Alendronate regulates cell invasion and MMP-2 secretion in human osteosarcoma cell lines

BACKGROUND: Osteosarcoma is the most common malignant bone tumor of childhood. Significant proportions of these patients eventually develop pulmonary metastases and succumb to their disease even after conventional multi-agent chemotherapy and surgical excision. Matrix metalloproteinase (MMP)-2 induced degradation of blood vessel basement membranes is an important pre-requisite for tumor invasion and metastasis. Bisphosphonates (BPs) have been known to inhibit tumor growth and metastasis in some tumors such as breast cancer, renal cell carcinoma, and prostate cancer, and may do so through inhibition of MMP secretion. We, therefore, tested the effect of BPs on tumor cell invasion, MMP-2 secretion, and apoptosis of osteosarcoma cell lines. PROCEDURE: Two osteosarcoma cell lines (SaOS-2, U(2)OS) were treated with alendronate (50, 100, and 150 microM) for 24 and 48 hr. Matrigel invasion assay was used to investigate the invasive potential of osteosarcoma cell lines before and after alendronate treatment. Real-time quantitative RT-PCR was used to determine the mRNA level of MMP-2 with and without alendronate treatment. Enzyme-linked immunosorbent assay (ELISA) was used to quantify the cytokine level of MMP-2 secreted in the condition medium. BP-induced cell apoptosis was evaluated by fluorescent flow cytometric analysis. RESULTS AND CONCLUSIONS: The results showed that alendronate inhibited cell invasion of both osteosarcoma cell lines in a dose-dependent manner. Alendronate reduced the mRNA level and cellular level of MMP-2 in both cell lines in a time and dose-dependent manner. Alendronate also induced significant apoptosis in both cell lines. Our finding suggests that alendronate downregulates MMP-2 secretion and induces apoptosis in osteosarcoma cells, which may both contribute to the reduction of invasive potential of the tumor cells.     

Methotrexate levels and outcome in osteosarcoma

BACKGROUND: Peak serum concentrations of methotrexate (MTX) have been reported to correlate with outcome in osteosarcoma (OS). Modification of the MTX dose to achieve peak levels between 700 and 1,000 micromol/L has been recommended. The goal of the study was to assess whether there is a correlation between histologic necrosis of the tumor and/or prognosis with peak MTX serum concentration. PROCEDURE: Treatment included multi-agent adjuvant chemotherapy, including high-dose MTX (12 g/m2). Peak MTX levels were drawn following a 4-hr infusion. Histologic evaluation for percent necrosis was done at the time of definitive resection. RESULTS: The median peak MTX level (n = 52 patients) was 1,060 micromol/L (range: 410-4,700 micromol/L), with significant intra-patient and inter-patient variability. Fifty-eight percent of the levels were 1,000 micromol/L or higher. Response to pre-operative chemotherapy was: 18% Grade I necrosis, 35% Grade II, 31% Grade III, and 16% Grade IV. No significant association was found between the mean peak MTX levels and necrosis (P = 0.44). Event-free survival (EFS) for the 48 patients with non-metastatic disease at diagnosis was 76% at 4 years of follow-up, with no association between the mean peak MTX level and EFS (P = 0.24). CONCLUSIONS: The absence of a demonstrable correlation between peak MTX levels and histologic necrosis or EFS may suggest that most patients achieve therapeutic levels when MTX is given at a dose of 12 g/m(2). The significant degree of intra-patient variability in peak levels poses a dilemma for pharmacokinetic adjustment. Continued use of HD-MTX in all patients, rather than dose adapted therapy, may be justified.     

