Coexpression of Notch1 and NF-kappaB signaling pathway components in human cervical cancer progression.
OBJECTIVE
Features of deregulated Notch1 signaling and NF-kappaB activation have independently been reported in cervical cancers. Here, we have extended these observations and examined both these pathways simultaneously in human cervical cancer tissue. Further, we have investigated the potential cross-talk between these pathways in a human cervical cancer derived cell line CaSki, which mirrors features of Notch activation as in the majority of human cervical cancers.


METHODS
Cervical tissue samples were analyzed for the expression of Notch1, Jagged 1, Hes1, pAKT, NF-kappaB p50, NF-kappaB p65, IkappaB-alpha, Bcl-2, CyclinD1, Cdk9, c-Fos, and p53 by immunohistochemistry. A total of 352 samples were analyzed which included 69 normal cervical tissue, 132 preinvasive lesions and 151 squamous cell carcinomas of the uterine cervix. Dual immunofluorescent analysis was performed to evaluate the coexpression of Notch1 and NF-kappaB. Transcriptional reporter assays and xenografts were undertaken with CaSki cells.


RESULTS
Features of Notch1 activation as measured by intracellular Notch1, high levels of Jagged1, Hes1 and Cdk9 were paralleled by nuclear translocation of both NF-kappaB p50 and p65 with target gene expression (IkappaB-alpha, Bcl-2, and CyclinD1) in human cervical cancer sections. Reporter assays in CaSki cells are consistent with Notch being an upstream regulator of NF-kappaB. Further, the xenografts recreate key aspects of human cancer tissue.


CONCLUSIONS
Results from this study suggest that there is a co-activation of Notch1 and NF-kappaB signaling pathways at the cellular level in the majority of human cervical cancers, with Notch as an upstream regulator.
Ramdass
Bharathi
B
National Centre For Biological Sciences, Tata Institute of Fundamental Research, UAS-GKVK Campus, Bangalore-560 065, India.
Maliekal
Tessy T
TT
Lakshmi
S
S
Rehman
Michael
M
Rema
P
P
Nair
Pradip
P
Mukherjee
Geetashree
G
Reddy
B K M
BK
Krishna
Sudhir
S
Radhakrishna Pillai
M
M
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D008819:Mice, Nude; D016328:NF-kappa B / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis / Q000235:genetics; D051881:Receptor, Notch1 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014183:Transplantation, Heterologous; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis / Q000235:genetics; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002578:Uterine Cervical Dysplasia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology
D016328:NF-kappa B; C497761:NOTCH1 protein, human; D016760:Proto-Oncogene Proteins c-fos; D051881:Receptor, Notch1; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt