Atenolol, a β1-adrenergic receptor blocker, is administered orally and its intestinal absorption has recently been indicated to be mediated by carrier protein and reduced markedly by ingestion of some fruit juices, such as apple and orange juices. This could be postulated to be a problem arising from the interaction of some components of fruit juices with atenolol at a transporter involved in its intestinal uptake, but the responsible transporter and its interacting components have not been identified yet. In an attempt to examine that possibility, we could successfully find that human organic cation transporter 1 (OCT1/SLC22A1), which is suggested to be expressed at the brush border membrane of enterocytes, is highly capable of transporting atenolol. In this attempt, OCT1 was stably expressed in Madin-Darby canine kidney II cells and the specific uptake of atenolol by the transporter was found to be saturable, conforming to the Michaelis-Menten kinetics with the maximum transport rate (Vmax) of 4.00 nmol/min/mg protein and the Michaelis constant (Km) of 3.08 mM. Furthermore, the OCT1-specific uptake was found to be inhibited by various flavonoids, including those contained in fruit juices that have been suggested to interfere with intestinal atenolol absorption. Particularly, phloretin and quercetin, which are major components of apple juice, were potent in inhibiting OCT1-mediated atenolol transport with the inhibition constants of 38.0 and 48.0 µM, respectively. It is also notable that the inhibition by these flavonoids was of the noncompetitive type. These results indicate that OCT1 is an atenolol transporter that may be involved in intestinal atenolol uptake and sensitive to fruit juices, although its physiological and clinical relevance remains to be further examined.

The intestinal absorption of atenolol has recently been reported to be reduced by simultaneous ingestion of fruit juices, such as apple juice. This finding implies a possibility that an unidentified carrier-mediated transport system, which could be interfered by some components of those juices, might be involved in atenolol absorption. In an attempt to explore that possibility, we successfully identified plasma membrane monoamine transporter (PMAT/SLC29A4) as a transporter that can operate for cellular atenolol uptake in the intestine, using Madin-Darby canine kidney II cells stably expressing PMAT. The specific uptake of atenolol by PMAT was greatest at around pH 6.0 and decreased with an increase in pH. At pH 6.0, the PMAT-specific uptake of atenolol was saturable with a Michaelis constant of 0.907 mM. Moreover, PMAT-specific atenolol uptake was extensively inhibited by phloretin and quercetin, which are the major flavonoids contained in apple juice, with the half maximal inhibitory concentrations of 33.3 and 116.3 μM, respectively. PMAT-specific atenolol uptake was also inhibited by several ß-blockers, suggesting that they may also be recognized and transported by PMAT. These results suggest that PMAT is an atenolol transporter that may be involved in intestinal atenolol absorption and sensitive to flavonoids contained in apple juice.

Background/Aim: Predicting the prognosis of metastatic urothelial carcinoma (mUC) patients is needed for clinical decisions. We examined the value of a modified Glasgow prognostic score (mGPS) as a predictive marker for mUC patients. Patients and Methods: In a multicenter study, 68 mUC patients received short hydration gemcitabine/ cisplatin (shGC) and 74 received pembrolizumab (PEM). Patients were allocated according to mGPS. Progression-free (PFS) and cancer-specific (CSS) survival were examined. Results: Higher mGPS reflected poorer PFS and CSS in shGC (p=0.03, p<0.0001, respectively) and PEM (p=0.02, p<0.001, respectively) patients. PFS for the high mGPS group was longer than that of the low mGPS group in the two cohorts (p <0.0001 for both), with similar CSS results (p<0.0001 and p<0.001, respectively). Multivariate analyses revealed high mGPS was a risk factor for poor CSS in both cohorts (HR=3.55, p<0.001, and HR=2.21, p<0.01, respectively). Conclusion: In the mUC patients receiving shGC or PEM, mGPS was a predictive prognostic marker.The incidence of bladder cancer is rising but the mortality rate has recently become reduced with improved treatment (1). However, for patients with metastatic urothelial carcinoma (mUC) the 5-year survival rate is approximately 5% and its prognosis appears poor (2). Evidence from several regimens has been used to improve the prognosis of mUC. Cisplatin-based chemotherapy is recommended as first-line treatment for mUC in National Comprehensive Cancer Network (NCCN) guidelines (3, 4). For decades, evidence from second-line therapy has been lacking. Recently, the efficacy of pembrolizumab (PEM) was described (5), which became the preferred regimen of second-line therapy for mUC under NCCN guidelines (4). However, the optimal timing of a switch in drug has not been established and a definitive prognostic marker for supporting drug selection is lacking. In this regard, useful biomarkers have appeared to assist physicians in identifying the timing of the cessation of the administration of drugs that lost their efficacy over time in patients with advanced cancers.Several evaluation methods related to nutrition or inflammation have been identified that can be used to assess the prognosis of cancer patients. Useful prognostic markers for mUC based on drugs have been reported previously. Predictive factors for the prognosis of patients with mUC who received cisplatin-based chemotherapy are: performance status (PS), hemoglobin levels, and liver metastasis (6). Sarcopenia, a quantitative measure of a loss in muscle mass and strength, is as a prognostic marker of patients with mUC who received gemcitabine and cisplatin (GC) (7). In a previous report, we described how the progression of sarcopenia was also considered a predictive marker of overall survival as found in patients with mUC who underwent gemcitabine and docetaxel treatment as secondline therapy (8). In research on biomarkers using blood samples, the neutrophil-lymphocyte ratio was also shown to reflect the response of pat...

