Clinical Aspects of Acute Lung Insufficiency (ALI/TRALI)

SUMMARY: Acute respiratory distress syndrome (ARDS) is a common clinical disorder caused by a variety of direct and indirect injuries to the lung, characterized by alveolar epithelial and endothelial injury resulting in damage to the pulmonary alveolar-capillary barrier. The cardinal clinical feature of ARDS, refractory arterial hypoxemia, is the result of protein-rich alveolar edema with impaired surfactant function, due to vascular leakage and vascular dysfunction with consequently impaired matching of ventilation to perfusion. Since its first description in 1967, considerable knowledge concerning the pathogenesis of ARDS has been obtained, however, a plethora of questions remain. Better understanding of the pathophysiology of ARDS has lead to the development of novel therapies, pharmacological strategies, and advances in mechanical ventilation. However, lung-protective ventilation is the only confirmed option in ARDS management improving survival, and few other therapies have translated into improved oxygenation or reduced ventilation time. But despite improvement in our understanding of the therapy and supportive care for patients with ARDS, mortality remains high. It is the purpose of this article to provide an overview of the definition, clinical features, and pathogenesis of ARDS, and to present and discuss therapeutic options currently available in order to effectively treat this severe disorder.

Prolonged cerebellar ataxia: an unusual complication of hypoglycemia

A 51-year-old male with a history of insulin-dependent diabetes and polysubstance abuse presented after overdose on insulin. Soon after resuscitation, he displayed a severe ataxia in all 4 limbs and was unable to walk; all of which persisted for at least 5 days. Laboratory testing was unrevealing, including relatively normal brain magnetic resonance imaging. He had recovered full neurologic function 3 months after the event. This report describes a case of reversible cerebellar ataxia as a rare complication of severe hypoglycemia that may occur in patients with abnormal cerebellar glucose metabolism. Thus, this phenomenon should be included in the differential diagnosis of patients with a history of hypoglycemia who present with ataxia. In this context, the differential diagnosis of cerebellar ataxia is discussed, as is the proposed mechanism for hypoglycemia-induced cerebellar dysfunction.

Acute myocardial infarction with normal coronary arteries in a patient with Hodgkin's disease: a late complication of irradiation and chemotherapy

We describe the case of a 31-year-old man who experienced an acute myocardial infarction 16 years after undergoing radiation and vinca alkaloid therapy for Hodgkin's disease. Even though coronary artery disease is a well-established complication after mediastinal radiation therapy, this adult patient had normal coronary angiographic results, with no traditional risk factors for coronary artery disease, and no hematologic or other abnormality associated with hypercoagulability.

[Histological classification of interstitial lung diseases]

The 2002 ATS/ERS consensus classification of idiopathic interstitial pneumonias standardizes definitions and criteria for classification and diagnosis of idiopathic interstitial pneumonias and replaces previous classifications. Based on clinico-radiologic-pathologic criteria seven entities were defined: idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, respiratory bronchiolitis-associated interstitial lung disease, desquamative interstitial pneumonia and lymphoid interstitial pneumonia. The following paper includes a brief overview of the histopathological diagnosis of these entities as compared to other diffuse interstitial pulmonary diseases and pulmonary manifestations of collagenvascular diseases.

Use of Key Words as an Adjunctive Learning Tool Improves Learning During a Perioperative Medicine Rotation for Anesthesiology Residents

Designing a successful block rotation for anesthesiology residents requires not only an appropriate curriculum but also a set of teaching tools, which promote learning. Traditional clinical rotations in Anesthesiology residencies emphasize clinical teaching, supported by interaction with staff. Since Perioperative Medicine is a non-traditional subject for anesthesia residents, we introduced a syllabus, and didactic curriculum to support clinical teaching. We hypothesized that the use of key words would enhance learning. Alternating groups of residents were assigned to receive key words, while control residents were expected to learn without key words. The key words were delivered in writing on the first day of the rotation and the syllabus was highlighted to identify the key words in the text. Pre and post-tests were administered to residents participating in the perioperative rotation. Learning was assessed by calculating the change in test scores. There was significantly more learning in the group given the key words. We conclude that key word designation improved learning in a rotation designed to teach perioperative medicine.

Antitumor effect of a neutralizing antibody to vascular endothelial growth factor on liver metastasis of endocrine neoplasm

Distant metastasis of gastrointestinal endocrine neoplasm is resistant to currently available treatments. Because hematogenic metastasis is dominant, anti-angiogenic drugs are expected to be a novel therapy for this neoplasm. In the present study, the therapeutic effect of vascular endothelial growth factor neutralizing antibody (VEGFAb) on liver metastasis of an endocrine neoplasm was investigated experimentally. Cecal transplantation into nude mice of small pieces of EN-1, a xenotransplanted human intestinal endocrine neoplasm, resulted in liver metastasis. A treated group (n = 19) received 100 micrograms/mouse of VEGFAb intraperitoneally on alternate days from day 10 after tumor transplantation, and the control group (n = 19) received saline. Five of the 19 control mice died of tumor progression, of which 2 could not be evaluated. The cecal tumor weighed 6316 +/- 2333 mg (n = 17) in the control group and 1209 +/- 837 mg (n = 19) in the treated group (P < 0.01) 6 weeks after transplantation. Liver metastasis developed in 16 of 17 control mice and in 2 of 19 treated mice (P < 0.01). The VEGF level of the whole cecal tumor in the control group was significantly higher than that in the treated group (305.1 +/- 174.1 vs. 54.7 +/- 41.2 mg; P < 0.001). VEGFAb did not cause any body weight loss (28.52 +/- 1.63 in the control vs. 28.44 +/- 1.71 g in the treated group). These results indicate that VEGFAb may be a novel therapeutic agent for endocrine neoplasm with distant metastasis.

Inhibition of liver metastasis of human pancreatic carcinoma by angiogenesis inhibitor TNP-470 in combination with cisplatin

The anti-tumor and anti-metastatic effects of O-(chloroacetyl-carbamoyl) fumagillol (TNP-470), an angiogenesis inhibitor, and cisplatin (CDDP), an anti-neoplastic agent, were investigated using our established liver-metastasizing pancreatic carcinoma line, HPC-3H4. HPC-3H4 was injected into the spleens of nude mice. Mice were randomly divided into 5 groups; a control group given saline solution, a group receiving 45 mg/kg TNP-470, a group receiving 90 mg/kg TNP-470, a group receiving 90 mg/kg TNP-470 in combination with 0.25 mg/kg CDDP, and a group receiving 0.25 mg/kg CDDP. In the control group, liver metastasis developed in 14 of 15 mice (93.3%). Liver metastasis developed in 9 of 11 mice (81.8%) receiving 0.25 mg/kg CDDP. It developed in 11 of 15 mice (73.3%) receiving 45 mg/kg TNP-470, in 17 of 18 mice (94.4%) receiving 90 mg/kg TNP-470, and in 4 of 10 mice (40%) receiving 90 mg/kg TNP-470 in combination with 0.25 mg/kg CDDP. TNP-470 in combination with CDDP displayed a significant inhibitory effect on liver metastasis compared to the control. Although TNP-470 alone and CDDP alone had no effect on the tumor growth in vivo, 90 mg/kg TNP-470 in combination with 0.25 mg/kg CDDP had a significant effect. In vitro examinations demonstrated that the growth of HPC-3H4 cells was only mildly inhibited by TNP-470, but the production of vascular endothelial growth factor (VEGF) by HPC-3H4 was clearly inhibited by TNP-470. The inhibitory effect on the production of VEGF was not strong with CDDP treatment. These results indicate that the angiogenesis inhibitor TNP-470 in combination with low-dose CDDP has inhibitory activity against liver metastasis of human pancreatic carcinoma.

Tumor-specific activation of mitogen-activated protein kinase in human colorectal and gastric carcinoma tissues

To search for the signaling events in colorectal carcinoma relevant to its tumorigenesis, we investigated the activity of mitogen-activated protein kinase (MAPK) in human colorectal carcinoma tissues and paired normal tissues. Of 64 cases examined, approximately 75% (48 cases) showed tumor-specific activation of MAPK by in situ kinase renaturation assay, as well as in vitro kinase assay with immunoprecipitated MAPK. In addition, tumor-specific activation of MAPK was associated with the activation of MAPK kinase in the cases we examined. However, no clear correlation of MAPK activation with lymph node involvement, metastatic rate, stage, histological classification, age or sex was observed. These results suggest that the MAPK pathway is involved in colorectal tumor development, but its activation alone is not sufficient for malignant conversion. In contrast to colorectal carcinoma, gastric carcinoma tissues showed a lower rate of MAPK activation, suggesting that the signaling pathway activated in colorectal carcinoma tissues may differ in part from that of gastric carcinoma.

