Neuropeptide Y (NPY) was continuously administered to Wistar rats in the normal and glioma bearing conditions intracarotidly via the external carotid artery and local cerebral blood flow (LCBF) was measured by a [14C] iodoantipyrine technique. In the normal rats, the LCBF at the injecting side of NPY markedly reduced in 2 minutes after beginning of drug administration. In glioma-bearing rats, LCBF in the cerebral cortex and caudate nucleus reduced to the same level as normal rats. However reduction of LCBF in the tumor was not significantly different from that of ipsilateral cortex and caudate nucleus. The results of this study suggest that flow moduration by NPY injection increases delivery of intra-carotid administered anticancer drugs to the brain tumor with concomitant decrease of neurotoxicity to the normal brain.

The plasma membrane in mammalian cells possesses unique permeability properties serving as a selective permeability barrier as well as transporters for nutrients and ions in maintaining cellular homeostasis. External ATP modulates the permeability barrier in transformed cells. The characteristics and possible mechanism for this permeability change are summarized. Application of this membrane change for cancer chemotherapy was also examined in both in vitro and in vivo. The uptake of D-glucose by mammalian cells was carried out by a facilitated diffusion through a specific transporter protein in the membrane. The control mechanism for glucose transport by growth factors based on the changes in the glucose transporter levels is summarized. Modulation of glycosylation in the transporter protein and its possible role are discussed.

The authors previously reported the advantages of a collagen gel embedded culture system for chemosensitivity tests for cancer. In this report, the chemosensitivities of surgically resected specimens were evaluated by the collagen gel embedded culture system and compared with the DNA ploidy pattern, measured by flow cytometry. The chemosensitivity and DNA ploidy pattern were determined in 11 patients with lung cancer, 8 with gastric cancer and 46 with colorectal cancer. Anticancer agents were MMC and CDDP at Cmax for one hour of exposure, and 5-FU, VDS, VP-16 and ADM at one tenth the Cmax for 24 hours of exposure. Results were compared with those of DNA histogram. In eight lung cancers which were demonstrated to be sensitive by the collagen gel system, 5 showed DNA aneuploidy (DA) and 3 DNA diploidy (DD). Seven cases (87.5%) of gastric cancer were demonstrated to be sensitive with the collagen gel system. Two of them showed DA and five DD. On the other hand, 19 cases (41.3%) of colorectal cancer were found to be sensitive, and 7 of them showed DA and twelve DD. Lung cancer and gastric cancer exhibiting aneuploidy demonstrated sensitivity with the collagen gel system, but the rate of sensitivity was only 28% in colorectal cancer, and even aneuploidy cases showed a low sensitivity.

Recently, the effectiveness of preoperative chemotherapy for cancer treatment has attracted much attention. The authors conducted a study to investigate the influence of 5'-DFUR administration on the cell cycle, based on DNA analysis using FCM in patients with breast cancer. A total of 53 patients with breast cancer (Stages I, II and III) were investigated concerning tumor PyNPase activity and cell cycle phase. Subjects were stratified according to tumor diameter, histologic type and ER in the group receiving preoperative 5'-DFUR administration (25 patients) and the group not receiving 5'-DFUR (28 patients). The subjects in the group on 5'-DFUR preoperative administration were classified into three sub-groups according to total dosages of 400 mg (8 patients), under 4,800 mg (8 patients) and 4,800 mg or over (9 patients). In terms of tumor diameter, significant increases (p = 0.027) of S-phase were observed in patients with the diameters of 5 cm or more in the sub-group of under 4,800 mg dosage. Similar tendencies were seen in all drug administration groups (p = 0.05). However, no influence was observed on S-phase in the group without 5'-DFUR administration. In terms of ER stratification, ER(-) patients in the dosing groups showed increasing tendencies in S-phase and significant differences of G1- as well as G2+M phases. No differences in PyNPase activity were noted in each stratified group. Preoperative administration of 5'-DFUR resulted in alterations of cell cycle in breast cancers. In patients with a total drug dosage of under 4,800 mg and with tumor diameters of 5 cm or more, increases of S-phase and decreases of G1-phase were observed. It was suggested that 5'-DFUR acted in DNA synthesizing stage to accumulate S-phase inhibiting cell cycles. Consequently, this drug is considered useful for neoadjuvant chemotherapy.

