Biomaterial Database

Upregulation of mucin4 in ER-positive/HER2-overexpressing breast cancer xenografts with acquired resistance to endocrine and HER2-targeted therapies. 2012

Albert C Chen, and Ilenia Migliaccio, and Mothaffar Rimawi, and Sara Lopez-Tarruella, and Chad J Creighton, and Suleiman Massarweh, and Catherine Huang, and Yen-Chao Wang, and Surinder K Batra, and M Carolina Gutierrez, and C Kent Osborne, and Rachel Schiff

Lester & Sue Smith Breast Center, Baylor College of Medicine, Houston, TX, USA.

We studied resistance to endocrine and HER2-targeted therapies using a xenograft model of estrogen receptor positive (ER)/HER2-overexpressing breast cancer. Here, we report a novel phenotype of drug resistance in this model. MCF7/HER2-18 xenografts were treated with endocrine therapy alone or in combination with lapatinib and trastuzumab (LT) to inhibit HER2. Archival tumor tissues were stained with hematoxylin and eosin and with mucicarmine. RNA extracted from tumors at early time points and late after acquired resistance were analyzed for mucin4 (MUC4) expression by microarray and quantitative reverse transcriptase-PCR. Protein expression of the MUC4, ER, and HER2 signaling pathways was measured by immunohistochemistry and western blotting. The combination of the potent anti-HER2 regimen LT with either tamoxifen (Tam + LT) or estrogen deprivation (ED + LT) can cause complete eradication of ER-positive/HER2-overexpressing tumors in mice. Tumors developing resistance to this combination, as well as those acquiring resistance to endocrine therapy alone, exhibited a distinct histological and molecular phenotype-a striking increase in mucin-filled vacuoles and upregulation of several mucins including MUC4. At the onset of resistance, MUC4 mRNA and protein were increased. These tumors also showed upregulation and reactivation of HER2 signaling, while losing ER protein and the estrogen-regulated gene progesterone receptor. Mucins are upregulated in a preclinical model of ER-positive/HER2-overexpressing breast cancer as resistance develops to the combination of endocrine and anti-HER2 therapy. These mucin-rich tumors reactivate the HER2 pathway and shift their molecular phenotype to become more ER-negative/HER2-positive.

UI	MeSH Term	Description	Entries
D008819	Mice, Nude	Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.	Athymic Mice,Mice, Athymic,Nude Mice,Mouse, Athymic,Mouse, Nude,Athymic Mouse,Nude Mouse
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D011799	Quinazolines	A group of aromatic heterocyclic compounds that contain a bicyclic structure with two fused six-membered aromatic rings, a benzene ring and a pyrimidine ring.	Quinazoline
D011960	Receptors, Estrogen	Cytoplasmic proteins that bind estrogens and migrate to the nucleus where they regulate DNA transcription. Evaluation of the state of estrogen receptors in breast cancer patients has become clinically important.	Estrogen Receptor,Estrogen Receptors,Estrogen Nuclear Receptor,Estrogen Receptor Type I,Estrogen Receptor Type II,Estrogen Receptors Type I,Estrogen Receptors Type II,Receptor, Estrogen Nuclear,Receptors, Estrogen, Type I,Receptors, Estrogen, Type II,Nuclear Receptor, Estrogen,Receptor, Estrogen
D001943	Breast Neoplasms	Tumors or cancer of the human BREAST.	Breast Cancer,Breast Tumors,Cancer of Breast,Breast Carcinoma,Cancer of the Breast,Human Mammary Carcinoma,Malignant Neoplasm of Breast,Malignant Tumor of Breast,Mammary Cancer,Mammary Carcinoma, Human,Mammary Neoplasm, Human,Mammary Neoplasms, Human,Neoplasms, Breast,Tumors, Breast,Breast Carcinomas,Breast Malignant Neoplasm,Breast Malignant Neoplasms,Breast Malignant Tumor,Breast Malignant Tumors,Breast Neoplasm,Breast Tumor,Cancer, Breast,Cancer, Mammary,Cancers, Mammary,Carcinoma, Breast,Carcinoma, Human Mammary,Carcinomas, Breast,Carcinomas, Human Mammary,Human Mammary Carcinomas,Human Mammary Neoplasm,Human Mammary Neoplasms,Mammary Cancers,Mammary Carcinomas, Human,Neoplasm, Breast,Neoplasm, Human Mammary,Neoplasms, Human Mammary,Tumor, Breast
D004965	Estrogen Antagonists	Compounds which inhibit or antagonize the action or biosynthesis of estrogenic compounds.	Estradiol Antagonists,Antagonists, Estradiol,Antagonists, Estrogen
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000068878	Trastuzumab	A humanized monoclonal antibody against the ERBB-2 RECEPTOR (HER2). As an ANTINEOPLASTIC AGENT, it is used to treat BREAST CANCER where HER2 is overexpressed.	Trastuzumab beta,Trastuzumab-qyyp,Trazimera,Herceptin,Trastuzumab qyyp,beta, Trastuzumab
D000077341	Lapatinib	A quinazoline derivative that inhibits EPIDERMAL GROWTH FACTOR RECEPTOR and HER2 (RECEPTOR, ERBB-2) tyrosine kinases. It is used for the treatment of advanced or metastatic breast cancer, where tumors overexpress HER2.	GW 282974X,GW 572016,GW-282974X,GW-572016,GW282974X,GW572016,Lapatinib Ditosylate,N-(3-chloro-4-(((3-fluorobenzyl)oxy)phenyl)-6-(5-(((2-methylsulfonyl)ethyl)amino)methyl) -2-furyl)-4-quinazolinamine,Tykerb