Remodeling of tannic acid crosslinked collagen type I induces apoptosis in ER+ breast cancer cells.
BACKGROUND
The naturally-occurring phytochemical tannic acid (TA) has anticancer properties. We have demonstrated that estrogen receptor-positive (ER+) breast cancer cells are more sensitive to effects of TA than triple-negative breast cancer cells and normal breast epithelial cells. In the present study, cells were grown on TA-crosslinked collagen beads. Growing cells remodel collagen and release TA, which affects attached cells.


METHODS
The ER+ breast cancer cell line MCF7 and the normal breast epithelial cell line MCF10A were grown on TA-crosslinked collagen beads in roller bottles. Concentrations of TA in conditioned media were determined. Induced apoptosis was imaged and quantified. Caspase gene expression was calculated by real-time polymerase chain reaction (PCR).


RESULTS
Both cell lines attached and grew on TA-crosslinked collagen beads where they remodeled collagen and released TA into surrounding medium. Released TA induced caspase-mediated apoptosis.


CONCLUSIONS
TA induced apoptosis in a concentration-dependent manner, with ER+ MCF7 cells displaying more sensitivity to effects of TA.
Department of Biological Sciences, Clemson University, Clemson, SC, U.S.A.
Terrika A
TA
Ngobili
Department of Bioengineering, Clemson University, Clemson, SC, U.S.A.
Hiral
H
Shah
Institute for Biological Interfaces of Engineering, Clemson University, Clemson, SC, U.S.A.
Jang Pyo
JP
Park
Institute for Biological Interfaces of Engineering, Clemson University, Clemson, SC, U.S.A.
Kerri W
KW
Kwist
Department of Bioengineering, Clemson University, Clemson, SC, U.S.A.
Beau
B
Inskeep
Department of Bioengineering, Clemson University, Clemson, SC, U.S.A. Institute for Biological Interfaces of Engineering, Clemson University, Clemson, SC, U.S.A Department of Chemical Engineering, Kansas State University, Manhattan, KS, U.S.A.
Karen J L
KJ
Burg
Institute for Biological Interfaces of Engineering, Clemson University, Clemson, SC, U.S.A brbooth@clemson.edu.
Brian W
BW
Booth
D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000737:chemistry / Q000473:pathology*; D020169:Caspases / Q000502:physiology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D024042:Collagen Type I / Q000494:pharmacology*; D005260:Female; D006801:Humans; D011960:Receptors, Estrogen / Q000032:analysis; D013634:Tannins / Q000494:pharmacology*; D023822:Tissue Engineering
D024042:Collagen Type I; D011960:Receptors, Estrogen; D013634:Tannins; D020169:Caspases
Apoptosis; breast cancer; tannic acid; tissue engineering