Nickel nanowires induced and reactive oxygen species mediated apoptosis in human pancreatic adenocarcinoma cells

Md. Zakir Hossain¹, Maurice G Kleve^2
1Applied Biosciences (Bionanotechnology Research), Department of Applied Science, ²Molecular Biotechnology and Microscopy Laboratory, Department of Biology, University of Arkansas at Little Rock, Little Rock, Arkansas, USA

Background: The ability to evade apoptosis is one of the key properties of cancer. The apoptogenic effect of nickel nanowires (Ni NWs) on cancer cell lines has never been adequately addressed. Due to the unique physicochemical characteristics of Ni NWs, we envision the development of a novel anticancer therapeutics specifically for pancreatic cancer. Thus, we investigated whether Ni NWs induce ROS-mediated apoptosis in human pancreatic adenocarcinoma (Panc-1) cells.
Methods: In this study Ni NWs were fabricated using the electrodeposition method. Synthesized Ni NWs were physically characterized by energy dispersive X-ray analysis, UV-Vis spectroscopy of NanoDrop 2000 (UV-Vis), magnetization study, scanning electron microscopy, and transmission electron microscopy. Assessment of morphological apoptotic characteristics by phase contrast microscopy (PCM), Ni-NWs-induced apoptosis staining with ethidium bromide (EB) and acridine orange (AO) followed by fluorescence microscopy (FM) was performed. For molecular biological and biochemical characterization, Panc-1 cell culture and cytotoxic effect of Ni NWs were determined by using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Quantitative apoptosis was analyzed by flow cytometry staining with propidium iodide through cell cycle arrest and generation of ROS using 2', 7'-dichlorofluorescein diacetate fluorescence intensity. In all experiments, Panc-1 cancer cells without any treatment were used as the negative controls.
Results: The intracellular uptake of Ni NWs through endocytosis by Panc-1 cells was observed by PCM. EB and AO staining of FM and MTT assay qualitatively and quantitatively confirmed the extent of apoptosis. Flow cytometric cell cycle arrest and ROS generation indicated Ni NWs as inducers of apoptotic cell death.
Conclusion: We investigated the role of Ni NWs as inducers of ROS-mediated apoptosis in Panc-1 cells. These results suggested that Ni NWs could be an effective apoptotic agent for Panc-1 cells and have good potential for further research into a clinical treatment selective for pancreatic cancer.

Keywords: Ni NWs, apoptosis, Panc-1, MTT assay, flow cytometry, cell cycle arrest, ROS