Downregulation of SAFB Sustains the NF-B Pathway by Targeting TAK1 during the Progression of Colorectal Cancer

SUB1 promotes colorectal cancer metastasis by activating NF-κB signaling via UBR5-mediated ubiquitination of UBXN1

Metastasis accounts for the major cause of colorectal cancer (CRC) related mortality due to the lack of effective treatments. In this study, we integrated the single-cell RNA-seq (scRNA-seq) and bulk RNA-seq data and identified the transcriptional coactivator SUB1 homolog (Sac-Saccharomyces cerevisiae)/PC4 (positive cofactor 4) associated with CRC metastasis. Elevated SUB1 expression was correlated with advanced tumor stage and poor survival in CRC. In vivo and vitro assays showed that SUB1 depletion could inhibit the invasive and metastatic abilities of CRC cells. SUB1 activated NF-κB signaling and its transcriptional target genes CXCL1 and CXCL3 to drive CRC metastasis. Mechanistically, SUB1 integrated with the E3 ubiquitin-protein ligase UBR5 and increased its protein level in CRC cells. Subsequently, the increased UBR5 mainly mediated Lys11-linked polyubiquitination and degradation of NF-κB negative regulator UBXN1, thus to activate the NF-κB signaling. Overall, our study demonstrated that SUB1 promoted CRC progression by modulating UBR5/UBXN1 and activating NF-κB signaling, providing a new therapeutic strategy for treating metastatic CRC through targeting SUB1.

Formin-like 2 promotes angiogenesis and metastasis of colorectal cancer by regulating the EGFL6/CKAP4/ERK axis

Increasing evidence indicates that angiogenesis plays a pivotal role in tumor progression. Formin-like 2 (FMNL2) is well-known for promoting metastasis; however, the molecular mechanisms by which FMNL2 promotes angiogenesis in colorectal cancer (CRC) remain unclear. Here, we found that FMNL2 promotes angiogenesis and metastasis of CRC in vitro and in vivo. The GDB/FH3 domain of FMNL2 directly interacts with epidermal growth factor-like protein 6 (EGFL6). Formin-like 2 promotes EGFL6 paracrine signaling by exosomes to regulate angiogenesis in CRC. Cytoskeleton associated protein 4 (CKAP4) is a downstream target of EGFL6 and is involved in CRC angiogenesis. Epidermal growth factor-like protein 6 binds to the N-terminus of CKAP4 to promote the migration of HUVECs by activating the ERK/MMP pathway. These findings suggest that FMNL2 promotes the migration of HUVECs and enhances angiogenesis and tumorigenesis in CRC by regulating the EGFL6/CKAP4/ERK axis. Therefore, the EGFL6/CKAP4/ERK axis could be a candidate therapeutic target for CRC treatment.

SKA1 promotes tumor metastasis via SAFB-mediated transcription repression of DUSP6 in clear cell renal cell carcinoma

The most hostile form of urologic cancer, clear cell renal cell carcinoma (ccRCC), has a high fatality rate and poor prognosis due to tumor metastasis at initial presentation. The complex process driving ccRCC metastasis is still unknown, though. In this study, we demonstrate that Spindle and kinetochore-associated protein 1 (SKA1) expression is significantly upregulated in ccRCC tissues and associated with aggressive clinicopathologic characteristics. Functionally, SKA1 knockdown on ccRCC cells reduced cancer cell motility both in vivo and in vitro research. These bioactivities of SKA1 may be brought on by its specific interaction with scaffold attachment factor B, according to the proposed mechanism (SAFB), which could further depress the transcription of dual specificity phosphatase 6 (DUSP6). Our findings may provide a new way of researching SKA1-regulated tumor metastasis, and indicate that SKA1 is a prospective therapeutic target for renal carcinoma.

Classical Angiogenic Signaling Pathways and Novel Anti-Angiogenic Strategies for Colorectal Cancer

Although productive progress has been made in colorectal cancer (CRC) researchs, CRC is the second most frequent type of malignancy and the major cause of cancer-related death among gastrointestinal cancers. As angiogenesis constitutes an important point in the control of CRC progression and metastasis, understanding the key signaling pathways that regulate CRC angiogenesis is critical in elucidating ways to inhibit CRC. Herein, we comprehensively summarized the angiogenesis-related pathways of CRC, including vascular endothelial growth factor (VEGF), nuclear factor-kappa B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), Wingless and int-1 (Wnt), and Notch signaling pathways. We divided the factors influencing the specific pathway into promoters and inhibitors. Among these, some drugs or natural compounds that have antiangiogenic effects were emphasized. Furthermore, the interactions of these pathways in angiogenesis were discussed. The current review provides a comprehensive overview of the key signaling pathways that are involved in the angiogenesis of CRC and contributes to the new anti-angiogenic strategies for CRC.

FOXS1 Promotes Tumor Progression by Upregulating CXCL8 in Colorectal Cancer

Background

Forkhead box S1 (FOXS1) is a member of the forkhead box (FOX) transcriptional factor superfamily. The biological roles and underlying regulatory mechanism of FOXS1 in CRC remain unclear.

Methods

Bioinformatics analysis, Western blotting, real-time PCR, and immunohistochemistry (IHC) were used to detect the expression FOXS1 in CRC. MTT assay, transwell assay, human umbilical vein endothelial cell tube formation assay, and chicken chorioallantoic membrane assay were performed to investigate the effects of FOXS1 on proliferation, invasion, and angiogenesis. Additionally, tumor formation assay and orthotopic implantation assay were used to investigate the effects of FOXS1 on tumor growth and metastasis in vivo. Furthermore, gene set enrichment analysis (GSEA) was used to analyze the correlation between FOXS1 and EMT or angiogenesis. The correlation between FOXS1 and CXCL8 expression was analyzed in clinical CRC samples using IHC.

