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ImportanceDespite similar histologic appearance among high-grade serous ovarian cancers (HGSOCs), clinical observations suggest vast differences in gross appearance. There is currently no systematic framework by which to classify HGSOCs according to their gross morphologic characteristics.ObjectiveTo develop and characterize a gross morphologic classification system for HGSOC.Design, Setting, and ParticipantsThis cohort study included patients with suspected advanced-stage ovarian cancer who presented between April 1, 2013, and August 5, 2016, to the University of Texas MD Anderson Cancer Center, a large referral center. Patients underwent laparoscopic assessment of disease burden before treatment and received a histopathologic diagnosis of HGSOC. Researchers assigning morphologic subtype and performing molecular analyses were blinded to clinical outcomes. Data analysis was performed between April 2020 and November 2021.ExposuresGross tumor morphologic characteristics.Main Outcomes and MeasuresClinical outcomes and multiomic profiles of representative tumor samples of type I or type II morphologic subtypes were compared.ResultsOf 112 women (mean [SD] age 62.7 [9.7] years) included in the study, most patients (84% [94]) exhibited a predominant morphologic subtype and many (63% [71]) had a uniform morphologic subtype at all involved sites. Compared with those with uniform type I morphologic subtype, patients with uniform type II morphologic subtype were more likely to have a favorable Fagotti score (83% [19 of 23] vs 46% [22 of 48]; P = .004) and thus to be triaged to primary tumor reductive surgery. Similarly, patients with uniform type II morphologic subtype also had significantly higher mean (SD) estimated blood loss (639 [559; 95% CI, 391-887] mL vs 415 [527; 95% CI, 253-577] mL; P = .006) and longer mean (SD) operative time (408 [130; 95% CI, 350-466] minutes vs 333 [113; 95% CI, 298-367] minutes; P = .03) during tumor reductive surgery. Type I tumors had enrichment of epithelial-mesenchymal transition (false discovery rate [FDR] q-value, 3.10 × 10−24), hypoxia (FDR q-value, 1.52 × 10−5), and angiogenesis pathways (FDR q-value, 2.11 × 10−2), whereas type II tumors had enrichment of pathways related to MYC signaling (FDR q-value, 2.04 × 10−9) and cell cycle progression (FDR q-value, 1.10 × 10−5) by integrated proteomic and transcriptomic analysis. Abundances of metabolites and lipids also differed between the 2 morphologic subtypes.Conclusions and RelevanceThis study identified 2 novel, gross morphologic subtypes of HGSOC, each with unique clinical features and molecular signatures. The findings may have implications for triaging patients to surgery or chemotherapy, identifying outcomes, and developing tailored therapeutic strategies.

Background: The incidence of venous thromboembolism (VTE) in patients with ovarian cancer is higher than most solid tumors, ranging between 10–30%, and a diagnosis of VTE in this patient population is associated with worse oncologic outcomes. The tumor-specific molecular factors that may lead to the development of VTE are not well understood. Objectives: The aim of this study was to identify molecular features present in ovarian tumors of patients with VTE compared to those without. Methods: We performed a multiplatform omics analysis incorporating RNA and DNA sequencing, quantitative proteomics, as well as immune cell profiling of high-grade serous ovarian carcinoma (HGSC) samples from a cohort of 32 patients with or without VTE. Results: Pathway analyses revealed upregulation of both inflammatory and coagulation pathways in the VTE group. While DNA whole-exome sequencing failed to identify significant coding alterations between the groups, the results of an integrated proteomic and RNA sequencing analysis indicated that there is a relationship between VTE and the expression of platelet-derived growth factor subunit B (PDGFB) and extracellular proteins in tumor cells, namely collagens, that are correlated with the formation of thrombosis. Conclusions: In this comprehensive analysis of HGSC tumor tissues from patients with and without VTE, we identified markers unique to the VTE group that could contribute to development of thrombosis. Our findings provide additional insights into the molecular alterations underlying the development of VTE in ovarian cancer patients and invite further investigation into potential predictive biomarkers of VTE in ovarian cancer.

