Establishment and characterization of an etoposide-resistant human small cell lung cancer cell line.

An etoposide-resistant subline, SBC-3/ETP, from a human small cell lung cancer cell line, SBC-3, was developed by continuous exposure to increasing concentrations of etoposide in culture. The SBC-3/ETP was 52.1-fold more resistant to etoposide than the parent cell line. The SBC-3/ETP was highly cross-resistant to teniposide, adriamycin, vinca alkaloids, 4-hydroperoxycyclophosphamide, CPT-11 and mitomycin C, and marginally cross-resistant to cisplatin, while the subline showed a collateral sensitivity to bleomycin. Topoisomerase I activity in the SBC-3/ETP was reduced to an extent of one half and topoisomerase II activity to an extent of one eighth in comparison with those of the SBC-3. Intracellular accumulation of [3H]-etoposide in the SBC-3/ETP was significantly lower in comparison to the SBC-3. An overexpression of MDR1 mRNA, and the presence of its product, P-glycoprotein, were detected in the SBC-3/ETP by Northern blotting and flowcytometry using a monoclonal antibody of the protein, MRK16. These results indicate that a decreased activity of topoisomerase II is the major factor for the development of etoposide resistance, and that an overexpression of the MDR1 gene is responsible, in part, for the development of resistance to the drug and some structurally unrelated compounds such as adriamycin and vinca alkaloids.</p

Triplet Chemotherapy with Cisplatin, Docetaxel, and Irinotecan for Patients with Recurrent or Refractory Non-small Cell Lung Cancer

We examined the feasibility of triplet chemotherapy using cisplatin, docetaxel, and irinotecan for patients with recurrent or refractory non-small cell lung cancer (NSCLC), retrospectively. Twenty-five patients (21 men and 4 women) with NSCLC and good performance status who were &#60;70 years old were analyzed. The median age was 58 years. Most patients had performance status 1 (16/25), stage IV disease (18/25) and adenocarcinoma-histology (16/25). Cisplatin and docetaxel were given on day 1 and irinotecan on day 2;the cycle was repeated every 3 weeks. The objective response rate was 39.1% (95% confidence interval:18.7-59.5%). The median survival time and actual 2-, 3-, and 5-year survival rates were 14.3 months, 32%, 20%, and 8%, respectively. Of note, only 6 patients were treated with gefitinib at the recurrence after triplet chemotherapy;of these, 4 (67%) achieved a partial response, which might result in favorable survival. Grade 3/4 toxicities consisted of neutropenia (100%), neutropenic fever (56%), nausea/vomiting (40%), and diarrhea (16%);no cases of treatment-related death occurred. Triplet chemotherapy showed impressive survival data in our clinical trial, but proved too toxic for use in treating patients with NSCLC in the clinical practice.</p

Is Adenosine Deaminase in Pleural Fluid a Useful Marker for Differentiating Tuberculosis from Lung Cancer or Mesothelioma in Japan, a Country with Intermediate Incidence of Tuberculosis?

The objective of this study was to evaluate the utility of the determination of adenosine deaminase (ADA) level in pleural fluid for the differential diagnosis between tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) in Japan, a country with intermediate incidence of tuberculosis (TB). We retrospectively reviewed the clinical records of 435 patients with pleural effusion and investigated their pleural ADA levels as determined by an auto analyzer. ROC analysis was also performed. The study included patients with MPE (n＝188), TPE (n＝124), benign nontuberculous pleural effusion (n＝94), and pleural effusion of unknown etiology (n＝29). The median ADA level in the TPE group was 70.8U/L, which was significantly higher than that in any other groups (p＜0.05). The area under the curve (AUC) in ROC analysis was 0.895. With a cut-off level for ADA of 36U/L, the sensitivity, specificity, positive predictive value, and negative predictive value were 85.5%, 86.5%, 69.7%, and 93.6%, respectively. As many as 9% of patients with lung cancer and 15% of those with mesothelioma were false-positive with this ADA cutoff setting. Although the ADA activity in pleural fluid can help in the diagnosis of TPE, it should be noted that some cases of lung cancer or mesothelioma show high ADA activity in geographical regions with intermediate incidence of TB, in contrast to high prevalence areas

Design of Picosecond Modelocked Nd : YAG Laser

Infrared picosecond puIse trains(～7 ns pulse separation) have been obtained from a passive modelocked Nd : YAG laser, Modelocking is achieved by a saturable absorber dye(NDL l12)in 1,2-dichloroethane. The pulse duration is measured by TPF technique to be～30 ps. The efficiency with which energy is transfered from a lamp to the Nd : YAG rod is determined by the delay time of emission from a krypton flashlamp. By varying the impedance characteristics of the krypton flashlamp, the optimum delay time (～105 μs) is obtained. In order to generate the stable picosecond pulse ( ～3 percent fluctuation), the output voltage fluctuation of Power supply must be held within ～2 percent. The SHG (532 nm) and the THG (355 nm) of picosecond pulses from the Nd : YAG laser were also obtained by using KDP(KH₂ P0₄)crystals of Type I and Type II Phase-matching, respectively

Recurrent superior mediastinal primary hemangiopericytoma 23 years after the complete initial excision: a case report.

