Ductal carcinoma in situ (DCIS) is a precursor lesion that can give rise to invasive breast cancer (IBC). It has been proposed that both the nature of the lesion and the tumor microenvironment play key roles in progression to IBC. Here, laser capture microdissected tissue samples from epithelium and stroma in normal breast, pure DCIS, and pure IBC were employed to define key gene expression profiles associated with disease progression.
Progression of ductal carcinoma in situ to invasive breast cancer is associated with gene expression programs of EMT and myoepithelia.
Specimen part, Subject
View SamplesBreast cancer is a highly heterogeneous disease that is categorized into distinct tumor subtypes based on specific molecular attributes, which ultimately influence therapeutic options. Unlike ER+ and/or HER2+ cancers that are subject to specific targeted therapies, triple negative breast cancers (TNBCs) do not express these receptors, which leaves patients with limited treatment options. Thus, significant focus has been placed on identifying molecular attributes of basal-like disease that could be used to develop and/or direct novel treatment regimens. Activation of MYC signaling and inactivation of the RB-pathway are frequent events in many types of human cancers. These pathways influence many biological processes, such as cell proliferation, that contribute to the aggressiveness and therapeutic response of tumors. The current study examines the interaction of the MYC and RB pathways in mammary epithelial cell tumorigenesis.
RB loss contributes to aggressive tumor phenotypes in MYC-driven triple negative breast cancer.
Sex, Age, Specimen part
View SamplesThe LXCXE peptide motif facilitates interaction between the RB tumor suppressor and a large number of cellular proteins that are expected to impinge on diverse biological processes. In vitro and in vivo analyses demonstrated that LXCXE-binding function is dispensable for RB promoter association and control of basal gene expression. Dependence on this function of RB is unmasked after DNA damage, wherein LXCXE-binding is essential for exerting control over E2F3 and suppressing cell cycle progression in the presence of genotoxic stress. Gene expression profiling revealed that the transcriptional program coordinated by this specific aspect of RB is associated with progression of human hepatocellular carcinoma and poor disease outcome. Consistent with these findings, biological challenge revealed a requirement for LXCXE-binding in suppression of genotoxin-initiated hepatocellular carcinoma in vivo. Together, these studies establish an essential role of the LXCXE-binding motif for RB-mediated transcriptional control, response to genotoxic insult, and tumor suppression.
RB restricts DNA damage-initiated tumorigenesis through an LXCXE-dependent mechanism of transcriptional control.
Treatment
View SamplesProstate cancer is dependent on androgen receptor (AR) signaling at all stages of the disease and cyclin D1 has been shown to negatively modulate the expression of the AR-dependent gene prostate specific antigen (KLK3/PSA).
Cyclin D1 is a selective modifier of androgen-dependent signaling and androgen receptor function.
Cell line, Treatment
View SamplesBAF57, a component of the SWI/SNF chromatin remodeling complex conglomerate,modulates androgen receptor activity to promote prostate cancer. However the molecular consequences of tumor associated BAF57 elevation have remianed undefined in advanced disease such as castration resistant prostate cancer and/or metastasis
Aberrant BAF57 signaling facilitates prometastatic phenotypes.
Specimen part, Treatment
View SamplesAnalysis of mammary glands from tet-inducible (rtTA) transgenic mice expressing cyclin D1 (Ccnd1). MMTV-rtTA transgenic mice (MMTV-Mouse Mammary Tumor Virus promoter) were cross-mated to cyclin D1 transgenic mice under the control of the tet operon. 8-week-old tetracycline-inducible cyclin D1/rtTA bi-transgenic pregnant female mice (12 days postcoitus) were treated with doxycycline through drinking water supplementation at a final concentration of 2 mg/ml. Control mice were rtTA transgenics alone and were treated in the same manner. After 7 days of doxycycline treatment, the mice were sacrificed and mammary glands taken for RNA isolation. Results provide insight into the in vivo gene expression pattern regulated by cyclin D1 through acute induction.
ChIP sequencing of cyclin D1 reveals a transcriptional role in chromosomal instability in mice.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cell cycle-coupled expansion of AR activity promotes cancer progression.
Cell line
View SamplesEvaluation of the genome wide impact of cell cycle position on DHT stimulated gene expression programs. Results show differential cell cycle regulated gene expression in different cell cycle phases.
Cell cycle-coupled expansion of AR activity promotes cancer progression.
Cell line
View SamplesCyclin D1b is a splice variant of the cell cycle regulator Cyclin D1 and is known to harbor divergent and highly oncogenic functions in human disease. While Cyclin D1b is induced during disease progression in many cancer types, the mechanisms underlying Cyclin D1b function remain poorly understood. Herein, models of human disease were utilized to resolve the downstream pathways requisite for the pro-tumorigenic functions of Cyclin D1b. Specifically, it was shown that Cyclin D1b modulates the expression of a large transcriptional network that cooperates with AR signaling to enhance tumor cell growth and invasive potential. Notably, Cyclin D1b promoted AR-dependent activation of genes associated with metastatic phenotypes. Further exploration determined that transcriptional induction of SNAI2 (Slug) was essential for Cyclin D1b- mediated proliferative and invasive properties, implicating Slug as a critical driver of disease progression. Importantly, Cyclin D1b expression highly correlated with that of Slug in clinical samples of advanced disease. Further, in vivo analyses provided strong evidence that Slug enhances both tumor growth and homing to distal soft tissues. Collectively, these findings reveal the underpinning mechanisms behind the pro-tumorigenic functions of Cyclin D1b, and demonstrate that the convergence of the Cyclin D1b-AR and Slug pathways results in the activation of processes critical for the promotion of lethal tumor phenotypes.
Convergence of oncogenic and hormone receptor pathways promotes metastatic phenotypes.
Specimen part, Cell line
View SamplesStat5a and Stat5b proteins are highly homologous with greater than 90% amino acid identity and share binding to the palindromic Stat5 consensus sequence, TTCNNNGAA, but individual roles of each transcription factor in breast cancer have not been thoroughly evaluated. To determine the degree of similarity between transcripts modulated by Stat5a and Stat5b proteins in human breast cancer, we utilized genome-wide transcript profiling to identify genes regulated specifically by Stat5a or Stat5b in response to prolactin.
Low levels of Stat5a protein in breast cancer are associated with tumor progression and unfavorable clinical outcomes.
Cell line
View Samples