SNAI1 Promotes the Cholangiocellular Phenotype, but not Epithelial-Mesenchymal Transition, in a Murine Hepatocellular Carcinoma Model

Cyanidin-3-O-Glucoside Induces the Apoptosis of Human Gastric Cancer MKN-45 Cells through ROS-Mediated Signaling Pathways

Cyanidin-3-O-glucoside (C3G), an active ingredient in anthocyanins, mainly exists in dark cereals. C3G was investigated for its effect on human gastric cancer (GC) cells, together with its molecular mechanism. The CCK-8 assay results showed that C3G had significant antiproliferative effects on GC cells, but it had little effect on normal cells. Western blot and flow cytometry results showed that C3G regulated the reduction of mitochondrial membrane potential and arrested the cell cycle in the G2/M phase through the AKT signaling pathway, causing the cells to undergo apoptosis. Additionally, in MKN-45 cells, C3G markedly raised intracellular reactive oxygen species (ROS) levels. The wound healing assay and Transwell assay results showed that MKN-45 cell migration was significantly inhibited. Western blot results showed that the expression of E-cadherin protein was upregulated and the expressions of β-catenin, N-cadherin, and Vimentin were downregulated. Additionally, following N-acetylcysteine treatment, the expression levels of these proteins were reduced. In conclusion, C3G caused MKN-45 cells to undergo apoptosis; arrested the cell cycle in the G2/M phase; hindered cell migration; and activated the MAPK, STAT3, and NF-κB signaling pathways, by inducing an increase in ROS levels. Thus, C3G may be a promising new medication for the treatment of GC.

MiR-23b-3p suppresses epithelial-mesenchymal transition, migration, and invasion of hepatocellular carcinoma cells by targeting c-MET

Background

Aberrant expression of c-MET is known to be associated with tumor recurrence and metastasis by promoting cell proliferation, epithelial-mesenchymal transition (EMT), and migration in hepatocellular carcinoma (HCC). Recently, miR-23b-3p has been identified as a tumor suppressor, but detailed role of miR-23b-3p in HCC is still unclear. Our study aimed to investigate how miR-23b-3p is associated with the malignant potential of HCC cells.

Methods

HCC tissues and their adjacent non-tumor tissues were acquired from 30 patients with HCC. Expression of EMT- or stemness-related genes were examined in the two HCC cell lines. Migration of HCC cells was analyzed using transwell and wound healing assays.

Results

c-MET was overexpressed in HCC tissues compared to the adjacent non-tumor tissues. c-MET knockdown inhibited EMT and reduced migration and invasion of HCC cells. Furthermore, c-MET was a target of miR-23b-3p, and miR-23b-3p expression was decreased in HCC tissues compared to non-tumor tissues. Treatment of miR-23b-3p inhibitor in HCC cells promoted EMT, cell migration, and invasion. In contrast, miR-23b-3p overexpression suppressed EMT, cell migration, and invasion, concomitantly reducing c-MET expression. Transfection of miR-23b-3p inhibitor with concomitant c-MET knockdown mitigated the effects of miR-23b-3p inhibitor on EMT in HCC cells. In addition, transforming growth factor beta1 (TGF-β1) stimulation after miR-23b-3p overexpression induced neither the mesenchymal phenotype nor migratory property of HCC cells.

Conclusion

In this study, we confirmed that miR-23b-3p downregulation significantly increased EMT, migration, and invasion of HCC cells. In addition, c-MET was confirmed to be a target of miR-23b-3p in HCC cells and regulated the functional effects of miR-23b-3p. These results suggest that miR-23b-3p can be used as a prognostic biomarker and candidate target for HCC treatment.

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c-MET is a target of miR-23b-3p and overexpressed in HCC tissues.

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MiR-23b-3p expression was decreased in HCC tissues compared to non-tumor tissues.

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Inhibition of miR-23b-3p induced migration and invasion via EMT in HCC cells.

