Association of immunoglobulin G4 and free light chain with idiopathic pleural effusion.

The cause of pleural effusion remains uncertain in approximately 15% of patients despite exhaustive evaluation. As recently described immunoglobulin (Ig)G4-related disease is a fibroinflammatory disorder that can affect various organs, including the lungs, we investigate whether idiopathic pleural effusion includes IgG4-associated etiology. Between 2000 and 2012, we collected 830 pleural fluid samples and reviewed 35 patients with pleural effusions undiagnosed after pleural biopsy at Yamaguchi-Ube Medical Center. Importantly, IgG4 immunostaining revealed infiltration of IgG4-positive plasma cells in the pleura of 12 patients (34%, IgG4+ group). The median effusion IgG4 level was 41 mg/dl in the IgG4+ group and 27 mg/dl in the IgG4- group (P < 0·01). The light and heavy chains of effusion IgG4 antibodies of patients in the IgG4+ group were heterogeneous by two-dimensional electrophoresis, indicating the absence of clonality of the IgG4 antibodies. Interestingly, the κ light chains were more heterogeneous than the λ light chains. The measurement of the κ and λ free light chain (FLC) levels in the pleural fluids showed significantly different κ FLC levels (median: 28·0 versus 9·1 mg/dl, P < 0·01) and κ/λ ratios (median: 2·0 versus 1·2, P < 0·001) between the IgG4+ and IgG4- groups. Furthermore, the κ/λ ratios were correlated with the IgG4+ /IgG+ plasma cell ratios in the pleura of the IgG4+ group. Taken together, these results demonstrate the involvement of IgG4 in certain idiopathic pleural effusions and provide insights into the diagnosis, pathogenesis and therapeutic opportunities of IgG4-associated pleural effusion.

Polymorphisms of UDP-glucuronosyltransferase gene and irinotecan toxicity: a pharmacogenetic analysis.

Irinotecan unexpectedly causes severe toxicity of leukopenia or diarrhea. Irinotecan is metabolized to form active SN-38, which is further conjugated and detoxified by UDP-glucuronosyltransferase (UGT) 1A1 enzyme. Genetic polymorphisms of the UGT1A1 would affect an interindividual variation of the toxicity by irinotecan via the alternation of bioavailability of SN-38. In this case-control study, retrospective review of clinical records and determination of UGT1A1 polymorphisms were performed to investigate whether a patient with the variant UGT1A1 genotypes would be at higher risk for severe toxicity by irinotecan. All patients previously received irinotecan against cancer in university hospitals, cancer centers, or large urban hospitals in Japan. We identified 26 patients who experienced severe toxicity and 92 patients who did not. The relationship was studied between the multiple variant genotypes (UGT1A1*28 in the promoter and UGT1A1*6, UGT1A1*27, UGT1A1*29, and UGT1A1*7 in the coding region) and the severe toxicity of grade 4 leukopenia (< or =0.9 x 10(9)/liter) and/or grade 3 (watery for 5 days or more) or grade 4 (hemorrhagic or dehydration) diarrhea. Of the 26 patients with the severe toxicity, the genotypes of UGT1A1*28 were homozygous in 4 (15%) and heterozygous in 8 (31%), whereas 3 (3%) homozygous and 10 (11%) heterozygous were found among the 92 patients without the severe toxicity. Multivariate analysis suggested that the genotype either heterozygous or homozygous for UGT1A1*28 would be a significant risk factor for severe toxicity by irinotecan (P < 0.001; odds ratio, 7.23; 95% confidence interval, 2.52-22.3). All 3 patients heterozygous for UGT1A1*27 encountered severe toxicity. No statistical association of UGT1A1*6 with the occurrence of severe toxicity was observed. None had UGT1A1*29 or UGT1A1*7. We suggest that determination of the UGT1A1 genotypes might be clinically useful for predicting severe toxicity by irinotecan in cancer patients. This research warrants a prospective trial to corroborate the usefulness of gene diagnosis of UGT1A1 polymorphisms prior tb irinotecan chemotherapy.

Loss of HLA haplotype in lung cancer cell lines: implications for immunosurveillance of altered HLA class I/II phenotypes in lung cancer.