Potentiation of paclitaxel cytotoxicity by inostamycin in human small cell lung carcinoma, Ms-1 cells

In the present study, we found that inostamycin increased the ability of paclitaxel to induce apoptosis in Ms-1 cells. A considerably higher concentration of paclitaxel was required for the induction of apoptosis in Ms-1 cells than in other cell lines tested. Treatment of Ms-1 cells with inostamycin, an inhibitor of phoshatidylinositol (PI) synthesis, reduced the dosage of paclitaxel required to induce cell death by apoptosis. This effect of inostamycin is specific to Ms-1 cells, and inostamycin did not increase the cytotoxicity of other antitumor drugs such as adriamycin, vinblastine, methotrexate, cisplatin, etoposide, or camptothecin in Ms-1 cells. Addition of inostamycin to paclitaxel-treated cells caused a significant increase in the sub G1 peak, representing apoptosis, which was accompanied by a decrease in the G2/M peak seen in paclitaxel-treated Ms-1 cells, without affecting paclitaxel-inhibited tubulin depolymerization. Moreover, paclitaxel did not enhance inostamycin-inhibited PI synthesis. The expression levels of Bcl-2, Bax, and Bcl-XL were not changed following the co-treatment with inostamycin plus paclitaxel, whereas the activated form of caspase-3 was markedly increased. Thus, inostamycin is a chemosensitizer of paclitaxel in small cell lung carcinoma Ms-1 cells.

Selection of human ovarian carcinoma cells with high dissemination potential by repeated passage of the cells in vivo into nude mice, and involvement of Le(x)-determinant in the dissemination potential

Cells of the human tumor cell line RMG-1, derived from a clear-cell adenocarcinoma of the ovary, were injected intraperitoneally into nude mice, and the cells obtained from the tumor nodules in the mesenterium were found to form a larger number of, and larger-sized, tumor nodules than the original RMG-1 cells. The RMG-1-h cells, transferred into culture from the tumor nodules after a 4th in vivo passage, showed a dissemination potential as high as that of cells disseminating directly from the tissues, and exceedingly higher than that of RMG-1 cells. To assess the molecular bases of the different biological properties of RMG-1 and RMG-1-h cells, we compared the content and expression of various carbohydrate antigens in both cells. The chromosomal profile of RMG-1-h cells revealed their human origin and was identical to that of the original RMG-1 cells. In contrast to the broad histogram for the Le(x)-bearing cells among RMG-1 cells in flow cytometry, the weakly and moderately positive cells toward anti-Le(x) antibody were found to be eliminated from the histogram for the RMG-1-h cells, resulting in the enrichment of cells strongly expressing Le(x), which may account for the high dissemination potential. In addition, the adhesion of RMG-1 cells to mesothelial cells was found to be significantly inhibited by pretreatment of the cells with anti-Le(x) antibody, indicating Le(x)-mediated cell-to-cell interaction between ovarian cancer cells and mesothelial cells. By TLC-immunostaining, two Le(x)-glycolipids, III3Fuc alpha-nLc4Cer and V3Fuc alpha-nLc6Cer were detected in both RMG-1 and RMG-1-h cells, and their total concentrations were not significantly different from each other. However, the hydrophobic moieties of Le(x)-glycolipids in RMG-1-h cells were different from those in RMG-1 cells, suggesting that a difference in the structure of the hydrophobic moieties of Le(x) is partly involved in the enhanced reactivity of RMG-1-h cells toward anti-Le(x) antibody. Thus, the high dissemination potential of ovarian cancer cells was shown to be mediated by the Le(x)-determinant and the Le(x)-bearing cells are enriched by repeated in vivo passage of the cells into nude mice.

Caspase-3 activation is not responsible for vinblastine-induced Bcl-2 phosphorylation and G2/M arrest in human small cell lung carcinoma Ms-1 cells

Vinblastine arrests cells in the G2/M phase of the cell cycle and subsequently induces cell death by apoptosis. We found that treatment of cells with vinblastine induced phosphorylation of Bcl-2, resulting in the dissociation of Bcl-2 and Bax. Moreover, vinblastine-induced apoptosis was suppressed by an inhibitor of caspase-3, Ac-DEVD-CHO; and a 17-kDa active fragment of caspase-3 was detected following vinblastine treatment, suggesting that caspase-3 is involved in vinblastine-induced apoptosis. However, Ac-DEVD-CHO affected neither vinblastine-induced Bcl-2 phosphorylation nor vinblastine-induced G2/M arrest. Vinblastine caused G2/M arrest prior to apoptosis, whereas vinblastine-induced apoptosis was not dependent on the duration of the G2/M phase. Thus, vinblastine-induced apoptosis might be mediated by the phosphorylation of Bcl-2, resulting in Bcl-2 inactivation, and by subsequent activation of caspase-3.

Allelic loss on chromosome 9q is associated with lymph node metastasis of primary breast cancer

Frequent allelic losses on chromosome 9 are seen in a wide variety of human tumors; moreover, two genes (P16 and PTC) whose mutant alleles confer predispositions to some inherited cancer syndromes have been identified on this chromosome. Using 15 highly polymorphic microsatellite markers distributed on both arms of chromosome 9, we tested 96 primary breast carcinomas for allelic loss in order to define the locations of genes that might be involved in this type of tumor. Allelic loss was observed in 37 of the tumors (39%) and detailed deletion mapping identified target regions at 9p21, 9q22.3 and 9q33. Losses at 9q22.3 and 9q33 were correlated with the presence of lymph node metastasis, and allelic loss at 9q22.3 was observed more frequently in scirrhous tumors than in less aggressive histologic types. Therefore, inactivation of tumor suppressor genes in 9q22.3 and 9q33 regions might play a role in progression of breast cancers, especially in metastasis to lymph nodes and in development of scirrhous tumors.

Immunological quantitation of DT-diaphorase in carcinoma cell lines and clinical colon cancers: advanced tumors express greater levels of DT-diaphorase

NAD(P)H:quinone oxidoreductase (DT-diaphorase; DTD) plays a major role in activating mitomycin C (MMC) in human colon and gastric carcinoma cell lines. Thus, measurement of DTD in clinical tumor samples could be beneficial in designing adjuvant chemotherapy. We explored immunological quantitation of DTD protein using a monoclonal antibody against DTD, demonstrating a close correlation between protein expression and enzyme activity of DTD in colon and gastric carcinoma cell lines and in colorectal tumor samples. This indicates that such immunoblot analysis is a simple alternative method for quantitating DTD in clinically excised samples. In most colorectal tumor samples, the tumors expressed larger amounts of DTD than did the peripheral normal tissues, suggesting a selective toxicity of MMC toward tumor cells. Also tumors with nodal metastases showed significantly higher DTD levels than did tumors without metastasis. These results raise the possibility that DTD expression is related to tumorigenesis and malignant progression of colorectal tumors. Measurement of DTD by the immunological method described here could be beneficial in designing a rational adjuvant chemotherapy with MMC.

Preferential binding of E7010 to murine beta 3-tubulin and decreased beta 3-tubulin in E7010-resistant cell lines

N-[2-[(4-Hydroxyphenyl)amino]-3-pyridyl]-4-methoxybenzenesulfonamide+ ++ (E7010) is a novel sulfonamide antimitotic agent, which is active against mouse and human tumors. E7010 binds to beta-tubulin and inhibits polymerization of microtubules. In order to clarify the mechanisms of E7010-resistance, two murine leukemic P388 subclones resistant to E7010, 0.5r-D and 4.0r-M, were characterized. The two clones showed approximately 10- and 100-fold resistance to E7010-induced growth-inhibitory effects, respectively, compared with the parental cells in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. These cell lines showed no cross-resistance to other anticancer agents such as taxanes, vinca alkaloids, mitomycin C, cisplatin and irinotecan hydrochloride (CPT-11). Increased alpha- and beta-tubulin protein and mRNA levels were observed in 0.5r-D and 4.0r-M cells as compared with the parental cells. We examined the isotype-specific expression of beta-tubulin in these E7010-resistant cells by a competitive reverse transcription-polymerase chain reaction method. Although a 50% increase in beta 5 isotype mRNA levels was observed in 4.0r-M cells, the levels of beta 3 isotype message in the two resistant clones were approximately 50% less than the parental cells. To elucidate the binding properties of E7010 with beta-tubulin isotypes, we prepared isotype-specific fusion proteins of beta-tubulins. Direct photoaffinity labeling of the isotype-specific fusion proteins with [14C]E7010 revealed that E7010 preferentially binds to the beta 3 isotype rather than beta 2, beta 4, and beta 5 isotype proteins. Therefore, altered expression of beta-tubulin isotypes, especially beta 3 isotype, to which E7010 binds with high affinity, may account for the decreased sensitivity of these resistant clones to E7010.

