Microglia Mediate Contact-Independent Neuronal Network Remodeling via Secreted Neuraminidase-3 Associated with Extracellular Vesicles.

Neurons communicate with each other through electrochemical transmission at synapses. Microglia, the resident immune cells of the central nervous system, modulate this communication through a variety of contact-dependent and -independent means. Microglial secretion of active sialidase enzymes upon exposure to inflammatory stimuli is one unexplored mechanism of modulation. Recent work from our lab showed that treatment of neurons with bacterial sialidases disrupts neuronal network connectivity. Here, we find that activated microglia secrete neuraminidase-3 (Neu3) associated with fusogenic extracellular vesicles. Furthermore, we show that Neu3 mediates contact-independent disruption of neuronal network synchronicity through neuronal glycocalyx remodeling. We observe that NEU3 is transcriptionally upregulated upon exposure to inflammatory stimuli and that a genetic knockout of NEU3 abrogates the sialidase activity of inflammatory microglial secretions. Moreover, we demonstrate that Neu3 is associated with a subpopulation of extracellular vesicles, possibly exosomes, that are secreted by microglia upon inflammatory insult. Finally, we demonstrate that Neu3 is necessary and sufficient to both desialylate neurons and decrease neuronal network connectivity. These results implicate Neu3 in remodeling of the glycocalyx leading to aberrant network-level activity of neurons, with implications in neuroinflammatory diseases such as Parkinson's disease and Alzheimer's disease.

Microglia mediate contact-independent neuronal pruning via secreted Neuraminidase-3 associated with extracellular vesicles.

Neurons communicate with each other through electrochemical transmission at synapses. Microglia, the resident immune cells of the central nervous system, can prune these synapses through a variety of contact-dependent and -independent means. Microglial secretion of active sialidase enzymes upon exposure to inflammatory stimuli is one unexplored mechanism of pruning. Recent work from our lab showed that treatment of neurons with bacterial sialidases disrupts neuronal network connectivity. Here, we find that activated microglia secrete Neuraminidase-3 (Neu3) associated with fusogenic extracellular vesicles. Furthermore, we show Neu3 mediates contact-independent pruning of neurons and subsequent disruption of neuronal networks through neuronal glycocalyx remodeling. We observe that NEU3 is transcriptionally upregulated upon exposure to inflammatory stimuli, and that a genetic knock-out of NEU3 abrogates the sialidase activity of inflammatory microglial secretions. Moreover, we demonstrate that Neu3 is associated with a subpopulation of extracellular vesicles, possibly exosomes, that are secreted by microglia upon inflammatory insult. Finally, we demonstrate that Neu3 is both necessary and sufficient to both desialylate neurons and decrease neuronal network connectivity. These results implicate Neu3 in remodeling of the glycocalyx leading to aberrant network-level activity of neurons, with implications in neuroinflammatory diseases such as Parkinson's disease and Alzheimer's disease.

Angiogenic and immunomodulatory biomarkers in axitinib-treated patients with advanced renal cell carcinoma.

Aim: Immunomodulatory mechanisms contributing to angiogenic inhibition in renal tumors are not well characterized. We report associations between efficacy and tumor-associated immune cells and mRNA/miRNA expression in patients from AXIS. Materials & methods: Immunohistochemistry (n = 52) and mRNA/miRNA expression analyses (n = 72) were performed on tumor samples. Results: In axitinib-treated patients, higher CXCR4 and TLR3 expression, respectively, was associated with longer progression-free survival (hazard ratio; 95% CI: 0.3; 0.1-0.8 and 0.4; 0.2-0.9) and showed interaction with treatment (p = 0.029 and p < 0.001); lower CCR7 expression was associated with objective response (odds ratio: 0.1; 95% CI: 0.01-1.0) and longer overall survival (hazard ratio: 3.9; 95% CI: 1.4-10.3). Conclusion: CCR7, CXCR4 and TLR3 expression levels may be prognostic/predictive of clinical benefit with axitinib. Clinical trial identifier: ClinicalTrials.gov NCT00678392.

Antitumor activity of crizotinib in lung cancers harboring a MET exon 14 alteration.

