CREPT/RPRD1B associates with Aurora B to regulate Cyclin B1 expression for accelerating the G2/M transition in gastric cancer

Degradation of STIM1 through FAM134B-mediated ER-phagy is potentially involved in cell proliferation

Autophagy is classified as nonselective or selective depending on the types of degrading substrates. Endoplasmic reticulum (ER)-phagy is a form of selective autophagy for transporting the ER-resident proteins to autolysosomes. FAM134B, a member of the family with sequence similarity 134, is a well-known ER-phagy receptor. Dysfunction of FAM134B results in several diseases including viral infection, inflammation, neurodegenerative disorder, and cancer, indicating that FAM134B has crucial roles in various kinds of intracellular functions. However, how FAM134B-mediated ER-phagy regulates intracellular functions is not well understood. In this study, we found that FAM134B knockdown in mammalian cells accelerated cell proliferation. FAM134B knockdown increased the protein amount of stromal interaction molecule 1 (STIM1), an ER Ca2+ sensor protein mediating the store-operated Ca2+ entry involved in G1 to S phase transition. FAM134B bound to STIM1 through its C-terminal cytosolic region. FAM134B knockdown reduced transport of STIM1 from the ER to autolysosomes. Finally, FAM134B knockdown accelerated G1 to S phase transition. These results suggest that FAM134B is involved in cell proliferation possibly through degradation of STIM1 via ER-phagy.

Identification and Functional Analysis of circRNAs during Goat Follicular Development

Litter size is a crucial quantitative trait in animals, closely linked to follicular development. Circular RNA (circRNA), a type of single-stranded closed-loop endogenous RNA with stable expression, plays pivotal roles in various biological processes, yet its function in goat follicular development remains unclear. In this study, we collected large (follicle diameter > 3 mm) and small (1 mm < follicle diameter < 3 mm) follicles from black goats in the Chuanzhong region for circRNA sequencing, with the aim of elucidating the functional circRNAs that influence follicle development in goats. Differential analysis revealed that 17 circRNAs were upregulated in large follicles, and 28 circRNAs were upregulated in small follicles. Functional enrichment analysis revealed significant enrichment of pathways related to reproduction, including cellular response to follicle-stimulating hormone stimulus, the PI3K-Akt signaling pathway, the MAPK signaling pathway, and the Notch signaling pathway. Based on the ceRNA mechanism, 45 differentially expressed circRNAs were found to target and bind a total of 418 miRNAs, and an intercalation network including miR-324-3p (circRNA2497, circRNA5650), miR-202-5p (circRNA3333, circRNA5501), and miR-493-3p (circRNA4995, circRNA5508) was constructed. In addition, conservation analysis revealed that 2,239 circRNAs were conserved between goats and humans. Prediction of translation potential revealed that 154 circRNAs may potentially utilize both N6-methyladenosine (m6A) and internal ribosome entry site (IRES) translation mechanisms. Furthermore, the differential expression and circularization cleavage sites of five circRNAs were validated through RT-qPCR and DNA sequencing. Our study constructed a circRNA map in goat follicle development, offering a theoretical foundation for enhancing goat reproductive performance.

AURKB/CDC37 complex promotes clear cell renal cell carcinoma progression via phosphorylating MYC and constituting an AURKB/E2F1-positive feedforward loop

As the second most common malignant tumor in the urinary system, renal cell carcinoma (RCC) is imperative to explore its early diagnostic markers and therapeutic targets. Numerous studies have shown that AURKB promotes tumor development by phosphorylating downstream substrates. However, the functional effects and regulatory mechanisms of AURKB on clear cell renal cell carcinoma (ccRCC) progression remain largely unknown. In the current study, we identified AURKB as a novel key gene in ccRCC progression based on bioinformatics analysis. Meanwhile, we observed that AURKB was highly expressed in ccRCC tissue and cell lines and knockdown AURKB in ccRCC cells inhibit cell proliferation and migration in vitro and in vivo. Identified CDC37 as a kinase molecular chaperone for AURKB, which phenocopy AURKB in ccRCC. AURKB/CDC37 complex mediate the stabilization of MYC protein by directly phosphorylating MYC at S67 and S373 to promote ccRCC development. At the same time, we demonstrated that the AURKB/CDC37 complex activates MYC to transcribe CCND1, enhances Rb phosphorylation, and promotes E2F1 release, which in turn activates AURKB transcription and forms a positive feedforward loop in ccRCC. Collectively, our study identified AURKB as a novel marker of ccRCC, revealed a new mechanism by which the AURKB/CDC37 complex promotes ccRCC by directly phosphorylating MYC to enhance its stability, and first proposed AURKB/E2F1-positive feedforward loop, highlighting AURKB may be a promising therapeutic target for ccRCC.

[High expression of COX6B2 in gastric cancer is associated with poor long-term prognosis and promotes cell proliferation and cell cycle progression by inhibiting p53 signaling]

OBJECTIVE

To investigate the effect of COX6B2 expression in gastric cancer tissues on the patients' long-term prognosis and its underlying mechanism.

METHODS

Based on the public databases and the medical records of patients, we analyzed the expression level of COX6B2 in gastric cancer and adjacent tissues and its influence on long-term prognosis of the patients. Enrichment analysis were used to predict the possible role of COX6B2 in gastric cancer. The effects of lentivirusmediated COX6B2 knockdown on biological behaviors of gastric cancer cells were examined using CCK-8 assay, flow cytometry, and Western blotting.

