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Biomedical subjects

Koji Matsumoto

Publications and source records attributed to Koji Matsumoto.

At least 19 recordsLinked to original sources
PubMed2026

Quality of life with palbociclib plus tamoxifen in hormone receptor-positive, HER2-negative advanced breast cancer: results from PATHWAY, an Asian international, double-blind, randomized phase 3 trial.

BACKGROUND: In the Asian international PATHWAY trial, palbociclib-tamoxifen demonstrated improved progression-free survival compared with placebo-tamoxifen in patients with HR+/HER2- locally advanced or metastatic breast cancer (ABC). This analysis compared quality of life (QoL) between treatment arms. METHODS: Pre/peri or postmenopausal women with HR+/HER2- ABC were randomly assigned 1:1 to receive palbociclib-tamoxifen or placebo-tamoxifen. Patient-reported outcomes were assessed on day 1 of cycles 1 (baseline), 4, and 7, and at the end of treatment (EOT) using the EORTC QLQ-C30 and QLQ-BR23 questionnaires. Least-square mean (LSM) changes in scores from baseline were calculated. Kaplan-Meier method was used to calculate time to deterioration (TTD) in the minimally important difference (MID) in the pain subscale. RESULTS: In the comparison between treatment arms, no significant differences were observed in LSM changes in scores from baseline in global QoL (cycle 4: 0.70 [95% confidence interval (CI): -5.00, 6.41]; cycle 7: 2.17 [95% CI: -4.14, 8.48]; EOT: -5.19 [95% CI: -11.64, 1.26]). For both the EORTC QLQ-C30 and QLQ-BR23 functional and symptom subscales, no clinically meaningful differences between treatment arms were found in the LSM changes in scores from baseline. Median TTD in the MID in the pain subscale was 32.5 months (95% CI: 11.7, not estimable) for the palbociclib-tamoxifen arm and 21.2 months (95% CI: 5.5, 43.5) for the placebo-tamoxifen arm (hazard ratio = 0.729 [95% CI: 0.467, 1.138]). CONCLUSIONS: The combination of palbociclib and tamoxifen delayed deterioration in patients' QoL while they experienced reduced risk for disease progression. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03423199; study registration date: February 6, 2018.

Humans↗
PubMed2026

Efficacy of S-1 Monotherapy for Salivary Duct Carcinoma With MYC Amplification.

BACKGROUND/AIM: Salivary duct carcinoma (SDC) is a rare, highly aggressive subtype of salivary gland carcinoma, commonly characterized by overexpression of erb-b2 receptor tyrosine kinase 2 [ERBB2, commonly known as human epidermal growth factor receptor 2 (HER2)] and androgen receptor positivity. Anti-HER2 therapy, platinum-based chemotherapy, and androgen-deprivation therapy (ADT) are commonly provided as standard systemic treatments for advanced SDC; however, effective therapeutic options after failure of these treatments remain limited. The clinical efficacy of S-1 monotherapy in SDC and its predictive biomarkers are not well established. Herein, we present a case in which S-1 monotherapy showed efficacy in a case of SDC after resistance to anti-HER2 therapy, platinum-based chemotherapy, and ADT. CASE REPORT: The patient was a 70-year-old man diagnosed with HER2-positive and androgen receptor-positive SDC of the submandibular gland, who presented with multiple lung metastases. He initially received trastuzumab plus docetaxel as first-line therapy, followed by platinum-based chemotherapy and ADT, but experienced disease progression after each treatment. Comprehensive genomic profiling revealed amplifications of ERBB2 and MYC proto-oncogene bHLH transcription factor (MYC). S-1 monotherapy was started as a late-line therapy. Computed tomography scans 2 months later showed shrinkage of lung and liver metastases, with disease control maintained for more than 5 months. CONCLUSION: S-1 monotherapy may represent a treatment option for patients with advanced SDC refractory to anti-HER2 therapy, platinum-based chemotherapy, and ADT, particularly in cases harboring MYC amplification.

