title: Orphan receptor tyrosine kinases ROR1 and ROR2 in hematological malignancies.
abstract: The receptor tyrosine kinase ROR1 has been shown to be overexpressed in chronic lymphocytic leukemia (CLL). The aim of this study was to further characterize the expression of ROR1 and the other member of the ROR family, ROR2, in other lymphoid and myeloid malignancies. Normal white blood cells and reactive lymph nodes were negative for ROR1 and ROR2. A significantly high and uniform surface expression of ROR1 was found in CLL/hairy cell leukemia (HCL) compared to mantle cell lymphoma (MCL), marginal zone lymphoma (MZL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), myelomas, acute lymphoblastic leukemia (ALL) and myeloid leukemias (p = 0.02 to < 0.001). The lowest proportion of ROR1+ cells was seen in FL, whereas CLL, HCL and CML had significantly higher numbers of ROR1+ cells. Longitudinal follow-up of individual patients with CLL revealed that ROR1+ cells remained stable over time in non-progressive patients, but increased when the disease progressed (p < 0.05). Thus, a variable staining pattern of ROR1 ranging from very high (CLL, HCL) and high (CML) to intermediate (myeloma and DLBCL) or low (FL) was noted. ROR2 was not detected in hematological malignancies.
authors.affiliation: Immune and Gene Therapy Laboratory, Cancer Center Karolinska, Karolinska University Hospital Solna, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Daneshmanesh
authors.forename: Anna
authors.initials: A
authors.lastname: Porwit
authors.forename: Mohammad
authors.initials: M
authors.lastname: Hojjat-Farsangi
authors.forename: Mahmood
authors.initials: M
authors.lastname: Jeddi-Tehrani
authors.forename: Katja Pokrovskaja
authors.initials: KP
authors.lastname: Tamm
authors.forename: Dan
authors.initials: D
authors.lastname: Grandér
authors.forename: Sören
authors.initials: S
authors.lastname: Lehmann
authors.forename: Stefan
authors.initials: S
authors.lastname: Norin
authors.forename: Fazel
authors.initials: F
authors.lastname: Shokri
authors.forename: Hodjattallah
authors.initials: H
authors.lastname: Rabbani
authors.forename: Håkan
authors.initials: H
authors.lastname: Mellstedt
authors.forename: Anders
authors.initials: A
authors.lastname: Österborg
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D019070:Cell Lineage / Q000235:genetics; D005434:Flow Cytometry; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D019337:Hematologic Neoplasms / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D057050:Receptor Tyrosine Kinase-like Orphan Receptors / Q000235:genetics / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C078716:ROR1 protein, human; C078717:ROR2 protein, human; D057050:Receptor Tyrosine Kinase-like Orphan Receptors