RESULTS

TCGA database and the results of immunohistochemistry, Western blotting and realtime PCR all demonstrated a significantly higher expression of COX6B2 in gastric cancer tissues (P < 0.05). Kaplan-Meier plotter database and Kaplan-Meier curves showed that the patients with high COX6B2 expression had significantly shorter postoperative survival (P < 0.05). A high expression of COX6B2 in gastric cancer tissues was closely correlated with clinicopathologic stage, CEA and CA19-9 (P < 0.05). A high expression of COX6B2, CEA level≥5 μg/L and CA19-9 level≥37 kU/L were independent risk factors affecting postoperative 5-year survival rate of gastric cancer patients (P < 0.05), and COX6B2 expression level had a predictive value for long-term prognosis of the patients (P < 0.05). GO and KEGG enrichment analyses showed that COX6B2 was mainly involved in the regulation of cell cycle. In the in vitro cell experiment, COX6B2 overexpression significantly promoted gastric cancer cell proliferation, increased the percentage of G1/S phase cells and inhibited the cellular expressions of p53 and p21 (P < 0.05).

CONCLUSION

s COX6B2 is highly expressed in gastric cancer and is closely correlated with a poor long-term prognosis of the patients possibly by promoting gastric cancer cell proliferation and regulating cell cycle.

Overexpression of Aurora Kinase B Is Correlated with Diagnosis and Poor Prognosis in Hepatocellular Carcinoma

Aurora kinase B (AURKB) overexpression promotes tumor initiation and development by participating in the cell cycle. In this study, we focused on the mechanism of AURKB in hepatocellular carcinoma (HCC) progression and on AURKB's value as a diagnostic and prognostic biomarker in HCC. We used data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) to analyze AURKB expression in HCC. We found that the expression levels of AURKB in HCC samples were higher than those in the corresponding control group. R packages were used to analyze RNA sequencing data to identify AURKB-related differentially expressed genes (DEGs), and these genes were found to be significantly enriched during the cell cycle. The biological function of AURKB was verified, and the results showed that cell proliferation was slowed down and cells were arrested in the G2/M phase when AURKB was knocked down. AURKB overexpression resulted in significant differences in clinical symptoms, such as the clinical T stage and pathological stage. Kaplan-Meier survival analysis, Cox regression analysis, and Receiver Operating Characteristic (ROC) curve analysis suggested that AURKB overexpression has good diagnostic and prognostic potential in HCC. Therefore, AURKB may be used as a potential target for the diagnosis and cure of HCC.

JS-K activates G2/M checkpoints through the DNA damage response and induces autophagy via CAMKKβ/AMPKα/mTOR pathway in bladder cancer cells

The aim of this study was to investigate the effects of JS-K, a nitric oxide donor prodrug, on DNA damage and autophagy in bladder cancer (BCa) cells and to explore the potential related mechanisms. Through detecting proliferation viability, cell morphology observation and colony formation assay low concentrations of JS-K significantly inhibited BCa growth while having no effect on normal cells. JS-K induced an increase in the level of DNA damage protein γH2AX and a decrease in the level of DNA damage repair-related proteins PCNA and RAD51 in BCa cells, indicating that JS-K can induce DNA damage in BCa cells and inhibit DNA damage repair. JS-K induced G2/M phase block and calcium overload using flow cytometry analysis. Moreover, we also investigated the levels of cell G2/M cycle checkpoint-related protein and autophagy-associated protein by western blot. The results of our study demonstrated that JS-K induced BCa cells G2/M phase arrest due to upregulating proteins related to DNA damage-related G2/M checkpoint activation (p-ATM, p-ATR, p-Chk1, p-Chk2, and p-Cdc2) and down-regulation of Cyclin B1 protein. In addition, our study demonstrated that JS-K-induced autophagy in BCa cells was related to the CAMKKβ/AMPKα/mTOR pathway.

Microenvironment-induced CREPT expression by cancer-derived small extracellular vesicles primes field cancerization

Rationale: Cancer local recurrence increases the mortality of patients, and might be caused by field cancerization, a pre-malignant alteration of normal epithelial cells. It has been suggested that cancer-derived small extracellular vesicles (CDEs) may contribute to field cancerization, but the underlying mechanisms remain poorly understood. In this study, we aim to identify the key regulatory factors within recipient cells under the instigation of CDEs. Methods: In vitro experiments were performed to demonstrate that CDEs promote the expression of CREPT in normal epithelial cells. TMT-based quantitative mass spectrometry was employed to investigate the proteomic differences between normal cells and tumor cells. Loss-of-function approaches by CRISPR-Cas9 system were used to assess the role of CREPT in CDEs-induced field cancerization. RNA-seq was performed to explore the genes regulated by CREPT during field cancerization. Results: CDEs promote field cancerization by inducing the expression of CREPT in non-malignant epithelial cells through activating the ERK signaling pathway. Intriguingly, CDEs failed to induce field cancerization when CREPT was deleted, highlighting the importance of CREPT. Transcriptomic analyses revealed that CDEs elicited inflammatory responses, primarily through activation of the TNF signaling pathway. CREPT, in turn, regulates the transduction of downstream signals of TNF by modulating the expression of TNFR2 and PI3K, thereby promoting inflammation-to-cancer transition. Conclusion: CREPT not only serves as a biomarker for field cancerization, but also emerges as a target for preventing the cancer local recurrence.

CCDC15 localizes to the centriole inner scaffold and controls centriole length and integrity

Centrioles are microtubule-based organelles responsible for forming centrosomes and cilia, which serve as microtubule-organizing, signaling, and motility centers. Biogenesis and maintenance of centrioles with proper number, size, and architecture are vital for their functions during development and physiology. While centriole number control has been well-studied, less is understood about their maintenance as stable structures with conserved size and architecture during cell division and ciliary motility. Here, we identified CCDC15 as a centriole protein that colocalizes with and interacts with the inner scaffold, a crucial centriolar subcompartment for centriole size control and integrity. Using ultrastructure expansion microscopy, we found that CCDC15 depletion affects centriole length and integrity, leading to defective cilium formation, maintenance, and response to Hedgehog signaling. Moreover, loss-of-function experiments showed CCDC15's role in recruiting both the inner scaffold protein POC1B and the distal SFI1/Centrin-2 complex to centrioles. Our findings reveal players and mechanisms of centriole architectural integrity and insights into diseases linked to centriolar defects.

