Christine W. Duarte

miR-125a regulates cell cycle, proliferation, and apoptosis by targeting the ErbB pathway in acute myeloid leukemia

microRNA profiling of acute myeloid leukemia patient samples identified miR-125a as being decreased. Current literature has investigated miR-125as role in normal hematopoiesis but not within acute myeloid leukemia. Analysis of the upstream region of miR-125a identified several CpG islands. Both precursor and mature miR-125a increased in response to a de-methylating agent, Decitabine. Profiling revealed the ErbB pathway as significantly decreased with ectopic miR-125a. Either ectopic expression of miR-125a or inhibition of ErbB via Mubritinib resulted in inhibition of cell cycle proliferation and progression with enhanced apoptosis revealing ErbB inhibitors as potential novel therapeutic agents for treating miR-125a-low AML.

Lineage-specific splicing of a brain-enriched alternative exon promotes glioblastoma progression

Tissue-specific alternative splicing is critical for the emergence of tissue identity during development, yet the role of this process in malignant transformation is undefined. Tissue-specific splicing involves evolutionarily conserved, alternative exons that represent only a minority of the total alternative exons identified. Many of these conserved exons have functional features that influence signaling pathways to profound biological effect. Here, we determined that lineage-specific splicing of a brain-enriched cassette exon in the membrane-binding tumor suppressor annexin A7 (ANXA7) diminishes endosomal targeting of the EGFR oncoprotein, consequently enhancing EGFR signaling during brain tumor progression. ANXA7 exon splicing was mediated by the ribonucleoprotein PTBP1, which is normally repressed during neuronal development. PTBP1 was highly expressed in glioblastomas due to loss of a brain-enriched microRNA (miR-124) and to PTBP1 amplification. The alternative ANXA7 splicing trait was present in precursor cells, suggesting that glioblastoma cells inherit the trait from a potential tumor-initiating ancestor and that these cells exploit this trait through accumulation of mutations that enhance EGFR signaling. Our data illustrate that lineage-specific splicing of a tissue-regulated alternative exon in a constituent of an oncogenic pathway eliminates tumor suppressor functions and promotes glioblastoma progression. This paradigm may offer a general model as to how tissue-specific regulatory mechanisms can reprogram normal developmental processes into oncogenic ones.

Improved Survival Outcomes in Cancer Patients with Hereditary Hemorrhagic Telangiectasia

Background: Hereditary hemorrhagic telangiectasia (HHT) is a genetic disorder characterized by deficiency in endoglin, an angiogenic protein. The net effect of endoglin expression on cancer outcomes from animal studies has proven controversial. We evaluated whether reduced systemic endoglin levels, expected in patients diagnosed with HHT, impacted clinical outcomes for cancer. Methods: A retrospective cohort analysis using Surveillance, Epidemiology, and End Results–Medicare was conducted to evaluate the effect of HHT on survival among patients diagnosed with breast, colorectal, lung, or prostate cancer between 2000 and 2007 (n = 540,520). We generated Kaplan–Meier survival curves and Cox models to compare the effect of HHT on all-cause survival for a composite of the four cancers, and separate models by cancer, adjusting for demographic variables, cancer type, cancer stage, and comorbidities. Results: All-cause survival analysis for a composite of the four cancers showed an adjusted HR of 0.69 [95% confidence interval (CI) of 0.51–0.91; P = 0.009] for HHT, indicating significantly improved survival outcome. When stratified by cancer type, HHT diagnosis showed a significant protective effect among breast cancer patients with an adjusted HR of 0.31 (95% CI, 0.13–0.75; P = 0.009). Conclusions: There was a significant association between HHT and improved survival outcome for a composite of patients with breast, prostate, colorectal, and lung cancer, and in analysis stratified by cancer, the association was significant for HHT patients with breast cancer. Impact: This study supports the hypothesis that systemically educed endoglin expression is associated with improved survival outcome in multiple cancers, and suggests that anti-endoglin antibody therapy may have broad-based application. Cancer Epidemiol Biomarkers Prev; 23(1); 117–25. ©2013 AACR.

High Throughput Kinomic Profiling of Human Clear Cell Renal Cell Carcinoma Identifies Kinase Activity Dependent Molecular Subtypes.

