Small-Molecule-Mediated Stabilization of PP2A Modulates the Homologous Recombination Pathway and Potentiates DNA Damage-Induced Cell Death.

High-grade serous carcinoma (HGSC) is the most common and lethal ovarian cancer subtype. PARP inhibitors (PARPi) have become the mainstay of HGSC-targeted therapy, given that these tumors are driven by a high degree of genomic instability (GI) and homologous recombination (HR) defects. Nonetheless, approximately 30% of patients initially respond to treatment, ultimately relapsing with resistant disease. Thus, despite recent advances in drug development and an increased understanding of genetic alterations driving HGSC progression, mortality has not declined, highlighting the need for novel therapies. Using a small-molecule activator of protein phosphatase 2A (PP2A; SMAP-061), we investigated the mechanism by which PP2A stabilization induces apoptosis in patient-derived HGSC cells and xenograft (PDX) models alone or in combination with PARPi. We uncovered that PP2A genes essential for cellular transformation (B56α, B56γ, and PR72) and basal phosphatase activity (PP2A-A and -C) are heterozygously lost in the majority of HGSC. Moreover, loss of these PP2A genes correlates with worse overall patient survival. We show that SMAP-061-induced stabilization of PP2A inhibits the HR output by targeting RAD51, leading to chronic accumulation of DNA damage and ultimately apoptosis. Furthermore, combination of SMAP-061 and PARPi leads to enhanced apoptosis in both HR-proficient and HR-deficient HGSC cells and PDX models. Our studies identify PP2A as a novel regulator of HR and indicate PP2A modulators as a therapeutic therapy for HGSC. In summary, our findings further emphasize the potential of PP2A modulators to overcome PARPi insensitivity, given that targeting RAD51 presents benefits in overcoming PARPi resistance driven by BRCA1/2 mutation reversions.

Prognostic Value of Tumor-Infiltrating Lymphocytes in Head and Neck Squamous Cell Carcinoma.

IMPORTANCE: Biomarkers that reflect prognosis and cellular immunity in patients with head and neck squamous cell carcinoma (HNSCC) are a prerequisite for improving individualized treatment that limits the intensity and morbidity of conventional treatment and may be useful in the introduction of new immunotherapy regimens. OBJECTIVE: To determine if specific classes of tumor-infiltrating lymphocytes (TILs) in pretreatment biopsy specimens have prognostic value for outcomes in a large training and validation cohort of patients with HNSCC. DESIGN, SETTING, AND PARTICIPANTS: In this prospective, epidemiologic study with a median follow-up of 47.5 months, in 464 previously untreated patients with available tissue for construction of tissue microarray, HNSCC disease sites included oral cavity (228), oropharynx (147), larynx (74), and hypopharynx (15). The training cohort consisted of 241 patients and the validation cohort consisted of 223 patients. Overall tumor stage was I (55), II (69), III (71), or IV (269). Patients were enrolled between November 2008 to October 2014. Data were analyzed between October 2018 to April 2019. MAIN OUTCOMES AND MEASURES: Semiquantitative levels of CD4, CD8, and FoxP3 lymphocytes were assessed by immunohistologic analysis and correlations with clinical prognostic factors, initial treatment modality, and overall survival (OS) and disease-specific (DSS) survival were determined. A principal component analysis was performed to generate a combined TIL-weighted sum score (TILws). RESULTS: Of the 464 participants, 135 (29%) were women; mean (SD) age was 61.1 (11.8) years. Higher CD8 counts were associated with improved OS in both training and validation sets (HR, 0.94; 95% CI, 0.90-0.98; and HR, 0.97; 95% CI, 0.95-0.99, respectively). Higher TILws levels were associated with improved OS and DSS in both the training set (HR, 0.91; 95% CI, 0.86-0.96; and HR, 0.93; 95% CI, 0.87-0.99, respectively) and validation set (HR, 0.96; 95% CI, 0.93-0.99; and HR, 0.94; 95% CI, 0.89-0.99, respectively). A multivariable Cox model controlling for batch, age, clinical stage, disease site, comorbidities, HPV status, and smoking, showed that higher TILws levels were associated with improved OS and DSS (HR, 0.94; 95% CI, 0.92-0.97; and HR, 0.94; 95% CI, 0.90-0.98, respectively). When grouped by treatment (surgery vs chemoradiation) and tested for interaction, treatment was found to be an effect modifier for CD4 levels and OS. Low CD4 levels were showed greater association with decreased survival in the chemoradiation cohort than the surgery cohort. CONCLUSIONS AND RELEVANCE: The findings from this large cohort study suggest that levels of TILs are an independent prognostic factor in patients with HNSCC. Subsets of TILs and combined TIL scores may be clinically useful predictive and prognostic factors.

Administration Safety of Blood Products - Lessons Learned from a National Registry for Transfusion and Hemotherapy Practice.

