Artocarpus communis Induces Autophagic Instead of Apoptotic Cell Death in Human Hepatocellular Carcinoma Cells

2015 ◽  
Vol 43 (03) ◽  
pp. 559-579 ◽  
Author(s):  
Cheng-Wei Tzeng ◽  
Wen-Sheng Tzeng ◽  
Liang-Tzung Lin ◽  
Chiang-Wen Lee ◽  
Ming-Hong Yen ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Death ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Hepatoma Cell ◽  
Apoptotic Cell Death ◽  
Human Hepatocellular Carcinoma ◽  
Acridine Orange Staining ◽  
Hepatoma Cell Lines

For centuries, natural plant extracts have played an important role in traditional medicine for curing and preventing diseases. Studies have revealed that Artocarpus communis possess various bioactivities, such as anti-inflammation, anti-oxidant, and anticancer activities. A. communis offers economic value as a source of edible fruit, yields timber, and is widely used in folk medicines. However, little is known about its molecular mechanisms of anticancer activity. Here, we demonstrate the antiproliferative activity of A. communis methanol extract (AM) and its dichloromethane fraction (AD) in two human hepatocellular carcinoma (HCC) cell lines, HepG2 and PLC/PRF/5. Colony assay showed the long-term inhibitory effect of both extracts on cell growth. DNA laddering and immunoblotting analyses revealed that both extracts did not induce apoptosis in the hepatoma cell lines. AM and AD-treated cells demonstrated different cell cycle distribution compared to UV-treated cells, which presented apoptotic cell death with high sub-G1 ratio. Instead, acridine orange staining revealed that AM and AD triggered autophagosome accumulation. Immunoblotting showed a significant expression of autophagy-related proteins, which indicated the autophagic cell death (ACD) of hepatoma cell lines. This study therefore demonstrates that A. communis AM and its dichloromethane fraction can induce ACD in HCC cells and elucidates the potential of A. communis extracts for development as anti tumor therapeutic agents that utilize autophagy as mechanism in mediating cancer cell death.

Cell Death Mechanisms Induced by INNO-406, a Novel Tyrosine Kinase Inhibitor for Imatinib-Resistant Ph+ Leukemia.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2177-2177
Author(s):  
Yuri Kamitsuji ◽  
Souichi Adachi ◽  
Motonobu Watanabe ◽  
Hiroshi Matsubara ◽  
Yasuhiro Mizushima ◽  
...  
Keyword(s):  
Cell Death ◽  
Dna Fragmentation ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death ◽  
Cellular Growth ◽  
Caspase Activity ◽  
Apoptosis Pathway ◽  
Cell Death Mechanisms

