Transcription factor AP-4 promotes tumorigenic capability and activates the Wnt/β-catenin pathway in hepatocellular carcinoma

circ_0006988 promotes gastric cancer cell proliferation, migration and invasion through miRNA-92a-2-5p/TFAP4 axis

Aim: To explore precise function and underlying mechanism of circ_0006988 in gastric cancer (GC).Materials & methods: GC tissues were collected clinically, and GC cells were purchased from the company. Quantitative real-time polymerase chain reaction and western blot were used to detect mRNA and protein expression. Functional analysis was performed through CCK-8, Transwell and scratch experiment. Binding relationship was validated through dual luciferase reporter and RNA immunoprecipitation assays. HGC-27 cells were subcutaneously injected into mice to construct a xenograft tumor model.Results: In GC tissues and cells, circ_0006988 overexpressed, promoting proliferation, migration and invasion. MiRNA-92a-2-5p downregulation or TFAP4 overexpression weakened effects of circ_0006988 silencing on GC progression.Conclusion: circ_0006988 facilitates GC development through miRNA-92a-2-5p/TFAP4 axis.

Genome binding properties of Zic transcription factors underlie their changing functions during neuronal maturation

BACKGROUND

The Zic family of transcription factors (TFs) promote both proliferation and maturation of cerebellar granule neurons (CGNs), raising the question of how a single, constitutively expressed TF family can support distinct developmental processes. Here we use an integrative experimental and bioinformatic approach to discover the regulatory relationship between Zic TF binding and changing programs of gene transcription during postnatal CGN differentiation.

RESULTS

We first established a bioinformatic pipeline to integrate Zic ChIP-seq data from the developing mouse cerebellum with other genomic datasets from the same tissue. In newborn CGNs, Zic TF binding predominates at active enhancers that are co-bound by developmentally regulated TFs including Atoh1, whereas in mature CGNs, Zic TF binding consolidates toward promoters where it co-localizes with activity-regulated TFs. We then performed CUT&RUN-seq in differentiating CGNs to define both the time course of developmental shifts in Zic TF binding and their relationship to gene expression. Mapping Zic TF binding sites to genes using chromatin looping, we identified the set of Zic target genes that have altered expression in RNA-seq from Zic1 or Zic2 knockdown CGNs.

CONCLUSIONS

Our data show that Zic TFs are required for both induction and repression of distinct, developmentally regulated target genes through a mechanism that is largely independent of changes in Zic TF binding. We suggest that the differential collaboration of Zic TFs with other TF families underlies the shift in their biological functions across CGN development.

Spermine oxidase regulates liver inflammation and fibrosis through β-catenin pathway

BACKGROUND

Spermine oxidase (SMOX), an inducible enzyme involved in the catabolic pathway of polyamine, was found to be upregulated in hepatocellular carcinoma and might be an important oncogene of it in our previous studies. This study attempted to further investigate its relationship with liver inflammation and fibrosis both in vitro and in vivo.

METHODS

The effect of SMOX inhibition on LPS-induced inflammatory response in mouse liver cell line AML12 was validated by using small interfering RNA or SMOX inhibitor MDL72527. Western blotting and immunofluorescence were utilized to verify whether LPS could induce β-catenin to transfer into the nucleus and whether it could be reversed by interfering with the expression of SMOX or using SMOX inhibitor. Then, the SMOX inhibitor MDL72527 and SMOX knockout mice were used to verify the hypothesis above in vivo.

RESULTS

The expression of SMOX could be induced by LPS in AML12 cells. The inhibition of SMOX could inhibit LPS-induced inflammatory response in AML12 cells. LPS could induce β-catenin transfer from cytoplasm to nucleus, while SMOX downregulation or inhibition could partially reverse this process. In vivo intervention with SMOX inhibitor MDL72527 or SMOX knockout mice could significantly improve the damage of liver function, reduce intrahepatic inflammation, inhibit the nuclear transfer of β-catenin in liver tissue, and alleviate carbon tetrachloride-induced liver fibrosis in mice.

CONCLUSION

SMOX can promote the inflammatory response and fibrosis of hepatocytes. It provides a new therapeutic strategy for hepatitis and liver fibrosis, inhibiting early liver cancer.

Ubiquitin-specific peptidase 15 regulates the TFAP4/PCGF1 axis facilitating liver metastasis of colorectal cancer and cell stemness

The tumor recurrence and metastasis of colorectal cancer (CRC) are responsible for most of CRC-linked mortalities. It is an urgent need to deeply investigate the pathogenesis of CRC metastasis and look for novel targets for its treatment. The current study aimed to investigate the effects of ubiquitin-specific peptidase 15 (USP-15) on the CRC progression. In vivo, a mouse model of liver metastasis of CRC tumor was established to investigate the role of USP-15. In vitro, the migrated and invasive abilities of CRC cells were assessed by transwell assay. Cell stemness was evaluated by using sphere formation assay. The underlying mechanism was further explored by employing the co-immunoprecipitation, dual luciferase reporter assay, oligonucleotide pull-down assay, and chromatin immunoprecipitation assay. The results showed that USP-15 was upregulated in CRC patients with liver metastasis and high metastatic potential cell lines of CRC. Loss of USP-15 repressed the epithelial-to-mesenchymal transition (EMT), migration, invasion, and stemness properties of CRC cells in vitro. Downregulation of USP-15 reduced the liver metastasis of mice in vivo. USP-15 upregulation obtained the contrary effects. Subsequently, USP-15 deubiquitinated transcription factor AP-4 (TFAP4) and enhanced its protein stability. TFAP4 could transcriptionally activated polycomb group ring finger 1 (PCGF1). The pro-cancer effects of USP-15 were rescue by the knockdown of TFAP4 or PCGF1. In conclusions: USP-15 facilitated the liver metastasis by the enhancement of cell stemness and EMT in CRC, which was at least partly mediated by the deubiquitination of TFAP4 upon the upregulation of PCGF1.

USP15, activated by TFAP4 transcriptionally, stabilizes SHC1 via deubiquitination and deteriorates renal cell carcinoma

Ubiquitin-specific peptidase 15 (USP15), a critical deubiquitinating enzyme, has been demonstrated to improve substrate stabilization by hydrolyzing the bond between the substrate and ubiquitin, and is implicated in multiple carcinogenic processes. Prompted by the information cited from The Cancer Genome Atlas (TCGA) database and the Cancer Proteogenomic Data Analysis Site (cProSite), USP15 is selectively overexpressed in clear cell renal cell carcinoma (ccRCC) samples. We aimed to investigate the function of USP15 on ccRCC malignant features, which was emphasized in its deubiquitination of SHC adaptor protein 1 (SHC1). The overexpression of USP15 promoted the capacity of proliferation, migration, and invasion in ccRCC CAKI1 and 769-P cells, and these malignant biological properties were diminished by USP15 deletion in 786-O cells. USP15 accelerated tumor growth and lung metastasis in vivo. In addition, deubiquitinase USP15 was further identified as a new protector for SHC1 from degradation by the ubiquitination pathway, the post-translational modification. In sequence, transcription factor activating enhancer binding protein 4 (TFAP4) was shown to be partly responsible for USP15 expression at the level of transcription, as manifested by the chromatin immunoprecipitation and pull-down assay. Based on the in vitro and in vivo data, we postulate that USP15 regulated by TFAP4 transcriptionally deteriorates ccRCC malignant biological properties via stabilizing SHC1 by deubiquitination.

N-glycosylation of Wnt3 regulates the progression of hepatocellular carcinoma by affecting Wnt/β-catenin signal pathway

BACKGROUND

Wnt/FZD-mediated signaling pathways are activated in more than 90% of hepatocellular carcinoma (HCC) cell lines. As a well-known secretory glycoprotein, Wnt3 can interact with FZD receptors on the cell surface, thereby activating the Wnt/β-catenin signaling pathway. However, the N-glycosylation modification site of Wnt3 and the effect of this modification on the biological function of the protein are still unclear.

AIM

To investigate the effect of Wnt3 N-glycosylation on the biological function of HCC cells.

METHODS

Site-directed mutagenesis was used to verify the Wnt3 N-glycosylation sites, actinomycin D treatment was used to detect the stability of Wnt3 after site-directed mutation, the binding of the N-glycosylation site-directed mutant Wnt3 to FZD7 was observed by laser confocal microscopy, and the effects of the N-glycosylation site-directed mutation of Wnt3 on the Wnt/β-catenin signaling pathway and the progression of HCC cells were detected by western blot and cell function experiments.

RESULTS

Wnt3 has two N-glycosylation-modified sites (Asn90 and Asn301); when a single site at amino acid 301 is mutated, the stability of Wnt3 is weakened; the binding ability of Wnt3 to FZD7 decreases when both sites are mutated simultaneously; and the level of proteins related to the Wnt/β-catenin signaling pathway is downregulated. Cell proliferation, migration and invasion are also weakened in the case of single 301 site and double-site mutations.

CONCLUSION

These results indicate that by inhibiting the N-glycosylation of Wnt3, the proliferation, migration, invasion and colony formation abilities of liver cancer cells can be weakened, which might provide new therapeutic strategies for clinical liver cancer in the future.

