title: Microgravity culture reduces apoptosis and increases the differentiation of a human colorectal carcinoma cell line.
abstract: Our hypothesis is that rotation increases apoptosis in standard tissue culture medium at shear stresses of greater than approximately 0.3 dyn/cm2. Human MIP-101 poorly differentiated colorectal carcinoma cells were cultured for 6 d in complete medium in monolayers, on Teflon-coated nonadherent surfaces (static three-dimensional [3D]) or in rotating 3D cultures either in microgravity in low-earth orbit (3D microg) or in unit gravity on the ground (3D 1g). Apoptosis (determined morphologically), proliferation (by MIB1 staining), and the expression of epidermal growth-factor receptor (EGF-R), TGF-alpha, or TGF-beta were assessed by immunohistochemistry, while the expression of the differentiation marker carcinoembryonic antigen (CEA) was assessed on Western blots. Over the course of 6 d, static 3D cultures displayed the highest rates of proliferation and lowest apoptosis. This was associated with high EGF-R, TGF-alpha, and TGF-beta expression which was greater than that of a monolayer culture. Both rotated 3D lg and 3D microg cultures displayed lower expression of EGF-R, TGF-alpha, or TGF-beta and proliferation than that of monolayer or static 3D cultures. However, rotated 3D microg displayed significantly less apoptosis and greater CEA expression than rotated 3D 1g cultures. When rotated cultures of MIP-101 cells were grown uncler static conditions for another 3 d, proliferation increased and apoptosis decreased. Thus, rotation appears to increase apoptosis and decrease proliferation, whereas static 3D cultures in either unit or microgravity have less apoptosis, and reduced rotation in microgravity increases CEA expression.
authors.affiliation: Gastrointestinal Oncology Research Laboratory, University of Pittsburgh Medical Center, Pensylvania 15213, USA. jessup@uthscsa.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Jessup
authors.forename: M
authors.initials: M
authors.lastname: Frantz
authors.forename: E
authors.initials: E
authors.lastname: Sonmez-Alpan
authors.forename: J
authors.initials: J
authors.lastname: Locker
authors.forename: K
authors.initials: K
authors.lastname: Skena
authors.forename: H
authors.initials: H
authors.lastname: Waller
authors.forename: P
authors.initials: P
authors.lastname: Battle
authors.forename: A
authors.initials: A
authors.lastname: Nachman
authors.lastname: Bhatti
authors.forename: M E
authors.initials: ME
authors.lastname: Weber
authors.forename: D A
authors.initials: DA
authors.lastname: Thomas
authors.forename: R L
authors.initials: RL
authors.lastname: Curbeam
authors.forename: T L
authors.initials: TL
authors.lastname: Baker
authors.forename: T J
authors.initials: TJ
authors.lastname: Goodwin
mesh_terms: D017209:Apoptosis; D019149:Bioreactors; D002272:Carcinoembryonic Antigen / Q000032:analysis; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000295:instrumentation / Q000379:methods; D002454:Cell Differentiation; D002455:Cell Division; D048429:Cell Size; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000473:pathology*; D003470:Culture Media; D066246:ErbB Receptors / Q000032:analysis; D006801:Humans; D012399:Rotation; D016211:Transforming Growth Factor alpha / Q000032:analysis; D016212:Transforming Growth Factor beta / Q000032:analysis; D014407:Tumor Cells, Cultured / Q000737:chemistry / Q000166:cytology*; D014893:Weightlessness
chemical_list: D002272:Carcinoembryonic Antigen; D003470:Culture Media; D016211:Transforming Growth Factor alpha; D016212:Transforming Growth Factor beta; D066246:ErbB Receptors