USP39-mediated deubiquitination of Cyclin B1 promotes tumor cell proliferation and glioma progression

BACKGROUND

The elevated Cyclin B1 expression contributes to various tumorigenesis and poor prognosis. Cyclin B1 expression could be regulated by ubiquitination and deubiquitination. However, the mechanism of how Cyclin B1 is deubiquitinated and its roles in human glioma remain unclear.

METHODS

Co-immunoprecipitation and other assays were performed to detect the interacting of Cyclin B1 and USP39. A series of in vitro and in vivo experiments were performed to investigate the effect of USP39 on the tumorigenicity of tumor cells.

RESULTS

USP39 interacts with Cyclin B1 and stabilizes its expression by deubiquitinating Cyclin B1. Notably, USP39 cleaves the K29-linked polyubiquitin chain on Cyclin B1 at Lys242. Additionally, overexpression of Cyclin B1 rescues the arrested cell cycle at G2/M transition and the suppressed proliferation of glioma cells caused by USP39 knockdown in vitro. Furthermore, USP39 promotes the growth of glioma xenograft in subcutaneous and in situ of nude mice. Finally, in human tumor specimens, the expression levels of USP39 and Cyclin B1 are positively relevant.

CONCLUSION

Our data support the evidence that USP39 acts a novel deubiquitinating enzyme of Cyclin B1 and promoted tumor cell proliferation at least in part through Cyclin B1 stabilization, represents a promising therapeutic strategy for tumor patients.

Cell division cycle-associated 8 is a prognostic biomarker related to immune invasion in hepatocellular carcinoma

BACKGROUND

Cell division cycle-associated 8 (CDCA8) is involved in numerous signaling networks, and it serves a crucial modulatory function in multiple malignant tumors. However, its significance in prognosis and immune infiltration in hepatocellular carcinoma (HCC) remains unclear.

MATERIALS AND METHODS

Herein, we examined the CDCA8 levels in tumor tissues, as well as its associated signaling pathways and correlation with immune infiltration. Additionally, we further clarified the prognostic significance of CDCA8 among HCC patients. HCC patient information was recruited from The Cancer Genome Atlas (TCGA). Using bioinformatics, the following parameters were analyzed among HCC patients: CDCA8 expression, enrichment analysis, immune infiltration, and prognosis analysis. Moreover, we employed in vitro investigations, such as, qRT-PCR, immunohistochemistry (IHC), and cell functional experiments to validate our results.

RESULTS

Elevated CDCA8 expression in HCC patients was markedly associated with T stage, pathological status (PS), tumor status (TS), histologic grade (HG), and AFP. Elevated CDCA8 expression HCC patients exhibited reduced overall survival (OS) (p < 0.001), disease-specific survival (DSS) (p < 0.001), and progress free interval (PFI) H(p < 0.001). According to the ROC analysis, the area under the curve (AUC) was 0.997. Multivariate analysis revealed that CDCA8 was a stand-alone prognostic indicator of patient OS (p = 0.009) and DSS (p = 0.006). A nomogram was then generated based on the multivariate analysis, and the C-indexes and calibration chart revealed excellent predictive performance in determining HCC patient outcome. Based on the GSEA analysis, CDCA8 modulated the P53, Notch, PPAR, E2F networks. We observed a direct link between CDCA8 levels and Th2 and T helper cells, and a negative link between CDCA8 levels and dendritic cells (DC), neutrophils, cytotoxic cells, and CD8 T cells. Furthermore, CDCA8 deficiency inhibited liver cancer cell proliferation and invasion.

CONCLUSION

In conclusion, these findings indicate that CDCA8 is a new molecular bioindicator of HCC patient prognosis, and it is an excellent candidate for therapeutic target against HCC.

The Regulation of Cyclins and Cyclin-Dependent Kinases in the Development of Gastric Cancer

Gastric cancer predominantly occurs in adenocarcinoma form and is characterized by uncontrolled growth and metastases of gastric epithelial cells. The growth of gastric cells is regulated by the action of several major cell cycle regulators including Cyclins and Cyclin-dependent kinases (CDKs), which act sequentially to modulate the life cycle of a living cell. It has been reported that inadequate or over-activity of these molecules leads to disturbances in cell cycle dynamics, which consequently results in gastric cancer development. Manny studies have reported the key roles of Cyclins and CDKs in the development and progression of the disease in either in vitro cell culture studies or in vivo models. We aimed to compile the evidence of molecules acting as regulators of both Cyclins and CDKs, i.e., upstream regulators either activating or inhibiting Cyclins and CDKs. The review entails an introduction to gastric cancer, along with an overview of the involvement of cell cycle regulation and focused on the regulation of various Cyclins and CDKs in gastric cancer. It can act as an extensive resource for developing new hypotheses for future studies.

HSPA6, a novel prognostic and therapeutic biomarker, associated with Ming classification in gastric cancer

OBJECTIVE

This study aimed to explore the clinical relevance of heat shock protein family A member 6 (HSPA6) in gastric cancer (GC) and its effect on GC cell proliferation.

METHODS

HSPA6 mRNA and protein levels were analyzed by bioinformatics, RT-qPCR, western blot and immunohistochemistry. HSPA6 was correlated with clinicopathological variables by the Chi-square test. Kaplan-Meier survival analysis and the univariate and multivariate Cox models were used to assess the prognostic value of HSPA6. Nomogram was used to predict overall survival in patients with GC. Knockdown or over-expression of HSPA6 in GC cell lines was constructed by lentiviral transduction. EdU and CCK-8 assay were used to detect cell proliferation. In vivo mouse tumor models were performed to evaluate the effects of HSPA6 on GC growth.

