Novel blended SNRPE-related spliceosomopathy phenotype characterized by microcephaly and congenital atrichia.

Variants in genes encoding core components of the spliceosomes are associated with craniofacial syndromes, collectively called craniofacial spliceosomopathies. SNRPE encodes a core component of pre-mRNA processing U-rich small nuclear ribonuclear proteins (UsnRNPs). Heterozygous variants in SNRPE have been reported in six families with isolated hypotrichosis simplex in addition to one case of isolated non syndromic congenital microcephaly. Here, we report a patient with a novel blended phenotype of microcephaly and congenital atrichia with multiple congenital anomalies due to a de novo intronic SNRPE deletion, c.82-28_82-16del, which results in exon skipping. As discussed within, this phenotype, which we propose be named SNRPE-related syndromic microcephaly and hypotrichosis, overlaps other craniofacial splicesosomopathies.

Discovery of a Potent and Selective Covalent p300/CBP Inhibitor.

Aberrant gene activation driven by the histone acetyltransferases p300 and CREB binding protein (CBP) has been linked to several diseases, including cancers. Because of this, many efforts have been aimed toward the targeting of the closely related paralogues, p300 and CBP, but these endeavors have been exclusively directed toward noncovalent inhibitors. X-ray crystallography of A-485 revealed that both p300 and CBP possess a cysteine (C1450) near the active site, thus rendering covalent inhibition an attractive chemical approach. Herein we report the development of compound 2, an acrylamide-based inhibitor of p300/CBP that forms a covalent adduct with C1450. We demonstrated using mass spectrometry that compound 2 selectively targets C1450, and we also validated covalent binding using kinetics experiments and cellular washout studies. The discovery of covalent inhibitor 2 gives us a unique tool for the study of p300/CBP biology.

Residency Specialty and National Resident Matching Program Outcomes as Predictors of Academic vs Non-Academic Position as an Attending Physician.

PURPOSE: Previous studies have shown that research can be used as a predictive factor for an academic career for physicians in the fields of radiation oncology, orthopedic surgery, and diagnostic radiology. We seek to determine if this factor is predictive for all medical specialties based on an analysis of public data on physicians who have trained at Hershey Medical Center (HMC) and public National Resident Matching Program (NRMP) charting outcomes. METHODS: We determined the location and job title of all graduates of HMC residency training programs through a combination of publicly available information on HMC's website and other institutions' websites. We separated these into academic and non-academic positions and performed Chi-square analysis to determine if the number of research experiences was predictive of an academic career. RESULTS: Participating in the residency specialties of general surgery, pathology, internal medicine, and neurological surgery are statistically significant predictors of an academic career upon graduation. The average number of research experiences obtained by matched U.S. medical students is not a statistically significant predictor of an academic career upon graduation. CONCLUSION: In contrast to previously published studies, a higher number of research experiences in medical school is not a significant predictor of an academic career for attending physicians who graduated residency at HMC.

Specific MHC-I Peptides Are Induced Using PROTACs.

Peptides presented by the class-I major histocompatibility complex (MHC-I) are important targets for immunotherapy. The identification of these peptide targets greatly facilitates the generation of T-cell-based therapeutics. Herein, we report the capability of proteolysis targeting chimera (PROTAC) compounds to induce the presentation of specific MHC class-I peptides derived from endogenous cellular proteins. Using LC-MS/MS, we identified several BET-derived MHC-I peptides induced by treatment with three BET-directed PROTAC compounds. To understand our ability to tune this process, we measured the relative rate of presentation of these peptides under varying treatment conditions using label-free mass spectrometry quantification. We found that the rate of peptide presentation reflected the rate of protein degradation, indicating a direct relationship between PROTAC treatment and peptide presentation. We additionally analyzed the effect of PROTAC treatment on the entire immunopeptidome and found many new peptides that were displayed in a PROTAC-specific fashion: we determined that these identifications map to the BET pathway, as well as, potential off-target or unique-to-PROTAC pathways. This work represents the first evidence of the use of PROTAC compounds to induce the presentation of MHC-I peptides from endogenous cellular proteins, highlighting the capability of PROTAC compounds for the discovery and generation of new targets for immunotherapy.

