TCOF1 upregulation in triple-negative breast cancer promotes stemness and tumour growth and correlates with poor prognosis

FOSL1 is a key regulator of a super-enhancer driving TCOF1 expression in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with an unmet clinical need, but its epigenetic regulation remains largely undefined. By performing multiomic profiling, we recently revealed distinct super-enhancer (SE) patterns in different subtypes of breast cancer and identified a number of TNBC-specific SEs that drive oncogene expression. One of these SEs, TCOF1 SE, was discovered to play an important oncogenic role in TNBC. However, the molecular mechanisms by which TCOF1 SE promotes the expression of the TCOF1 gene remain to be elucidated. Here, by using combinatorial approaches of DNA pull-down assay, bioinformatics analysis and functional studies, we identified FOSL1 as a key transcription factor that binds to TCOF1 SE and drives its overexpression. shRNA-mediated depletion of FOSL1 results in significant downregulation of TCOF1 mRNA and protein levels. Using a dual-luciferase reporter assay and ChIP-qPCR, we showed that binding of FOSL1 to TCOF1 SE promotes the transcription of TCOF1 in TNBC cells. Importantly, our data demonstrated that overexpression of FOSL1 drives the activation of TCOF1 SE. Lastly, depletion of FOSL1 inhibits tumor spheroid growth and stemness properties of TNBC cells. Taken together, these findings uncover the key epigenetic role of FOSL1 and highlight the potential of targeting the FOSL1-TCOF1 axis for TNBC treatment.

Exploring the interplay between triple-negative breast cancer stem cells and tumor microenvironment for effective therapeutic strategies

Triple-negative breast cancer (TNBC) is a highly aggressive and metastatic malignancy with poor treatment outcomes. The interaction between the tumor microenvironment (TME) and breast cancer stem cells (BCSCs) plays an important role in the development of TNBC. Owing to their ability of self-renewal and multidirectional differentiation, BCSCs maintain tumor growth, drive metastatic colonization, and facilitate the development of drug resistance. TME is the main factor regulating the phenotype and metastasis of BCSCs. Immune cells, cancer-related fibroblasts (CAFs), cytokines, mesenchymal cells, endothelial cells, and extracellular matrix within the TME form a complex communication network, exert highly selective pressure on the tumor, and provide a conducive environment for the formation of BCSC niches. Tumor growth and metastasis can be controlled by targeting the TME to eliminate BCSC niches or targeting BCSCs to modify the TME. These approaches may improve the treatment outcomes and possess great application potential in clinical settings. In this review, we summarized the relationship between BCSCs and the progression and drug resistance of TNBC, especially focusing on the interaction between BCSCs and TME. In addition, we discussed therapeutic strategies that target the TME to inhibit or eliminate BCSCs, providing valuable insights into the clinical treatment of TNBC.

ACAT1 promotes proliferation and metastasis of bladder cancer via AKT/GSK3β/c-Myc signaling pathway

Acetyl-CoA acetyltransferase 1 (ACAT1) plays a significant role in the regulation of gene expression and tumorigenesis. However, the biological role of ACAT1 in bladder cancer (BLCA) has yet to be elucidated. This research aimed to elucidate the bioinformatics features and biological functions of ACAT1 in BLCA. Here, we demonstrate that ACAT1 is elevated in BLCA tissues and is correlated with specific clinicopathological features and an unfavorable prognosis for survival in BLCA patients. ACAT1 was identified as an independent risk factor in BLCA. Phenotypically, both in vitro and in vivo, ACAT1 knockdown suppressed BLCA cell proliferation and migration, while ACAT1 overexpression had the opposite effect. Mechanistic assays revealed that ACAT1 enhances BLCA cell proliferation and metastasis through the AKT/GSK3β/c-Myc signaling pathway by modulating the cell cycle and EMT. Taken together, the results of our study reveal that ACAT1 is an oncogenic driver in BLCA that enhances tumor proliferation and metastasis, indicating its potential as a diagnostic and therapeutic target for this disease.

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.

