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Enhanced cytotoxic activity of cetuximab in EGFR-positive lung cancer by conjugating with gold nanoparticles.

Qian Y, Qiu M, Wu Q, Tian Y, Zhang Y, Gu N, Li S, Xu L, Yin R - Sci Rep (2014)

Bottom Line: Overall, the therapeutic effect of C225-AuNPs was more pronounced in EGFR(high) A549 cells compared with EGFR(low) H1299 cells.C225-AuNPs significantly suppressed A549 cell proliferation and migration capacity and accelerated apoptosis compared with C225, and this effect was probably due to enhanced EGFR endocytosis and the subsequent suppression of downstream signaling pathway.Finally in the tumor xenograft of nude mice, treatment with C225-AuNPs also led to a significant reduction in tumor weight and volume with low toxicity.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Thoracic Surgery, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing Medical University Affiliated Cancer Hospital, Cancer Institute of Jiangsu Province, Nanjing, P.R. China 210009 [2] The First Clinical College, Nanjing Medical University, Nanjing, P.R. China 210029.

ABSTRACT
Cetuximab (C225) is a unique agent, targeting epidermal growth factor receptor (EGFR)-positive cancer. However, the therapeutic effect of C225 in EGFR high-expressing non-small cell lung cancer (NSCLC) remains poor. Here, we report that conjugation of C225 with gold nanoparticles (AuNPs) enhances the cytotoxicity of C225 in NSCLC both in vitro and in vivo. The NSCLC cell lines A549 (EGFR(high)) and H1299 (EGFR(low)) were employed to investigate different responses to C225, IgG-AuNPs and C225-AuNPs. The antitumor properties of C225-AuNPs were explored in vivo by establishing a tumor xenograft model in nude mice. Overall, the therapeutic effect of C225-AuNPs was more pronounced in EGFR(high) A549 cells compared with EGFR(low) H1299 cells. The cytotoxic effect of C225-AuNPs in A549 cells increased in a dose-dependent manner. C225-AuNPs significantly suppressed A549 cell proliferation and migration capacity and accelerated apoptosis compared with C225, and this effect was probably due to enhanced EGFR endocytosis and the subsequent suppression of downstream signaling pathway. Finally in the tumor xenograft of nude mice, treatment with C225-AuNPs also led to a significant reduction in tumor weight and volume with low toxicity. Our findings suggest that C225-AuNPs conjugate has promising potential for targeted therapy of EGFR positive NSCLC patients.

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Representative transmission electron microscope (TEM) images of (A) bare gold nanoparticles (AuNPs) with an average diameter of 14 nm and (B) Cetuximab-conjugated gold nanoparticles (C225-AuNPs). (C) The hydrodynamic size of AuNPs and C225-AuNPs measured by dynamic light scattering (DLS).
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f1: Representative transmission electron microscope (TEM) images of (A) bare gold nanoparticles (AuNPs) with an average diameter of 14 nm and (B) Cetuximab-conjugated gold nanoparticles (C225-AuNPs). (C) The hydrodynamic size of AuNPs and C225-AuNPs measured by dynamic light scattering (DLS).

Mentions: The physical characteristics of C225-AuNPs and IgG-AuNPs were summarized in Table 1. The properties of C225-conjugated AuNPs were determined by TEM, zeta potential measurement, and Dynamic light scattering. TEM images reveal that unmodified AuNPs are monodispersed with average size of 14 nm (Fig. 1A & 1B). From the dynamic light scattering (DLS) measurement, the hydrodynamic size of C225-AuNPs is estimated to be 25 nm after BSA blocking, which is larger than the unmodified AuNPs (about 14 nm) due to the contribution of protein adsorption layer (Fig. 1C). Zeta potential measurements show that surface potential of the unconjugated AuNPs is negatively charged with approximately −42.7 mV. When coated with C225, the zeta potential increase to −20.4 mV, demonstrating successful conjugation. With respect to the coupling ratio between AuNPs and C225, 13.97 μg/ml C225 were conjugated to 1 ml AuNPs (14 nm, 47.8 μg/ml) detecting by BCA protein detection kits, so we can further calculate the number of coupling ratio through the calculation of the following methods. First, we calculated the number of AuNPs: NAuNPs = 47.8 μg/(V × ρ) = 1.72 × 1015 (dAuNPs = 14 nm, VAuNPs = πd3/6 = 1.436 × 10–24 m3, ρAuNPs = 1.932 × 104 kg/m3), the molecular weight of C225 is 145.5 kg/mol, so we can get the number of C225: NC225 = 13.97 μg/M * NA = 5.78 × 1016, The conjugation number of C225 molecules per gold nanoparticle was determined to be 34 (NC225:NAuNPs ≈ 34).


Enhanced cytotoxic activity of cetuximab in EGFR-positive lung cancer by conjugating with gold nanoparticles.

