Elevated expression of ASF1B correlates with poor prognosis in human lung adenocarcinoma

A novel telomere-associated genes signature for the prediction of prognosis and treatment responsiveness of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a prevalent malignancy worldwide, characterized by its high malignancy and poor prognosis. Telomeres, crucial components of eukaryotic chromosomes, have been increasingly recognized for their involvement in tumorigenesis, development, and impact on the prognosis of cancer patients. However, the precise role of telomere-associated genes in HCC remains incompletely elucidated.

METHODS

The Cancer Genome Atlas (TCGA) database was utilized to download data from 374 HCC and 50 normal liver tissue samples. Differential genes were screened and intersected with 2093 telomere-related genes (TRGs) in GeneCards, resulting in the identification of 704 TRGs exhibiting survival differences. Through univariate Cox regression analysis, multivariate Cox regression analysis, and LASSO regression, a prognostic model consisting of 18 TRGs for HCC risk assessment was developed. The single-cell and spatial transcriptomics were utilized to analyze the expression and distribution of 18 TRGs in HCC. Subsequently, Mendelian randomization (MR) analysis confirmed a causal relationship between ASF1A and alcoholic HCC among the identified 18 TRGs. The expression and functional significance of ASF1A in HCC cell lines were investigated through colony formation assays, Transwell migration assays, and wound healing experiments.

RESULTS

We developed a prognostic risk model for HCC incorporating 18 TRGs. Kaplan-Meier analysis demonstrated that the overall survival (OS) rate of the high-risk group was significantly inferior to that of the low-risk group. Cox regression analysis identified age (HR = 1.017, 95% CI: 1.002-1.032, P = 0.03), stage (HR = 1.389, 95% CI: 1.111-1.737, P = 0.004), and risk score (HR = 5.097, 95% CI: 3.273-7.936, P < 0.001) as three independent risk factors for HCC patients. The five-year receiver operating characteristic curve (ROC) and multivariate Cox regression analysis further validated the accuracy of our model. Time-dependent ROC results revealed that the 1-year, 3-year, and 5-year AUC values were AUC = 0.801, AUC = 0.734, and AUC = 0.690, respectively. The expression and distribution of 18 TRGs in HCC were further validated through single-cell and spatial transcriptomics data. Additionally, immune subtype analysis indicated a significantly lower proportion of C3 and C4 subtypes in the high-risk TRG group compared to the low-risk group. Meanwhile, tumor immune dysfunction and exclusion (TIDE) were significantly higher in the high-risk group than in the low-risk group. Furthermore, we observed differences in IC50 values among nine chemotherapeutic drugs across different TRG risk subtypes which partially confirmed our model's predictive efficacy for immunotherapy. Amongst these eighteen TRGs analyzed by MR analysis, ASF1A was found to be associated with alcoholic HCC pathogenesis. We further confirmed ASF1A was significant overexpression in HCC by Western blotting. We also explored it's the carcinogenic role of ASF1A in HCC via the transwell, wound healing, and clone formation experiments.

CONCLUSION

In this study, we developed a novel prognostic model comprising 18 TRGs for HCC, which exhibited remarkable accuracy in predicting HCC patients' prognosis. Additionally, through MR analysis, we have successfully established a causal relationship between ASF1A and alcoholic HCC for the first time, which also provided a new theoretical foundation for the management of alcoholic HCC.

Molecular Subtypes Defined by Cuproptosis-Associated Genes, Prognostic Model Development, and Tumor Immune Microenvironment Characterization in Adrenocortical Carcinoma

Introduction

This study aims to explore the role of cuproptosis-related genes in ACC, utilizing data from TCGA and GEO repositories, and to develop a predictive model for patient stratification.

Methods

A cohort of 123 ACC patients with survival data was analyzed. RNA-seq data of 17 CRGs were examined, and univariate Cox regression identified prognostic CRGs. A cuproptosis-related network was constructed to show interactions between CRGs. Consensus clustering classified ACC into three subtypes, with transcriptional and survival differences assessed by PCA and survival analysis. Gene set variation analysis (GSVA) and ssGSEA evaluated functional and immune infiltration characteristics across subtypes. Differentially expressed genes (DEGs) were identified, and gene clusters were established. A risk score (CRG_score) was generated using LASSO and multivariate Cox regression, validated across datasets. Tumor microenvironment, stem cell index, mutation status, drug sensitivity, and hormone synthesis were examined in relation to the CRG_score. Protein expression of key genes was validated, and functional studies on ASF1B and NDRG4 were performed.