Loss of expression of HLA class I antigens has been demonstrated in a wide variety of tumors and is considered to be one of the mechanisms whereby tumors escape T-cell surveillance. Genomic DNA of MHC class I/II molecules in seven lung cancer cell lines was investigated and compared with that in peripheral blood mononuclear cells. In three cell lines, OU-LC-A1, OU-LC-A2, and OU-LC-AS1, a loss of HLA haplotype was observed. Aberrations of HLA class I/II in tumor cell lines should be considered when MHC-restricted phenomena in vitro models are assessed and clinical use of tumor vaccination in vivo is considered.

Risk factors for development of radiation pneumonitis following radiation therapy with or without chemotherapy for lung cancer.

PURPOSE: To determine the risk factors contributing to development of radiation pneumonitis (RP) in patients with lung cancer who undergo radiation therapy to the thorax. METHODS AND MATERIALS: Development and severity of RP were retrospectively analyzed for 89 patients with lung cancer who underwent radiation therapy with or without chemotherapy at the National Shikoku Cancer Center Hospital between 1991 and 1995. The severity of RP was determined using a modified grading scale based on that of the Radiation Therapy Oncology Group and the European Organization for the Research and Treatment of Cancer. RESULTS: Fifty-two (58%) patients developed RP: 34 patients with Grade 1, 5 with Grade 2, 8 with Grade 3, and 5 with Grade 5 RP. Severe RP tended to develop earlier than less severe RP, but not to a significant extent (p = 0.151). On logistic regression analysis including both patient condition and treatment factors, development of Grade 1 or more severe RP was most frequently observed for Stage I-II disease (p = 0.011). The use of chemotherapy, large daily radiation dose, and once-daily fractionation (vs. twice-daily fractionation) were possibly related to the development of RP (p = 0.057, p = 0.069, and p = 0.092, respectively). For the group of 48 patients who underwent chemoradiation therapy, the use of large daily radiation dose was a significant risk factor for RP (p = 0.014). In addition, the use of once-daily fractionation was a marginally significant risk factor (p = 0.052). Among chemotherapy drugs administered, cisplatin was a favorable factor (p = 0.011), while adriamycin was a risk factor (p = 0.061). CONCLUSIONS: In radiation therapy for lung cancer, administration of a large daily dose should be avoided in order to prevent RP, particularly when radiation therapy is combined with chemotherapy.

Metastasis to the penis in a patient with squamous cell carcinoma of the lung with a review of reported cases.

Metastasis to the penis is very rare in lung cancer. We describe a patient with squamous cell carcinoma of the lung who developed a metastatic lesion in the penis. A 75-year-old Japanese male visited a local hospital complaining cough and bloody sputum. A chest plain radiograph and computed tomographic (CT) scans of the chest demonstrated a right hilar mass. He was diagnosed with squamous cell carcinoma of the lung at stage IIIB (T4N2M0). Then he was treated with concurrent chemoradiotherapy consisting of cisplatin, docetaxel, and thoracic irradiation, and after the chemoradiotherapy, he achieved a partial response. However, 6 months later, he visited an urologist complaining of firm mass in the penis with slight pain. A biopsy of the corpus cavernosum penis was performed, which provided a histological diagnosis of squamous cell carcinoma. The histology of the specimen was consistent with that of previous lung cancer, so he was considered to have penile metastasis from squamous cell carcinoma of the lung. Radiotherapy was given to the metastatic tumor in the penis. The penile tumor was diminished and the pain was completely relieved. In addition, we review reported cases to investigate the clinical characteristics and appropriate management of this rare involvement.

Immunohistochemical detection of mutant p53 protein in small-cell lung cancer: relationship to treatment outcome.

We investigated the expression of mutant p53 proteins in small-cell lung cancer (SCLC) immunohistochemically, by identification of stabilized mutant p53 proteins with a much longer half-life than the wild-type protein. Of 103 tumor specimens obtained by transbronchial tumor biopsy for histologic diagnosis, 52 (50%) showed positive staining for p53 protein with a p53 monoclonal antibody, DO-1. Positive staining for p53 protein was not correlated with age, sex, performance status, lifetime cigarette consumption, serum concentration of neuron-specific enolase and extent of disease. Complete response rates in patients with a mutant p53 protein-positive tumor were significantly lower than those in p53-negative patients (25% versus 59%; P=0.0005, by chi-square test). Similarly, survival periods in patients with a mutant p53 protein-positive tumor were significantly shorter than those in mutant p53-protein-negative patients (10.8 months versus 20.6 months; P=0.0001, by generalized Wilcoxon test). Multivariate analysis using Cox's proportional hazards model revealed that the presence of mutant p53 protein is an independent factor associated with differences in overall survival (hazards ratio=2.72; 95% confidence interval, 1.71-4.34; P=0.0001). These observations suggest that the expression of mutant p53 proteins in SCLC may be an important factor predicting poor prognosis.