Humans↗
PubMed2006

Prediction of response to repeat utilization of anthracycline in recurrent breast cancer patients previously administered anthracycline-containing chemotherapeutic regimens as neoadjuvant or adjuvant chemotherapy.

PURPOSE: The aim of this study was to identify the predictors of the response to doxorubicin plus cyclophosphamide in patients with recurrent breast cancer (RBC) previously treated with anthracycline-containing regimens in a neoadjuvant or adjuvant setting. METHOD: Between December 1993 and October 2005, 664 patients had received combined doxorubicin plus cyclophosphamide chemotherapy (doxorubicin, 40 mg/m(2), iv on day 1; cyclophosphamide, 500 mg/m(2), iv on day 1, every 21 days) for RBC at our institution. In this study, we retrospectively analyzed the efficacy of doxorubicin plus cyclophosphamide in 99 of these 664 RBC patients who had also previously been administered an anthracycline-based chemotherapy in a neoadjuvant or adjuvant setting. RESULTS: The median cumulative dose of the previously administered anthracycline was 156 mg/m(2). The median disease-free interval (DFI) and median anthracycline-free interval were 33.8 and 43.7 months, respectively. The overall response rate to doxorubicin plus cyclophosphamide therapy was 38.4% (95% CI; range, 28.8-48.0%). The median time to progression and overall survival were 6.2 and 17.5 months, respectively. The results of a multivariate logistic regression analysis revealed a significant association of the response to doxorubicin plus cyclophosphamide therapy with the DFI (P = 0.02); human epidermal receptor type 2 (HER2) status also tended to affect the response rate, however the association was not statistically significant (P = 0.06). CONCLUSION: DFI and HER2 status may be associated with the response to repeat utilization of anthracycline-containing regimens in RBC patients also treated previously with anthracycline-containing chemotherapeutic regimens in a neoadjuvant or adjuvant setting.

Adult↗
PubMed2006

Strain differences in the responsiveness between Sprague-Dawley and Fischer rats to nephropathy induced by FYX-051, a xanthine oxidoreductase inhibitor.

To determine a rat strain appropriate for carcinogenicity testing of FYX-051, a xanthine oxidoreductase inhibitor, we performed a 4-week oral toxicity study by administering 0.3, 1 and 3 mg/kg, and 1, 3 and 10 mg/kg of FYX-051 to male Sprague-Dawley (SD) and Fischer (F344) rats, respectively. Histopathology revealed that the degree of FYX-051-induced nephropathy was 3-fold stronger in SD rats than in F344 rats. Our previous study demonstrated that the key factor of species differences in FYX-051-induced nephropathy is purine metabolism. This observation led us to examine the involvement of purine metabolism in differences among two strains of rats. However, purine metabolism was proven not to be implicated as an important factor. Subsequently, other factors responsible for the strain differences were examined. FYX-051-induced increases in plasma xanthine concentrations were higher in SD rats than in F344 rats, suggesting more remarkable effects on pharmacodynamics in the former than the latter. Urinary volume was greater in F344 rats administered 10 mg/kg of FYX-051 (6.8 ml/h/kg) than in SD rats administered 3 mg/kg of FYX-051 (5.0 ml/h/kg), implying easier xanthine excretion in the former. Urinary xanthine solubility was 55 mg/dl in F344 rats aged 6 weeks, in contrast to 38 mg/dl in SD rats of the same age. Also, there were no significant differences in exposure levels at the same dose between SD and F344 rats. The outcomes of exposure levels and renal histopathology in both rats suggest the possibility that F344 rats could be exposed to a 3-fold higher amount of drug than SD rats in a carcinogenicity bioassay. The present study, therefore, suggested that strain differences of nephrotoxicity were caused by the combined effects of pharmacodynamics, xanthine excretion capacity, and urinary xanthine solubility. Furthermore, these results indicate that F344 rats would be a suitable strain for the carcinogenicity study of FYX-051.

Animals↗
PubMed2006

Light-responsive transcriptional regulation of the suf promoters involved in cyanobacterium Synechocystis sp. PCC 6803 Fe-S cluster biogenesis.

