Metformin Regulates the Expression of CD133 Through the AMPK-CEBPβ Pathway in Hepatocellular Carcinoma Cell Lines

Bibliographic Details
Title: Metformin Regulates the Expression of CD133 Through the AMPK-CEBPβ Pathway in Hepatocellular Carcinoma Cell Lines
Authors: Osamu Maehara, Shunsuke Ohnishi, Ayaka Asano, Goki Suda, Mitsuteru Natsuizaka, Koji Nakagawa, Masanobu Kobayashi, Naoya Sakamoto, Hiroshi Takeda
Source: Neoplasia: An International Journal for Oncology Research, Vol 21, Iss 6, Pp 545-556 (2019)
Publisher Information: Elsevier, 2019.
Publication Year: 2019
Collection: LCC:Neoplasms. Tumors. Oncology. Including cancer and carcinogens
Subject Terms: Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282
More Details: CD133 is a cellular surface protein, which has been reported to be a cancer stem cell marker, and thus is considered a potential target for cancer treatment. Metformin, one of the biguanides used for the treatment of diabetes, is also known to reduce the risk of cancer development and cancer stem-like cells (CSCs), including the expression of CD133. However, the mechanism underlying the reduction of the expression of CD133 by metformin is not yet understood. This study shows that metformin suppressed CD133 expression mainly by affecting the CD133 P1 promoter via adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling but not the mammalian target of rapamycin (mTOR). AMPK inhibition rescued the reduction of CD133 by metformin. Further experiments demonstrated that CCAAT/enhancer-binding protein beta (CEBPβ) was upregulated by metformin and that two isoforms of CEBPβ reciprocally regulated the expression of CD133. Specifically, the liver-enriched activator protein (LAP) isoform increased the expression of CD133 by directly binding to the P1 promoter region, whereas the liver-enriched inhibitory protein (LIP) isoform suppressed the expression of CD133. Consistent with these findings, a three dimensional (3D) culture assay and drug sensitivity assay demonstrated that LAP-overexpressing cells formed large spheroids and were more resistant to 5-fluorouracil (5-FU) treatment, whereas LIP-overexpressing cells were more sensitive to 5-FU and showed combined effects with metformin. Our results indicated that metformin-AMPK-CEBPβ signaling plays a crucial role in regulating the gene expression of CD133. Additionally, regulating the ratio of LAP/LIP may be a novel strategy for targeting CSCs for the treatment of cancer.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1476-5586
Relation: http://www.sciencedirect.com/science/article/pii/S1476558619300624; https://doaj.org/toc/1476-5586
DOI: 10.1016/j.neo.2019.03.007
Access URL: https://doaj.org/article/ca28a1a386bc4e6eaeaeadc671f67188
Accession Number: edsdoj.28a1a386bc4e6eaeaeadc671f67188
Database: Directory of Open Access Journals
More Details
ISSN:14765586
DOI:10.1016/j.neo.2019.03.007
Published in:Neoplasia: An International Journal for Oncology Research
Language:English