Signaling pathways in liver cancer: pathogenesis and targeted therapy

Liver cancer remains one of the most prevalent malignancies worldwide with high incidence and mortality rates. Due to its subtle onset, liver cancer is commonly diagnosed at a late stage when surgical interventions are no longer feasible. This situation highlights the critical role of systemic treatments, including targeted therapies, in bettering patient outcomes. Despite numerous studies on the mechanisms underlying liver cancer, tyrosine kinase inhibitors (TKIs) are the only widely used clinical inhibitors, represented by sorafenib, whose clinical application is greatly limited by the phenomenon of drug resistance. Here we show an in-depth discussion of the signaling pathways frequently implicated in liver cancer pathogenesis and the inhibitors targeting these pathways under investigation or already in use in the management of advanced liver cancer. We elucidate the oncogenic roles of these pathways in liver cancer especially hepatocellular carcinoma (HCC), as well as the current state of research on inhibitors respectively. Given that TKIs represent the sole class of targeted therapeutics for liver cancer employed in clinical practice, we have particularly focused on TKIs and the mechanisms of the commonly encountered phenomena of its resistance during HCC treatment. This necessitates the imperative development of innovative targeted strategies and the urgency of overcoming the existing limitations. This review endeavors to shed light on the utilization of targeted therapy in advanced liver cancer, with a vision to improve the unsatisfactory prognostic outlook for those patients.

Regulation of Follicular Development in Chickens: WIF1 Modulates Granulosa Cell Proliferation and Progesterone Synthesis via Wnt/β-Catenin Signaling Pathway

Proliferation, apoptosis, and steroid hormone secretion by granulosa cells (GCs) and theca cells (TCs) are essential for maintaining the fate of chicken follicles. Our previous study showed that the Wnt inhibitor factor 1 (WIF1) plays a role in follicle selection. However, the significance of WIF1 in GC- and TC-associated follicular development was not explicitly investigated. This study found that WIF1 expression was strongly downregulated during follicle selection (p < 0.05) and was significantly higher in GCs than in TCs (p < 0.05). WIF1 inhibits proliferation and promotes apoptosis in GCs. Additionally, it promotes progesterone secretion in prehierarchal GCs (pre-GCs, 1.16 ± 0.05 ng/mg vs. 1.58 ng/mg ± 0.12, p < 0.05) and hierarchal GCs (hie-GCs, 395.00 ng/mg ± 34.73 vs. 527.77 ng/mg ± 27.19, p < 0.05) with the participation of the follicle-stimulating hormone (FSH). WIF1 affected canonical Wnt pathways and phosphorylated β-catenin expression in GCs. Furthermore, 604 upregulated differentially expressed genes (DEGs) and 360 downregulated DEGs in WIF1-overexpressed GCs were found through RNA-seq analysis (criteria: |log2⁡(FoldChange)| > 1 and p_adj < 0.05). Cytokine-cytokine receptor interaction and the steroid hormone biosynthesis pathway were identified. In addition, the transcript of estrogen receptor 2 (ESR2) increased significantly (log2⁡(FoldChange) = 1.27, p_adj < 0.05). Furthermore, we found that WIF1 regulated progesterone synthesis by upregulating ESR2 expression in GCs. Additionally, WIF1 suppressed proliferation and promoted apoptosis in TCs. Taken together, these results reveal that WIF1 stimulates follicle development by promoting GC differentiation and progesterone synthesis, which provides an insight into the molecular mechanism of follicle selection and egg-laying performance in poultry.

Emerging trends in gastrointestinal cancers: Targeting developmental pathways in carcinogenesis and tumor progression

Gastrointestinal carcinomas are a group of cancers associated with the digestive system and its accessory organs. The most prevalent cancers related to the gastrointestinal tract are colorectal, gall bladder, gastric, hepatocellular, and esophageal cancers, respectively. Molecular aberrations in different signaling pathways, such as signal transduction systems or developmental pathways are the chief triggering mechanisms in different cancers Though a massive advancement in diagnostic and therapeutic interventions results in improved survival of patients with gastrointestinal cancer; the lower malignancy stages of these carcinomas are comparatively asymptomatic. Various gastrointestinal-related cancers are detected at advanced stages, leading to deplorable prognoses and increased rates of recurrence. Recent molecular studies have elucidated the imperative roles of several signaling pathways, namely Wnt, Hedgehog, and Notch signaling pathways, play in the progression, therapeutic responsiveness, and metastasis of gastrointestinal-related cancers. This book chapter gives an interesting update on recent findings on the involvement of developmental signaling pathways their mechanistic insight in gastrointestinalcancer. Subsequently, evidences supporting the exploration of gastrointestinal cancer related molecular mechanisms have also been discussed for developing novel therapeutic strategies against these debilitating carcinomas.

Genome binding properties of Zic transcription factors underlie their changing functions during neuronal maturation

Background

The Zic family of transcription factors (TFs) promote both proliferation and maturation of cerebellar granule neurons (CGNs), raising the question of how a single, constitutively expressed TF family can support distinct developmental processes. Here we use an integrative experimental and bioinformatic approach to discover the regulatory relationship between Zic TF binding and changing programs of gene transcription during CGN differentiation.

Results

We first established a bioinformatic pipeline to integrate Zic ChIP-seq data from the developing mouse cerebellum with other genomic datasets from the same tissue. In newborn CGNs, Zic TF binding predominates at active enhancers that are co-bound by developmentally-regulated TFs including Atoh1, whereas in mature CGNs, Zic TF binding consolidates toward promoters where it co-localizes with activity-regulated TFs. We then performed CUT&RUN-seq in differentiating CGNs to define both the time course of developmental shifts in Zic TF binding and their relationship to gene expression. Mapping Zic TF binding sites to genes using chromatin looping, we identified the set of Zic target genes that have altered expression in RNA-seq from Zic1 or Zic2 knockdown CGNs.

Conclusion

Our data show that Zic TFs are required for both induction and repression of distinct, developmentally regulated target genes through a mechanism that is largely independent of changes in Zic TF binding. We suggest that the differential collaboration of Zic TFs with other TF families underlies the shift in their biological functions across CGN development.

Transcription factors-related molecular subtypes and risk prognostic model: exploring the immunogenicity landscape and potential drug targets in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the most prevalent form of liver cancer, with a high mortality rate and poor prognosis. Mutated or dysregulated transcription factors (TFs) are significantly associated with carcinogenesis. The aim of this study was to develop a TF-related prognostic risk model to predict the prognosis and guide the treatment of HCC patients.

METHODS

RNA sequencing data were obtained from the TCGA database. The ICGC and GEO databases were used as validation datasets. The consensus clustering algorithm was used to classify the molecular subtypes of TFs. Kaplan‒Meier survival analysis and receiver operating characteristic (ROC) analysis were applied to evaluate the prognostic value of the model. The immunogenic landscape differences of molecular subtypes were evaluated by the TIMER and xCell algorithms. Autodock analysis was used to predict possible binding sites of trametinib to TFs. RT‒PCR was used to verify the effect of trametinib on the expression of core TFs.

RESULTS

According to the differential expression of TFs, HCC samples were divided into two clusters (C1 and C2). The survival time, signaling pathways, abundance of immune cell infiltration and responses to chemotherapy and immunotherapy were significantly different between C1 and C2. Nine TFs with potential prognostic value, including HMGB2, ESR1, HMGA1, MYBL2, TCF19, E2F1, FOXM1, CENPA and ZIC2, were identified by Cox regression analysis. HCC patients in the high-risk group had a poor prognosis compared with those in the low-risk group (p < 0.001). Moreover, the area under the ROC curve (AUC) values of the 1-year, 2-year and 3-year survival rates were 0.792, 0.71 and 0.695, respectively. The risk model was validated in the ICGC database. Notably, trametinib sensitivity was highly correlated with the expression of core TFs, and molecular docking predicted the possible binding sites of trametinib with these TFs. More importantly, the expression of core TFs was downregulated under trametinib treatment.

CONCLUSIONS

A prognostic signature with 9 TFs performed well in predicting the survival rate and chemotherapy/immunotherapy effect of HCC patients. Trimetinib has potential application value in HCC by targeting TFs.

FOLR1-stabilized β-catenin promotes laryngeal carcinoma progression through EGFR/AKT/GSK-3β pathway

Folate receptor 1 (FOLR1) is overexpressed in numerous epithelial malignancies; however, its role in laryngeal squamous cell carcinoma (LSCC) remains unclear. In the present study, we demonstrated that FOLR1 messenger RNA and protein expression levels were higher in LSCC tissues than in the adjacent normal tissues. Additionally, FOLR1 promoted the proliferation and migration of LSCC cells, whereas small interfering RNA-mediated knockdown of β-catenin abolished these effects. Moreover, FOLR1 stabilizes β-catenin by inhibiting its ubiquitination and degradation. Furthermore, blocking the interaction between epidermal growth factor receptor (EGFR) and the EGFR/AKT/glycogen synthase (GSK)3β signaling axis both abolished FOLR1's effects on the expression and nuclear aggregation of β-catenin. In summary, our work reveals a novel mode in which FOLR1 promotes the proliferation and migration of LSCC by enhancing the stability and nuclear translocation of β-catenin through the EGFR/AKT/GSK3β axis.

