Expression of Tumor Suppressors PTEN and TP53 in Isogenic Glioblastoma U-251MG Cells Affects Cellular Mechanical Properties — An AFM-Based Quantitative Investigation

Abstract

Glioblastoma is the most common and malign form of brain cancer that is highly resistant to therapy and particularly hard to cure since the blood-barrier is not very permeable to drugs. Moreover, a surgery is always highly risky. Thus, there is a real need to develop technique enabling accurate identification of potentially tumor cells at an early stage. It is getting well established that cancer cells are usually softer than their normal homologues and Atomic Force Microscopy (AFM) has proven itself over the last decade to be a tool of choice to characterize cells mechanical properties. Among the various AFM techniques, Force Spectroscopy (FS), especially Force Volume (FV) is the most commonly used. In the present study, AFM has been used to successfully characterize malignant and modified less malignant forms of glioblastoma U-251MG isogenic cells, using FV and Peak Force Tapping (PFT), a newly released AFM mode. Although both modes are quantitative and easy to use, PFT appears as the most relevant. Benefits and drawbacks of both techniques are discussed.

Atomic Force Microscopy for Protein Detection and Their Physicoсhemical Characterization

“…Among various models, Herz model has been widely applied to describe tip-surface contact omitting adhesion forces and to extract sample Young’s modulus but it has lots of limitations for proteins [ 86 ]. Herz model was developed for a semi-infinite elastic sphere of homogenous and isotropic materials, and proteins are nonhomogeneous and nonisotropic.…”

Асм-Исследования Клеточных Структур В Биомедицинских Исследованиях

“…Berquand и соавторы [15] представили результаты АСМ-характеристики злокачественных и модифицированных, менее злокачественных форм глиобластомы, U-251MG клеток. Глиобластома является наиболее распространенной и злокачественной формой рака мозга, которая обладает высокой устойчивостью к терапии, поскольку энцефалический барьер мало проницаем для лекарств.…”

“…Для исследования были использованы два режима force volume (FV) и Peak Force Tapping (PFT). Оба режима являются количественными и простыми в использовании, но авторы [15] считают, что PFT представляется наиболее релевантным. На основе данных, полученных в FV-и PFT-режимах, показано, что клетки глиобластомы U-251MG примерно в три раза более мягкие и в два раза более деформируемые, в отличие от их рекомбинантных аналогов.…”