Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The results of several studies suggest that alterations in various cell cycle regulatory genes are involved in the pathogenesis of osteosarcomas. Experiments in animal models provide preliminary data on the feasibility of gene therapy in osteosarcoma and chondrosarcoma. Prediction of response to chemotherapy remains a major focus of imaging research. Several clinicopathologic studies have explored the mechanisms underlying multidrug resistance in osteosarcoma patients receiving neoadjuvant chemotherapy. HER2/erbB2 expression, linked to poor prognosis, has been proposed as a therapeutic target in osteosarcoma. In clinical studies of osteosarcoma, further data confirm the activity of ifosfamide and carboplatin but provide little support for the use of immunotherapy. A retrospective analysis showed no value for dose intensification of doxorubicin/cisplatin, but the results of a prospective trial should be more informative. Recent evidence confirms that secondary osteosarcomas and malignant fibrous histiocytomas of bone should be treated with aggressive chemotherapy regimens, similar to those used for osteosarcomas.
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PMID:Osteosarcomas and other cancers of bone. 1088 18

Prognostic biologic factors that can be assessed at the time of diagnosis for patients with osteogenic sarcoma have not been identified. The current study was designed to evaluate the prognostic significance of the human epidermal growth factor receptor 2 as it relates to histologic response to preoperative chemotherapy and event-free survival. A retrospective immunohistochemical study was performed on material from patients who were newly diagnosed with osteogenic sarcoma who were treated according to the T12 protocol from the authors' institution between 1986 to 1993. Staining for HER2/erbB-2 was accomplished using standard monoclonal antibodies and methods. At the time of initial biopsy, 42.6% of the samples showed HER2/erbB-2 overexpression. Higher levels of expression were observed in samples from patients with clinically detectable metastases at initial presentation and at relapse. Expression of HER2/erbB-2 correlated with inferior event-free survival in patients with nonmetastatic disease (47% versus 79% at 5 years). In addition, HER2/erbB-2 expression was associated with significantly less tumor necrosis after preoperative chemotherapy as determined by the Huvos grading system. These data suggest that HER2/erbB-2 should be evaluated prospectively as a prognostic indicator and clinical trials using antibodies that target this receptor should be considered for the treatment of patients with osteogenic sarcoma.
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PMID:Human epidermal growth factor receptor 2 as a prognostic indicator in osteogenic sarcoma. 1115 5

Tumor response to preoperative chemotherapy is an important prognostic factor for localized, operable extremity osteosarcoma. Other clinical variables include tumor size and location, age and sex, and serum enzymes. Advances in molecular oncology yielded a second group of factors such as multidrug resistance status, loss of heterozygosity of RB gene, and HER2/erbB-2 expression. The aim of this study was to investigate the expression and the prognostic value of the newly described erbB-4 receptor in specimens from adults with bone sarcomas treated by pre- and postoperative chemotherapy. Thirty-three patients with non-metastatic bone sarcoma have been treated by two doxorubicin-based induction chemotherapy regimen, followed by limb sparing surgery and tailored adjuvant chemotherapy. Pre-chemotherapy tissue specimens were investigated for the expression of erbB-4 receptor and post-induction specimens were assessed for pathological response. The clinical response rates were 32-36%. The degree of induced necrosis was correlated with the disease-free survival (DFS). Patients achieving >/=90% necrosis had an improved DFS over patients with poor histological response. ErbB-4 expression was significantly associated with poor histologic response and shorter DFS. ErbB-4 expression may be used for prognostication of adults with bone sarcomas.
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PMID:Induction chemotherapy for bone sarcoma in adults: correlation of results with erbB-4 expression. 1288 46

The expression of HER-2/neu has been proposed to be a prognostic indicator in osteosarcoma. To clarify the actual frequency of HER-2/neu expression in primary malignant cartilaginous tumors, we examined 89 cases comprising 17 conventional chondrosarcomas, 33 mesenchymal chondrosarcomas, and 39 clear cell chondrosarcomas. We used real-time PCR (LightCycler) assay to quantify the HER-2/neu gene status. The crossing point of HER-2 in normal control bone was 27.77. The crossing points of HER-2 in conventional, mesenchymal, and clear cell chondrosarcomas were 28.48+/-1.79, 27.74+/-3.02, 28.57+/-1.54, respectively. In conclusion, the amplification and overexpression of the HER-2/neu oncogene is absent or at least very rare in malignant cartilaginous tumors. The level of expression of HER-2/neu was similar in all cartilaginous tumor types.
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PMID:Evaluation of HER-2/neu status by real-time quantitative PCR in malignant cartilaginous tumors. 1476 42

