Clinical characteristics and prognostic value of MEX3A mRNA in liver cancer

Targeting the Hippo/YAP1 signaling pathway in hepatocellular carcinoma: From mechanisms to therapeutic drugs (Review)

The Hippo signaling pathway plays a pivotal role in regulating cell growth and organ size. Its regulatory effects on hepatocellular carcinoma (HCC) encompass diverse aspects, including cell proliferation, invasion and metastasis, tumor drug resistance, metabolic reprogramming, immunomodulatory effects and autophagy. Yes‑associated protein 1 (YAP1), a potent transcriptional coactivator and a major downstream target tightly controlled by the Hippo pathway, is influenced by various molecules and pathways. The expression of YAP1 in different cell types within the liver tumor microenvironment exerts varying effects on tumor outcomes, warranting careful consideration. Therefore, research on YAP1‑targeted therapies merits attention. This review discusses the composition and regulation mechanism of the Hippo/YAP1 signaling pathway and its relationship with HCC, offering insights for future research and cancer prevention strategies.

Hsa_circ_0008133 contributes to lung cancer progression by promoting glycolysis metabolism through the miR-760/MEX3A axis

BACKGROUND

Lung cancer is a very common cancer with poor prognosis and high mortality. Circular RNAs (circRNAs) have been confirmed to be related to the occurrence of lung cancer, and circ_0008133 has been found to be possibly related to lung cancer.

METHODS

Expression of circ_0008133, miR-760, and mex-3 RNA binding family member A (MEX3A) messenger RNA (mRNA) was detected using quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, colony number, migration, and invasion were assessed using cell counting kit-8 (CCK8), colony formation, wound healing, and transwell assays. Glucose consumption and lactate production were detected using commercial kits. Protein expression was measured using western blot. Dual-luciferase reporter assay and RNA pull-down assay were used to analyze the relationships between miR-760 and circ_0008133 or MEX3A. The effects of circ_0008133 knockdown on tumor growth in vivo were examined by the nude mice expriment. Immunohistochemistry (IHC) assay analyzed Ki-67 expression.

RESULTS

Circ_0008133 and MEX3A were markedly boosted in lung cancer tissues and cells. Circ_0008133 knockdown decreased lung cancer cell viability, glucose consumption, lactate production, colony formation, migration, and invasion. In mechanism, circ_0008133 might positively regulate MEX3A expression by sponging miR-760. Additionally, knockdown of circ_0008133 inhibited tumor growth in vivo.

CONCLUSION

Circ_0008133 accelerated the progression of lung cancer by promoting glycolysis metabolism through the miR-760/MEX3A axis.

MEX3A determines in vivo hepatocellular carcinoma progression and induces resistance to sorafenib in a Hippo-dependent way

BACKGROUND

Hepatocellular carcinoma (HCC) is most common malignant tumor worldwide, and one of the most lethal malignancies. MEX3A, RNA-binding protein, is profoundly implicated in tumor initiation and progression. But its role and potential mechanism in HCC remains fully unclear.

METHODS

The expression of MEX3A in HCC was analysis using the data derived from the Cancer Genome Atlas (TCGA) dataset and further confirmed by HCC samples and cells lines. The roles of MEX3A in the proliferation, migration and sorafenib resistance were detected both in vitro and vivo. In addition, the underline mechanism was investigated.

RESULTS

In this study, MEX3A expression was upregulated in HCC tissue and cell lines. Knockdown or overexpression of MEX3A disturbed the proliferation, migration and apoptosis of HCC cells by modulating the activation of Hippo signaling pathway. The expression of MEX3A was negatively associated with sorafenib sensitivity and upregulated in sorafenib resistant HCC cells. MEX3A knockdown facilitated the expression of WWC1, a negative modulator of Hippo signaling pathway, and led to increase of the phosphorylation of LATS1 and YAP1. Pharmacological inhibition of LATS1 or WWC1 overexpression alleviated the proliferative and migrated suppression and increased sorafenib sensitivity, whereas WWC1 inhibition using genetic interference strategy showed opposite trend in MEX3A knockdown HCC cells. Importantly, MEX3A knockdown led to growth and lung metastasis inhibition using xenograft model established by means of subcutaneous or tail vein injection. In addition, a combination of MEX3A knockdown and WWC1 overexpression dramatically enhances the growth inhibition of sorafenib in vivo.

CONCLUSION

MEX3A may facilitate HCC progression and hinder sorafenib sensitivity via inactivating Hippo signaling. The present study suggested that targeting MEX3A can be served as a novel therapeutic strategy for HCC.

