Investigating the role of Atypical Chemokine Receptor 3 in cancer development

Atypical Chemokine Receptor 3 (ACKR3) is a seven-transmembrane spanning receptor with pleiotropic functions in development, homeostasis and pathophysiology. The spatiotemporal expression of ACKR3 is tightly regulated, a fact that highlights its importance in several biological processes. ACKR3, similar to the other atypical chemokine receptors, does not signal through G proteins. ACKR3 exerts its functions by a) recruiting the β arrestins and b) scavenging its ligands thus shaping their concentration in the extracellular milieu. ACKR3 expression is often dysregulated in pathophysiological conditions, including cancer. There is a growing body of evidence that implicates ACKR3 in certain types of human cancers. In the present study, we interrogated publicly available databases of cancer patients in order to assess ACKR3 expression in different types of human cancers. These analyses revealed that ACKR3 is upregulated in several types of human cancers, including lung cancer. To this end, we investigated the role of ACKR3 in cancer progression with a particular focus on lung cancer. In order to overcome the lack of specific ACKR3 antibodies, we used a GFP fluorescent reporter mouse to assess ACKR3 expression in the different stromal cell populations in the lung. Our approach revealed that ACKR3 is expressed in the fibroblasts, blood and lymphatic endothelial cells in the resting lung. Furthermore, in this study, we tried to address the discrepancies in the literature about ACKR3 expression that is a result of the nonspecific nature of commercially available antibodies. More specifically, we tested commercially available flow cytometry anti-ACKR3 antibodies in the GFP/ACKR3 reporter mouse. Our approach revealed that both of the ACKR3 antibodies that were tested were inefficient in staining but also nonspecific in all the cell populations that were tested. Subsequently, we employed the CRISPR/Cas9 genome editing technologies to generate ACKR3 null cancer cell lines that we used subsequently in vivo in different mouse models. Our study identified ACKR3 as a positive regulator in lung cancer progression. Furthermore, ACKR3 was also identified as a crucial player at the early steps of metastasis and colonisation of metastatic circulating tumour cells in the lung. Collectively our data suggest that ACKR3 is a promising candidate for drug targeting in certain types of human lung cancer

Physical growth of neonates of smoking mothers

Aim. Το compare the intra and extra uterine growth of smoking mothers’ children to that of non-smoking in relationship to the number of cigarettes smoked/day. Design. Weight length and head circumference were measured in 236 neonates of smoking mothers and 236 control newborns of non-smoking mothers. Children were re-examined at 1 and 2 years. The anthropometric parameters were correlated to the number of cigarettes/day and to cord blood α-fetoprotein and erythroprotein concentrations. Results. Newborns of mothers who smoked 1-9 cigarettes/day had similar anthropometric parameters with the controls. Significant retardation in weight, length and head circumference was present in the newborns whose mothers smoked 10-19 and ≥20 cigarettes/day. At 2 years the length of children whose mothers smoked ≥20 10-19 and 1-9 cigarettes was significantly smaller than in the controls (p=0,00001, 0,0003 and 0,002 respectively). Also, the head circumference of children whose mothers smoked ≥20 cigarettes was significantly smaller than in the other groups. There was a negative correlation between α-fetoprotein and growth. Conclusions. The findings suggest that there is a threshold in the amount of tobacco smoke beyond which intrauterine growth retardation appears. At 2 years there is extra-uterine growth retardation in the smoking mothers’ children that is independently associated with maternal smoking.Σκοπός. H σύγκριση της ενδομήτριας και εξωμήτριας αύξησης παιδιών των οποίων οι μητέρες κάπνιζαν στην εγκυμοσύνη με την αύξηση παιδιών μη καπνιστριών μητέρων και σε συσχέτιση με τον αριθμό των τσιγάρων που κάπνιζε η έγκυος ημερησίως. Σχεδιασμός. Μετρήθηκαν το βάρος το μήκος και η περίμετρος κεφαλής 256 νεογνών καπνιστριών μητέρων και 256 νεογνών μη καπνιστριών μητέρων. Τα παιδιά επανεξετάστηκαν στην ηλικία του ενός και των δυο ετών. Οι σωματομετρικές παράμετροι συσχετίσθηκαν με τον αριθμό των τσιγάρων που κατανάλωνε η έγκυος ημερησίως και με τις συγκεντρώσεις της α-εμβρυϊκής πρωτεΐνης και ερυθροποιητίνης στο αίμα του ομφάλιου λώρου. Αποτελέσματα. Τα νεογνά των οποίων οι μητέρες κάπνιζαν 1-9 τσιγάρα/ημέρα είχαν παρόμοιες σωματομετρικές παραμέτρους με εκείνες των μαρτύρων. Στα νεογνά των οποίων οι μητέρες κάπνιζαν 10-19 και ≥20 τσιγάρα/ημέρα υπήρχε σημαντική υπολειπόμενη αύξηση του βάρους, του μήκους και της περιμέτρου κεφαλής. Στην ηλικία των 2 ετών το μήκος των παιδιών των οποίων οι μητέρες κάπνιζαν ≥20 10-19 και 1-9 τσιγάρα ήταν σημαντικά μικρότερο εκείνου των μαρτύρων (p=0,00001, 0,0003 και 0,002 αντίστοιχα). Επίσης η περίμετρος κεφαλής των παιδιών των οποίων οι μητέρες κάπνιζαν ≥20 τσιγάρα ήταν σημαντικά μικρότερη εκείνης των άλλων ομάδων. Υπήρχε αρνητική συσχέτιση μεταξύ α-εμβρυϊκής πρωτεΐνης και αύξησης. Συμπεράσματα. Τα ευρήματα υποδηλώνουν ότι υπάρχει ουδός στο ποσό του καπνού του τσιγάρου πέραν του οποίου εμφανίζεται ενδομήτρια καθυστέρηση της αύξησης. Στην ηλικία των 2 ετών στα παιδιά των καπνιστριών μητέρων παρατηρείται καθυστέρηση της αύξησης η οποία συσχετίζεται ανεξάρτητα με το κάπνισμα, στην εγκυμοσύνη

