Neutrophil elastase inhibitor (ONO-5046-Na) inhibits the growth of human lung cancer cell lines transplanted into severe combined immunodeficiency (scid) mice.

We examined the in vivo effects of ONO-5046xNa, a specific neutrophil elastase (NE) inhibitor, on the growth of 2 non-small cell lung cancer cell lines, EBC-1 and PC-3, transplanted into severe combined immunodeficiency (scid) mice. The daily intraperitoneal injection of ONO-5046xNa (50 mg/kg/day) completely suppressed the tumor growth in EBC-1, a human squamous carcinoma cell line which produces immunoreactive NE. By contrast, in PC-3, a human adenocarcinoma cell line which is unable to produce immunoreactive NE, the ONO-5046xNa treatment caused delayed growth of the tumor. These findings suggest that ONO-5046xNa may have a clinical role in preventing the growth of human non-small cell lung cancer.