Identification of SHCBP1 as a novel downstream target gene of SS18-SSX1 and its functional analysis in progression of synovial sarcoma

Abstract

The SS18-SSX1 fusion gene has been shown to play important roles in the development of synovial sarcoma (SS), but the underlying molecular mechanisms and its downstream target genes are still not clear. Here SHC SH2-domain binding protein 1 (SHCBP1) was identified and validated to be a novel downstream target gene of SS18-SSX1 by using microarray assay, quantitative real-time (qPCR) and western blot. Expression of SHCBP1 was firstly confirmed in SS cell line and SS tissues. The effects of SHCBP1 overexpression or knockdown on SS cell proliferation and tumorigenicity were then studied by cell proliferation, DNA replication, colony formation, flow cytometric assays, and its in vivo tumorigenesis was determined in the nude mice. Meanwhile, the related signaling pathways of SHCBP1 were also examined in SS cells. The results indicated that SHCBP1 was significantly increased in SS cells and SS tissues compared with adjacent noncancerous tissues. The expression of SHCBP1 was demonstrated to be positively correlated with the SS18-SSX1 level. Overexpression and ablation of SHCBP1 promoted and inhibited, respectively, the proliferation and tumorigenicity of SS cells in vitro. SHCBP1 knockdown also significantly inhibited SS cell growth in nude mice, and lowered the MAPK/ERK and PI3K/AKT/mTOR signaling pathways and cyclin D1 expression. Our findings disclose that SHCBP1 is a novel downstream target gene of SS18-SSX1, and demonstrate that the oncogene SS18-SSX1 promotes tumorigenesis by increasing the expression of SHCBP1, which normally acts as a tumor promoting factor.

Overexpression of SHCBP1 promotes migration and invasion in gliomas by activating the NF‐κB signaling pathway

“…Knockdown of SHCBP1 significantly decreased p-AKT expression, but not total AKT levels, in synovial sarcoma cells. 31 Additionally, Chen et al reported that silencing SHCBP1 in mouse neuroectodermal stem cells markedly decreased the level of p-AKT in the presence of FGF2. 32…”

Overexpression of BMP‑7 reverses TGF‑β1‑induced epithelial‑mesenchymal transition by attenuating the Wnt3/β‑catenin and/Smad2/3 signaling pathways in HK‑2 cells

“…Lentiviral vectors for BMP-7 overexpression. pgcl-green fluorescent protein (GFP)-lentivirus carrying a full-length human BMP-7 cDnA sequence (Lv-BMP-7) and a non-targeting sequence (Lv-Control) were synthesized by Shanghai GeneChem Co., Ltd. Lentivirus packaging and infection were performed as described previously (21). One day before transfection, 1.2x10 7 HEK 293T cells were plated at 90-95% confluence (in 15-cm dishes).…”

FLVCR1 promotes the proliferation and tumorigenicity of synovial sarcoma through inhibiting apoptosis and autophagy

“…For depletion of FLVCR1, a human FLVCR1-targeting shRNA sequence was cloned into pGCSIL-green fluorescent protein (GFP) vector to generate pGCSIL-GFP-FLVCR1-RNAi, with target sequence 5'-CCC TGAAGAGTACTCCTATAA-3' (synthesized by Shanghai GeneChem Co., Ltd., Shanghai, China), or control scrambled shRNA (Lv-shCon sequence, 5'-TTCTCCGAACGTGTCA CGT-3'). Lentiviruses production and infection were performed as previously reported (7). Stable cell lines (SW982 and HS-SY-II) expressing FLVCR1 shRNAs were selected for 10 days with 0.5 µg/ml puromycin.…”

“…Western blotting. Standard western blot assays were performed as described previously (7,23). Briefly, cells were harvested in the NE-PER™ Nuclear and Cytoplasmic Extraction Reagents (cat.…”

“…However, early and late recurrences often occur (4,5), and the 5-year survival rate is estimated to be only 27-55% (6). Mounting evidence indicates that certain proteins are dysregulated in primary tumors and are associated with the development and progression of SS (7)(8)(9). Understanding the specific functions and disclosing the underlying mechanisms of these proteins involved in the occurrence and development of SS may facilitate identification of effective targeting strategies for SS.…”