Publications by authors named "Ingrid Espinoza"

Resistance to mitochondrial apoptosis is a major driver of chemoresistance in pancreatic ductal adenocarcinoma (PDAC). However, pharmacological manipulation of the mitochondrial apoptosis threshold in PDAC cells remains an unmet therapeutic goal. We hypothesized that fatty acid synthase inhibitors (FASNis), a family of targeted metabolic therapeutics recently entering the clinic, could lower the apoptotic threshold in chemoresistant PDAC cells and be synergistic with BH3 mimetics that neutralize anti-apoptotic proteins.

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The HER3/4 ligand heregulin-β2 (HRG) is a secreted growth factor that transactivates the ligand-less receptor HER2 to promote aggressive phenotypes in breast cancer. HRG can also localize to the nucleus of breast cancer cells, but both the nuclear translocation mechanism and the physiological role of nuclear HRG remain elusive. Here we show that nucleolin-driven nuclear moonlighting of HRG uncouples its role as a driver of endocrine resistance from its canonical HER network-activating role in breast cancer.

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Triple-negative/basal-like breast cancer (BC) is characterized by aggressive biological features, which allow relapse and metastatic spread to occur more frequently than in hormone receptor-positive (luminal) subtypes. The molecular complexity of triple-negative/basal-like BC poses major challenges for the implementation of targeted therapies, and chemotherapy remains the standard approach at all stages. The matricellular protein cysteine-rich angiogenic inducer 61 (CCN1/CYR61) is associated with aggressive metastatic phenotypes and poor prognosis in BC, but it is unclear whether anti-CCN1 approaches can be successfully applied in triple-negative/basal-like BC.

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Background: Colorectal cancer (CRC) is one of the most common cancers worldwide characterized by disparities in age, gender, race and anatomic sites. The mechanism underlying pathogenesis, progression and disparities of CRC remains unclear. This study aims to reveal the association of expression levels of enzymes related to cholesteryl ester (CE) metabolism with pathogenesis, progression and disparities of CRC.

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CCN1/CYR61 promotes angiogenesis, tumor growth and chemoresistance by binding to its integrin receptor αβ in endothelial and breast cancer (BC) cells. CCN1 controls also tissue regeneration by engaging its integrin receptor αβ to induce fibroblast senescence. Here, we explored if the ability of CCN1 to drive an endocrine resistance phenotype in estrogen receptor-positive BC cells relies on interactions with either αβ or αβ.

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: The major histocompatibility complex class I polypeptide-related sequence A () is one of the ligands of the natural killer group 2D (NKG2D) activating receptor. MICA stimulates NKG2D, which further triggers activation of natural killer cells and leads to killing of infected target cells. To subvert the biological function of NKG2D, tumor cells utilize an escape strategy by shedding overexpressed MICA.

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Inhibitors of the lipogenic enzyme fatty acid synthase (FASN) have attracted much attention in the last decade as potential targeted cancer therapies. However, little is known about the molecular determinants of cancer cell sensitivity to FASN inhibitors (FASNis), which is a major roadblock to their therapeutic application. Here, we find that pharmacological starvation of endogenously produced FAs is a previously unrecognized metabolic stress that heightens mitochondrial apoptotic priming and favors cell death induction by BH3 mimetic inhibitors.

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The identification of clinically important molecular mechanisms driving endocrine resistance is a priority in estrogen receptor-positive (ER+) breast cancer. Although both genomic and non-genomic cross-talk between the ER and growth factor receptors such as human epidermal growth factor receptor 2 (HER2) has frequently been associated with both experimental and clinical endocrine therapy resistance, combined targeting of ER and HER2 has failed to improve overall survival in endocrine non-responsive disease. Herein, we questioned the role of fatty acid synthase (FASN), a lipogenic enzyme linked to HER2-driven breast cancer aggressiveness, in the development and maintenance of hormone-independent growth and resistance to anti-estrogens in ER/HER2-positive (ER+/HER2+) breast cancer.

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To date very few promising leads from natural products (NP) secondary metabolites with antiviral and immunomodulatory properties have been identified for promising/potential intervention for COVID-19. Using in-silico docking studies and genome based various molecular targets, and their in vitro anti-SARS CoV-2 activities against whole cell and/or selected protein targets, we select a few compounds of interest, which can be used as potential leads to counteract effects of uncontrolled innate immune responses, in particular those related to the cytokine storm. A critical factor for prevention and treatment of SARS-CoV-2 infection relates to factors independent of viral infection or host response.

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In colorectal cancer (CRC), high expression of trefoil factor 3 (TFF3) is associated with tumor progression and reduced patient survival; however, bioinformatics analyses of public 'omics' databases show low TFF3 expression in CRCs as compared to normal tissues. Thus, we examined TFF3 expression in CRCs and matching normal tissues to evaluate its role in CRC progression. TFF3 gene expression was characterized using the bioinformatics portal UALCAN (http://ualcan.

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Sustained HER2/HER3 signaling due to the overproduction of the HER3 ligand heregulin (HRG) is proposed as a key contributor to endocrine resistance in estrogen receptor-positive (ER+) breast cancer. The molecular mechanisms linking HER2 transactivation by HRG-bound HER3 to the acquisition of a hormone-independent phenotype in ER+ breast cancer is, however, largely unknown. Here, we explored the possibility that autocrine HRG signaling drives cytokine-related endocrine resistance in ER+ breast cancer cells.

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HER2 transactivation by the HER3 ligand heregulin (HRG) promotes an endocrine-resistant phenotype in the estrogen receptor-positive (ER+) luminal-B subtype of breast cancer. The underlying biological mechanisms that link them are, however, incompletely understood. Here, we evaluated the putative role of the lipogenic enzyme fatty acid synthase (FASN) as a major cause of HRG-driven endocrine resistance in ER+/HER2-negative breast cancer cells.

