In cancer, the epithelial-to-mesenchymal transition (EMT) is associated with tumour stemness, metastasis and resistance to therapy. It has recently been proposed that, rather than being a binary process, EMT occurs through distinct intermediate states. However, there is no direct in vivo evidence for this idea. Here we screen a large panel of cell surface markers in skin and mammary primary tumours, and identify the existence of multiple tumour subpopulations associated with different EMT stages: from epithelial to completely mesenchymal states, passing through intermediate hybrid states. Although all EMT subpopulations presented similar tumour-propagating cell capacity, they displayed differences in cellular plasticity, invasiveness and metastatic potential. Their transcriptional and epigenetic landscapes identify the underlying gene regulatory networks, transcription factors and signalling pathways that control these different EMT transition states. Finally, these tumour subpopulations are localized in different niches that differentially regulate EMT transition states.

FAT1, which encodes a protocadherin, is one of the most frequently mutated genes in human cancers [1][2][3][4][5] . However, the role and the molecular mechanisms by which FAT1 mutations control tumour initiation and progression are poorly understood. Here, using mouse models of skin squamous cell carcinoma and lung tumours, we found that deletion of Fat1 accelerates tumour initiation and malignant progression and promotes a hybrid epithelial-to-mesenchymal transition (EMT) phenotype. We also found this hybrid EMT state in FAT1-mutated human squamous cell carcinomas. Skin squamous cell carcinomas in which Fat1 was deleted presented increased tumour stemness and spontaneous metastasis. We performed transcriptional and chromatin profiling combined with proteomic analyses and mechanistic studies, which revealed that loss of function of FAT1 activates a CAMK2-CD44-SRC axis that promotes YAP1 nuclear translocation and ZEB1 expression that stimulates the mesenchymal state. This loss of function also inactivates EZH2, promoting SOX2 expression, which sustains the epithelial state. Our comprehensive analysis identified drug resistance and vulnerabilities in FAT1-deficient tumours, which have important implications for cancer therapy. Our studies reveal that, in mouse and human squamous cell carcinoma, loss of function of FAT1 promotes tumour initiation, progression, invasiveness, stemness and metastasis through the induction of a hybrid EMT state.

The present Consensus Statement represents a collective agreement among 50 international experts to establish a standardized practice of VATS lobectomy for the thoracic surgical community after 20 years of clinical experience.

Chronic lung allograft dysfunction (CLAD) remains the major barrier to long-term success after lung transplantation. This report compares gross and microscopic features of lungs removed from patients receiving a redo-transplant as treatment for CLAD.Lungs donated by patients with either the bronchiolitis obliterans syndrome (BOS) or restrictive allograft syndrome (RAS) phenotype of CLAD and appropriate control lungs (eight per group) were airinflated, frozen solid and kept frozen while a multi-detector computed tomography (MDCT) was obtained. The lung was then cut into 2-cm thick transverse slices and sampled for micro-CT and histopathology.The MDCT showed reduced lung volume with increased lung weight and density in RAS versus BOS and control ( p<0.05). Although pre-terminal bronchioles were obstructed in both phenotypes, RAS lungs showed a reduction of pre-terminal bronchioles ( p<0.01). Micro-CT and matched histopathology showed that RAS was associated with reduced numbers of terminal bronchioles/lung compared to BOS and controls ( p<0.01), with expansion of the interstitial compartment and obliteration of the alveolar airspaces by fibrous connective tissue.RAS is associated with greater destruction of both pre-terminal and terminal bronchioles. Additionally, the interstitial compartments are expanded and alveolar airspaces are obliterated by accumulation of fibrous connective tissue. @ERSpublications Restrictive allograft syndrome is associated with greater destruction of both pre-terminal and terminal bronchioles

BackgroundHomeostatic turnover of the extracellular matrix conditions the structure and function of the healthy lung. In lung transplantation, long-term management remains limited by chronic lung allograft dysfunction, an umbrella term used for a heterogeneous entity ultimately associated with pathological airway and/or parenchyma remodeling.ObjectiveThis study assessed whether the local cross-talk between the pulmonary microbiota and host cells is a key determinant in the control of lower airway remodeling posttransplantation.MethodsMicrobiota DNA and host total RNA were isolated from 189 bronchoalveolar lavages obtained from 116 patients post lung transplantation. Expression of a set of 11 genes encoding either matrix components or factors involved in matrix synthesis or degradation (anabolic and catabolic remodeling, respectively) was quantified by real-time quantitative PCR. Microbiota composition was characterized using 16S ribosomal RNA gene sequencing and culture.ResultsWe identified 4 host gene expression profiles, among which catabolic remodeling, associated with high expression of metallopeptidase-7, -9, and -12, diverged from anabolic remodeling linked to maximal thrombospondin and platelet-derived growth factor D expression. While catabolic remodeling aligned with a microbiota dominated by proinflammatory bacteria (eg, Staphylococcus, Pseudomonas, and Corynebacterium), anabolic remodeling was linked to typical members of the healthy steady state (eg, Prevotella, Streptococcus, and Veillonella). Mechanistic assays provided direct evidence that these bacteria can impact host macrophage-fibroblast activation and matrix deposition.ConclusionsHost-microbes interplay potentially determines remodeling activities in the transplanted lung, highlighting new therapeutic opportunities to ultimately improve long-term lung transplant outcome.

By making a tunnel between the bronchovascular structures and parenchyma from anteriorly to posteriorly, one can open the fissure completely with staplers at an early stage of an anatomical lung resection. This combines the advantages of both the 'fissureless' hilum first technique and classic (open) fissure first dissection, i.e. minimal air leak and optimal anatomical overview before bronchovascular structures are divided, potentially avoiding inadvertent transections. A cohort of 198 consecutive patients operated with this alternative fissureless technique demonstrates the feasibility and non-inferiority regarding hospital stay, chest tube duration, operation time and complications in comparison with the hilum first technique.

OBJECTIVES Large retrospective series have indicated lower rates of cN0 to pN1 nodal upstaging after video-assisted thoracic surgery (VATS) compared with open resections for Stage I non-small-cell lung cancer (NSCLC). The objective of our multicentre study was to investigate whether the presumed lower rate of N1 upstaging after VATS disappears after correction for central tumour location in a multivariable analysis. METHODS Consecutive patients operated for PET-CT based clinical Stage I NSCLC were selected from prospectively managed surgical databases in 11 European centres. Central tumour location was defined as contact with bronchovascular structures on computer tomography and/or visibility on standard bronchoscopy. RESULTS Eight hundred and ninety-five patients underwent pulmonary resection by VATS (n = 699, 9% conversions) or an open technique (n = 196) in 2014. Incidence of nodal pN1 and pN2 upstaging was 8% and 7% after VATS and 15% and 6% after open surgery, respectively. pN1 was found in 27% of patients with central tumours. Less central tumours were operated on by VATS compared with the open technique (12% vs 28%, P < 0.001). Logistic regression analysis showed that only tumour location had a significant impact on N1 upstaging (OR 6.2, confidence interval 3.6–10.8; P < 0.001) and that the effect of surgical technique (VATS versus open surgery) was no longer significant when accounting for tumour location. CONCLUSIONS A quarter of patients with central clinical Stage I NSCLC was upstaged to pN1 at resection. Central tumour location was the only independent factor associated with N1 upstaging, undermining the evidence for lower N1 upstaging after VATS resections. Studies investigating N1 upstaging after VATS compared with open surgery should be interpreted with caution due to possible selection bias, i.e. relatively more central tumours in the open group with a higher chance of N1 upstaging.

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