Results

The results showed that FOXS1 expression was upregulated in CRC tissues compared with adjacent normal intestine tissues. A high FOXS1 expression is positively correlated with poor survival. FOXS1 promoted the malignant behavior of CRC cancer cells in vitro, including proliferation, invasion, and angiogenesis. In addition, FOXS1 promoted tumor growth and metastasis in nude mice. Mechanistically, FOXS1 upregulated the expression of C–X–C motif chemokine ligand 8 (CXCL8) at the transcriptional level. Knockdown of CXCL8 blocked FOXS1 induced the enhancement of the EMT and angiogenesis. GSEAs in public CRC datasets revealed strong correlations between FOXS1 expression and EMT marker and angiogenesis markers. IHC showed that FOXS1 expression was positively correlated with CXCL8 expression and CD31 expression in clinical CRC samples.

Conclusion

The results suggest that FOXS1 promotes angiogenesis and metastasis by upregulating CXCL8 in CRC. Interference with the FOXS1/CXCL8 axis may serve as a potential therapeutic target for the treatment of metastatic CRC.

Bioinformatics Analysis of Prognosis-Related Genes and Expression of CXCL8 in Colorectal Cancer

Background

Colorectal cancer (CRC), one of the main causes of death, remains a leading cause of mortality in gastrointestinal cancer and tends to affect the younger generation. However, the pathological process of colorectal cancer is unclear. Exploring potential pathogenesis and therapeutic targets of CRC is significant as its high prevalence and high mortality. Nowadays, the rapid development of bioinformatics provides us an opportunity to explore potential molecular markers of CRC.

Materials and Methods

First, three CRC gene chips with paracancerous controls were downloaded from the Gene Expression Omnibus (GEO) database. Second, after combining and batch correcting the three chips using the R language and Perl language, the differentially expressed genes (DEGs) were selected to investigate how they affect the CRC occurrence and development by GO and KEGG enrichment analysis. Third, based on the STRING website and the Cytoscape software, the protein-protein interaction (PPI) network was constructed and the core genes were screened out. Finally, through polymerase chain reaction (PCR) and immunohistochemistry (IHC), the expression and function of the core gene CXCL8 in CRC were explored.

Results

GSE10950, GSE44076, and GSE75970, including 126 intestinal cancer samples and 126 paracancer samples, were screened as the datasets. 192 DEGs were screened, including 43 upregulated genes and 149 downregulated genes. Through the DEGs screened out, GO enrichment analysis, KEGG enrichment analysis, and the construction of PPI interaction network were carried out. Finally, according to the nodes and edges in the PPI network, the DEGs were sorted and the core genes were selected. Through basic experiments, the first ranked CXCL8 was further studied, and the results suggest that the expression of CXCL8 is related to the proliferation, migration, invasion, and even distant metastasis of CRC.

Conclusion

The present study showed that DEGs of CRC are associated with multiple tumor-related biological processes and signaling pathways. The core gene CXCL8 has the potential to be a new therapeutic target for CRC.

Tenovin-1 inhibited dengue virus replication through SIRT2

Dengue fever is a common arbovirus disease, which has been spread to the entire tropical world. At present, effective drugs for the treatment of dengue fever have not yet appeared, and the dengue vaccines studied in various countries have also experienced severe adverse reactions. Thus it is urgent to find new chemicals against dengue virus. Now we found Sirtuins (SIRTs) were increased during dengue virus infection and tenovin-1, a SIRT1/2 inhibitor, showed an impressive antiviral ability in vitro. In BHK-21 cells, tenovin-1 inhibited the replication of DENV2 with an EC50 at 3.41 ± 1.10 μM, also inhibited other three types of dengue viruses with EC50 at 0.97 ± 1.11 μM, 1.81 ± 1.08 μM, 3.81 ± 1.34 μM respectively. Moreover, the cytopathic effect-induced DENV2 was largely improved by tenovin-1 treatment and the release of progeny viruses was inhibited by tenovin-1 treatment. At the same time, the viral protein level and mRNA level were decreased with tenovin-1 treatment after dengue virus infection. From the drug-addition assay, the tenovin-1 played its antiviral after viral infection, which indicated tenovin-1 was not a microbicide. Apart from its antiviral effect, tenovin-1 inhibited the inflammatory response caused by DENV2, reducing the release of inflammatory factors during viral infection. The antiviral effect of tenovin-1 was abrogated with SIRT agonist or SIRT2 knockdown treatment, which indicated the effect of tenovin-1 was on-target. In conclusion, tenovin-1 was proved to be a promising compound against flavivirus infection through SIRT2, which should be pay more attention for further study.

