Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.
Child ; Adolescent ; Humans ; Bone Neoplasms/drug therapy* ; Signal Transduction ; Bone and Bones/metabolism* ; Treatment Outcome ; Osteosarcoma/drug therapy* ; Tumor Microenvironment

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*

In recent years, studies have found that mitochondrial transfer between leukemic cells and different types of cells in their bone marrow microenvironment, especially mesenchymal stem cells, plays a key role in the occurrence, development and drug resistance of hematological malignant tumors. This paper mainly introduces the role and latest research progress of mitochondrial transfer in acute and chronic myeloid leukemia, acute lymphoblastic leukemia and multiple myeloma, and briefly describes the mechanism of drug resistance caused by mitochondrial transfer in leukemic cells during chemotherapy. The aim is to provide a new idea and theoretical basis for using intercellular mitochondrial transfer as a potential therapeutic target.
Bone Marrow ; Hematologic Neoplasms/metabolism* ; Humans ; Mesenchymal Stem Cells ; Mitochondria ; Multiple Myeloma/metabolism* ; Tumor Microenvironment

OBJECTIVE: To screen for aberrantly expressed genes in osteosarcoma cells and investigate the role of RHPN2 in regulating the proliferation, apoptosis, migration and tumorigenic abilities of osteosarcoma cells. METHODS: We used GEO2R to analyze the differential gene expression profile between osteosarcoma cells and normal cells in the GSE70414 dataset. RTqPCR and Western blotting were performed to detect RHPN2 expression in osteosarcoma cell lines MG-63, 143B and SAOS2. Two RHPN2-shRNA and a control NC-shRNA were designed to silence the expression of RHPN2 in 143B cells, and CCK8 assay, colony-forming assay, annexin V-FITC/PI staining and scratch assays were carried out to examine the changes in proliferation, apoptosis and migration of the cells. We also established nude mouse models bearing osteosarcoma xenografts derived 143B cells and RHPN2-shRNA-transfected 143B cells, and assessed the effect of RHPN2 silencing on osteosarcoma cell tumorigenesis using HE staining. Kaplan-Meier survival curves were used to analyze the correlation between RHPN2 expression and survival outcomes of patients with osteosarcoma. RESULTS: RHPN2 expression was significantly upregulated in osteosarcoma cell lines MG-63, 143B and SAOS2 (P < 0.01). Silencing of RHPN2 significantly inhibited the proliferation and migration of 143B cells in vitro, promoted cell apoptosis (P < 0.01), and suppressed tumorigenic capacity of the cells in nude mice. A high expression of RHPN2 was significantly correlated with a poor prognosis of patients with osteosarcoma (P < 0.05). CONCLUSION RHPN2 is highly expressed in osteosarcoma cells to promote cell proliferation and migration and inhibits cell apoptosis. A high expression of RHPN2 is associated with a poorer prognosis of the patients with osteosarcoma.
Adaptor Proteins, Signal Transducing/metabolism* ; Animals ; Apoptosis ; Bone Neoplasms/metabolism* ; Carcinogenesis ; Cell Line, Tumor ; Cell Movement/physiology* ; Cell Proliferation/physiology* ; Humans ; Immediate-Early Proteins ; Mice ; Mice, Nude ; Osteosarcoma/metabolism* ; RNA, Small Interfering/genetics*

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*

Multiple myeloma (MM) is a common hematologic tumor characterized by malignant proliferation of clonal plasma cells, the exact pathogenesis of which is not yet fully understood. The extracellular vesicles (EV) are structures released by cells into their surroundings that do not have a functional nucleus and can communicate between cells or deliver biologically active proteins and nucleic acids to target cells. EV play an important role in the interaction between myeloma cells and the bone marrow microenvironment, and they can promote MM progression. In this paper, we summarize the recent research progress in the mechanism of action of EV on MM in order to provide inspiration for exploring new strategies for MM treatment and prognostic stratification.
Bone Marrow/metabolism* ; Extracellular Vesicles/pathology* ; Hematologic Neoplasms/metabolism* ; Humans ; Multiple Myeloma/pathology* ; Nucleic Acids/metabolism* ; Tumor Microenvironment

