[Effects of Tyrosine Kinase Inhibitors on Control of PT-INR in Patients Receiving Warfarin].

Few studies have evaluated the influence of anticancer drugs on the anticoagulation response to warfarin(WF). This retrospective, single-center, observationalstudy evaluated the changes in prothrombin time-internationalnormal ized ratio (PT-INR)in patients receiving a combination of WF and anticancer drugs. We compared(a)PT-INR changes between groups receiving WF and concomitantly started on either tyrosine kinase inhibitors(TKI)(WF+TKI group: n=14)or anticancer drugs other than TKI(WF+non-TKI group: n=20)and(b)PT-INR changes between groups that were started on WF concomitantly while receiving either TKI(TKI+WF group: n=16)or anticancer drugs other than TKI(non-TKI+WF group: n=13). (a)PT-INR changes were significantly larger in the WF+TKI group than in the WF+non-TKI group(2.23 vs 0.42, p<0.001). In the WF+TKI group, the WF dose was reduced after all 14 patients(100.0%)showed increased PT-INR.(b)PT-INR changes during the WF induction period were significantly larger in the TKI+WF group than in the non-TKI+WF group(2.18 vs 0.68, p<0.001). In the TKI+WF group, the WF dose was reduced after 12 patients(75.0%)showed increased PT-INR. It might be necessary to consider a reduction in WF dose when WF is administered in combination with TKIs.

Functional availability of gamma-herpesvirus K-cyclin is regulated by cellular CDK6 and p16INK4a.

Viral K-cyclin derived from Kaposi's sarcoma-associated herpesvirus is homologous with mammalian D-type cyclins. Here, we demonstrated the regulatory mechanisms for K-cyclin function and degradation in human embryonic kidney HEK293 and primary effusion lymphoma JSC-1 cell lines. Proteasome inhibitor MG132 treatment induced an accumulation of ubiquitinated K-cyclin in these cells, and co-expression of CDK6 prevented K-cyclin ubiquitination. Also K-cyclin mutants incompetent for CDK6-binding were destabilized by proteasome pathway. Furthermore, silencing of p16INK4a promoted K-cyclin-CDK6 complex formation and hence induced K-cyclin-associated kinase activity in HEK293 cells. These observations indicate that CDK6-bound K-cyclin is functionally stable but monomeric K-cyclin is targeted to ubiquitin-dependent degradation pathway in these cells. Our data suggest that the balance between CDK6 and p16INK4a regulates the availability of functional K-cyclin in human cells.

Identification of risk factors for venous thromboembolism and evaluation of Khorana venous thromboembolism risk assessment in Japanese lung cancer patients.

BACKGROUND: The reported incidence of venous thromboembolism (VTE) in cancer patients is 4-20%. The Khorana VTE risk score (KRS) and the Vienna VTE risk score (VRS) have been proposed as scoring models for evaluation of cancer-associated VTE. However, the risk factors of VTE in Japanese lung cancer patients have not been clarified. METHODS: This retrospective study included 682 hospitalized Japanese patients with newly diagnosed lung cancer who were examined for VTE on admission between January 2014 and December 2016. RESULTS: Seventy-one (10.4%) of the 682 patients were diagnosed with VTE. Multivariate logistic regression analysis showed that body mass index (BMI) ≥25 kg/m2 (OR, 2.02; 95% CI, 1.06-3.72), white blood cell (WBC) count >11 × 109/L (OR, 2.31; 95% CI, 1.11-4.61), pre-chemotherapy serum D-dimer concentration ≥1.44 µg/mL (OR, 2.73; 95% CI, 1.49-4.99), and non-small cell lung cancer (OR, 3.13; 95% CI, 1.32-9.23) were significantly associated with VTE in these patients. The cut-off values for BMI, WBC count, and D-dimer concentration determined using receiver operating characteristic curves were 25.4 kg/m2, 11.2 × 109/L, and 1.95 µg/mL, respectively. CONCLUSIONS: In this study, we were able to identify four independent risk factors for cancer-associated VTE in Japanese lung cancer patients for the first time. Moreover, we showed that a cut-off level of ≥25 kg/m2 for BMI was a risk factor for VTE in this cohort.

Comparison of cisplatin-induced nephrotoxicity when using conventional versus short hydration in gastric cancer-a retrospective study.

Although a short hydration protocol for cisplatin has been recently developed for use in lung cancer, this has yet to be established for gastric cancer. This study reviewed medical records of patients with gastric cancer who received XPT(capecitabine/cisplatin/trastuzumab) therapy containing cisplatin. Patients received either the conventional or short hydration regimen. Nephrotoxicity was compared between these two regimens by monitoring the serum creatinine. Out of the 26 total patients, 19 received the conventional regimen while 7 received the short hydration regimen. There was a higher nephrotoxicity was observed in the group receiving the conventional regimen (42.1%, 8/19) as compared to the short hydration regimen (0%, 0/7). There was a statistically significant difference in nephrotoxicity between the regimens (P = 0.039). Study results suggest that short hydration may be a feasible regimen for XPT therapy in gastric cancer patients.

Enzymatic properties of human CYP2W1 expressed in Escherichia coli.

The human genome project revealed a new member of the P450 family 2, CYP2W1, which has orthologous form in other vertebrate species, suggesting CYP2W1's significant physiological function. Recently, it was reported that CYP2W1 can metabolize arachidonic acid. In this study, we isolated human CYP2W1 cDNA, and successfully expressed truncated CYP2W1 lacking N-terminal 20 amino acids in Escherichia coli cells. In the bicistronic expression system for human CYP2W1 and NADPH-P450 reductase, the formation of blue pigment, indigo, was observed in bacterial cultures. Based on this result, we revealed that CYP2W1 catalyzes the oxidation of indole. In addition, CYP2W1 showed monooxygenase activity towards 3-methylindole and chlorzoxazone. However, no activity was observed towards fatty acids including arachidonic acid. Further analysis using an E. coli expression system will reveal substrate specificity of CYP2W1 and why this P450 isoform is universally conserved in vertebrates.