title: Potential role of β-elemene on histone H1 in the H22 ascites hepatoma             cell line.
abstract: β-Elemene is extracted from the Chinese medicinal herb Curcuma Wenyujin. It has a broad-spectrum antitumor effect on many types of cancer. However, the exact mechanism of action of β-elemene in hepatocellular carcinoma (HCC) remains unknown. Histone H1 is thought to act as a repressor of transcription by promoting the compaction of chromatin into higher order structures. We found that histone H1 plays an important role in the antitumor function of β-elemene. In this study, histone H1 expression in the H22 murine hepatocellular carcinoma cell line was confirmed, with P388D1 cells serving as a positive control. Furthermore, H22 cells were cultured with β-elemene for different time-points in vitro and treated with different dose-dependent β-elemene in an experimental H22 HCC xenograft transplantation model to confirm whether β-elemene inhibited the growth of H22 tumor cells. In addition, measurements of histone H1 expression both in vitro and in vivo enabled us to demonstrate that β-elemene affects the expression of histone H1 only at the protein level, but is not involved in regulation at the gene level. Our results clearly show that the effect of β-elemene on inhibiting the growth of H22 tumor cells is time- and dose-dependent. In conclusion, β-elemene inhibits the growth of H22 cells by enhancing the expression of histone H1 only at the protein level. This finding may provide insight into a new mechanism of the antitumor action of β-elemene.
authors.affiliation: Department of Traditional Chinese Medicine, The Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116023, PR China.
authors.forename: Fazhen
authors.initials: F
authors.lastname: Bao
authors.forename: Jie
authors.initials: J
authors.lastname: Qiu
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015870:Gene Expression / Q000187:drug effects; D006657:Histones / Q000235:genetics* / Q000378:metabolism; D008114:Liver Neoplasms, Experimental / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D012717:Sesquiterpenes / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D006657:Histones; D012717:Sesquiterpenes; C445979:beta-elemene