Abstract
Chronic arsenic exposure causes skin cancer, although the underlying molecular mechanisms are not well defined. Altered microRNA and mRNA expression likely play a pivotal role in carcinogenesis. Changes in genome-wide differential expression of miRNA and mRNA at 3 strategic time points upon chronic sodium arsenite (As3+) exposure were investigated in a well-validated HaCaT cell line model of arsenic-induced cutaneous squamous cell carcinoma (cSCC). Quadruplicate independent HaCaT cell cultures were exposed to 0 or 100 nM As3+ for up to 28-weeks (wk). Cell growth was monitored throughout the course of exposure and epithelial-mesenchymal transition (EMT) was examined employing immunoblot. Differentially expressed miRNA and mRNA profiles were generated at 7, 19, and 28-wk by RNA-seq, followed by identification of differentially expressed mRNA targets of differentially expressed miRNAs through expression pairing at each time point. Pathway analyses were performed for total differentially expressed mRNAs and for the miRNA targeted mRNAs at each time point. RNA-seq predictions were validated by immunoblot of selected target proteins. While the As3+-exposed cells grew slower initially, growth was equal to that of unexposed cells by 19-wk (transformation initiation), and exposed cells subsequently grew faster than passage-matched unexposed cells. As3+-exposed cells had undergone EMT at 28-wk. Pathway analyses demonstrate dysregulation of carcinogenesis-related pathways and networks in a complex coordinated manner at each time point. Immunoblot data largely corroborate RNA-seq predictions in the endoplasmic reticulum stress (ER stress) pathway. This study provides a detailed molecular picture of changes occurring during the arsenic-induced transformation of human keratinocytes.
Original language | English |
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Pages (from-to) | 2351-2365 |
Number of pages | 15 |
Journal | Archives of Toxicology |
Volume | 95 |
Issue number | 7 |
DOIs | |
State | Published - Jul 2021 |
Bibliographical note
Publisher Copyright:© 2021, The Author(s).
Funding
This study was supported by National Institute of Environmental Health Sciences grants R21ES023627 (JCS), R21ES030334 (JCS), R01ES027778 (JCS) and P30ES030283 (JCS). The authors thank Ms. Elizabeth Ann Hudson, Research Associate, Center for Genetics and Molecular Medicine, University of Louisville, Louisville, KY, USA, for her technical expertise with RNA-seq experiments. The authors also thank Dr. Walter H. Watson, Associate Professor, Departments of Pharmacology & Toxicology and Medicine, University of Louisville, Louisville, KY, USA, for his helpful critique and suggestions during the preparation of this manuscript.
Funders | Funder number |
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National Institute of Environmental Health Sciences (NIEHS) | R21ES030334, R21ES023627, P30ES030283, R01ES027778 |
University of Louisville |
Keywords
- Arsenic
- Differential gene expression
- Endoplasmic reticulum stress
- Passage matching
- Pathway analysis
- Skin carcinogenesis
ASJC Scopus subject areas
- Toxicology
- Health, Toxicology and Mutagenesis