Lipid raft-mediated miR-3908 inhibition of migration of breast cancer cell line MCF-7 by regulating the interactions between AdipoR1 and Flotillin-1

FLOT1 promotes gastric cancer progression and metastasis through BCAR1/ERK signaling

Flotillin-1 (FLOT1) is a member of the flotillin family and serves as a hallmark of lipid rafts involved in the process of signaling transduction and vesicular trafficking. Here, we find FLOT1 promotes gastric cancer cell progression and metastasis by interacting with BCAR1, through ERK signaling. FLOT1 regulates BCAR1 phosphorylation and translocation. Overexpression of FLOT1 increases, while knockdown of FLOT1 decreases gastric cancer cell proliferation, migration and invasion. BCAR1 knockdown could block FLOT1 induced gastric cancer cell proliferation, migration and invasion. Re-expression of wildtype rather than mutant BCAR1 (Y410F) could partially restore FLOT1 knockdown induced gastric cancer cell migration and invasion, while the restore could be inhibited by ERK inhibitor. Furthermore, FLOT1 and BCAR1 expression is closely related to gastric cancer patients' poor outcome. Thus, our findings confirm that BCAR1 mediates FLOT1 induced gastric cancer progression and metastasis through ERK signaling, which may provide a novel pathway for gastric cancer treatment.

Adiponectin, the adiponectin paradox, and Alzheimer's Disease: Is this association biologically plausible?

Dementia, especially Alzheimer's Disease (AD) and vascular dementia, is a major public health problem that continues to expand in both economically emerging and hegemonic countries. In 2017, the World Alzheimer Report estimated that over 50 million people were living with dementia globally. Metabolic dysfunctions of brain structures such as the hippocampus and cerebral cortex have been implicated as risk factors for dementia. Several well-defined metabolic risk factors for AD include visceral obesity, chronic inflammation, peripheral and brain insulin resistance, type 2 diabetes mellitus (T2DM), hypercholesterolemia, and others. In this review, we describe the relationship between the dysmetabolic mechanisms, although still unknown, and dementia, particularly AD. Adiponectin (ADPN), the most abundant circulating adipocytokine, acts as a protagonist in the metabolic dysfunction associated with AD, with unexpected and intriguing dual biological functions. This contradictory role of ADPN has been termed the adiponectin paradox. Some evidence suggests that the adiponectin paradox is important in amyloidogenic evolvability in AD. We present cumulative evidence showing that AD and T2DM share many common features. We also review the mechanistic pathways involving brain insulin resistance. We discuss the importance of the evolvability of amyloidogenic proteins (APs), defined as the capacity of a system for adaptive evolution. Finally, we describe potential therapeutic strategies in AD, based on the adiponectin paradox.

Design and Synthesis of Fibroblast Growth Factor Receptor (FGFR) and Histone Deacetylase (HDAC) Dual Inhibitors for the Treatment of Cancer

The activation of the STAT signal after incubation with the HDAC inhibitor represents a key mechanism causing resistance to HDAC inhibitors in some solid tumor cells, while the FGFR inhibitor could downregulate the level of pSTAT3. Inspired by the therapeutic prospect of FGFR/HDAC dual inhibitors, we designed and synthesized a series of quinoxalinopyrazole hydroxamate derivatives as FGFR/HDAC dual inhibitors. Among them, compound 10e potently inhibited FGFR1-4 and HDAC1/2/6/8 and presented improved antiproliferative effects of tumor cells. Further studies indicated that 10e also downregulated the expression of pSTAT3, potentially overcoming resistance to HDAC inhibitors. What's more, 10e significantly inhibited the tumor growth in HCT116 and SNU-16 xenograft models with favorable pharmacokinetic profiles. Collectively, these results supported that 10e could be a new drug candidate for malignant tumors.

Genomic Analyses of Non-Coding RNAs Overlapping Transposable Elements and Its Implication to Human Diseases

It is estimated that up to 80% of the human genome is transcribed into RNA molecules but less than 2% of the genome encodes the proteins, and the rest of the RNA transcripts that are not translated into protein are called non-coding RNAs (ncRNAs). Many studies have revealed that ncRNAs have biochemical activities as epigenetic regulators at the post-transcriptional level. Growing evidence has demonstrated that transposable elements (TEs) contribute to a large percentage of ncRNAs’ transcription. The TEs inserted into certain parts of the genome can act as alternative promoters, enhancers, and insulators, and the accumulation of TEs increases genetic diversity in the human genome. The TEs can also generate microRNAs, so-called miRNA-derived from transposable elements (MDTEs), and are also implicated in disease progression, such as infectious diseases and cancer. Here, we analyzed the origin of ncRNAs and reviewed the published literature on MDTEs related to disease progression.

