Prostate cancer often metastasizes to the bone, leading to morbidity and mortality. While metastasis‐associated protein 1 (MTA1) is highly overexpressed in metastatic tumors and bone metastatic lesions, its exact role in the development of metastasis is unknown. Here, we report the role of MTA1 in prostate cancer progression and bone metastasis in vitro and in vivo. We found that MTA1 silencing diminished formation of bone metastases and impaired tumor growth in intracardiac and subcutaneous prostate cancer xenografts, respectively. This was attributed to reduced colony formation, invasion, and migration capabilities of MTA1 knockdown cells. Mechanistic studies revealed that MTA1 silencing led to a significant decrease in the expression of cathepsin B (CTSB), a cysteine protease critical for bone metastasis, with an expected increase in the levels of E‐cadherin in both cells and xenograft tumors. Moreover, meta‐analysis of clinical samples indicated a positive correlation between MTA1 and CTSB. Together, these results demonstrate the critical role of MTA1 as an upstream regulator of CTSB‐mediated events associated with cell invasiveness and raise the possibility that targeting MTA1/CTSB signaling in the tumor may prevent the development of bone metastasis in prostate cancer.

Lung cancer histologic diagnosis is clinically relevant because there are histology-specific treatment indications and contraindications. Histologic diagnosis can be challenging owing to tumor characteristics, and it has been shown to have less-than-ideal agreement among pathologists reviewing the same specimens. Microarray profiling studies using frozen specimens have shown that histologies exhibit different gene expression trends; however, frozen specimens are not amenable to routine clinical application. Herein, we developed a gene expression-based predictor of lung cancer histology for FFPE specimens, which are routinely available in clinical settings. Genes predictive of lung cancer histologies were derived from published cohorts that had been profiled by microarrays. Expression of these genes was measured by quantitative RT-PCR (RT-qPCR) in a cohort of patients with FFPE lung cancer. A histology expression predictor (HEP) was developed using RT-qPCR expression data for adenocarcinoma, carcinoid, small cell carcinoma, and squamous cell carcinoma. In cross-validation, the HEP exhibited mean accuracy of 84% and κ = 0.77. In separate independent validation sets, the HEP was compared with pathologist diagnoses on the same tumor block specimens, and the HEP yielded similar accuracy and precision as the pathologists. The HEP also exhibited good performance in specimens with low tumor cellularity. Therefore, RT-qPCR gene expression from FFPE specimens can be effectively used to predict lung cancer histology.

Background. Platelet function analysis utilizing platelet-rich plasma and optical density based aggregometry fails to identify patients at risk for uremia associated complications. Methods. We employed whole blood platelet aggregation analysis based on impedance as well as determination of ATP release from platelet granules detected by a chemiluminescence method. Ten chronic kidney disease (CKD) stage 4 or 5 predialysis patients underwent platelet evaluation. Our study aims to evaluate this platform in this patient population to determine if abnormalities could be detected. Results. Analysis revealed normal aggregation and ATP release to collagen, ADP, and high-dose ristocetin. ATP release had a low response to arachidonic acid (0.37 ± 0.26 nmoles, reference range: 0.6–1.4 nmoles). Platelet aggregation to low-dose ristocetin revealed an exaggerated response (20.9 ± 18.7 ohms, reference range: 0–5 ohms). Conclusions. Whole blood platelet analysis detected platelet dysfunction which may be associated with bleeding and thrombotic risks in uremia. Diminished ATP release to arachidonic acid (an aspirin-like defect) in uremic patients may result in platelet associated bleeding. An increased aggregation response to low-dose ristocetin (a type IIb von Willebrand disease-like defect) is associated with thrombus formation. This platelet hyperreactivity may be associated with a thrombotic diathesis as seen in some uremic patients.

MicroRNAs (miRNAs) regulate the expression of protein-coding genes and represent potential biomarkers for childhood acute lymphoblastic leukemia (ALL). However, information linking miRNAs with their messenger RNA (mRNA) target genes modulating white blood cell (WBC) count is lacking. Here, we analyzed miRNAs and gene expression data from pediatric patients with ALL to identify a signature of miRNAs involved in ALL and their mRNA target genes, molecular networks, and biological pathways modulating WBC. We discovered a signature of miRNAs differentially expressed in ALL and a signature of mRNA target genes distinguishing patients with high WBC from patients with low WBC. In addition, we identified molecular networks and biological pathways, among them PI3/AKT, JAK/STAT, IL-17, TGF-β, apoptosis, IL-15, STAT3, IGF-1, FGF, mTOR, VEGF, NF-kB, and P53 signaling pathways, enriched for or targeted by miRNAs. The discovered miRNAs and their target genes and pathways represent potential clinically actionable biomarkers and therapeutic targets.

The prevalence of celiac disease is low in an urban, predominately male, African-American population with iron deficiency. Routine small intestinal biopsy for celiac disease in similar populations should not be done. EGD remains clinically important.

Our study revealed aberrant genetic aberrations in signaling networks that may contribute to race-specific aspects of leukemogenesis. Our results suggest the value of WES as a tool for development of individual gene signatures and gene scores for AA and EA children afflicted by B-ALL. These findings may ultimately impact disease management and contribute to the elimination of disparate outcomes in AA children with B-ALL.

About 80% of the time that prostate cancer cells metastasize, they spread to the bones. Metastasis involves activation of invasive programs through genetic and epigenetic alterations, including changes in expression of chromatin remodeler proteins. We have previously identified metastasis-associated protein 1 (MTA1), a chromatin remodeler, as a component of vicious cycle of bone metastasis and confirmed significantly higher expression of MTA1 in bone metastatic samples from patients. In an attempt to dissect molecular mechanisms of MTA1 action, we performed integrative analysis of our bone metastasis signature data along with MTA1 ChIP-Seq data, which revealed mucin 1 (MUC1) and cathepsin B (CTSB) as strong potential candidates responsible for MTA1-driven invasiveness.Here, we show that loss of function studies with MTA1 in PC3M cells exhibit reduced expression for MUC1 and CTSB. We also demonstrate that depletion of MTA1 in PC3M aggressive prostate cancer cellsdoes not affect cell proliferation but leads to decrease in colony forming ability, invasive and migratory property of these cells. When PC3M cells silenced for MTA1 and tagged with luciferase are used to generate subcutaneous or intracardiac xenografts, it leads to reduced tumor progression or decreased metastasis to bone, respectively as evident by bioluminescent measurements and histology of tumors. Ongoing experiments aim to validate the role of MUC1 and CTSB in MTA1-driven invasiveness and metastasis in prostate cancer. Citation Format: Avinash Kumar, Swati Dhar, Gisella Campanelli, Nasir A. Butt, Christian R. Gomez, Jason M. Schallheim, Anait S. Levenson. MTA1 promotes tumor progression and bone metastasis in prostate cancer via positive regulation of MUC1 and CTSB [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1959. doi:10.1158/1538-7445.AM2017-1959

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