Overexpression of RALY promotes migration and predicts poor prognosis in hepatocellular carcinoma

O-GlcNAcylated RALY Contributes to Hepatocellular Carcinoma Cells Proliferation by Regulating USP22 mRNA Nuclear Export

Hepatocellular carcinoma (HCC) is one of the most prevalent and deadly tumors; however, its pathogenic mechanism remains largely elusive. In-depth researches are needed to reveal the expression regulatory mechanisms and functions of the RNA-binding protein RALY in HCC. Here, we identify RALY as a highly expressed oncogenic factor that affects HCC cells proliferation both in vitro and in vivo. O-GlcNAcylation of RALY at Ser176 enhances its stability by protecting RALY from TRIM27-mediated ubiquitination, thus maintaining hyper-expression of the RALY protein. Mechanistically, RALY interacts with USP22 messenger RNA, as revealed by RNA immunoprecipitation, to increase their cytoplasmic localization and protein expression, thereby promoting the proliferation of HCC cells. Furthermore, we develop a novel RALY protein degrader based on peptide proteolysis-targeting chimeras, named RALY-PROTAC, which we chemically synthesize by linking a RALY-targeting peptide with the E3 ubiquitin ligase recruitment ligand pomalidomide. In conclusion, our findings demonstrate a novel mechanism by which O-GlcNAcylation/RALY/USP22 mRNA axis aggravates HCC cells proliferation. RALY-PROTACs as degraders of the RALY protein exhibit potential as therapeutic drugs for RALY-overexpressing HCC.

The RNA binding protein RALY suppresses p53 activity and promotes lung tumorigenesis

The tumor suppressor p53 plays a pivotal role in tumor prevention. The activity of p53 is mainly restrained by the ubiquitin E3 ligase Mdm2. However, it is not well understood how the Mdm2-p53 pathway is intricately regulated. Here we report that the RNA binding protein RALY functions as an oncogenic factor in lung cancer. RALY simultaneously binds to Mdm2 and the deubiquitinating enzyme USP7. Via these interactions, RALY not only stabilizes Mdm2 by stimulating the deubiquitinating activity of USP7 toward Mdm2 but also increases the trans-E3 ligase activity of Mdm2 toward p53. Consequently, RALY enhances Mdm2-mediated ubiquitination and degradation of p53. Functionally, RALY promotes lung tumorigenesis, at least partially, via negative regulation of p53. These findings suggest that RALY destabilizes p53 by modulating the function of Mdm2 at multiple levels. Our study also indicates a critical role for RALY in promoting lung tumorigenesis via p53 inhibition.

RNA-binding proteins: Underestimated contributors in tumorigenesis

mRNA export, translation, splicing, cleavage or capping determine mRNA stability, which represents one of the primary aspects regulating gene expression and function. RNA-binding proteins (RBPs) bind to their target mRNAs to regulate multiple cell functions by increasing or reducing their stability. In recent decades, studies of the role of RBPs in tumorigenesis have revealed an increasing number of proteins impacting the prognosis, diagnosis and cancer treatment. Several RBPs have been identified based on their interactions with oncogenes or tumor suppressor genes in human cancers, which are involved in apoptosis, the epithelial-mesenchymal transition (EMT), DNA repair, autophagy, cell proliferation, immune response, metabolism, and the regulation of noncoding RNAs. In this review, we propose a model showing how RBP mutations influence tumorigenesis, and we update the current knowledge regarding the molecular mechanism by which RBPs regulate cancer. Special attention is being devoted to RBPs that represent prognostic and diagnostic factors in cancer patients.

RNA binding protein RALY activates the cholesterol synthesis pathway through an MTA1 splicing switch in hepatocellular carcinoma

Alternative splicing is an important RNA processing event that contributes to RNA complexity and protein diversity in cancer. Accumulating evidence demonstrates the essential roles of some alternatively spliced genes in carcinogenesis. However, the potential roles of alternatively spliced genes in hepatocellular carcinoma (HCC) are still largely unknown. Here we showed that the HnRNP Associated with Lethal Yellow Protein Homolog (RALY) gene is upregulated and associated with poor outcomes in HCC patients. RALY acts as a tumor-promoting factor by cooperating with splicing factor 3b subunit 3 (SF3B3) and modulating the splicing switch of Metastasis Associated 1 (MTA1) from MTA-S to MTA1-L. Normally, MTA1-S inhibits cell proliferation by reducing the transcription of cholesterol synthesis genes. In HCC, RALY and SF3B3 cooperate to regulate the MTA1 splicing switch, leading to a reduction in the MTA1-S level, and alleviating the inhibitory effect of MTA1-S on cholesterol synthesis genes, thus promoting HCC cell proliferation. In conclusion, our results revealed that the RALY-SF3B3/MTA1/cholesterol synthesis pathway contributes essentially to hepatic carcinogenesis and could serve as a promising therapeutic target for HCC.

