Inhibition of Glioma Cell Line A-172 MMP Activity and Cell Invasion In Vitro by a Nutrient Mixture
M.W. Roomi, V. Ivanov, T. Kalinovsky, A. Niedzwiecki, M. Rath
Medical Oncology 2007, 24(2): 231-238
Medical Oncology 2007, 24(2): 231-238
Standard multimodality therapy of gliomas is associated with poor patient survival and significant toxicity. Abnormal expression of matrix metalloproteinases (MMPS) is associated with tumor growth and invasion. We investigated the effect of a combination of natural compounds (NM), primarily composed of lysine, proline, ascorbic acid and green tea extract in vitro on glioma cell line A-172, by measuring MMP secretion, invasion through Matrigel, and cell proliferation. Glioma cells A-172 (ATCC) were grown in modified Dulbecco�s Eagle medium with10% fetal bovine serum and antibiotics and treated with NM at 0, 10, 50, 100, 500 and 1000 �g/ml concentration in triplicate at each dose. Cell proliferation was assayed by MTT, MMP secretion by zymography, invasion through Matrigel, and morphology by H&E staining. Zymography showed one band corresponding to MMP-2, which was inhibited by NM in a dose dependent fashion, with virtual total inhibition at 500-�g/ml concentration. Invasion through Matrigel was completely inhibited at 1000 �g/ml NM. NM was not toxic to glioma cell line A-172 at lower concentrations and exhibited toxicity of 50 % over the control at 1000 �g/ml. These results are significant as the nutrient mixture significantly inhibited MMP secretion and invasion-important parameters for cancer prevention without toxic effects, suggesting NM as a potential therapeutic agent for treatment of glioma.
Stephen what do you think about the study above?
ReplyDeleteThe first thing you have to ask about any in vitro study is this: are the tested concentrations of the drug/compound realistic? Are equal concentrations of free, unmetabolized drug anywhere close to achievable in plasma or target tissue? In vitro evidence should be regarded as the very first indication that a drug/compound is worthy of further study, but by itself it doesn't say very much.
ReplyDeleteIn the second study, large anti-invasive effects were seen at a Nutrient Mixture concentration of 500 ug/mL. By weight, the nutrient mixture is about one-quarter green tea extract, of which 35% is EGCG. So, is 44 ug/mL of EGCG achievable?
44 ug/mL = 44000 ug/L. Max plasma concentration of unconjugated EGCG after an 800 mg dose is about 440 ug/L, or about 100 times less.
The Nutrient Mixture also caused increased glioma cell proliferation by 40% at 50 ug/mL, and by about 10% at 10 ug/mL, and these lower concentrations are probably closer to physiological levels than the higher concentrations. Personally I would not want to dose up on Nutrient Mixture looking at Figure 1, unless there were some in vivo evidence showing actual tumor inhibition in a living body.