Comprehensive Analysis of Prognostic Microenvironment-Related Genes in Invasive Breast Cancer

A Comprehensive Analysis of the Effect of A>I(G) RNA-Editing Sites on Genotoxic Drug Response and Progression in Breast Cancer

Dysregulated A>I(G) RNA editing, which is mainly catalyzed by ADAR1 and is a type of post-transcriptional modification, has been linked to cancer. A low response to therapy in breast cancer (BC) is a significant contributor to mortality. However, it remains unclear if there is an association between A>I(G) RNA-edited sites and sensitivity to genotoxic drugs. To address this issue, we employed a stringent bioinformatics approach to identify differentially RNA-edited sites (DESs) associated with low or high sensitivity (FDR 0.1, log2 fold change 2.5) according to the IC50 of PARP inhibitors, anthracyclines, and alkylating agents using WGS/RNA-seq data in BC cell lines. We then validated these findings in patients with basal subtype BC. These DESs are mainly located in non-coding regions, but a lesser proportion in coding regions showed predicted deleterious consequences. Notably, some of these DESs are previously reported as oncogenic variants, and in genes related to DNA damage repair, drug metabolism, gene regulation, the cell cycle, and immune response. In patients with BC, we uncovered DESs predominantly in immune response genes, and a subset with a significant association (log-rank test p < 0.05) between RNA editing level in LSR, SMPDL3B, HTRA4, and LL22NC03-80A10.6 genes, and progression-free survival. Our findings provide a landscape of RNA-edited sites that may be involved in drug response mechanisms, highlighting the value of A>I(G) RNA editing in clinical outcomes for BC.

Bioinformatic analysis reveals the clinical value of SASH3 in survival prognosis and immune infiltration of acute myelocytic leukemia (AML)

Acute myeloid leukemia (AML), a malignant clonal disease, is the most prevalent form of leukemia, and it is associated with a poor prognosis and unfavorable treatment outcomes in both pediatric and adult populations. Accordingly, enhancing anti-tumor responses using immunomodulators is a promising therapeutic strategy and a new avenue for treating AML. In this study, we used publicly available data from The Cancer Genome Atlas and Genotype-Tissue Expression databases to investigate the correlation between SAM and SH3 domain-containing 3 (SASH3) and AML, and we performed Cox regression and Kaplan-Meier analyses to assess the clinical characteristics associated with overall survival among patients with AML. Additionally, we analyzed the relationship between immune infiltration and SASH3. Compared with that in the normal group, patients with AML were characterized by significantly higher levels of SASH3 expression (P = 3.05e-34), which was strongly associated with survival outcomes. We observed a significant correlation between SASH3 expression and the expression of cancer-related genes (HCK, SYK, FYN, ITGB2, PIK3CD, FGR, PIK3R5, VAV1, LCP2, and GRB2) and pathways. Our findings in this study indicate that SASH3 plays a key role in AML development and survival outcomes and in the regulation of small GTPase-mediated signal transduction and immune-related pathways. Accordingly, targeting SASH3 may offer a promising approach for the treatment of AML and may potentially influence the progression of other cancers via multiple immune pathways.

Integrated analysis of single-cell RNA-seq and bulk RNA-seq unravels the heterogeneity of cancer-associated fibroblasts in TNBC

BACKGROUND

The treatment of triple-negative breast cancer (TNBC) is one of the main focuses and key difficulties because of its heterogeneity, and the source of this heterogeneity is unclear.

METHODS

Single-cell RNA (scRNA) and transcriptomics data of TNBC and normal breast samples were retrieved from Gene Expression Omnibus (GEO) database and TCGA-BRCA database. These cells were clustered using the t-SNE and UMAP method, and the marker genes for each cluster were found. We annotated the clusters using the published literature, CellMarker database and "SingleR" R package.

RESULTS

A total of 1535 cells and 21785 genes from 6 TNBC patients and 2068 cells and 15868 genes from 3 normal breast tissues were used for downstream analyses. The scRNA data were divided into 14 clusters labeled into 8 cell types, including epithelial cells, immunocytes, CAFs/fibroblasts and etc. In the TNBC samples, CAFs were divided into three clusters and labelled as prCAFs, myCAFs and emCAFs, and the marker genes were DCN, FAP and RGS5, respectively. The prCAF subgroup is functionally characterized by promoting proliferation and multi drug resistance; myCAF subgroup is involved in constituting the extracellular matrix and collagen production, matrix composition and collagen production, and the emCAF functionally characterized by energy metabolism.

CONCLUSIONS

TNBC has inter- and intra-tumor heterogeneity, and CAF is one of the sources of this heterogeneity. CD74, SASH3, CD2, TAGAP and CCR7 served as significant marker genes with prognostic and therapeutic value.