We examined the cytotoxic activities of recombinant human tumor necrosis factor (rHTNF-alpha) and five chemotherapeutic agents, CTX, 5-Fu, VCR, DDP, KSM, against two human ovarian cancer cell lines, OVCAR3 and CAOV3, using the MTT assay. The results showed that cytotoxicities of rHTNF-alpha at 5 x 10-5 x 10(4) u/ml against OVCAR3 cell line for 24 h exposure were from 14.2 +/- 6.8% to 67.2 +/- 3.0%, and those against CAOV3 cell line were from 8.2 +/- 4.3% to 60.9 +/- 1.3%. The cytotoxic effects of all five chemotherapeutic agents against the two cell lines were much lower than that of rHTNF-alpha. Further, we studied the combined anticancer potential of rHTNF-alpha with chemotherapeutic agents against the two cell lines. Various degrees of synergism in cytotoxicities of DDP or KSM in combination with rHTNF-alpha were observed. The cytotoxic effect of rHTNF-alpha on CAOV3 cell were also morphologically observed under phase contrast and electron microscope. Based on experiment in vitro, the in vivo anticancer activity of rHTNF-alpha alone or in combination with KSM was examined against human ovarian cancer OVCAR3 subcutaneously transplanted in nude mice. After 8 weeks of treatment, a statistically significant difference of mean tumor volume was found between the control group and groups that received rHTNF-alpha or rHTNF-alpha plus KSM (P < 0.01).

Thevetoside (TS) is one of the cardiac glycosides. A study of antitumor activity was carried out in 6 types of murine tumors in vivo, such as the ascitic tumors H22, EAC, P388, and solid tumors S180, U14, Lewis lung carcinoma, which were treated with i.p. TS 1.5 mg.kg-1.d-1 alone or in combination with chlormethine (Chl) 0.3, 0.5, or 1.0 mg.kg-1.d-1. TS only showed a remarkable inhibition on the growth of 3 types of solid tumors with inhibition rates of 48.7%-56.7%. The effect of the combination therapy was much pronounced than that of independent administration. The life span under combined therapy was increased 82.4% to > 122.1%. For solid tumors, the combined administration gave inhibition rates of 65.6%-72.5%.

The inhibitory effect of a third generation retinoid R8923 and all-trans retinoic acid (RA) on malignant transformation of Balb/3T3-A31 cells induced by 3-methylcholanthrene (3-MCA) and 12-0-tetradecanoyl phorbol-13-acetate(TPA) was studied in paper. Malignant transformation of Balb/3T3-A31 cells was evaluated by scoring transformation foci and soft agar assay. Actively growing Balb/3T3-A31 cells (1.5 x 10(4) cells per 60-mm-diameter glass dish) were cultured in 5ml of Eagle's Minimum Essential Medium supplemented with 10 percent fetal bovine serum. Twenty-four hours after plating, the cells were treated with 3-MCA (2 micrograms/ml) for 72 hours. TPA was added into the medium at a concentration of 100 ng/ml for 2 weeks. Thirty-six days after cell plating, the transformation foci were counted and the soft agar assay of the cells isolated from each glass dish was performed. Results showed that there were 16.0 +/- 1.58 transformation foci/dish and the colony forming efficiency in soft agar assay was 138.6 +/- 14.47/10(3) cells in 3-MCA and TPA treated dishes (control group). When the cells were exposed to R8923 or RA (at a concentration of 10(-6) M), the transformation foci were 11.2 +/- 0.84 /dish and 9.2 +/- 1.10/dish respectively, and the corresponding colony forming efficiency values were 66.1 +/- 7.68/10(3) cells and 64.8 +/- 4.46/10(3) cells. They were significantly lower than that of the control group. These results demonstrated that R8923 and RA could effectively inhibit 3-MCA and TPA induced malignant transformation of Balb/3T3-A31 cells and suggested that R8923 is a potential drug for cancer chemoprevention.

Sixteen p-substituted benzoylaminobenzoic acids and their methyl esters were synthesized, of which nine were not found in literature. All of the topic compounds were evaluated for their differentiation induction in activities of human promyelotic leukemia cells HL-60. Compounds III1, III2, III4, and III5 possessed potential activities. The differentiation rate, of III4 and III5 was 70% respectively. But it was less than that of retinoic acid (97%).

