ABSTRACT
The continual proliferation and differentiation of trophoblasts are critical for the maintenance of pregnancy. It is well known that the tissue stem cells are associated with the development of tissues and pathologies. It has been demonstrated that side-population (SP) cells identified by fluorescence-activated cell sorting (FACS) are enriched with stem cells. The SP cells in HTR-8/SVneo cells derived from human primary trophoblast cells were isolated by FACS. HTR-8/SVneo-SP cell cultures generated both SP and non-SP (NSP) subpopulations. In contrast, NSP cell cultures produced NSP cells and failed to produce SP cells. These SP cells showed self-renewal capability by serial colony-forming assay. Microarray expression analysis using a set of HTR-8/SVneo-SP and -NSP cells revealed that SP cells overexpressed several stemness genes including caudal type homeobox2 (CDX2) and bone morphogenic proteins (BMPs), and lymphocyte antigen 6 complex locus D (LY6D) gene was the most highly up-regulated in HTR-8/SVneo-SP cells. LY6D gene reduced its expression in the course of a 7-day cultivation in differentiation medium. SP cells tended to reduce its fraction by treatment of LY6D siRNA indicating that LY6D had potential to maintain cell proliferation of HTR-8/SVneo-SP cells. On ontology analysis, epithelial-mesenchymal transition (EMT) pathway was involved in the up-regulated genes on microarray analysis. HTR-SVneo-SP cells showed enhanced migration. This is the first report that LY6D was important for the maintenance of HTR-8/SVneo-SP cells. EMT was associated with the phenotype of these SP cells.
Subject(s)
Cell Adhesion Molecules/genetics , Cell Adhesion Molecules/physiology , Cell Proliferation/genetics , Gene Expression , Trophoblasts/cytology , Up-Regulation , Cell Adhesion Molecules/metabolism , Cell Line , Cell Movement/genetics , Epithelial-Mesenchymal Transition/genetics , Epithelial-Mesenchymal Transition/physiology , Female , Fetal Growth Retardation/etiology , GPI-Linked Proteins/genetics , GPI-Linked Proteins/metabolism , GPI-Linked Proteins/physiology , Humans , Hypertension, Pregnancy-Induced/etiology , Pregnancy , Pregnancy Maintenance/genetics , Pregnancy Maintenance/physiology , Trophoblasts/metabolismABSTRACT
OBJECTIVES: We previously demonstrated that side-population (SP) cells found in human endometrial cancer tissue have features of cancer stem cells (CSCs). Endometrial cancer SP cells show enhanced migration, the potential to differentiate into the mesenchymal cell lineage, and they are associated with the epithelial-mesenchymal transition (EMT). In this study, we analyzed the expression and function of a specific protein, SPARC (secreted protein acidic and rich in cysteine) which we found to be up-regulated in endometrial cancer. METHODS: We performed microarray expression analysis to screen for up-regulated genes in CSCs using a set of RK12V-SP cells and -non-SP (NSP) cells. We used the MetaCore package to identify the Gene GO pathway MAPs associated with the up-regulated genes. Here, we investigated the expression and functions of SPARC, one of the genes up-regulated in endometrial CSCs. We established SPARC-overexpressing cells by transfecting endometrial cancer cells (Ishikawa cells [IK-SPARC cells]). We characterized these cells' growth rate, tumorigenicity, migration and invasion activity. The levels and locations of SPARC protein expression in Hec1SP cells-derived tumors and endometrial cancer tissues were examined by immunohistochemistry. RESULTS: SPARC was detected by microarray expression analysis during screens for up-regulated genes in SP and NSP CSC. The level of SPARC expression was enhanced in Hec1 SP cells compared with that in Hec1 non-SP cells. SPARC enhanced fibronectin expression and promoted migration activity in IK cells. SPARC expression suppressed tumor growth but promoted formation of tumor stroma. SPARC was expressed in endometrial cancer tissues, in particular, poorly differentiated endometrioid adenocarcinoma, clear and serous adenocarcinoma,but not in normal endometrial tissue. CONCLUSION: This is the first report of overexpression of SPARC in endometrial cancer stem-like cells. SPARC expression is associated with cell migration and stroma formation.
Subject(s)
Cell Movement/physiology , Endometrial Neoplasms/genetics , Endometrial Neoplasms/pathology , Gene Expression Regulation, Neoplastic , Neoplastic Stem Cells/metabolism , Osteonectin/biosynthesis , Osteonectin/genetics , Animals , Female , HumansABSTRACT
Osteoid osteoma is a benign bone tumor traditionally treated nonoperatively or by operative excision. However, radiofrequency ablation (RFA) is being used increasingly for treatment of osteoid osteoma, as there are several reports supporting its effectiveness. We present a case of osteoid osteoma of femur in an 18-year-old boy. The patient complained of pain in right hip and knee joint. The osteoid osteoma lesion was successfully treated by percutaneous computed tomography (CT)-guided RFA using the cool-tip RFA system under general anesthesia. He had total pain relief within 24 hours following the procedure. No complications were recorded. He discharged on foot two days after RFA therapy. Complete regression of symptoms was observed at 2-year follow-up. CT-guided RFA for osteoid osteoma is a safe, effective and minimally invasive procedure with high success rate and lack of relapse.