RESULTS

HSPA6 were significantly upregulated in the GC tissues compared to the normal stomach epithelium and were associated with Ming classification (p < 0.001) and tumor size (p = 0.002). Patients with high expression of HSPA6 showed worse survival compared to the low expression group. HSPA6 was identified to be an independent prognostic biomarker for GC. HSPA6 was functionally annotated with the cell cycle, G2M checkpoint and Hippo pathway. Knockdown of HSPA6 suppressed XGC-1 cell proliferation both in vitro and in vivo. Overexpression of HSPA6 in AGS cells increased proliferation rates, increased the levels of cyclinB1 and YAP and decreased that of phosphorylated YAP. HSPA6 knockdown in the NUGC2 cells had the opposite effect.

CONCLUSIONS

HSPA6 promotes GC proliferation by the Hippo pathway, as a novel prognostic biomarker and potential therapeutic target.

Long non-coding RNA NEAT1 mediated RPRD1B stability facilitates fatty acid metabolism and lymph node metastasis via c-Jun/c-Fos/SREBP1 axis in gastric cancer

Background

Lymph node metastasis is one of most common determinants of the stage and prognosis of gastric cancer (GC). However, the key molecular events and mechanisms mediating lymph node metastasis remain elusive.

Methods

RNA sequencing was used to identify driver genes responsible for lymph node metastasis in four cases of gastric primary tumors, metastatic lesions of lymph nodes and matched normal gastric epithelial tissue. qRT–PCR and IHC were applied to examine RPRD1B expression. Metastatic functions were evaluated in vitro and in vivo. RNA-seq was used to identify target genes. ChIP, EMSA and dual luciferase reporter assays were conducted to identify the binding sites of target genes. Co-IP, RIP, MeRIP, RNA-FISH and ubiquitin assays were applied to explore the underlying mechanisms.

Results

The top 8 target genes (RPRD1B, MAP4K4, MCM2, TOPBP1, FRMD8, KBTBD2, ADAM10 and CXCR4) that were significantly upregulated in metastatic lymph nodes of individuals with GC were screened. The transcriptional cofactor RPRD1B (regulation of nuclear pre-mRNA domain containing 1B) was selected for further characterization. The clinical analysis showed that RPRD1B was significantly overexpressed in metastatic lymph nodes and associated with poor outcomes in patients with GC. The Mettl3-induced m⁶A modification was involved in the upregulation of RPRD1B. Functionally, RPRD1B promoted lymph node metastasis capabilities in vitro and in vivo. Mechanistic studies indicated that RPRD1B increased fatty acid uptake and synthesis by transcriptionally upregulating c-Jun/c-Fos and activating the c-Jun/c-Fos/SREBP1 axis. In addition, NEAT1 was upregulated significantly by c-Jun/c-Fos in RPRD1B-overexpressing cells. NEAT1, in turn, increased the stability of the RPRD1B mRNA by recruiting the m⁶A “reader” protein hnRNPA2B1 and reduced the degradation of the RPRD1B protein by inhibiting TRIM25-mediated ubiquitination. Notably, this functional circuitry was disrupted by an inhibitor of c-Jun/c-Fos/AP1 proteins (SR11302) and small interfering RNAs targeting NEAT1, leading to a preferential impairment of lymph node metastasis.

Conclusions

Based on these findings, RPRD1B facilitated FA metabolism and assisted primary tumor implantation in lymph nodes via the c-Jun/c-Fos/SREBP1 axis, which was enhanced by a NEAT1-mediated positive feedback loop, serving as a potential therapeutic target for GC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02449-4.

A Deep Neural Network for Gastric Cancer Prognosis Prediction Based on Biological Information Pathways

Background

Gastric cancer (GC) is one of the deadliest cancers in the world, with a 5-year overall survival rate of lower than 20% for patients with advanced GC. Genomic information is now frequently employed for precision cancer treatment due to the rapid advancements of high-throughput sequencing technologies. As a result, integrating multiomics data to construct predictive models for the GC patient prognosis is critical for tailored medical care.

Results

In this study, we integrated multiomics data to design a biological pathway-based gastric cancer sparse deep neural network (GCS-Net) by modifying the P-NET model for long-term survival prediction of GC. The GCS-Net showed higher accuracy (accuracy = 0.844), area under the curve (AUC = 0.807), and F1 score (F1 = 0.913) than traditional machine learning models. Furthermore, the GCS-Net not only enables accurate patient survival prognosis but also provides model interpretability capabilities lacking in most traditional deep neural networks to describe the complex biological process of prognosis. The GCS-Net suggested the importance of genes (UBE2C, JAK2, RAD21, CEP250, NUP210, PTPN1, CDC27, NINL, NUP188, and PLK4) and biological pathways (Mitotic Anaphase, Resolution of Sister Chromatid Cohesion, and SUMO E3 ligases) to GC, which is consistent with the results revealed in biological- and medical-related studies of GC.

Conclusion

The GCS-Net is an interpretable deep neural network built using biological pathway information whose structure represents a nonlinear hierarchical representation of genes and biological pathways. It can not only accurately predict the prognosis of GC patients but also suggest the importance of genes and biological pathways. The GCS-Net opens up new avenues for biological research and could be adapted for other cancer prediction and discovery activities as well.

Purification and Analysis of the CREPT Antibody from Mouse Ascites

Methods

Cells were cultivated properly to obtain 3E10 CREPT monoclonal antibody cells in the logarithmic growth stage. Monoclonal antibody cells were injected into the abdominal cavity of sensitized mice. The flowing ascites were observed for 7-15 days. The antibody protein was obtained by collection, filtration, dilution, loading, and chromatography. Furthermore, its binding force was detected by SDS-PAGE and Western blot techniques.

Results

The antibody protein was successfully obtained with a purity of 1895 μg/mL with high liveness.

Conclusion

This study establishes a one-step purification method for obtaining monoclonal antibody with high liveness and purity for CREPT ascites antibody. This method is simple to perform and lays a foundation for the preparation and purification of humanized monoclonal antibodies in the future. In addition, it provides a basis for further research to investigate how CREPT affects the occurrence and development of different tumors.

