Date on Master's Thesis/Doctoral Dissertation


Document Type

Doctoral Dissertation

Degree Name

Ph. D.


Pharmacology and Toxicology

Degree Program

Pharmacology and Toxicology, PhD

Committee Chair

States, J. Christopher

Committee Co-Chair (if applicable)

Klinge, Carolyn M.

Committee Member

Klinge, Carolyn M.

Committee Member

Rai, Shesh N.

Committee Member

Damodaran, Chendil

Committee Member

Kalbfleisch, Theodore

Author's Keywords

arsenic; arsenic-induced skin cancer; miRNA, mRNA; HaCaT cells; chronic exposure


Arsenic is a naturally prevalent metalloid. Chronic arsenic ingestion through drinking water causes skin cancer. Arsenic-induced cancer mechanisms are not well defined. Epigenetic changes, including microRNA expression changes, might be playing a role. This dissertation investigates the impact of miRNA expression changes in arsenic-induced skin cancer. MiRNA expression was measure and compared using 3 different techniques, RTq-PCR, hybridization arrays and RNA-sequencing. MiRNAs differential expression in skin lesions was phenotype- and stage-related. Immortalized human keratinocytes (HaCaT) were transformed by chronic low arsenite exposure serving as a model for arsenic-induced skin carcinogenesis. Early changes in miRNAs and target mRNAs contribute to arsenic-induced carcinogenesis. Throughout the time course of arsenic exposure, dysregulation of cells’ growth and cancer-related pathways were identified. Comparisons between the miRNA profiles in lesions and cells predict some miRNAs may serve as biomarkers and/or therapeutic targets for arsenic-induced tumors. This dissertation provides strong evidences of epigenetic changes related to carcinogenesis in arsenic-induced skin cancer.