MEX3A induces the development of thyroid cancer via targeting CREB1

Thyroid cancer is a prevalent form of endocrine cancer, and its global incidence has been steadily increasing. MEX3A is a protein that is known to be highly expressed in various human malignant tumors, including thyroid cancer, and it has been linked to patient prognosis. However, the molecular mechanisms underlying MEX3A's tumorigenic capabilities in thyroid cancer are not fully understood. In this study, we aimed to investigate the role of MEX3A in thyroid cancer. We confirmed that MEX3A was overexpressed in both thyroid cancer tissues and cell lines. Additionally, we found a positive correlation between high levels of MEX3A and the AJCC stage. To further understand the functional significance of MEX3A in thyroid cancer, we depleted MEX3A expression in B-CPAP and TPC-1 cells. Interestingly, we observed a significant reduction in thyroid cancer cell proliferation and migration, as well as ameliorated cell apoptosis and arrested tumor growth upon MEX3A depletion. These findings strongly suggested that MEX3A played a critical role in the development of thyroid cancer. Furthermore, our study uncovered an important interaction between MEX3A and CREB1 (cAMP response element-binding protein 1). The interaction between MEX3A and CREB1 appeared to contribute to the tumor-promoting effects of MEX3A in thyroid cancer by directly targeting CREB1. Silencing CREB1 was observed to alleviate the malignant phenotypes promoted by MEX3A in thyroid cancer cells. Together, this study highlighted the importance of the MEX3A-CREB1 interaction in thyroid cancer development and suggested the therapeutic potential of targeting MEX3A for the treatment of this disease.

Investigation of the Potential Correlation Between RNA-Binding Proteins in the Evolutionarily Conserved MEX3 Family and Non-small-Cell Lung Cancer

Members of the MEX3 (muscle excess 3) family, uniquely characterised as mRNA binding proteins, play emerging roles in the post-transcriptional regulation of programmed biological processes, including tumour cell death and immune mechanisms, and have been shown to be involved in a variety of diseases. However, the role of MEX3 in non-small cell lung cancer (NSCLC) has not been fully elucidated. In this study, we found no significant changes in the sequence and copy number of the MEX3 gene through analysis using the COSMIC database, revealing its stability during malignancy development. Its expression in NSCLC was examined using the Oncomine™ database, and the prognosis of each member gene was analysed by Kaplan–Meier. The results showed that overexpression of MEX3A, MEX3B, MEX3C and MEX3D was associated with significantly worse OS in patients with LUAD, while overexpression of MEX3D was also associated with significantly worse OS in patients with LUSC. Afterwards, we applied the Tumour Immunology Estimation Resource (TIMER) tool to assess the correlation between different MEX3 and infiltrative immune cell infiltration. Ultimately, we found that most MEX3 members were highly expressed in NSCLC, with high expression suggesting poor prognosis and correlating with immune cell infiltration. The complexity and heterogeneity of NSCLC was understood through MEX3, setting the framework for the prognostic impact of MEX3 in NSCLC patients and the development of new targeted therapeutic strategies in the future.

Grass Carp Mex3A Promotes Ubiquitination and Degradation of RIG-I to Inhibit Innate Immune Response

As one of the Mex3 family members, Mex3A is crucial in cell proliferation, migration, and apoptosis in mammals. In this study, a novel gene homologous to mammalian Mex3A (named CiMex3A, MW368974) was cloned and identified in grass carp, which is 1,521 bp in length encoding a putative polypeptide of 506 amino acids. In CIK cells, CiMex3A is upregulated after stimulation with LPS, Z-DNA, and especially with intracellular poly(I:C). CiMex3A overexpression reduces the expressions of IFN1, ISG15, and pro-inflammatory factors IL8 and TNFα; likewise, Mex3A inhibits IRF3 phosphorylation upon treatment with poly(I:C). A screening test to identify potential targets suggested that CiMex3A interacts with RIG-I exclusively. Co-localization analysis showed that Mex3A and RIG-I are simultaneously located in the endoplasmic reticulum, while they rarely appear in the endosome, mitochondria, or lysosome after exposure to poly(I:C). However, RIG-I is mainly located in the early endosome and then transferred to the late endosome following stimulation with poly(I:C). Moreover, we investigated the molecular mechanism underlying CiMex3A-mediated suppression of RIG-I ubiquitination. The results demonstrated that Mex3A truncation mutant (deletion in the RING domain) can still interact physically with RIG-I, but fail to degrade it, suggesting that Mex3A also acts as a RING-type E3 ubiquitin ligase. Taken together, this study showed that grass carp Mex3A can interact with RIG-I in the endoplasmic reticulum following poly(I:C) stimulation, and then Mex3A facilitates the ubiquitination and degradation of RIG-I to inhibit IRF3-mediated innate antiviral immune response.

