scholarly journals MicroRNA-451 regulates stemness of side population cells via PI3K/Akt/mTOR signaling pathway in multiple myeloma

Oncotarget ◽  
2015 ◽  
Vol 6 (17) ◽  
pp. 14993-15007 ◽  
Author(s):  
Juan Du ◽  
Shuyan Liu ◽  
Jie He ◽  
Xi Liu ◽  
Ying Qu ◽  
...  
BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenfeng He ◽  
Yonghui Fu ◽  
Yongliang Zheng ◽  
Xiaoping Wang ◽  
Bin Liu ◽  
...  

Abstract Background Side population (SP) cells, which have similar features to those of cancer stem cells, show resistance to dexamethasone (Dex) treatment. Thus, new drugs that can be used in combination with Dex to reduce the population of SP cells in multiple myeloma (MM) are required. Diallyl thiosulfinate (DATS, allicin), a natural organosulfur compound derived from garlic, has been shown to inhibit the proliferation of SP cells in MM cell lines. Therefore, we investigated the effect of a combination of DATS and Dex (DAT + Dex) on MM SP cells. Methods SP cells were sorted from MM RPMI-8226 and NCI-H929 cell lines using Hoechst 33342-labeled fluorescence-activated cell sorting. The growth of SP cells was evaluated using the cell counting kit-8 assay. Cell cycle and apoptosis assays were conducted using a BD Calibur flow cytometer. miRNA expression was measured using quantitative reverse transcription-polymerase chain reaction. Phosphoinositide 3-kinase (PI3K), phosphorylated AKT (p-AKT), AKT, p-mechanistic target of rapamycin (mTOR), and mTOR levels were measured using western blot analysis. Results Our results showed that the combination of DATS+Dex inhibited sphere formation, colony formation, and proliferation of MM SP cells by inducing apoptosis and cell cycle arrest in the G1/S phase. In addition, the combination of DATS+Dex promoted miR-127-3p expression and inhibited PI3K, p-AKT, and p-mTOR expression in SP cells. Knockdown of miR-127-3p expression weakened the effect of DATS+Dex on cell proliferation, colony formation, apoptosis, and cell cycle of MM SP cells. Additionally, knockdown of miR-127-3p activated the PI3K/AKT/mTOR signaling pathway in MM SP cells cotreated with DATS+Dex. Conclusion We demonstrated that cotreatment with DATS+Dex reduced cell proliferation, promoted apoptosis, and caused cell cycle arrest of MM SP cells by promoting miR-127-3p expression and deactivating the PI3K/AKT/mTOR signaling pathway.


Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1870-1870
Author(s):  
Yanyan Gu ◽  
Jonathan L. Kaufman ◽  
Lawrence H. Boise ◽  
Sagar Lonial

Abstract Abstract 1870 Introduction: The development and survival of normal plasma cells as well as multiple myeloma cells depend on an elaborately regulated ubiquitin proteasome system (UPS). Proteasome inhibitors such as bortezomib have proved to be highly active in the treatment of multiple myeloma. MLN4924, a newly developed investigational NEDD8 activating enzyme (NAE) inhibitor, exhibits promising anti-tumor effect through both clinical and laboratory observation. We sought to evaluate the individual signaling effects of MLN4924 in multiple myeloma, with the intent of further understanding the mechanism of action and identifying potential combinations. Methods: Human myeloma cell lines (MM.1S, MM.1R and U266) were treated with increasing concentrations of MLN4924 for 24, 48 and 72 hrs respectively or concurrently with bortezomib. Cell viability (MTT), apoptosis, western blot, RT-qPCR and siRNA assays were used to identify the cellular and molecular sequelae of MLN4924 treatment. Results: Single agent studies demonstrate that MLN4924 induces cytotoxicity in all three MM cell lines. Cytotoxicity is associated with increased apoptosis and suppression of AKT and mTOR signaling pathway, as detected by FACS and western blot. MLN4924 suppresses protein turnover of Cullin-ring ligases substrates leading to stabilization of specific proteins, such as p27, CDT1, NRF2. We find that REDD1, a substrate of CUL4 A–DDB 1–ROC1–β-TRCP ubiquitin ligase and negative regulator of mTOR pathway, increases in as early as 2 hours when treated with MLN4924. Knock-down of REDD1 using siRNA alleviates MLN4924 induced AKT, mTOR signaling suppression as well as the growth inhibition, which suggests that MLN4924 inhibits AKT, mTOR signaling through upregulating REDD1 protein leading to cytotoxicity. Combining MLN4924 with bortezomib synergistically enhances the antitumor effect of MLN4924. Western blot confirms the development of significantly increased procaspase and PARP cleavage, as well as substantial down regulation of AKT and mTOR signaling. Neither IL-6 nor IGF-1 is able to abrogate these combination effects. When we silence REDD1 in the combination assay in MM.1R, we find less cell apoptosis and suppression of AKT, mTOR pathway, which further support that REDD1 is an important regulator for MLN4924 induced cytotoxicity in MMs. Conclusion: MLN4924 is a potent investigational antitumor compound suppressing mTOR signaling pathways in myeloma cell lines. Down-regulation of the mTOR signaling pathway is associated with increased expression of REDD1. Combination of MLN4924 with the proteasome inhibitor bortezomib induces synergistic apoptosis in MMs cell lines which can overcome the prosurvival effects of growth factor (IL-6 and IGF-1). These findings could positively impact clinical combination strategies. Disclosures: Kaufman: Millenium: Consultancy; Onyx Pharmaceuticals: Consultancy; Novartis: Consultancy; Keryx: Consultancy; Merck: Research Funding; Celgene: Research Funding. Lonial:Millennium Pharmaceuticals, Inc.: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Bristol-Myers Squibb: Consultancy; Onyx: Consultancy; Merck: Consultancy.


2020 ◽  
Author(s):  
Minfen Zhang ◽  
Hui Chen ◽  
Ping Qin ◽  
Tonghui Cai ◽  
Lingjun Li ◽  
...  

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