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)

Since the first promising results of Nouel et al. 1972, additional positive experience has been obtained with 57Co-Bleomycin (57Co-BLM) as a tumour-localizing agent. In this preclinical study, mice with transplanted osteosarcoma and lymphosarcoma were used and rats with transplanted rhabdomyosarcoma. 57CoCl2 served as a control substance. 57Co-BLM had concentrated in the tumours with a factor 2 to 10 as compared to the (normal) liver of the animals. No preferential concentration in the tumours was found when 57CoCl2 was used. The highest specific activity of 57Co-BLM (cpm/mg protein) was found in a fraction containing mitochondria and lysosomes. Evidence for a lysosomal localization of this diagnostic compound was obtained from experiments in which the mitochondrial-lysosomal fraction was treated with hypertonic media of different osmolarities. Conditions could be found in which many lysosomes burst while almost all mitochondrial were intact. From these experiments it appeared that the radioactivity in the particles obtained from animals injected wtih 57Co-BLM was released very rapidly. It is concluded that 57Co-BLM is preferentially localized in the heavy lysosomes sedimenting together with most of the mitochondria of the cell and that these structures are more fragile than the light lysosomes.
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PMID:Intracellular distribution of 57Co-bleomycin. 7 27

Dose response curves were obtained for normal human fibroblasts and for several cell lines derived from human tumors, including melanomas and an osteosarcoma. Most of the tumor lines are similar in radiosensitivity to the normal fibroblasts, except for the melanoma lines, which are significantly more resistant. The two melanoma lines differ, one being much more radioresistant than the other. Potentially lethal damage repair (PLDR) has been studied in these cell lines as well. The extent of PLDR does not appear to correlate with radioresistance; for example, the most resistant melanoma line shows very little repair of PLD. In addition, the normal fibroblasts repair PLD at least as well as any of the tumor derived lines, which casts doubts on the wisdom of introducing into clinical practice inhibitors of PLD until a clear differential between normal tissues and tumors has been demonstrated in vivo. Low dose-rate studies with normal human fibroblasts indicate a smaller dose-rate effect than for most established cell lines of rodent origin. Indeed, in the human cells studied, the effect of sublethal damage repair is quantitatively similar to the repair of potentially lethal damage. Dose response curves for acute and protracted exposures have been obtained for cells derived from patients with cancer-prone syndromes including ataxia telangiectasia (AT) and Bloom's syndrome. Both cell lines are much more radiosensitive than normal human fibroblasts; the AT cells show a dose-rate effect, while Bloom's syndrome cells do not.
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PMID:Response of cells of human origin, normal and malignant, to acute and low dose rate irradiation. 351 54

Recent advances in adjuvant chemotherapy for malignant bone tumor have been improving the survival rate and making limb-salvage surgery a reliable technique. Ewing's sarcoma is treated by multiple agent chemotherapy. We treat Ewing's sarcoma by Rosen's T-11 protocol (CYT.ADM.MTX.VCR.ACT-D.BLM). This protocol is very effective, but results are poorer than for osteosarcoma. Newly developed protocols such as EICESS (European Intergroup Cooperative Ewing's Sarcoma Study)-92, including new drugs, should be investigated. The results with malignant fibrous histiocytoma are comparable to those for osteosarcoma. We have performed an original chemotherapy protocol, called "K-1 protocol." Patients were treated with three courses of intraarterial infusion of cisplatin (120 mg/m2) and caffeine (1.0-1.5 mg/m2/day for three days continuously) at two-week intervals. If the effect was insufficient, ADM (30 mg/m2/day for two days continuously) is added to this protocol. We treat malignant lymphoma in collaboration with a hematologist and radiologist. The 5-year survival rate of non-Hodgkin's lymphoma in our series was 56% in clinical stage III and 34% in clinical stage IV. We are trying third-generation chemotherapy to improve the survival rate.
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PMID:[Chemotherapy for Ewing's sarcoma, malignant fibrous histiocytoma and malignant lymphoma]. 821 63

Primary bone tumors represent about 7% of paediatric malignancies. Osteosarcoma and Ewing's tumor are the most frequent ones, however they are rare in facial bones. Mandibular localization is slightly more frequent and of better prognosis than maxillary one. Until 1995 there were only about 70 cases reported in the medical literature, mainly in the oncological or dental periodics. Our material consists of two children with Ewing's tumor of the mandible and one patient with osteosarcoma. The diagnosis was based on histopathological or cytological studies. The combined treatment--chemotherapy and radiotherapy--was performed in two patients with Ewing's tumor. The recommended resection of the mandible including the tumor mass has not been performed. No facial asymmetry is seen after termination of the radiotherapy. The boy with osteosarcoma underwent primary mandibular partial resection; a two-year chemotherapy was introduced only when metastases in the regional lymph nodes occurred (BLM, CTX, ACT-D, ADM, CDDP). The mandible was reconstructed surgically in 5 years after termination of radiotherapy and the anatomical relationship in the masticatory organ was restored. All children are now in good condition under our long-term observation. We present these cases of mandibular tumors regarding their rare occurrence and positive results of the introduced treatment.
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PMID:[Malignant tumors of mandible in children]. 1073 62