Pharmacokinetics and antitumor activity of MX2.HCl (MX2), a new morpholino anthracycline, were investigated in rats transplanted 9L gliosarcoma cells in the brain. (1) Pharmacokinetics: AUC of MX2 in the brain tumors which received intracarotid and intravenous injection of 2mg/kg of MX2 were 117.50 and 55.94 micrograms.hr/g, respectively. AUC of the brain tissue was 1.38-3.90 micrograms.hr/g. (2) Antitumor activity: The inhibition of cell growth at the concentration of 0.1 micrograms/ml was 73.1% with MTT assay. The mean survival time in tumor-bearing rats after intracarotid and intravenous injection of 2mg/kg of MX2 prolonged significantly. Therefore, it seems that MX2 will become an efficacious drug for the treatment of malignant glioma.

Interactive effects of combined treatment with hyperthermia and chemotherapeutic agents or chemical substances were interpreted in the experimental aspects of medical sciences. It was also interpreted how a physiological circumferential conditions in vivo influenced on thermosensitivities of cells, tissues or individuals. Among the physiological conditions, hypoxia and insufficient nutrition apparently enhance thermosensitivity while reduce radiosensitivity. Interactive effects in combined treatments with hyperthermia and alkylating agents varies among the alkylating agent adopted. DNA strand scission by alkylating agent is increased and repair of the DNA damage is suppressed in combination with hyperthermia. Almost all the antimetabolites and botanic alkaloids are reported to show no appreciable interactive effect in combination with hyperthermia. However, a sort of derivatives of mitotic toxins interacts with hyperthermia (unpublished data). Effects of anticancer antibiotics vary due to the variety of the mechanism of action of the antibiotics. Therefore, interactive effects of these antibiotics with hyperthermia also vary among the antibiotics. Most marked interaction with hyperthermia was shown in Mitomycin C, while the cell killing effect of Actinomycin D itself was reduced reportedly by the combined hyperthermia. Further development in thermophysiology may perform an extent of elevation in human whole body temperature. It has been considered internal heating may be more efficient than external heating for the hyperthermia alone. In the other hand, local heating can chemosensitize within the localized heated area where the blood concentration of anticancer drug is even, although variety of intervention could be devised to localize anticancer drug distribution. Variety of heating modalities and the apparatus would be developed which contribute for further interdisciplinary oncotherapy in near future.

Multidrug resistance to anticancer drugs proved to be related to the MDR1 gene which encodes the P-glycoprotein, an energy-dependent drug-efflux pump for lipophilic drugs. We investigated the expression of the MDR1 gene in clinical samples by RT-PCR. The subjects were all resected cases of 14 colorectal cancers, five gastric cancers, two esophageal cancers, two gallbladder cancers and 20 lung cancers. Adrenal gland was used as a positive control. Total RNA was extracted from a fresh tissue sample. The cDNA was synthesized from 1 microgram of total RNA using reverse transcriptase. With the above cDNA as the template, amplification of the 157-bp fragment of the MDR1 gene was performed using PCR. The PCR product was polyacrylamide gel-electrophoresed and ethidium bromide-stained. In addition, a dot blot analysis was performed to quantify the amount of PCR product. Since PCR was performed simultaneously under the same conditions, the PCR product was quantified at four stages, from (3+) to (-), to indicate the degree of expression of MDR1 mRNA. Adrenal gland showed (3+)-(2+) and colorectal cancer exhibited mostly (2+)-(1+). Both cancerous and non-cancerous areas evidenced a similar degree of expression in the cases of colorectal cancer. The MDR1 gene was expressed at low levels in other digestive tract cancers and in lung cancer. The levels of MDR1 expression revealed no correlation to either histological type or clinical stage. The present method may contribute to designing anti-cancer protocols.

