Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
68
result(s) for
"Tuck, David P"
Sort by:
Molecular Phenotypes in Triple Negative Breast Cancer from African American Patients Suggest Targets for Therapy
2013
Triple negative breast cancer (TNBC) is characterized by high proliferation, poor differentiation and a poor prognosis due to high rates of recurrence. Despite lower overall incidence African American (AA) patients suffer from higher breast cancer mortality in part due to the higher proportion of TNBC cases among AA patients compared to European Americans (EA). It was recently shown that the clinical heterogeneity of TNBC is reflected by distinct transcriptional programs with distinct drug response profiles in preclinical models. In this study, gene expression profiling and immunohistochemistry were used to elucidate potential differences between TNBC tumors of EA and AA patients on a molecular level. In a retrospective cohort of 136 TNBC patients, a major transcriptional signature of proliferation was found to be significantly upregulated in samples of AA ethnicity. Furthermore, transcriptional profiles of AA tumors showed differential activation of insulin-like growth factor 1 (IGF1) and a signature of BRCA1 deficiency in this cohort. Using signatures derived from the meta-analysis of TNBC gene expression carried out by Lehmann et al., tumors from AA patients were more likely of basal-like subtypes whereas transcriptional features of many EA samples corresponded to mesenchymal-like or luminal androgen receptor driven subtypes. These results were validated in The Cancer Genome Atlas mRNA and protein expression data, again showing enrichment of a basal-like phenotype in AA tumors and mesenchymal subtypes in EA tumors. In addition, increased expression of VEGF-activated genes together with elevated microvessel area determined by the AQUA method suggest that AA patients exhibit higher tumor vascularization. This study confirms the existence of distinct transcriptional programs in triple negative breast cancer in two separate cohorts and that these programs differ by racial group. Differences in TNBC subtypes and levels of tumor angiogenesis in AA versus EA patients suggest that targeted therapy choices should be considered in the context of race.
Journal Article
Prognostic value of the veterans affairs frailty index in older patients with non‐small cell lung cancer
by
Dumontier, Clark
,
Brophy, Mary T.
,
Driver, Jane A.
in
Aged
,
Carcinoma, Non-Small-Cell Lung - diagnosis
,
Carcinoma, Non-Small-Cell Lung - epidemiology
2022
Background Older patients with non‐small cell lung cancer (NSCLC) are a heterogeneous population with varying degrees of frailty. An electronic frailty index such as the Veterans Affairs Frailty Index (VA‐FI) can potentially help identify vulnerable patients at high risk of poor outcomes. Methods NSCLC patients ≥65 years old and diagnosed in 2002–2017 were identified using the VA Central Cancer Registry. The VA‐FI was calculated using administrative codes from VA electronic health records data linked with Medicare and Medicaid data. We assessed associations between the VA‐FI and times to mortality, hospitalization, and emergency room (ER) visit following diagnosis by Kaplan–Meier analysis and multivariable stratified Cox models. We also evaluated the change in discrimination and calibration of reference prognostic models after adding VA‐FI. Results We identified a cohort of 42,204 older NSCLC VA patients, in which 55.5% were classified as frail (VA‐FI >0.2). After adjustment, there was a strong association between VA‐FI and the risk of mortality (HR = 1.23 for an increase of four deficits or, equivalently, an increase of 0.129 on VA‐FI, p < 0.001), hospitalization (HR = 1.16 for four deficits, p < 0.001), and ER visit (HR = 1.18 for four deficits, p < 0.001). Adding VA‐FI to baseline prognostic models led to statistically significant improvements in time‐dependent area under curves and did not have a strong impact on calibration. Conclusion Older NSCLC patients with higher VA‐FI have significantly elevated risks of mortality, hospitalizations, and ER visits following diagnosis. An electronic frailty index can serve as an accessible tool to identify patients with vulnerabilities to inform clinical care and research. Older non‐small cell lung cancer patients with higher values of an electronic frailty index have elevated risks of mortality and acute care utilization following diagnosis. Such an electronic index can help identify vulnerable patients to inform clinical decision‐making and research.