Spontaneous biloma as a complication of small cell lung cancer.

Biloma is an extraductular collection of bile within a defined capsular space. Prior reports have documented an association between biloma and abdominal trauma, and between biloma and iatrogenic injury resulting from abdominal surgery, percutaneous catheter drainage, or transhepatic cholangiogram. To our knowledge, bilomas have not previously been associated with lung cancer. We report a case of spontaneous biloma that developed as a complication of small cell lung cancer.

Complementary roles of pro-gastrin-releasing peptide (ProGRP) and neuron specific enolase (NSE) in diagnosis and prognosis of small-cell lung cancer (SCLC).

In this study, we evaluated the clinical usefulness of ProGRP and NSE for diagnosis and prognosis of small-cell lung cancer (SCLC). Serum levels of ProGRP and NSE were determined in 108 healthy subjects, 103 patients with benign pulmonary diseases, 142 with non-small cell lung cancer (NSCLC), and 114 with SCLC. Sensitivity of ProGRP in diagnosis of SCLC was significantly higher than that of NSE (64.9 vs. 43.0%, P < 0.001). The difference was substantial in patients with limited disease (56.5 vs. 20.3%, P < 0.001). However, 11 of 40 SCLC patients with normal levels of serum ProGRP (27.5%) showed elevated levels of serum NSE. In the SCLC patients receiving chemotherapy, the CR rate in patients with elevated NSE levels was significantly lower than in patients with normal levels of NSE (18.5 vs. 61.7%, P < 0.001). Elevation of both ProGRP and NSE was a poor prognostic factor, and patients with elevated levels of either ProGRP or NSE showed shorter survival than those without. From multivariate analysis, NSE was found to have a greater effect on survival of SCLC patients than ProGRP. These findings indicate that ProGRP is more sensitive than NSE for diagnosis of SCLC, while NSE is superior to ProGRP as a prognostic factor. In conclusion, both ProGRP and NSE are useful tumor markers and they have a complementary role for each other in diagnosis and prognosis of SCLC.

Comparative study of prophylactic cranial irradiation in patients with small cell lung cancer achieving a complete response: a long-term follow-up result.

Between 1981 and 1986, a total of 46 patients with small cell lung cancer (SCLC) achieving a complete response by chemotherapy with or without chest irradiation were randomized either to receive prophylactic cranial irradiation (PCI) or not. With a median follow-up time of 8.5 years for both groups, only five of 23 patients (22%) in the PCI group developed brain relapse, while 12 out of 23 (52%) in the no PCI group did so (P < 0.05). The frequency of patients developing a sole brain relapse during their whole clinical course was 4% for the PCI group and 17% for the no PCI group, however, the difference was not statistically significant. Patient survival was better for the PCI group (median survival time of 21 months, and 5-year survival rate of 22%) as compared with the no PCI group (median survival time of 15 months, and 5-year survival rate of 13%), showing a marginal significance (P = 0.097). Late neurologic toxicity was infrequent; only one developed a mild deterioration among seven long-term disease-free survivors in the PCI group. These results appear to warrant further clinical trials to clarify the utility of PCI in patients with SCLC achieving a complete response.

Intramedullary spinal cord recurrence after high-dose chemotherapy and autologous peripheral blood progenitor cell transplantation for limited-disease small cell lung cancer.

Intramedullary spinal cord metastasis is very rare in small-cell lung cancer (SCLC), and develops in only 2% of neurological disorders associated with SCLC according to previous reports. We describe here a patient with SCLC who developed intramedullary spinal cord recurrence after high-dose chemotherapy (HDCT) followed by autologous blood progenitor cell transplantation (ABPCT). A 59-year-old Japanese male was referred to us for diagnosis and treatment of an abnormal shadow on a chest radiograph. Based on transbronchial biopsy and staging procedures, he was diagnosed with limited-disease (LD)-SCLC. He received concurrent chemoradiotherapy followed by late intensification with HDCT supported by ABPCT. He achieved complete response and was discharged after receiving prophylactic cranial irradiation (PCI). However 6 months later, he noticed rapidly progressive weakness of the left lower extremity and bowel/bladder dysfunction. Magnetic resonance imaging (MRI) of the spinal cord disclosed an intramedullary tumor exhibiting an enhancement effect with Gd-DTPA at the 11-12th level of the thoracic vertebra. Immediately, radiotherapy to the spinal cord metastasis was given at a dose of 30 Gy, and his neurological disorders were completely resolved. At this time of reporting, he is doing well without recurrence. This case indicates that intramedullary spinal cord is one of the recurrence sites implicated after HDCT and PCI in LD-SCLC.

