The immortalization and transformation of cultured human cells has far-reaching implications for both cell and cancer biology. Human cell transformation studies will increase our understanding of the mechanisms underlying carcinogenesis and differentiation. The neoplastic process can now be studied in a model human cell culture system. The accompanying biochemical and genetic changes, once identified, will help define the relationship between malignancy and differentiation. The present studies indeed demonstrate that the neoplastic process can now be studied in a human cell model system. Primary human cells treated with various carcinogens became immortalized in culture but were not tumorigenic. Additional exposure to either retroviruses, chemical carcinogenes or X-ray irradiation to these cells induced morphological alterations associated with the acquisition of neoplastic properties. These findings demonstrate the malignant transformation of human primary cells in culture by the combined action of either a DNA transforming virus and a retrovirus or a DNA virus and a chemical or X-ray irradiation, and support an multistep process for neoplastic conversion. It has been known that normal human cells in culture are remarkably resistant to experimentally induced tumorigenicity. However, as shown above, normal human cells could now be transformed into tumorigenic cells.
*Cell Transformation, Neoplastic/genetics ; Cells, Cultured ; DNA, Viral ; Fibroblasts/pathology ; Human ; Keratinocytes/cytology/pathology ; Osteosarcoma/genetics/pathology

Ameloblastoma ; pathology ; Bone Neoplasms ; classification ; genetics ; pathology ; Chondromatosis ; pathology ; Chondrosarcoma ; classification ; pathology ; Enchondromatosis ; pathology ; Humans ; Osteosarcoma ; classification ; pathology ; Sarcoma, Ewing ; pathology ; Societies, Medical ; United States ; World Health Organization

Humans ; MicroRNAs/genetics* ; Cell Line, Tumor ; Osteosarcoma/pathology* ; Neoplasm Invasiveness ; Cell Proliferation ; Bone Neoplasms/pathology* ; Cell Movement ; Neoplasm Metastasis

OBJECTIVE: To explore the effect of miR-143 regulating matrix metalloproteinase(MMP)-13 expression on migration and invasion of osteosarcoma cells. METHODS: The mouse osteosarcoma cell line 143B cells were cultured in 96-well plates, and blank group, negative group, positive group, and intervention group were set up. Then, the blank group did no treatment 50 μg miR-143 mimic was added to positive group, negative group added equal mimic NC (control sequence of miR-143 mimic), the intervention group was added 50 μg miR-143 mimic and 10 μg MMP-13 protein, all groups continued to culture for 3 to 6 hours, and finally the serum was aspirated to treat for half an hour. The protein expressions of miR-143 and MMP-13 in each group were measured by fluorescence quantitative PCR experiment and Western blot experiment, respectively, and the invasion and migration abilities of cells were measured by Transwell and scratch experiments. RESULTS: The expression of MMP-13 protein in the positive group and the intervention group was significantly lower than that in the blank group, and the positive group was lower than the intervention group (P<0.05);The mean numbers of invasive cells in blank group, negative group, positive group and intervention group were (1 000.01±44.77), (959.25±46.32), (245.04±4.33), (634.06±33.78) cells/field, respectively;the scratch healing rate of the positive group and the intervention group was significantly lower than that of the blank group, and the positive group was lower than the intervention group (P<0.05). CONCLUSION MMP-13 is a target of miR-143, which can reduce the migration and invasion ability of osteosarcoma cells by inhibiting the expression of MMP-13.
Osteosarcoma/pathology* ; MicroRNAs/genetics* ; Matrix Metalloproteinase 13/genetics* ; Neoplasm Invasiveness ; Animals ; Mice ; Cell Line, Tumor ; Cell Movement

