MicroRNAs in Cancer: the 22nd Hiroshima Cancer Seminar/the 4th Japanese Association for RNA Interference Joint International Symposium, 30 August 2012, Grand Prince Hotel Hiroshima.

The joint international symposium of the 22nd Hiroshima Cancer Seminar and the 4th Japanese Association for RNA Interference focused on a pivotal role of microRNAs in carcinogenesis, progression and therapy of human cancer. Mammalian immune regulator MCPIP1 (Zc3h12a) RNase acts as a novel suppressor of microRNA activity and biogenesis, suggesting the involvement of MCPIP1 in the alteration of microRNA biogenesis in tumorigenesis. Gene set enrichment analysis and functional assignment of microRNAs via enrichment analysis enable the prediction of microRNA activities from mRNA expression data by combining rank-based enrichment analysis and weighted evaluation of microRNA-mRNA interactions. MiR-124 and miR-203 function as tumor-suppressor microRNAs silenced by DNA methylation in hepatocellular carcinoma. Stella-induced DNA hypomethylation would confer the pathogenic function of DNA hypomethylation in cancer. Senescence-associated microRNA, miR-22, suppresses tumor growth and metastasis in vivo in a murine breast cancer model, and exosomal senescence-associated microRNA may affect the tumor microenvironment. The therapeutic potential of microRNAs for preventing and treating lung cancer using the Kras(LSL-G12D/+);p53(LSL-R172H/+)mouse model suggests that miR-34 may be useful in sensitizing tumors to other conventional therapeutics. MiR-1 and miR-133a cluster may function as tumor suppressors regulating novel pathways in human cancers. The down-regulation of miR-148a is implicated in invasion of gastric cancer, while high miR-21 expression in colorectal cancer is associated with poor survival. Neutral sphingomyelinase 2 regulates exosomal microRNA secretion and promotes angiogenesis within the tumor microenvironment as well as metastasis; in particular, the exosomal miR-210 secretion by neutral sphingomyelinase 2 confers the formation of the tumor vessel network.

Recent progress in carcinogenesis, progression and management of upper GI cancer: the 21st Hiroshima Cancer Seminar--the 5th Three Universities' Consortium International Symposium, 6 November 2011, International Conference Center Hiroshima.

The 21st Hiroshima Cancer Seminar focused on recent progress of carcinogenesis, progression and management of upper gastrointestinal cancers. ß-Catenin and p120 mediate peroxisome proliferator-activated receptor δ-dependent proliferation induced by Helicobacter pylori in gastric epithelia. Helicobacter pylori CagA plays an important role in stomach carcinogenesis via altered signal transduction and cell polarity by interactions with several host proteins. Inflammation caused by H. pylori infection is responsible for inducing aberrant DNA methylation. The gastric gland mucin-specific αGlcNAc plays dual roles in preventing gastric cancer, inhibition of H. pylori infection and suppression of tumor-promoting inflammation. Information obtained from transcriptome dissection greatly contributes to understanding the molecular character of each mucin phenotype of gastric cancer. The standardized biomarkers will serve as good predictive and prognostic markers for gastric cancer. A microRNA expression profile may be useful for the diagnosis of gastric cancer. Bone marrow-derived mesenchymal stem cells may provide an advantageous microenvironment for re-acquisition of stemness of gastric cancer cells. Recent progress in molecular biology research has enabled the clinical development of molecular targeting agents for gastric cancer, such as trastuzumab. The target molecule-based inhibition of the stromal reaction in the microenvironment may hold promise as an effective anti-tumor therapy. Since robotic surgery is feasible and safe, and provides adequate and precise lymph node dissection, it may be one of the good options for gastric cancer in the near future.

Recent progress in carcinogenesis, progression and therapy of breast cancer: the 20th Hiroshima Cancer Seminar--the 4th Three Universities' Consortium International Symposium, October 2010: 31 October 2010, International Conference Center Hiroshima.