Results

Three ACC subtypes were identified with distinct survival outcomes. Subtype B showed the worst prognosis, while subtype C had the best. We identified 214 DEGs linked to cell proliferation and classified patients into three gene clusters, confirming their prognostic value. The CRG_score predicted patient outcomes, with high-risk patients demonstrating worse survival and possible resistance to immunotherapy. Drug sensitivity analysis suggested higher responsiveness to doxorubicin and etoposide in high-risk patients.

Conclusion

This study suggests the potential prognostic value of CRGs in ACC. The CRG_score model provides a robust tool for risk stratification, with implications for treatment strategies.

ASF1B acted as a prognostic biomarker for stomach adenocarcinoma

Stomach adenocarcinoma (STAD) has a high mortality rate due to the lack of highly sensitive biomarkers. Therefore, the search for potential tumor markers is of great value. ASF1B is a prognostic marker for a variety of tumors, while the prognostic value and immune microenvironment of ASF1B in STAD remain unclear, and to be determined. Kaplan-Meier analysis was performed to analyze the prognostic role of ASF1B in STAD. Functional enrichment of ASF1B was explored with GO and KEGG pathway analysis. We also explored the correlation between ASF1B expression and immune infiltration in STAD. ASF1B was significantly upregulated in STAD tissues and high expression of ASF1B indicated a poor overall survival, progression-free survival, and first progression rate in STAD. The functional enrichment analysis of ASF1B and related genes showed high enrichment in the cell cycle and DNA repair, and the ASF1B high expression group was also mainly enriched in pathways such as the cell cycle. Analysis of tumor immune infiltration showed that ASF1B expression was significantly associated with the majority of immune cell infiltration in STAD. Moreover, STAD patients with high ASF1B expression had a higher tumor mutation burden score, microsatellite instability score, PD-1 immunophenoscore, and immune checkpoint expression. Our results suggest that ASF1B was an independent prognostic factor for STAD as well as a potential target for immunotherapy.

The interaction between ASF1B and TLK1 promotes the malignant progression of low-grade glioma

AIM

Low-grade glioma (LGG), which is the second most frequent adult brain malignancy, severely threatens patients' health and has a high recurrence rate. Histone H3/H4 chaperone anti-silencing function 1 B (ASF1B) has a tight association with the initiation and development of tumours. The expression and regulation mechanism of ASF1B in LGG were discussed.

METHODS

ASF1B expression in LGG patients as well as the association of ASF1B with overall survival and disease-free survival of LGG patients were predicted by GEPIA database. The independent prognostic value of ASF1B in LGG patients was investigated by TCGA database. RT-qPCR, together with western blot was applied for the assessment of ASF1B in LGG cell lines. After ASF1B expression was inhibited, CCK8 and colony formation assays judged cell proliferation. Flow cytometry analysis and TUNEL assay appraised cell cycle as well as apoptosis. Cell migratory and invasive capacities were measured by wound healing as well as Transwell assays. Western blot tested the expression of proliferation-, cycle-, apoptosis-, and metastasis-associated proteins. STRING and GeneMANIA database predicted the relationship between ASF1B and tousled-like kinase 1 (TLK1). ChIP assay testified the affinity of ASF1B with TLK1. Subsequently, TLK1 was overexpressed and ASF1B expression interfered, and the functional assays were executed.

RESULTS

ASF1B was discovered to be increased in LGG tissues and cells and indicates an unfavourable prognosis for LGG patients. ASF1B was not an independent prognostic factor for LGG. ASF1B deficiency obstructed the proliferation, cell cycle as well as metastasis of LGG cells, and induced cell death, which might be realized through the interaction with TLK1.

