Transdifferentiation is uncoupled from progenitor pool expansion during hair cell regeneration in the zebrafish inner ear.

Death of mechanosensory hair cells in the inner ear is a common cause of auditory and vestibular impairment in mammals, which have a limited ability to regrow these cells after damage. In contrast, non-mammalian vertebrates including zebrafish can robustly regenerate hair cells following severe organ damage. The zebrafish inner ear provides an understudied model system for understanding hair cell regeneration in organs that are highly conserved with their mammalian counterparts. Here we quantitatively examine hair cell addition during growth and regeneration of the larval zebrafish inner ear. We used a genetically encoded ablation method to induce hair cell death and observed gradual regeneration with correct spatial patterning over two weeks following ablation. Supporting cells, which surround and are a source of new hair cells, divide in response to hair cell ablation, expanding the possible progenitor pool. In parallel, nascent hair cells arise from direct transdifferentiation of progenitor pool cells uncoupled from progenitor division. These findings reveal a previously unrecognized mechanism of hair cell regeneration with implications for how hair cells may be encouraged to regenerate in the mammalian ear.

Topographical and cell type-specific connectivity of rostral and caudal forelimb corticospinal neuron populations.

Corticospinal neurons (CSNs) synapse directly on spinal neurons, a diverse assortment of cells with unique structural and functional properties necessary for body movements. CSNs modulating forelimb behavior fractionate into caudal forelimb area (CFA) and rostral forelimb area (RFA) motor cortical populations. Despite their prominence, the full diversity of spinal neurons targeted by CFA and RFA CSNs is uncharted. Here, we use anatomical and RNA sequencing methods to show that CSNs synapse onto a remarkably selective group of spinal cell types, favoring inhibitory populations that regulate motoneuron activity and gate sensory feedback. CFA and RFA CSNs target similar spinal neuron types, with notable exceptions that suggest that these populations differ in how they influence behavior. Finally, axon collaterals of CFA and RFA CSNs target similar brain regions yet receive highly divergent inputs. These results detail the rules of CSN connectivity throughout the brain and spinal cord for two regions critical for forelimb behavior.

Monocarboxylate Transporter 1 (MCT1) Mediates Succinate Export in the Retina.

Purpose: Succinate is exported by the retina and imported by eyecup tissue. The transporters mediating this process have not yet been identified. Recent studies showed that monocarboxylate transporter 1 (MCT1) can transport succinate across plasma membranes in cardiac and skeletal muscle. Retina and retinal pigment epithelium (RPE) both express multiple MCT isoforms including MCT1. We tested the hypothesis that MCTs facilitate retinal succinate export and RPE succinate import. Methods: We assessed retinal succinate export and eyecup succinate import in short-term ex vivo culture using gas chromatography-mass spectrometry. We tested the dependence of succinate export and import on pH, proton ionophores, conventional MCT substrates, and the MCT inhibitors AZD3965, AR-C155858, and diclofenac. Results: Succinate exits retinal tissue through MCT1 but does not enter the RPE through MCT1 or any other MCT. Intracellular succinate levels are a contributing factor that determines if an MCT1-expressing tissue will export succinate. Conclusions: MCT1 facilitates export of succinate from retinas. An unidentified, non-MCT transporter facilitates import of succinate into RPE.

Cell-specific cis-regulatory elements and mechanisms of non-coding genetic disease in human retina and retinal organoids.

Cis-regulatory elements (CREs) play a critical role in the development and disease-states of all human cell types. In the retina, CREs have been implicated in several inherited disorders. To better characterize human retinal CREs, we performed single-nucleus assay for transposase-accessible chromatin sequencing (snATAC-seq) and single-nucleus RNA sequencing (snRNA-seq) on the developing and adult human retina and on induced pluripotent stem cell (iPSC)-derived retinal organoids. These analyses identified developmentally dynamic, cell-class-specific CREs, enriched transcription-factor-binding motifs, and putative target genes. CREs in the retina and organoids are highly correlated at the single-cell level, and this supports the use of organoids as a model for studying disease-associated CREs. As a proof of concept, we disrupted a disease-associated CRE at 5q14.3, confirming its principal target gene as the miR-9-2 primary transcript and demonstrating its role in neurogenesis and gene regulation in mature glia. This study provides a resource for characterizing human retinal CREs and showcases organoids as a model to study the function of CREs that influence development and disease.

Gene regulatory networks controlling temporal patterning, neurogenesis, and cell-fate specification in mammalian retina.

