Organosulphur Compounds Induce Apoptosis and Cell Cycle Arrest in Cervical Cancer Cells via Downregulation of HPV E6 and E7 Oncogenes
Background:
The quest for strong, safe and cost-effective natural antiproliferative agents that could
reduce cancer has been the focus now a days. In this regard, the organosulfur compounds from garlic (Allium
sativum L.), like Diallyl Sulfide (DAS) and Diallyl Disulfide (DADS), have been shown to exhibit potent
antiproliferative and anticancer properties in many studies. However, the potential of these compounds against
viral oncoproteins in cervical cancer has not been fully elucidated yet.
Objective:
The objective of this study was to analyze the antiproliferative and apoptotic properties of DADS and
DAS in HPV16+ human cervical cancer Caski cell line.
Methods:
Caski (cervical cancer cells) were cultured and followed by the treatment of various concentrations of
organosulphur compounds (DADS and DAS), cell viability was measured by MTT assay. The apoptotic assay
was performed by DAPI and Hoechst3342 staining. Reactive Oxygen Species (ROS) was estimated by DCFDA
staining protocol. The distributions of cell cycle and apoptosis (FITC-Annexin V assay) were analyzed by flow
cytometry. Finally, gene expression analysis was performed via quantitative real time PCR.
Results:
Our results showed that DAS and DADS exerted a significant antiproliferative effect on Caski cells by
reducing the cell viability and inducing a dose-related increment in intracellular ROS production along with
apoptosis in Caski cells. DAS and DADS also induced cell cycle arrest in G0/G1 phase, which was supported by
the downregulation of cyclin D1 and CDK4 and upregulation of CDK inhibitors p21WAF1/CIP1 and p27KIP1
in Caski cells. Additionally, DAS and DADS lead to the downregulation of viral oncogene E6 and E7 and restoration
of p53 function.
Conclusion:
Thus, this study confirms the efficacy of both the organosulfur compounds DADS and DAS
against cervical cancer cells.