Identification of the Real Hub Gene and Construction of a Novel Prognostic Signature for Pancreatic Adenocarcinoma Based on the Weighted Gene Co-expression Network Analysis and Least Absolute Shrinkage and Selection Operator Algorithms

Background: Pancreatic adenocarcinoma (PAAD) has a considerably bad prognosis, and its pathophysiologic mechanism remains unclear. Thus, we aimed to identify real hub genes to better explore the pathophysiology of PAAD and construct a prognostic panel to better predict the prognosis of PAAD using the weighted gene co-expression network analysis (WGCNA) and the least absolute shrinkage and selection operator (LASSO) algorithms. Methods: WGCNA identified the modules most closely related to the PAAD stage and grade based on the Gene Expression Omnibus. The module genes significantly associated with PAAD progression and prognosis were considered as the real hub genes. Eligible genes in the most significant module were selected for construction and validation of a multigene prognostic signature based on the LASSO-Cox regression analysis in The Cancer Genome Atlas and the International Cancer Genome Consortium databases, respectively. Results: The brown module identified by WGCNA was most closely associated with the clinical characteristics of PAAD. Scaffold attachment factor B (SAFB) was significantly associated with PAAD progression and prognosis, and was identified as the real hub gene of PAAD. Moreover, both transcriptional and translational levels of SAFB were significantly lower in PAAD tissues compared with normal pancreatic tissues. In addition, a novel multigene-independent prognostic signature consisting of SAFB, SP1, and SERTAD3 was identified and verified. The predictive accuracy of our signature was superior to that of previous studies, especially for predicting 3- and 5-year survival probabilities. Furthermore, a prognostic nomogram based on independent prognostic variables was developed and validated using calibration curves. The predictive ability of this nomogram was also superior to the well-established AJCC stage and histological grade. The potential mechanisms of different prognoses between the high- and low-risk subgroups were also investigated using functional enrichment analysis, GSEA, ssGSEA, immune checkpoint analysis, and mutation profile analysis. Conclusion: SAFB was identified as the real hub gene of PAAD. A novel multigene-independent prognostic signature was successfully identified and validated to better predict PAAD prognosis. An accurate nomogram was also developed and verified to aid in the accurate treatment of tumors, as well as in early intervention.

S100P contributes to promoter demethylation and transcriptional activation of SLC2A5 to promote metastasis in colorectal cancer

BACKGROUND

SLC2A5 is a high-affinity fructose transporter, which is frequently upregulated in multiple human malignant tumours. However, the function and molecular mechanism of SLC2A5 in colorectal cancer (CRC) remain unknown.

METHODS

We detected the expression levels of SLC2A5 in CRC tissues and CRC cell lines by western blotting, qRT-PCR and immunohistochemistry. CRC cell lines with stable overexpression or knockdown of SLC2A5 were constructed to evaluate the functional roles of SLC2A5 in vitro through conventional assays. An intrasplenic inoculation model was established in mice to investigate the effect of SLC2A5 in promoting metastasis in vivo. Methylation mass spectrometry sequencing, methylation specific PCR, bisulphite sequencing PCR, ChIP-qPCR and luciferase reporter assay were performed to investigate the molecular mechanism underlying transcriptional activation of SLC2A5.

RESULTS

We found that SLC2A5 was upregulated in colorectal tumour tissues. Functionally, a high level of SLC2A5 expression was associated with increased invasion and metastasis capacities of CRC cells both in vitro and in vivo. Mechanistically, we unveiled that S100P could integrate to a specific region of SLC2A5 promoter, thereby reducing its methylation levels and activating SLC2A5 transcription.

CONCLUSIONS

Our results reveal a novel mechanism that S100P mediates the promoter demethylation and transcription activation of SLC2A5, thereby promoting the metastasis of CRC.

Protein phase separation and its role in chromatin organization and diseases

In the physical sciences, solid, liquid, and gas are the most familiar phase states, whose essence is their existence reflecting the different spatial distribution of molecular components. The biological molecules in the living cell also have differences in spatial distribution. The molecules organized in the form of membrane-bound organelles are well recognized. However, the biomolecules organized in membraneless compartments called biomolecular condensates remain elusive. The liquid-liquid phase separation (LLPS), as a new emerging scientific breakthrough, describes the biomolecules assembled in special distribution and appeared as membraneless condensates in the form of a new "phase" compared with the surrounding liquid milieu. LLPS provides an important theoretical basis for explaining the composition of biological molecules and related biological reactions. Mounting evidence has emerged recently that phase-separated condensates participate in various biological activities. This article reviews the occurrence of LLPS and underlying regulatory mechanisms for understanding how multivalent molecules drive phase transitions to form the biomolecular condensates. And, it also summarizes recent major progress in elucidating the roles of LLPS in chromatin organization and provides clues for the development of new innovative therapeutic strategies for related diseases.

Interplay between genome organization and epigenomic alterations of pericentromeric DNA in cancer

In eukaryotic genome biology, the genomic organization inside the three-dimensional (3D) nucleus is highly complex, and whether this organization governs gene expression is poorly understood. Nuclear lamina (NL) is a filamentous meshwork of proteins present at the lining of inner nuclear membrane that serves as an anchoring platform for genome organization. Large chromatin domains termed as lamina-associated domains (LADs), play a major role in silencing genes at the nuclear periphery. The interaction of the NL and genome is dynamic and stochastic. Furthermore, many genes change their positions during developmental processes or under disease conditions such as cancer, to activate certain sorts of genes and/or silence others. Pericentromeric heterochromatin (PCH) is mostly in the silenced region within the genome, which localizes at the nuclear periphery. Studies show that several genes located at the PCH are aberrantly expressed in cancer. The interesting question is that despite being localized in the pericentromeric region, how these genes still manage to overcome pericentromeric repression. Although epigenetic mechanisms control the expression of the pericentromeric region, recent studies about genome organization and genome-nuclear lamina interaction have shed light on a new aspect of pericentromeric gene regulation through a complex and coordinated interplay between epigenomic remodeling and genomic organization in cancer.

