Jeff Johnson1, Zonggao Shi1, Yueying Liu1, M Sharon Stack2. 1. Department of Chemistry and Biochemistry, University of Notre Dame, South Bend, IN 46617, United States; Harper Cancer Research Institute, University of Notre Dame, South Bend, IN 46617, United States. 2. Department of Chemistry and Biochemistry, University of Notre Dame, South Bend, IN 46617, United States; Harper Cancer Research Institute, University of Notre Dame, South Bend, IN 46617, United States. Electronic address: sstack@nd.edu.
Abstract
BACKGROUND: Oral squamous cell carcinoma (OSCC) is diagnosed in 640,000 patients yearly with a poor (50%) 5-year survival rate that has not changed appreciably in decades. PAITENTS AND METHODS: To investigate molecular changes that drive OSCC progression, cDNA microarray analysis was performed using human OSCC cells that form aggressive poorly differentiated tumors (SCC25-PD) in a murine orthotopic xenograft model compared to cells that produce well-differentiated tumors (SCC25-WD). RESULTS: As this analysis revealed that 59 upregulated genes were NF-κB target genes, the role of NF-κB activation in alteration of the transcriptional profile was evaluated. The mRNA and protein upregulation of a panel NF-κB target genes was validated by real-time qPCR and immunohistochemistry. Additionally, nuclear translocation of RelA was greatly increased in SCC25-PD, increased nuclear RelA was observed in oral tumors initiated with SCC25-PD compared with tumors initiated by SCC25-WD, and nuclear RelA correlated with stage of disease on two human OSCC tissue microarrays. Treatment of SCC25-PD cells with the IKKβ-inhibitor sc-514, that effectively prevents RelA phosphorylation on Ser 536, reversed nuclear-translocation of RelA and strongly inhibited NF-κB gene activation. Furthermore, blocking the phosphorylation of RelA using the MSK1/2 inhibitor SB 747651A significantly reduced the mRNA upregulation of a subset of target genes. Treatment with sc-514 or SB747651A markedly diminished cellular invasiveness. CONCLUSIONS: These studies support a model wherein NF-κB is constitutively active in aggressive OSCC, while blocking the NF-κB pathway reduces NF-κB target gene upregulation and cellular invasiveness.
BACKGROUND:Oral squamous cell carcinoma (OSCC) is diagnosed in 640,000 patients yearly with a poor (50%) 5-year survival rate that has not changed appreciably in decades. PAITENTS AND METHODS: To investigate molecular changes that drive OSCC progression, cDNA microarray analysis was performed using human OSCC cells that form aggressive poorly differentiated tumors (SCC25-PD) in a murine orthotopic xenograft model compared to cells that produce well-differentiated tumors (SCC25-WD). RESULTS: As this analysis revealed that 59 upregulated genes were NF-κB target genes, the role of NF-κB activation in alteration of the transcriptional profile was evaluated. The mRNA and protein upregulation of a panel NF-κB target genes was validated by real-time qPCR and immunohistochemistry. Additionally, nuclear translocation of RelA was greatly increased in SCC25-PD, increased nuclear RelA was observed in oral tumors initiated with SCC25-PD compared with tumors initiated by SCC25-WD, and nuclear RelA correlated with stage of disease on two human OSCC tissue microarrays. Treatment of SCC25-PD cells with the IKKβ-inhibitor sc-514, that effectively prevents RelA phosphorylation on Ser 536, reversed nuclear-translocation of RelA and strongly inhibited NF-κB gene activation. Furthermore, blocking the phosphorylation of RelA using the MSK1/2 inhibitor SB 747651A significantly reduced the mRNA upregulation of a subset of target genes. Treatment with sc-514 or SB747651A markedly diminished cellular invasiveness. CONCLUSIONS: These studies support a model wherein NF-κB is constitutively active in aggressive OSCC, while blocking the NF-κB pathway reduces NF-κB target gene upregulation and cellular invasiveness.
Authors: Shaista Naqvi; Andrew Macdonald; Claire E McCoy; Joanne Darragh; Alastair D Reith; J Simon C Arthur Journal: Biochem J Date: 2012-01-01 Impact factor: 3.857
Authors: Isaac K Sundar; Sangwoon Chung; Jae-Woong Hwang; John D Lapek; Michael Bulger; Alan E Friedman; Hongwei Yao; James R Davie; Irfan Rahman Journal: PLoS One Date: 2012-02-01 Impact factor: 3.240
Authors: Jeff J Johnson; Daniel L Miller; Rong Jiang; Yueying Liu; Zonggao Shi; Laura Tarwater; Russell Williams; Rashna Balsara; Edward R Sauter; M Sharon Stack Journal: J Biol Chem Date: 2016-02-02 Impact factor: 5.157