SPOCK1 as a potential cancer prognostic marker promotes the proliferation and metastasis of gallbladder cancer cells by activating the PI3K/AKT pathway

Abstract

BackgroundGallbladder cancer (GBC) is a leading cause of cancer-related death worldwide, and its prognosis remains poor, with 5-year survival of approximately 5%. In this study, we analyzed the involvement of a novel proteoglycan, Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1), in the tumor progression and prognosis of human GBC.MethodsSPOCK1 expression levels were measured in fresh samples and stored specimens of GBC and adjacent nontumor tissues. The effect of SPOCK1 on cell growth, DNA replication, migration and invasion were explored by Cell Counting Kit-8, colony formation, EdU retention assay, wound healing, and transwell migration assays, flow cytometric analysis, western blotting, and in vivo tumorigenesis and metastasis in nude mice.ResultsSPOCK1 mRNA and protein levels were increased in human GBC tissues compared with those in nontumor tissues. Immunohistochemical analysis indicated that SPOCK1 levels were increased in tumors that became metastatic, compared with those that did not, which was significantly associated with histological differentiation and patients with shorter overall survival periods. Knockdown of SPOCK1 expression by lentivirus-mediated shRNA transduction resulted in significant inhibition of GBC cell growth, colony formation, DNA replication, and invasion in vitro. The knockdown cells also formed smaller xenografted tumors than control GBC cells in nude mice. Overexpression of SPOCK1 had the opposite effects. In addition, SPOCK1 promoted cancer cell migration and epithelial-mesenchymal transition by regulating the expression of relevant genes. We found that activation of the PI3K/Akt pathway was involved in the oncogenic functions of SPOCK1 in GBC.ConclusionsSPOCK1 activates PI3K/Akt signaling to block apoptosis and promote proliferation and metastasis by GBC cells in vitro and in vivo. Levels of SPOCK1 increase with the progression of human GBC. SPOCK1 acts as an oncogene and may be a prognostic factor or therapeutic target for patients with GBC.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-014-0276-y) contains supplementary material, which is available to authorized users.

Up-regulation of SPOCK1 induces epithelial–mesenchymal transition and promotes migration and invasion in esophageal squamous cell carcinoma

“…It is dysregulated in many organs and tissues including the brain, cartilage, vascular endothelium, lymphocytes, and neuromuscular junctions (Cifuentes-Diaz et al 2000;Shu et al 2015). Recently, SPOCK1 was also found to be up-regulated in hepatocellular carcinomas, overexpression of SPOCK1 blocks apoptosis and promotes HCC cell invasiveness and metastasis in mice (Li et al 2013b).…”

MYBL2 is a Potential Prognostic Marker that Promotes Cell Proliferation in Gallbladder Cancer

“…After permeabilization with 0.5% Triton-X, the cells were reacted with 1× Apollo reaction cocktail (RiboBio) for 30 min. Subsequently, the cellular DNA content was stained with Hoechst 33342 for 30 min and visualized under a fluorescence microscope [5]. …”

“…Many cases of GBC are not resectable at presentation, the 5-year survival rate for GBC patients is only approximately 5%, and the overall median survival time of these patients is less than 1 year [3, 4]. The major cause of such a poor prognosis is the early infiltration of neoplasm cells through haematogenous, lymphatic, perineural routes and direct invasion into the liver and other adjacent organs [5, 6]. Considering the poor outcomes, GBC patient prognosis must be improved through the development of effective therapeutic targets and biomarkers that predict the therapeutic responses of this fatal disease.…”

Downregulation of SPARC Is Associated with Epithelial-Mesenchymal Transition and Low Differentiation State of Biliary Tract Cancer Cells

“…Sparc is highly expressed in invasive ductal carcinoma of the breast [24], non-small-cell lung cancer [25] and in pancreatic cancer [26] compared to normal controls. SPOCK1, a protein belonging to the same family of Ca 2+ -binding proteoglycans as SPARC, was described to promote gall bladder cancer [27]. In contrast, in colorectal [28] and ovarian cancer [14] its expression is reduced in cancer cells, and this downregulation is associated with a high degree of metastasis formation and lower sensitivity to chemotherapy.…”