OGFOD1 negatively regulated by miR-1224-5p promotes proliferation in human papillomavirus-infected laryngeal papillomas

circPOLA2 promotes proliferation, invasion, migration, and epithelial-mesenchymal transition in breast cancer via the miR-1224-5p/HMGA2 axis

OBJECTIVE

This study aimed to investigate the carcinogenic role of circPOLA2 in Breast Cancer (BC) and reveal its potential mechanism as a competitive endogenous RNA.

METHODS

Differentially expressed circRNAs, miRNAs, and mRNAs in BC tissues and cell lines were screened and analyzed by RT-qPCR. The interaction among circPOLA2, miR-1224-5p, and HMGA2 was tested using dual luciferase reporter assay and RNA pull-down assay. Cell proliferation was detected by MTT and colony formation assay, apoptosis was detected by flow cytometry, migration, and invasion was detected by Transwell assay, and EMT-related proteins were detected by Western blot.

RESULTS

circPOLA2 and HMGA2 levels were elevated in BC, while miR-1224-5p level was reduced. Knocking down circPOLA2 decreased the expression of HMGA2 by elevating miR-1224-5p expression. Knocking down circPOLA2 or HMGA2 or elevating miR-1224-5p reduced the proliferative, migratory, invasive, and anti-apoptotic capacities of BC cells.

CONCLUSION

Knockdown of circPOLA2 inhibits BC cell proliferation, migration, and invasion and delays BC tumor progression by regulating the miR-1224-5p/HMGA2 axis, providing a new strategy and target for therapeutic intervention in BC.

Circ_0008450 regulates keloid-derived fibroblast proliferation, migration, invasion and apoptosis with increased IGFBP5 through sponging miR-1224-5p

BACKGROUND

Keloids (KD) are benign fibroproliferative tumors and circular RNAs (circRNAs) may participate in KD progression. At present, whether circ_0008450 regulates keloid-derived fibroblast phenotypes remains unclear. This study aimed to explore the functions of circ_0008450 in keloid (KD)-derived fibroblast phenotypes and the underlying mechanism.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay was performed to determine the expression of circ_0008450, miR-1224-5p, insulin like growth factor binding protein 5 (IGFBP5) and extracellular matrix (ECM)-related markers. 5-Ethynyl-2'-deoxyuridine (EdU) assay was conducted to assess cell proliferation ability. Flow cytometry analysis was used to analyze cell cycle and cell apoptosis. Scratch assay and transwell assay were utilized to examine cell migration and invasion. Mechanism assays were executed to verify the relations of circ_0008450, miR-1224-5p and IGFBP5.

RESULTS

Circ_0008450 was highly expressed in KD tissues and KD-derived fibroblasts. Circ_0008450 silencing inhibited KD-derived fibroblast proliferation, cell cycle, and motility and promoted apoptosis. The effect of circ_0008450 knockdown on KD-derived fibroblast processes was ameliorated by miR-1224-5p downregulation. IGFBP5 was a target gene of miR-1224-5p. IGFBP5 upregulation abated miR-1224-5p-mediated effects on KD-derived fibroblast processes.

CONCLUSION

Circ_0008450 promoted KD-derived fibroblast proliferation, migration, and invasion and repressed apoptosis via sponging miR-1224-5p and elevating IGFBP5.

Mesenchymal stem cells-derived exosomal miR-653-5p suppresses laryngeal papilloma progression by inhibiting BZW2

OBJECTIVES

Although miR-653-5p has been validated to participate in the progression of multiple types of cancer, the functional role of exosomal miR-653-5p derived from Mesenchymal Stem Cells (MSCs) in Laryngeal Papilloma (LP) has still remained elusive. Hence, this study aimed to investigate the role of MSCs-derived exosomal miR-653-5p in LP.

METHODS

LP tissues (n = 15) and adjacent normal tissues (n = 10) were collected to examine the expression level of miR-653-5p. The expression level of miR-653-5p in LP cells and normal cells was also detected. Then, miR-653-5p was overexpressed or silenced to explore its effects on the proliferation, migration, invasion, and apoptosis of LP cells. Thereafter, the effects of exosomal miR-653-5p derived from MSCs on LP cell progression and the potential regulatory mechanism of miR-653-5p were assessed.

RESULTS

It was revealed that the expression level of miR-653-5p was downregulated in LP tissues and cells. In addition, miR-653-5p suppressed the proliferation, migration, invasion, and apoptosis of LP cells. Exosomes derived from MSCs played a suppressive role in LP development and mediated the transmission of miR-653-5p to LP cells. Further exploration identified Basic leucine Zipper and W2 domains 2 (BZW2) as the target of miR-653-5p. More importantly, the rescue experiments revealed that MSCs-secreted exosomal miR-653-5p efficiently inhibited the aggressive phenotypes of LP cells, which could be significantly reversed by BZW2 overexpression in LP cells.

CONCLUSION

MSCs-derived exosomal miR-653-5p exerted inhibitory effects on LP progression through targeting BZW2, which provided a novel idea for the therapy of LP.

