Analysis of electric cigarette liquid effect on mouse brain tumor growth through EGFR and ERK activation

Abstract

Introduction Recently, electric cigarettes with liquid (e-liquid) were introduced as an alternative to tobacco smoking. They were promoted as possible cessation aids and were considered to be potentially less harmful than traditional tobacco-based cigarettes. However, there is little information on the toxicants present in e-liquids and their possible carcinogenic effects. Methods Western blot analysis was performed to identify the protein levels of cancer progression related signal transducers. Patient-derived brain tumor cells (CSC2) were injected into mouse brains and tumor growth was then observed by performing magnetic resonance imaging (MRI) and hematoxylin and eosin (H&E) staining of the whole brain. Immunohistochemistry (IHC) staining and Immunofluorescence staining were performed to study the expression of pEGFR and pERK. Results Western blotting revealed that e-liquids increased pEGFR and pERK expression in a dose dependent manner. Animal experiments revealed that the e-liquid treated group had accelerated tumor growth and poor prognosis compared to the vehicle group. Histological staining showed activation of pEGFR and pERK in the e-liquid treated group. Conclusion Our study revealed that e-liquid activates pEGFR and pERK, leading to accelerated brain tumor growth and poor prognosis.

Toxicological Aspects Associated with Consumption from Electronic Nicotine Delivery System (ENDS): Focus on Heavy Metals Exposure and Cancer Risk

“…The overexpression ranges from 43% to 89% in non-small cell lung cancer [ 121 ]. It has been reported that patient-derived glioblastoma stem-like cells exposed to e-liquids showed an increased level of phospho-EGFR, leading to autophagy deficiency and to the activation of ERK [ 122 , 123 ]. In addition, in vivo studies showed that the injection of patient-derived brain tumor cells into mice brains accelerated tumor growth and the poor prognosis in the e-liquid-treated group compared to the control group [ 94 , 95 ].…”

Electronic cigarette liquids impair metabolic cooperation and alter proteomic profiles in V79 cells

“…Carcinogenic and tumour promoting properties of e-cigarettes were also reported. E-cigarette exposure acted as a lung carcinogen and a potential bladder carcinogen in mice and mouse xenografts from patient-derived brain tumour treated with e-cigarette liquid had accelerated growth and worse prognosis compared to the control group [28,29]. Exposure to e-cigarettes was found to increase cisplatin resistance in oral cancer cells, indicating their role in therapy-resistance in cancer as well [30].…”