Treatment of metastatic osteosarcoma with the somatostatin analog OncoLar: significant reduction of insulin-like growth factor-1 serum levels

BACKGROUND: Insulin-like growth factor-1 (IGF-1) has been implicated in the growth and/or metastasis of osteosarcoma (OS) and chondrosarcoma based on in vitro and experimental animal studies. STUDY PURPOSE: To determine the degree of growth hormone (GH), IGF-1 axis blockade, toxicities, and antitumor effect of OncoLar (ONC) (Novartis, East Hanover, NJ, U.S.A.) in OS. DESIGN/METHODS: A phase 1 study with ONC enrolled 21 OS patients (median age 19 y) in four cohorts: ONC 60 mg or 90 mg intramuscularly every 4 weeks with/without tamoxifen (TAM) 20 mg oral daily. RESULTS: There were no dose-limiting toxicities. Nineteen percent of patients had grade III drug-related toxicities including: 62% of patients showed progressive disease after two courses (8 wk). Nineteen percent received four courses. No clinical responses were observed. At weeks two and eight of therapy, IGF-1 serum levels dropped 46% ( < 0.0001, n = 21) and 53% ( = 0.003, n = 10). The difference of the area under the curve (AUC) minus baseline AUC (DeltaAUC) for arginine-stimulated GH serum levels at week two was lower than baseline ( < 0.01). At weeks two and eight, GH peak values were lower than baseline ( < 0.0001 and = 0.002, respectively). CONCLUSIONS: A long-acting somatostatin analog was able to lower IGF-1 levels of OS patients. IGF-BP-3 and GH were only transiently reduced. Although ONC was well tolerated, no sustained clinical responses were observed. The pathophysiology of serum versus tissue concentrations of IGF-1 as well as the interplay of IGFs, IGF-binding proteins, and other growth factors and cytokines in osteosarcoma warrants further investigation. A better understanding of these processes should lead to a more effective exploitation of these pathways for the targeted therapy of OS.     

Survivin反义寡核苷酸对骨肉瘤MG-63细胞系增殖和凋亡的影响

目的观察Survivin基因反义寡核苷酸对骨肉瘤细胞增殖和凋亡的影响。方法靶向Survivin基因的反义寡核苷酸经脂质体介导转染骨肉瘤MG63细胞系，倒置显微镜观察转染后细胞形态学变化、半定量RT-PCR检测Survivin基因mRNA的表达，噻唑蓝(MTT)法检测细胞的增殖情况，吖啶橙荧光染色法观察细胞凋亡情况。结果转染反义寡核苷酸后，MG63细胞中Survivin基因mRNA水平表达显著下降；细胞增殖受到显著抑制，抑制率达61％；倒置显微镜显示细胞变圆，漂浮细胞增多；吖啶橙染色显示转染组细胞出现明显核碎裂等凋亡改变。结论Survivin基因的反义寡核苷酸可以显著抑制骨肉瘤细胞增殖，促进细胞凋亡。     

唑来膦酸对骨肉瘤细胞体外血管生成拟态的影响

目的 研究唑来膦酸对骨肉瘤细胞体外血管生成拟态的影响.方法 应用Ⅰ型胶原蛋白凝胶的三维培养基对骨肉瘤细胞进行培养,观察骨肉瘤细胞是否能形成血管拟态以及唑来膦酸对其的影响,并运用电镜和激光共聚焦显微镜观察细胞的超微结构的改变.结果 唑来膦酸明显抑制骨肉瘤细胞形成血管生成拟态,减少骨肉瘤细胞表面的微绒毛和破坏细胞骨架F-actin.结论 唑来膦酸显著改变骨肉瘤细胞的超微结构,这个可能是其抑制血管生成拟态的形成的机制之一.     

Epithelioid osteosarcoma of the jaw

Epithelioid osteosarcoma (OS) is a rare sub‐type of OS with an aggressive behavior. An epithelioid OS was diagnosed in an 8‐year‐old female with painful swelling of the left jaw. After two courses of chemotherapy (cisplatin/methotrexate/doxorubicin), the patient presented a progressive disease. After hemimandibulectomy, 13 courses of post‐operative chemotherapy (cisplatin/methotrexate/doxorubicin/ifosfamide) were performed. Histological and ultra‐structural examination showed a high grade neoplasm consisting of sheets of epithelioid cells with focal osteoid formation. The patient is alive and in complete remission 42 months from diagnosis. Pediatr Blood Cancer 2009;52:877–879. © 2009 Wiley‐Liss, Inc.     

