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Colorectal cancer (CRC) is a prevalent malignant tumor of the digestive tract. Circular RNAs may play important roles in the progression of CRC. In this study, we investigated the roles and mechanisms of action of circ-MALAT1 in CRC. Gene expression and protein abundance were determined using qRT-PCR and western blot, respectively. Cell proliferation and migration were assessed by MTT, clone formation, and wound-healing assays. The interactions among the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (circ-MALAT1), miR-506-3p, and lysine acetyltransferase 6B (KAT6B) were predicted using the StarBase software and confirmed by the luciferase activity assay. Circ-MALAT1 and KAT6B were upregulated, while miR-506-3p was downregulated in CRC cells. We validated that knocking down of circ-MALAT1 suppressed proliferation, migration, and epithelial-mesenchymal transition (EMT) of CRC cells, and these effects were abolished by miR-506-3p downregulation or KAT6B sufficiency. Our study suggests that circ-MALAT1 could sponge miR-506-3p to regulate the expression of KAT6B. Moreover, KAT6B sufficiency could neutralize miR-506-3p-dependent growth arrest, migration, and EMT. Circ-MALAT1 promotes cell proliferation, migration, and EMT of CRC cells via the miR-506-3p/KAT6B axis, thereby acting as a novel potential therapeutic target for the treatment of colorectal cancer., (© 2023 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia, Ltd on behalf of Kaohsiung Medical University.)

Pulmonary hypertension (PH) is complex disease as a result of obstructive pulmonary arterial remodeling, which in turn results in elevated pulmonary arterial pressure (PAP) and subsequent right ventricular heart failure, eventually leading to premature death. However, there is still a lack of a diagnostic blood-based biomarker and therapeutic target for PH. Because of the difficulty of diagnosis, new and more easily accessible prevention and treatment strategy are being explored. New target and diagnosis biomarkers should also allow for early diagnosis. In biology, miRNAs are short endogenous RNA molecules that are not coding. It is known that miRNAs can regulate gene expression and affect a variety of biological processes. Besides, miRNAs have been proven to be a crucial factor in PH pathogenesis. miRNAs have various effects on pulmonary vascular remodeling and are expressed differentially in various pulmonary vascular cells. Nowadays, it has been shown to be critical in the functions of different miRNAs in the pathogenesis of PH. Therefore, clarifying the mechanism of miRNAs regulating pulmonary vascular remodeling is of great importance to explore new therapeutic targets of PH and improve the survival qualify and time of patients. This review is focused on the role, mechanism, and potential therapeutic targets of miRNAs in PH and puts forward possible clinical treatment strategies., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

With the rapid increase in its incidence in the last decade, colorectal cancer (CRC) is becoming one of the most life-threatening cancers. Circular RNA PTK2 (circPTK2) has multiple functions in oncogenesis, including in CRC. However, it remains elusive if circPTK2 also plays an important role in CRC malignancy. The levels of circPTK2, miR-506-3p, and AKT serine/threonine kinase 2 (AKT2) were measured by qPCR. The protein level of AKT2 was evaluated by western blotting assay. The proliferation, migration, and invasion of CRC cancer cells were evaluated by MTT, colony formation, wound-healing, and transwell assays. The interaction between circPTK2 and miR-506-3p and between miR-506-3p and AKT2 mRNA were verified by dual-luciferase reporter assay. The expressions of circPTK2 and AKT2 were elevated in CRC cells, with a concomitant reduction of miR-506-3p. The knockdown of circPTK2 suppressed the proliferation, migration, and invasion of CRC cells. CircPTK2 targeted miR-506-3p and negatively regulated its expression. Furthermore, miR-506-3p overexpression suppressed the CRC progression by downregulating the AKT2 expression. AKT2 overexpression or miR-506-3p inhibition restored the suppression of growth and invasiveness of CRC cancer cells caused by circPTK2 silencing. The circPTK2/miR-506-3p/AKT2 axis plays a novel and essential role in promoting CRC progression, providing potential targets for CRC therapeutic modality., (© 2022 The Authors. The Kaohsiung Journal of Medical Sciences published by John Wiley & Sons Australia, Ltd on behalf of Kaohsiung Medical University.)

Mammalian Target of Rapamycin (mTOR) is involved in the proliferation and survival of pulmonary artery smooth muscle cells (PASMCs) in human pulmonary hypertension (PH) and animal PH models, and miRNAs are reported to play a key role in modulation of the proliferation of PASMCs. The purposes of this study are to determine the functions of miR-100 and mTOR in cardiovascular remodeling of the hypoxic PH rats and to clarify the correlation between them. We established a rat model of hypoxic PH, which showed an increase in right ventricle systolic pressure, right ventricular and pulmonary vascular remodeling, accompanied by an up-regulation of mTOR and a down-regulation of miR-100. Next, we established an in vitro model of hypoxia-induced proliferation of PASMCs. Consistent with the in vivo findings, hypoxia induced proliferation of PASMCs, accompanied by a down-regulation of miR-100 and an up-regulation of mTOR; these phenomena were reversed by miR-100 mimics or the antagonist of mTOR. Finally, the dual-luciferase reporter gene assay was utilized to reveal the direct interaction between miR-100 and the 3 '-UTR region of mTOR gene. Based on these observations, we conclude that miR-100 can modulate the proliferation of PASMCs in hypoxic PH rats through suppressing the mTOR expression., (Copyright © 2015. Published by Elsevier B.V.)