Objectives We aimed to compare clinical and survival outcomes in high grade ovarian cancer (HGOC) stratified by homologous recombination deficiency (HRD) status undergoing frontline and/or maintenance therapy. Methods We performed a retrospective analysis of HGOC from April 2013 to June 2019. Clinical outcomes were analyzed by (1) germline BRCA+ (2) germline BRCA - and somatic BRCA/HRD+, or (3) BRCA-/HRD-. Progression free (PFS) and overall survival (OS) were estimated using Kaplan-Meier methods and modeled via Cox proportional hazards regression. Results 187 patients met inclusion criteria. 106 patients had germline BRCA mutation, 26 somatic BRCA/HRD+, and 55 BRCA/HRD-. Multivariate analysis for PFS revealed that age (HR 1.02, 95% CI 1.00–1.04), p=0.01), stage (HR 5.7, 95% CI 1.39–23.4, p=0.02), R0 resection at TRS (HR 0.41, 95% CI 0.21–0.83, p=0.01), and BRCA/HRD- status (HR 1.63, 95% CI 1.07–2.48, p=0.02) were significant factors impacting PFS. Multivariate analysis for OS revealed age (HR 1.07, 95% CI 1.03–1.10, p Conclusions Germline BRCA-mutant, somatic BRCA/HRD+ HGOC was associated with improved PFS and OS regardless of primary TRS or NACT. BRCA-/HRD- was a negative prognostic factor for survival in HGOC. PARPi maintenance therapy was associated with improved PFS in Germline BRCA-mutant, somatic BRCA/HRD+ HGOC

2536 Background: TIL therapy has been used extensively in metastatic melanoma patients for many years, now with ongoing efforts to commercialize treatment. The efficacy of TIL outside of melanoma is largely unknown thus we designed and implemented a trial using TIL manufactured at a single academic center for treatment refractory metastatic colorectal (CRC), pancreas (PDAC) and ovarian (OVA) cancers. Methods: Patients with CRC, PDAC and OVA refractory to standard therapies with ECOG PS 0-1 and normal organ function were eligible for TIL harvest. Ex vivo TIL expansion and manufacturing was conducted at the MD Anderson TIL lab under conditions that included IL2 and 41BB stimulation (using urelumab). All patients received a lymphodepletion regimen consisting of cyclophosphamide 60mg/kg days -7 and -6 and fludarabine 25mg/m2 days -5 through day -1, followed by infusion of pooled ex-vivo expanded TIL. Patients received up to 6 doses of high dose IL-2 (600,000 IU/kg) after TIL infusion. The primary endpoint was evaluation of the objective response rate (ORR) using RECIST 1.1 criteria with secondary endpoints including disease control rate, duration of response, PFS, OS and safety. Results: A total of 17 patients underwent TIL harvest and 16 were treated on protocol; including 8 CRC, 5 PDAC and 3 OVA. Median age was 57.5 (range 33-70) and 50% were females. Median number of lines of prior therapy was 2 (range 1-8). Median number of TIL infused was 76 X 109 (range 20.3 x 109-150 x 109). Median doses of cyclophosphamide and fludarabine administered were 2 (range, 2-2) and 3 (range, 1-5), respectively. Median doses of IL-2 administered was 6 (range, 1-6). There were no responders. Best response included prolonged SD in a patient with PDAC lasting until 18 months. Grade 3 or higher toxicities attributable to therapy was seen in 14 subjects (87.5%; 95% CI: 61.7 – 98.4) with the majority of toxicities representing expected pancytopenia from lymphodepletion. Infusion product analysis showed the presence of effector memory cells with high expression of CD39 irrespective of tumor type. Early on-treatment biopsy of PDAC patient with prolonged SD showed presence of proliferating (KI67+) CD4+ and CD8+ TIL. Conclusions: Generation of TIL at a single academic center for CRC, PDAC and OVA is feasible and treatment is associated with no new safety signals. For these tumor types, further research is required to identify host factors associated with resistance to TIL therapy and optimize manufacturing processes to create more effective TIL cell therapy. Clinical trial information: NCT03610490.

