LKB1 gene inactivation has recently been demonstrated in a subset of lung carcinoma and has been proven to trigger epithelial-mesenchymal transition in lung adenocarcinoma cells.
LKB1 status influences the molecular circuitry (Wnt/β-catenin pathway), cellular biology, and may serve as a potential therapeutic node in genetically defined subsets of lung cancer.
All together our results show that STK11ex1-2 mutations delineate an aggressive subtype of lung cancer for which a targeted treatment through STK11 inhibition might offer new opportunities.
As LKB1 is a target for mutational inactivation in lung cancer and was recently shown to regulate hepatic Crtc2/CREB transcriptional activity in mice, we now present evidence suggesting disruption of an LKB1/Crtc pathway in cancer.
Co-occurring genomic alterations, particularly in tumour suppressor genes such as TP53 and LKB1 (also known as STK11), have emerged as core determinants of the molecular and clinical heterogeneity of oncogene-driven lung cancer subgroups through their effects on both tumour cell-intrinsic and non-cell-autonomous cancer hallmarks.
Collectively, our results decipher the mechanism through which LKB1 deficiency promotes lung cancer progression and metastasis, and provide a mechanistic rationale for therapeutic attack of these processes.
Dual molecular targeted therapy for mTOR and PI3K may be a promising therapeutic strategy in the specific population of patients with lung cancer with LKB1 loss.
Expression profiling in human lung cancer cell lines and mouse lung tumours identified a variety of metastasis-promoting genes, such as NEDD9, VEGFC and CD24, as targets of LKB1 repression in lung cancer.
Further, CP alone or in combination with rapamycin strongly inhibited the in vitro and in vivo growth of tumors harboring mutations in KEAP1 or both KEAP1 and LKB1 that are frequently observed in lung cancer.
Furthermore, our results give some insights into the understanding of how LKB1 inactivation contributes to lung carcinogenesis and emphasizes the central role played by LKB1 in lung cancer development.
Growth and molecular profile of lung cancer cells expressing ectopic LKB1: down-regulation of the phosphatidylinositol 3'-phosphate kinase/PTEN pathway.
High-throughput RNA interference screens in lung cancer cell lines from genetically engineered mouse models driven by activated KRAS with or without coincident Lkb1 deletion led to the identification of Dtymk, encoding deoxythymidylate kinase (DTYMK), which catalyzes dTTP biosynthesis, as synthetically lethal with Lkb1 deficiency in mouse and human lung cancer lines.
However, most of recent studies in LKB1 gene status only focus on point mutations and small deletion, and thus may underestimate the actual frequency of LKB1 genetic alteration in lung cancer.