Biomedical subjects

M Tabata

Publications and source records attributed to M Tabata.

314 records · Page 18Linked to original sources

PubMedDate not supplied

Effect of docetaxel with cisplatin or vinorelbine on lung cancer cell lines.

Docetaxel shows substantial activity against lung cancer. To find the optimal drug combination for docetaxel, we evaluated the effects of cisplatin, etoposide, mitomycin C, irinotecan, vindesine, and vinorelbine using three human lung cancer cell lines, ABC-1, EBC-1, and SBC-3. Drug cytotoxicity was determined by MTT assay. Tumor cells were incubated for 96 hours in the presence of docetaxel and each of the test drugs stated above. The combined drug interaction was evaluated by median-effect plot analysis and improved IC50-isobologram analysis. Both methods showed strong antagonism (subadditive or protective effect) between docetaxel and etoposide when tested on ABC-1 and EBC-1 cells. Docetaxel and cisplatin displayed additive effects on all cell lines tested, when evaluated by improved IC50-isobologram analysis. The combination of docetaxel and vinorelbine exerted synergistic effect on the growth inhibition of SBC-3 cells, which showed a wide range of fractional cytotoxicity when analyzed by median-effect plot and supraadditive when analyzed by improved IC50-isobologram. These observations suggest a possibility that docetaxel can be used in combination with vinorelbine or cisplatin in the treatment of lung cancer.

Antineoplastic Combined Chemotherapy Protocols↗

PubMedDate not supplied

In vitro evaluation of antimicrotubule agents in human small-cell lung cancer cell lines.

BACKGROUND: The improvement of treatment outcome of small-cell lung cancer (SCLC), and search for new effective drugs and to overcome drug-resistance are essential. MATERIALS AND METHODS: We evaluated the cytotoxicity of antimicrotubule agents to seven human SCLC cell lines consisting of one cell line (SBC-3) established from a previously untreated patient as a representative of drug-sensitive cell line, three cell lines (SBC-2, SBC-4, and -7) derived from treated patients as representatives of intrinsic drug-resistance cell lines, and three drug-resistant sublines (SBC-3/ADM, SBC-3/ETP, and SBC-3/CDDP) selected by continuous exposure of the SBC-3 cell line to increasing concentrations of doxorubicin, etoposide, or cisplatin as representatives of acquired drug-resistant cell lines. RESULTS: IC50 values for SBC-2, -3, -4, and -7 cells of antimicrotubule agents were markedly lower than those of doxorubicin, etoposide, and cisplatin. Both SBC-3/ADM and SBC-3/ETP subline were highly resistant to paclitaxel, docetaxel, vinorelbine, vincristine, vindesine, and vinblastine. However, an SBC-3/ADM subline was not fully cross-resistant to rhizoxin, and an SBC-3/ETP subline was as sensitive to rhizoxin as an SBC-3 cell line. A cisplatin-resistant subline, SBC-3/CDDP, showed no cross-resistance to the antimicrotubule agents. CONCLUSION: These results suggest that antimicrotubule agents are useful for SCLC, and rhizoxin may be particularly effective in the salvage treatment of refractory or relapsed patients.

Antibiotics, Antineoplastic↗

PubMedDate not supplied

Morphology of the designed biodegradable cisplatin microsphere.

We observed the morphological changes in microspheres containing cisplatin (CDDP) embedded in poly-d,l,-lactic acid (PLA) and polyethylene glycol acid (CDDP-PPMS). The in vitro release of CDDP from CDDP-PPMS continued for more than four weeks. Scanning electron microscopy revealed that though the particles of CDDP-PPMS were spherical and superficially smooth, small pores with a superficial irregularity appeared six months later. CDDP-PPMS particles were found in the stomata of the omentum after intraperitoneal administration. When CDDP-PPMS was administered after Yoshida sarcoma cells were intraperitoneally transplanted, CDDP-PPMS was observed histologically in the necrotic tissues of the omentum. These experimental results confirmed the release of CDDP from CDDP-PPMS and the histological efficacy of CDDP-PPMS in the omentum against peritoneal metastasis.

Animals↗

PubMedDate not supplied

Detection of occult tumor cells in peripheral blood from patients with small cell lung cancer by reverse transcriptase-polymerase chain reaction.

