Inhibition of DKC1 induces telomere-related senescence and apoptosis in lung adenocarcinoma

Exploration of telomere-related biomarkers for lung adenocarcinoma and targeted drug prediction

AIM

Bioinformatics analyses were performed to identify telomere biomarkers to develop a diagnostic model for lung adenocarcinoma (LUAD) and to predict potential target drugs for patients with LUAD.

BACKGROUND

Telomeres function crucially in maintaining genome stability and chromosome integrity, and telomere-related genes (TRGs) serve as potential prognostic markers in a variety of cancers. However, studies focusing on TRGs in LUAD are limited.

OBJECTIVE

To screen key telomere-related markers for LUAD and to evaluate their potential impact on the occurrence and development of LUAD.

METHODS

LUAD samples were collected from University of California Santa Cruz (UCSC) Xena and 2093 telomere-related genes (TRGs) were obtained from TelNet database. Hub genes were screened using "WGCNA" package. Differentially expressed genes (DEGs) between tumor and control samples were filtered using "DESeq" package. Protein-protein interaction (PPI) network analysis was performed to select candidate genes, from which telomere-related biomarkers were identified by machine learning and used to develop a nomogram. Functional enrichment pathways of the biomarkers were analyzed using "clusterProfiler" package. Correlation between immune cell infiltration and the biomarkers was examined by Spearman method. Targeted drugs were predicted and molecular docking models were developed using AutoDockTools. Finally, the screened biomarkers were validated by performing in vitro cellular assays.

RESULTS

A total of 259 hub genes, 2848 DEGs, and 48 differentially expressed TRGs in LUAD were screened. Subsequently, 13 candidate genes were obtained by PPI network analysis. LASSO and support vector machine-recursive feature elimination (SVM-RFE) algorithms further reduced the number of telomere-related biomarkers to four (CCNB1, CDC20, PLK1, and TOP2A). A nomogram with a strong predictive performance was created. These four biomarkers were mainly enriched in the mitogenic pathways and exhibited a strong correlation with immune cell infiltration. Three drugs (Lucanthone, Fulvestrant, and Myricetin) targeting the four biomarkers were predicted to be able to treat LUAD. Finally, in vitro cellular experiments demonstrated that CCNB1 and PLK1 have potential effects on proliferation, migration, invasion and AKT/mTOR signaling pathway in LUAD cells.

CONCLUSION

This study provided novel diagnostic biomarkers, therapeutic targets, and potential drugs for LUAD.

Long-term high fat diet aggravates the risk of lung fibrosis and lung cancer: transcriptomic analysis in the lung tissues of obese mice

Background

Previous studies reported significant relationships between obesity and pulmonary dysfunction. Here, we investigated genetic alterations in the lung tissues of high fat diet (HFD) induced obese mouse through transcriptomic and molecular analyses.

Methods

Eight-week-old male C57BL/6J mice were fed either a normal chow diet (NCD) or HFD for 12 weeks. We performed RNA sequencing, functional analysis of altered genes using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway data, Database for Annotation, Visualization and Integrated Discovery (DAVID) analysis, protein network analysis, quantitative real-time polymerase chain reaction, and Western blotting.

Results

We performed RNA sequencing analysis in the lung tissue of HFD mice. GO and KEGG pathway data presented higher expressions of genes related to lung fibrosis, and the changes of several pathways including regulation of nitrogen compound metabolic process, G protein-coupled receptor signaling, cancer pathway, and small cell lung cancer pathway. DAVID analysis and protein network analysis showed the changes of vascular endothelial growth factor, hypoxia-inducible factor-1 and rat sarcoma virus signaling related to vascular permeability, and protein network of MYC proto-oncogene gene related to cancer. In addition, we found increased protein and mRNA levels of the growth/differentiation factor 15 and alpha smooth muscle actin genes related to lung fibrosis in lung tissue of HFD mice.

Conclusions

HFD contributes to an increased risk of lung fibrosis and lung cancer. Thus, we propose that the genetic modulation and the molecular regulation of target pathways are essential to suppress pulmonary fibrosis in obese patients.