Role of heat treatment in childhood cancers: distinct resistance profiles of solid tumor cell lines towards combined thermochemotherapy

BACKGROUND: Since information on the efficacy of hyperthermia in combination with chemotherapy on pediatric tumors is limited, we performed a systematic analysis on the synergistic effects of a combined application of heat and chemotherapy on 20 tumor cell lines derived from patients with neuroblastomas, Ewing tumors, germ cell tumors (GCT), and osteosarcomas. METHODS: Cisplatin (cDDP), a cross-linking agent, and etoposide (VP-16), a topoisomerase II inhibitor, were examined either alone or in combination with heat (42 degrees C, 43 degrees C) by using the XTT-assay 1. RESULTS: Our data demonstrate that heat stress at 43 degrees C for 1 hr, but not at 42 degrees C, leads to a notable cytotoxic effect on the different tumor cells. The comparison of mean survival fractions reveals values between 62% for neuroblastoma cells and 76% for Ewing tumor cells. Analyzing the sensitivity to chemotherapy alone, our results show that cDDP (5 microg/ml) reduces cell growth to 47% in Ewing tumor cells, to 61% in neuroblastoma cells, to 75% in GCT cells, and to 76% in osteosarcoma cells. Treatment with VP-16 (10 microg/ml) decreases cell survival to mean values between 58% (neuroblastomas) and 77% (osteosarcomas). Simultaneous application of heat and chemotherapy enhances synergistically cDDP cytotoxicity in all tumor types tested, whereas the efficacy of VP-16 is only slightly influenced by additional application of hyperthermia. The cytotoxicity of cDDP (5 microg/ml) can be increased by a factor of between 1.5 and 2.5 at 42 degrees C and from 2.6 to 14.0 at 43 degrees C. Furthermore, the results show that the sensitivity to heat (43 degrees C) as well as the sensitivity to chemotherapy and combined thermochemotherapy varies considerably between cell lines of the same tumor group. CONCLUSIONS: Simultaneous application of hyperthermia synergistically enhances the cytotoxicity of the alkylating agent cDDP, but not of the topoisomerase II inhibitor VP-16, in a defined spectrum of cell lines from different pediatric tumor entities.     

Fas expression in lung metastasis from osteosarcoma patients

The authors' animal studies have shown that the metastatic potential of osteosarcoma (OS) cells correlates inversely with Fas expression-that is, Fas-negative cells metastasize but Fas-positive cells do not. One reason for this in the context of OS lung metastases may be that Fas-positive cells are eliminated by engagement with the Fas ligand (FasL) constitutively expressed on the surface of pneumocytes, whereas Fas-negative tumor cells are not. The purpose of this study was to determine the status of Fas expression in OS lung metastases from patients. Specifically, archived paraffin-embedded specimens of lung metastases from 38 patients with OS were analyzed by immunohistochemistry. Lung nodules from 23 of the 38 patients (60%) were Fas negative, those from 12 patients (32%) were weakly positive, and that from only 1 patient (3%) was strongly positive. Findings in the samples from the remaining two patients (5%) could not be interpreted because of extensive necrosis. Most patients with the weakly positive tumors and the single patient with the strongly positive tumor received chemotherapy prior to lung resection. There was a significant correlation between Fas expression and the administration of preoperative salvage chemotherapy (P = 0.0013). These data indicate that loss of Fas may be one mechanism by which OS cells evade host resistance in the lung. Chemotherapy may induce regression by upregulating Fas.     