Photoperiod Induces the Epigenetic Change of the GNAQ Gene in OVX+E2 Ewes

GNAQ, a member of the alpha subunit encoding the q-like G protein, is a critical gene in cell signaling, and multiple studies have shown that upregulation of GNAQ gene expression ultimately inhibits the proliferation of gonadotropin-releasing hormone (GnRH) neurons and GnRH secretion, and ultimately affects mammalian reproduction. Photoperiod is a key inducer which plays an important role in gene expression regulation by affecting epigenetic modification. However, fewer studies have confirmed how photoperiod induces epigenetic modifications of the GNAQ gene. In this study, we examined the expression and epigenetic changes of GNAQ in the hypothalamus in ovariectomized and estradiol-treated (OVX+E2) sheep under three photoperiod treatments (short photoperiod treatment for 42 days, SP42; long photoperiod treatment for 42 days, LP42; 42 days of short photoperiod followed by 42 days of long photoperiod, SP-LP42). The results showed that the expression of GNAQ was significantly higher in SP-LP42 than in SP42 and LP42 (p < 0.05). Whole genome methylation sequencing (WGBS) results showed that there are multiple differentially methylated regions (DMRs) and loci between different groups of GNAQ. Among them, the DNA methylation level of DMRs at the CpG1 locus in SP42 was significantly higher than that of SP-LP42 (p < 0.01). Subsequently, we confirmed that the core promoter region of the GNAQ gene was located with 1100 to 1500 bp upstream, and the DNA methylation level of all eight CpG sites in SP42 was significantly higher than those in LP42 (p < 0.01), and significantly higher than those in SP-LP42 (p < 0.01), except site 2 and site 4 in the first sequencing fragment (p < 0.05) in the core promoter region. The expression of acetylated GNAQ histone H3 was significantly higher than that of the control group under three different photoperiods (p < 0.01); the acetylation level of sheep hypothalamic GNAQ genomic protein H3 was significantly lower under SP42 than under SP-LP42 (p < 0.05). This suggests that acetylated histone H3 binds to the core promoter region of the GNAQ gene, implying that GNAQ is epigenetically regulated by photoperiod through histone acetylation. In summary, the results suggest that photoperiod can induce DNA methylation in the core promoter region and histone acetylation in the promoter region of the GNAQ gene, and hypothesize that the two may be key factors in regulating the differential expression of GNAQ under different photoperiods, thus regulating the hypothalamus-pituitary-gonadal axis (HPGA) through the seasonal estrus in sheep. The results of this study will provide some new information to understand the function of epigenetic modifications in reproduction in sheep.

CENPA-driven STMN1 Transcription Inhibits Ferroptosis in Hepatocellular Carcinoma

Background and Aims

The growing knowledge of ferroptosis has suggested the regulatory role of ferroptosis in hepatocellular carcinoma (HCC), but the pertinent molecular mechanisms remain unclear. Herein, this study investigated the mechanistic basis of ferroptosis-related genes (ferrGenes) in the growth of HCC.

Methods

Differentially expressed human ferrGenes and tumor-related transcription factors (TFs) were obtained from the The Cancer Genome Atlas (TCGA) dataset and the GTEx dataset. Spearman method-based correlation analysis were conducted to construct TF-ferrGene coexpression regulatory network. Key genes associated with prognosis were singled out with Lasso regression and multivariate Cox analysis to construct the prognostic risk model. Then the accuracy and independent prognostic ability of the model were evaluated. Expression of CENPA and STMN1 was determined in clinical HCC tissues and HCC cells, and their binding was analyzed with dual-luciferase and chromatin immunoprecipitation (ChIP) assays. Furthermore, ectopic expression and knockdown assays were performed in HCC cells to assess the effect of CENPA and STMN1 on ferroptosis and malignant phenotypes.

Results

The prognostic risk model constructed based on the eight TF-ferrGene regulatory network-related genes accurately predicted the prognosis of HCC patients. It was strongly related to the clinical characteristics of HCC patients. Moreover, CENPA/STMN1 might be a key TF-ferrGene regulatory network in ferroptosis of HCC. CENPA and STMN1 were overexpressed in HCC tissues and cells. Additionally, CENPA facilitated STMN1 transcription by binding to STMN1 promoter, thus facilitating the malignant phenotypes and suppressing the ferroptosis of HCC cells.

Conclusions

Taken together, CENPA curbs the ferroptosis of HCC cells by upregulating STMN1 transcription, thereby promoting HCC growth.

Molecular Mechanism of Vitamin D Receptor Modulating Wnt/β-catenin Signaling Pathway in Gastric Cancer

Background: Gastric cancer is the most common gastrointestinal cancer worldwide. The latest data showed that it was the fourth leading cause of cancer-related death. The unobvious symptom and the difficulties lying in the early diagnosis largely affect the effect of the treatment. Therefore, it becomes particularly important to investigate the related genes and signal transduction pathways in gastric cancer. Our previous study found that the vitamin D receptor (VDR) gene FokI polymorphism may be associated with susceptibility to gastric cancer in the Chinese Han population. However, the mechanism of VDR affecting gastric cancer is unknown. In this study, we explored the molecular mechanism and the possible signaling pathway of VDR modulating carcinogenesis and progression of gastric cancer. Methods: The expression of VDR in gastric cancer cell lines was interfered by plasmid transfection and RNA interference technology. And then we analyzed the cell viability and invasive ability by MTT assay, colony formation assay, and transwell migration assay, and detected the expression of VDR and several signaling proteins in gastric cancer cells by SDS-PAGE and Western blotting. Results: The overexpression of VDR can significantly inhibit the viability and invasive ability of gastric cancer cells; on the contrary, when VDR siRNA inhibits the expression of VDR, the viability and invasive ability of gastric cancer cells enhanced. VDR expression levels in gastric cancer cells treated with 1,25 (OH) 2D3 showed a time-dependent increased expression; and with the increase of the VDR expression, the expression of β-catenin decreased gradually, but the expression of E-cadherin showed a time-dependent increase (P < 0.05). Compared with the mutant-type VDR gene(ff) cells, the degree of β-catenin decline was significantly enhanced after transfected with homozygous wild-type VDR gene (FF) plasmids (p<0.05). Conclusions: The results of this study indicate that VDR FokI polymorphism plays an important role in the malignant phenotype of gastric cancer cells, such as proliferation, invasion, and clone formation. When the VDR is activated by its ligand, it can prevent the nuclear import of β-catenin, affect the E-cadherin level, inhibit the proliferation of gastric cancer cells, which suggested that VDR FokI gene may play a role of cancer suppressor via Wnt/β-catenin signaling pathway.

Role of microRNAs in regulation of doxorubicin and paclitaxel responses in lung tumor cells

Lung cancer as the leading cause of cancer related mortality is always one of the main global health challenges. Despite the recent progresses in therapeutic methods, the mortality rate is still significantly high among lung cancer patients. A wide range of therapeutic methods including chemotherapy, radiotherapy, and surgery are used to treat lung cancer. Doxorubicin (DOX) and Paclitaxel (TXL) are widely used as the first-line chemotherapeutic drugs in lung cancer. However, there is a significant high percentage of DOX/TXL resistance in lung cancer patients, which leads to tumor recurrence and metastasis. Considering, the side effects of these drugs in normal tissues, it is required to clarify the molecular mechanisms of DOX/TXL resistance to introduce the efficient prognostic and therapeutic markers in lung cancer. MicroRNAs (miRNAs) have key roles in regulation of different pathophysiological processes including cell division, apoptosis, migration, and drug resistance. MiRNA deregulations are widely associated with chemo resistance in various cancers. Therefore, considering the importance of miRNAs in chemotherapy response, in the present review, we discussed the role of miRNAs in regulation of DOX/TXL response in lung cancer patients. It has been reported that miRNAs mainly induced DOX/TXL sensitivity in lung tumor cells by the regulation of signaling pathways, autophagy, transcription factors, and apoptosis. This review can be an effective step in introducing miRNAs as the non-invasive prognostic markers to predict DOX/TXL response in lung cancer patients.

Antler-derived microRNA PC-5p-1090 inhibits HCC cell proliferation, migration, and invasion by targeting MARCKS, SMARCAD1, and SOX9

The capability of microRNAs (miRNAs) to regulate gene expression across species has opened new avenues for miRNA-based therapeutics. Here, we investigated the potential of PC-5p-1090 (miR-PC-1090), a miRNA found in deer antlers, to control the malignant phenotypes of hepatocellular carcinoma (HCC) cells. Using Cell Counting Kit-8 and transwell assays, we found that heterologous expression of miR-PC-1090 inhibited HCC cell proliferation, migration, and invasion. Bioinformatics analysis indicated that predicted miR-PC-1090 targets, including MARCKS, SMARCAD1, and SOX9, were significantly elevated in HCC tissues, and their high expressions were associated with poor overall survival of HCC patients. Moreover, mechanistic investigations revealed that miR-PC-1090 promoted the degradation of MARCKS and SMARCAD1 mRNAs and hindered the translation of SOX9 mRNA by recognizing their 3' untranslated regions. Subsequent loss-of-function and rescue experiments confirmed the involvement of MARCKS, SMARCAD1, and SOX9 in miR-PC-1090-suppressed HCC cell proliferation, migration, and invasion. Notably, MARCKS knockdown induced the downregulation of phosphorylated MARCKS and a corresponding upregulation of phosphorylated AKT in HCC. Conversely, miR-PC-1090 repressed MARCKS phosphorylation and effectively circumvented the activation of the PI3K/AKT pathway. Furthermore, miR-PC-1090 regulates the Wnt/β-catenin pathway through SMARCAD1- and SOX9-mediated reduction of β-catenin expression. Overall, our results illustrate the tumor-suppressive activity and molecular mechanism of antler-derived miR-PC-1090 in HCC cells, indicating its potential as a multiple-target agent for HCC treatment.

