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Waste is endemic in the U.S. health care system. Operating rooms are a source of significant solid waste. Surgeons are integral to many decisions in the operating room.Online survey of surgeons at 2 major academic centers in the United States assessing perspectives on intraoperative waste and willingness to work to actively reduce intraoperative waste.We received responses from 219 surgeons: 90% agreed or strongly agreed that waste of sterile surgical items is an issue, and 95% agreed or strongly agreed to a willingness to change the operating room workflow to reduce waste. Surgeons estimated 26% of single-use, sterile supplies opened for surgery were unused at the end of the case. The barriers to waste reduction cited most frequently were: (1) lack of awareness of waste, (2) lack of concern for waste, and (3) lack of time to address the waste.Surgeons understand there is significant waste in the operating room and are willing to change their workflow to reduce waste. Changes in operating room practices that reduce waste will be beneficial to health systems' finances and their efforts to improve population health through a reduction in consumption and pollution. Efforts should be directed toward reducing operating room waste with an initial focus on the elimination of unnecessary waste of sterile surgical supplies. Further work is needed to determine the precise sources of perioperative waste and what initiatives can be implemented to reduce this burden while maintaining high-value patient care.

Extrachromosomal circular DNA (eccDNA) are present within all eukaryotic organisms and actively contribute to gene expression changes. MicroDNA (200-1000bp) are the most abundant type of eccDNA and can amplify tRNA, microRNA, and novel si-like RNA sequences. Due to the heterogeneity of microDNA and the limited technology to directly quantify circular DNA molecules, the specific DNA repair pathways that contribute to microDNA formation have not been fully elucidated. Using a sensitive and quantitative assay that quantifies eight known abundant microDNA, we report that microDNA levels are dependent on resection after double-strand DNA break (DSB) and repair by Microhomology Mediated End Joining (MMEJ). Further, repair of DSB without resection by canonical Non-Homologous End Joining (c-NHEJ) diminishes microDNA formation. MicroDNA levels are induced locally even by a single site-directed DSB, suggesting that excision of genomic DNA by two closely spaced DSB is not necessary for microDNA formation. Consistent with all this, microDNA levels accumulate as cells undergo replication in S-phase, when DNA breaks and repair are elevated, and microDNA levels are decreased if DNA synthesis is prevented. Thus, formation of microDNA occurs during the repair of endogenous or induced DNA breaks by resection-based DNA repair pathways.

Extrachromosomal circular DNAs (eccDNA) are widespread in normal and cancer cells and are known to amplify oncogenic genes. However, the mechanisms that form eccDNA have never been fully elucidated due to the complex interactions of DNA repair pathways and lack of a method to quantify eccDNA abundance. Through the development of a sensitive and quantitative assay for eccDNA we show that the formation of eccDNA is through resection dependent repair of double-strand DNA breaks, especially micro-homology mediated end joining, and through mismatch repair. The most significant decreases in eccDNA levels occurred in cells lacking PARP1, POLQ, NBS1, RAD54, and FAN1. Further, a significant increase in eccDNA occurred in cells lacking c-NHEJ proteins DNA-PKcs, XRCC4, XLF, LIG4 and 53BP1. This suggests that when alt-NHEJ pathways are utilized to repair DNA breaks by necessity, the formation of eccDNA is increased. Induced and site-directed double-strand DNA breaks increase eccDNA formation, even from a single break. Additionally, we find that eccDNA levels accumulate as cells undergo replication in S-phase and that levels of eccDNA are decreased if DNA synthesis is prevented. Together, these results show that the bulk of eccDNA form by resection based alt-NHEJ pathways, especially during DNA replication and the repair of double-strand breaks.

