RNA Binding Proteins as Drivers and Therapeutic Target Candidates in Pancreatic Ductal Adenocarcinoma

Long Non-Coding RNAs and RNA-Binding Proteins in Pancreatic Cancer Development and Progression

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer and is responsible for about 467,000 cancer deaths annually. An oftentimes asymptomatic early phase of this disease results in a delayed diagnosis, and patients often present with advanced disease. Current treatment options have limited survival benefits, and only a minor patient population carries actionable genomic alterations. Hence, innovative personalized treatment strategies that consider molecular, cellular and functional analyses are urgently needed for pancreatic cancer patients. However, the majority of the genetic alterations found in PDAC are currently undruggable, or patients' response is not as expected. Therefore, non-genomic biomarkers and alternative molecular targets should be considered in order to advance the clinical management of PDAC patients. In line with this, recent gene expression and single-cell transcriptome analyses have identified molecular subtypes and transcriptional cell states that affect disease progression and drug efficiency. In this review, we will introduce long non-coding RNAs (lncRNAs) as well as RNA-binding proteins (RBPs) that are able to modulate the transcriptome of a cell through diverse mechanisms, thereby contributing to disease progression. We will provide a brief overview about the general functions of lncRNAs and RBPs, respectively. Subsequently, we will highlight selected lncRNAs and RBPs that have been shown to play a role in PDAC development, progression and drug response. Finally, we will present strategies aiming to interfere with the expression and function of lncRNAs and RBPs.

Tumor-Intrinsic Kinome Landscape of Pancreatic Cancer Reveals New Therapeutic Approaches

SIGNIFICANCE

We provide a comprehensive tumor-intrinsic kinome landscape that provides a roadmap for the use of kinase inhibitors in PDAC treatment approaches.

RNA-binding protein transcripts as potential biomarkers for detecting Primary Sclerosing Cholangitis and for predicting its progression to Cholangiocarcinoma

Primary Sclerosing Cholangitis (PSC) is a persistent inflammatory liver condition that affects the bile ducts and is commonly diagnosed in young individuals. Despite efforts to incorporate various clinical, biochemical and molecular parameters for diagnosing PSC, it remains challenging, and no biomarkers characteristic of the disease have been identified hitherto. PSC is linked with an uncertain prognosis, and there is a pressing need to explore multiomics databases to establish a new biomarker panel for the early detection of PSC's gradual progression into Cholangiocarcinoma (CCA) and for the development of effective therapeutic interventions. Apart from non-coding RNAs, other components of the Ribonucleoprotein (RNP) complex, such as RNA-Binding Proteins (RBPs), also hold great promise as biomarkers due to their versatile expression in pathological conditions. In the present review, an update on the RBP transcripts that show dysregulated expression in PSC and CCA is provided. Moreover, by utilizing a bioinformatic data mining approach, we give insight into those RBP transcripts that also exhibit differential expression in liver and gall bladder, as well as in body fluids, and are promising as biomarkers for diagnosing and predicting the prognosis of PSC. Expression data were bioinformatically extracted from public repositories usingTCGA Bile Duct Cancer dataset for CCA and specific NCBI GEO datasets for both PSC and CCA; more specifically, RBPs annotations were obtained from RBP World database. Interestingly, our comprehensive analysis shows an elevated expression of the non-canonical RBPs, FANCD2, as well as the microtubule dynamics regulator, ASPM, transcripts in the body fluids of patients with PSC and CCA compared with their respective controls, with the same trend in expression being observed in gall bladder and liver cancer tissues. Consequently, the manipulation of tissue expression of RBP transcripts might be considered as a strategy to mitigate the onset of CCA in PSC patients, and warrants further experimental investigation. The analysis performed herein may be helpful in the identification of non-invasive biomarkers for the early detection of PSC and for predicting its progression into CCA. In conclusion, future clinical research should investigate in more depth the full potential of RBP transcripts as biomarkers for human pathologies.