CONCLUSION

The interaction between ASF1B and TLK1 promoted the malignant progression of LGG.Key messagesTLK1 interacts with ASF1B.Interference with ASF1B inhibits the proliferative, invasive and migratory capabilities and induces the cycle arrest, along with the apoptosis of LGG cells.The interaction between ASF1B and TLK1 promotes the malignant progression of LGG.

miR-24-3p Regulates Epithelial-Mesenchymal Transition and the Malignant Phenotype of Pancreatic Adenocarcinoma by Regulating ASF1B Expression

Anti-silencing function protein 1 homolog B (ASF1B) has been implicated in the occurrence and development of cancers. The present work explored the functional role and the expression regulation of ASF1B in pancreatic ductal adenocarcinoma (PDAC). Based on the real-time quantitative PCR (qRT-PCR) and immunohistochemistry (IHC), ASF1B was significantly upregulated in PDAC tissues. High expression of ASF1B was associated with a poor overall survival (OS) and recurrence-free survival (DFS) in the PDAC patients. ASF1B also showed a relatively higher expression in PDAC cells (AsPC-1, PANC-1) when compared with human pancreatic ductal epithelial cells (HPDFe-6). CCK8 and clone formation assay demonstrated that silencing ASF1B impaired the proliferation in PANC-1 and AsPC-1 cells, and Annexin V-PI staining showed an increased level of apoptosis upon ASF1B silencing. ASF1B silencing also suppressed the migration and invasion in PDAC cells, as revealed by Transwell assays. We further showed that miR-24-3p was downregulated in PDAC tissues and cells, which functionally interacted with ASF1B by dual-luciferase reporter assay. miR-24-3p negatively regulated ASF1B expression to modulate the malignant phenotype of PDAC cells. ASF1B shows high expression in PDAC, which promotes the malignancy and EMT process of PDAC cells. miR-24-3p is a negative regulator of ASF1B and is downregulated in PDAC cells. Our data suggest that targeting ASF1B/miR-24-3p axis may serve as an intervention strategy for the management of PDAC.

Anti-silencing function 1B knockdown suppresses the malignant phenotype of colorectal cancer by inactivating the phosphatidylinositol 3-kinase/AKT pathway

BACKGROUND

Mounting studies have highlighted the pivotal influence of anti-silencing function 1B (ASF1B) on the malignancy of cancers.

AIM

To explore the influence and mechanism of ASF1B in colorectal cancer (CRC).

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect mRNA expression of ASF1B. Immunohistochemical staining was performed to detect protein expression of ASF1B and Ki67 in tumor tissues. Western blot analysis was used to determine levels of ASF1B and proliferation/epithelial mesenchymal transition (EMT)/stemness-related proteins. In addition, the proliferation of CRC cells was assessed using Cell Counting Kit-8 and 5-Ethynyl-2’-Deoxyuridine assays. The migration and invasion of CRC cells were evaluated using transwell assays. Stemness of CRC cells was tested using the sphere formation assay. To construct a xenograft tumor model, HCT116 cells were introduced into mouse flanks via subcutaneous injection.

RESULTS

ASF1B expression was markedly increased in CRC tissues and cells, and it was inversely correlated with overall survival of CRC patients and was positively associated with the tumor node metastasis (TNM) stage of CRC patients. Silencing of ASF1B suppressed proliferation, migration, invasion, stemness and EMT of CRC cells as well as tumorigenesis of xenograft mice. Furthermore, protein levels of P-phosphatidylinositol 3-kinase (p-PI3K) and p-AKT were decreased after silencing of ASF1B in CRC cells. The inhibitory effects of ASF1B knockdown on cell proliferation, stemness and EMT were partly abolished by PI3K activator in CRC cells.

CONCLUSION

Silencing of ASF1B inactivated the PI3K/AKT pathway to suppress CRC malignancy in vitro.

AC099850.3/NCAPG Axis Predicts Poor Prognosis and is Associated with Resistance to EGFR Tyrosine-Kinase Inhibitors in Lung Adenocarcinoma

Background

TKI-acquired resistance markedly interferes with treatment of lung cancer patients with EGFR mutant features. Long non-coding RNAs (lncRNAs) modify EGFR-TKI resistance during tumor progression. Non-structural maintenance of chromosomes condensin I complex subunit G (NCAPG) is a mitosis-related protein that is involved in tumorigenesis. We investigated the potential regulatory lncRNAs of NCAPG in lung adenocarcinoma (LUAD) and assessed their roles in EGFR-TKI resistance.