Disheveled3 enhanced EMT and cancer stem-like cells properties via Wnt/β-catenin/c-Myc/SOX2 pathway in colorectal cancer

BACKGROUND

Epithelial-to-mesenchymal transition (EMT) and cancer stem-like cells (CSLCs) play crucial role in tumor metastasis and drug-resistance. Disheveled3 (DVL3) is involved in malignant behaviors of cancer. However, the role and potential mechanism of DVL3 remain elusive in EMT and CSLCs of colorectal cancer (CRC).

METHODS

UALCAN and PrognoScan databases were employed to evaluate DVL3 expression in CRC tissues and its correlation with CRC prognosis, respectively. Transwell, sphere formation and CCK8 assay were used to assess metastasis, stemness and drug sensitivity of CRC cells, respectively. Western blotting and dual luciferase assay were performed to analyze the protein expression and Wnt/β-catenin activation, respectively. Lentiviral transfection was used to construct the stable cell lines. Animal studies were performed to analyze the effect of silencing DVL3 on tumorigenicity and metastasis of CRC cells in vivo.

RESULTS

DVL3 was overexpressed in CRC tissues and several CRC cell lines. DVL3 expression was also higher in CRC tissues with lymph node metastasis than tumor tissues without metastasis, and correlated with poor prognosis of CRC patients. DVL3 positively regulated the abilities of migration, invasion and EMT-like molecular changes in CRC cells. Moreover, DVL3 promoted CSLCs properties and multidrug resistance. We further identified that Wnt/β-catenin was crucial for DVL3-mediated EMT, stemness and SOX2 expression, while silencing SOX2 inhibited DVL3-mediated EMT and stemness. Furthermore, c-Myc, a direct target gene of Wnt/β-catenin, was required for SOX2 expression and strengthened EMT and stemness via SOX2 in CRC cells. Finally, knockdown of DVL3 suppressed tumorigenicity and lung metastasis of CRC cells in nude mice.

CONCLUSION

DVL3 promoted EMT and CSLCs properties of CRC via Wnt/β-catenin/c-Myc/SOX2 axis, providing a new strategy for successful CRC treatment.

CDK9 inhibitors downregulate DKK1 expression to suppress the metastatic potential of HCC cells

BACKGROUND

Elevated expression of Dickkopf-1 (DKK1) is frequently observed in hepatocellular carcinoma (HCC) patients with poor clinical outcomes. Several reports indicating the functional involvement of DKK1 in HCC progression have suggested DKK1 as a promising therapeutic target for HCC.

OBJECTIVE

In this study, to develop an efficient way to target DKK1, we assessed the effect of CDK9 inhibitors on DKK1 expression linked to metastatic movement of HCC.

METHODS

The expression of DKK1 in CDK9 inhibitor-treated HCC cells was measured by western blot, ELISA and quantitative real-time reverse transcription PCR. Wound healing assay, migration assay, invasion assay and western blot were examined to evaluate the functional role of DKK1 in CDK9 inhibitors-treated HCC.

RESULTS

Inactivation of CDK9 either by a catalytic inhibitor being clinically evaluated or by a specific CDK9 protein degrader largely downregulated DKK1 expression at the transcript and protein levels. In addition, CDK9 inhibitors suppressed the migration and invasion of HCC cells. We observed that ectopic high expression of DKK1 at least partially reversed the defects in metastatic movement of HCC cells mediated by CDK9 inhibitors. We further discovered that the DKK1-nuclear β-catenin axis associated with the metastatic potential of HCC cells was impaired by CDK9 inhibitors.

CONCLUSION

Taken together, our findings suggest that CDK9 inhibitors are potent tools to target DKK1, which can suppress the metastatic progression of HCC.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients' response to therapy.

Targeting NK-1R attenuates renal fibrosis via modulating inflammatory responses and cell fate in chronic kidney disease

Background

Renal fibrosis is the final common pathway of chronic kidney disease (CKD), which is clinically irreversible and without effective therapy. Renal tubules are vulnerable to various insults, and tubular injury is involving in the initiation and evolution of renal inflammation and fibrosis. Neurokinin-1 receptor (NK-1R) functions by interacting with proinflammatory neuropeptide substance P (SP), exerting crucial roles in various neurological and non-neurological diseases. However, its roles in renal inflammation and fibrosis are still unknown.

Methods

We collected renal biopsy specimens and serum samples of individuals with or without CKD. Additionally, knockout mice lacking NK-1R expression, SP addition and NK-1R pharmacological antagonist treatment in the unilateral ureteral obstruction (UUO) model, and NK-1R-overexpressed HK-2 cells were employed.

Results

Renal SP/NK-1R and serum SP were increased in patients with CKD and mice experiencing UUO and correlated with renal fibrosis and function. SP addition enhanced UUO-induced progressive inflammatory responses and renal fibrosis, whereas genetically or pharmacologically targeting NK-1R attenuated these effects. Mechanistically, TFAP4 promoted NK-1R transcription by binding to its promoter, which was abolished by mutation of the binding site between TFAP4 and NK-1R promoter. Furthermore, SP acted through the NK-1R to activate the JNK/p38 pathways to modulate cell fate of tubular epithelial cells including growth arrest, apoptosis, and expression of profibrogenic genes.

Conclusion

Our data reveals that SP/NK-1R signaling promotes renal inflammatory responses and fibrosis, suggesting NK-1R could be a potential therapeutic target for the patients with CKD.

Pathogenesis and Current Treatment Strategies of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent liver cancer with high lethality and low five-year survival rates leading to a substantial worldwide burden for healthcare systems. HCC initiation and progression are favored by different etiological risk factors including hepatitis B virus (HBV) and hepatitis C virus (HCV) infection, non-/and alcoholic fatty liver disease (N/AFLD), and tobacco smoking. In molecular pathogenesis, endogenous alteration in genetics (TP53, TERT, CTNNB1, etc.), epigenetics (DNA-methylation, miRNA, lncRNA, etc.), and dysregulation of key signaling pathways (Wnt/β-catenin, JAK/STAT, etc.) strongly contribute to the development of HCC. The multitude and complexity of different pathomechanisms also reflect the difficulties in tailored medical therapy of HCC. Treatment options for HCC are strictly dependent on tumor staging and liver function, which are structured by the updated Barcelona Clinic Liver Cancer classification system. Surgical resection, local ablative techniques, and liver transplantation are valid and curative therapeutic options for early tumor stages. For multifocal and metastatic diseases, systemic therapy is recommended. While Sorafenib had been the standalone HCC first-line therapy for decades, recent developments had led to the approval of new treatment options as first-line as well as second-line treatment. Anti-PD-L1 directed combination therapies either with anti-VEGF directed agents or with anti-CTLA-4 active substances have been implemented as the new treatment standard in the first-line setting. However, data from clinical trials indicate different responses on specific therapeutic regimens depending on the underlying pathogenesis of hepatocellular cancer. Therefore, histopathological examinations have been re-emphasized by current international clinical guidelines in addition to the standardized radiological diagnosis using contrast-enhanced cross-sectional imaging. In this review, we emphasize the current knowledge on molecular pathogenesis of hepatocellular carcinoma. On this occasion, the treatment sequences for early and advanced tumor stages according to the recently updated Barcelona Clinic Liver Cancer classification system and the current algorithm of systemic therapy (first-, second-, and third-line treatment) are summarized. Furthermore, we discuss novel precautional and pre-therapeutic approaches including therapeutic vaccination, adoptive cell transfer, locoregional therapy enhancement, and non-coding RNA-based therapy as promising treatment options. These novel treatments may prolong overall survival rates in regard with quality of life and liver function as mainstay of HCC therapy.

TCF7/SNAI2/miR-4306 feedback loop promotes hypertrophy of ligamentum flavum

Background

Hypertrophy of ligamentum flavum (HLF) is the mainly cause of lumbar spinal stenosis (LSS), but the precise mechanism of HLF formation has not been fully elucidated. Emerging evidence indicates that transcription factor 7 (TCF7) is the key downstream functional molecule of Wnt/β-catenin signaling, which participated in regulating multiple biological processes. However, the role and underlying mechanism of TCF7 in HLF is still unclear.

Methods

We used mRNAs sequencing analysis of human LF and subsequent confirmation with RT-qPCR, western blot and immunohistochemistry to identified the TCF7 in HLF tissues and cells. Then effect of TCF7 on HLF progression was investigated both in vitro and in vivo. Mechanically, chromatin immunoprecipitation, dual-luciferase reporter assays, and rescue experiments were used to validate the regulation of TCF7/SNAI2/miR-4306 feedback loop.

Results

Our results identified for first time that the TCF7 expression was obviously elevated in HLF tissues and cells compared with control, and also found that TCF7 expression had significant positive correlation with LF thickness and fibrosis score. Notably, TCF7 inhibition suppressed the hyper-proliferation and fibrosis phenotype of HLF cells in vitro and ameliorated progression of HLF in mice in vivo, whereas TCF7 overexpression promoted hyper-proliferation and fibrosis phenotype of HLF cells in vitro. Our data further revealed that TCF7 interacted with SNAI2 promoter to transactivated the SNAI2 expression, thereby promoting hyper-proliferation and fibrosis phenotype of HLF cells in vitro. Furthermore, miR-4036 negatively regulated by SNAI2 could negatively feedback regulate TCF7 expression by directly binding to TCF7 mRNA 3’-UTR, thus inhibiting the hyper-proliferation and fibrosis phenotype of HLF cells in vitro.

Conclusions

Our study demonstrated that TCF7 inhibition could suppress HLF formation by modulating TCF7/SNAI2/miR-4306 feedback loop, which might be considered as a novel potential therapeutic target for HLF.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03677-0.

