Transcriptomics and proteomics revealed sex differences in human pulmonary microvascular endothelial cells.

Marked sexual dimorphism is displayed in the onset and progression of pulmonary hypertension (PH). Females more commonly develop pulmonary arterial hypertension, yet females with pulmonary arterial hypertension and other types of PH have better survival than males. Pulmonary microvascular endothelial cells play a crucial role in pulmonary vascular remodeling and increased pulmonary vascular resistance in PH. Given this background, we hypothesized that there are sex differences in the pulmonary microvascular endothelium basally and in response to hypoxia that are independent of the sex hormone environment. Human pulmonary microvascular endothelial cells (HPMECs) from healthy male and female donors, cultured under physiological shear stress, were analyzed using RNA sequencing and label-free quantitative proteomics. Gene set enrichment analysis identified a number of sex-different pathways in both normoxia and hypoxia, including pathways that regulate cell proliferation. In vitro, the rate of proliferation in female HPMECs was lower than in male HPMECs, a finding that supports the omics results. Interestingly, thrombospondin-1, an inhibitor of proliferation, was more highly expressed in female cells than in male cells. These results demonstrate, for the first time, important differences between female and male HPMECs that persist in the absence of sex hormone differences and identify novel pathways for further investigation that may contribute to sexual dimorphism in pulmonary hypertensive diseases.NEW & NOTEWORTHY There is marked sexual dimorphism in the development and progression of pulmonary hypertension. We show differences in RNA and protein expression between female and male human pulmonary microvascular endothelial cells grown under conditions of physiological shear stress, which identify sex-different cellular pathways both in normoxia and hypoxia. Importantly, these differences were detected in the absence of sex hormone differences. The pathways identified may provide novel targets for the development of sex-specific therapies.

Exosomes: a new perspective in EGFR-mutated lung cancer.

Exosomes are major contributors in cell to cell communication due to their ability to transfer biological material such as protein, RNA, DNA, and miRNA. Additionally, they play a role in tumor initiation, promotion, and progression, and recently, they have emerged as a potential source of information on tumor detection and may be useful as diagnostic, prognostic, and predictive tools. This review focuses on exosomes from lung cancer with a focus on EGFR mutations. Here, we outline the role of exosomes and their functional effect in carcinogenesis, tumor progression, and metastasis. Finally, we discuss the possibility of exosomes as novel biomarkers in early detection, diagnosis, assessment of prognosis, and prediction of therapeutic response in EGFR-mutated lung cancer.

FHITlow /pHER2high signature in non-small cell lung cancer is predictive of anti-HER2 molecule efficacy.

Despite its efficacy in solid tumours, in particular HER2+ breast cancer, HER2-targeted therapy has given rise to disappointing results in non-small cell lung cancer (NSCLC). With the aim of refining the target population for anti-HER2 therapies in NSCLC, we investigated the relationships between HER2 and the tumour suppressor fragile histidine triad (FHIT) in lung tumour cells. First, we observed a negative correlation between FHIT expression and the activated form of HER2 (pHER2) in NSCLC samples and in lung tumour cell lines. Moreover, the silencing or overexpression of FHIT in lung cell lines led to an increase or decrease of HER2 activity, respectively. We also demonstrated that two anti-HER2 drugs, irbinitinib and trastuzumab, restore a more epithelial phenotype and counteract cell invasiveness and growth of FHIT-silenced tumour cell lines. Finally, we showed that the FHITlow /pHER2high phenotype predicts sensitivity to an anti-HER2 therapy in primary tumour cells from NSCLC patients. Our results show that FHIT regulates the activity of HER2 in lung tumour cells and that FHIT-inactivated tumour cells are sensitive to HER2 inhibitors. A new subclass of patients with NSCLC may be eligible for an anti-HER2 therapy. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Exosomes from EGFR-Mutated Adenocarcinoma Induce a Hybrid EMT and MMP9-Dependant Tumor Invasion.

Exosomes, a class of extra cellular nano-sized vesicles (EVs), and their contents have gained attention as potential sources of information on tumor detection and regulatory drivers of tumor progression and metastasis. The effect of exosomes isolated from patients with an Epidermal Growth Factor Receptor (EGFR)-mutated adenocarcinoma on the promotion of epithelial-mesenchymal transition (EMT) and invasion were examined. Exosomes derived from serum of patients with EGFR-mutated non-small cell lung cancer (NSCLC) mediate the activation of the Phosphoinositide 3-kinase (PI3K)/AKT/ mammalian target of rapamycin (mTOR) pathway and induce an invasion through the up-regulation of matrix metalloproteinase-9 (MMP-9) in A549 cells. We observed a significant increase in the expression of vimentin, a mesenchymal marker, while retaining the epithelial characteristics, as evidenced by the unaltered levels of E-cadherin and Epithelial cell adhesion molecule (EPCAM). We also observed an increase of nuclear factor erythroid 2-related factor 2 (NFR2) and P-cadherin expression, markers of hybrid EMT. Exosomes derived from EGFR-mutated adenocarcinoma serum could be a potential mediator of hybrid EMT and tumor invasion. Understanding how cancerous cells communicate and interact with their environment via exosomes will improve our understanding of lung cancer progression and metastasis formation.