The ALDH Family Contributes to Immunocyte Infiltration, Proliferation and Epithelial-Mesenchymal Transformation in Glioma

Gliomas are malignant tumors that originate from the central nervous system. The aldehyde dehydrogenase family has been documented to affect cancer progression; however, its role in gliomas remains largely unexplored. Bulk RNA-seq analysis and single-cell RNA-Seq analysis were performed to explore the role of the aldehyde dehydrogenases family in gliomas. Training cohort contained The Cancer Genome Atlas data, while data from Chinese Glioma Genome Atlas and Gene Expression Omnibus were set as validation cohorts. Our scoring system based on the aldehyde dehydrogenases family suggested that high-scoring samples were associated with worse survival outcomes. The enrichment score of pathways were calculated by AUCell to substantiate the biofunction prediction results that the aldehyde dehydrogenases family affected glioma progression by modulating tumor cell proliferation, migration, and immune landscape. Tumor immune landscape was mapped from high-scoring samples. Moreover, ALDH3B1 and ALDH16A1, two main contributors of the scoring system, could affect glioblastoma cell proliferation and migration by inducing cell-cycle arrest and the epithelial-mesenchymal transition. Taken together, the aldehyde dehydrogenases family could play a significant role in the tumor immune landscape and could be used to predict patient prognosis. ALDH3B1 and ALDH16A1 could influence tumor cell proliferation and migration.

Identification of 5 Hub Genes Related to the Early Diagnosis, Tumour Stage, and Poor Outcomes of Hepatitis B Virus-Related Hepatocellular Carcinoma by Bioinformatics Analysis

BACKGROUND

The majority of primary liver cancers in adults worldwide are hepatocellular carcinomas (HCCs, or hepatomas). Thus, a deep understanding of the underlying mechanisms for the pathogenesis and carcinogenesis of HCC at the molecular level could facilitate the development of novel early diagnostic and therapeutic treatments to improve the approaches and prognosis for HCC patients. Our study elucidates the underlying molecular mechanisms of HBV-HCC development and progression and identifies important genes related to the early diagnosis, tumour stage, and poor outcomes of HCC.

METHODS

GSE55092 and GSE121248 gene expression profiling data were downloaded from the Gene Expression Omnibus (GEO) database. There were 119 HCC samples and 128 nontumour tissue samples. GEO2R was used to screen for differentially expressed genes (DEGs). Volcano plots and Venn diagrams were drawn by using the ggplot2 package in R. A heat map was generated by using Heatmapper. By using the clusterProfiler R package, KEGG and GO enrichment analyses of DEGs were conducted. Through PPI network construction using the STRING database, key hub genes were identified by cytoHubba. Finally, KM survival curves and ROC curves were generated to validate hub gene expression.

RESULTS

By GO enrichment analysis, 694 DEGs were enriched in the following GO terms: organic acid catabolic process, carboxylic acid catabolic process, carboxylic acid biosynthetic process, collagen-containing extracellular matrix, blood microparticle, condensed chromosome kinetochore, arachidonic acid epoxygenase activity, arachidonic acid monooxygenase activity, and monooxygenase activity. In the KEGG pathway enrichment analysis, DEGs were enriched in arachidonic acid epoxygenase activity, arachidonic acid monooxygenase activity, and monooxygenase activity. By PPI network construction and analysis of hub genes, we selected the top 10 genes, including CDK1, CCNB2, CDC20, BUB1, BUB1B, CCNB1, NDC80, CENPF, MAD2L1, and NUF2. By using TCGA and THPA databases, we found five genes, CDK1, CDC20, CCNB1, CENPF, and MAD2L1, that were related to the early diagnosis, tumour stage, and poor outcomes of HBV-HCC.

CONCLUSIONS

Five abnormally expressed hub genes of HBV-HCC are informative for early diagnosis, tumour stage determination, and poor outcome prediction.

Integrative analysis of the gastric cancer long non-coding RNA-associated competing endogenous RNA network

Gastric cancer (GC) is a common type of cancer, and identification of novel diagnostic biomarkers associated with this disease is important. The present study aimed to identify novel diagnostic biomarkers associated with the prognosis of GC, using an integrated bioinformatics approach. Differentially expressed long non-coding RNAs (lncRNAs) associated with GC were identified using Gene Expression Omnibus datasets (GSE58828, GSE72305 and GSE99416) and The Cancer Genome Atlas database. A competing endogenous RNA network that incorporated five lncRNAs [long intergenic non-protein coding RNA 501 (LINC00501), LINC00365, SOX21 antisense divergent transcript 1 (SOX21-AS1), GK intronic transcript 1 (GK-IT1) and DLEU7 antisense RNA 1 (DLEU7-AS1)], 29 microRNAs and 114 mRNAs was constructed. Gene Ontology and protein-protein interaction network analyses revealed that these lncRNAs may be involved in 'biological regulation', 'metabolic process', 'cell communication', 'developmental process', 'cell proliferation', 'reproduction' and the 'cell cycle'. The results of receiver operating characteristic curve analysis demonstrated that LINC00501 (AUC=0.819), LINC00365 (AUC=0.580), SOX21-AS1 (AUC=0.736), GK-IT1 (AUC=0.823) and DLEU7-AS1 (AUC=0.932) had the potential to become valuable diagnostic biomarkers for GC. Associations with clinicopathological characteristics demonstrated that LINC00501 expression was significantly associated with sex (P=0.015) and tumor grade (P=0.022). Furthermore, LINC00365 expression was significantly associated with lymph node metastasis (P=0.025). Gene set enrichment analysis revealed that LINC00501, LINC00365 and SOX21-AS1 were enriched in signaling pathways associated with GC. Reverse transcription-quantitative PCR analysis demonstrated that LINC00501 expression (P=0.043) was significantly upregulated in GC tissues, whereas the expression levels of LINC00365 (P=0.033) and SOX21-AS1 (P=0.037) were significantly downregulated in GC tissues. Taken together, the results of the present study suggest that LINC00501, LINC00365, SOX21-AS1, GK-IT1 and DLEU7-AS1 may be used as novel diagnostic biomarkers for GC, and may be functionally associated with GC development and progression.

