1
|
Bii VM, Rudoy D, Klezovitch O, Vasioukhin V. Lethal giant larvae gene family ( Llgl1 and Llgl2 ) functions as a tumor suppressor in mouse skin epidermis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.06.531408. [PMID: 36945368 PMCID: PMC10028895 DOI: 10.1101/2023.03.06.531408] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Loss of cell polarity and tissue disorganization occurs in majority of epithelial cancers. Studies in simple model organisms identified molecular mechanisms responsible for the establishment and maintenance of cellular polarity, which play a pivotal role in establishing proper tissue architecture. The exact role of these cell polarity pathways in mammalian cancer is not completely understood. Here we analyzed the mammalian orthologs of drosophila apical-basal polarity gene lethal giant larvae ( lgl ), which regulates asymmetric stem cell division and functions as a tumor suppressor in flies. There are two mammalian orthologs of lgl ( Llgl1 and Llgl2 ). To determine the role of the entire lgl signaling pathway in mammals we generated mice with ablation of both Llgl1 and Llgl2 in skin epidermis using K14-Cre ( Llgl1/2 -/- cKO mice). Surprisingly, we found that ablation of Llgl1/2 genes does not impact epidermal polarity in adult mice. However, old Llgl1/2 cKO mice present with focal skin lesions which are missing epidermal layer and ripe with inflammation. To determine the role of lgl signaling pathway in cancer we generated Trp53 -/- /Llgl1/2 -/- cKO and Trp53 -/+ /Llgl1/2 -/- cKO mice. Loss of Llgl1/2 promoted squamous cell carcinoma (SCC) development in Trp53 -/- cKO and caused SCC in Trp53 -/+ cKO mice, while no cancer was observed in Trp53 -/+ cKO controls. Mechanistically, we show that ablation of Llgl1/2 causes activation of aPKC and upregulation of NF-kB signaling pathway, which may be necessary for SCC in Trp53 -/+ /Llgl1/2 -/- cKO mice. We conclude that Lgl signaling pathway functions as a tumor suppressor in mammalian skin epidermis.
Collapse
|
2
|
Chang WT, Liu PY, Gao ZH, Lee SW, Lee WK, Wu SN. Evidence for the Effectiveness of Remdesivir (GS-5734), a Nucleoside-Analog Antiviral Drug in the Inhibition of I K(M) or I K(DR) and in the Stimulation of I MEP. Front Pharmacol 2020; 11:1091. [PMID: 32792942 PMCID: PMC7385287 DOI: 10.3389/fphar.2020.01091] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/06/2020] [Indexed: 12/13/2022] Open
Abstract
Remdesivir (RDV, GS-5734), a broad-spectrum antiviral drug in the class of nucleotide analogs, has been particularly tailored for treatment of coronavirus infections. However, to which extent RDV is able to modify various types of membrane ion currents remains largely uncertain. In this study, we hence intended to explore the possible perturbations of RDV on ionic currents endogenous in pituitary GH3 cells and Jurkat T-lymphocytes. The whole-cell current recordings of ours disclosed that upon membrane depolarization in GH3 cells the exposure to RDV concentration-dependently depressed the peak or late components of I K(DR) elicitation with effective IC50 values of 10.1 or 2.8 μM, respectively; meanwhile, the value of dissociation constant of RDV-induced blockage of I K(DR) on the basis of the first-order reaction was yielded to be 3.04 μM. Upon the existence of RDV, the steady-state inactivation curve of I K(DR) was established in the RDV presence; moreover, the recovery became slowed. However, RDV-induced blockage of I K(DR) failed to be overcome by further addition of either α,β-methylene ATP or cyclopentyl-1,3-dipropylxanthine. The RDV addition also lessened the strength of M-type K+ current with the IC50 value of 2.5 μM. The magnitude of voltage hysteresis of I K(M) elicited by long-lasting triangular ramp pulse was diminished by adding RDV. Membrane electroporation-induced current in response to large hyperpolarization was enhanced, with an EC50 value of 5.8 μM. Likewise, in Jurkat T-lymphocytes, adding RDV declined I K(DR) amplitude concomitantly with the raised rate of current inactivation applied by step depolarization. Therefore, in terms of the RDV molecule, there appears to be an unintended activity of the prodrug on ion channels. Its inhibition of both I K(DR) and I K(M) occurring in a non-genomic fashion might provide additional but important mechanisms through which in vivo cellular functions are seriously perturbed.
Collapse
Affiliation(s)
- Wei-Ting Chang
- College of Medicine, Institute of Clinical Medicine, National Cheng Kung University, Tainan, Taiwan
- Division of Cardiovascular Medicine, Chi-Mei Medical Center, Tainan, Taiwan
- Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan
| | - Ping-Yen Liu
- Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan
- Division of Cardiovascular Medicine, Department of Internal Medicine, College of Medicine, National Cheng Kung University Hospital, Tainan, Taiwan
| | - Zi-Han Gao
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan
| | - Shih-Wei Lee
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan
| | - Wen-Kai Lee
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan
| |
Collapse
|