Methods

Data for 1678 lung cancer patients were retrieved from TCGA and GEO databases and used to evaluate NCAPG and lncRNAs expressions, as well as their prognostic significance in LUAD. Protein levels of NCAPG in LUAD were validated by immuno-histochemistry. To assess the relationship between NCAPG levels and EGFR-TKIs sensitivity, a cohort of 57 LUAD patients administered with EGFR-TKIs was used.

Results

Both NCAPG and lncRNA AC099850.3 were over-expressed in LUAD tissues, and correlated with tumor progression and poor prognosis in LUAD. LncRNA AC099850.3 was identified as a potential regulator of NCAPG expressions. The AC099850.3/NCAGP axis was markedly correlated with EGFR mutations and IC₅₀ of EGFR-TKIs. Besides, elevated NCAPG levels were associated with EGFR-TKIs resistance in 57 LUAD patients undergoing TKIs treatment. Gene set enrichment analysis revealed that both AC099850.3 and NCAGP were abundant in the cell cycle and the p53 signaling pathway.

Conclusion

The AC099850.3/NCAPG axis is a potential prognostic predictor and therapeutic biomarker for EGFR-TKIs in LUAD.

Involvement of elevated ASF1B in the poor prognosis and tumorigenesis in pancreatic cancer

Anti-silencing function 1B (ASF1B) has been reported to be associated with the occurrence of many kinds of tumors. However, the biological effect and action mechanism of ASF1B in pancreatic cancer (PC) tumorigenesis remain unclear. The expression and prognosis value of ASF1B in PC were analyzed using GEPIA, GEO, and Kaplan-Meier plotter databases. The diagnostic value of ASF1B in PC was determined by receiver operating characteristic curve. The relationship between ASF1B expression and the clinical feathers in PC was investigated based on TCGA. qRT-PCR and western blot analyses were used to measure ASF1B expression in PC cells. Cell proliferation was evaluated by MTT and EdU assays, and apoptosis was examined by TUNEL and caspase-3 activity assays. Western blot analysis was utilized to detect the expression of proliferating cell nuclear antigen (PCNA), cyclin D1, Bax, Bcl-2, and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling proteins. ASF1B was overexpressed in several digestive cancers, including PC. Upregulated ASF1B was correlated with the poor prognosis and clinical features in PC patients. The area under the curve (AUC) value of ASF1B was 0.990. ASF1B was also overexpressed in PC cells. ASF1B silencing inhibited PC cell proliferation, promoted apoptosis, and increased caspase-3 activity, which were accompanied by the reduction of PCNA and cyclin D1 expression and increase of the ratio of Bax/Bcl-2 expression. Additionally, ASF1B silencing suppressed the PI3K/Akt pathway and 740Y-P treatment partially abolished the effects of ASF1B knockdown on PC cells. In conclusion, ASF1B silencing retarded proliferation and promoted apoptosis in PC cells by inactivation of the PI3K/Akt pathway.

Downregulation of ASF1B inhibits tumor progression and enhances efficacy of cisplatin in pancreatic cancer

Pancreatic cancer is an aggressive and lethal cancer with the highest mortality rate. Hence, the development of new targeting and innovative treatment strategies is needed. Recent studies reported that the histone chaperone anti-silencing function 1B (ASF1B) can be used as a diagnosis and prognosis cancer biomarker. However, functional studies of ASF1B in pancreatic cancer have not been performed. This study compared expression levels of ASF1B in pancreatic cancer specimens with those of normal tissues using publicly available online databases. We found that ASF1B was commonly overexpressed in pancreatic cancer specimens, which is associated with poor prognosis. ASF1B downregulation in pancreatic cancer cells reduced their colony formation, proliferation, migration, and invasion abilities, and inhibited MMP9 activity. Furthermore, ASF1B expression downregulation increased cell cycle S-phase arrest and DNA damage though activation of the checkpoint kinases Chk1 and Chk2 pathways. Additionally, increased caspase (caspases-3 and -9) activation and PARP cleavage led to enhanced caspase-dependent apoptosis and improved cisplatin sensitivity. Collectively, our results indicate that ASF1B may serve as a potential biomarker of pancreatic cancer and a novel therapeutic target.

