Influence of Delipation on the Energy Metabolism in Pig Parthenogenetically Activated Embryos

This study was designed not only to measure the effect of delipation on the developmental viability of pig parthenogenetically activated (PA) embryos, but also to evaluate the changes of mitochondria DNA (mtDNA), reactive oxygen species (ROS) level, adenosine triphosphate (ATP) content and gene (Acsl3, Acadsb, Acaa2, Glut1) expression level at different stages after delipation. Results showed that no effect was observed on the cleavage ability, but significant lower blastocyst rate was obtained in delipated embryos. Copy number of mtDNA decreased gradually from MII to four-cell stages and subsequently kept consistent with blastocyst stage both in delipated and control embryos, but the copy number of mtDNA in delipated embryos was similar to that in the control groups no matter at which developmental stage was observed. Both in delipated and control embryos, ATP content progressive decreased from one-cell to blastocyst stages, while just at one-cell stage, a significant decrease of ATP level was observed in delipated embryos compared with that of control. The level of ROS increased obviously after delipation at cleavage stage, but no difference was seen at blastocyst stage. Finally, the expression level of genes related to fatty acids beta-oxidation (Acadsb and Acaa2) was decreased, while the expression level of genes related to glucose metabolism (Glut 1) was upregulated after delipation. In conclusion, the reduction of lipids in pig oocytes will affect the developmental competence of pig PA embryos by disturbed energy metabolism and ROS stress.

Optimizing CT for the evaluation of vestibular aqueduct enlargement: Inter-rater reproducibility and predictive value of reformatted CT measurements

Enlarged vestibular aqueduct (EVA), the most frequent identifiable cause of congenital hearing loss, is evaluated with high-definition multi-detector CT in the axial plane. Our purpose was to determine which reformatted CT measurements are most reproducible. Seven multiplanar reformatted images were created for each of the 64 temporal bones in patients with EVA. Intraclass correlation coefficients (ICC) were used to assess inter-observer variability, and both linear regression and ROC analyses were used to compare the measurements with severity of hearing loss, as assessed by pure tone audiometry. All seven measurements had excellent inter-observer variability, with average-measure ICC ranging from 0.92 to 0.98. There was no statistically significant correlation between the radiologic degree of aqueduct enlargement and severity of hearing loss using any of the seven measurements; ROC analyses revealed areas under the curves ranging from 0.57 to 0.73. Optimal accuracy was obtained with a threshold of 1.75 mm as measured at the aqueductal aperture in the Pöschl plane, with sensitivity of 0.75 and specificity of 0.63. Although the radiologic measurement may not serve as a reliable tool for assessing severity of EVA, Pöschl plane reformatting has proven to be better than conventional axial acquisition plane for identifying patients with clinically significant hearing loss.

The imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs)

OBJECTIVE

To explore the imaging features of meningeal Ewing sarcoma/peripheral primitive neuroectodermal tumours (pPNETs).

METHODS

The imaging features and pathological characteristics of eight cases of surgically and pathologically confirmed Ewing sarcoma/pPNET were analysed retrospectively in light of recent literature on the disease.

RESULTS

The peak age was between 10 and 20 years. The lesions tended to be spindle shaped and dural based, usually widely so. CT showed that the lesions had slightly uneven high density in five cases and iso-low mixed density in three cases; marked heterogeneous enhancement was seen in all cases after contrast injection. MRI of the lesions showed varying proportions of isointense and hypointense signal in all cases on unenhanced T1 weighted imaging and varying proportions of isointense and hyperintense signal on T2 weighted imaging. After contrast injection, marked heterogeneous enhancement was seen in all cases; three cases showed a short and nodular dural tail and five cases showed adjacent skull erosion and osteolysis. Pathological results included high cell density, haemorrhage and necrosis. The cells resembled lymphocytes and spindle cells with transparent cytoplasm. CD99 and vimentin were expressed by all tumour cells.

CONCLUSION

Features of meningeal Ewing sarcoma/pPNETs include peak incidence at 10-20 years of age, a broad connection to the meninges, a thick dural tail involved with tumour, skull and scalp erosion and early metastasis. Necrosis and cystic changes are the common histological findings.

ADVANCES IN KNOWLEDGE

The imaging features of meningeal Ewing sarcoma/pPNETs have not been reported. The study helps to identify meningeal Ewing sarcoma/pPNETs and meningioma.

Management of Refractory Tympanostomy Tube Otorrhea with Ear Wicks

Objectives:

Report our experience with ear wicks for the treatment of chronic tympanostomy tube otorrhea, failing to improve with oral and/or topical antibiotics.