MEX3A promotes nasopharyngeal carcinoma progression via the miR-3163/SCIN axis by regulating NF-κB signaling pathway

Mex-3 RNA Binding Family Member A (MEX3A) is an RNA-binding protein that plays complex and diverse roles in the development of various malignancies. However, its role and mechanism in nasopharyngeal carcinoma (NPC) remain undefined and were therefore evaluated in this study. By analyzing Gene Expression Omnibus data and using tissue microarrays, we found that MEX3A is significantly upregulated in NPC and negatively associated with prognosis. Notably, MEX3A depletion led to decreased cell proliferation, invasion, and migration, but increased apoptosis in NPC cells in vitro, while inhibiting tumor growth in vivo. Using whole-transcript expression arrays and bioinformatic analysis, we identified scinderin (SCIN) and miR-3163 as potential downstream targets of MEX3A in NPC. The regulatory mechanisms of MEX3A, SCIN and miR-3163 were further investigated using rescue experiments. Importantly, SCIN depletion and miR-3163 inhibition reversed and rescued the oncogenic effects of MEX3A, respectively. Moreover, NF-κB signaling inhibition reversed the oncogenic effects of both SCIN and MEX3A. In summary, our results demonstrate that MEX3A may promote NPC development and progression via the miR-3163/SCIN axis by regulating NF-κB signaling, thus providing a potential target for NPC treatment.

Development and Validation of a Pyroptosis-Related Signature for Predicting Prognosis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) has emerged as a primary health problem and threat to global mortality, especially in China. Since pyroptosis as a new field for HCC prognosis is not well studied, it is important to open a specific prognostic model. In this study, consensus clustering method for 42 pyroptosis-related genes to classify 374 HCC patients in the TCGA database. After cox regression analysis of the differentially expressed genes between the two clusters, LASSO-Cox analysis was then performed to construct a pyroptosis-related prognostic model with 11 genes including MMP1, KPNA2, LPCAT1, NEIL3, CDCA8, SLC2A1, PSRC1, CBX2, HAVCR1, G6PD, MEX3A. The ICGC dataset was served as the validation cohort. Patients in the high-risk group had significantly lower overall survival (OS) rates than those in the low-risk group (p < 0.05). COX regression analysis showed that our model could be used as an independent prognostic factor to predict prognosis of patients and was significantly correlated with clinicopathological characteristics. Nomogram showing the stability of the model predicting the 1, 3, 5 year survival probability of patients. In addition, based on the risk model, ssGSEA analysis revealed significant differences in the level of immune cell infiltration and activation of immune-related functional pathways between high and low-risk groups, and patients with the high-risk score may benefit more from treatment with immune checkpoint inhibitors. Furthermore, patients in the high-risk group were more tend to develop chemoresistance. Overall, we identified a novel pyroptosis-related risk signature for prognosis prediction in HCC patients and revealed the overall immune response intensity of the tumor microenvironment. All these findings make the pyroptosis signature shed light upon a latent therapeutic strategy aimed at the treatment and prevention of cancers.

Expression and clinical significance of BDH1 in liver cancer

Liver cancer is a deadly disease with generally poor patient outcomes. BDH1 is a key enzyme that regulates the metabolism and synthesis of ketone bodies. This study sought to explore the prognostic relevance of BDH1 mRNA expression in liver cancer.We utilized the Cancer Genome Atlas datasets to analyze the relationship between BDH1 expression and clinical outcomes. We used Kaplan-Meier curves and Cox analyses to explore the relevance of BDH1 mRNA levels to patient prognosis. Further gene set enrichment analysis was conducted as a means of comparing differences in gene expression as a function of BDH1 expression.Liver cancer samples exhibited significantly decreased BDH1 mRNA expression, and that this downregulation was correlated with a number of clinicopathological variables including gender, histologic grade, stage, TNM classification, and both overall and relapse-free survival. We further determined that BDH1 mRNA expression was an independent predictor of liver cancer patient prognosis. A subsequent gene set enrichment analysis found genes affected by BDH1 expression to be those enriched in pathways relating to MYC and wnt/β-catenin signaling.Our preliminary findings demonstrate for the first time that low expression of BDH1 mRNA is a potentially valuable independent prognostic indicator for liver cancer detection.

MicroRNA-139-5p Suppresses Cell Malignant Behaviors in Breast Cancer through Targeting MEX3A

OBJECTIVE

The study was designed to evaluate the underlying mechanism of microRNA-139-5p in breast cancer (BC).

METHODS

Expression statuses of microRNA-139-5p and MEX3A were measured by qRT-PCR and western blotting. The anticancer effect of microRNA-139-5p in vitro was tested by a set of assays. Interaction between microRNA-139-5p and MEX3A was validated by dual-luciferase detection.

RESULTS

MicroRNA-139-5p expression in BC cells was obviously low, while MEX3A was significantly overexpressed. MicroRNA-139-5p restrained proliferative, invasive, and migratory abilities of BC cells and increased apoptosis level of BC cells, while MEX3A exerted a promoting effect on BC cell growth. Dual-luciferase reporter detection confirmed that microRNA-139-5p bound to MEX3A 3'-UTR.

CONCLUSIONS

MicroRNA-139-5p inhibited the development of BC by targeting MEX3A. MicroRNA-139-5p/MEX3A may be a target for BC therapy.

