Options for coronary translocation and other considerations in aortic root translocation (Bex-Nikaidoh procedure)

Introduction: The surgical options for patients with transposition of the great arteries (TGA), ventricular septal defect (VSD), and left ventricular outflow tract obstruction include intracardiac baffling with the right ventricle to pulmonary artery (PA) conduit (Rastelli procedure), 'reparation a l'etage ventriculaire' or aortic root translocation (Bex-Nikaidoh procedure). The Bex-Nikaidoh procedure allows a more normal, anatomically aligned left ventricular outflow tract. However, the operation is technically demanding, and coronary translocation remains one of the major challenges for successful root translocation. Methods: All patients who underwent aortic root translocation in a single institute over a period of 2 years from January 2015 to December 2017 were included in the study. Surgical technique and early outcomes are described with specific focus on the different observed coronary artery patterns and surgical strategies for translocation. Results: Fourteen patients underwent aortic root translocation. The coronary artery patterns observed could be categorized into four different patterns based on the size of the pulmonary annulus and the relative position of the PA relative to the aorta. Successful translocation of the coronary arteries was achieved in every patient. Mean follow-up was 18.42 ± 9.22 months. There was no mortality and no reoperation during the follow-up period. Conclusion: The Bex-Nikaidoh procedure is a promising surgical option for TGA, VSD, and pulmonary stenosis. Good outcomes are achievable despite wide variations in anatomy using a tailored approach for coronary translocation

Tumor Derived Mutations of Protein Tyrosine Phosphatase Receptor Type K Affect Its Function and Alter Sensitivity to Chemotherapeutics in Glioma

<div><p>Poor prognosis and resistance to therapy in malignant gliomas is mainly due to the highly dispersive nature of glioma cells. This dispersive characteristic results from genetic alterations in key regulators of cell migration and diffusion. A better understanding of these regulatory signals holds promise to improve overall survival and response to therapy. Using mapping arrays to screen for genomic alterations in gliomas, we recently identified alterations of the protein tyrosine phosphatase receptor type kappa gene (PTPRK) that correlate to patient outcomes. These PTPRK alterations are very relevant to glioma biology as PTPRK can directly sense cell–cell contact and is a dephosphorylation regulator of tyrosine phosphorylation signaling, which is a major driving force behind tumor development and progression. Subsequent sequencing of the full length PTPRK transcripts revealed novel PTPRK gene deletion and missense mutations in numerous glioma biopsies. PTPRK mutations were cloned and expressed in PTPRK-null malignant glioma cells. The effect of these mutations on PTPRK anti-oncogenic function and their association with response to anti-glioma therapeutics, such as temozolomide and tyrosine kinase inhibitors, was subsequently analyzed using <i>in vitro</i> cell-based assays. These genetic variations altered PTPRK activity and its post-translational processing. Reconstitution of wild-type PTPRK in malignant glioma cell lines suppressed cell growth and migration by inhibiting EGFR and β-catenin signaling and improved the effect of conventional therapies for glioma. However, PTPRK mutations abrogated tumor suppressive effects of wild-type PTPRK and altered sensitivity of glioma cells to chemotherapy.</p></div

NOTCH3 Is a Prognostic Factor That Promotes Glioma Cell Proliferation, Migration and Invasion via Activation of CCND1 and EGFR

<div><p>Using a GWA analysis of a comprehensive glioma specimen population, we identified whole gain of chromosome 19 as one of the major chromosomal aberrations that correlates to patients’ outcomes. Our analysis of significant loci revealed for the first time NOTCH3 as one of the most significant amplification. NOTCH3 amplification is associated with worse outcome compared to tumors with non-amplified locus. NOTCH receptors (NOTCH1-4) are key positive regulators of cell-cell interactions, angiogenesis, cell adhesion and stem cell niche development which have been shown to play critical roles in several human cancers. Our objective is to determine the molecular roles of NOTCH3 in glioma pathogenesis and aggressiveness. Here we show for the first time that NOTCH3 plays a major role in glioma cell proliferation, cell migration, invasion and apoptosis. Therefore, our study uncovers the prognostic value and the oncogenic function of NOTCH3 in gliomagenesis and supports NOTCH3 as a promising target of therapy in high grade glioma. Our studies allowed the identification of a subset of population that may benefit from GSI- or anti-NOTCH3- based therapies. This may lead to the design of novel strategies to improve therapeutic outcome of patients with glioma by establishing medical and scientific basis for personalized chemotherapies.</p></div

NOTCH3 knockdown in U87-MG and U251-MG cells reduced expression of NOTCH3 and its target.