RBM23 Drives Hepatocellular Carcinoma by Activating NF-κB Signaling Pathway

Purpose

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide, and angiogenesis has been proven to be significantly involved in its progression. However, the molecular mechanism underlying HCC angiogenesis has not been well researched. In this study, RNA Binding Motif Protein 23 (RBM23) was identified as a novel proangiogenic factor in HCC cell lines and tissues.

Materials and Methods

Firstly, we analyzed the correlation of clinical specimens. In HCC tissues, the levels of RBM23 and microvessel density (MVD) showed a strong positive correlation. Furthermore, data from related cytology experiments showed that the knockdown of RBM23 expression in HCC cells significantly inhibited the tube formation by the human vascular endothelial cells in vitro. The mechanism of this phenomenon was found to be through increasing the mRNA of p65 and enhanced the nuclear accumulation of p65. Consequently, RBM23 activated the NF-κB signaling pathway and promoted expression of the proangiogenic cytokines selectively. Results and Conclusion. In summary, this study revealed that RBM23 promotes the angiogenesis properties of HCC via the NF-κB signaling pathway. It may, therefore, be a potential therapeutic target for the treatment of hepatocellular carcinoma.

SAIL: a new conserved anti-fibrotic lncRNA in the heart

Long non-coding RNAs (lncRNAs) account for a large proportion of genomic transcripts and are critical regulators in various cardiac diseases. Though lncRNAs have been reported to participate in the process of diverse cardiac diseases, the contribution of lncRNAs in cardiac fibrosis remains to be fully elucidated. Here, we identified a novel anti-fibrotic lncRNA, SAIL (scaffold attachment factor B interacting lncRNA). SAIL was reduced in cardiac fibrotic tissue and activated cardiac fibroblasts. Gain- and loss-of-function studies showed that knockdown of SAIL promoted proliferation and collagen production of cardiac fibroblasts with or without TGF-β1 (transforming growth factor beta1) treatment, while overexpression of SAIL did the opposite. In mouse cardiac fibrosis induced by myocardial infarction, knockdown of SAIL exacerbated, whereas overexpression of SAIL alleviated cardiac fibrosis. Mechanically, SAIL inhibited the fibrotic process by directly binding with SAFB via 23 conserved nucleotide sequences, which in turn blocked the access of SAFB to RNA pol II (RNA polymerase II) and reduced the transcription of fibrosis-related genes. Intriguingly, the human conserved fragment of SAIL (hSAIL) significantly suppressed the proliferation and collagen production of human cardiac fibroblasts. Our findings demonstrate that SAIL regulates cardiac fibrosis by regulating SAFB-mediated transcription of fibrotic related genes. Both SAIL and SAFB hold the potential to become novel therapeutic targets for cardiac fibrosis.

Loss of FGFR3 Delays Acute Myeloid Leukemogenesis by Programming Weakly Pathogenic CD117-Positive Leukemia Stem-Like Cells

Chemotherapeutic patients with leukemia often relapse and produce drug resistance due to the existence of leukemia stem cells (LSCs). Fibroblast growth factor receptor 3 (FGFR3) signaling mediates the drug resistance of LSCs in chronic myeloid leukemia (CML). However, the function of FGFR3 in acute myeloid leukemia (AML) is less understood. Here, we identified that the loss of FGFR3 reprograms MLL-AF9 (MA)-driven murine AML cells into weakly pathogenic CD117-positive leukemia stem-like cells by activating the FGFR1-ERG signaling pathway. FGFR3 deletion significantly inhibits AML cells engraftment in vivo and extends the survival time of leukemic mice. FGFR3 deletion sharply decreased the expression of chemokines and the prolonged survival time in mice receiving FGFR3-deficient MA cells could be neutralized by overexpression of CCL3. Here we firstly found that FGFR3 had a novel regulatory mechanism for the stemness of LSCs in AML, and provided a promising anti-leukemia approach by interrupting FGFR3.

Cooperation between ETS transcription factor ETV1 and histone demethylase JMJD1A in colorectal cancer

ETS variant 1 (ETV1) is an oncogenic transcription factor. However, its role in colorectal cancer has remained understudied. The present study demonstrated that ETV1 downregulation led to reduced HCT116 colorectal cancer cell growth and clonogenic activity. Furthermore, the ETV1 mRNA levels were enhanced in colorectal tumors and were associated with disease severity. In addition, ETV1 directly bound to Jumonji C domain-containing (JMJD) 1A, a histone demethylase known to promote colon cancer. ETV1 and JMJD1A, but not a catalytically inactive mutant thereof, cooperated in inducing the matrix metalloproteinase (MMP)1 gene promoter that was similar to the cooperation between ETV1 and another histone demethylase, JMJD2A. RNA-sequencing revealed multiple potential ETV1 target genes in HCT116 cells, including the FOXQ1 and TBX6 transcription factor genes. Moreover, JMJD1A co-regulated FOXQ1 and other ETV1 target genes, but not TBX6, whereas JMJD2A downregulation had no impact on FOXQ1 as well as TBX6 transcription. Accordingly, the FOXQ1 gene promoter was stimulated by ETV1 and JMJD1A in a cooperative manner, and both ETV1 and JMJD1A bound to the FOXQ1 promoter. Notably, the overexpression of FOXQ1 partially reversed the growth inhibitory effects of ETV1 ablation on HCT116 cells, whereas TBX6 impaired HCT116 cell growth and may thereby dampen the oncogenic activity of ETV1. The latter also revealed for the first time, to the best of our knowledge, a potential tumor suppressive function of TBX6. Taken together, the present study uncovered a ETV1/JMJD1A-FOXQ1 axis that may drive colorectal tumorigenesis.

