OBJECTIVETo explore the mechanism of serotonin-promoted osteoblast differentiation.

METHODSExpression levels of collagen I and lysyl oxidase (LOX) in osteoblast were measured by RT-PCR after treated by (50, 100, 200 and 400 ng/L) serotonin. LOX siRNA effect was measured by Western blot, and protein levels of collagen I were determined by ELISA after treated by serotonin. Expression levels of Smad2 and Smad3 in osteoblasts were also measured by RT-PCR after treated by serotonin.Moreover, expression levels of LOX were measured by RT-PCR after Smad3 was knockout.

RESULTSSerotonin promoted collagen I and LOX expression. The expression level of collagen I was significantly decreased by LOX siRNA. Furthermore, serotonin up-regulated the expression of Smad2 and Smad3 in osteoblasts, and the expression level of LOX was inhibited by Smad3 siRNA.

CONCLUSIONSerotonin promoted collagen I expression by activating Smads signaling pathway and up-regulating the LOX expression.

Blotting, Western ; Cell Differentiation ; Cells, Cultured ; Collagen Type I ; metabolism ; Humans ; Osteoblasts ; drug effects ; metabolism ; Protein-Lysine 6-Oxidase ; metabolism ; RNA, Small Interfering ; Serotonin ; pharmacology ; Signal Transduction ; Smad2 Protein ; metabolism ; Smad3 Protein ; metabolism ; Up-Regulation

OBJECTIVETo compare the expressions of lysyl oxidase (LOX) and matrix metalloproteinases-2 (MMP-2) in gastric cancer and pericancerous tissues, in gastric cancers with and without lymph node metastasis, and to analyze the effects of LOX and MMP-2 on tumor invasion and metastasis.

METHODSGastric cancer and pericancerous tissues were collected from 46 patients who underwent surgery. Levels of LOX and MMP-2 mRNA were detected by RT-PCR. Protein abundance of LOX and MMP-2 was examined using Western blot.

RESULTSExpressions of LOX and MMP-2 mRNA, and protein in 46 gastric cancers were significantly higher than that in 46 pericancerous tissues. In gastric cancer with lymph node metastasis, the levels of LOX and MMP-2 mRNA and protein were higher than those in gastric cancers without lymph node metastasis (P < 0.05). In the groups of gastric cancer with lymph node metastasis, expression of LOX was positively correlated with MMP-2 protein expression (P < 0.01).

CONCLUSIONSExpressions of LOX and MMP-2 in gastric cancer tissues are significantly higher than that in pericancerous tissues. The expressions of LOX and MMP-2 in gastric cancer with lymph node metastasis are higher than that in gastric cancer without lymph node metastasis. Expressions of LOX and MMP-2 are positively correlated. The results suggest that LOX and MMP-2 may promote the growth and metastasis of gastric cancer.

Adenocarcinoma ; metabolism ; pathology ; surgery ; Biomarkers, Tumor ; metabolism ; Female ; Gastrectomy ; Humans ; Lymphatic Metastasis ; Male ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Middle Aged ; Neoplasm Invasiveness ; Protein-Lysine 6-Oxidase ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Stomach ; metabolism ; surgery ; Stomach Neoplasms ; metabolism ; pathology ; surgery

Carcinoma-associated fibroblasts (CAFs) are the main cellular components of the tumor microenvironment and promote cancer progression by modifying the extracellular matrix (ECM). The tumor-associated ECM is characterized by collagen crosslinking catalyzed by lysyl oxidase (LOX). Small extracellular vesicles (sEVs) mediate cell-cell communication. However, the interactions between sEVs and the ECM remain unclear. Here, we demonstrated that sEVs released from oral squamous cell carcinoma (OSCC)-derived CAFs induce collagen crosslinking, thereby promoting epithelial-mesenchymal transition (EMT). CAF sEVs preferably bound to the ECM rather than being taken up by fibroblasts and induced collagen crosslinking, and a LOX inhibitor or blocking antibody suppressed this effect. Active LOX (αLOX), but not the LOX precursor, was enriched in CAF sEVs and interacted with periostin, fibronectin, and bone morphogenetic protein-1 on the surface of sEVs. CAF sEV-associated integrin α2β1 mediated the binding of CAF sEVs to collagen I, and blocking integrin α2β1 inhibited collagen crosslinking by interfering with CAF sEV binding to collagen I. CAF sEV-induced collagen crosslinking promoted the EMT of OSCC through FAK/paxillin/YAP pathway. Taken together, these findings reveal a novel role of CAF sEVs in tumor ECM remodeling, suggesting a critical mechanism for CAF-induced EMT of cancer cells.
Humans ; Paxillin/metabolism* ; Protein-Lysine 6-Oxidase/metabolism* ; Carcinoma, Squamous Cell/pathology* ; Epithelial-Mesenchymal Transition ; Integrin alpha2beta1/metabolism* ; Mouth Neoplasms/pathology* ; Collagen/metabolism* ; Fibroblasts ; Extracellular Vesicles/metabolism* ; Cell Line, Tumor ; Tumor Microenvironment