TCOF1 promotes the colorectal cancer progression by stabilizing β-catenin

Colorectal cancer (CRC) is one of the highest mortality rates worldwide, and various studies reported to the occurrence of CRC. In particular, the Wnt/β-catenin pathway is known to be a major factor in the progression of CRC and β-catenin involved in the expression of its downstream target genes. We searched for TCOF1 through sliver staining to identify a new binding partner for β-catenin and to investigate the role of the gene involved in CRC. Treacle Ribosome Biogenesis Factor 1 (TCOF1) is a nucleolar protein that regulates the transcription of ribosomal DNA (rDNA). There are many reports of genetic studies on TCOF1 mutations and defects, but its function in CRC remains unknown. We demonstrated that TCOF1 and β-catenin expression in tissue microarray (TMA) containing 101 individual CRC and 17 adjacent normal samples. Additionally, the effects of TCOF1 knockdown or overexpression were examined proliferation, colony formation assay, western blot, and quantitative real-time PCR (qRT-PCR). TCOF1 knockdown or overexpression regulates cell proliferation about three-fold and the phosphorylation of β-catenin, cyclin D1 expression levels. Besides, we discovered the mechanism through which TCOF1 regulates the stability of β-catenin was involved in degradation through proteasome using ubiquitination assay. Finally, we confirmed the interaction of TCOF1 with the tankyrase inhibitor NVP-TNKS656, which destabilizes β-catenin through in vitro and in vivo. Collectively, this study shows that significantly correlation was observed that TCOF1 and β-catenin were risk factor for tumor progression. The stability of β-catenin via regulating TCOF1 expression could be a potential strategy for therapeutic with CRC.

HnRNPAB is an independent prognostic factor in non‑small cell lung cancer and is involved in cell proliferation and metastasis

Heterogeneous nuclear ribonucleoprotein A/B (hnRNPAB) is an RNA binding protein that is closely associated with the biological function and metabolism of RNA, which is involved in the malignant transformation of various tumor cells. However, the role and mechanisms of hnRNPAB in non-small cell lung cancer (NSCLC) are still unclear. In the present study, the expression levels of hnRNPAB in NSCLC and normal tissues were analyzed using the human protein atlas database and UALCAN database. The clinical significance of hnRNPAB was assayed using the data of NSCLC cases from The Cancer Genome Atlas database. Subsequently, two stable NSCLC cell lines with hnRNPAB knockdown were constructed and the effects of hnRNPAB silencing on cell viability, migration, invasion and epithelial-mesenchymal transition (EMT) were identified. Genes associated with hnRNPAB expression in NSCLC were screened using the Linked Omics database and verified by quantitative real-time PCR (RT-qPCR). The database analysis indicated that hnRNPAB was mainly expressed in the nucleus of NSCLC cells. Compared with the normal tissues, hnRNPAB expression was overexpressed in NSCLC tissues and was closely associated with the overall survival, sex, tumor-node-metastases classification, and poor prognosis of patients with lung adenocarcinoma. Functionally, knockdown of hnRNPAB inhibited the proliferation, migration, invasion and EMT of NSCLC cells and arrested the cell cycle at G₁ phase. Mechanistically, the bioinformatics analysis and RT-qPCR verification demonstrated that hnRNPAB knockdown led to a significant expression change of genes associated with tumorigenesis. In conclusion, the present study indicated that hnRNPAB played an important role in the malignant transformation of NSCLC, supporting the significance of hnRNPAB as a novel potential therapeutic target for the early diagnosis and prognosis of NSCLC.

Tumor Suppressive Role of MicroRNAs in Triple Negative Breast Cancer

Triple-negative breast cancers are highly aggressive, a heterogeneous form of breast cancer with a high re-occurrence rate that further lacks an efficient treatment strategy and prognostic marker. The tumor microenvironment of the disease comprises cancer-associated fibroblasts, cancer stem cells, immunological molecules, epithelial-mesenchymal transition, and a metastatic microenvironment that contributes to disease progression and metastasis to distant sites. Emerging evidence indicated that miRNA clusters would be of clinical utility as they exert an oncogenic or tumor suppressor role in TNBC. The present review article aims to highlight the therapeutic significance of miRNA in targeting the above-mentioned signaling cascades and modulating the intracellular crosstalk in the tumor microenvironment of TNBC. Prognostic implications of miRNAs to depict disease-free survival, distant metastasis-free survival, relapse-free survival, and overall survival outcome were also unveiled.

The integrative analysis based on super-enhancer related genes for predicting different subtypes and prognosis of patient with lower-grade glioma

Objective: Emerging evidence revealed that super-enhancer plays a crucial role in the transcriptional reprogramming for many cancers. The purpose aimed to explored how the super-enhancer related genes affects the prognosis and tumor immune microenvironment (TIME) of patients with low-grade glioma (LGG). Methods: In this study, the differentially expressed genes (DEGs) between LGG cohorts and normal brain tissue cohort were identified by the comprehensive analysis of the super-enhancer (SE) related genes. Then non-negative matrix factorization was performed to seek the optimal classification based on the DEGs, while investigating prognostic and clinical differences between different subtypes. Subsequently, a prognostic related signature (SERS) was constructed for the comprehensive evaluation in term of individualized prognosis, clinical characteristics, cancer markers, genomic alterations, and immune microenvironment of patients with LGG. Results: Based on the expression profiles of 170 DEGs, we identified three SE subtypes, and the three subtypes showed significant differences in prognostic, clinicopathological features. Then, nine optimal SE-related genes were selected to construct the SERS through the least absolute shrinkage and selection operator Cox regression analysis. Survival analysis showed that SERS had strong and stable predictive ability for the prognosis of LGG patients in the The Cancer Genome Atlas, China Glioma Genome Atlas, and Remdrandt cohorts, respectively. We also found that SERS was highly correlated with clinicopathological features, tumor immune microenvironment, cancer hallmarks, and genomic alterations in LGG patients. In addition, the predictive power of SERS for immune checkpoint inhibitor treatment is also superior. The qRT-PCR results and immunohistochemical results also confirmed the difference in the expression of four key genes in normal cells and tumors, as well as in normal tissues and tumor tissues. Conclusion: The SERS could be suitable to utilize individualized prognosis prediction and immunotherapy options for LGG patients in clinical application.

