Targeting TMEM205 mediated drug resistance in ovarian clear cell carcinoma using oncolytic virus.

BACKGROUND: Ovarian clear cell carcinoma (OCCC) accounts for approximately 8-10% of epithelial ovarian cancers in the United States. Although it is rare, OCCC usually presents with treatment challenges and the overall prognosis is far worse than high grade serous ovarian cancer HGSOC. The objective of this study was to examine the therapeutic relevance of combining oncolytic virus with cisplatin for ovarian cancer clear cell carcinoma (OCCC). RESULTS: We identified that TMEM205, a recently discovered transmembrane protein, contributes to chemoresistance in OCCC cells via the exosomal pathway. Mechanistically, TMEM205 undergoes ligand-independent constitutive endocytosis and co-localizes with Rab11 to contribute to the late recycling endosomes in a clathrin-independent manner. Further, we observed that oncolytic virus (oHSV) pretreatment followed by treatment with cisplatin decreases TMEM205 expression and sensitizes cells to cisplatin in a synergistic manner in OCCC cells. TMEM205 interacts with glycoprotein-C of oHSV post-infection; both of these proteins undergo ubiquitination and ultimately get shuttled outside the cell via exosomes. Thus, we demonstrate the mechanotransduction pathway of TMEM205-mediated chemoresistance along with targeting this pathway using oHSV and cisplatin as a powerful therapeutic strategy for OCCC. oHSV combination with cisplatin inhibits OCCC tumor growth in vivo in immunodeficient and immunocompetent mice models. CONCLUSION: Our results suggest that the combination of oHSV and cisplatin in immunocompetent as well as immune deficient OCCC tumor bearing mice reduces overall tumor burden as well as metastatic disease thereby providing survival benefit. Additionally, the detection of TMEM205 in exosomal cargo early in OCCC development has potential to be exploited as a biomarker.

The long game: Evolution of clinical decision making throughout residency and fellowship.

BACKGROUND: The purpose of this study was to explore the trajectory of autonomy in clinical decision making. METHODS: We conducted a qualitative secondary analysis of interviews with 45 residents and fellows from the General Surgery and Obstetrics & Gynecology departments across all clinical postgraduate years (PGY) using convenience sampling. Each interview was recorded, transcribed and iteratively analyzed using a framework method. RESULTS: A total of 16 junior residents, 22 senior residents and 7 fellows participated in 12 original interviews. Early in training residents take their abstract ideas about disease processes and make them concrete in their applications to patient care. A transitional stage follows in which residents apply concepts to concrete patient care. Chief residents re-abstract their concrete technical and clinical knowledge to prepare for future surgical practice. CONCLUSIONS: Understanding where each learner is on this pathway will assist development of curriculum that fosters resident readiness for practice at each PGY level.

Aberrant expression of TMEM205 signaling promotes platinum resistance in ovarian cancer: An implication for the antitumor potential of DAP compound.

INTRODUCTION: TMEM205 is a novel transmembrane protein associated with platinum resistance (PR) in epithelial ovarian carcinoma (OC), however, the specific mechanisms associated with this resistance remain to be elucidated. METHODS: TMEM205 expression was evaluated in platinum-sensitive (PS) versus platinum resistant (PR) ovarian cancer cell lines and patient serum/tissues. Exosomal efflux of platinum was evaluated with inductively coupled plasma mass spectrometry (ICP-MS) after pre-treatment with small molecule inhibitors (L-2663/L-2797) of TMEM205 prior to treatment with platinum. Cytotoxicity of combination treatment was confirmed in vitro and in an in vivo model. RESULTS: TMEM205 expression was 10-20 fold higher in PR compared to PS ovarian cancer cell lines, serum samples, and tissues. Co-localization with CD1B was confirmed by in-situ proximity ligation assay suggesting that TMEM205 may mediate PR via the exosomal pathway. Exosomal secretion was significantly increased 5-10 fold in PR cell lines after treatment with carboplatin compared to PS cell lines. Pre-treatment with L-2663 prior to carboplatin resulted in significantly increased intracellular concentration of fluorescently-labeled cisplatin and decreased exosomal efflux of platinum. Decreased cell survival and tumor growth in vitro and in vivo was observed when PR cells were treated with a combination of L-2663 with carboplatin compared to carboplatin alone. CONCLUSION: TMEM205 appears to be involved in the development of PR in ovarian cancer through the exosomal efflux of platinum agents. This study provides pre-clinical evidence that TMEM205 could serve as a possible biomarker for PR as well as a therapeutic target in combination with platinum agents.

