ABSTRACT
PURPOSE: Triple-negative breast cancer (TNBC) lacks an approved targeted therapy. Despite initial good response to chemotherapy, 30% of the patients relapse within 5 years after treatment. EGFR overexpression is a common marker in TNBC, and its expression has been correlated with poor outcome. Inhibition of fatty acid synthase (FASN) activity leads to apoptosis of human carcinoma cells overexpressing FASN. We tested the hypothesis that blocking FASN in combination with anti-EGFR signaling agents would be an effective antitumor strategy in sensitive and chemoresistant TNBC. EXPERIMENTAL DESIGN: Several TNBC cell lines and 29 primary tumors were included to determine whether FASN is a potential target in TNBC. Doxorubicin-resistant TNBC cell lines (231DXR and HCCDXR) have been developed and characterized in our laboratory. Cellular and molecular interactions of anti-FASN compounds (EGCG and C75) with cetuximab were analyzed. In vivo tumor growth inhibition was evaluated after cetuximab, EGCG, or the combination in TNBC orthoxenograft models. RESULTS: TNBC cell lines showed overexpression of FASN enzyme and its inhibition correlated to FASN levels. FASN staining was observed in all of the 29 TNBC tumor samples. In vitro, EGCG and C75 plus cetuximab showed strong synergism in sensitive and chemoresistant cells. In vivo, the combination of EGCG with cetuximab displayed strong antitumor activity against the sensitive and chemoresistant TNBC orthoxenografts, without signs of toxicity. CONCLUSIONS: Our results show that the simultaneous blockade of FASN and EGFR is effective in preclinical models of sensitive and chemoresistant TNBC. Clin Cancer Res; 22(18); 4687-97. ©2016 AACR.
Subject(s)
Antineoplastic Agents/pharmacology , ErbB Receptors/antagonists & inhibitors , Fatty Acid Synthases/antagonists & inhibitors , Triple Negative Breast Neoplasms/metabolism , Animals , Cell Line, Tumor , Cetuximab/pharmacology , Disease Models, Animal , Doxorubicin/pharmacology , Drug Evaluation, Preclinical , Drug Resistance, Neoplasm , Drug Synergism , ErbB Receptors/metabolism , Fatty Acid Synthases/metabolism , Female , Humans , Mice , Molecular Targeted Therapy , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/pathology , Tumor Burden/drug effects , Xenograft Model Antitumor AssaysABSTRACT
Blocking the enzyme Fatty Acid Synthase (FASN) leads to apoptosis of HER2-positive breast carcinoma cells. The hypothesis is that blocking FASN, in combination with anti-HER2 signaling agents, would be an effective antitumor strategy in preclinical HER2+ breast cancer models of trastuzumab and lapatinib resistance. We developed and molecularly characterized in vitro HER2+ models of resistance to trastuzumab (SKTR), lapatinib (SKLR) and both (SKLTR). The cellular interactions of combining anti-FASN polyphenolic compounds (EGCG and the synthetic G28UCM) with anti-HER2 signaling drugs (trastuzumab plus pertuzumab and temsirolimus) were analyzed. Tumor growth inhibition after treatment with EGCG, pertuzumab, temsirolimus or the combination was evaluated in two in vivo orthoxenopatients: one derived from a HER2+ patient and another from a patient who relapsed on trastuzumab and lapatinib-based therapy. SKTR, SKLR and SKLTR showed hyperactivation of EGFR and p-ERK1/2 and PI3KCA mutations. Dual-resistant cells (SKLTR) also showed hyperactivation of HER4 and recovered levels of p-AKT compared with mono-resistant cells. mTOR, p-mTOR and FASN expression remained stable in SKTR, SKLR and SKLTR. In vitro, anti-FASN compounds plus pertuzumab showed synergistic interactions in lapatinib- and dual- resistant cells and improved the results of pertuzumab plus trastuzumab co-treatment. FASN inhibitors combined with temsirolimus displayed the strongest synergistic interactions in resistant cells. In vivo, both orthoxenopatients showed strong response to the antitumor activity of the combination of EGCG with pertuzumab or temsirolimus, without signs of toxicity. We showed that the simultaneous blockade of FASN and HER2 pathways is effective in cells and in breast cancer models refractory to anti-HER2 therapies.