Methods:

Retrospective review of 7 children with tympanostomy tubes and recurrent otorrhea failing medical management in 2012 at a tertiary care center. We describe the outcomes of patients after wick placement and Ciprodex ear drops.

Results:

The average age of patients in this study is 30 months (21-48months). The average age of tympanostomy tube insertion was 17 months (8-32 months). All patients had Armstrong grommet tubes placed. Three patients found effusions during time of insertion. All children failed previous topical and/or oral antibiotic treatment. An ear wick was placed during the clinic visit, and ciprodex drops were continued. Wicks were removed in approximately one week. Culture results showed 4 patients had Methicillin-resistant Staphylococcus aureus and 3 had Pseudomonas aeruginosa. After wick placement, 7/7 (100%) patients’ otorrhea resolved. One patient had recurrent otorrhea at further follow-up visit.

Conclusions:

Tympanostomy tube placement is one of the most common surgical procedures in children. Refractory otorrhea continues to be a complication that has a negative effect on patient quality of life and remains a challenge to treat. It can be difficult to adequately deliver topical therapy to young children. Placement of an ear wick improves topical delivery to the ear and may eradicate otorrhea in patients who failed prior topical and oral antibiotics.

PDEF promotes luminal differentiation and acts as a survival factor for ER-positive breast cancer cells

Breast cancer is a heterogeneous disease and can be classified based on gene expression profiles that reflect distinct epithelial subtypes. We identify prostate-derived ETS factor (PDEF) as a mediator of mammary luminal epithelial lineage-specific gene expression and as a factor required for tumorigenesis in a subset of breast cancers. PDEF levels strongly correlate with estrogen receptor (ER)-positive luminal breast cancer, and PDEF transcription is inversely regulated by ER and GATA3. Furthermore, PDEF is essential for luminal breast cancer cell survival and is required in models of endocrine resistance. These results offer insights into the function of this ETS factor that are clinically relevant and may be of therapeutic value for patients with breast cancer treated with endocrine therapy.

Abstract 2313: Differences in estrogen receptor signaling in normal mammary epithelial cells and ER-positive primary breast tumors and metastases

Background: The estrogen receptor (ER) is expressed in ≈70% of sporadic breast cancer and activates genes driving cell proliferation and tumorigenesis. We have previously performed genome-wide analysis of ER binding sites in MCF-7 breast cancer cells and identified distinct mechanisms of tumorigenic ER signaling. Using EpCAM and CD49f as markers to enrich for ER-positive (ER+) cells obtained from primary non-malignant breast tissue, we seek to elucidate differences in ER signaling between normal and primary and metastatic ER+ breast cancer cells.

Methods: Viable breast epithelial cells were obtained from patients undergoing reduction mammoplasties, and ER+ breast cancer cells from primary tumors and metastatic effusions. Following dissociation into single cells, EpCAM+ cell subpopulations were isolated and stimulated with estradiol. Gene expression microarray analysis, chromatin immunoprecipitation and DNA sequencing (ChIP-seq) on transcription factors and histone modifications as well as DNAse I hypersensitivity assays (DHS) were performed, and compared to MCF-7 breast cancer cells.

Results: Triplicates of normal, ER+ breast cancers, and metastatic ER+ cancer were analyzed. Gene expression profiles revealed differences in estradiol regulated genes between primary normal, breast tumor, and metastatic ER+ breast cancer cells. Genes that promote cell cycling and cell proliferation were downregulated in non-malignant tissue but were upregulated in breast cancer cells. Our ChIP-seq results showed differential binding of ER between normal and ER+ breast cancer with little common overlap, and motif analysis of these binding sites demonstrated the enrichment of ERE motifs in common sites, TCF12 motifs in unique normal sites, and FOXA1 motifs in unique breast cancer sites. Analyses of the distribution of histone modifications and DHS regions demonstrated distinct patterns at shared, normal, and breast cancer ER binding sites, suggesting functionality and further validating differential ER binding.

Conclusions: There are contrasting differences in ER signaling between normal mammary and ER+ breast cancer cells, with estrogen appearing to have anti-proliferative effects in normal luminal cells compared to pro-proliferative effects in BC. ER ChIP-seq has identified unique motifs, distribution of histone modifications, and DHS regions specific to unique normal, cancer and shared ER binding sites. Our studies point to TCF12 as a potential ER pioneer cofactor in non-malignant breast tissue and provide more data in support of FOXA1 as an important ER coregulator in ER+ breast cancer. Our data provides evidence for key alterations in ER-signaling during tumorigenesis and could lead to the identification of novel strategies to target breast cancer specific ER signaling.