MEX3A knockdown inhibits the tumorigenesis of colorectal cancer via modulating CDK2 expression

Colorectal cancer (CRC) is a malignant tumor of the gastrointestinal tract and a leading cause of cancer-associated mortality worldwide. Mex-3 RNA binding family member A (MEX3A) promotes the progression of multiple types of cancer, including ovarian and cervical cancer. However, to the best of our knowledge, the role of MEX3A in CRC is not completely understood. Therefore, the present study aimed to investigate the function of MEX3A in CRC. The mRNA and protein expression levels of MEX3A in CRC cells were analyzed using reverse transcription-quantitative PCR and western blotting, respectively. Cell Counting Kit-8 assays were used to measure cell viability. Cell apoptosis and cell cycle distribution were detected via flow cytometry, and CRC cell invasion was analyzed by performing Transwell assays. Moreover, the mitochondrial membrane potential in CRC cells was measured via JC-1 staining. The results of the present study revealed that the expression levels of MEX3A were upregulated in CRC tissues compared with adjacent healthy tissues. MEX3A knockdown notably inhibited CRC cell viability, and induced apoptosis and mitochondrial injury. In addition, MEX3A knockdown markedly induced G₁ phase cell cycle arrest in CRC cells via downregulating CDK2 expression. In conclusion, the findings of the present study suggested that MEX3A knockdown may inhibit the tumorigenesis of CRC cells by regulating CDK2 expression. Therefore, MEX3A may serve as a novel target for CRC treatment.

Mex-3 RNA binding MEX3A promotes the proliferation and migration of breast cancer cells via regulating RhoA/ROCK1/LIMK1 signaling pathway

Breast cancer has been known as cancer with high mortality rates. It has been studied that MEX3A (Mex-3 RNA Binding Family Member A) is involved in carcinogenesis by accelerating cancer proliferation and migration. Therefore, this research aimed to study how MEX3A regulates the biological behaviors of breast cancer. Firstly, we used GEPIA and KM-plotter databases to evaluate MEX3A expression in human breast cancer tissue compared to adjacent normal tissue. Immunohistochemistry was employed to assess MEX3A protein expression in clinical specimens. MEX3A mRNA expression level was assessed through quantitative real-time PCR (RT-qPCR). Western blotting was used to detect protein expression. Moreover, Cell Count Kit-8 (CCK-8) assay, wound healing assay and transwell invasion assay were used to determine the proliferation, migration and invasion of breast cancer cells, respectively. Our study found that MEX3A expression level was much higher in human breast cancer tissues as compared to adjacent normal tissues. Similarly, breast cancer cell lines showed higher expression of MEX3A as compared to the normal breast cells. This higher expression of MEX3A was linked with the poor survival of breast cancer. Moreover, we found that overexpression of MEX3A stimulated proliferation and migration in the breast cancer cells. However, inhibition of MEX3A significantly reduced the proliferation and migration of breast cancer cells. In addition, we determined that MEX3A could activate RhoA/ROCK1/LIMK1 signaling in the breast cancer cells. Overall, our study concluded that MEX3A promotes its migration and proliferation in breast cancer cells via modulating RhoA/ROCK1/LIMK1 signaling pathway.

Comprehensive Analysis of Prognostic Value of MEX3A and Its Relationship with Immune Infiltrates in Ovarian Cancer

MEX3A is a critical RNA-binding ubiquitin ligase that is upregulated in various types of cancer. However, the correlations of MEX3A with prognosis and its molecular mechanism in ovarian cancer (OC) remain unclear. The expression level, prognostic values, and the genetic variations of MEX3A were analyzed via Gene Expression Profiling Interactive Analysis (GEPIA) Oncomine, Kaplan-Meier plotter, and cBioPortal. We used the LinkedOmics database to investigate the functions of MEX3A coexpressed genes and performed visualizing gene interaction network analysis on the GeneMANIA website. The correlations between MEX3A and cancer immune infiltration were analyzed by the Tumor Immune Estimation Resource (TIMER) site and the TISIDB database. Furthermore, in vitro analysis was performed to evaluate the biological functions of MEX3A in OC cells. Our study showed that the expression of the MEX3A in OC was higher than in normal tissues; it had the greatest prognostic value in OC, and strong physical interaction with PABPC1, LAMTOR2, KHDRBS2, and IGF2BP2, which indicated the association between MEX3A and immune infiltration. We also found that MEX3A was negatively related to infiltrating levels of several types of immune cells, including macrophages, neutrophils, dendritic cells (DCs), B cells, and CD8+ T cells. Additionally, in vitro experiments demonstrated that MEX3A promotes proliferation and migration in OC cells. Taken together, MEX3A might influence the biological functions of OC cells by regulating the immune infiltration in the microenvironment as a prognostic biomarker and a potential therapeutic target.