Objectives: Despite similar histologic appearance amongst high-grade serous ovarian cancers (HGSOC), anecdotally there are differences in gross appearance. However, no systematic framework to classify morphologic differences exists. Therefore, we aimed to determine whether high-grade serous ovarian cancers (HGSOC) can be reliably divided into distinct gross morphologic subtypes and to assess clinical outcomes and molecular features of these subtypes. Methods: A retrospective review was performed of video-recordings from patients who underwent laparoscopic assessment of disease burden prior to primary debulking surgery (PDS) or neoadjuvant chemotherapy (NACT). Video recordings were reviewed by at least 2 physicians. A total of 4 sites (diaphragm, omentum, peritoneum, and pelvis) were assessed and classified as type I (deep, infiltrative disease with distortion of surrounding tissue) or type II (superficial, exophytic disease bordered by normal tissue). Tumor tissues from 16 of these chemotherapy-naive patients were analyzed by multi-platform omics (RNA sequencing, proteomics). Clinical outcomes were assessed utilizing a prospectively collected database and compared by morphology using t-test or Fisher's exact test. Results: Of the 99 evaluable patients, 60 exhibited uniform morphology at all involved metastatic sites (65% type I and 35% type II), and 81 exhibited a predominating morphology (58% type I and 42% type II). A total of 164 images were reviewed by a third physician with 83.5% inter-rater concordance (κ=0.6446). Patients with uniform type 1 (n=34)tumor morphology were more likely to exhibit an excellent response to NACT (defined as radiologic or CA-125 complete response) than those with type II (n=16) tumor morphology (47% vs 18%, p=0.13). Patients with type II predominant tumor morphology had a significantly higher estimated blood loss at the time of interval debulking surgery (p=0.008) as well as longer operative time (p=0.03) compared with type I tumor morphology. Patients with complete type II morphology were more likely to have a modified Fagotti score of Conclusions: There are at least two distinct gross morphological patterns of HGSOC with unique molecular differences and responses to chemotherapy. These findings could have major clinical implications for tailored therapeutic strategies. Download : Download high-res image (97KB) Download : Download full-size image

5568 Background: Nearly 50% of patients with high grade ovarian cancer (HGOC) harbor a germline or somatic mutation in BRCA1/BRCA2 or have tumors characterized by homologous recombination deficiency (HRD). HRD is associated with response to poly(ADP-ribose) polymerase inhibitors (PARPi) in HGOC. Although PARPi show great promise, there is interest in investigating how HRD status affects outcomes and can be used to objectively tailor other treatment strategies. We aimed to compare clinical and survival outcomes in HGOC stratified by HRD status. Methods: We performed a retrospective analysis of all advanced HGOC from April 2013 to June 2019. Patients were included if germline BRCA and HRD status was known. Clinical outcomes were analyzed and stratified by (1) germline BRCA+ (2) germline BRCA - and somatic BRCA/HRD+, or (3) BRCA-/HRD-. Progression free (PFS) and overall survival (OS) were estimated using Kaplan-Meier methods stratified by HRD status and modeled via Cox proportional hazards regression. Results: 1271 patients with advanced HGOC presented during the study period of which 187 met inclusion criteria. 106 patients had germline BRCA mutation, 26 somatic BRCA/HRD+, and 55 BRCA/HRD-. Patients who had HRD- tumor had older median age at diagnosis (63 vs. 54 and 60 years, p

