Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells
Nobiletin (NOB) is a polymethoxylated flavonoid isolated from citrus fruit peel that has been shown to possess anti-tumor, antithrombotic, antifungal, anti-inflammatory and anti-atherosclerotic activities. The main purpose of this study was to explore the potential of using NOB to induce apoptosis i...
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doaj-19ea39c005d949a1976bf99ec1d46f2c2020-11-25T02:20:27ZengMDPI AGMolecules1420-30492019-08-012416288110.3390/molecules24162881molecules24162881Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer CellsYih-Gang Goan0Wen-Tung Wu1Chih-I Liu2Choo-Aun Neoh3Yu-Jen Wu4Department of Surgery, Kaohsiung Veterans General Hospital Pingtung Branch, Pingtung 91202, TaiwanDepartment of Food Science and Nutrition, Meiho University, Pingtung 91202, TaiwanDepartment of Nursing, Meiho University, Pingtung 91202, TaiwanDepartment of Research, Pingtung Christian Hospital, Pingtung 90059, TaiwanDepartment of Nursing, Meiho University, Pingtung 91202, TaiwanNobiletin (NOB) is a polymethoxylated flavonoid isolated from citrus fruit peel that has been shown to possess anti-tumor, antithrombotic, antifungal, anti-inflammatory and anti-atherosclerotic activities. The main purpose of this study was to explore the potential of using NOB to induce apoptosis in human bladder cancer cells and study the underlying mechanism. Using an MTT assay, agarose gel electrophoresis, a wound-healing assay, flow cytometry, and western blot analysis, this study investigated the signaling pathways involved in NOB-induced apoptosis in BFTC human bladder cancer cells. Our results showed that NOB at concentrations of 60, 80, and 100 μM inhibited cell growth by 42%, 62%, and 80%, respectively. Cells treated with 60 μM NOB demonstrated increased DNA fragmentation, and flow cytometry analysis confirmed that the treatment caused late apoptotic cell death. Western blot analysis showed that mitochondrial dysfunction occurred in NOB-treated BFTC cells, leading to cytochrome <i>C</i> release into cytosol, activation of pro-apoptotic proteins (caspase-3, caspase-9, Bad, and Bax), and inhibition of anti-apoptotic proteins (Mcl-1, Bcl-xl, and Bcl-2). NOB-induced apoptosis was also mediated by regulating endoplasmic reticulum stress via the PERK/elF2α/ATF4/CHOP pathway, and downregulating the PI3K/AKT/mTOR pathway. Our results suggested that the cytotoxic and apoptotic effects of NOB on bladder cancer cells are associated with endoplasmic reticulum stress and mitochondrial dysfunction.https://www.mdpi.com/1420-3049/24/16/2881nobiletinmitochondrial dysfunctionendoplasmic reticulum stressPI3K/AKT/mTOR pathway |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Yih-Gang Goan Wen-Tung Wu Chih-I Liu Choo-Aun Neoh Yu-Jen Wu |
spellingShingle |
Yih-Gang Goan Wen-Tung Wu Chih-I Liu Choo-Aun Neoh Yu-Jen Wu Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells Molecules nobiletin mitochondrial dysfunction endoplasmic reticulum stress PI3K/AKT/mTOR pathway |
author_facet |
Yih-Gang Goan Wen-Tung Wu Chih-I Liu Choo-Aun Neoh Yu-Jen Wu |
author_sort |
Yih-Gang Goan |
title |
Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells |
title_short |
Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells |
title_full |
Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells |
title_fullStr |
Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells |
title_full_unstemmed |
Involvement of Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and the PI3K/AKT/mTOR Pathway in Nobiletin-Induced Apoptosis of Human Bladder Cancer Cells |
title_sort |
involvement of mitochondrial dysfunction, endoplasmic reticulum stress, and the pi3k/akt/mtor pathway in nobiletin-induced apoptosis of human bladder cancer cells |
publisher |
MDPI AG |
series |
Molecules |
issn |
1420-3049 |
publishDate |
2019-08-01 |
description |
Nobiletin (NOB) is a polymethoxylated flavonoid isolated from citrus fruit peel that has been shown to possess anti-tumor, antithrombotic, antifungal, anti-inflammatory and anti-atherosclerotic activities. The main purpose of this study was to explore the potential of using NOB to induce apoptosis in human bladder cancer cells and study the underlying mechanism. Using an MTT assay, agarose gel electrophoresis, a wound-healing assay, flow cytometry, and western blot analysis, this study investigated the signaling pathways involved in NOB-induced apoptosis in BFTC human bladder cancer cells. Our results showed that NOB at concentrations of 60, 80, and 100 μM inhibited cell growth by 42%, 62%, and 80%, respectively. Cells treated with 60 μM NOB demonstrated increased DNA fragmentation, and flow cytometry analysis confirmed that the treatment caused late apoptotic cell death. Western blot analysis showed that mitochondrial dysfunction occurred in NOB-treated BFTC cells, leading to cytochrome <i>C</i> release into cytosol, activation of pro-apoptotic proteins (caspase-3, caspase-9, Bad, and Bax), and inhibition of anti-apoptotic proteins (Mcl-1, Bcl-xl, and Bcl-2). NOB-induced apoptosis was also mediated by regulating endoplasmic reticulum stress via the PERK/elF2α/ATF4/CHOP pathway, and downregulating the PI3K/AKT/mTOR pathway. Our results suggested that the cytotoxic and apoptotic effects of NOB on bladder cancer cells are associated with endoplasmic reticulum stress and mitochondrial dysfunction. |
topic |
nobiletin mitochondrial dysfunction endoplasmic reticulum stress PI3K/AKT/mTOR pathway |
url |
https://www.mdpi.com/1420-3049/24/16/2881 |
work_keys_str_mv |
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