Single-cell analysis reveals the multiple patterns of immune escape in the nasopharyngeal carcinoma microenvironment.

BACKGROUND: Single-cell transcriptomics has revolutionised our understanding of the cellular composition of the tumour microenvironment (TME) in nasopharyngeal carcinoma (NPC). Despite this progress, a key limitation of this technique has been its inability to capture epithelial/tumour cells, which has hindered further investigation of tumour heterogeneity and immune escape in NPC. METHODS: In this study, we aimed to address these limitations by analysing the transcriptomics and spatial characteristics of NPC tumour cells at single-cell resolution using scRNA/snRNA-seq and imaging mass cytometry techniques. RESULTS: Our findings demonstrate multiple patterns of immune escape mechanisms in NPC, including the loss of major histocompatibility complex (MHC) molecules in malignant cells, induction of epithelial-mesenchymal transition in fibroblast-like malignant cells and the use of hyperplastic cells in tumour nests to protect tumour cells from immune infiltration. Additionally, we identified, for the first time, a CD8+ natural killer (NK) cell cluster that is specific to the NPC TME. CONCLUSIONS: These findings provide new insights into the complexity of NPC immune landscape and may lead to novel therapeutic strategies for this disease.

Ferroptosis-related gene ATG5 is a novel prognostic biomarker in nasopharyngeal carcinoma and head and neck squamous cell carcinoma.

Nasopharyngeal carcinoma (NPC), a subtype of head and neck squamous cell carcinoma (HNSCC), is a malignant tumor that originates in the mucosal epithelium of the nasopharynx. Ferroptosis plays a key role in tumor suppression, while its prognostic value and critical factors in NPC have not been further explored. We select the Cancer Genome Atlas (TCGA) HNSCC dataset and the Gene Expression Omnibus (GEO) dataset of NPC samples, and find that ferroptosis-related factor ATG5 shows a high expression level with poor overall survival (OS) in HNSCC and NPC samples and is positively correlated with PD-L1/PD-L2 expression (p < 0.05). Furthermore, ATG5 high expression HNSCC patients show poor efficacy and short survival after receiving immune checkpoint blockade therapy treatment (p < 0.05). Moreover, ATG5 is significantly positively correlated with G2M checkpoint pathway (ρ Spearman = 0.41, p < 0.01), and G2M checkpoint inhibitor drugs have lower IC50 in HNSCC patients with high expression of ATG5 (p < 0.01), indicating the potential value of G2M inhibitors in HNSCC/NPC treatment. In summary, our study shows that ferroptosis-related factors play a key role in immune infiltration in NPC and HNSCC, and ATG5, as a key immune invasion-related ferroptosis-related factor, has the potential to be a novel prognostic biomarker and a potential target in therapy for NPC and HNSCC.

Deciphering the Subtype Differentiation History of SARS-CoV-2 Based on a New Breadth-First Searching Optimized Alignment Method Over a Global Data Set of 24,768 Sequences.

SARS-CoV-2 has caused a worldwide pandemic. Existing research on coronavirus mutations is based on small data sets, and multiple sequence alignment using a global-scale data set has yet to be conducted. Statistical analysis of integral mutations and global spread are necessary and could help improve primer design for nucleic acid diagnosis and vaccine development. Here, we optimized multiple sequence alignment using a conserved sequence search algorithm to align 24,768 sequences from the GISAID data set. A phylogenetic tree was constructed using the maximum likelihood (ML) method. Coronavirus subtypes were analyzed via t-SNE clustering. We performed haplotype network analysis and t-SNE clustering to analyze the coronavirus origin and spread. Overall, we identified 33 sense, 17 nonsense, 79 amino acid loss, and 4 amino acid insertion mutations in full-length open reading frames. Phylogenetic trees were successfully constructed and samples clustered into subtypes. The COVID-19 pandemic differed among countries and continents. Samples from the United States and western Europe were more diverse, and those from China and Asia mainly contained specific subtypes. Clades G/GH/GR are more likely to be the origin clades of SARS-CoV-2 compared with clades S/L/V. Conserved sequence searches can be used to segment long sequences, making large-scale multisequence alignment possible, facilitating more comprehensive gene mutation analysis. Mutation analysis of the SARS-CoV-2 can inform primer design for nucleic acid diagnosis to improve virus detection efficiency. In addition, research into the characteristics of viral spread and relationships among geographic regions can help formulate health policies and reduce the increase of imported cases.

