egcg and gist tumors

Green tea (-)-epigalocatechin-3-gallate inhibits KIT activity and causes caspase-dependent cell death in gastrointestinal stromal tumor including imatinib-resistant cells.

Chi HT, Vu HA, Iwasaki R, Thao le B, Hara Y, Taguchi T, Watanabe T, Sato Y.

Source

Division of Ultrafine Structure, Department of Pathology, Research Institute of International Medical Center of Japan, Tokyo, Japan.

Abstract

Imatinib, a selective tyrosine kinase inhibitor, has been used as a standard first-line therapy for gastrointestinal stromal tumor (GIST) patients. Unfortunately, most patients responding to imatinib will eventually exhibit the resistance, the cause of which is not fully understood. The serious clinical problems of imatinib-resistance demand alternative treatment strategy. (-)-Epigallocatechin-3-gallate (EGCG), a main component of green tea catechin, has been demonstrated potential anti-tumor effects on various types of cancer cells. Here, we report for the first time that EGCG has shown anti-tumor effects on gastrointestinal stromal tumor cell line GIST-T1 by suppressing cell proliferation and eventually inducing cell death via caspase-dependent pathways. GIST-T1 and imatinib resistant GIST-T1 (GIST-T1 IR) cells were used to assess the effects of EGCG. In both cell types, KIT activity was completely inhibited after 4 h treatment with 60 muM EGCG. EGCG specifically inhibited activated KIT, which was demonstrated by using Ba/F3 cells transfected with human wild-type KIT construct. At a dose of 30 muM EGCG, the KIT activity remains but at more than 40 muM EGCG, the KIT activity was abolished in these transfected-Ba/F3 cells. Our results suggest that EGCG has a promising potential as a natural KIT inhibitor and therefore it could be used as a novel therapeutic or preventive reagent for GISTs including the imatinib-resistant cases.

Stomach cancer
Laboratory studies have found that green tea polyphenols inhibit the growth of stomach cancer cells in test tubes. The exposure of human stomach cancer KATO III cells to egcg led to both growth inhibition and the induction of programmed cell death (apoptosis) (Oncol Rep, 5(2):527-9 1998 Mar-Apr).


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DOSAGE

http://newsblog.mayoclinic.org/2010/06/04/green-tea-extract-appears-to-keep-cancer-in-check-in-majority-of-cll-patients/

The article that was published about this study is available at http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727287/?tool=pubmed. The sentence defining the dosage states, “Polyphenon E with a standardized dose of epigallocatechin-3-gallate (EGCG) was administered using the standard phase I design with three to six patients per dose level (range, 400 to 2,000 mg by mouth twice a day).” The article later suggests that people tolerated the maximum dose well and that some people who received the higher doses seemed to do better in some respects, which is probably why they used the highest dosage in the next study. Still, as someone with no expertise in this area, I wouldn’t try to dose myself based on this information, and I can see why the Mayo people don’t want to specify a dosage in the context of patients asking what they should take. I went to an integrative medicine specialist at a major cancer center, who recommended 1,000 mg. twice a day. I’m not sure whether a regular oncologist would necessarily know about this; some of them tend to be dismissive of anything other than meds as such.


EM says:

February 2, 2012 at 3:11 pm

I was diagnosed with CLL about 6 months ago. I am 52 years old, female and otherwise in really good health. Since it is very early in the diagnosis with no symptoms (other than some slightly enlarged lymph nodes), I have been in the watch and wait phase. My internist (who discovered the CLL through a routine blood test) prescribed a series of supplements included EGCG. I have been taking AOR Active Green tea (700mg/455 catechins) twice a day. Along with the EGCG I have also been taking Tumeric, Reservatrol, Vitamin D and Omega-3 Fish oil twice a day. I just went back for my check several weeks ago and the news was great! My WBC went down to 6800 from 11,500 and my LYMPH went down 51% from 61% and NEUT up to 36% from 31%! Yay! Of course, we can’t be 100% sure that is all the supplements at work, but I will take the good news nonetheless and continue with my course as is. I have also read “Anti-Cancer – A New Way of Life” by David Servan-Schrieber. Though at times it can be a bit technical, the diet/mind/body portion of it is wonderfully written and I would highly recommend it to read