The DDX6/KIFC1 signaling axis, as regulated by YY1, contributes to the malignant behavior of pancreatic cancer

Human DEAD/H box RNA helicase DDX6 acts as an oncogene in several different types of cancer, where it participates in RNA processing. Nevertheless, the role of DDX6 in pancreatic cancer (PC), together with the underlying mechanism, has yet to be fully elucidated. In the present study, compared with adjacent tissues, the level of DDX6 was abnormally increased in human PC tissues, and this increased level of expression was associated with poor prognosis. Furthermore, the role of DDX6 in PC was investigated by overexpressing or silencing the DDX6 in the PC cell lines, SW1990 and PaTu-8988t. A xenograft model was established by injecting nude mice with either DDX6-overexpressing or DDX6-silenced SW1990 cells. DDX6 overexpression promoted the proliferation and cell cycle transition, inhibited the cell apoptosis of PC cells, and accelerated tumor formation, whereas DDX6 knockdown elicited the opposite effects. DDX6 exerted positive effects on PC. RNA immunoprecipitation assay showed that DDX6 bound to kinesin family member C1 (KIFC1) mRNA, which was further confirmed by RNA pull-down assay. These results suggested that DDX6 positively regulated the expression of KIFC1. KIFC1 overexpression enhanced the proliferative capability of PC cells with DDX6 knockdown and inhibited their apoptosis. By contrast, DDX6 overexpression reversed the inhibitory effect of KIFC1 silencing on tumor proliferation. Subsequently, the transcription factor Yin Yang 1 (YY1) was shown to negatively regulate DDX6 at both the mRNA and protein levels. Dual-luciferase reporter assay verified that YY1 targeted the promoter of DDX6 and inhibited its transcription. High expression levels of YY1 decreased the proliferation of PC cells and promoted cell apoptosis, although these effects were reversed by DDX6 overexpression. Taken together, YY1 may target the DDX6/KIFC1 axis, thereby negatively regulating its expression, leading to an inhibitory effect on pancreatic tumor.

Insulin-like Growth Factor II mRNA-Binding Protein 1 Regulates Pancreatic Cancer Cell Growth through the Surveillance of CDC25A mRNA

A number of data indicate that the sources of different kinds of PDAC may be discovered at the transcription/transduction stage. RNA metabolism is manipulated at various steps by different RNA-binding proteins (RBPs), and the deregulation or irregular activity of RBPs is known to contribute to tumor promotion and progression. The insulin-like growth factor 2 mRNA-binding protein family (IMPs), and IMP1 in particular, has been linked with a poor prognosis in PDAC patients; however, little is known about its contribution in PDAC carcinogenesis. In this study, we investigated the function of IMP1 in PDAC. To evaluate IMP1 expression and correlation with PDAC prognosis, we utilized several public databases. Using a specific siRNA IMP1, we analyzed cell death and cell cycle progression in PDAC cell lines and 3D spheroids. The role of IMP1 was also evaluated in vivo in a Panc-1-derived tumor xenograft murine model. Public data suggest that PDAC patients with higher expression of IMP1 showed poor overall and progression-free survival. IMP1 silencing leads to reduced cell growth in PDAC cells and three-dimensional spheroids. Abrogation of IMP1 in PDAC cells showed lower levels of CDC25A, increased phosphorylation of the cyclin-dependent kinase (CDK)2, and accumulation of PDAC cells in the G1 phase. Immunoprecipitation experiments revealed that IMP1 binds CDC25A mRNA, thus controlling cell-cycle progression. Ultimately, we proved that suppression of IMP1 blocked in vivo growth of Panc-1 transferred into immunodeficient mice. Our results indicate that IMP1 drives the PDCA cell cycle and represents a novel strategy for overcoming PDCA cell proliferation.

IGF2BP1-An Oncofetal RNA-Binding Protein Fuels Tumor Virus Propagation

The oncofetal RNA-binding protein IGF2BP1 has been reported to be a driver of tumor progression in a multitude of cancer entities. Its main function is the stabilization of target transcripts by shielding these from miRNA-mediated degradation. However, there is growing evidence that several virus species recruit IGF2BP1 to promote their propagation. In particular, tumor-promoting viruses, such as hepatitis B/C and human papillomaviruses, benefit from IGF2BP1. Moreover, recent evidence suggests that non-oncogenic viruses, such as SARS-CoV-2, also take advantage of IGF2BP1. The only virus inhibited by IGF2BP1 reported to date is HIV-1. This review summarizes the current knowledge about the interactions between IGF2BP1 and different virus species. It further recapitulates several findings by presenting analyses from publicly available high-throughput datasets.