ZNF143 Expression is Associated with COPD and Tumor Microenvironment in Non-Small Cell Lung Cancer

Background

Chronic obstructive pulmonary disease (COPD) is an inflammatory-related disease highly associated with increased lung cancer risk. Studies have explored the tumor promoting roles for zinc finger protein 143 (ZNF143). However, the role of ZNF143 in COPD and tumor microenvironment of non-small cell lung cancer (NSCLC) has not been fully elucidated.

Methods

COPD-related key genes were identified by differential gene expression evaluation, WGCNA and SVM-RFE analysis using mRNA expression data retrieved from public databases. ROC analysis was conducted to evaluate the diagnostic value of ZNF143. Correlation between ZNF143 and clinic-pathological features, associations with tumor-infiltrating immune cells (TICs) and the relationship with predictors of immunotherapy efficacy were explored. ZNF143 gene expression was validated by qRT-PCR using an independent cohort.

Results

Bioinformatic and machine learning analysis showed that ZNF143 was a COPD-related gene. ZNF143 expression was significantly upregulated in COPD and is a potential diagnostic biomarker in COPD with AUC > 0.85. ZNF143 expression was significantly upregulated in lung squamous cell carcinoma (LUSC) and lung adenocarcinoma (LUAD). ZNF143 expression levels were significantly higher in LUAD patients with COPD relative to the levels in patients only with LUAD. Upregulation of ZNF143 in patients with comorbidity of NSCLC and COPD was further confirmed by qRT-PCR analysis. High expression of ZNF143 was significantly correlated with advanced TNM stage in LUSC. High ZNF143 expression was associated with activated TICs in both LUAD and LUSC samples. Moreover, ZNF143 expression was significantly correlated with the levels of several known predictors of immunotherapy efficacy, including PD-L1, PD-L2, TMB and TIDE in NSCLC.

Conclusion

ZNF143 is a novel COPD biomarker. High expression level of ZNF143 is associated with immune microenvironment and high risk of progression of COPD to NSCLC.

Comprehensive Analysis Identified ASF1B as an Independent Prognostic Factor for HBV-Infected Hepatocellular Carcinoma

Purpose

Hepatitis B (HBV)-infected hepatocellular carcinoma is one of the most common cancers, and it has high incidence and mortality rates worldwide. The incidence of hepatocellular carcinoma has been increasing in recent years, and existing treatment modalities do not significantly improve prognosis. Therefore, it is important to find a biomarker that can accurately predict prognosis.

Methods

This study was analyzed using the The Cancer Genome Atlas (TCGA) database and validated by the International Cancer Genome Consortium (ICGC) database. The STRING database was used to construct a gene co-expression network and visualize its functional clustering using Cytoscape. A prognostic signature model was constructed to observe high and low risk with prognosis, and independent prognostic factors for HBV-infected hepatocellular carcinoma were identified by Cox regression analysis. The independent prognostic factors were then analyzed for expression and survival, and their pathway enrichment was analyzed using gene set enrichment analysis (GSEA).

Results

805 differentially expressed genes (DEGs) were obtained by differential analysis. Protein–protein interaction (PPI) showed that DEGs were mostly clustered in functional modules, such as cellular matrix response, cell differentiation, and tissue development. Prognostic characterization models showed that the high-risk group was associated with poor prognosis, while Cox regression analysis identified ASF1B as the only independent prognostic factor. As verified by expression and prognosis, ASF1B was highly expressed in HBV-infected hepatocellular carcinoma and led to a poor prognosis. GSEA showed that high ASF1B expression was involved in cell cycle-related signaling pathways.