Gene regulatory networks (GRNs), consisting of transcription factors and their target sites, control neurogenesis and cell-fate specification in the developing central nervous system. In this study, we use integrated single-cell RNA and single-cell ATAC sequencing (scATAC-seq) analysis in developing mouse and human retina to identify multiple interconnected, evolutionarily conserved GRNs composed of cell-type-specific transcription factors that both activate genes within their own network and inhibit genes in other networks. These GRNs control temporal patterning in primary progenitors, regulate transition from primary to neurogenic progenitors, and drive specification of each major retinal cell type. We confirm that NFI transcription factors selectively activate expression of genes promoting late-stage temporal identity in primary retinal progenitors and identify other transcription factors that regulate rod photoreceptor specification in postnatal retina. This study inventories cis- and trans-acting factors that control retinal development and can guide cell-based therapies aimed at replacing retinal neurons lost to disease.

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.

Distinct progenitor populations mediate regeneration in the zebrafish lateral line.

Mechanosensory hair cells of the zebrafish lateral line regenerate rapidly following damage. These renewed hair cells arise from the proliferation of surrounding support cells, which undergo symmetric division to produce two hair cell daughters. Given the continued regenerative capacity of the lateral line, support cells presumably have the ability to replenish themselves. Utilizing novel transgenic lines, we identified support cell populations with distinct progenitor identities. These populations show differences in their ability to generate new hair cells during homeostasis and regeneration. Targeted ablation of support cells reduced the number of regenerated hair cells. Furthermore, progenitors regenerated after targeted support cell ablation in the absence of hair cell damage. We also determined that distinct support cell populations are independently regulated by Notch signaling. The existence of independent progenitor populations could provide flexibility for the continued generation of new hair cells under a variety of conditions throughout the life of the animal.

Cumulative mitochondrial activity correlates with ototoxin susceptibility in zebrafish mechanosensory hair cells.

Mitochondria play a prominent role in mechanosensory hair cell damage and death. Although hair cells are thought to be energetically demanding cells, how mitochondria respond to these demands and how this might relate to cell death is largely unexplored. Using genetically encoded indicators, we found that mitochondrial calcium flux and oxidation are regulated by mechanotransduction and demonstrate that hair cell activity has both acute and long-term consequences on mitochondrial function. We tested whether variation in mitochondrial activity reflected differences in the vulnerability of hair cells to the toxic drug neomycin. We observed that susceptibility did not correspond to the acute level of mitochondrial activity but rather to the cumulative history of that activity.

Does Obesity Affect Pathologic Agreement of Initial and Final Tumor Grade of Disease in Endometrial Cancer Patients?

OBJECTIVES: The objectives of this study were to compare preoperative and postoperative tumor grade to determine if surgical staging decisions for endometrial cancer based on preoperative biopsy are feasible and whether obesity affects the agreement. METHODS: A retrospective cohort study of women with endometrial cancer between January 2010 and December 2011 was performed. Demographics, stage of final pathology, biopsy method, preoperative and postoperative tissue grade, and histology were abstracted and stratified by patient body mass index (obese ≥30 kg/m and nonobese <30 kg/m). Patients with incomplete records or uterine sarcoma were excluded. The agreement between preoperative and postoperative tumor grade for all patients and in obese and nonobese patients was determined using weighted κ statistics. RESULTS: Four hindered forty-five patients were included: 161 nonobese patients and 284 obese patients. The proportion of preoperative sampling via office biopsy and dilation and curettage was similar in each cohort. Overall, the agreement between preoperative and postoperative pathology was only fair (weighted κ = 0.21). Stratified by body mass index, the agreement between preoperative and postoperative grade remains fair in obese and slight in nonobese patients (weighted κ = 0.21 and 0.19, respectively). Substantial increases in tumor grade from preoperative to postoperative pathologic specimens occurred in both cohorts. CONCLUSIONS: Obesity does not appear to significantly alter the correlation between preoperative biopsy and final tumor grade. With only fair correlation between preoperative and postoperative pathologic evaluation, utilization of preoperative biopsy pathology results as a triage tool for surgical staging should be avoided. However, the discordance between preoperative and postoperative pathology in favor of a higher grade on final pathology in both groups may cause some surgeons to favor staging.

Effectiveness of cyanoacrylate microbial sealant in the reduction of surgical site infection in gynecologic oncology procedures: A phase III single institution prospective randomized trial.

