Predictors built from gene expression data accurately predict ER, PR, and HER2 status, and divide tumor grade into high-grade and low-grade clusters; intermediate-grade tumors are not a unique group. In contrast, gene expression data cannot be used to predict tumor size or lymphatic-vascular invasion.
Predicting features of breast cancer with gene expression patterns.
No sample metadata fields
View SamplesThe gene expression of two different tumorigenic human breast epithelial cell types (HMLER and BPLER) is compared with their immortalized parental cell-of-origin (HME and BPE).
Transformation of different human breast epithelial cell types leads to distinct tumor phenotypes.
Sex, Specimen part, Disease
View SamplesIntegrated DNA and expression array analysis in primary human breast tumors identified chromosome 8q22 copy number gain and a suite of over-expressed genes in this region highly relevant to subsequent recurrence.
Amplification of LAPTM4B and YWHAZ contributes to chemotherapy resistance and recurrence of breast cancer.
Age, Specimen part, Subject
View Samplesbulk breast tumor RNA from patient
X chromosomal abnormalities in basal-like human breast cancer.
No sample metadata fields
View SamplesGene expression for 47 human breast tumor cases;
X chromosomal abnormalities in basal-like human breast cancer.
No sample metadata fields
View SamplesBreast cancers with HER2 overexpression are sensitive to drugs targeting the receptor or its kinase activity. HER2-targeting drugs are initially effective against HER2- positive breast cancer, but resistance inevitably occurs. We previously found that nuclear factor kappa B is hyper-activated in the subset of HER-2 positive breast cancer cells and tissue specimens. In this study, we report that constitutively active NF-B rendered HER2-positive cancer cells resistant to anti-HER2 drugs, and cells selected for Lapatinib resistance up-regulated NF-B. In both circumstances, cells were anti-apoptotic and grew rapidly as xenografts. Lapatinib-resistant cells were refractory to HER2 and NF-B inhibitors alone but were sensitive to their combination, suggesting a novel therapeutic strategy. A subset of NF-B-responsive genes was overexpressed in HER2-positive and triple-negative breast cancers, and patients with this NF-B signature had poor clinical outcome. Anti-HER2 drug resistance may be a consequence of NF-B activation, and selection for resistance results in NF-B activation, suggesting this transcription factor is central to oncogenesis and drug resistance. Clinically, the combined targeting of HER2 and NF-B suggests a potential treatment paradigm for patients who relapse after anti-HER2 therapy. Patients with these cancers may be treated by simultaneously suppressing HER2 signaling and NF-B activation.
NF-κB activation-induced anti-apoptosis renders HER2-positive cells drug resistant and accelerates tumor growth.
Specimen part
View SamplesUsing EWS-FLI and its parental transcription factor, FLI1, we created a unique experimental system to address questions regarding the genomic mechanisms by which chimeric transcription factors cause cancer. We found that in tumor cells, EWS-FLI targets regions of the genome distinct from FLI1, despite identical DNA-binding domains. In primary endothelial cells, however, EWS-FLI and FLI1 demonstrate similar targeting. To understand this mistargeting, we examined chromatin organization. Regions targeted by EWS-FLI are normally repressed and nucleosomal in primary endothelial cells. In tumor cells, however, bound regions are nucleosome-depleted and harbor the chromatin signature of enhancers. We next demonstrated that through chimerism, EWS-FLI acquired the ability to alter chromatin. Expression of EWS-FLI results in nucleosome depletion at targeted sites, whereas silencing of EWS-FLI in tumor cells restored nucleosome occupancy. Thus, the EWS-FLI chimera acquired chromatin-altering activity, leading to mistargeting, chromatin disruption, and ultimately transcriptional dysregulation.
Tumor-specific retargeting of an oncogenic transcription factor chimera results in dysregulation of chromatin and transcription.
Cell line
View SamplesThe MaxiK potassium channel is a key modulator of smooth muscle tone. Due to its calcium and voltage sensitivity, MaxiK is activated following depolarization and Ca2+ mobilization, therefore relaxing the muscle. We investigate the effects of silencing MaxiK for 48h in corpus cavernosuml smooth muscle (CCSM) cells to identify possible mechanisms of compensation through molecular crosstalk between pathways regulating smooth muscle tone.
Silencing MaxiK activity in corporal smooth muscle cells initiates compensatory mechanisms to maintain calcium homeostasis.
Specimen part
View SamplesTo assess pathologic complete response (pCR), clinical response, feasibility, safety, and potential predictors of response to preoperative trastuzumab plus vinorelbine in patients with operable, human epidermal growth factor receptor 2 (HER2)-positive breast cancer. EXPERIMENTAL DESIGN: 48 patients received preoperative trastuzumab and vinorelbine weekly for 12 weeks. Single and multigene biomarker studies were done in an attempt to identify predictors of response. RESULTS: 8 of 40 (20%) patients achieved pCR (95% confidence interval, 9-36%). Of 9 additional patients recruited for protocol-defined toxicity analysis, 8 were evaluable; 42 of 48 (88%) patients had clinical response (16 patients, clinical complete response; 26 patients, clinical partial response). T(1) tumors more frequently exhibited clinical complete response (P = 0.05) and showed a trend to exhibit pCR (P = 0.07). 5 (13%) patients experienced grade 1 cardiac dysfunction during preoperative treatment. Neither HER2 nor estrogen receptor status changed significantly after exposure to trastuzumab and vinorelbine. RNA profiling identified three top-level clusters by unsupervised analysis. Tumors with extremes of response [pCR (n = 3) versus nonresponse (n = 3)] fell into separate groups by hierarchical clustering. No predictive genes were identified in pCR tumors. Nonresponding tumors were more likely to be T(4) stage (P = 0.02) and express basal markers (P < 0.00001), growth factors, and growth factor receptors. Insulin-like growth factor-I receptor membrane expression was associated with a lower response rate (50% vs 97%; P = 0.001). CONCLUSIONS: Preoperative trastuzumab plus vinorelbine is active and well tolerated in patients with HER2-positive, operable, stage II/III breast cancer. HER2-overexpressing tumors with a basal-like phenotype, or with expression of insulin-like growth factor-I receptor and other proteins involved in growth factor pathways, are more likely to be resistant to this regimen.
Predictors of resistance to preoperative trastuzumab and vinorelbine for HER2-positive early breast cancer.
Sex, Specimen part, Disease
View SamplesIn the present study, the transcriptional analysis of CD biopsies reveals profound alterations in the ileum transportome profile. More than 60 SLC transporters showed different expression pattern compared with the healthy donors, being mostly decreased. Changes were confirmed in almost all the eighteen altered SLCs analyzed by RT-PCR. The results obtained display alterations in amino acid transporters, purinome members, Zn transporters and metallothioneins. All together, these alterations which mainly involve transporters localized at the apical membrane of the enterocyte anticipate impaired amino acid uptake and purinergic responses. Remarkably, incubation of explants with specific commensal bacteria restored almost all CD transportome alterations.
Transportome Profiling Identifies Profound Alterations in Crohn's Disease Partially Restored by Commensal Bacteria.
Specimen part, Disease
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