Comparison of cancer cells cultured in 2D vs 3D reveals differences in AKT/mTOR/S6-kinase signaling and drug response

Abstract

Three-dimensional (3D) cancer models are used as preclinical systems to mimic physiologic drug responses. We provide evidence for strong changes of proliferation and metabolic capacity in three dimensions by systematically analyzing spheroids of colon cancer cell lines. Spheroids showed relative lower activities in the AKT, mammalian target of rapamycin (mTOR) and S6K (also known as RPS6KB1) signaling pathway compared to cells cultured in two dimensions. We identified spatial alterations in signaling, as the level of phosphorylated RPS6 decreased from the spheroid surface towards the center, which closely coordinated with the tumor areas around vessels in vivo. These 3D models displayed augmented antitumor responses to AKT-mTOR-S6K or mitogen-activated protein kinase (MAPK) pathway inhibition compared to those in 2D models. Inhibition of AKT-mTOR-S6K resulted in elevated ERK phosphorylation in 2D culture, whereas under these conditions, ERK signaling was reduced in spheroids. Inhibition of MEK1 (also known as MAP2K1) led to decreased AKT-mTOR-S6K signaling in 3D but not in 2D culture. These data indicate a distinct rewiring of signaling in 3D culture and during treatment. Detached tumor-cell clusters in vessels, in addition to circulating single tumor cells, play a putative role in metastasis in human cancers. Hence, the understanding of signaling in spheroids and the responses in the 3D models upon drug treatment might be beneficial for anti-cancer therapies.

A biomaterial screening approach reveals microenvironmental mechanisms of drug resistance

“…In our soft 3D environments, basal and drug-stimulated signaling were significantly suppressed, in agreement with other data in spheroids and on soft substrates 43–45 . JNK appears to be a broad adaptive response 46, 47 ; however, MLR identified MEK as the most significant driver of ECM-mediated resistance to sorafenib.…”

Bioprinting of Multiscaled Hepatic Lobules within a Highly Vascularized Construct

“…We found that the drug resistance or sensitivity between 2D and 3D differed due to dimensionality and the presence or absence of ECM and ECs. [ 51 ] Mix was inappropriate to measure hepatic toxicity due to the largest value of standard deviation (SD). Subsequently, as shown in Figure A, we obtained multiscaled hepatic lobes by layer‐by‐layer deposition of hepatic lobules.…”

Recent Advances in Microfluidic Platforms Applied in Cancer Metastasis: Circulating Tumor Cells' (CTCs) Isolation and Tumor‐On‐A‐Chip

“…To date, various kinds of in vitro and in vivo experimental models have been exploited to investigate the basic and applied researches on oncology . Among conventional tumor models, 2D monolayers are routinely utilized in culture of cancer cells on thermoplastics for metastatic study and drug screening due to the advantages of reproductivity, easy availability, low cost, and ease of operation …”

“…The 2D monolayer culture model cannot recapitulate the native tissue's 3D architecture, features of cancel cell dormancy, hypoxia, and antiapoptosis as well as cell–matrix and cell–cell interactions . As the 2D culture does not truly mimic 3D TME, cellular signaling and drug sensitivity of cancer cells cultured on 2D or 3D models are disparate . Furthermore, the shape and fate of cells cultured on 2D monolayer model are different from those living in native tissues, which is influential in a series of signal transduction, cellular functions (e.g., proliferation, differentiation, and apoptosis), response to external stimuli, and drug resistance .…”