The 20th Hiroshima Cancer seminar focused upon breast cancer research and treatment particularly on the mechanism of tumorigenesis and drug resistance and development of novel therapeutics. Several molecules such as retinoblastoma and p16 were raised as key factors in tumorigenesis and invasiveness. Estrogen-related pathways seem to be closely involved in the process. For the tumor lacking hormone receptor and human epidermal growth factor 2, some other mechanisms could be responsible. It seems that MicroRNA 22 directing some putative targets such as SIRT1, Sp1 and CDK6 plays a crucial role in breast tumor growth and metastasis. In addition, ribophorin and the associated molecules might be engaged in breast cancer stemness. Obviously, these molecules provide potential for therapeutic targets. It was also discussed about new drug development such as anti-human epidermal growth factor 2 therapy, anti-angiogenesis, pro-tumor aspects of anti-cancer therapy and application of circulating markers for monitoring, imaging and health-care system. Furthermore, we discussed risk factors, prevention and screening to reduce invasive cancers as well. Throughout the conference, panelists and attendee indicated the importance of translational research and biomarker exploration in order to realize efficient and individualized therapy for breast cancer.

Recent progress in carcinogenesis, progression and therapy of lung cancer: the 19th Hiroshima Cancer Seminar: the 3rd Three Universities' Consortium International Symposium, November 2009.

This symposium presented recent progress of the pathogenesis and treatment of lung cancer. Aberrantly increased expression of miR-21 plays a significant role in lung carcinogenesis and is a potential therapeutic target in both epidermal growth factor receptor-mutant and wild-type cases. miR-34 may be necessary for the radiation-induced DNA damage response. Detailed expression profiling analyses of transcriptome have potential to provide increased understanding of the molecular biology of lung cancer. An embryonic signature is present in lung adenocarcinoma only, associated with a worse clinical outcome. Cytoplasmic expression of caveolin and membranous expression of CD26 are specific to mesothelioma. Nectin-4 is a new candidate for serum and tissue biomarker as well as a therapeutic target for lung cancer. Clinical presentations have provided us a great deal information on epidermal growth factor receptor mutations for personalized therapy, combination therapy with inhibitors of the tyrosine kinase activity of epidermal growth factor receptor and cytotoxic agents, antibody-dependent cellular cytotoxicity activity, and current management of lung cancer depending on both the extent of the disease and the treatment approach.

An ankle sprain with long-term swelling and pain successfully treated with the traditional Japanese herbal medicine Jidabokuippo: A case report.

In this report, we present a case in which long-term swelling and pain because of an ankle sprain were successfully treated with the traditional Japanese herbal (Kampo) medicine Jidabokuippo. Jidabokuippo was created in Japan and has been used to treat swelling and pain associated with trauma. A 44-year-old woman sprained her right ankle and received the standard treatments including icing and immobilization for three weeks. However, the swelling, redness, and pain of her ankle continued for two months after the treatments. After initiating Jidabokuippo, her pain and swelling were promptly improved. This suggests that Jidabokuippo is a potentially promising pharmacotherapy for patients with ankle sprain which has not recovered smoothly. It is said that Jidabokuippo can be prescribed simply referring to pain and swelling of the affected areas; therefore, it should be considered as a treatment for trauma patients with long-term swelling and pain.

Discontinuation or reduction in benzodiazepine use by treatment with the traditional herbal medicine Hangekobokuto, case reports.

In this report, we present two cases in which benzodiazepines (BZDs) were able to be successfully reduced or discontinued by treatment with traditional Japanese herbal medicine (Kampo medicine), including Hangekobokuto (HKT). These two patients with long-term use of BZDs due to mental disorders suffered epigastric symptoms. After starting Kampo therapy including HKT, their epigastric symptoms were improved and they were able to reduce or discontinue the use of BZDs. This suggests that HKT is a potentially promising substitutive pharmacotherapy for patients with long-term use of BZDs. HKT should be considered as a treatment for patients with mental disorders who have taken BZDs for a long time and suffer from medically unexplained epigastric symptoms.

Modifying Effect of Chronic Atrophic Gastritis on Radiation Risk for Noncardia Gastric Cancer According to Histological Type.

