stilbenes and Precursor-T-Cell-Lymphoblastic-Leukemia-Lymphoma

Resveratrol and its higher hydroxylated analogs have been reported to possess a variety of biological properties including antioxidant as well as prooxidant effects. The antioxidant properties are assumed to enable these compounds to protect cells from oxidative damage, however prooxidant activity are held likely to be responsible for their cytotoxic or pro-apoptotic effects. In present study the effects of resveratrol (Res) and its three derivatives: 3,3',4,4'-tetrahydroxy-trans-stilbene (M6), 3,4,4',5-tetrahydroxy-trans-stilbene (M8) and 3,3',4,4',5,5'-hexahydroxy-trans-stilbene (M12) were investigated on T cell leukemia Jurkat cells. The tested compounds have cytotoxic activity against cancer cells and IC50 values obtained in the Alamar blue assay were: 58.4 μM, 48.1 μM, 33.4 μM for and 13.8 μM for Res, M6, M8, M12, respectively. Furthermore, we also observed an increased activity of caspase 3 and 9, with significantly higher values in cells incubated with M8 and M12 than Res and M6. Cell death was accompanied by loss of mitochondrial potential, oxidative stress, decrease of glutathione level as well as loss of both mRNA expression and activity of superoxide dismutase (MnSOD). Cytotoxic activity may be connected with the formation of short-living prooxidative metabolites as compounds M8 and M12 were very instable in incubation medium. In conclusion, we elucidated the mechanisms responsible for cytotoxicity of hydroxylated resveratrol analogs in leukemia cells which may also apply to other polyphenols.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Drug Stability; Humans; Hydroxylation; Jurkat Cells; Molecular Structure; Oxidation-Reduction; Oxidative Stress; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Reactive Oxygen Species; Real-Time Polymerase Chain Reaction; Resveratrol; Stilbenes

To explore the effects of resveratrol-induced apoptosis and autophagy in T-cell acute lymphoblastic leukemia (T-ALL) cells and potential molecular mechanisms.. The anti-proliferation effect of resveratrol-induced, apoptosis and autophagy on T-ALL cells were detected by using MTT test, immunofluorescence, electronic microscope, and flow cytometry, respectively. Western blotting was performed for detecting changes of apoptosis-associated proteins, cell cycle regulatory proteins and state of activation of Akt, mTOR, p70S6K, 4E-BP1, and p38-MAPK.. Resveratrol inhibited the proliferation and induced apoptosis and autophagy in T-ALL cells in a dose and time-dependent manner. It also induced cell cycle arrest at G0/G1 phase via up regulating cyclin-dependent kinase (CDK) inhibitors p21 and p27 and down regulating cyclin A and cyclin D1. Western blotting revealed that resveratrol significantly decreased the expression of antiapoptotic proteins (Mcl-1 and Bcl-2) and increased the expression of proapoptotic proteins (Bax, Bim, and Bad), and induced cleaved-caspase-3 in a time-dependent manner. Significant increase in ratio of LC3-II/LC3-I and Beclin 1 was also detected. Furthermore, resveratrol induced significant dephosphorylation of Akt, mTOR, p70S6K, and 4E-BP1, but enhanced specific phosphorylation of p38-MAPK which could be blocked by SB203580. When autophagy was suppressed by 3-MA, apoptosis in T-ALL cells induced by resveratrol was enhanced.. Our findings have suggested that resveratrol induces cell cycle arrest, apoptosis, and autophagy in T-ALL cells through inhibiting Akt/mTOR/p70S6K/4E-BP1 and activating p38-MAPK signaling pathways. Autophagy might play a role as a self-defense mechanism in T-ALL cells treated by resveratrol. Therefore, the reasonable inhibition of autophagy in T-ALL cells may serve as a promising strategy for resveratrol induced apoptosis and can be used as adjuvant chemotherapy for T-ALL.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Autophagy; Cell Culture Techniques; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Flow Cytometry; Humans; p38 Mitogen-Activated Protein Kinases; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Proto-Oncogene Proteins c-akt; Resveratrol; Stilbenes; T-Lymphocytes; TOR Serine-Threonine Kinases