PUS1 May Be a Potential Prognostic Biomarker and Therapeutic Target for Hepatocellular Carcinoma

Transcriptomic profile of RNA pseudouridine modification as a biomarker for cellular senescence associated with survival outcomes in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is considered as an age-related disease, and cellular senescence (CS) plays a crucial role in cancer development and progression. Previous studies have shown the role of epigenetic changes in aging and cancer development, but the role of RNA pseudouridine (Ψ) modification in aging and cancer remains to be explored.

RESULTS

Using bulk RNA sequencing, CRC cells with low Ψ writers expression levels have higher CS levels. We developed the Psi Score for assessing the transcriptomic profile of RNA Ψ modification regulation and found that the Psi Score correlates with CS. Furthermore, Psi-related senescence may be mediated by mTOR, TGF-β, TNF-α, and inflammatory response signaling pathways. Meanwhile, Psi Score could predict the anti-cancer treatment outcomes of anti-aging interventions and could be used to predict the response to immunotherapy.

CONCLUSIONS

Overall, these findings reveal that RNA Ψ modification connected aging and cancer and provided novel insights into biomarker-guided cancer regimens.

Advancements in pseudouridine modifying enzyme and cancer

Pseudouridine (Ψ) is a post-transcriptional modifier of RNA, often referred to as the 'fifth nucleotide' owing to its regulatory role in various biological functions as well as because of its significant involvement in the pathogenesis of human cancer. In recent years, research has revealed various Ψ modifications in different RNA types, including messenger RNA, transfer RNA, ribosomal RNA, small nuclear RNA, and long noncoding RNA. Pseudouridylation can significantly alter RNA structure and thermodynamic stability, as the Ψ-adenine (A) base pair is more stable than the typical uridine (U)-A base pair is due to its structural similarity to adenine. Studies have linked Ψ expression to the development and progression of several digestive system cancers, such as liver cancer and colorectal cancer, and nondigestive system cancers, such as breast cancer, non-small cell lung cancer, prostate cancer, glioblastoma, ovarian cancer, oral squamous cell carcinoma, and pituitary cancer. The present review briefly outlines the chemical structure, synthesis, and regulatory mechanisms of Ψ. This review summarizes the effects of pseudouridylation on various substrates of RNA and briefly discusses methods for detecting Ψ. Last, it focuses on how RNA pseudouridylation influences different cancers, emphasizing the search for novel approaches to cancer diagnosis, treatment, and prognosis through Ψ modification.

Identification of genes related to ribosomal proteins in colorectal cancer: exploring their potential as biomarkers, prognostic indicators, and therapeutic targets

BACKGROUND

Colorectal cancer (CRC) ranks as the third most commonly diagnosed cancer in both females and males, underscoring the need for the identification of effective biomarkers.

METHODS AND RESULTS

We assessed the expression levels of ribosomal proteins (RPs) at both mRNA and protein levels. Subsequently, leveraging the STRING database, we constructed a protein-protein interaction network and identified hub genes. The co-expression network of differentially expressed genes associated with CRC and their target hub RPs was constructed using the weighted gene co-expression network analysis algorithm. Gene ontology and molecular signatures database were conducted to gain insights into the biological roles of genes associated with the identified module. To confirm the results, the expression level of the candidate genes in the CRC samples compared to the adjacent healthy was evaluated by the RT-qPCR method. Our findings indicated that the genes related to RPs were predominantly enriched in biological processes associated with Myc Targets, Oxidative Phosphorylation, and cell proliferation. Also, results demonstrated that elevated levels of GRWD1, MCM5, IMP4, and RABEPK that related to RPs were associated with poor prognostic outcomes for CRC patients. Notably, IMP4 and RABEPK exhibited higher diagnostic value. Moreover, the expression of IMP4 and RABEPK showed a significant association with drug resistance using cancer cell line encyclopedia and genomics of drug sensitivity in cancer databases. Also, the results showed that the expression level of IMP4 and RABEPK in cancerous samples was significantly higher compared to the adjacent healthy ones.

CONCLUSION

The general results of this study have shown that many genes related to RPs are increased in cancer and could be associated with the death rate of patients. We also highlighted the therapeutic and prognostic potentials of RPs genes in CRC.

Pseudouridylation-mediated gene expression modulation

RNA-guided pseudouridylation, a widespread post-transcriptional RNA modification, has recently gained recognition for its role in cellular processes such as pre-mRNA splicing and the modulation of premature termination codon (PTC) readthrough. This review provides insights into its mechanisms, functions, and potential therapeutic applications. It examines the mechanisms governing RNA-guided pseudouridylation, emphasizing the roles of guide RNAs and pseudouridine synthases in catalyzing uridine-to-pseudouridine conversion. A key focus is the impact of RNA-guided pseudouridylation of U2 small nuclear RNA on pre-mRNA splicing, encompassing its influence on branch site recognition and spliceosome assembly. Additionally, the review discusses the emerging role of RNA-guided pseudouridylation in regulating PTC readthrough, impacting translation termination and genetic disorders. Finally, it explores the therapeutic potential of pseudouridine modifications, offering insights into potential treatments for genetic diseases and cancer and the development of mRNA vaccine.

Maternally Inherited Essential Hypertension May Be Associated with the Mutations in Mitochondrial tRNAGlu Gene

Background

Mitochondrial DNA (mtDNA) mutations are associated with essential hypertension (EH), but the molecular mechanism remains largely unknown.

Objective

The aim of this study is to explore the association between mtDNA mutations and EH.

Methods

Two maternally inherited families with EH are underwent clinical, genetic and biochemical assessments. mtDNA mutations are screened by PCR-Sanger sequencing and phylogenetic, and bioinformatics analyses are performed to evaluate the pathogenicity of mtDNA mutations. We also generate cytoplasmic hybrid (cybrid) cell lines to analysis mitochondrial functions.

Results

Matrilineal relatives exhibit variable degree of clinical phenotypes. Molecular analysis reveals the presence of m.A14693G and m.A14696G mutations in two pedigrees. Notably, the m.A14693G mutation occurs at position 54 in the TψC loop of tRNAGlu, a position which is critical for post-transcriptionally modification of tRNAGlu. While the m.A14696G mutation creates a novel base-pairing (51C-64G). Bioinformatic analysis shows that these mutations alter tRNAGlu secondary structure. Additionally, patients with tRNAGlu mutations exhibit markedly decreased in mtDNA copy number, mitochondrial membrane potential (MMP) and ATP, whereas the levels of reactive oxygen species (ROS) increase significantly.

Conclusion

The m.A14696G and m.A14693G mutations lead to failure in tRNAGlu metabolism and cause mitochondrial dysfunction that is responsible for EH.