The findings from previously published studies have suggested that radiation exposure is associated with increased mortality and incidence of gastric cancer. However, few cohort studies have incorporated risk factors such as Helicobacter pylori (H. pylori) infection or chronic atrophic gastritis (CAG). The current study is aimed at evaluating the modifying effect of CAG on radiation risk of noncardia gastric cancer by histological type, by reanalyzing data from a nested case-control study conducted within the longitudinal clinical cohort of atomic bomb survivors. The analysis was restricted to 297 intestinal- or diffuse-type noncardia cases and 873 controls rematched to the cases on gender, age, city, and time and type of serum storage, and countermatched on radiation dose. Multivariable-adjusted relative risks [95% confidence interval (CI)] of noncardia gastric cancer were 3.9 (2.1-7.2) for H. pylori IgG seropositivity with cytotoxin-associated gene A (CagA) IgG low titer, 2.6 (1.9-3.6) for CAG, 1.9 (1.3-2.8) for current smoking, and 1.4 (1.1-1.9) for 1 Gy irradiation. Among subjects without CAG, the relative risk (95% CI) of noncardia gastric cancer at 1 Gy was 2.3 (1.4-3.7), whereas relative risk (95% CI) at 1 Gy was 1.1 (0.8-1.5) among subjects with CAG (for the overall interaction, P = 0.012). By histological type, the risk at 1 Gy was high for diffuse type without CAG, with adjusted relative risk (95% CI) of 3.8 (2.0-7.6), but was not high for diffuse type with CAG or for intestinal-type irrespective of CAG status. The results indicate that radiation exposure is associated with increased risk of diffuse-type noncardia gastric cancer without CAG, and this association exists despite adjustment for H. pylori infection and smoking habit.

Discrimination of prediction models between cold-heat and deficiency-excess patterns.

OBJECTIVE: The purpose of this study was to extract important patient questionnaire items by creating random forest models for predicting pattern diagnosis considering an interaction between deficiency-excess and cold-heat patterns. DESIGN: A multi-centre prospective observational study. SETTING: Participants visiting six Kampo speciality clinics in Japan from 2012 to 2015. MAIN OUTCOME MEASURE: Deficiency-excess pattern diagnosis made by board-certified Kampo experts. METHODS: We used 153 items as independent variables including, age, sex, body mass index, systolic and diastolic blood pressures, and 148 subjective symptoms recorded through a questionnaire. We sampled training data with an equal number of the different patterns from a 2 × 2 factorial combination of deficiency-excess and cold-heat patterns. We constructed the prediction models of deficiency-excess and cold-heat patterns using the random forest algorithm, extracted the top 10 essential items, and calculated the discriminant ratio using this prediction model. RESULTS: BMI and blood pressure, and subjective symptoms of cold or heat sensations were the most important items in the prediction models of deficiency-excess pattern and of cold-heat patterns, respectively. The discriminant ratio was not inferior compared with the result ignoring the interaction between the diagnoses. CONCLUSIONS: We revised deficiency-excess and cold-heat pattern prediction models, based on balanced training sample data obtained from six Kampo speciality clinics in Japan. The revised important items for diagnosing a deficiency-excess pattern and cold-heat pattern were compatible with the definition in the 11th version of international classification of diseases.

Recent progress in pathogenesis and management of colorectal cancer. Eighteenth International Symposium of the Hiroshima Cancer Seminar, November 2008.

This symposium presented recent progress of the pathogenesis and treatment of colorectal cancer (CRC). Field cancerization by modified stem cells may be the earliest changes associated with CRC. CD34+-immature myeloid cells are deeply involved in CRC invasion. Inflammatory mediators stimulate cancer progression. We must strive for a better understanding of the molecular mechanisms responsible for this connection. Serial analysis of gene expression data analysis has identified novel biomarkers for cancer detection and possible prognosis. Better endoscopic techniques are suitable for early detection and resection of colonic lesions. Chemoprevention of CRC using sulindac and aberrant crypt foci as a clinical endpoint have shown glutathione S-transferase pi as a possible new target. A new drug delivery system using nanoparticles is being developed with SN-38, a biologically active metabolite of irinotecan. Survival of Japanese male patients with CRC is the best in the world due to lymph node dissection and surveillance. The use of laparoscopic surgery has increased, especially for advanced cancer. A treatment trial by the Sanin Study Group suggests that modified 5-fluorouracil and leucovorin with oxaliplatin treatment could be carried out in elderly patients. A great deal of information for understanding carcinogenesis and treatment has provided us with novel strategies for the management and prevention of CRC.

LTA 252GG and GA genotypes are associated with diffuse-type noncardia gastric cancer risk in the Japanese population.

BACKGROUND: There are limited numbers of reports on the association of lymphotoxin-alpha (LTA) genotypes with gastric cancer. METHODS: A nested case-control study was carried out in the longitudinal cohort of atomic bomb survivors using stored sera before diagnosis (mean, 2.3 years) and blood cells. Enrolled were 287 cases with noncardia gastric cancer of diffuse and intestinal types and three controls per case selected from cohort members matched on age, gender, city, and time and type of serum storage and counter-matched on radiation dose. RESULTS: LTA 252GG and GA genotypes were associated with the prevalence of Helicobacter pylori IgG seropositivity and higher antibody titer against H. pylori cytotoxin-associated gene A (CagA) protein in controls and they were an independent risk factor for noncardia gastric cancer of diffuse type (RR = 2.8 (95% CI: 1.3-6.3), p = .01, and RR = 2.7 (95% CI: 1.5-4.8), p < .001), but not for intestinal type, after adjusting for H. pylori IgG seropositivity, CagA antibody titers, chronic atrophic gastritis, smoking, and radiation dose. Cessation of smoking (RR = 0.4 (95% CI: 0.2-0.7), p < .001) and never smoking (RR = 0.4 (95% CI: 0.3-0.6), p < .001) were both protective for future noncardia gastric cancer. Radiation dose was associated with noncardia gastric cancer in subjects with both the LTA 252G-allele and never smoking/quit smoking histories (RR = 3.8 (95% CI: 1.7-5.9), p = .009). CONCLUSION: The LTA 252 genotype is associated with noncardia gastric cancer of diffuse type in Japan and interacted with radiation dose.

Prediction of deficiency-excess pattern in Japanese Kampo medicine: Multi-centre data collection.

OBJECTIVE: The purpose of the present study was to compare important patient questionnaire items by creating a random forest model for predicting deficiency-excess pattern diagnosis in six Kampo specialty clinics. DESIGN: A multi-centre prospective observational study. SETTING: Participants who visited six Kampo specialty clinics in Japan from 2012 to 2015. MAIN OUTCOME MEASURE: Deficiency-excess pattern diagnosis made by board-certified Kampo experts. METHODS: To predict the deficiency-excess pattern diagnosis by Kampo experts, we used 153 items as independent variables, namely, age, sex, body mass index, systolic and diastolic blood pressures, and 148 subjective symptoms recorded through a questionnaire. We extracted the 30 most important items in each clinic's random forest model and selected items that were common among the clinics. We integrated participating clinics' data to construct a prediction model in the same manner. We calculated the discriminant ratio using this prediction model for the total six clinics' data and each clinic's independent data. RESULTS: Fifteen items were commonly listed in top 30 items in each random forest model. The discriminant ratio of the total six clinics' data was 82.3%; moreover, with the exception of one clinic, the independent discriminant ratio of each clinic was approximately 80% each. CONCLUSIONS: We identified common important items in diagnosing a deficiency-excess pattern among six Japanese Kampo clinics. We constructed the integrated prediction model of deficiency-excess pattern.

Radiation therapy for cancer. The fifteenth anniversary of Hiroshima Cancer Seminar Foundation, the Seventeenth International Symposium of Hiroshima Cancer Seminar, November 2007.

This symposium presented what we do to really know about new technology for radiation therapy and what we do to realize our final goal of selective radiation therapy and CRT for cancer. It no doubt provided us for a great deal of information on technological and conceptual advances in radiation therapy and radiation biology.

Low-positive antibody titer against Helicobacter pylori cytotoxin-associated gene A (CagA) may predict future gastric cancer better than simple seropositivity against H. pylori CagA or against H. pylori.

