TY - JOUR
T1 - Expression and functional role of c-kit ligand (SCF) in human multiple myeloma cells
AU - Lemoli, R. M.
AU - Fortuna, A.
AU - Grande, A.
AU - Gamberi, B.
AU - Bonsi, L.
AU - Fogli, M.
AU - Amabile, M.
AU - Cavo, M.
AU - Ferrari, S.
AU - Tura, S.
PY - 1994
Y1 - 1994
N2 - In this study we investigated the proliferation of three well-documented MM lines and 10 bone marrow samples from myeloma patients in response to rh-SCF alone and combined with Interleukin-6 (IL-6), IL 3 and IL 3/GM-CSF fusion protein PIXY 321. Neoplastic plasma cells were highly purified (>90%) by immunomagnetic depletion of T, myeloid, monocytoid and NK cells. The number of S-phase cells was evaluated after 3 and 7 d of liquid culture by the bromodeoxyuridine (BRDU) incorporation assay. The proliferation of RPMI 8226 and U266 cell lines was also assessed by a clonogenic assay. All the experiments were performed in serum-free conditions. RPMI 8226 cell line was not stimulated by SCF which also did not augment the proliferative activity of IL-6, IL-3 and PIXY-321. Conversely, SCF addition resulted in 2.4-fold increase of the number of U266 colonies and in a higher number of U266 and MT3 cells in S-phase (24.5 ± 2% SEM v 14.5 ± 1% SEM and 32 ± 3% SEM v 21 ± 4% SEM, respectively; P <0.05). The c-kit ligand also enhanced the proliferation of MT3 and U266 cells mediated by the other cytokines. Anti-SCF polyclonal antibodies completely abrogated the proliferative response of MT3 cells to exogenous SCF and markedly reduced the spontaneous growth of the same cell line. Reverse transcriptase-polymerase chain reaction amplification (RT-PCR) did detect SCP mRNA in MT3 and RPMI 8226 cells. Moreover, secreted SCF was found, in a biologically active form, in the supernatant of the two cell lines by the MO7e proliferation assay. When tested on fresh myeloma samples, SCF increased the number of S-phase plasma cells (4.7 ± 1.6% v 3.4 ± 1.3% in control cultures; P = 0.02). Significant proliferation was also induced by IL-6 (71 ± 2.3% of BRDU+ cells; P = 0.006), IL-3 (5.3 ± 13%; P = 0.01) and PIXY-321 (5.4 ± 1.6%; P = 0.02). The addition of SCF significantly enhanced the proliferation of myeloma cells responsive to IL-6. In summary, our results indicate that SCF is expressed in MM cells and stimulates the proliferation of neoplastic plasma cells.
AB - In this study we investigated the proliferation of three well-documented MM lines and 10 bone marrow samples from myeloma patients in response to rh-SCF alone and combined with Interleukin-6 (IL-6), IL 3 and IL 3/GM-CSF fusion protein PIXY 321. Neoplastic plasma cells were highly purified (>90%) by immunomagnetic depletion of T, myeloid, monocytoid and NK cells. The number of S-phase cells was evaluated after 3 and 7 d of liquid culture by the bromodeoxyuridine (BRDU) incorporation assay. The proliferation of RPMI 8226 and U266 cell lines was also assessed by a clonogenic assay. All the experiments were performed in serum-free conditions. RPMI 8226 cell line was not stimulated by SCF which also did not augment the proliferative activity of IL-6, IL-3 and PIXY-321. Conversely, SCF addition resulted in 2.4-fold increase of the number of U266 colonies and in a higher number of U266 and MT3 cells in S-phase (24.5 ± 2% SEM v 14.5 ± 1% SEM and 32 ± 3% SEM v 21 ± 4% SEM, respectively; P <0.05). The c-kit ligand also enhanced the proliferation of MT3 and U266 cells mediated by the other cytokines. Anti-SCF polyclonal antibodies completely abrogated the proliferative response of MT3 cells to exogenous SCF and markedly reduced the spontaneous growth of the same cell line. Reverse transcriptase-polymerase chain reaction amplification (RT-PCR) did detect SCP mRNA in MT3 and RPMI 8226 cells. Moreover, secreted SCF was found, in a biologically active form, in the supernatant of the two cell lines by the MO7e proliferation assay. When tested on fresh myeloma samples, SCF increased the number of S-phase plasma cells (4.7 ± 1.6% v 3.4 ± 1.3% in control cultures; P = 0.02). Significant proliferation was also induced by IL-6 (71 ± 2.3% of BRDU+ cells; P = 0.006), IL-3 (5.3 ± 13%; P = 0.01) and PIXY-321 (5.4 ± 1.6%; P = 0.02). The addition of SCF significantly enhanced the proliferation of myeloma cells responsive to IL-6. In summary, our results indicate that SCF is expressed in MM cells and stimulates the proliferation of neoplastic plasma cells.
KW - Autocrine-paracrine growth loop
KW - Cell proliferation
KW - Gene expression
KW - Multiple myeloma
KW - SCF
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M3 - Article
C2 - 7529540
AN - SCOPUS:0028126793
VL - 88
SP - 760
EP - 769
JO - British Journal of Haematology
JF - British Journal of Haematology
SN - 0007-1048
IS - 4
ER -