Oncogenic Potential of the Dual-Function Protein MEX3A

MEX3A belongs to the MEX3 (Muscle EXcess) protein family consisting of four members (MEX3A-D) in humans. Characteristic for MEX3 proteins is their domain structure with 2 HNRNPK homology (KH) domains mediating RNA binding and a C-terminal really interesting new gene (RING) domain that harbors E3 ligase function. In agreement with their domain composition, MEX3 proteins were reported to modulate both RNA fate and protein ubiquitination. MEX3 paralogs exhibit an oncofetal expression pattern, they are severely downregulated postnatally, and re-expression is observed in various malignancies. Enforced expression of MEX3 proteins in various cancers correlates with poor prognosis, emphasizing their oncogenic potential. The latter is supported by MEX3A's impact on proliferation, self-renewal as well as migration of tumor cells in vitro and tumor growth in xenograft studies.

MEX3A suppresses proliferation and EMT via inhibiting Akt signaling pathway in cervical cancer

MEX3A, one member of the human MEX3 gene family, exerts different effects on a variety of human cancer cells. However, the biological functions and regulatory mechanism have not been explored in cervical cancer. In our study, we used multiple approaches to determine the functions and underlying molecular mechanism of MEX3A in cervical tumorigenesis, including CCK-8 assay, BrdU assay, FACS for cell cycle and apoptosis, wound healing assay, Transwell migration and invasion assays, immunohistochemistry (IHC) assay, Transfection, real-time RT-PCR and Western blotting analysis. IHC results showed that the expression levels of MEX3A were decreased in cervical cancer patients with advanced clinical stages and lymph node involvement. Moreover, upregulation of MEX3A attenuated cell proliferation, migration and invasion and induced cell cycle arrest at G0/G1 phase in human cervical cancer cells, whereas knockdown of MEX3A exhibited the opposite effects. Mechanistically, MEX3A exerted its tumor suppressive functions via inactivation of Akt signaling pathway and inhibiting epithelial to mesenchymal transition (EMT). Importantly, Akt activation by its activator SC79 reversed the biological functions of MEX3A overexpression. Furthermore, MEX3A inhibited tumor growth in xenograft models. Overall, our investigation suggested that MEX3A participated in antitumor activity in cervical cancer by inhibition of the Akt signaling pathway and EMT. Hence, targeting MEX3A might have a therapeutic potential to treat cervical cancer.

The effects of MEX3A knockdown on proliferation, apoptosis and migration of osteosarcoma cells

Background

Osteosarcoma is an aggressive malignant tumor which has attracted worldwide attention. MEX3A may be associated with tumors while has not yet seen its coverage on osteosarcoma. Herein, this study was to investigate the correlation between MEX3A and the progression of osteosarcoma.

Methods

Firstly, we determined that expression of MEX3A was significantly higher in osteosarcoma tissues than that in marginal bone by immunohistochemical staining. Additionally, MEX3A expression was downregulated by the RNAi‐mediated knockdown. The functions of MEX3A knockdown on proliferation, apoptosis, cell cycle, migration was assessed by MTT assay, flow cytometry, wound-healing assay and Transwell assay, respectively. Knockdown of MEX3A resulted in suppressing cell proliferation, increasing cell apoptosis, inducing the G2 phase cell cycle arrest, and attenuating cellular migration. Furthermore, mouse xenograft model confirmed inhibitory effects of MEX3A knockdown on osteosarcoma formation.

Results

The preliminary exploration on the molecular mechanism of MEX3A in osteosarcoma cells showed that the induction of apoptosis needs the participation of a series of apoptosis- associated factors, such as upregulation of Caspase 3, Caspase 8 and HSP60, downregulation of HSP27 and XIAP.

Conclusions

In summary, these findings predicated that therapy directed at decreasing MEX3A expression is a potential osteosarcoma treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-01882-3.

Discovery of key genes as novel biomarkers specifically associated with HPV-negative cervical cancer

Cervical cancer is a common female malignancy that is mainly caused by human papillomavirus (HPV) infection. However, the incidence of HPV-negative cervical cancer has shown an increasing trend in recent years. Because the mechanism of HPV-negative cervical cancer development is unclear, this study aims to find the pattern of differential gene expression in HPV-negative cervical cancer and verify the underlying potential mechanism. Differentially expressed genes were compared among HPV-positive cervical cancer, HPV-negative cervical cancer, and normal cervical tissues retrieved from TCGA. Subsequently, dysregulated differentially expressed genes specifically existed in HPV-negative cervical cancer tissues and HPV-negative cell lines were validated by qRT-PCR, western blotting, and immunohistochemical staining. We found seventeen highly expressed genes that were particularly associated with HPV-negative cervical cancer from analysis of TCGA database. Among the 17 novel genes, 7 genes (preferentially expressed antigen in melanoma [PRAME], HMGA2, ETS variant 4 [ETV4], MEX3A, TM7SF2, SLC19A1, and tweety-homologs 3 [TTYH3]) displayed significantly elevated expression in HPV-negative cervical cancer cells and HPV-negative cervical cancer tissues. Additionally, higher expression of MEX3A and TTYH3 was associated with a shorter overall survival of patients with HPV-negative cervical cancer. Our study implies that these seven genes are more likely to provide novel insights into the occurrence and progression of HPV-negative cervical cancer.