BACKGROUND: To investigate the IgG antibody titer against Helicobacter pylori CagA as a risk factor for future noncardia gastric cancer. METHODS: A nested case-control study was done in the longitudinal cohort of atomic bomb survivors using stored sera before diagnosis (mean, 2.3 years). Enrolled were 299 cancer cases and 3 controls per case selected from cohort members matched on age, gender, city, and time and type of serum storage and countermatched on radiation dose. RESULTS: H. pylori IgG seropositive with CagA IgG low titer was the strongest risk factor for noncardia gastric cancer [relative risk (RR), 3.9; 95% confidence interval (95% CI), 2.1-7.0; P < 0.001], especially for intestinal-type tumor (RR, 9.9, 95% CI, 3.5-27.4; P < 0.001), compared with other risk factors, H. pylori IgG seropositive with CagA IgG negative (RR, 2.2; 95% CI, 1.3-3.9; P = 0.0052), H. pylori IgG seropositive with CagA IgG high titer (RR, 2.0; 95% CI, 1.3-3.2; P = 0.0022), chronic atrophic gastritis (RR, 2.4; 95% CI, 1.8-3.3; P < 0.001), current smoking (RR, 2.3; 95% CI, 1.4-3.5; P < 0.001), or radiation dose (RR, 2.1; 95% CI, 1.2-3.1; P = 0.00193). Current smoking showed significantly higher risk for diffuse-type than intestinal-type tumors (P = 0.0372). Radiation risk was significant only for nonsmokers, all noncardia, and diffuse-type gastric cancers. CONCLUSIONS: A low CagA IgG titer is a useful biomarker to identify a high-risk group and it also provides a clue to understanding host-pathogen interaction.

Cellular and molecular aspects of gastric cancer.

Gastric cancer remains a global killer with a shifting burden from the developed to the developing world. The cancer develops along a multistage process that is defined by distinct histological and pathophysiological phases. Several genetic and epigenetic alterations mediate the transition from one stage to another and these include mutations in oncogenes, tumour suppressor genes and cell cycle and mismatch repair genes. The most significant advance in the fight against gastric cancer came with the recognition of the role of Helicobacter pylori (H pylori) as the most important acquired aetiological agent for this cancer. Recent work has focussed on elucidating the complex host/microbial interactions that underlie the neoplastic process. There is now considerable insight into the pathogenesis of this cancer and the prospect of preventing and eradicating the disease has become a reality. Perhaps more importantly, the study of H pylori-induced gastric carcinogenesis offers a paradigm for understanding more complex human cancers. In this review, we examine the molecular and cellular events that underlie H pylori-induced gastric cancer.

The Relation between Hepatotoxicity and the Total Coumarin Intake from Traditional Japanese Medicines Containing Cinnamon Bark.

Cinnamon bark is commonly used in traditional Japanese herbal medicines (Kampo medicines). The coumarin contained in cinnamon is known to be hepatotoxic, and a tolerable daily intake (TDI) of 0.1 mg/kg/day, has been quantified and used in Europe to insure safety. Risk assessments for hepatotoxicity by the cinnamon contained in foods have been reported. However, no such assessment of cinnamon bark has been reported and the coumarin content of Kampo medicines derived from cinnamon bark is not yet known. To assess the risk for hepatotoxicity by Kampo medicines, we evaluated the daily coumarin intake of patients who were prescribed Kampo medicines and investigated the relation between hepatotoxicity and the coumarin intake. The clinical data of 129 outpatients (18 male and 111 female, median age 58 years) who had been prescribed keishibukuryogankayokuinin (TJ-125) between April 2008 and March 2013 was retrospectively investigated. Concurrent Kampo medicines and liver function were also surveyed. In addition to TJ-125, the patients took some of the other 32 Kampo preparations and 22 decoctions that include cinnamon bark. The coumarin content of these Kampo medicines was determined by high performance liquid chromatography (HPLC). TJ-125 had the highest daily content of coumarin (5.63 mg/day), calculated from the daily cinnamon bark dosage reported in the information leaflet inserted in each package of Kampo medicine. The coumarin content in 1g cinnamon bark decoction was 3.0 mg. The daily coumarin intake of the patients was 0.113 (0.049-0.541) mg/kg/day, with 98 patients (76.0%) exceeding the TDI. Twenty-three patients had an abnormal change in liver function test value, but no significant difference was found in the incidence of abnormal change between the group consuming less than the TDI value (6/31, 19.4%) and the group consuming equal to or greater than the TDI value (17/98, 17.3%). In addition, no abnormal change related to cinnamon bark was found for individual patients. This paper was done to assess the risk of hepatotoxicity by the coumarin contained in Kampo medicines and to clarify whether or not the Kampo preparations in general use that contain cinnamon bark may be safely used in clinical practice.

