Molecular Mechanisms of Alpha 9-Nicotinic Acetylcholine Receptor (Alpha 9-nAChRs)-Mediated Trastuzumab (Herceptin R) Drug Resistance in Breast Cancer Cells

Project: A - Government Institutionb - Ministry of Science and Technology

Description

Our recent study (J Natl Cancer Inst, 102, 1322‐1335, 2010) demonstrated that the α9‐nicotinic receptor (α9‐nAChR) was detected at higher levels in advanced‐stage breast tumor tissues (tumor/normal >8 fold, n=276) of Taiwanese patients. This research group will focus on α9‐nAChR‐mediated tumorigenesis mechanisms and will establish novel therapeutic strategies to overcome drug resistance in breast cancer. This 3‐year proposal is comprised of the following aims: Year‐1 study: To explore the molecular mechanisms of α9‐nAChR‐mediated carcinogenesis, clinical samples of advanced stage tumor patients will be collected (component project‐1, CP‐1). A molecular epidemiology study of selected family history will be established (CP‐2). The role of breast tumor stem cells in advanced‐stage breast cancer and the development of stem cell‐killing drugs will be explored (CP‐3). Validation of the antitumor effects of α9‐nAChR‐specific antagonists, lead compounds synthesis, and novel drug formulations will be explored (CP‐4, 5). Year‐2 study: We will a) establish in vitro models to evaluate α9‐nAChR‐induced tumor invasion and metastatic properties (CP‐1), b) study the genetic polymorphisms in the selected breast cancer populations using exome sequencing (CP‐2), c) evaluate the stem cell killing effects of α9‐nAChR specific antagonists (CP‐3), and d) develop a of cell proliferation/migration model to screen for α9‐nAChR‐specific antagonists (CP‐4). The α9‐nAChR‐specific antagonists established by CP‐3 and CP‐4 will be conjugated with Herceptin® and developed as a new liposomal delivery drug (CP‐5). The antitumor activity of this new formula will be further validated by in vitro assays established using CP 1‐4. Year‐3 study: Establish of animal experimental plateform for studying the dynamic mechanisms of α9‐nAChR/HER‐2 complex formation (CP‐1). The α9‐nAChR/HER‐2 complex formation make up the whole luciferase activity and catalyze luciferin into luminescence. This cells will be established and transplanted into nude mice as a screening tool to evaluate α9‐nAChR/HER‐2 complex formation in vivo (CP‐4). To discover novel α9‐nAChR ‐induced breast cancer‐related miRNAs by miRNAs microarray analysis and then perform the combination analysis with clinico‐pathological data to find diagnosis and prognosis‐related miRNAs (CP‐2). Combination treatment of selected α9‐nAChR antagonist and clinical used anticancer agents to validate the antitumor effects on stem cells killing by animal model (CP‐3). The final goal is to establish a novel antitumor agents. In which the CP‐5 will preparation of PEGylated Liposome‐α9‐nAChR antagonist, and characterization of MAb‐Liposome‐α9‐nAChR antagonist. To validate the antitumor effects, in vitro release, recognition properties, binding and internalization of MAb‐Liposome‐α9‐nAChR antagonist, In vitro cytotoxicity, In vivo safety, in vivo antitumor activity and pharmacokinetic study will be completed (CP‐5).
StatusFinished
Effective start/end date8/1/117/31/12

Keywords

  • Nicotinic acetylcholine receptor
  • Breast cancer
  • Inhibitor