Objective: To explore the effects of circTNPO1 on the proliferation and metastasis of osteosarcoma (OS) by sponging miR-338-3p. Methods: The expression of circTNPO1 on osteoblasts and multiple OS cell lines were detected by qRT-PCR. CircTNPO1 stable knockdown 143B cell line was constructed by sh-circTNPO1. Cell count kit 8 (CCK-8) assay and wound healing assay were applied to evaluate the proliferation and metastasis of this cell. Luciferase reporter assay was used to explore the binding between circTNPO1 and miR-338-3p. In xenograft tumor model, miR-338-3p inhibitor or its control was injected into the circTNPO1 knockdown tumors. The weight and size of the tumors were evaluated and Ki-67 expression was detected by immunohistochemistry. Results: The RNA expression of circTNPO1 in OS cell lines U2OS, HOS, MG63, 143B, ZOS and ZOSM were 2.73±0.27, 3.18±0.54, 4.33±0.52, 5.75±0.65, 4.50±0.49 and 3.96±0.35, respectively, higher than 1.00±0.09 in hFOB1.19 (P<0.001). CCK-8 assay revealed that after 48 h and 72 h, the absorbance of sh-circTNPO1 #1 was 0.81±0.05 and 1.09±0.06, while sh-circTNPO1 #2 143B cells was 0.84±0.04 and 1.2±0.04, which were sharply reduced compared with the control (1.00±0.06 and 1.49±0.06, P<0.001); after 48 h and 72 h, the absorbance of 143B cells transfected with circTNPO1 #1 and miR-338-3p (0.92±0.06 and 1.32±0.07) were higher than those of cells transfected with sh-circTNPO1 cells and miR NC (0.92±0.06 and 1.32±0.07, P<0.050). Wound healing assay demonstrated that the 24 hour-migration rates of sh-circTNPO1 #1 and sh-circTNPO1 #2 cells were (24.43±2.15)% and (39.70±4.20)% respectively, which were significantly lower than that of the control [(56.51±3.27)%, P<0.010]; the migration rates of sh-circTNPO1 #1+ miR NC and sh-circTNPO1 #1+ miR-338-3p inhibitor were (26.70±2.21)% and (46.10±5.71)%, with a significant difference (P<0.005). In xenograft tumor model, the weight and size of tumors in control, sh-circTNPO1 #1+ miR NC and sh-circTNPO1 #1+ miR-338-3p inhibitor mice were (458.80±158.10) mg, (262.50±82.09) mg, (395.40±137.60) mg and (593.00±228.40) mm(2,) (203.30±144.20) mm(2,) (488.60±208.60) mm(2,) respectively. Compared with control, sh-circTNPO1 tumors were significantly smaller (P<0.01). Injection with miR-338-3p inhibitor significantly reversed both the weight and size of tumors (P<0.05). Conclusion: CircTNPO1 promotes the proliferation and metastasis of OS by sponging miR-338-3p, which could be a new target for OS treatments.
Animals ; Bone Neoplasms/pathology* ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation/genetics* ; Gene Expression Regulation, Neoplastic ; Humans ; Ki-67 Antigen/metabolism* ; Mice ; MicroRNAs/metabolism* ; Osteosarcoma/secondary* ; RNA, Circular/metabolism* ; Sincalide/metabolism*