G-Protein-Coupled Estrogen Receptor 1 Promotes Gender Disparities in Hepatocellular Carcinoma via Modulation of SIN1 and mTOR Complex 2 Activity.

Due to its intricate heterogeneity and limited treatment, hepatocellular carcinoma (HCC) has been considered a major cause of cancer-related mortality worldwide. Increasing evidence indicates that G-protein-coupled estrogen receptor 1 (GPER1) can promote estrogen-dependent hepatocellular proliferation by activating AKT signaling. The mTOR complex 2 (mTORC2), whose integrity and activity are modulated by its subunit Sin1, controls the activation of AKT by phosphorylation at position S473. In this study, we investigate the modulation of Sin1 and how estrogen signaling may influence the mTORC2-AKT cascade in HCC cells and a DEN-induced mouse model. We have found that estradiol-dependent Sin1 expression is transcriptionally modulated by GPER1 as well as ERα. GPER1 is able to regulate Sin1 stability via nuclear translocation, therefore increasing Sin1-mTORC2-AKT activation. Moreover, Sin1 interacts with ERα and further enhances its transcriptional activity. Sin1 is highly expressed in acute liver injury and in cases of HCC harboring high expression of GPER1 and constitutive activation of mTORC2-AKT signaling. GPER1 inhibition using the antagonist G-15 reverses DEN-induced acute liver injury by suppressing Sin1 expression and mTORC2-AKT activation. Notably, SIN1 expression varies between male and female mice in the context of both liver injury and liver cancer. In addition, high SIN1 expression is predictive of good prognosis in both male and female patients with HCC who are free from hepatitis virus infection and who report low alcohol consumption. Hence, here we demonstrate that Sin1 can be regulated by GPER1 both through nongenomic and indirect genomic signaling. IMPLICATIONS: This study suggests that Sin1 may be a novel HCC biomarker which is gender-dependent and sensitive to particular risk factor.

Sin1 promotes proliferation and invasion of prostate cancer cells by modulating mTORC2-AKT and AR signaling cascades.

AIMS: Prostate cancer (PCa) is the most common type of cancer and a major cause of death in men worldwide. Aberrant Androgen receptor (AR) and PI3K-AKT signaling are very frequent in PCa patients and, therefore, considered as therapeutic targets in the clinic. Sin1 is an essential component of mTORC2 complex, which determines full AKT activation and PCa development in PTEN-/- mice. Here we examined the role of Sin1 in human PCa cell lines and respective tumor samples. MAIN METHODS: Western blotting and immunohistochemistry (IHC) were performed to analyze the expression of Sin1-mTORC2-AKT related proteins in human PCa cells, as well as prostate tumors and normal tissue counterparts. Cell viability and invasion assays were also pursued in the presence or not of Sin1 in PCa cells. Immunoprecipitation assays were additionally carried out to examine the interaction of Sin1 with AR. KEY FINDINGS: We have presently demonstrated that high levels of Sin1 expression in human PCa tissues correlate with cancer progression. Sin1-mediated cell proliferation and invasion of PCa cells occurs by regulating mTORC2-AKT signaling, epithelial-mesenchymal transition and matrix metalloproteinases. Moreover, androgens are able to induce Sin1 expression, which is further translocated to the nucleus of PCa cells. Finally, Sin1 interacts with AR to suppress its transcriptional activity. SIGNIFICANCE: Taken together, these data indicate that both Sin1-mediated mTORC2-AKT signaling and Sin1-AR interaction regulate PCa development. Hence, Sin1 may be considered a novel biomarker of PCa progression.