OBJECTIVES: Surgery is a cornerstone for patients with gynecologic malignancies. Surgical site infections (SSI) remain a source of post-operative morbidity. Consequences range from escalated costs, delay in adjuvant therapy, and increased morbidity. Our primary objective was to evaluate the effectiveness of a cyanoacrylate microbial sealant (CMS) to reduce post-operative SSI following laparotomy for suspected gynecologic malignancy. METHODS: Patients were randomized using a 1:1 allocation to receive either standard skin preparation or standard preparation with CMS and stratified by BMI. Patients were followed for 6weeks for SSI. Demographic data was collected through the EMR. Associations between SSI, use of CMS, and clinicopathologic factors were explored using descriptive statistics, chi-square and multivariate analysis. RESULTS: 300 patients underwent randomization. Median age of the cohort was 58. Arms were matched and there was no difference in rate of medical comorbidities. Mean BMI was 38.8kg/m2 in patients randomized to BMI≥30 and 26.3kg/m2 randomized to BMI<30. Surgical characteristics for the entire cohort: 66% malignancy, 91% clean-contaminated, 21% bowel surgery, 25% transfusion. Seventy-six (25%) patients developed a SSI: 43 patients (28%) treated with CMS, compared to 33 (21%) patients treated without CMS (p=0.18). Multivariate model demonstrated that BMI≥30 (p<0.005), surgery for malignancy (p=0.010), transfusion in the OR (p<0.001), and closure with staples (p=0.0005) were associated with post-operative SSI. CONCLUSIONS: Patients presenting to a gynecologic oncologist for surgery frequently present with multiple risk factors for SSI and laparotomy is complicated by surgical-site complications in up to 30% of cases. The addition of CMS alone does not appear to reduce risk of overall SSI. Additional risk-reducing strategies including use of antimicrobial agents and optimization of modifiable risk factors prior to surgery should be explored as pathways for reducing this significant post-operative morbidity.

Distance from a Comprehensive Cancer Center: A proxy for poor cervical cancer outcomes?

OBJECTIVE: To evaluate the potential relationship between outcomes in cervical cancer patients based on distance from our Comprehensive Cancer Center (CCC). METHODS: A retrospective cohort study of cervical cancer patients was performed. Abstracted data included: demographics, clinicopathologic variables, treatment, and survival. Analyses both by quartiles and distance <100 and ≥100miles from our institution were performed. Data were analyzed using SAS version 9.2. RESULTS: 390 patients living a median distance of 58.1miles (range 1.2-571miles) from our CCC were identified. Patients were generally white (n=249), non-smokers (n=226), with Stage IB disease (n=222), squamous histology (n=295) and underwent primary surgical therapy (n=229). Patients were divided into both quartiles as well as two strata: <100 and ≥100miles for comparison. Progression-free survival (PFS) and overall survival (OS) favored patients living closer to our center with a lower median OS for patients living ≥100miles (65.4vs. 99.4months; p=0.040). Cox proportional hazard modeling noted that advanced stage was predictive of inferior PFS and OS, while other clinical covariates including age, BMI, race, smoking status and histology had a variable impact on outcomes and distance >100miles was associated with a higher risk of death (hazard ratio [HR]=1.68, 95% confidence interval [CI] 1.11-2.54). CONCLUSION: Overall survival for patients living >100miles from our CCC was worse when compared to patients in closer proximity. Outreach efforts and utilization of navigators may help decrease the impact of geographic and racial disparities on outcomes.

IL-12 Expressing oncolytic herpes simplex virus promotes anti-tumor activity and immunologic control of metastatic ovarian cancer in mice.

