Gonzalez-Torres C, Gaytan-Cervantes J, Vazquez-Santillan K, Mandujano-Tinoco EA, Ceballos-Cancino G, Garcia-Venzor A, Zampedri C, Sanchez-Maldonado P, Mojica-Espinosa R, Jimenez-Hernandez LE, Maldonado V. NF-κB Participates in the Stem Cell Phenotype of Ovarian Cancer Cells.
Arch Med Res 2017;
48:343-351. [PMID:
28886875 DOI:
10.1016/j.arcmed.2017.08.001]
[Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 08/24/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND
NF-κB is a transcription factor involved in cancer stem cells maintenance of many tumors. Little is known about the specific stem-associated upstream regulators of this pathway in ovarian cancer. The Aim of the study was to analyze the role of the canonical and non-canonical NF-κB pathways in stem cells of ovarian cancer cell lines.
METHODS
Stem cells were isolated using sorting cytometry. Western blot and RT-PCR were used to quantify protein and messenger RNA levels. Loss and gain of function assays were performed using siRNAs and dominant-negative proteins, respectively. NF-κB binding activity was measured with a reporter gene assay. The stem phenotype was estimated with clonogenic assays using soft agar, colony formation, ovospheres formation and in vivo tumorigenicity assays.
RESULTS
The CD44+ subpopulation of SKOV3 ovarian cancer cell line presented higher mRNA levels of key stemness genes, an increased tumorigenic capacity and higher expression of the RelA, RelB and IKKα. When the canonical pathway was inhibited by means of a dominant-negative version of IkBα, the stem cell population was reduced, as shown by a reduced CD44+ subpopulation, a decrease in the expression of the stemness genes and a reduction of the stem phenotype. In addition, IKKα, the main upstream non-canonical kinase, was highly expressed in the CSC population. Accordingly, when IKKα was inhibited using shRNAs, the expression of the stemness genes was reduced.
CONCLUSIONS
This report is the first to show the importance of several elements of both NF-κB pathway in maintaining the ovarian cancer stem cell population.
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