Bioinformatics Analysis Identifies IL6ST as a Potential Tumor Suppressor Gene for Triple-Negative Breast Cancer

Improved insight into the molecular mechanisms of triple-negative breast cancer (TNBC) is required to predict prognosis and develop a new therapeutic strategy for targeted genes. The aim of this study was to identify genes significantly associated with TNBC and further analyze their prognostic significance. The Cancer Genome Atlas (TCGA) TNBC database and gene expression profiles of GSE76275 from Gene Expression Omnibus (GEO) were used to explore differentially co-expressed genes in TNBC compared with those in normal tissues and non-TNBC breast cancer tissues. Differential gene expression and weighted gene co-expression network analyses identified 24 differentially co-expressed genes. Functional annotation suggested that these genes were primarily enriched in processes such as metabolism, membrane, and protein binding. The protein-protein interaction (PPI) network further identified ten hub genes, five of which (MAPT, CBS, SOX11, IL6ST, and MEX3A) were confirmed to be differentially expressed in an independent dataset (GSE38959). Moreover, CBS and MEX3A expression was upregulated, whereas IL6ST expression was downregulated in TNBC tissues compared to that in other breast cancer subtypes. Furthermore, lower expression of IL6ST was associated with worse overall survival in patients with TNBC. Thus, IL6ST might play an important role in TNBC progression and could serve as a tumor suppressor gene for diagnosis and treatment.

Mex3a promotes oncogenesis through the RAP1/MAPK signaling pathway in colorectal cancer and is inhibited by hsa-miR-6887-3p

Background

Although Mex3 RNA‐binding family member A (Mex3a) has demonstrated an important role in multiple cancers, its role and regulatory mechanism in CRC is unclear. In this study, we aimed to investigate the role and clinical significance of Mex3a in CRC and to explore its underlying mechanism.

Methods

Western blotting and quantitative real‐time polymerase chain reaction (qRT‐PCR) were performed to detect the expression levels of genes. 5‐Ethynyl‐2'‐deoxyuridine (EDU) and transwell assays were utilized to examine CRC cell proliferation and metastatic ability. The R software was used to do hierarchical clustering analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Overexpression and rescue experiments which included U0126, a specific mitogen activated protein kinase kinase/extracellular regulated protein kinase (MEK/ERK) inhibitor, and PX‐478, a hypoxia‐inducible factor 1 subunit alpha (HIF‐1α) inhibitor, were used to study the molecular mechanisms of Mex3a in CRC cells. Co‐immunoprecipitation (Co‐IP) assay was performed to detect the interaction between two proteins. Bioinformatics analysis including available public database and Starbase software (starbase.sysu.edu.cn) were used to evaluate the expression and prognostic significance of genes. TargetScan (www.targetscan.org) and the miRDB (mirdb.org) website were used to predict the combination site between microRNA and target mRNA. BALB/c nude mice were used to study the function of Mex3a and hsa‐miR‐6887‐3p in vivo.

Results

Clinicopathological and immunohistochemical (IHC) studies of 101 CRC tissues and 79 normal tissues demonstrated that Mex3a was a significant prognostic factor for overall survival (OS) in CRC patients. Mex3a knockdown substantially inhibited the migration, invasion, and proliferation of CRC cells. Transcriptome analysis and mechanism verification showed that Mex3a regulated the RAP1 GTPase activating protein (RAP1GAP)/MEK/ERK/HIF‐1α pathway. Furthermore, RAP1GAP was identified to interact with Mex3a in Co‐IP experiments. Bioinformatics and dual‐luciferase reporter experiments revealed that hsa‐miR‐6887‐3p could bind to the 3'‐untranslated regions (3'‐UTR) of the Mex3a mRNA. hsa‐miR‐6887‐3p downregulated Mex3a expression and inhibited the tumorigenesis of CRC both in vitro and in vivo.

Conclusions

Our study demonstrated that the hsa‐miR‐6887‐3p/Mex3a/RAP1GAP signaling axis was a key regulator of CRC and Mex3a has the potential to be a new diagnostic marker and treatment target for CRC.

Evaluation of FGFR1 as a diagnostic biomarker for ovarian cancer using TCGA and GEO datasets

Background

Malignant ovarian cancer is associated with the highest mortality of all gynecological tumors. Designing therapeutic targets that are specific to OC tissue is important for optimizing OC therapies. This study aims to identify different expression patterns of genes related to FGFR1 and the usefulness of FGFR1 as diagnostic biomarker for OC.

Methods

We collected data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. In the TCGA cohort we analyzed clinical information according to patient characteristics, including age, stage, grade, longest dimension of the tumor and the presence of a residual tumor. GEO data served as a validation set. We obtained data on differentially expressed genes (DEGs) from the two microarray datasets. We then used gene set enrichment analysis (GSEA) to analyze the DEG data in order to identify enriched pathways related to FGFR1.