Despite the widespread use of kinase-targeted agents in clear cell renal cell carcinoma (CC-RCC), comprehensive kinase activity evaluation (kinomic profiling) of these tumors is lacking. Thus, kinomic profiling of CC-RCC may assist in devising a classification system associated with clinical outcomes, and help identify potential therapeutic targets. Fresh frozen CC-RCC tumor lysates from 41 clinically annotated patients who had localized disease at diagnosis were kinomically profiled using the PamStation®12 high-content phospho-peptide substrate microarray system (PamGene International). Twelve of these patients also had matched normal kidneys available that were also profiled. Unsupervised hierarchical clustering and supervised comparisons based on tumor vs. normal kidney and clinical outcome (tumor recurrence) were performed and coupled with advanced network modeling and upstream kinase prediction methods. Unsupervised clustering analysis of localized CC-RCC tumors identified 3 major kinomic groups associated with inflammation (A), translation initiation (B), and immune response and cell adhesions (C) processes. Potential driver kinases implicated include PFTAIRE (PFTK1), PKG1, and SRC, which were identified in groups A, B, and C, respectively. Of the 9 patients who had tumor recurrence, only one was found in Group B. Supervised analysis showed decreased kinase activity of CDK1 and RSK1-4 substrates in those which progressed compared to others. Twelve tumors with matching normal renal tissue implicated increased PIM’s and MAPKAPK’s in tumors compared to adjacent normal renal tissue. As such, comprehensive kinase profiling of CC-RCC tumors could provide a functional classification strategy for patients with localized disease and identify potential therapeutic targets.

Derivation and Validation of the CREST Model for Very Early Prediction of Circulatory Etiology Death in Patients Without ST-Segment–Elevation Myocardial Infarction After Cardiac Arrest

Background: No practical tool quantitates the risk of circulatory-etiology death (CED) immediately after successful cardiopulmonary resuscitation in patients without ST-segment–elevation myocardial infarction. We developed and validated a prediction model to rapidly determine that risk and facilitate triage to individualized treatment pathways. Methods: With the use of INTCAR (International Cardiac Arrest Registry), an 87-question data set representing 44 centers in the United States and Europe, patients were classified as having had CED or a combined end point of neurological-etiology death or survival. Demographics and clinical factors were modeled in a derivation cohort, and backward stepwise logistic regression was used to identify factors independently associated with CED. We demonstrated model performance using area under the curve and the Hosmer-Lemeshow test in the derivation and validation cohorts, and assigned a simplified point-scoring system. Results: Among 638 patients in the derivation cohort, 121 (18.9%) had CED. The final model included preexisting coronary artery disease (odds ratio [OR], 2.86; confidence interval [CI], 1.83–4.49; P⩽0.001), nonshockable rhythm (OR, 1.75; CI, 1.10–2.77; P=0.017), initial ejection fraction<30% (OR, 2.11; CI, 1.32–3.37; P=0.002), shock at presentation (OR, 2.27; CI, 1.42–3.62; P<0.001), and ischemic time >25 minutes (OR, 1.42; CI, 0.90–2.23; P=0.13). The derivation model area under the curve was 0.73, and Hosmer-Lemeshow test P=0.47. Outcomes were similar in the 318-patient validation cohort (area under the curve 0.68, Hosmer-Lemeshow test P=0.41). When assigned a point for each associated factor in the derivation model, the average predicted versus observed probability of CED with a CREST score (coronary artery disease, initial heart rhythm, low ejection fraction, shock at the time of admission, and ischemic time >25 minutes) of 0 to 5 was: 7.1% versus 10.2%, 9.5% versus 11%, 22.5% versus 19.6%, 32.4% versus 29.6%, 38.5% versus 30%, and 55.7% versus 50%. Conclusions: The CREST model stratified patients immediately after resuscitation according to risk of a circulatory-etiology death. The tool may allow for estimation of circulatory risk and improve the triage of survivors of cardiac arrest without ST-segment–elevation myocardial infarction at the point of care.

Elevated Plasma Levels of the Pituitary Hormone Cthrc1 in Individuals with Red Hair but Not in Patients with Solid Tumors

Background An increasing number of studies report that Cthrc1 is expressed in various cancer cells. The present study sought to identify which cells in tumors and remodeling tissues express Cthrc1 and investigate the range of circulating human Cthrc1 levels in health and disease. Methodology/Principle Findings Highly specific monoclonal antibodies were generated to detect Cthrc1 by ELISA in plasma and in tissues by immunohistochemistry. In human colon, gastric, breast, endometrial, pancreatic, kidney, lung and skin cancer, Cthrc1 was expressed by activated stromal cells and not the cancer cells themselves. Similarly, conditions evoking tissue remodeling, such as wound repair or angiotensin II-mediated hypertension, induced Cthrc1 expression in interstitial and adventitial fibroblasts and perivascular stromal cells. Levels of Cthrc1 in plasma from healthy subjects were near the lower detection limit except for individuals with red hair, who had up to several hundred fold higher levels. Elevated Cthrc1 was also found in patients with diabetes, inflammatory conditions, and infections, but not solid tumors. Transgenic mouse studies suggested that Cthrc1 expression by stromal cells does not contribute to circulating levels. In human pituitaries, Cthrc1 was expressed in the anterior and intermediate lobes with unencapsulated Cthrc1 accumulations typically surrounded by chromophobe cells. Conclusions We identify Cthrc1 as a marker for activated stromal cells. Cthrc1 is a pituitary hormone with significantly elevated levels in subjects carrying variant alleles of the melanocortin-1 receptor as wells as in patients with inflammatory conditions.

Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores.

To determine whether hepatic depletion of vitamin A (VA) stores has an effect on the postnatal heart, studies were carried out with mice lacking liver retinyl ester stores fed either a VA-sufficient (LRVAS) or VA-deficient (LRVAD) diet (to deplete circulating retinol and extrahepatic stores of retinyl esters). There were no observable differences in the weights or gross morphology of hearts from LRVAS or LRVAD mice relative to sex-matched, age-matched, and genetically matched wild-type (WT) controls fed the VAS diet (WTVAS), but changes in the transcription of functionally relevant genes were consistent with a state of VAD in LRVAS and LRVAD ventricles. In silico analysis revealed that 58/67 differentially expressed transcripts identified in a microarray screen are products of genes that have DNA retinoic acid response elements. Flow cytometric analysis revealed a significant and cell-specific increase in the number of proliferating Sca-1 cardiac progenitor cells in LRVAS animals relative to WTVAS controls. Before myocardial infarction, LRVAS and WTVAS mice had similar cardiac systolic function and structure, as measured by echocardiography, but, unexpectedly, repeat echocardiography demonstrated that LRVAS mice had less adverse remodeling by 1 wk after myocardial infarction. Overall, the results demonstrate that the adult heart is responsive to retinoids, and, most notably, reducing hepatic VA stores (while maintaining circulating levels of VA) impacts ventricular gene expression profiles, progenitor cell numbers, and response to injury.

Discovery of phenotypic networks from genotypic association studies with application to obesity

Genome-wide Association Studies (GWAS) have resulted in many discovered risk variants for several obesity-related traits. However, before clinical relevance of these discoveries can be achieved, molecular or physiological mechanisms of these risk variants needs to be discovered. One strategy is to perform data mining of phenotypically-rich data sources such as those present in dbGAP (database of Genotypes and Phenotypes) for hypothesis generation. Here we propose a technique that combines the power of existing Bayesian Network (BN) learning algorithms with the statistical rigour of Structural Equation Modelling (SEM) to produce an overall phenotypic network discovery system with optimal properties. We illustrate our method using the analysis of a candidate SNP data set from the AMERICO sample, a multi-ethnic cross-sectional cohort of roughly 300 children with detailed obesity-related phenotypes. We demonstrate our approach by showing genetic mechanisms for three obesity-related SNPs.

A prospective evaluation of the candle wax sign: A visual clue to diagnose aggressive basal cell carcinoma

patients that did not develop a second cutaneous melanoma (CMM) in the methotrexate (MTX)-exposed and MTX-unexposed groups. The number of patients at risk in the respective groups is specified at 0, 15, 30, and 45 years after the first reported CMM. The data include both in situ and invasive melanomas. The observation period constituted the time from the first CMM diagnosis to whichever came first: the end of the study period (December 31, 2014), death, or the diagnosis of a consecutive primary CMM. Local recurrence of a melanoma was not included as a consecutive primary CMM. J AM ACAD DERMATOL VOLUME 77, NUMBER 1 Research Letters 163

Visualization of Cancer and Cardiovascular Disease Co-Occurrence With Network Methods

PURPOSE Cancer and cardiovascular disease (CVD) are common causes of morbidity and mortality, and measurement and interpretation of their co-occurrence rate have important implications for public health and patient care. Here, we present the raw and adjusted co-occurrence rates of cancer and CVD in the overall population by using a visually intuitive network approach. METHODS By using baseline survey and linked health outcome data from 490,842 individuals age 40 to 69 years from the UK Biobank, we recorded diagnoses between 1997 and 2014 of specific cancers and specific CVDs ascertained through hospital claims. We measured raw and adjusted rates of CVD for the following groups: individuals with Hodgkin or non-Hodgkin lymphoma, lung and trachea cancer, uterus cancer, colorectal cancer, prostate cancer, breast cancer, or no recorded diagnosed cancer during this time period. Analysis accounted for age, sex, and behavioral risk factors, without regard to the order of occurrence of cancer and CVD. RESULTS A significantly increased rate of CVD was found in patients with multiple types of cancers, including Hodgkin and non-Hodgkin lymphoma and lung and trachea, uterus, colorectal, and breast cancer, compared with patients without cancer by using age and sex-adjusted models. Increased co-occurrence for many CVD categories remained after correction for behavioral risk factors. Construction of co-occurrence networks highlighted heart failure as a shared CVD diagnosis across multiple cancer types, including breast cancer, lung cancer, non-Hodgkin lymphoma, and colorectal cancer. Smoking, physical activity, and other lifestyle factors accounted for some but not all of the increased co-occurrence for many of the CVD diagnoses. CONCLUSION Increased co-occurrence of several common CVD conditions is seen widely across multiple malignancies, and shared diagnoses, such as heart failure, were highlighted by using network methods.