Comparison of cancer cells in 2D vs 3D culture reveals differences in AKT-mTOR-S6K signaling and drug responses.
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 anti-tumor 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.
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Angelika
A
Riedl
Clinical Institute of Pathology, Medical University of Vienna, Währinger Gürtel 18-20, Vienna A-1090, Austria.|Ludwig Boltzmann Institute for Cancer Research, Währinger Strasse 13A, Vienna 1090, Austria.
Michaela
M
Schlederer
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Karoline
K
Pudelko
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Mira
M
Stadler
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Stefanie
S
Walter
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Daniela
D
Unterleuthner
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Christine
C
Unger
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Nina
N
Kramer
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria.
Markus
M
Hengstschläger
Clinical Institute of Pathology, Medical University of Vienna, Währinger Gürtel 18-20, Vienna A-1090, Austria.|Ludwig Boltzmann Institute for Cancer Research, Währinger Strasse 13A, Vienna 1090, Austria.|Unit of Pathology of Laboratory Animals (UPLA), University of Veterinary Medicine Vienna, Vienna 1210, Austria.
Lukas
L
Kenner
Institute of Cell Biology, Histology and Embryology, Medical University of Graz, Harrachgasse 21, Graz 8010, Austria.
Dagmar
D
Pfeiffer
Clinical Institute of Pathology, Medical University of Vienna, Währinger Gürtel 18-20, Vienna A-1090, Austria.
Georg
G
Krupitza
Institute of Medical Genetics, Medical University of Vienna, Währinger Straße 10, Vienna A-1090, Austria helmut.dolznig@meduniwien.ac.at.
Helmut
0000-0002-6063-3585
H
Dolznig
D018929:Cell Culture Techniques / Q000379:methods*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D048430:Cell Shape / Q000187:drug effects; D003110:Colonic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D010641:Phenotype; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D038762:Ribosomal Protein S6 Kinases, 70-kDa / Q000378:metabolism*; D015398:Signal Transduction; D018874:Spheroids, Cellular / Q000378:metabolism / Q000473:pathology; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
D047428:Protein Kinase Inhibitors; C546842:MTOR protein, human; D051057:Proto-Oncogene Proteins c-akt; D038762:Ribosomal Protein S6 Kinases, 70-kDa; D058570:TOR Serine-Threonine Kinases
AKT–mTOR–S6K signaling; Drug response; MAPK signaling; Spheroid