Project description:The aberrant overexpression of mucin 1 (MUC1) and human epidermal growth factor receptor 2 (HER2) are often observed in breast cancer. However, the role of concomitant of MUC1/HERR2 in the development of breast cancer has not been fully illustrated. Following analysis public microarray datasets that revealed a correlation of double positive of MUC1 and HER2 to a worse clinical outcome, we generated a mouse model overexpressing both Her2 and MUC1 cytoplasmic domain (MUC1-CD) to investigate their interaction in mammary carcinogenesis. Coexpression of Her2 and MUC1-CD confers growth advantage and promotes the development of spontaneous mammary tumors. Genomic analysis uncovers that enforced expression of MUC1-CD and Her2 induces mammary tumor lineage plasticity which is supported by gene reprogramming and mammary stem cell enrichment. With gain- and loss-of function strategies, we show that coexpression of Her2 and MUC1-CD was associated with down-regulation of TCA cycle genes in tumors. Importantly, the reduction of TCA cycle genes induced by MUC1-CD is is significantly connected to the poor prognosis in HER2+ breast cancer patients. In addition, MUC1 augments Her2 signaling pathway by inducing Her2/Egfr dimerization. These findings collectively demonstrate the vital role of MUC1-CD/Her2 collaboration in shaping mammary tumor landscape and highlight the prognostic and therapeutic implication of MUC1 in patients with Her2+ breast cancer.
Project description:Neuroendocrine prostate cancer (NEPC) is a highly aggressive malignancy of increasing prevalence with an unmet need for targeted therapeutic approaches. The oncogenic MUC1-C protein is overexpressed in castration-resistant prostate cancer (CRPC) and NEPC; however, there is no known role for MUC1-C in driving lineage plasticity to these advanced PC phenotypes. The present studies demonstrate that upregulation of MUC1-C in androgen-independent (AI) PC cells suppresses androgen receptor (AR) axis signaling and induces the neural BRN2 transcription factor by a previously unrecognized MYC-mediated mechanism. MUC1-C activates the BRN2 pathway in association with induction of MYCN, EZH2 and NE differentiation markers (ASCL1, AURKA and SYP), which are linked to NEPC progression. We also show that MUC1-C suppresses the p53 pathway, induces the Yamanaka pluripotency factors (OCT4, SOX2, KLF4 and MYC) and drives stemness. Of potential clinical relevance, targeting MUC1-C decreases PC self-renewal capacity and tumorigenicity, supporting the treatment of CRPC and NEPC with agents directed against this oncoprotein. These findings and the demonstration that MUC1-C is upregulated and associated with suppression of AR signaling, and increases in BRN2 expression and the NEPC score in PC tissues highlight the unanticipated importance of MUC1-C as a master effector of lineage plasticity in progression to advanced PC with NE features.
Project description:Mucin 1 (MUC1) is a transmembrane mucin expressed at the apical surface of epithelial cells at different mucosal surfaces including breast and intestine. The MUC1 extracellular domain contains a variable number of tandem repeats (VNTR) of 20 amino acids, which are heavily O-linked glycosylated. Monoclonal antibodies against the MUC1 VNTR can be powerful tools because of their multiplicity of binding and possible applications in the diagnosis and treatment of MUC1-expressing cancers. One such antibody is the hybridoma mouse monoclonal 139H2 which is also widely used as a research tool to study non-cancer MUC1. Here we report direct mass spectrometry-based sequencing of hybridoma-derived 139H2 IgG, which enabled reverse engineering of a recombinant 139H2.
Project description:The MUC1-C protein evolved in mammals for adaptation of barrier tissues to loss of homeostasis. Prolonged activation of MUC1-C in settings of chronic inflammation promotes lineage plasticity, epigenetic reprogramming and the cancer stem cell (CSC) state. The effects of MUC1-C on the metabolism of CSCs remain unexplored. We used single cell RNA sequencing (scRNA-seq) to analyze the diversity of BT-549 spheroid cultures with and without knockdown of MUC1 to examine the effects of MUC1 on CSC renewal and metbolic states.
Project description:The NuRD chromatin remodeling and deacetylation complex, which includes MTA1, MBD3, CHD4 and HDAC1 among other components, is of importance for development and cancer progression. The oncogenic MUC1-C protein activates EZH2 and BMI1 in the epigenetic reprogramming of triple-negative breast cancer (TNBC) cells. However, there is no known link between MUC1-C and chromatin remodeling complexes. The present studies demonstrate that MUC1-C binds directly to the MYC HLH/LZ domain. In turn, we identified a previously unrecognized MUC1-C®MYC pathway that regulates the NuRD complex. We show that MUC1-C/MYC complexes selectively activate the MTA1 and MBD3 genes and posttranscriptionally induce CHD4 expression in basal- and not luminal-type BC cells. The results further show that MUC1-C forms complexes with these NuRD components on the ESR1 promoter. In this way, silencing MUC1-C (i) decreased MTA1/MBD3/CHD4/HDAC1 occupancy and increased H3K27 acetylation on the ESR1 promoter, and (ii) induced ESR1 expression and downstream estrogen response pathways. We also demonstrate that targeting MUC1-C and these NuRD components induces expression of FOXA1, GATA3 and other markers associated with the luminal phenotype. These findings and results from gain-of-function studies support a model in which MUC1-C activates the NuRD complex in driving luminal®basal dedifferentiation and plasticity of TNBC cells.
Project description:Goal of study: To determine differentially expressed genes with potential roles in tolerance and immunity in MUC1-immunized WT and MUC1.Tg mice WT (C57Bl/6) and MUC1.Tg mice were immunized (i.v.) with dendritic cells loaded with sythetic, human MUC1 peptide. At 24h and 72h splenic RNA from vaccination groups (n=3) was pooled and microarray performed.
Project description:The MUC1-C protein evolved in mammals for adaptation of barrier tissues to loss of homeostasis. Prolonged activation of MUC1-C in settings of chronic inflammation promotes lineage plasticity, epigenetic reprogramming and the cancer stem cell (CSC) state. The effects of MUC1-C on the metabolism of CSCs remain unexplored. The present studies performed on purified populations of triple-negative breast cancer (TNBC) CSCs demonstrate that MUC1-C integrates the capacity for self-renewal with the activation of aerobic glycolysis. We show that MUC1-C is essential for (i) CSC mammosphere formation and tumorigenicity and (ii) activation of GLUT1, HK2 and other glycolytic genes. We further show that MUC1-C activates nuclear genes that encode components of mitochondrial Complexes II-V of the electron transfer chain (ETC). Of importance, MUC1-C also represses mitochondrial DNA (mtDNA) genes encoding components of Complexes I-V. The observed involvement of MUC1-C in the suppression of mtDNA genes is explained by MUC1-C-mediated (i) downregulation of the mitochondrial transcription factor A (TFAM), which is required for mtDNA transcription, and (ii) induction of the mitochondrial transcription termination factor 3 (mTERF3). In support of this pathway to suppress mitochondrial ROS production, targeting MUC1-C increases (i) mtDNA gene transcription, (ii) superoxide levels and (iii) loss of self-renewal capacity. These findings indicate that MUC1-C regulates CSC self-renewal and redox balance by integrating activation of glycolysis with suppression of oxidative phosphorylation.
Project description:The purpose of this study is to evaluate the safety and effectiveness of CAR-T cell immunotherapy in patients with MUC1 positive relapsed or refractory solid tumor.