Conclusion

Bioinformatic analysis identified ASF1B as an independent prognostic factor in HBV-infected hepatocellular carcinoma, and its high expression led to a poor prognosis. Furthermore, it may promote hepatocellular carcinoma progression by affecting cell cycle-related signaling pathways.

ASF1B Serves as a Potential Therapeutic Target by Influencing Cell Cycle and Proliferation in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors with high morbidity and mortality. Therefore, it is very important to find potential biomarkers that can effectively predict the prognosis and progression of HCC. Recent studies have shown that anti-silencing function 1B (ASF1B) may be a new proliferative marker for tumor diagnosis and prognosis. However, the expression and function of ASF1B in hepatocellular carcinoma remain to be determined. In this study, integrated analysis of the Cancer Genome Atlas (TCGA), genotypic tissue expression (GTEx), and Gene Expression Omnibus (GEO) databases revealed that ASF1B was highly expressed in HCC. Kaplan-Meier survival curve showed that elevated ASF1B expression was associated with poor survival in patients with liver cancer. Correlation analysis of immune infiltration suggested that ASF1B expression was significantly correlated with immune cell infiltration in HCC patients. Gene set enrichment analysis (GSEA) indicated that ASF1B regulated the cell cycle, DNA Replication and oocyte meiosis signaling. Our experiments confirmed that ASF1B was highly expressed in HCC tissues and HCC cell lines. Silence of ASF1B inhibited hepatocellular carcinoma cell growth in vitro. Furthermore, ASF1B deficiency induced apoptosis and cell cycle arrest. Mechanistically, ASF1B knockdown reduced the expression of proliferating cell nuclear antigen (PCNA), cyclinB1, cyclinE2 and CDK9.Moreover, ASF1B interacted with CDK9 in HCC cells. Taken together, these results suggest that the oncogenic gene ASF1B could be a target for inhibiting hepatocellular carcinoma cell growth.

Identification of Survival-Associated Hub Genes in Pancreatic Adenocarcinoma Based on WGCNA

Pancreatic adenocarcinoma is one of the leading causes of cancer-related death worldwide. Since little clinical symptoms were shown in the early period of pancreatic adenocarcinoma, most patients were found to carry metastases when diagnosis. The lack of effective diagnosis biomarkers and therapeutic targets makes pancreatic adenocarcinoma difficult to screen and cure. The fundamental problem is we know very little about the regulatory mechanisms during carcinogenesis. Here, we employed weighted gene co-expression network analysis (WGCNA) to build gene interaction network using expression profile of pancreatic adenocarcinoma from The Cancer Genome Atlas (TCGA). STRING was used for the construction and visualization of biological networks. A total of 22 modules were detected in the network, among which yellow and pink modules showed the most significant associations with pancreatic adenocarcinoma. Dozens of new genes including PKMYT1, WDHD1, ASF1B, and RAD18 were identified. Further survival analysis yielded their valuable effects on the diagnosis and treatment of pancreatic adenocarcinoma. Our study pioneered network-based algorithm in the application of tumor etiology and discovered several promising regulators for pancreatic adenocarcinoma detection and therapy.

Protumor Effects of Histone H3-H4 Chaperone Antisilencing Feature 1B Gene on Lung Adenocarcinoma: In Silico and In Vitro Analyses

BACKGROUND

ASF1B is a member of the histone H3-H4 chaperone antisilencing feature 1 (ASF1). ASF1B reportedly acts as an oncogene in several cancers including, breast cancer and cervical cancer. To date, the role of ASF1B in lung adenocarcinoma (LUAD) is not elucidated.

METHODS

The TCGA database, containing data for 33 cancer types, was used to explore the dysregulation and prognostic value of the ASF1B gene in pan-cancer data. R software packages and public databases/webservers were applied for bioinformatics and statistical analyses. Using in vitro models, immunoprecipitation and immunofluorescence were utilized to investigate if BCAR1 interacted with ASF1B in LUAD. Further, transfection experiments were performed to validate the expression pattern of ASF1B in LUAD and examine its regulating role in tumor-associated processes including tumor cell proliferation and migration.

