Translational downregulation of Twist1 expression by antiproliferative gene, B-cell translocation gene 2, in the triple negative breast cancer cells

LncRNAs as nodes for the cross-talk between autophagy and Wnt signaling in pancreatic cancer drug resistance

Pancreatic cancer is a malignancy with high mortality. In addition to the few symptoms until the disease reaches an advanced stage, the high fatality rate is attributed to its rapid development, drug resistance and lack of appropriate treatment. In the selection and research of therapeutic drugs, gemcitabine is the first-line drug for pancreatic cancer. Solving the problem of gemcitabine resistance in pancreatic cancer will contribute to the progress of pancreatic cancer treatment. Long non coding RNAs (lncRNAs), which are RNA transcripts longer than 200 nucleotides, play vital roles in cellular physiological metabolic activities. Currently, our group and others have found that some lncRNAs are aberrantly expressed in pancreatic cancer cells, which can regulate the process of cancer through autophagy and Wnt/β-catenin pathways simultaneously and affect the sensitivity of cancer cells to therapeutic drugs. This review presents an overview of the recent evidence concerning the node of lncRNA for the cross-talk between autophagy and Wnt/β-catenin signaling in pancreatic cancer, together with the practicability of lncRNAs and the core regulatory factors as targets in therapeutic resistance.

Combination treatment of T1-44, a PRMT5 inhibitor with Vactosertib, an inhibitor of TGF-β signaling, inhibits invasion and prolongs survival in a mouse model of pancreatic tumors

Pancreatic ductal adenocarcinoma (PDAC) is the most lethal type of cancer and the third leading cause of cancer death with the lowest 5-year survival rate. Heterogeneity, difficulty in diagnosis, and rapid metastatic progression are the causes of high mortality in pancreatic cancer. Recent studies have shown that Protein arginine methyltransferase 5 (PRMT5) is overexpressed in pancreatic cancers, and these patients have a worse prognosis. Recently, PRMT5 as an anti-cancer target has gained considerable interest. In this study, we investigated whether inhibition of PRMT5 activity was synergistic with blockade of TGF-β1 signaling, which plays an important role in the construction of the desmoplastic matrix in pancreatic cancer and induces therapeutic vulnerability. Compared with T1-44, a selective inhibitor of PRMT5 activity, the combination of T1-44 with the TGF-β1 signaling inhibitor Vactosertib significantly reduced tumor size and surrounding tissue invasion and significantly improved long-term survival. RNA sequencing analysis of mouse tumors revealed that the combination of T1-44 and Vactosertib significantly altered the expression of genes involved in cancer progression, such as cell migration, extracellular matrix, and apoptotic processes. In particular, the expression of Btg2, known as a tumor suppressor factor in various cancers, was markedly induced by combination treatment. Ectopic overexpression of Btg2 inhibited the EMT response, blocking cell migration, and promoted cancer cell death. These data demonstrate that the combination therapy of T1-44 with Vactosertib is synergistic for pancreatic cancer, suggesting that this novel combination therapy has value in the treatment strategy of patients with pancreatic cancer.

Triptonide effectively inhibits triple-negative breast cancer metastasis through concurrent degradation of Twist1 and Notch1 oncoproteins

Background

Triple-negative breast cancer (TNBC) is highly metastatic and lethal. Due to a lack of druggable targets for this disease, there are no effective therapies in the clinic.

Methods

We used TNBC cells and xenografted mice as models to explore triptonide-mediated inhibition of TNBC metastasis and tumor growth. Colony formation assay was used to quantify the tumorigenesis of TNBC cells. Wound-healing and cell trans-well assays were utilized to measure cell migration and invasion. Tube formation assay was applied to access tumor cell-mediated vasculogenic mimicry. Western blot, quantitative-PCR, immunofluorescence imaging, and immunohistochemical staining were used to measure the expression levels of various tumorigenic genes in TNBC cells.