We describe here a patient with a recurrent hemangiopericytoma of the superior mediastinum 23 years after an initial complete resection. In the current biopsy specimen, the tumor cells were much more anaplastic than those seen 23 years ago. Although the patient was treated with chemotherapy, which consisted of ifosfamide and epirubicin, the tumor was unresponsive and he died 6 months later from disease progression. Careful long-term follow-up is mandatory for patients with hemangiopericytomas because recurrence with greater malignancy can develop following an extended disease-free interval.</p

Neural cell adhesion molecule expression and clinical features in small cell lung cancer: a semi-quantitative immunohistochemical approach using an immunogold-silver staining method.

The neural cell adhesion molecule (NCAM) is a family of cell surface sialoglycoproteins mediating homotypic and heterotypic cell-cell adhesion. In tumors, NCAM is supposed to be involved with the malignant features characterized by invasive growth and metastasis. In the present study, we evaluated the correlation between NCAM expression of tumors obtained from small cell lung cancer (SCLC) patients and the clinical outcome. NCAM expression was determined semi-quantitatively by an immunogold-silver staining method using the SCLC cluster 1 monoclonal antibody NCC-LU-243. Of 20 SCLC patients studied, six patients with tumors with high NCAM expression had a poor response to chemotherapy, and a short disease-free (p = 0.011) and overall (p = 0.003) survival as compared with 14 patients having tumors with low NCAM expression. These findings indicate that the therapeutic outcome of SCLC may be partly predicted by determining the NCAM expression of the tumor.</p

Comparison of chemosensitivity tests: clonogenic assay versus MTT assay.

When the development of chemotherapeutic agents reaches the clinical trial stage, it is necessary to perform drug sensitivity tests quickly in order to select the most promising agents for the treatment of cancer. In order to assess the possibility of using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay as a substitute for the human tumor clonogenic assay (HTCA), we evaluated the correlation between the results obtained by these 2 assays in 5 human lung cancer cell lines. The correlation coefficient between the results of the HTCA and the MTT assay was 0.673, indicating a relatively good correlation. The correlation was most prominent in platinum analogues (r = 0.939) and good in anthracyclines/anthracenedione (r = 0.611). However, no significant correlation was observed in vinca alkaloids, etoposide, irinotecan, SN-38 (an active metabolite of irinotecan), and rhizoxin. The results of the MTT assay showed a high degree of correlation with those of the HTCA in predicting the sensitivity of cancer cell lines to platinum analogues, and anthracyclines/anthracenedione. These results suggest that the MTT assay may be more convenient and quickly performed than the HTCA and can replace HTCA in evaluating the effects of anticancer agents, especially the platinum analogues and anthracyclines/anthracenedione.</p

MDR1 gene expression and treatment outcome in small cell lung cancer: MDR1 gene expression as an independent prognostic factor.

We report a preliminary study to determine whether MDR1 gene expression level in small cell lung cancer (SCLC) tumors is a useful predictor of tumor response to chemotherapy and patient survival in association with myc amplification in the tumor. We analyzed 18 patients with SCLC receiving adriamycin and etoposide combination chemotherapy between August 1989 and November 1991; 16 males and 2 females, median age of 68 years, and 7 with limited disease and 11 with extensive disease. MDR1 mRNA expression level and myc family gene amplification were simultaneously determined by polymerase chain reaction using transbronchial biopsy specimens which were obtained at diagnosis. Patients with tumors expressing low MDR1 mRNA responded more favorably to chemotherapy than those with tumors expressing high MDRI mRNA, however, the difference in tumor response was statistically not significant (84.6% versus 40%). The overall survival was significantly shorter in the latter than in the former (7.2 months versus 11.7 months; p = 0.023). The survival of the 4 patients with tumor showing myc family gene amplification was almost identical to that of patients with tumors showing no amplification of the gene (8.2 months versus 8.8 months; p = 0.73). Multivariate Cox's regression analysis supports the notion that MDR1 may be a useful independent prognostic factor.</p

Comparison of antitumor activity of new anthracycline analogues, ME2303, KRN8602, and SM5887 using human lung cancer cell lines.

In an attempt to predict the clinical activity of newly developed anthracycline analogues, ME2303, KRN8602, and SM5887 in the treatment of lung cancer, we compared antitumor activity of these drugs with that of adriamycin, using six human lung cancer cell lines and two drug-resistant human lung cancer sublines. Taking the pharmacokinetic data into consideration, we evaluated the relative antitumor activity: the ratio of area under the concentration-time curve of each drug to the 50% inhibitory concentration of the drug. Regarding this ratio, ME2303 was more potent than adriamycin, SM5887, and KRN8602. Cross-resistance of the new analogues to adriamycin was investigated using an adriamycin-resistant small cell lung cancer subline, SBC-3/ADM100 and an etoposide-resistant subline, SBC-3/ETP. SBC-3/ADM100 being 106-fold more resistant to adriamycin than the parent SBC-3 showed less resistance to the analogues: 1.80-fold to KRN8602, 3.80-fold to SM5887, and 8.60-fold to ME2303. SBC-3/ETP which was 52.1-fold more resistant to etoposide and 39.5-fold more resistant to adriamycin were also less resistant to the new analogues: 3.27-fold to KRN8602, 9.07-fold to SM5887, and 17.3-fold to ME2303. In conclusion, ME2303 was found to be the most potent agent among drugs tested for the treatment of lung cancer, and KRN8602 can be expected to be beneficial for the treatment of drug-resistant small cell lung cancer.</p