Journal Article
Differentiated cells are more efficient than adult stem cells for cloning by somatic cell nuclear transfer
by
Kuo, Lynn
,
Yu, Hui
,
Tian, X Cindy
in
Adult Stem Cells - cytology
,
Adult Stem Cells - physiology
,
Agriculture
2006
Since the creation of Dolly via somatic cell nuclear transfer (SCNT)
1
, more than a dozen species of mammals have been cloned using this technology
2
. One hypothesis for the limited success of cloning via SCNT (1%–5%)
3
is that the clones are likely to be derived from adult stem cells
4
. Support for this hypothesis comes from the findings that the reproductive cloning efficiency for embryonic stem cells is five to ten times higher than that for somatic cells as donors
5
,
6
and that cloned pups cannot be produced directly from cloned embryos derived from differentiated B and T cells or neuronal cells
7
,
8
,
9
,
10
. The question remains as to whether SCNT-derived animal clones can be derived from truly differentiated somatic cells. We tested this hypothesis with mouse hematopoietic cells at different differentiation stages: hematopoietic stem cells, progenitor cells and granulocytes. We found that cloning efficiency increases over the differentiation hierarchy, and terminally differentiated postmitotic granulocytes yield cloned pups with the greatest cloning efficiency.
Journal Article
Loss of the retinoblastoma binding protein 2 (RBP2) histone demethylase suppresses tumorigenesis in mice lacking Rb1 or Men1
by
Fujiwara, Yuko
,
Blair, Lauren P
,
Cherniack, Andrew D
in
Animals
,
binding proteins
,
Biological Sciences
2011
Aberrations in epigenetic processes, such as histone methylation, can cause cancer. Retinoblastoma binding protein 2 (RBP2; also called JARID1A or KDM5A) can demethylate tri- and dimethylated lysine 4 in histone H3, which are epigenetic marks for transcriptionally active chromatin, whereas the multiple endocrine neoplasia type 1 (MEN1) tumor suppressor promotes H3K4 methylation. Previous studies suggested that inhibition of RBP2 contributed to tumor suppression by the retinoblastoma protein (pRB). Here, we show that genetic ablation of Rbp2 decreases tumor formation and prolongs survival in Rb1+/– mice and Men1-defective mice. These studies link RBP2 histone demethylase activity to tumorigenesis and nominate RBP2 as a potential target for cancer therapy.
Journal Article
PAM50 proliferation score as a predictor of weekly paclitaxel benefit in breast cancer
by
Ruiz, Amparo
,
Bernard, Philip S.
,
Hudis, Clifford
in
Analysis
,
Anthracyclines
,
Antineoplastic Combined Chemotherapy Protocols - therapeutic use
2013
To identify a group of patients who might benefit from the addition of weekly paclitaxel to conventional anthracycline-containing chemotherapy as adjuvant therapy of node-positive operable breast cancer. The predictive value of PAM50 subtypes and the 11-gene proliferation score contained within the PAM50 assay were evaluated in 820 patients from the GEICAM/9906 randomized phase III trial comparing adjuvant FEC to FEC followed by weekly paclitaxel (FEC-P). Multivariable Cox regression analyses of the secondary endpoint of overall survival (OS) were performed to determine the significance of the interaction between treatment and the (1) PAM50 subtypes, (2) PAM50 proliferation score, and (3) clinical and pathological variables. Similar OS analyses were performed in 222 patients treated with weekly paclitaxel versus paclitaxel every 3 weeks in the CALGB/9342 and 9840 metastatic clinical trials. In GEICAM/9906, with a median follow up of 8.7 years, OS of the FEC-P arm was significantly superior compared to the FEC arm (unadjusted HR = 0.693,
p
= 0.013). A benefit from paclitaxel was only observed in the group of patients with a low PAM50 proliferation score (unadjusted HR = 0.23,
p
< 0.001; and interaction test,
p
= 0.006). No significant interactions between treatment and the PAM50 subtypes or the various clinical–pathological variables, including Ki-67 and histologic grade, were identified. Finally, similar OS results were obtained in the CALGB data set, although the interaction test did not reach statistical significance (
p
= 0.109). The PAM50 proliferation score identifies a subset of patients with a low proliferation status that may derive a larger benefit from weekly paclitaxel.
Journal Article
Lineage Specificity of Gene Expression Patterns
by
Nakayama, Yasuhiro
,
Kohya, Naohiko
,
Chang, Joseph T.
in
B lymphocytes
,
Biological Sciences
,
Biology
2004
The hematopoietic system offers many advantages as a model for understanding general aspects of lineage choice and specification. Using oligonucleotide microarrays, we compared gene expression patterns of multiple purified hematopoietic cell populations, including neutrophils, monocytes, macrophages, resting, centrocytic, and centroblastic B lymphocytes, dendritic cells, and hematopoietic stem cells. Some of these cells were studied under both resting and stimulated conditions. We studied the collective behavior of subsets of genes derived from the Biocarta database of functional pathways, hand-tuned groupings of genes into broad functional categories based on the Gene Ontology database, and the metabolic pathways in the Kyoto Encyclopedia of Genes and Genomes database. Principal component analysis revealed strikingly pervasive differences in relative levels of gene expression among cell lineages that involve most of the subsets examined. These results indicate that many processes in these cells behave differently in different lineages. Much of the variation among lineages was captured by the first few principal components. Principal components biplots were found to provide a convenient visual display of the contributions of the various genes within the subsets in lineage discrimination. Moreover, by applying tree-constructing methodologies borrowed from phylogenetics to the expression data from differentiated cells and stem cells, we reconstructed a tree of relationships that resembled the established hematopoietic program of lineage development. Thus, the mRNA expression data implicity contained information about developmental relationships among cell types.
