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)

We report the pathology and outcome of secondary skull base tumors in patients previously treated with external beam radiation for retinoblastoma (Rb). Rb patients are at increased risk of second head and neck primary malignancies due to early radiation exposure during treatment and loss of RB1 protein in genetic carriers. An institutional database was reviewed for patients with retinoblastoma who had previously received radiation therapy and subsequently developed skull base tumors. Seventeen patients met the selection criteria. The median age of Rb diagnosis was 12 months. Thirteen cases underwent enucleation in addition to radiation therapy as part of initial Rb treatment. A median of 19 years elapsed between the diagnosis of Rb and diagnosis of skull base malignancy. The most common tumors were osteogenic sarcoma (39%) and leiomyosarcoma (22%). Eleven (71%) patients received postoperative chemotherapy, and 7 (41%) received postoperative radiotherapy. Three (24%) patients underwent salvage surgery for recurrent disease. Five-year survival was 68%, and 10-year survival was 51% by Kaplan-Meier analysis. Secondary malignancy in Rb patients is a well-defined event. The use of surgery with appropriate adjuvant therapy was associated with a 51% 10-year survival in this study population.
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PMID:Secondary skull base malignancies in survivors of retinoblastoma: the memorial sloan kettering cancer center experience. 2245 10

Passage through the Retinoblastoma protein (RB1)-dependent restriction point and the loading of minichromosome maintenance proteins (MCMs) are two crucial events in G1-phase that help maintain genome integrity. Deregulation of these processes can cause uncontrolled proliferation and cancer development. Both events have been extensively characterized individually, but their relative timing and inter-dependence remain less clear. Here, we describe a novel method to simultaneously measure MCM loading and passage through the restriction point. We exploit that the RB1 protein is anchored in G1-phase but is released when hyper-phosphorylated at the restriction point. After extracting cells with salt and detergent before fixation we can simultaneously measure, by flow cytometry, the loading of MCMs onto chromatin and RB1 binding to determine the order of the two events in individual cells. We have used this method to examine the relative timing of the two events in human cells. Whereas in BJ fibroblasts released from G0-phase MCM loading started mainly after the restriction point, in a significant fraction of exponentially growing BJ and U2OS osteosarcoma cells MCMs were loaded in G1-phase with RB1 anchored, demonstrating that MCM loading can also start before the restriction point. These results were supported by measurements in synchronized U2OS cells.
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PMID:Simultaneous measurement of passage through the restriction point and MCM loading in single cells. 2625 Jan 17