Citation Format: David Chi, Housheng He, Tony Yeung, Rinath Jeselsohn, Stuart Schnitt, Judy Garber, Andrea Richardson, Elgene Lim, Myles Brown. Differences in estrogen receptor signaling in normal mammary epithelial cells and ER-positive primary breast tumors and metastases. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2313. doi:10.1158/1538-7445.AM2013-2313

Abstract 1788: The CDK inhibitor dinaciclib sensitizes triple-negative breast cancer cells to PARP inhibition

Background: Triple Negative Breast Cancer (TNBC) comprises 15% of all breast cancers, and has a poor prognosis relative to other breast cancer subtypes. Inhibition of poly (ADP-ribose) polymerase (PARP) causes the degeneration of single-strand DNA breaks to more lethal double-strand breaks (DSBs), and also traps PARP-DNA complexes, which must be repaired or bypassed by homologous recombination (HR). BRCA1 plays a critical role in HR and its activity is in part regulated by cyclin-dependent kinase 1 (CDK1)-mediated phosphorylation. PARP inhibition results in synthetic lethality in cells that have impaired HR, such as BRCA-deficient cells. Other CDK family members activate additional components of the HR pathway. Here, we show that HR-proficient TNBC cells can be sensitized to PARP inhibition through use of CDK inhibition to impair BRCA1 function and disrupt HR.

Methods: We examined the effects of dinaciclib (CDK1, 2, 5 and 9 inhibitor), γ-irradiation and veliparib (PARP inhibitor) on a panel of BRCA1 wild type TNBC cell lines (MDA-MB-231, MDA-MB-468, and BT549). Levels of phospho-S1497 BRCA1 (pBRCA1; CDK phosphorylation site), γ-H2AX, and RAD51 were measured by western blot to assess effects on HR proteins. A direct assessment of DSB repair was measured using the U2OS-DR-GFP reporter system. Cell viability was measured using Cell-Titer Glo assays. Patient-derived TNBC xenograft models were established in immunocompromised NOD-SCID-IL2γ-/- mice, and implanted orthotopically into cohorts of mice for in vivo efficacy studies.

Results: There was a significant reduction in total and pBRCA1 and RAD51 protein levels with increasing concentrations of dinaciclib in all TNBC cell lines. In response to 10 Gy γ-irradiation treatment, pretreatment with dinaciclib (20 nM) reduced the percentage of cells with greater than five BRCA1 foci from 54% to 5% (P < 0.001); and the percentage of cells with greater than 5 RAD51 foci from 26% to 4% (P = 0.001). In U2OS-DR-GFP assays, expression of GFP was detected in 3.4% of the vehicle group and in 1.9% of dinaciclib treated cells. Cell viability assays following five days of dinaciclib, veliparib or the combination revealed in vitro cytotoxic synergy in all three TNBC cell lines. In an orthotopic TNBC model derived from a primary patient sample, the relative tumor volumes over a 30-day treatment period for vehicle, dinaciclib, veliparib and combination- treated mice were 5.6-fold, 3.3-fold, 3.2-fold and 0.66-fold (P < 0.001) that of the initial tumor volume at the start of treatment. Tumor volume decreased only in the combination arm.

Conclusion: CDK inhibition effectively inhibits HR, and renders BRCA-proficient TNBC cells sensitive to PARP inhibition. This combination represents an effective strategy for the treatment of TNBC.

Citation Format: Shawn F. Johnson, Neil Johnson, David Chi, Benjamin Primack, Alan D. D'Andrea, Elgene Lim, Geoffrey I. Shapiro. The CDK inhibitor dinaciclib sensitizes triple-negative breast cancer cells to PARP inhibition. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1788. doi:10.1158/1538-7445.AM2013-1788

Molecular cytogenetic analysis of wheat – Elymus repens introgression lines with resistance to Fusarium head blight