Effects of a gonadotropin-releasing hormone agonist on rat ovarian adenocarcinoma cell lines in vitro and in vivo

To evaluate the biologic effects of the gonadotropin-releasing hormone (GnRH) agonist buserelin on rat ovarian adenocarcinoma cells in vivo and in vitro, female Wistar rats with primary ovarian adenocarcinoma induced by 7, 12-dimethylbenz(a)anthracene (DMBA) and the DMBA-OC-1 cell line established from a DMBA-induced rat tumor were used in this study. In vivo, daily administration of buserelin significantly suppressed the release of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and progesterone as compared with controls. Buserelin did not inhibit the growth of DMBA-induced tumors. However, histopathologically, there was increased central necrosis and a decrease in the number of neoplastic cells, with proliferation of connective tissue, in the group treated with buserelin. In vitro, FSH-induced proliferation of DMBA-OC-1 cells was suppressed by buserelin. Thus, this basic experimental study supports the potential use of a GnRH agonist to suppress the growth of ovarian cancer.

Abnormalities of the FHIT transcripts in osteosarcoma and Ewing sarcoma

In a study of FHIT gene abnormalities by reverse transcription-polymerase chain reaction (RT-PCR) and sequence analysis of the PCR products, we found normal and abnormal PCR products in 11 osteosarcomas, one osteosarcoma cell line and 3 Ewing sarcomas, and a normal PCR product only in 5 osteosarcomas and 8 Ewing sarcomas. Sequence analysis of the abnormal PCR products revealed 7 osteosarcomas lacking exons 4 to 6, 7, 8 or 9, two lacking exons 5 to 7 or 10, and two lacking exons 6 to 8 or 10. In the aberrant transcripts of the 11 osteosarcomas, fusion had occurred in the exon/intron junctions in 2 tumors, between a segment within an exon and a complete exon in 3, and between segments within exons in 6. The 3 Ewing sarcomas had lost exon 4 or 5 to exon 6 or 10, and fusion had occurred in the exon/intron junction in one, and between segments within exons in 2. These findings suggest that both abnormal or variant splicing and other mechanisms such as genomic instabilities in the FHIT locus may have resulted in the expression of aberrant transcripts. One osteosarcoma and one cell line established from this osteosarcoma showed different abnormal FHIT transcripts, indicating that the tumor cells with the initial aberrant transcripts may not have had a selective advantage for proliferation. The FHIT abnormalities did not seem to be correlated with lung metastasis or a poor clinical outcome in our patients with osteosarcoma or Ewing sarcoma.

Somatic mutations in the RET protooncogene in Japanese and Chinese sporadic medullary thyroid carcinomas

Despite advances in the understanding of the genotype-phenotype correlation in multiple endocrine neoplasia type 2A and 2B (multiple endocrine neoplasia (MEN) 2A, MEN 2B), and familial medullary thyroid carcinoma (FMTC), the frequency and prognostic relevance of RET protooncogene mutations in sporadic medullary thyroid carcinomas (MTCs) remain controversial. To study somatic mutations in the RET protooncogene in Japanese and Chinese sporadic MTCs and to analyze comparatively the correlation between RET mutation and tumor differentiation, we investigated somatic mutations in the RET protooncogene in 20 Japanese and 20 Chinese sporadic MTCs by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Of the 40 sporadic MTCs, 13 had a point mutation in codon 918 of exon 16, a frequency of 32.5%. There was no significant difference in the frequency between Japanese and Chinese sporadic MTCs, as 30% of the Japanese and 35% of the Chinese sporadic MTCs contained this mutation. We did not observe any correlation between the presence or absence of codon 918 mutation and tumor differentiation in either Japanese or Chinese sporadic MTCs. Our findings indicate that the frequency of RET somatic mutations is similar in Japanese and Chinese sporadic MTCs, and the presence or absence of RET mutation does not correlate with the differentiation of sporadic MTCs.

Expression of uroplakin Ib and uroplakin III genes in tissues and peripheral blood of patients with transitional cell carcinoma

Uroplakins (UPs), urothelium-specific transmembrane proteins, are present only in urothelial cells. We have determined the nucleotide sequences of human UP-Ib and UP-III and synthesized specific primer pairs. The two UP genes were expressed in both cancerous and noncancerous urothelial taken from all patients examined by reverse transcription-polymerase chain reaction (RT-PCR). These genes were also detected in the peripheral blood of 3 patients with metastatic transitional cell carcinoma (TCC), but not in that from 9 patients with non-metastatic TCC or 3 healthy volunteers. The sensitivity of our assay was sufficient to detect one cancer cell in 5 ml of peripheral blood. Detection of UP gene-expression in blood by RT-PCR may provide helpful information for the diagnosis and management of TCC.

Induction of apoptosis in human pancreatic carcinoma cells by a synthetic bleomycin-like ligand

Histidine-pyridine-histidine-3 (HPH-3) is an oxygen-activating ligand based on the structure of bleomycin. HPH-3 induced the death of human pancreatic adenocarcinoma AsPC-1 cells in 24 h, causing apoptotic morphology and internucleosomal degradation of DNA. HPH-3-induced cell death was not inhibited by antioxidants such as reduced glutathione and N-acetylcysteine, whereas hydrogen peroxide-induced cell death was inhibited by them, indicating that hydrogen peroxide is not involved in the induction of apoptosis by HPH-3. Induction of apoptosis by HPH-3 was inhibited by zinc and copper ions, indicating that chelation with ferrous ion is responsible for induction of apoptosis, as is the case in chelation by bleomycin to cleave DNA. Bleomycin A2 and its fragment having no DNA-binding region, glycopeptide-3, did not induce apoptosis in AsPC-1 cells. Bleomycin A2 induced G2/M block in flow-cytometric analysis, but HPH-3 did not and instead induced an apoptotic pre-G1 peak. Thus, HPH-3 induced apoptosis in human pancreatic carcinoma cells, which is a unique characteristic among bleomycin-related compounds.

Association of replication error positive phenotype with lymphocyte infiltration in endometrial cancers

Microsatellite instability (MI) has been detected in certain sporadic cancers as well as in hereditary non-polyposis colorectal cancer (HNPCC). In order to determine the precise clinicopathological characteristics of MI in endometrial cancer, we examined 90 sporadic endometrial cancers (83 endometrioid adenocarcinomas, 3 adenosquamous carcinomas, 3 papillary serous carcinomas, and 1 clear cell carcinoma) and eight lesions of endometrial hyperplasia for replication error (RER) using polymerase chain reaction amplification of CA repeated microsatellite sequences at 15 loci. RER was observed in 23 (28%) of the 83 endometrioid adenocarcinomas at at least one locus and in 19 (23%) at two or more loci (RER+ phenotype) in the seven most commonly observed loci, but not in carcinomas of other histological types or in endometrial hyperplasia. Lymphocyte infiltration around carcinoma cells, which is one of the histological features seen in tumors from HNPCC, was severer in RER+ phenotype tumors (79%, 11/14) than in the RER- tumors (25%, 11/44) (marked/moderate infiltration versus slight, P < 0.001, chi 2 test), when 58 tumors with muscular invasion were examined. The RER+ phenotype was associated with a higher parity and gravidity (P < 0.05, Wilcoxon test). However, RER+ phenotype was not associated with tumor stage, histological grade, muscular invasion, lymph node metastasis or patient survival. In conclusion, MI occurs in a subset of endometrial cancers, which often show marked infiltration of lymphocytes around the tumor.