Background: High-grade serous ovarian cancer (HGSOC) remains the leading cause of death from gynecologic malignancies. Here, we examined tumoral proteome changes following neoadjuvant chemotherapy (NACT) to identify potential predictive and prognostic biomarkers of response to primary chemotherapy. Methods: A total of 65 tissue specimens from 10 patients with advanced-stage HGSOC were collected from matched pre- and post-NACT (3 cycles of dose-dense paclitaxel and carboplatin). Protein expression was assessed using reverse-phase protein arrays (RPPA). All relative protein levels using 297 antibodies were normalized by the expression level of pre-treatment samples, and then protein expression alterations and functional analyses were performed by Reactome pathway analysis followed by statistical analysis. Results: The protein expression patterns of samples tended to cluster according to the time point (pre- and post-treatment) by a non-supervised clustering analysis using all the proteins assessed in the RPPA panel. Five differentially expressed proteins among 239 proteins (adj. p Conclusion: Our findings identified significant proteomic alterations following NACT, and could provide insights into interval proteomic alterations following induction chemotherapy in advanced-stage ovarian cancer patients. These data present information to optimize future clinical trial designs for patients with ovarian cancer. Citation Format: Sanghoon Lee, Li Zhao, Joseph Celestino, Kelly M. Rangel, Richard A. Hajek, Mark S. Kim, Sara E. Sharafi, Jinsong Liu, Nicole D. Fleming, Karen H. Lu, Jianhua Zhang, P. Andrew Futreal, Gordon B. Mills, Shannon N. Westin, Anil K. Sood, Amir A. Jazaeri, Robert L. Coleman. Functional proteomic aberrations post-chemotherapy with paclitaxel and carboplatin in patients with advanced ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2941.

Systemic lupus erythematosus (SLE) is a debilitating and incurable autoimmune disease characterized by the uncontrolled production of autoantibodies and inflammatory damage to multiple organ systems. Dysregulated follicular helper T cell (TFH) responses are a cardinal feature and putative driver of disease in both mice and humans, where these cells contribute to unrestrained inflammation and autoantibody production by B cells. There is currently no safe and effective way to selectively eliminate TFH as a means to therapeutically alleviate diseases caused by these cells. Although cell surface biomarkers that are unique (lineage-specific targets) to TFH remain undefined, these cells express markedly more programmed cell death protein 1 (PD-1) than other immune cells. We recently engineered a novel programmed death-ligand 1 (PD-L1)-based chimeric antigen receptor (CAR) that when expressed on human natural killer (NK) cells, facilitated discriminate targeting of PD-1high follicular T cells while sparing other PD-1-expressing lymphocytes. The inherent specificity of this approach lies in the lower affinity interactions between PD-L1 and PD-1 compared to that likely achieved with a PD-1-specific single-chain variable fragment-based CAR. Here, we develop a mouse T cell version of the PD-L1 CAR platform to show that selective depletion of PD-1high T cells is safe and effective at undermining harmful autoreactive T and B cell responses in mouse models of SLE-like disease. We believe this affinity-based CAR approach for PD-1high target cell elimination represents a novel clinical tool for treatment of TFH-driven diseases like SLE.

Follicular helper T cells (TFH) are critical for vaccine and infection elicitation of long-lived humoral immunity, but exaggerated TFH responses can promote autoimmunity and other pathologies. Unfortunately, no clinical interventions are currently available for selective depletion of TFH cells to alleviate these disease conditions. We engineered a novel chimeric antigen receptor (CAR) that facilitates specific targeting of cells highly expressing human programmed cell death protein 1 (PD-1), a cardinal feature of TFH cells. CAR-expressing natural killer (NK) cells robustly degranulate in response to PD-1, resulting in discriminatory elimination of human tonsil TFH cells while sparing other T and B-cell subsets. Given that CAR NK cells are emerging as a safe and effective alternative to CAR T cells in cancer immunotherapy, our results suggest a new, clinically-translatable application of CAR NK cells for selective depletion of pathogenic TFH cells in specific disease states.

SUMMARY The diversity and heterogeneity within high-grade serous ovarian cancer (HGSC), which is the most lethal gynecologic malignancy, is not well understood. Here, we perform comprehensive multi-platform omics analyses, including integrated analysis, and immune monitoring on primary and metastatic sites from highly clinically annotated HGSC samples based on a laparoscopic triage algorithm from patients who underwent complete gross resection (R0) or received neoadjuvant chemotherapy (NACT) with excellent or poor response. We identify significant distinct molecular abnormalities and cellular changes and immune cell repertoire alterations between the groups, including a higher rate of NF1 copy number loss, and reduced chromothripsis-like patterns, higher levels of strong-binding neoantigens, and a higher number of infiltrated T cells in the R0 versus the NACT groups., Graphical Abstract, In Brief High-grade serous ovarian cancer (HGSC) patients with no gross residual disease (R0) after primary surgery have the greatest improvement in clinical outcomes. A deep understanding of molecular and cellular heterogeneity of HGSC is lacking. Findings by Lee et al. highlight major molecular and cellular differences between clinically defined subgroups of HGSC.

