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Background: Chronic obstructive pulmonary disease (COPD) contributes to the incidence and prognosis of lung cancer. The presence of COPD significantly increases the risk of lung squamous cell carcinoma (LSCC). COPD may promote an immunosuppressive microenvironment in LSCC by regulating the expression of immune‐inhibitory factors in T cells, although the mechanisms remain unclear. In this study, we aimed to decipher the tumour microenvironment signature for LSCC with COPD at a single‐cell level. Methods: We performed single‐cell RNA sequencing on tumour tissues from LSCC with or without COPD, then investigated the features of the immune and tumour cells. We employed multiple techniques, including multispectral imaging, flow cytometry, tissue microarray analysis, survival analysis, co‐culture systems and in vitro and in vivo treatment experiments, to validate the findings obtained from single‐cell analyses. Results: LSCC with COPD showed increased proportions of tumour‐associated macrophages (TAMs) and higher levels of CD8+ T cell exhaustion molecules, which contributed to an immunosuppressive microenvironment. Further analysis revealed a critical cluster of CD74+ tumour cells that expressed both epithelial and immune cell signatures, exhibited a stronger capacity for tumorigenesis and predicted worse overall survival. Notably, migration inhibitory factor (MIF) secreted by TAMs from LSCC with COPD may promote the activation of CD74. MIF‐CD74 may interact with CD8+ T cells and impair their anti‐tumour activity by regulating the PI3K‐STAT3‐programmed cell death‐1 ligand 1 signalling pathway, facilitating tumour proliferation and immune evasion. Conclusions: Our comprehensive picture of the tumour ecosystem in LSCC with COPD provides deeper insights into relevant immune evasion mechanisms and potential targets for immunotherapy. Highlight: Our results demonstrated higher proportions of tumour‐associated macrophages (TAMs) and higher levels of exhaustion molecules in CD8+ T cells in the microenvironment of LSCC with COPD.CD74+tumour cells were associated with poor disease prognosis.Migration inhibitory factor (MIF)‐CD74 may interact with CD8+ T cells and impair their anti‐tumour activity by regulating the PI3K‐STAT3‐PD‐L1 signalling pathway, facilitating immune evasion. [ABSTRACT FROM AUTHOR]

A previously unknown beta coronavirus, SARS‐CoV‐2, was discovered from a cluster of patients with pneumonia of unknown cause in Wuhan since the end of 2019. Ever since the start of COVID‐19, government administrations, academic institutions, and technology enterprises are under unprecedented cooperation in controlling this outbreak from pathogen identification, epidemic situation assessment, to outbreak containment. Timely identification, isolation, and whole‐genome sequencing of SARS‐CoV‐2 have laid the foundation for effective control of this novel infection. With the increasing case numbers worldwide, more real‐time information is emerging, changing our understandings to SARS‐CoV‐2 outbreak, and nonetheless refining the outbreak control responses. The efficient management of COVID‐19 requires global collaboration and an efficient share of information. [ABSTRACT FROM AUTHOR]

DNA mismatch repair (MMR) status was considered to be a potential prognostic factor for colorectal cancer (CRC) but with conflicting reports, and varied in terms of TNM stages. Its relationship with prognosis in stage II‐III CRC had not yet been systematically established. Therefore, we retrieved eligible studies published through May 2019, and screened out 51 studies that reported survival data (overall survival [OS] and/or disease‐free survival [DFS]) in 28 331 CRC patients at stage II‐III, totally 16.4% of whom were characterized as deficient MMR (dMMR). Significant associations of dMMR status were observed with longer OS (Hazard Ratio [HR] = 0.74, 95% CI: 0.68‐0.82; P <.001), as well as DFS (HR = 0.67, 95% CI: 0.59‐0.75, P <.001). However, dMMR patients received no statistically significant benefit from fluoropyrimidine‐based treatment for either OS (HR = 0.84, 95%CI: 0.60‐1.17; P =.31) or DFS (HR = 0.83, 95%CI: 0.60‐1.15; P =.27), compared with that in proficient MMR (pMMR) patients for both OS (HR = 0.55, 95% CI: 0.43‐0.71; P <.001) and DFS (HR = 0.60, 95% CI: 0.50‐0.73; P <.001). Our analysis indicate that dMMR CRC patients at stage II‐III had higher OS and DFS than pMMR ones, and fluoropyrimidine‐based chemotherapy could improve survival in pMMR patients rather than dMMR ones. [ABSTRACT FROM AUTHOR]

Previous studies indicate that ion channels are mediators of bioelectricity promoting wound closure/regeneration in nonmammalian, lower vertebrate systems. The role of ion channels however in regeneration of wounds in mammalian systems that do not regenerate as adults is not yet defined. Using a mammalian model system that allows us to determine differentially expressed genes when skin regenerates and when skin does not regenerate after wound induction, we identified two potassium channels, kcnh2 and kcnj8, to be (1) differentially expressed between the two states and (2) highly expressed after wound induction at the nonregenerative state. We also found that kcnh2 small molecule inhibitor enhanced wound healing while kcnj8 small molecule inhibitor did not. In contrast, kcnj8 activator accelerated wound healing and even augmented the effect of kcnh2 inhibition. These results provide evidence for the first time that potassium channels may mediate skin wound healing and regeneration interactively. [ABSTRACT FROM AUTHOR]

BRAFV600E/K is a frequent mutationally active tumor-specific kinase in melanomas that is currently targeted for therapy by the specific inhibitor PLX4032. Our studies with melanoma tumor cells that are BRAFV600E/K and BRAFWT showed that, paradoxically, while PLX4032 inhibited ERK1/2 in the highly sensitive BRAFV600E/K, it activated the pathway in the resistant BRAFWT cells, via RAF1 activation, regardless of the status of mutations in NRAS or PTEN. The persistently active ERK1/2 triggered downstream effectors in BRAFWT melanoma cells and induced changes in the expression of a wide-spectrum of genes associated with cell cycle control. Furthermore, PLX4032 increased the rate of proliferation of growth factor-dependent NRAS Q61L mutant primary melanoma cells, reduced cell adherence and increased mobility of cells from advanced lesions. The results suggest that the drug can confer an advantage to BRAFWT primary and metastatic tumor cells in vivo and provide markers for monitoring clinical responses. [ABSTRACT FROM AUTHOR]