Pemetrexed, a multitargeted antifolate drug, demonstrates lower efficacy in comparison to methotrexate against osteosarcoma cell lines

The folate inhibitor methotrexate (MTX) is an important component of osteosarcoma (OS) treatment regimens. New generation multitargeted antifolates, such as pemetrexed (PMX), have shown promise in the treatment of various solid tumors. In this study, the in vitro efficacy of MTX and PMX was compared in OS cell lines. MTX demonstrated a superior cytotoxic effect in comparison to PMX in all tested cell lines. Apoptosis assays revealed that both MTX and PMX induce apoptosis but MTX demonstrated superior efficacy. These in vitro results suggest that PMX as a single agent may not demonstrate improved efficacy compared to MTX in OS patients.     

Treatment results of osteosarcoma of the extremity in children and adolescents at Ege University Hospital

Twenty-five patients were treated for osteosarcoma of the extremity at Ege University Hospital. Eight of them were metastatic. All patients received cisplatin, doxorubicin, ifosfamide, and methotrexate preoperatively. Twenty-three patients underwent surgery at around week 15 (11-18 weeks). All but one underwent limb-sparing surgery. While good responders continued to receive the same drugs, poor responders were given the same regimen before 1996, but high-dose ifosfamide alone after 1996. For all patients the projected event-free survival (EFS) rates were 63.5% at 2 years and 53% at 5 years. The projected overall survival (OS) rates were 72% at 2 years and 62% at 5 years. For nonmetastatic patients, 5-year EFS and OS rates were 67% as compared with metastatic patients (25 and 50%)(p =. 01 for EFS; p > .05 for OS). The results show that nonmetastatic patients with osteosarcoma of the extremity have favorable prognosis on this therapy regimen, allowing a high rate of limb-sparing surgery.     

Immediate free flap mandibular reconstruction in osteosarcoma of the mandible in childhood

Mandibular osteogenic sarcoma (OS) is a very rare entity in childhood. Adequate surgical rejection with a wide margin of normal tissue is the mainstay of treatment of this site, while the role of adjuvant chemotherapy remains uncertain. A case is presented of a 15 1/2-year-old male with a huge OS of the mandible. The boy underwent surgical resection of the mandible with immediate fibula free flap reconstruction and is alive and free of disease 6 1/2 years following unitial diagnosis. This case suggests that immediate bone reconstitution with vascularized grafts have good functional and morphological results for osteosarcoma of the lower jaw.     

Interferon-gamma sensitizes osteosarcoma cells to Fas-induced apoptosis by up-regulating Fas receptors and caspase-8

BACKGROUND: Osteosarcoma is the third most frequent neoplasm in adolescents. Although chemotherapy, frequently used in pre- and post-operative settings, has resulted in significant improvement in disease-free survival, some patients show little sensitivity to chemotherapy and alternative therapeutic strategies are needed. Because the Fas ligand/Fas receptor (CD95, APO-1) apoptosis pathway is a potential therapeutic target in osteosarcomas, we examined the effect of IFN-gamma on Fas-induced apoptosis in four osteosarcoma cell lines. PROCEDURE AND RESULTS: As measured by flow cytometry, all cell lines expressed cell surface IFN-gamma receptors, and when cultured for 2 days in the presence of IFN-gamma, all cell lines exhibited a significant increase in expression of Fas receptors. By flow cytometric detection of intracellular fragmented DNA as a marker of apoptosis, all cell lines cultured with either IFN-gamma or anti-Fas antibody (clone CH-11) alone showed only moderate apoptosis, whereas significantly high levels of apoptosis occurred in cells cultured with both IFN-gamma and CH-11. Western blotting analysis also revealed that IFN-gamma caused up-regulation of caspase-8 in all cell lines, but no change in Fas-associated death domain protein (FADD/MORT1) or caspase-3. Both caspase-8 and caspase-3 were activated when apoptosis was induced with both IFN-gamma and CH-11. Addition to cultures of z-IETD-fmk, an inhibitor of caspase-8, significantly blocked this apoptosis. CONCLUSIONS: IFN-gamma sensitizes osteosarcoma cells to Fas-induced apoptosis through up-regulation of Fas receptor and caspase-8. Combined immunotherapy with IFN-gamma and either anti-Fas monoclonal antibody or cytotoxic T cells that bear Fas ligand might be a useful adjunctive therapy for patients with osteosarcoma.     

