Search

Objectives/Hypothesis Recent preclinical and clinical studies on head and neck squamous cell carcinoma (HNSCC) revealed synergistic effects when combining anti-EGFR agents with conventional chemotherapeutic drugs. Activation of the PI3-kinase/AKT/mTOR signaling pathway has been identified as an important mechanism implicated in tumor progression and resistance to EGFR inhibitors. The aim of this study was to investigate the effects of combining the mTOR inhibitor temsirolimus (Tem) with the anti-EGFR agent cetuximab (Cet) and conventional chemotherapeutic drugs (cisplatin and fluorouracil (C/F)) on an orthotopic model of HNSCC. Study Design Preclinical in vivo study. Methods We evaluated the anti-tumor efficacy (measured tumor volume) of Tem, Cet, and C/F, administered alone or in combination. Investigations were performed using a human HNSCC cell line, CAL33, injected into the mouth floor of nude mice. Results As compared with the control, the combination of Tem and Cet led to the highest tumor inhibition and induced almost complete tumor growth arrest (P = 0.001). Tem significantly enhanced the impact of the Cet-C/F combination on tumor growth (P < 0.001). The highest inhibitory effects of treatments on cell proliferation (Ki67 labeling), MAPK (pP42/44 labeling), and PI3K/AKT/mTOR (pS6R labeling) signaling pathways were found with the Tem-Cet association. Conclusion In this orthotopic HNSCC model, the combination of Tem with Cet produced synergistic effects on tumor growth. These results were corroborated by a strong inhibition of both MAPK and PI3K-mTOR signaling pathways. Level of Evidence N/A. Laryngoscope, 126:E156–E163, 2016

Background Radiotherapy (RT) is the standard treatment for uveal melanoma. However it can cause damage to the retina and optic nerve. This study examined the in vitro and in vivo effects of the anti-VEGF monoclonal antibody bevacizumab associated with radiotherapy (RT) on tumor growth and tumor proliferation and vasculature on OCM-1 human uveal melanoma cell line. Methods The anti-proliferative effects of bevacizumab, RT and their combination were tested both in vitro (OCM-1 cells co-cultured with HUVEC cells in Transwell plates) and in vivo (OCM-1 tumor xenografts in nude mice). In addition, treatment effects in vitro on VEGF secretion, as well as treatment effects in vivo on tumor proliferation (Ki67 labelling), tumor vasculature (VEGFR2 labelling) and VEGF tumoral concentration were analyzed. Results Bevacizumab given alone had a significant impact on tumor growth in vivo (and moderate effects in vitro). The bevacizumab-RT combination had additive effects in vitro (tumor cell proliferation) and in vivo (tumor growth), which translated into a significant decrease in Ki67 expression, VEGFR2 labelling and VEGF tumoral content. Conclusions The bevacizumab-RT combination could be a promising clinical option to explore for the management of human uveal melanoma, since it may allow RT dose reduction without loss of antitumor efficacy.

We previously reported on head and neck tumor xenografts that the tumor regression induced by a triple combination of irradiation (RT), anti-EGFR and anti-angiogenic therapies was followed, after treatment arrest, by tumor re-growth characterized by activation of the AKT signaling pathway. Since mTOR is the main AKT-related messenger, the aim of this study was to add the mTOR inhibitor temsirolimus to a tri-therapy with RT plus anti-EGFR and anti-angiogenic drugs in order to improve anti-tumor effects. The human head and neck cancer cell line CAL33 (over-expressing EGFR and secreting VEGF-A) was xenografted in nude mice. Treatment (20 mice per treatment group) was administered for 2 weeks and consisted of either vehicle (control), temsirolimus (5mg/kg i.p. five times a week), tri-therapy with RT (6 Gy three times a week) combined with cetuximab (0.5mg/kg i.p. five times a week) and bevacizumab (5mg/kg i.p. five times a week) or the temsirolimus-tri-therapy association. The time to reach a tumor volume of 2000 mm(3) was significantly different between the four treatment groups (Log Rank p0.0001), with a median of 29.5, 44.5, 67.0 and 70.0 days for control, temsirolimus, tri-therapy and combination groups, respectively. The combination of temsirolimus plus tri-therapy produced the longest growth-inhibiting effects (tri-therapy versus combination, p=0.01). No significant interaction was observed between temsirolimus and the tri-therapy, suggesting that temsirolimus, on the one hand, and RT-cetuximab-bevacizumab, on the other, exert additive effects on tumor growth inhibition. These decreases observed on tumor growth were corroborated by the parallel decreases observed on tumor proliferation (Ki67) and on anti-apoptotic markers (Bcl2). These results suggest that temsirolimus exhibits synergistic antiproliferative effects when administered in combination with irradiation, anti-EGFR and anti-angiogenic therapies in head and neck cancer patients.