CLINICAL TRIAL REGISTRATION NUMBER

chictr-ior-17011021.

The Role and Mechanism of microRNA-1224 in Human Cancer

microRNAs (miRNAs) are a type of small endogenous non-coding RNAs composed of 20-22 nucleotides, which can regulate the expression of a gene by targeting 3’ untranslated region (3’-UTR) of mRNA. Many studies have reported that miRNAs are involved in the occurrence and progression of human diseases, including malignant tumors. miR-1224 plays significant roles in different tumors, including tumor proliferation, metastasis, invasion, angiogenesis, biological metabolism, and drug resistance. Mostly, it serves as a tumor suppressor. With accumulating proofs of miR-1224, it can act as a potential bio-indicator in the diagnosis and prognosis of patients with cancer. In this article, we review the characteristics and research progress of miR-1224 and emphasize the regulation and function of miR-1224 in different cancer. Furthermore, we conclude the clinical implications of miR-1224. This review may provide new horizons for deeply understanding the role of miR-1224 as biomarkers and therapeutic targets in human cancer.

Phosphorylation of OGFOD1 by Cell Cycle-Dependent Kinase 7/9 Enhances the Transcriptional Activity of RNA Polymerase II in Breast Cancer Cells

Simple Summary

Among the causes of accelerating cancer properties, dysregulated transcription is considerably prominent in many cancers. However, it is difficult to target transcriptional machineries due to their fundamental importance. Compared to breast cancer cell lines, we found that OGFOD1 aggravates cancers by enhancing RNA polymerase II transcriptional activity and it is improved by cell cycle-dependent kinases. Overall, we uncovered the novel mechanism for how OGFOD1 maliciously functions in breast cancers, suggesting it as a rational cancer treatment target protein.

Abstract

2-oxoglutarate and iron-dependent oxygenase domain-containing protein 1 (OGFOD1) expression is upregulated in a variety of cancers and has been related to poor prognosis. However, despite this significance to cancer progression, the precise oncogenic mechanism of OGFOD1 is not understood. We demonstrated that OGFOD1 plays a role in enhancing the transcriptional activity of RNA polymerase II in breast cancer cells. OGFOD1 directly binds to the C-terminal domain of RNA polymerase II to alter phosphorylation status. The elimination of OGFOD1 resulted in decreased tumor development. Additionally, cell cycle-dependent kinase 7 and cell cycle-dependent kinase 9, critical enzymes for activating RNA polymerase II, phosphorylated serine 256 of OGFOD1, whereas a non-phosphorylated mutant OGFOD1 failed to enhance transcriptional activation and tumor growth. Consequently, OGFOD1 helps promote tumor growth by enhancing RNA polymerase II, whereas simultaneous phosphorylation of OGFOD1 by CDK enzymes is essential in stimulating RNA polymerase II-mediated transcription both in vitro and in vivo, and expression of target genes.

MiR-1224-5p Activates Autophagy, Cell Invasion and Inhibits Epithelial-to-Mesenchymal Transition in Osteosarcoma Cells by Directly Targeting PLK1 Through PI3K/AKT/mTOR Signaling Pathway

Background

Osteosarcoma (OS) is one of the most common malignant bone tumors with a poor overall prognosis. MiR-1224-5p plays an important role in cancer, but its function and mechanism in OS have not been studied.

Materials and Methods

The expression of miR-1224-5p and PLK1 was detected by qRT-PCR in OS cells, adjacent tissues, and cell lines. Dual-luciferase reporter gene assay was used to verify the interaction between miR-1224-5p and PLK1. The expression of miR-1224-5p and PLK1 was intervened by transfection with miR-1224-5p mimic, NC mimic, pc-NC and PLK1, respectively. MTT, colony formation assay, Transwell and flow cytometry were used to observe the cell proliferation, invasion and apoptosis. Western blot was used to detect the expression levels of PLK1, PI3K/AKT/mTOR signaling pathway-related proteins, autophagy-related proteins, and epithelial-mesenchymal transition (EMT)-related proteins in the cells.

Results

We found that miR-1224-5p was down-regulated and PLK1 expression was up-regulated in OS tissues and cells. On the other hand, it is further confirmed that PLK1 was a target gene of miR-1224-5p. Overexpression of miR-1224-5p inhibited the proliferation, invasion while promoted the apoptosis of OS cells, whereas overexpression of PLK1 promoted the proliferation, invasion and inhibited the apoptosis of OS cells. In the miR-1224-5p group (overexpression of miR-1224-5p), PI3K, AKT, and mTOR protein phosphorylation levels were significantly reduced, while autophagic activity was significantly activated, and the degree of EMT was significantly reduced. But the results in the PLK1 group (overexpression of PLK1) were the opposite. In addition, overexpression of miR-1224-5p reversed the effect of PLK1 upregulation on OS cells.

Conclusion

MiR-1224-5p targets PLK1 to inhibit PI3K/AKT/mTOR signaling pathway, thus mediating the proliferation, invasion, apoptosis, autophagy and EMT in OS cells.