Aim： To assess the synergistic actions of lidamycin （LDM） and chloroquine （CQ）, a lysosomal enzyme inhibitor, in human non-small cell lung cancer （NSCLC） cells, and to elucidate the potential mechanisms. Methods： Human NSCLC cell lines A549 and H460 were treated with CQ and/or LDM. Cell proliferation was analyzed using MTI- assay and apoptosis was quantified using flow cytometry. Western blotting was used to detect the protein levels of caspase 3, PARP, Bcl-2, Bax, p53, LC3-1 and LC3-11. A H460 cell xenograft model in BALB/c nude mice was used to evaluate the anticancer efficacy of CQ and LDM in vivo. Results： Both LDM and CQ concentration-dependently suppressed the proliferation of A549 and H460 ceils in vitro （the ICso values of LDM were 1.70±0.75 and 0.043±0.026 nmol/L, respectively, while the IC50 values of CQ were 71.3±6.1 and 55.6±12.5 pmol/L, respectively）. CQ sensitized both NSCLC cell lines to LDM, and the majority of the coefficients of drug interaction （CDIs） for combination-doses were less than 1. The ratio of apoptosis of H460 cells induced by a combined treatment of CQ and LDM （77.0%±5.2%） was significantly higher than those caused by CQ （23.1%±4.2%） or by LDM （65.1%±4.1%） alone. Furthermore, the combined treatment markedly increased the cleaved PARP and cleaved caspase 3 in H460 cells, which were partly reversed by pretreatment with the caspase inhibitor zVAD.fmk, zVAD.fmk also partially reversed the inhibitory effect of the combination treatment on the proliferation of H460 cells. The combination therapy group had a notable increase in expression of Bax and a very slight decrease in expression of Bcl-2 and p53 protein. LDM alone scarcely affected the level of LC3-11 in H460 cells, but slightly reduced CQ-induced LC3-11 expression. 3-MA, an autophagy inhibitor also sensitized H460 cells to LDM. In nude mice bearing H460 cell xenograft, administration of LDM （25 pg/kg, iv） and CQ （60 mg/kg, ip） suppressed tumor growth by 57.14% and 73.02%, respectively. Conclusion： The synergistic anticancer effect of LDM and CQ in vitro results from activation of a caspase-dependent and p53- independent apoptosis pathway as well as inhibition of cytoprotective autophagy.
Canstatin, which possesses a significant inhibition effect on the migration of endothelial cells and a strong anticancer effect [1,2], has been applied in the treatment of many cancers including human oral, breast, prostate, pancreatic, and colorectal [3-7]. However, because the expression of bioactive recombinant canstatin is very low using the current expression systems, e.g. prokaryotic Escherichia coli expression system , its application has still been limited to clinical trials. Several eukaryotic cell expression systems have been exploited for canstatin production, such as Bombyx mori cells  and Drosophila melanogaster S2 cells , but they also have a lot of disadvantages, for example, high culture cost, poor yield, and difficulty in purification. Therefore, it is necessary and urgent to develop an optimal expression system for the large-scale production of the recombinant canstatin.
AIM: To investigate the antitumor and anti-angiogenic activity of Ganoderma lucidum polysaccharides peptide (GLPP). METHODS: Antitumor effect of GLPP was observed in tumor-bearing mice in vivo. At the same time,the effects of GLPP on proliferation of tumor cells and human umbilical cord vascular endothelial cell (HUVEC) were detected by MTr assay in vitro. Subsequently, spleen lymphocytes proliferation of nude mice was stimulated by LPS or ConA. To investigate the anti-angiogenic effect of GLPP, GLPP 80 μg per disc and GLPP-treated serum 10μL per disc were added to the chick chorioallantoic membrane (CAM) respectively in vivo. RESULTS: GLPP 50, 100, and 200 mg/kg inhibited growth of Sarcoma 180 in BALB/c mice markedly by 35.2 %, 45.2 %, and 61.9 %,respectively. GLPP which was directly added to the cultured medium did not inhibit PG cell proliferation in vitro;but GLPP-treated serum 50, 100, 200 mg/kg potently inhibited PG cell proliferation by 22.5 %, 26.8 %, and 30.3 %,respectively; and reduced the xenograft (human lung carcinoma cell PG) in BALB/c nude mice greatly in vivo by 55.5 %, 46.0 %, and 46.8 %, respectively. Lymphocytes proliferation of nude mice could be stimulated by LPS 5 mg/L but not by ConA 2.5 mg/L, indicating that GLPP could not promote the T lymphocyte proliferation and neutral red phagocytosis of peritoneal macrophages of nude mice. The CAM assay showed that GLPP and GLPP-treated serum had anti-angiogenic effect. GLPP (1, 10, and 100 mg/L) inhibited HUVEC proliferation in vitro with the inhibitory rate of 9.4 %, 15.6 %, and 40.4 %, respectively. CONCLUSION: GLPP has antitumor and antiangiogenic activity. The anti-angiogenesis of GLPP may be a new mechanism underlying its anti-tumor effects.
OBJECTIVE： To test if myricanone （02H2405）, a cyclic diarylheptanoid, has anticancer effects on two different cancer cell lines HeLa and PC3. The present study was conducted with a note on the drug-DNA interaction and apoptotic signalling pathway. METHODS： Several studies like cytotoxicity, nuclear damage, annexin-V-fluorescein isothiocyanate （FITC）/propidium iodide （PI）-Iabelled apoptotic assay and cell cycle arrest, immunoblot and reverse transcriptase-polymerase chain reaction （RT-PCR） were used following standard protocols. Circular dichroism （CD） spectroscopy was also done to evaluate whether myricanone effectively interacted with DNA to bring about conformational changes that could strongly inhibit the cancer cell proliferation. RESULTS： Myricanone showed a greater cytotoxic effect on PC3 cells than on HeLa cells. Myricanone promoted G0/G arrest in HeLa cells and S phase arrest in PC3 cells. Nuclear condensation and annexin V-FITC/PI studies revealed that myricanone promoted apoptotic cell death. CD spectroscopic data indicated that myricanone had an interaction with calf thymus DNA that changed DNA structural conformation. RT-PCR and immunoblot studies revealed that myricanone activated the apoptotic signalling cascades through down-regulation of transcription factors like nuclear factor-KB （NF-KB） （p65）, and signal transducers and activators of transcription 3 （STAT3）; cell cycle regulators like cyclin D1, and survivin and other signal proteins like Bcl-2 and up-regulation of Bax, caspase-9 and caspase-3. CONCLUSION： Myricanone induced apoptosis in both types of cancer cells by triggering caspase activation, and suppression of cell proliferation by down-regulation of NF-KB and STAT3 signalling cascades, which makes it a suitable candidate for possible use in the formulation of therapeutic alent for combatin cancer.