Recombinant mouse IGF 1 or MH S macrophage selleck chemicals Bicalutamide condi tioned media was sufficient to stimulate the proliferation of neoplastic LM2, JF32 and E9 cells and non neoplastic E10 cells. The degree of growth stimu lated by 50 ng/mL IGF 1 was similar to that of M CM in each line. These results confirm that IGF 1 alone can stimulate the growth of long estab lished neoplastic and non neoplastic cell lines, as well as cells isolated more recently from primary mouse lung tumors, consistent with previous reports on human cancer cell lines. In order to determine any relevant role of EGFR in mediating macrophage stimu lated tumor cell proliferation in these cell lines, recom binant mouse EGF was added at 2 ng/mL. This is roughly 500 times the reported EC50 for growth stimula tion and 20 times higher than levels found in the BALF from tumor bearing animals.

Inhibitors,Modulators,Libraries EGF had no significant effect on tumor cell proliferation when added alone, and did not significantly affect the ability of either IGF 1 or M CM to stimulate neoplastic growth. This is not surprising in view of recent studies showing that EGFR inhibitors Inhibitors,Modulators,Libraries do not inhibit growth of lung cells with KRAS mutations. As IGF 1 was sufficient to induce neoplastic prolifera tion, we determined whether the IGF 1 and M CM growth effects were additive. A dose of 50 ng/ml IGF 1 stimulated neoplastic growth to a similar extent as M CM . 2 ng/mL IGF is the reported EC50 for IGF 1 stimulated proliferation in vitro as well as the concentration detected in the BALF of tumor bearing mice in vivo.

Inhibitors,Modulators,Libraries IGF 1 dose depen dently stimulated the proliferation of both Inhibitors,Modulators,Libraries LM2 and JF32 cells, and augmented the growth stimulating effects of M CM when added in combination. Inhibitors,Modulators,Libraries To determine if IGF 1R signaling mediates both IGF 1 and M CM sti mulation, lung cancer cells were pre treated with vehicle or 5 uM NVP AEW541, and cell numbers determined as indicated. IGF 1 and M CM each significantly increased cell numbers after 48 and 72 hrs, while pharmacological inhibition of IGF 1R signaling blocked IGF 1 and M CM growth effects in both neoplastic lines. Parallel comparison of MTS values indicated a highly significant correlation between live cell numbers and relative MTS scores. Furthermore, both IGF 1 and M CM increased the fraction of BrdU LM2 cells 12 24 hrs after treatment, corresponding with significantly increased cell numbers.

These observa tions suggest that IGF 1, but not EGF, plays a major role in macrophage stimulated neoplastic growth in vitro, consistent with the elevated IGF 1 levels observed in lung tumor bearing animals in vivo. M CM stimulation of neoplastic growth is diminished when IGF 1 content is decreased In order http://www.selleckchem.com/products/Cisplatin.html to determine if IGF 1 was a molecular mediator directly responsible for growth stimulated by M CM, we decreased M CM IGF 1 content through two indepen dent avenues immuno depletion and siRNA interference.