Knockdown circular RNA circGFRA1 inhibits glioma cell proliferation and migration by upregulating microRNA-99a

Forkhead box transcription factors (FOXOs and FOXM1) in glioma: from molecular mechanisms to therapeutics

Glioma is the most aggressive and malignant type of primary brain tumor, comprises the majority of central nervous system deaths, and is categorized into different subgroups according to its histological characteristics, including astrocytomas, oligodendrogliomas, glioblastoma multiforme (GBM), and mixed tumors. The forkhead box (FOX) transcription factors comprise a collection of proteins that play various roles in numerous complex molecular cascades and have been discovered to be differentially expressed in distinct glioma subtypes. FOXM1 and FOXOs have been recognized as crucial transcription factors in tumor cells, including glioma cells. Accumulating data indicates that FOXM1 acts as an oncogene in various types of cancers, and a significant part of studies has investigated its function in glioma. Although recent studies considered FOXO subgroups as tumor suppressors, there are pieces of evidence that they may have an oncogenic role. This review will discuss the subtle functions of FOXOs and FOXM1 in gliomas, dissecting their regulatory network with other proteins, microRNAs and their role in glioma progression, including stem cell differentiation and therapy resistance/sensitivity, alongside highlighting recent pharmacological progress for modulating their expression.

The roles and mechanisms of circular RNAs related to mTOR in cancers

BACKGROUND

Circular RNAs (circRNAs) are stable molecules with covalently closed structures that have an irreplaceable role in the occurrence, progression, and even treatment of plenty of cancers. Mammalian/mechanistic target of rapamycin (mTOR) is a key regulator in cancers and plays several biological functions, such as proliferation, migration, invasion, autophagy, and apoptosis.

METHODS

All data were collected through PubMed and CNKI, using terms including "circRNA," "mTOR," "caner," "signaling pathway," "biomarker," "diagnosis," "treatment." Articles published in Chinese and English were included.

RESULTS

In this review, the expression, function, and mechanism of circRNA-associated mTOR in cancers were described. CircRNA-associated-mTOR can regulate the progression and therapy of a variety of cancers in multiple signaling pathways, such as phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt)/mTOR, mitogen-activated protein kinase (MAPK)/mTOR, and AMP-activated protein kinase (AMPK)/mTOR axis. These cancers including esophageal carcinoma (circLPAR3, ciRS-7), gastric cancer (circNRIP1, hsa_circ_0010882, hsa_circ_0000117, hsa_circ_0072309, and circST3GAL6), colorectal cancer (hsa_circ_0000392, hsa_circ_0084927, hsa_circ_0104631, and circFBXW7), liver cancer (circC16orf62, hsa_circ_100338, hsa_circ_0004001, hsa_circ_0004123, hsa_circ_0075792, hsa_circ_0079299, and hsa_circ_0002130), pancreatic cancer (circ-IARS and circRHOBTB3), renal carcinoma (ciRS-7), bladder cancer (circUBE2K), prostate cancer (circMBOAT2 and circ-ITCH), ovarian cancer (circEEF2, circRAB11FIP1, circMYLK, and circTPCN), endometrial cancer (hsa_circ_0002577 and circWHSC1), lung cancer (circHIPK3, hsa_circ_0001666), thyroid cancer (hsa_circ_0007694 and hsa_circ_0008274), glioma (circGFRA1, circ-MAPK4, circPCMTD1, and hsa_circ_0037251), osteosarcoma (circTCF25), leukemia (circ-PRKDC), and breast cancer (hsa_circ_0000199, circUBAP2, and circWHSC1).

The Expression Profile of miRNA in Glioma and the Role of miR-339-5p in Glioma

Objective

To reveal the expression profile of miRNA in glioma and the effects of microRNA-339-5p (miR-339-5p) on glioma.

Methods

The glioma and normal tissues were randomly selected for miRNA gene chip detection and qRT-PCR verification. The U87 cells were separated into miR-NC, miR-339-5p mimic, and miR-339-5p suppressor group. Clonogenesis test, flow cell technique, Transwell, and cell scratch assay were utilized to verify the roles of miR-339-5p in cell proliferation, cell apoptosis, cell invasion, and cell migration. The epithelial-meso-transformation-associated proteins was verified by Western blot.

Results

A total of 49 miRNAs (16 upregulated and 33 downregulated) were differentially expressed in glioma tissues, and miR-339-5p was the most downregulated. The clone number, invasion number, and healing rate of cells in miR-339-5p mimic group were decreased compared with miR-NC group (P < 0.05); the clone quantity, invasion number, and healing rate of cells in miR-339-5p inhibitor group were increased compared with miR-NC group (P < 0.05). The apoptosis rate of human glioma U87 cells in miR-339-5P mimic group was compared with miR-NC group (P < 0.05); the apoptosis rate of human glioma U87 cells in miR-339-5p suppressor group decreased compared with miR-NC group (P < 0.05). Compared with miR-NC group, the protein expression of Twist, Snsnail, N-cadherin, and Vimentin in miR-339-5p mimic group was considerably decreased, whereas E-cadherin was elevated (P < 0.05). Compared with miR-NC group, the protein expression of Twist, Snsnail, N-cadherin, and Vimentin in miR-339-5p suppressor group was considerably increased, whereas E-cadherin was considerably decreased (P < 0.05).

Conclusion

Forty-nine glioma-related miRNAs were screened out, and miRNA expression was significantly different between glioma and normal tissues. The downregulated miR-339-5p in glioma can regulate the proliferative, apoptotic, invasive, and migratory abilities of glioma U87 cells and might suppress the occurrence and development of glioma.

Nano-Albumin Particles Loaded with miR-20a Inhibitor Targeting Met Protein to Reverse Proliferation of Intestinal Cancer Cells

This study explored miR-20a’s role in intestinal cancer cells. SW480 cell line was divided into control group, agonist group, inhibitor group, and negative control group, followed by analysis of cell proliferation, apoptosis, Met, Bad, and Bcl-2 protein expressions. Results showed that miR-20a expression in the agonist group was the highest, followed by blank group and negative control group, and inhibitor group was lowest. S-phase and G2/M cell number from inhibitor group was lowest, and cell apoptosis rate was highest. However, the agonist group showed contrary changes. There was no difference in G0/G1 phase cell number among the four groups (P > 0.05). Moreover, the expressions of Bad, Bcl-2, Met, Wnt, β-catenin, and p-Wnt in inhibitor group were all lower, while the expressions in agonist group were all high (P < 0.05). S-phase and G2/M cell number in inhibitor group was lowest, while cell apoptosis was highest. The agonist group was opposite, with G0/G1 phase cells in each group showing no difference (P > 0.05). Wnt, β-catenin, and p-Wnt expressions were lowest in the inhibitor group, while the agonist group was opposite. These results together showed that the miR-20a directly targeted and regulated Met protein. Finally, the miR-20a inhibited intestinal cancer cell proliferation mainly through inhibiting Wnt/β-catenin signaling activity.