BACKGROUND: Despite advances in surgical aggressiveness and conventional chemotherapy, ovarian cancer remains the most lethal cause of gynecologic cancer mortality; consequently there is a need for new therapeutic agents and innovative treatment paradigms for the treatment of ovarian cancer. Several studies have demonstrated that ovarian cancer is an immunogenic disease and immunotherapy represents a promising and novel approach that has not been completely evaluated in ovarian cancer. Our objective was to evaluate the anti-tumor activity of an oncolytic herpes simplex virus "armed" with murine interleukin-12 and its ability to elicit tumor-specific immune responses. We evaluated the ability of interleukin-12-expressing and control oncolytic herpes simplex virus to kill murine and human ovarian cancer cell lines in vitro. We also administered interleukin-12-expressing oncolytic herpes simplex virus to the peritoneal cavity of mice that had developed spontaneous, metastatic ovarian cancer and determined overall survival and tumor burden at 95 days. We used flow cytometry to quantify the tumor antigen-specific CD8+ T cell response in the omentum and peritoneal cavity. RESULTS: All ovarian cancer cell lines demonstrated susceptibility to oncolytic herpes simplex virus in vitro. Compared to controls, mice treated with interleukin-12-expressing oncolytic herpes simplex virus demonstrated a more robust tumor antigen-specific CD8+ T-cell immune response in the omentum (471.6 cells vs 33.1 cells; p = 0.02) and peritoneal cavity (962.3 cells vs 179.5 cells; p = 0.05). Compared to controls, mice treated with interleukin-12-expressing oncolytic herpes simplex virus were more likely to control ovarian cancer metastases (81.2 % vs 18.2 %; p = 0.008) and had a significantly longer overall survival (p = 0.02). Finally, five of 6 mice treated with interleukin-12-expressing oHSV had no evidence of metastatic tumor when euthanized at 6 months, compared to two of 4 mice treated with sterile phosphate buffer solution. CONCLUSION: Our pilot study demonstrates that an interleukin-12-expressing oncolytic herpes simplex virus effectively kills both murine and human ovarian cancer cell lines and promotes tumor antigen-specific CD8+ T-cell responses in the peritoneal cavity and omentum, leading to reduced peritoneal metastasis and improved survival in a mouse model.

Improved outcomes with dose-dense paclitaxel-based neoadjuvant chemotherapy in advanced epithelial ovarian carcinoma.

OBJECTIVE: We compared tolerability, toxicity, response, and interval debulking surgery (IDS) outcomes between patients who received weekly dose-dense paclitaxel (DDP) and every three-week platinum to standard every three-week taxane plus platinum neoadjuvant chemotherapy (NACT) for advanced epithelial ovarian cancer (EOC). METHODS: We conducted a retrospective study of patients receiving NACT at our center between June 1, 2012 and July 31, 2015. Patients with stage III/IV EOC who received at least one cycle of DDP (weekly paclitaxel plus every three-week carboplatin) or standard taxane (every three-week paclitaxel or docetaxel plus carboplatin) therapy were included. Abstracted data included demographics, tolerability, grade 3/4 toxicity, response, and IDS outcomes. Fisher's exact and student t-test were used for statistical significance. RESULTS: Twenty-one patients received DDP and 40 received standard taxane. Tolerability was comparable. More patients receiving DDP experienced grade 3 or 4 toxicity when considered in aggregate (86% vs. 40%; p=0.001). Pathologic complete response (pCR) was achieved in 14% of DDP patients versus 3% of standard (p=0.11). 48% of patients in the DDP group were debulked to no residual disease (NRD) versus 28% in the standard group (p=0.16). CONCLUSIONS: While associated with an increase in severe toxicity compared to standard three-week taxane, DDP appears to facilitate higher rates of pCR and NRD for patients receiving NACT in this preliminary study. These results warrant further investigation of DDP for patients with advanced EOC and assessment of impact on long-term survival outcomes.

Evolutionary Diagnosis of non-synonymous variants involved in differential drug response.

BACKGROUND: Many pharmaceutical drugs are known to be ineffective or have negative side effects in a substantial proportion of patients. Genomic advances are revealing that some non-synonymous single nucleotide variants (nsSNVs) may cause differences in drug efficacy and side effects. Therefore, it is desirable to evaluate nsSNVs of interest in their ability to modulate the drug response. RESULTS: We found that the available data on the link between drug response and nsSNV is rather modest. There were only 31 distinct drug response-altering (DR-altering) and 43 distinct drug response-neutral (DR-neutral) nsSNVs in the whole Pharmacogenomics Knowledge Base (PharmGKB). However, even with this modest dataset, it was clear that existing bioinformatics tools have difficulties in correctly predicting the known DR-altering and DR-neutral nsSNVs. They exhibited an overall accuracy of less than 50%, which was not better than random diagnosis. We found that the underlying problem is the markedly different evolutionary properties between positions harboring nsSNVs linked to drug responses and those observed for inherited diseases. To solve this problem, we developed a new diagnosis method, Drug-EvoD, which was trained on the evolutionary properties of nsSNVs associated with drug responses in a sparse learning framework. Drug-EvoD achieves a TPR of 84% and a TNR of 53%, with a balanced accuracy of 69%, which improves upon other methods significantly. CONCLUSIONS: The new tool will enable researchers to computationally identify nsSNVs that may affect drug responses. However, much larger training and testing datasets are needed to develop more reliable and accurate tools.

There and back again: development and regeneration of the zebrafish lateral line system.

