miR-149 Suppresses the Proliferation and Metastasis of Human Gastric Cancer Cells by Targeting FOXC1

Research progress on the regulatory mechanisms of FOXC1 expression in cancers and its role in drug resistance

The Forkhead box C1 (FOXC1) transcription factor is an important member of the FOX family. After initially being identified in triple-negative breast cancer (TNBC) with significant oncogenic function, FOXC1 was subsequently demonstrated to be involved in the development of more than 16 types of cancers. In recent years, increasing studies have focused on the deregulatory mechanisms of FOXC1 expression and revealed that FOXC1 expression was regulated at multiple levels including transcriptional regulation, post-transcription regulation and post-translational modification. Moreover, dysregulation of FOXC1 is also implicated in drug resistance in various types of cancer, especially in breast cancer, which further emphasizes the translational and clinical significance of FOXC1 as a therapeutic target in cancer treatment. This review summarizes recent findings on mechanisms of FOXC1 dysregulation in cancers and its role in chemoresistance, which will help to better understand the oncogenic role of FOXC1, overcome FOXC1-mediated drug resistance and develop targeted therapy for FOXC1 in cancers.

Update on the association of miR-149 rs2292832 C>T polymorphism with gastric cancer risk: A meta-analysis study of gastrointestinal cancers

OBJECTIVE

Single nucleotide polymorphisms in microRNAs are believed to affect the occurrence and progression of cancer by altering the expression and biological functions of microRNAs. Several studies investigated the role of the miR-149 rs2292832 C>T polymorphism on the risk of gastric cancer (GC), but got conflicting results.

METHODS

We performed a comprehensive and systematic search through the PubMed MEDLINE, Google Scholar, Science Direct, Scopus, CNKI, and Web of science, 8 studies were included in the meta-analysis to determine whether miR-149 rs2292832 C>T polymorphism contributed to the risk of GC.

RESULTS

Pooled data indicated that miR-149 rs2292832 C>T polymorphism was not associated with GC risk. In the stratified analysis by ethnicity, miR-149 rs2292832 C>T polymorphism significantly increased GC risk under the allele comparison model (odds ratio [OR] = 1.27, 95% CI = 1.04-1.55, Pheterogeneity = 0.18, P = .02), recessive model (OR = 1.44, 95% CI = 1.04-2.01, Pheterogeneity = 0.19, P = .03) among Caucasians; but decreased GC risk under the allele comparison model (OR = 0.89, 95% CI = 0.81-0.98, Pheterogeneity = 0.22, P = .02) and dominant model (OR = 0.82, 95% CI = 0.72-0.93, Pheterogeneity = 0.15, P = .01) among Asian.

CONCLUSION

Our meta-analysis suggests a positive correlation between miR-149 rs2292832 C>T polymorphism and GC development among Caucasians, but negative correlation among Asian population.

18β-glycyrrhetinic acid promotes gastric cancer cell autophagy and inhibits proliferation by regulating miR-328-3p/signal transducer and activator of transcription 3

BACKGROUND

Gastric cancer (GC) is one of the most common cancer types worldwide, and its prevention and treatment methods have garnered much attention. As the active ingredient of licorice, 18β-glycyrrhetinic acid (18β-GRA) has a variety of pharmacological effects. The aim of this study was to explore the effective target of 18β-GRA in the treatment of GC, in order to provide effective ideas for the clinical prevention and treatment of GC.

AIM

To investigate the mechanism of 18β-GRA in inhibiting cell proliferation and promoting autophagy flux in GC cells.

METHODS

Whole transcriptomic analyses were used to analyze and screen differentially expressed microRNAs (miRNAs) in GC cells after 18β-GRA intervention. Lentivirus-transfected GC cells and the Cell Counting Kit-8 were used to detect cell proliferation ability, cell colony formation ability was detected by the clone formation assay, and flow cytometry was used to detect the cell cycle and apoptosis. A nude mouse transplantation tumor model of GC cells was constructed to verify the effect of miR-328-3p overexpression on the tumorigenicity of GC cells. Tumor tissue morphology was observed by hematoxylin and eosin staining, and microtubule-associated protein light chain 3 (LC3) expression was detected by immunohistochemistry. TransmiR, STRING, and miRWalk databases were used to predict the relationship between miR-328-3p and signal transducer and activator of transcription 3 (STAT3)-related information. Expression of STAT3 mRNA and miR-328-3p was detected by quantitative polymerase chain reaction (qPCR) and the expression levels of STAT3, phosphorylated STAT3 (p-STAT3), and LC3 were detected by western blot analysis. The targeted relationship between miR-328-3p and STAT3 was detected using the dual-luciferase reporter gene system. AGS cells were infected with monomeric red fluorescent protein-green fluorescent protein-LC3 adenovirus double label. LC3 was labeled and autophagy flow was observed under a confocal laser microscope.

