Abstract 3940: Inactivation of the PARD3 gene is a recurrent event in lung squamous cell carcinomas and affects STAT3 activity and tumor invasiveness
Abstract Correct apicobasal polarization and intercellular adhesions are essential for the appropriate development of normal epithelia. Here, we investigated the contribution of the partitioning defective 3 gene, PARD3, to the carcinogenesis of lung squamous cell carcinomas (LSCCs). Tumor-specific PARD3 alterations were found in eight per cent of the tumors, placing PARD3 among the most common tumor suppressor genes in LSCC. Some PAR3 mutant proteins prevented the formation of contacts between neighboring cells, i.e. had reduced ability to form tight junctions and actin-based protrusions. This affected subsequent downstream signaling, i.e. binding to aPKC and activation of RAC1. Further, we…
PARD3 Inactivation in Lung Squamous Cell Carcinomas Impairs STAT3 and Promotes Malignant Invasion.
Abstract Correct apicobasal polarization and intercellular adhesions are essential for the appropriate development of normal epithelia. Here, we investigated the contribution of the cell polarity regulator PARD3 to the development of lung squamous cell carcinomas (LSCC). Tumor-specific PARD3 alterations were found in 8% of LSCCs examined, placing PARD3 among the most common tumor suppressor genes in this malignancy. Most PAR3-mutant proteins exhibited a relative reduction in the ability to mediate formation of tight junctions and actin-based protrusions, bind atypical protein kinase C, activate RAC1, and activate STAT3 at cell confluence. Thus, PARD3 alterations prevented the formation of c…
Abstract 5379: Recurrent inactivation of PARD3, a polarity-related gene, in squamous cell carcinomas of the lung.
Abstract In spite of the recent advances in cancer genomics, the genetics underlying the development of lung squamous cell carcinomas (SCC) is still poorly understood. Here, we investigated the contribution of the cell polarity-related gene, PARD3, to lung SCC carcinogenesis. First, we tested for PARD3 alterations in lung cancer cell lines from various histopathological types. The analysis confirmed an intragenic deletion at the H157 cells and unveiled biallelic mutations in another cell line. Both cell lines are SCCs, which circumscribed PARD3 alterations to this lung cancer type. Next, we extended the genetic screening, which included the determination of mutations and of intragenic delet…
Genomic Profiling of Patient-Derived Xenografts for Lung Cancer Identifies B2M Inactivation Impairing Immunorecognition
Abstract Purpose: We aimed to maximize the performance of detecting genetic alterations in lung cancer using high-throughput sequencing for patient-derived xenografts (PDXs). Experimental Design: We undertook an integrated RNA and whole-exome sequencing of 14 PDXs. We focused on the genetic and functional analysis of β2-microglobulin (B2M), a component of the HLA class-I complex. Results: We identified alterations in genes involved in various functions, such as B2M involved in immunosurveillance. We extended the mutational analysis of B2M to about 230 lung cancers. Five percent of the lung cancers carried somatic mutations, most of which impaired the correct formation of the HLA-I complex. …