TPS2650 Background: Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TIL) has a long history of efficacy in metastatic melanoma, and is being increasingly considered across other solid tumors. Preclinical data generated at MD Anderson Cancer Center has demonstrated the ability to grow TIL from a variety of tumor types including various types of sarcomas, ovarian and pancreas cancers. We are testing the efficacy of TIL across multiple tumor types using two different manufacturing protocols. Methods: We are conducting two ongoing investigator initiated basket TIL therapy trials. The first (NCT03449108) includes cohorts with poorly differentiated soft tissue and bone sarcomas, osteosarcoma, and platinum resistant ovarian cancer. The TIL product used in this trial is an investigational cell product (LN-145, Iovance Biotherapeutics, Inc.). The second trial (NCT03610490) includes cohorts of osteosarcoma, platinum resistant ovarian cancer, and pancreatic cancer (who have progressed on, or received maximal benefit from, front-line therapy). For this trial, TIL are manufactured at MD Anderson Cancer Center using a protocol that includes the use of urelumab (an agonistic anti-CD137 antibody) combined with T cell receptor activation during TIL expansion. In both trials eligible subjects undergo tumor harvest using a surgical excisional biopsy of the tumor for TIL manufacturing, receive a modified cyclophosphamide and fludarabaine lymphodepletion regimen and up to six doses of IL-2 (600,000 IU/kg) following TIL infusion. No intervening therapy is allowed between tumor harvest and initiation of lymphodepletion. The primary endpoint for each cohort is ORR as assessed by investigators using RECIST 1.1 criteria. The Simon’s two stage design is used to monitor the efficacy of each cohort independently. In the first stage, 10 patients will be treated per cohort. If there is no confirmed response in these 10 evaluable patients, the cohort will be terminated. If the cohort moves forward to Stage II, an additional 8 patients will be treated leading to a total of 18 patients. Three or more responders out of 18 treated patients for the cohort will be considered clinically relevant to justify further investigation. Enrollment is ongoing in all cohorts in both trials. An accrual update will be provided at the annual meeting. Clinical trial information: NCT03449108, NCT03610490.

This study was designed to conduct systematic reviews of existing evaporative cooling system maintenance guidelines and of published Legionnaires' disease outbreaks to determine what, if any, maintenance practices were in place at the time of the disease outbreaks and then to contrast the reported practices with the published guidelines for evaporative cooling systems. For the first review, similarities in the reported recommendations were assessed; in the second review, any reported information about the state of the evaporative cooling system during the outbreak investigation was summarized. The systematic reviews yielded 38 current guidelines for evaporative cooling systems and 38 published outbreak investigations. The guidelines varied regarding the recommended type and dose of biocides, frequency of general inspections and total system maintenance, the preferred disinfection and cleaning procedures when testing a system for microbiological contamination, the type and frequency of testing procedures, and interpretation of test results. Overall, the maintenance guidelines did not contain sufficiently detailed procedures to prevent the problems that were observed in the outbreak investigations. These maintenance procedures included lack or improper use of a biocide; infrequent testing for microbiological contamination; improper use or maintenance of drift eliminators; and lack of a total system cleaning within 6 months of the outbreak for cooling systems that were either under continuous use, recently started up, or frequently switched on and off. This study suggests that more specific and standardized maintenance guidelines for the control of Legionella bacteria are needed and that these guidelines must be properly implemented to help reduce further Legionnaires' disease outbreaks associated with evaporative cooling systems.