// Kimberly Mayes 1 , Zeinab Elsayed 1 , Aiman Alhazmi 1 , Michael Waters 2 , Suehyb G. Alkhatib 1 , Mark Roberts 1 , Carolyn Song 1 , Kristen Peterson 1 , Vivian Chan 1 , Nikhil Ailaney 1 , Pumoli Malapati 1 , Tana Blevins 3 , Berislav Lisnic 4 , Catherine I. Dumur 3 and Joseph W. Landry 1 1 The Department of Human and Molecular Genetics, Virginia Institute of Molecular Medicine, Massey Cancer Center, Virginia Commonwealth University, Richmond, Virginia 23298, USA 2 The Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia 23298, USA 3 The Department of Pathology, Virginia Commonwealth University, Richmond, Virginia 23298, USA 4 The Center for Proteomics and Department for Histology and Embryology, University of Rijeka, Faculty of Medicine, 51000 Rijeka, Croatia Correspondence to: Joseph W. Landry, email: joseph.landry@vcuhealth.org Keywords: BPTF, chromatin remodeling, antitumor immunity, NK cell, heparanase Received: January 31, 2017 Accepted: April 26, 2017 Published: May 12, 2017 ABSTRACT Using syngeneic BALB/c mouse breast cancer models, we show that the chromatin remodeling subunit bromodomain PHD finger transcription factor (BPTF) suppresses natural killer (NK) cell antitumor activity in the tumor microenvironment (TME). In culture, BPTF suppresses direct natural cytotoxicity receptor (NCR) mediated NK cell cytolytic activity to mouse and human cancer cell lines, demonstrating conserved functions. Blocking mouse NCR1 in vivo rescues BPTF KD tumor weights, demonstrating its importance for the control of tumor growth. We discovered that BPTF occupies heparanase ( Hpse ) regulatory elements, activating its expression. Increased heparanase activity results in reduced cell surface abundance of the NCR co-ligands: heparan sulfate proteoglycans (HSPGs). Using gain and loss of function approaches we show that elevated heparanase levels suppress NK cell cytolytic activity to tumor cells in culture. These results suggest that BPTF activates heparanase expression, which in turn reduces cell surface HSPGs and NCR co-ligands, inhibiting NK cell activity. Furthermore, gene expression data from human breast cancer tumors shows that elevated BPTF expression correlates with reduced antitumor immune cell signatures, supporting conserved roles for BPTF in suppressing antitumor immunity. Conditional BPTF depletion in established mouse breast tumors enhances antitumor immunity, suggesting that inhibiting BPTF could provide a novel immunotherapy.

Using syngeneic BALB/c mouse breast cancer models, we show that the chromatin remodeling subunit bromodomain PHD finger transcription factor (BPTF) suppresses natural killer (NK) cell antitumor activity in the tumor microenvironment (TME). In culture, BPTF suppresses direct natural cytotoxicity receptor (NCR) mediated NK cell cytolytic activity to mouse and human cancer cell lines, demonstrating conserved functions. Blocking mouse NCR1 in vivo rescues BPTF KD tumor weights, demonstrating its importance for the control of tumor growth. We discovered that BPTF occupies heparanase (Hpse) regulatory elements, activating its expression. Increased heparanase activity results in reduced cell surface abundance of the NCR co-ligands: heparan sulfate proteoglycans (HSPGs). Using gain and loss of function approaches we show that elevated heparanase levels suppress NK cell cytolytic activity to tumor cells in culture. These results suggest that BPTF activates heparanase expression, which in turn reduces cell surface HSPGs and NCR co-ligands, inhibiting NK cell activity. Furthermore, gene expression data from human breast cancer tumors shows that elevated BPTF expression correlates with reduced antitumor immune cell signatures, supporting conserved roles for BPTF in suppressing antitumor immunity. Conditional BPTF depletion in established mouse breast tumors enhances antitumor immunity, suggesting that inhibiting BPTF could provide a novel immunotherapy. Citation Format: Kimberly Mayes, Zeinab Elsayed, Aiman Alhazmi, Michael Waters, Suehyb Alkhatib, Mark Roberts, Carolyn Song, Kristen Peterson, Vivian Chan, Nikhil Ailaney, Pumoli Malapati, Tana Blevins, Berislav Lisnic, Catherine Dumur, Joseph Landry. Tumor cell intrinsic BPTF inhibits NK cell activity and the abundance of natural cytotoxicity receptor co-ligands [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A28.