Global and precise identification of functional miRNA targets in mESCs by integrative analysis

MicroRNA (miRNA) loaded Argonaute (AGO) complexes regulate gene expression via direct base pairing with their mRNA targets. Previous works suggest that up to 60% of mammalian transcripts might be subject to miRNA‐mediated regulation, but it remains largely unknown which fraction of these interactions are functional in a specific cellular context. Here, we integrate transcriptome data from a set of miRNA‐depleted mouse embryonic stem cell (mESC) lines with published miRNA interaction predictions and AGO‐binding profiles. Using this integrative approach, combined with molecular validation data, we present evidence that < 10% of expressed genes are functionally and directly regulated by miRNAs in mESCs. In addition, analyses of the stem cell‐specific miR‐290‐295 cluster target genes identify TFAP4 as an important transcription factor for early development. The extensive datasets developed in this study will support the development of improved predictive models for miRNA‐mRNA functional interactions.

FN1 overexpression is correlated with unfavorable prognosis and immune infiltrates in breast cancer

Objective: To investigate the correlation of fibronectin 1 (FN1) expression with prognosis and tumor-infiltrating immune cells in breast cancer (BRCA).

Methods: FN1 mRNA and protein expressions were analyzed through Tumor Immune Estimation Resource (TIMER), Gene Set Cancer Analysis (GSCA), Human Protein Atlas (HPA) databases, and immunohistochemical analysis. The clinicopathological characteristics and genetic factors affecting the FN1 mRNA expression were assessed by various public databases. Then, we analyzed the prognostic value of FN1 in BRCA by Kaplan-Meier plotter, receiver operating characteristic, and Cox regression analyses. Further, the UCSC Xena database was used to retrieve TCGA-BRCA expression profiles for functional enrichment analysis and immune cell infiltration analysis. The potential drugs for the BRCA patients with high- FN1 expression were identified using the connectivity map analysis.

Results: FN1 was upregulated in BRCA tissues compared with normal tissues. High FN1 mRNA expression was correlated with poor clinical outcomes and had good performance in predicting the survival status of BRCA patients. Further, Cox regression analysis showed that FN1 was an independent prognostic factor for predicting the overall survival of patients with BRCA. Moreover, hypermethylation of FN1 contributed to a better prognosis for BRCA patients. Functional enrichment analyses revealed the ECM-receptor interaction pathway and focal adhesion as the common pathways. Moreover, FN1 showed a significant association with tumor-infiltrating immune cells and immune checkpoint inhibitors. Several drugs such as telmisartan, malotilate, and seocalcitol may have therapeutic effects in BRCA patients with high FN1 expression.

Conclusion: FN1 might serve as a novel prognostic biomarker and a novel therapeutic target for BRCA. Besides, the association of FN1 with immune cells and immune checkpoint inhibitors may provide assistance for BRCA treatment.

Regulation of SUMOylation Targets Associated With Wnt/β-Catenin Pathway

Wnt/β-catenin signaling is a delicate and complex signal transduction pathway mediated by multiple signaling molecules, which plays a significant role in regulating human physiology and pathology. Abnormally activated Wnt/β-catenin signaling pathway plays a crucial role in promoting malignant tumor occurrence, development, recurrence, and metastasis, particularly in cancer stem cells. Studies have shown that the Wnt/β-catenin signaling pathway controls cell fate and function through the transcriptional and post-translational regulation of omics networks. Therefore, precise regulation of Wnt/β-catenin signaling as a cancer-targeting strategy may contribute to the treatment of some malignancies. SUMOylation is a post-translational modification of proteins that has been found to play a major role in the Wnt/β-catenin signaling pathway. Here, we review the complex regulation of Wnt/β-catenin signaling by SUMOylation and discuss the potential targets of SUMOylation therapy.

LINC00514 facilitates cell proliferation, migration, invasion, and epithelial-mesenchymal transition in non-small cell lung cancer by acting on the Wnt/β-catenin signaling pathway

The long non-coding RNA (lncRNA) LINC00514 was identified to play an essential oncogenic function in different human cancers, but its effects in non-small cell lung cancer (NSCLC) are yet to be elucidated. In this study, we evaluated the function of LINC00514 in NSCLC. LINC00514 expression and prognosis in NSCLC were analyzed using qRT-PCR and online bioinformatic tools. The bioeffects of LINC0514 in NSCLC cells were examined using cell counting kit-8, colony formation, and transwell assays. Western blotting was used to measure the expression of the target proteins. The LINC00514 regulation of the Wnt/β-catenin signaling pathway was assessed using a specific agonist (LiCl) and luciferase reporter assay. We found that LINC00514 expression was elevated in NSCLC cells and clinical samples and that increased LINC00514 expression predicted poorer patient prognosis. Silencing LINC00514 suppresses proliferation, migration, and invasion of NSCLC cells. Downregulation of LINC00514 inhibited Wnt/β-catenin signaling and epithelial-mesenchymal transition (EMT). Moreover, suppression of the biological phenotypes of NSCLC cells induced by LINC00514 gene silencing was restored after LiCl treatment. Finally, we found that silencing LINC00514 attenuated the growth of xenograft tumors in vivo. Altogether, this study provides the latest convincing evidence that LINC00514 facilitates the malignant biological behavior of NSCLC cells through activation of the Wnt/β-catenin pathway, which might offer a beneficial approach for the treatment of NSCLC.

Enhancer of zeste homolog 2 promotes hepatocellular cancer progression and chemoresistance by enhancing protein kinase B activation through microRNA-381-mediated SET domain bifurcated 1

Metastasis and chemoresistance are the leading causes of death in patients with hepatocellular carcinoma (HCC). microRNAs (miRNAs or miRs) may be useful as diagnostic, therapeutic and prognostic markers for HCC. In this study, we set out to investigate the possible role of miR-381 in HCC development and chemoresistance along with the related mechanism. Microarray-based gene expression profiling was carried out to analyze the expression of SET domain bifurcated 1 (SETDB1) and histone methyltransferase enhancer of zeste homolog 2 (EZH2) followed by validation in clinical HCC tissues and cells. The potential binding between miR-381 and SETDB1 was found and verified. Then, the role of SETDB1 in HCC in relation to miR-381 and protein kinase B (AKT) pathway was explored through gain- and loss-of-function approaches. After expression determination of EZH2, SETDB1, miR-381, and AKT pathway-related factors, their reactions were analyzed and their functional roles in HCC progression and chemoresistance were investigated in vitro and in vivo. SETDB1 was aberrantly upregulated in clinical HCC tissues and cells. This upregulation activated AKT pathway by promoting its tri-methylation on K64. SETDB1 promoted the proliferation, migration and chemoresistance through the AKT pathway in HCC cells. In a xenograft mouse model, SETDB1 promoted HCC cell tumorigenesis in vivo by activating the AKT pathway. Furthermore, EZH2 suppressed miR-381 by catalyzing the activity of H3K27me3 on its promoter region. In conclusion, EZH2 suppressed miR-381 expression by promoting H3K27me3 activity on its promoter region to facilitate SETDB1 expression, thereby activating the AKT pathway to promote hepatocarcinogenesis and chemoresistance.

Inhibitory effect of CC chemokine ligand 23 (CCL23)/ transcription factor activating enhancer binding protein 4 (TFAP4) on cell proliferation, invasion and angiogenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a highly vascularized solid tumor with a fast growth rate. According to bioinformatics analysis, CC chemokine ligand 23 (CCL23) has clinical significance for survival and prognosis in HCC. The online databases TCGA and CCLE were used to analyze the expression level of CCL23, and its expression was also measured in HCC cell lines by RT-qPCR and Western blotting. The STRING database and co-immunoprecipitation were employed to evaluate the association between CCL23 and transcription factor activating enhancer binding protein 4 (TFAP4). Overexpression plasmids for CCL23 (Ov-CCL23) and TFAP4 (Ov-TFAP4) were transfected into Huh-7 cells to detect TFAP4 expression. Huh-7 cells injected with OV-negative control (NC)/Ov-CCL23 or OV-NC/Ov-CCL23 plus Ov-TFAP4 were utilized to study the function of CCL23/TFAP4. Cell proliferation, invasion and human umbilical vein endothelial cell tube formation assays were conducted. The database revealed decreased expression of CCL23 in HCC and that it was commonly downregulated in HCC cell lines. TFAP4 expression was negatively correlated with CCL23. The overexpression of CCL23 inhibited the proliferation and invasion of Huh-7 cells, whereas TFAP4 blocked these effects. Similarly, the supernatant of CCL23-upregulated cells exhibited significantly lower tube formation potential, and low vascular endothelial growth factor A (VEGFA), VEGFRs expression compared with those of non-transfected Huh-7 cells, while TFAP4 plasmid co-transfected markedly increased these. Taken together, the present study suggests that CCL23 is expressed at low levels in HCC; it inhibits HCC cell proliferation, invasion and angiogenesis in vitro; and its action is negatively associated with and can be blocked by TFAP4.

