scholarly journals Spirulina Crude Protein Promotes the Migration and Proliferation in IEC-6 Cells by Activating EGFR/MAPK Signaling Pathway

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 205
Author(s):  
Su-Jin Jeong ◽  
Jeong-Wook Choi ◽  
Min-Kyeong Lee ◽  
Youn-Hee Choi ◽  
Taek-Jeong Nam

Spirulina is a type of filamentous blue-green microalgae known to be rich in nutrients and to have pharmacological effects, but the effect of spirulina on the small intestine epithelium is not well understood. Therefore, this study aims to investigate the proliferative effects of spirulina crude protein (SPCP) on a rat intestinal epithelial cells IEC-6 to elucidate the mechanisms underlying its effect. First, the results of wound-healing and cell viability assays demonstrated that SPCP promoted migration and proliferation in a dose-dependent manner. Subsequently, when the mechanisms of migration and proliferation promotion by SPCP were confirmed, we found that the epidermal growth factor receptor (EGFR) and mitogen-activated protein (MAPK) signaling pathways were activated by phosphorylation. Cell cycle progression from G0/G1 to S phase was also promoted by SPCP through upregulation of the expression levels of cyclins and cyclin-dependent kinases (Cdks), which regulate cell cycle progression to the S phase. Meanwhile, the expression of cyclin-dependent kinase inhibitors (CKIs), such as p21 and p27, decreased with SPCP. In conclusion, our results indicate that activation of EGFR and its downstream signaling pathway by SPCP treatment regulates cell cycle progression. Therefore, these results contribute to the research on the molecular mechanism for SPCP promoting the migration and proliferation of rat intestinal epithelial cells.

2020 ◽  
Vol 177 (1) ◽  
pp. 226-234 ◽  
Author(s):  
Shuyan Lu ◽  
Tae Sung ◽  
Marina Amaro ◽  
Brad Hirakawa ◽  
Bart Jessen ◽  
...  

Abstract Cyclin-dependent kinases (CDKs) are serine/threonine kinases that regulate cell cycle and have been vigorously pursued as druggable targets for cancer. There are over 20 members of the CDK family. Given their structural similarity, selective inhibition by small molecules has been elusive. In addition, collateral damage to highly proliferative normal cells by CDK inhibitors remains a safety concern. Intestinal epithelial cells are highly proliferative and the impact of individual CDK inhibition on intestinal cell proliferation has not been well studied. Using the rat intestinal epithelial (IEC6) cells as an in vitro model, we found that the selective CDK4/6 inhibitor palbociclib lacked potent anti-proliferative activity in IEC6 relative to the breast cancer cell line MCF7, indicating the absence of intestinal cell reliance on CDK4/6 for cell cycle progression. To further illustrate the role of CDKs in intestinal cells, we chose common targets of CDK inhibitors (CDK 1, 2, 4, 6, and 9) for targeted gene knockdown to evaluate phenotypes. Surprisingly, only CDK1 and CDK9 knockdown demonstrated profound cell death or had moderate growth effects, respectively. CDK2, 4, or 6 knockdowns, whether single, double, or triple combinations, did not have substantial impact. Studies evaluating CDK1 knockdown under various cell seeding densities indicate direct effects on viability independent of proliferation state and imply a potential noncanonical role for CDK1 in intestinal epithelial biology. This research supports the concept that CDK1 and CDK9, but not CDKs 2, 4, or 6, are essential for intestinal cell cycle progression and provides safety confidence for interphase CDK inhibition.


Nutrition ◽  
2020 ◽  
pp. 111087
Author(s):  
Rosa Elayne Marques de Freitas ◽  
Pedro Henrique Quintela Soares de Medeiros ◽  
Francisco Adelvane de Paulo Rodrigues ◽  
Marco Antonio de Freitas Clementino ◽  
Camila Fernandes ◽  
...  

2008 ◽  
Vol 28 (10) ◽  
pp. 3190-3197 ◽  
Author(s):  
Angelique W. Whitehurst ◽  
Rosalyn Ram ◽  
Latha Shivakumar ◽  
Boning Gao ◽  
John D. Minna ◽  
...  

ABSTRACT Multiple molecular lesions in human cancers directly collaborate to deregulate proliferation and suppress apoptosis to promote tumorigenesis. The candidate tumor suppressor RASSF1A is commonly inactivated in a broad spectrum of human tumors and has been implicated as a pivotal gatekeeper of cell cycle progression. However, a mechanistic account of the role of RASSF1A gene inactivation in tumor initiation is lacking. Here we have employed loss-of-function analysis in human epithelial cells for a detailed investigation of the contribution of RASSF1 to cell cycle progression. We found that RASSF1A has dual opposing regulatory connections to G1/S phase cell cycle transit. RASSF1A associates with the Ewing sarcoma breakpoint protein, EWS, to limit accumulation of cyclin D1 and restrict exit from G1. Surprisingly, we found that RASSF1A is also required to restrict SCFβTrCP activity to allow G/S phase transition. This restriction is required for accumulation of the anaphase-promoting complex/cyclosome (APC/C) inhibitor Emi1 and the concomitant block of APC/C-dependent cyclin A turnover. The consequence of this relationship is inhibition of cell cycle progression in normal epithelial cells upon RASSF1A depletion despite elevated cyclin D1 concentrations. Progression to tumorigenicity upon RASSF1A gene inactivation should therefore require collaborating genetic aberrations that bypass the consequences of impaired APC/C regulation at the G1/S phase cell cycle transition.


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