A case-control study of lung cancer screening in Okayama Prefecture, Japan.

The effectiveness of lung cancer screening in reducing mortality still remains uncertain. In order to evaluate the efficacy of lung cancer screening, a case-control study was conducted in Okayama Prefecture, Japan. The study area consisted of 34 municipalities where a population-based lung cancer screening had been conducted. Chest X-ray examinations for all participants and sputum cytology for high-risk participants were offered annually. The cases analyzed in this study consisted of 412 individuals aged between 40 and 79 who died of lung cancer. A total of 3490 controls, two to ten for each case matched by gender, year of birth, and living district were randomly collected. Screening histories of cases were compared with those of and matched controls for the identical calendar period prio to diagnosis of the case. Smoking adjusted odds ratio (OR) of death from lung cancer for screened individuals versus unscreened, within 12 months before diagnosis, was calculated as 0.59 (95% confidence interval: 0.46-0.74; P=0.0001). The OR for women (0.39, 95% confidence interval: 0.24-0.64) was lower than that for men (0.67, 95% confidence interval: 0.51-0.87), although both were statistically significant. These results suggest that lung cancer screening contributes to reducing lung cancer mortality by 41%.

Estimation of chronic phase duration in Ph-positive chronic myelocytic leukemia treated with busulfan: statistical analysis on Japanese patients.

Chronic phase duration was analyzed in 148 Japanese patients with Ph-positive chronic myelocytic leukemia (CML) treated only with busulfan, and multivariate proportional hazard models were constructed to infer the prognosis of a given patient, and to evaluate the prognostic importance of the clinical findings. To make an accurate estimation of an individual patient's prognosis, we introduced a piecewise linear model for describing a hazard function in each prognostic variable. Of the 11 prognostic variables initially analyzed, the absolute count of peripheral basophils was revealed as the most important prognostic factor. A high basophil count was clearly a factor in cases with poor prognosis. The statistical model selection based on the criteria of model approximation finally suggested a model with three covariates; absolute count of peripheral basophils, platelet count, and presence or absence of additional chromosome abnormalities superimposed on the translocation of 9;22. By analyses based on the above model, we estimated that the median of the chronic phase duration for the patients with poor and good prognosis was 12 and 75 months, respectively. The piecewise linear model was well suited for an accurate estimation of an individual patient's prognosis. Thus, the model constructed here would become a reliable control to evaluate investigational approaches, such as hydroxyurea, interferons, and/or bone marrow transplantation.

Analysis and rearrangement of human karyotypes by computer.

A system useful for the collection and analysis of a large number of abnormal karyotypes and for studies on the relationship between cytogenetic abnormalities and clinical features of diseases is reported. The program is based on the disintegration and rearrangement of abnormal karyotypes recorded according to the 1978 International System for Human Cytogenetic Nomenclature (ISCN).

Combination of nedaplatin and vindesine for treatment of relapsed or refractory non-small-cell lung cancer.

PURPOSE: A phase II study of nedaplatin and vindesine was conducted to evaluate their efficacy and safety for treatment of relapsed or refractory non-small-cell lung cancer (NSCLC). METHODS: Between August 1996 and September 1998, 48 patients who had previously received chemotherapy, thoracic radiotherapy, and/or surgery were enrolled in the study. Patients were required to have an Eastern Cooperative Oncology Group performance status of 0 to 2 and an age between 20 and 79 years. Treatment consisted of nedaplatin (80 mg/m2, day 1) and vindesine (3 mg/m2, days 1 and 8) every 3 to 4 weeks. RESULTS: Of 48 patients, 7 (14.6%) exhibited an objective response. Four (50%) of eight chemotherapy-naive patients had a partial response. However, of the 40 patients who had received prior chemotherapy, a partial response was observed in only 3 (7.5%). At a median follow-up time of 85.1 weeks, the median survival time was 43.6 weeks (95% confidence interval 34.4-52.7) for patients who had received chemotherapy, with a survival rate of 40% at 1 year. Grade 3 or 4 neutropenia occurred in 43 of 48 patients (90%), and neutropenic fever was observed in 3 of the 43 patients, one of whom died of sepsis. Pharmacokinetic and pharmacodynamic analyses of platinum were performed in 43 patients during the first cycle of chemotherapy. Percent reduction in absolute neutrophil count was correlated not only with the area under the plasma ultrafilterable platinum concentration versus time curve (r = 0.41, P = 0.007) but also with the duration of ultrafilterable platinum concentration above 1 microg/ml (r = 0.41, P = 0.007). Patients with progressive disease exhibited a shorter duration of ultrafilterable platinum concentration over 1 microg/ml (P = 0.046) than those with other responses. CONCLUSION: A combination of nedaplatin and vindesine was unsatisfactory as second-line chemotherapy for NSCLC, although the combination was well tolerated. The duration of ultrafilterable platinum concentration above 1 microg/ml was an important pharmacokinetic parameter for predicting both chemotherapy-induced neutropenia and treatment outcome.

