[Molecular mechanism of norcantharidin inducing apoptosis in liver cancer cells].

OBJECTIVE: To elucidate the molecular mechanism of norcantharidin (NCTD) in inducing apoptosis of liver cancer cells so as to provide basic rationales for its application in liver cancer treatment. METHODS: Liver cancer cell lines of SMMC-7721 and BEL-7402 were treated with NCTD. The cell growth inhibition was measured by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, cell death detected by trypan blue exclusion assay and apoptosis examined by Annexin V/PI staining and flow cytometry. The cleavage of caspase-9, -3 and PARP, and the expression of the anti-apoptotic Bcl-2 proteins were analyzed by Western blot. RESULTS: The MTT results showed that, after a treatment with NCTD for 24, 48 and 72 h, the IC50 of NCTD in SMMC-7721 cell line was 12, 6 and 1.6 µg/ml respectively; in BEL-7402, the IC50 10, 4 and 2 µg/ml respectively. Trypan blue exclusion assay showed that NCTD mediated substantial cell death in two cancer cell lines. Apoptosis assay showed that, after a 12 h treatment with 10 µg/ml NCTD, 27% of SMMC-7721 cells were induced to undergo apoptosis, an increment of 20% over the untreated control cells (7%); 30% of BEL-7402 cells became apoptotic, an increment of 22% over the untreated control cells (8%). Western blot analysis showed that NCTD treatment potently induced the activation of caspase-9, -3 and the cleavage of PARP, and markedly down-regulated the expression of Bcl-2, Bcl-X(L) and Mcl-1. CONCLUSION: NCTD strongly inhibits liver cancer cell growth and potently induces apoptotic cell death in two liver cancer cell lines. The strong anticancer activity of NCTD may be induced through targeting multiple Bcl-2 anti-apoptotic family members.

Crizotinib synergizes with cisplatin in preclinical models of ovarian cancer.

Crizotinib, a small molecule inhibitor of anaplastic lymphoma kinase (ALK), c-ros oncogene 1 (ROS1) and c-MET (also called MET or hepatocyte growth factor receptor), has been approved by the Food and Drug Administration for the treatment of patients with advanced non-small cell lung cancer whose tumors have rearrangements in the ALK or ROS1 gene. However, the anticancer effect of crizotinib on ovarian cancer is still unclear. In this study, our data show that crizotinib can actively induce cell growth inhibition, cell cycle arrest at G2/M phase and apoptosis with the decreasing phosphorylation of the downstream signaling effectors AKT and ERK in human ovarian cancer cells. Crizotinib also increases the intracellular reactive oxidative species (ROS) levels, and pretreating with ROS scavenger N-acety-L-cysteine partially reverses crizotinib-induced apoptosis. Moreover, crizotinib can synergistically inhibit ovarian cancer cells growth in vitro and in vivo when combines with cisplatin. Altogether, crizotinib potently potentiates the activity of cisplatin in ovarian cancer, suggesting the synergistic effect of crizotinib and cisplatin may be valuable for ovarian cancer patients' treatment.

Note: Stability control of intermediate frequencies of a three laser far-infrared polarimeter-interferometer system.

Stability of the intermediate frequency (IF) in the far-infrared polarimeter-interferometer diagnostic system is critically important for the long pulse discharge experiments on the EAST tokamak. In this note, a real-time remote/local IF stability control system is described. The measured plasma parameters, including the Faraday rotation angle, electron density, lower hybrid wave, and plasma current, are obtained with the aid of this newly developed IF stability control system.

Cervical cancer systemic inflammation score: a novel predictor of prognosis.

Inflammation contributes to development and progression in a variety of cancers, including cervical cancer. We developed a novel cervical cancer systemic inflammation score (CCSIS) based on the preoperative platelet-to-lymphocyte ratio (PLR) and serum albumin levels. A retrospective analysis of clinical data from 795 patients with operable cervical cancer was then conducted to investigate the prognostic value of CCSIS and its association with the patients' clinicopathological features, overall survival (OS), and disease-free survival (DFS). CCSIS was predictive of OS and DFS. High CCSIS was correlated with more advanced FIGO stages, poor tumor differentiation, and the presence of PLN and LVSI. Both albumin levels and the PLR were independent prognostic indicators for operable cervical cancer. The use of the CCSIS could improve risk stratification and traditional clinicopathological analysis in cervical cancer.

Effects of removal of the N-terminal amino acid residues on the activity and conformation of firefly luciferase.

A series of deletion mutants were constructed using polymerase chain reaction (PCR) to investigate the roles of luciferase N-terminal residues. The coding sequences of the first 0 (Luc0), 6 (Luc6), 7 (Luc7), 8 (Luc8), 9 (Luc9), 10 (Luc10) and 20 (Luc20) amino acids of the N-terminus were deleted and inserted into the prokaryotic expression vector pBV220. The results showed that the enzymes were completely inactivated when the first eight or more N-terminal amino acids were removed. The recombinant Luc0 and mutants Luc6 and Luc7 were purified to homogeneity by ammonium sulfate precipitation and liquid chromatography for determination of their activity and conformational changes. The activity assay showed that removal of the first six amino acids resulted in 29% loss of enzymatic activity while removal of the first seven amino acids resulted in nearly complete inactivation (with remaining activity <0.5% of the original activity). Circular dichroism spectra showed no significant secondary structure changes. But the fluorescence emission maximum red-shift indicated some conformational changes. Luc6 and Luc7 were more sensitive to guanidine unfolding than Luc0. The present result indicated the significant role of Ile7 to the luciferase stability.