Resection of the considerable part of the arch of the mandible disturbs breathing, swallowing, speaking and alters the facial symmetry. One-staged reconstruction of the mandible is contraindicated in patients with malignant tumor and serious prognosis. The course of the combined treatment in 9-year-old boy with osteosarcoma of the mandible is presented (May 1987--resection of the anterior part of the body of the mandible and suprahyoid lymphadenectomy); the most severe postoperative functional disorders were treated immediately (tracheostomy, nasogastric tube for 3 weeks). The reconstruction of the mandible and restoration of the anatomical relationship in the masticatory organ were performed after 5 years. Because of the metastatic disease in the nuchal and cervical lymph nodes boy underwent chemotherapy (Jan 5th 1988-Feb 21st 1990) of the primary site of the tumor 7 months after surgery. The following cytostatic drugs were administered; BLM, CTX, ACT-D, ADM, CDDP. The functional rehabilitation, small correctional surgery and improvement in perception in the oral cavity facilitated the restoration of important functions of the masticatory organ (proved by the following studies: gustometric, manometric, logopedic, stereognostic, rentgenotelevision of the swallowing process). In addition, the self-perception and the boy's social status improved significantly after favourable change in patient's appearance.
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PMID:[Functional reconstruction of the masticatory organ after combined therapy in a 9-year-old boy with osteosarcoma of the mandible]. 1073 93

Expression of the cyclin-dependent kinase inhibitor gene p21 is induced after DNA damage and plays a role in cell survival. The exact mechanism of induction is not known, but enhancement of mRNA stability has recently been implicated as an important factor. To obtain further insight into the dynamics of p21 gene expression at the individual cell level, normal fibroblasts, GM1492 fibroblasts from a Bloom's syndrome patient, and U2OS osteosarcoma cells were UVC irradiated, fixed at different time points, and subjected to mRNA fluorescence in situ hybridization (FISH) and immunocytochemical staining. In mock-irradiated normal fibroblasts, a subfraction of cells revealed low levels of p21 mRNA synthesis. After UVC treatment, p21 transcripts accumulated over time in nuclear locations other than transcription foci. At 6 hr after irradiation, almost 50% of the cells displayed p21 mRNA in three different distribution patterns within the nuclei. The highest frequency of cells with cytoplasmic accumulation of p21 mRNA was seen at 17 hr after UVC treatment. We conclude that increased p21 gene transcription and possibly stabilization of newly synthesized p21 mRNA contribute to elevated levels of p21 protein after UVC irradiation. (J Histochem Cytochem 50:81-89, 2002)
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PMID:Induction of p21 mRNA synthesis after short-wavelength UV light visualized in individual cells by RNA FISH. 1174 97

Although the prognosis and quality of life of patients with osteosarcoma were improved significantly during the past decades, the pathogenesis and etiology of this disease remain obscure. Significant interest and effort in this cancer led to the identification of numerous etiologic agents. Several chemical agents such as beryllium, viruses such as FBJ, subsequently found to contain the src-oncogene, and radiation were shown to be potent inducers of osteosarcoma. Paget's disease, electrical burn, or trauma all are thought to be other factors that may contribute to the pathogenesis. More recently, patients with hereditary diseases such as Rothmund-Thomson syndrome, Bloom syndrome, and Li-Fraumeni syndrome were found to have an increased risk of having osteosarcoma develop. During the past few years, the molecular analysis brought a wealth of new information with numerous genes that were associated with osteosarcoma and its clinical disease progression. They can be categorized into self-sufficiency in growth signals, insensitivity to growth inhibitory signals, evasion of apoptosis, limitless replicative potential, sustained angiogenesis, and tissue evasion and metastasis. Although the understanding of these processes in osteosarcoma still is incomplete, it may have the potential to significantly affect the patient care in the future.
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PMID:Etiology of osteosarcoma. 1195 94