Human tumor cloning assay (HTCA) and thymidine incorporation assay (TIA) were both performed using a double-layer-agar system with continuous exposure of cells to standard anticancer drugs. The rate of evaluable assays was 44% (280 of 638 tumor samples) in HTCA and 48% (216 of 452) in TIA. When the tumor samples were restricted to the gastric and colorectal cancers, it was significantly higher in TIA than HTCA (p < 0.01). HTCA was 95% reliable for predicting in vivo resistance and 52% reliable for in vivo sensitivity, whereas TIA was 88% reliable for in vivo resistance and 44% for in vivo sensitivity. These results seem to suggest that it is unnecessary to select just clonogenic tumor cells among whole tumor cell population in assessing chemosensitivity of human tumors. The current study also indicates that chemotherapy with in vitro sensitive drugs assessed by TIA produced longer survival of the patients with stage III or IV gastric cancer. Most of clinical correlation trials including this study, however, have been performed retrospectively. The prospective study is necessary to determine whether drug selection by in vitro assays is superior to that by an experienced oncologist. In addition, further studies on pharmacokinetics of anticancer drugs are required to solve some other problems inherent to the current chemosensitivity assays.

More than 35 candidate drugs have been under their clinical studies in Japan currently. These include antimetabolites, drugs originated from natural products, miscellaneous compounds and hormones. Since the time of appearance of cisplatin and taxol, we found the possibility to discover new active drugs against human solid cancers. Our recent clinical studies on topoisomerase inhibitors and microtubules inhibitors have also been proving the clinical usefulness of these drugs for cancer treatment. From now on, we have to think the drug development from ethical aspects, improving quality of life and prolonging the survival of the treated patients. For these purposes, we have to be careful to choose candidate drugs for their clinical trials.

In an attempt to predict the antitumor activity of a new podophyllotoxin analogue, NK 611, in the treatment of lung cancer, we compared the drug with etoposide and teniposide using four human small cell lung cancer (SCLC) cell lines, SBC-2, -3, -4, -7, and two non-small cell lung cancer cell lines, ABC-1, EBC-1. In terms of the fifty percent tumor growth inhibitory concentration (IC 50) determined by MTT assay, teniposide was most potent among the drugs. The degree of cross-resistance of each drug was investigated using an etoposide-resistant SCLC subline (SBC-3/ETP), an adriamycin-resistant subline (SBC-3/ADM 100), and a cisplatin-resistant subline (SBC-3/CDDP). As for relative resistant (the ratio of IC 50 for resistant subline to that for the parent subline), NK 611 was least cross-resistant to etoposide, adriamycin, and cisplatin among drugs tested. These results indicate that NK 611 may play a role in a salvage chemotherapy for patients with resistant SCLC.

Colony-stimulating factors (CSFs) are glycoprotein growth factors that influence the proliferation and differentiation of hematopoietic progenitor cells. Among CFSs granulocyte colony-stimulating factor (G-CSF) is thought to be major stimulator of production of human neutrophilic granulocyte. G-CSF have recently moved from the basic research to the clinical use and have been suggested to have important roles in cancer management. Today two kinds of recombinant G-CSF which have similar specific activity are commercially available, one is derived from ovarian cells of Chinese hamster and the other from E. coli. (Variant type of E. coli is now in trial.) Difference of these two is whether carbohydrate chain primarily seen in molecule of natural form is contained or not. In this report recombinant product of G-CSF for the clinical use is introduced. Preclinical study with recombinant G-CSF have suggested that it would stimulate granulocyte production in cancer patients with myelosuppression due to chemotherapy. Thus, after evaluation of toxicities and possible efficacy recombinant G-CSF has been introduced into phase II trial for the prevention of chemotherapy-induced neutropenia in various cancers. In this setting 2 micrograms/kg of subcutaneous administration for 14 days after aggressive chemotherapy was suggested to be optimal and to be acceptable for toxicities including bone pain or headache. In conclusion recombinant G-CSF is thought to be very useful drug for reduction of nadir of cancer chemotherapy-induced neutropenia and shortening of period of neutropenia.

TT-62 is a new derivative of FdUMP, which is the active metabolite of 5-FU. A phase I clinical study of TT-62 was conducted by a cooperative study. The same patients received single and 2-week oral administration of TT-62. Starting from 60 mg/m2 (1n), the dose was escalated to 420 mg/m2 (7n). In the single administration, the maximum tolerated dose (MTD) could not be determined. In the 2-week administration, MTD was 420 mg/m2, and the dose limiting factor was gastro-intestinal disturbances such as anorexia, nausea, vomiting and diarrhea. Increases in GOT.GPT and a decrease in hemoglobin content were observed. After administration was stopped all side effects disappeared. TT-62 was detected mainly in the plasma, while trace amounts of 5-FU and FUdR were also detected. TT-62 was excreted mostly in the urine, as alpha-fluoro-beta-alanine (FBAL). The cumulative urinary excretion of FBAL was about 80% of the total dose, and the oral absorption of TT-62 was thus thought to be good.