Subject(s)
Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Drug Resistance, Neoplasm , Fatty Acid Synthase, Type I/antagonists & inhibitors , Receptor, ErbB-2/antagonists & inhibitors , Animals , Antibodies, Monoclonal, Humanized/pharmacology , Catechin/analogs & derivatives , Catechin/pharmacology , Cell Adhesion , Cell Line, Tumor , Dose-Response Relationship, Drug , Female , Gallic Acid/analogs & derivatives , Gallic Acid/pharmacology , Humans , Lapatinib , Mice , Mice, Inbred NOD , Mice, SCID , Mutation , Naphthalenes/pharmacology , Neoplasm Invasiveness , Neoplasm Transplantation , Quinazolines/pharmacology , Signal Transduction/drug effects , Sirolimus/analogs & derivatives , Sirolimus/pharmacology , Trastuzumab/pharmacologyABSTRACT
OBJECTIVE: Overexpression of fatty acid synthase (FASN), the enzyme involved in the de novo synthesis of fatty acids, has been reported in several human carcinomas, including breast cancer, and has been related to poor prognosis. Our aim was to analyze the association of FASN tumor tissue expression with clinicopathological and anthropometrical features in early-stage breast cancer patients. METHODS: We prospectively studied 53 women with early-stage breast cancer who were treated with surgical operation and postoperative chemotherapy. RESULTS: Menopause status and age were strongly associated with higher levels of FASN tumor expression (P < 0.005 and P = 0.038, respectively). Body mass index and pathological stage were also related to FASN tumor expression. CONCLUSIONS: Our findings suggest that FASN could be a potential therapeutic target in postmenopausal breast cancer patients. However, further studies are needed.
Subject(s)
Breast Neoplasms/enzymology , Fatty Acid Synthase, Type I/genetics , Menopause/genetics , Adult , Aged , Body Fat Distribution , Body Mass Index , Breast Neoplasms/pathology , Breast Neoplasms/surgery , Chemotherapy, Adjuvant , Cross-Sectional Studies , Female , Gene Expression , Humans , Middle Aged , Obesity/enzymology , Prognosis , Prospective Studies , SpainABSTRACT
BACKGROUND: Fatty acid synthase (FASN) is overexpressed and hyperactivated in several human carcinomas, including lung cancer. We characterize and compare the anti-cancer effects of the FASN inhibitors C75 and (-)-epigallocatechin-3-gallate (EGCG) in a lung cancer model. METHODS: We evaluated in vitro the effects of C75 and EGCG on fatty acid metabolism (FASN and CPT enzymes), cellular proliferation, apoptosis and cell signaling (EGFR, ERK1/2, AKT and mTOR) in human A549 lung carcinoma cells. In vivo, we evaluated their anti-tumour activity and their effect on body weight in a mice model of human adenocarcinoma xenograft. RESULTS: C75 and EGCG had comparable effects in blocking FASN activity (96,9% and 89,3% of inhibition, respectively). In contrast, EGCG had either no significant effect in CPT activity, the rate-limiting enzyme of fatty acid ß-oxidation, while C75 stimulated CPT up to 130%. Treating lung cancer cells with EGCG or C75 induced apoptosis and affected EGFR-signaling. While EGCG abolished p-EGFR, p-AKT, p-ERK1/2 and p-mTOR, C75 was less active in decreasing the levels of EGFR and p-AKT. In vivo, EGCG and C75 blocked the growth of lung cancer xenografts but C75 treatment, not EGCG, caused a marked animal weight loss. CONCLUSIONS: In lung cancer, inhibition of FASN using EGCG can be achieved without parallel stimulation of fatty acid oxidation and this effect is related mainly to EGFR signaling pathway. EGCG reduce the growth of adenocarcinoma human lung cancer xenografts without inducing body weight loss. Taken together, EGCG may be a candidate for future pre-clinical development.
Subject(s)
4-Butyrolactone/analogs & derivatives , Adenocarcinoma/drug therapy , Adenocarcinoma/metabolism , Catechin/analogs & derivatives , Fatty Acid Synthases/antagonists & inhibitors , Fatty Acids/metabolism , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , 4-Butyrolactone/pharmacology , Adenocarcinoma/enzymology , Adenocarcinoma/pathology , Adenocarcinoma of Lung , Analysis of Variance , Animals , Apoptosis/drug effects , Carnitine O-Palmitoyltransferase/metabolism , Catechin/pharmacology , Cell Line, Tumor , Fatty Acid Synthases/metabolism , Female , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/pathology , Mice , Mice, Inbred BALB C , Mice, Nude , Phosphorylation/drug effects , Random Allocation , Signal Transduction/drug effects , Weight Loss/drug effects , Xenograft Model Antitumor AssaysABSTRACT
Fatty acid synthase (FASN) is a lipogenic enzyme that is highly expressed in different human cancers. Here we report the development of a new series of polyphenolic compounds 5-30 that have been evaluated for their cytotoxic capacity in SK-Br3 cells, a human breast cancer cell line with high FASN expression. The compounds with an IC(50) < 50 µM have been tested for their ability to inhibit FASN activity. Among them, derivative 30 blocks the 90% of FASN activity at low concentration (4 µM), is highly cytotoxic in a broad panel of tumor cells, induces apoptosis, and blocks the activation of HER2, AKT, and ERK pathways. Remarkably, 30 does not activate carnitine palmitoyltransferase-1 (CPT-1) nor induces in mice weight loss, which are the main drawbacks of other previously described FASN inhibitors. Thus, FASN inhibitor 30 may aid the validation of this enzyme as a therapeutic target for the treatment of cancer.