Nuclear ribonucleoprotein RALY targets virus nucleocapsid protein and induces autophagy to restrict porcine epidemic diarrhea virus replication

Porcine epidemic diarrhea virus (PEDV) causes diarrhea and dehydration in pigs and leads to great economic losses in the commercial swine industry. However, the underlying molecular mechanisms of host response to viral infection remain unclear. In the present study, we investigated a novel mechanism by which RALY, a member of the heterogeneous nuclear ribonucleoprotein family, significantly promotes the degradation of the PEDV nucleocapsid (N) protein to inhibit viral replication. Furthermore, we identified an interaction between RALY and the E3 ubiquitin ligase MARCH8 (membrane-associated RING-CH 8), as well as the cargo receptor NDP52 (nuclear dot protein 52 kDa), suggesting that RALY could suppress PEDV replication by degrading the viral N protein through a RALY–MARCH8–NDP52–autophagosome pathway. Collectively, these results suggest a preventive role of RALY against PEDV infection via the autophagy pathway and open up the possibility of inducing RALY in vivo as an effective prophylactic and preventive treatment for PEDV infection.

RALY regulate the proliferation and expression of immune/inflammatory response genes via alternative splicing of FOS

RALY is a multifunctional RNA-binding protein involved in cancer metastasis, prognosis, and chemotherapy resistance in various cancers. However, the molecular mechanism of which is still unclear. We have established RALY overexpression cell lines and studied the effect of RALY on proliferation and apoptosis in HeLa cells. Then we used RNA-seq to analyze the transcriptomes data. Lastly, RT-qPCR experiments had performed to confirm the RNA-seq results. We found that the overexpression of RALY in HeLa cells inhibited proliferation. Moreover, the overexpression of RALY changed the gene expression profile, and the significant upregulation of genes involved immune/inflammatory response related biological process by NOD-like receptor signaling pathway cytokine-cytokine receptor interaction. The significant downregulation genes involved innate immune response by the Primary immunodeficiency pathway. Notably, IFIT1, IFIT2, IFTI3, IFI44, HERC4, and OASL expression had inhibited by the overexpression of RALY. Furthermore, RALY negatively regulates the expression of transcription factors FOS and FOSB. Notably, we found that 645 alternative splicing events had regulated by overexpression of RALY, which is highly enriched in transcription regulation, RNA splicing, and cell proliferation biological process by the metabolic pathway. We show that RALY regulates the expression of immune/inflammatory response-related genes via alternative splicing of FOS in HeLa cells. The novel role of RALY in regulating immune/inflammatory gene expression may explain its function in regulating chemotherapy resistance and provides novel insights into further exploring the molecular mechanism of RALY in regulating cancer immunity and chemo/immune therapies.

Over-expression of RALYL suppresses the progression of ovarian clear cell carcinoma through inhibiting MAPK and CDH1 signaling pathways

Background: The molecular mechanism in the progression of ovarian clear cell carcinoma (OCCC) remains unclear. Objective: This study aimed to investigate the potential function of RAYLY in OCCC. Methods: To validate RAYLY expression, immunohistochemistry, quantitative real-time PCR and western blotting were performed in OCCC tissues and the cell lines of OCCC and epithelial ovarian carcinoma (EOC). Subsequently, the biological effects of RALYL were evaluated through colony formation, and cell proliferation, migration and invasion assays. Finally, RNA-sequencing and gene set enrichment analysis (GSEA) were conducted to explore potential mechanism of RALYL in OCCC. Results: In our study, RALYL was significantly down-regulated in a majority of OCCC tissues compared to adjacent non-tumorous tissues, and OCCC cells had a lower expression level of RALYL than that of EOC cells. OCCC patients with high RALYL expression had a better pathological stage and prognosis. In vitro, over-expression of RALYL inhibited cell proliferation, migration and invasion in OCCC. GSEA analysis and western blot indicated an enrichment of MAPK and CDH1 signaling pathways in OCCC cells without RALYL over-expression. Conclusions: RALYL played an important role in the progression of OCCC, and might serve as a potential prognostic biomarker and novel therapeutic target for OCCC.