The reverse transcriptase-polymerase chain reaction (RT-PCR) of tumor-specific or -associated genes is a sensitive assay for detecting a minimal number of tumor cells in peripheral blood (PB) or bone marrow (BM). In this study, we determined whether mRNA of bombesin receptors is detectable in PB or peripheral blood progenitor cell (PBPC) samples from patients with small cell lung cancer. Among three bombesin-like peptide receptors, we used the neuromedin B receptor (NMB-R) gene as a target, because of the most frequent expression on SCLC cell lines. The lower limit of detection was one tumor cell in one million normal PB cells and there was no detection in normal PB or BM cells unlike a cytokeratin 19 gene. The NMB-R gene was detected in 14 (31.8%) of 44 PB samples from patients with SCLC at diagnosis and 2 (15.4%) of 13 samples of PBPC collected during a recovery phase after chemotherapy followed by administration of G-CSF (filgrastim). At diagnosis, patients whose PB was positive for the NMB-R gene had a significantly shorter survival than those who were negative. Our observation suggests that this assay may be useful in diagnosing metastatic disease and monitoring minimal residual disease in patients with SCLC.

Aged↗

PubMedDate not supplied

The production of antraquinones in callus cultures of Cassia tora.

Callus cultures were extablished from the seedlings of Cassia tora on a chemically defined medium supplemented with 2, 4-D and kinetin. A phytochemical investigation of callus tissues demonstrated the presence of chrysophanol, emodin, physcion, and an unidentified pigment, all of which are contained in the seeds of the original plant. The maximum content of antraquinones on a fresh weight basis was 0.334 percent, which is higher than the content of total anthraquinones in the dry seeds. Furthermore, it was shown that the production of these compounds is influenced by the concentrations of auxin and cytokinin supplied to the culture medium.

2,4-Dichlorophenoxyacetic Acid↗

PubMedDate not supplied

Small cell lung cancer can express CD34 antigen.

In humans CD34 is a valid and reliable marker for hematopoletic stem and progenitor cells. In general, solid tumors, with the exception of endothelial cancers, do not express CD34. Accordingly, immunological selection of CD34+ hematopoietic stem/progenitor cells can be used to remove CD34- malignant cells in the setting of autotransplantation. To rule out CD34 expression on tumor cells from small cell lung cancer (SCLC), eleven SCLC cell lines were analyzed by flow cytometry. Interestingly, two of these were positive for CD34 and their expression of full-length CD34 was further confirmed by reverse transcriptase and polymerase chain reaction (RT-PCR). This finding indicates that prior to subjecting SCLC patients to the above treatment modality, preparing CD34+ hematopoietic stem/progenitor cells from SCLC patients for autotransplantation, CD34 expression on their tumor cells should be screened using immunohistochemistry and/or flow cytometry.

Antigens, CD34↗

PubMedDate not supplied

Cisplatin-resistant human small cell lung cancer cell line shows collateral sensitivity to vinca alkaloids.

A cisplatin-resistant cell line, SBC-3/CDDP, was established from a human small-cell lung cancer cell line, SBC-3. The SBC-3/CDDP cells were 13.1-fold more resistant to cisplatin than the parent SBC-3 cells. We investigated the cellular changes of this cell line with regard to the development of resistance to cisplatin. The SBC-3/CDDP cells showed various characteristics as follows: a) increased intracellular glutathione and glutathione S-transferase content b) decreased intracellular accumulation of cisplatin, c) increased topoisomerase I activity and the same topoisomerase II activity as the parent SBC-3 cells, and 4) strong cross-resistance to the platinum analogues and mitomycin C, moderate cross-resistance to 7-ethyl-10-hydroxy-camptothecin (SN-38), 4-hydroperoxy cyclophosphamide, etoposide, Adriamycin and methotrexate, and collateral sensitivity to vinca alkaloids and 5-fluorouracil. From these observations, the SBC-3/CDDP cells could be useful as a well characterized cisplatin-resistant cell line, and the resistance pattem in this cell line will give us much information for eradication of cisplatin-resistant tumor cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMedDate not supplied

An alteration of ganglioside composition in cisplatin-resistant lung cancer cell line.

Previously we established cell lines resistant to Adriamycin and cisplatin to elucidate the mechanisms involved in acquired drug-resistance. In this study, we investigated ganglioside composition in drug-resistant cell lines. The Adriamycin-resistant cell line, SBC-3/ADM100, exhibited a ganglioside composition ratio similar to that of the parent SBC-3 cells. Densitometric analysis by resorcinol showed a 1.61-fold increase of ganglioside GM2 in SBC-3/ADM100 cells, when compared to the parent SBC-3 cells. The cisplatin-resistant cell line, SBC-3/CDDP, showed a simplified ganglioside pattern, expressing only gangliosides GM3 and GM2. SBC-3/CDDP cells showed a marked increase in ganglioside GM3. These findings suggest that the alteration of ganglioside composition may be actively involved in the acquisition of drug-resistance.

Antineoplastic Agents↗