Summary Tumor-associated macrophages (TAMs) represent a major component of the tumor microenvironment supporting tumorigenesis. TAMs re-education has been proposed as a strategy to promote tumor inhibition. However, whether this approach may work in prostate cancer is unknown. Here we find that Pten -null prostate tumors are strongly infiltrated by TAMs expressing C-X-C chemokine receptor type 2 (CXCR2), and activation of this receptor through CXCL2 polarizes macrophages toward an anti-inflammatory phenotype. Notably, pharmacological blockade of CXCR2 receptor by a selective antagonist promoted the re-education of TAMs toward a pro-inflammatory phenotype. Strikingly, CXCR2 knockout monocytes infused in Pten pc−/− ; Trp53 pc−/− mice differentiated in tumor necrosis factor alpha (TNF-α)-releasing pro-inflammatory macrophages, leading to senescence and tumor inhibition. Mechanistically, PTEN -deficient tumor cells are vulnerable to TNF-α-induced senescence, because of an increase of TNFR1 . Our results identify TAMs as targets in prostate cancer and describe a therapeutic strategy based on CXCR2 blockade to harness anti-tumorigenic potential of macrophages against this disease.

Recent studies revealed that acquired resistance to AZD9291 is mediated mainly by the EGFR C797S mutation or loss of the EGFR T790M mutation in patients *Corresponding author.Disclosure: The authors declare no conflict of interest.

No abstract

No abstract

Background The identification of diagnostic/prognostic biomarkers for asbestos-related diseases is relevant for early diagnosis and patient survival and may contribute to understanding the molecular mechanisms underlying the disease development and progression. Aims To identify a pattern of miRNAs as possible diagnostic biomarkers for patients with malignant pleural mesothelioma (MPM) and asbestosis (ASB) and as prognostic biomarkers for MPM patients. Methods miRNA-16, miRNA-17, miRNA-126, and miRNA-486 were quantified in plasma and formalin-fixed paraffin-embedded samples to evaluate their diagnostic and prognostic roles compared to patients with other noncancerous pulmonary diseases (controls). Results. The expression of all the miRNAs was significantly lower in patients with MPM and ASB than that in controls. miRNA-16, miRNA-17, and miRNA-486 in plasma and tissue of MPM patients were significantly correlated. Furthermore, the expression of miRNA-16 in plasma and tissue, and miRNA-486 only in tissue, was positively related with cumulative survival in MPM patients. Conclusions All the miRNA levels were decreased in patients with MPM or ASB, supporting the role of circulating miRNAs as a potential tool for diseases associated with exposure to asbestos fibers. miRNA-16 was directly related to MPM patient prognosis, suggesting its possible use as a prognostic marker in MPM patients.

The diagnostic criteria of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) are not well defined, and DIPNECH can be mistaken for carcinoids associated with neuroendocrine cell hyperplasia (NECH). In this study, we compared clinical, radiologic, histologic, immunohistochemical, and molecular features of DIPNECH and isolated carcinoids with/without NECH. The study population included 151 cases (77 female patients and 74 male patients), 19 with DIPNECH and 132 with carcinoids with/without NECH. None of the cases displayed molecular alterations or anaplastic lymphoma kinase expression. Compared with individuals with carcinoids with/without NECH, patients with DIPNECH were more likely to be female individuals (P<0.0001), nonsmokers (P=0.021), and symptomatic, and to have an obstructive/mixed respiratory defect, peripheral location of the lesions, and air trapping (P<0.0001) on chest computed tomography, and constrictive bronchiolitis on histology (P<0.0001). Among immunohistochemical markers, DIPNECH was associated with higher expression of thyroid transcription factor-1, CD10, and gastrin-releasing peptide/bombesin-like peptide (P<0.0001). Yet, when a purely histopathologic definition of DIPNECH was applied, 40% of isolated carcinoids also met the diagnostic criteria for DIPNECH, even in the absence of symptoms and/or radiologic abnormalities. Therefore, as DIPNECH represents a distinct clinical syndrome, we suggest the term DIPNECH be limited to cases presenting with respiratory symptoms, functional and/or radiologic abnormalities, and constrictive bronchiolitis on histology.

No abstract

Activation of NOTCH signalling is associated with advanced prostate cancer and treatment resistance in prostate cancer patients. However, the mechanism that drives NOTCH activation in prostate cancer remains still elusive. Moreover, preclinical evidence of the therapeutic efficacy of NOTCH inhibitors in prostate cancer is lacking. Here, we provide evidence that PTEN loss in prostate tumours upregulates the expression of ADAM17, thereby activating NOTCH signalling. Using prostate conditional inactivation of both Pten and Notch1 along with preclinical trials carried out in Pten-null prostate conditional mouse models, we demonstrate that Pten-deficient prostate tumours are addicted to the NOTCH signalling. Importantly, we find that pharmacological inhibition of γ-secretase promotes growth arrest in both Pten-null and Pten/Trp53-null prostate tumours by triggering cellular senescence. Altogether, our findings describe a novel pro-tumorigenic network that links PTEN loss to ADAM17 and NOTCH signalling, thus providing the rational for the use of γ-secretase inhibitors in advanced prostate cancer patients.