Different responses other than the formation of DNA-adducts between the livers of carcinogen-resistant rats (DRH) and carcinogen-sensitive rats (Donryu) to 3'-methyl-4-dimethylaminoazobenzene administration

Carcinogen-resistant inbred DRH rats developed from the Donryu strain showed a remarkably low incidence of liver tumors when they were fed diets containing hepatocarcinogens such as 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). In this work, we examined various characteristics of male DRH and Donryu rats during 3'-Me-DAB administration for 8 weeks. 32P-Postlabeling analysis showed that essentially similar levels of DNA-adducts were generated by the metabolites of 3'-Me-DAB in the livers of these two strains of rats at several time points. However, both GADD45 (growth arrest and DNA damage-inducible) and O6-methylguanine methyltransferase (putatively DNA damage-inducible) mRNA levels were increased significantly in Donryu rat livers, but were increased to a lesser extent in DRH rats. [3H]Thymidine incorporation into hepatic DNA began to increase around 10 to 20 days after the start of 3'-Me-DAB administration in Donryu rats probably due to DNA repair, while no significant change occurred in DRH rats under the same conditions. Furthermore, inductions of heme oxygenase (due to degradation of heme-proteins) and hepatocyte growth factor (HGF; cell death and regeneration of hepatocytes) mRNAs were greater in Donryu rat livers than those of DRH, suggesting that the former were more sensitive to cytotoxic effects of 3'-Me-DAB than the latter. Another remarkable difference observed between these two strains was the significant induction of cytochrome P-450 2E1 mRNA in Donryu rat livers; this may contribute to the generation of reactive oxygen intermediates. Finally, increases of glutathione S-transferase (P-form) and gamma-glutamyltranspeptidase mRNAs as marker enzymes of preneoplastic changes of hepatocytes were clearly seen only in Donryu rat livers at 6 to 8 weeks after the start of 3'-Me-DAB administration. These results indicate that the different susceptibility to hepatocarcinogenesis between these two strains of rats may arise from events other than the DNA adduct formation.

Mortality and cancer incidence in Misasa, Japan, a spa area with elevated radon levels

A historical cohort study was conducted in Misasa town, Tottori prefecture, Japan, where radon spas have been operating for a long time. Misasa town was divided into an elevated radon level area and a control area, with mean indoor radon levels of about 60 and 20 Bq/m3, respectively. In total, 3,083 subjects in the elevated radon level area and 1,248 in the control area, all aged 40 or older on January 1, 1976, were followed up until December 31, 1993, for a mean period of 14 years. The mortality rates from all causes exhibited no difference between the elevated radon level area and the control area for both sexes. No difference was observed in the incidence of all-site cancers (age, period-adjusted rate ratios by Poisson regression, RR = 1.06, 95% confidence interval (CI) 0.79-1.42 for males, RR = 0.90, 95% CI 0.65-1.24 for females), while stomach cancer incidence seemed to decrease for both sexes (RR = 0.70, 95% CI 0.44-1.11 for male, RR = 0.58, 95% CI 0.34-1.00 for female) and lung cancer incidence for males only seemed to increase (RR = 1.65, 95% CI 0.83-3.30 for male, RR = 1.07, 95% CI 0.28-4.14 for female) in the elevated radon level area. Caution is needed in the interpretation of these findings, however, since the individual exposure level was not measured and major confounding factors, such as smoking and diet, could not be controlled in this study.

Development of high-grade renal cell carcinomas in rats independently of somatic mutations in the Tsc2 and VHL tumor suppressor genes

Ferric nitrilotriacetate (Fe-NTA) induces renal proximal tubular damage that ultimately leads to a high incidence of renal cell carcinoma (RCC) in rats. The RCCs are characterized by 1) high incidence of pulmonary metastasis and peritoneal invasion, 2) high incidence of tumor-associated mortality and 3) possible involvement of reactive oxygen species in carcinogenesis. The present study investigated the possible role of Tsc2 and VHL tumor suppressor genes in this model. Thirty-four Fe-NTA-induced primary RCCs and 20 other primary or metastatic tumors of rats were searched for genetic alteration in all the coding exons of both genes by polymerase chain reaction-single-strand-conformation polymorphism analysis and sequencing in conjunction with morphological evaluation. In the Fe-NTA-induced RCCs, frequency of metastasis or invasion was proportionally associated with the nuclear grade of the tumor (grades 1-3). Only one Fe-NTA-induced RCC of grade 1 revealed missense mutations with loss of heterozygosity in exon 10 of the Tsc2 gene (codons 334, GTG (Val) to GCG (Ala), and 336, TAT (Tyr) to CAT (His). No mutation was found in the VHL gene. The results suggest that 1) high-grade RCCs can develop in the absence of mutations in the Tsc2 and VHL genes in rats, and that 2) Tsc2 gene somatic mutation can nonetheless be one of the causes of non-Eker rat RCCs.

Infrequent mutations of the hOGG1 gene, that is involved in the excision of 8-hydroxyguanine in damaged DNA, in human gastric cancer

DNA glycosylase, encoded by the hOGG1 gene, repairs 8-hydroxyguanine (oh8Gua), which is an oxidatively damaged mutagenic base. To clarify whether the DNA repair activity of hOGG1 protein is involved in gastric carcinogenesis, we examined 9 gastric cancer cell lines and 35 primary gastric cancers for mutations and genetic polymorphisms of the hOGG1 gene by polymerase chain reaction-single strand conformation polymorphism analysis. A G-to-A transition was detected in a gastric cancer cell line, MKN1. This nucleotide change caused the conversion of the amino acid from Arg to His at codon 154, which is located in a domain highly conserved among human, mouse, and yeast OGG1 proteins. No mutation was detected in primary gastric cancers. We compared the distribution of the polymorphic alleles associated with enzymatic activity (hOGG1-Ser326 vs. hOGG1-Cys326) between 35 gastric cancer patients and 42 healthy individuals. Although the frequency of the Cys326 allele, associated with low enzymatic activity, in gastric cancer patients was a little higher than that in healthy individuals, the difference did not reach statistical significance. These results suggest that low hOGG1 activity due to mutations and genetic polymorphisms is involved in the development of only a small subset of gastric cancers.

Expression of cadherin-catenin cell adhesion molecules, phosphorylated tyrosine residues and growth factor receptor-tyrosine kinases in gastric cancers

Tyrosine phosphorylation of beta-catenin, an intracytoplasmic E-cadherin-binding protein, has been shown to disrupt the cadherin-mediated cell adhesion system in vitro. In order to investigate the relationships of expression and tyrosine phosphorylation of cadherin-catenin molecules and expression of growth factor receptor-tyrosine kinase with loose cell-to-cell adhesion, immunohistochemical staining for E-cadherin, alpha- and beta-catenin, phosphorylated tyrosine residues and tyrosine kinase receptors, including c-erbB-2, epidermal growth factor-receptor (EGF-R), c-met and K-sam, in 17 undifferentiated- and 10 differentiated-type human gastric cancers was performed. Loss or reduced expressions of E-cadherin and alpha- and beta-catenin (11, 11, 10 cancers, respectively) were observed in the former, but not the latter. Diffuse cytoplasmic staining of E-cadherin, alpha- and beta-catenin and phosphotyrosine residues was observed frequently in the undifferentiated-type cancers. The cytoplasmic localization of phosphotyrosine residues in undifferentiated-type cancers was correlated significantly with K-sam expression (P < 0.01) and diffuse cytoplasmic staining of E-cadherin (P < 0.05) and beta-catenin (P < 0.05). Expression of K-sam protein was detected significantly more frequently in undifferentiated- (6/17; P < 0.05) than differentiated-type adenocarcinomas whereas the converse applied to c-erbB-2 expression (8/10 of the latter, P < 0.05). Tyrosine phosphorylation of beta-catenin was directly confirmed in the protein extracts of one undifferentiated-type gastric cancer. These data indicate that alteration of tyrosine phosphorylation status associated with K-sam expression may cause the cytoplasmic distribution of cadherin-catenin molecules and loose cell-cell adhesion in undifferentiated-type gastric cancers.

