Medicine and Health Sciences Commons^™

Lysosomal Lipid Peroxidation Regulates Tumor Immunity, Monika Bhardwaj, Jennifer J Lee, Amanda M Versace, Sandra L Harper, Aaron R Goldman, Mary Ann S Crissey, Vaibhav Jain, Mahendra Pal Singh, Megane Vernon, Andrew E. Aplin, Seokwoo Lee, Masao Morita, Jeffrey D Winkler, Qin Liu, David W Speicher, Ravi K Amaravadi

Department of Surgery Faculty Papers

Lysosomal inhibition elicited by palmitoyl-protein thioesterase 1 (PPT1) inhibitors such as DC661 can produce cell death, but the mechanism for this is not completely understood. Programmed cell death pathways (autophagy, apoptosis, necroptosis, ferroptosis, and pyroptosis) were not required to achieve the cytotoxic effect of DC661. Inhibition of cathepsins, or iron or calcium chelation, did not rescue DC661-induced cytotoxicity. PPT1 inhibition induced lysosomal lipid peroxidation (LLP), which led to lysosomal membrane permeabilization and cell death that could be reversed by the antioxidant N-acetylcysteine (NAC) but not by other lipid peroxidation antioxidants. The lysosomal cysteine transporter MFSD12 was required for intralysosomal transport …

Advanced-Stage Melanoma At Presentation Following The Peak Of The Pandemic: A Covid-19 Cancer Canary In A Coal Mine, Ryan Lamm, Md, Walker Lyons, Md, Winnie So, Rn, Alliric I. Willis, Md, Facs, Msph

Department of Surgery Faculty Papers

Background: For melanoma patients, timely identification and tumor thickness are directly correlated with outcomes. COVID-19 impacted both patients' ability and desire to see physicians. We sought to identify whether the pandemic correlated with changes in melanoma thickness at presentation and subsequent treatment timeline.

Methods: Retrospective chart review was performed on patients who underwent surgery for melanoma in an academic center surgical oncology practice from May 2019 to September 2021. Patients were split into two cohorts: "pre-pandemic" from May 2019 to May 2020 and "pandemic," after May 2020, representing when these patients received their initial diagnostic biopsy. Demographic and melanoma-specific variables …

Posttranscriptional Regulation Of Parg Mrna By Hur Facilitates Dna Repair And Resistance To Parp Inhibitors, Saswati N. Chand, Mahsa Zarei, M. J. Schiewer, Akshay R. Sanan, Carmella Romeo, Shruti Lal, Joseph A. Cozzitorto, Avinoam Nevler, Laura Scolaro, Eric R. Londin, Wei Jiang, Nicole Meisner-Kober, Michael J. Pishvaian, Karen E. Knudsen, Charles Yeo, John M Pascal, Jordan M. Winter, Jonathan R. Brody

Department of Surgery Faculty Papers

The majority of pancreatic ductal adenocarcinomas (PDAC) rely on the mRNA stability factor HuR (ELAV-L1) to drive cancer growth and progression. Here, we show that CRISPR-Cas9–mediated silencing of the HuR locus increases the relative sensitivity of PDAC cells to PARP inhibitors (PARPi). PDAC cells treated with PARPi stimulated translocation of HuR from the nucleus to the cytoplasm, specifically promoting stabilization of a new target, poly (ADP-ribose) glycohydrolase (PARG) mRNA, by binding a unique sequence embedded in its 3⁰ untranslated region. HuR-dependent upregulation of PARG expression facilitated DNA repair via hydrolysis of polyADP-ribose on related repair proteins. Accordingly, strategies to …

Crispr Knockout Of The Hur Gene Causes A Xenograft Lethal Phenotype., Shruti Lal, Edwin C, Cheung, Mahsa Zarei, Ranjan Preet, Saswati N. Chand, Nicole C. Mambelli-Lisboa, Carmella Romeo, Matthew C. Stout, Eric Londin, Austin Goetz, Cinthya Y. Lowder, Avinoam Nevler, Charles Yeo, Paul M. Campbell, Jordan M. Winter, Dan A. Dixon, Jonathan Brody

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDA) is the third leading cause of cancer-related deaths in the United States, whereas colorectal cancer is the third most common cancer. The RNA-binding protein HuR (ELAVL1) supports a pro-oncogenic network in gastrointestinal (GI) cancer cells through enhanced HuR expression. Using a publically available database, HuR expression levels were determined to be increased in primary PDA and colorectal cancer tumor cohorts as compared with normal pancreas and colon tissues, respectively. CRISPR/Cas9 technology was successfully used to delete the HuR gene in both PDA (MIA PaCa-2 and Hs 766T) and colorectal cancer (HCT116) cell lines. HuR deficiency has …

Enos Transfection Of Adipose-Derived Stem Cells Yields Bioactive Nitric Oxide Production And Improved Results In Vascular Tissue Engineering., Stephen Mcilhenny, Ping Zhang, Thomas Tulenko, Jason Comeau, Sarah Fernandez, Aleksandra Policha, Matthew Ferroni, Elizabeth J Faul, Gabor Bagameri, Irving Shapiro, Paul J. Dimuzio

Department of Surgery Faculty Papers

This study evaluates the durability of a novel tissue engineered blood vessel (TEBV) created by seeding a natural vascular tissue scaffold (decellularized human saphenous vein allograft) with autologous adipose-derived stem cells (ASC) differentiated into endothelial-like cells. Previous work with this model revealed the graft to be thrombogenic, likely due to inadequate endothelial differentiation as evidenced by minimal production of nitric oxide (NO). To evaluate the importance of NO expression by the seeded cells, we created TEBV using autologous ASC transfected with the endothelial nitric oxide synthase (eNOS) gene to produce NO. We found that transfected ASC produced NO at levels …

Peritoneal Perfusion With Oxygenated Perfluorocarbon Augments Systemic Oxygenation., Shamus R Carr, Joshua P Cantor, Atul S Rao, Thiru V Lakshman, Joshua E Collins, Joseph S Friedberg

Department of Surgery Faculty Papers

BACKGROUND: Despite maximal ventilatory support, many patients die from hypoxia in the setting of potentially reversible pulmonary failure. There remains a pressing need for additional pulmonary supportive care measures, especially techniques that do not require systemic anticoagulation. The objective of our experiments was to determine whether systemic oxygenation could be increased in a large animal, with induced hypoxia, by perfusing the abdominal cavity with oxygenated perfluorocarbons.

METHODS: Fifteen pigs with a mean (+/- SD) weight of 45 +/- 5 kg were intubated and rendered hypoxic by ventilating them with a blend of nitrogen and oxygen to achieve subatmospheric concentrations of …