Qian Y, Qiu M, Wu Q, Tian Y, Zhang Y, Gu N, Li S, Xu L, Yin R - Sci Rep (2014)

Representative transmission electron microscope (TEM) images of (A) bare gold nanoparticles (AuNPs) with an average diameter of 14 nm and (B) Cetuximab-conjugated gold nanoparticles (C225-AuNPs). (C) The hydrodynamic size of AuNPs and C225-AuNPs measured by dynamic light scattering (DLS).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4265789&req=5

f1: Representative transmission electron microscope (TEM) images of (A) bare gold nanoparticles (AuNPs) with an average diameter of 14 nm and (B) Cetuximab-conjugated gold nanoparticles (C225-AuNPs). (C) The hydrodynamic size of AuNPs and C225-AuNPs measured by dynamic light scattering (DLS).
Mentions: The physical characteristics of C225-AuNPs and IgG-AuNPs were summarized in Table 1. The properties of C225-conjugated AuNPs were determined by TEM, zeta potential measurement, and Dynamic light scattering. TEM images reveal that unmodified AuNPs are monodispersed with average size of 14 nm (Fig. 1A & 1B). From the dynamic light scattering (DLS) measurement, the hydrodynamic size of C225-AuNPs is estimated to be 25 nm after BSA blocking, which is larger than the unmodified AuNPs (about 14 nm) due to the contribution of protein adsorption layer (Fig. 1C). Zeta potential measurements show that surface potential of the unconjugated AuNPs is negatively charged with approximately −42.7 mV. When coated with C225, the zeta potential increase to −20.4 mV, demonstrating successful conjugation. With respect to the coupling ratio between AuNPs and C225, 13.97 μg/ml C225 were conjugated to 1 ml AuNPs (14 nm, 47.8 μg/ml) detecting by BCA protein detection kits, so we can further calculate the number of coupling ratio through the calculation of the following methods. First, we calculated the number of AuNPs: NAuNPs = 47.8 μg/(V × ρ) = 1.72 × 1015 (dAuNPs = 14 nm, VAuNPs = πd3/6 = 1.436 × 10–24 m3, ρAuNPs = 1.932 × 104 kg/m3), the molecular weight of C225 is 145.5 kg/mol, so we can get the number of C225: NC225 = 13.97 μg/M * NA = 5.78 × 1016, The conjugation number of C225 molecules per gold nanoparticle was determined to be 34 (NC225:NAuNPs ≈ 34).

Bottom Line: Overall, the therapeutic effect of C225-AuNPs was more pronounced in EGFR(high) A549 cells compared with EGFR(low) H1299 cells.C225-AuNPs significantly suppressed A549 cell proliferation and migration capacity and accelerated apoptosis compared with C225, and this effect was probably due to enhanced EGFR endocytosis and the subsequent suppression of downstream signaling pathway.Finally in the tumor xenograft of nude mice, treatment with C225-AuNPs also led to a significant reduction in tumor weight and volume with low toxicity.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Thoracic Surgery, Jiangsu Key Laboratory of Molecular and Translational Cancer Research, Nanjing Medical University Affiliated Cancer Hospital, Cancer Institute of Jiangsu Province, Nanjing, P.R. China 210009 [2] The First Clinical College, Nanjing Medical University, Nanjing, P.R. China 210029.

ABSTRACT
Cetuximab (C225) is a unique agent, targeting epidermal growth factor receptor (EGFR)-positive cancer. However, the therapeutic effect of C225 in EGFR high-expressing non-small cell lung cancer (NSCLC) remains poor. Here, we report that conjugation of C225 with gold nanoparticles (AuNPs) enhances the cytotoxicity of C225 in NSCLC both in vitro and in vivo. The NSCLC cell lines A549 (EGFR(high)) and H1299 (EGFR(low)) were employed to investigate different responses to C225, IgG-AuNPs and C225-AuNPs. The antitumor properties of C225-AuNPs were explored in vivo by establishing a tumor xenograft model in nude mice. Overall, the therapeutic effect of C225-AuNPs was more pronounced in EGFR(high) A549 cells compared with EGFR(low) H1299 cells. The cytotoxic effect of C225-AuNPs in A549 cells increased in a dose-dependent manner. C225-AuNPs significantly suppressed A549 cell proliferation and migration capacity and accelerated apoptosis compared with C225, and this effect was probably due to enhanced EGFR endocytosis and the subsequent suppression of downstream signaling pathway. Finally in the tumor xenograft of nude mice, treatment with C225-AuNPs also led to a significant reduction in tumor weight and volume with low toxicity. Our findings suggest that C225-AuNPs conjugate has promising potential for targeted therapy of EGFR positive NSCLC patients.

Show MeSH
Related in: MedlinePlus