Nine kinds of antineoplastic agents and 2 boron-10 compounds were encapsulated respectively into the immunoliposomes targeted with monoclonal antibody, MGb2, against human gastric cancer. The immunoliposomes were characterized in vitro and in vivo with different nude mouse xenograft models and different routes of administration. The immunore activity was well preserved. The diameter was 100nm for reverse-phase evaporation vesicles and 35nm for small unilamellar vesicles. 1,000-10,000 molecules of antitumor agent were entrapped and 30-80 molecules of MGb2 incorporated per one liposome. They showed selective cytotoxicity to human gastric cancer cell SGC-7901 but very low toxicity to human normal embryonic lung cell SL7. Biodistribution studies indicated that both were better than non-specific liposomes and free drugs. Boronated immunoliposomes could carry boron-10 specifically to SGC-7901 and showed targeted boron neutron capture therapy effects after thermal neutron irradiation. The results confirmed the specific antitumor effects of immunoliposomes in vitro and in vivo and demonstrated the potentiality of the immunoliposomes in the targeting therapy of human gastric cancer.

Ten esters of cephalotaxine with amino acids possessing widely different structural features have been synthesized and tested for antitumor activity. Preliminary data showed that compound 6 is the most active one. However, it is still less potent than harringtonine. Other synthetic esters possess varying activities at 10 micrograms/ml. Preliminary structure activity relationship of these esters was discussed.

Bimolane, 1,2-bis(4-morpholinomethyl-3,5-dioxopiperazinyl) ethane, is a new antineoplastic agent synthesized first in China. The effects of bimolane on the rate of S phase cells, mitotic index, and cytokinesis in human peripheral blood lymphocytes cultured in vitro were studied by autoradiography with [3H]TdR and counting the number of mono- and multi-nucleated lymphocytes. Results showed that bimolane (5, 10, 20 micrograms.ml-1) inhibited the progression of cell cycle, so that the rate of S and M phases decreased. Bimolane inhibited cytokinesis, which formed bi- and multi-nucleated cells. The effects were concentration-dependent. Bimolane induced micronuclei in mono- and bi-nucleated lymphocytes. Our results indicate that bimolane is a cytotoxic and genotoxic agent.

In search for cancer chemoprevention agents, seven new amide compounds have been synthesized. The structures have been determined based on spectral and chemical data. N-4-(ethoxycarbophenyl)-alpha-naphthamide and N-4-(ethoxycarbophenyl)-beta-naphthamide were shown to be 81% and 79% effective, respectively, for inducing different in HL-60 human promyelocytic leukemia cells at the concentration of 10(-5) mol/L in NBT tests.

Organotin compounds were found to obviously inhibit the activity of phospholipid/Ca(2+)-dependent protein kinase (PKC) in rat brain tissue and the proliferation of tumor cell lines in vitro. The results showed that a correlation exists between the effects on PKC and anti-proliferative and antitumor activities. The structure-activity relationship was shown to be as follows: (1) R, the organic group determines the biological activity; (2) electronegativity of the halogen can affect the activity. The organotin compounds inhibit tumor cells by its [SnR2]2+, and inhibit G1-->S phases of HL-60 cell cycle. The IC50 of [SnPh2F2], [SnPh2(CysOS)].H2O and [SnPh2Cl2.phen(CH3)2] are respectively 25, 15 and 20 mumol.L-1 on PKC, 0.5, 4.0 and 0.3 mumol.L-1 on HL-60 cells, 2.7, 9 and 1.5 mumol.L-1 on BEL-7402 cells, 2.2, 15 and 5.0 mumol.L-1 on KB cells. But no induction of differentiation of leukemic cell lines HL-60 and K562 was observed.

The title compounds were synthesized by condensation of 5-fluoro- 2, 4, 6-triaminoquinazoline (6a) with various substituted benzaldehydes to produce the corresponding Schiff bases, followed by reduction. II and III were obtained by formylation and nitrosation of I, respectively, IV were obtained by reduction of II. Primary screening for suppressive therapeutic effects against P. berghei in mice showed that six of the twenty-two compounds produced 100% suppression when administered orally at a dose of 1 mg.kg-1. All compounds exhibited potent activity against L1210 cell in vitro. Among them I4 was more active than MTX. A number of compounds showed moderate activities against Diplococcus pneumoniae in vitro tests.