KEAP1 mutation in lung adenocarcinoma promotes immune evasion and immunotherapy resistance

Summary: Lung cancer treatment has benefited greatly through advancements in immunotherapies. However, immunotherapy often fails in patients with specific mutations like KEAP1, which are frequently found in lung adenocarcinoma. We established an antigenic lung cancer model and used it to explore how Keap1 mutations remodel the tumor immune microenvironment. Using single-cell technology and depletion studies, we demonstrate that Keap1-mutant tumors diminish dendritic cell and T cell responses driving immunotherapy resistance. This observation was corroborated in patient samples. CRISPR-Cas9-mediated gene targeting revealed that hyperactivation of the NRF2 antioxidant pathway is responsible for diminished immune responses in Keap1-mutant tumors. Importantly, we demonstrate that combining glutaminase inhibition with immune checkpoint blockade can reverse immunosuppression, making Keap1-mutant tumors susceptible to immunotherapy. Our study provides new insight into the role of KEAP1 mutations in immune evasion, paving the way for novel immune-based therapeutic strategies for KEAP1-mutant cancers

Rlf–Mycl Gene Fusion Drives Tumorigenesis and Metastasis in a Mouse Model of Small Cell Lung Cancer

Abstract Small cell lung cancer (SCLC) has limited therapeutic options and an exceptionally poor prognosis. Understanding the oncogenic drivers of SCLC may help define novel therapeutic targets. Recurrent genomic rearrangements have been identified in SCLC, most notably an in-frame gene fusion between RLF and MYCL found in up to 7% of the predominant ASCL1-expressing subtype. To explore the role of this fusion in oncogenesis and tumor progression, we used CRISPR/Cas9 somatic editing to generate a Rlf–Mycl-driven mouse model of SCLC. RLF–MYCL fusion accelerated transformation and proliferation of murine SCLC and increased metastatic dissemination and the diversity of metastatic sites. Tumors from the RLF–MYCL genetically engineered mouse model displayed gene expression similarities with human RLF–MYCL SCLC. Together, our studies support RLF–MYCL as the first demonstrated fusion oncogenic driver in SCLC and provide a new preclinical mouse model for the study of this subtype of SCLC. Significance: The biological and therapeutic implications of gene fusions in SCLC, an aggressive metastatic lung cancer, are unknown. Our study investigates the functional significance of the in-frame RLF–MYCL gene fusion by developing a Rlf–Mycl-driven genetically engineered mouse model and defining the impact on tumor growth and metastasis. This article is highlighted in the In This Issue feature, p. 2945 </jats:sec

BRG1 Loss Predisposes Lung Cancers to Replicative Stress and ATR Dependency

Inactivation of SMARCA4/BRG1, the core ATPase subunit of mammalian SWI/SNF complexes, occurs at very high frequencies in non-small cell lung cancers (NSCLC). There are no targeted therapies for this subset of lung cancers, nor is it known how mutations in BRG1 contribute to lung cancer progression. Using a combination of gain- and loss-of-function approaches, we demonstrate that deletion of BRG1 in lung cancer leads to activation of replication stress responses. Single-molecule assessment of replication fork dynamics in BRG1-deficient cells revealed increased origin firing mediated by the prelicensing protein, CDC6. Quantitative mass spectrometry and coimmunoprecipitation assays showed that BRG1-containing SWI/SNF complexes interact with RPA complexes. Finally, BRG1-deficient lung cancers were sensitive to pharmacologic inhibition of ATR. These findings provide novel mechanistic insight into BRG1-mutant lung cancers and suggest that their dependency on ATR can be leveraged therapeutically and potentially expanded to BRG1-mutant cancers in other tissues