The anti-invasive and anti-metastatic effects with new retinoid 4-acetamidophenyl retinoate (4-APR) were studied using in vitro and in vivo experiments. 4-APR, at the dose of 43.3 mg.kg-1.day-1 p.o., was shown to reduce the spontaneous lung metastatic foci of Lewis lung carcinoma. 4-APR was also found to inhibit the artificial lung metastasis of B16-F10 cells by 67.9% and 36.6% and suppress the reconstituted basement membrane invasion of B16-F10 cells by 54.2% and 41.9% at the concentrations of 10(-5) mol.L-1 and 10(-6) mol.L-1, respectively.

C1027, composed of an enediyne chromophore and an apoprotein of 110 amino acid residues, is a new highly potent macromolecular antitumor antibiotic. In order to prepare monoclonal antibodies (McAb) against C1027 by hybridoma technique, natural C1027 was inactivated by ultraviolet and coupled with human serum albumin, then immunized BALB/c mice. After cell fusion and screening by ELISA, a hybridoma secreting anti-C1027 McAb designated as F9 was obtained. McAb F9 specifically reacted with C1027 as determined by immunoblot assay. No obvious difference was observed between the reactivity of McAb F9 to natural C1027 and that of McAb F9 to ultraviolet inactivated C1027. This result indicates that the ultraviolet-sensitive chromophore of C1027 may not participate in the epitope for McAb F9. The isotype of F9 is IgG1 and its affinity constant was found to be (2.2 +/- 0.47) x 10(7) L.mol-1 according to Beatty's method. By clonogenic assay, McAb F9 neither affected the cytotoxicity of C1027 to KB cells nor blocked the activity of the chromophore. McAb F9 also specifically reacted with the recombinant truncated C1027 apoprotein in which 16 amino acid residues at the C terminus were deleted. This study suggests that F9 is a valuable McAb for the research of C1027 apoprotein engineering, C1027 related immunoconjugates and screening of new macromolecular antitumor substances with homology to the protein part of C1027.

Methotrexate(MTX) and the methotrexate-alpha-peptides(MTX-alpha-phenylalanine and MTX-alpha-arginine i.e. MTX-alpha-Phe and MTX-alpha-Arg) were prepared with the technique of solid-phase peptide synthesis. Its purity was verified as a single peak by HPLC and its molecular weight was measured by mass spectrometry. MTX-alpha-Phe could be hydrolyzed to MTX by carboxypeptidase A. The cytotoxic effect of released MTX was found to be 100 times stronger than that of the peptide in vitro. It is suggested that MTX-alpha-Phe is a satisfactory prodrug in the treatment of cancer.

To formulate criteria of judjing multidrug resistance gene(mdr-1 gene) expression level and to provide basis for predicting chemotherapy response and prognosis.

In order to search for tumor cells apoptosis inducer, the apoptosis effects and mechanism of tea polyphenols were studied. Tea polyphenols is an active compounds purified from tea. The apoptosis effects of tea polyphenols were observed on the human gastric carcinoma cells (MGC) by MTT reduction test, DNA agarose gel electrophoresis and transmission electron microscopy (TEM) technique. Having been treated by tea polyphenols in 125 micrograms.ml-1 for 24 h, DNA extracted from MGC cells showed a typical internuclesosomal DNA degradation, i.e., DNA ladder and apoptotic vehicles were observed under TEM. The effects of tea polyphenols were shown to parallel with its cytotoxic activity in MGC cells. These results suggest that the mechanism of antitumor action of tea polyphenols is related to its apoptosis inducing activity.

To explore an anti-tumor effect of indomethacin on human colon adenocarcinoma cell line HCT116, and its mechanism.

A human lung cancer cell line (A549) mutant with hypoxanthine guanine phosphoribosyltransferase (HGPRT) deficiency and resistance to 8-AG was established by treatment of the A549 cells with 3 micrograms.ml-1 N-methyl-N'-nitro-nitrosoguanidine (MNNG), and prescreened in 0.25% agarose DMEM semisolid medium containing 20 micrograms.ml-1 8-AG. The mutant cells are resistant to cytotoxic effect of 8-AG and sensitive to hypoxanthine-aminopterin thymidine (HAT) selective medium. The mutant cells can be used as a candidate parental cells to fuse with the somatic cells.

A negative selection system for glioma gene therapy was established in vitro. C 6 rat glioma cells were infected with recombined retrovirus which contain Escherichia coli cytosine deaminase (EC-CD) gene. The enzyme CD can transform the non-toxic prodrug 5-Fluorocytosine (5-FC) to the highly cellular toxic compound 5-Fluorouracil (5-FU). The growth inhibition studies proved that CD-positive cells were highly sensitive to 5-FC, the IC50 about 3 mumol/L, compared with an IC50 of approximately 6000 mumol/L in parental C 6 cells. Both CD-positive and negative cells were sensitive to 5-FU at very low concentration (IC50 < 1 mumol/L). Mixed cellular assay showed CD-positive cells had "bystander effect" on CD-negative cells when exposed to 5-FC. Our results demonstrate that EC-CD gene should be an efficient suicide gene for the treatment of glioma.

The aim of this study was to find out the anti-cancer activity of Tanshinone and its mechanism of action. Human hepatic carcinoma cell line (SMMC-7721) and leukemia cell line (HL60) were treated with tanshinone the cancer cell proliferation indices were measured by Brdu Labeling and immuno-histochemical stain of PCNA. The Brdu labeling rates of human hepatic carcinoma and leukemia cells treated with tanshinone were 8.95% and 19.01%, which were lower than those of controls (28.0%, 25.57%) respectively (P < 0.01), PCNA positive rates were 57.0% and 30.32%, which were significantly lower than those of controls (74.3%, 47.05%) (P < 0.01). The results indicate that Brdu labeling and PCNA detection may have important utility in the studies of tumor cell proliferation and the relative factors affecting the cell proliferation. The inhibitory effect of tanshinone on cancer cell proliferation might be associated with inhibiting DNA synthesis, PCNA expression and activity of DNA polymerase delta of the tumor cells.