Reduction of perception of chronic fatigue in an observational study of patients receiving 12 weeks of Kampo therapy.

OBJECTIVE: The aim of this study was to observe the influence of Kampo therapy on latent chronic fatigue of patients with chronic diseases. SUBJECTS: One hundred and seventy-three (173) consecutive patients with chronic diseases came to our department for the first time. DESIGN: This was a prospective study. Patients were divided into two groups: a chronic fatigue group (CFG) and a nonchronic fatigue group (NCFG). Based on Kampo diagnosis, both groups were prescribed Kampo formulae as an extract or decoction for 12 weeks. OUTCOME MEASURES: By using questionnaires, patients were assessed concerning their physical and mental types of fatigue, their sleep situation, and their attitude toward work or housekeeping, both before and after 12 weeks of treatment, according to Kampo diagnosis. RESULTS: The mental fatigue, physical fatigue, and sleep scores of both groups, and the work score of CFG, were decreased. The rate of reduction of the fatigue score was significantly greater in CFG than in NCFG. The factor responsible for this difference in fatigue score was physical fatigue. CONCLUSIONS: A reduction of the perception of chronic fatigue was observed in patients receiving 12 weeks of Kampo therapy.

Differential effects of retinoic acid on the growth of isogenic metastatic and non-metastatic breast cancer cell lines and their association with distinct expression of retinoic acid receptor beta isoforms 2 and 4.

The human retinoic acid receptor beta (RARbeta) has three isoforms (beta1, beta2, and beta4), which play important, distinct roles in mediating the effects of retinoic acid on cell growth and apoptosis. Whereas RARbeta2 is a potent inhibitor of breast cancer cell proliferation, RARbeta4 can act as a dominant-negative repressor of RARbeta2-mediated growth suppression. In this study we investigated the effects of all-trans-retinoic acid (ATRA) on two clones derived from the breast cancer cell line MDA-MB-435: a non-metastatic clone (NM-2C5) and a metastatic clone (M-4A4). ATRA treatment of the NM-2C5 cells resulted in growth inhibition and apoptosis, whereas the M-4A4 cells were resistant to ATRA. Analyses of the expression of RARbeta isoforms revealed that the sensitive NM-2C5 clone expressed only RARbeta2, whereas the resistant M-4A4 cells expressed both RARbeta2 and RARbeta4 mRNA and protein. ATRA treatment increased RARbeta2 mRNA level in NM-2C5 cells, whereas the same treatment of the M-4A4 cells resulted in an increase in RARbeta4 and a decrease in RARbeta2 mRNA. ATRA treatment of NM-2C5 cells increased the protein levels of the histone acetyl transferases p300 and CBP, suppressed the level of histone deacetylase and increased the level of acetylated histone H4. ATRA also decreased Bcl-2 and increased Bax and decreased VEGF. In contrast, the same treatment of the M-4A4 cells resulted in opposite effects. These results suggest that the effects of ATRA on the growth of the metastatic and non-metastatic breast cancer cell lines depend on the expression of RARbeta isoforms and that the expression of RARbeta4 may contribute to metastatic properties.

Histone Acetylation and Retinoic Acid Receptor beta DNA Methylation as Novel Targets for Gastric Cancer Therapy.