Implications of RNA pseudouridylation for cancer biology and therapeutics: a narrative review

BACKGROUND

Pseudouridine (Ψ), a C5-glycoside isomer of uridine, stands as one of the most prevalent RNA modifications in all RNA types. Distinguishing from the C-N bond linking uridine to ribose, the link between Ψ and ribose is a C-C bond, endowing Ψ modified RNA distinct properties and functions in various biological processes. The conversion of uridine to Ψ is governed by pseudouridine synthases (PUSs). RNA pseudouridylation is implicated in cancer biology and therapeutics.

OBJECTIVES

In this review, we will summarize the methods for detecting Ψ, the process of Ψ generation, the impact of Ψ modification on RNA metabolism and gene expression, the roles of dysregulated Ψ and pseudouridine synthases in cancers, and the underlying mechanism.

METHODS

We conducted a comprehensive search of PubMed from its inception through February 2024. The search terms included "pseudouridine"; "pseudouridine synthase"; "PUS"; "dyskerin"; "cancer"; "tumor"; "carcinoma"; "malignancy"; "tumorigenesis"; "biomarker"; "prognosis" and "therapy". We included studies published in peer-reviewed journals that focused on Ψ detection, specific mechanisms involving Ψ and PUSs, and prognosis in cancer patients with high Ψ expression. We excluded studies lacking sufficient methodological details or appropriate controls.

RESULTS

Ψ has been recognized as a significant biomarker in cancer diagnosis and prognosis. Abnormal Ψ modifications mediated by various PUSs result in dysregulated RNA metabolism and impaired RNA function, promoting the development of various cancers. Overexpression of PUSs is common in cancer cells and predicts poor prognosis. PUSs inhibition arrests cell proliferation and enhances apoptosis in cancer cells, suggesting PUS-targeting cancer therapy may be a potential strategy in cancer treatment.

DISCUSSION

High Ψ levels in serum, urine, and saliva may suggest cancer, but do not specify the type, requiring additional lab markers and imaging for accurate diagnosis. Standardized detection methods are also crucial for reliable results. PUSs are linked to cancer, but more researches are needed to understand their mechanisms in different cancers. Anticancer treatments targeting PUSs are still under developed.

Telomere-related prognostic signature for survival assessments in lung adenocarcinoma

Background

Telomere-related genes (TRGs) are important in many different types of cancers. However, there is a lack of research on the relationship between their expression and prognosis in lung adenocarcinoma (LUAD) patients. This study is to investigate the prognostic value of TRGs in LUAD and to develop a TRG signature that can predict patient survival.

Methods

A total of 2,086 TRGs were obtained from a database of genes involved in telomere maintenance (TelNet), while the clinical information and tumor RNA expression profiles of 513 LUAD patients were acquired from The Cancer Genome Atlas (TCGA) database. Statistical methodologies, such as least absolute shrinkage and selection operator (LASSO)-Cox, were employed to construct a prognostic model with predictive capabilities.

Results

We analyzed 1,339 telomere-associated differentially expressed genes and identified a ten-gene predictive signature for LUAD. This signature exhibited effective prognostic classification capabilities across multiple datasets, including GSE3141 (58 samples), GSE8894 (63 samples), GSE50081 (127 samples), and GSE72094 (398 samples). Furthermore, we screened tumor-sensitive drugs targeting this signature. High telomere levels were associated with reduced survival in lung cancer patients who underwent surgery. Compared to the traditional TNM (tumor node metastasis classification) grading method, our telomere-associated gene panel demonstrated superior prediction accuracy. Notably, patients in the high-risk group, defined by the telomere-associated signature, exhibited improved responses to immunotherapy, suggesting potential benefits for this subgroup of patients.

Conclusions

This study presents a comprehensive molecular signature comprising TRGs, which holds potential for functional and therapeutic investigations. Additionally, it serves as an integrated tool to identify crucial molecules for immunotherapy in lung cancer.