Loss of FGFR3 Accelerates Bone Marrow Suppression-Induced Hematopoietic Stem and Progenitor Cell Expansion by Activating FGFR1-ELK1-Cyclin D1 Signaling

Patients with chemotherapy or radiation therapy often generate anemia and low immunity due to the therapy-induced bone marrow (BM) suppression. To enhance hematopoietic regeneration during the therapy-induced BM suppression urgently need to be solved. Fibroblast growth factors (FGFs) play important regulatory roles in hematopoietic stem and progenitor cell (HSPC) expansion in vitro and in vivo by the FGF receptor (FGFR1-4)-mediated signaling pathway. FGFR3 is an important member of the FGFR family, and its regulatory function in hematopoiesis is largely unknown. Using knockout (KO) mice of FGFR3, we found that loss of FGFR3 does not affect HSPC functions or lineage differentiation during steady-state hematopoiesis, but FGFR3 deletion accelerates HSPC expansion and hematopoiesis recovery via a cell-autonomous manner under 5-fluorouracil-induced BM suppression. Our results showed that FGFR3 inactivation accelerates BM suppression-induced HSPC expansion by upregulating FGFR1 and its downstream transcriptional factor, ELK, which regulates the expression of the cyclin D1 gene at the level of transcription. Further studies confirmed that loss of FGFR3 in hematopoietic cells inhibits in vivo leukemogenesis under BM suppression. Our data found a novel hematopoietic regulatory mechanism by which FGFR3 deletion promotes HSPC expansion under BM suppression and also provided a promising approach to enhance antileukemia and hematopoietic regeneration by inhibiting FGFR3 functions in HSPCs combined with leukemic chemotherapy.

CREB5 promotes invasiveness and metastasis in colorectal cancer by directly activating MET

BACKGROUND

cAMP responsive element binding protein 5 (CREB5) is a transcriptional activator in eukaryotic cells that can regulate gene expression. Previously, we found that CREB5 was involved in the occurrence and development of colorectal cancer (CRC) using bioinformatics analysis. However, the biological roles and underlying regulatory mechanism of CREB5 in CRC remain unclear.

METHODS

Real-time PCR, western blotting, and immunohistochemistry were used to examine CREB5 expression. In vitro experiments including migration assay, wound-healing assay, chicken chorioallantoic membrane assay, and human umbilical vein endothelial cells tube formation assay were used to investigate the effects of CREB5 on CRC cell migration and tumor angiogenesis ability. Additionally, an orthotopic implantation assay was performed in nude mice to confirm the effects of CREB5 in vivo. Furthermore, gene set enrichment analysis was performed to explore the potential mechanism of CREB5 in CRC.

RESULTS

We found that CREB5 expression was highly upregulated in CRC. CREB5 overexpression was positively correlated with advanced WHO stages and TNM stages and shorter survival in CRC patients. Moreover, CREB5 overexpression promoted while CREB5 silencing reduced the invasiveness and metastatic capacity of CRC cells both in vitro and in vivo. Furthermore, CREB5 directly interacted with the MET promoter and activated the hepatocyte growth factor-MET signalling pathway. Importantly, inhibition of MET reduced the invasion and metastasis of CREB5-overexpressing CRC cells, suggesting that CREB5 promotes metastasis mainly through activation of MET signalling.

CONCLUSION

Our study demonstrates a crucial role for CREB5 in CRC metastasis by directly upregulating MET expression. CREB5 may be both a potential prognostic marker and a therapeutic target to effectively overcome metastasis in CRC.

Upregulation of OSBPL3 by HIF1A promotes colorectal cancer progression through activation of RAS signaling pathway

Oxysterol-binding protein like protein 3 (OSBPL3) has been shown involving in the development of several human cancers. However, the relationship between OSBPL3 and colorectal cancer (CRC), particularly the role of OSBPL3 in the proliferation, invasion and metastasis of CRC remains unclear. In this study, we investigated the role of OSBPL3 in CRC and found that its expression was significantly higher in CRC tissues than that in normal tissues. In addition, high expression of OSBPL3 was closely related to poor differentiation, advanced TNM stage and poor prognosis of CRC. Further experiments showed that over-expression of OSBPL3 promoted the proliferation, invasion and metastasis of CRC in vitro and in vivo models. Moreover, we revealed that OSBPL3 promoted CRC progression through activation of RAS signaling pathway. Furthermore, we demonstrated that hypoxia induced factor 1 (HIF-1A) can regulate the expression of OSBPL3 via binding to the hypoxia response element (HRE) in the promoter of OSBPL3. In summary, Upregulation of OSBPL3 by HIF1A promotes colorectal cancer progression through activation of RAS signaling pathway. This novel mechanism provides a comprehensive understanding of both OSBPL3 and the RAS signaling pathway in the progression of CRC and indicates that the HIF1A–OSBPL3–RAS axis is a potential target for early therapeutic intervention in CRC progression.

