Non-coding RNAs have an integral regulatory role in numerous functions related to lung cancer development. Here, we report identification of a novel lncRNA, termed TP53-inhibiting lncRNA (TILR), which was found to function as a constitutive negative regulator of p53 expression, including activation of downstream genes such as p21 and MDM2, and induction of apoptosis. A proteomic search for TILR-associated proteins revealed an association with PCBP2, while the mid-portion of TILR was found to be required for both PCBP2 and p53 mRNA binding.
View Article and Find Full Text PDFWe previously reported that ROR1 is a crucial downstream gene for the TTF-1/NKX2-1 lineage-survival oncogene in lung adenocarcinoma, while others have found altered expression of ROR1 in multiple cancer types. Accumulated evidence therefore indicates ROR1 as an attractive molecular target, though it has yet to be determined whether targeting Ror1 can inhibit tumor development and growth in vivo. To this end, genetically engineered mice carrying homozygously floxed Ror1 alleles and an SP-C promoter-driven human mutant EGFR transgene were generated.
View Article and Find Full Text PDFThe receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a transcriptional target of the lineage-survival oncogene NKX2-1/TTF-1 in lung adenocarcinomas. In addition to its kinase-dependent role, ROR1 functions as a scaffold protein to facilitate interaction between caveolin-1 (CAV1) and CAVIN1, and consequently maintains caveolae formation, which in turn sustains pro-survival signaling toward AKT from multiple receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR), MET (proto-oncogene, receptor tyrosine kinase), and IGF-IR (insulin-like growth factor receptor 1). Therefore, ROR1 is an attractive target for overcoming EGFR-TKI resistance due to various mechanisms such as EGFR T790M double mutation and bypass signaling from other RTKs.
View Article and Find Full Text PDFThe receptor tyrosine kinase-like orphan receptor 1 (ROR1) sustains prosurvival signalling directly downstream of the lineage-survival oncogene NKX2-1/TTF-1 in lung adenocarcinoma. Here we report an unanticipated function of this receptor tyrosine kinase (RTK) as a scaffold of cavin-1 and caveolin-1 (CAV1), two essential structural components of caveolae. This kinase-independent function of ROR1 facilitates the interactions of cavin-1 and CAV1 at the plasma membrane, thereby preventing the lysosomal degradation of CAV1.
View Article and Find Full Text PDFAccumulation of genetic and epigenetic changes alters regulation of a web of interconnected genes including microRNAs (miRNAs), which confer hallmark capabilities and characteristic cancer features. In this study, the miRNA and messenger RNA expression profiles of 126 non-small cell lung cancer specimens were analyzed, with special attention given to the diversity of lung adenocarcinomas. Of those, 76 adenocarcinomas were classified into two major subtypes, developing lung-like and adult lung-like, based on their distinctive miRNA expression profiles resembling those of either developing or adult lungs, respectively.
View Article and Find Full Text PDFThe occurrence of inactivating mutations in SWI/SNF chromatin-remodeling genes in common cancers has attracted a great deal of interest. However, mechanistic strategies to target tumor cells carrying such mutations are yet to be developed. This study proposes a synthetic-lethality therapy for treating cancers deficient in the SWI/SNF catalytic (ATPase) subunit, BRG1/SMARCA4.
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