Multiomics and machine learning-based analysis of pancancer pseudouridine modifications

Pseudouridine widely affects the stability and function of RNA. However, our knowledge of pseudouridine properties in tumors is incomplete. We systematically analyzed pseudouridine synthases (PUSs) expression, genomic aberrations, and prognostic features in 10907 samples from 33 tumors. We found that the pseudouridine-associated pathway was abnormal in tumors and affected patient prognosis. Dysregulation of the PUSs expression pattern may arise from copy number variation (CNV) mutations and aberrant DNA methylation. Functional enrichment analyses determined that the PUSs expression was closely associated with the MYC, E2F, and MTORC1 signaling pathways. In addition, PUSs are involved in the remodeling of the tumor microenvironment (TME) in solid tumors, such as kidney and lung cancers. Particularly in lung cancer, increased expression of PUSs is accompanied by increased immune checkpoint expression and Treg infiltration. The best signature model based on more than 112 machine learning combinations had good prognostic ability in ACC, DLBC, GBM, KICH, MESO, THYM, TGCT, and PRAD tumors, and is expected to guide immunotherapy for 19 tumor types. The model was also effective in identifying patients with tumors amenable to etoposide, camptothecin, cisplatin, or bexarotene treatment. In conclusion, our work highlights the dysregulated features of PUSs and their role in the TME and patient prognosis, providing an initial molecular basis for future exploration of pseudouridine. Studies targeting pseudouridine are expected to lead to the development of potential diagnostic strategies and the evaluation and improvement of antitumor therapies.

Molecular mechanisms underlying the regulation of tumour suppressor genes in lung cancer

Tumour suppressor genes play a cardinal role in the development of a large array of human cancers, including lung cancer, which is one of the most frequently diagnosed cancers worldwide. Therefore, extensive studies have been committed to deciphering the underlying mechanisms of alterations of tumour suppressor genes in governing tumourigenesis, as well as resistance to cancer therapies. In spite of the encouraging clinical outcomes demonstrated by lung cancer patients on initial treatment, the subsequent unresponsiveness to first-line treatments manifested by virtually all the patients is inherently a contentious issue. In light of the aforementioned concerns, this review compiles the current knowledge on the molecular mechanisms of some of the tumour suppressor genes implicated in lung cancer that are either frequently mutated and/or are located on the chromosomal arms having high LOH rates (1p, 3p, 9p, 10q, 13q, and 17p). Our study identifies specific genomic loci prone to LOH, revealing a recurrent pattern in lung cancer cases. These loci, including 3p14.2 (FHIT), 9p21.3 (p16INK4a), 10q23 (PTEN), 17p13 (TP53), exhibit a higher susceptibility to LOH due to environmental factors such as exposure to DNA-damaging agents (carcinogens in cigarette smoke) and genetic factors such as chromosomal instability, genetic mutations, DNA replication errors, and genetic predisposition. Furthermore, this review summarizes the current treatment landscape and advancements for lung cancers, including the challenges and endeavours to overcome it. This review envisages inspired researchers to embark on a journey of discovery to add to the list of what was known in hopes of prompting the development of effective therapeutic strategies for lung cancer.

Potentials of ribosomopathy gene as pharmaceutical targets for cancer treatment

Ribosomopathies encompass a spectrum of disorders arising from impaired ribosome biogenesis and reduced functionality. Mutation or dysexpression of the genes that disturb any finely regulated steps of ribosome biogenesis can result in different types of ribosomopathies in clinic, collectively known as ribosomopathy genes. Emerging data suggest that ribosomopathy patients exhibit a significantly heightened susceptibility to cancer. Abnormal ribosome biogenesis and dysregulation of some ribosomopathy genes have also been found to be intimately associated with cancer development. The correlation between ribosome biogenesis or ribosomopathy and the development of malignancies has been well established. This work aims to review the recent advances in the research of ribosomopathy genes among human cancers and meanwhile, to excavate the potential role of these genes, which have not or rarely been reported in cancer, in the disease development across cancers. We plan to establish a theoretical framework between the ribosomopathy gene and cancer development, to further facilitate the potential of these genes as diagnostic biomarker as well as pharmaceutical targets for cancer treatment.