The widely conserved SUF system is involved in Fe-S cluster repair and biogenesis. In cyanobacterium Synechocystis sp. PCC 6803, transcription of the sufBCDS operon encoding the Suf complex is negatively regulated by the upstream sufR gene encoded by the complementary strand. In this report, two promoters for the sufBCDS operon (P1 and P2) and another promoter for sufR (PsufR) was identified, and it was shown that P1 was activated by a shift to high light conditions. We also showed that Thermosynechococcus SufR negatively regulated P1 and PsufR but not P2, in a reconstituted in vitro transcription system using His(6)-tagged RNA polymerase.

Base Sequence↗
PubMed2006

Correlation of p53 and MIB-1 expression with both the systemic recurrence and survival in cases of phyllodes tumors of the breast.

Phyllodes tumors are rare primary tumors of the breast. The study aimed at evaluating the immunohistochemical features of phyllodes tumors of the breast that may be useful for predicting the clinical outcome. We examined the immunohistochemical expression of the epidermal growth factor receptor (EGFR), HER2/neu, CD117/c-kit, p53, and MIB-1, and analyzed correlations between the immunohistochemical findings and the clinical outcome. The study included 41 patients with phyllodes tumor (20 benign, 5 borderline, and 16 malignant). Systemic recurrence occurred in 9 patients. The 2-year survival rate was 84%, and the 2-year recurrence-free survival rate was 77%. Six patients developed systemic recurrence within the first year after surgery. None of the phyllodes tumors was positive for HER2/neu or CD117/c-kit. Positive staining for p53 was seen in 10 phyllodes tumors (24%), and the median MIB-1 index was 10%. Both p53 expression and the MIB-1 index, but not the expression status of EGFR, were significantly correlated with the recurrence-free and overall survival. p53 expression status and MIB-1 index may be significant prognostic factors in patients with phyllodes tumors, and careful postoperative follow-up may be important in those cases showing positive expression of p53 and/or MIB-1 index.

Adult↗
PubMed2006

Tumor-marker analysis and verification of prognostic models in patients with cancer of unknown primary, receiving platinum-based combination chemotherapy.

OBJECTIVES: To evaluate the usefulness of tumor-marker measurements and to identify prognostic factors in patients with cancer of unknown primary (CUP), receiving platinum-based combination chemotherapy and to verify the adjustment of previously reported prognostic models in this population. METHODS: We conducted univariate and multivariate analyses in consecutive patients with CUP receiving platinum-based combination chemotherapy. Previously reported prognostic models were then validated in this population. RESULTS: A total of 93 patients were analyzed and the response rate to platinum-based chemotherapeutic regimens among the 93 patients was 39.8%. The median time to progression and overall survival period were 4.1 and 12.4 months, respectively. The ST-439 level was significantly higher in patients with histologically confirmed adenocarcinoma than in patients with poorly differentiated adenocarcinoma or poorly differentiated carcinoma. A multivariate analysis indicated that performance status, the number of involved organs, and the serum lactate dehydrogenase level were the prognostic factors of the outcome. Both the previously reported prognostic models for predicting the duration of survival in this population were shown to be valid. CONCLUSION: Tumor-marker measurements are not helpful in the management of patients with CUP. Previously reported prognostic models may be useful for selecting indication for chemotherapy or for stratifying the patients in clinical trial.

Adult↗
PubMed2006

IgG antibodies to HPV16, 52, 58 and 6 L1-capsids and spontaneous regression of cervical intraepithelial neoplasia.

To identify the predictive markers for spontaneous regression of cervical intraepithelial neoplasia (CIN), we examined whether IgG antibody responses to common human papillomavirus (HPV) L1-capsids correlate with CIN regression. In a cohort study, a total of 116 Japanese women with CIN grade I/II were tested for cervical HPV DNA and serum IgG antibodies to HPV16/52/58/6 L1-capsids. Our data suggest that baseline IgG reactivities to HPV L1-capsids do not serve as a predictive marker of CIN regression, in contrast to histological CIN grades and HPV DNA status.

