TY - JOUR
T1 - Cell cycle- and protein kinase C-specific effects of resiniferatoxin and resiniferonol 9,13,14-ortho-phenylacetate in intestinal epithelial cells
AU - Frey, Mark R.
AU - Clark, Jennifer A.
AU - Bateman, Nicholas W.
AU - Kazanietz, Marcelo G.
AU - Black, Adrian R.
AU - Black, Jennifer D.
N1 - Funding Information:
The authors wish to thank Laura Kunneva for expert technical assistance and Dr. Janice Sufrin for helpful discussions. This work was supported by NIH grants DK54909, DK60632, and CA16056 and by grants from the Mae Stone Goode Foundation and the Roswell Park Alliance Foundation.
PY - 2004/5/15
Y1 - 2004/5/15
N2 - We have previously reported that protein kinase C (PKC) signaling can trigger hallmark events of cell cycle withdrawal in intestinal epithelial cells, including downregulation of cyclin D1, induction of p21Waf1/Cip1, and activation of the growth suppressor function of pocket proteins. In the current study, we compared the cell cycle- and PKC-specific effects of the vanilloid resiniferatoxin (RTX), its parent diterpene resiniferonol 9,13,14-ortho-phenylacetate (ROPA), and the PKC agonist PMA in the IEC-18 non-transformed intestinal crypt cell line. ROPA and PMA were found to produce strikingly similar alterations in cell cycle progression and PKC activity in IEC-18 cells, although PMA was approximately 1000-fold more potent in producing these effects. Both agents induced a transient PKC-dependent blockade in G 1→S progression associated with transient downregulation of cyclin D1 and induction of p21Waf1/Cip1. In contrast, RTX produced a prolonged PKC-independent cell cycle arrest in G0/G1 phase which was maintained for longer than 24 h. This arrest was vanilloid receptor-independent and associated with prolonged downregulation of cyclin D1 mRNA and protein, with little effect on levels of p21Waf1/Cip1. Combined exposure to RTX and ROPA produced a sustained and complete cell cycle blockade in IEC-18 cells, associated with depletion of cyclin D1 and sustained enhancement of p21Waf1/Cip1 levels. PMA, ROPA, RTX and the RTX/ROPA combination were capable of activating ERK1/2 signaling in IEC-18 cells, albeit with different kinetics. In contrast, only PMA and ROPA activated JNK1/2 and p38 in this system. Notably, some preparations of commercially obtained RTX produced effects indistinguishable from those of the RTX/ROPA combination, suggesting that certain batches of the compound may contain significant amounts of ROPA (or another PKC agonist activity). Together, these data demonstrate that structurally related compounds can produce similar cell cycle-specific effects but through distinct mechanisms. In addition, they add to a growing body of evidence that vanilloids can have antiproliferative effects in a variety of cell types.
AB - We have previously reported that protein kinase C (PKC) signaling can trigger hallmark events of cell cycle withdrawal in intestinal epithelial cells, including downregulation of cyclin D1, induction of p21Waf1/Cip1, and activation of the growth suppressor function of pocket proteins. In the current study, we compared the cell cycle- and PKC-specific effects of the vanilloid resiniferatoxin (RTX), its parent diterpene resiniferonol 9,13,14-ortho-phenylacetate (ROPA), and the PKC agonist PMA in the IEC-18 non-transformed intestinal crypt cell line. ROPA and PMA were found to produce strikingly similar alterations in cell cycle progression and PKC activity in IEC-18 cells, although PMA was approximately 1000-fold more potent in producing these effects. Both agents induced a transient PKC-dependent blockade in G 1→S progression associated with transient downregulation of cyclin D1 and induction of p21Waf1/Cip1. In contrast, RTX produced a prolonged PKC-independent cell cycle arrest in G0/G1 phase which was maintained for longer than 24 h. This arrest was vanilloid receptor-independent and associated with prolonged downregulation of cyclin D1 mRNA and protein, with little effect on levels of p21Waf1/Cip1. Combined exposure to RTX and ROPA produced a sustained and complete cell cycle blockade in IEC-18 cells, associated with depletion of cyclin D1 and sustained enhancement of p21Waf1/Cip1 levels. PMA, ROPA, RTX and the RTX/ROPA combination were capable of activating ERK1/2 signaling in IEC-18 cells, albeit with different kinetics. In contrast, only PMA and ROPA activated JNK1/2 and p38 in this system. Notably, some preparations of commercially obtained RTX produced effects indistinguishable from those of the RTX/ROPA combination, suggesting that certain batches of the compound may contain significant amounts of ROPA (or another PKC agonist activity). Together, these data demonstrate that structurally related compounds can produce similar cell cycle-specific effects but through distinct mechanisms. In addition, they add to a growing body of evidence that vanilloids can have antiproliferative effects in a variety of cell types.
KW - BIM I
KW - Cell cycle
KW - PDBu
KW - PKC
KW - PMA
KW - Protein kinase C
KW - ROPA
KW - RTX
KW - Resiniferatoxin
KW - bisindolylmaleimide I
KW - phorbol 12,13-dibutyrate
KW - phorbol 12-myristate 13-acetate
KW - protein kinase C
KW - resiniferatoxin
KW - resiniferonol 9,13,14-ortho-phenylacetate
UR - http://www.scopus.com/inward/record.url?scp=2342655784&partnerID=8YFLogxK
U2 - 10.1016/j.bcp.2004.02.006
DO - 10.1016/j.bcp.2004.02.006
M3 - Article
C2 - 15130764
AN - SCOPUS:2342655784
SN - 0006-2952
VL - 67
SP - 1873
EP - 1886
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
IS - 10
ER -