Pharmacokinetic Study of Adjuvant Gemcitabine Therapy for Biliary Tract Cancer following Major Hepatectomy (KHBO1101)

Background

Biliary tract cancer (BTC) patients who have undergone surgical resection with major hepatectomy cannot tolerate the standard gemcitabine regimen (1,000 mg/m² on days 1, 8, and 15 every 4 weeks) due to severe toxicities such as myelosuppression. Our dose-finding study of adjuvant gemcitabine therapy for biliary tract cancer following major hepatectomy determined that the recommended dose is 1,000 mg/m² on days 1 and 15 every 4 weeks. Here, we evaluate the pharmacokinetics and pharmacodynamics of gemcitabine in these subjects.

Methods

We evaluated BTC patients scheduled to undergo surgical resection with major hepatectomy followed by gemcitabine therapy. A pharmacokinetic evaluation of gemcitabine and its main metabolite, 2′,2′-difluorodeoxyuridine (dFdU), was conducted at the initial administration of gemcitabine, which was given by intravenous infusion over 30 min at a dose of 800–1,000 mg/m². Physical examination and adverse events were monitored for 12 weeks.

Results

Thirteen patients were enrolled from August 2011 to January 2013, with 12 ultimately completing the pharmacokinetic study. Eight patients had hilar cholangiocarcinoma, three had intrahepatic cholangiocarcinoma, and one had superficial spreading type cholangiocarcinoma. The median interval from surgery to first administration of gemcitabine was 65.5 days (range, 43–83 days). We observed the following toxicities: neutropenia (n = 11, 91.7%), leukopenia (n = 10, 83.3%), thrombocytopenia (n = 6, 50.0%), and infection (n = 5, 41.7%). Grade 3 or 4 neutropenia was observed in 25% (n = 3) of patients. There were differences in clearance of gemcitabine and dFdU between our subjects and the subjects who had not undergone hepatectomy.

Conclusion

Major hepatectomy did not affect the pharmacokinetics of gemcitabine or dFdU.

Trial Registration

UMIN-CTR in (JPRN) UMIN000005109     

Baseline Serum Osteopontin Levels Predict the Clinical Effectiveness of Tocilizumab but Not Infliximab in Biologic-Na?ve Patients with Rheumatoid Arthritis: A Single-Center Prospective Study at 1 Year (the Keio First-Bio Cohort Study)

ObjectiveTo explore the baseline predictors of clinical effectiveness after tocilizumab or infliximab treatment in biologic-naïve rheumatoid arthritis patients.MethodsConsecutive biologic-naïve patients with rheumatoid arthritis initiating infliximab (n = 57) or tocilizumab (n = 70) treatment were included in our prospective cohort study. Our cohort started in February 2010, and the patients observed for at least 1 year as of April 2013 were analysed. We assessed baseline variables including patients'' characteristics (age, sex, disease duration, prednisolone dose, methotrexate dose, other disease-modifying antirheumatic drug use, Clinical Disease Activity Index [CDAI]) and serum biomarker levels (C-reactive protein, immunoglobulin M-rheumatoid factor, anti-cyclic citrullinated protein/peptide antibodies, interferon-γ, interleukin (IL)-1β, IL-2, IL-6, IL-8, IL-10, IL-17, tumor necrosis factor-α, soluble intercellular adhesion molecule-1, bone alkaline phosphatase, osteonectin, osteopontin) to extract factors associated with clinical remission (CDAI≤2.8) at 1 year using univariate analyses, and the extracted factors were entered into a multivariate logistic regression model. Similar analyses were also performed for Simplified Disease Activity Index (SDAI) remission (≤3.3) and Disease Activity Score with 28 joint counts, erythrocyte sedimentation rate (DAS28-ESR) remission (<2.6).ResultsThere were no significant differences in the baseline characteristics except for methotrexate use between the groups. In the multivariate analyses, the low baseline osteopontin levels (OR 0.9145, 95% CI 0.8399–0.9857) were identified as predictors of CDAI remission in the tocilizumab group, whereas no predictors of CDAI remission were found in the infliximab group. Similar results were obtained when using SDAI and DAS28-ESR remission criteria.ConclusionBaseline low serum osteopontin levels predict clinical remission 1 year after tocilizumab treatment and not infliximab treatment in biologic-naïve patients with rheumatoid arthritis. Our prediction model provided insights into how to optimize the choice of biologics and warrants external validation in other cohorts.     

Identification and characterization of quantitative trait loci for root elongation by using introgression lines with genetic background of Indica-type rice variety IR64

The root is the sole organ taking up water and nutrients from soils. Hence, root system architecture (RSA) is important for enhancing high-level and stable rice (Oryza sativa L.) production. However, the genetic improvement of RSA has received less attention than yield and yield components. Here, we aimed to identify and characterize quantitative trait loci (QTLs) for RSA by determining the maximum root length (MRL) of seedlings grown hydroponically under various concentrations of NH₄ ⁺. We used a total of 280 introgression lines (ILs) with an Indica-type variety IR64 genetic background, consisting of ten sibling ILs groups, to detect the QTLs. Greater variation of MRL was found in three sibling ILs groups. In total, five QTLs were detected by single marker analyses: two each on chromosomes 5 and 6 and one on chromosome 7. Among them, the most effective QTL was detected on a segment derived from IR69093-41-2-3-2 (YP5), which was localized to the long-arm of chromosome 6. The QTL, designated as qRL6.4-YP5, concerned in root elongation. MRL and total root length of a near-isogenic line (NIL) for qRL6.4-YP5 were significantly (15.2–24.6 %) higher than those of IR64 over a wide range of NH₄ ⁺ concentrations. Root number and weight of the NIL were the same as those of IR64. These results indicated that qRL6.4-YP5 was a constitutive QTL for root length in response to change in nitrogen concentrations. To enhance yield potential by improving RSA, qRL6.4-YP5 might help to improve root development in rice molecular breeding programs with marker-assisted selection.     

