Medine Zeynep Gungor1,2, Merve Uysal1,2, Mehmet Ozturk1,3,4, Serif Senturk5,6,7. 1. Izmir Biomedicine and Genome Center, Izmir, 35340, Turkey. 2. Department of Genome Sciences and Molecular Biotechnology, Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, 35340, Turkey. 3. Department of Medical Biology, Faculty of Medicine, Izmir Tinaztepe University, Izmir, 35400, Turkey. 4. Department of Molecular Biology and Genetics, Bilkent University, Ankara, 06800, Turkey. 5. Izmir Biomedicine and Genome Center, Izmir, 35340, Turkey. serif.senturk@ibg.edu.tr. 6. Department of Genome Sciences and Molecular Biotechnology, Izmir International Biomedicine and Genome Institute, Dokuz Eylul University, Izmir, 35340, Turkey. serif.senturk@ibg.edu.tr. 7. Department of Molecular Biology and Genetics, Bilkent University, Ankara, 06800, Turkey. serif.senturk@ibg.edu.tr.
Abstract
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most challenging malignancies, with high morbidity and mortality rates. The transforming growth factor-β (TGF-β) pathway plays a dual role in HCC, acting as both tumor suppressor and promoter. A thorough understanding of the mechanisms underlying its opposing functions is important. The growth suppressive effects of TGF-β remain largely unknown for mesenchymal HCC cells. Using a systematic approach, here we assess the cytostatic TGF-β responses and intracellular transduction of the canonical TGF-β/Smad signaling cascade in mesenchymal-like HCC cell lines. METHODS: Nine mesenchymal-like HCC cell lines, including SNU182, SNU387, SNU398, SNU423, SNU449, SNU475, Mahlavu, Focus, and Sk-Hep1, were used in this study. The cytostatic effects of TGF-β were evaluated by cell cycle analysis, BrdU labeling, and SA-β-Gal assay. RT-PCR and western blot analysis were utilized to determine the mRNA and protein expression levels of TGF-β signaling components and cytostatic genes. Immunoperoxidase staining and luciferase reporter assays were performed to comprehend the transduction of the canonical TGF-β pathway. RESULTS: We report that mesenchymal-like HCC cell lines are resistant to TGF-β-induced growth suppression. The vast majority of cell lines have an active canonical signaling from the cell membrane to the nucleus. Three cell lines had lost the expression of cytostatic effector genes. CONCLUSION: Our findings reveal that cytostatic TGF-β responses have been selectively lost in mesenchymal-like HCC cell lines. Notably, their lack of responsiveness was not associated with a widespread impairment of TGF-β signaling cascade. These cell lines may serve as valuable models for studying the molecular mechanisms underlying the loss of TGF-β-mediated cytostasis during hepatocarcinogenesis.
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most challenging malignancies, with high morbidity and mortality rates. The transforming growth factor-β (TGF-β) pathway plays a dual role in HCC, acting as both tumor suppressor and promoter. A thorough understanding of the mechanisms underlying its opposing functions is important. The growth suppressive effects of TGF-β remain largely unknown for mesenchymal HCC cells. Using a systematic approach, here we assess the cytostatic TGF-β responses and intracellular transduction of the canonical TGF-β/Smad signaling cascade in mesenchymal-like HCC cell lines. METHODS: Nine mesenchymal-like HCC cell lines, including SNU182, SNU387, SNU398, SNU423, SNU449, SNU475, Mahlavu, Focus, and Sk-Hep1, were used in this study. The cytostatic effects of TGF-β were evaluated by cell cycle analysis, BrdU labeling, and SA-β-Gal assay. RT-PCR and western blot analysis were utilized to determine the mRNA and protein expression levels of TGF-β signaling components and cytostatic genes. Immunoperoxidase staining and luciferase reporter assays were performed to comprehend the transduction of the canonical TGF-β pathway. RESULTS: We report that mesenchymal-like HCC cell lines are resistant to TGF-β-induced growth suppression. The vast majority of cell lines have an active canonical signaling from the cell membrane to the nucleus. Three cell lines had lost the expression of cytostatic effector genes. CONCLUSION: Our findings reveal that cytostatic TGF-β responses have been selectively lost in mesenchymal-like HCC cell lines. Notably, their lack of responsiveness was not associated with a widespread impairment of TGF-β signaling cascade. These cell lines may serve as valuable models for studying the molecular mechanisms underlying the loss of TGF-β-mediated cytostasis during hepatocarcinogenesis.
Authors: J G Park; J H Lee; M S Kang; K J Park; Y M Jeon; H J Lee; H S Kwon; H S Park; K S Yeo; K U Lee Journal: Int J Cancer Date: 1995-07-28 Impact factor: 7.396
Authors: John G Tate; Sally Bamford; Harry C Jubb; Zbyslaw Sondka; David M Beare; Nidhi Bindal; Harry Boutselakis; Charlotte G Cole; Celestino Creatore; Elisabeth Dawson; Peter Fish; Bhavana Harsha; Charlie Hathaway; Steve C Jupe; Chai Yin Kok; Kate Noble; Laura Ponting; Christopher C Ramshaw; Claire E Rye; Helen E Speedy; Ray Stefancsik; Sam L Thompson; Shicai Wang; Sari Ward; Peter J Campbell; Simon A Forbes Journal: Nucleic Acids Res Date: 2019-01-08 Impact factor: 16.971