RRP9 promotes gemcitabine resistance in pancreatic cancer via activating AKT signaling pathway

BACKGROUND

Pancreatic cancer (PC) is a highly lethal malignancy regarding digestive system, which is the fourth leading factor of cancer-related mortalities in the globe. Prognosis is poor due to diagnosis at advanced disease stage, low rates of surgical resection, and resistance to traditional radiotherapy and chemotherapy. In order to develop novel therapeutic strategies, further elucidation of the molecular mechanisms underlying PC chemoresistance is required. Ribosomal RNA biogenesis has been implicated in tumorigenesis. Small nucleolar RNAs (snoRNAs) is responsible for post-transcriptional modifications of ribosomal RNAs during biogenesis, which have been identified as potential markers of various cancers. Here, we investigate the U3 snoRNA-associated protein RRP9/U3-55 K along with its role in the development of PC and gemcitabine resistance.

METHODS

qRT-PCR, western blot and immunohistochemical staining assays were employed to detect RRP9 expression in human PC tissue samples and cell lines. RRP9-overexpression and siRNA-RRP9 plasmids were constructed to test the effects of RRP9 overexpression and knockdown on cell viability investigated by MTT assay, colony formation, and apoptosis measured by FACS and western blot assays. Immunoprecipitation and immunofluorescence staining were utilized to demonstrate a relationship between RRP9 and IGF2BP1. A subcutaneous xenograft tumor model was elucidated in BALB/c nude mice to examine the RRP9 role in PC in vivo.

RESULTS

Significantly elevated RRP9 expression was observed in PC tissues than normal tissues, which was negatively correlated with patient prognosis. We found that RRP9 promoted gemcitabine resistance in PC in vivo and in vitro. Mechanistically, RRP9 activated AKT signaling pathway through interacting with DNA binding region of IGF2BP1 in PC cells, thereby promoting PC progression, and inducing gemcitabine resistance through a reduction in DNA damage and inhibition of apoptosis. Treatment with a combination of the AKT inhibitor MK-2206 and gemcitabine significantly inhibited tumor proliferation induced by overexpression of RRP9 in vitro and in vivo.

CONCLUSIONS

Our data reveal that RRP9 has a critical function to induce gemcitabine chemoresistance in PC through the IGF2BP1/AKT signaling pathway activation, which might be a candidate to sensitize PC cells to gemcitabine. Video abstract.

Signature based on RNA-binding protein-related genes for predicting prognosis and guiding therapy in non-small cell lung cancer

Background: Studies have reported that RNA-binding proteins (RBPs) are dysregulated in multiple cancers and are correlated with the progression and prognosis of disease. However, the functions of RBPs in non-small cell lung cancer (NSCLC) remain unclear. The present study aimed to explore the function of RBPs in NSCLC and their prognostic and therapeutic value.

Methods: The mRNA expression profiles, DNA methylation data, gene mutation data, copy number variation data, and corresponding clinical information on NSCLC were downloaded from The Cancer Genome Atlas, Gene Expression Omnibus, and the University of California Santa Cruz Xena databases. The differentially expressed RBPs were identified between tumor and control tissues, and the expression and prognostic value of these RBPs were systemically investigated by bioinformatics analysis. A quantitative polymerase chain reaction (qPCR) was performed to validate the dysregulated genes in the prognostic signature.

