Efficacy verification and microscopic observations of an anticancer peptide, CB1a, on single lung cancer cell

• Published in: Biochimica et biophysica acta 2012-12, Vol.1818 (12), p.2927-2935
• Main Authors: Kao, Feng-Sheng, Pan, Yun-Ru, Hsu, Ray-Quen, Chen, Hueih-Min
• Format: Article
• Language: English
• Subjects: Anticancer peptide; Antineoplastic Agents - pharmacology; Apoptosis - drug effects; Atomic force microscopy; Cancer cell; CB1a; Cell Line, Tumor; Cell Membrane - drug effects; Cell Proliferation - drug effects; Humans; Insect Proteins - chemistry; Insect Proteins - pharmacology; Lung Neoplasms - drug therapy; Microscopy, Atomic Force; Peptide Fragments - pharmacology; single cell
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/j.bbamem.2012.07.019

In this work, we introduce a new customized anti-lung cancer peptide, CB1a, with IC50 of about 25.0±1.6μM on NCI-H460 lung cancer cells. Using a multi-cellular tumor spheroid (MCTS) model, results show that CB1a is potent in preventing the growth of lung cancer tumor-like growths in vitro. Additionally, atomic force microscopy (AFM) was used to examine cell surface damage of a single cancer. The mechanism for cell death under CB1a toxicity was verified as being largely due to cell surface damage. Moreover, with a treatment dosage of CB1a at 25μM, Young's module (E) shows that the elasticity and stiffness of cancer cell decreased with time such that the interaction time for a 50% reduction of E (IT50) was about 7.0min. This new single-cell toxicity investigation using IT50 under AFM assay can be used to separately verify drug efficacy in support of the traditional IC50 measurement in bulk solution. These results could be of special interest to researchers engaged in new drug development. In this work, two points are presented: (1) CB1a can be developed as potential anticancer drug and (2) a new approach indicates the efficacy of CB1a. Using a multi-cellular tumor spheroid (MCTS) model, results show that CB1a is potent in preventing the growth of lung cancer tumor-like growths in vitro (Fig. A). Additionally, atomic force microscopy (AFM) was used to examine cell surface damage of a single cancer. The mechanism for cell death under CB1a toxicity was verified as being largely due to cell surface damage. Moreover, with a treatment dosage of CB1a at 25μM, Young's module (E) shows that the elasticity and stiffness of cancer cell decreased with time such that the Interaction Time for a 50% reduction of E (IT50) was about 7.0min (Fig. B). This new single-cell toxicity investigation using IT50 under AFM assay can be used to separately verify drug efficacy in support of the traditional IC50 measurement in bulk solution. [Display omitted] ► We originally observed the surface damage of a single lung cancer cell by a custom peptide using AFM. ► We created a new term” IT50” for cell-killed evaluation. ► Cross verification of drug efficacy by measuring both IT50 and IC50 was proposed for the first time.