Vancomycin-resistant Enterococcus in pediatric oncology patients: balancing infection prevention and family-centered care.

In February 2007, we experienced an abrupt 8-fold increase in vancomycin-resistant Enterococcus (VRE)-positive pediatric hematology/oncology patients in isolation per day, peaking at 12 patients in isolation per day in June 2007. We enforced and expanded infection prevention practices and initiated a rigorous 6-month clearance process. After noting an eventual decrease, we modified clearance to a 3-month process, maintaining <1 patient/day in isolation by June 2009, subjectively improving family and staff satisfaction after this 2-year process. VRE infection was relatively uncommon (7.8%), although continued VRE colonization portended an overall poorer prognosis.

Iniparib nonselectively modifies cysteine-containing proteins in tumor cells and is not a bona fide PARP inhibitor.

PURPOSE: PARP inhibitors are being developed as therapeutic agents for cancer. More than six compounds have entered clinical trials. The majority of these compounds are ß-nicotinamide adenine dinucleotide (NAD(+))-competitive inhibitors. One exception is iniparib, which has been proposed to be a noncompetitive PARP inhibitor. In this study, we compare the biologic activities of two different structural classes of NAD(+)-competitive compounds with iniparib and its C-nitroso metabolite. EXPERIMENTAL DESIGN: Two chemical series of NAD(+)-competitive PARP inhibitors, iniparib and its C-nitroso metabolite, were analyzed in enzymatic and cellular assays. Viability assays were carried out in MDA-MB-436 (BRCA1-deficient) and DLD1(-/-) (BRCA2-deficient) cells together with BRCA-proficient MDA-MB-231 and DLD1(+/+) cells. Capan-1 and B16F10 xenograft models were used to compare iniparib and veliparib in vivo. Mass spectrometry and the (3)H-labeling method were used to monitor the covalent modification of proteins. RESULTS: All NAD(+)-competitive inhibitors show robust activity in a PARP cellular assay, strongly potentiate the activity of temozolomide, and elicit robust cell killing in BRCA-deficient tumor cells in vitro and in vivo. Cell killing was associated with an induction of DNA damage. In contrast, neither iniparib nor its C-nitroso metabolite inhibited PARP enzymatic or cellular activity, potentiated temozolomide, or showed activity in a BRCA-deficient setting. We find that the nitroso metabolite of iniparib forms adducts with many cysteine-containing proteins. Furthermore, both iniparib and its nitroso metabolite form protein adducts nonspecifically in tumor cells. CONCLUSIONS: Iniparib nonselectively modifies cysteine-containing proteins in tumor cells, and the primary mechanism of action for iniparib is likely not via inhibition of PARP activity.

Detection of differentially expressed basal cell proteins by mass spectrometry.

The ability of cells to modulate interactions with each other and the substrate is essential for epithelial tissue remodeling during processes such as wound healing and tumor progression. However, despite strides made in the field of proteomics, proteins involved in adhesion have been difficult to study. Here, we report a method for the enrichment and analysis of proteins associated with the basal surface of the cell and its underlying matrix. The enrichment involves deroofing the cells with 20 mM ammonium hydroxide and the removal of cytosolic and organellar proteins by stringent water wash. Proteomic profiling was achieved by LC-FTMS, which allowed comparison of differentially expressed or shared proteins under different cell states. First, we analyzed and compared the basal cell components of mouse keratinocytes lacking the cell-cell junction molecule plakoglobin with their control counterparts. Changes in the molecules involved in motility and invasion were detected in plakoglobin-deficient cells, including decreased detection of fibronectin, integrin beta(4), and FAT tumor suppressor. Second, we assessed the differences in basal cell components between two human oral squamous cell carcinoma lines originating from different sites in the oral cavity (CAL33 and UM-SCC-1). The data show differences between the two lines in the type and abundance of proteins specific to cell adhesion, migration, and angiogenesis. Therefore, the method described here has the potential to serve as a platform to assess proteomic changes in basal cell components including extracellular and adhesion-specific proteins involved in wound healing, cancer, and chronic and acquired adhesion-related disorders.