Hepatitis C virus (HCV) is a serious global problem, and present therapeutics are inadequate to cure HCV infection. In the present study, various antiviral assays show that As2O3 at submicromolar concentrations is capable of inhibiting HCV replication. The 50% effective concentration (EC50) of As2O3 required to inhibit HCV replication was 0.35 microM when it was determined by a reporter-based H...

BACKGROUND Cases of QT prolongation, torsades de pointes, and sudden death have been reported with arsenic trioxide (As2O3), a highly effective agent for acute promyelocytic leukemia. In this study, we evaluated the effects of As2O3 on repolarizing cardiac ion currents. METHODS AND RESULTS In HERG- or KCNQ1+KCNE1-transfected CHO cells (n=32; total), As2O3 caused concentration-dependent block ...

Multidrug resistance (MDR) to doxorubicin (DOX) limits its effectiveness against tumor cells. Arsenic trioxide (As2O3) has been reported to reduce MDR in various types of cancer, but the mechanisms involving Ras and p-glycoprotein (P-gp) remain to be fully elucidated. The objectives of the present study were to evaluate As2O3 in reversing MDR to DOX, and to identify the association in antitumor...

BACKGROUND Currently, the optimal maintenance therapy for patients with acute promyelocytic leukemia (APL) who have achieved complete remission (CR) after completing consolidation chemotherapy remains controversial. The comparative effectiveness of the all-trans retinoic acid (ATRA) plus arsenic trioxide (As2O3) maintenance strategy with classic ATRA plus chemotherapy has not been evaluated. In...

Despite considerable efficacy of arsenic trioxide (As2O3) in acute promyelocytic leukemia (APL) treatment, other non-APL leukemias, such as chronic myeloid leukemia (CML), are less sensitive to As2O3 treatment. However, the underlying mechanism is not well understood. Here we show that relative As2O3-resistant K562 cells have significantly lower ROS levels than As2O3-sensitive NB4 cells. We com...

Arsenic, a well-known human carcinogen, has been reported to induce hepatic oxidative stress and hepatic injury. Eriodictyol, a flavonoid found in citrus fruits, has been reported to have antioxidant effects. In this study, we aimed to investigate the protective effects of eriodictyol on arsenic trioxide (As2O3)-induced liver injury and to clarify the molecular mechanism. Male Wistar rats were ...

The treatment of acute promyelocytic leukemia (APL) patients who present or develop resistance to ATRA is still a problem. Recently, we proposed a pulsed-ATRA regimen, able to reduce the incidence of resistance if compared to continuous administration, and to reinduce complete molecular remission in relapsed patients. Arsenic trioxide (As2O3) is effective in APL refractory or relapsed after ATR...

Small cell lung carcinoma (SCLC) is an extremely aggressive form of cancer and current treatment protocols are insufficient. SCLC have neuroendocrine characteristics and show phenotypical similarities to the childhood tumor neuroblastoma. As multidrug-resistant neuroblastoma cells are highly sensitive to arsenic trioxide (As2O3) in vitro and in vivo, we here studied the cytotoxic effects of As2...

PURPOSE Arsenic trioxide (As2O3) was introduced into the treatment of refractory or relapsed acute promyelocytic leukemia and showed a striking effectiveness in China and United States multicenter study. However, the mechanistic basis for the carcinogenic or therapeutic effects of arsenics is still poorly understood. So, this study is performed to determine whether As2O3 induces apoptosis throu...

Since the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (As2O3) for the treatment of acute promyelocytic leukemia (APL), the overall survival rate has improved dramatically. However, relapse/refractory patients showing resistance to ATRA and/or As2O3 are recognized as a clinically significant problem. Genetic mutations resulting in amino acid substitution in the retinoic a...