Heat-shock protein 72 in human osteosarcoma: T-lymphocyte reactivity and cytotoxicity

Heat-shock proteins (hsp) have been shown to be involved in tumor immunity. The expression of hsp72, the inducible form of the 70-kDa family, is increased in human osteosarcoma and correlates with a good response to neoadjuvant chemotherapy. It is selectively expressed on the surface of osteosarcoma cell lines where it acts as a target molecule for natural killer cells. Because hsps are strongly immunogenic, this study investigates the role of hsps as antigens in human osteosarcoma. Osteosarcoma cells and infiltrating T lymphocytes were isolated from osteosarcoma specimens from 3 patients with high-grade osteosarcoma. Two of the tumors immunohistochemically expressed hsp72, whereas one did not. T-cell lines isolated from both hsp72-positive osteosarcomas had a significantly proliferative response upon stimulation with recombinant human hsp72, whereas the T lymphocytes from the hsp72-negative osteosarcoma did not recognize hsp72. The lines had a significantly proliferative response upon stimulation with autologous osteosarcoma cells and exerted cytotoxicity. Cytotoxicity and proliferation could be increased by heat treatment of the target cell in the hsp72 responsive lines. These results demonstrate that hsp72 is involved in the interaction of T lymphocytes and osteosarcoma cells in a specific group of osteosarcomas expressing hsp72. Because of the cytotoxic potential of these T lymphocytes, induction of hsp72 in osteosarcomas might lead to an increased immune response and rejection of the osteosarcoma.     

Essential erbB family phosphorylation in osteosarcoma as a target for CI-1033 inhibition

BACKGROUND: The role of erbB tyrosine kinases, especially Her-2, in osteosarcoma has engendered intense debate. Some investigators identified an association between low-level Her-2 expression, compared to none, and poor patient outcome. Others questioned the importance of apparent cytoplasmic expression of Her-2, since membranous overexpression is associated with poor outcome in carcinomas. We previously demonstrated that primary osteosarcoma cells express cell-surface EGFR and Her-2, with the p80 isoform of Her-4 localized to the nucleus. We wished to determine if erbB kinases in osteosarcoma were phosphorylated, and if this was required for growth. PROCEDURES: We cultured early passage osteosarcoma cell lines in the presence or absence of the pan-erbB inhibitor CI-1033 and examined the phosphorylation status of EGFR, Her-2, and Her-4 by immunohistochemistry, cell-based ELISA, flow cytometry and two dimensional Western blot. We also assessed the impact of CI-1033 upon osteosarcoma growth and survival in vitro. RESULTS: EGFR, Her-2, and Her-4 were constitutively phosphorylated in early passage osteosarcoma cells cultured in vitro. CI-1033 abrogated erbB receptor phosphorylation and caused growth inhibition and apoptosis in a titratible fashion with concentrations of 1 muM or more. CONCLUSIONS: EGFR, Her-2, and Her-4 are constitutively phosphorylated in early passage osteosarcoma cells in tissue culture, and erbB signaling provides essential growth and anti-apoptotic signals to osteosarcoma cells. This suggests that erbB overexpression is not required for erbB to promote malignancy, but rather that overexpression is one of several mechanisms that generate unregulated erbB signaling.     