Bioinformatics Analysis of Candidate Genes and Pathways Related to Hepatocellular Carcinoma in China: A Study Based on Public Databases

Background and Objective: Hepatocellular carcinoma (HCC) is a highly aggressive malignant tumor of the digestive system worldwide. Chronic hepatitis B virus (HBV) infection and aflatoxin exposure are predominant causes of HCC in China, whereas hepatitis C virus (HCV) infection and alcohol intake are likely the main risk factors in other countries. It is an unmet need to recognize the underlying molecular mechanisms of HCC in China.

Methods: In this study, microarray datasets (GSE84005, GSE84402, GSE101685, and GSE115018) derived from Gene Expression Omnibus (GEO) database were analyzed to obtain the common differentially expressed genes (DEGs) by R software. Moreover, the gene ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed by using Database for Annotation, Visualization and Integrated Discovery (DAVID). Furthermore, the protein-protein interaction (PPI) network was constructed, and hub genes were identified by the Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape, respectively. The hub genes were verified using Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN, and Kaplan-Meier Plotter online databases were performed on the TCGA HCC dataset. Moreover, the Human Protein Atlas (HPA) database was used to verify candidate genes’ protein expression levels.

Results: A total of 293 common DEGs were screened, including 103 up-regulated genes and 190 down-regulated genes. Moreover, GO analysis implied that common DEGs were mainly involved in the oxidation-reduction process, cytosol, and protein binding. KEGG pathway enrichment analysis presented that common DEGs were mainly enriched in metabolic pathways, complement and coagulation cascades, cell cycle, p53 signaling pathway, and tryptophan metabolism. In the PPI network, three subnetworks with high scores were detected using the Molecular Complex Detection (MCODE) plugin. The top 10 hub genes identified were CDK1, CCNB1, AURKA, CCNA2, KIF11, BUB1B, TOP2A, TPX2, HMMR and CDC45. The other public databases confirmed that high expression of the aforementioned genes related to poor overall survival among patients with HCC.

Conclusion: This study primarily identified candidate genes and pathways involved in the underlying mechanisms of Chinese HCC, which is supposed to provide new targets for the diagnosis and treatment of HCC in China.

CREPT/RPRD1B promotes tumorigenesis through STAT3-driven gene transcription in a p300-dependent manner

BACKGROUND

Signal transducer and activator of transcription 3 (STAT3) has been shown to upregulate gene transcription during tumorigenesis. However, how STAT3 initiates transcription remains to be exploited. This study is to reveal the role of CREPT (cell cycle-related and elevated-expression protein in tumours, or RPRD1B) in promoting STAT3 transcriptional activity.

METHODS

BALB/c nude mice, CREPT overexpression or deletion cells were employed for the assay of tumour formation, chromatin immunoprecipitation, assay for transposase-accessible chromatin using sequencing.

RESULTS

We demonstrate that CREPT, a recently identified oncoprotein, enhances STAT3 transcriptional activity to promote tumorigenesis. CREPT expression is positively correlated with activation of STAT3 signalling in tumours. Deletion of CREPT led to a decrease, but overexpression of CREPT resulted in an increase, in STAT3-initiated tumour cell proliferation, colony formation and tumour growth. Mechanistically, CREPT interacts with phosphorylated STAT3 (p-STAT3) and facilitates p-STAT3 to recruit p300 to occupy at the promoters of STAT3-targeted genes. Therefore, CREPT and STAT3 coordinately facilitate p300-mediated acetylation of histone 3 (H3K18ac and H3K27ac), further augmenting RNA polymerase II recruitment. Accordingly, depletion of p300 abolished CREPT-enhanced STAT3 transcriptional activity.

CONCLUSIONS

We propose that CREPT is a co-activator of STAT3 for recruiting p300. Our study provides an alternative strategy for the therapy of cancers related to STAT3.

CREPT is required for murine stem cell maintenance during intestinal regeneration

Intestinal stem cells (ISCs) residing in the crypts are critical for the continual self-renewal and rapid recovery of the intestinal epithelium. The regulatory mechanism of ISCs is not fully understood. Here we report that CREPT, a recently identified tumor-promoting protein, is required for the maintenance of murine ISCs. CREPT is preferably expressed in the crypts but not in the villi. Deletion of CREPT in the intestinal epithelium of mice (Vil-CREPTKO) results in lower body weight and slow migration of epithelial cells in the intestine. Vil-CREPTKO intestine fails to regenerate after X-ray irradiation and dextran sulfate sodium (DSS) treatment. Accordingly, the deletion of CREPT decreases the expression of genes related to the proliferation and differentiation of ISCs and reduces Lgr5+ cell numbers at homeostasis. We identify that CREPT deficiency downregulates Wnt signaling by impairing β-catenin accumulation in the nucleus of the crypt cells during regeneration. Our study provides a previously undefined regulator of ISCs.

CREPT is required for murine stem cell maintenance during intestinal regeneration

Intestinal stem cells (ISCs) residing in the crypts are critical for the continual self-renewal and rapid recovery of the intestinal epithelium. The regulatory mechanism of ISCs is not fully understood. Here we report that CREPT, a recently identified tumor-promoting protein, is required for the maintenance of murine ISCs. CREPT is preferably expressed in the crypts but not in the villi. Deletion of CREPT in the intestinal epithelium of mice (Vil-CREPTKO) results in lower body weight and slow migration of epithelial cells in the intestine. Vil-CREPTKO intestine fails to regenerate after X-ray irradiation and dextran sulfate sodium (DSS) treatment. Accordingly, the deletion of CREPT decreases the expression of genes related to the proliferation and differentiation of ISCs and reduces Lgr5+ cell numbers at homeostasis. We identify that CREPT deficiency downregulates Wnt signaling by impairing β-catenin accumulation in the nucleus of the crypt cells during regeneration. Our study provides a previously undefined regulator of ISCs.

