Comparison of Three Different Methods for Determining Cell Proliferation in Breast Cancer Cell Lines

Summary

This protocol describes the use of three different methods for analyzing cell proliferation in breast cancer cell lines. This includes the use of conventional cell counting, luminescence-based cell viability, and cell counting through the use of a cell imager. Each offers advantages for the reproducible measurement of cell proliferation.

Abstract

Measuring cell proliferation can be performed by a number of different methods, each with varying levels of sensitivity, reproducibility and compatibility with high-throughput formatting. This protocol describes the use of three different methods for measuring cell proliferation in vitro including conventional hemocytometer counting chamber, a luminescence-based assay that utilizes the change in the metabolic activity of viable cells as a measure of the relative number of cells, and a multi-mode cell imager that measures cell number using a counting algorithm. Each method presents its own advantages and disadvantages for the measurement of cell proliferation, including time, cost and high-throughput compatibility. This protocol demonstrates that each method could accurately measure cell proliferation over time, and was sensitive to detect growth at differing cellular densities. Additionally, measurement of cell proliferation using a cell imager was able to provide further information such as morphology, confluence and allowed for a continual monitoring of cell proliferation over time. In conclusion, each method is capable of measuring cell proliferation, but the chosen method is user-dependent.

Introduction

The tumor suppressor gene, p53, is an essential regulator of a number of cellular processes, including cell cycle arrest, apoptosis and senescence¹. It is responsible for maintaining genomic stability, and is therefore crucial for maintaining the balance of cell death and cell growth. Mutations in p53 are common in cancer and are the major cause of p53 inactivation leading to uncontrolled cancer cell proliferation². Interestingly, mutations in p53 only account for approximately 25% of breast cancers³, suggesting that other mechanisms are responsible for the loss of p53 function. The recently discovered p53 isoforms have been shown to b....

Protocol

1. Preparing Cells for Proliferation Assays

Note: Prepare the two cell lines in the same manner and seed in the same format for each method to be analyzed.

1. Grow MCF-7-LeGO and MCF-7-Δ40p53 ⁷ cells to 75-80% confluence in T 75 cm² tissue culture flasks using phenol-red free Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% fetal bovine serum (FBS), 200 mM L-glutamine, 2 µg/ml insulin and 1 µg/ml Puromycin at 37 °C with 5% CO₂. Handle cells in a sterile biosafety cabinet class II.
   Note: The amount of time it takes to grow the cells to confluence varies dep....

Results

To study different methods of measuring the proliferation of cultured cells, the cell proliferation of MCF-7-Δ40p53 transduced cells was compared to the non-transduced MCF-7-LeGO breast cancer cell line. The three methods that were compared – the conventional hemocytometer method, cell viability luminescence assay, and cell imaging analysis- are outlined in the schematic diagram (Figure 1). Each method has advantages and disadvantages to accurately measure cell counting o.......

Discussion

In this protocol three different methods of measuring cell proliferation in cultured cells were examined. Each method was capable of reproducible and accurate measurements of cell proliferation over 96 hr, and the results were comparable between each of the methods tested (Figure 2 and 3). Both the luminescence-based assay and cell imaging method produced the most robust results, showing linear increases in cell proliferation after 96 hr (Figure 2b, c). Additionally, cel.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Dulbecco's Modified Eagle Medium, no phenol-red	ThermoFisher Scientific	21063-045	Supplemented with 10% FBS, 200 mM L-glutamine, 2 µg/ml insulin and 1 µg/ml puromycin
L-glutamine solution (100x)	ThermoFisher Scientific	25030-081
Insulin solution human	Sigma-Aldrich	I9278-5ML
Fetal bovine serum (FBS)	Bovogen Biologicals	SFBS-F-500ml
Puromycin dihydrochloride	Sigma-Aldrich	P9620-10ML
0.5% trypsin-EDTA solution (10x)	ThermoFisher Scientific	15400-054	Dilute to 2x in DPBS
Dulbecco's Phosphate Buffered Saline (DPBS) (1x)	ThermoFisher Scientific	30028-02
Tissue culture flask, 75 cm2 growth area	Greiner Bio-One	658175
Scepter 2.0 Cell Counter	Merck Millipore		Automated cell counter
96 well multiwell plate, flat bottom	Nunc	167008
Improved Neubauer Hemocytometer	BOECO Germany	BOE 01
Olympus IX51 inverted microscope	Olympus	IX51
CellTiter-Glo 2.0 Assay	Promega	G9242	Luminescence-based assay
Cytation 3 Cell Imaging Multi-Mode Reader	BioTek		Plate reader for luminescence, fluorescence and brightfield cell imaging
Gen5 Data Analysis Software	BioTek	GEN5