The TdT-mediated dUTP nick end labeling assay precisely assesses the DNA damage in human tumor xenografts

Cultured HL-60, HeLa S3 and WiDr cells grown in male BALB/c nu/nu mice were studied by conventional and field-inversion DNA gel electrophoresis (FIGE), as well as by means of cytomorphological approaches, including TdT-mediated dUTP nick end labeling (TUNEL) assay. Chemosensitivity tests revealed HL-60 to be sensitive to vindesine (VDS), and HeLa S3 and WiDr to mitomycin C (MMC). Although VDS-treated HL-60 exhibited condensation of chromatin and a DNA ladder, MMC-exposed HL-60 cells showed apoptotic figures without typical DNA ladders. With MMC-treated WiDr cells, neither DNA ladders nor apoptotic figures were observed. Cells characterized by chromatin condensation were TUNEL-positive in both treated and untreated cases with the exception of the MMC-treated WiDr case, in which many TUNEL-positive cells were observed without cytomorphological changes. On FIGE, DNA fragments of approximately 50, 300 and 400 kbp were detected in groups treated with both effective and ineffective drugs, as well as in untreated controls. Furthermore, change of the time parameters in FIGE resulted in different sizes (550 and 850 kbp) of DNA fragments. These findings indicate that i) cell death is not always detectable in terms of apoptotic figures or DNA oligonucleosomal fragmentation, ii) only the TUNEL assay is a reliable tool to detect DNA damage and, iii) FIGE does not provide accurate size profiles of macromolecular DNA fragments.

Mutation analysis of the WT1 gene in myelodysplastic syndromes

The WT1 tumor suppressor gene was examined for mutations in a panel of 44 patients with myelodysplastic syndromes (MDS) including acute myelogenous leukemias (AML) secondary to MDS, using polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) analysis and sequencing analysis. A WT1 mutation was detected in one out of 17 cases of AML secondary to MDS. This mutation exists upstream of the zinc finger region and is predicted to produce a truncated WT1 protein lacking the zinc finger region. No mutations were detected in 27 MDS patients who had not progressed to AML. This is the first report of analysis for WT1 mutations in a large number of MDS patients, suggesting that WT1 mutations are uncommon in MDS. Abnormalities in this gene may, however, contribute to a small proportion of cases showing progression from MDS into AML.

Differential expression of DNA topoisomerase II alpha and II beta genes between small cell and non-small cell lung cancer

DNA topoisomerase II (Topo II) inhibitors are widely used in lung cancer chemotherapy, but small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) show different sensitivity to them. In this study, we examined the gene expression levels of both isoforms of Topo II (II alpha and II beta) in lung cancer specimens to investigate the differential expression between SCLC and NSCLC. The expression levels of the Topo II alpha and Topo II beta genes were assessed in 80 autopsy samples (40 primary tumors and 40 corresponding normal lung tissues) by using the reverse transcription polymerase chain reaction. We found that the expression levels of the Topo II alpha gene in tumors were significantly higher than those in normal lung tissues, and that those in SCLC were significantly higher than those in NSCLC. There were no significant differences in Topo II beta gene expression between tumors and normal lung tissues and between SCLC and NSCLC. Further-more, correlation analysis revealed that Topo II alpha expression was correlated with Topo II beta expression in both tumor and normal lung tissues. These results indicate that a difference exists in the regulation of the Topo II gene between lung tumors and normal lung tissues. Our finding of differential expression of Topo II alpha between SCLC and NSCLC also suggests that the Topo II alpha expression level is associated with sensitivity to Topo II inhibitors.

Somatic mutations of the PTEN/MMAC1 gene in fifteen Japanese endometrial cancers: evidence for inactivation of both alleles

Loss of heterozygosity (LOH) of chromosome 10q is observed in approximately 40% of endometrial cancers. Mutations in PTEN/MMAC1, a gene recently isolated from the 10q23 region, are responsible for two dominantly inherited neoplastic syndromes, Cowden disease and Bannayan-Zonana syndrome. Somatic mutations of this gene have also been detected in sporadic cancers of the brain, prostate and breast. To investigate the potential role of this putative tumor suppressor gene in endometrial carcinogenesis as well, we examined 46 primary endometrial cancers for LOH at the 10q23 region, and for mutations in the entire coding region and exon-intron boundaries of the PTEN/MMAC1 gene. LOH was identified in half of the 38 informative cases, and subtle somatic mutations were detected in 15 tumors (33%). Our results suggest that of the genes studied so far in endometrial carcinomas, PTEN/MMAC1 is the most commonly mutated one, and that inactivation of both copies by allelic loss and/or mutation, a pattern that defines genes as "tumor suppressors," contributes to tumorigenesis in endometrial cancers.

Sequence analysis of genes encoding rodent homologues of the human tumor-rejection antigen SART-1

Human SART-1 (hSART-1) gene encodes a 125 kD protein with a leucine-zipper motif expressed in the nucleus of all proliferating cells, and a 43 kD protein expressed in the cytosol of most epithelial cancers. In this study, two rodent genes (rSART-1 and mSART-1) homologous to hSART-1 were cloned from cDNA libraries of murine brain and a rat tumor cell line, respectively. mSART-1 and rSART-1 were highly homologous to hSART-1 with 86% and 84% identity at the nucleotide level, and 95% and 91% at the protein level, respectively. The leucine zipper domain and two basic amino acid portions that bind DNA, as well as peptide sequences recognized by human cytotoxic T lymphocytes (CTLs), were all conserved in these rodent genes. Nuclear protein homologous to the 125 kD hSART-1(800) protein, but not to the 43 kD cytosol SART-1(259) protein, was detectable with specific antibody in the nuclear fractions of rodent tumor cell lines, and normal rodent fetal liver and testis. These rodent genes should be a novel tool for studies on the biological roles of the SART-1 gene, and also in the construction of animal models of specific immunotherapy using SART-1 gene products.

Rhenium-186-mercaptoacetyltriglycine-labeled monoclonal antibody for radioimmunotherapy: in vitro assessment, in vivo kinetics and dosimetry in tumor-bearing nude mice

Stability and immunoreactivity of 186Re-labeled monoclonal antibody were examined, and its in vivo kinetics was investigated in tumor-bearing Balb/c nu/nu female mice to assess the feasibility of using it in radioimmunotherapy (RIT). A murine IgG1, A7, against a 45 kD glycoprotein in human colon cancer was radiolabeled with 186Re by using a chelating method with a mercaptoacetyltriglycine (MAG3). 186Re-MAG3 complex was conjugated to A7 after esterification of 186Re-MAG3 with tetrafluorophenol (TFP). The efficiency of 186Re-MAG3-TFP production and the labeling efficiency of A7 were 51-59% and 57-60%, respectively. Immunoreactivity of purified 186Re-MAG3-A7 was 68.2% at infinite antigen excess. In 0.9% NaCl at 4 degrees C, the radioactivity (12.7 MBq/mg, 3.55 MBq/ml) dissociated with time from 186Re-MAG3-A7 as a small molecular weight moiety because of autoradiolysis. The addition of ascorbic acid, 5 mg/ml, as a radioprotectant or storage at -80 degrees C could effectively prevent the radiolysis of 186Re-MAG3-A7 for 7 days. Immunoreactivity of 186Re-MAG3-A7, 6.70 MBq/mg (6.66 MBq/ml), stored in the presence of ascorbic acid was well retained up to 8 days after the preparation. In colon cancer xenografted mice, 31.0% of the injected dose/g of 186Re-MAG3-A7 had accumulated in the tumors at 24 h postinjection. Estimated radiation dose to tumors was 14.9 cGy/37 kBq up to 8 days postinjection which was 12-fold greater than the whole-body radiation dose. These in vivo characteristics were superior to those of A7 labeled with radioiodine, affording greater therapeutic ratios than 131I-A7. Because of the better image quality of 186Re-MAG3-A7 as well as more favorable dosimetry, 186Re-MAG3-A7 would be a better choice for RIT of colon cancer than 131I-A7. These results indicated the feasibility of RIT with 186Re-MAG3-A7, though the prevention of radiolysis of the labeled antibody should be considered.

Nonsense mutation at codon 63 of the BRCA1 gene in Japanese breast cancer patients

The involvement of abnormalities of the BRCA1 gene in breast cancers in Japanese patients without any family history of this cancer was investigated by polymerase chain reaction-based single-strand conformation polymorphism analysis of the DNA sequences corresponding to the zinc finger domain (exons 2, 3 and 5) and the binding domain with Rad51 (exon 11) of the BRCA1 protein. An identical nonsense mutation at codon 63 (TTA to TAA) was found in 2 of 56 (3.5%) breast cancers from independent patients. The nucleotide change was also detected in the DNAs from non-cancerous tissues of both patients and therefore was a germline mutation. One of the patients was a member of a pedigree involving 3 ovarian cancer and 1 gastric cancer patients, while the other patient had no family history of malignancy. The same germline mutation at codon 63 was reported in four other independent Japanese pedigrees with frequent breast cancer, but not in such families in other countries. These observations suggest that the mutation commonly originated from a single Japanese ancestor. No other mutation of the BRCA1 gene was observed in the samples analyzed in this study. A low incidence of germline mutation and the absence of somatic mutation suggest that the aberration of the BRCA1 gene is involved only in a subset of Japanese breast cancers.