Proteomic analysis of hypopharyngeal and laryngeal squamous cell carcinoma sheds light on differences in survival

The link between differences in molecular expression and survival among advanced laryngeal (LSCC) and hypopharyngeal squamous carcinoma (HPSCC) remains unclear. Here, we applied the Surveillance, Epidemiology, and End Results (SEER) program, Isobaric tag for relative and absolute quantitation (iTRAQ) with Liquid chromatography-mass spectrometry (LC–MS/MS) proteomics data and The Cancer Genome Atlas (TCGA) related data to discover the possible disparities between HPSCC and LSCC. Our results showed a significantly worse 5-year overall-survival in HPSCC compared with LSCC before and after adjusting for clinical parameters. 240 differentially expressed proteins were enriched in molecular networks of cytoskeleton remodeling and antigen presentation. Moreover, HPSCC consisted of less T-central-memory cells, T-follicular-helper cells, TGF-β response, and CD4⁺  T memory resting cells, but more wound healing than LSCC. Furthermore, 9 mRNAs expression were  significantly and independently correlated to overall survival in 126 HPSCC and LSCC patients, which was further validated in another cohort of head and neck cancers. These findings support that Immunity signatures as well as pathway networks that include cytoskeleton remodeling and antigen presentation may contribute to the observed differences in survival between HPSCC and LSCC.

Transposon Insertion Mutagenesis in Mice for Modeling Human Cancers: Critical Insights Gained and New Opportunities

Transposon mutagenesis has been used to model many types of human cancer in mice, leading to the discovery of novel cancer genes and insights into the mechanism of tumorigenesis. For this review, we identified over twenty types of human cancer that have been modeled in the mouse using Sleeping Beauty and piggyBac transposon insertion mutagenesis. We examine several specific biological insights that have been gained and describe opportunities for continued research. Specifically, we review studies with a focus on understanding metastasis, therapy resistance, and tumor cell of origin. Additionally, we propose further uses of transposon-based models to identify rarely mutated driver genes across many cancers, understand additional mechanisms of drug resistance and metastasis, and define personalized therapies for cancer patients with obesity as a comorbidity.

RALY may cause an aggressive biological behavior and a dismal prognosis in non-small-cell lung cancer

RALY is a member of the heterogeneous nuclear ribonucleoprotein (hnRNP), an RNA-binding protein that plays a role in mRNA splicing and metabolism, may be involved in tumorigenesis and development. Some studies have shown that RALY plays a role in promoting cancer in a variety of tumors. However, the biological function and molecular mechanism of RALY in non-small cell lung cancer (NSCLC) remain unknown. TCGA databases were used to gather RALY expression data in NSCLC, the results indicate that RALY is highly expressed in cancer tissue of NSCLC patients. Then we demonstrated that RALY gene expression was notably upregulated in NSCLC tissue and cell lines (A549 and SK-MES-1), and was associated with lymph node metastasis (P = 0.007) and poorer overall survival in NSCLC patients. Subsequently, RALY in A549 and SK-MES-1 cells was knocked down by lentivirus to analyze the consequences of RALY on the biological behavior of NSCLC cell lines. Our results indicated that RALY knockdown impaired NSCLC cells proliferation, migration, and invasion, as well as arrested cells in G1 phase, and the reintroduction of RALY recused its biological phenotype. Furthermore, RALY knockdown down-regulated the expression levels of c-Myc, Cyclin D1, CDK4, MMP9, Rho A ,Rho C, N-cadherin and β-catenin, and up-regulated the expression levels of P27, Rho B and E-cadherin. Therefore, targeting RALY could be a promising molecular target for NSCLC treatment.

The Long Non-coding RNA ZFAS1 Sponges miR-193a-3p to Modulate Hepatoblastoma Growth by Targeting RALY via HGF/c-Met Pathway

Hepatoblastoma (HB) is the most common and aggressive malignant hepatic neoplasm in childhood and the therapeutic outcomes remain undesirable due to its recurrence and metastasis. Recently, long non-coding RNA (lncRNA) zinc finger antisense 1 (ZFAS1) has been reported to be an oncogenic gene in multiple cancers. However, the expression status and specific role of ZFAS1 involved in cancer progression of human HB remain unknown. This study aimed to identify the role of ZFAS1/miR-193a-3p/RALY axis in the development of HB. Here we showed that the expression of ZFAS1 was significantly upregulated in both HB tissues and cell lines. High ZFAS1 expression was significantly associated with aggressive tumor phenotypes and poorer overall survival in HB. In vitro and in vivo function assays indicated that silencing of ZFAS1 significantly suppressed HB cell proliferation and invasion. Furthermore, miR-193a-3p was identified to be the target of ZFAS1. Subsequently, RALY was confirmed to be regulated by miR-193a-3p/ZFAS1 axis. Mechanistically, our results indicated that the ZFAS1 participated to the progression of HB via regulating the HGF/c-Met signaling. Collectively, these data demonstrated that ZFAS1 acted as an oncogene to promote initiation and progression of HB by regulating miR-193a-3p/RALY (RALY Heterogeneous Nuclear Ribonucleoprotein) axis via HGF/c-Met Pathway, which provides an efficient marker and new therapeutic target for HB.