Disease-related cellular protein networks differentially affected under different EGFR mutations in lung adenocarcinoma

It is unclear how epidermal growth factor receptor EGFR major driver mutations (L858R or Ex19del) affect downstream molecular networks and pathways. This study aimed to provide information on the influences of these mutations. The study assessed 36 protein expression profiles of lung adenocarcinoma (Ex19del, nine; L858R, nine; no Ex19del/L858R, 18). Weighted gene co-expression network analysis together with analysis of variance-based screening identified 13 co-expressed modules and their eigen proteins. Pathway enrichment analysis for the Ex19del mutation demonstrated involvement of SUMOylation, epithelial and mesenchymal transition, ERK/mitogen-activated protein kinase signalling via phosphorylation and Hippo signalling. Additionally, analysis for the L858R mutation identified various pathways related to cancer cell survival and death. With regard to the Ex19del mutation, ROCK, RPS6KA1, ARF1, IL2RA and several ErbB pathways were upregulated, whereas AURK and GSKIP were downregulated. With regard to the L858R mutation, RB1, TSC22D3 and DOCK1 were downregulated, whereas various networks, including VEGFA, were moderately upregulated. In all mutation types, CD80/CD86 (B7), MHC, CIITA and IFGN were activated, whereas CD37 and SAFB were inhibited. Costimulatory immune-checkpoint pathways by B7/CD28 were mainly activated, whereas those by PD-1/PD-L1 were inhibited. Our findings may help identify potential therapeutic targets and develop therapeutic strategies to improve patient outcomes.

Downregulation of Siah1 promotes colorectal cancer cell proliferation and migration by regulating AKT and YAP ubiquitylation and proteasome degradation

Background

Colorectal cancer (CRC) is one of the most common malignant tumors in the world. Siah E3 ubiquitin protein ligase 1 (Siah1) has been identified as a tumor suppressor gene and plays an important role in the development of malignant tumors. However, the potential role and molecular mechanism of Siah1 in the development and progression of CRC is still unclear.

Methods

To explore the role and molecular mechanism of Siah1 in the development and progression of CRC, we examined the expression of Siah1 in CRC tissue samples and analyzed its association with progression and prognosis in CRC. In addition, overexpression and knockdown of Siah1 was used to investigate its activity in CRC cells. We also use bioinformatics to analyze and verify the significant roles of Siah1 in critical signaling pathways of CRC.

Results

We found that the expression of Siah1 was significantly downregulated in CRC tissues, and low expression of Siah1 was associated with aggressive TNM staging and poor survival of CRC patients. Moreover, we revealed that overexpression of Siah1 in CRC cells markedly inhibited CRC cell proliferation and invasion in vitro and in vivo, while knockdown of Siah1 enhanced CRC cell proliferation and invasion. Furthermore, we found that Siah1 prohibited cell proliferation and invasion in CRC partially through promoting AKT (the serine-threonine protein kinase) and YAP (yes associated protein) ubiquitylation and proteasome degradation to regulate the activity of MAPK(mitogen-activated protein kinase 1), PI3K-AKT (phosphatidylinositol 3-kinase-the serine-threonine protein kinase) and Hippo signaling pathways.

Conclusions

These findings suggested that Siah1 is a novel potential prognostic biomarker and plays a tumor suppressor role in the development and progression of CRC.

The combination of two-dimensional and three-dimensional analysis methods contributes to the understanding of glioblastoma spatial heterogeneity

Heterogeneity is regarded as the major factor leading to the poor outcomes of glioblastoma (GBM) patients. However, conventional two-dimensional (2D) analysis methods, such as immunohistochemistry and immunofluorescence, have limited capacity to reveal GBM spatial heterogeneity. Thus, we sought to develop an effective analysis strategy to increase the understanding of GBM spatial heterogeneity. Here, 2D and three-dimensional (3D) analysis methods were compared for the examination of cell morphology, cell distribution and large intact structures, and both types of methods were employed to dissect GBM spatial heterogeneity. The results showed that 2D assays showed only cross-sections of specimens but provided a full view. To visualize intact GBM specimens in 3D without sectioning, the optical tissue clearing methods CUBIC and iDISCO+ were used to clear opaque specimens so that they would become more transparent, after which the specimens were imaged with a two-photon microscope. The 3D analysis methods showed specimens at a large spatial scale at cell-level resolution and had overwhelming advantages in comparison to the 2D methods. Furthermore, in 3D, heterogeneity in terms of cell stemness, the microvasculature, and immune cell infiltration within GBM was comprehensively observed and analysed. Overall, we propose that 2D and 3D analysis methods should be combined to provide much greater detail to increase the understanding of GBM spatial heterogeneity.

TBX2 Identified as a Potential Predictor of Bone Metastasis in Lung Adenocarcinoma via Integrated Bioinformatics Analyses and Verification of Functional Assay

Objective: Bone metastasis from patients with advanced lung adenocarcinoma (LAC) is a very serious complication. To better understand the molecular mechanism, our current study sheds light on identification of hub genes mediating bone metastatic spread by combining bioinformatic analysis with functional verification. Methods: First, we downloaded a lung adenocarcinoma dataset (GSE76194) from Gene Expression Omnibus, analyzed differentially expressed genes (DEGs) through Limma package in R software and constructed a protein-protein interaction network. Based on that preliminary data, we further performed modular and topological analysis using Cystoscope to obtain biological connected genes. Through literature searching and performing mRNA expression analysis on the other independent public dataset (GSE10799), we finally focused on TBX2. Functional effects of TBX2 were performed in tumorigenicity assays including migration and invasion assays, cell proliferation assay, and cell cycle assay. In addition, mechanically, we found enriched pathways related to bone metastasis using Gene Set Enrichment Analysis (GSEA) and validated our results by western blot. Result: A total of 1132 significant genes were sorted initially. We selected common significant genes (log FC>2; p<0.01) from both the biological network data and microarray data. In total, 44 such genes were identified. we found TBX2, along with 10 other genes, to be reported with relevance to bone metastasis in other cancer types. Moreover, TBX2 showed significantly higher expression levels in patients that were found positive for metastasis to bone marrow compared to patients that did not exhibit this type of metastasis in the other separated cohort (GSE10799). Thus, we finally focused on TBX2. We found that TBX2 had detectable expression in LAC cell lines and silencing endogenous TBX2 expression in A549 and H1299 cell lines markedly suppressed migration and invasion, cell proliferation and arrested cell-cycle. Pathway enrichment analyses suggested that TBX2 drove LAC oncogenesis and metastasis through various pathways with epithelial mesenchymal transition (EMT) figuring prominently in the bone metastatic group, which was evidenced by western blot. Conclusion: Collectively, TBX2 plays as a potential predictor of bone metastasis from LAC, yielding a better promise view towards "driver" gene responsible for bone metastasis.

