中山大学肿瘤防治中心 SUN YAT-SEN UNIVERSITY CANCER CENTER 1 Emodin azide methyl anthraquinone derivative induces proteasomal degradation of Her2/neu in Her2/neu-overexpressing.

SUN YAT-SEN UNIVERSITY CANCER CENTER 1 Emodin azide methyl anthraquinone derivative induces proteasomal degradation of Her2/neu in Her2/neu-overexpressing cancer cells Li-sheng Zheng, Yan-yan Yan, Li-wu Fu Cancer Center, Sun Yat-sen University SUN YAT-SEN UNIVERSITY CANCER CENTER 2 Overexpression of HER2/neu is common in multiple malignancies, including breast, ovarian, lung and prostate cancer, etc. Clinical studies have demonstrated that elevated HER2/neu expression correlates with poor prognosis in multiple malignancies During the last decade, HER2/neu has been targeted in order to develop novel anticancer drugs Trastuzumab (Herceptin) Lapatinib (Tykerb) efficacy and long-term use in patients are quite limited due to resistance to these inhibitors or severe side effects Background SUN YAT-SEN UNIVERSITY CANCER CENTER 3 Anthraquinone derivative Active ingredient of various Chinese herbs including rhubarb, Polygonum cuspidatum Anti-bacterial, anti-inflammatory, anti-tumor Emodin Structure of emodin Background Block auto- or trans-phosphorylation of HER2/neu Increases the susceptibility of HER2/neu overexpressing cancer cells to standard cytotoxic therapeutic agents SUN YAT-SEN UNIVERSITY CANCER CENTER 4 anticancer activity not obvious side effects such as cardiac toxicity We and Professor Lian-quan Gu group (School of Chemistry and Chemical Engineering, Sun Yat-sen University) modified structure of emodin and synthesized a series of emodin anthraquinone derivatives Background Structure of emodin AMAD SUN YAT-SEN UNIVERSITY CANCER CENTER 5 AMAD shows potent anticancer effect on breast cancer and lung adenocarcinoma cell lines SUN YAT-SEN UNIVERSITY CANCER CENTER 6 AMAD inhibits the growth of human non-small cell lung carcinoma H460 cell xenografts in nude mice SUN YAT-SEN UNIVERSITY CANCER CENTER 7 AMAD down-regulates Her2/neu protein expression SUN YAT-SEN UNIVERSITY CANCER CENTER 8 AMAD inhibits Her2/neu downstream signaling pathways SUN YAT-SEN UNIVERSITY CANCER CENTER 9 AMAD increses Her2/neu protein instability SUN YAT-SEN UNIVERSITY CANCER CENTER 10 AMAD induces polyubiquitination of HER2/neu SUN YAT-SEN UNIVERSITY CANCER CENTER 11 AMAD depletes HER2/neu by proteasomal degradation SUN YAT-SEN UNIVERSITY CANCER CENTER 12 AMAD inhibited Her2/neu binding to Hsp90 SUN YAT-SEN UNIVERSITY CANCER CENTER 13 Knockdown Her2/neu by siRNA induces growth inhibition SUN YAT-SEN UNIVERSITY CANCER CENTER 14 Combination of AMAD and siRNA against Her2 synergistically induces apoptosis SUN YAT-SEN UNIVERSITY CANCER CENTER 15 Combination of AMAD and siRNA against Her2 further promotes HER2/neu degradation and inhibites downstream signaling pathways SUN YAT-SEN UNIVERSITY CANCER CENTER 16 Discussion Apigenin and Geldanamycin can induce HER2 protein degradation by ubiquitin-proteasome pathway Downregulation of HER2 by AMAD is dependent of Her2 protein stability but not mRNA level Dissociation of Her2/Hsp90 heterocomplex by AMAD may be correlated with promoted proteasomal degradation of Her2 protein HER2 specific: AMAD does not decrease the expression of Her1 protein SUN YAT-SEN UNIVERSITY CANCER CENTER 17 AMAD exerts potent cytotoxic effects on MDA-MB-453 and Calu-3 cells. AMAD inhibits the proliferation via MAPK and PI(3)K/Akt pathway signaling. AMAD targets HER2/neu to ubiquitinylation-dependent proteasomal degradation. Combined AMAD with siRNA against HER2/neu further promotes Her2/neu degradation, induces apoptosis and inhibits the proliferation. Conclusions SUN YAT-SEN UNIVERSITY CANCER CENTER 18 !