DKC1 aggravates gastric cancer cell migration and invasion through up-regulating the expression of TNFAIP6

Gastric cancer (GC) is one hackneyed malignancy tumor accompanied by high death rate. DKC1 has been discovered to serve as a facilitator in several cancers. Additionally, it was discovered from one study that DKC1 displayed higher expression in GC tissues than in the normal tissues. Nevertheless, its role and regulatory mechanism in GC is yet to be illustrated. In this study, it was proved that DKC1 expression was upregulated in GC tissues through GEPIA and UALCAN databases. Moreover, we discovered that DKC1 exhibited higher expression in GC cells. Functional experiments testified that DKC1 accelerated cell proliferation, migration, and invasion in GC. Further investigation disclosed that the weakened cell proliferation, migration, and invasion stimulated by DKC1 knockdown can be reversed after TNFAIP6 overexpression. Lastly, through in vivo experiments, it was demonstrated that DKC1 strengthened tumor growth. In conclusion, our work uncovered that DKC1 aggravated GC cell migration and invasion through upregulating the expression of TNFAIP6. This discovery might highlight the function of DKC1 in GC treatment.

Folic acid alleviated oxidative stress-induced telomere attrition and inhibited apoptosis of neurocytes in old rats

PURPOSE

Oxidative stress has been reported to cause telomere attrition, which triggers cell apoptosis. Apoptosis of neurocytes may play an essential role in the pathogenesis of neurodegenerative diseases. This study hypothesized that folic acid (FA) supplementation decreased neurocyte apoptosis by alleviating oxidative stress-induced telomere attrition in 25-month-old Sprague Dawley (SD) rats.

METHODS

Three-month-old male SD rats were randomly divided into four diet groups by different concentrations of folic acid in equal numbers, with intervention for 22 months. Folate, homocysteine (Hcy), reactive oxygen species (ROS) levels, antioxidant activities, and telomere length in the brain tissues were tested at 11, 18, and 22 months of intervention, and 8-hydroxy-deoxyguanosine (8-OHdG) levels, neurocyte apoptosis and telomere length in the cerebral cortex and hippocampal regions were tested during the 22-month intervention. An automated chemiluminescence system, auto-chemistry analyzer, Q-FISH, qPCR, and TUNEL assay were used in this study.

RESULTS

The rats had lower folate concentrations and higher Hcy, ROS, and 8-OHdG concentrations in brain tissue with aging. However, FA supplementation increased folate concentrations and antioxidant activities while decreasing Hcy, ROS, and 8-OHdG levels in rat brain tissue after 11, 18, and 22 months of intervention. Furthermore, FA supplementation alleviated telomere length shortening and inhibited neurocyte apoptosis during the 22-month intervention.

CONCLUSION

FA supplementation alleviated oxidative stress-induced telomere attrition and inhibited apoptosis of neurocytes in 25-month-old rats.

Effects of HSV-G47Δ Oncolytic Virus on Telomerase and Telomere Length Alterations in Glioblastoma Multiforme Cancer Stem Cells Under Hypoxia and Normoxia Conditions

BACKGROUND

Due to the existence of tumor stem cells with tumorigenicity properties and resistance patterns, treatment of glioblastoma is not easy. Hypoxia is a major concern in glioblastoma therapy. Telomerase activity and telomere length alterations have been known to play a critical role in glioblastoma progression and invasion.

OBJECTIVE

This study aimed to investigate the effects of HSV-G47Δ oncolytic virus on telomerase and telomere length alterations in U251GBMCSCs (U251-Glioblastoma cancer stem cells) under hypoxia and normoxia conditions.

METHODS

U251-CSCs were exposed to the HSV-G47Δ virus in optimized MOI (Multiplicity of infection= 1/14 hours). An absolute telomere length and gene expression of telomerase subunits were determined using an absolute human telomere length quantification PCR assay. Furthermore, a bioinformatics pathway analysis was carried out to evaluate physical and genetic interactions between dysregulated genes with other potential genes and pathways.

RESULTS

Data revealed that U251CSCs had longer telomeres when exposed to HSV-G47Δ in normoxic conditions but had significantly shorter telomeres in hypoxic conditions. Furthermore, hTERC, DKC1, and TEP1 genes were significantly dysregulated in hypoxic and normoxic microenvironments. The analysis revealed that the expression of TERF2 was significantly reduced in both microenvironments, and two critical genes from the MRN complex, MER11 and RAD50, were significantly upregulated in normoxic conditions. RAD50 showed a significant downregulation pattern in the hypoxic niche. Our results suggested that repair complex in the telomeric structure could be targeted by HSV-G47Δ in both microenvironments.