Journal Article
Hypoxia-induced protein CAIX is associated with somatic loss of BRCA1 protein and pathway activity in triple negative breast cancer
2012
The purpose of this study is to explore the relationship between tumor hypoxia assessed by CA IX protein expression and loss of BRCA1 function in triple negative breast cancer (TNBC). Protein expression of CA IX and BRCA1 was evaluated by AQUA™ technology on two breast cancer cohorts: an unselected cohort of 637 breast cancer patients and a TNBC cohort of 120 patients. Transcriptional profiling was performed on FFPE samples from the TNBC cohort to evaluate a gene expression signature associated with BRCA1 mutation (van’t Veer et al., Nature 415(6871):530–536,
2002
). CA IX is expressed in 7 % of the unselected breast cancer cohort and in 25 % of the TNBCs and is significantly associated with the triple negative phenotype. CA IX protein expression and BRCA1 protein expression are inversely correlated in both cohorts. Patients expressing high levels of CA IX show significantly worse overall survival (
p
= 0.02). Importantly, high CA IX protein expression occurs in patients who show the BRCA1 mutant signature and low levels of BRCA1 protein. These data suggest that elevated CA IX protein in TNBC is associated with a BRCA1 mutant signature and loss of BRCA1 function. CA IX may be a useful biomarker to identify triple negative patients with defective homologous recombination, who might benefit from PARP inhibitor therapy.
Journal Article
Quantitative Assessment of Tissue Biomarkers and Construction of a Model to Predict Outcome in Breast Cancer Using Multiple Imputation
2009
John W. Emerson1, Marisa Dolled-Filhart2, Lyndsay Harris3, David L. Rimm2 and David P. Tuck21Department of Statistics, Yale University, New Haven, Connecticut 06520. 2Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510. 3Medical Oncology, Yale University School of Medicine, New Haven, Connecticut 06510.AbstractMissing data pose one of the greatest challenges in the rigorous evaluation of biomarkers. The limited availability of specimens with complete clinical annotation and quality biomaterial often leads to underpowered studies. Tissue microarray studies, for example, may be further handicapped by the loss of data points because of unevaluable staining, core loss, or the lack of tumor in the histospot. This paper presents a novel approach to these common problems in the context of a tissue protein biomarker analysis in a cohort of patients with breast cancer. Our analysis develops techniques based on multiple imputation to address the missing value problem. We first select markers using a training cohort, identifying a small subset of protein expression levels that are most useful in predicting patient survival. The best model is obtained by including both protein markers (including COX6C, GATA3, NAT1, and ESR1) and lymph node status. The use of either lymph node status or the four protein expression levels provides similar improvements in goodness-of-ï¬ t, with both significantly better than a baseline clinical model. Using the same multiple imputation strategy, we then validate the results out-of-sample on a larger independent cohort. Our approach of integrating multiple imputation with each stage of the analysis serves as an example that may be replicated or adapted in future studies with missing values.
Journal Article
Global variation in CYP2C8–CYP2C9 functional haplotypes
by
Speed, William C
,
Kang, Soonmo Peter
,
Kidd, Kenneth K
in
Africa
,
Aryl Hydrocarbon Hydroxylases - genetics
,
Asia
2009
We have studied the global frequency distributions of 10 single nucleotide polymorphisms (SNPs) across 132 kb of
CYP2C8
and
CYP2C9
in ∼2500 individuals representing 45 populations. Five of the SNPs were in noncoding sequences; the other five involved the more common missense variants (four in
CYP2C8
, one in
CYP2C9
) that change amino acids in the gene products. One haplotype containing two
CYP2C8
coding variants and one
CYP2C9
coding variant reaches an average frequency of 10% in Europe; a set of haplotypes with a different
CYP2C8
coding variant reaches 17% in Africa. In both cases these haplotypes are found in other regions of the world at <1%. This considerable geographic variation in haplotype frequencies impacts the interpretation of
CYP2C8/CYP2C9
association studies, and has pharmacogenomic implications for drug interactions.
Journal Article