RESULTS

ASF1B was found to be significantly elevated in LUAD and the majority of cancer types, except PCPG (pheochromocytoma and paraganglioma). The overexpression of ASF1B was associated with worse prognostic outcomes in most cancer types including LUAD. ASF1B was associated with lymph node metastasis, and in vitro, it promoted the proliferation and migration of LUAD cells. ASF1B knockdown suppressed LUAD cell proliferation and migration and also diminished the expression of cell cycle, metastasis, and EMT signaling-associated proteins. BCAR1 was found positively correlated and interacting with ASF1B, and BCAR1 overexpression reversed the effects of ASF1B knockdown in LUAD cells.

CONCLUSION

These findings indicated that ASF1B plays a significant role in the tumor progression of LUAD and BCAR1 mediates the tumor-promotive effects of ASF1B, acting as an intermediate protein. Therefore, the ASF1B/BCAR1 axis might be regarded as a putative therapeutic target for LUAD.

ASF1B Promotes Oncogenesis in Lung Adenocarcinoma and Other Cancer Types

Anti-silencing function 1B histone chaperone (ASF1B) is known to be an important modulator of oncogenic processes, yet its role in lung adenocarcinoma (LUAD) remains to be defined. In this study, an integrated assessment of The Cancer Genome Atlas (TCGA) and genotype-tissue expression (GTEx) datasets revealed the overexpression of ASF1B in all analyzed cancer types other than LAML. Genetic, epigenetic, microsatellite instability (MSI), and tumor mutational burden (TMB) analysis showed that ASF1B was regulated by single or multiple factors. Kaplan-Meier survival curves suggested that elevated ASF1B expression was associated with better or worse survival in a cancer type-dependent manner. The CIBERSORT algorithm was used to evaluate immune microenvironment composition, and distinct correlations between ASF1B expression and immune cell infiltration were evident when comparing tumor and normal tissue samples. Gene set enrichment analysis (GSEA) indicated that ASF1B was associated with proliferation- and immunity-related pathways. Knocking down ASF1B impaired the proliferation, affected cell cycle distribution, and induced cell apoptosis in LUAD cell lines. In contrast, ASF1B overexpression had no impact on the malignant characteristics of LUAD cells. At the mechanistic level, ASF1B served as an indirect regulator of DNA Polymerase Epsilon 3, Accessory Subunit (POLE3), CDC28 protein kinase regulatory subunit 1(CKS1B), Dihydrofolate reductase (DHFR), as established through proteomic profiling and Immunoprecipitation-Mass Spectrometry (IP-MS) analyses. Overall, these data suggested that ASF1B serves as a tumor promoter and potential target for cancer therapy and provided us with clues to better understand the importance of ASF1B in many types of cancer.

Comprehensive analysis of pan-cancer reveals potential of ASF1B as a prognostic and immunological biomarker

Background

Anti‐silencing function 1 (ASF1) is a conserved histone H3–H4 chaperone protein. ASF1B, a paralog of ASF1, acts by promoting cell proliferation and influencing cell cycle progression. Although there is some evidence demonstrating that ASF1B plays a key role in the development, progression, and prognosis of certain cancers, there are no pan‐cancer analyses of ASF1B.

Methods

We used a range of bioinformatics approaches to investigate the predictive role of ASF1B, including its correlation with prognosis, tumor mutational burden (TMB), microsatellite instability (MSI), tumor microenvironment (TME), and immune cell infiltration, in diverse cancer types.

Results

We found that ASF1B was highly expressed in 22 cancers and was negatively correlated with the prognosis of multiple major cancer types. Furthermore, ASF1B expression was correlated with TMB in 21 cancers and with MSI in 7 cancers. We found that ASF1B was coexpressed with genes encoding immune activators, immune suppressors, major histocompatibility complexes, chemokines, and chemokine receptors. We further found that the role of ASF1B in the infiltration of different types of immune cells varied across tumor types. ASF1B may potentially affect several key immune‐related pathways, such as those involved in antigen processing and presentation, natural killer cell‐mediated cytotoxicity, and autoimmune thyroid disease.

Conclusions

Our findings show that ASF1B may serve as a prognostic marker and potential immunotherapeutic target for several malignancies due to its role in tumorigenesis and immune infiltration.