title: Prolactin influences proliferation and apoptosis of a human IgE secreting myeloma cell line, U266.
abstract: In certain types of solid tumours and lymphomas prolactin (PRL) potentiates tumour cell proliferation and exerts anti-apoptotic effect. Tumour cells themselves can produce PRL and express PRL-receptors. Hyperprolactinemia is associated with different tumours, also. Multiple myeloma (MM) is a haematological malignancy caused by the clonal expansion of terminally differentiated plasma cells in the bone marrow. Recently, we demonstrated PRL immunostaining in bone marrow cells of MM patients and an elevated level of serum PRL of MM patients with advanced disease. In the present study, we tested the effect of PRL on a U266 human myeloma cell line and demonstrated constitutive and melphalan-stimulated intracytoplasmic PRL in U266 cells. Exogeneous PRL inhibited the proliferation and immunoglobulin (Ig) production of U266 myeloma cells. Concerning etoposide-induced apoptosis, PRL had a double-faceted effect depending on the applied dose: high, pharmacological doses (corresponding to hyperprolactinemia), inhibited apoptosis, whereas near physiological doses exerted a pro-apoptotic effect. These data indicate a definite effect of PRL on a human myeloma cell line. We demonstrated a direct inhibition of PRL on tumour cell growth, while its reciprocal effect on apoptosis refers to an important regulatory role of PRL.
authors.affiliation: National Institute of Haematology and Immunology, Budapest, Hungary.
authors.forename: Klara
authors.initials: K
authors.lastname: Gadó
authors.forename: Eva
authors.initials: E
authors.lastname: Pállinger
authors.forename: Péter
authors.initials: P
authors.lastname: Kovács
authors.forename: Edit
authors.initials: E
authors.lastname: Takács
authors.forename: István
authors.initials: I
authors.lastname: Szilvási
authors.forename: Béla E
authors.initials: BE
authors.lastname: Tóth
authors.forename: György
authors.initials: G
authors.lastname: Nagy
authors.forename: Gyula
authors.initials: G
authors.lastname: Domján
authors.forename: András
authors.initials: A
authors.lastname: Falus
mesh_terms: D017209:Apoptosis; D002455:Cell Division; D006801:Humans; D007073:Immunoglobulin E / Q000378:metabolism*; D009101:Multiple Myeloma / Q000378:metabolism / Q000473:pathology*; D011388:Prolactin / Q000096:biosynthesis / Q000502:physiology*; D014407:Tumor Cells, Cultured
chemical_list: D007073:Immunoglobulin E; D011388:Prolactin