Antitumor effects of BOF-A2 given intermittently was evaluated with human gastric (H-111, H-83), colorectal (H-110, H-143) and lung (H-74, LC-376) cancers xenografted in nude mice and compared with those by continuous administration. BOF-A2 was orally given 3 or 4 times per week at 30 or 35 mg/kg over 4 weeks. This drug was effective to 5 strains except H-110 (IR > or = 58%), remarkably effective to H-81 and H-143 (IR > or = 80%) and caused tumor regression in mice bearing H-81 especially. Moreover, the drug was effective to H-74 which is rather insensitive to 5-FU and its known derivatives. When the drug was given orally to nude mice xenografted LC-376, 5-FU levels in the tumor tissue was notably durative for a long time as compared to UFT. It would be concluded that BOF-A2 was much effective to insensitive tumor to fluorinated pyrimidines or other anticancer, because of persistence of high levels of 5-FU in the tumor tissue. On the other hand, diarrhea which is caused by other fluorinated pyrimidines or consecutive administration of BOF-A2, was mild by the intermittent administration of BOF-A2.

Phenotypic heterogeneity in lung cancer was investigated immunochemically, using monoclonal antibody NE150, PE35 and OE130. The presence of NE150 neuroendocrine and PE35 panepithelial antigens and the absence of another epithelial antigen, OE130, i. e., NE150+/PE35+/OE130- is the typical phenotype of small cell lung cancer, while NE150-/PE35+/OE130+ is that of non-small cell lung cancer. The results obtained from the cell lines with no prior therapy indicated a good correlation between the antigen phenotype and chemo-radiosensitivity, suggesting that antigen phenotype may reflect some intrinsic resistance which could be related to differentiations in the status of the lung cancer.

The effect of KW-2228, a derivative of recombinant human granulocyte colony stimulating factor, on neutropenia associated with chemotherapy was studied in pediatric patients with malignant tumor. To patients repeatedly treated with the same chemotherapy, KW-2228 was administered subcutaneously at 1 microgram/kg or intravenously at 2 micrograms/kg once a day in the 2nd course of the chemotherapy. During the administration term of KW-2228, the nadir of neutrophils went up, and the duration of neutrophil count under 500/microliters as well as the interval for recovery of the count to 500/microliters were remarkably shortened, compared with those during the observation term. Further, the duration of fever in patients and the administration days of antibacterial agent were also reduced. The effective rate judged by attending doctors was as high as 78.9%, consisting of 83.3% in 42 cases of subcutaneous administration and 73.5% in 34 cases of intravenous administration. Side effects such as slight skeletal pain and slight fever in one case each (2.3% in total) were improved without treatment. It is concluded that KW-2228 may be a useful drug for treatment of neutropenia associated with chemotherapy in pediatric patients with malignant tumor.

Since the introduction of hormonal treatment for prostatic cancer by Huggins and Hodges in 1941, severe side effects of synthetic estrogen, which have overcome its benefit, have been reported in the U.S.A. and in European countries. However, in Japan the adverse effects of estrogen have been reported to be milder than in western countries, and estrogen still has an important role in the treatment of prostatic cancer in Japan. In this communication, the side-effects of synthetic estrogen administered to 109 prostatic cancer patients, who were admitted to Kyoto University Hospital between 1980-1990 are reported. Fifty-three (48.6%) of the 109 patients suffered adverse side effects of the estrogen, specifically cardiac disease (20.2%), fluid retention (14.7%) and hypertension (13.8%). Five of these patients died. Among the risk factors analyzed, daily dose, past history of cardio-vascular disease and ECG abnormalities were significantly correlated with the appearance of adverse effects. The reasons why the frequency of lethal side-effects is lower in our cases compared to findings reported by the Veterans Administration group may be the lower daily dose and cessation of estrogen administration when mild adverse effects appear and some other unknown factors, although the background of the patients and method of analysis are not comparable among them. The overall frequency of side-effects in prostatic cancer patients administered estrogen in our cases is not necessarily lower than in western countries, but the severity of the side effects was milder in our cases. We must be a ware of the potential adverse effects of estrogen.

