Immunocytochemical staining showed that the expression of LKB1 was significantly decreased in adenocarcinoma and mucinous adenocarcinoma tissues, and this reduced expression induced the invasion and metastasis of CRC.
Alterations characteristic of adenocarcinoma (EGFR, KRAS, ALK receptor tyrosine kinase [ALK], ROS1, and serine/threonine kinase 11 [STK11]) were detected in the LCC-AD subgroup but not in LCC-SqCC, whereas squamous-lineage alterations (phosphatidylinositol-4,5-biphosphate 3-kinase catalytic subunit alpha [PIK3CA], SRY-box 2 [SOX2], fibroblast growth factor receptor 1 [FGFR1], and AKT1) were detected in the LCC-SqCC subgroup but not in the LCC-AD group.
Ion AmpliSeq Cancer Panel detected 9 potentially actionable variants in 29 adenocarcinomas that were wild type by the 8-gene panel testing (9 of 29, 31.0%) in the following genes: ERBB2 (3 of 29, 10.3%), STK11 (2 of 29, 6.8%), PTEN (2 of 29, 6.8%), FBXW7 (1 of 29, 3.4%), and BRAF G469A (1 of 29, 3.4%).
LKB1 protein expression and Smad1 phosphorylation analysis in a cohort of non-small cell lung cancer patients demonstrated a negative correlation predominantly in a subset enriched in adenocarcinomas.
Taken together, our findings define new personalized therapeutic strategies that may be rapidly translated into clinical use for the treatment of KRAS/LKB1-mutant adenocarcinomas and squamous cell tumors.
Multivariate analysis indicated that adenocarcinoma (P<0.05), lymph node metastasis (P<0.05), advanced TNM stage (P<0.001) and reduced expression of LKB1 (P<0.05) and Beclin1 (P<0.001) are all independent prognostic indicators for the survival of NSCLC patients.
For adenocarcinoma, remaining four epitypes were associated with unsupervised and supervised gene expression phenotypes, and differences in molecular features, including global hypomethylation, promoter hypermethylation, genomic instability, expression of proliferation-associated genes, and mutations in KRAS, TP53, KEAP1, SMARCA4, and STK11.
Whereas CUL2 mRNA expression levels of greater than 1.7 was predictive for major response (p = 0.02) in adeno- and squamous cell carcinoma, STK11 was predominantly response predictive for adenocarcinomas.
We sequenced the LKB1 gene in 22 lung cancer cell lines and 100 Japanese patients with lung cancer (including 81 adenocarcinomas, 14 squamous cell carcinomas and five other histological types) who had undergone curative pulmonary resection.
Genotype-phenotype analysis did not yield any significant differences between patients carrying mutations in LKB1/STK11 versus those without mutations, even with respect to primary biliary adenocarcinoma.
Acquired mutations in LKB1 are rarely observed in most sporadic tumor types except for adenocarcinomas of the lung where up to 50% harbor inactivating mutations.
The inactivation of Stk11 in 27% (6/22) of IPMNs versus 7% (4/56) of pancreatic adenocarcinomas suggests genetic disparities in the pathogenesis of these closely related neoplasms.
Somatic mutations of the STK11 gene were confirmed in 6 (55%) of the 11 mucinous MDAs and 1 (5%) of the 19 mucinous adenocarcinomas, but not in the 5 nonmucinous adenocarcinomas, the 15 squamous cell carcinomas, nor the 5 endocervical glands with gastric metaplasia.