Identification of a novel glycolysis-related signature to predict the prognosis of patients with breast cancer

Background

Breast cancer (BC) has a high incidence and mortality rate in females. Its conventional clinical characteristics are far from accurate for the prediction of individual outcomes. Therefore, we aimed to develop a novel signature to predict the survival of patients with BC.

Methods

We analyzed the data of a training cohort from the Cancer Genome Atlas (TCGA) database and a validation cohort from the Gene Expression Omnibus (GEO) database. After the applications of Gene Set Enrichment Analysis (GSEA) and Cox regression analyses, a glycolysis-related signature for predicting the survival of patients with BC was developed; the signature contained AK3, CACNA1H, IL13RA1, NUP43, PGK1, and SDC1. Furthermore, on the basis of expression levels of the six-gene signature, we constructed a risk score formula to classify the patients into high- and low-risk groups. The receiver operating characteristic (ROC) curve and the Kaplan-Meier curve were used to assess the predicted capacity of the model. Later, a nomogram was developed to predict the outcomes of patients with risk score and clinical features over a period of 1, 3, and 5 years. We further used Human Protein Atlas (HPA) database to validate the expressions of the six biomarkers in tumor and sample tissues, which were taken as control.

Results

We constructed a six-gene signature to predict the outcomes of patients with BC. The patients in the high-risk group showed poor prognosis than those in the low-risk group. The area under the curve (AUC) values were 0.719 and 0.702, showing that the prediction performance of the signature is acceptable. Additionally, Cox regression analysis revealed that these biomarkers could independently predict the prognosis of BC patients with BC without being affected by clinical factors. The expression levels of all six biomarkers in BC tissues were higher than that in normal tissues; however, AK3 was an exception.

Conclusion

We developed a six-gene signature to predict the prognosis of patients with BC. Our signature has been proved to have the ability to make an accurate prediction and might be useful in expanding the hypothesis in clinical research.

MicroRNA-638 inhibits the progression of breast cancer through targeting HOXA9 and suppressing Wnt/β-cadherin pathway

Background

Previous studies had shown that microRNA-638 (miR-638) exhibited different effects in malignant tumors. Moreover, the function of miR-638 has not been reported in breast cancer. Hence, we designed this research to explore the function of miR-638 in breast cancer.

Methods

Firstly, miR-638 expressions were measured in breast cancer tissues via RT-qPCR. Protein expressions were detected through immunocytochemical (IHC) assay and western blot analysis. Then, Cell Counting Kit-8 (CCK-8) assay and Transwell assay were conducted to observe proliferation and motility of the cells. Dual luciferase assay was performed to confirm the binding site between miR-638 and Homeobox protein Hox-A9 (HOXA9).

Results

Reduced expression of miR-638 was detected in breast cancer. And low miR-638 expression was related to poor prognosis in patients with breast cancer. Functionally, the viability, migration, and invasion of the breast cancer cells were suppressed by miR-638 overexpression. Furthermore, miR-638 can directly bind to HOXA9, and increased expression of HOXA9 was also detected in breast cancer. In particular, HOXA9 upregulation can impair anti-tumor effect of miR-638 in breast cancer, and miR-638 can hinder the Wnt/β-cadherin pathway and epithelial-mesenchymal transition (EMT) in breast cancer.

Conclusion

miR-638 inhibits breast cancer progression through binding to HOXA9.

Combinatorial Effect of DCA and Let-7a on Triple-Negative MDA-MB-231 Cells: A Metabolic Approach of Treatment

Dichloroacetate (DCA) is a metabolic modulator that inhibits pyruvate dehydrogenase activity and promotes the influx of pyruvate into the tricarboxylic acid cycle for complete oxidation of glucose. DCA stimulates oxidative phosphorylation (OXPHOS) more than glycolysis by altering the morphology of the mitochondria and supports mitochondrial apoptosis. As a consequence, DCA induces apoptosis in cancer cells and inhibits the proliferation of cancer cells. Recently, the role of miRNAs has been reported in regulating gene expression at the transcriptional level and also in reprogramming energy metabolism. In this article, we indicate that DCA treatment leads to the upregulation of let-7a expression, but DCA-induced cancer cell death is independent of let-7a. We observed that the combined effect of DCA and let-7a induces apoptosis, reduces reactive oxygen species generation and autophagy, and stimulates mitochondrial biogenesis. This was later accompanied by stimulation of OXPHOS in combined treatment and was thus involved in metabolic reprogramming of MDA-MB-231 cells.