An antitumor substance, RA-700, isolated from Rubia akane or Rubia cordifolia has the novel structure. Phase I clinical study was conducted by the RA-700 clinical study group consisting of 6 institutions. A single dose administration and 5-day schedule administration were evaluated with 14 patients respectively. RA-700 was given from 0.2 to 1.4 mg/m2 in single i.v. dose study, from 0.4 to 2.0 mg/m2 in 5-day i.v. schedule study. Nausea and vomiting, fever, stomachache, mild hypotension and slight abnormality of electric-cardiogram were observed as the toxicities. In pharmacokinetic study, the elimination half-lives (t1/2) of RA-700 in plasma were 55 min, of alpha-phase and 3.9 hrs. of beta-phase by single dose study, and 23-25 min. of alpha-phase and 6-14 hrs. of beta-phase by 5-day schedule study. Accumulation was not found by 5-day schedule administration, and metabolite were not observed in plasma and urine. It seems that RA-700 is metabolized by the liver and excreted in the feces. In conclusion, the maximum tolerated dose was 1.4 mg/m2 for 5-day schedule administration.

The antitumor activity of navelbine (vinorelbine ditartrate, KW-2307) against murine and human transplantable tumors was compared with those of other vinca alkaloids, vindesine (VDS), vincristine (VCR) or vinblastine (VLB). KW-2307 and VDS increased the life span of mice bearing ascitic tumors (P 388 leukemia, L 1210 leukemia, EL-4 lymphoma, Colon 26, FM 3 A mammary carcinoma and M 5076 sarcoma) slightly more than VCR or VLB. A significant difference was not found in the antitumor activities against 6 murine solid tumors (B 16 melanoma, Colon 26, FM 3 A mammary carcinoma, Lewis lung carcinoma, M 5076 sarcoma and Sarcoma 180). However, a remarkable difference was observed in the antitumor activities against 11 human tumors inoculated into nude mice. The activity of KW-2307 was more than those of other 3 drugs against 4 human non-small cell lung carcinomas (Lu-65, Lu-99, LC-6 and L-27) and 2 stomach carcinomas (St-4 and St-40). KW-2307 and VDS were also effective in inhibiting the growth of 2 human breast carcinomas (MX-1 and Br-10).

In order to elucidate the effect of tumor vascularity on a various regimens concentration in tumor tissue, correlation among tegafur, 5-fluorouracil (5-FU), uracil concentrations in tissue and the microangiography were examined in 27 patients with colorectal cancer after preoperative administration of UFT (400 mg/day for 7 days). The concentrations of tegafur, 5-FU and uracil in tumor were higher than those in normal tissue (p < 0.01). There was no definite correlation between tissue concentration in each regimen and the extra or intramural vascular changes. A significant high concentration of 5-FU was found in the protuberant cancer and the ulcerative cancer with horizontal growth than that in the ulcerative cancer with vertical growth (p < 0.05). The present study indicates that the vascular changes within a tumor and the vascular pattern of tumor may be a contributing factor affecting the tissue concentration in the regimens.

Four fluorinated pyrimidines that are in the stage of clinical trials at present in Japan were reviewed: BOF-A2, Ro09-1390, TT-62 and S-1. Both BOF-A 2 and S-1 are a compound of 5-FU derivative combined or mixed with an inhibitor of 5-FU degradation in order to prolong the blood 5-FU level as well as increase selective toxicity to tumor. Furthermore, an inhibitor of 5-FU phosphorylation in G1 tract contained in S-1 reduces G1 toxicity such as diarrhea etc due to prolongation of blood 5-FU level. Ro09-1390 is an improved compound of 5'-DFUR, which intends to reduce diarrhea caused by the latter. TT-62 is a FdUMP derivative and an active metabolite of 5-FU for oral formulation, which is superior to available 5-FU type anticancer agents in efficacy, and doesn't show cross tolerance to 5-FU.