Bioinformatics analysis and single-cell RNA sequencing: elucidating the ubiquitination pathways and key enzymes in lung adenocarcinoma

Single-cell RNA-seq analysis revealed the stemness of a specific cluster of B cells in acute lymphoblastic leukemia progression

Background

Childhood acute lymphoblastic leukemia (ALL) is a common pediatric cancer. The heterogeneous characterization of B cells in ALL progression poses new challenges to researchers. We used single-cell sequencing to explore the critical role of B cells in regulating the ALL immune microenvironment.

Method

We collected the single cell (sc) RNA-seq data of ALL and health sample from the gene expression omnibus (GEO) database, the "Seurat" and "harmony" R package was used for quality control and scRNA-seq analysis, in which the CellMarker2.0 database was used for cell type annotation. Subsequently, the FindAllMarkers function was used to identify the differentially expressed genes (DEGs) among various cell types and the DAVID database was applied for the biological process of DEGs. Then, the "inferCNV" package was used for copy number variation, regulons and cell communication were performed by SCENIC tool and CellChat package. The role of the target gene in regulating ALL progression was assessed using RT-qPCR, Transwell and scratch healing assays.

Results

We identified nine mainly cell clusters after scRNA-seq analysis, in which the B cells had higher infiltration proportion in the ALL samples and were sub-clustered into five cell sub-groups. The B cells 1 is closely associated with cell proliferation and stemness (TNFAIP3 and KDM5B), and the significant CNV of amplification occurred on chr6 and chr21 that supported stemness of B cells1. RXRB is a key transcription factor mediated the proliferation of B cells 1, which in turn suppressed hematopoietic stem cells (HSCs) proliferation and promoted cytotoxic NK/T cells activation through diverse cell communication ways. One of the key regulators of B cells is MYC, which promotes the migration and invasive ability of cell line leukemia cell lines.

Conclusion

This study reveals the stemness characteristics of B cells and their critical role in ALL progression, a finding that provides new potential directions for the development of targeted therapies against ALL.

HPV-driven heterogeneity in cervical cancer: study on the role of epithelial cells and myofibroblasts in the tumor progression based on single-cell RNA sequencing analysis

Background

Cervical cancer (CC) is a neoplasia with a high heterogeneity. We aimed to explore the characteristics of tumor microenvironment (TME) for CC treatment.

Methods

HPV positive (+) and negative (-) samples from cervical cancer (CC) patients were sourced from the Gene Expression Omnibus (GEO) database. The single-cell RNA sequencing (scRNA-seq) data were processed and annotated for cell types utilizing the Seurat package. Following this, the expression levels and biological roles of the marker genes were analyzed applying real-time PCR (RT-PCR) and transwell assays. Furthermore, the enrichment of genes with significantly differential expressions and copy number variations was assessed by the ClusterProlifer and inferCNV software packages.

Results

Seven main cell clusters were classified based on a total of 12,431 cells. The HPV- CC samples exhibited a higher immune cell infiltration level, while epithelial cells and myofibroblasts had higher proportion in the HPV+ CC samples with extensive heterogeneity. Immune pathways including antigen treatment and presentation, immunoglobulin production and T cell mediated immunity were significantly activated in the HPV- CC group with lower cell cycle and proliferation activity. However, the anti-tumor immunity of these cells was inhibited in HPV+ CC group with higher cell proliferation activity. Moreover, the amplification and loss of CNVs also supported that these cells in HPV- CC samples were prone to anti-tumor activation. Further cell validation results showed that except GZMA, the levels of APOC1, CEACAM6, FOXP3, SFRP4 and TFF3 were all higher in CC cells Hela, and that silencing TFF3 could inhibit the migration and invasion of CC cells in-vitro.

Conclusion

This study highlighted the critical role of HPV infection in CC progression, providing a novel molecular basis for optimizing the current preventive screening and personalized treatment for the cancer.

Characterization of the malignant cells and microenvironment of infantile fibrosarcoma via single-cell RNA sequencing

BACKGROUND

Infantile fibrosarcoma (IFS) is the most prevalent soft tissue sarcoma in children under 1 year old and is known for its rapid growth. The tumor lacks specific immunohistochemical tumor marker and a general view of tumor microenvironment (TME). Its primary therapeutic intervention places patients at a risk of disability or mutilation. This study aimed to elucidate the universal transcriptional characteristics of IFS and explore novel targets for diagnosis and therapy using single-cell RNA sequencing (scRNA-seq).

METHODS

Fresh tissue samples of IFS for scRNA-seq were collected from four patients before other treatments were administered. We conducted cell clustering, inferring copy number variation from scRNA-seq (InferCNV) analysis, gene differential expression analysis, cell function evaluation, Pearson correlation analysis, and cell-cell and ligand-receptor interaction analysis to investigate the distinct ecosystem of IFS.

RESULTS

According to the single-cell resolution data, we depicted the cell atlas of IFS, which comprised 14 cell populations. Through comparison with normal cells, the malignant cells were distinguished, and potential novel markers (POSTN, IGFBP2 and CTHRC1) were identified. We also found four various functional malignant cell subtypes, three of which exhibited cancer stem cells (CSCs) phenotypes, and investigated the interplay between these subtypes and nonmalignant cells in the TME of IFS. Endothelial cells and macrophages were found to dominate the cell-cell communication landscape within the microenvironment, promoting tumorigenesis via multiple receptor-ligand interactions.

CONCLUSIONS

This study provides a comprehensive characterization of the tumor transcriptome and TME of IFS at the cellular level, offering valuable insights for clinically significant advancements in the immunohistochemical diagnosis and treatment of IFS.

TMEM43 promotes the development of hepatocellular carcinoma by activating VDAC1 through USP7 deubiquitination

Background

Transmembrane protein 43 (TMEM43), a member of the TMEM subfamily, is encoded by a highly conserved gene and widely expressed in most species from bacteria to humans. In previous studies, TMEM43 has been found to play an important role in a variety of tumors. However, the role of TMEM43 in cancer remains unclear.

Methods

We utilized the RNA sequencing (RNA-seq) and The Cancer Genome Atlas (TGCA) databases to explore and identify genes that may play an important role in the occurrence and development of hepatocellular carcinoma (HCC), such as TMEM43. The role of TMEM43 in HCC was explored through Cell Counting Kit-8 (CCK-8) cloning, flow cytometry, and Transwell experiments. The regulatory relationship between TMEM43 and voltage-dependent anion channel 1 (VDAC1) was investigated through coimmunoprecipitation (co-IP) and western blot (WB) experiments. WB was used to study the deubiquitination effect of ubiquitin-specific protease 7 (USP7) on TMEM43.

Results

In this study, we utilized the RNA-seq and TGCA databases to mine data and found that TMEM43 is highly expressed in HCC. The absence of TMEM43 in cancer cells was shown to inhibit tumor development. Further research detected an important regulatory relationship between TMEM43 and VDAC1. In addition, we found that USP7 affected the progression of HCC by regulating the ubiquitination level of TMEM43 through deubiquitination.

Conclusions

Our study demonstrated that USP7 participates in the growth of HCC tumors through TMEM43/VDAC1.Our results suggest that USP7/TMEM43/VDAC1 may have predictive value and represent a new treatment strategy for HCC.