benzofurans and Precursor-Cell-Lymphoblastic-Leukemia-Lymphoma

Histone deacetylase (HDAC) inhibitor abexinostat is under investigation for the treatment of various cancers. Epigenetic changes including aberrant HDAC activity are associated with cancers, including myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and acute lymphoblastic leukemia (ALL). In this phase 1 dose-escalation study, 17 patients with relapsed/refractory higher-risk MDS, AML, or ALL received oral abexinostat (60, 80 [starting dose], 100, or 120 mg) twice daily (bid) on Days 1-14 of 21-day cycles. The most common treatment-related grade ≥3 adverse events were thrombocytopenia (29%) and neutropenia (24%), none of which led to discontinuation. Maximum-tolerated dose was not reached. Of 12 evaluable patients, best response was stable disease in 1 patient. This study was closed due to limited clinical benefit. Future development of oral abexinostat 100 mg bid in patients with MDS, AML, or ALL should focus on combination regimens. ISRCTN registry: 99680465.

Topics: Adult; Aged; Benzofurans; Drug Resistance, Neoplasm; Female; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Leukemia, Myeloid, Acute; Male; Middle Aged; Myelodysplastic Syndromes; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Recurrence; Retreatment; Treatment Outcome; Young Adult

Salvia miltiorrhiza (SM) Bunge is one of the widely-used Chinese medicinal herbs. In this study, the chemical constituents and anticancer potential of SM stems and leaves were examined with those of respective callus cultures. The callus culture for stem and leaf explants was initiated in modified Murashige and Skoog (MS) medium. Active constituents of respective extracts were analyzed by high performance liquid chromatography coupled with DAD and MS (HPLC-DAD-MS). Rosmarinic acid (RA) and salvianolic acid B (Sal B) were determined to be the main phenolic compounds. Quantitative analyses revealed that callus stem extracts produced higher amount of RA and Sal B (stem RA: 1.27±0.38%; stem Sal B: 0.87±0.20%) than callus leaf did (leaf RA: 0.28±0.02%; leaf Sal B: 0.07±0.03%). Stem and leaf callus extracts exerted cytotoxic effects towards CCRF-CEM cells (stem: 13.1±0.90 μg/ml; leaf: 18.1±0.33 μg/ml). As expected, stem extract with higher amount of RA and Sal B showed lower IC50 value than leaf extract. These findings suggest the possibility to isolate bioactive constituents with anticancer properties from in vitro callus cultures of stems and leaves of SM.

Topics: Benzofurans; Chromatography, High Pressure Liquid; Cinnamates; Depsides; Drugs, Chinese Herbal; Plant Extracts; Plant Leaves; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Rosmarinic Acid; Salvia miltiorrhiza

With an increasing cancer rate worldwide, there is an urgent quest for the improvement of anticancer drugs. One of the main problems of present chemotherapy in treatment of tumor patients is the toxicity of drugs. Most of the existent anticancer drugs, unfortunately, attack also proliferating normal cells. In recent years, traditional Chinese herbal remedies have gradually gained considerable attention as a new source of anticancer drugs. Although their healing mechanisms are still largely unknown, some of the drugs have been used to help cancer patients fight their disease at reduced side effects compared to other treatments. In our study, we show that Rocaglamide (Roc), derived from the traditional Chinese medicinal plants Aglaia, induces apoptosis through the intrinsic death pathway in various human leukemia cell lines and in acute lymphoblastic leukemia, chronic myeloid leukemia and acute myeloid leukemia cells freshly isolated from patients. Investigation of the molecular mechanisms by which Roc kills tumors revealed that it induces a consistent activation of the stress-response mitogen-activated protein kinase (MAPK) p38 accompanied with a long-term suppression of the survival MAPK extracellular signal-regulated kinase. These events affect proapoptotic Bcl-2 family proteins leading to depolarization of the mitochondrial membrane potential and trigger caspase-mediated apoptosis involving caspase-9, -8, -3 and -2. Importantly, Roc shows no effects on MAPKs in normal lymphocytes and therefore has no or very low toxicity on healthy cells. Up to now, more than 50 different Roc derivatives have been isolated from Aglaia. Our study suggests that Roc derivatives may be promising candidates for the development of new drugs against hematologic malignancies.

Topics: Acute Disease; Antineoplastic Agents; Apoptosis; Benzofurans; Cell Line, Tumor; Drugs, Chinese Herbal; Humans; JNK Mitogen-Activated Protein Kinases; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Tubulin