Elymus repens (L.) Gould (2n = 6x = 42, StStStStHH) is a hexaploid perennial wheatgrass species from the tribe Triticeae, distantly related to bread wheat Triticum aestivum L. (2n = 6x = 42, AABBDD). As a potential source of resistance to Fusarium head blight (FHB), E. repens was crossed to common wheat to transfer resistance genes. The progeny were advanced to homozygosity by single seed descent. A total of eight BC1F9 progeny lines were selected and characterized in this study. The chromosome numbers of these derived lines ranged from 42 to 56, including lines with 44, 52, and 54 chromosomes. All of the lines were cytologically stable in terms of meiotic chromosome behavior. The univalent frequency in the lines varied between 0.34 and 2.36 per cell. Similarly, the multivalent frequency did not exceed 1% in any of the lines. GISH analysis revealed that the number of intact wheat chromosomes in the various lines varied between 40 and 44. Numerous translocated chromosomes were detected in all lines. The translocations involved chromosomal segments from wheat, and the St and H genomes of E. repens. Furthermore, trigenomic translocated chromosomes were detected in some of the lines. The introgression into wheat chromosomes included not only terminal types but also interstitial segments. The Fusarium head blight resistance of the eight lines, following point inoculation, varied from 5.65% infected florets to 11.46% compared with the check cultivars T. aestivum ‘Roblin’ and T. aestivum ‘Crocus’ at 100% and 85%, respectively.

Abstract PD01-08: Differences in estrogen receptor signaling in non-malignant primary ER-positive breast epithelial cells and breast cancer

Background: The estrogen receptor (ER) is expressed in ∼70% of sporadic breast cancer and activates genes driving cell proliferation and tumorigenesis. We have previously performed genome-wide analysis of ER binding sites in MCF-7 breast cancer cells, and identified distinct mechanisms of ER signaling. We have also previously used EpCAM and CD49f as markers to enrich for viable ER-positive (ER+) cells obtained from non malignant breast tissue. Here, we seek to elucidate differences in ER signaling between non-malignant and ER+ breast cancer cells.

Methods: Primary breast epithelial cells were obtained from patients undergoing reduction mammoplasties and surgical excision of ER+ breast cancer. After dissociation of breast reductions into a single-cell suspension, ER+ mature luminal (ML; EpCAM+CD49f−) and luminal progenitor (LP; EpCAM+CD49f+) subpopulations were obtained by flow cytometry. Following estrogen stimulation, RNA was extracted for gene microarray analysis. ER chromatin immunoprecipitation and DNA sequencing (ChIP-seq) was performed. These results were compared to MCF-7 breast cancer cells.

Results: Reduction mammoplasty and ER+ breast cancer tissues were analyzed, and compared to MCF-7 cells. Gene expression profiles were different between non-malignant tissue and ER+ breast cancer cells following estrogen stimulation, with a 2–3 fold higher number of ER regulated genes in ER+ breast cancer compared to ER+ non malignant cells, and few overlapping estrogen regulated genes. Genes that promotes cell cycling and cell proliferation were downregulated in non-malignant tissue, but were upregulated in breast cancer cells (P < 10–5). CYP1A1, a major estradiol metabolizing enzyme, was upregulated in normal cells but downregulated in ER+ breast cancer cells. Motif analysis of ER ChIP-seq data in normal and ER+ breast cancer tissues demonstrated an enrichment of ER motifs in the overlapping sites and an enrichment of FOXA1 motifs in ER+ breast cancer cells and TCF12 motifs in non-malignant ER+ epithelial cells.

Conclusions: There are contrasting differences in ER signaling between normal mammary and breast cancer cells, with estrogen having anti-proliferative effects in normal luminal cells compared to pro-proliferative effects in breast cancer. ER ChIP-Seq has identified TCF12 as a major co-factor in non-malignant breast tissue whilst FOXA1 is a major co-factor in ER+ breast cancer. Our data provides evidence for key alterations in ER-signaling during tumorigenesis, and identifies potential mechanisms to target cancer specific ER signaling.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD01-08.

Patterns of injury and otolaryngology intervention in pediatric neck trauma

BACKGROUND

Neck trauma in the pediatric population is relatively rare with limited discussion in the literature describing the injury patterns and outcomes of all neck trauma victims. This study characterizes pediatric neck trauma both inside and outside the context of injuries requiring otolaryngology (ENT) intervention.

METHODS

Patients sustaining neck trauma presenting to a single tertiary care hospital between January 2001 and June 2010 were included. Demographic information was obtained in addition to information regarding the initial hospital stay and follow up visits related to the initial trauma.

RESULTS

Seventy-four patients were included. Blunt injuries were found in 44 children with 30 sustaining penetrating injuries. Twenty-eight percent of patients had an ENT consultation. Those patients with injuries warranting ENT consultation were nearly 3 times more likely to require intubation than those without an ENT consultation (p=0.009). Laryngotracheal injuries were documented in 11 patients with 6 of these characterized as major injuries and 5 minor injuries.

