Combined application of anti-VEGF and anti-EGFR attenuates the growth and angiogenesis of colorectal cancer mainly through suppressing AKT and ERK signaling in mice model

Abstract

BackgroundAngiogenesis is generally involved during the cancer development and hematogenous metastasis. Vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) are considered to have an important role in tumor-associated angiogenesis. However, the effects of simultaneously targeting on VEGF and EGFR on the growth and angiogenesis of colorectal cancer (CRC), and its underlying mechanisms remain unknown.MethodsImmunohistochemical staining was used to detect the VEGF and EGFR expression in different CRC tissue specimens, and the correlation between VEGF/EGFR expression with the clinicopathologic features was analyzed. Cell counting kit‑8 (CCK-8) and transwell assays were used to assess the cellular proliferation and invasion of CRC cells after treated with anti-VEGF antibody and/or anti-EGFR antibody in vitro, respectively. Moreover, in vivo tumor formation was performed on nude mice model, and the tumor microvessel density (MVD) was determined by anti-CD34 staining in different groups. Finally, we evaluated the impact of anti-VEGF antibody and/or anti-EGFR antibody on the activation of downstream signaling effectors using western blot.ResultsVEGF and EGFR were upregulated in CRC tissues, and their expression levels were correlated with hepatic metastasis. Blockage on VEGF or EGFR alone could inhibit the cellular proliferation and metastasis while their combination could reach a good synergism in vitro. In addition, in vivo xenograft mice model demonstrated that the tumor formation and angiogenesis were strongly suppressed by combination treatment of anti-VEGF and anti-EGFR antibodies. Besides, the combination treatment significantly reduced the activation of AKT and ERK1/2, but barely affected the activation of c-Myc, NF-κB/p65 and IκBα in CRC cells tumors. Interestingly, anti-VEGF antibody or anti-EGFR antibody alone could attenuate the phosphorylation of STAT3 as compared with negative control group, whereas the combined application not further suppressed but at least partially restored the activation of STAT3 in vivo.ConclusionsSimultaneous targeting on VEGF and EGFR does show significant inhibition on CRC tumor growth and angiogenesis in mice model, and these effects are mainly attributed to suppression of the AKT and ERK signaling pathways.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2834-8) contains supplementary material, which is available to authorized users.

Identification of O-GlcNAcylation Modification in Diabetic Retinopathy and Crosstalk with Phosphorylation of STAT3 in Retina Vascular Endothelium Cells

“…Increased STAT3 activity can promote protein dimerization and translocation to regulate expression of critical genes such as cell survival Cellular Physiology and Biochemistry Cellular Physiology and Biochemistry factors [42][43][44], signaling pathways [45,46], and MnSOD activity in mitochondria [47]. We determined JAK2 expression provided insight into the mechanisms of O-GlcNAcylation on p705STAT3 expression.…”

Dual EGFR blockade with cetuximab and erlotinib combined with anti-VEGF antibody bevacizumab in advanced solid tumors: a phase 1 dose escalation triplet combination trial

“…Wheler and colleagues demonstrated that cetuximab and erlotinib combination was well tolerated and five out of 20 patients (25%) had achieved partial response and stable disease ≥ 6 months in patients with NSCLC [35]. VEGF and EGFR signaling pathways are intercorrelated; via up-regulating VEGF by EGFR expression and VEGF up-regulation independently contributing to EGFR resistance [29,[38][39][40][41]. Preclinical evidence suggested that inhibiting both pathways suppress AKT and ERK signaling and have notably shrunken the tumor growth in CRC cells lines [39].…”

“…VEGF and EGFR signaling pathways are intercorrelated; via up-regulating VEGF by EGFR expression and VEGF up-regulation independently contributing to EGFR resistance [29,[38][39][40][41]. Preclinical evidence suggested that inhibiting both pathways suppress AKT and ERK signaling and have notably shrunken the tumor growth in CRC cells lines [39]. In preclinical models and early phase trials, combination of VEGF and EGFR inhibition has shown activity in advanced solid tumors, including CRC, NSCLC, breast cancer, renal cell carcinoma and HNSCC [28,[42][43][44].…”

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