Search

Background: Colorectal cancer(CRC) is a highly heterogeneous malignant tumor that significantly impacts clinical diagnosis and treatment. Single-cell RNA sequencing is an innovative method for exploring tumor heterogeneity and understanding its role at cellular and genetic levels. Method: The colorectal cancer Single-cell RNA sequencing data were analysed on the immune. RNA-seq data in bulk form was utilized to assess the major genes of the immune cell subsets linked to CRC. We conducted an analysis of the abundance of immune cells in the microenvironment of CRC, and also performed weighted gene co-expression network analysis. Gene set enrichment analysis helped perform two analytical procedures of subtype groups. Furthermore, Least absolute shrinkage and selection operator regression was employed to analyse and screen for a gene signature. Finally, quantitative PCR was performed to detect the expression levels of signature genes in CRC. Results: The Single-cell RNA sequencing (GSE146771) dataset was integrated to obtain 9 cell clusters. The Single-sample gene set enrichment analysis showed that the related gene expression of T-cell subsets of different functional statuses could vary greatly between patients with GSE146771. Immune cell analysis of TCGA-CRC indicated an improved overall survival rate for patients with elevated Th2 cell abundance. Five-gene signature (Risk Score = -0.205 × CDC25C - 0.231 × GSTCD - 0.010 × KPNA2 - 0.002 × KIF15 - 0.171 × ORC1) was developed by weighted correlation network analysis, and lasso Cox regression. Then, the risk prediction efficacy of the signature was validated in four GSE datasets. Furthermore, the expression of five genes was reduced in CRC tissue by quantitative PCR. Conclusion: Five-gene signature based on CRC heterogeneity was developed as a prognosis predictor, which can serve as a potential treatment target. [ABSTRACT FROM AUTHOR]

The present work aims to prove the concept of tumor-targeted drug delivery mediated by platelets. Doxorubicin (DOX) attached to nanodiamonds (ND-DOX) was investigated as the model payload drug of platelets. In vitro experiments first showed that ND-DOX could be loaded in mouse platelets in a dose-dependent manner with a markedly higher efficiency and capacity than free DOX. ND-DOX-loaded platelets (Plt@ND-DOX) maintained viability and ND-DOX could be stably held in the platelets for at least 4 hr. Next, mouse Lewis lung cancer cells were found to activate Plt@ND-DOX and thereby stimulate cargo unloading of Plt@ND-DOX. The unloaded ND-DOX was taken up by co-cultured cancer cells which consequently exhibited loss of viability, proliferation suppression and apoptosis. In vivo, Plt@ND-DOX displayed significantly prolonged blood circulation time over ND-DOX and DOX in mice, and Lewis tumor grafts demonstrated infiltration, activation and cargo unloading of Plt@ND-DOX in the tumor tissue. Consequently, Plt@ND-DOX effectively reversed the growth of Lewis tumor grafts which exhibited significant inhibition of cell proliferation and apoptosis. Importantly, Plt@ND-DOX displayed a markedly higher therapeutic potency than free DOX but without the severe systemic toxicity associated with DOX. Our findings are concrete proof of platelets as efficient and efficacious carriers for tumor-targeted nano-drug delivery with the following features: 1) large loading capacity and high loading efficiency, 2) good tolerance of cargo drug, 3) stable cargo retention and no cargo unloading in the absence of stimulation, 4) prolonged blood circulation time, and 5) excellent tumor distribution and tumor-activated drug unloading leading to high therapeutic potency and few adverse effects. Platelets hold great potential as efficient and efficacious carriers for tumor-targeted nano-drug delivery. [ABSTRACT FROM AUTHOR]