Upregulating microRNA-373-3p promotes apoptosis and inhibits metastasis of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies in the digestive system. Abnormal miR-373-3p and TFAP4 expressions are critical in many malignant tumors, but it is unclear whether they work in the context of HCC. qRT-PCR measured miR-373-3p expression in HCC tissues and adjacent normal tissues. Flow cytometry and Western blot analyzed cell apoptosis. EMT, Transwell, and wound healing assay examined HCC cell migration and EMT, respectively. Western blot determined the profile of TFAP4/PI3K/AKT. IHC detected Ki67, E-cadherin, and vimentin in the tumor tissues. Moreover, the downstream target of miR-373-3p was predicted using the database. Dual luciferase activity assay and RIP verified the binding correlation between TFAP4 and miR-373-3p. In HCC tissues and cell lines, miR-373-3p was downregulated, and its overexpression stepped up HCC cell apoptosis and suppressed migration and EMT. Furthermore, miR-373-3p overexpression elevated Bax and caspase 3 expressions and attenuated Bcl2’s level. A xenograft tumor experiment in nude mice unveiled that miR-373-3p overexpression dampened tumor growth and proliferation. miR-373-3p cramped PI3K/AKT pathway activation. miR-373-3p negatively modulated TFAP4, and TFAP4 overexpression inverted miR-373-3p-mediated anti-tumor effects. Additionally, TFAP4 enhanced IGF1 expression, and promoted IGF1R-PI3K/AKT pathway activation. Collectively, miR-373-3p functions as an anti-tumor gene in HCC by inhibiting TFAP4/PI3K/AKT pathway.

TFAP4 promotes the growth of prostate cancer cells by upregulating FOXK1

Transcription factor activating enhancer binding protein 4 (TFAP4) has been indicated to be correlated with the progression of various human malignancies. However, the effect and regulatory mechanism of TFAP4 in prostate cancer (PC) remain unclear. The protein and mRNA expression were detected by western blotting and RT-qPCR. TFAP4 was overexpressed or knocked down in PC cells. The viability, invasion and migration of PC cells were analyzed by CCK-8, Transwell and wound healing assays. The colony formation was also determined. TFAP4 expression was upregulated in PC patients and cells; high TFAP4 expression predicted poor prognosis, and was associated with a range of clinicopathological features, including metastasis, clinical stage and Gleason score. Moreover, overexpression of TFAP4 promoted cell viability, migration, and invasion in vitro, whereas knockdown of TFAP4 revealed the opposite results. TFAP4 also positively regulated forkhead box K1 (FOXK1) expression. In addition, overexpression of FOXK1 reversed the effects of TFAP4 knockdown on PC cells. These findings clarified the biologic significance of TFAP4 in PC progression and revealed an association between TFAP4 and FOXK1, thus providing a new potential target for clinical therapy of PC.

Bioinformatics analysis of constructing a HCV-related hepatocellular carcinoma miRNA-mRNA regulation network

Hepatocellular carcinoma (HCC) is one of the tumors with a higher mortality rate globally, which significantly threatens people's health. Hepatitis C virus (HCV) infection is a major driving factor of HCC. This study aims to determine the key microRNA (miRNA), hub genes, and related pathways, construct potential miRNA-mRNA regulatory networks, and clarify the new molecular mechanism of HCV-related HCC. In this study, 16 differentially expressed miRNAs (DE miRNAs) were identified. The prediction of potential transcription factors and target genes not only found that SP1 and ERG1 may potentially regulate most of the screened DE miRNAs, but it also obtained 2923 and 1782 predicted target genes for the up-regulation and down-regulation of DE miRNAs, respectively. Subsequently, the introduction of differentially expressed genes dataset GSE62232 for target gene verification yielded 98 and 147 potential up-regulation and down-regulation target genes. The gene ontology (GO) and Kyoto encyclopedia of genes and genomes pathway enrichment analysis showed that they were mainly enriched in the cell cycle process, that is, subsequently, 20 hub genes were screened out through the protein-protein interaction network, and related genes were further evaluated using the GEPIA database. Based on the above analysis, the miRNA-hub gene regulatory network was constructed. In short, this research's hub genes and miRNAs closely related to HCV-related HCC were screened and identified through bioinformatics analysis and then built their connection. These results are expected to find potential therapeutic targets for HCV-related HCC.

FUBP1 promotes colorectal cancer stemness and metastasis via DVL1-mediated activation of Wnt/β-catenin signaling

Distant metastasis is, unfortunately, the leading cause of death in colorectal cancer (CRC). Approximately 50% of CRC patients develop liver metastases, while 10–30% of patients develop pulmonary metastases. The occurrence of metastasis is considered to be almost exclusively driven by cancer stem cells (CSCs) formation. However, the key molecules that confer the transformation to stem cells in CRC, and subsequent metastasis, remain unclear. Far upstream element‐binding protein 1 (FUBP1), a transcriptional regulator of c‐Myc, was screened in CSCs of CRC by mass spectrometry and was examined by immunohistochemistry in a cohort of CRC tissues. FUBP1 was upregulated in 85% of KRAS‐mutant and 25% of wild‐type CRC patients. Further, whether in KRAS‐mutant or wild‐type patients, elevated FUBP1 was positively correlated with CRC lymph node metastasis and clinical stage, and negatively associated with overall survival. Overexpression of FUBP1 significantly enhanced CRC cell migration, invasion, tumor sphere formation, and CD133 and ALDH1 expression in vitro, and tumorigenicity in vivo. Mechanistically, FUBP1 promoted the initiation of CSCs by activating Wnt/β‐catenin signaling via directly binding to the promoter of DVL1, a potent activator of β‐catenin. Knockdown of DVL1 significantly inhibited the transformation to stem cells in, as well as the tumorigenicity of, CRC. Activation of Wnt/β‐catenin signaling by DVL1 increased pluripotent transcription factors, including c‐Myc, NANOG, and SOX2. Moreover, FUBP1 was upregulated at the post‐transcriptional level. Elevated FUBP1 levels in KRAS wild‐type CRC patients is due to the decrease in Smurf2, which promotes ubiquitin‐mediated degradation of FUBP1. In contrast, FUBP1 was upregulated in KRAS‐mutant patients through both inhibition of caspase 3‐dependent cleavage and decreased Smurf2. Our results demonstrate, for the first time, that FUBP1 is an oncogene, initiating the development of CSCs, as well as a new powerful endogenous Wnt‐signaling agonist that could provide an important prognostic factor and therapeutic target for metastasis in both KRAS‐mutant and wild‐type CRC.

Runt-related transcription factor 1 (Runx1) aggravates pathological cardiac hypertrophy by promoting p53 expression

Cardiac hypertrophy and the resultant heart failure are among the most common causes of morbidity and mortality worldwide; thus, identifying the key factor mediating pathological cardiac hypertrophy is critically important for developing the strategy to protect against heart failure. Runx1 (Runt‐related transcription factor 1) acts as an essential transcription factor that functions in a variety of cellular processes including differentiation, proliferation, tissue growth and DNA damage response. However, relatively little is known about the role of Runx1 in heart, especially cardiac hypertrophy and heart failure. In the present study, we investigated the role of Runx1 in experimentally pathological cardiac hypertrophy. The in vitro model was induced by Ang II exposure to cultured neonatal rat cardiomyocytes, and the in vivo pathological cardiac hypertrophy models were induced by chronic pressure overload in mice. Runx1 expression is increased in heart tissues from mice with pressure overload–induced cardiac hypertrophy and in neonatal rat cardiomyocytes in response to Ang II stimulation. Moreover, knockdown of cardiac Runx1 alleviates the pressure overload–induced cardiac hypertrophy. Mechanistically, Runx1 activates the p53 signalling by binding to the p53 gene and promotes its transcription. Rescue experiments indicate that Runx1 promotes cardiac hypertrophy in a p53‐dependent manner. Remarkably, we demonstrated that Ro5‐3335 (a Runx1 inhibitor) acts as a potential therapeutic drug for treating pathological cardiac hypertrophy. In summary, we conclude that Runx1 is a novel mediator and therapeutic target for pathological cardiac hypertrophy.

Silencing of the Long Non-Coding RNA TTN-AS1 Attenuates the Malignant Progression of Osteosarcoma Cells by Regulating the miR-16-1-3p/TFAP4 Axis

Objectives

Osteosarcoma (OS) is a type of bone malignancy. This study attempted to explore the effect of long non-coding RNA TTN-AS1 (TTN-AS1) on OS and to determine its molecular mechanisms.

Methods

The expression of TTN-AS1, microRNA-16-1-3p (miR-16-1-3p), and transcription factor activating enhancer binding protein 4 (TFAP4) in OS was assessed using qRT-PCR. The OS cell proliferation, migration, and invasion were measured using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound-healing, and transwell assays. N-cadherin and MMP-2 protein level was determined with western blot. Interactions between TTN-AS1 and miR-16-1-3p or TFAP4 and miR-16-1-3p were confirmed using the dual-luciferase reporter assay. Additionally, an OS xenograft tumor model was constructed to assess the effect of TTN-AS1 on tumor growth.

Results

TTN-AS1 and TFAP4 expression was increased in OS, while miR-16-1-3p expression was decreased. TTN-AS1 silencing restrained OS cell proliferation, migration, invasion, N-cadherin and MMP-2 protein expression, and hindered tumor growth. MiR-16-1-3p overexpression retarded the malignant behavior of OS cells. TTN-AS1 played a carcinostatic role by down-regulating miR-16-1-3p in the OS cells. Moreover, miR-16-1-3p inhibition or TFAP4 elevation weakened the suppressive effect of TTN-AS1 silencing on OS cell tumor progression.

Conclusion

TTN-AS1 promoted the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of OS cells via mediating the miR-16-1-3p/TFAP4 axis. TTN-AS1 may be a critical target for improving OS.

