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Biomedical subjects

Meredith S Irwin

Publications and source records attributed to Meredith S Irwin.

3 recordsLinked to original sources

Factors Impacting Overall Survival Post-Relapse in High-Risk Neuroblastoma: Children's Oncology Group Outcomes From 2000 to 2019.

PURPOSE: Prior studies of features impacting post-relapse survival in high-risk neuroblastoma (HRNB) evaluated patient cohorts that did not receive contemporary high-risk or relapse therapies. We describe overall survival (OS) after first progression or first relapse of HRNB in a modern cohort. METHODS: Patients with HRNB enrolled on COG ANBL00B1(NCT00904241) between 2000 and 2019, who had relapsed or progressive disease were eligible. Clinical and molecular risk factors at diagnosis, therapy era, clinical trial enrollment, and clinical features at relapse, including site of and time to relapse, were evaluated. OS post-relapse was compared between groups using log-rank tests and Cox models. RESULTS: Among 4253 eligible HRNB patients, 1616 had relapse or progression as a first event. Five-year OS post-relapse was 19.1&#xa0;&#xb1;&#xa0;1.1%. The risk group with the lowest post-relapse survival was observed in patients with INSS Stage 4 or 4S disease <&#xa0;18 months of age at diagnosis with MYCN amplified (MYCN-A) tumors. The other significant most unfavorable factors at diagnosis included diagnosis 2000-2004, tumor MYCN-A, 1p loss of heterozygosity (LOH), and elevated LDH or ferritin. Unfavorable factors at relapse included the time to relapse <&#xa0;36 months from diagnosis, and combined local and metastatic disease at relapse. Multivariable analysis indicated that those with tumors harboring 1p LOH, age &#x2264;&#xa0;5 years at diagnosis, or earlier treatment therapy era (2000-2004) had a higher risk of post-relapse death. CONCLUSIONS: While the 5-year OS rate was low in this cohort, there are subsets of patients with relapsed HRNB who demonstrate long-term survival. TRIALS REGISTRATION: ClinicalTrials.gov identifier: NCT00904241.

Humans↗

Akt phosphorylates the Yes-associated protein, YAP, to induce interaction with 14-3-3 and attenuation of p73-mediated apoptosis.

We have used an affinity purification method to identify substrates of protein kinase B/Akt. One protein that associates with 14-3-3 in an Akt-dependent manner is shown here to be the Yes-associated protein (YAP), which is phosphorylated by Akt at serine 127, leading to binding to 14-3-3. Akt promotes YAP localization to the cytoplasm, resulting in loss from the nucleus where it functions as a coactivator of transcription factors including p73. p73-mediated induction of Bax expression following DNA damage requires YAP function and is attenuated by Akt phosphorylation of YAP. YAP overexpression increases, while YAP depletion decreases, p73-mediated apoptosis following DNA damage, in an Akt inhibitable manner. Akt phosphorylation of YAP may thus suppress the induction of the proapoptotic gene expression response following cellular damage.

14-3-3 Proteins↗

Chemosensitivity linked to p73 function.

Most chemotherapeutic agents induce DNA damage, leading to p53 accumulation and apoptosis. The factors that determine chemosensitivity in p53-defective tumor cells are poorly understood. We found that the p53 family member p73 is induced by a wide variety of chemotherapeutic drugs. Blocking p73 function with a dominant-negative mutant, siRNA, or homologous recombination led to chemoresistance of human tumor cells and engineered transformed cells, irrespective of p53 status. Mutant p53 can inactivate p73 and downregulation of mutant p53 enhanced chemosensitivity. These findings indicate that p73 is a determinant of chemotherapeutic efficacy in humans.

Animals↗