OBJECTIVE: To investigate the prognostic value and mechanism of long non-coding RNA DLEU1(LncRNA DLEU1) in osteosarcoma. METHODS: The tissue samples and clinical data of 86 patients with osteosarcoma treated by orthopaedic surgery in our hospital from January 2012 to December 2014 were retrospectively collected. The expression of LncRNA DLEU1 in pathological tissues was detected by qRT-PCR, then the patients were divided into high and low expression of LncRNA DLEU1 groups. Osteosarcoma cell line HOS was divided into two groups, down-regulated expression group (si-DLEU1 group) and negative control group (si-NC group). LncRNA DLEU1 siRNA and negative control sequence were transfected by Lipofectamine 3000. Chi-square test was used to analyze the relationship between the expression of LncRNA DLEU1 and the clinicopathological factors of osteosarcoma. Kaplan-Meier method was used to compare the difference of the overall survival rate of osteosarcoma patients between the high and low expression groups of LncRNA DLEU1. The risk factors affecting the overall survival rate of osteosarcoma were analyzed by single factor and multifactor analysis. The number of invasive cells in the two groups was determined and compared by Transwell assay. RESULTS: The expression of LncRNA DLEU1 in osteosarcoma tissue was higher than that in adjacent tissues (P<0.001). The expression of LncRNA DLEU1 in human osteosarcoma cell lines (MG-63, U-2 OS, and HOS) was significantly higher than that in human osteoblast line hFOB 1.19 (P<0.001). The expression of LncRNA DLEU1 was significantly correlated with Enneking stage (P<0.001), distant metastasis (P=0.016), and histological grade (P=0.028). The 1-year overall survival rate of the LncRNA DLEU1 high expression group was significantly higher than that of the low expression group (90.7% vs 60.5%, P<0.001). The 5-year overall survival rate of the LncRNA DLEU1 high expression group was significantly higher than that of the low expression group (32.6% vs 11.6%, P<0.001). Univariate analysis showed that Enneking stage (P<0.001), tumor size (P=0.043), distant metastasis (P<0.001), histological grade (P<0.001), and expression of LncRNA DLEU1 (P<0.001) were risk factors for overall survival of osteosarcoma patients. Multivariate analysis showed that high expression of LncRNA DLEU1 [HR=1.948, 95% CI(1.141, 3.641), P=0.012] and distant metastasis[HR=4.108, 95% CI(2.169, 7.780), P<0.001] were independent risk factors for overall survival of osteosarcoma patients. The number of invasive cells in si-DLEU1 group was significantly lesser than that in si-NC group(139±13 vs 357±31, P<0.001). CONCLUSION High expression of LncRNA DLEU1 is a molecular marker affecting the prognosis of osteosarcoma patients. Downregulation of LncRNA DLEU1 can inhibit the invasion of osteosarcoma cells.
Humans ; Prognosis ; RNA, Long Noncoding/metabolism* ; Retrospective Studies ; Cell Proliferation/genetics* ; Cell Line, Tumor ; Osteosarcoma/genetics* ; Bone Neoplasms/pathology*

Immediate early response gene X-1 (IEX-1) gene was discovered by Charles in 1993, which plays an important role in regulating apoptosis. Previous studies demonstrated that IEX-1 gene was expressed in a variety of human tissues and played an important role in regulating apoptosis and cell growth through a positive or negative way. It can inhibit cell growth and apoptosis. However, it can also promote cell apoptosis. There is evidence that IEX-1 is involved in viral infections and cardiovascular diseases and it is highly expressed in many tumor tissues. The regulatory mechanisms for IEX-1 under normal and pathophysiological conditions are complicated and remain largely unknown. In this paper, we reviewed the recent progress of IEX-1 in different disease models.
Apoptosis ; genetics ; Apoptosis Regulatory Proteins ; genetics ; physiology ; Cell Proliferation ; Humans ; Membrane Proteins ; genetics ; physiology ; Neoplasms ; genetics ; metabolism ; pathology ; Osteosarcoma ; metabolism ; pathology

To compare the expression level of metastasis associated-1 (MTA1) gene in high and low metastatic human osteosarcoma cell lines and examine the relationship of MTA1 expression and the metastasis potentiality of osteosarcoma cells, the expression of MTA1 in MG-63 osteosarcoma cell lines with high and low metastasis potential was detected by semiquantitative TR-PCR. Boyden chamber invasion assay was used to evaluate the invasive capacity in vitro in two osteosarcoma cell lines. The low metastasis MG-63 cells were transfected with MTA1 full-length cDNA expression plasmid by lipofectamine and the changes of MTA1 expression and in vitro invasion potential were examined after the transfection. Our results showed that MG63 cell line with high metastasis potential expressed significantly higher MTA1 than that of MG63 cells with low metastasis as reavealed by RT-PCR. The invasion potential of low metastasis MG63 cell line was increased after MTA1 gene transfection. It is concluded that there may be a relationship between MTA 1 and invasive potentiality of human osteosarcoma cells, and the mechanism of MTA1 in osteosarcoma metastasis and its possible role in associated gene therapy deserve further study.
Bone Neoplasms/*metabolism ; Bone Neoplasms/pathology ; Gene Expression Regulation, Neoplastic ; Histone Deacetylases/*biosynthesis ; Histone Deacetylases/genetics ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Osteosarcoma/*metabolism ; Osteosarcoma/pathology ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Repressor Proteins/*biosynthesis ; Repressor Proteins/genetics ; Tumor Cells, Cultured

