Cell cycle pathway dysregulation in human keratinocytes during chronic exposure to low arsenite

Abstract

Background Arsenic is naturally prevalent in the earth’s crust and widely distributed in air and water. Chronic low arsenic exposure is associated with several cancers in vivo, including skin cancer, and with transformation in vitro of cell lines including immortalized human keratinocytes (HaCaT). Arsenic also is associated with cell cycle dysregulation at different exposure levels in multiple cell lines. In this work, we analyzed gene expression in HaCaT cells to gain an understanding of gene expression changes contributing to transformation at an early time point. Methods HaCaT cells were exposed to 0 or 100 nM NaAsO2 for 7 weeks. Total RNA was purified and analyzed by microarray hybridization. Differential expression with fold change ≥|1.5| and p-value ≤0.05 was determined using Partek Genomic Suite™ and pathway and network analyses using MetaCore™ software (FDR ≤0.05). Cell cycle analysis was performed using flow cytometry. Results 644 mRNAs were differentially expressed. Cell cycle/cell cycle regulation pathways predominated in the list of dysregulated pathways. Genes involved in replication origin licensing were enriched in the network. Cell cycle assay analysis showed an increase in G2/M compartment in arsenite-exposed cells. Conclusions Arsenite exposure induced differential gene expression indicating dysregulation of cell cycle control, which was confirmed by cell cycle analysis. The results suggest that cell cycle dysregulation is an early event in transformation manifested in cells unable to transit G2/M efficiently. Further study at later time points will reveal additional changes in gene expression related to transformation processes.

Dynamic alteration in miRNA and mRNA expression profiles at different stages of chronic arsenic exposure-induced carcinogenesis in a human cell culture model of skin cancer

“…4). This observation is consistent with the widely accepted hypothesis that cell cycle dysregulation is an early event in arsenic-induced carcinogenesis (Al-Eryani et al 2017 ; Hunt et al 2014 ; States 2015 ; Tam et al 2020 ; Zhou and Xi 2018 ). Interestingly, the nucleotide excision repair (NER) pathway is induced at 7-wk (Fig.…”

“…1 ) in agreement with data from other groups (Pi et al 2008 ; Sun et al 2009 ). The slower growth rates in As 3+ exposed cells at early stages of exposure could reflect the well-characterized cell cycle arrest/delay effects of As 3+ exposure (Al-Eryani et al 2017 ; States 2015 ; States et al 2002 ; Tam et al 2020 ). This inference is supported by the pathway analysis which shows a multitude of cell cycle related pathways being dysregulated at 7-wk (Fig.…”

“…showed that continuous exposure of HaCaT cells for 28-wk to a low level (100 nM) of sodium arsenite transformed these cells and resulted in an aggressive squamous cell carcinoma phenotype upon inoculation of nude mice (Pi et al 2008 ). Previous studies in our laboratory showed that chronic As 3+ exposure for 7-wk led to differential small RNA and mRNA expression (Al-Eryani et al 2017 ). HaCaT cells chronically exposed to 100 nM NaAsO 2 were observed to grow slower until 19–20-wk when transformation starts (Pi et al 2008 ; Sun et al 2009 ).…”

A tEMTing target? Clinical and experimental evidence for epithelial-mesenchymal transition in the progression of cutaneous squamous cell carcinoma (a scoping systematic review)

“…The acute and chronic toxicity of arsenite can be replicated in vitro by exposing HaCaT cells to arsenite (0.1–1 µM) for up to 28 weeks [ 124 , 131 ]. Al-Eryani et al [ 132 ] found a significant dysregulation of EMT and cell cycle genes as early as 7 weeks after exposure to arsenite. Banerjee et al [ 131 ] reported decreases in ZO-1, a tight junction protein, and increased Slug after 19 weeks.…”

Akt Regulated Phosphorylation of GSK-3β/Cyclin D1, p21 and p27 Contributes to Cell Proliferation Through Cell Cycle Progression From G1 to S/G2M Phase in Low-Dose Arsenite Exposed HaCat Cells

“…For example, Ouyang et al (2008) found that repeated NaAsO 2 exposure (2.5 μM, 8 weeks) could induce the increased anchorage independent growth capacity in HaCat cells. Al-Eryani et al (2017) reported that NaAsO 2 exposure (0.1 μM, 7 weeks) resulted in differential gene expression which indicated the dysregulation of cell cycle control. Liu et al (2015) proved that apart from the increase of cellular proliferation, low-dose As 2 O 3 (0.1 and 0.2 μM, 4 weeks) exposure could also induce the malignant transformation of HaCat cells such as epithelial-to-mesenchymal transition, matrix metalloproteinases activation, and anchorage-independent growth.…”