Progression of mouse transformed leydig-cells from estrogen-sensitive to estrogen-insensitive growth phenotype concomitant with loss of leukotriene d-4 receptor.

We have previously shown that growth enhancement of murine transformed Leydig cells (B-1F) by estrogen is partly mediated through inhibition of leukotriene formation due to suppression of 5-lipoxygenase activity; leukotrienes, which inhibit the proliferation of B-1F cells, play an important role in an autocrine loop for B-1F cells to proliferate in an estrogen-sensitive manner. An estrogen-insensitive cell line, termed Cl 4(-), was established from B-1F cells and maintained in serum-free culture medium without addition of estrogen. The proliferation of Cl 4(-) cells was not affected by the addition of 10(-11)-10(-6) M 17 beta-estradiol, whereas an estrogen receptor in Cl 4(-) cells appeared to be normal, as judged by its binding to estrogens.