The progress of research on the the anterior cruciate ligament (ACL) wound healing demonstrates that the synovial tissue in the knee joint plays a very important role in the healing process of injured ACL. Therefore, the molecular response mechanisms of lysyl oxidase (LOX) and matrix metalloproteina (MMP) in normal/injured ACL fibroblast cells could be considered to perform the major analysis function of injured ACL healing mechanism. The mRNA expressions of LOXs and MMPs and the activity expressions of MMP-2 in ACL fibroblasts co-cultured with synovial cells were analyzed by quantitative real-time PCR and zymography. The results showed that co-culture could regulate the mRNA expressions of LOXs and MMPs in the ACL fibroblasts cells. These results suggest that the differential expressions of LOXs and MMP-1, 2, 3 in co-cultured ACL indicate that interaction crosstalk do exist between ACL cells and synovial cells and provide a theoretical basis for subsequent exploration of the mechanisms and treatment of ACL injury and repair.
Anterior Cruciate Ligament ; cytology ; Anterior Cruciate Ligament Injuries ; Coculture Techniques ; Fibroblasts ; cytology ; metabolism ; Humans ; Knee Injuries ; physiopathology ; Knee Joint ; cytology ; Matrix Metalloproteinases ; genetics ; metabolism ; Protein-Lysine 6-Oxidase ; genetics ; metabolism ; Synovial Membrane ; cytology ; Wound Healing ; physiology

OBJECTIVETo study the effects of lysyl oxidase (LOX) on the migration and adhesion of the human gastric cancer cell line HGC-27 cells in vitro.

METHODSThe human gastric cancer cell line HGC-27 cells were cultured in vitro, and treated with different concentration of β-aminopropionitrile (BAPN). The ability of migration was assessed by wound-healing assay. The ability of adhesion was detected by homogenous and heterogeneous adhesion experiments.

RESULTSCompared that with 0 mmol/L BAPN, the ability of migration of the cells after treatment with 0.2 mmol/L BAPN was descended at 8, 24, 32 and 48 h; the number of cells with homogeneous adhesion was increased from (6.97 ± 0.07) × 10(3)/ml to (7.78 ± 0.11) × 10(3)/ml; and the number of cells with heterogeneous adhesion was decreased from (8.98 ± 0.15) × 10(3)/ml to (8.35 ± 0.10) × 10(3)/ml, both < 0.05. Compared with that of cells treated with 0 mmol/L and 0.2 mmol/L BAPN, the migration ability of cells after treatment with 0.3 mmol/L BAPN was descended at 8, 24, 32 and 48 h; the number of cells with homogeneous adhesion was raised to (8.02 ± 0.11) × 10(3)/ml and the number of cells with heterogeneous adhesion was down to (7.93 ± 0.07) × 10(3)/ml (P < 0.05).

CONCLUSIONLOX may promote the metastasis of cancer cells by enhancing invasion, increasing heterogeneous adhesion and decreasing homogeneous adhesion.

Aminopropionitrile ; administration & dosage ; pharmacology ; Cell Adhesion ; drug effects ; Cell Line, Tumor ; Cell Movement ; drug effects ; Dose-Response Relationship, Drug ; Humans ; Neoplasm Invasiveness ; Protein-Lysine 6-Oxidase ; antagonists & inhibitors ; metabolism ; physiology ; Stomach Neoplasms ; enzymology ; pathology

Alterations of genes are known to be critical for the induction of tumorigenesis, but the mechanism of ovarian carcinogenesis is little understood and remains to be elucidated. In this study, we investigated the roles of brca1, brca2 and p53 genes in the development of ovarian cancer using conditional knockout mice generated by a Cre-loxP recombinant system. Following the application of recombinant adenovirus expressing Cre in vitro, the proliferation of ovarian surface epithelium (OSE) was increased. For instance, a significant increase in cell growth was observed in OSE cells in vitro by conditional knockout isolated from the mice bearing concurrent floxed copies of brca1 and brca2/p53. However, the proliferative effect of the ovarian cells was not observed in concurrent brca1/brca2 or p53 knockout mice in vivo, indicating that we could not observe the direct evidence of the involvement of brca1, brca2, and p53 in ovarian carcinogenesis. Since morphological changes including tumor formation were not observed in mice bearing floxed copies of concurrent brca1/brca2 or p53, the inactivation of brca1/2 or p53 is not sufficient for the induction of tumor formation. Taken together, these results suggest that the deficiency of these genes may not be involved directly in the mechanism of ovarian carcinogenesis.
Animals ; BRCA1 Protein/*genetics/metabolism ; BRCA2 Protein/*genetics/metabolism ; Cell Proliferation ; Cell Transformation, Neoplastic/*genetics ; Epithelium/*pathology ; Extracellular Matrix Proteins/genetics ; Female ; Gene Silencing ; Mice ; Mice, Knockout ; Ovarian Neoplasms/*genetics ; Protein-Lysine 6-Oxidase/genetics ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53/*genetics/metabolism