{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,12]],"date-time":"2026-05-12T19:28:40Z","timestamp":1778614120337,"version":"3.51.4"},"reference-count":36,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2019,11,19]],"date-time":"2019-11-19T00:00:00Z","timestamp":1574121600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Natural Science Foundation of Guangdong Province  and NIEHS","award":["(GZ192753F) , (1R21 ES029620-01)."],"award-info":[{"award-number":["(GZ192753F) , (1R21 ES029620-01)."]}]}],"content-domain":{"domain":["www.mdpi.com"],"crossmark-restriction":true},"short-container-title":["Cells"],"abstract":"<jats:p>The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has shown strong and explicit cancer cell-selectivity, which results in little toxicity toward normal tissues, and has been recognized as a potential, relatively safe anticancer agent. However, several cancers are resistant to the apoptosis induced by TRAIL. A recent study found that shikonin b (alkannin, 5,8-dihydroxy-2-[(1S)-1-hydroxy-4-methylpent-3-en-1-yl]naphthalene-1,4-dione) might induce apoptosis in TRAIL-resistant cholangiocarcinoma cells through reactive oxygen species (ROS)-mediated caspases activation. However, the strong cytotoxic activity has limited its potential as an anticancer drug. Thus, the current study intends to discover novel shikonin derivatives which can sensitize the liver cancer cell to TRAIL-induced apoptosis while exhibiting little toxicity toward the normal hepatic cell. The trypan blue exclusion assay, western blot assay, 4\u2032,6-diamidino-2-phenylindole (DAPI) staining and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay as well as the \u2018comet\u2019 assay, were used to study the underlying mechanisms of cell death and to search for any mechanisms of an enhancement of TRAIL-mediated apoptosis in the presence of ASH. Herein, we demonstrated that non-cytotoxic doses of acetylshikonin (ASH), one of the shikonin derivatives, in combination with TRAIL, could promote apoptosis in HepG2 cells. Further studies showed that application of ASH in a non-cytotoxic dose (2.5 \u03bcM) could increase intracellular ROS production and induce DNA damage, which might trigger a cell intrinsic apoptosis pathway in the TRAIL-resistant HepG2 cell. Combination treatment with a non-cytotoxic dose of ASH and TRAIL activated caspase and increased the cleavage of PARP-1 in the HepG2 cell. However, when intracellular ROS production was suppressed by N-acetyl-l-cysteine (NAC), the synergistic effects of ASH and TRAIL on hepatocellular carcinoma (HCC) cell apoptosis was abolished. Furthermore, NAC could alleviate p53 and the p53 upregulated modulator of apoptosis (PUMA) expression induced by TRAIL and ASH. Small (or short) interfering RNA (siRNA) targeting PUMA or p53 significantly reversed ASH-mediated sensitization to TRAIL-induced apoptosis. In addition, Bax gene deficiency also abolished ASH-induced TRAIL sensitization. An orthotopical HCC implantation mice model further confirmed that co-treated ASH overcomes TRAIL resistance in HCC cells without exhibiting potent toxicity in vivo. In conclusion, the above data suggested that ROS could induce DNA damage and activating p53\/PUMA\/Bax signaling, and thus, this resulted in the permeabilization of mitochondrial outer membrane and activating caspases as well as sensitizing the HCC cell to apoptosis induced by TRAIL and ASH treatment.<\/jats:p>","DOI":"10.3390\/cells8111466","type":"journal-article","created":{"date-parts":[[2019,11,19]],"date-time":"2019-11-19T11:30:17Z","timestamp":1574163017000},"page":"1466","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":22,"title":["RETRACTED: Acetylshikonin Sensitizes Hepatocellular Carcinoma Cells to Apoptosis through ROS-Mediated Caspase Activation"],"prefix":"10.3390","volume":"8","author":[{"given":"Ming","family":"Hong","sequence":"first","affiliation":[{"name":"Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou 51000, China"},{"name":"Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou 51000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jinke","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Pharmacology &amp; Toxicology, University of Kansas, Lawrence, KS 66045, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Siying","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Pharmacology &amp; Toxicology, University of Kansas, Lawrence, KS 66045, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mohammed","family":"M.Almutairi","sequence":"additional","affiliation":[{"name":"Department of Pharmacology &amp; Toxicology, University of Kansas, Lawrence, KS 66045, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e236","DOI":"10.1016\/S1470-2045(18)30272-9","article-title":"Short vs. long course adjuvant chemotherapy for colon cancer","volume":"19","author":"Gunjur","year":"2018","journal-title":"Lancet Oncol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1016\/S1470-2045(18)30127-X","article-title":"Adjuvant therapy in colon cancer: Less is more","volume":"19","author":"Ilson","year":"2018","journal-title":"Lancet Oncol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1016\/S1470-2045(14)70137-8","article-title":"Exploring better strategies for EGFR antibodies in colon cancer","volume":"15","author":"Cervantes","year":"2014","journal-title":"Lancet Oncol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1643","DOI":"10.3390\/cancers7030855","article-title":"MicroRNAs and Chinese Medicinal Herbs: New Possibilities in Cancer Therapy","volume":"7","author":"Hong","year":"2015","journal-title":"Cancers"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"10057","DOI":"10.1002\/jcb.28289","article-title":"Effects of ebv-miR-BART7 on tumorigenicity, metastasis, and TRAIL sensitivity of non-small cell lung cancer","volume":"120","author":"Wang","year":"2019","journal-title":"J. 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