title: PRG4 expression in myxoid liposarcoma maintains tumor cell growth through suppression of an antitumor cytokine IL-24.
abstract: PRG4 is one of the downstream molecules of the myxoid liposarcoma (MLS)-specific fusion oncoproteins TLS-CHOP and EWS-CHOP. Exogenous PRG4 expression increases the tumorigenicity of cells injected in nude mice. The molecular functions of PRG4 in tumorigenesis and/or tumor progression of MLS cells, however, still remain unclear. In this report, we demonstrated that siRNA-mediated knockdown of PRG4 suppressed the growth of the MLS-derived cell lines 1955/91 and 2645/94. In addition, PRG4 knockdown promoted adipocytic differentiation in 1955/91 cells. Thus, PRG4 may play essential roles in MLS cell growth and have potential as a therapeutic target. On the other hand, our previous study has revealed that TLS-CHOP suppresses expression of an anti-tumor cytokine IL-24, contributing to tumor cell survival. In this study, we found that double knockdown of PRG4 and IL-24 did not inhibit MLS cell growth, and single knockdown of PRG4 remarkably increased IL-24 expression. These results suggest that the growth inhibitory effect of PRG4 knockdown is caused by induction of IL-24 expression, and PRG4 may contribute to maintain MLS cell growth through repression of IL-24 expression.
authors.affiliation: Department of Pathology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-shi, Wakayama 641-8509, Japan; Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan. Electronic address: k-oikawa@wakayama-med.ac.jp.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Oikawa
authors.affiliation: Department of Pathology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-shi, Wakayama 641-8509, Japan.
authors.forename: Anna
authors.initials: A
authors.lastname: Mizusaki
authors.affiliation: Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Takanashi
authors.affiliation: Department of Pathology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-shi, Wakayama 641-8509, Japan; Department of Clinical Laboratory, Kinan Hospital, 46-70 Shinjo, Tanabe-shi, Wakayama 646-8588, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ozaki
authors.affiliation: Department of Pathology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-shi, Wakayama 641-8509, Japan.
authors.forename: Fuyuki
authors.initials: F
authors.lastname: Sato
authors.affiliation: Department of Molecular Pathology, Tokyo Medical University, 6-1-1 Shinjuku, Shinjuku-ku, Tokyo 160-8402, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kuroda
authors.affiliation: Department of Pathology, Wakayama Medical University, 811-1 Kimiidera, Wakayama-shi, Wakayama 641-8509, Japan.
authors.forename: Yasuteru
authors.initials: Y
authors.lastname: Muragaki
mesh_terms: D050156:Adipogenesis; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007378:Interleukins / Q000235:genetics*; D018208:Liposarcoma, Myxoid / Q000235:genetics* / Q000473:pathology; D011509:Proteoglycans / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D000099180:Interleukin-24; D000099158:Proteoglycan 4
chemical_list: D007378:Interleukins; D011509:Proteoglycans; D034741:RNA, Small Interfering; D000099180:Interleukin-24; C419197:PRG4 protein, human; D000099158:Proteoglycan 4
keywords: FUS-DDIT3; IL-24; Myxoid liposarcoma; PRG4; TLS-CHOP