OBJECTIVE: To observe the effect of early intervention of bone-nearby acupuncture (BNA) combined with electroacupuncture (EA) on the expression of histone deacetylase1(HDAC1), histone deacetylase 2 (HDAC2) andμ-opioid recepter (MOR) in dorsal root ganglia (DRG) of bone cancer pain-morphine tolerance (BCP-MT) rats, and to explore its possible mechanism. METHODS: A total of 35 SD rats were randomized into a sham BCP group (=6), a BCP group (=7), a MT group (=7), a BNA+EA group (=8) and a shame BNA group (=7). Except of the sham BCP group, cancer cell inoculation operation at left tibia was given in the other 4 groups to establish the bone cancer pain model. In the MT group, the BNA+EA group and the shame BNA group, intraperitoneal injection of morphine hydrochloride was given to establish the morphine tolerance model. After the operation, bone-nearby acupuncture combined with electroacupuncture was applied at "Zusanli" (ST 36) and "Kunlun" (BL 60) in the BNA+EA group, with dilatational wave, 2 Hz/100 Hz in frequency, 0.5 to 1.5 mA in intensity. Intervention in the shame BNA group was applied at the same time and acupoints as those in the BNA+EA group, the needles were pierced the skin without any electrical stimulation. The needles were retained for 30 min, once a day for continuous 7 days in both BNA+EA and shame BNA groups. Before and 10, 11, 15, 22 days after the operation, the left paw withdrawal threshold (PWT) was measured in the 5 groups. The levels of HDAC1, HDAC2 and MOR in DRG were detected by Western blot. RESULTS: Ten days after the cancer cell inoculation operation, the PWT of the BCP, MT, BNA+EA and sham BNA groups was decreased compared with the sham BCP group (<0.01). Eleven days after the operation, the PWT of the MT, BNA+EA and sham BNA groups was increased compared with the BCP group (<0.01). Twenty-two days after the operation, the difference was no significant between the BCP group and MT group (>0.05); the PWT of the BNA+EA group was increased compared with the MT and sham BNA group (<0.01). In the BCP group, the DRG levels of HDAC1 and HDCA2 were increased, while the level of MOR was decreased compared with the sham BCP group (<0.05, <0.01). In the MT group, the DRG level of HDAC1 was increased compared with the BCP group (<0.05). In the BNA+EA group, the DRG level of HDAC1 was decreased compared with the MT group and the sham BNA group (<0.01, <0.05), while the level of MOR was increased (<0.01). CONCLUSION Early intervention of bone-nearby acupuncture combined with electroacupuncture can relieve the morphine tolerance in bone cancer pain rats, it may relate to down-regulating the expression of HDAC1 and up-regulating the expression of MOR in the dorsal root ganglia.
Acupuncture Points ; Animals ; Bone Neoplasms ; complications ; Cancer Pain ; therapy ; Drug Tolerance ; Electroacupuncture ; Ganglia, Spinal ; metabolism ; Histone Deacetylases ; metabolism ; Morphine ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Opioid, mu ; metabolism

To investigate the effect of miR-30a/HMGA2-mediated autophagy in osteosarcoma cells on apoptosis induced by chemotherapeutics. 
 Methods: A total of 30 osteosarcoma tissues of sensitive and resistant to chemotherapeutics were divided into a chemotherapy-sensitive group and a chemotherapy-resistant group. The mRNA expression levels of miR-30a and high mobility group protein A2 (HMGA2) in the chemotherapy-sensitive group and the chemotherapy-resistant group, and the mRNA expression levels of miR-30a in osteosarcoma U2-OS cells treated by cisplatin, doxorubicin and methotrexate at different concentrations were detected by real-time PCR. The expression levels of autophagy related protein Beclin 1, microtubule associated protein 1 light chain 3B (LC3B) and autophagy factor P62 were detected by Western blotting. The osteosarcoma U2-OS cells were transfected with miR-30a mimics and miR-30a inhibitors to construct a miR-30a high expression group, a miR-30a low expression group and a control group. The expression levels of Beclin 1, LC3B and P62 in osteosarcoma U2-OS cells after treatment of cisplatin and doxorubicin in these 3 groups were detected by Western blotting; the level of autophagy was detected by monodansylcada (MDC) staining; the level of ROS was detected by dihydroethidium (DHE); the level of cell surviving rate was detected by cell counting kit-8 (CCK-8); the level of apoptosis was detected by annexin APC/PI double staining; the level of mitochondria oxidative damage was detected by mitochondrial membrane potential assay kit with JC-1 (JC-1 method). The interaction between miR-30a and HMGA2 was detected by dual luciferase reporter assay. The osteosarcoma U2-OS cells were transfected with HMGA2 mimics and HMGA2-shRNA to construct a high HMGA2 group, a low HMGA2 group, and a control group. The expression levels of Beclin 1, LC3B and P62 in osteosarcoma U2-OS cells after the treatment of cisplatin were detected by Western blotting.
 Results: The level of miR-30a in the chemotherapy-resistant tissues was significantly lower than that in the chemotherapy-sensitive tissues (P<0.05), and the expression of HMGA2 was opposite comparing to that of miR-30a (P<0.05). After the treatment by low concentration (5 μmol/L) of chemotherapeutics, the level of miR-30a was down-regulated in osteosarcoma U2-OS cells, accompanied with up-regulation of Beclin 1 and LC3B (P<0.01) and down-regulation of P62 (P<0.01). Compared with the control group, the expression levels of Beclin 1 and LC3B were significantly decreased (P<0.05), and the expression level of P62 was significantly increased (P<0.05) in the miR-30a high expression group, which was opposite in the miR-30a low expression group. In the miR-30a high expression group treated by chemotherapeutics, the level of autophagy and the cell survival rate were lower than those in group with low expression of miR-30a, while the levels of ROS, the mitochondrial oxidative damage and the apoptosis were higher than those in group with low expression of miR-30a (all P<0.05). The targeting interaction between HMGA2 and miR-30a were verified by dual luciferase reporter assay. Compared with the control group, the expression levels of Beclin 1 and LC3B were significantly increased (P<0.05), and the expression level of P62 was significantly decreased (P<0.05) in the HMGA2 high expression group, which was opposite in the HMGA2 low expression group.
 Conclusion: Suppression of miR-30a/HMGA2-mediated autophagy in osteosarcoma cells is likely to enhance the therapeutic effect of chemotherapeutics.
Apoptosis ; Apoptosis Regulatory Proteins ; Autophagy ; Beclin-1 ; Bone Neoplasms ; Cell Line, Tumor ; HMGA2 Protein ; metabolism ; Humans ; MicroRNAs ; genetics ; Osteosarcoma