E3 Ubiquitin Ligase Pub1 Is implicated in Endocytosis of a GPI-Anchored Protein Ecm33 in Fission Yeast

We previously identified three glycosylphosphatidylinositol (GPI)-anchored proteins including Ecm33, as multicopy suppressors of the phenotypes of a mutant allele of cis4⁺ that encodes a zinc transporter in fission yeast. Here, we further identified two multicopy suppressor genes, ubi1 ⁺ and ubc4 ⁺, encoding ubiquitin-ribosomal fusion protein and ubiquitin conjugating enzyme E2, respectively. In addition, Ubi1 or Ubc4 overexpression failed to suppress the phenotypes of the double deletion of cis4 ⁺ and pub1 ⁺ gene, which encodes a HECT-type ubiquitin ligase E3. During exponential phase GFP-Ecm33 localized at the growing cell tips of the cell surface and the medial region in wild-type cells. Notably, during the post-exponential and stationary phase, GFP-Ecm33 in wild-type cells was internalized and mostly localized to the Golgi/endosomes, but it was still stably localized at the cell surface in Δpub1 cells. The Δpub1 cells showed osomoremedial phenotypes to various drugs indicating their defects in cell wall integrity. Altogether, our findings reveal a novel role for Pub1 in endocytosis of Ecm33 and regulation of cell wall integrity in fission yeast.     

Prognostic Value of FDG PET Imaging in Patients with Laryngeal Cancer

Background and Purpose

To investigate the prognostic value of ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) in patients with laryngeal cancer.

Materials and Methods

The study included 51 patients of whom 30 underwent definitive radiotherapy with or without chemotherapy and 21 underwent radical surgery with or without adjuvant chemoradiation therapy. FDG uptake by both the primary lesion and the neck node was measured using the maximum standardized uptake value (SUVmax). The effects of clinicopathological factors including primary tumor SUVmax and nodal SUVmax on progression-free survival, local control, nodal progression-free survival, and distant metastasis-free survival were evaluated using the log-rank test and Cox method.

Results

The median duration of follow-up was 48.6 months (range 8 to 82.1 months). Univariate analysis showed that nodal SUVmax, N status, and tumor TNM stage were significantly associated with recurrence, whereas primary tumor SUVmax, age, treatment strategy and T status were not. Multivariate analysis demonstrated that only the nodal SUVmax was a significantly unfavorable factor for progression-free survival (p = 0.029, hazard ratio 0.54, 95% CI 0.38-0.87) and nodal progression-free survival (p = 0.023, hazard ratio 0.51, 95% CI 0.34-0.81). ROC curve analysis and log-rank test showed that patients with a high nodal SUVmax (≧4) had a significantly lower progression-free survival rate than those with a low SUVmax (<4; p<0.0001).

Conclusions

The pretreatment SUVmax of nodal disease in patients with laryngeal cancer is prognostic for recurrence.     

KRN633, an Inhibitor of Vascular Endothelial Growth Factor Receptor Tyrosine Kinase,Induces Intrauterine Growth Restriction in Mice

We previously reported that treatment with KRN633, a vascular endothelial growth factor receptor tyrosine kinase inhibitor, during mid‐pregnancy caused intrauterine growth restriction resulting from impairment of blood vessel growth in the labyrinthine zone of the placenta and fetal organs. However, the relative sensitivities of blood vessels in the placenta and fetal organs to vascular endothelial growth factor (VEGF) inhibitors have not been determined. In this study, we aimed to examine the effects of KRN633 on the vasculatures of organs in mother mice and their newborn pups by immunohistochemical analysis. Pregnant mice were treated daily with KRN633 (5 mg/kg) either from embryonic day 13.5 (E13.5) to E17.5 or from E13.5 to the day of delivery. The weights of the pups of KRN633‐treated mice were lower than those of the pups of vehicle‐treated mothers. However, no significant difference in body weight was observed between the vehicle‐ and KRN633‐treated mice. The vascular development in the organs (the pancreas, kidney, and intestine) and intestinal lymphatic formation of the pups of KRN633‐treated mothers was markedly impaired. In contrast, the KRN633 treatment showed no significant effect on the vascular beds in the organs, including the labyrinthine zone of the placenta, of the mother mice. These results suggest that blood vessels in fetal organs are likely to be more sensitive to reduced VEGF signaling than those in the mother. A partial loss of VEGF function during pregnancy could suppress vascular growth in the fetus without affecting the vasculature in the mother mouse, thereby increasing the risk of intrauterine growth restriction.     

Cleavage of Short RNAs Containing Higher Ordered Structures by Hammerhead Ribozymes

Abstract

Cleavage of two types of secondary structure-forming substrates by their cognate hammerhead ribozymes were studied by measuring their kinetic parameters. A substrate with a self-complementary structure (GGUCCUAGGA, CL-3) was slowly cleaved by a two-stranded ribozyme. An isomer having no complementary sequence (GGUCGUAGCA, CL-3N) was cleaved more than 10 times faster than the self-complementary substrate. A newly designed ribozyme which contained a stable loop and stem cleaved the self-complementary decamer 40 times faster than the two-stranded ribozyme. A 15 mer which derived from a ras mRNA was found to have an intermolecular base pairs and was used to design more efficient ribozymes. Gel mobility shift assay was employed to investigate the binding properties of substrates to ribozymes. Investigations of the thermodynamic stability of the ribozyme-substrate complex are essential in the design of ribozymes that efficiently cleave RNA.