<p>(<b>A</b>) Western blot of U87-MG and U251-MG cells showing silencing of NOTCH3 protein expression at both full length and cleaved forms following shRNA treatment. GAPDH was used as loading control. (<b>B</b>) Quantitative-real time PCR showing downregulation of NOTCH3 transcripts and several of its known targets in U87-MG and U251-MG cells following shRNA knockdown. *indicates p<0.05, **indicates p<0.01 and **indicates p<0.001 (ANOVA and Tukey’s multiple comparison test).</p

NOTCH3 knockdown in U87-MG cells represses glioma cells growth and hinders cell migration and invasion.

<p>(<b>A</b>) Cell viabilities of U87-MG and U251-MG cells following NOTCH3 knockdown were determined using MTT assay. The data represent mean ± SE of three independent experiments performed in triplicate. (<b>B</b>) Growth curves U87-MG and (<b>C</b>) U251-MG cells resulting from specific NOTCH3 knockdown were monitored with crystal violet staining at indicated time points. The results are plotted as the average growth (A_540nm) ± SE of three independent experiments. (<b>D</b>) Colony formation ability of glioma cells was determined with soft agar colony formation assay. Data represent mean ± SE of three independent experiments. (<b>E</b>) Wound healing assay for U87-MG cells. ImageJ software was used to measure changes in cell migration per time in U87-MG cells transduced with sh235 (N = 20) or control (N = 23) lentivirus. Results are expressed as relative migration to the baseline. (<b>F</b>) Matrigel cell invasion assay. U87-MG cells expressing sh235 or scrambled control lentivirus were seeded into the upper chamber of the matrigel coated transwells. Invasive cells were stained with crystal violet, photographed under an inverted light microscope and quantified using ImageJ software in four representative fields. *indicates p<0.05, **indicates p<0.01 and **indicates p<0.001 (ANOVA and Tukey’s multiple comparison test).</p

Identification of Different Classes of Luminal Progenitor Cells within Prostate Tumors

Primary prostate cancer almost always has a luminal phenotype. However, little is known about the stem/progenitor properties of transformed cells within tumors. Using the aggressive Pten/Tp53-null mouse model of prostate cancer, we show that two classes of luminal progenitors exist within a tumor. Not only did tumors contain previously described multipotent progenitors, but also a major population of committed luminal progenitors. Luminal cells, sorted directly from tumors or grown as organoids, initiated tumors of adenocarcinoma or multilineage histological phenotypes, which is consistent with luminal and multipotent differentiation potentials, respectively. Moreover, using organoids we show that the ability of luminal-committed progenitors to self-renew is a tumor-specific property, absent in benign luminal cells. Finally, a significant fraction of luminal progenitors survived in vivo castration. In all, these data reveal two luminal tumor populations with different stem/progenitor cell capacities, providing insight into prostate cancer cells that initiate tumors and can influence treatment response

Identification of Different Classes of Luminal Progenitor Cells within Prostate Tumors

Primary prostate cancer almost always has a luminal phenotype. However, little is known about the stem/progenitor properties of transformed cells within tumors. Using the aggressive Pten/Tp53-null mouse model of prostate cancer, we show that two classes of luminal progenitors exist within a tumor. Not only did tumors contain previously described multipotent progenitors, but also a major population of committed luminal progenitors. Luminal cells, sorted directly from tumors or grown as organoids, initiated tumors of adenocarcinoma or multilineage histological phenotypes, which is consistent with luminal and multipotent differentiation potentials, respectively. Moreover, using organoids we show that the ability of luminal-committed progenitors to self-renew is a tumor-specific property, absent in benign luminal cells. Finally, a significant fraction of luminal progenitors survived in vivo castration. In all, these data reveal two luminal tumor populations with different stem/progenitor cell capacities, providing insight into prostate cancer cells that initiate tumors and can influence treatment response