GWAS of allometric body-shape indices in UK Biobank identifies loci suggesting associations with morphogenesis, organogenesis, adrenal cell renewal and cancer

Genetic studies have examined body-shape measures adjusted for body mass index (BMI), while allometric indices are additionally adjusted for height. We performed the first genome-wide association study of A Body Shape Index (ABSI), Hip Index (HI) and the new Waist-to-Hip Index and compared these with traditional indices, using data from the UK Biobank Resource for 219,872 women and 186,825 men with white British ancestry and Bayesian linear mixed-models (BOLT-LMM). One to two thirds of the loci identified for allometric body-shape indices were novel. Most prominent was rs72959041 variant in RSPO3 gene, expressed in visceral adipose tissue and regulating adrenal cell renewal. Highly ranked were genes related to morphogenesis and organogenesis, previously additionally linked to cancer development and progression. Genetic associations were fewer in men compared to women. Prominent region-specific associations showed variants in loci VEGFA and HMGA1 for ABSI and KLF14 for HI in women, and C5orf67 and HOXC4/5 for ABSI and RSPO3, VEGFA and SLC30A10 for HI in men. Although more variants were associated with waist and hip circumference adjusted for BMI compared to ABSI and HI, associations with height had previously been reported for many of the additional variants, illustrating the importance of adjusting correctly for height.

OCT3/4 enhances tumor immune response by upregulating the TET1-dependent NRF2/MDM2 axis in bladder cancer

This study aimed to investigate the function of OCT3/4 on tumor immune escape in bladder cancer. Initially, the expression of OCT3/4, TET1, NRF2 and MDM2 was quantified in tumor tissues and cells, followed by gain- or loss-of-function studies to define their roles in cell migration, invasion and apoptosis and tumorigenicity in nude mice. Bladder cancer presented with abundant expression levels of OCT3/4, TET1, NRF2 and MDM2. We found that OCT3/4 promoted TET1 expression via binding to its promoter and that TET1 recruited MLL protein to NRF2 promoter and upregulated its expression, while NRF2 enhanced MDM2 expression. Upregulated MDM2 accelerated tumor immune escape in bladder cancer in mice. OCT3/4 knockdown suppressed the cell migration and invasion while inducing apoptosis, and consequently prevented tumor growth and immune escape in mice. Collectively, OCT3/4 may promote the progression of tumor immune escape in bladder cancer through acting as a promoter of the TET1/NRF2/MDM2 axis.

Tumor suppressor role of sFRP‑4 in hepatocellular carcinoma via the Wnt/β‑catenin signaling pathway

Hepatocellular carcinoma (HCC) is a malignant tumor located in the liver. Secreted frizzled-related protein 4 (sFRP-4) is associated with cancer occurrence, but the relationship between sFRP-4 and HCC is not completely understood. The present study aimed to investigate the role and mechanism underlying sFRP-4 in HCC. sFRP-4 mRNA expression levels were determined via reverse transcription-quantitative PCR and immunohistochemistry. The Cell Counting Kit-8 assay was performed to evaluate HCCLM3 and Huh7 cell viability. Moreover, HCCLM3 and Huh7 cell proliferation were assessed using the BrdU ELISA assay kit, and cell apoptosis was measured via flow cytometry. Western blotting was conducted to measure β-catenin and GSK-3β protein expression levels. The results demonstrated that sFRP-4 expression was significantly downregulated in HCC tissues and cells compared with adjacent healthy tissues and MIHA cells, respectively. Moreover, the results indicated that compared with the control group, sFRP-4 overexpression inhibited HCC cell viability and proliferation, and accelerated HCC cell apoptosis. Furthermore, the results suggested that sFRP-4 inhibited the Wnt/β-catenin signaling pathway by upregulating GSK-3β expression and downregulating β-catenin expression, thus restraining the malignant behavior of HCC cells. In conclusion, the present study indicated that sFRP-4 served a tumor suppressor role in HCC cells by restraining the Wnt/β-catenin signaling pathway.

MicroRNA-124 suppresses the invasion and proliferation of breast cancer cells by targeting TFAP4

MicroRNA (miRNA/miR)-124 is widely accepted as the suppressor of different tumors. The present study aimed to improve understanding of the potential role of miR-124 in breast cancer. The gene expression profile change derived from the overexpression of miR-124 was investigated using RNA sequencing and bioinformatics analysis of the breast cancer cell line SKBR3. The results demonstrated that the gene expression profile of SKBR3 cells significantly changed. In addition, the transcription factor activating enhancer-binding protein 4 (TFAP4) gene was identified among the top 10 differentially expressed genes, and was identified as a novel target gene of miR-124 using a dual-luciferase reporter assay. TFAP4 knockdown in notably impaired SKBR3 cell migration and proliferation, which was consistent with decreasing migration and proliferation ability following overexpression of miR-124. Taken together, these results suggest that overexpression of miR-124 can suppress the migration and proliferation of SKBR3 cells by tarsgeting TFAP4. Thus, TFAP4 may act as a novel therapeutic target of breast cancer.

Identification of novel human Wnt target genes using adult endodermal tissue-derived organoids

Canonical Wnt signaling plays a key role during organ development, homeostasis and regeneration and these processes are conserved between invertebrates and vertebrates. Mutations in Wnt pathway components are commonly found in various types of cancer. Upon activation of canonical Wnt signaling, β-catenin binds in the nucleus to members of the TCF-LEF family and activates the transcription of target genes. Multiple Wnt target genes, including Lgr5/LGR5 and Axin2/AXIN2, have been identified in mouse models and human cancer cell lines. Here we set out to identify the transcriptional targets of Wnt signaling in five human tissues using organoid technology. Organoids are derived from adult stem cells and recapitulate the functionality as well as the structure of the original tissue. Since the Wnt pathway is critical to maintain the organoids from the human intestine, colon, liver, pancreas and stomach, organoid technology allows us to assess Wnt target gene expression in a human wildtype situation. We performed bulk mRNA sequencing of organoids immediately after inhibition of Wnt pathway and identified 41 genes as commonly regulated genes in these tissues. We also identified large numbers of target genes specific to each tissue. One of the shared target genes is TEAD4, a transcription factor driving expression of YAP/TAZ signaling target genes. In addition to TEAD4, we identified a variety of genes which encode for proteins that are involved in Wnt-independent pathways, implicating the possibility of direct crosstalk between Wnt signaling and other pathways. Collectively, this study identified tissue-specific and common Wnt target gene signatures and provides evidence for a conserved role for these Wnt targets in different tissues.

Transcription Factor AP4 Mediates Cell Fate Decisions: To Divide, Age, or Die

Simple Summary

Here, we review the literature on Activating Enhancer-Binding Protein 4 (AP4)/transcription factor AP4 (TFAP4) function and regulation and its role in cancer. Elevated expression of AP4 was detected in tumors of various organs and is associated with poor patient survival. AP4 is encoded by a Myc target gene and mediates cell fate decisions by regulating multiple processes, such as cell proliferation, epithelial-mesenchymal transition, stemness, apoptosis, and cellular senescence. Thereby, AP4 may be critical for tumor initiation and progression. In this review article, we summarize published evidence showing how AP4 functions as a transcriptional activator and repressor of a plethora of direct target genes in various physiological and pathological conditions. We also highlight the complex interactions of AP4 with c-Myc, N-Myc, p53, lncRNAs, and miRNAs in feed-back loops, which control AP4 levels and mediate AP4 functions. In the future, a better understanding of AP4 may contribute to improved prognosis and therapy of cancer.

Abstract

Activating Enhancer-Binding Protein 4 (AP4)/transcription factor AP4 (TFAP4) is a basic-helix-loop-helix-leucine-zipper transcription factor that was first identified as a protein bound to SV40 promoters more than 30 years ago. Almost 15 years later, AP4 was characterized as a target of the c-Myc transcription factor, which is the product of a prototypic oncogene that is activated in the majority of tumors. Interestingly, AP4 seems to represent a central hub downstream of c-Myc and N-Myc that mediates some of their functions, such as proliferation and epithelial-mesenchymal transition (EMT). Elevated AP4 expression is associated with progression of cancer and poor patient prognosis in multiple tumor types. Deletion of AP4 in mice points to roles of AP4 in the control of stemness, tumor initiation and adaptive immunity. Interestingly, ex vivo AP4 inactivation results in increased DNA damage, senescence, and apoptosis, which may be caused by defective cell cycle progression. Here, we will summarize the roles of AP4 as a transcriptional repressor and activator of target genes and the contribution of protein and non-coding RNAs encoded by these genes, in regulating the above mentioned processes. In addition, proteins interacting with or regulating AP4 and the cellular signaling pathways altered after AP4 dysregulation in tumor cells will be discussed.

An integrated pan-cancer analysis of TFAP4 aberrations and the potential clinical implications for cancer immunity

Studies have shown that transcription factor activating enhancer binding protein 4 (TFAP4) plays a vital role in multiple types of cancer; however, the TFAP4 expression profile is still unknown, as is its value within the human pan‐cancer analysis. The present study comprehensively analysed TFAP4 expression patterns from 33 types of malignancies, along with the significance of TFAP4 for prognosis prediction and cancer immunity. TFAP4 displayed inconsistent levels of gene expression across the diverse cancer cell lines, and displayed abnormal expression within most malignant tumours, which closely corresponded to overall survival. More importantly, the TFAP4 level was also significantly related to the degree of tumour infiltration. TFAP4 was correlated using gene markers in tumour‐infiltrating immune cells and immune scores. TFAP4 expression was correlated with tumour mutation burden and microsatellite instability in different cancer types, and enrichment analyses identified TFAP4‐associated terms and pathways. The present study comprehensively analysed the expression of TFAP4 across 33 distinct types of cancers, which revealed that TFAP4 may possibly play a vital role during cancer formation and development. TFAP4 is related to differing degrees of immune infiltration within cancers, which suggests the potential of TFAP4 as an immunotherapy target in cancers. Our study demonstrated that TFAP4 plays an important role in tumorigenesis as a prognostic biomarker, which highlights the possibility of developing new targeted treatments.