Results

Here, we showed that triptonide, a small molecule from the traditional Chinese medicinal herb Tripterygium wilfordii Hook F, potently inhibited TNBC cell migration, invasion, and vasculogenic mimicry, and effectively suppressed TNBC tumor growth and lung metastasis in xenografted mice with no observable toxicity. Molecular mechanistic studies revealed that triptonide strongly triggered the degradation of master epithelial-mesenchymal transition (EMT)-inducing protein Twist1 through the lysosomal system and reduced Notch1 expression and NF-κB phosphorylation, which consequently diminished the expression of pro-metastatic and angiogenic genes N-cadherin, VE-cadherin, and vascular endothelial cell growth factor receptor 2 (VEGFR2).

Conclusions

Triptonide effectively suppressed TNBC cell tumorigenesis, vasculogenic mimicry, and strongly inhibited the metastasis of TNBC via degradation of Twist1 and Notch1 oncoproteins, downregulation of metastatic and angiogenic gene expression, and reduction of NF-κB signaling pathway. Our findings provide a new strategy for treating highly lethal TNBC and offer a potential new drug candidate for combatting this aggressive disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01488-7.

Cyclophilin A regulates A549 cells apoptosis via stabilizing Twist1 protein

Cyclophilin A (CypA) is an essential member of the immunophilin family. As an intracellular target of immunosuppressive drug cyclosporin A (CsA) or a peptidyl-prolyl cis/trans isomerase (PPIase), it catalyzes the cis-trans isomerization of proline amidic peptide bonds, through which, it regulates a variety of biological processes, such as intracellular signaling, transcription, and apoptosis. In this study, we found that intracellular CypA enhanced Twist1 phosphorylation at Ser68 and inhibited apoptosis in A549 cells. Mechanistically, CypA could mediate the phosphorylation of Twist1 at Ser68 via p38 MAPK, which inhibited its ubiquitination-mediated degradation. In addition, CypA increased Twist-p65 interaction and nuclear accumulation, which regulated Twist1-dependent expression of CDH1 and CDH2. Our findings collectively indicated the role of CypA in Twist1-mediated A549 cells apoptosis through stabilizing Twist1 protein.

The emerging role of RNA N6-methyladenosine methylation in breast cancer

N6-methyladenosine (m6A) modification is the most prevalent internal mRNA modification and is involved in many biological processes in eukaryotes. Accumulating evidence has demonstrated that m6A may play either a promoting or suppressing role in breast cancer, including in tumorigenesis, metastasis and angiogenesis. In this review, we summarize the latest research progress on the biological function and prognostic value of m6A modification in breast cancer, as well as potential related therapeutic strategies.

Genome-wide translation patterns in gliomas: An integrative view

Gliomas are the most frequent tumors of the central nervous system (CNS) and include the highly malignant glioblastoma (GBM). Characteristically, gliomas have translational control deregulation related to overactivation of signaling pathways such as PI3K/AKT/mTORC1 and Ras/ERK1/2. Thus, mRNA translation appears to play a dominant role in glioma gene expression patterns. The, analysis of genome-wide translated transcripts, together known as the translatome, may reveal important information for understanding gene expression patterns in gliomas. This review provides a brief overview of translational control mechanisms altered in gliomas with a focus on the current knowledge related to the translatomes of glioma cells and murine glioma models. We present an integrative meta-analysis of selected glioma translatome data with the aim of identifying recurrent patterns of gene expression preferentially regulated at the level of translation and obtaining clues regarding the pathological significance of these alterations. Re-analysis of several translatome datasets was performed to compare the translatomes of glioma models with those of their non-tumor counterparts and to document glioma cell responses to radiotherapy and MNK modulation. The role of recurrently altered genes in the context of translational control and tumorigenesis are discussed.

LncRNA XIST Inhibits the Progression of Oral Squamous Cell Carcinoma via Sponging miR-455-3p/BTG2 Axis

Objective

Oral squamous cell carcinoma (OSCC) is one of the most common cancers, accounting for over 90% of malignant lesions in the oral cavity. Long non-coding RNAs play an important role in the development of OSCC. This study aimed to investigate the effects of lncRNA XIST on the malignant behaviors of OSCC cells and its possible molecular mechanisms.