The RECQL4 helicase gene is a member of the RECQL gene family, mutated in some Rothmund-Thomson syndrome (RTS) patients. Other members of this gene family are BLM mutated in Bloom syndrome, WRN mutated in Werner syndrome and RECQL and RECQL5. All polypeptides encoded by RECQL genes share a central region of seven helicase domains. The function of RECQL4 remains unknown, but based on the domain homology it possesses ATP-dependent DNA helicase activity such as BLM and WRN. Rothmund-Thomson, Bloom and Werner syndromes have overlapping clinical features, of which high predisposition to malignancies is the most remarkable feature. Here we report a fourth syndrome resulting in mutations in the RECQL genes. RAPADILINO syndrome is an autosomal recessive disorder characterized by short stature, radial ray defects and other malformations, as well as infantile diarrhoea, but not by a significant cancer risk. Four mutations in the RECQL4 gene were found in the Finnish patients, the most common mutation representing exon 7 in-frame deletion saving the helicase domain and showing dominant effect over other three nonsense mutations. The tissue expression of Recql4 in mouse well agrees with the tissue symptoms of RAPADILINO. The skeletal malformations in RAPADILINO and RTS patients as well as the high osteosarcoma risk in RTS propose a special role for RECQL4 in bone development.
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PMID:Molecular defect of RAPADILINO syndrome expands the phenotype spectrum of RECQL diseases. 1295 69

Rothmund-Thomson syndrome (RTS) is a genodermatosis presenting with a characteristic facial rash (poikiloderma) associated with short stature, sparse scalp hair, sparse or absent eyelashes and/or eyebrows, juvenile cataracts, skeletal abnormalities, radial ray defects, premature aging and a predisposition to cancer. The prevalence is unknown but around 300 cases have been reported in the literature so far. The diagnostic hallmark is facial erythema, which spreads to the extremities but spares the trunk, and which manifests itself within the first year and then develops into poikiloderma. Two clinical subforms of RTS have been defined: RTSI characterised by poikiloderma, ectodermal dysplasia and juvenile cataracts, and RTSII characterised by poikiloderma, congenital bone defects and an increased risk of osteosarcoma in childhood and skin cancer later in life. The skeletal abnormalities may be overt (frontal bossing, saddle nose and congenital radial ray defects), and/or subtle (visible only by radiographic analysis). Gastrointestinal, respiratory and haematological signs have been reported in a few patients. RTS is transmitted in an autosomal recessive manner and is genetically heterogeneous: RTSII is caused by homozygous or compound heterozygous mutations in the RECQL4 helicase gene (detected in 60-65% of RTS patients), whereas the aetiology in RTSI remains unknown. Diagnosis is based on clinical findings (primarily on the age of onset, spreading and appearance of the poikiloderma) and molecular analysis for RECQL4 mutations. Missense mutations are rare, while frameshift, nonsense mutations and splice-site mutations prevail. A fully informative test requires transcript analysis not to overlook intronic deletions causing missplicing. The diagnosis of RTS should be considered in all patients with osteosarcoma, particularly if associated with skin changes. The differential diagnosis should include other causes of childhood poikiloderma (including dyskeratosis congenita, Kindler syndrome and Poikiloderma with Neutropaenia), other rare genodermatoses with prominent telangiectasias (including Bloom syndrome, Werner syndrome and Ataxia-telangiectasia) and the allelic disorders, RAPADILINO syndrome and Baller-Gerold syndrome, which also share some clinical features. A few mutations recur in all three RECQL4 diseases. Genetic counselling should be provided for RTS patients and their families, together with a recommendation for cancer surveillance for all patients with RTSII. Patients should be managed by a multidisciplinary team and offered long term follow-up. Treatment includes the use of pulsed dye laser photocoagulation to improve the telangiectatic component of the rash, surgical removal of the cataracts and standard treatment for individuals who develop cancer. Although some clinical signs suggest precocious aging, life expectancy is not impaired in RTS patients if they do not develop cancer. Outcomes in patients with osteosarcoma are similar in RTS and non-RTS patients, with a five-year survival rate of 60-70%. The sensitivity of RTS cells to genotoxic agents exploiting cells with a known RECQL4 status is being elucidated and is aimed at optimizing the chemotherapeutic regimen for osteosarcoma.
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PMID:Rothmund-Thomson syndrome. 2011 79

The RECQ family of DNA helicases is a conserved group of enzymes that are important for maintaining genomic integrity. In humans, there are five RECQ helicase genes, and mutations in three of them-BLM, WRN, and RECQL4-are associated with the genetic disorders Bloom syndrome, Werner syndrome, and Rothmund-Thomson syndrome (RTS), respectively. Importantly all three diseases are cancer predisposition syndromes. Patients with RTS are highly and uniquely susceptible to developing osteosarcoma; thus, RTS provides a good model to study the pathogenesis of osteosarcoma. The "tumor suppressor" role of RECQL4 and the other RECQ helicases is an area of active investigation. This chapter reviews what is currently known about the cellular functions of RECQL4 and how these may relate to tumorigenesis, as well as ongoing efforts to understand RECQL4's functions in vivo using animal models. Understanding the RECQ pathways may provide insight into avenues for novel cancer therapies in the future.
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PMID:RECQ DNA helicases and osteosarcoma. 2492 72


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