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1.
Oncogene ; 36(43): 5958-5968, 2017 10 26.
Article in English | MEDLINE | ID: mdl-28650466

ABSTRACT

Cellular heterogeneity is a common feature in breast cancer, yet an understanding of the coexistence and regulation of various tumor cell subpopulations remains a significant challenge in cancer biology. In the current study, we approached tumor cell heterogeneity from the perspective of Wnt pathway biology to address how different modes of Wnt signaling shape the behaviors of diverse cell populations within a heterogeneous tumor landscape. Using a syngeneic TP53-null mouse model of breast cancer, we identified distinctions in the topology of canonical Wnt ß-catenin-dependent signaling activity and non-canonical ß-catenin-independent Ror2-mediated Wnt signaling across subtypes and within tumor cell subpopulations in vivo. We further discovered an antagonistic role for Ror2 in regulating canonical Wnt/ß-catenin activity in vivo, where lentiviral shRNA depletion of Ror2 expression augmented canonical Wnt/ß-catenin signaling activity across multiple basal-like models. Depletion of Ror2 expression yielded distinct phenotypic outcomes and divergent alterations in gene expression programs among different tumors, despite all sharing basal-like features. Notably, we uncovered cell state plasticity and adhesion dynamics regulated by Ror2, which influenced Ras Homology Family Member A (RhoA) and Rho-Associated Coiled-Coil Kinase 1 (ROCK1) activity downstream of Dishevelled-2 (Dvl2). Collectively, these studies illustrate the integration and collaboration of Wnt pathways in basal-like breast cancer, where Ror2 provides a spatiotemporal function to regulate the balance of Wnt signaling and cellular heterogeneity during tumor progression.


Subject(s)
Breast Neoplasms/genetics , Dishevelled Proteins/genetics , Mammary Neoplasms, Animal/genetics , Receptor Tyrosine Kinase-like Orphan Receptors/genetics , rho GTP-Binding Proteins/genetics , rho-Associated Kinases/genetics , Animals , Breast Neoplasms/pathology , Cell Adhesion/genetics , Female , Gene Expression Regulation, Neoplastic , Humans , Mammary Neoplasms, Animal/pathology , Mice , Tumor Suppressor Protein p53/genetics , Wnt Signaling Pathway/genetics , beta Catenin/genetics , rhoA GTP-Binding Protein
2.
Forensic Sci Int ; 133(1-2): 63-78, 2003 Apr 23.
Article in English | MEDLINE | ID: mdl-12742691

ABSTRACT

This study (1) compares urine, skin swabs, and PharmChek sweat patches for monitoring drug use; (2) measures possible environmental contamination in recent cocaine (COC) users; and (3) evaluates various immunoassays (IA) for screening COC in diverse matrices. Unique aspects include daily urine monitoring of 10 participants for 4 weeks, multiple monitoring methods, analysis for all specimens by IA and gas chromatography (GC)/mass spectrometry (MS), and the potential for continued illicit drug use by participants. Urine served as the "gold standard" specimen for determining drug use. Only cocaine and related substances were detected. Trace amounts of drugs were found on the skin (<50 ng per swab) of urine-negative participants' hands or forehead. In contrast, larger quantities of COC were found on the skin of individuals with BE-positive urines or individuals living with drug users (up to 20 microg per swab). Patch COC amounts among the three regular users (250-9000, 0-240, 160-22,000 ng per patch) exceeded BE (50-950, none, 30-2200 ng per patch). Pre-swabs, valuable for interpreting the source or time frame of positive patch results, contained substantial COC (38-1160, 0-152, 34-762 ng per swab) prior to patch application; therefore, patch results may represent current use, prior use, contamination, or a combination. In three individuals with no indication of cocaine use, false positives (defined as sweat patch positive when urine specimens were <300ng BE/ml) occurred at a 7% rate. Proposed cut-off concentrations of 75 ng cocaine per patch and 300 ng BE/ml urine curtail the incidence of false positives in this limited population. Three immunoassays were compared to screen specimens for cocaine: a modified, manual Microgenics CEDIA; a Cozart ELISA; and an OraSure ELISA. CEDIA's limit of detection (LOD) was 81ng/ml, compared with LODs of 4 ng/ml for the Cozart ELISA and 1.5 ng/ml for the OraSure ELISA. Cozart correlated with OraSure results for COC concentrations <2000 ng per swab (n=117), r(2)=0.79.


Subject(s)
Cocaine/analysis , Dopamine Uptake Inhibitors/analysis , Skin/chemistry , Substance Abuse Detection/methods , Sweat/chemistry , Adult , Female , Gas Chromatography-Mass Spectrometry , Humans , Immunoassay , Male , Middle Aged
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