Methods

Real-time quantitative PCR and Western blot were used to detect the RNA and protein level, respectively. CAL27 and SCC25 cells with the lowest expression level of XIST were used for further study. MTT, transwell assay, colony formation, and xenograft model were applied to examine the effect of XIST on the progression of OSCC. FISH assay was performed to investigate the co-location of XIST and miR-455-3p in OSCC cells. The bioinformatics analysis, luciferase, and RNA pull down assay were utilized to predict and verify the target genes of miR-455-3p.

Results

XIST was downregulated in OSCC tissues and cell lines. Overexpression of XIST inhibited the proliferation, migration, and invasion ability of OSCC cells. Bioinformatics analysis and luciferase reporter assay confirmed XIST could bind to miR-455-3p. Besides, miR-455-3p directly targeted BTG2 in OSCC cells. Rescue experiments further confirmed the positive interaction between miR-455-3p and XIST as well as between miR-455-3p and BTG2.

Conclusion

XIST was down-regulated in OSCC. XIST regulated the expression of BTG2 via sponging miR-455-3p. XIST/miR-455-3p/BTG2 signal axis inhibited the malignant progression of OSCC.

Roles of eIF3m in the tumorigenesis of triple negative breast cancer

Background

Without targets, triple negative breast cancer (TNBC) has the worst prognosis in all subtypes of breast cancer (BC). Recently, eukaryotic translation initiation factor 3 m (eIF3m) has been declared to be involved in the malignant progression of various neoplasms. The aim of this study is to explore biological functions of eIF3m in TNBC.

Methods

Multiple databases, including Oncomine, KM-plotter and so on, were performed to analyze prognosis and function of eIF3m in TNBC. After transfection of eIF3m-shRNA lentivirus, CCK-8, colony formation assay, cell cycle analysis, wound healing assay, transwell assays, mitochondrial membrane potential assay and cell apoptosis analysis were performed to explore the roles of eIF3m in TNBC cell bio-behaviors. In addition, western blotting was conducted to analyze the potential molecular mechanisms of eIF3m.

Results

In multiple databases, up-regulated eIF3m had lower overall survival, relapse-free survival and post progression survival in BC. EIF3m expression in TNBC was obviously higher than in non-TNBC or normal breast tissues. Its expression in TNBC was positively related to differentiation, lymph node invasion and distant metastasis. After knockdown of eIF3m, cell proliferation, migration, invasion and levels of mitochondrial membrane potential of MDA-MB-231 and MDA-MB-436 were all significantly suppressed, while apoptosis rates of them were obviously increased. In addition, eIF3m could regulate cell-cycle, epithelial–mesenchymal transition and apoptosis-related proteins. Combined with public databases and RT-qPCR, 14 genes were identified to be modulated by eIF3m in the development of TNBC.

Conclusions

eIF3m is an unfavorable indicator of TNBC, and plays a vital role in the process of TNBC tumorigenesis.

CircZNF609/miR-134-5p/BTG-2 axis regulates proliferation and migration of glioma cell

Objectives

MicroRNAs are abundant in eukaryotic cells and play key roles in cancers. Circular RNAs (CircRNAs) served as the competing endogenous RNAs (ceRNAs) in mediating multiple cell processes. This study aims to define the role of CircRNA CircZNF609/miR-134-5p in glioma as well as the underlying regulating mechanism.

Methods

Relative expression of miR-134-5p, CircZNF609 and BTG-2 mRNA was determined by quantitative real-time PCR. Cell proliferation was analysed by CCK-8 assay. Cell migration was assessed by cell wound scratch assay. The direct regulatory of miR-134-5p on BTG-2 and CircZNF609 was verified by luciferase report gene assay.

Key findings

MiR-134-5p was significantly upregulated in glioma cells. The overexpression of miR-134-5p inhibited cell proliferation and migration of glioma cell U251 and U87. Reversely, knock-down of miR-134-5p enhanced cell proliferation and migration. Both BTG-2 and CircZNF609 are the direct targets of miR-134-5p, and their expression could be negatively regulated by miR-134-5p. CircZNF609 was significantly upregulated in U251 and U87 cells and acted as an oncogene to promote cell proliferation and cell migration of glioma cell U251 and U87.

Conclusions

These data proved that CircZNF609 served as a competing RNA to bind miR-134-5p that promoted BTG-2 expression leading to reduced proliferation and migration of glioma cell.