Recruiting 5/11-11/14 Solid Tumors or Lymphoma GRN163L MTD, toxicities, PK, biologic effects, effect on telomeres and telomerase Trial ongoing, no study results yet available * Study end dates are estimated. DLT -dose limiting toxicity; MTD -maximum tolerated dose; PK -pharmacokinetics; PD -pharmacodynamics; PFS -progression free survival; ORR -objective response rate; AEs -adverse events; aPTT -active thromboplastin time; t.i.w. -three times a week

Melanoma is the most fatal skin cancer, often highly resistant to chemotherapy. Here we show that treatment with an 11-base DNA oligonucleotide homologous to the telomere 3' overhang sequence (T-oligo) induces apoptosis of several established human melanoma cell lines, including the aggressive MM-AN line, whereas normal human melanocytes exposed to the same or higher T-oligo concentrations show only transient cell cycle arrest, implying that malignant cells are more sensitive to T-oligo effects. When MM-AN cells were briefly exposed to T-oligo in culture and injected into the flank or tail vein of SCID mice, eventual tumor volume and number of metastases were reduced 85-95% compared with control mice. Similarly, T-oligos administered intralesionally or systemically selectively inhibited the growth of previously established MM-AN tumor nodules in the flank and peritoneal cavity by 85 to 90% without detectable toxicity. We previously showed that T-oligos act through ATM, p95/Nbs1, E2F1, p16INK4A, p53, and the p53 homologue p73 to modulate downstream effectors and now additionally demonstrate striking down-regulation of the inhibitor of apoptosis protein livin/ML-IAP. We suggest that T-oligo mimics a physiologic DNA damage signal that is frequently masked in malignant cells and thereby activates innate cancer prevention responses. T-oligos may provide a novel therapeutic approach to melanoma.

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Backgroundc-Met and EGFR receptors are widely expressed on cancer cells; they are implicated in the development and progression of cancer through a plethora of effects on cell cycle progression, apoptosis, motility and metastasis and are potential targets for combination therapy. EGFR receptor tyrosine kinases are currently being targeted in a number of malignancies.MethodsApoptosis was studied by FACS analysis using propidium iodide. EGF and HGF signaling intermediates were studied by western blotting. Cell proliferation was determined by MTT assays. Cell motility was done by time lapse confocal microscopy.Resultsc-Met and EGFR were both expressed in A549, H1838, H2170, SW900, SW1573, H358, SKLU-1, and H1993 non small cell lung cancer (NSCLC) cell lines. Both EGF and HGF at 100 ng/ml in medium showed a synergistic effect on cell proliferation at 48–72 h as seen by a proliferation assay in A549, H1838, and SKMES cells. In A549 and H1838 cell lines, HGF (40 ng/ml) and EGF (5 ng/ml) induced synergistic phosphorylation on c-Met (Tyr 1003/1230/1234/1235). Additionally, synergistic phosphorylation of Akt (Ser-473) and phospho-ERK1+ERK2 (Thr202/Tyr204) was also seen indicating that EGF and HGF could induce synergistic phosphorylation of important signaling intermediates. Treatment with EGF and HGF at 100 ng/ml for 2 h also leads to an additive effect in inducing cell motility (especially membrane ruffling) in H1993 cells. A novel c-Met small molecule tyrosine kinase inhibitor SU11274 and EGFR tyrosine kinase inhibitors Tyrphostin AG1478 and gefitinib (Iressa) were tested to study their effect in combination on proliferation and apoptosis in lung cancer cells. Interestingly, a synergistic effect on inhibition of cell proliferation was seen in the presence of SU11274 and Tyrphostin AG1478. 0.5 µM Tyrphostin AG1478 and 2 µM SU11274 inhibited growth by 21% and 25%, respectively; a combination of both tyrosine kinase inhibitors inhibited growth by 65%. Interestingly, EGFR inhibitor (gefitinib, Iressa) and c-Met inhibitor (SU11274) also had a synergistic effect on apoptosis in H358 cells.ConclusionThere was a synergistic effect of EGF and HGF on proliferation, downstream activation of signal transduction and an additive effect seen on motility. These studies show that a combination of HGF and EGF tyrosine kinase inhibitors on NSCLC, could potentially be targeted in a synergistic fashion.