title: Susceptibility to exogenously added interferon-beta protein depends on intracellular interferon-beta mRNA level in human glioma cells.
abstract: Exogenously added human interferon-beta (HuIFN-beta) protein possesses a remarkable antiproliferative activity in human glioma and melanoma. Endogenous HuIFN-beta protein, which is produced by its gene transfer using cationic liposomes, has much more effective antiproliferative activity against these tumors, even in cells resistant to exogenously added HuIFN-beta protein. As the first step to elucidate the possible difference in antiproliferative mechanisms between exogenous and endogenous HuIFN-beta protein, we here investigated the relationship between the intracellular level of its mRNA and susceptibility to exogenously added HuIFN-beta protein. In this study, we used seven human glioma cell lines (SK-MG-1, SK-MG-4, SK-AO2, U87MG, U251SP, U251MG and T98) and one human melanoma cell line (MMAN). At first, we examined the relationship between spontaneous expression of HuIFN-beta mRNA and susceptibility to exogenously added HuIFN-beta protein (50 IU/ml) in human glioma cells and then confirmed a significant correlation between them. Next, we confirmed that administration of 0-100 IU/ml exogenously added HuIFN-beta protein upregulated the HuIFN-beta mRNA in a dose-dependent manner using the RT-PCR technique and that the HuIFN-beta mRNA was suppressed by siRNA for HuIFN-beta in SK-MG-1 and MMAN cells. Furthermore, we confirmed that the siRNA for HuIFN-beta significantly suppressed the antiproliferative effect of SK-MG-1 cells treated with 10-100 IU/ml HuIFN-beta protein and MMAN cells with 25 and 50 IU/ml HuIFN-beta protein. We found this phenomenon in another human glioma cell line, U87MG cells, as well. This finding would suggest that susceptibility to exogenously added HuIFN-beta protein is related to the amount of intracellular HuIFN-beta mRNA in human glioma and melanoma cells.
authors.affiliation: Department of Neurosurgery, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, 466-8550 Nagoya, Japan.
authors.forename: Hirokatsu
authors.initials: H
authors.lastname: Osawa
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mizuno
authors.forename: Manabu
authors.initials: M
authors.lastname: Hatano
authors.forename: Norimoto
authors.initials: N
authors.lastname: Nakahara
authors.forename: Takaya
authors.initials: T
authors.lastname: Tsuno
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Kuno
authors.forename: Masato
authors.initials: M
authors.lastname: Endo
authors.forename: Jun
authors.initials: J
authors.lastname: Yoshida
mesh_terms: D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005910:Glioma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007369:Interferon Inducers / Q000494:pharmacology; D016899:Interferon-beta / Q000235:genetics / Q000494:pharmacology*; D008545:Melanoma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011070:Poly I-C / Q000494:pharmacology; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D034741:RNA, Small Interfering / Q000494:pharmacology
chemical_list: D007369:Interferon Inducers; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016899:Interferon-beta; D011070:Poly I-C