Results: A prognostic RBP-related signature was successfully constructed based on eight RBPs represented as a risk score using least absolute shrinkage and selection operator (LASSO) regression analysis. The high-risk group had a worse overall survival (OS) probability than the low-risk group (p < 0.001) with 1-, 3-, and 5-year area under the receiver operator characteristic curve values of 0.671, 0.638, and 0.637, respectively. The risk score was associated with the stage of disease (p < 0.05) and was an independent prognostic factor for NSCLC when adjusted for age and UICC stage (p < 0.001, hazard ratio (HR): 1.888). The constructed nomogram showed a good predictive value. The P53, focal adhesion, and NOD-like receptor signaling pathways were the primary pathways in the high-risk group (adjusted p value <0.05). The high-risk group was correlated with increased immune infiltration (p < 0.05), upregulated relative expression levels of programmed cell death 1 (PD1) (p = 0.015), cytotoxic T-lymphocyte-associated protein 4 (CTLA4) (p = 0.042), higher gene mutation frequency, higher tumor mutational burden (p = 0.034), and better chemotherapy response (p < 0.001). The signature was successfully validated using the GSE26939, GSE31210, GSE30219, and GSE157009 datasets. Dysregulation of these genes in patients with NSCLC was confirmed using the qPCR in an independent cohort (p < 0.05).

Conclusion: An RBP-related signature was successfully constructed to predict prognosis in NSCLC, functioning as a reference for individualized therapy, including immunotherapy and chemotherapy.

Biological Characterization and Clinical Value of OAS Gene Family in Pancreatic Cancer

Background

OAS gene family plays an important role in antiviral process, but its role in pancreatic cancer has not yet been studied.

Methods

We analyzed the expression, prognostic value and biological function of the OAS gene family in human pancreatic cancer through comprehensive bioinformatic analysis and cellular level validation.

Results

OAS family was highly expressed in pancreatic cancer, and this high expression significantly affected the clinical stage and prognosis of the tumor. OAS gene family was closely related to the immune infiltration of pancreatic cancer, especially neutrophils and dendritic cells, and many immune-related factors and pathways are enriched in the tumor, such as type I interferon signaling pathway and NOD-like receptor signaling pathway.

Conclusion

Taken together, high expression of OAS family is closely related to poor prognosis of pancreatic cancer. OAS gene family may serve as the biomarker and even therapeutic target of pancreatic cancer.

hnRNPC Promotes Malignancy in Pancreatic Cancer through Stabilization of IQGAP3

Due to challenges in early-stage detection, aggressive behavior, and poor response to systemic therapy, pancreatic cancer is one of the most fatal cancer types globally. The role of RNA-binding protein (RBP) transcription and translation of cancer cells has been well demonstrated, although their roles in pancreatic cancer is less well understood. In this study, we found that heterogeneous nuclear ribonucleoprotein C (hnRNPC), a RBP, is highly expressed in pancreatic ductal adenocarcinoma (PDAC) tissues and cells. In addition, we discovered that overexpression of hnRNPC in PDAC cells in vitro increased cell proliferation, migration, invasion, and metastasis. The presence of hnRNPC promoted tumorigenesis of pancreatic cells in metastatic in vivo models, which was also validated. In silico analyses revealed that hnRNPC is a strong positive regulator of IQ Motif Containing GTPase Activating Protein 3 (IQGAP3) activity. The experimental confirmation of this association revealed a direct interaction of IQGAP3 and hnRNPC to induce cell growth and invasion in PDAC cells by activating the epithelial-mesenchymal transition. In light of the findings that hnRNPC accelerates PDAC progression by interfering with IQGAP3, it appears that this technique for diagnosis and treatment of PDAC may have promise.

Systematic Analysis of the Expression Profile and Prognostic Significance of the IGF2BP Family in Lung Adenocarcinoma

BACKGROUND

Lung adenocarcinoma (LUAD)，the most common type of lung cancer associated with poor prognosis, has become a major health problem for human health. IGF2BPs are types of N6-methyladenosine reader proteins, comprising IGF2BP1, IGF2BP2, and IGF2BP3, that promote LUAD progression. However, the expression profiles and prognostic value of IGF2BPs in LUAD remain unclear.

OBJECTIVE

To analyze the expression profiles and prognostic significance of the IGF2BP family in lung adenocarcinoma.

METHODS

In our study, we utilized LUAD patient and normal or para-carcinoma tissue data from TCGA database and the GTEx project. Using survival analysis, Kaplan-Meier curves, and Cox proportional hazards model, we analyzed the expression profiles and prognostic significance of the IGF2BP family.

