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Hartal-Benishay LH, Saadi E, Toubiana S, Shaked L, Lalzar M, Abu Hatoum O, Tal S, Selig S, Barki-Harrington L. MBTPS1 regulates proliferation of colorectal cancer primarily through its action on sterol regulatory element-binding proteins. Front Oncol 2022; 12:1004014. [PMID: 36300096 PMCID: PMC9592115 DOI: 10.3389/fonc.2022.1004014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 09/05/2022] [Indexed: 11/21/2022] Open
Abstract
Among the main metabolic pathways implicated in cancer cell proliferation are those of cholesterol and fatty acid synthesis, both of which are tightly regulated by sterol regulatory element-binding proteins (SREBPs). SREBPs are activated through specific cleavage by membrane-bound transcription factor protease 1 (MBTPS1), a serine protease that cleaves additional substrates (ATF6, BDNF, CREBs and somatostatin), some of which are also implicated in cell proliferation. The goal of this study was to determine whether MBTPS1 may serve as a master regulator in proliferation of colorectal cancer (CRC). Tumors from CRC patients showed variable levels of MBTPS1 mRNA, which were in positive correlation with the levels of SREBPs and ATF6, and in reverse correlation with BDNF levels. Chemical inhibition of MBTPS1 activity in two CRC-derived cell lines resulted in a marked decrease in the levels of SREBPs, but not of its other substrates and a marked decrease in cell proliferation, which suggested that MBTPS1 activity is critical for proliferation of these cells. In accordance, CRISPR/Cas9 targeted knockout (KO) of the MBTPS1 gene resulted in the survival of only a single clone that presented a phenotype of severely attenuated proliferation and marked downregulation of several energy metabolism pathways. We further showed that survival of the MBTPS1 KO clone was dependent upon significant upregulation of the type-1 interferon pathway, the inhibition of which halted proliferation entirely. Finally, rescue of the MBTPS1 KO cells, resulted in partial restoration of MBTPS1 levels, which was in accordance with partial recovery in proliferation and in SREBP levels. These finding suggest that MBTPS1 plays a critical role in regulating colon cancer proliferation primarily through SREBP-associated lipid metabolism, and as such may serve as a possible therapeutic target in CRC.
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Affiliation(s)
- Liat H. Hartal-Benishay
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Esraa Saadi
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Shir Toubiana
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa, Israel
| | - Lior Shaked
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Maya Lalzar
- Bioinformatics Service Unit, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Ossama Abu Hatoum
- Department of Surgery, Ha’emek Medical Center, Afula, Israel
- Department of Medicine, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa, Israel
| | - Sharon Tal
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
| | - Sara Selig
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine and Research Institute, Technion, Haifa, Israel
- Laboratory of Molecular Medicine, Rambam Health Care Campus, Haifa, Israel
| | - Liza Barki-Harrington
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa, Israel
- *Correspondence: Liza Barki-Harrington,
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Abstract
Innate immune responses are key to maintain adequate host-microbial interactions. However, those signals are needed to efficiently trigger rapid and targeted antimicrobial responses in case of pathogen encounter. Several molecules have evolved to regulate intensity and coordinate signaling to avoid detrimental consequences to the host. Regulation can occur at the cell surface, within the cytoplasm, and at the transcriptional level. Innate immune regulation seems to be equally important than stimulation, as disruption of immunoregulatory molecules modulates the risk for several diseases. This is the case for colitis and inflammatory bowel disease but also colorectal cancer and intestinal infections. In this review, we recapitulate the molecular mechanisms underlying regulation of innate immune signals and mention their implications in several disease states including inflammatory bowel disease.
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Bacterial ligand stimulates TLR2-dependent chemokines of colon cell. Immunobiology 2014; 219:350-6. [PMID: 24565410 DOI: 10.1016/j.imbio.2013.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 12/02/2013] [Accepted: 12/28/2013] [Indexed: 01/05/2023]
Abstract
Shigella spp. are known to penetrate the colonic epithelial cells causing shigellosis, which results in production of convalescent antibodies against porin, the surface exposed major outer membrane protein. Porin has been categorized as primarily TLR2-ligand and here we validated its signaling procedure in colonic INT-407 cells simulating the host scenario. Porin up-regulated TLR2 and -6 followed by TLR2·MYD88 complex formation suggesting direct involvement of MYD88 for downstream signaling. Translocation of NF-κB p65 and p50 subunits on to the nucleus indicates involvement of the transcription factor in signaling. Porin-induced TLR signaling specifically stimulated the pro-inflammatory chemokine panel comprising of MIP-1α, MCP-1 and IL-8. Inhibition studies of TLR2 and NF-κB led to abrogation of the pro-inflammatory chemokine response, showing TLR-dependent signaling through NF-κB regulate gut activity. This work elucidates TLR2 not only scans pathogen-associated molecule but also has a direct role in maneuvering colon cell response.
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