Background Recent preclinical and clinical studies indicate beneficial effects from combining radiotherapy with either anti-angiogenic drugs or anti-epidermal growth factor receptor (EGFR)-targeting agent. To investigate the effect of combining these approaches, we evaluated in vivo the antitumor efficacy of the anti-angiogenic compound sunitinib, an oral, multi-targeted tyrosine kinase inhibitor that inhibits among others vascular endothelial growth factor (VEGF) receptors-1, -2 and -3, cetuximab, a mAb targeting the EGFR, and irradiation (RT) given alone and in combination. Materials and methods Investigations were carried out using a VEGF-secreting human head and neck tumor cell line, CAL33, with a high EGFR content, growing as orthotopic xenografts in nude mice. Three days after tumor cell injection, sunitinib (20 mg/kg, p.o.), cetuximab (1 mg/kg, i.p.), both 5 days/week seven doses, and RT (6 Gy, 3 days/week, four doses) were administered alone and in combination during 9 days. Results Concomitant administration of drugs produced a marked and significant supra-additive decrease, and the addition of RT completely abolished tumor growth. The drug association markedly reduced tumor cell proliferation (Ki67) and the number of the vessels, but enhanced cell differentiation. Conclusion The efficacy of this combination of sunitinib, cetuximab and RT may be of clinical importance in the management of head and neck cancer patients.

Recent preclinical and clinical studies on head and neck squamous cell carcinoma (HNSCC) revealed synergistic effects when combining anti-EGFR agents with conventional chemotherapeutic drugs. Activation of the PI3-kinase/AKT/mTOR signaling pathway has been identified as an important mechanism implicated in tumor progression and resistance to EGFR inhibitors. The aim of this study was to investigate the effects of combining the mTOR inhibitor temsirolimus (Tem) with the anti-EGFR agent cetuximab (Cet) and conventional chemotherapeutic drugs (cisplatin and fluorouracil (C/F)) on an orthotopic model of HNSCC.Preclinical in vivo study.We evaluated the anti-tumor efficacy (measured tumor volume) of Tem, Cet, and C/F, administered alone or in combination. Investigations were performed using a human HNSCC cell line, CAL33, injected into the mouth floor of nude mice.As compared with the control, the combination of Tem and Cet led to the highest tumor inhibition and induced almost complete tumor growth arrest (P = 0.001). Tem significantly enhanced the impact of the Cet-C/F combination on tumor growth (P0.001). The highest inhibitory effects of treatments on cell proliferation (Ki67 labeling), MAPK (pP42/44 labeling), and PI3K/AKT/mTOR (pS6R labeling) signaling pathways were found with the Tem-Cet association.In this orthotopic HNSCC model, the combination of Tem with Cet produced synergistic effects on tumor growth. These results were corroborated by a strong inhibition of both MAPK and PI3K-mTOR signaling pathways.N/A.