Current understanding of CREPT and p15RS, carboxy-terminal domain (CTD)-interacting proteins, in human cancers

CREPT and p15RS, also named RPRD1B and RPRD1A, are RPRD (regulation of nuclear pre-mRNA-domain-containing) proteins containing C-terminal domain (CTD)-interacting domain (CID), which mediates the binding to the CTD of Rpb1, the largest subunit of RNA polymerase II (RNAPII). CREPT and p15RS are highly conserved, with a common yeast orthologue Rtt103. Intriguingly, human CREPT and p15RS possess opposite functions in the regulation of cell proliferation and tumorigenesis. While p15RS inhibits cell proliferation, CREPT promotes cell cycle and tumor growth. Aberrant expression of both CREPT and p15RS was found in numerous types of cancers. At the molecular level, both CREPT and p15RS were reported to regulate gene transcription by interacting with RNAPII. However, CREPT also exerts a key function in the processes linked to DNA damage repairs. In this review, we summarized the recent studies regarding the biological roles of CREPT and p15RS, as well as the molecular mechanisms underlying their activities. Fully revealing the mechanisms of CREPT and p15RS functions will not only provide new insights into understanding gene transcription and maintenance of DNA stability in tumors, but also promote new approach development for tumor diagnosis and therapy.

FOX transcription factor family in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) is a multistep process, involving the progressive accumulation of molecular alterations and transcriptomic alterations. The Forkhead-box (FOX) transcription factor family is characterized by its unique DNA binding domain (FKH or winged-helix domain). Human FOX family consists of about 17 subfamilies, at least 43 members. Some of them are liver-enriched transcription factors, suggesting that they may play a crucial role in the development or/and functions of the liver. Dysregulation of FOX transcription factors may contribute to the pathogenesis of HCC because they can activate or suppress the expression of various tumor-related molecules, and pinpoint different molecular and cellular events. Here we summarized, analyzed and discussed the status and the functions of the human FOX family of transcription factors in HCC, aiming to help the further development of them as potential therapeutic targets or/and diagnostic/prognostic markers for HCC.

Identification of key gene modules and hub genes of human mantle cell lymphoma by coexpression network analysis

Purpose

Mantle cell lymphoma (MCL) is a rare and aggressive subtype of non-Hodgkin lymphoma that is incurable with standard therapies. The use of gene expression analysis has been of interest, recently, to detect biomarkers for cancer. There is a great need for systemic coexpression network analysis of MCL and this study aims to establish a gene coexpression network to forecast key genes related to the pathogenesis and prognosis of MCL.

Methods

The microarray dataset GSE93291 was downloaded from the Gene Expression Omnibus database. We systematically identified coexpression modules using the weighted gene coexpression network analysis method (WGCNA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis were performed on the modules deemed important. The protein-protein interaction networks were constructed and visualized using Cytoscape software on the basis of the STRING website; the hub genes in the top weighted network were identified. Survival data were analyzed using the Kaplan-Meier method and were compared using the log-rank test.

Results

Seven coexpression modules consisting of different genes were applied to 5,000 genes in the 121 human MCL samples using WGCNA software. GO and KEGG enrichment analysis identified the blue module as one of the most important modules; the most critical pathways identified were the ribosome, oxidative phosphorylation and proteasome pathways. The hub genes in the top weighted network were regarded as real hub genes (IL2RB, CD3D, RPL26L1, POLR2K, KIF11, CDC20, CCNB1, CCNA2, PUF60, SNRNP70, AKT1 and PRPF40A). Survival analysis revealed that seven genes (KIF11, CDC20, CCNB1, CCNA2, PRPF40A, CD3D and PUF60) were associated with overall survival time (p < 0.05).

Conclusions

The blue module may play a vital role in the pathogenesis of MCL. Five real hub genes (KIF11, CDC20, CCNB1, CCNA2 and PUF60) were identified as potential prognostic biomarkers as well as therapeutic targets with clinical utility for MCL.

A cell-permeable peptide-based PROTAC against the oncoprotein CREPT proficiently inhibits pancreatic cancer

Cancers remain a threat to human health due to the lack of effective therapeutic strategies. Great effort has been devoted to the discovery of drug targets to treat cancers, but novel oncoproteins still need to be unveiled for efficient therapy.

Methods: We show that CREPT is highly expressed in pancreatic cancer and is associated with poor disease-free survival. CREPT overexpression promotes but CREPT deletion blocks colony formation and proliferation of pancreatic cancer cells. To provide a proof of concept for CREPT as a new target for the inhibition of pancreatic cancer, we designed a cell-permeable peptide-based proteolysis targeting chimera (PROTAC), named PRTC, based on the homodimerized leucine-zipper-like motif in the C-terminus domain of CREPT to induce its degradation in vivo.

Results: PRTC has high affinity for CREPT, with Kd = 0.34 +/- 0.11 μM and is able to permeate into cells because of the attached membrane-transportable peptide RRRRK. PRTC effectively induces CREPT degradation in a proteasome-dependent manner. Intriguingly, PRTC inhibits colony formation, cell proliferation, and motility in pancreatic cancer cells and ultimately impairs xenograft tumor growth, comparable to the effect of CREPT deletion.

Conclusions: PRTC-induced degradation of CREPT leads to inhibition of tumor growth, which is promising for the development of new drugs against pancreatic cancer. In addition, using an interacting motif based on the dimerized structure of proteins may be a new way to design a PROTAC aiming at degrading any protein without known interacting small molecules or peptides.

