Background: Human papillomavirus 16 (HPV 16) infections ultimately affect response to therapy and survival from head and neck squamous cell carcinoma (HNSCC). We hypothesize HPV 16 entry in epithelial cells is regulated by reactive oxygen substances (ROS). For example, anthraquinones derived from microbe order Actinomycetales; tobacco derived poly-cyclic aromatic hydrocarbons (PAH), tobacco specific nitrosamines (TSNA), and nicotine. ROS participate in varying ways in malignant transformation of keratinocytes to enhance furin proprotein convertase (FC); epidermal growth factor receptor (EGFR) expressions and HPV 16 entry.
Methods: To focus on HPV 16 entry we used pesudoparticles that lack oncogene capability and express a plasmid with green fluorescent protein (GFP). We used 110 samples of marine-derived Actinomycete extracts with HPV 16 negative 293TT cells or hTERT immortalized human oral keratinocytes (HOK). An identical approach was initiated to study HPV 16 entry with benzo[a]pyrene (B[a]P); dibenzo[a,l]pyrene (DBP); nicotine and nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and anthraquinone. Assay variations included cell density, type of plate, attachment to collagen, and dilutions in vehicles. 12 samples exhibited significant changes in 293TT HPV PsV uptake as measured through fluorimeter plate reader counts and chloromethyl ketone (CMK) inhibition of FC with entry of HPV PsV compared to controls. In addition, we studied 4 extracts by immunocytochemistry and Western immunoblot for FC activity and EGFR expression.
Results: A comparative increase or decrease HPV 16 entry through a range of -2.23% to +204.3% (p<0.001) was recorded for extracts. Anthraquinone and selective PAH, and dose related effects from TSNA and nicotine treatments produced enhanced HPV 16 entry. Moreover, HPV 16 entry required FC activity and EGFR expression.
Conclusions: Further study is required to evaluate clinical significance for HPV 16 infection risk and related factors considered in this study. However, these results do indicate a relationship that has not been documented in previous studies of HPV 16 entry.
In a dose dependent manner, marine-derived Actinomycetes extracts that contain anthraquinone, PAHs, TSNA and nicotine can induce a ROS state in epithelial cells to cause HPV 16 entry.
HPV 16 entry event is linked to activity of furin and EGFR.
A variety of environmental exposures provide an oxidative state that contributes to increased risk for HPV 16 entry into epithelial cells in clinical settings.
Keywords: Actinomycetes, Human papilloma virus subtype 16, Epidermal growth factor receptor, Furin convertase, Poly-cyclic aromatic-hydrocarbon, Tobacco specific nitrosamine, Nicotine, Reactive oxygen substances
Schwartz J, Lathe A, Liu T, et al. Dose Related Effect of Actinomycete Extracts, Tobacco Derived Carcinogens and Nicotine on Human Papillomavirus 16 Entry into Epithelium. J Cancer Stud Ther. 2015;2(1):1-15.