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MiR-23b-3p/c-MET axis may serve as a therapeutic target for HCC.

DYRK1A reinforces epithelial-mesenchymal transition and metastasis of hepatocellular carcinoma via cooperatively activating STAT3 and SMAD

Background

Hepatocellular carcinoma (HCC) accounts for the majority of liver cancer cases, while metastasis is considered the leading cause of HCC-related death. However, the currently available treatment strategies for efficient suppression of metastasis are limited. Therefore, novel therapeutic targets to inhibit metastasis and effectively treat HCC are urgently required.

Methods

Wound healing and Transwell assays were used to determine the migration and invasion abilities of HCC cells in vitro. Quantitative real-time PCR (qRT-PCR), protein array, immunofluorescence, and immunoprecipitation experiments were used to study the mechanism of DYRK1A-mediated metastasis. A tail vein metastasis model and H&E staining were utilized to assess metastatic potential in vivo.

Results

The results of the current study demonstrated that dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) was upregulated in HCC tissues compared with normal liver tissues. Additionally, the level of DYRK1A was increased in primary HCC tissues of patients with metastasis compared with those of patients without metastasis, and DYRK1A overexpression correlated with worse outcomes in liver cancer patients. Gain- and loss-of-function studies suggested that DYRK1A enhanced the invasion and migration abilities of HCC cells by promoting epithelial-mesenchymal transition (EMT). Regarding the promoting effect of DYRK1A on cell invasion, the results showed that DYRK1A was coexpressed with TGF-β/SMAD and STAT3 signalling components in clinical tumour samples obtained from patients with HCC. DYRK1A also activated TGF-β/SMAD signalling by interacting with tuberous sclerosis 1 (TSC1) and enhanced metastasis of HCC cells by activating STAT3. Furthermore, DYRK1A promoted EMT by cooperatively activating STAT3/SMAD signalling.

Conclusion

Overall, the present study not only uncovered the promoting effect of DYRK1A on HCC metastasis and revealed the mechanism but also provided a new approach to predict and treat metastatic HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00817-y.

Notch signaling in the pathogenesis, progression and identification of potential targets for cholangiocarcinoma (Review)

Cholangiocarcinoma (CCA) is an aggressive type of bile duct cancer that is characterized by a high mortality rate due to its late diagnosis and ineffective treatment. The aim of the present systematic review was to analyze the association between Notch signaling and CCA in terms of its pathogenesis, progression and potential treatment targets. Relevant information was gathered from the PubMed, ScienceDirect and Scopus databases using the search terms 'cholangiocarcinoma' AND 'Notch signaling'. Of the 90 articles identified, 28 fulfilled the eligibility criteria and were included in the analysis. It was concluded that overexpression/upregulation of Notch ligands, such as Jagged1 and Notch receptors (Notch1, Notch2 and Notch3), as well as upregulation of the upstream Notch signaling pathway, promoted CCA development and progression. In addition, downregulation of Notch1 signaling through several possible interventions appears to be a promising strategy for inhibition of CCA development and progression. Therefore, the Notch signaling pathway may be considered as a potential target for CCA control.

18β-Glycyrrhetinic Acid Has Anti-Cancer Effects via Inducing Apoptosis and G2/M Cell Cycle Arrest, and Inhibiting Migration of A549 Lung Cancer Cells

Background

18β-glycyrrhetinic acid (18β-Gly), which is extracted from licorice root, has various pharmacological properties; however, its anti-cancer effects on lung cancer cells have not been fully established.

Purpose

In this study, we investigated the underlying molecular mechanisms of 18β-Gly.