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Despite the lack of a complete understanding of the disparities involved, prostate cancer (PCa) has both higher incidence and death rates in African American Men (AAM) relative to those of Caucasian American Men (CAM). MHC class I polypeptide related sequence A (MICA) is an innate immunity protein involved in tumor immunoevasion. Due to a lack of reports of race-specific expression of MICA in PCa, we evaluated MICA expression in patients' tumors and in cell lines from a racially diverse origin.

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We hypothesized that identifying plasma glycoproteins that predict the development of heart failure following myocardial infarction (MI) could help to stratify subjects at risk. Plasma collected at visit 2 (2005-2008) from an MI subset of Jackson Heart Study participants underwent glycoproteomics and was grouped by the outcome: (1) heart failure hospitalization after visit 2 ( = 15) and (2) without hospitalization by 2012 ( = 45). Proteins were mapped for biological processes and functional pathways using Ingenuity Pathway Analysis and linked to clinical characteristics.

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Background: The survival of patients with B-acute lymphoblastic leukemia (B-ALL) is significantly lower in African American (AA) children compared with European American children (EA). Here, we present a whole exome sequencing (WES) study showing race-specific genetic variations that may play a role on the disparate outcomes among AA and EA children with B-ALL.

Patients And Methods: Five AA and 15 EA patients ranging in age from 1 to 18 years were enrolled.

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Sex differences in heart failure development following myocardial infarction (MI) are not fully understood. We hypothesized that differential MI signaling could explain variations in outcomes. Analysis of the mouse heart attack research tool 1.

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Objective: Limited research has evaluated the individual and combined associations of physical activity (PA), cardiorespiratory fitness (CRF) and muscle strengthening activities (MSA) on generalized anxiety, panic and depressive symptoms. We evaluated this topic in a representative sample of young (20-39 years) adults, with considerations by sex.

Methods: Data from the 1999-2004 National Health and Nutrition Examination Survey (N = 2088) were used.

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The angiogenic inducer CCN1 (Cysteine-rich 61, CYR61) is differentially activated in metastatic breast carcinomas. However, little is known about the precise mechanisms that underlie the pro-metastatic actions of CCN1. Here, we investigated the impact of CCN1 expression on fatty acid synthase (FASN), a metabolic oncogene thought to provide cancer cells with proliferative and survival advantages.

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Hepatoma upregulated protein (HURP) is a multifunctional protein with clinical promise. This protein has been demonstrated to be a predictive marker for the outcome in high-risk prostate cancer (PCa) patients, besides being a resistance factor in PCa. Although changes in oxygen tension (pO2) are associated with PCa aggressiveness, the role of hypoxia in the regulation of tumor progression genes such as HURP has not yet been described.

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The correction of specific signaling defects can reverse the oncogenic phenotype of tumor cells by acting in a dominant manner over the cancer genome. Unfortunately, there have been very few successful attempts at identifying the primary cues that could redirect malignant tissues to a normal phenotype. Here we show that suppression of the lipogenic enzyme fatty acid synthase (FASN) leads to stable reversion of the malignant phenotype and normalizes differentiation in a model of breast cancer (BC) progression.

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Crohn's disease and ulcerative colitis are the primary inflammatory bowel diseases (IBDs) affecting the gastrointestinal tract. The current therapy aims at decreasing inflammation and reducing symptoms. This typically requires immune suppression by steroids, thiopurines, methotrexate, or tumor necrosis factor inhibitors.

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Despite progression in diagnosis and treatment, prostate cancer (PCa) still represents the main cause of cancer-related mortality and morbidity in men. Although radiation therapy offers clinical benefit over other therapeutic modalities, the success of this therapeutic modality is commonly hampered by the resistance of advanced tumors. So far, the mechanisms governing tumor resistance to radiotherapy are not discussed in detail.

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Telomere length, shape and function depend on a complex of six core telomere-associated proteins referred to as the telosome or shelterin complex. We here demonstrate that the isoform β2 of the heregulin family of growth factors (HRGβ2) is a novel interactor of the telosome/shelterin complex in human telomeres. Analysis of protein-protein interactions using a high-throughput yeast two-hybrid (Y2H) screen identified RAP1, the only telomere protein that is conserved from yeasts to mammals, as a novel interacting partner of HRGβ2.

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Article Synopsis
  • p53 and Notch-1 are both crucial in breast cancer biology, with Notch-1 inhibiting p53 activity in certain cancer cells while p53 has varied effects on Notch in different cell types.
  • In studies with MCF-7 cells and normal human mammary epithelial cells, overexpression of p53 or its activation via Nutlin-3 was shown to decrease Notch's transcriptional activity and target gene expression.
  • The research indicates that p53 interacts with Notch and MAML1, forming a complex that inhibits Notch-dependent transcription, suggesting that restoring p53 function in breast cancers lacking it could hinder Notch signaling as a therapeutic approach.
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Background: Several treatment strategies target the human epidermal growth factor receptor 2 (HER2) in breast carcinomas, including monoclonal antibodies directed against HER2's extracellular domain (ECD) and small molecule inhibitors of its tyrosine kinase activity. Yet, novel therapies are needed that prevent HER2 dimerization with other HER family members, because current treatments are only partially effective.

Methods: To test the hypothesis that HER2 activation requires a protein sequence in the HER2-ECD that mediates HER2 homo- and heterodimerization, we introduced a series of deletion mutations in the third subdomain of HER2-ECD.

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