Antibodies, Viral↗
PubMed2006

Involvement of a cellular ubiquitin-protein ligase E6AP in the ubiquitin-mediated degradation of extensive substrates of high-risk human papillomavirus E6.

Human scribble (hScrib), which was identified as substrate of human papillomavirus (HPV) E6 for ubiquitin-mediated degradation dependent on ubiquitin-protein ligase E6AP, is a human homolog of Drosophila neoplastic tumor suppressor scribble, in which mutation causes loss of polarity and overgrowth of epithelia. Drosophila discs large (Dlg) is one of neoplastic tumor suppressors, which genetically links to scribble. E6 also targets human Dlg (hDlg) for ubiquitin-mediated degradation. Ubiquitin-protein ligase involved in this process has not been identified thus far. Here we investigated mechanism underlying degradation of three target proteins of E6, hScrib, hDlg, and p53 by using eighteen HPV 16 E6 mutants with single amino acid substitution. In vitro degradation ability of each E6 mutant was equivalent for these tumor suppressors. We investigated whether E6AP is involved in ubiquitin-mediated degradation of hDlg. In vitro binding assay revealed that hDlg formed ternary complex with E6-E6AP complex. The ability of E6 mutants to degrade these tumor suppressors was correlated with their ability to interact with E6AP. Furthermore, hDlg was targeted for in vitro ubiquitination in the presence of both E6 and E6AP. These data revealed that E6AP is extensively involved in the ubiquitin-mediated degradation of E6-dependent substrates as a cellular E3 ubiquitin-protein ligase.

Adaptor Proteins, Signal Transducing↗
PubMed2006

[A feasibility study of doxorubicin/cisplatin (AP) for postoperative chemotherapy in patients with advanced endometrial cancer].

OBJECTIVE: We evaluated the feasibility of doxorubicin/cisplatin (AP) for postoperative chemotherapy in patients with advanced endometrial cancer. METHODS: Patients with newly diagnosed advanced endometrial cancer received AP (doxorubicin 60 mg/m(2), cisplatin 50 mg/m(2)) every 3 weeks. Treatment was continued until disease progression or completion of 6 courses. Toxicities were evaluated every cycle according to NCI-CTCAE Ver.3.0. RESULTS: Fifteen patients were enrolled from April 2004 through December 2005. All patients successfully completed therapy. There were two patients who needed dose reduction and nine patients with prolongation of treatment interval. Patients with over Grade 3/4 toxicity were observed to have leucopenia (47%), neutropenia (67%), anemia (26%), and vomiting (13%). No grade 3/4 cardiac and renal failure were observed. CONCLUSIONS: The doxorubicin/cisplatin (AP) regimen is tolerated and can be safely given without severe toxicity.

Adenocarcinoma↗
PubMed2005

The safety and efficacy of the weekly dosing of irinotecan for platinum- and taxanes-resistant epithelial ovarian cancer.

OBJECTIVE: Irinotecan is one of the drugs that might be effective against platinum- and taxanes-resistant epithelial ovarian cancer. We investigated efficacy and safety of the weekly dosing schedule of irinotecan. METHODS: From September 2001 to March 2003, 28 eligible patients who have histologically confirmed epithelial ovarian cancer, which was resistant or refractory to both platinum and taxanes, were consecutively treated at the National Cancer Center Hospital. Irinotecan (100 mg/m(2)) was administered intravenously over 90 min on days 1, 8, and 15. The chemotherapy was repeated every 4 weeks, up to 6 cycles. RESULTS: A total of 107 treatment cycles of irinotecan were administered to 28 patients. The median number of prior chemotherapy regimen was 3. Among 28 patients, 8 (29%) responded to irinotecan (2 complete responses and 6 partial responses). The median time to progression was 17 weeks. Three patients experienced hematological toxicities of Grade 4. Five patients experienced non-hematological toxicities Grade 3 or 4. No treatment-related death occurred. CONCLUSION: The weekly dosing schedule of irinotecan seems to be effective and safe salvage chemotherapy regimen for platinum- and taxanes-resistant or refractory epithelial ovarian cancer. Gastrointestinal toxicities, especially diarrhea, were moderate and manageable in an outpatient setting.