Results

Our results showed that 18β-Gly had significant cytotoxic effects and no apparent side effects. 18β-Gly induced mitochondria-dependent apoptosis of A549 lung cancer cells. In addition, after treatment with 18β-Gly, intracellular reactive oxygen species (ROS) levels were significantly increased, and G2/M cell cycle arrest and inhibition of cell migration were induced via the mitogen-activated protein kinase (MAPK)/signal transducer and activator of transcription 3 (STAT3)/nuclear factor kappa (NF-κB) signaling pathways. After pretreatment with the ROS scavenger N-acetyl-L-cysteine or MAPK inhibitors, the expression levels of phosphorylated p38 (p-p38), phosphorylated c-Jun N-terminal kinase, inhibitor of nuclear factor kappa B, cleaved caspase-3 (cle-cas-3), cleaved poly (ADP ribose) polymerase (cle-PARP), p-p53, p27, p21, and E-cadherin were decreased; and levels of phosphorylated extracellular signal-regulated kinase, p-STAT3, NF-κB, Bcl-2, cyclin B1, cyclase-dependent kinase 1/2 (CDK1/2), N-cadherin, vimentin, and snail homolog 1 (SNAI 1) were increased. In addition, the percentage of cells in the G2/M phase was decreased, and inhibition of migration was reduced.

Conclusion

In summary, 18β-Gly induced apoptosis and G2/M cell cycle arrest and inhibited migration via the ROS/MAPK/STAT3/NF-κB signaling pathways in A549 lung cancer cells. Therefore, 18β-Gly is a novel promising candidate for the treatment of lung cancer.

Long-Term Hypoxia Maintains a State of Dedifferentiation and Enhanced Stemness in Fetal Cardiovascular Progenitor Cells

Early-stage mammalian embryos survive within a low oxygen tension environment and develop into fully functional, healthy organisms despite this hypoxic stress. This suggests that hypoxia plays a regulative role in fetal development that influences cell mobilization, differentiation, proliferation, and survival. The long-term hypoxic environment is sustained throughout gestation. Elucidation of the mechanisms by which cardiovascular stem cells survive and thrive under hypoxic conditions would benefit cell-based therapies where stem cell survival is limited in the hypoxic environment of the infarcted heart. The current study addressed the impact of long-term hypoxia on fetal Islet-1+ cardiovascular progenitor cell clones, which were isolated from sheep housed at high altitude. The cells were then cultured in vitro in 1% oxygen and compared with control Islet-1+ cardiovascular progenitor cells maintained at 21% oxygen. RT-PCR, western blotting, flow cytometry, and migration assays evaluated adaptation to long term hypoxia in terms of survival, proliferation, and signaling. Non-canonical Wnt, Notch, AKT, HIF-2α and Yap1 transcripts were induced by hypoxia. The hypoxic niche environment regulates these signaling pathways to sustain the dedifferentiation and survival of fetal cardiovascular progenitor cells.

Overexpression of Mothers Against Decapentaplegic Homolog 7 Activates the Yes-Associated Protein/NOTCH Cascade and Promotes Liver Carcinogenesis in Mice and Humans

BACKGROUND AND AIMS

Mothers against decapentaplegic homolog (SMAD) 7 is an antagonist of TGF-β signaling. In the present investigation, we sought to determine the relevance of SMAD7 in liver carcinogenesis using in vitro and in vivo approaches.

APPROACH AND RESULTS

We found that SMAD7 is up-regulated in a subset of human HCC samples with poor prognosis. Gene set enrichment analysis revealed that SMAD7 expression correlates with activated yes-associated protein (YAP)/NOTCH pathway and cholangiocellular signature genes in HCCs. These findings were substantiated in human HCC cell lines. In vivo, overexpression of Smad7 alone was unable to initiate HCC development, but it significantly accelerated c-Myc/myeloid cell leukemia 1 (MCL1)-induced mouse HCC formation. Consistent with human HCC data, c-Myc/MCL1/Smad7 liver tumors exhibited an increased cholangiocellular gene expression along with Yap/Notch activation and epithelial-mesenchymal transition (EMT). Intriguingly, blocking of the Notch signaling did not affect c-Myc/MCL1/Smad7-induced hepatocarcinogenesis while preventing cholangiocellular signature expression and EMT, whereas ablation of Yap abolished c-Myc/MCL1/Smad7-driven HCC formation. In mice overexpressing a myristoylated/activated form of AKT, coexpression of SMAD7 accelerated carcinogenesis and switched the phenotype from HCC to intrahepatic cholangiocarcinoma (iCCA) lesions. In human iCCA, SMAD7 expression was robustly up-regulated, especially in the most aggressive tumors, and directly correlated with the levels of YAP/NOTCH targets as well as cholangiocellular and EMT markers.