Results

Differential expression analysis revealed that FGFR1 was significantly downregulated in OC specimens. 303 patients were included in the TCGA cohort. The GEO dataset confirmed these findings using information on 75 Asian patients. The GSE105437 and GSE12470 database highlighted the significant diagnostic value of FGFR1 in identifying OC (AUC = 1, p = 0.0009 and AUC = 0.8256, p = 0.0015 respectively).

Conclusions

Our study examined existing TCGA and GEO datasets for novel factors associated with OC and identified FGFR1 as a potential diagnostic factor. Further investigation is warranted to characterize the role played by FGFR1 in OC.

Systematic Construction and Validation of an RNA-Binding Protein-Associated Model for Prognosis Prediction in Hepatocellular Carcinoma

BACKGROUND

Evidence from prevailing studies show that hepatocellular carcinoma (HCC) is among the top cancers with high mortality globally. Gene regulation at post-transcriptional level orchestrated by RNA-binding proteins (RBPs) is an important mechanism that modifies various biological behaviors of HCC. Currently, it is not fully understood how RBPs affects the prognosis of HCC. In this study, we aimed to construct and validate an RBP-related model to predict the prognosis of HCC patients.

METHODS

Differently expressed RBPs were identified in HCC patients based on the GSE54236 dataset from the Gene Expression Omnibus (GEO) database. Integrative bioinformatics analyses were performed to select hub genes. Gene expression patterns were validated in The Cancer Genome Atlas (TCGA) database, after which univariate and multivariate Cox regression analyses, as well as Kaplan-Meier analysis were performed to develop a prognostic model. Then, the performance of the prognostic model was assessed using receiver operating characteristic (ROC) curves and clinicopathological correlation analysis. Moreover, data from the International Cancer Genome Consortium (ICGC) database were used for external validation. Finally, a nomogram combining clinicopathological parameters and prognostic model was established for the individual prediction of survival probability.

RESULTS

The prognostic risk model was finally constructed based on two RBPs (BOP1 and EZH2), facilitating risk-stratification of HCC patients. Survival was markedly higher in the low-risk group relative to the high-risk group. Moreover, higher risk score was associated with advanced pathological grade and late clinical stage. Besides, the risk score was found to be an independent prognosis factor based on multivariate analysis. Nomogram including the risk score and clinical stage proved to perform better in predicting patient prognosis.

CONCLUSIONS

The RBP-related prognostic model established in this study may function as a prognostic indicator for HCC, which could provide evidence for clinical decision making.

SOX11 promotes epithelial/mesenchymal hybrid state and alters tropism of invasive breast cancer cells

SOX11 is an embryonic mammary epithelial marker that is normally silenced prior to birth. High SOX11 levels in breast tumours are significantly associated with distant metastasis and poor outcome in breast cancer patients. Here, we show that SOX11 confers distinct features to ER-negative DCIS.com breast cancer cells, leading to populations enriched with highly plastic hybrid epithelial/mesenchymal cells, which display invasive features and alterations in metastatic tropism when xenografted into mice. We found that SOX11+DCIS tumour cells metastasize to brain and bone at greater frequency and to lungs at lower frequency compared to cells with lower SOX11 levels. High levels of SOX11 leads to the expression of markers associated with mesenchymal state and embryonic cellular phenotypes. Our results suggest that SOX11 may be a potential biomarker for breast tumours with elevated risk of developing metastases and may require more aggressive therapies.

GPSM2 Serves as an Independent Prognostic Biomarker for Liver Cancer Survival

Background and Objective:

Liver cancer is a malignancy with a poor prognosis. G protein signaling modulator 2 is mainly related to cell division and cell cycle regulation. In this review, the relationship between G protein signaling modulator 2 and clinical characteristics of patients with liver cancer has been explored, especially with respect to its prognostic value.

Methods:

G protein signaling modulator 2 messenger RNA expression and clinicopathological characteristics of patients with liver cancer were obtained from The Cancer Genome Atlas. The expression level of G protein signaling modulator 2 RNA-Seq was validated by using Gene Expression Omnibus. Chi-square test was performed to evaluate the relationship between G protein signaling modulator 2 expression and clinical characteristics. The threshold value of G protein signaling modulator 2 in the diagnosis of liver cancer was evaluated by a receiver–operating characteristic curve. Cox regression analysis and Kaplan-Meier curves were performed to evaluate the relationship between G protein signaling modulator 2 and liver cancer prognosis, which included overall and residual-free survival, and explored the prognostic value of G protein signaling modulator 2. Liver cancer survival analyses were validated by using the data of G protein signaling modulator 2 RNA-Seq from the International Cancer Genome Consortium.