Adult↗
PubMed2005

Simultaneous treatment with citrate prevents nephropathy induced by FYX-051, a xanthine oxidoreductase inhibitor, in rats.

The possible mechanism of the underlying nephropathy found in the rat toxicity study of FYX-051, a xanthine oxidoreductase inhibitor, was investigated. Rats received oral treatment of either 1 or 3 mg/kg of FYX-051, with and without citrate for four weeks to elucidate whether nephropathy could be caused by materials deposited in the kidney. Furthermore, analysis of the renal deposits in rats was also performed. Consequently, interstitial nephritis comprising interstitial inflammatory cell infiltration, dilatation, basophilia and epithelial necrosis of renal tubules and collecting ducts, deposits in renal tubules and collecting ducts, and so forth was seen in six of the eight rats and in all eight rats in the 1 and 3 mg/kg FYX-051 alone groups, respectively, with the intensity in the 3 mg/kg group being moderate to severe. In the simultaneous treatment with citrate group, however, no alterations were observed in the kidney, except for minimal interstitial nephritis in one instance in the 3 mg/kg FYX-051 + citrate group along with an increased urinary pH, leading to an increase in xanthine solubility. Analysis of intrarenal deposits showed that the entity would be composed of xanthine crystals. The present study, therefore, showed that nephropathy in rats occurring after the administration of FYX-051 was a secondary change caused by xanthine crystals being deposited in the kidney, and no other causes could be implicated in this kidney lesion.

Animals↗
PubMed2005

Efficacy of weekly paclitaxel in patients with docetaxel-resistant metastatic breast cancer.

BACKGROUND: Partial cross-resistance to paclitaxel and docetaxel has been demonstrated in pre-clinical studies. PATIENTS AND METHODS: We retrospectively evaluated the efficacy of weekly paclitaxel 80 mg/m(2) in 82 patients with docetaxel-resisitant metastatic breast cancer. Docetaxel resistance was classified into primary resistance, defined as progressive disease while receiving docetaxel, and secondary resistance, defined as progression after achievement of a documented clinical response to docetaxel. Secondary resistance was subclassified according to the interval between the final infusion of docetaxel and the start of weekly paclitaxel into: (1) short interval, < or =120 days, and (2) long interval, >120 days. RESULTS: The response rate of the 82 patients was 19.5% (95% confidence interval, 10.8-27.9%). The response rate according to the docetaxel resistance category was: primary resistance (n = 24), 8.3%; secondary resistance (n = 58), 24.1% (short interval [n = 39], 17.9%, and long interval, [n = 19], 36.8%). The differences in response rates among the three categories were statistically significant (p = 0.0247, Cochran-Mantel-Haenszel test). The interval between from the final docetaxel infusion and disease progression were predictors for response of weekly paclitaxel. CONCLUSION: Weekly paclitaxel is modestly effective and safe in docetaxel-resistant metastatic breast cancer patients. However, weekly paclitaxel should not be recommended for primary resistance patients with docetaxel.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Interobserver variation in the histopathological assessment of nonalcoholic steatohepatitis.

Pathological assessment is considered as the gold standard for the diagnosis of nonalcoholic steatohepatitis (NASH). However, there is no agreement of histological features required for the diagnosis of NASH. In the present study, eight experienced hepatopathologists read liver biopsy specimen slides of 21 cases of NASH and suspected NASH independently and were asked to assess histopathological features and render a diagnosis. Interobserver variation among pathologists was evaluated by kappa statistics. Significant, good agreement was present in evaluation of the extent of steatosis and grade of fibrosis. Agreement was moderate concerning the localization of steatosis, localization of fibrosis, and glycogen nuclei. Only slight or poor agreement was seen in evaluation of type of steatosis, ballooning, intralobular necroinflammatory change, portal inflammation, and degree of neutrophilic infiltration. Thus the agreement varied for histological variables. Significant, moderate agreement was seen in the diagnosis of NASH but agreement was poor in the diagnosis of suggestive NASH. The agreement for the diagnosis of NASH was not high as for the individual histological findings that were thought to be the basis of the diagnosis. In conclusion, some histological features in NASH might prove useful for the development of a standardized and reliable pathological diagnosis and scoring system.