CONCLUSION

In the glioblastoma treatment strategy, telomerase and telomere complex could be potential targets for HSV-G47Δ in both microenvironments.

Multi-omics analysis reveals PUS1 triggered malignancy and correlated with immune infiltrates in NSCLC

Non-small cell lung cancer (NSCLC) is the main pathological type of lung cancer. In this study, multi-omics analysis revealed a significant increase of pseudouridine synthase 1 (PUS1) in NSCLC and the high expression of PUS1 was associated with shorter OS (Overall Survival), PFS (Progression Free Survival), and PPS (Post Progression Survival) of NSCLC patients. Clinical subgroup analysis showed that PUS1 may be involved in the occurrence and development of NSCLC. Besides, TIMER, ESTIMATE, and IPS analysis suggested that PUS1 expression was associated with immune cell infiltration, and the expression of PUS1 was significantly negatively correlated with DC cell infiltration. GESA analysis also indicated PUS1 may involve in DNA_REPAIR, E2F_TARGETS, MYC_TARGETS_V2, G2M_CHECKPOINT and MYC_TARGETS_V1 pathways and triggered NSCLC malignancy through MCM5 or XPO1. Furthermore, PUS1 may be a potential target for NSCLC therapy.

Investigation of Gene Networks in Three Components of Immune System Provides Novel Insights into Immune Response Mechanisms against Edwardsiella tarda Infection in Paralichthys olivaceus

As a quintessential marine teleost, Paralichthys olivaceus demonstrates vulnerability to a range of pathogens. Long-term infection with Edwardsiella tarda significantly inhibits fish growth and even induces death. Gills, blood, and kidneys, pivotal components of the immune system in teleosts, elicit vital regulatory roles in immune response processes including immune cell differentiation, diseased cell clearance, and other immunity-related mechanisms. This study entailed infecting P. olivaceus with E. tarda for 48 h and examining transcriptome data from the three components at 0, 8, and 48 h post-infection employing weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis. Network analyses revealed a series of immune response processes after infection and identified multiple key modules and key, core, and hub genes including xpo1, src, tlr13, stat1, and mefv. By innovatively amalgamating WGCNA and PPI network methodologies, our investigation facilitated an in-depth examination of immune response mechanisms within three significant P. olivaceus components post-E. tarda infection. Our results provided valuable genetic resources for understanding immunity in P. olivaceus immune-related components and assisted us in further exploring the molecular mechanisms of E. tarda infection in teleosts.

RNA modifications in cancer

Currently, more than 170 modifications have been identified on RNA. Among these RNA modifications, various methylations account for two-thirds of total cases and exist on almost all RNAs. Roles of RNA modifications in cancer are garnering increasing interest. The research on m6A RNA methylation in cancer is in full swing at present. However, there are still many other popular RNA modifications involved in the regulation of gene expression post-transcriptionally besides m6A RNA methylation. In this review, we focus on several important RNA modifications including m1A, m5C, m7G, 2'-O-Me, Ψ and A-to-I editing in cancer, which will provide a new perspective on tumourigenesis by peeking into the complex regulatory network of epigenetic RNA modifications, transcript processing, and protein translation.

Dyskerin and telomerase RNA component are sex-differentially associated with outcomes and Sunitinib response in patients with clear cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) displays sex-biased incidence, outcomes, molecular alterations and treatment efficacy; however, clinical managements are largely identical in male and female patients. Moreover, many biomarkers have been identified as predictors for ccRCC outcomes and response to therapeutic drugs, such as multitargeted tyrosine-kinase receptor (TKR) inhibitors, but little is known about their sex-specificity. Dyskerin (DKC1), encoded by the DKC1 gene within Xq28, is a telomerase co-factor stabilizing telomerase RNA component (TERC) and overexpressed in various cancers. Here, we determined whether DKC1 and/or TERC affect ccRCC sex-differentially.

METHODS

DKC1 and TERC expression in primary ccRCC tumors was assessed using RNA sequencing and qPCR. DKC1 association with molecular alterations and overall or progression-free survival (OS or PFS) was analyzed in the TCGA cohort of ccRCC. The IMmotion 151 and 150 ccRCC cohorts were analyzed to evaluate impacts of DKC1 and TERC on Sunitinib response and PFS.