BACKGROUND: Compared to blood component safety, the administration of blood may not be as safe as intended. The German Interdisciplinary Task Force for Clinical Hemotherapy (IAKH) specialized registry for administration errors of blood products was chosen for a detailed analysis of reports. METHODS: Voluntarily submitted critical incident reports (n = 138) from 2009 to 2013 were analyzed. RESULTS: Incidents occurred in the operation room (34.1%), in the ICU (25.2%), and in the peripheral ward (18.5%). Procedural steps with errors were administration to the patient (27.2%), indication and blood order (17.1%), patient identification (17.1%), and blood sample withdrawal and tube labeling (18.0%). Bedside testing (BST) of blood groups avoided errors in only 2.6%. Associated factors were routine work conditions (66%), communication error (36%), emergency case (26%), night or weekend team (39%), untrained personnel (19%). Recommendations addressed process and quality (n = 479) as well as structure quality (n = 314). In 189 instances, an IT solution would have helped to avoid the error. CONCLUSIONS: The administration process is prone to errors at the patient assessment for the need to transfuse and the application of blood products to patients. BST is only detecting a minority of handling errors. According to the expert recommendations for practice improvement, the potential to improve transfusion safety by a technical solution is considerable.

Tumor infiltrating lymphocytes and survival in patients with head and neck squamous cell carcinoma.

BACKGROUND: Because immune responses within the tumor microenvironment are important predictors of tumor biology, correlations of types of tumor infiltrating lymphocytes (TILs) with clinical outcomes were determined in 278 patients with head and neck squamous cell carcinoma (HNSCC). METHODS: Infiltrating levels of CD4 (helper T cells), CD8 (cytotoxic/suppressor T cells), FoxP3 (regulatory T cells), CD68 (myeloid-derived suppressor cells,) and CD1a (Langerhans) cells were measured in tissue microarrays (TMAs). Cox models tested associations with patient outcomes after adjusting for all known prognostic factors. Median follow-up was 36.6 months. RESULTS: Higher CD4 and CD8 TIL levels were associated with improved overall survival (OS; hazard ratio [HR] = 0.77; 95% confidence interval [CI] = 0.65-0.93; p = .005 and HR = 0.77; 95% CI = 0.64-0.94; p = .008, respectively), and relapse-free survival (RFS; p = .03 and .05, respectively). After controlling for prognostic factors, higher CD4 levels predicted improved OS and disease-specific survival (DSS; p = .003 and p = .004, respectively). CONCLUSION: The findings suggest that TILs are a significant independent prognostic factor for HNSCC that differ by treatment. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1074-1084, 2016.

Tumor infiltrating lymphocytes (TIL) and prognosis in oral cavity squamous carcinoma: a preliminary study.

OBJECTIVES: Tumor infiltrating lymphocytes (TILs) in the microenvironment reflect may tumor biology and predict outcome. We previously demonstrated that infiltrates of CD4, CD8, and FoxP3 positive lymphocytes were associated with HPV-status and survival in oropharyngeal cancers. To determine if TILs were of prognostic importance in oral cancer, TIL levels were evaluated retrospectively in 52 oral cancer patients treated with surgery and correlations with outcome determined. METHODS: Complete TIL and clinical data were available for 39 patients. Levels of CD4, CD8, FoxP3 (Treg), CD68 and NK cells were assessed by immunohistochemistry in tumor cores on a tissue microarray. Associations with clinical variables, tobacco and alcohol use and histologic features were assessed using Spearman correlation coefficient and the non-parametric Kruskal-Wallis testing. Time-to-event outcomes were determined using univariate and multivariate Cox models. Median follow up was 60 months. RESULTS: The ratio of CD4/CD8 (p=.01) and CD8 infiltrates (p=.05) were associated with tumor recurrence but not overall survival. Lower CD4 infiltrates were associated with alcohol use (p=.005) and poor tumor differentiation (p=.02). Interestingly, higher levels of CD68+ macrophages were found associated with positive nodes (p=.06) and poorer overall survival (p=.07). Overall and DSS survival were significantly shorter for patients with positive nodes, extracapsular spread, or perineural invasion. CONCLUSION: Infiltrating immune cell levels in oral cavity cancer appear influenced by health behaviors and tumor characteristics. In contrast to oropharynx cancer, infiltrates of CD68 positive tumor associated macrophages may contribute to metastatic behavior and outcome in advanced oral cavity carcinoma.

Ribosomal protein S27-like is a physiological regulator of p53 that suppresses genomic instability and tumorigenesis.