BACKGROUND: Bone marrow-derived mesenchymal stem cells (BM-MSCs) play an important role in cancer development and progression. However, the mechanism by which they enhance the chemoresistance of ovarian cancer is unknown. METHODS: Conditioned media of BM-MSCs (BM-MSC-CM) were analyzed using a technique based on microRNA arrays. The most highly expressed microRNAs were selected for testing their effects on glycolysis and chemoresistance in SKOV3 and COC1 ovarian cancer cells. The targeted gene and related signaling pathway were investigated using in silico analysis and in vitro cancer cell models. Kaplan-Merier survival analysis was performed on a population of 59 patients enrolled to analyze the clinical significance of microRNA findings in the prognosis of ovarian cancer. RESULTS: MiR-1180 was the most abundant microRNA detected in BM-MSC-CM, which simultaneously induces glycolysis and chemoresistance (against cisplatin) in ovarian cancer cells. The secreted frizzled-related protein 1 (SFRP1) gene was identified as a major target of miR-1180. The overexpression of miR-1180 led to the activation of Wnt signaling and its downstream components, namely Wnt5a, β-catenin, c-Myc, and CyclinD1, which are responsible for glycolysis-induced chemoresistance. The miR-1180 level was inversely correlated with SFRP1 mRNA expression in ovarian cancer tissue. The overexpressed miR-1180 was associated with a poor prognosis for the long-term (96-month) survival of ovarian cancer patients. CONCLUSIONS BM-MSCs enhance the chemoresistance of ovarian cancer by releasing miR-1180. The released miR-1180 activates the Wnt signaling pathway in cancer cells by targeting SFRP1. The enhanced Wnt signaling upregulates the glycolytic level (i.e. Warburg effect), which reinforces the chemoresistance property of ovarian cancer cells.
Adenosine Triphosphate/chemistry* ; Adult ; Aged ; Bone Marrow Cells/cytology* ; Cell Line, Tumor ; Cell Proliferation ; Cells, Cultured ; Drug Resistance, Neoplasm/genetics* ; Female ; Flow Cytometry ; Follow-Up Studies ; Glycolysis ; Humans ; Intercellular Signaling Peptides and Proteins/metabolism* ; Membrane Proteins/metabolism* ; Mesenchymal Stem Cells/cytology* ; MicroRNAs/genetics* ; Middle Aged ; Multivariate Analysis ; Ovarian Neoplasms/genetics* ; Up-Regulation ; Wnt Signaling Pathway