A novel CXCR4 antagonist counteracts paradoxical generation of cisplatin-induced pro-metastatic niches in lung cancer.

Platinum-based chemotherapy remains widely used in advanced non-small cell lung cancer (NSCLC) despite experimental evidence of its potential to induce long-term detrimental effects, including the promotion of pro-metastatic microenvironments. In this study, we investigated the interconnected pathways underlying the promotion of cisplatin-induced metastases. In tumor-free mice, cisplatin treatment resulted in an expansion in the bone marrow of CCR2+CXCR4+Ly6Chigh inflammatory monocytes (IMs) and an increase in lung levels of stromal SDF-1, the CXCR4 ligand. In experimental lung metastasis assays, cisplatin-induced IMs promoted the extravasation of tumor cells and the expansion of CD133+CXCR…

Circulating mir-320a promotes immunosuppressive macrophages M2 phenotype associated with lung cancer risk

miRNAs play a central role in the complex signaling network of cancer cells with the tumor microenvironment. Little is known on the origin of circulating miRNAs and their relationship with the tumor microenvironment in lung cancer. Here, we focused on the cellular source and relative contribution of different cell types to circulating miRNAs composing our risk classifier of lung cancer using in vitro/in vivo models and clinical samples. A cell‐type specific expression pattern and topography of several miRNAs such as mir‐145 in fibroblasts, mir‐126 in endothelial cells, mir‐133a in skeletal muscle cells was observed in normal and lung cancer tissues. Granulocytes and platelets are the major …

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…

P2.01-017 Circulating miRNAs in Lung Cancer Are Associated to Pro-Tumorigenic and Immunosuppressive Microenvironment

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…

Methylation profile in tumor and sputum samples of lung cancer patients detected by spiral computed tomography: A nested case-control study

We evaluated the aberrant promoter methylation profile of a panel of 3 genes in DNA from tumor and sputum samples, in view of a complementary approach to spiral computed tomography (CT) for early diagnosis of lung cancer. The aberrant promoter methylation of RARbeta2, p16(INK4A) and RASSF1A genes was evaluated by methylation-specific PCR in tumor samples of 29 CT-detected lung cancer patients, of which 18 had tumor-sputum pairs available for the analysis, and in the sputum samples from 112 cancer-free heavy smokers enrolled in a spiral CT trial. In tumor samples from 29 spiral CT-detected patients, promoter hypermethylation was identified in 19/29 (65.5%) cases for RARbeta2, 12/29 (41.4%) f…

Abstract 4981: Circulating mir-320 promotes immunosuppressive macrophages M2 phenotype associated with lung cancer progression

Abstract INTRODUCTION miRNAs play a role in the complex network of signaling between cancer cells and tumor microenvironment. We previously reported the identification of diagnostic miRNA signatures (MSC) based on 24-miRNAs in plasma samples of lung cancer patients detected by low dose computed tomography (LDCT) screening. MATERIAL and METHODS To evaluate the potential origin of the miRNAs of the diagnostic signature, we analyzed their expression by real-time or digital PCR in both cells and conditioned medium (CM) from different cell types of the lung microenvironment as well as in plasma samples of heavy smokers and patients. Lung tissues and cell-blocks were analyzed by miRNAs in situ hy…

SDF-1/CXCR4 inhibition prevents paradoxical generation of cisplatin-induced pro-metastatic niches

AbstractPlatinum-based chemotherapy remains widely used in advanced non-small cell lung cancer (NSCLC) despite its ineffectiveness in long-term control of metastasis.Here, we uncover the interconnected pathways subtending cisplatin-induced metastasis promotion.We report that cisplatin treatment of tumor-free mice results in bone-marrow expansion of CCR2+CXCR4+Ly6Chigh inflammatory monocytes (IM) concomitantly with increased levels in the lungs of stromal SDF-1, the CXCR4 ligand. In experimental metastasis assays, cisplatin-induced IM favor tumor cells extravasation and expansion of CD133+CXCR4+ metastasis initiating cells (MICs), facilitating lung metastasis formation. At the primary tumor,…

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. …