Cell-based studies showed that several Mdm2-binding ribosomal proteins, upon overexpression, stabilize and activate p53. In contrast, here we show in a mouse knockout study that Mdm2-binding ribosomal protein S27-like (Rps27l), upon disruption, activates p53. Germline inactivation of Rps27l triggers ribosomal stress to stabilize Mdm2, which degrades Mdm4 to reduce Mdm2-Mdm4 E3 ligase towards p53, leading to p53-dependent apoptotic depletion of hematopoietic stem cells and postnatal death, which is rescued by Trp53 deletion. Paradoxically, while increased p53 is expected to inhibit tumorigenesis, Rps27l⁻/⁻;Trp53⁺/⁻ mice develop lymphomas at higher incidence with p53 loss-of-heterozygosity and severe genome aneuploidy, suggesting that Rps27l disruption impose a selection pressure against p53. Thus, Rps27l has dual functions in p53 regulation: under Trp53⁺/⁺ background, Rps27l disruption triggers ribosomal stress to induce p53 and apoptosis, whereas under Trp53⁺/⁻ background, Rps27l disruption triggers genomic instability and Trp53 deletion to promote tumorigenesis. Our study provides a new paradigm of p53 regulation.

AZGP1 autoantibody predicts survival and histone deacetylase inhibitors increase expression in lung adenocarcinoma.

INTRODUCTION: The importance of alpha-2-glycoprotein 1, zinc (AZGP1) in lung adenocarcinoma (AD) remains largely unknown. Analysis of serum autoantibodies to tumor antigens combined with gene expression profiling of primary tumors may provide insight into the mechanisms underlying lung carcinogenesis and identify new AD biomarkers. METHODS: T7 phage cDNA libraries were used to identify AZGP1 autoantibodies in the serum of 473 patients (192 ADs, 192 matched controls, and 89 additional ADs for confirmation of findings). AZGP1 mRNA expression was examined in 86 ADs and 10 control lung tissue samples using oligonucleotide microarrays. AZGP1 protein expression was studied in 230 tissue samples (222 ADs; 8 controls) with immunohistochemistry. Kaplan-Meier analyses were used to correlate circulating autoantibody and tissue mRNA production with survival. AD cell lines A549 and SKLU1 were treated with 5-aza-2;-deoxycytidine (5-AZA) and trichostatin A (TSA) to examine the role of promoter methylation and histone deacetylation in the expression of AZGP1. Real-time polymerase chain reaction was used to quantify the effects of treatment. RESULTS: In patients with AD, AZGP1 autoantibodies were observed in 40% of serum samples. Autoantibody production correlated with improved overall 5-year survival (p = 0.002) and improved survival in those with stage I to II disease (p = 0.008). A verification analysis was performed for the survival benefit and found similar results with p values of 0.02 and 0.036, respectively. Although abundant mRNA expression was found in a subset of tumors, mRNA expression did not correlate with prognosis. In normal lung, AZGP1 mRNA and protein expression were low or absent, whereas in AD they were highly expressed in 31.3% and 42.8% of samples, respectively. To determine whether AZGP1 expression in this subset of tumors might be affected by epigenetic mechanisms, low AZGP1-expressing A549 and SKLU1 AD cell lines were treated with TSA and 5-AZA. A 713-fold and 169-fold increase in mRNA expression were noted on treatment with TSA, respectively. Treatment with 5-AZA had minimal effect on AZGP1 mRNA expression. CONCLUSIONS: The presence of AZGP1 serum autoantibody may be used as a prognostic marker in patients with AD. Furthermore, up-regulation of AZGP1 mRNA in AD may be affected by chromatin remodeling by means of histone acetylation.

Effect of image normalization on carotid plaque classification and the risk of ipsilateral hemispheric ischemic events: results from the asymptomatic carotid stenosis and risk of stroke study.

The aim of this study was to determine the effect of image normalization on plaque classification and the risk of ipsilateral ischemic neurologic events in patients with asymptomatic carotid stenosis. The first 1,115 patients recruited to the Asymptomatic Carotid Stenosis and Risk of Stroke (ACSRS) study with a follow-up of 6 to 84 months (mean 37.1 months) were included in this study. Duplex ultrasonography was used for grading the degree of internal carotid artery stenosis and for plaque characterization (types 1-5), which was performed before and after image normalization. One hundred sixteen ipsilateral ischemic hemispheric events occurred. Image normalization resulted in 60% of plaques being reclassified. Before image normalization, a high event rate was associated with all types of plaque. After image normalization, 109 (94%) of the events occurred in patients with plaque types 1 to 3. For patients with European Carotid Stenosis Trial (ECST) 70 to 99% diameter stenosis (equivalent to North American Symptomatic Carotid Endarterectomy Trial [NASCET] 50-99%) with plaque types 1 to 3, the cumulative stroke rate was 14% at 7 years (2% per year), and for patients with plaque types 4 and 5, the cumulative stroke rate was 0.9% at 7 years (0.14% per year). The results suggest that asymptomatic patients with plaque types 4 and 5 classified as such after image normalization are at low risk irrespective of the degree of stenosis.