Abstract The blockade of Bcr-Abl signaling suppresses cellular growth and induces cell death in Bcr-Abl-positive (Bcr-Abl+) cells. We herein assessed the cell death mechanisms induced by INNO-406 (formerly NS-187; Kimura et al, Blood 2005), in four CML-derived Bcr-Abl+ cell lines (K562, KT-1, BV173 and MYL), and Ba/F3 harboring wild type bcr-abl (Ba/F3/wt bcr-abl). When cells are treated by INNO-406, the accumulation of subG1 fraction was seen in all five cell lines. This cell death was accompanied by loss of mitochondrial membrane potential and was inhibited by over-expression of Bcl-2, indicating that INNO-406-induced cell death is mainly mediated by mitochondria-dependent apoptosis. Caspase-3 activation in INNO-406-treated cell was also common among all cell lines. However, the inhibition of caspase activity by ZVAD-fmk (ZVAD), a pan-caspase inhibitor, was variable in the cell lines tested. In K562, KT-1 and BV173 cells treated with INNO-406, ZVAD almost completely prevented apoptosis (i.e. showing atypical feature for apoptosis, no DNA fragmentation and no accumulation of subG1 fraction), with cell death resulting from morphologically non-apoptotic cell death. The percentages of non-apoptotic cells under ZVAD co-treated with INNO-406 varied among the three cell lines, suggesting that the dependence on non-apoptotic cell death is variable. While, in MYL and Ba/F3/wt bcr-abl cells, despite the sufficient inhibition of caspases’ activity, the inhibition of the cell death by ZVAD was only partial and these cell lines still underwent apoptosis (i.e. showing DNA fragmentation and the accumulation of subG1 population), suggesting the presence of caspase-independent apoptotic machineries. In addition, assay data for apoptosome activities (complex of Apaf-1, cytochrome c and caspase-9 that initiates and drives cysteine protease activities of caspase in mitochondrial-mediated pathway) suggested that cell types could be largely subdivided into two groups, namely those cells with high apoptosome activity (K562, KT-1 and BV173) that undergo non-apoptotic, and, those cells with low apoptosome activity (MYL and Ba/F3/wt bcr-abl.) that undergo caspase-independent apoptosis when caspase activity was blocked by ZVAD. These data indicate that there is a common initial pathway for cell death due to INNO-406, while the pathway for cell death commitment (i.e. dependence on apoptosome/caspases-mediated apoptosis pathway that has been commonly believed to be central for apoptosis execution) vary among cellular context in Bcr-Abl+ leukemic cells. Moreover, in a mouse model of primary human CML in blast crisis, INNO-406 caused cell death with fragmented nuclei typical to apoptosis and “necklace-like” nuclei not typical of apoptosis, further implicating the significance of involvement of caspase-independent, non-apoptotic cell death in vivo. Further studies of the role of caspase-independent cell death in patient-derived Bcr-Abl+ cells and the molecular mechanisms that lead to mitochondrial-depolarization and caspase-independent apoptotic and/or non-apoptotic cell death may help the development of novel therapeutic strategies against Bcr-Abl+ leukemias.

scholarly journals GSTZ1 sensitizes hepatocellular carcinoma cells to sorafenib-induced ferroptosis via inhibition of NRF2/GPX4 axis

2020 ◽  
Author(s):  
Qiujie Wang ◽  
Bin Cheng ◽  
Qiang Xue ◽  
Qingzhu Gao ◽  
Ailong Huang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Hepatoma Cell ◽  
Redox Homeostasis ◽  
Lipid Peroxides ◽  
Tumor Growth Inhibition ◽  
Related Factor ◽  
Hepatoma Cell Lines

AbstractIncreasing evidence supports that ferroptosis plays an important role in tumor growth inhibition. Sorafenib, originally identified as an inhibitor of multiple oncogenic kinases, has been shown to induce ferroptosis in hepatocellular carcinoma (HCC). However, some hepatoma cell lines are less sensitive to sorafenib-induced ferroptotic cell death. Glutathione S-transferase zeta 1 (GSTZ1), an enzyme in the catabolism of phenylalanine, has been found to negatively regulate the master regulator of cellular redox homeostasis nuclear factor erythroid 2-related factor 2 (NRF2). This study aimed to investigate the role of GSTZ1 in sorafenib-induced ferroptosis in HCC cell lines and determine the involved molecular mechanisms. Mechanistically, GSTZ1 depletion enhanced the activation of the NRF2 pathway and increased the glutathione peroxidase 4 (GPX4) level, thereby suppressing sorafenib-induced ferroptosis. The combination of sorafenib and RSL3, a GPX4 inhibitor, significantly inhibited GSTZ1 deficient cell viability and promoted ferroptosis, accompanied with ectopic increases of iron and lipid peroxides. An in vivo experiment showed that the combination of sorafenib and RSL3 had a synergic therapeutic effect on HCC progression in Gstz1−/− mice. In conclusion, GSTZ1 was significantly downregulated in sorafenib resistant hepatoma cells. GSTZ1 enhanced sorafenib-induced ferroptosis by inhibiting the NRF2/GPX4 axis in HCC cells. GSTZ1 deficiency was resistant to sorafenib-induced ferroptosis and is, therefore, a potential therapeutic approach for treating HCC by synergizing sorafenib and RSL3 to induce ferroptosis.

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