Concurrent inhibition of NF-kappaB, cyclooxygenase-2, and epidermal growth factor receptor leads to greater anti-tumor activity in pancreatic cancer.
Inactivation of survival pathways such as NF-kappaB, cyclooxygenase (COX-2), or epidermal growth factor receptor (EGFR) signaling individually may not be sufficient for the treatment of advanced pancreatic cancer (PC) as suggested by recent clinical trials. 3,3'-Diindolylmethane (B-DIM) is an inhibitor of NF-kappaB and COX-2 and is a well-known chemopreventive agent. We hypothesized that the inhibition of NF-kappaB and COX-2 by B-DIM concurrently with the inhibition of EGFR by erlotinib will potentiate the anti-tumor effects of cytotoxic drug gemcitabine, which has been tested both in vitro and in vivo. Inhibition of viable cells in seven PC cell lines treated with B-DIM, erlotinib, or gemcitabine alone or their combinations was evaluated using 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Significant inhibition in cell viability was observed in PC cells expressing high levels of COX-2, EGFR, and NF-kappaB proteins. The observed inhibition was associated with an increase in apoptosis as assessed by ELISA. A significant down-regulation in the expression of COX-2, NF-kappaB, and EGFR in BxPC-3, COLO-357, and HPAC cells was observed, suggesting that simultaneous targeting of EGFR, NF-kappaB, and COX-2 is more effective than targeting either signaling pathway separately. Our in vitro results were further supported by in vivo studies showing that B-DIM in combination with erlotinib and gemcitabine was significantly more effective than individual agents. Based on our preclinical in vitro and in vivo results, we conclude that this multi-targeted combination could be developed for the treatment of PC patients whose tumors express high levels of COX-2, EGFR, and NF-kappaB.
Ali
Shadan
S
Division of Hematology/Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan 48201, USA.
Banerjee
Sanjeev
S
Schaffert
Jacqueline M
JM
El-Rayes
Bassel F
BF
Philip
Philip A
PA
Sarkar
Fazlul H
FH
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology*; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000494:pharmacology; D004195:Disease Models, Animal; D004357:Drug Synergism; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000069347:Erlotinib Hydrochloride; D005260:Female; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D051379:Mice; D016513:Mice, SCID; D016328:NF-kappa B / Q000037:antagonists & inhibitors* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D011799:Quinazolines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D016896:Treatment Outcome; D014410:Tumor Stem Cell Assay; D023041:Xenograft Model Antitumor Assays; D000093542:Gemcitabine
D000970:Antineoplastic Agents; D016861:Cyclooxygenase Inhibitors; D007211:Indoles; D016328:NF-kappa B; D011799:Quinazolines; D003841:Deoxycytidine; D000069347:Erlotinib Hydrochloride; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D066246:ErbB Receptors; C016392:3,3'-diindolylmethane; D000093542:Gemcitabine