RESULTS

DKC1 and TERC expression was significantly upregulated in ccRCC tumors. High DKC1 expression predicts shorter PFS independently in female but not male patients. Tumors in the female DKC1-high group exhibited more frequent alterations in PIK3CA, MYC and TP53 genes. Analyses of the IMmotion 151 ccRCC cohort treated with the TKR inhibitor Sunitinib showed that female patients in the DKC1-high group was significantly associated with lower response rates (P = 0.021) accompanied by markedly shortened PFS (6.1 vs 14.2 months, P = 0.004). DKC1 and TERC expression correlated positively with each other, and higher TERC expression predicted poor Sunitinib response (P = 0.031) and shorter PFS (P = 0.004), too. However, DKC1 rather than TERC acted as an independent predictor (P < 0.001, HR = 2.0, 95% CI 1.480-2.704). In male patients, DKC1 expression was associated with neither Sunitinib response (P = 0.131) nor PFS (P = 0.184), while higher TERC levels did not predict response rates. Similar results were obtained from the analysis of the Sunitinib-treated IMmotion 150 ccRCC patients.

CONCLUSIONS

DKC1 serves as an independent female-specific predictor for survival and Sunitinib efficacy in ccRCC, which contribute to better understanding of the sex-biased ccRCC pathogenesis and improve personalized interventions of ccRCC.

Telomere-related prognostic biomarkers for survival assessments in pancreatic cancer

Human telomeres are linked to genetic instability and a higher risk of developing cancer. Therefore, to improve the dismal prognosis of pancreatic cancer patients, a thorough investigation of the association between telomere-related genes and pancreatic cancer is required. Combat from the R package "SVA" was performed to correct the batch effects between the TCGA-PAAD and GTEx datasets. After differentially expressed genes (DEGs) were assessed, we constructed a prognostic risk model through univariate Cox regression, LASSO-Cox regression, and multivariate Cox regression analysis. Data from the ICGC, GSE62452, GSE71729, and GSE78229 cohorts were used as test cohorts for validating the prognostic signature. The major impact of the signature on the tumor microenvironment and its response to immune checkpoint drugs was also evaluated. Finally, PAAD tissue microarrays were fabricated and immunohistochemistry was performed to explore the expression of this signature in clinical samples. After calculating 502 telomere-associated DEGs, we constructed a three-gene prognostic signature (DSG2, LDHA, and RACGAP1) that can be effectively applied to the prognostic classification of pancreatic cancer patients in multiple datasets, including TCGA, ICGC, GSE62452, GSE71729, and GSE78229 cohorts. In addition, we have screened a variety of tumor-sensitive drugs targeting this signature. Finally, we also found that protein levels of DSG2, LDHA, and RACGAP1 were upregulated in pancreatic cancer tissues compared to normal tissues by immunohistochemistry analysis. We established and validated a telomere gene-related prognostic signature for pancreatic cancer and confirmed the upregulation of DSG2, LDHA, and RACGAP1 expression in clinical samples, which may provide new ideas for individualized immunotherapy.

Loss of dyskerin facilitates the acquisition of metastatic traits by altering the mevalonate pathway

The initial dissemination of cancer cells from many primary tumors implies intravasation to lymphatic nodes or blood vessels. To investigate the mechanisms involved, we analyzed the expression of small non-coding RNAs in cutaneous squamous cell carcinoma (cSCC), a prevalent tumor that mainly spreads to lymph nodes. We report the reduced expression of small nucleolar RNAs in primary cSCCs that metastasized when compared to non-metastasizing cSCCs, and the progressive loss of DKC1 (dyskerin, which stabilizes the small nucleolar RNAs) along the metastasis. DKC1 depletion in cSCC cells triggered lipid metabolism by altering the mevalonate pathway and the acquisition of metastatic traits. Treatment of DKC1-depleted cells with simvastatin, an inhibitor of the mevalonate pathway, blocked the expression of proteins involved in the epithelial-to-mesenchymal transition. Consistently, the expression of the enzyme 3-hydroxy-3-methylglutaryl-CoA synthase 1 was associated with pathological features of high metastatic risk in cSCC patients. Our data underpin the relevance of the mevalonate metabolism in metastatic dissemination and pave the possible incorporation of therapeutic approaches among the antineoplastic drugs used in routine patient care.