Cucurbitacin E Chemosensitizes Colorectal Cancer Cells via Mitigating TFAP4/Wnt/β-Catenin Signaling

Chemoresistance and toxicity are the main obstacles that limit the efficacy of 5-fluorouracil (5-FU) in colorectal cancer (CRC) therapy. Hence, it is urgent to identify new adjuvants that can sensitize CRC cells to conventional chemotherapeutic approaches. Cucurbitacin E (CE) is a natural triterpenoid, widely distributed in dietary plants, and shows antitumor effects. Here, we report that CE enhances the sensitivity of CRC cells to chemotherapy via attenuating the expression of adenosine 5'-triphosphate (ATP)-binding cassette transporters ABCC1 and MDR1. Combined with CE-functionalized magnetite nanoparticles and gene ontology analysis, we found that CE-binding proteins may involve Wnt/β-catenin signaling. To validate the findings, β-catenin was upregulated in drug-resistant cell lines, and the synergistic effects of CE and chemotherapeutics were accompanied by the downregulation of β-catenin. Moreover, TFAP4 was identified as an intracellular target of CE. Remarkably, the combination of CE and 5-FU treatment attenuated β-catenin, MDR1, and ABCC1 expressions, while TFAP4 overexpression reversed their expressions by 2.68 ± 0.46-, 0.72 ± 0.44-, and 0.93 ± 0.21-fold, respectively. Thus, our results indicate that CE sensitizes CRC cells to chemotherapy by decreasing the TFAP4/Wnt/β-catenin signaling, suggesting that the dietary compound CE can be used as a chemosensitizing adjuvant for CRC treatment.

Tissue and sex-specific programming of DNA methylation by perinatal lead exposure: implications for environmental epigenetics studies

Early developmental environment can influence long-term health through reprogramming of the epigenome. Human environmental epigenetics studies rely on surrogate tissues, such as blood, to assess the effects of environment on disease-relevant but inaccessible target tissues. However, the extent to which environment-induced epigenetic changes are conserved between these tissues is unclear. A better understanding of this conservation is imperative for effective design and interpretation of human environmental epigenetics studies. The Toxicant Exposures and Responses by Genomic and Epigenomic Regulators of Transcription (TaRGET II) consortium was established by the National Institute of Environmental Health Sciences to address the utility of surrogate tissues as proxies for toxicant-induced epigenetic changes in target tissues. We and others have recently reported that perinatal exposure to lead (Pb) is associated with adverse metabolic outcomes. Here, we investigated the sex-specific effects of perinatal exposure to a human environmentally relevant level of Pb on DNA methylation in paired liver and blood samples from adult mice using enhanced reduced-representation bisulphite sequencing. Although Pb exposure ceased at 3 weeks of age, we observed thousands of sex-specific differentially methylated cytosines in the blood and liver of Pb-exposed animals at 5 months of age, including 44 genomically imprinted loci. We observed significant tissue overlap in the genes mapping to differentially methylated cytosines. A small but significant subset of Pb-altered genes exhibit basal sex differences in gene expression in the mouse liver. Collectively, these data identify potential molecular targets for Pb-induced metabolic diseases, and inform the design of more robust human environmental epigenomics studies.

WNT/β-catenin signaling in the development of liver cancers

The WNT/β-catenin signaling pathway is a highly conserved and tightly controlled molecular mechanism that regulates embryonic development, cellular proliferation and differentiation. Of note, accumulating evidence has shown that the aberrant of WNT/β-catenin signaling promotes the development and/or progression of liver cancer, including hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), the two most prevalent primary liver tumours in adults. There are two different WNT signaling pathways have been identified, which were termed non-canonical and canonical pathways, the latter involving the activation of β-catenin. β-catenin, acting as an intracellular signal transducer in the WNT signaling pathway, is encoded by CTNNB1 and plays a critical role in tumorigenesis. In the past research, most liver tumors have mutations in genes encoding key components of the WNT/β-catenin signaling pathway. In addition, several of other signaling pathways also can crosswalk with β-catenin. In this review, we discuss the most relevant molecular mechanisms of action and regulation of WNT/β-catenin signaling in the development and pathophysiology of liver cancers, as well as in the development of therapeutics.

Dermatopontin inhibits WNT signaling pathway via CXXC finger protein 4 in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of tumor associated deaths globally. Annually, the prevalence of HCC is increasing and the lack of early prognostic indicators manifests a dismal prognosis for HCC patients. A deep understanding of the molecular events that promote HCC progression are required for the design of new diagnostics and therapeutics. Dermatopontin (DPT) is an extracellular matrix protein that regulates the metastatic phenotypes of many cancers. However, the effects of DPT on HCC cell growth remain undefined. In this study, we demonstrate that the exogenous expression of DPT inhibits HCC cell growth both in vitro and in vivo. Furthermore, we show that DPT regulates CXXC4, which in turn targets c-Myc, EZH2, SOX2 and β-catenin, through its ability to impact Wnt signaling pathway. These data suggest that DPT regulates CXXC4, c-Myc, EZH2, SOX2 and β-catenin, through Wnt signaling to repress HCC proliferation. This highlights DPT as promising target for future HCC diagnostics and therapeutic targets.

MiR-429 suppresses proliferation and invasion of breast cancer via inhibiting the Wnt/β-catenin signaling pathway

Background

microRNAs (miRNAs) have been verified as molecular targets for regulating tumor proliferation, invasion, and metastasis in tumor progression. However, the relationship between miRNAs and cellular energy metabolism in breast cancer still needs to be clarified. This study aimed to investigate the role of miR‐429 in breast cancer progression.

Methods

Bioinformatic analyses were employed to detect the relationship between miR‐429 and cancer‐related signaling pathways. We used a Kaplan‐Meier curve to analyze survival rate in patients with high or low expression of miR‐429. We used real‐time quantitative PCR (RT‐qPCR) to detect the expression of miR‐429 in different cell lines. Sh‐con, over‐miR‐429, miR‐429 inhibitor, and sh‐inhibitor control were transfected. Colony formation and EDU assay were used to detect the proliferation of transfected cells. Wound healing and transwell assays were performed to detect the mobility and invasion ability of transfected cells. Western blot assay was used to detect relative protein expression in transfected cells and different tissues. Bioinformatic analyses were conducted to detect the target proteins expression in different breast cancer databases. Dual luciferase reporter assay was used to confirm the binding site between miR‐429 and fibronectin 1 (FN1).

Results

The results of our study indicate that MiR‐429 and its target genes are associated with cancer‐related signaling pathways and that higher miR‐429 expression corresponds with a better prognosis. When miR‐429 was overexpressed, the proliferation, invasion of MDA‐MB‐231 were inhibited. MiR‐429 was able to suppress the Wnt/β‐catenin signaling pathway, and FN1 overexpression could rescue the influence of over‐miR‐429.

Conclusions

The results of our study suggest that miR‐429 suppresses the proliferation and invasion of breast cancer via inhibiting the Wnt/β‐catenin signaling pathway.

Restoration of RNA helicase DDX5 suppresses hepatitis B virus (HBV) biosynthesis and Wnt signaling in HBV-related hepatocellular carcinoma

Rationale: RNA helicase DDX5 is downregulated during hepatitis B virus (HBV) replication, and poor prognosis HBV-related hepatocellular carcinoma (HCC). The aim of this study is to determine the mechanism and significance of DDX5 downregulation for HBV-driven HCC, and identify biologics to prevent DDX5 downregulation. Methods: Molecular approaches including immunoblotting, qRT-PCR, luciferase transfections, hepatosphere assays, Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), and RNA-seq were used with cellular models of HBV replication, HBV infection, and HBV-related liver tumors, as well as bioinformatic analyses of liver cancer cells from two independent cohorts. Results: We demonstrate that HBV infection induces expression of the proto-oncogenic miR17~92 and miR106b~25 clusters which target the downregulation of DDX5. Increased expression of these miRNAs is also detected in HBV-driven HCCs exhibiting reduced DDX5 mRNA. Stable DDX5 knockdown (DDX5^KD) in HBV replicating hepatocytes increased viral replication, and resulted in hepatosphere formation, drug resistance, Wnt activation, and pluripotency gene expression. ATAC-seq of DDX5^KD compared to DDX5 wild-type (WT) cells identified accessible chromatin regions enriched in regulation of Wnt signaling genes. RNA-seq analysis comparing WT versus DDX5^KD cells identified enhanced expression of multiple genes involved in Wnt pathway. Additionally, expression of Disheveled, DVL1, a key regulator of Wnt pathway activation, was significantly higher in liver cancer cells with low DDX5 expression, from two independent cohorts. Importantly, inhibitors (antagomirs) to miR17~92 and miR106b~25 restored DDX5 levels, reduced DVL1 expression, and suppressed both Wnt activation and viral replication. Conclusion : DDX5 is a negative regulator of Wnt signaling and hepatocyte reprogramming in HCCs. Restoration of DDX5 levels by miR17~92 / miR106b~25 antagomirs in HBV-infected patients can be explored as both antitumor and antiviral strategy.