RESULTS

The expression of miR-328-3p was significantly upregulated after 18β-GRA intervention in AGS cells (P = 4.51E-06). Overexpression of miR-328-3p inhibited GC cell proliferation and colony formation ability, arrested the cell cycle in the G0/G1 phase, promoted cell apoptosis, and inhibited the growth of subcutaneous tumors in BALB/c nude mice (P < 0.01). No obvious necrosis was observed in the tumor tissue in the negative control group (no drug intervention or lentivirus transfection) and vector group (the blank vector for lentivirus transfection), and more cells were loose and necrotic in the miR-328-3p group. Bioinformatics tools predicted that miR-328-3p has a targeting relationship with STAT3, and STAT3 was closely related to autophagy markers such as p62. After overexpressing miR-328-3p, the expression level of STAT3 mRNA was significantly decreased (P < 0.01) and p-STAT3 was downregulated (P < 0.05). The dual-luciferase reporter gene assay showed that the luciferase activity of miR-328-3p and STAT3 3’ untranslated regions of the wild-type reporter vector group was significantly decreased (P < 0.001). Overexpressed miR-328-3p combined with bafilomycin A₁ (Baf A₁) was used to detect the expression of LC3 II. Compared with the vector group, the expression level of LC3 II in the overexpressed miR-328-3p group was downregulated (P < 0.05), and compared with the Baf A₁ group, the expression level of LC3 II in the overexpressed miR-328-3p + Baf A₁ group was upregulated (P < 0.01). The expression of LC3 II was detected after intervention of 18β-GRA in GC cells, and the results were consistent with the results of miR-328-3p overexpression (P < 0.05). Additional studies showed that 18β-GRA promoted autophagy flow by promoting autophagosome synthesis (P < 0.001). qPCR showed that the expression of STAT3 mRNA was downregulated after drug intervention (P < 0.05). Western blot analysis showed that the expression levels of STAT3 and p-STAT3 were significantly downregulated after drug intervention (P < 0.05).

CONCLUSION

18β-GRA promotes the synthesis of autophagosomes and inhibits GC cell proliferation by regulating the miR-328-3p/STAT3 signaling pathway.

miR-30c-2-3p suppresses the proliferation of human renal cell carcinoma cells by targeting TOP2A

Background

The ambiguity of renal cell carcinoma (RCC) symptoms hinders early diagnosis, thereby contributing to high mortality rates. By attaching to the 3'-untranslated region (UTR) of the target gene, microRNAs (miRNAs) exert significant control over the expression of genes.

Objectives

To investigate the influence of miR-30c-2-3p and DNA topoisomerase II alpha (TOP2A) on RCC growth and the mechanisms underlying the regulation of its expression.

Methods

The expression of miRNA-30c-2-3p and TOP2A in RCC cells was examined using quantitative real-time polymerase chain reaction (qRT-PCR). MiR-30c-2-3p mimics, its inhibitors, and controls, as well as TOP2A short hairpin RNA (shRNA) and controls, were used to transfect the human RCC cell lines 786-O, Caki-1, and ACHN. Additionally, the roles of miRNA-30c-2-3p and TOP2A in the growth of RCC were evaluated using the cell counting kit (CCK)-8 test, colony formation assay, apoptosis analysis, and Western blotting. Meanwhile, binding of miRNA-30c-2-3p and TOP2A was verified using dual-luciferase reporter assays and Western blotting.

Results

miR-30c-2-p is underexpressed in RCC cells. Overexpression of miR-30c-2-p promotes apoptosis and inhibits proliferation of ACHN, Caki-1, and 786-O cells. miR-30c-2-3p targets TOP2A, which is elevated in RCC tissues and cells, whereas TOP2A silencing inhibits the proliferation ability of RCC cells. The miRNA-30c-2-3p inhibitor compromises TOP2A shRNA-induced apoptosis of RCC. RCC cells cotransfected with miRNA-30c-2-3p inhibitors and TOP2A shRNAs have a higher proliferation rate than those transfected with only TOP2A shRNAs.

Conclusions

Collectively, our results verify that miRNA-30c-2-3p has a tumor suppressor property. miRNA-30c-2-3p inhibits the proliferation of RCC through regulation of TOP2A. The data provide a viable therapeutic target for RCC.

Dietary stilbenes as modulators of specific miRNAs in prostate cancer

Accumulated experimental data have suggested that natural plant products may be effective miRNA-modulating chemopreventive and therapeutic agents. Dietary polyphenols such as flavonoids, stilbenes, and lignans, among others, have been intensively studied for their miRNA-mediated cardioprotective, antioxidant, anti-inflammatory and anticancer properties. The aim of this review is to outline known stilbene-regulated miRNAs in cancer, with a special focus on the interplay between various miRNAs and MTA1 signaling in prostate cancer. MTA1 is an epigenetic reader and an oncogenic transcription factor that is overexpressed in advanced prostate cancer and metastasis. Not surprisingly, miRNAs that are linked to MTA1 affect cancer progression and the metastatic potential of cells. Studies led to the identification of MTA1-associated pro-oncogenic miRNAs, which are regulated by stilbenes such as resveratrol and pterostilbene. Specifically, it has been shown that inhibition of the activity of the MTA1 regulated oncogenic miR-17 family of miRNAs, miR-22, and miR-34a by stilbenes leads to inhibition of prostatic hyperplasia and tumor progression in mice and reduction of proliferation, survival and invasion of prostate cancer cells in vitro. Taken together, these findings implicate the use of resveratrol and its analogs as an attractive miRNA-mediated chemopreventive and therapeutic strategy in prostate cancer and the use of circulating miRNAs as potential predictive biomarkers for clinical development.