With the growing focus on patient-centered care, patient reported outcomes (PROs) are becoming an important component to clinical trials and quality metrics. The objective of this study was to pilot the collection of patient reported symptom burden in women undergoing surgery in a gynecologic oncology practice.Perioperative patient reported symptom burden was measured for women undergoing laparotomy on the gynecologic oncology service at the University of Texas MD Anderson Cancer Center. Symptoms were assessed using the M.D. Anderson Symptom Inventory (MDASI-OC), a 27 item tool validated for use in patients with ovarian cancer. The MDASI-OC was administered as a preoperative baseline, daily while admitted to the hospital after surgery, twice a week on the first week after discharge and then weekly until 8 weeks postoperatively.29 patients were evaluable. Seventy-five percent of patients had a diagnosis of ovarian cancer. Of those patients, half underwent a primary debulking surgery and the other half had neoadjuvant chemotherapy prior to interval cytoreductive surgery. In the postoperative inpatient setting, the five symptoms with the highest overall burden were fatigue, pain, abdominal pain, dry mouth and drowsiness. Longitudinal change of the top 5 symptoms during hospitalization did not show any significant difference between those who had neoadjuvant chemotherapy and those who did not.The collection of longitudinal PROs to assess symptom burden is feasible in patients undergoing gynecologic oncology surgery. Patient reported outcomes are a crucial component of patient-centered research and the longitudinal collection and analysis of symptom burden can allow for more meaningful comparisons of surgical technique and perioperative care.

The detection of CTCs prior to and during therapy is an independent and strong prognostic marker, and it is predictive of poor treatment outcome. A major challenge is that different technologies are available for isolation and characterization of CTCs in peripheral blood (PB). We compare the CellSearch system and AdnaTest BreastCancer Select/Detect, to evaluate the extent that these assays differ in their ability to detect CTCs in the PB of MBC patients. CTCs in 7.5 ml of PB were isolated and enumerated using the CellSearch, before new treatment. Two cutoff values of ≥2 and ≥5 CTCs/7.5 ml were used. AdnaTest requires 5 ml of PB to detect gene transcripts of tumor markers (GA733-2, MUC-1, and HER2) by RT-PCR. AdnaTest was scored positive if ≥1 of the transcript PCR products for the 3 markers were detected at a concentration ≥0.15 ng/μl. A total of 55 MBC patients were enrolled. 26 (47%) patients were positive for CTCs by the CellSearch (≥2 cutoff), while 20 (36%) were positive (≥5 cutoff). AdnaTest was positive in 29 (53%) with the individual markers being positive in 18% (GA733-2), 44% (MUC-1), and 35% (HER2). Overall positive agreement was 73% for CTC≥2 and 69% for CTC≥5. These preliminary data suggest that the AdnaTest has equivalent sensitivity to that of the CellSearch system in detecting 2 or more CTCs. While there is concordance between these 2 methods, the AdnaTest complements the CellSearch system by improving the overall CTC detection rate and permitting the assessment of genomic markers in CTCs.

Exposure of cells to DNA-damaging agents induces hyperphosphorylation of the C-terminal domain (CTD) of mammalian RNA polymerase II (RNAP II) large subunit (LS); the hyperphosphorylated RNAP II is then ubiquitinated. The purpose of this study was to verify that cisplatin-induced RNAP II ubiquitination is transcription dependent in living cells and to determine whether 7-hydroxystaurosporine (UCN-01) inhibits the ubiquitination induced by cisplatin. Cisplatin at clinically achievable concentrations (2.5-10 micro M) induced the ubiquitination of RNAP II in exponentially growing A2780 human ovarian tumor cells; the effect was drug-dose and exposure-time dependent. Such induction, however, was not observed in colcemid-selected mitotic cells. When detergent extraction was applied, the ubiquitinated RNAP II was recovered in the detergent-insoluble fraction, indicating that the protein was tightly bound to DNA. In an in vitro transcription reaction that consists of nuclear extracts and an immobilized DNA template containing a site-specific cisplatin lesion, the elongating RNAP II that was stalled at a cisplatin lesion site on the template was targeted by ubiquitins. Together, our results indicate that the ubiquitination is associated with transcription-coupled repair. We previously showed that the Ser/The kinase-inhibitor UCN-01 inhibits nucleotide excision repair. Here, we further determined the effect of UCN-01 on the phosphorylation and ubiquitination of RNAP II LS in a whole-cell system. Immunoblotting results showed that UCN-01 suppressed the cisplatin-induced ubiquitination and the cisplatin-induced shift from the hypophosphorylated IIa to the hyperphosphorylated IIo, without affecting the basal levels of the IIo and IIa forms of the RNAP II CTD, suggesting that UCN-01 acts by suppressing cisplatin-mediated induction of the one or more kinases that is responsible for the conversion of the IIo that is important for ubiquitination.