Agarose gel electrophoresis and spectroscopy were used to investigate the interaction of AD-89 with DNA. The effect of drug on intact cell DNA was evaluated by using alkaline elution technique. The results showed that AD-89 decreased the mobility of supercoiled PUC9 DNA significantly. The interaction of calf thymus DNA with AD-89 led to the red shift of the peaks of absorption, and the greater the ratio of DNA/AD-89 was the greater the red shift would be. These results are similar to those of mitoxantrone (DHAQ) and thus suggest that AD-89 is an intercalator. The results of alkaline elution showed that AD-89 produced single-strand breaks at high dose. In contrast to DHAQ, AD-89 did not produce protein-associated breaks. AD-89 produced significantly DNA interstrand cross-linking at 5 and 10 mumol/ L. It also produced DNA protein crosslinks. These results demonstrate that AD-89 is an intercalator and can produce DNA interstrand cross-linking.

From July 1994 to June 1995, a prospective multicenter phase III clinical trial was conducted to evaluate the efficacy of Injectio Emulsioni Elemeni in the management of malignant effusions. Four hundred and eighty-four patients, including 313 with pleural effusion and 171 with peritoneal effusion, were evaluable. The drug was administered in 0.5% emulsion, with a dosage of 200 mg/m2 for intrapleural injection once every week for 1-2 weeks and 300-400 mg/m2 for intraperitoneal injection once or twice every week for 2 weeks. The response rates were 77.6% in patients with malignant pleural effusion, 66.1% in patients with peritoneal effusion. There were no bone marrow, liver, cardiac and renal toxicities; while fever, local pain and gastro-intestinal reaction were the major adverse effects. It is concluded that Elemenum emulsion is one of the active agents in the management of malignant effusions.

In this experiment, the sensitivity of human osteosarcoma cells to various concentration gradients of HDMTX, VCR, CBP, MMC, VP16, PMB and their time-effect relationship were examined in vitro with MTT assay among 23 cases' fresh osteosarcoma (OS) tissues. It was found that OS was sensitive to MMC and PMB when the drug concentrations were equal to the calculated in vivo drug concentrations. When the concentrations were 5 times as high as those of the calculated in vivo concentrations, OS was sensitive to HDMTX, CBP, MMC and PMB. The positive rates of sensitivity were highest in 72 hours with an average of 55.1%.

The relationship between the effect of retinoic acid (RA) on the growth of breast cancer cell and their estrogen receptor (ER) status as well as the relationship between RA effect and the expression of retinoic acid receptorsd (RAR alpha) were studied by cell growth assay, Northern Blot and gene transfection. It was found that RA could only inhibit the growth of ER-positive but not ER-negative breast cancer cells. RAR alpha mRNA level was significantly higher in ER-positive breast cancer cell lines than that in ER-negative breast cancer cell line. The expressions of other subtypes of RAR in ER-positive cells were not significantly different from those in ER-negative ones. When, RAR alpha cDNA was introduced and ixpressed in RA-resistant, ER-negative MDA-MB-231 breast cancer cell line, its growth was strongly inhibited by RA. These results indicate that RAR alpha plays a major role in the retinoi-dmediated inhibition of growth in human breast cancer cells.

To study the internalization law of immunotargeting drug for hepatocellular carcinoma and its significance.

To detect DNA damage caused by fotemustine (Fot).

Using Video Enhancement Contrast (VEC) microscopy, we recorded the morphological changes of same HL-60 cell in the processes of apoptosis induced by harringtonine. Our results show that all of apoptotic cells need several nucleus blebs before their chromatin condensation. Every nucleus bleb is induced by a relative membrane bleb. The number of membrane blebs is much higher than that of nucleus blebs, so there are only some of membrane blebs which can induce nucleus blebs. It suggested that membrane and nucleus blebs probably are related to apoptotic chromatin condensation. After HL-60 cells pretreated with cytochalasin B(CB), apoptotic chromatin condensation delayed eight hours, but no membrane bleb, nucleus bleb and apoptotic body formed eventually. So membrane and nucleus blebs during apoptosis are related to microfilament re-organization and can accelerate apoptotic chromatin condensation, but are unnecessary for apoptotic chromatin condensation. All this suggested that nuclear changes and cytoplasmic changes during HL-60 cell apoptosis are independent.

Vitamin A and its analogus, the retinoids, are agents that are known to induce differentiation and inhibit growth on cell in vitro and in vivo. These agents show promise as prophylactic and therapeutic ones in human cancer and were noted extensively by scholars abroad, but the research has just been developed in recent years in our country. Retinamide (named briefly R II), a kind of new retinoids made in China, can induce differentiation and inhibit growth of cell, but its toxic effect is smaller than its maternal chemical compound (retinoic acid). Using automatic image analysis technology, polyacrylamide gel LDH isoenzyme electrophoresis, radioimmunoassay and condensing reaction of Con A, we have observed induction of differentiation of the R II on SGC-7901 cells. Our experiments indicate that R II can inhibit cell proliferation, decrease obviously average DNA content and nuclear area, reduce CEA secretion and condensing of the cells, and change LDH isozymoraphy of SGC-7901 cell with promoting H-type LDH and reducing M-type LDH. The change of morphology under light microscope by R II showed that the cells spread, flattened and partially lined up, and the alkalophilic quality of cytoplasm became weak. These results suggest that SGC-7901 cell under the action of R II should undergo the changes of reverse differentiation in morphological, physiological and bio-chemical aspects.