Human T-lymphotropic virus type-I infection, antibody titers and cause-specific mortality among atomic-bomb survivors

There have been few longitudinal studies on the long-term health effects of human T-lymphotropic virus type-I (HTLV-I) infection. The authors performed a cohort study of HTLV-I infection and cause-specific mortality in 3,090 atomic-bomb survivors in Nagasaki, Japan, who were followed from 1985-1987 to 1995. The prevalence of HTLV-I seropositivity in men and women was 99/1,196 (8.3%) and 171/1,894 (9.0%), respectively. During a median follow-up of 8.9 years, 448 deaths occurred. There was one nonfatal case of adult T-cell leukemia/lymphoma (incidence rate = 0.46 cases/1,000 person-years; 95% confidence interval [CI] 0.01-2.6). After adjustment for sex, age and other potential confounders, significantly increased risk among HTLV-I carriers was observed for deaths from all causes (rate ratio [RR] = 1.41), all cancers (RR = 1.64), liver cancer (RR = 3.04), and heart diseases (RR = 2.22). The association of anti-HTLV-I seropositivity with mortality from all non-neoplastic diseases (RR = 1.40) and chronic liver diseases (RR = 5.03) was of borderline significance. Possible confounding by blood transfusions and hepatitis C/B (HCV/HBV) viral infections could not be precluded in this study. However, even after liver cancer and chronic liver diseases were excluded, mortality rate was still increased among HTLV-I carriers (RR = 1.32, 95% CI 0.99-1.78), especially among those with high antibody titers (RR = 1.56, 95% CI 0.99-2.46, P for trend = 0.04). These findings may support the idea that HTLV-I infection exerts adverse effects on mortality from causes other than adult T-cell leukemia/lymphoma. Further studies on confounding by HCV/HBV infections and the interaction between HCV/HBV and HTLV-I may be required to analyze the increased mortality from liver cancer and chronic liver diseases.

Expression of the TCL1 gene at 14q32 in B-cell malignancies but not in adult T-cell leukemia

The TCL1 gene was recently cloned as a candidate target within the 14q32.1 breakpoint cluster region observed in T-cell malignancies. We examined the TCL1 gene expression in 21 patients with adult T-cell leukemia (ATL) and 5 cell lines, because ATL is reported to have frequent chromosome 14 band q32 aberrations. However, 20 of the ATL patients and all 5 cell lines lacked any TCL1 expression on northern blot analysis, and TCL1 transcripts were only very faintly detected in the remaining one patient. Expansion of our analysis to include other types of hematopoietic malignancies revealed strong expression of the TCL1 gene in almost all tumor cells of B-cell lineage except myelomas. However, no TCL1 signals were encountered in cells of T-cell or myeloid lineages. In normal human tissues TCL1 was found to be expressed in the spleen, lymph nodes and B-lymphocytes of peripheral blood. These results indicate that TCL1 is not a major target gene for ATL, but that it may play a role in B-cell differentiation and proliferation.

Molecular analysis of Ewing's sarcoma: another fusion gene, EWS-E1AF, available for diagnosis

Ewing's sarcoma, one of the most malignant tumors of children and young adults, expresses specific chimeric genes, e.g. EWS-FLI-1, EWS-ERG, EWS-ETV1 and EWS-FEV. In this paper, we extensively characterized a new fusion gene, EWS-EIAF by means of whole cDNA sequencing, RNA blot analysis, DNA blot analysis and chromosomal analysis, and showed it to be available for the diagnosis of Ewing's sarcoma and to participate in the oncogenesis of Ewing's sarcoma. Furthermore, we conducted a genetic analysis of Ewing family tumors in conjunction with immunohistochemical analysis and ultrastructural analysis. Our results demonstrate some limitations of both genetic analysis and histopathological analysis, and establish the relationship between neurogenic phenotypes and chimera genes.

Lung cancer patients have increased 8-hydroxydeoxyguanosine levels in peripheral lung tissue DNA

The 8-hydroxydeoxyguanosine (8-OH-dG) levels in the peripheral parts of human lung tissues were compared between lung cancer patients (n=70) and non-cancer patient controls (n=15). An increased level of 8-OH-dG was observed in the lung cancer group, in both the adenocarcinoma and non-adenocarcinoma (mainly squamous cell carcinoma) groups, as compared to the non-cancer control group. This result suggests that reactive oxygen species are partly involved in the induction of lung carcinomas (both adenocarcinoma and non-adenocarcinoma).

Antitumor immunity induction by intracellular hyperthermia using magnetite cationic liposomes

Induction of antitumor immunity to T-9 rat glioma by intracellular hyperthermia using functional magnetic particles was investigated. Magnetite cationic liposomes (MCLs), which have a positive surface charge, were used as heating mediators for intracellular hyperthermia. Solid T-9 glioma tissues were formed subcutaneously on both femurs of female F344 rats, and MCLs were injected via a needle only into the left solid tumors (treatment side). The rats were then divided into two groups, which received no irradiation, or irradiation for 30 min given three times at 24-h intervals with an alternating magnetic field (118 kHz, 384 Oe). On the treatment side, the tumor tissue disappeared completely in many rats exposed to the magnetic field. The tumor tissue on the opposite side also disappeared completely, even though MCLs were not injected into the right solid tumors. To examine whether a long-lasting and tumor-specific immunity could be generated, the rats that had been cured by the hyperthermia treatment were rechallenged with T-9 cells 3 months later. After a period of transient growth, all tumors disappeared. Furthermore, immunocytochemical assay revealed that the immune response induced by the hyperthermia treatment was mediated by both CD8+ and CD4+ T cells and accompanied by a marked augmentation of tumor-selective cytotoxic T lymphocyte activity. These results suggest that our magnetic particles are potentially effective tools for hyperthermic treatment of solid tumors, because in addition to killing of the tumor cells by heat, a host immune response is induced.

Applicability of combination with tirapazamine in boron neutron capture therapy

SCC VII tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine (BrdU) to label all proliferating cells. After injection of tirapazamine (TPZ), a bioreductive agent, combined with sodium borocaptate-10B (BSH) or dl-p-boronophenylalanine-10B (BPA) administration, the tumors were irradiated with thermal neutrons, and then isolated and incubated with cytochalasin-B (a cytokinesis blocker). The micronucleus (MN) frequency in cells without BrdU labeling (quiescent (Q) cells) was determined by means of immunofluorescence staining for BrdU, and that for total cells was obtained from tumors not pretreated with BrdU. Even when no 10B-compound was administered, TPZ increased the MN frequency of tumor cells including Q cells, resulting in reduction of the difference in MN frequency between total and Q cells, mainly by increasing the MN frequency of Q cells. TPZ increased the MN frequency of Q cells when combined with BPA administration, but TPZ showed no apparent effect on each cell population when combined with BSH. Namely, TPZ reduced the difference in MN frequency between total and Q cells caused by 10B-compound administration, especially when BPA was administered. From the viewpoint of the overall cell killing effect in boron neutron capture therapy (BNCT), combination with TPZ appeared to be useful in BPA-BNCT, but not in BSH-BNCT.

Growth inhibition of CD20-positive B lymphoma cell lines by IDEC-C2B8 anti-CD20 monoclonal antibody

Treatment with IDEC-C2B8 (C2B8), the chimeric anti-CD20 antibody, was shown in a phase I-II study to be very effective for the treatment of low-grade B-cell lymphoma, in contrast to the results of most previous immunotherapies with monoclonal antibodies. In a study designed to elucidate the reason for this efficacy, two cell lines derived from lymphomas with BCL2 gene rearrangement (SU-DHL-4 and SU-DHL-6) showed remarkable growth inhibition and cell-death, and two other cell lines derived from a diffuse lymphoma (RC-K8) and a mantle cell lymphoma (SP-49) showed moderate growth inhibition, but neither a CD20 weakly positive cell line (NALL-1) nor a negative cell line (MOLT-4) showed any growth inhibition. An examination of the intensity of cell-surface CD20 expression showed no correlation between intensity and degree of growth inhibition among the four cell lines showing growth inhibition. Morphological examination revealed condensed and fragmented nuclei and budding of the plasma membrane, both characteristic of apoptosis, with some cells in these cell lines showing growth inhibition by C2B8. Such apoptosis was also confirmed by flow cytometric analysis, suggesting that, at least in part, apoptosis plays a role in this growth inhibition. This growth-inhibitory mechanism may thus account for the effectiveness of C2B8 antibody therapy.