Resident Self-Entrustment and Expectations of Autonomy: OB > GYN?

INTRODUCTION: Entrustment is a key component connecting to resident preparedness for surgical practice in the operating room (OR). Residents' self-entrustment of their surgical competencies closely associates with their OR training experience and granted autonomy. Some recent studies have investigated how attending surgeons entrusted residents in the OR. There is little to no data, however, in examining these issues from the resident perspective. The goal of this study was to identify the perception and expectations of autonomy from residents' perspective, as well as the self-entrustment of their surgical competencies in obstetrics (OB) and gynecologic (GYN) procedures. METHODS: Focus group interviews of OB/GYN residents were performed. Residents were selected by convenience sampling. Audio recordings of each interview were transcribed, iteratively analyzed, and emergent themes identified, using a framework method. RESULTS: A total of 123 minutes of interviews were recorded. Eight junior residents (PGY1-2) and 12 senior residents (PGY3-4) participated. Our data illustrated that (1) the perception of autonomy shifted significantly throughout residency training; (2) residents demonstrated higher expectations and self-entrustment for OB surgical procedures than for GYN surgical procedures upon graduation; and (3) case volume, modalities of OR teaching and mutual communication are 3 factors influencing resident self-entrustment of their surgical competencies. CONCLUSIONS: Residents showed disparities in their self-entrustment and expectations of autonomy between OB and GYN surgical procedures. Better understanding these differences and the 3 influencing factors could help programs develop a potential solution for improvement in resident entrustment and autonomy upon graduation.

Residents' method for gaining operative autonomy.

INTRODUCTION: The goal of this study was to explore the resident construct for their perceived successful method of actions that lead to OR autonomy during residency and the strategies they employed. METHODS: We conducted focus group interviews with residents from the General Surgery (GS) and Obstetrics & Gynecology (OBGYN) departments at a single academic institution across all clinical postgraduate years (PGY) using convenience sampling. Audio recordings of each interview were transcribed, analyzed and emergent themes were identified using a framework method. RESULTS: A total of 38 residents participated. A 3-stage resident method to gain operative autonomy emerged. This progresses from building rapport, developing mutual entrustment, and finally to obtaining autonomy. We identified 4 common strategies used by residents to construct this method: smart communication, attention to attending preferences, helpful allies and visible attributes. CONCLUSION: Our findings provide insight into resident strategies to achieve progressive autonomy in the OR helping programs improve resident's learning efficiency.

The Reliability of Intraoperative Assessment on Predicting Tumor Size, Myometrial Invasion, and Cervical Involvement in Patients With a Preoperative Diagnosis of Complex Atypical Hyperplasia or (Clinical Stage I) Endometrial Cancer: A Prospective Cohort Study.

OBJECTIVES: The objective of this study is to assess the reliability of intraoperative uterine assessment compared with the final pathologic evaluation in patients with endometrial cancer (EC) and whether assessment improves with experience. METHODS: After Institutional Review Board approval, a prospective cohort study of women surgically managed with biopsy-proven complex atypical hyperplasia (CAH) or EC between March 2015 and December 2016 was performed. Demographics, preoperative biopsy results, procedure, intraoperative and final pathologic evaluation of lesion size, myometrial invasion, and lower uterine segment/cervical involvement were abstracted. The agreement between the intraoperative and final pathologic evaluation of tumor involvement of the uterus was determined using the kappa statistic and the intraclass correlation coefficient. RESULTS: A total of 264 patients with a preoperative diagnosis of CAH or EC were included-71 (26.9%) with CAH and 193 (73.1%) with EC. The mean age was 62.6±11.5, and mean body mass index was 37.2±10.1. The majority of women were white (67%). A total of 227 (85.9%) patients underwent a laparoscopic or robotic hysterectomy, whereas 36 (13.6%) underwent an abdominal hysterectomy. 233 (88.3%) patients had EC and 21 (7.9%) patients had CAH on final pathology. There was a fair agreement between the intraoperative estimation of myometrial invasion (κ=0.37). A moderate agreement exists between the intraoperative estimation of lower uterine segment/cervical involvement (κ=0.57). There was a strong agreement between intraoperative tumor size assessment and the final path (intraclass correlation coefficient=0.74). The intraoperative correlation of tumor size was similar for the first half of the cohort (κ=0.50) and the second half (κ=0.46) chronologically. CONCLUSIONS: Despite only a fair correlation in the myometrial invasion, intraoperative assessment of cervical involvement and especially tumor size is more readily identified and overall accurate. Therefore, intraoperative evaluation is an additional tool to use when making the decision to proceed with surgical staging.

