Frequent co-expression of EGFR and NeuGcGM3 ganglioside in cancer: it’s potential therapeutic implications

Interaction between epidermal growth factor receptor (EGFR) signaling with GM3 ganglioside expression has been previously described. However, little is known about EGFR and NeuGcGM3 co-expression in cancer patients and their therapeutic implications. In this paper, we evaluate the co-expression of EGFR and NeuGcGM3 ganglioside in tumors from 92 patients and in two spontaneous lung metastasis models of mice (Lewis lung carcinoma (3LL-D122) in C57BL/6 and mammary carcinoma (4T1) in BALB/c). As results, co-expression of EGFR and NeuGcGM3 ganglioside was frequently observed in 63 of 92 patients (68 %), independently of histological subtype. Moreover, EGFR is co-expressed with NeuGcGM3 ganglioside in the metastasis of 3LL-D122 and 4T1 murine models. Such dual expression appears to be therapeutically relevant, since combined therapy with mAbs against these two molecules synergistically increase the survival of mice treated. Overall, our results suggest that NeuGcGM3 and EGFR may coordinately contribute to the tumor cell biology and that therapeutic combinations against these two targets might be a valid strategy to explore.Fil: Palomo, Addys González. Centro de Inmunología Molecular; CubaFil: Santana, Rancés Blanco. Centro de Inmunología Molecular; CubaFil: Pérez, Xiomara Escobar. Instituto Nacional de Oncología y Radiobiología; CubaFil: Santana, Damián Blanco. Instituto Nacional de Oncología y Radiobiología; CubaFil: Gabri, Mariano Rolando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; ArgentinaFil: Monzon, Kalet León. Centro de Inmunología Molecular; CubaFil: Pérez, Adriana Carr. Centro de Inmunología Molecular; Cub

Synergistic potentiation of the anti-metastatic effect of anti EGFR mAb by its combination with immunotherapies targeting the ganglioside NGcGM3

Several Anti-EGFR mAbs are register for the treatment of human cancer. However, their impact on patients overall survival has been limited by tumor resistance. N-Glycolyl variant of GM3 ganglioside (NGcGM3) is specifically expressed in some human tumors, and it has been associated with a poor prognosis. Several reports have documented that GM3 physically associates to EGFR inhibiting its ligand depend phosphorylation, but it also facilitates an alternative/compensatory signaling cascade mediated by Uroquinase Plasminogen Activator Receptor (uPAR) and integrin α5β1 interaction. However, the difference between NGc and N-Acetylated (NAc) variants of GM3 regarding such interactions is unknown. We hypothesized that enrichment of NGcGM3 expression in tumors relates to advantages of this ganglioside, on ensuring both EGFR and uPAR pathways optimal function. We explored the impact of combining an anti-EGFR (7A7 mAb) with anti-NGcGM3 therapies: NGcGM3/VSSP vaccine or 14F7 mAb. Both combinations synergistically increase overall survival in two models of lung metastasis: 3LL-D122 and 4T1; but combination with NGcGM3/VSSP vaccine is significantly more effective. In 3LL-D122-metastasis, of mice treated with the best combination, both EGFR and uPAR/α5β1 integrin pathways are turn off (I.e expression of uPAR/α5β1; and phosphorylation of EGFR, Stat3, Src and FAK are reduced); and tumor angiogenesis is decreased. Interestingly, combination treatment increases tumor infiltrating CD4+T, CD8+T and NK+-cells. Furthermore, a positive clinical outcome is reported for a cancer patient treated with an anti-EGFR mAb and anti-NGcGM3 therapy. Overall, our results support the combination of anti EGFR antibodies with therapies targeting NGcGM3 to increase their efficacy in future clinical trials.Fil: González Palomo, Addys. No especifíca;Fil: López Medinilla, Armando. No especifíca;Fil: Segatori, Valeria Inés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Barroso, María del Carmen. No especifíca;Fil: Blanco, Rances. No especifíca;Fil: Gabri, Mariano Rolando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pérez, Adriana Carr. No especifíca;Fil: Monzón, Kalet León. No especifíca

The combination of very-small size proteoliposomes and alum is a safe adjuvant alternative for inducing anti-EGF antibodies: a preclinical study

Immunization with human recombinant EGF chemically bound to the P64k protein of Neisseria meningitides (hrEGF-P64k) and adjuvanted in Montanide ISA 51 VG (Montanide) is an efficient strategy to induce polyclonal antibodies (PAbs) response targeting this self -antigen in cancer patients, which is the basis of the CIMAvax-EGF vaccine. The neutralizing potential of EGF-specific induced PAbs supports promising clinical data obtained to date with this vaccine. Herein, we evaluated a combination of very small-size proteoliposomes (VSSP) and aluminum hydroxide (Alum) as a novel adjuvant to induce specific PAbs with neutralizing and anti-proliferative properties on tumor cells, considering EGF as a model antigen. Toxicity at the injection site was not detected for the vaccine formulation containing VSSP/Alum, and it was immunogenic in BALB/c mice, as evidenced by the induction of high titers of EGF-specific polyclonal antibodies (PAbs). While schedule optimization increased the magnitude of the PAbs response induced by VSSP/Alum, induced PAbs’s avidity and intrinsic neutralizing potential were comparable to the humoral response induced by Montanide. Also, VSSP addition switched IgG subclasses distribution into a Th1-like pattern, as obtained with Montanide and desirable for a cancer vaccine. Finally, equivalent PAbs titers were induced by the vaccine formulations adjuvanted in VSSP/Alum or Montanide in tumor-bearing-mice, and immunosuppressed mice, suggesting the feasibility of the VSSP/Alum combined adjuvant for inducing anti-EGF antibodies in cancer patients at advanced stages of the disease