Surgical significance of telomerase activity in noncancerous liver tissue from patients with hepatocellular carcinoma

Telomerase activity has been detected in tissue from noncancerous liver of patients with chronic liver disease, but its functional significance remains to be elucidated. We therefore evaluated the telomerase activity in surgically obtained noncancerous liver tissue from 20 hepatocellular carcinoma (HCC) patients. Two samples of noncancerous liver tissue were obtained from each patient: one from the parenchyma adjacent to the HCC nodules of the resected specimen; the other from the parenchyma distant from the HCC nodules of the remnant liver. Telomerase activity was assayed by a non-radioisotope quantitative system based on "TRAP-eze." Five samples from the noncancerous liver tissue adjacent to the HCC nodules (25.0%) were telomerase-positive; all such cases showed high-grade malignant potential, such as intrahepatic metastasis and/or portal vascular invasion and infiltration of the fibrous capsule in the corresponding HCC nodules, and telomerase positivity showed neither a relationship with the histological activity index scores nor a correlation with liver function. Interestingly, no telomerase activity was detected in any of the 20 samples obtained from the parenchyma of the remnant liver. These results indicate that telomerase in noncancerous liver tissue is associated not with the hepatic condition accompanying HCC, but with the biological characteristics of the tumor itself, and may derive from infiltrating cancer cells. Determination of telomerase status may aid in designing more effective surgical procedures.

Inhibitory effects of ginsenoside Rh2 on tumor growth in nude mice bearing human ovarian cancer cells

Ginsenoside Rh2 (Rh2), isolated from an ethanol extract of the processed root of Panax ginseng CA Meyer, inhibits the growth of B16 melanoma cells. This study was designed to evaluate the ability of Rh2 to inhibit growth of human ovarian cancer cells (HRA) in vitro and in nude mouse. Rh2 inhibited proliferations of various established human ovarian cancer cell lines in a dose-dependent manner between 10 and 60 microM in vitro and induced apoptosis at around the IC50 dose. When HRA cells were inoculated s.c. into the right flank of nude mice, all mice formed a palpable tumor within 14 days. Although i.p. administration of Rh2 alone hardly inhibited the tumor growth, when Rh2 was combined with cis-diamminedichloroplatinum(II) (CDDP) the tumor growth was significantly inhibited, compared to treatment with CDDP alone. When mice were treated p.o. with Rh2 daily (but not weekly), the tumor growth was significantly (P<0.01) inhibited, compared to CDDP treatment alone. When Rh2 was combined with CDDP, the degree of tumor growth retardation was not potentiated. The survival time was significantly (P<0.05) longer than that of medium alone-treated controls or the group treated with CDDP alone. Then, we examined whether p.o. administration of Rh2 has a dose-dependent inhibitory effect on the tumor growth. I.p. and weekly administration of CDDP had more potent antitumor activity in the order of 1 mg/kg, 2 mg/kg and 4 mg/kg, whereas p.o. and daily administration of Rh, (0.4 to 1.6 mg/kg) not only had antitumor activity comparable to that of 4 mg/kg CDDP, but also resulted in a significant increase of the survival. Doses of Rh2 used in this study did not result in any adverse side-effects as confirmed by monitoring hematocrit values and body weight, unlike 4 mg/kg CDDP, which had severe side-effects. It is noteworthy that p.o. but not i.p. treatment with Rh2 resulted in induction of apoptotic cells in the tumor in addition to augmentation of the natural killer activity in spleen cells from tumor-hearing nude mice. Thus, particularly in view of the toxicity of CDDP, Rh2 alone would seem to warrant further evaluation for treatment of recurrent or refractory ovarian tumor.

Fluorescence in situ hybridization analysis of 12;21 translocation in Japanese childhood acute lymphoblastic leukemia

Fluorescence in situ hybridization (FISH) analysis was applied to detect t(12;21) using two yeast artificial chromosome probes and cosmid probes covering the TEL(ETV6) and the AML1 gene to clarify the incidence of abnormality of t(12;21) in Japanese childhood acute lymphoblastic leukemia (ALL). We detected seven TEL/AML1 fusion positive patients (9.5%), all of whom were diagnosed as B-lineage ALL, among 74 childhood ALL. On the other hand, no TEL/AML1 fusion positive patients were found among 37 adult ALL. The incidence among Japanese seemed to be lower than that among other nations. Of the seven patients with the TEL/AML1 fusion, five exhibited normal karyotype, one was t(8;12)(q11;p13), i(21q) and the remaining one exhibited a near-triploid karyotype in conventional G-banding. The FISH method clearly demonstrated that all patients with the TEL/AML1 fusion had subpopulations of leukemic cells with deletion of the normal TEL allele, which is significant for understanding the progression of leukemia with t(12;21).

Fas and mutant estrogen receptor chimeric gene: a novel suicide vector for tamoxifen-inducible apoptosis

Several cancer gene therapy strategies involve suicide genes to kill the neoplasm, or to regulate effector cells such as lymphocytes. We have developed an inducible apoptosis system with a Fas-estrogen receptor fusion protein (MfasER) for rapid elimination of transduced cells. In the present study, we further improved this molecular switch for estrogen-inducible apoptosis to overcome concerns with the wild-type estrogen receptor and its natural ligand, 17beta-estradiol (E2). The ligand-binding domain of MfasER was replaced with that of a mutant estrogen receptor which is unable to bind estrogen yet retains affinity for a synthetic ligand, 4-hydroxytamoxifen (Tm). The resultant fusion protein (MfasTmR) and MfasER were expressed in L929 cells for examination of their ligand specificities. Tm induced apoptosis in MfasTmR-expressing cells (L929MfasTmR) at 10(-8) M or higher concentrations, but induced no apoptosis in MfasER-expressing cells (L929MfasER) at up to 10(-6) M. On the other hand, E2 induced apoptosis in L929MfasER at concentrations as low as 10(-10)-10(-9) M, while it did so partially in L929MfasTmR at concentrations greater than 10(-7) M. Thus, L929MfasTmR cells were highly susceptible to Tm, but refractory to E2, with 100-1,000 times more tolerance than L929MfasER. These results suggest that the MfasTmR/Tm system would induce apoptosis in the target cells more safely in vivo, working independently of endogenous estrogen.

Expression of G1-->S transition regulatory molecules in human urothelial cancer

Growth of cancer cells is characterized by accelerated passage through the cell cycle, which is often caused by deregulation of the G1-->S transition. In this study the expression of G1-->S transition regulatory molecules was analyzed in 32 transitional cell carcinoma specimens and fifteen normal tissues obtained by cystectomy or nephroureterectomy of mainly locally advanced tumors, as well as six bladder cancer cell lines. Expression of mRNAs for cyclins D1 and D2 and cyclin-dependent kinases (CDK) 2 and 4 was investigated by quantitative reverse transcription-polymerase chain reaction. Overexpression of cyclin D1 compared to normal mucosa was observed in 3 tumors (9.4%), but in neither of the cell lines. All tumors with overexpression were moderately differentiated (G2) pT1 or pT2 tumors, and thus among the less advanced specimens. Cyclin D2 was not expressed in normal bladder mucosa or in tumors. The expression of CDK4 mRNA varied within the same range in mucosa, tumors, and cell lines. CDK2 mRNA expression varied more strongly and was diminished in individual tumors and in four cell lines. It is concluded that cyclin D1 overexpression can play an important role in the early stage of urothelial tumorigenesis, driving cell proliferation. Ectopic expression of cyclin D2 or amplification of CDK4 does not occur at a significant frequency in urothelial carcinomas. Different expression patterns of cyclin D1 and CDK2 indicate heterogeneity in the mechanisms of G1-->S transition deregulation in individual bladder tumors which may elicit differences in their biological and clinical behavior.