MET exon 14 alterations are oncogenic drivers of non-small-cell lung cancers (NSCLCs)1. These alterations are associated with increased MET activity and preclinical sensitivity to MET inhibition2. Crizotinib is a multikinase inhibitor with potent activity against MET3. The antitumor activity and safety of crizotinib were assessed in 69 patients with advanced NSCLCs harboring MET exon 14 alterations. Objective response rate was 32% (95% confidence interval (CI), 21-45) among 65 response-evaluable patients. Objective responses were observed independent of the molecular heterogeneity that characterizes these cancers and did not vary by splice-site region and mutation type of the MET exon 14 alteration, concurrent increased MET copy number or the detection of a MET exon 14 alteration in circulating tumor DNA. The median duration of response was 9.1 months (95% CI, 6.4-12.7). The median progression-free survival was 7.3 months (95% CI, 5.4-9.1). MET exon 14 alteration defines a molecular subgroup of NSCLCs for which MET inhibition with crizotinib is active. These results address an unmet need for targeted therapy in people with lung cancers with MET exon 14 alterations and adds to an expanding list of genomically driven therapies for oncogenic subsets of NSCLC.

Lorlatinib in advanced ROS1-positive non-small-cell lung cancer: a multicentre, open-label, single-arm, phase 1-2 trial.

BACKGROUND: Lorlatinib is a potent, brain-penetrant, third-generation tyrosine kinase inhibitor (TKI) that targets ALK and ROS1 with preclinical activity against most known resistance mutations in ALK and ROS1. We investigated the antitumour activity and safety of lorlatinib in advanced, ROS1-positive non-small-cell lung cancer (NSCLC). METHODS: In this open-label, single-arm, phase 1-2 trial, we enrolled patients (aged ≥18 years) with histologically or cytologically confirmed advanced ROS1-positive NSCLC, with or without CNS metastases, with an Eastern Cooperative Oncology Group performance status of 2 or less (≤1 for phase 1 only) from 28 hospitals in 12 countries worldwide. Lorlatinib 100 mg once daily (escalating doses of 10 mg once daily to 100 mg twice daily in phase 1 only) was given orally in continuous 21-day cycles until investigator-determined disease progression, unacceptable toxicity, withdrawal of consent, or death. The primary endpoint was overall and intracranial tumour response, assessed by independent central review. Activity endpoints were assessed in patients who received at least one dose of lorlatinib. This study is ongoing and is registered with ClinicalTrials.gov, NCT01970865. FINDINGS: Between Jan 22, 2014, and Oct 2, 2016, we assessed 364 patients, of whom 69 with ROS1-positive NSCLC were enrolled. 21 (30%) of 69 patients were TKI-naive, 40 (58%) had previously received crizotinib as their only TKI, and eight (12%) had previously received one non-crizotinib ROS1 TKI or two or more ROS1 TKIs. The estimated median duration of follow-up for response was 21·1 months (IQR 15·2-30·3). 13 (62%; 95% CI 38-82) of 21 TKI-naive patients and 14 (35%; 21-52) of 40 patients previously treated with crizotinib as their only TKI had an objective response. Intracranial responses were achieved in seven (64%; 95% CI 31-89) of 11 TKI-naive patients and 12 (50%; 29-71) of 24 previous crizotinib-only patients. The most common grade 3-4 treatment-related adverse events were hypertriglyceridaemia (13 [19%] of 69 patients) and hypercholesterolaemia (ten [14%]). Serious treatment-related adverse events occurred in five (7%) of 69 patients. No treatment-related deaths were reported. INTERPRETATION: Lorlatinib showed clinical activity in patients with advanced ROS1-positive NSCLC, including those with CNS metastases and those previously treated with crizotinib. Because crizotinib-refractory patients have few treatment options, lorlatinib could represent an important next-line targeted agent. FUNDING: Pfizer.

Pharmacogenomic analyses of sunitinib in patients with pancreatic neuroendocrine tumors.

Aim: Evaluate associations between clinical outcomes and SNPs in patients with well-differentiated pancreatic neuroendocrine tumors receiving sunitinib. Patients & methods: Kaplan-Meier and Cox proportional hazards models were used to analyze the association between SNPs and survival outcomes using data from a sunitinib Phase IV (genotyped, n = 56) study. Fisher's exact test was used to analyze objective response rate and genotype associations. Results: After multiplicity adjustment, progression-free and overall survivals were not significantly correlated with SNPs; however, a higher objective response rate was significantly associated with IL1B rs16944 G/A versus G/G (46.4 vs 4.5%; p = 0.001). Conclusion: IL1B SNPs may predict treatment response in patients with pancreatic neuroendocrine tumors. VEGF pathway SNPs are potentially associated with survival outcomes.

