Phosphatidylinositol 3-Kinase/Protein Kinase B/Mammalian Target of the Rapamycin Pathway-Related Protein Expression in Lung Squamous Cell Carcinoma and Its Correlation with Lymph Node Metastasis

The targeted therapy of lung squamous cell carcinoma (LSCC), a pathological type of non-small-cell lung cancer, is relatively lacking by contrast with lung adenocarcinoma. The overexpression or inhibition of intracellular signaling pathways leads to disease. To evaluate genes for a targeted therapy in LSCC, we analyzed PI3K pathway components in LSCC tissues and found elevated PI3K levels in LSCC tissues compared with adjacent counterparts. A comparison of PI3K levels in tissues with and without metastasis revealed that the PI3K pathway activity was greatly increased in metastatic tissues. Our findings suggest that the metastasis of cancer cells in patients with LSCC is closely related to the overexpression of PI3K pathway components in cancer tissues. We performed in vitro cell culture experiments and found that inhibition of PI3K activity decreased proliferation and increased apoptosis in H520 cells, suggesting that PI3K pathway inhibition limits LSCC cell proliferation. We hypothesize that LSCC metastasis is related to the overexpression of PI3K pathway components and inhibiting this pathway may help reduce the risk of lymph node metastasis in LSCC patients.