-1, but in none of the four patients in group A-2. These results strongly support the idea that G-CSF can effectively treat and prevent ADM-induced oral mucositis.

A possible mechanism for the cytotoxicity of a polyacetylenic alcohol, panaxytriol: inhibition of mitochondrial respiration

A polyacetylenic alcohol, panaxytriol, isolated fromPanax ginseng C. A. Meyer inhibits both tumor cell growth into mice. Our preliminary studies indicated that panaxytriol localizes to the mitochondria in human breast carcinoma cells (Breast M25-SF). This study focused on the effects of panaxytriol on mitochondrial structures and function in Breast M25-SF. The results indicate that panaxytriol rapidly inhibits cellular respiration and disrupts cellular energy balance in Breast M25-SF. At concentrations between 11.3 and 180 μM, panaxytriol causes a dose-dependent inhibition of the conversion of the tetrazolium (MTT assay) by mitochondrial dehydrogenase within 2 h. A 1-h treatment with 180 μM panaxytriol causes a significant loss of rhodamine-123 from cells with mitochondria prestained with rhodamine-123 (by flow cytometry). Specific toxic changes were observed by electron microscopy in the mitochondria of Breast M25-SF within 1 h after treatment with more than 180 μM panaxytriol. These data indicate that 180 μM panaxytriol rapidly disrupts cellular energy balance and respiration in Breast M25-SF and suggest that panaxytriol may lower cellular ATP concentrations. After treatment with 180 μM panaxytriol, cellular ATP levels were 40% of those in control cells after 1 h. ATP depletion preceded the loss of cellular viability. Neither ATP depletion nor cytolysis was found in human erythrocytes that have no mitochondria. Thus, ATP depletion resulting from a direct inhibition of mitochondrial respiration is a critical early in the cytotoxicity of panaxytriol.

Novel antiproliferative falcarindiol furanocoumarin ethers from the root of Angelica japonica.

Four novel antiproliferative furanocoumarin ethers of falcarindiol, named japoangelols A (8.5), B (7.2), C (7.4), and D (8.4), were isolated from the root of Angelica japonica together with panaxynol (0.3), falcarindiol (3.2), (9Z)-1,9-heptadecadiene-4,6-diyne-3,8,11-triol (2.2), and 8-acetoxyfalcarinol (3.2). Structures were established from the spectroscopic evidence, and the inhibitory activities (ED50, microgram/ml, shown in the parentheses) were evaluated using the MTT assay.

Melanoma antigen-encoding gene-1 expression in invasive gastric carcinoma: Correlation with stage of disease

A human melanoma antigen‐encoding gene‐1, MAGE‐1 gene, may be linked to the neoplastic transformation. In the present study, we extended this association with human gastric carcinomas. Specifically, we focused on the relationship between MAGE‐1 gene expression and the histologic stage of gastric carcinoma.

CEA-mediated homotypic aggregation of human colorectal carcinoma cells in a malignant effusion

This study was performed to clarify the role of carcinoembryonic antigen (CEA) in the aggregation of colorectal carcinoma (CRC) cells in malignant effusions. We analysed freshly purified CRC cells from one patient, which expressed CEA (98% positive cells) on the surface and formed huge cell aggregates in the patients ascites. The carcinoma cells expressed Sialyl Lewis A (82%), Sialyl Lewis X (92%) and the beta 1 integrin subunit (78%) but did not express the pair-ligands for these molecules. Cell aggregation was completely inhibited by anti-CEA mAb. The decreased CEA expression induced by phosphatidylinositol-specific phospholipase C (PI-PLC) treatment led to decreased cell aggregation. We also examined the correlation between the degree of cell aggregation and CEA expression using smears of ascites fluid from 27 patients with colorectal cancer. There was a significant correlation between the degree of cell aggregation and CEA expression by CRC cells. The present study provided the first evidence that CEA molecules mediate the homotypic aggregation of CRC cells in malignant effusions.