ALK Resistance Mutations and Efficacy of Lorlatinib in Advanced Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer.

PURPOSE: Lorlatinib is a potent, brain-penetrant, third-generation anaplastic lymphoma kinase (ALK)/ROS1 tyrosine kinase inhibitor (TKI) with robust clinical activity in advanced ALK-positive non-small-cell lung cancer, including in patients who have failed prior ALK TKIs. Molecular determinants of response to lorlatinib have not been established, but preclinical data suggest that ALK resistance mutations may represent a biomarker of response in previously treated patients. PATIENTS AND METHODS: Baseline plasma and tumor tissue samples were collected from 198 patients with ALK-positive non-small-cell lung cancer from the registrational phase II study of lorlatinib. We analyzed plasma DNA for ALK mutations using Guardant360. Tumor tissue DNA was analyzed using an ALK mutation-focused next-generation sequencing assay. Objective response rate, duration of response, and progression-free survival were evaluated according to ALK mutation status. RESULTS: Approximately one quarter of patients had ALK mutations detected by plasma or tissue genotyping. In patients with crizotinib-resistant disease, the efficacy of lorlatinib was comparable among patients with and without ALK mutations using plasma or tissue genotyping. In contrast, in patients who had failed 1 or more second-generation ALK TKIs, objective response rate was higher among patients with ALK mutations (62% v 32% [plasma]; 69% v 27% [tissue]). Progression-free survival was similar in patients with and without ALK mutations on the basis of plasma genotyping (median, 7.3 months v 5.5 months; hazard ratio, 0.81) but significantly longer in patients with ALK mutations identified by tissue genotyping (median, 11.0 months v 5.4 months; hazard ratio, 0.47). CONCLUSION: In patients who have failed 1 or more second-generation ALK TKIs, lorlatinib shows greater efficacy in patients with ALK mutations compared with patients without ALK mutations. Tumor genotyping for ALK mutations after failure of a second-generation TKI may identify patients who are more likely to derive clinical benefit from lorlatinib.

Phase III Trial of Adjuvant Sunitinib in Patients with High-Risk Renal Cell Carcinoma: Exploratory Pharmacogenomic Analysis.

PURPOSE: In the S-TRAC trial, adjuvant sunitinib prolonged disease-free survival (DFS) versus placebo in patients with loco-regional renal cell carcinoma at high risk of recurrence after nephrectomy. An exploratory analysis evaluated associations between SNPs in several angiogenesis- or hypoxia-related genes and clinical outcomes in S-TRAC. PATIENTS AND METHODS: Blood samples were genotyped for 10 SNPs and one insertion/deletion mutation using TaqMan assays. DFS was compared using log-rank tests for each genotype in sunitinib versus placebo groups and between genotypes within each of three (sunitinib, placebo, and combined sunitinib plus placebo) treatment groups. P values were unadjusted. RESULTS: In all, 286 patients (sunitinib, n = 142; placebo, n = 144) were genotyped. Longer DFS [HR; 95% confidence interval (CI)] was observed with sunitinib versus placebo for VEGFR1 rs9554320 C/C (HR 0.44; 95% CI, 0.21-0.91; P = 0.023), VEGFR2 rs2071559 T/T (HR 0.46; 95% CI, 0.23-0.90; P = 0.020), and eNOS rs2070744 T/T (HR 0.53; 95% CI, 0.30-0.94; P = 0.028). Shorter DFS was observed for VEGFR1 rs9582036 C/A versus C/C with sunitinib, placebo, and combined therapies (P ≤ 0.05), and A/A versus C/C with sunitinib (P = 0.022). VEGFR1 rs9554320 A/C versus A/A was associated with shorter DFS in the placebo (P = 0.038) and combined (P = 0.006) groups. CONCLUSIONS: Correlations between VEGFR1 and VEGFR2 SNPs and longer DFS with sunitinib suggest germline SNPs are predictive of improved outcomes with adjuvant sunitinib in patients with renal cell carcinoma. Independent validation studies are needed to confirm these findings.

Immune Biomarkers Predictive for Disease-Free Survival with Adjuvant Sunitinib in High-Risk Locoregional Renal Cell Carcinoma: From Randomized Phase III S-TRAC Study.

