Objective To explore the cell subsets and characteristics related to the prognosis of osteosarcoma by analyzing the cellular composition of tumor tissue samples from different osteosarcoma patients.Methods The single-cell sequencing data and bulk sequencing data of different osteosarcoma patients were downloaded.We extracted the information of cell samples for dimensionality reduction,annotation,and cell function analysis,so as to identify the cell subsets and clarify the cell characteristics related to the prognosis of osteosarcoma.The development trajectory of macrophages with prognostic significance was analyzed,and the prognostic model of osteosarcoma was established based on the differentially expressed genes of macrophage differentiation.Results The cellular composition presented heterogeneity in the patients with osteosarcoma.The infiltration of mononuclear phagocytes in osteosarcoma had prognostic significance(P=0.003).Four macrophage subsets were associated with prognosis,and their signature transcription factors included RUNX3(+),ETS1(+),HOXD11(+),ZNF281(+),and PRRX1(+).Prog_Macro2 and Prog_Macro4 were located at the end of the developmental trajectory,and the prognostic ability of macrophage subsets increased with the progression of osteosarcoma.The prognostic model established based on the differentially expressed genes involved in macrophage differentiation can distinguish the survival rate of osteosarcoma patients with different risks(P<0.001).Conclusion Macrophage subsets are closely related to the prognosis of osteosarcoma and can be used as the key target cells for the immunotherapy of osteosarcoma.
Humans ; Prognosis ; Osteosarcoma/genetics* ; Immunotherapy ; Macrophages ; Transcription Factors ; Bone Neoplasms/genetics* ; Homeodomain Proteins ; Repressor Proteins

OBJECTIVEOsteosarcoma is the most common type of malignant bone tumor in children and adolescents. The role of E3 ligases in tumorigenesis is currently a focus in tumor research. In the present study, we investigated the role of the E3 ligase tripartite motif 21 (TRIM21) in osteosarcoma cell proliferation.

METHODS3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assays were used to assess osteosarcoma cell viability. U2-OS cells stably carrying a recombinant lentivirus expressing tetracycline-regulated TRIM21 were screened. Co-immunoprecipitation was coupled with LCMS/MS analysis to identify novel interacting partners of TRIM21. Co-immunoprecipitation and bimolecular fluorescence complementation (BIFC) were performed to validate the interactions between TRIM21 and its novel partner YWHAZ. A TRIM21-ΔRING construct was generated to test the effects of TRIM21 ligase activity on YWHAZ.

RESULTSTRIM21 positively regulated osteosarcoma cell proliferation. Overexpression of TRIM21 enhanced osteosarcoma cell tolerance toward various stresses. YWHAZ protein was identified as a novel interacting partner of TRIM21 and its expression levels were negatively regulated by TRIM21. The RING domain of TRIM21 was required for TRIM21 negative regulation of YWHAZ expression. However, overexpression of YWHAZ did not affect positive regulation of osteosarcoma cell proliferation by TRIM21.

CONCLUSIONOur results further clarify the molecular mechanisms underlying the pathogenesis of osteosarcoma.

14-3-3 Proteins ; genetics ; metabolism ; Cell Proliferation ; genetics ; Humans ; Osteosarcoma ; genetics ; Ribonucleoproteins ; genetics ; metabolism ; Tumor Cells, Cultured

OBJECTIVE: To investigate the inhibitory effect of miR-125b-5p on proliferation and migration of osteosarcoma and the role of RAB3D in mediating this effect. METHODS: The expression level of miR-125b-5p was detected by qRT-PCR in a normal bone cell line (hFOB1.19) and in two osteosarcoma OS cell lines (MG63 and HOS). A miR-125b-5p mimic or inhibitor was transfected in the osteosarcoma cell lines via liposome and the changes in cell proliferation and migration were detected with EDU and Transwell experiments. Bioinformatic analysis was conducted for predicting the target gene of miR-125b-5p, and the expression level of RAB3D in hFOB1.19, MG63, and HOS cells was detected by Western blotting. In the two osteosarcoma cell lines transfected with miR-125b-5p mimic or inhibitor, the expression levels of RAB3D mRNA and protein in osteosarcoma cells were examined with qRT-PCR and Western blotting. The effects of RAB3D overexpression, RAB3D knockdown, or overexpression of both miR-125b-5p and RAB3D on the proliferation and migration of cells were assessed using EDU and Transwell experiments. RESULTS: The two osteosarcoma cell lines had significantly lower expression levels of miR-125b-5p (P < 0.05). Bioinformatic analysis predicted that RAB3D was a possible target gene regulated by miR-125b-5p. In osteosarcoma cells, overexpression of miR-125b-5p significantly lowered the expression of RAB3D protein (P < 0.05); inhibiting miR-125b-5p expression significantly decreased RAB3D expression only at the protein level (P < 0.05) without obviously affecting its mRNA level. Modulation of miR-125b-5p and RAB3D levels produced opposite effects on proliferation and migration of osteosarcoma cells, and in cells with overexpression of both miR-125b-5p and RAB3D, the effect of RAB3D on cell proliferation and migration was blocked by miR-125b-5p overexpression (P < 0.05). CONCLUSION Overexpression of miR-125b-5p inhibits the proliferation and migration of osteosarcoma cells by regulating the expression of RAB3D at the post-transcriptional level.
Humans ; Bone Neoplasms/genetics* ; Cell Proliferation ; MicroRNAs/genetics* ; Osteosarcoma/genetics* ; rab3 GTP-Binding Proteins/genetics* ; RNA, Messenger