Flotillin membrane domains in cancer

Flotillins 1 and 2 are two ubiquitous, highly conserved homologous proteins that assemble to form heterotetramers at the cytoplasmic face of the plasma membrane in cholesterol- and sphingolipid-enriched domains. Flotillin heterotetramers can assemble into large oligomers to form molecular scaffolds that regulate the clustering of at the plasma membrane and activity of several receptors. Moreover, flotillins are upregulated in many invasive carcinomas and also in sarcoma, and this is associated with poor prognosis and metastasis formation. When upregulated, flotillins promote plasma membrane invagination and induce an endocytic pathway that allows the targeting of cargo proteins in the late endosomal compartment in which flotillins accumulate. These late endosomes are not degradative, and participate in the recycling and secretion of protein cargos. The cargos of this Upregulated Flotillin–Induced Trafficking (UFIT) pathway include molecules involved in signaling, adhesion, and extracellular matrix remodeling, thus favoring the acquisition of an invasive cellular behavior leading to metastasis formation. Thus, flotillin presence from the plasma membrane to the late endosomal compartment influences the activity, and even modifies the trafficking and fate of key protein cargos, favoring the development of diseases, for instance tumors. This review summarizes the current knowledge on flotillins and their role in cancer development focusing on their function in cellular membrane remodeling and vesicular trafficking regulation.

Cholesterol and Sphingolipid Enriched Lipid Rafts as Therapeutic Targets in Cancer

Lipid rafts are critical cell membrane lipid platforms enriched in sphingolipid and cholesterol content involved in diverse cellular processes. They have been proposed to influence membrane properties and to accommodate receptors within themselves by facilitating their interaction with ligands. Over the past decade, technical advances have improved our understanding of lipid rafts as bioactive structures. In this review, we will cover the more recent findings about cholesterol, sphingolipids and lipid rafts located in cellular and nuclear membranes in cancer. Collectively, the data provide insights on the role of lipid rafts as biomolecular targets in cancer with good perspectives for the development of innovative therapeutic strategies.

Epstein-Barr virus-derived circular RNA LMP2A induces stemness in EBV-associated gastric cancer

Cancer stem cells (CSCs) are cancer-initiating cells that are not only a source of tumorigenesis but also the cause of tumour progression, metastasis and therapy resistance. EBV-associated gastric cancer (EBVaGC) is a distinct subtype of gastric cancer with unique clinicopathological and molecular features. However, whether CSCs exist in EBVaGC, and the tumorigenic mechanism of EBV, remains unclear. Here, NOD/SCID mice were injected subcutaneously with the EBVaGC cell line SNU719 and treated with 5-fluorouracil weekly. Successive generations of xenografts yielded a highly malignant EBVaGC cell line, SNU-4th, which displays properties of CSCs and mainly consists of CD44⁺ CD24^- cells. In SNU-4th cells, an EBV-encoded circRNA, ebv-circLMP2A, expression increased and plays crucial roles in inducing and maintaining stemness phenotypes through targeting miR-3908/TRIM59/p53 axis. Additionally, high expression of ebv-circLMP2A is significantly associated with metastasis and poor prognosis in patients with EBVaGC. These findings not only provide evidence for the existence of CSCs in EBVaGC and elucidate the pathogenic mechanism of ebv-circLMP2A in EBVaGC, but also provide a promising therapeutic target for EBVaGC.

The cross-talk between adipokines and miRNAs in health and obesity-mediated diseases

BACKGROUND

Multiple studies have revealed a direct correlation between obesity and the development of multiple comorbidities, including metabolic diseases, cardiovascular disorders, chronic inflammatory disease, and cancers. However, the molecular mechanism underlying the link between obesity and the progression of these diseases is not completely understood. Adipokines are factors that are secreted by adipocytes and play a key role in whole body homeostasis. Collaboratively, miRNAs are suggested to have key functions in the development of obesity and obesity-related disorders. Based on recently emerging evidence, obesity leads to the dysregulation of both adipokines and obesity-related miRNAs. In the present study, we described the correlations between obesity and its related diseases that are mediated by the mutual regulatory effects of adipokines and miRNAs.

METHODS

We reviewed current knowledge of the modulatory effects of adipokines on miRNAs activity and their relevant functions in pathological conditions and vice versa.

RESULTS

Our research reveals the ability of adipokines and miRNAs to control the expression and activity of the other class of molecules, and their effects on obesity-related diseases.

CONCLUSIONS

This study may help researchers develop a roadmap for future investigations and provide opportunities to develop new therapeutic and diagnostic methods for treating obesity-related diseases.