CREPT Promotes Melanoma Progression Through Accelerated Proliferation and Enhanced Migration by RhoA-Mediated Actin Filaments and Focal Adhesion Formation

Melanoma is one of the most aggressive cancers, and patients with distant metastases have dire outcomes. We observed previously that melanoma progression is driven by a high migratory potential of melanoma cells, which survive and proliferate under harsh environmental conditions. In this study, we report that CREPT (cell-cycle related and expression-elevated protein in tumor), an oncoprotein highly expressed in other cancers, is overexpressed in melanoma cells but not melanocytes. Overexpression of CREPT stimulates cell proliferation, migration, and invasion in several melanoma cell lines. Further, we show that CREPT enhances melanoma progression through upregulating and activating Ras homolog family member A (RhoA)-induced actin organization and focal adhesion assembly. Our study reveals a novel role of CREPT in promoting melanoma progression. Targeting CREPT may be a promising strategy for melanoma treatment.

TPD7 inhibits the growth of cutaneous T cell lymphoma H9 cell through regulating IL-2R signalling pathway

IL‐2R pathway is a key regulator in the development of immune cells and has emerged as a promising drug target in cancer treatment, but there is a scarcity of related inhibitors. TPD7 is a novel biphenyl urea taspine derivate, which has been shown anti‐cancer effect. Here, we demonstrated the anti‐cancer activity of TPD7 in cutaneous T cell lymphoma and investigated the underlying mechanism of TPD7 through IL‐2R signalling. The inhibitory effect of TPD7 on cell viability exhibited a strong correlation with the expression level of IL‐2R, and cutaneous T cell lymphoma H9 and HUT78 cells were most sensitive to TPD7. TPD7 was nicely bound to IL‐2R and down‐regulated the mRNA and protein levels of IL‐2R. Furthermore, TPD7 suppressed the downstream cascades of IL‐2R including JAK/STAT, PI3K/AKT/mTOR and PLCγ/Raf/MAPK signalling, resulting in Bcl‐2 mitochondrial apoptosis pathway and cell cycle proteins CDK/Cyclins regulation. And, these were verified by flow cytometry analysis that TPD7 facilitated cell apoptosis in H9 cells via mitochondrial pathway and impeded cell cycle progression at G2/M phase. TPD7 is a novel anti‐cancer agent and may be a potential candidate for cutaneous T cell lymphoma treatment by regulating IL‐2R signalling pathway.

Magnoflorine improves sensitivity to doxorubicin (DOX) of breast cancer cells via inducing apoptosis and autophagy through AKT/mTOR and p38 signaling pathways

Breast cancer is a leading cause of cancer death among women worldwide. Doxorubicin (DOX) is a broad-spectrum anti-breast cancer agent, but its clinical use is restricted due to irreversible tissue toxicity. Thereby, new therapeutic approaches are urgently required to promote the sensitivity of breast cancer cells to DOX. Magnoflorine (Mag), a quaternary alkaloid isolated from Chinese herb Magnolia or Aristolochia, has various biological activities, such as anti-inflammation, anti-cancer, and anti-anxiety. In the study, we explored the effects Mag on the sensitivity of breast cancer cells to DOX. We demonstrated that Mag strongly promoted DOX-induced anti-proliferative effects in breast cancer cells while not in normal cells. Mag addition markedly promoted the effects of DOX on the inhibition of migration and invasion in breast cancer cells. DOX-triggered DNA damage in breast cancer cells was further accelerated by combination with Mag. DOX-induced cell distribution in G2/M phase was markedly elevated when co-treated with Mag. Additionally, DOX/Mag combinational treatment significantly induced apoptosis in breast cancer cells when compared to DOX alone group through inducing Caspase-3 cleavage. Moreover, Mag markedly promoted the role of DOX in autophagy induction by elevating light chain 3 (LC3)-II expression. Combination treatment with DOX and Mag significantly inhibited the activation of phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling, and promoted p38 mitogen-activated protein kinase (MAPK) pathway. In addition, treatment with wortmannin (Wor, a blocker of autophagosome formation) markedly reduced DOX/Mag-induced p38 MAPK activation and LC3 conversion in breast cancer cells. Further, in MCF-7 xenograft model, DOX combined with Mag displayed a significant anti-tumor effect with little toxicity to organs such as liver, heart, kidney and spleen. These findings suggested that Mag promoted the anti-cancer effects of DOX to induce cellular apoptosis and autophagy in breast cancer cells.

Identification of novel biomarkers and small molecule drugs in human colorectal cancer by microarray and bioinformatics analysis

Background

Colorectal cancer (CRC) is one of the most common malignant tumors. In the present study, the expression profile of human multistage colorectal mucosa tissues, including healthy, adenoma, and adenocarcinoma samples was downloaded to identify critical genes and potential drugs in CRC.

Methods

Expression profiles, GSE33113 and GSE44076, were integrated using bioinformatics methods. Differentially expressed genes (DEGs) were analyzed by R language. Functional enrichment analyses of the DEGs were performed using the Database for Annotation, visualization, and integrated discovery (DAVID) database. Then, the search tool for the retrieval of interacting genes (STRING) database and Cytoscape were used to construct a protein–protein interaction (PPI) network and identify hub genes. Subsequently, survival analysis was performed among the key genes using Gene Expression Profiling Interactive Analysis (GEPIA). Connectivity Map (CMap) was used to query potential drugs for CRC.

Results

A total of 428 upregulated genes and 751 downregulated genes in CRC were identified. The functional changes of these DEGs were mainly associated with cell cycle, oocyte meiosis, DNA replication, p53 signaling pathway, and progesterone‐mediated oocyte maturation. A PPI network was identified by STRING with 482 nodes and 2,368 edges. Survival analysis revealed that high mRNA expression of AURKA, CCNB1, CCNF, and EXO1 was significantly associated with longer overall survival. Moreover, CMap predicted a panel of small molecules as possible adjuvant drugs to treat CRC.

Conclusion

Our study found key dysregulated genes involved in CRC and potential drugs to combat it, which may provide novel insights and potential biomarkers for prognosis, as well as providing new CRC treatments.