title: Co-targeting of Cyclooxygenase-2 and FoxM1 is a viable strategy in inducing anticancer effects in colorectal cancer cells.
abstract: BACKGROUND
  Cross-talk between deregulated signaling pathways in cancer cells causes uncontrolled growth and proliferation. These cancers cells become more aggressive and quickly develop resistance to therapy. Therefore targeting of these deregulated pathways simultaneously can result in efficient cell death of cancer cells. In this study we investigated co-expression of Cox-2 and FoxM1 in a cohort of colorectal carcinoma (CRC) samples and also examined whether inhibition of Cox-2 and FoxM1 simultaneously can lead to inhibition of cell viability and induction of apoptosis in colorectal cancer cell lines and in vivo xenografts.
  
  
  METHODS
  Protein expression of Cox-2 and FoxM1 was determined in a large cohort of 770 clinical CRC samples in a tissue micro-array format by immunohistochemistry. Cell death was measured using live dead assay. Apoptosis was measured by annexin V/PI dual staining. Immunoblotting was performed to examine the expression of proteins. Calcusyn software was utilized to estimate the synergistic doses using chou and Talalay method.
  
  
  RESULTS
  Co-expression of Cox-2 and FoxM1 was detected in 33.3 % (232/697) of CRC's and associated with an aggressive phenotype characterized by younger age (p = 0.0191), high proliferative index marker; Ki-67 (p = 0.004) and MMP-9 (p = 0.0116) as well as activation of AKT (p = 0.0214). In vitro, inhibition of FoxM1 and Cox-2 with pharmacological inhibitors; Thiostrepton and NS398 resulted in efficient down-regulation of FoxM1 and Cox-2 expression along with in-activation of AKT and inhibition of colony formation, invasion and migratory capability of CRC cells. In addition, there was also inhibition of cell viability and induction of apoptosis via the mitochondrial apoptotic pathway in CRC cell lines. Finally, treatment of CRC xenograft tumors in nude mice with combination of Cox-2 and FoxM1 inhibitors inhibited tumor growth significantly via down-regulation of Cox-2 and FoxM1 expression.
  
  
  CONCLUSIONS
  These findings demonstrate that co-expression of Cox-2 and FoxM1 might play a critical role in the pathogenesis of CRC. Therefore, targeting of these pathways simultaneously with sub toxic doses of pharmacological inhibitors can be a potential therapeutic approach for the treatment of this subset of CRC.
authors.affiliation: Human Cancer Genomic Research, Research Center, Riyadh, Saudi Arabia. amaqbool@kfshrc.edu.sa.
authors.forename: Maqbool
authors.initials: M
authors.lastname: Ahmed
authors.affiliation: Human Cancer Genomic Research, Research Center, Riyadh, Saudi Arabia. arajabali@kfshrc.edu.sa.
authors.forename: Azhar R
authors.initials: AR
authors.lastname: Hussain
authors.affiliation: Human Cancer Genomic Research, Research Center, Riyadh, Saudi Arabia. asiraj@kfshrc.edu.sa.
authors.forename: Abdul K
authors.initials: AK
authors.lastname: Siraj
authors.affiliation: Human Cancer Genomic Research, Research Center, Riyadh, Saudi Arabia. suddinkhan@gmail.com.
authors.forename: Shahab
authors.initials: S
authors.lastname: Uddin
authors.affiliation: Department of Surgery, Colorectal unit, Riyadh, Saudi Arabia. nsanea@kfshrc.edu.sa.
authors.forename: Nasser
authors.initials: N
authors.lastname: Al-Sanea
authors.affiliation: Department of Pathology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia. dayelf@kfshrc.edu.sa.
authors.forename: Fouad
authors.initials: F
authors.lastname: Al-Dayel
authors.affiliation: Department of Surgery, Security Forces Hospital, Riyadh, Saudi Arabia. malasseri@gmail.com.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al-Assiri
authors.affiliation: Human Cancer Genomic Research, Research Center, Riyadh, Saudi Arabia. bshaham@kfshrc.edu.sa.
authors.forename: Shaham
authors.initials: S
authors.lastname: Beg
authors.affiliation: Human Cancer Genomic Research, Research Center, Riyadh, Saudi Arabia. kkuraya@kfshrc.edu.sa.|Al-Faisal University, Riyadh, Saudi Arabia. kkuraya@kfshrc.edu.sa.
authors.forename: Khawla S
authors.initials: KS
authors.lastname: Al-Kuraya
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D005260:Female; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D009578:Nitrobenzenes / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D013883:Thiostrepton / Q000494:pharmacology; D047368:Tumor Burden; D023041:Xenograft Model Antitumor Assays
chemical_list: D000970:Antineoplastic Agents; D052246:Cyclooxygenase 2 Inhibitors; C107585:FOXM1 protein, human; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D051546:Cyclooxygenase 2; D013883:Thiostrepton