The overexpression of HER-2/neu and p53 has been associated with poor outcome in many neoplasms. Their role in patients with osteosarcoma is unclear. We studied the expression of HER-2/neu and p53 in 22 osteosarcoma samples (from 20 patients--2 had locally recurrent disease) biopsied at the University of Medicine and Dentistry of New Jersey (UMDNJ) from 1996-2000 using both immunohistochemical (IHC) and fluorescence in situ hybridization (FISH) analysis. Fourteen patients (14 samples) presented with Stage II and 6 patients (8 samples) presented with Stage III disease. Median follow-up is two years (range one year to five years). Four of 22 (18%) samples showed focal membranous or cytoplasmic positivity for HER-2/neu and six of 22 samples (27%) showed nuclear positivity for p53 by IHC analysis. In contrast, none of 22 tested samples showed gene amplification for HER-2/neu by FISH analysis. Seven of 13 HER-2/neu and p53 negative patients (54%) are currently disease free (between one year to five years). In this sample of patients, the HER-2/neu oncogene is not overexpressed or amplified in osteosarcoma; six of 22 samples (27%) showed overexpression of p53 by IHC analysis. By FISH, none of the samples demonstrated deletion of p53. Neither HER2/neu nor p53 expression was important for the biology of osteosarcoma in this population.
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PMID:HER-2/neu and p53 in osteosarcoma: an immunohistochemical and fluorescence in situ hybridization analysis. 1506 60

Low-grade osteosarcoma is a rare variant of osteosarcoma. Although malignant, it must be distinguished from conventional osteosarcomas because of its excellent prognosis. Numerous published papers have described the expression of HER2/neu oncogene in osteosarcoma as a poor prognostic factor; however their results are discordant. To address the expression of HER2/neu and to validate the assessment methods of amplification of the HER2/neu oncogene, the authors have employed quantitative real-time PCR and fluorencent in situ hybridization analysis (FISH) in 21 low-grade osteosarcomas. We calculated the quantification of HER2/neu oncogene amplification as the ratio of measured HER2/neu gene/beta-globin reference gene in real-time PCR. All 21 cases had amplified signals in the quantitative real-time PCR. However, in the FISH analysis, HER2/neu oncogene amplification was only identified in 26% (5/19). The exact reasons for the discordance between these two methods are unknown; however, variable histological features might play a potential role. In conclusion, as our study showed amplification of HER2/neu oncogene in low-grade osteosarcoma, we assume that expression of HER2/neu is not a poor prognostic factor in low-grade osteosarcoma.
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PMID:Quantitative assessment of HER2/neu expression by real-time PCR and fluorescent in situ hybridization analysis in low-grade osteosarcoma. 1520 72

Expression of HER2 was evaluated by immunohistochemical techniques in 84 osteosarcoma (OS) and 113 Ewing's sarcoma (ES) paraffin-embedded tumour biopsies. HER2 gene status was also assessed in a panel of cell lines as well as in vitro efficacy of trastuzumab (a humanised antibody directed against HER2) as single agent or in combination with the insulin-like growth factor I receptor (IGF-IR) IR3 antibody. Overexpression of HER2 was present in 32% of OS and 16% of ES and was significantly associated with the increased expression of P-glycoprotein, a surface molecule responsible for multidrug resistance. Event-free survival analyses revealed a prognostic value for HER2 and/or P-glycoprotein expression in OS, but not in ES. However, despite its prognostic relevance, no therapeutic effectiveness was observed pre-clinically for trastuzumab-driven therapy, in both OS or ES cell lines, unless the antibody was associated with anti-IGF-IR targeting strategies. Therefore, the therapeutic potential of trastuzumab in these neoplasms may be better exploited in combined treatments with anti-IGF-IR approaches.
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PMID:Prognostic and therapeutic relevance of HER2 expression in osteosarcoma and Ewing's sarcoma. 1591 90

