Recent developments in application of single-cell RNA sequencing in the tumour immune microenvironment and cancer therapy

The advent of single-cell RNA sequencing(scRNA-seq)has provided insight into the tumour immune microenvironment(TIME).This review focuses on the application of scRNA-seq in investigation of the TIME.Over time,scRNA-seq methods have evolved,and components of the TIME have been deciphered with high resolution.In this review,we first introduced the principle of scRNA-seq and compared different sequencing approaches.Novel cell types in the TIME,a continuous transitional state,and mutual intercommunication among TIME components present potential targets for prognosis prediction and treatment in cancer.Thus,we concluded novel cell clusters of cancerassociated fibroblasts(CAFs),T cells,tumour-associated macrophages(TAMs)and dendritic cells(DCs)discovered after the application of scRNA-seq in TIME.We also proposed the development of TAMs and exhausted T cells,as well as the possible targets to interrupt the process.In addition,the therapeutic interventions based on cellular interactions in TIME were also summarized.For decades,quantification of the TIME components has been adopted in clinical practice to predict patient survival and response to therapy and is expected to play an important role in the precise treatment of cancer.Summarizing the current findings,we believe that advances in technology and wide application of single-cell analysis can lead to the discovery of novel perspectives on cancer therapy,which can subsequently be implemented in the clinic.Finally,we propose some future directions in the field of TIME studies that can be aided by scRNA-seq technology.

SR-BI expression regulates the gastric cancer tumor immune microenvironment and is associated with poor prognosis

Aim:Scavenger receptor class B,type I(SR-BI)is an integral plasma membrane protein that has been reported to be overexpressed in various malignancies,such as renal cancer,breast cancer,and prostate cancer,and is an independent prognostic factor.However,the clinical value and expression of SR-BI in GC are unknown.Our research aimed to explore the role of SR-BI in combination with immune markers as a diagnostic and prognostic marker for gastric cancer(GC).Methods:GC tissues,paracancerous tissues,and clinicopathological data of 149 patients were collected.The expression level of SR-BI,Tumor-infiltrating lymphocytes(TILs),and PD-L1 were evaluated by immunohistochemistry(IHC).The associations of the SR-BI staining intensity with clinicopathological features and immune markers were determined by the chi-square test.Univariate and multivariate COX regression analyses were used to evaluate independent prognostic factors.Kaplan–Meier analyses were performed to plot the survival curve.Results:Our results indicated that SR-BI was expressed at higher levels in tumor tissues than in adjacent paracancerous tissues(p<0.001),and patients with high levels of SR-BI expression had a worse prognosis.Univariate and multivariate analyses revealed that high SR-BI expression was an independent factor for poor prognosis.The chi-square test determined that the expression of SR-BI was negatively correlated with CD4+T cells and CD8+T cells(CD4+T cells,p=0.013;CD8+T cells,p=0.021),and positively correlated with PD-L1(p=0.022).Finally,survival analysis revealed that CD4+T cells were associated with the prognosis of GC patients(p=0.019),and the combined survival analysis of SR-BI and CD4+T cells was also statistically significant(p=0.030).Conclusion:SR-BI is highly expressed in GC tissue and associated with poor prognosis.Moreover,SR-BI can also regulate the GC tumor immune microenvironment.

Physical exercise reverses immuno-cold tumor microenvironment via inhibiting SQLE in non-small cell lung cancer

Dear Editor,Physical exercise has been shown to be associated with reduced cancer incidence and cancer-associated mortality[1,2],but the underlying mechanisms are obscure.Immunometabolic regulation has emerged as one of the most prominent mechanisms explaining the effects of exercise on cancer[1,2].Physical exercise primarily lowers blood cholesterol and triglycerides,and protects against cardiovascular diseases[3].However,whether physical exercise can modulate cholesterol metabolism in tumor cells is currently unknown.

The role of FGFR inhibitors in the treatment of intrahepatic cholangiocarcinoma-unveiling the future challenges in drug therapy

Intrahepatic cholangiocarcinoma(iCCA)is a rare malignancy,constituting approximately 3-5%of hepatic tumors,with an increasing incidence in recent years(1).Early stage iCCA typically presents asymptomatically,often resulting in its detection at advanced stages.Surgical resection remains the primary therapeutic approach for iCCA;however,a substantial proportion of patients are precluded from surgery due to disease progression,necessitating a reliance on pharmaceutical interventions(2).