CONCLUSION

Pediatric neck trauma represents a spectrum of injuries from ecchymosis to major laryngotracheal injury. Otolaryngology involvement is not necessary in all cases; however, one must be aware of the risk of laryngotracheal injury, particularly with blunt trauma and there should be a low threshold for Otolaryngology consultation and endoscopy.

Single-protein nanomechanical mass spectrometry in real time

Nanoelectromechanical systems (NEMS) resonators can detect mass with exceptional sensitivity. Previously, mass spectra from several hundred adsorption events were assembled in NEMS-based mass spectrometry using statistical analysis. Here, we report the first realization of single-molecule NEMS-based mass spectrometry in real time. As each molecule in the sample adsorbs on the resonator, its mass and position of adsorption are determined by continuously tracking two driven vibrational modes of the device. We demonstrate the potential of multimode NEMS-based mass spectrometry by analysing IgM antibody complexes in real time. NEMS-based mass spectrometry is a unique and promising new form of mass spectrometry: it can resolve neutral species, provide a resolving power that increases markedly for very large masses, and allow the acquisition of spectra, molecule-by-molecule, in real time.

CT vs MRI to Evaluate Hearing Loss in Children

Objective: 1) To report the findings of both computed tomography (CT) and magnetic resonance imaging (MRI) in children with hearing loss. 2) To find if there is a significant difference between these 2 radiographic modalities and between hearing loss groups.

Method: Retrospective review of 120 children diagnosed with sensorineural hearing loss from 2005 to 2011 with both CT and MRI at a tertiary care center. Patients were divided into an asymmetric vs symmetric population and a mild/moderate hearing loss vs severe/profound hearing loss group. Radiographic findings were obtained via chart review.

Results: Asymmetric hearing loss was found in 55% of patients, while 45% had symmetric loss. Group 1 (mild and moderate loss) accounted for 60%,while group 2 (severe and profound loss) was found in 40% of patients. More abnormalities were found in the asymmetric compared to symmetric population on both CT ( P = .0001) and MRI ( P = .02). A significant difference was noted between the number of anomalies in group 2 vs group 1 hearing loss on the MRI ( P = .0002), but not CT ( P = .19). No significant difference was found between MRI and CT within any of the groups.

Conclusion: Both radiographic tests found more abnormalities in the asymmetric population. Only MRI found more abnormalities in group 2 vs group 1 with statistical significance. The decision to use CT vs MRI remains controversial because they are complementary. However, obtaining an MRI in severe and profound hearing loss may be beneficial.

Estrogen receptor (ER) signaling in normal, BRCA (B) 1 and B2 mutation associated, and ER-positive breast cancer (BC) mammary cells

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Background: ER is expressed in ≈70% of sporadic BC and activates genes driving cell proliferation and tumorigenesis. B1 and B2 mutation associated BC have predominant triple negative and ER+ phenotypes respectively, yet hormonal manipulation with oophorectomy reduces BC risk in both B1 and B2 carriers. We have previously performed genome-wide analysis of ER binding sites in MCF-7 BC cells, and identified distinct mechanisms of ER signaling. Here, we seek to elucidate differences in ER signaling between non-malignant (normal, B1 and B2) and ER+ BC mammary cells. Methods: Breast tissue were obtained from patients undergoing reduction mammoplasties (normal), prophylactic mastectomies (B1 and B2 carriers) and surgical excision of ER+ BC. After dissociation into a single-cell suspension, ER+ EpCAM+CD49f- mature luminal (ML) and EpCAM+CD49f+ luminal progenitor (LP) subpopulations were obtained by flow cytometry. Following estrogen stimulation, RNA was extracted for gene microarray analysis. ER chromatin immunoprecipitation and DNA sequencing (ChIP-seq) was performed and DNA libraries prepared and sequenced. Results: Triplicates ofnormal, prophylactic B1 and B2, and ER+ BC tissues were analyzed.Gene ontology analysis indicates different gene expression signatures between non-malignant tissue and MCF-7 BC cells following estrogen stimulation. Genes that promotes cell cycling and proliferation were downregulated in non-malignant tissue, but were upregulated in BC cells (P < 10-5). Hierarchical clustering of the gene microarray by mutation status revealed distinct LP gene signatures in normal, B1 and B2 breast tissue, whilst the ML signatures were largely indistinguishable between the three tissue types. Conclusions: There are contrasting differences in ER signaling between normal mammary and BC cells, with estrogen having anti-proliferative effects in normal luminal cells compared to pro-proliferative effects in BC. Our data suggest that alterations in ER signaling play a major role in breast tumorigenesis. Differences in the LP population between B1 and B2 breast tissue may account for their distinct BC phenotypes.