BACKGROUND: The pathogenesis of osteosarcoma (OS) is still unclear, and it is still necessary to find new targets and drugs for anti-OS. This study aimed to investigate the role and mechanism of the anti-OS effects of miR-296-5p. METHODS: We measured the expression of miR-296-5p in human OS cell lines and tissues. The effect of miR-296-5p and its target gene staphylococcal nuclease and tudor domain containing 1 on proliferation, migration, and invasion of human OS lines was examined. The Student's t test was used for statistical analysis. RESULTS: We found that microRNA (miR)-296-5p was significantly downregulated in OS cell lines and tissues (control vs. OS, 1.802 ± 0.313 vs. 0.618 ± 0.235, t = 6.402, P < 0.01). Overexpression of miR-296-5p suppressed proliferation, migration, and invasion of OA cells. SND1 was identified as a target of miR-296-5p by bioinformatic analysis and dual-luciferase reporter assay. Overexpression of SND1 abrogated the effects induced by miR-296-5p upregulation (miRNA-296-5p vs. miRNA-296-5p + SND1, 0.294 ± 0.159 vs. 2.300 ± 0.277, t = 12.68, P = 0.003). CONCLUSION Our study indicates that miR-296-5p may function as a tumor suppressor by targeting SND1 in OS.
Bone Neoplasms/genetics* ; Cell Line, Tumor ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Endonucleases/genetics* ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Humans ; MicroRNAs/genetics* ; Osteosarcoma/genetics*

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

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*

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 study the effects and mechanisms of miR-181a-5p on the proliferation, cycle and migration of HOS osteosarcoma cells. METHODS: Real-time quantitative PCR was used to detect the expression of miR-181a-5p and HOXB4 in osteoblast hFOB1.19 cell line and osteosarcoma cell lines (HOS, U2OS, MG63). miR-181a-5p mimics and miR-181a-5p inhibitors were respectively transfected into HOS cells by Lipofectamine 2000, and miR NC group was set as control group. CCK-8 method was used to detect the change in cell proliferation. Flow cytometry was used to detect the changes in cell cycles. Wound healing experiments and Transwell migration experiments were used to detect the changes in cell migration ability. The target gene of miR-181a-5p was predicted by Targetscan website and validated by Dual-luciferase reporter gene system and Western blot. RESULTS: Compared with osteoblast hFOB1.19, miR-181a-5p was low expressed in osteosarcoma cells HOS, U2OS, and MG63(P<0.05), while HOXB4 was high expressed in osteosarcoma cells HOS, U2OS, and MG63(P<0.05). Compared with the miR NC group, over expression of miR-181a-5p inhibited the proliferation and migration of osteosarcoma HOS cells, and the number of cells in S phase decreased(P<0.05). However, knockdown miR-181a-5p promoted the proliferation and migration of osteosarcoma HOS cells, the cells in S phase increased(P<0.05). Bioinformatics prediction and Dual-luciferase reporter gene system validate HOXB4 as a downstream target gene of miR-181a-5p(P<0.05). Western blot showed that miR-181a-5p over expression or knockdown significantly down-regulated or up-regulated HOXB4 expressions in the HOS cells respectively(P<0.05). CONCLUSION miR-181a-5p is down expressed in osteosarcoma cells, and over-expression miR-181a-5p inhibits the proliferation, cell cycle and migration ability of osteosarcoma cells by targeting HOXB4.
Humans ; Apoptosis ; Bone Neoplasms/genetics* ; Cell Line, Tumor ; Cell Proliferation/genetics* ; Homeodomain Proteins/genetics* ; MicroRNAs/metabolism* ; Osteosarcoma/genetics* ; Transcription Factors/genetics*

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

OBJECTIVETo construct a cDNA library of osteosarcoma SAOS-2 cells and screen the proteins interacting with the bone morphogenetic protein-2 (BMP-2) to explore the role of BMP-2 in the development of prostate cancer.

METHODSThe total RNA was extracted from SAOS-2 cells, from which poly(A)(+)RNA was purified to generate the cDNA using RT-PCR with primer SMARTIII and primer CDSIIIoligo(dT). The library was constructed and screened by cotransformation of the double-stranded cDNA (dscDNA) and linearized pGADT7-Rec with the bait plasmid to the yeast AH109. The proteins interacting with BMP-2 were screened by AH109 mating with the bait strain Y187, and the interaction was confirmed using far-Western blot analysis.

RESULTSThe cDNA library of human osteosarcoma SAOS-2 cells was constructed, which was characterized by high diversity and sufficient capacity. The dscDNA size range was between 250-5000 bp, with a cotransformation efficiency of 4.3 x 10(5) and recombination efficiency of 1.9 x 10(6), and 4.3 x 10(5) clones were screened. The mating efficiency was 32% and 1.0 x 10(6) clones were screened by the bait of BMP-2, and 4 positive clones was obtained and sequenced.

CONCLUSIONThe diversity and capacity of the cDNA library meet the needs for screening genes related to prostate cancer.

Bone Morphogenetic Protein 2 ; genetics ; Cell Line, Tumor ; Gene Library ; Humans ; Male ; Osteosarcoma ; genetics ; Prostatic Neoplasms ; genetics ; RNA, Neoplasm ; genetics ; Two-Hybrid System Techniques