RESULTS

Patients with high expression levels of IGF2BPs showed significant association with poor overall survival (p < 0.05). Moreover, the somatic mutation rates of IGF2BP1, IGF2BP2, IGF2BP3 were determined as 2.65, 1.59, and 1.76%, respectively, by investigating the genetic mutation. In addition, there were significant associations between TMB and IGF2BP family expression profiles, which positively correlated with the expression of PD-1 (p < 0.05). Cox proportional hazard model for LUAD showed the risk score for IGF2BP1, p-TNM stage, and so forth, all independent prognostic indicators for LUAD patients. Finally, the co-expression genes were obtained to build a PPI network and analyze the hub genes of the IGF2BP family.

CONCLUSION

Our study provides further insights into the role of the IGF2BP family in LUAD and identifies 10 genes that may be associated with IGF2BPs in LUAD patients.

Towards an Ideal In Cell Hybridization-Based Strategy to Discover Protein Interactomes of Selected RNA Molecules

RNA-binding proteins are crucial to the function of coding and non-coding RNAs. The disruption of RNA–protein interactions is involved in many different pathological states. Several computational and experimental strategies have been developed to identify protein binders of selected RNA molecules. Amongst these, ‘in cell’ hybridization methods represent the gold standard in the field because they are designed to reveal the proteins bound to specific RNAs in a cellular context. Here, we compare the technical features of different ‘in cell’ hybridization approaches with a focus on their advantages, limitations, and current and potential future applications.

Delivery of CRISPR-Cas9 system for screening and editing RNA binding proteins in cancer

RNA-binding proteins (RBPs) play an important role in RNA metabolism, regulating the stability, localization, and functional dynamics of RNAs. Alternation in the RBP-RNA network has profound implications in cellular physiology, and is related to the development and spread of cancer in certain cases. To regulate the expression of specific genes and their biological activities, various strategies have been applied to target RBPs for cancer treatments, including small-molecule inhibitors, small-interfering RNA, peptides, and aptamers. Recently, the deployment of the CRISPR-Cas9 technology has provided a new platform for RBP screening and regulation. This review summarizes the delivery systems of the CRISPR-Cas9 system and their role in RBP-based cancer therapeutics, including identification of novel RBPs and regulation of cancer-associated RBPs. The efficient delivery of the CRISPR-Cas9 system is important to the profound understanding and clinical transition of RBPs as cancer therapeutic targets.

Identification of Key Deregulated RNA-Binding Proteins in Pancreatic Cancer by Meta-Analysis and Prediction of Their Role as Modulators of Oncogenesis

RNA-binding proteins (RBPs) play a significant role in multiple cellular processes with their deregulations strongly associated with cancer. However, there are not adequate evidences regarding global alteration and functions of RBPs in pancreatic cancer, interrogated in a systematic manner. In this study, we have prepared an exhaustive list of RBPs from multiple sources, downloaded gene expression microarray data from a total of 241 pancreatic tumors and 124 normal pancreatic tissues, performed a meta-analysis, and obtained differentially expressed RBPs (DE-RBPs) using the Limma package of R Bioconductor. The results were validated in microarray datasets and the Cancer Genome Atlas (TCGA) RNA sequencing dataset for pancreatic adenocarcinoma (PAAD). Pathway enrichment analysis was performed using DE-RBPs, and we also constructed the protein-protein interaction (PPI) network to detect key modules and hub-RBPs. Coding and noncoding targets for top altered and hub RBPs were identified, and altered pathways modulated by these targets were also investigated. Our meta-analysis identified 45 upregulated and 15 downregulated RBPs as differentially expressed in pancreatic cancer, and pathway enrichment analysis demonstrated their important contribution in tumor development. As a result of PPI network analysis, 26 hub RBPs were detected and coding and noncoding targets for all these RBPs were categorized. Functional exploration characterized the pathways related to epithelial-to-mesenchymal transition (EMT), cell migration, and metastasis to emerge as major pathways interfered by the targets of these RBPs. Our study identified a unique meta-signature of 26 hub-RBPs to primarily modulate pancreatic tumor cell migration and metastasis in pancreatic cancer. IGF2BP3, ISG20, NIP7, PRDX1, RCC2, RUVBL1, SNRPD1, PAIP2B, and SIDT2 were found to play the most prominent role in the regulation of EMT in the process. The findings not only contribute to understand the biology of RBPs in pancreatic cancer but also to evaluate their candidature as possible therapeutic targets.

