Molecular profiling of tumour budding implicates TGFβ-mediated epithelial-mesenchymal transition as a therapeutic target in oral squamous cell carcinoma.
Although tumour budding is an adverse prognostic factor for many cancer types, the molecular mechanisms governing this phenomenon are incompletely understood. Therefore, understanding the molecular basis of tumour budding may provide new therapeutic and diagnostic options. We employ digital image analysis to demonstrate that the number of tumour buds in cytokeratin-stained sections correlates with patients having lymph node metastases at diagnosis. The tumour bud count was also a predictor of overall survival, independent of TNM stage. Tumour buds and paired central tumour areas were subsequently collected from oral squamous cell carcinoma (OSCC) specimens, using laser capture microdissection, and examined with RNA sequencing and miRNA-qPCR arrays. Compared with cells from the central parts of the tumours, budding cells exhibited a particular gene expression signature, comprising factors involved in epithelial-mesenchymal transition (EMT) and activated TGFβ signalling. Transcription factors ZEB1 and PRRX1 were up-regulated concomitantly with the decreased expression of mesenchymal-epithelial (MET) transcription factors (eg OVOL1) in addition to Krüppel-like factors and Grainyhead-like factors. Moreover, miR-200 family members were down-regulated in budding tumour cells. We used immunohistochemistry to validate five markers of the EMT/MET process in 199 OSCC tumours, as well as in situ hybridization in 20 OSCC samples. Given the strong relationship between tumour budding and the development of lymph node metastases and an adverse prognosis, therapeutics based on inhibiting the activation of TGFβ signalling may prove useful in the treatment of OSCC.
Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Rigshospitalet and University of Copenhagen, Denmark.
D H
DH
Jensen
Department of Odontology, Faculty of Health, University of Copenhagen, Denmark.
E
E
Dabelsteen
Department of Oncology, Rigshospitalet and University of Copenhagen, Denmark.
L
L
Specht
Department of Pathology, Rigshospitalet and University of Copenhagen, Denmark.
A M K
AM
Fiehn
Department of Pathology, Rigshospitalet and University of Copenhagen, Denmark.
M H
MH
Therkildsen
Department of Genomic Medicine, Rigshospitalet and University of Copenhagen, Denmark.
L
L
Jønson
Department of Genomic Medicine, Rigshospitalet and University of Copenhagen, Denmark.
J
J
Vikesaa
Department of Genomic Medicine, Rigshospitalet and University of Copenhagen, Denmark.
F C
FC
Nielsen
Department of Otorhinolaryngology, Head and Neck Surgery and Audiology, Rigshospitalet and University of Copenhagen, Denmark.
C
C
von Buchwald
D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D018572:Disease-Free Survival; D015195:Drug Design; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods; D015972:Gene Expression Regulation, Neoplastic; D020022:Genetic Predisposition to Disease; D006258:Head and Neck Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D053208:Kaplan-Meier Estimate; D061346:Laser Capture Microdissection; D008207:Lymphatic Metastasis; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000401:mortality / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics; D000077195:Squamous Cell Carcinoma of Head and Neck; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000235:genetics* / Q000378:metabolism
D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D035683:MicroRNAs; D016212:Transforming Growth Factor beta
TGFβ; epithelial-mesenchymal transition; lymph node metastasis; oral squamous cell carcinoma; tumour budding