Inhibition of colon carcinogenesis by 2-methoxy-5-amino-N-hydroxybenzamide, a novel derivative of mesalamine.
OBJECTIVE
Mesalamine has been reported to protect against inflammatory bowel disease-related colorectal cancer (CRC), but several drug-related issues have limited its use in chemopreventive programs. We evaluated the antineoplastic properties of mesalamine derivatives using in vitro and in vivo models of CRC.


METHODS
CRC cell proliferation and cell-cycle progression were evaluated by flow cytometry after exposure to mesalamine or mesalamine derivatives. Cyclins, cyclin-dependent kinases, and endoplasmic reticulum stress-related molecules were examined by immunoblotting. The in vivo antineoplastic effect of 2-methoxy-5-amino-N-hydroxybenzamide (2-14) was evaluated in a syngenic, CT26-derived xenograft mouse model of CRC and in the azoxymethane/dextran sulfate sodium-induced mouse model of colitis-associated CRC.


RESULTS
The mesalamine derivative 2-14 was 10-fold more potent than mesalamine in inhibiting CRC cell proliferation. After exposure to 2-14, cyclin D1 expression was reduced and G0/G1 phase cells accumulated. These events were preceded by activation of eukaryotic translation initiation factor 2-alpha kinase 3 (pancreatic endoplasmic reticulum eIF2alpha kinase), phosphorylation of eukaryotic translation initiation factor 2alpha, induction of activating transcription factor 4, and splicing of X-box binding protein 1 messenger RNA, events that define endoplasmic reticulum stress. Silencing of PERK restored cyclin D1 levels, allowing cells to overcome the cell-cycle block induced by 2-14. Mice injected with 2-14 developed fewer CRC xenograft-derived tumors. Moreover, 2-14 injection reduced the development of neoplastic lesions induced by azoxymethane and dextran sulfate sodium in mice.


CONCLUSIONS
The mesalamine derivative 2-14 inhibited CRC cell proliferation in vitro and prevented CRC progression in mouse models.
Stolfi
Carmine
C
Department of Internal Medicine, University of Tor Vergata, Rome, Italy.
Sarra
Massimiliano
M
Caruso
Roberta
R
Fantini
Massimo Claudio
MC
Fina
Daniele
D
Pellegrini
Roberto
R
Palmieri
Giampiero
G
Macdonald
Thomas T
TT
Pallone
Francesco
F
Monteleone
Giovanni
G
D000636:Aminosalicylic Acids / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D016588:Anticarcinogenic Agents / Q000737:chemistry / Q000494:pharmacology; D001397:Azoxymethane / Q000494:pharmacology; D001549:Benzamides / Q000737:chemistry / Q000494:pharmacology*; D002273:Carcinogens / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003092:Colitis / Q000188:drug therapy* / Q000473:pathology*; D003110:Colonic Neoplasms / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology*; D019938:Cyclin D1 / Q000378:metabolism; D016264:Dextran Sulfate / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000187:drug effects; D005434:Flow Cytometry; D016193:G1 Phase / Q000187:drug effects; D020868:Gene Silencing; D045325:HCT116 Cells; D006801:Humans; D019804:Mesalamine / Q000737:chemistry; D051379:Mice; D016192:Resting Phase, Cell Cycle / Q000187:drug effects; D023041:Xenograft Model Antitumor Assays; D019892:eIF-2 Kinase / Q000235:genetics
D000636:Aminosalicylic Acids; D016588:Anticarcinogenic Agents; D001397:Azoxymethane; D001549:Benzamides; D002273:Carcinogens; D019938:Cyclin D1; D016264:Dextran Sulfate; D019804:Mesalamine; D019892:eIF-2 Kinase; C547423:2-methoxy-5-amino-N-hydroxybenzamide; C530105:Ccnd1 protein, mouse