The usefulness of chemical-shift magnetic resonance imaging for the evaluation of osteoid osteoma

<div><p>Abstract Objective: The purpose of this study was to determine whether chemical-shift magnetic resonance imaging (MRI) could be useful in the diagnosis of osteoid osteoma when clinical and radiological tumor features are inconclusive. Materials and Methods: This retrospective study included 17 patients who underwent chemical-shift MRI for the evaluation of osteoid osteoma. For all patients, two musculoskeletal radiologists independently recorded signal intensities on in-phase and out-of-phase images in the nidus of the tumor, in abnormal-intensity bone marrow surrounding the lesion, and in normal-appearing bone marrow. For each region, relative signal intensity ratios were calculated by dividing out-of-phase by in-phase values. Relative ratios > 1 were considered indicative of neoplastic lesions. Statistical analysis was carried out to analyze the sample. Inter-observer and intra-observer agreement for each imaging method were assessed using intraclass correlation coefficients according to the Fleiss method and a value > 0.65 was considered to indicate substantial agreement. Results: The mean relative signal intensity ratios were 1.2 (range, 0.9-1.4) for the nidus and 0.35 (range, 0.11-0.66) for the surrounding tissue; these values differed significantly from the relative signal-intensity ratios for normal-appearing bone marrow (p < 0.05). Conclusion: Chemical-shift MRI is useful for the diagnosis and evaluation of osteoid osteoma.</p></div

Analysis of SOX2 and OCT4 expression in osteosarcoma cells treated with chemotherapy agents.

<p><b>A</b>. Correlation between presence of metastasis in osteosarcoma patients and SOX2 expression in cells derived from their tumors. <b>B</b>. Western blot analysis of SOX2 and OCT4 expression in primary tumor cells directly isolated from osteosarcoma patients (OS1 and OS6) before (PRE) and after (POST) chemotherapy treatments. Cyclophilin B was used as loading control. <b>C</b>. Western blot analysis of SOX2 and OCT4 expression in primary tumor cells (OS1 and OS9) after <i>in vitro</i> treatment with cisplatin, doxorubicin or methotrexate. * <i>P</i> < 0.05, ** <i>P</i> < 0.01, Mann-Whitney U test.</p

Analysis of SOX2 expression in human osteosarcoma tissue and cells directly isolated from patients.

<p><b>A</b>. Representative immunohistochemistry images showing expression of SOX2 in osteosarcoma tissues from four patients (OS1, OS2, OS6 and OS12). <b>B</b>. Western blot analysis of SOX2 expression in primary tumor cells directly isolated from the tumor sites of eight osteosarcoma patients. Cyclophilin B was used as loading control. <b>C</b>. Representative immunocytochemistry image showing SOX2 expression in cells (OS6) immediately after tumor tissue dissociation. Scale bar, 100μm. <b>D</b>. Quantification of SOX2-positive cells from immunofluorescence in freshly dissociated samples from 11 osteosarcoma patients. <b>E</b>. Immunofluorescence staining of osteoprotegerin in patient-derived osteosarcoma cells in culture. Scale bar = 50 μm. OPG, osteoprotegerin.</p

Effect of chemotherapeutic agents in osteosarcoma cells viability.

<p><b>A</b>. MTT analysis of osteosarcoma cells isolated from 18 PRE samples (from 18 different patients) and 10 POST samples (from 8 different patients, as samples from OS2 and OS3 were collected at two different time-points after chemotherapy). <b>B-D</b>. MTT analysis of osteosarcoma cells isolated from four patients (OS1, OS4, OS6 and OS14) and treated with vehicle or <b>B</b>. cisplatin, <b>C</b>. doxorubicin, or <b>D</b>. methotrexate for 72h. * <i>P</i> < 0.05, ** <i>P</i> < 0.01, *** <i>P</i> < 0.001, Mann-Whitney U test.</p

Osteosarcoma patients’ characteristics, tumor topography, evolution, and surgical procedure.

<p>Osteosarcoma patients’ characteristics, tumor topography, evolution, and surgical procedure.</p

Effect of chemotherapeutic agents in SSEA4 expression in osteosarcoma cells.

<p><b>A, B</b>. Flow cytometry analysis (<b>A</b>) and quantification (<b>B</b>) of CD133, CD15 and SSEA4 expression in patient-derived osteosarcoma cells. <b>C, D</b>. Flow cytometry analysis (<b>C</b>) and quantification (<b>D</b>) of SSEA4 expression in primary osteosarcoma cells treated with cisplatin, doxorubicin or methotrexate. <b>E</b>. Bioluminescent imaging of mice injected with luciferase-expressing SaOs2 osteosarcoma cells and treated with cisplatin and doxorubicin (Cis+Dox), or cisplatin, doxorubicin and methotrexate (Cis+Dox+Mtx). <b>F</b>. Quantification of total flux from tumors. <b>G, H</b>. Flow cytometry analysis (<b>G</b>) and quantification (<b>H</b>) of SSEA4 expression in osteosarcoma cells isolated from tumors treated with cisplatin and doxorubicin (Cis+Dox), or cisplatin, doxorubicin and methotrexate (Cis+Dox+Mtx). * <i>P</i> < 0.05, ** <i>P</i> < 0.01, *** <i>P</i> < 0.001, Mann-Whitney U test.</p