A cancer stem cell associated gene signature for predicting overall survival of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most prevalent type of primary liver cancer characterized by high mortality and morbidity rate. The lack of effective treatments and the high frequency of recurrence lead to poor prognosis of patients with HCC. Therefore, it is important to develop robust prediction tools for predicting the prognosis of HCC. Recent studies have shown that cancer stem cells (CSC) participate in HCC progression. The aim of this study was to explore the prognostic value of CSC-related genes and establish a prediction model based on data from The Cancer Genome Atlas (TCGA) database. In this study, 475 CSC-related genes were obtained from the Molecular Signature Database and 160 differentially expressed CSC-related genes in HCC patients were identified using the limma R package in the TCGA database. A total of 79 CSC-related genes were found to be associated with overall survival (OS). Using the least absolute shrinkage and selection operator (LASSO) and multivariate Cox regressions, a 3-gene signature (RAB10, TCOF1, and PSMD14) was constructed. Receiver operating characteristic (ROC) curves and Kaplan-Meier survival curves were constructed to test the prediction performance of the signature. Performance of the signature was validated using the International Cancer Genome Consortium (ICGC) dataset. In addition, immune feature and functional enrichment analyses were carried out to explore the underlying mechanisms. Moreover, a co-expression network was constructed using the weighted gene correlation network analysis (WGCNA) method to select genes significantly associated with risk scores in HCC in the TCGA dataset. The SGO2 gene was found to be significantly associated with risk scores of HCC. In vitro experiments revealed that it can promote HCC cell proliferation. Therefore, SGO2 may be a potential therapeutic target for HCC treatment. The constructed nomogram can help clinicians make decisions about HCC treatment.

Treacle is Upregulated in Cancer and Correlates With Poor Prognosis

Treacle/TCOF1 is an adaptor protein specifically associated with nucleolar chromatin. In the nucleolus it stimulates ribosome biogenesis, thereby promoting growth and proliferation. A second role of Treacle has emerged as a coordinator of the nucleolar responses to DNA damage, where it facilitates nucleolar DNA repair and cellular survival after genotoxic insults. The involvement of Treacle in multiple fundamental processes such as growth, proliferation, and genome stability, which are tightly linked to cancer, raises the question of Treacle’s role in the development of this disease. On one hand, overexpression of Treacle could stimulate nucleolar transcription and ribosome biogenesis providing a growth advantage in cancer cells. On the other hand, the function of Treacle as a gatekeeper in response to nucleolar DNA damage could favor mutations that would impair its function. In this perspective, we analyze paired Treacle expression data from the Cancer Genome Atlas (TCGA) and correlate expression with patient survival in different cancer types. We also discuss other recently published observations of relevance to the role of Treacle in cancer. In light of these new observations, we propose possible roles of Treacle in carcinogenesis and discuss its potential as a therapeutic target.

Treacle Sticks the Nucleolar Responses to DNA Damage Together

The importance of chromatin environment for DNA repair has gained increasing recognition in recent years. The nucleolus is the largest sub-compartment within the nucleus: it has distinct biophysical properties, selective protein retention, and houses the specialized ribosomal RNA genes (collectively referred to as rDNA) with a unique chromatin composition. These genes have high transcriptional activity and a repetitive nature, making them susceptible to DNA damage and resulting in the highest frequency of rearrangements across the genome. A distinct DNA damage response (DDR) secures the fidelity of this genomic region, the so-called nucleolar DDR (n-DDR). The composition of the n-DDR reflects the characteristics of nucleolar chromatin with the nucleolar protein Treacle (also referred to as TCOF1) as a central coordinator retaining several well-characterized DDR proteins in the nucleolus. In this review, we bring together data on the structure of Treacle, its known functions in ribosome biogenesis, and its involvement in multiple branches of the n-DDR to discuss their interconnection. Furthermore, we discuss how the functions of Treacle in ribosome biogenesis and in the n-DDR may contribute to Treacher Collins Syndrome, a disease caused by mutations in Treacle. Finally, we outline outstanding questions that need to be addressed for a more comprehensive understanding of Treacle, the n-DDR, and the coordination of ribosome biogenesis and DNA repair.