The relevance of using 3D cell cultures, in addition to 2D monolayer cultures, when evaluating breast cancer drug sensitivity and resistance

Abstract

Solid tumours naturally grow in 3D wherein the spatial arrangement of cells affects how they interact with each other. This suggests that 3D cell culture may mimic the natural in vivo setting better than traditional monolayer (2D) cell culture, where cells are grown attached to plastic. Here, using HER2-positive breast cancer cell lines as models (BT474, HCC1954, EFM192A), the effects of culturing cells in 3D using the poly-HEMA method compared to 2D cultures were assessed in terms of cellular viability, response/resistance to anti-cancer drugs, protein expression and enzyme activity. Scanning electron microscopy showed the morphology of cells in 3D to be substantially different to those cultured in 2D. Cell viability in 3D cells was substantially lower than that of cells in 2D cultures, while 3D cultures were more resistant to the effects of HER-targeted (neratinib) and classical chemotherapy (docetaxel) drugs. Expression of proteins involved in cell survival, transporters associated with drug resistance and drug targets were increased in 3D cultures. Finally, activity of drug metabolising enzyme CYP3A4 was substantially increased in 3D compared to 2D cultures. Together this data indicates that the biological information represented by 3D and 2D cell cultures is substantially different i.e. 3D cell cultures demonstrate higher innate resistance to anti-cancer drugs compared to 2D cultures, which may be facilitated by the altered receptor proteins, drug transporters and metabolising enzyme activity. This highlights the importance of considering 3D in addition to 2D culture methods in pre-clinical studies of both newer targeted and more traditional anti-cancer drugs.

Galectin-3, a Druggable Vulnerability for KRAS-Addicted Cancers

“…While αvβ3 might drive KRAS independence in 2D by activating Akt in a manner that circumvents KRAS, we focus primarily on 3D growth conditions that mimic the in vivo tumor growth environment required for invasion and metastasis [31]. As such, we believe that the growth advantage imparted by αvβ3/KRAS in 3D can be explained by their ability to promote Akt activity that drives both macropinocytosis and redox balance, features that may be less critical for cells growing in a 2D monolayer with media containing full serum.…”

Electron microscopic analysis of different cell types in human pancreatic cancer spheres

“…Subsequently, these spheres grow and form irregular, oblong to club-shaped floating colonies. There are several reports of the electron microscopic analysis of cancer spheres or spheroids, involving the hanging-drop method, culture on a scaffold, or culture in low-attachment plates (20,21). SEM images of PANC-1 cells in hanging-drop experiments show a ruffled surface and lightly packed cells with deep pore-like structures (22).…”

Stemness in Cancer: Stem Cells, Cancer Stem Cells, and Their Microenvironment

“…Cells grown in 3D matrices have different gene signatures and show a better capacity to resist chemotherapeutic agents [199, 200]. The development of 3D organoid culture systems will help to understand how cell hierarchies emerge from original CSCs.…”