Background: Hedgehog signaling is known to be involved in both lung organogenesis and lung carcinogenesis. The aim of this study was to examine potential downstream targets of the hedgehog signaling pathway in non-small-cell lung cancer.
Methods: Protein expression of Bmi1, FoxF1, Nanog, and γ-catenin was examined by immunohistochemistry in 80 non-small-cell lung cancer samples. Correlations with the previously immunohistochemically recovered results for sonic hedgehog, Ptch1, Smo, Gli1, and Gli2 in the same cohort of tumors as well as the clinicopathological characteristics of the tumors were also evaluated.
Results: Bmi1 was expressed in 78/80 (97.5 %) cases of non-small-cell lung cancer and correlated with male gender and expression of Gli1. Positive expression of FoxF1 was found in 62/80 (77.5 %) cases. Expression of FoxF1 correlated with lymph node metastases, Bmi1, and hedgehog pathway activation. Overexpression of Nanog was also noted in 74/80 (92.5 %) tumors and correlated with Bmi1. Cytoplasmic accumulation of γ-catenin was observed in 85 % (68/80) of the tumors and correlated with the expression of Bmi1, FoxF1, and Nanog.
Conclusion: Several developmental pathways seem to be implicated in non-small-cell lung cancer. It is also suggested that Bmi1 and FoxF1 may cooperate with hedgehog signaling in non-small-cell lung carcinogenesis.