Growth inhibition by tyrosine kinase inhibitors in mesothelioma cell lines.

Clinical outcome following chemotherapy for malignant pleural mesothelioma is poor and improvements are needed. This preclinical study investigates the effect of five tyrosine kinase inhibitors (PTK787, ZD6474, ZD1839, SU6668 and SU11248) on the growth of three mesothelioma cell lines (NCI H226, NCI H28 and MSTO 211H), the presence of growth factor receptors and inhibition of their downstream signalling pathways. GI50 values were determined: ZD6474 and SU11248, mainly VEGFR2 inhibitors, gave the lowest GI50 across all cell lines (3.5-6.9 microM) whereas ZD1839 gave a GI50 in this range only in H28 cells. All cell lines were positive for EGFR, but only H226 cells were positive for VEGFR2 by Western blotting. ZD6474 and ZD1839 inhibited EGF-induced phosphorylation of EGFR, AKT and ERK, whereas VEGF-induced phosphorylation of VEGFR2 was completely inhibited with 0.1 microM SU11248. VEGFR2 was detected in tumour samples by immunohistochemistry. VEGFR2 tyrosine kinase inhibitors warrant further investigation in mesothelioma.

Alteration in urinary matrix metalloproteinase-9 to tissue inhibitor of metalloproteinase-1 ratio predicts recurrence in nonmuscle-invasive bladder cancer.

PURPOSE: The purpose is to assess the prognostic significance of matrix metalloproteinase (MMP)-9 in patients with bladder cancer using a combination of ELISA (to measure MMP-9 in voided urine) and immunohistochemistry (to study MMP-9 in bladder tumors). The relationship between MMP-9 and its principal inhibitor, tissue inhibitor of metalloproteinase (TIMP)-1 (in voided urine samples) was also studied. EXPERIMENTAL DESIGN: A total of 134 patients with bladder tumors (7 cis, 76 T(a), 27 T(1), 24 T(2)-T(4); 40 G1, 43 G2, and 44 G3), 33 patients with benign urological conditions, and 36 healthy volunteers was studied. Samples from 106 patients with bladder cancer and 12 controls were stained for MMP-9. Clinical follow-up data were available on 116 patients (median: 25 months; range: 4-36 months). RESULTS: MMP-9 was present in all urine samples analyzed. There were no differences between patients with cancer and patients with benign disorders. However, patients had significantly higher urinary MMP-9 than normal volunteers (P = 0.0167). Urinary MMP-9 was associated with bladder tumors of advanced stage (P = 0.0065) and large size (P < 0.0001) but not with grade (P = 0.14), multiplicity (P = 0.31), recurrence (P = 0.55), progression (P = 0.83), or survival (P = 0.55). Low MMP-9:TIMP-1 ratios in patients with nonmuscle-invasive tumors were associated with higher recurrence rates (P = 0.0035). Sixty percent (64 of 106) of bladder tumor specimens expressed MMP-9 compared with none of 12 normal urothelial biopsies (P < 0.0001). MMP-9 staining was associated with tumor size (P = 0.014), disease progression (P = 0.005), and poor disease-specific survival (P = 0.022) but was unrelated to tumor stage (P = 0.46), grade (P = 0.26), multiplicity (P = 0.85), or recurrence rate (P = 0.62). CONCLUSIONS: High urinary MMP-9 levels are associated with large bladder tumors. A low urinary MMP-9:TIMP-1 ratio may indicate a higher risk of intraluminal nonmuscle-invasive tumor recurrence and may assist in planning follow-up surveillance protocols.