MicroRNA (miRNA) expression profiles for lung cancers were examined to investigate miRNA's involvement in lung carcinogenesis. miRNA microarray analysis identified statistical unique profiles, which could discriminate lung cancers from noncancerous lung tissues as well as molecular signatures that differ in tumor histology. miRNA expression profiles correlated with survival of lung adenocarcinomas, including those classified as disease stage I. High hsa-mir-155 and low hsa-let-7a-2 expression correlated with poor survival by univariate analysis as well as multivariate analysis for hsa-mir-155. The miRNA expression signature on outcome was confirmed by real-time RT-PCR analysis of precursor miRNAs and cross-validated with an independent set of adenocarcinomas. These results indicate that miRNA expression profiles are diagnostic and prognostic markers of lung cancer.

In the neurological mutant mouse reeler, the histological organization of the neocortex develops abnormally and essentially results in an inversion of the relative positions of the cortical layers. The reeler mutation, therefore, provides an insight into the molecular mechanisms underlying the formation of the cortical layers. We have generated a monoclonal antibody (CR-50) that probes a distinct allelic antigen present in wild-type but not in reeler mutant mice. CR-50 reacted specifically with Cajal-Retzius neurons, one of the first cortical neurons to differentiate in the neocortex, but whose functional role is not known. When dissociated cerebral cortical cells were incubated with CR-50 in reaggregation culture, the genotype-dependent histogenetic assembly of wild-type cortical cells resembled that of reeler mutants. These findings revealed that the selective expression of a distinct molecule on Cajal-Retzius neurons is critical for the normal lamination of cortical neurons in the mammalian neocortex.

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