Purpose: Adjuvant sunitinib therapy compared with placebo prolonged disease-free survival (DFS) in patients with locoregional high-risk renal cell carcinoma (RCC) in the S-TRAC trial (ClinicalTrials.gov number NCT00375674). A prospectively designed exploratory analysis of tissue biomarkers was conducted to identify predictors of treatment benefit.Experimental Design: Tissue blocks were used for immunohistochemistry (IHC) staining of programmed cell death ligand 1 (PD-L1), CD4, CD8, and CD68. DFS was compared between < versus ≥ median IHC parameter using the Kaplan-Meier method. For biomarkers with predictive potential, receiver operating characteristics curves were generated.Results: Baseline characteristics were similar in patients with (n = 191) and without (n = 419) IHC analysis. Among patients with IHC, longer DFS was observed in patients with tumor CD8+ T-cell density ≥ versus < median [median (95% CI), not reached (6.83-not reached) versus 3.47 years (1.73-not reached); hazard ratio (HR) 0.40 (95% CI, 0.20-0.81); P = 0.009] treated with sunitinib (n = 101), but not with placebo (n = 90). The sensitivity and specificity for CD8+ T-cell density in predicting DFS were 0.604 and 0.658, respectively. Shorter DFS was observed in placebo-treated patients with PD-L1+ versus PD-L1- tumors (HR 1.75; P = 0.103). Among all patients with PD-L1+ tumors, DFS was numerically longer with sunitinib versus placebo (HR 0.58; P = 0.175).Conclusions: Greater CD8+ T-cell density in tumor tissue was associated with longer DFS with sunitinib but not placebo, suggesting predictive treatment effect utility. Further independent cohort validation studies are warranted. The prognostic value of PD-L1 expression in primary tumors from patients with high-risk nonmetastatic RCC should also be further explored. Clin Cancer Res; 24(7); 1554-61. ©2018 AACR.

A phase I study of PF-04449913, an oral hedgehog inhibitor, in patients with advanced solid tumors.

PURPOSE: To estimate the maximum tolerated dose (MTD) of single-agent PF-04449913, and to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity in patients with advanced tumors. EXPERIMENTAL DESIGN: A 3+3 design was used in this open-label, multicenter, phase I study and dose escalation/de-escalation applied until identification of the MTD. PF-04449913 was orally administered once daily in continuous 28-day treatment cycles. The starting dose was 80 mg. RESULTS: A total of 23 patients were enrolled; 19 were evaluable for first-cycle dose-limiting toxicity (DLT). The first-cycle DLT rate at the 640 mg dose level was 33.3%, and the MTD was estimated to be 320 mg once daily. The recommended phase II dose was not determined. PF-04449913 was generally well tolerated at doses of 80 to 320 mg once daily. The most common treatment-related adverse events (AE) were grade 1-2 dysgeusia, fatigue, decreased appetite, nausea, dizziness, dehydration, and diarrhea. Treatment-related grade 3 AEs only occurred in patients receiving PF-04449913 640 mg once daily. No treatment-related grade 4-5 AEs were reported. Pharmacokinetic analysis indicated a generally dose-proportional kinetics with biphasic elimination, supporting once-daily dosing. PF-04449913 modulated hedgehog signaling at the dose levels tested, as demonstrated by >80% downregulation of GLI1 expression in the skin of treated patients. Eight patients (34.8%) achieved stable disease; none had complete or partial response. Three patients with disease progression at enrollment had prolonged disease stabilization (≥6 months). CONCLUSIONS: The results obtained in this study support further evaluation of PF-04449913 in patients with advanced solid tumors.

Phase II open-label study of sunitinib in patients with advanced breast cancer.

This multicenter, open-label phase II study was conducted to evaluate sunitinib monotherapy in patients with either metastatic or locoregionally recurrent advanced breast cancer. Patients received sunitinib 37.5 mg on a continuous daily dosing schedule. The primary endpoint was objective response rate (ORR); the predefined target ORR was 25 %. All 83 patients enrolled into the study received study treatment. The majority of patients (90 %) had metastatic disease; 92 % had received prior systemic therapies, and 60 % had received two or more regimens for early and/or advanced disease. The ORR was 8 % (95 % exact CI, 4-17), comprising seven partial responses. In patients with superficial lesions (defined as cutaneous or palpable chest wall lesions), the ORR was 20 % (three of 15 evaluable patients), which was higher than that in patients with non-superficial disease (9 %; six of 64 patients). Median progression-free survival in the overall population was 3.6 months (95 % CI, 2.4-3.9); median overall survival was 15.6 months (95 % CI, 14.0-22.7). No new or unexpected safety findings were reported. The most commonly reported adverse events (AEs) were fatigue (60 %), diarrhea (54 %), and nausea (49 %). The most commonly reported grade 3/4 AEs were fatigue (17 %), neutropenia (16 %), and thrombocytopenia (11 %). Four patients (5 %) had a dose reduction due to an AE, and 39 patients (47 %) had temporary discontinuations of therapy due to AEs. Two on-study deaths were reported, one due to a pulmonary embolism (considered related to treatment) and one attributed to dyspnea and a myocardial infarction (considered unrelated to treatment). Patient-reported outcomes suggested that sunitinib treatment did not have a negative impact overall on patients' functional domains or the majority of symptom scales. The trial did not meet its prespecified primary endpoint, and in view of the negative results obtained in several other trials, sunitinib will not be developed further for this indication.

