Polyamine catabolism in colorectal cancer cells following treatment with oxaliplatin, 5-fluorouracil and N1, N11 diethylnorspermine.
OBJECTIVE
Our previous studies showed that combined treatment of oxaliplatin and N(1), N(11) diethyl-norspermine (DENSPM) results in massive induction of spermidine/spermine N(1)-acetyltransferase (SSAT) mRNA and activity. Since oxaliplatin and 5-fluorouracil (5FU) are used clinically in treatment of colorectal cancers, this study examines the effect of adding DENSPM to oxaliplatin/5FU combination on SSAT and spermine oxidase (SMO) in HCT-116 cells.


METHODS
HCT-116 cells were treated with clinically relevant concentrations of drugs for 20 h followed by 24 h in drug free medium. SSAT and SMO mRNA and protein were assayed by QRT-PCR and Westerns respectively; polyamine pools were measured by HPLC. SSAT and SMO mRNA in tumor biopsies from patients with rectal cancer receiving oxaliplatin, capecitabine and radiation were measured by QRT-PCR.


RESULTS
Oxaliplatin + 5FU + DENSPM produced significantly higher levels of SSAT and SMO mRNA, protein and activity than those seen with oxaliplatin+5FU with a significant depletion of cellular spermine and spermidine pools. Oxaliplatin/DENSPM was superior to 5FU/DENSPM in SSAT induction but similar for SMO. Oxaliplatin + DENSPM revealed synergistic growth inhibition at >IC(50) concentrations and antagonism at <IC(50). SMO and SSAT induction occurred in 60 and 30% of the patient samples examined.


CONCLUSIONS
These studies demonstrated that combining DENSPM with oxaliplatin + 5FU provides an added benefit by aiming at the clinically relevant therapeutic target, the polyamine catabolism. Further, we show for the first time, that SMO and SSAT induction could be measured in tumor biopsies in patients receiving chemo-radiation. Optimization of treatment conditions in vivo should facilitate a clinical evaluation of the three drug combination.
Hector
Suzanne
S
Department of Medicine, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA.
Tummala
Ramakumar
R
Kisiel
Nicholas D
ND
Diegelman
Paula
P
Vujcic
Slavoljub
S
Clark
Kimberly
K
Fakih
Marwan
M
Kramer
Debora L
DL
Porter
Carl W
CW
Pendyala
Lakshmi
L
D000123:Acetyltransferases / Q000235:genetics / Q000378:metabolism*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology* / Q000627:therapeutic use; D015153:Blotting, Western; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D004357:Drug Synergism; D005472:Fluorouracil / Q000494:pharmacology / Q000627:therapeutic use; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D009944:Organoplatinum Compounds / Q000494:pharmacology / Q000627:therapeutic use; D000077150:Oxaliplatin; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000235:genetics / Q000378:metabolism*; D011073:Polyamines / Q000378:metabolism*; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology; D013096:Spermine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D000097667:Polyamine Oxidase; D000099228:Diamine N-Acetyltransferase
D000123:Acetyltransferases; D005472:Fluorouracil; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000587:Oxidoreductases Acting on CH-NH Group Donors; D011073:Polyamines; D013096:Spermine; D000097667:Polyamine Oxidase; D000099228:Diamine N-Acetyltransferase; C059685:N(1),N(11)-diethylnorspermine