Amee Patel

Deep sequencing of the small RNA transcriptome of normal and malignant human B cells identifies hundreds of novel microRNAs.

A role for microRNA (miRNA) has been recognized in nearly every biologic system examined thus far. A complete delineation of their role must be preceded by the identification of all miRNAs present in any system. We elucidated the complete small RNA transcriptome of normal and malignant B cells through deep sequencing of 31 normal and malignant human B-cell samples that comprise the spectrum of B-cell differentiation and common malignant phenotypes. We identified the expression of 333 known miRNAs, which is more than twice the number previously recognized in any tissue type. We further identified the expression of 286 candidate novel miRNAs in normal and malignant B cells. These miRNAs were validated at a high rate (92%) using quantitative polymerase chain reaction, and we demonstrated their application in the distinction of clinically relevant subgroups of lymphoma. We further demonstrated that a novel miRNA cluster, previously annotated as a hypothetical gene LOC100130622, contains 6 novel miRNAs that regulate the transforming growth factor-β pathway. Thus, our work suggests that more than a third of the miRNAs present in most cellular types are currently unknown and that these miRNAs may regulate important cellular functions.

An ATM/Chk2-Mediated DNA Damage-Responsive Signaling Pathway Suppresses Epstein-Barr Virus Transformation of Primary Human B Cells

SUMMARY Epstein-Barr virus (EBV), an oncogenic herpesvirus that causes human malignancies, infects and immortalizes primary human B cells in vitro into indefinitely proliferating lymphoblastoid cell lines, which represent a model for EBV-induced tumorigenesis. The immortalization efficiency is very low suggesting that an innate tumor suppressor mechanism is operative. We identify the DNA damage response (DDR) as a major component of the underlying tumor suppressor mechanism. EBV-induced DDR activation was not due to lytic viral replication nor did the DDR marks co-localize with latent episomes. Rather, a transient period of EBV-induced hyper-proliferation correlated with DDR activation. Inhibition of the DDR kinases ATM and Chk2 markedly increased transformation efficiency of primary B cells. Further, the viral latent oncoproteins EBNA3C was required to attenuate the EBV-induced DNA damage response We propose that heightened oncogenic activity in early cell divisions activates a growth-suppressive DDR which is attenuated by viral latency products to induce cell immortalization.

PAK1 Mediates Resistance to PI3K Inhibition in Lymphomas

Purpose: The phosphoinositide 3-kinase (PI3K) pathway is known to play an active role in many malignancies. The role of PI3K inhibition in the treatment of lymphomas has not been fully delineated. We sought to identify a role for therapeutic PI3K inhibition across a range of B-cell lymphomas. Experimental Design: We selected three small molecule inhibitors to test in a panel of 60 cell lines that comprised diverse lymphoma types. We tested the selective PI3K inhibitor BKM120 and the dual PI3K/mTOR inhibitors BEZ235 and BGT226 in these cell lines. We applied gene expression profiling to better understand the molecular mechanisms associated with responsiveness to these drugs. Results: We found that higher expression of the PAK1 gene was significantly associated with resistance to all three PI3K inhibitors. Through RNA–interference-mediated knockdown of the PAK1 gene, we showed a dramatic increase in the sensitivity to PI3K inhibition. We further tested a small-molecule inhibitor of PAK1 and found significant synergy between PI3K and PAK1 inhibition. Conclusion: Thus, we show that PI3K inhibition is broadly effective in lymphomas and PAK1 is a key modulator of resistance to PI3K inhibition. Clin Cancer Res; 19(5); 1106–15. ©2012 AACR.

Effectiveness of Pediatric Pill Swallowing Interventions: A Systematic Review

BACKGROUND AND OBJECTIVE: Pediatric patients commonly have difficulty swallowing pills. Targeted interventions have shown to improve medication administration and treatment compliance. The objective was to evaluate studies performed on pill swallowing interventions in the pediatric population since 1987. METHODS: We performed a comprehensive PubMed search and a bibliography review to identify articles for our review. We selected articles published in English between December 1986 and December 2013 that included >10 participants aged 0 to 21 years with pill swallowing difficulties without a comorbid condition affecting their swallowing. Reviewers extracted the relevant information and rated the quality of each study as “poor,” “fair,” or “good” based on the sample size and study design. RESULTS: We identified 4 cohort studies and 1 case series that met our criteria. All 5 studies found their intervention to be successful in teaching children how to swallow pills. Interventions included behavioral therapies, flavored throat spray, verbal instructions, specialized pill cup, and head posture training. Quality ratings differed between the articles, with 3 articles rated as “fair,” 1 article as “good,” and 1 article as “poor.” CONCLUSIONS: Pill swallowing difficulties are a barrier that can be overcome with a variety of successful interventions. Addressing this problem and researching more effective ways of implementing these interventions can help improve medication administration and compliance in the pediatric population.

A Pilot Study of the Pediatric Oral Medications Screener (POMS)

OBJECTIVE Oral medications are commonly used to treat acute and chronic conditions, but formal evaluation of a childs pill-swallowing ability rarely occurs. In this pilot study, the Pediatric Oral Medication Screener (POMS) was used to physically assess a childs pill swallowing ability and identify children who would benefit from a targeted intervention. METHODS We identified children 3 to 17 years old admitted to a general pediatric service over a 3-month period in 2014. Patients were asked to swallow several different-sized placebo formulations. If subjects did not meet age-based goals, they were referred for pill swallowing interventions (POMS+). Follow-up parental surveys were performed for patients completing the intervention. RESULTS The prospective pilot study recruited 34 patients. Twenty-eight patients (82%) passed the screening, and a majority of this group started or continued taking pill medications. Six did not pass the screen. Three of the 6 completed the intervention, improved their pill swallowing ability, and were taking oral pill medications at discharge. Parent prediction of pill swallowing was accurate only 56% of the time. Follow-up survey of the 3 families who completed POMS+ reported satisfaction with the program, and 2 of the patients had continued success with swallowing pills 5 months later. CONCLUSIONS The POMS was effective at identifying children who could benefit from an intervention to improve pill-swallowing ability. Our analysis demonstrated that POMS has the potential to improve patient satisfaction and discharge planning.