Background: Preclinical and clinical studies on head and neck squamous cell carcinoma (HNSCC) demonstrated synergistic anti-tumoral effects when combining anti-EGFR agents with conventional chemotherapeutic drugs such as cisplatin (C) and 5-fluorouracil (F). In a previous experimental study, our group pointed out an enhancement of PIK3CA signaling (pAKT) in tumors re-growing after cetuximab-based treatment (Bozec et al. Br J Cancer 2007). This context justifies investigations on mTOR inhibitors combined with cetuximab (Cetux) in HNSCC. Methods: The effects on tumor growth of treatments combining an mTOR inhibitor (Temsirolimus (Tem)), an anti-EGFR (Cetux) and a clinically validated-chemotherapeutic regimen (C+F) were examined in an orthotopic (floor of the mouth) model of human HNSCC (CAL33 cell line, over-expressing EGFR, secreting VEGF-A, H1047R PIK3CA mutated). In parallel, in-vitro experiments were conducted in order to strengthen the data arising from the in-vivo study. On day 0, cells were injected in nude NMRI mice. Treatment was started on day 3 and consisted of 8 groups (10 mice/group) treated as follows: Control, Tem (5 mg/kg i.p. five times a week), Cetux (2.5 mg/kg i.p. once a week), cisplatin (6 mg/kg) + 5-fluorouracil (17 mg/kg) (i.p. once a week), concomitant treatment combining Tem with either Cetux, C+F, or Cetux+C+F. The tumor growth was recorded by IVIS imaging and on day 13 after animal euthanasia with a caliper ruler. Results: All tested treatments produced significant growth inhibition as compared to controls (p Conclusion: These data on the association of temsilorimus with cetuximab could serve as a strong basis for innovative treatments aiming at an optimal management of patients with recurrent/metastatic HNSCC. Citation Format: Alexandre Bozec, Nathalie Ebran, Martino Monteverde, Nicolas Toussan, Anne Cayre, Marie-Cristine Etienne-Grimaldi, Cristiana Lo Nigro, Anne Sudaka, Marco Merlano, Frederique Penault-Llorca, Gerard Milano. Combination of mTOR targeting with cetuximab and conventional chemotherapy: a preclinical study on an orthotopic xenograft model of head and neck cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2069. doi:10.1158/1538-7445.AM2013-2069

Background : Constitutive activation of AKT following PTEN inactivation is a well-known mechanism involved in tumor initiation and progression. Since mTOR is one of the main AKT-related messengers, mTOR inhibitors such as temsirolimus are promising anticancer drugs. Our group (Bozec A. Br J Cancer, 2007) previously reported, on head and neck tumour xenografts, that the tumour regression induced by the combination of radiotherapy (RT) with anti-EGFR and anti-angiogenic therapies was followed (after treatment arrest) by tumor re-growth. Importantly, this tumour re-growth was accompanied by a significant decrease in PTEN expression and an increase in phospho-AKT expression. The aim of this study was thus to add a mTOR targeting drug (temsirolimus) to a tri-therapy consisting of RT + anti-EGFR + anti-angiogenic drugs so as to prolong anti-tumor effects. Methods : The human head and neck cancer cell line CAL33 (exhibiting high EGFR content and secreting VEGF-A) was xenografted in the flank of nude mice. Treatment (20 mice per treatment group) was administered for 2 weeks, starting 14 days after cell injection. It consists of either vehicule (control), temsirolimus (5 mg/kg i.p. 5 times a week), tri-therapy with RT (6 Gy 3 times a week) + cetuximab (0.5 mg/kg i.p. 5 times a week) + bevacizumab (5 mg/kg i.p. 5 times a week) or the temsirolimus-tri-therapy combination. Mice were sacrificed when tumor volumes reached 2500 mm3. Tumor volume and mice weight (estimation of global toxicity) were measured once a week. Results : The time to reach a tumor volume of 2000 mm3 was significantly different between the 4 treatment groups (Log Rank p < 0.0001), with a median of 29.5, 44.5, 67.0 and 70.0 days for control, temsirolimus, tri-therapy and combination groups, respectively. The combination of temsirolimus and the tri-therapy produced the longest growth-inhibiting effects (tri-therapy versus combination, p = 0.01). No significant interaction was observed between temsirolimus and combination treatments, suggesting that temsirolimus on one hand and RT-cetuximab-bevacizumab on the other hand, exert additive effects on tumor growth inhibition. No animal weight loss could be attributed to any of the tested treatments. IHC analyses of tumor vasculature, proliferation status (Ki67) and downstream signalling phospho-proteins (pAKT . . .) are ongoing. Conclusion : These experimental results suggest that temsirolimus could represent a promising drug for testing in combination with irradiation, anti-EGFR and anti-angiogenic therapies in head and neck cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3482.