Construction and Validation of an Immune-Based Prognostic Model for Pancreatic Adenocarcinoma Based on Public Databases

Background

Pancreatic adenocarcinoma (PAAD) is a highly lethal and aggressive tumor with poor prognoses. The predictive capability of immune-related genes (IRGs) in PAAD has yet to be explored. We aimed to explore prognostic-related immune genes and develop a prediction model for indicating prognosis in PAAD.

Methods

The messenger (m)RNA expression profiles acquired from public databases were comprehensively integrated and differentially expressed genes were identified. Univariate analysis was utilized to identify IRGs that related to overall survival. Whereafter, a multigene signature in the Cancer Genome Atlas cohort was established based on the least absolute shrinkage and selection operator (LASSO) Cox regression analysis. Moreover, a transcription factors regulatory network was constructed to reveal potential molecular processes in PAAD. PAAD datasets downloaded from the Gene Expression Omnibus database were applied for the validations. Finally, correlation analysis between the prognostic model and immunocyte infiltration was investigated.

Results

Totally, 446 differentially expressed immune-related genes were screened in PAAD tissues and normal tissues, of which 43 IRGs were significantly related to the overall survival of PAAD patients. An immune-based prognostic model was developed, which contained eight IRGs. Univariate and multivariate Cox regression revealed that the risk score model was an independent prognostic indicator in PAAD (HR > 1, P < 0.001). Besides, the sensitivity of the model was evaluated by the receiver operating characteristic curve analysis. Finally, immunocyte infiltration analysis revealed that the eight-gene signature possibly played a pivotal role in the status of the PAAD immune microenvironment.

Conclusion

A novel prognostic model based on immune genes may serve to characterize the immune microenvironment and provide a basis for PAAD immunotherapy.

The biological function of IGF2BPs and their role in tumorigenesis

The insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) pertain to a highly conservative RNA-binding family that works as a post-transcriptional fine-tuner for target transcripts. Emerging evidence suggests that IGF2BPs regulate RNA processing and metabolism, including stability, translation, and localization, and are involved in various cellular functions and pathophysiologies. In this review, we summarize the roles and molecular mechanisms of IGF2BPs in cancer development and progression. We mainly discuss the functional relevance of IGF2BPs in embryo development, neurogenesis, metabolism, RNA processing, and tumorigenesis. Understanding IGF2BPs role in tumor progression will provide new insight into cancer pathophysiology.

Genomic relevance of FGF14 and associated genes on the prognosis of pancreatic cancer

BACKGROUND

Fibroblast (FGFs) and insulin (IGF) growth factor pathways are among 10 most recurrently altered genomic pathways in pancreatic ductal adenocarcinoma (PDAC). However, the prognostic and therapeutic relevance of FGF and IGF pathways in PDAC is largely unknown.

METHODS

We investigated the relationship between fibroblast and insulin pathway gene expression and clinicopathological features in three independent transcriptomic cohorts of 532 PDAC patients. Furthermore, we have examined the coexpressed genes specific to the prognostic marker identified from these cohorts. Statistical tests including Fisher-exact\Chi-square, Kaplan-Meier, Pearson Correlation and cox regression analyses were performed. Additionally, pathway analysis of gene-specific co-expressed genes was also performed.