Multiple genetic and epigenetic alterations in oncogenes, tumor-suppressor genes, cell-cycle regulators, cell adhesion molecules and DNA repair genes, as well as genetic instability and telomerase activation, are responsible for tumor genesis and progression of gastric cancer. The scenario of these epigenetic alterations found in gastric cancer differs, depending on the two types of gastric cancer, indicating that there are at least two types of CpG (cytidine phosphate guanosine) island methylator phenotypes in the intestinal-type and diffuse-type of gastric cancer. In addition to promoter methylation, acetylated histone H4 is obviously reduced in a majority of gastric carcinoma. Histone H4 is progressively deacetylated from the early stage (precancerous lesions) to the late stage (invasion and metastasis) in gastric carcinogenesis. Since there is no difference in the level of acetylated histone H4 between the intestinal-type and diffuse-type of gastric cancer, histone H4 deacetylation may be involved in both types of gastric cancer. This article proposes histone acetylation and retinoic acid receptor beta DNA methylation as novel targets for gastric cancer therapy. (c) 2002 Prous Science. All rights reserved.

Expression of thymidylate synthase, thymidine phosphorylase, dihydropyrimidine dehydrogenase, E2F-1, Bak, Bcl-X, and Bcl-2, and clinical outcomes for gastric cancer patients treated with bolus 5-fluorouracil.

Few studies have investigated the biological factors associated with sensitivity to bolus infusions of 5-fluorouracil (5FU), including sequential methotrexate (MTX)/5FU therapy. We investigated the relationship between the expression of thymidylate synthase (TS), thymidine phosphorylase (TP), dihydropyrimidine dehydrogenase (DPD), E2F-1, Bcl-2, Bak, and Bcl-X, and the chemotherapeutic effects of sequential MTX/5FU. We studied 38 patients with unresectable or recurrent gastric cancer, treated weekly with sequential MTX/5FU (MTX 100 mg/m2, 5FU 600 mg/m2, by bolus infusions, with a three-hour interval). Expression of the above proteins was examined in initial biopsy samples with immunohistochemical methods. Immunohistochemical reactivity was defined as positive when over 25% of cancer cells showed strong staining in the cytoplasm for TS, TP, DPD, Bak, Bcl-2, and Bcl-X, and in the nucleus for E2F-1. The overall response rate was 28% in the 29 patients who had measurable lesions. Bak-negative patients showed a higher response rate than Bak-positive patients (39% versus 9%, respectively; p=0.1096), although expression of the other proteins was not associated with chemosensitivity. The median survival time (MST) of all patients was 256 days. Bak-negative patients survived significantly longer than Bak-positive patients (MST, 302 days versus 134 days, respectively; p=0.0044). Bcl-X-negative patients survived significantly longer than Bcl-X-positive patients (MST, 302 days versus 215 days, respectively; p=0.0080). Furthermore, patients negative for both Bak and Bcl-X had significantly better prognoses than other patients (MST, 373 days; p<0.0001). Within the limits of the small patient population, multivariate analysis using the Cox proportional hazards model showed that Bak, Bcl-X, and histological type were independent variables predicting survival (p=0.0008, 0.0081, and 0.0082, respectively). Although previously described predictive markers for protracted infusion of 5FU, including TS, TP, and DPD, might not be associated with clinical outcome in patients treated with sequential MTX/5FU, Bak may be a useful marker for chemoresponse and survival. Furthermore, both Bcl-X expression and the coupled expression of Bak and Bcl-X, as well as histological type, may be useful predictive markers for survival.

No mutations of the Bub1 gene in human gastric and oral cancer cell lines.

Chromosomal instability is one of the most important characteristics underlying tumorigenesis. Certain colorectal cancers with chromosomal instability have been shown to have inactivation of a spindle assembly checkpoint party due to mutation of Bub1, a mitotic checkpoint gene. We performed sequencing analysis on reverse transcriptase-polymerase chain reaction (RT-PCR) product of the Bub1 cDNA (entire coding sequence) from 8 human gastric cancer cell lines. In addition, genomic PCR products of Bub1 exon 8, 10, 12, 15 and kinase domain from 9 oral cancer cell lines were analyzed by polymerase chain reaction-single-stand conformation polymorphism (PCR-SSCP). Although sequencing analysis of the Bub1 cDNA revealed several point mutations in 8 gastric cancer cell lines, we could not confirm the mutations by analyzing genomic DNA. Furthermore, genomic PCR-SSCP analysis revealed no mutations in exon 8, 10, 12, 15 and kinase domain of the Bub1 gene in any oral cancer cell lines examined. These results suggest that mutation of the Bub1 gene might not play a role in human stomach and oral carcinogenesis.