Harringtonine (HT) and homoharringtonine (HHT) are two alkaloids isolated from the bark of the evergreen tree Cephalotaxus hainanensis Li in the 1970s. They were found to have activity against murine leukemia, Lewis lung carcinoma and B16 melanoma, and used as anti-leukemia drugs clinically. Apoptosis is an active process of programmed cell suicide and now is believed to be an important target for tumor chemotherapy. In this report, the apoptosis inducing effect of HT and HHT in HL-60 cells were observed. The experiments demonstrated that 2 x 10(-7) mol.L-1 of HT and 10(-7) mol.L-1 of HHT could induce apoptosis in HL-60 cells when the cells were exposed to HT and HHT for 4 h. In agarose gel electrophoresis, DNA extracted from HL-60 cells treated with HT and HHT showed a typical internucleosomal DNA degradation, i.e., DNA ladder and parallel morphological changes as nuclear chromosome segmentation and condensation as well as cytoplasma vacuolation. This effect of HT and HHT was shown to appear in a concentration- and time-dependent manner. The efficacy of HT and HHT in inducing apoptosis of HL-60 cells was found to parallel with their cytotoxic activity in HL-60 cells. These results suggest that the mechanism of antitumor action of HT and HHT is related to their apoptosis inducing activity.

Antibiotic C3368-B (CB), identified as 3,9-dihydroxy-1-methoxy-7-methylanthraquinone, is produced by a fungus strain, Chrysosporium verrucosum Tubaki, isolated from a soil sample collected from Antarctica. CB was found to be a highly-active nucleoside transport inhibitor. By radiolabelled nucleoside assay, CB was shown to markedly inhibit thymidine and uridine transport in Ehrlich carcinoma cells, with IC50 values of 7.5 and 9.6 mumol.L-1 respectively. CB showed fairly low cytotoxicity to tumor cells. The IC50 values for epidermoid cancer KB cells and hepatoma BEL-7402 cells in clonogenic assay was 77 and 69 mumol.L-1. At relatively noncytotoxic concentrations, CB markedly enhanced the cytotoxicity of methotrexate, 5-fluorouracil, mitomycin C against KB cells and BEL-7402 cells. CB was also found to partly reverse the multi-drug resistance to vincristine and actinomycin D in leukemia L1210/MDR cells. The IC50 values were reduced by 4.9-fold (1.75 to 0.36 mumol.L-1) for vincristine and 3.3-fold (0.39 to 0.12 mumol.L-1) for actinomycin D. These results suggest that CB, as a newly-found nucleoside transport inhibitor, may be potentially useful in cancer chemotherapy.

Glycyrrhetinic acid (GA) is an active component of Glycyrrhiza uralensis Fisch. In this study, the effects of glycyrrhetinic acid on DNA damage and unscheduled DNA synthesis induced by benzo (alpha) pyrene were studied. Mouse ear edema was visible obviously at the 6th h after topical application of single dose croton oil. A topical application of croton oil on the back of ICR mice for 5 h, induced elevation of ornithine decarboxylase (ODC) activity in epidermal. The administration of glycyrrhetinic acid (50-200 mg.kg-1.d-1) to animals for 3 days exhibited 20%-80% inhibition of epidermal ornithine decarboxylase activity in a dose-dependent manner. Benzo (alpha) pyrene obviously caused DNA damage and unscheduled DNA synthesis mediated by S9 fraction in Chinese hamster lung cell line. Glycyrrhetinic acid was found to protect the rapid DNA damage induced by benzo (alpha) pyrene. At concentration of 5 micrograms.ml-1, glycyrrhetinic acid exhibited 70% protection. At 20 micrograms.ml-1, this action was more potent and approached to 80%. The addition of hydroxyurea 10 mmol.L-1 suppressed DNA replicative synthesis to 84.04% and benzo (alpha) pyrene stimulated the DNA repair synthesis (6-fold). Glycyrrhetinic acid (20 micrograms.ml-1 and 50 micrograms.ml-1 significantly decreased the stimulation of DNA repair synthesis induced by benzo (alpha) pyrene. This suggests that glycyrrhetinic acid has effective anti-initiating and anti-promoting activities and could be used for cancer chemopreventive purpose.

