N. Mori et al., ENHANCING EFFECT OF INTERLEUKIN-2 ON PRODUCTION OF PARATHYROID HORMONE-RELATED PROTEIN BY ADULT T-CELL LEUKEMIA-CELLS, Japanese journal of cancer research, 84(4), 1993, pp. 425-430
Leukemic cells from patients with adult T-cell leukemia (ATL) can prod
uce a calcium-regulating protein, parathyroid hormone-related protein
(PTHrP). Moreover, it has been reported that ATL cells produce some cy
tokines besides PTHrP and that these cells respond to the T-cell growt
h factors, interleukin-2 (IL-2) and interleukin-4 (IL-4). To elucidate
whether PTHrP produced by ATL cells is regulated by IL-2 or IL-4, we
investigated the in vitro effects of IL-2 and IL-4 on the release of P
THrP. IL-2 increased the release of PTHrP into the conditioned medium
from leukemic cells in some, but not all, ATL patients; however, IL-4
did not affect the PTHrP release. PTHrP messenger RNA (mRNA) levels we
re increased in ATL cells cultured in the presence of IL-2. These data
suggest that IL-2 plays a role in the regulation of hypercalcemia by
enhancing the production of PTHrP in ATL patients.