Search results for "Bone Neoplasm"
showing 10 items of 148 documents
Let-7d miRNA Shows Both Antioncogenic and Oncogenic Functions in Osteosarcoma-Derived 3AB-OS Cancer Stem Cells
2015
Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 an…
MicroRNA-29b-1 impairs in vitro cell proliferation, self‑renewal and chemoresistance of human osteosarcoma 3AB-OS cancer stem cells
2014
Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we…
Genetic and Molecular Characterization of The Human Osteosarcoma 3AB-OS Cancer Stem Cell Line: A Possible Model For Studying Osteosarcoma Origin and …
2013
Finding new treatments targeting cancer stem cells (CSCs) within a tumor seems to be critical to halt cancer and improve patient survival. Osteosarcoma is an aggressive tumor affecting adolescents, for which there is no second-line chemotherapy. Uncovering new molecular mechanisms underlying the development of osteosarcoma and origin of CSCs is crucial to identify new possible therapeutic strategies. Here, we aimed to characterize genetically and molecularly the human osteosarcoma 3AB-OS CSC line, previously selected from MG63 cells and which proved to have both in vitro and in vivo features of CSCs. Classic cytogenetic studies demonstrated that 3AB-OS cells have hypertriploid karyotype wit…
Absence of mutation at the GAP-related domain of the neurofibromatosis type 1 gene in sporadic neurofibrosarcomas and other bone and soft tissue sarc…
1995
The NF1 gene encodes neurofibromin, a GTPase-activating protein containing a GAP-related domain (NF1-GRD) that is capable of downregulating ras by stimulating ras intrinsic GTPase activity. We tested 44 sarcomas, nine of which corresponded to sporadic neurofibrosarcomas, for mutations at the NF1-GRD by the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, finding no mutation in every sample tested. We suggest that inactivation of the NF1-GRD by gene mutation seems not to be an important event in the tumorigenesis of sarcomas.
WRN protects against topo I but not topo II inhibitors by preventing DNA break formation
2008
The Werner syndrome helicase/3′-exonuclease (WRN) is a major component of the DNA repair and replication machinery. To analyze whether WRN is involved in the repair of topoisomerase-induced DNA damage we utilized U2-OS cells, in which WRN is stably down-regulated (wrn-kd), and the corresponding wild-type cells (wrn-wt). We show that cells not expressing WRN are hypersensitive to the toxic effect of the topoisomerase I inhibitor topotecan, but not to the topoisomerase II inhibitor etoposide. This was shown by mass survival assays, colony formation and induction of apoptosis. Upon topotecan treatment WRN deficient cells showed enhanced DNA replication inhibition and S-phase arrest, whereas af…
Bisphosphonate-related osteonecrosis of the jaw (BRONJ): run dental management designs and issues in diagnosis
2007
Recently, jawbone osteonecrosis has been largely reported as a potential adverse effect of bisphosphonate (BP) administration. Because of the peculiar pharmacokinetic and pharmacodynamic features of the BF (mainly for i.v. administration), their efficacy and large use, some major issues have to be taken into account extendedly both by oncologists and by dentists: 1) therapeutic dental protocol for patients with diagnosis of bisphosphonate-related osteonecrosis of the jaw (BRONJ); 2) dental strategies for patients in former or current i.v. BF treatment and in absence of BRONJ signs; 3) strategies for patients before i.v. BF treatment. Clinical features and guidelines for the management of th…
Professional diagnostic delay in osteosarcomas of the jaws
2020
A series of 20 consecutive patients with an osteosarcoma of the jaws has been evaluated with regard to possible professional diagnostic delay. When set at an arbitrarily chosen period beyond three months, professional delay occurred in 15 patients, the mean being 21 months and the median 11 months. In five of the 15 patients a wrong diagnosis has been rendered on the biopsy specimen, being fibrous dysplasia (2x), osteoma (2x) and, in case of palatomaxillary swelling, pleomorphic adenoma (1x). In the other ten patients the initial clinicoradiographic features were misleading and apparently not indicative of a malignancy, except for one patient in whom a distinct widening of the periodontal l…
Translocation (10;11;22)(p14;q24;q12) Characterized by Fluorescence in Situ Hybridization in a Case of Ewing's Tumor
2001
It is well recognized that the identification by classic cytogenetics of t(11;22)(q24;q12) is a useful aid in the accurate diagnosis of Ewing's sarcoma and related tumors. This translocation induces the EWS/FLI-1 fusion transcript, which can be detected by reverse transcription-polymerase chain reaction. Recent studies have also used fluorescence in situ hybridization (FISH) to demonstrate the translocation. The authors coupled classic cytogenetics and FISH on tumor cells from the original specimen, the local recurrence, and the pulmonary metastasis as well as from the xenografted tumors in a case of extraosseous Ewing's sarcoma. FISH analysis not only confirmed the cytogenetic results but …
A case of guillain-barre syndrome in a patient with non small cell lung cancer treated with chemotherapy
2006
Guillain-Barré Syndrome (GBS) is a demyelinating polyneuropathy of probable autoimmune pathogenesis characterized by rapidly progressive symmetric paralysis. In the literature some cases of GBS associated with anticancer chemotherapy are reported. We present a case of a 55-year old woman who complained of progressive motor deficit in four limbs, areflexia in lower limbs and facial nerve paralysis one week after beginning cisplatin-gemcitabine chemotherapy for metastatic lung cancer. The cerebrospinal fluid analysis showed a strong positive Pandy reaction with 435 mg/dl total protein. The electromyography and the electroneuronography established the diagnosis of inflammatory demyelinating po…
Spontaneous bisphosphonate-related osteonecrosis of the left hemi-mandible: Similarities with phossy jaw.
2013
Intravenous bisphosphonates (BP) play a key role in the treatment of bone metastases. As a long-term side effects BP, a form of avascular osteonecrosis of the jaw has been reported. Although, invasive oral local procedures are often present in clinical history of patients suffering from bisphosphonates-related osteonecrosis of the jaws (BRONJ), about up to 50% of BRONJ are spontaneous. We report a case of a 68-year-old female with a spontaneous wide bone sequestration of the left mandibular body onset after infusion of zoledronic acid for 18 cycles for osseous metastasis due to metastatic anaplastic thyroidal carcinoma. Surprisingly the clinical aspects of the patient initially reminded us …