Lymphocytes from 28 untreated laryngeal cancer patients and 23 healthy controls were cultured in vitro and exposured to pingyangmycin (bleomycin A5), a clastogen. The lymphocytes were arrested in metaphase and analyzed. The total chromosome aberration rate, mean chromatid break rate per cell and cell aberration rate were 1.98% +/- 0.05%, 0.57% +/- 0.35%, and 42.8% +/- 12% respectively for laryngeal cancer patients. However, for healthy controls these values were 0.94% +/- 0.04%, 0.28% +/- 0.12%, and 27% +/- 12% respectively. Statistical analysis showed there are significant differences between the two groups. The data indicate that under our experimental conditions chromatid break rate 0.40 can be considered to be a borderline value, 0.80 hypersensitive value. For any individual, if the chromatid break rate is 0.40 or more, one should be ranked as having cancer risk. If 0.80 or more, then, highly cancer risk.

Human multidrug resistance gene (mdr1) was introduced into mouse embryonic stem cells (ES-5 line) by calcium phosphate mediated transfection, and transfected ES-5 cells were then selected by stepwise increase in colchicine concentration (30, 50, 100, and 200 ng/ml respectively). Finally, we obtained 4 clones that could be stably grown in culture medium with colchicine at 200 ng/ml and designated as ES-mdr1 clones A, B, C, and D. Southern blot analysis of DNA from ES-mdr1 A and D cells digested by Hind III and hybridized with mdr1 cDNA 5 A probe was shown in Fig. 3. Characteristic 4.8 and 2.4 kb fragments of mdr1 gene were found as expected and their amplification under increased concentration of colchicine in culture medium was also evident from the figure. Slot blot and Northern analysis of total RNA and poly A+ RNA extracted from ES-mdr1 cells were shown in Fig. 4 and 5, demonstrating that ES-mdr1 cells could express mdr1 mRNA. Indirect immunofluorescence analysis with antibodies against p170 glycoprotein indicated that p170 protein translated from mdr1 mRNA was present at the surface of ES-mdr1 cells (Plate I, Fig. 2). The biological characteristics of ES-mdr1 cells cultured in medium containing 200 ng/ml colchicine were investigated. The cells maintained their undifferentiated morphology and grew in nests (Plate I, Fig. 1), like the parental ES-5 cells. When ES-mdr1 cells were cultured in suspension in vitro, these cells were still capable of producing simple and cystic embryoid bodies. ES-mdr1 cells injected subcutaneously into 129 mice formed tumor-like outgrowths giving a great variety of cell types (Plate I, Fig. 4). These results indicated that the integration and expression of human mdr1 gene and selection against colchicine did not affect the pluripotency of ES-mdr1 cells both in vitro and in vivo. However, ES-mdr1 cells, unlike their parental ES-5 cells, could no longer be induced to differentiate by either RA or HMBA (Plate I, Figs. 3a, 3b), indicating that the human mdr1 gene transfected ES cells had changed their competence of inducible response to differentiation in vitro. The details and possible significance of such change require further studies. From the above preliminary data, we are of the opinion that ES-mdr1 cells may serve as a model to study the mode of action of p170 glycoprotein at cellular level and to screen possible means to counteract the action of mdr1 gene.(ABSTRACT TRUNCATED AT 400 WORDS)

The argyrophilic staining of nucleolar onganizer region (AgNOR), a simple colorimetric test, has been adapted for chemosensitivity testing of human gastric and colorectal cancers. Seven different chemotherapeutic agents were tested. The drug sensitivity was measured and compared according to the decrease rate of AgNOR granules between control tumor cells and tumor cells treated with antitumor drugs. Only 3 of 10 cases of advanced gastric carcinoma were sensitive to one antitumor agent. Most colorectal carcinoma cases (18/20) were sensitive to at least one antitumor agent. The sensitive sequence of antitumor agents we have had in this study was relative to clinic. The method and characteristics of AgNOR assay as a chemosensitivity test was introduced. It's value is being observed.

Clerodendrum B(I) at dosage of 100g/kg ip or sc for 7 days was shown to have antitumor effect on hepatic carcinoma and sarcoma 180 in mice. In the mean time, 100g/kg sc of (I) interrupted 3H-TdR incorporation into DNA of sarcoma 180 cells in mice, 100, 10g/kg sc of (I) could suppress the phagocytic activity of the peritoneal macrophage against the CRBC (chicken red blood cells) in mice, 100g/kg sc of (I) also made the production of serum hemolysin less than one half of that of the control in mice immunized with SRBC. Clerodendrum C at 100g/kg could inhibit the growth of hepatic carcinoma in mice.