title: The bone marrow metastasis niche in retinoblastoma.
abstract: BACKGROUND
  Retinoblastoma (Rb) is a progressive cancer which mainly occurs in children, and which is caused by different genetic or epigenetic alterations that lead to inactivation of both alleles of the RB1 gene. Hereditary and non-hereditary forms of Rb do exist, and the hereditary form is associated with an increased risk of secondary malignancies. Metastasis to distant organs is a critical feature of many tumors, and may be caused by various molecular alterations at different stages. Recognition of these alterations and, thus, insight into the processes underlying the development of metastases may result in novel preventive as well as effective targeted treatment options. Rb is associated with metastases to various organs and tissues, including the bone marrow (BM).
  
  
  METHODS
  Here, we provide an overview of mutations and other molecular changes known to be involved in Rb development and metastasis to the BM. This overview is based on a literature search ranging from 1990 to 2015.
  
  
  CONCLUSIONS
  The various BM metastasis-related molecular changes identified to date may be instrumental for a better diagnosis, prognosis and classification of Rb patients, as well as for the development of novel comprehensive (targeted) therapies.
authors.affiliation: Department of Hematology, Allied Medical School, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Khosravi
authors.forename: Saeid
authors.initials: S
authors.lastname: Shahrabi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Shahjahani
authors.forename: Najmaldin
authors.initials: N
authors.lastname: Saki
mesh_terms: D001853:Bone Marrow / Q000378:metabolism* / Q000473:pathology; D019046:Bone Marrow Neoplasms / Q000235:genetics* / Q000556:secondary; D002648:Child; D016161:Genes, Retinoblastoma / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D009154:Mutation; D019572:Retinal Neoplasms / Q000235:genetics* / Q000473:pathology; D012175:Retinoblastoma / Q000235:genetics* / Q000473:pathology; D055153:Stem Cell Niche