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Rosa R.,University of Naples Federico II | Rosa R.,The Surgical Center | Melisi D.,Unita di Farmacologia Sperimentale | Melisi D.,University of Houston | And 12 more authors.
Clinical Cancer Research | Year: 2011

Purpose: K-Ras somatic mutations are a strong predictive biomarker for resistance to epidermal growth factor receptor (EGFR) inhibitors in patients with colorectal and pancreatic cancer. We previously showed that the novel Toll-like receptor 9 (TLR9) agonist immunomodulatory oligonucleotide (IMO) has a strong in vivo activity in colorectal cancer models by interfering with EGFR-related signaling and synergizing with the anti-EGFR monoclonal antibody cetuximab. Experimental Design: In the present study, we investigated, both in vitro and in vivo, the antitumor effect of IMO alone or in combination with cetuximab in subcutaneous colon and orthotopic pancreatic cancer models harboring K-Ras mutations and resistance to EGFR inhibitors. Results: We showed that IMO was able to significantly restore the sensitivity of K-Ras mutant cancer cells to cetuximab, producing a marked inhibition of cell survival and a complete suppression of mitogen-activated protein kinase phosphorylation, when used in combination with cetuximab. IMO interfered with EGFR-dependent signaling, modulating the functional interaction between TLR9 and EGFR. In vivo, IMO plus cetuximab combination caused a potent and long-lasting cooperative antitumor activity in LS174T colorectal cancer and in orthotopic AsPC1 pancreatic cancer. The capability of IMO to restore cetuximab sensitivity was further confirmed by using K-Ras mutant colorectal cancer cell models obtained through homologous recombination technology. Conclusions: We showed that IMO markedly inhibits growth of K-Ras mutant colon and pancreatic cancers in vitro andinnudemice andcooperates with cetuximab viamultiplemechanismsof action. Therefore, we propose IMO plus cetuximab as a therapeutic strategy for K-Ras wild-type as well for K-Ras mutant, cetuximab-resistant colorectal and pancreatic cancers. ©2011 AACR.

Fiorino F.,University of Naples Federico II | Magli E.,University of Naples Federico II | Perissutti E.,University of Naples Federico II | Severino B.,University of Naples Federico II | And 11 more authors.
European Journal of Medicinal Chemistry | Year: 2011

Serotonin (5-hydroxytryptamine, 5-HT) is one of the most important neuromediator involved in numerous physiological and pathophysiological processes. In addition it is well established that 5-HT acts as a growth factor on several types of non-tumoral and tumoral cells, and recently it was also related to oncogenes. 5-HT1A receptor expression was identified in prostatic tumor cell lines (PC3 cells) and in human hormone refractory prostate cancer tissue. Based on these observations, development of 5-HT1A antagonists could be useful in inhibiting the growth of cancer cells. In order to investigate on potential use of 5-HT1A ligands as antiproliferative agents, we have analyzed a new set of 1-naphtylpiperazine derivatives. In binding studies, several molecules showed affinity in nanomolar and subnanomolar range at 5-HT1A and moderate to no affinity for other relevant receptors (5-HT2A, 5-HT2C, D1, D2, α1 and α2). All compounds were then evaluated in order to assess their antiproliferative activity using PC3 cells and the most active compounds (1 and 2) were fully characterized to define the mechanism responsible for the observed antiproliferative effect. © 2011 Elsevier Masson SAS.

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