CONCLUSIONS

The present data indicate that SMAD7 contributes to liver carcinogenesis by activating the YAP/NOTCH signaling cascade and inducing a cholangiocellular and EMT signature.

The Hippo Effector Transcriptional Coactivator with PDZ-Binding Motif Cooperates with Oncogenic β-Catenin to Induce Hepatoblastoma Development in Mice and Humans

Hepatoblastoma (HB) is the most common pediatric liver tumor. Though Wnt/β-catenin and Hippo cascades are implicated in HB development, studies on crosstalk between β-catenin and Hippo downstream effector transcriptional coactivator with PDZ-binding motif (TAZ) in HB are lacking. Expression levels of TAZ and β-catenin in human HB specimens were assessed by immunohistochemistry. Functional interplay between TAZ and β-catenin was determined by overexpression of an activated form of TAZ (TAZS89A), either alone or combined with an oncogenic form of β-catenin (ΔN90-β-catenin), in mouse liver via hydrodynamic transfection. Activation of TAZ often co-occurred with that of β-catenin in clinical specimens. Although the overexpression of TAZS89A alone did not induce hepatocarcinogenesis, concomitant overexpression of TAZS89A and ΔN90-β-catenin triggered the development of HB lesions exhibiting both epithelial and mesenchymal features. Mechanistically, TAZ/β-catenin-driven HB development required TAZ interaction with transcriptional enhanced associate domain factors. Blockade of the Notch cascade did not inhibit TAZ/β-catenin-dependent HB formation in mice but suppressed the mesenchymal phenotype. Neither Yes-associated protein nor heat shock factor 1 depletion affected HB development in TAZ/β-catenin mice. In human HB cell lines, silencing of TAZ resulted in decreased cell growth, which was further reduced when TAZ knockdown was associated with suppression of either β-catenin or Yes-associated protein. Overall, our study identified TAZ as a crucial oncogene in HB development and progression.

Effect of Diphtheria Toxin-Based Gene Therapy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a major global malignancy, responsible for >90% of primary liver cancers. Currently available therapeutic options have poor performances due to the highly heterogeneous nature of the tumor cells; recurrence is highly probable, and some patients develop resistances to the therapies. Accordingly, the development of a novel therapy is essential. We assessed gene therapy for HCC using a diphtheria toxin fragment A (DTA) gene-expressing plasmid, utilizing a non-viral hydrodynamics-based procedure. The antitumor effect of DTA expression in HCC cell lines (and alpha-fetoprotein (AFP) promoter selectivity) is assessed in vitro by examining HCC cell growth. Moreover, the effect and safety of the AFP promoter-selective DTA expression was examined in vivo using an HCC mice model established by the hydrodynamic gene delivery of the yes-associated protein (YAP)-expressing plasmid. The protein synthesis in DTA transfected cells is inhibited by the disappearance of tdTomato and GFP expression co-transfected upon the delivery of the DTA plasmid; the HCC cell growth is inhibited by the expression of DTA in HCC cells in an AFP promoter-selective manner. A significant inhibition of HCC occurrence and the suppression of the tumor marker of AFP and des-gamma-carboxy prothrombin can be seen in mice groups treated with hydrodynamic gene delivery of DTA, both 0 and 2 months after the YAP gene delivery. These results suggest that DTA gene therapy is effective for HCC.