Treatment of refractory osteosarcoma with fractionated cyclophosphamide and etoposide

PURPOSE: Standard multiagent chemotherapy for osteosarcoma may include platinum compounds, doxorubicin, and high-dose methotrexate. By identifying new chemotherapeutic strategies, the outcome of these patients can be improved and the toxicity of treatment regimens decreased. PATIENTS AND METHODS: The authors evaluated the activity of the combination of cyclophosphamide (500 mg/m2 per day for 5 days) and etoposide (100 mg/m2 per day for 5 days) given with granulocyte colony-stimulating factor (G-CSF) to children with osteosarcoma unresponsive to conventional treatment. RESULTS: Fourteen patients with refractory osteosarcoma were treated with this combination. Twelve patients had been previously treated with a multiagent regimen that included carboplatin, ifosfamide, methotrexate, and doxorubicin. Seven of 11 evaluable patients had a poor histologic response in their primary tumor at the time of definitive surgery (Huvos grade 1 or 2). Sites of relapse included lung, bone, and brain. A total of 47 courses were given. An overall response rate of 28.5% was achieved. A complete response was obtained in one patient (7.1%), a partial response was obtained in three patients (21.4%), and stable disease for 1 to 4 months was achieved in five patients (35.7%). Five patients (35.7%) had progressive disease. Grade 4 neutropenia was the primary form of toxicity observed; the median duration of absolute neurophil count less than 500/microL was 4 days. CONCLUSIONS: The combination of cyclophosphamide and etoposide resulted in a response rate of 28.5% in patients with refractory or relapsed osteosarcoma, and its incorporation into front-line therapies deserves further evaluation.     

Tumor size as a predictor of outcome in pediatric non-metastatic osteosarcoma of the extremity

BACKGROUND: Better predictors of outcome would allow improved risk-adapted therapy for pediatric nonmetastatic osteosarcoma of the extremity. We investigated the predictive value of MR imaging-based measures of absolute and relative tumor size and volume at the time of diagnosis. We also assessed the relation of tumor size to age and histologic response. METHODS: We retrospectively abstracted demographic, treatment history, and outcome information of patients treated on a single institutional protocol. A single pediatric oncologic radiologist manually measured each primary lesion and the affected native bone in three dimensions on MR images obtained at the time of diagnosis. Eight parameters of tumor size were analyzed for their value in predicting overall survival (OS) and event-free survival (EFS). RESULTS: The median age of the 42 patients was 13.5 years (range: 5.9-18.7 years); 50% were female and 74% were Caucasian. Absolute tumor volume was an important predictor of OS (P < 0.05); absolute tumor depth (analyzed as a continuous variable) was a significant predictor of OS (P = 0.018) and EFS (P = 0.036). Relative measures of tumor size were not found to predict outcome. No relation was seen between tumor size and histologic response. CONCLUSIONS: Absolute tumor size at the time of diagnosis is significantly predictive of OS and EFS. If validated in a larger study, this indicator should be used in the design of risk-adapted treatment protocols for osteosarcoma.     

Risk factors associated with delayed methotrexate clearance and increased toxicity in pediatric patients with osteosarcoma

High‐dose methotrexate (HD‐MTX; 12 g/m²) is part of standard therapy for pediatric osteosarcoma (OS). Risk factors associated with MTX toxicity in children with OS are not well defined. We investigated the association between peak MTX levels (four‐hour) and delayed MTX clearance or treatment toxicity. Information was retrieved from electronic medical records of 33 OS patients treated with HD‐MTX at Texas Children's Hospital from 2008 to 2015. We found that the four‐hour MTX level did not contribute to toxicity or delayed MTX clearance. We demonstrated that certain demographic characteristics are associated with delayed clearance and increased toxicity.     

Bilateral renal metastases from osteosarcoma: A case report and review of the literature

Improvements in multimodal therapy for osteosarcoma (OS) have increased event-free and overall survival. But have also led to a greater number of recurrences in uncommon sites. We report a young adult with OS who developed late bilateral renal relapse. Late recurrences to the kidneys have a more aggressive clinical behavior and poor prognosis documented by 15 cases of OS metastastic to the kidney in the literature. Two of those patients had a long survival after chemotherapy and surgery. This suggests that the disease can be controlled with early detection and treatment.