Role of the NF-κB signaling pathway in the pathogenesis of colorectal cancer

The NF-κB signaling pathway is a key regulator of CRC cell proliferation, apoptosis, angiogenesis, inflammation, metastasis, and drug resistance. Over-activation of the NF-κB pathway is a feature of colorectal cancer (CRC). While new combinatorial treatments have improved overall patient outcome; quality of life, cost of care, and patient survival rate have seen little improvement. Suppression of the NF-κB signaling pathway using biological or specific pharmacological inhibitors is a potential therapeutic approach in the treatment of colon cancer. This review summarizes the regulatory role of NF-κB signaling pathway in the pathogenesis of CRC for a better understanding and hence a better management of the disease.

The Nuclear Matrix Protein SAFB Cooperates with Major Satellite RNAs to Stabilize Heterochromatin Architecture Partially through Phase Separation

Interphase chromatin is hierarchically organized into higher-order architectures that are essential for gene functions, yet the biomolecules that regulate these 3D architectures remain poorly understood. Here, we show that scaffold attachment factor B (SAFB), a nuclear matrix (NM)-associated protein with RNA-binding functions, modulates chromatin condensation and stabilizes heterochromatin foci in mouse cells. SAFB interacts via its R/G-rich region with heterochromatin-associated repeat transcripts such as major satellite RNAs, which promote the phase separation driven by SAFB. Depletion of SAFB leads to changes in 3D genome organization, including an increase in interchromosomal interactions adjacent to pericentromeric heterochromatin and a decrease in genomic compartmentalization, which could result from the decondensation of pericentromeric heterochromatin. Collectively, we reveal the integrated roles of NM-associated proteins and repeat RNAs in the 3D organization of heterochromatin, which may shed light on the molecular mechanisms of nuclear architecture organization.

Arctigenin alleviates TGF-β1-induced epithelial-mesenchymal transition and PAI-1 expression via AMPK/NF-κB pathway in peritoneal mesothelial cells

Peritoneal fibrosis (PF) caused by long-term peritoneal dialysis is closely associated with the epithelial-mesenchymal transition (EMT) of human peritoneal mesothelial cells (HPMCs). Moreover, the anti-fibrotic role of Arctigenin (Arc) has been reported in several fibrosis disorders. Therefore, the preventive effect of Arc on transforming growth factor-β1 (TGF-β1)-induced EMT and the underlying mechanisms in HPMCs was investigated in this study. Firstly, the PD model was established by TGF-β1 stimulation in cultured HPMCs in vitro, we found that TGF-β1 significantly increased the EMT markers (α-SMA, vimentin, and fibronectin) and plasminogen activator inhibitor type 1 (PAI-1) expressions, but decreased epithelial marker (E-cadherin). Co-treatment with Arc (10, 20, 40 μM) ameliorated TGF-β1-induced EMT in a dose-dependent manner, and the expression of PAI-1 was also inhibited by Arc, which was abrogated by restoration of PAI-1. Moreover, Arc enhanced the phosphorylated AMP-activated protein kinase (AMPK), but inhibited the phosphorylated IκBα level and nuclear translocation of nuclear factor κB (NF-κB) p65 in TGF-β1-induced HPMCs. ChIP and Luciferase reporter assays verified that the increased binding capacity of NF-κB to the promoter of PAI-1 induced by TGF-β1 was reversely attenuated by Arc in HPMCs. However, the effect of Arc on TGF-β1-induced NF-κB activation, PAI-1 expression and EMT in HPMCs was attenuated by AMPK agonist Compound C. In conclusion, these data demonstrated that Arc suppressed TGF-β1-induced EMT by activating the AMPK/NF-κB pathway to inhibit PAI-1 expression in HPMCs. Therefore, Arc might act as a potential therapeutic agent for PD treatment.

Hypermethylation Of ADHFE1 Promotes The Proliferation Of Colorectal Cancer Cell Via Modulating Cell Cycle Progression

Background

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Studies have demonstrated that epigenetic modifications play essential roles in the development of CRC. ADHFE1 is a differentially expressed gene that has been reported to be hypermethylated in CRC. However, the role and mechanism of ADHFE1 in the proliferation of CRC remain unclear.

Materials and methods

ADHFE1 expression was analyzed in CRC tissues by IHC and qRT-PCR, and the relationship between ADHFE1 expression and the clinicopathological parameters was analyzed. Cell proliferation were assessed by the in vitro and in vivo experimental models. GSEA assay was performed to explore the mechanism of ADHFE1 in the proliferation of CRC. Flow cytometry and Western blot were used to detect the activation of the cell cycle signaling. Bisulfite genomic sequence (BSP) assay was used to test the methylation degree of ADHFE1 gene promoter in CRC tissues.