<b><i>Background:</i></b> We evaluated the prognostic efficacy of the Geriatric Nutritional Risk Index (GNRI) in second-line pembrolizumab (PEM) therapy for patients with metastatic urothelial carcinoma (mUC). <b><i>Patients and Methods:</i></b> From January 2018 to October 2019, 52 mUC patients, treated previously with platinum-based chemotherapy, underwent second-line PEM therapy. Peripheral blood parameters were measured at the start of treatment: serum neutrophil-to-lymphocyte ratio (NLR), serum albumin, serum C-reactive protein (CRP), and body height and weight. PEM was intravenously administered (200 mg every 3 weeks). The patients were organized into two groups based on their GNRI (&#x3c;92 [low GNRI] and ≥92 [high GNRI]), and the data were retrospectively analyzed. Adverse events (AEs) were evaluated and imaging studies assessed for all patients. Analyses of survival and recurrence were performed using Kaplan-Meier curves. Potential prognostic factors affecting cancer-specific survival (CSS) were assessed by univariate and multivariate Cox regression analyses. <b><i>Results:</i></b> patients’ baseline characteristics, except for their BMI and objective response rate, did not significantly differ between the two groups. The median total number of cycles of PEM therapy was significantly higher for the high-GNRI group (<i>n</i> [range]: 6 [2–20] vs. 3 [1–6]). The median CSS with second-line PEM therapy was 3.6 months (95% confidence interval [CI]: 2.5–6.1) and 11.8 months (95% CI: 6.2–NA) in the low-GNRI and the high-GNRI group (<i>p</i> &#x3c; 0.01), respectively. Significant differences in CSS between the low- and high-CRP or -NRL groups were not found. Multivariate Cox proportional-hazards regression analysis revealed that a poor Eastern Cooperative Oncology Group performance status, visceral metastasis, and a low GNRI were significant prognostic factors for short CSS (95% CI: 1.62–6.10, HR: 3.14; 95% CI: 1.13–8.11, HR: 3.03; 95% CI: 1.32–8.02, HR: 3.25, respectively). Of the AEs, fatigue showed a significantly higher incidence in the low-GNRI group. <b><i>Conclusions:</i></b> For mUC patients receiving second-line PEM therapy, the GNRI is a useful predictive biomarker for survival outcome.

A suicide gene therapy using herpes simplex virus thymidine kinase (HSV-TK) with ganciclovir (GCV) has been under development as a tumor-targeted therapy; however, the mechanism of cellular GCV uptake, which is prerequisite in the therapy, has not been clarified. In an attempt to resolve this situation and gain information to optimize HSV-TK/GCV system for cancer therapy, we found that human equilibrative nucleobase transporter 1 (ENBT1) can transport GCV with a Michaelis constant of 2.75 mM in Madin-Darby canine kidney II (MDCKII) cells stably transfected with this transporter. In subsequent experiments using green fluorescent protein (GFP)-tagged ENBT1 (GFP-ENBT1) and HSV-TK, the uptake of GCV (30 μM), which was minimal in MDCKII cells and unchanged by their transfection with HSV-TK alone, was increased extensively by their transfection with GFP-ENBT1, together with HSV-TK. Accordingly, cytotoxicity, which was assessed by the WST-8 cell viability assay after the treatment of those cells with GCV (30 μM) for 72 hours, was induced in those transfected with GFP-ENBT1, together with HSV-TK but not in those transfected with HSV-TK alone. These results suggest that ENBT1 could facilitate GCV uptake and thereby enhance cytotoxicity in HSV-TK/GCV system. We also identified Helacyton gartleri (HeLa) and HepG2 as cancer cell lines that are rich with ENBT1 and A549, HCT-15 and MCF-7 as those poor with ENBT1. Accordingly, the HSV-TK/GCV system was effective in inducing cytotoxicity in the former but not in the latter. Thus, ENBT1 was found to be a GCV transporter that could enhance the performance of HSV-TK/GCV suicide gene therapy.