Cell-line-specific stimulation of tumor cell aggressiveness by wound healing factors - a central role for STAT3.
BACKGROUND
Local recurrence is a major factor affecting survival after treatment for head and neck squamous cell carcinoma (HNSCC). It is possible that the normal processes involved in wound healing after surgical removal of a primary tumor can boost the regrowth of residual cancer cells, thereby contributing to the recurrent growth. In this work, we collected human wound fluids and used them to investigate the effect of wound healing factors on HNSCC cell lines in vitro.


METHODS
Wound fluids were collected from thyroidectomized patients diagnosed with benign disease and were included in assays of cell proliferation, migration, cell scattering, and invasion. The involvement of intracellular signaling pathways and membrane receptors were investigated by western blotting and the inclusion of specific inhibitors.


RESULTS
One out of four cell lines was greatly stimulated in proliferation, migration, cell scattering, and invasion by the addition of wound fluid as compared with addition of fetal bovine or human serum. These effects were accompanied by a sharp increase in activation of signal transducer and activator of transcription 3 (STAT3). Inhibition of STAT3 activation abolished the wound fluid response, showing that STAT3 plays an important role in the wound healing response. Several of the observed phenotypic changes were epithelial-to-mesenchymal transition (EMT)-like, but the appropriate changes were not seen in any of the EMT markers investigated. The involvement of c-Met or epidermal growth factor receptor family members was excluded, while the interleukin-6 receptor was found to be partly responsible for the activation of STAT3.


CONCLUSIONS
In conclusion, we found cell-line-specific effects of wound healing factors on HNSCC, setting the stage for therapy development and predictive opportunities.
Department of Oncology, Lund University, Lund, Sweden. Lars.Ekblad@med.lu.se
Lars
L
Ekblad
Gustaf
G
Lindgren
Emma
E
Persson
Elisabeth
E
Kjellén
Johan
J
Wennerberg
D001685:Biological Factors / Q000494:pharmacology*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D058750:Epithelial-Mesenchymal Transition / Q000187:drug effects; D045604:Extracellular Fluid / Q000502:physiology; D005122:Exudates and Transudates / Q000378:metabolism; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D018365:Neoplasm, Residual; D051058:Oncogene Protein v-akt / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000502:physiology; D014945:Wound Healing / Q000502:physiology*
D001685:Biological Factors; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; D051058:Oncogene Protein v-akt