Early-Stage Progression of Breast Cancer

Breast cancer can be defined as a group of diseases with heterogeneous origins, molecular profiles and behaviors characterized by uncontrolled proliferation of cells within the mammary tissue. Around one in eight women in the US will develop breast cancer in their lifetime, making it the second most frequently diagnosed cancer behind skin cancer [1]. In 2015, an estimated 231,840 cases of invasive carcinoma were diagnosed, and over 40,000 deaths were caused by breast cancer which accounts for almost 7% of all cancer mortality each year. In 2015, 60,290 cases of in situ breast cancer were diagnosed, representing over 14% of all new cancer cases among women and men. The steep increase in diagnosis of early‐stage breast cancer over the past 10 years is believed to be a result of more frequent mammography. However, since over half of these in situ lesions will not progress to invasive breast cancer, controversies have arisen about approaches to treatment and prevention of progression of early‐stage in situ breast cancer. Understanding the mechanisms of transition of normal breast to in situ pre‐neoplastic lesions and invasive breast cancer is currently a major focus of breast cancer research with implications for preventive and clinical management of breast cancer. In this review, we give an overview of current knowledge on the molecular and pathological changes that occur during early‐stage progression of breast cancer and describe some of the current models that are used to study this process

The AIB1/NCOA3/SRC-3 Oncogene

A member of the NCOA/SRC/p160 co-activator family, AIB1 is amplified and overexpressed in multiple cancer types, notably breast, ovarian, and pancreatic cancer. Common to all members of the NCOA/SRC/p160 family are bHLH-PAS, receptor interaction, and CBP/p300 interacting activation domains. The protein acts as a scaffold to support the transcriptional activity of many DNA binding transcription factors, such as the ER, AP-1, E2F, NFκB, and TEADs. In doing so, the multi-domain protein facilitates chromatin remodeling and oncogenic gene transcription. Further, the AIB1Δ4 isoform promotes tumorigenesis and metastasis through interaction with chromatin in the nucleus or at the periphery of the cell. Pathologically, AIB1 promotes the transformation of normal tissue to cancerous lesions in multiple diseases, and loss delays progression. AIB1 has also been implicated in cancer recurrence and pharmacological resistance. We will discuss the structure and isoforms of AIB1, the physiological consequences of its interaction with transcription factors and hormone receptors, and clinical significance of the protein

Impaired CXCL12 signaling contributes to resistance of pancreatic cancer subpopulations to T cell-mediated cytotoxicity

Pancreatic cancer remains largely unresponsive to immune modulatory therapy attributable in part to an immunosuppressive, desmoplastic tumor microenvironment. Here, we analyze mechanisms of cancer cell-autonomous resistance to T cells. We used a 3D co-culture model of cancer cell spheroids from the KPC (LSL-Kras(G12D/+)/LSL-Trp53(R172H/+)/p48-Cre) pancreatic ductal adenocarcinoma (PDAC) model, to examine interactions with tumor-educated T cells isolated from draining lymph nodes of PDAC-bearing mice. Subpopulations of cancer cells resistant to these tumor-educated T cells were isolated from the in vitro co-culture and their properties compared with sensitive cancer cells. In co-culture with resistant cancer cell subpopulations, tumor-educated T cells showed reduced effector T cell functionality, reduced infiltration into tumor cell spheroids and decreased induction of apoptosis. A combination of comparative transcriptomic analyses, cytometric and immunohistochemistry techniques allowed us to dissect the role of differential gene expression and signaling pathways between sensitive and resistant cells. A decreased expression of the chemokine CXCL12 (SDF-1) was revealed as a common feature in the resistant cell subpopulations. Adding back CXCL12 reversed the resistant phenotype and was inhibited by the CXCR4 inhibitor AMD3100 (plerixafor). We conclude that reduced CXCL12 signaling contributes to PDAC subpopulation resistance to T cell-mediated attack

What Are Effective Program Characteristics of Self-Management Interventions in Patients With Heart Failure? An Individual Patient Data Meta-analysis

To identify those characteristics of self-management interventions in patients with heart failure (HF) that are effective in influencing health-related quality of life, mortality, and hospitalizations

Proteomic Analysis of Pathways Involved in Estrogen-Induced Growth and Apoptosis of Breast Cancer Cells

Estrogen is a known growth promoter for estrogen receptor (ER)-positive breast cancer cells. Paradoxically, in breast cancer cells that have been chronically deprived of estrogen stimulation, re-introduction of the hormone can induce apoptosis.Here, we sought to identify signaling networks that are triggered by estradiol (E2) in isogenic MCF-7 breast cancer cells that undergo apoptosis (MCF-7:5C) versus cells that proliferate upon exposure to E2 (MCF-7). The nuclear receptor co-activator AIB1 (Amplified in Breast Cancer-1) is known to be rate-limiting for E2-induced cell survival responses in MCF-7 cells and was found here to also be required for the induction of apoptosis by E2 in the MCF-7:5C cells. Proteins that interact with AIB1 as well as complexes that contain tyrosine phosphorylated proteins were isolated by immunoprecipitation and identified by mass spectrometry (MS) at baseline and after a brief exposure to E2 for two hours. Bioinformatic network analyses of the identified protein interactions were then used to analyze E2 signaling pathways that trigger apoptosis versus survival. Comparison of MS data with a computationally-predicted AIB1 interaction network showed that 26 proteins identified in this study are within this network, and are involved in signal transduction, transcription, cell cycle regulation and protein degradation.G-protein-coupled receptors, PI3 kinase, Wnt and Notch signaling pathways were most strongly associated with E2-induced proliferation or apoptosis and are integrated here into a global AIB1 signaling network that controls qualitatively distinct responses to estrogen