Evidence from a meta-analysis for the prognostic and clinicopathological importance of DKC1 in malignancies

Aim: We conducted a meta-analysis to evaluate the prognostic and clinicopathological relevance of DKC1 in various cancers. Methods: We searched Web of Science, Embase, PubMed, Wanfang and CNKI. Stata SE15.1 was used to calculate the hazard ratio and relative risk with 95% CIs to assess the possible correlations between DKC1 expression levels and overall and disease-free survival, as well as with clinicopathological parameters. Results: We included nine studies, with a total of 2574 patients. There was a meaningful link between elevated DKC1 and poorer disease-free (p < 0.001) and overall survival (p < 0.001). Also, it was linked to advanced tumor node metastasis stage (p = 0.005). Conclusion: High DKC1 expression was predictive of worse prognosis and poorer clinicopathological parameters.

Translational Regulation by eIFs and RNA Modifications in Cancer

Translation is a fundamental process in all living organisms that involves the decoding of genetic information in mRNA by ribosomes and translation factors. The dysregulation of mRNA translation is a common feature of tumorigenesis. Protein expression reflects the total outcome of multiple regulatory mechanisms that change the metabolism of mRNA pathways from synthesis to degradation. Accumulated evidence has clarified the role of an increasing amount of mRNA modifications at each phase of the pathway, resulting in translational output. Translation machinery is directly affected by mRNA modifications, influencing translation initiation, elongation, and termination or altering mRNA abundance and subcellular localization. In this review, we focus on the translation initiation factors associated with cancer as well as several important RNA modifications, for which we describe their association with cancer.

H/ACA snoRNP Gene Family as Diagnostic and Prognostic Biomarkers for Hepatocellular Carcinoma

Background

The H/ACA small nucleolar ribonucleoprotein (snoRNP) gene family, including GAR1 ribonucleoprotein (GAR1), NHP2 ribonucleoprotein (NHP2), NOP10 ribonucleoprotein (NOP10), and dyskerin pseudouridine synthase 1 (DKC1), play important roles in ribosome biogenesis. However, the potential clinical value of the H/ACA snoRNP gene family in hepatocellular carcinoma (HCC) has not yet been reported.

Methods

Bioinformation databases were used to analyze the expression and roles of the H/ACA snoRNP gene family in HCC. Survival analysis, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes enrichment pathway (KEGG) analyses were performed using R software. Tumor Immune Estimation Resource (TIMER) was used to analyze the correlation between the expression of the H/ACA snoRNP gene family and immune infiltration in HCC. Finally, immunohistochemistry and Western blotting were performed to verify the protein expression of the H/ACA snoRNP gene family in HCC tissues and adjacent tissues.

Results

The expression of the H/ACA snoRNP gene family was significantly increased in HCC samples compared to normal tissues, and the area under the curve (AUC) of GAR1, NHP2, NOP10, and DKC1 was 0.898, 0.962, 0.884, and 0.911, respectively. Increased expression of the H/ACA snoRNP gene family was associated with poor prognosis in HCC patients (Hazard Ratio, HR = 1.44 [1.02-2.04], 1.70 [1.20-2.40], 1.53 [1.09-2.17], and 1.43 [1.02-2.03], respectively; log-rank P = 0.036, 0.003, 0.014, 0.039, respectively). GO and KEGG analyses showed that co-expressed genes were primarily enriched in ribosome biogenesis. In addition, upregulated expression of H/ACA snoRNP gene family was related to the infiltration of various immune cells and multiple T cell exhaustion markers in HCC patients. Immunohistochemical analysis and Western blotting showed that the protein expression of H/ACA snoRNP gene family was higher in HCC tissues than in adjacent tissues of clinical samples.

Conclusion

H/ACA snoRNP gene family expression was higher in HCC tissues than in normal or adjacent tissues and was highly associated with poor prognosis of HCC patients and, therefore, has the potential to serve as diagnostic and prognostic biomarkers for HCC.