OBJECTIVE: Osteosarcoma(OS) and Ewing's sarcoma (EWS) are the two most common primary malignant bone tumors in children. The aim of the study was to identify key genes in OS and EWS and investigate their potential pathways. METHODS: Expression profiling (GSE16088 and GSE45544) were obtained from GEO DataSets. Differentially expressed genes were identified using GEO2R and key genes involved in the occurrence of both OS and EWS were selected using venn diagram. Gene ontology and pathway enrichment analyses were performed for the ensembl. Protein-protein interaction (PPI) networks were established by STRING. Further, UCSC was used to predict the transcription factors of the cell division cycke 5-like(CDC5L) gene, and GEPIA was used to analyze the correlation between the transcription factors and the CDC5L gene. RESULTS: The results showed that CDC5L gene was the key gene involved in the pathogenesis of OS and EWS. The gene is mainly involved in mitosis, and is related to RNA metabolism, processing of capped intron-containing pre-mRNA, mRNA and pre-mRNA splicing. CONCLUSION CDC5L, as a key gene, plays a role in development of OS and EWS, which may be reliable targets for diagnosis and treatment of these primary malignant tumors.
Bone Neoplasms/pathology* ; Cell Cycle Proteins/genetics* ; Child ; Computational Biology ; Gene Expression Profiling ; Humans ; Osteosarcoma/genetics* ; RNA-Binding Proteins/genetics* ; Sarcoma, Ewing/genetics*

OBJECTIVETo investigate the effects of recombinant AZURIN protein of P. aeruginosa on growth and apoptosis of U2OS cells.

METHODSThe AZURIN gene was amplified from the genome of P.aeruginosa by PCR, and cloned into prokaryotic expression vector pQE30. The soluble AZURIN protein was expressed in E. coli cells M15, then purified and refolded. After treatment of AZURIN, the cell cycle, proliferation and apoptosis were determined by morphological observation, MTT assay, flow cytometry(FCM) and DNA fragmentation assay. Mitochondrial membrane potential(DeltaPsim) was measured by FCM.

RESULTSThe purity of recombinant protein AZURIN reached to 99.1%. Proliferation of U2OS cells were significantly inhibited 12 h after AZURIN (100-200 mg/L) treatment. Apoptosis peak and DNA ladder were observed. Mitochondrial membrane potential decreased gradually from 12 h to 72 h after AZURIN treatment.

CONCLUSIONThe recombinant AZURIN inhibit the growth of the human osteosarcoma U2OS cells and inducs apoptosis in vitroìwhich may be associated with the decrease of mitochondrial membrane potential.

Apoptosis ; drug effects ; Azurin ; genetics ; pharmacology ; Bone Neoplasms ; pathology ; therapy ; Cell Proliferation ; drug effects ; Humans ; Osteosarcoma ; pathology ; therapy ; Recombinant Proteins ; genetics ; pharmacology ; Tumor Cells, Cultured

OBJECTIVETo study the influence of CD44 a cell-matrix adhesion molecule on the proliferation, adhesiveness and invasiveness of osteosarcoma cell lines, in order to investigate the growth and invasion mechanism of osteosarcoma.

METHODSThree osteosarcoma cell lines MG-63, HOS and U2-OS were routinely cultured. Flow cytometry and Western blot analysis were used for detecting the positive rates and relative amount of CD44 protein in the three cell lines. RT-PCR method was also used to compare the differences in the expression of CD44 mRNA among the 3 cell lines. Then, MTT method, adhesion detection, and Microcon-migration assay were used to detect the changes of the cells' proliferation rate, adhesive and invasive abilities after blocking the role of CD44 by using a special neutralizing antibody.

RESULTSThe results of flow cytometry showed that the percentage of CD44 positive cells were both over 99% in HOS and U2-OS, while that in MG-63 was only (2.10 +/- 0.46)%. The average fluorescence density of CD44 in HOS was significantly higher than in U2-OS. Western blot also showed that the relative content of CD44 protein in HOS was notably higher than that in U2-OS, while CD44 was negatively expressed in MG-63. The expression of CD44 mRNA was significantly lower in MG-63 than in both HOS and U2-OS, which were consistent with the expression of CD44 protein. The proliferation rates and adhesive abilities of MG-63 and HOS have no significant difference, but both were significantly higher than that of U2-OS. The invasive abilities of HOS was dramatically higher than MG-63 and U2-OS. After the role of CD44 was blocked by anti-CD44 neutralizing antibody, the proliferation rates of the 3 cell lines did not change significantly. While the HOS and MG-63 adhesion indices decreased dramatically (P < 0.05), the invasive abilities of HOS and U2-OS also decreased notably (P < 0.01).

CONCLUSIONSCD44 could promote the adhesiveness and invasiveness of osteosarcoma cell line HOS. CD44 may take part in promoting the process of U2-OS invasion and the adhesion of MG-63. On the other hand, CD44 could not affect the osteosarcoma cell proliferation rates.

Bone Neoplasms ; metabolism ; pathology ; Cell Adhesion ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Hyaluronan Receptors ; biosynthesis ; genetics ; physiology ; Neoplasm Invasiveness ; Osteosarcoma ; metabolism ; pathology ; RNA, Messenger ; biosynthesis ; genetics