Elevated levels and distinct patterns of expression of A-type cyclins and their associated cyclin-dependent kinases in male germ cell tumors.

Aberrant expression of several key regulators controlling the G1/S phase of the cell cycle has been implicated in human male germ cell tumorigenesis. Given the critical role of cyclin A2 at both the G1/S and G2/M transitions and the essential role for cyclin A1 in male germ cell development, our present study focused on the involvement of the A-type cyclins in the transformation and progression of male germ cell tumors (GCTs). The expression of the A-type cyclins and their catalytic partners Cdk1 and Cdk2 was examined in all types and stages of human male GCTs, including carcinoma in situ(CIS), seminoma and non-seminoma GCTs, along with normal testis samples. Elevated levels of cyclin A2, Cdk1 and Cdk2 were detected in the majority of GCTs and were correlated with the invasiveness of the tumors (p < 0.05). Cyclin A1 expression was virtually undetectable in CIS and seminoma, but was aberrantly expressed in all non-seminomatous GCTs. Cyclin A2 expression was strongly correlated with that of its catalytic partners Cdk1 and Cdk2 in all types of testicular tumors examined (p < 0.05), whereas a strong correlation between cyclin A1 and Cdk1 or Cdk2 was only seen in non-seminomatous GCTs (p < 0.05). Histone kinase activities of cyclin A1/Cdks and cyclin A2/Cdks were found to be elevated in tumors. Our data suggest that aberrant expression of A-type cyclins and their Cdks is a significant factor in male germ cell tumorigenesis. The abundant ectopic expression of cyclin A1 in non-seminomatous GCTs and its absence in CIS and seminomas is likely linked to the tumor transformation and progression and may be relevant to clinical prognosis.

Detection of hTERT mRNA in colonic brush specimens as an adjunct to cytopathologic diagnosis of colonic adenocarcinoma.

OBJECTIVE: To investigate the role of reverse transcriptase polymerase chain reaction (RT-PCR) in determining telomerase catalytic subunit (hTERT) mRNA to assist with the diagnosis of colonic adenocarcinoma (CCA) in colonic brush cytology specimens. STUDY DESIGN: Twenty-seven colonic brushes of CCA were obtained. Initial cytologic diagnoses included CCA, suspicious for CCA (SFC), atypical (ATY) and unsatisfactory. The cytologic specimens were reviewed. A homogeneous RT-PCR assay for hTERT mRNA was performed on 27 colonic brushes of CCA and 24 controls (10 negative brushes, 6 resected CCA and 8 benign colonic mucosa from resected specimens). A RT-PCR assay for beta 2-microglobulin was used as an internal control for mRNA quality. RESULTS: On review, the initial cytopathologic diagnosis of CCA was confirmed in all 7 cases. In addition, 7 of 19 initially interpreted as SFC and ATY seemed to demonstrate unequivocal cytomorphologic features of malignancy. Telomerase mRNA was more often expressed in CCA than in negative controls in both brush (30%) and resected specimens (57%) (P < .05). Seven cases with hTERT mRNA expression were initially diagnosed as CCA (three), SFC (three) and ATY (one). CONCLUSION: CCA may be underdiagnosed in brush cytopathology. The expression of hTERT mRNA may be determined by RT-PCR in brush specimens and may eventually prove to be a useful diagnostic adjunct in the interpretation of inconclusive cases of CCA. Sparse cellularity in brush specimens may result in a relatively low rate of hTERT detection in colonic brushes of CCA; inflammatory changes may contribute to a higher-than-expected rate of hTERT expression in benign colonic epithelium.