Significant correlation of nitric oxide synthase activity and p53 gene mutation in stage I lung adenocarcinoma

Nitric oxide (NO) and its derivatives can directly cause DNA damage and mutation in vitro and may play a role in the multistage carcinogenic process. It has been reported that NO induces mutation in the p53 tumor suppressor gene; we therefore analyzed the relationship between NO synthase (NOS) activity and p53 gene status in early-stage lung adenocarcinoma. Surgical samples were classified into two categories: 14 lung adenocarcinomas with high NOS activity (>25 pmol/min/g tissue, category A), and 16 with low NOS activity (<25 pmol/min/g tissue, category B). A yeast functional assay for p53 mutations disclosed a red colony that corresponded to a mutation in the p53 gene in 8 cases (57.1%) in category A and 3 cases (18.8%) in category B, the frequency being significantly higher in the former (P<0.05). A p53 DNA sequence analysis revealed that 5 of the 8 p53 mutation-positive samples in category A had a G:C-to-T:A transversion, which is reported to be a major target of NO. The mechanism of carcinogenesis of adenocarcinoma is not fully understood, but these results suggest that an excess of endogenously formed NO may induce a p53 gene mutation containing mainly G:C-to-T:A transversion in the early stage of lung adenocarcinoma. Our results suggest that NO has potential mutagenic and carcinogenic activity, and may play important roles in human lung adenocarcinoma.

Release of cytokines from human umbilical vein endothelial cells treated with platinum compounds in vitro

Endothelial cells (EC) produce cytokines, such as interleukin (IL)-1, IL-6, IL-8 and granulocyte-macrophage colony-stimulating factor (GM-CSF). These cytokines have an important role in the proliferation and differentiation of hematopoietic progenitor cells. On the other hand, anticancer agents generally cause hematopoietic disorders. However, little is known about the effects of chemotherapeutic agents on the secretion of cytokines from EC. Therefore, we investigated if treatment with platinum compounds may stimulate EC to secrete cytokines. EC newly isolated from a human umbilical vein were exposed to cisplatin, carboplatin, or TRK-710 for 80 min, then the cells were washed and placed in fresh medium. The levels of cytokines in the fresh medium were measured by the ELISA method, the levels of intracellular hydrogen peroxide (H2O2) were measured by flow cytometry, and the rhodamine 123-stained live mitochondria of the EC were observed under a confocal laser microscope. Platinum compounds induced cytokine production in human EC: cisplatin most prominently induced the release of IL-1 and IL-6, and TRK-710 had the greatest ability to induce the release of GM-CSF. Intracellular H2O2 production and IL-8 release were transiently induced immediately after treatment with platinum compounds, leading to IL-1 release when H2O2 production was eliminated. These results may provide new insights into the hematological toxicity induced by anticancer agents and the role of IL-1 and IL-6 secreted from EC in this toxicity.

Provirus load in patients with human T-cell leukemia virus type 1 uveitis correlates with precedent Graves' disease and disease activities

We previously demonstrated the increased provirus load in the peripheral blood of patients with human T-cell leukemia virus type 1 (HTLV-1) uveitis (HU). To delineate the relevance of the increased provirus load to clinical and immunologic parameters, we studied the correlation between them. Seventy-nine HU patients (24 male and 55 female) were included in the study, with their informed consent. Plasma samples and genomic DNA of the peripheral blood mononuclear cells were isolated and the provirus load was estimated by semi-quantitative polymerase chain reaction of the gag region sequence. Serum levels of anti-HTLV-1 antibodies and soluble IL-2R were determined by electrochemiluminescence immuno assay and by ELISA, respectively. Disease activities were assessed and graded 0 to 4 according to the evaluation system. Recurrence of the disease during the follow-up period was diagnosed ophthalmologically. The provirus load was significantly higher in the HU patients after Graves' disease (GD) than in those without GD (P<0.05). It correlated with disease activities assessed in terms of vitreous inflammation and interval to recurrence (both P<0.05). In the HU patients without GD, it correlated with the serum levels of soluble IL-2 receptor (P<0.01), and nearly with those of HTLV-1 antibody (P=0.063). These correlations were not found in the HU patients after GD under methimazole treatment. The results suggested a direct involvement of HTLV-1-infected cells in the pathogenesis of uveitis, and raise the possibility that hyperthyroidism may contribute to the clonal expansion of HTLV-1-infected cells.

Cytotoxic mechanisms of FK317, a new class of bioreductive agent with potent antitumor activity

FK317 is a member of a new class of bioreductive agents that exhibit strong cytotoxicity against various human cancer cells. The effect of FK317 was found to be stronger than that of mitomycin C (MMC), adriamycin (ADR) or cisplatin (CDDP). Alkaline elution analysis indicated that FK317 formed interstrand DNA-DNA and DNA-protein cross-links in cells. On the other hand, no DNA single-strand breaks were observed in the cells treated with FK317. In a cell-free system the deacetylated metabolites produced cross-linked DNA under reductive conditions, though FK317 itself did not form DNA-DNA cross-links. In order to elucidate the metabolic activation mechanisms, we established an FK317-resistant subline from human non-small cell lung cancer cells (Lu99) by stepwise and brief exposure (1 h) to FK317. The resistant subline (Lu99/317) showed cross-resistance to MMC and carboquone (CQ), but not to ADR or CDDP. DT-diaphorase, which is one of the activation enzymes of MMC and CQ, was deficient in Lu99/317 cells as determined by enzyme activity assay. However, the levels of NADPH:cytochrome P450 reductase, which is another activation enzyme for MMC and CQ, were comparable in resistant and parent cell lines. Treatment of the cells with dicumarol, an inhibitor of DT-diaphorase, reduced the cytotoxicity of FK317 to Lu99 cells, but not to Lu99/317 cells. These results indicate that deacetylation of FK317 is necessary for its reductive activation, and deacetylated FK317 is reduced by DT-diaphorase to form an active metabolite, which produces DNA-DNA interstrand and DNA-protein cross-links that lead to cell death.

Increased hepatic nicotinamide N-methyltransferase activity as a marker of cancer cachexia in mice bearing colon 26 adenocarcinoma

When a cachexigenic subclone (clone 20) of murine colon 26 adenocarcinoma was transplanted into female BALB/c mice, hepatic NNMT activity continued to increase until death in proportion to progressive carcass weight loss, a marker of cancer cachexia. On the other hand, noncachexigenic subclone (clone 5)-transplanted mice showed neither increase of NNMT activity nor carcass weight loss. Among cytostatic fluorinated pyrimidines, 5'-dFUrd could inhibit the increase of NNMT activity and prevent weight loss in mice bearing clone 20. On the other hand, 2'-dFUrd did not show these effects. 5-FUra and Tegafur inhibited the increase of NNMT activity at higher concentrations. These findings suggest that the levels of hepatic NNMT activity are closely associated with the degree of weight loss, and they appear to be a useful marker of cancer cachexia.

Identification of glutathione S-transferase p-1 as the class pi form dominantly expressed in mouse hepatic adenomas

To clarify which of the two genes for pi class glutathione S-transferases (GSTs) (p-1 and p-2) is dominantly expressed in mouse hepatic adenomas, the relative mRNA levels were examined by means of the reverse transcription-polymerase chain reaction (RT-PCR). Hepatic adenomas were induced in male and female B6C3F1 mice by diethylnitrosamine treatment. Northern blot analysis revealed that pi class mRNA levels were decreased in adenomas of male mice, but increased in those of females, with reference to the respective surrounding non-adenoma tissues. In contrast to the marked sex difference in surrounding tissues, pi class GST mRNA levels in adenomas were almost the same in both males and females. To evaluate p-1 and p-2 mRNA levels separately, the products of RT-PCR employing primers common for both cDNAs were digested with the endonuclease BanI (specific for p-2) and then resolved by electrophoresis. The p-1 mRNA was thus found to be dominant in adenomas of both female and male mice. The p-2 mRNA levels were increased in the lesions as compared with those in the surrounding non-adenoma tissues. Recombinant p-1 and p-2 proteins were expressed in Escherichia coli. Unlike p-1, the p-2 protein did not show any significant activity towards 1-chloro-2,4-dinitrobenzene and did not bind to S-hexylglutathione-Sepharose despite immunological cross-reactivity. The dominant pi class form in adenomas could also be identified as p-1 by its binding to S-hexylglutathione-Sepharose. Single radial immunodiffusion analyses confirmed that the p-1 protein levels were in line with the mRNA findings, i.e., 1.9+/-0.3 mg/g adenoma as compared to 6.5+/-1.2 mg/g non-adenoma tissue for males and 2.2+/-0.6 mg/g as compared to 0.7+/-0.2 mg/g for females. The results thus indicated that the change of pi class forms in adenomas is caused mainly by alteration in the p-1 level and the contribution of p-2 is minimal.