pirarubicin and thiazolyl-blue

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various tumor cells. The anthracycline doxorubicin (DOX) can sensitize several types of cancer cells to TRAIL-mediated apoptosis. Here we report that DOX enhances TRAIL-induced apoptosis and cytotoxicity against prostate cancer cells. Cytotoxicity was determined by a MTT assay. Synergistic effect was assessed by isobolographic analysis. Caspase activity was determined by a quantitative colorimetric assay. The combination treatment with DOX and TRAIL resulted in a synergistic cytotoxic effect on LNCaP, LNCaP-Bcl-2, PC-3, and PC93 human prostate cancer cell lines, but not on normal human prostatic stromal cells. Synergistic cytotoxicity was also obtained even when the exposure time was shortened from 24 to 8 or 2 h. A similar effect was achieved with TRAIL in combination with epirubicin, pirarubicin, or amrubicin. The synergy obtained in cytotoxicity with TRAIL and DOX was also achieved in apoptosis. DOX treatment significantly activated caspase-8, -6, and -3 in LNCaP cells. Furthermore, the synergistic cytotoxicity of TRAIL and DOX was completely inhibited by Z-VAD-FMK, and partly inhibited by Ac-IETD-CHO, Ac-DQTD-CHO, or Ac-DMQD-CHO. These findings indicate that DOX enhances TRAIL-induced apoptosis and cytotoxicity in prostate cancer by activation of caspase cascades, and suggest that TRAIL in combination with DOX have a therapeutic potential in the treatment of prostate cancer.

Topics: Acridine Orange; Anthracyclines; Antibiotics, Antineoplastic; Apoptosis; Apoptosis Regulatory Proteins; Caspase 3; Caspase 6; Caspase 8; Caspase 9; Caspases; Coloring Agents; Dose-Response Relationship, Drug; Doxorubicin; Epirubicin; Humans; Immunohistochemistry; Male; Membrane Glycoproteins; Prostatic Neoplasms; Recombinant Proteins; Tetrazolium Salts; Thiazoles; Time Factors; TNF-Related Apoptosis-Inducing Ligand; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

There is no well-defined curative treatment for advanced and unresectable hepatocellular carcinoma. The widely used transarterial chemoembolization (TACE) with a doxorubicin-Lipiodol emulsion has not been shown to improve survival in randomized studies. Further, obstruction of the hepatic artery used in the procedure is badly tolerated in patients with cirrhosis. Drugs with a more rapid penetration into the cancer cells are likely to eliminate the need for obstruction of the hepatic artery. We therefore compared the cytotoxicity of another anthracycline pirarubicin with that of the commonly used doxorubicin. In this report, we show that pirarubicin has a greater in vitro cytotoxic effect than doxorubicin on the HepG2 and Hu-H7 human hepatoma cell lines. Pirarubicin emulsion with Lipiodol is more stable at 37 degrees C than doxorubicin-Lipiodol. Moreover, pirarubicin accumulates at a greater extent in the oil phase, permitting Lipiodol to act as a slow-releasing vector for the anthracycline. Further, amiodarone, a multidrug resistance inhibitor, was shown to decrease the intrinsic resistance of HepG2 and Hu-H7 cells to both anthracyclines, and the presence of polysorbate 80 in the amiodarone preparation increased the stability of the anthracycline-Lipiodol emulsions. We therefore conclude that pirarubicin is a better candidate for TACE than doxorubicin. The rapid and increased cytotoxicity of pirarubicin on hepatoma cancer cells and the stability of the pirarubicin-Lipiodol amiodarone emulsion could avoid the complete obstruction of the hepatic artery by Gelfoam sponges, and provide a better tolerated method of TACE in patients with latent liver insufficiency.

Topics: Amiodarone; Antibiotics, Antineoplastic; Carcinoma, Hepatocellular; Chemoembolization, Therapeutic; Chromatography, High Pressure Liquid; Doxorubicin; Drug Resistance, Multiple; Drug Stability; Emulsions; Enzyme Inhibitors; Humans; Iodized Oil; Liver Neoplasms; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured

The effect of the anti-tuberculosis drug rifampicin on pirarubicin activity was investigated in multidrug-resistant cells overexpressing P-glycoprotein. Rifampicin increased the sensitivity of pirarubicin to anthracycline-resistant mouse leukemic P388 cells and significantly enhanced the cytotoxicity and intracellular accumulation of pirarubicin in resistant cells, but had no effect in parent cells. By contrast, two other rifamycins, rifamycin B and SV, had no effect on pirarubicin accumulation in resistant cells. Rifampicin also enhanced pirarubicin-induced apoptosis and G2/M blockade on the cell cycle in resistant cells. These results show that rifampicin enhances the cytotoxic action of pirarubicin in resistant cells, at least partly via the inhibition of cellular pirarubicin efflux.

Topics: Animals; Antibiotics, Antineoplastic; Antibiotics, Antitubercular; Apoptosis; Cell Cycle; Doxorubicin; Drug Resistance, Multiple; Drug Synergism; Gene Expression Regulation, Neoplastic; Genes, MDR; Leukemia P388; Mice; Rifampin; Tetrazolium Salts; Thiazoles

In vitro MTT assay was applied for examining chemosensitivity with 104 samples; 56 primary tumors, 31 lymph node, 9 liver, and 8 peritoneal metastases, obtained from 87 patients with advanced gastric carcinoma. The rate of effectiveness of various anticancer drugs were as follows; etoposide, 87.7%; cisplatin, 55.1%; mitomycin C, 51.5%; pirarubicin, 50.0%; aclarubicin, 48.8%; carboquone, 31.8%; doxorubicin, 20.3%; and 5-fluorouracil, 12.9%. Etoposide was found to be most effective against gastric carcinoma in this test. Concerning with the metastatic lesions, liver metastases were resistant to all tested drugs. On the other hand, peritoneal metastases were sensitive to etoposide, mitomycin C, and pirarubicin. The results indicate heterogeneity of the chemosensitivity between primary and metastatic lesions, and it was supposed that etoposide might be useful against human gastric cancer.

Topics: Antineoplastic Agents; Carbazilquinone; Cisplatin; Doxorubicin; Drug Screening Assays, Antitumor; Etoposide; Fluorouracil; Humans; Mitomycin; Mitomycins; Stomach Neoplasms; Tetrazolium Salts; Thiazoles; Tumor Cells, Cultured