Results:

The expression level of G protein signaling modulator 2 messenger RNA was remarkably higher in liver cancer than that in healthy tissues (P < 2.2 × e⁻¹⁶), which was also validated by data from the GSE14520 database. In addition, high G protein signaling modulator 2 expression significantly correlated with histological grade (P = .020), vital status (P < .001), clinical (P = .001), and T stage (P = .001). The receiver–operating characteristic curves showed G protein signaling modulator 2 to be an advantageous diagnostic molecule for liver cancer (area under curve = 0.893). Furthermore, the results of Cox analysis and Kaplan-Meier curves suggested that the upregulation of G protein signaling modulator 2 expression is linked to poor prognosis and G protein signaling modulator 2 messenger RNA could be an independent predictor for liver cancer, which was validated by data from the International Cancer Genome Consortium database.

Conclusions:

G protein signaling modulator 2 messenger RNA was overexpressed in liver cancer, and G protein signaling modulator 2 is an independent prognostic factor. G protein signaling modulator 2 is expected to be a treatment target for cancer.

The Role of the RNA-Binding Protein Family MEX-3 in Tumorigenesis

The muscle excess 3 (MEX-3) protein was first identified in Caenorhabditis elegans (C. elegans), and its respective homologues were also observed in vertebrates, including humans. It is a RNA-binding protein (RBP) with an additional ubiquitin E3 ligase function, which further acts as a post-transcriptional repressor through unknown mechanisms. In humans, MEX-3 proteins post-transcriptionally regulate a number of biological processes, including tumor immunological relevant ones. These have been shown to be involved in various diseases, including tumor diseases of distinct origins. This review provides information on the expression and function of the human MEX-3 family in healthy tissues, as well after malignant transformation. Indeed, the MEX-3 expression was shown to be deregulated in several cancers and to affect tumor biological functions, including apoptosis regulation, antigen processing, and presentation, thereby, contributing to the immune evasion of tumor cells. Furthermore, current research suggests MEX-3 proteins as putative markers for prognosis and as novel targets for the anti-cancer treatment.

Evaluation of musculoskeletal phenotype of the G608G progeria mouse model with lonafarnib, pravastatin, and zoledronic acid as treatment groups

Hutchinson-Gilford progeria syndrome (HGPS) is a uniformly fatal condition that is especially prevalent in skin, cardiovascular, and musculoskeletal systems. A wide gap exists between our knowledge of the disease and a promising treatment or cure. The aim of this study was to first characterize the musculoskeletal phenotype of the homozygous G608G BAC-transgenic progeria mouse model, and to determine the phenotype changes of HGPS mice after a five-arm preclinical trial of different treatment combinations with lonafarnib, pravastatin, and zoledronic acid. Microcomputed tomography and CT-based rigidity analyses were performed to assess cortical and trabecular bone structure, density, and rigidity. Bones were loaded to failure with three-point bending to assess strength. Contrast-enhanced µCT imaging of mouse femurs was performed to measure glycosaminoglycan content, thickness, and volume of the femoral head articular cartilage. Advanced glycation end products were assessed with a fluorometric assay. The changes demonstrated in the cortical bone structure, rigidity, stiffness, and modulus of the HGPS G608G mouse model may increase the risk for bending and deformation, which could result in the skeletal dysplasia characteristic of HGPS. Cartilage abnormalities seen in this HGPS model resemble changes observed in the age-matched WT controls, including early loss of glycosaminoglycans, and decreased cartilage thickness and volume. Such changes might mimic prevalent degenerative joint diseases in the elderly. Lonafarnib monotherapy did not improve bone or cartilage parameters, but treatment combinations with pravastatin and zoledronic acid significantly improved bone structure and mechanical properties and cartilage structural parameters, which ameliorate the musculoskeletal phenotype of the disease.

The Prediction and Prognostic Significance of INPP5K Expression in Patients with Liver Cancer

Liver cancer is a devastating disease for humans with poor prognosis. Although the survival rate of patients with liver cancer has improved in the past decades, the recurrence and metastasis of liver cancer are still obstacles for us. Inositol polyphosphate-5-phosphatase K (INPP5K) belongs to the family of phosphoinositide 5-phosphatases (PI 5-phosphatases), which have been reported to be associated with cell migration, polarity, adhesion, and cell invasion, especially in cancers. However, there have been few studies on the correlation of INPP5K and liver cancer. In this study, we explored the prognostic significance of INPP5K in liver cancer through bioinformatics analysis of data collected from The Cancer Genome Atlas (TCGA) database. Chi-square and Fisher exact tests were used to evaluate the relationship between INPP5K expression and clinical characteristics. Our results showed that low INPP5K expression was correlated with poor outcomes in liver cancer patients. Univariate and multivariate Cox analyses demonstrated that low INPP5K mRNA expression played a significant role in shortening overall survival (OS) and relapse-free survival (RFS), which might serve as the useful biomarker and prognostic factor for liver cancer. In conclusion, low INPP5K mRNA expression is an independent risk factor for poor prognosis in liver cancer.