Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells.
Transforming growth factor-β (TGF-β) is an important inducer of the epithelial-to-mesenchymal transition (EMT) in various cancers. Our previous study demonstrated that prohaptoglobin (proHp) stimulates Smad1/5 activation via ALK1, a TGF-β type I receptor, in endothelial cells, suggesting that proHp...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2022-01-01
|
| Series: | PLoS ONE |
| Online Access: | https://doi.org/10.1371/journal.pone.0266409 |
| _version_ | 1811238378298933248 |
|---|---|
| author | Mi-Kyung Oh Hansol Joo In-Sook Kim |
| author_facet | Mi-Kyung Oh Hansol Joo In-Sook Kim |
| author_sort | Mi-Kyung Oh |
| collection | DOAJ |
| description | Transforming growth factor-β (TGF-β) is an important inducer of the epithelial-to-mesenchymal transition (EMT) in various cancers. Our previous study demonstrated that prohaptoglobin (proHp) stimulates Smad1/5 activation via ALK1, a TGF-β type I receptor, in endothelial cells, suggesting that proHp plays a role in TGF-β signaling. However, the function of proHp in cellular events downstream of Smads remains unclear. The current study investigated the effects of proHp on TGF-β-mediated Smad-dependent EMT induction and cell invasion in vitro using proHp-overexpressing SK-Hep1 liver cancer cells. The results of Western blotting, quantitative real-time RT-PCR, and immunocytochemistry indicated that proHp downregulated expression of mesenchymal marker and EMT regulator such as N-cadherin, vimentin, and twist, and upregulated expression of the epithelial marker E-cadherin. Compared with control cells, proHp-overexpressing cells exhibited high levels of ALK1/2/3 receptors and markedly increased Smad1/5 phosphorylation. Interestingly, proHp attenuated TGF-β-induced expression of mesenchymal markers and Smad2/3 phosphorylation. It also significantly suppressed cell invasion and migration. Knockdown of Smad1/5 abolished the inhibitory effects of proHp on TGF-β-stimulated Smad2/3 phosphorylation and mesenchymal marker expression. These findings indicate that proHp suppresses the TGF-β-induced EMT and cell invasion in vitro by enhancing Smad1/5 activation via ALK1/2/3 receptors and thus suppressing the Smad2/3 signaling pathway in SK-Hep1 cells. This study suggests that proHp may prevent a de-differentiation of hepatic cells and induce a cell differentiation by regulating the Smad signaling pathway. |
| first_indexed | 2024-04-12T12:40:43Z |
| format | Article |
| id | doaj.art-97a46360981b4fb9880dae2c646f9f06 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-12T12:40:43Z |
| publishDate | 2022-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-97a46360981b4fb9880dae2c646f9f062022-12-22T03:32:47ZengPublic Library of Science (PLoS)PLoS ONE1932-62032022-01-01175e026640910.1371/journal.pone.0266409Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells.Mi-Kyung OhHansol JooIn-Sook KimTransforming growth factor-β (TGF-β) is an important inducer of the epithelial-to-mesenchymal transition (EMT) in various cancers. Our previous study demonstrated that prohaptoglobin (proHp) stimulates Smad1/5 activation via ALK1, a TGF-β type I receptor, in endothelial cells, suggesting that proHp plays a role in TGF-β signaling. However, the function of proHp in cellular events downstream of Smads remains unclear. The current study investigated the effects of proHp on TGF-β-mediated Smad-dependent EMT induction and cell invasion in vitro using proHp-overexpressing SK-Hep1 liver cancer cells. The results of Western blotting, quantitative real-time RT-PCR, and immunocytochemistry indicated that proHp downregulated expression of mesenchymal marker and EMT regulator such as N-cadherin, vimentin, and twist, and upregulated expression of the epithelial marker E-cadherin. Compared with control cells, proHp-overexpressing cells exhibited high levels of ALK1/2/3 receptors and markedly increased Smad1/5 phosphorylation. Interestingly, proHp attenuated TGF-β-induced expression of mesenchymal markers and Smad2/3 phosphorylation. It also significantly suppressed cell invasion and migration. Knockdown of Smad1/5 abolished the inhibitory effects of proHp on TGF-β-stimulated Smad2/3 phosphorylation and mesenchymal marker expression. These findings indicate that proHp suppresses the TGF-β-induced EMT and cell invasion in vitro by enhancing Smad1/5 activation via ALK1/2/3 receptors and thus suppressing the Smad2/3 signaling pathway in SK-Hep1 cells. This study suggests that proHp may prevent a de-differentiation of hepatic cells and induce a cell differentiation by regulating the Smad signaling pathway.https://doi.org/10.1371/journal.pone.0266409 |
| spellingShingle | Mi-Kyung Oh Hansol Joo In-Sook Kim Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells. PLoS ONE |
| title | Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells. |
| title_full | Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells. |
| title_fullStr | Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells. |
| title_full_unstemmed | Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells. |
| title_short | Prohaptoglobin inhibits the transforming growth factor-β-induced epithelial-to-mesenchymal transition in vitro by increasing Smad1/5 activation and suppressing the Smad2/3 signaling pathway in SK-Hep1 liver cancer cells. |
| title_sort | prohaptoglobin inhibits the transforming growth factor β induced epithelial to mesenchymal transition in vitro by increasing smad1 5 activation and suppressing the smad2 3 signaling pathway in sk hep1 liver cancer cells |
| url | https://doi.org/10.1371/journal.pone.0266409 |
| work_keys_str_mv | AT mikyungoh prohaptoglobininhibitsthetransforminggrowthfactorbinducedepithelialtomesenchymaltransitioninvitrobyincreasingsmad15activationandsuppressingthesmad23signalingpathwayinskhep1livercancercells AT hansoljoo prohaptoglobininhibitsthetransforminggrowthfactorbinducedepithelialtomesenchymaltransitioninvitrobyincreasingsmad15activationandsuppressingthesmad23signalingpathwayinskhep1livercancercells AT insookkim prohaptoglobininhibitsthetransforminggrowthfactorbinducedepithelialtomesenchymaltransitioninvitrobyincreasingsmad15activationandsuppressingthesmad23signalingpathwayinskhep1livercancercells |