Journal Article↗
PubMed2005

Nepenthesin, a unique member of a novel subfamily of aspartic proteinases: enzymatic and structural characteristics.

Carnivorous plants are known to secrete acid proteinases to digest prey, mainly insects, for nitrogen uptake. In our recent study, we have purified, for the first time, to homogeneity two acid proteinases, nepenthesin I (Nep I) and nepenthesin II (Nep II) from the pitcher fluid of Nepenthes distillatoria and investigated their enzymatic and structural characteristics. Both enzymes were optimally active at pH approx. 2.6 toward acid-denatured hemoglobin; the specificity of Nep I toward oxidized insulin B chain appears to be similar, but slightly wider than those of other aspartic proteinases (APs). At or below 50 degrees C both enzymes were remarkably stable; especially Nep I was extremely stable over a wide range of pH from 3 to 10 for over 30 days. This suggests an evolutionary adaptation of the enzymes to their specific habitat. We have also cloned the cDNAs and deduced the complete amino acid sequences of the precursors of Nep I and Nep II from the pitcher tissue of Nepenthes gracilis. Although the corresponding mature enzymes are homologous with ordinary pepsin-type APs, both enzymes had a high content of cysteine residues (12 residues per molecule), which are assumed to form six unique disulfide bonds as suggested by computer modeling and are thought to contribute toward the remarkable stability of Neps. Moreover, the amino acid sequence identity of Neps with ordinary APs, including plant vacuolar APs, are remarkably low (approx. 20%), and phylogenetic comparison shows that Neps are distantly related to them to form a novel subfamily of APs with a high content of cysteine residues and a characteristic insertion, named 'the Nep-type AP (NAP)-specific insertion', including a large number of novel, orthologous plant APs emerging in the gene/protein databases.

Amino Acid Sequence↗
PubMed2004

Impaired antigen presentation and effectiveness of combined active/passive immunotherapy for epithelial tumors.

BACKGROUND: Although immunization with tumor antigens can eliminate many transplantable tumors in animal models, immune effector mechanisms associated with successful immunotherapy of epithelial cancers remain undefined. METHODS: Skin from transgenic mice expressing the cervical cancer-associated tumor antigen human papillomavirus type 16 (HPV16) E6 or E7 proteins from a keratin 14 promoter was grafted onto syngeneic, non-transgenic mice. Skin graft rejection was measured after active immunization with HPV16 E7 and adoptive transfer of antigen-specific T cells. Cytokine secretion of lymphocytes from mice receiving skin grafts and immunotherapy was detected by enzyme-linked immunosorbent assay, and HPV16 E7-specific memory CD8+ T cells were detected by flow cytometry and ELISPOT. RESULTS: Skin grafts containing HPV16 E6-or E7-expressing keratinocytes were not rejected spontaneously or following immunization with E7 protein and adjuvant. Adoptive transfer of E7-specific T-cell receptor transgenic CD8+ T cells combined with immunization resulted in induction of antigen-specific interferon gamma-secreting CD8+ T cells and rejection of HPV16 E7-expressing grafts. Specific memory CD8+ T cells were generated by immunotherapy. However, a further HPV16 E7 graft was rejected from animals with memory T cells only after a second E7 immunization. CONCLUSIONS: Antigen-specific CD8+ T cells can destroy epithelium expressing HPV16 E7 tumor antigen, but presentation of E7 antigen from skin is insufficient to reactivate memory CD8+ T cells induced by immunotherapy. Thus, effective cancer immunotherapy in humans may need to invoke sufficient effector as well as memory T cells.

Adjuvants, Immunologic↗