A Microfluidic Chip Enables Isolation of Exosomes and Establishment of Their Protein Profiles and Associated Signaling Pathways in Ovarian Cancer.

Because of limits on specificity and purity to allow for in-depth protein profiling, a standardized method for exosome isolation has yet to be established. In this study, we describe a novel, in-house microfluidic-based device to isolate exosomes from culture media and patient samples. This technology overcomes contamination issues because sample separation is based on the expression of highly specific surface markers CD63 and EpCAM. Mass spectrometry revealed over 25 exosome proteins that are differentially expressed in high-grade serous ovarian cancer (HGSOC) cell lines compared with normal cells-ovarian surface epithelia cells and fallopian tube secretory epithelial cells (FTSEC). Top exosome proteins were identified on the basis of their fold change and statistical significance between groups. Ingenuity pathway analysis identified STAT3 and HGF as top regulator proteins. We further validated exosome proteins of interest (pSTAT3, HGF, and IL6) in HGSOC samples of origin-based cell lines (OVCAR-8, FTSEC) and in early-stage HGSOC patient serum exosome samples using LC/MS-MS and proximity extension assay. Our microfluidic device will allow us to make new discoveries for exosome-based biomarkers for the early detection of HGSOC and will contribute to the development of new targeted therapies based on signaling pathways that are unique to HGSOC, both of which could improve the outcome for women with HGSOC. SIGNIFICANCE: A unique platform utilizing a microfluidic device enables the discovery of new exosome-based biomarkers in ovarian cancer.

Utilization of an Alternative Docetaxel-based Intraperitoneal Chemotherapy Regimen in Patients With Ovarian, Fallopian Tube or Primary Peritoneal Carcinoma: A Continued Need for Ovarian Cancer Patients.

OBJECTIVE: The objective of this study was to report the tolerability and toxicity of a regimen consisting of intravenous (IV) docetaxel and intraperitoneal (IP) cisplatin and paclitaxel with granulocyte colony-stimulating factor support. MATERIALS AND METHODS: We conducted a retrospective cohort study of patients with surgical stage II-IV epithelial ovarian, fallopian tube or primary peritoneal carcinoma treated with an outpatient IP chemotherapy regimen consisting of docetaxel 75 mg/m IV and cisplatin 75 mg/m IP day 1 followed by paclitaxel 60 mg/m IP day 8 every 21 days. Grade 3 and 4 toxicity, dose delays and reductions, port complications, and tolerability are reported. Outcomes, including response rate, progression-free survival (PFS), overall survival (OS) are also reported. RESULTS: A total of 60 patients received this IP regimen. Most common toxicities included neutropenia (47%), gastrointestinal (28%), and anemia (25%). Most patients (85%) experienced no IP port complications. Dose delay or reduction was required in 30% of patients. Two-thirds completed all prescribed cycles, with 80% of total planned cycles completed. Complete response was achieved for 88%, and 43% are currently without evidence of disease. Median PFS for all patients was 25.5 months (95% confidence interval [CI], 20.4-30.5 mo) while OS for all patients was 56.8 months (95% CI, 47.7-65.9 mo). For the 44 patients with stage III disease, median PFS was 22.1 months (95% CI, 16.3-28.0 mo), while median OS was 56.8 months (95% CI, 47.3-66.3 mo). CONCLUSIONS: This docetaxel-based IP chemotherapy regimen demonstrates an improved tolerability profile compared with GOG172. Additional evaluations on alternative IP regimens remain warranted. Short follow-up time limits survival assessment, but results are encouraging.