An Investigation of the Effects of Tea Component on the Inhibition of Leukocyte Nicotinic Acetylcholine Receptor Expression on Breast Cancer Patients

Our recent study (J Natl Cancer Inst, 102, 1322-1335, 2010) demonstrated that the expression levels of 9-nAChR in breast cancer tissues were very high (>8 fold higher than the level in normal tissue) in Taiwanese patients (n=276), particularly in the tissues of late-stage patients (those in stages 3 and 4). In order to monitoring the real-time nAChRs expression in human, we used the expression nAChRs of leukocytes as the evaluation index. In our experiment, we found nicotine exposure could induce nAChR expression on monocyte and promote foam cell formation. Though our ongoing preliminart clinical trial data, we found a strong nAChRs inhibition of 50 participants by two month Pu'er tea capsule taking. In vitro (Förster resonance energy transfer, FRET) and in vivo (Split luciferase) experiments, data illustrated 9-nAChR activation is through complex formation with growth factor receptors on breast cancer cells. Further investigation of drugs which interfering 9-nAChR complex may help developing novel treatment strategies for breast cancer therapies. Three years proposal are listed below: Year One: Aim 1: The correlation of nAChRs expressions between breast tumors and leukocytes on breast cancer patients. 1. Establishment of bio-bank database of clinical breast tumor samples. 2. Analyzing nAChRs expressions of leukocytes subtypes on breast cancer patients. 3. Seeking the pathologic significances of nAChR expressions on leukocytes and breast tumors by using cross validation. Aim 2: Clinical trial of Pu'er tea suppressing nAChRs expressions on leukocytes. 1. Participants recruitment. (The first year) 2. Observation of suppressed nAChRs expressions on leukocytes by Pu'er tea. 3. Establishment of nicotine exposure measurement ex-vivo. Year Two: Aim 1: In vitro experiments of active compounds in tea suppressing nAChRs expressions on leukocytes. 1. Study whether or not nicotine promoting the nAChRs expressions on leukocytes. 2. Observation the correlation of nAChRs expressions and foam cell formation on leukocytes. 3. Investigating the mechanism of EGCG suppresses foam cell formation through nAChRs inhibition on leukocytes. Aim 2: Clinical trial of Pu'er tea suppressing nAChRs expressions on leukocytes. 1. Participants recruitment. (The second year) 2. Analyzing the metabolic disease improvement by Pu'er tea capsule taking. 3. Analyzing the sensitive improvement of breast cancer therapy by Pu'er tea capsule taking. Year Three: Aim: The investigation of 9-nAChR complex formation in breast cancer therapy. 1. Establishment of fluorescence fusion protein system for 9-nAChR complex study in live cell model. 2. Establishment of split-luciferase system for 9-nAChR complex study in animal model. 3. Observation whether or not nAChR antagonists interfering 9-nAChR complex formation. 4. Study the synergic effect by nAChR antagonists and clinical breast cancer drugs. 5. Building a long-term breast cancer therapy evaluation of nAChR antagonists on 9-nAChR complex.