IADR Abstract Archives
A New Function for EGFR Inhibition is Suppression of Tobacco and Alcohol Carcinogenesis and Human Papillomavirus 16 Entry
Objectives: Risk for malignant transformation in human oral keratinocytes (HOK) from metabolism of ethyl alcohol (ETOH), tobacco products or human papillomavirus oncogenic subtype 16 (HPV 16) infection is reported. We examined various HOK cell types responses to these factors to test our hypothesis that inhibition of epidermal growth factor receptor (EGFR) also suppressed furin; proprotein convertase (FC) activity and HPV 16 entry in HOK.
Methods: Immortalized HOK by HPV 16 (HPV 16B) or human telomerase (hTERT); primary foreskin keratinocytes (NHFK), primary HOK, buccal keratinocytes (NHBK) and oral cancer cells, SCC-25 were treated with dibenz (a,l)pyrene and anthraquinone: nitrosamine( NNAL) or ethyl alcohol (ETOH) and acetaldehyde (AA). ETOH was tested for synthesis of malondialdehyde (MDA); alcohol dehydrogenase expression (ADH) and both ETOH, and PAH were evaluated by Western immunoblot for oncogene changes, and phosphorylated EGFR. Inhibition of EGFR by WZ4002 and Erlotinib and/or carcinogens effect in a HPV16 entry assay was also performed. This assay uses green fluorescent pseudoparticles (PsV); chloromethylketone(CMK) inhibition of furin and activity and cell distribution of furin to characterize HPV 16 entry.
Results: ETOH (10 microMolar) increased expression of phosphorylated EGFR and HV16 entry through furin activity and nuclear and cytoskeletal distribution change.This effect was suppressed with CMK and blockage of ADH while aldehyde dehydrogenase (ALDH) enhanced HPV16 entry. Similarly PAH, DBP (8 nanoMolar), anthraquinone, and NNAL (6.9 microMolar) enhanced HPV 16 entry through furin activity and nuclear and cytoskeletal distribution which also increased phosphorylated EGFR. However WZ4002 and Erlotinib suppressed EGFR and FC activity. ETOH and DBP treatments also produced loss of cell cycle kinase regulation and tumor suppressor function.
Conclusions: EGFR inhibitors reduce tobacco carcinogenesis, malignant keratinocyte growth and HPV 16 entry. This observation is novel and may have important clinical relevance for treatment of HPV related dermatologic conditions.
Methods: Immortalized HOK by HPV 16 (HPV 16B) or human telomerase (hTERT); primary foreskin keratinocytes (NHFK), primary HOK, buccal keratinocytes (NHBK) and oral cancer cells, SCC-25 were treated with dibenz (a,l)pyrene and anthraquinone: nitrosamine( NNAL) or ethyl alcohol (ETOH) and acetaldehyde (AA). ETOH was tested for synthesis of malondialdehyde (MDA); alcohol dehydrogenase expression (ADH) and both ETOH, and PAH were evaluated by Western immunoblot for oncogene changes, and phosphorylated EGFR. Inhibition of EGFR by WZ4002 and Erlotinib and/or carcinogens effect in a HPV16 entry assay was also performed. This assay uses green fluorescent pseudoparticles (PsV); chloromethylketone(CMK) inhibition of furin and activity and cell distribution of furin to characterize HPV 16 entry.
Results: ETOH (10 microMolar) increased expression of phosphorylated EGFR and HV16 entry through furin activity and nuclear and cytoskeletal distribution change.This effect was suppressed with CMK and blockage of ADH while aldehyde dehydrogenase (ALDH) enhanced HPV16 entry. Similarly PAH, DBP (8 nanoMolar), anthraquinone, and NNAL (6.9 microMolar) enhanced HPV 16 entry through furin activity and nuclear and cytoskeletal distribution which also increased phosphorylated EGFR. However WZ4002 and Erlotinib suppressed EGFR and FC activity. ETOH and DBP treatments also produced loss of cell cycle kinase regulation and tumor suppressor function.
Conclusions: EGFR inhibitors reduce tobacco carcinogenesis, malignant keratinocyte growth and HPV 16 entry. This observation is novel and may have important clinical relevance for treatment of HPV related dermatologic conditions.