The HER2 gene, located on 17q, encodes a 185-kD transmembrane tyrosine kinase receptor. Amplification of this gene with overexpression of the gene product occurs in about 30% of cases of breast cancer and is considered to be a poor prognostic indicator for this tumor. Results for HER2 expression in osteosarcoma are controversial, with some studies reporting up to 61% of positive cases and others reporting only negative results. Further, expression of HER2 is reported to be a favorable prognostic indicator by some groups and unfavorable by others. The present study used tissue microarrays containing 34 samples of osteosarcoma from 18 patients to analyze HER2 expression by immunohistochemistry and gene copy number by chromogenic in situ hybridization. The microarray included 13 pretreatment biopsies, 11 posttreatment resection specimens, and 10 resected metastases and comprised 18 osteoblastic, 6 chondroblastic, 5 fibroblastic, and 5 mixed subtypes. HER2 protein expression was seen in 4 of 34 (12%) tumor samples that originated from 2 of 18 patients (11%). The staining pattern was consistently weak and focal, and immunohistochemical overexpression of the HER2 protein, defined as complete membrane positivity, was never observed. Further, the presence of HER2 gene amplification was not detected in any osteosarcoma by chromogenic in situ hybridization. Therefore, therapies based on antibodies directed against the HER2 protein are unlikely to have much value in the treatment of pediatric osteosarcomas. From a technical standpoint, this study also demonstrates the value of tissue microarrays in screening tumors at the protein and gene levels using conventional light microscopy.
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PMID:HER2 amplification and overexpression is not present in pediatric osteosarcoma: a tissue microarray study. 1621 48

Activation of intracellular mitogenic signal transduction pathways driven by the ErbB family of receptor tyrosine kinases has been implicated in the development and/or progression of a variety of cancers. Studies on ErbB receptors in osteosarcoma have focused on HER-2 and have produced conflicting results with few studies evaluating the expression of the epidermal growth factor receptor (EGFR). In this study, we determined the level of expression of EGFR and the mutational status of the EGFR receptor in a subset of osteosarcoma tumor samples as well as in a series of established bone tumor-derived cell lines. EGFR protein expression was detected in the form of strong membranous staining by immunohistochemistry in 21 (57%) of 37 cases analyzed. Six of 12 (50%) osteosarcoma cell lines revealed moderate to high expression levels of EGFR. Two somatic alterations (E829E and R831C) were identified in the cytoplasmic domain of the EGFR gene in 1 of 10 tumor samples. The significance of these findings for the pathobiology of osteosarcomas will be investigated further.
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PMID:Epidermal growth factor receptor in osteosarcoma: expression and mutational analysis. 1750 61

Inhibitors of specific tyrosine kinases are attractive lead compounds for development of targeted chemotherapies for many tumors, including osteosarcoma. We asked whether inhibition of specific tyrosine kinases would decrease the motility, colony formation, and/or invasiveness by human osteosarcoma cell lines (TE85, MNNG, 143B, SAOS-2, LM-7). An EGF-R inhibitor reduced motility of all five cell lines by 50% to 80%. In contrast, an IGF-1R inhibitor preferentially reduced motility by 42% in LM-7 cells and a met inhibitor preferentially reduced motility by 80% in MNNG cells. The inhibitors of EGF-R, IGF-1R, and met reduced colony formation by more than 80% in all tested cell lines (TE85, MNNG, 143B). The EGF-R inhibitor reduced invasiveness by 62% in 143B cells. The JAK inhibitor increased motility of SAOS-2 and LM7 cells without affecting colony formation or invasiveness. Inhibitors of HER-2, NGF-R, and PDGF-Rs did not affect motility, invasiveness, or colony formation. These results support the hypothesis that specific tyrosine kinases regulate tumorigenesis and/or metastasis in osteosarcoma.
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PMID:Specific tyrosine kinase inhibitors regulate human osteosarcoma cells in vitro. 1860 65


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