Results

Here, we verified that ADHFE1 was down-regulated and hypermethylated in CRC tissues. The down-regulation of ADHFE1 was correlated with poor differentiation and advanced TNM stage of CRC patients. And ADHFE1 expression restored when the CRC cell line SW620 was treated with the demethylating agent 5-Aza-CdR. Overexpression of ADHFE1 inhibited the proliferation of CRC, while ADHFE1 knockdown promoted the proliferation of CRC cells in vitro and in vivo. Moreover, ADHFE1 overexpression could induce a significant G1-S cell cycle arrest in CRC cells and vice versa.

Conclusion

Hypermethylation of ADHFE1 might promote cell proliferation by modulating cell cycle progression in CRC, potentially providing a new therapeutic target for CRC patients.

Hypermethylation of DMTN promotes the metastasis of colorectal cancer cells by regulating the actin cytoskeleton through Rac1 signaling activation

Background

Colorectal cancer (CRC) is one of the most common digestive malignant tumors, and DMTN is a transcriptionally differentially expressed gene that was identified using CRC mRNA sequencing data from The Cancer Genome Atlas (TCGA). Our preliminary work suggested that the expression of DMTN was downregulated in CRC, and the Rac1 signaling pathway was significantly enriched in CRC tissues with low DMTN expression. However, the specific functions and underlying molecular mechanisms of DMTN in the progression of CRC and the upstream factors regulating the downregulation of the gene remain unclear.

Methods

DMTN expression was analyzed in CRC tissues, and the relationship between DMTN expression and the clinicopathological parameters was analyzed. In vitro and in vivo experimental models were used to detect the effects of DMTN dysregulation on invasion and metastasis of CRC cells. GSEA assay was performed to explore the mechanism of DMTN in invasion and metastasis of CRC. Westernblot, Co-IP and GST-Pull-Down assay were used to detect the interaction between DMTN and ARHGEF2, as well as the activation of the RAC1 signaling. Bisulfite genomic sequence (BSP) assay was used to test the degree of methylation of DMTN gene promoter in CRC tissues.

Results

We found that the expression of DMTN was significantly decreased in CRC tissues, and the downregulation of DMTN was associated with advanced progression and poor survival and was regarded as an independent predictive factor of CRC patient prognosis. The overexpression of DMTN inhibited, while the knockdown of DMTN promoted, invasion and metastasis in CRC cells. Moreover, hypermethylation and the deletion of DMTN relieved binding to the ARHGEF2 protein, activated the Rac1 signaling pathway, regulated actin cytoskeletal rearrangements, and promoted the invasion and metastasis of CRC cells.

Conclusion

Our study demonstrated that the downregulation of DMTN promoted the metastasis of colorectal cancer cells by regulating the actin cytoskeleton through RAC1 signaling activation, potentially providing a new therapeutic target to enable cancer precision medicine for CRC patients.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0958-1) contains supplementary material, which is available to authorized users.

FOXF1 promotes angiogenesis and accelerates bevacizumab resistance in colorectal cancer by transcriptionally activating VEGFA

Forkhead box F1 (FOXF1) has been recently implicated in the progression and metastasis of lung cancer and breast cancer. However, the biological functions and underlying mechanisms by which FOXF1 regulates the progression of colorectal cancer (CRC) are largely unknown. As shown in our previous study, FOXF1 is upregulated in 182 CRC tissues, and elevated FOXF1 expression is significantly associated with microvessel density and advanced TNM (T = primary tumour; N = regional lymph nodes; M = distant metastasis) stages. In this study, 43 CRC tissues collected from patients who underwent treatment with first-line standard chemotherapeutic regimens in combination with bevacizumab were used to explore the correlation between FOXF1 expression and resistance to bevacizumab. In addition, FOXF1 regulated angiogenesis by inducing the transcription of vascular endothelial growth factor A1 (VEGFA) in vitro and in vivo. Furthermore, upregulation of FOXF1 enhanced bevacizumab resistance in CRC, and inhibition of VEGFA attenuated angiogenesis and bevacizumab resistance in FOXF1-overexpressing CRC cells. These results suggest that FOXF1 plays critical roles in CRC angiogenesis and bevacizumab resistance by inducing VEGFA transcription and that FOXF1 represents a potentially new therapeutic strategy and biomarker for anti-angiogenic therapy against CRC.

FOXF1 Induces Epithelial-Mesenchymal Transition in Colorectal Cancer Metastasis by Transcriptionally Activating SNAI1

Forkhead Box F1 (FOXF1) has been recently implicated in cancer progression and metastasis of lung cancer and breast cancer. However, the biological functions and underlying mechanisms of FOXF1 in the regulation of the progression of colorectal cancer (CRC) are largely unknown. We showed that FOXF1 was up-regulated in 93 paraffin-embedded archived human CRC tissue, and both high expression and nuclear location of FOXF1 were significantly associated with the aggressive characteristics and poorer survival of CRC patients. The GSEA analysis showed that the higher level of FOXF1 was positively associated with an enrichment of EMT gene signatures, and exogenous overexpression of FOXF1 induced EMT by transcriptionally activating SNAI1. Exogenous overexpression FOXF1 functionally promoted invasion and metastasis features of CRC cells, and inhibition of SNAI1 attenuates the invasive phenotype and metastatic potential of FOXF1-overexpressing CRC cells. Furthermore, the results of the tissue chip showed that the expression of FOXF1 was positively correlated with SNAI1 in CRC tissues chip. These results suggested that FOXF1 plays a critical role in CRC metastasis by inducing EMT via transcriptional activation of SNAI1, highlighting a potential new therapeutic strategy for CRC.