When mammalian cells are exposed to cisplatin or ultraviolet irradiation, the RNA polymerase II (RNAP II) large subunit becomes ubiquitinated and is subsequently degraded via the proteasomal pathway. Using a DNA template immobilized on magnetic beads in an in vitro transcription reaction, we showed that a pause of the elongating RNAP II complex caused by nucleotide starvation induced the ubiquitination of the stalled RNAP II. The ubiquitinated RNAP II dissociated from the ternary complex when transcription was allowed to resume. The dissociated (free) RNAP II remained ubiquitinated. The proteasome inhibitor MG132 increased the accumulation of ubiquitinated free RNAP II but did not affect the amount of ubiquitinated, template-bound RNAP II, indicating that the ubiquitinated RNAP II was displaced from the template and then degraded by the proteasomes. Our work shows that the elongation complex that was stalled at the template by nucleotide starvation is targeted by the ubiquitin-conjugating system and that ubiquitination facilitates displacement of the stalled RNAP II from the template. Our findings together with the findings by others that DNA damaging agents induced the ubiquitination in mammalian cells that are nucleotide excision repair competent, suggest that the RNAP II ubiquitination may have a role in the regulation of transcription-coupled DNA repair.

Objectives: It is well known that patients with cancer and a concurrent venous thromboembolism (VTE) have poorer oncologic outcomes. Despite the fact that 25-40% of ovarian cancer patients develop a VTE, the role of tumor specific factors in VTE development is not known. Therefore, we aim to identify genomic factors in ovarian cancer that could be related to development of VTE or the associated impact on patient outcomes. Methods: We obtained ovarian high grade serous carcinoma (HGSC) samples from patients diagnosed between 2013 and 2019 for RNA sequencing. Sixteen cases of VTE were identified and matched with 16 controls (no VTE) based on histologic subtype, age (±10 years) and BMI (±10kg/m2). Bioinformatics analyses were carried out to identify genes and pathways that could contribute to the development of VTE. Results: In the 16 cases, the timing of VTE was variable, ranging from onset at the time of diagnosis of ovarian cancer (n=9; 56%), during neoadjuvant chemotherapy (NACT; n=2, 12.5%), and within 28 days of surgery or during adjuvant chemotherapy (n=5; 31.3%). A quality control assessment of the RNA sequencing analysis showed no evidence of batch effect. We found that there were 130 differentially expressed genes (DEGs) upregulated in the VTE group and 62 DEGs were upregulated in the control group. The F3 gene which encodes tissue factor, a major factor in the procoagulant activity of cancer, was upregulated in nearly all VTE samples. In contrast, F3 was not expressed in the majority of the control samples. An outcome analysis utilizing datasets from The Cancer Genome Atlas (TCGA) comparing ovarian tissues from patients with and without VTE also identified that seven of these DEGs showed a consistently higher expression level in the VTE cohort compared to ovarian tissue controls. A Cox regression using age, grade, and gene expression indicated that 13 of the DEGs were associated with poorer overall survival. Specifically, GAPDHP65 and NRSN2-AS1 were found to have a hazard ratio of > 1.5 (p=0.018 and Download : Download high-res image (255KB) Download : Download full-size image Conclusions: In this study, we provide the first comprehensive analysis of tumor tissue molecular factors and gene expression specific to VTE in HGSC. We identified several differentially expressed genes within tumor tissue that could represent a unique gene signature for which to target prevention of VTE and to develop novel therapeutics.