Synchronous primary lung cancer presenting with small cell carcinoma and non-small cell carcinoma: diagnosis and treatment.

Synchronous primary lung cancer (SPLC) occurs in up to 0.5% of patients with lung cancer. Among SPLC cases, coexistence of small cell carcinoma (SCLC) and non-small cell carcinoma has been reported in a very small fraction. Futhermore, there have been no reports discussing treatment and prognosis of SPLC presenting with SCLC and NSCLC. We report on two cases of SPLC presenting SCLC in limited stage and operable NSCLC. One patient developed synchronously SCLC and adenocarcinoma of the lung, while the other SCLC and squamous cell carcinoma of the lung. The clonal origin of these synchronous lung cancers was evaluated using immunohistochemical and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analyses. Both of the patients were diagnosed based on transbronchial lung biopsy (TBLB) and mediastinoscopic biopsy. They were successfully treated with chemoradiotherapy and adjuvant surgery, and are now doing well without any signs of tumor progression for about one year. In both cases, a response of mediastinal lymph node for concurrent chemoradiotherapy was quite different from that of the mass in the lung field. In case 2, p53 mutation was observed in the SCLC tissue, but not in the NSCLC tissue by PCR-SSCP. In both cases, carcinoembryonic antigen was documented in the NSCLC tissue, but not in the SCLC tissue by immunohistochemical staining. This report indicates the importance of the accurate diagnosis of SPLC by employing TBLB and/or media-stinoscopy for the optimal treatment of patients having SPLC presenting with SCLC and NSCLC. Diagnostic criteria and standard treatment of this disease should be established.

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.

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.

High-dose ifosfamide, carboplatin and etoposide with autologous peripheral blood progenitor cell transplantation for small-cell lung cancer.

BACKGROUND: We investigated the feasibility and efficacy of high-dose chemotherapy consisting of ifosfamide, carboplatin and etoposide (HD-ICE) facilitated by autologous peripheral blood progenitor cell transplantation (ABPCT) for the treatment of small-cell lung cancer (SCLC). PATIENTS AND METHODS: Eleven patients aged 44 to 63 years old (5 with extensive disease [ED] and 6 with limited disease [LD]) were entered into this study. Induction chemotherapy consisted of 3 to 4 cycles of cisplatin and irinotecan for ED-SCLC, and cisplatin and etoposide for LD-SCLC. Patients with LD-SCLC received concurrent chest radiotherapy along with the first cycle of induction chemotherapy. After induction therapy, peripheral blood progenitor cells (PBPC) were collected following G-CSF administration during a recovery phase from high-dose etoposide (1,500 mg/m2). Eight patients (4 with ED and 4 with LD) with adequate organ function were treated with HD-ICE (15 g/m2 ifosfamide, 1,200 mg/m2 carboplatin and 1,500 mg/m2 etoposide) followed by ABPCT. RESULTS: Hematologic recovery was rapid and non-hematological toxicities were acceptable without treatment-related mortality. In ED-SCLC, all of the 4 patients achieved complete response (CR) or near CR but developed a relapse of the disease. In LD-SCLC, 2 of 4 patients with LD-SCLC are alive in continuous CR for 18 and 21 months after the beginning of induction therapy. CONCLUSIONS: Despite a limited number of patients and short follow-up time, these preliminary results indicate that marrow-ablative therapy (HD-ICE) supported by ABPCT is feasible in the treatment of elderly patients with LD- and ED-SCLC.

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.

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.