RESULTS

The dysregulation of six genes including FGF9, FGF14, FGFR1, FGFR4, IGF2BP2 and IGF2BP3 were significantly associated with different clinical characteristics (including grade, stage, recurrence and nodes) in PDAC cohorts. 11 genes (including FGF9, FGF13, FGF14, FGF17, FGFR1, FGFRL1, FGFBP3, IGFBP3, IGF2BP2, IGF2BP3 and IGFBPL1) showed association with overall survival in different PDAC cohorts. Interestingly, overexpression of FGF14 was found associated with better overall survival (OS) in all three cohorts. Of note, multivariate analysis also revealed FGF14 as an independent prognostic marker for better OS in all three cohorts. Furthermore, FMN2 and PGR were among the top genes that correlated with FGF14 in all 3 cohorts. Of note, overexpression of FMN2 and PGR was found significantly associated with good overall survival in PDAC patients, suggesting FMN2 and PGR can also act as potential markers for the prediction of prognosis in PDAC patients.

CONCLUSION

FGF14 may define a distinct subset of PDAC patients with better prognosis. Moreover, FGF14-based sub-classification of PDAC suggests that FMN2 and PGR can be employed as good prognostic markers in PDAC and this classification may lead to new therapeutic approaches.

Musashi-1-A Stemness RBP for Cancer Therapy?

The RNA-binding protein Musashi-1 (MSI1) promotes stemness during development and cancer. By controlling target mRNA turnover and translation, MSI1 is implicated in the regulation of cancer hallmarks such as cell cycle or Notch signaling. Thereby, the protein enhanced cancer growth and therapy resistance to standard regimes. Due to its specific expression pattern and diverse functions, MSI1 represents an interesting target for cancer therapy in the future. In this review we summarize previous findings on MSI1's implications in developmental processes of other organisms. We revisit MSI1's expression in a set of solid cancers, describe mechanistic details and implications in MSI1 associated cancer hallmark pathways and highlight current research in drug development identifying the first MSI1-directed inhibitors with anti-tumor activity.

RNA-Binding Proteins as Regulators of Migration, Invasion and Metastasis in Oral Squamous Cell Carcinoma

Nearly 7.5% of all human protein-coding genes have been assigned to the class of RNA-binding proteins (RBPs), and over the past decade, RBPs have been increasingly recognized as important regulators of molecular and cellular homeostasis. RBPs regulate the post-transcriptional processing of their target RNAs, i.e., alternative splicing, polyadenylation, stability and turnover, localization, or translation as well as editing and chemical modification, thereby tuning gene expression programs of diverse cellular processes such as cell survival and malignant spread. Importantly, metastases are the major cause of cancer-associated deaths in general, and particularly in oral cancers, which account for 2% of the global cancer mortality. However, the roles and architecture of RBPs and RBP-controlled expression networks during the diverse steps of the metastatic cascade are only incompletely understood. In this review, we will offer a brief overview about RBPs and their general contribution to post-transcriptional regulation of gene expression. Subsequently, we will highlight selected examples of RBPs that have been shown to play a role in oral cancer cell migration, invasion, and metastasis. Last but not least, we will present targeting strategies that have been developed to interfere with the function of some of these RBPs.

IGF2BP1 silencing inhibits proliferation and induces apoptosis of high glucose-induced non-small cell lung cancer cells by regulating Netrin-1

Non-small cell lung cancer (NSCLC) accompanied by diabetes is an important risk factor affecting the prognosis of patients with NSCLC in clinical practice. However, the effect of high glucose (HG) in the pathogenesis of NSCLC remains elusive. It has been found that the RNA-binding protein Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) plays important roles in various diseases, including NSCLC and diabetes. The aim of this study was to explore the role of IGF2BP1 in HG-treated NSCLC cells, and further investigate its underlying molecular mechanism. Results showed that IGF2BP1 was highly expressed in HG-treated NSCLC cells. Knockdown of IGF2BP1 inhibited cancer cell proliferation, migration and invasion, as well as induced cell cycle arrest and apoptosis. Besides, IGF2BP1 silencing decreased the Netrin-1 level in HG-treated NSCLC cells. Reintroduction of Netrin-1 expression rescued IGF2BP1 deficiency-induced cell proliferation reduction, migration suppression, cell cycle arrest and apoptosis. These findings suggest that IGF2BP1 silencing inhibits the occurrence of tumor events through down-regulating Netrin-1 expression, indicating that the IGF2BP1/Netrin-1 axis exerts an oncogenic role in HG-treated NSCLC cells.