Silver nanoparticles induces apoptosis of cancer stem cells in head and neck cancer

• Published in: Toxicology reports Vol. 12; pp. 10 - 17
• Main Authors: Kaur, Rupinder, Singh, Khushwant, Agarwal, Sonam, Masih, Marilyn, Chauhan, Anita, Gautam, Pramod Kumar
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.06.2024; Elsevier
• Subjects: AgNPs; Anti-cancer; Apoptosis; Cell Cycle; Cell viability; CSCs; AgNPs; Cell viability; Anti-cancer; Cell Cycle; CSCs; Apoptosis
• ISSN: 2214-7500; 2214-7500
• DOI: 10.1016/j.toxrep.2023.11.008

Several nano formulations of silver nanoparticles with bioconjugates, herbal extracts and anti-cancerous drug coating have been vividly studied to target cancer. Despite of such extensive studies, AgNPs (silver nanoparticles) have not reached the stage of clinical use. Out of all possible reasons for this failure, the unexplored effect on Cancer Stem Cell (CSC) population and mechanism of action of AgNPs, are the most plausible ones and are worked upon in this study. AgNPs were synthesized by chemical reduction method using sodium citrate and characterized by UV, FTIR, XRD and electron microscopy. CSC population was isolated from Cal33 cell line by MACS technique. MTT assay, trypan blue exclusion assay, Annexin V and PI based apoptosis assay and cell cycle assay were performed. The results showed that synthesized AgNPs have cytotoxic activity on all cancer cell lines tested with the IC50 value of a wide range (1.5–49.21 µg/ml for cell lines and 0.0643–0.1211 µg/ml for splenocytes and thymocytes). CSCs Cal33 showed higher resistance to AgNP treatment and arrest in G1/G0 phase upon cell cycle analysis. AgNPs as an anti-cancer agent although have great potential but is limited by its off-target effects on normal cells and less effective on cancer stem cells at lower concentrations. [Display omitted] •AgNPs displayed anti-tumor role on Head & neck cancer, Breast cancer and Prostate cancer cell lines.•Cal33 an oral squamous cell carcinoma cell line responded to lower doses of AgNPs.•Anti-tumor potential of AgNPs on CSCs derived from Cal33 cell line was observed, CSCs responded to higher IC50 doses.•Splenocyte and thymocyte harvested form mouse and HEK293T were used as control to observe off target effects.•The mechanism behind apoptosis of CSCs was observed to be cell cycle arrest in CSC Cal33 and Cal33 cells.