The zebrafish lateral line is a sensory system used to detect changes in water flow. It is comprised of clusters of mechanosensory hair cells called neuromasts. The lateral line is initially established by a migratory group of cells, called a primordium, that deposits neuromasts at stereotyped locations along the surface of the fish. Wnt, FGF, and Notch signaling are all important regulators of various aspects of lateral line development, from primordium migration to hair cell specification. As zebrafish age, the organization of the lateral line becomes more complex in order to accommodate the fish's increased size. This expansion is regulated by many of the same factors involved in the initial development. Furthermore, unlike mammalian hair cells, lateral line hair cells have the capacity to regenerate after damage. New hair cells arise from the proliferation and differentiation of surrounding support cells, and the molecular and cellular pathways regulating this are beginning to be elucidated. All in all, the zebrafish lateral line has proven to be an excellent model in which to study a diverse array of processes, including collective cell migration, cell polarity, cell fate, and regeneration.

The survival detriment of venous thromboembolism with epithelial ovarian cancer.

OBJECTIVE: The aim of this study is to evaluate the effect of venous thromboembolism (VTE) chronology with respect to surgery on survival with epithelial ovarian cancer (EOC). METHODS: An IRB approved, retrospective review was performed of patients treated for Stage I-IV EOC from 1996 to 2011. Cox proportional hazards model was used to assess associations between VTE and the primary outcomes of progression free survival (PFS) and overall survival (OS). SAS 9.3 was used for statistical analyses. RESULTS: 586 patients met study criteria. Median age was 63 years (range, 17-94); median BMI was 27.1 kg/m(2) (range, 13.7-67.0). Most tumors were high grade serous (68.3%) and advanced stage (III/IV, 75.4%). 3.7% had a preoperative VTE; 13.2% had a postoperative VTE. Upon multivariate analysis adjusting for age, stage, histology, performance status, and residual disease, preoperative VTE was predictive of OS (HR 3.1, 95% CI: 1.6-6.1, p=0.001) but not PFS (p=0.55). Postoperative VTE was associated with shorter PFS (HR 1.45, 95% CI: 1.04-2.02, p=0.03) and OS (HR 1.8, 95% CI: 1.3-2.6, p=0.001). When VTE timing was modeled, preoperative VTE (HR 3.5, 95% CI: 1.8-6.9, p<0.001) and postoperative VTE after primary therapy (HR 2.3, 95% CI: 1.4-3.6, p=0.001) were predictive of OS. CONCLUSION: Preoperative and postoperative VTE appear to have a detrimental effect on OS with EOC. When modeled as a binary variable, postoperative VTE attenuated PFS; however, when VTE timing was modeled, postoperative VTE was not associated with PFS. It is unclear whether VTE is an inherent poor prognostic marker or if improved VTE prophylaxis and treatment may enable similar survival to patients without these events.

Inpatient versus outpatient management of neutropenic fever in gynecologic oncology patients: is risk stratification useful?

OBJECTIVE: This study aimed to evaluate the utility of risk stratification of gynecologic oncology patients with neutropenic fever (NF). METHODS: A retrospective chart review of gynecologic cancer patients admitted with NF from 2007 to 2011 was performed, wherein demographic, oncologic, and NF characteristics (hospitalization length, complications, and death) were collected. The Multinational Association for Supportive Care in Cancer (MASCC) risk index score was calculated; low risk was considered ≥ 21. SAS 9.2 was used for statistical analyses. RESULTS: Eighty-three patients met the study criteria. Most (92%) were Caucasian and had advanced stage disease (71%). Primary tumors were 58% ovary, 35% endometrium, and 6% cervix. All patients were receiving chemotherapy on admission (72% for primary, 28% for recurrent disease). Forty-eight percent had a positive culture, and most (58%) positive cultures were urine. Seventy-six percent of patients were considered low risk. High-risk patients were more likely to have a severe complication (10% versus 50%, p=0.0003), multiple severe complications (3% versus 20%, p=0.0278), ICU admission (2% versus 40%, p<0.0001), overall mortality (2% versus 15%, p=0.0417), and death due to neutropenic fever (0% versus 15%, p=0.0124). MASCC had a positive predictive value of 50% and negative predictive value of 90%. The median MASCC score for all patients was 22 (range, 11-26), but the median MASCC score for those with death or a severe complication was 17 (range, 11-24). CONCLUSION: Based on this pilot data, MASCC score appears promising in determining suitability for outpatient management of NF in gynecologic oncology patients. Prospective study is ongoing to confirm safety and determine impact on cost.