Project description:Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis due to early dissemination and rapid growth. We here analyze gene expression profile of 23 clinical SCLC samples. EZH2 was found to be highly expressed in SCLC samples compared to 42 normal tissues including the normal lung, and other PRC2 members, SUZ12 and EED, were also highly expressed in SCLC. To obtain target genes of PRC2 in SCLC, H3K27me3 mark was mapped in three SCLC cell lines, Lu130, H209 and DMS53, and compared to normal small airway epithelial cells (SAEC). Whereas H3K27me3(+) genes in SAEC were significantly overlapped with PRC-target genes in ES cells (P=1.7x10-31), genes with H3K27me3 in SCLC cell lines but not in SAEC were not significantly overlapped with PRC-target genes in ES cells (P=0.64). These genes with H3K27me3 specifically in SCLC cell lines but not in SAEC showed decreased expression, not only in SCLC cell lines but also in clinical SCLCs, and showed enrichment of GO-terms such as plasma membrane (P=8.1x10-21) and cell adhesion (P=1.7x10-8). Introduction of JUB, a gene showing specific H3K27me3 modification and the strongest repression in the three SCLC cell lines, resulted in repression of cellular growth in DMS53. In clinical SCLC cases, lower JUB level correlated to shorter survival (P=0.002), or a set of PRC target genes (JUB, EPHB4) and marker genes of classic type SCLC (GRP, ASCL1) correlated to shorter survival (P=0.0001) and classified SCLC into two groups with distinct prognosis. Growth of SCLC cell lines was repressed when treated with 3-Deazaneplanocin A, an inhibitor against PRC2. It is suggested that high expression of PRC2 in SCLC contributed to repression of genes including non-PRC-target genes in ES cells, and that the gene repression may play a role in genesis of SCLC. Gene expression in 23 clinical SCLC samples, 42 normal tissue samples, 3 small cell lung cancer (SCLC) cell lines, and normal small airway epithelial cell (SAEC) was analyzed by Affymetrix arrays. This dataset is part of the TransQST collection.
Project description:Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis. Expression array analysis of 23 SCLC cases and 42 normal tissues revealed that EZH2 and other PRC2 members were highly expressed in SCLC. ChIP-seq for H3K27me3 suggested that genes with H3K27me3(+) in SCLC were extended not only to PRC2-target genes in ES cells but also to other target genes such as cellular adhesion-related genes. These H3K27me3(+) genes in SCLC were repressed significantly, and introduction of the most repressed gene JUB into SCLC cell line lead to growth inhibition. Shorter overall survival of clinical SCLC cases correlated to repression of JUB alone, or a set of four genes including H3K27me3(+) genes. Treatment with EZH2 inhibitors, DZNep and GSK126, resulted in growth repression of SCLC cell lines. High PRC2 expression was suggested to contribute to gene repression in SCLC, and may play a role in genesis of SCLC.
Project description:Small cell lung cancer (SCLC) is a subtype of lung cancer with poor prognosis due to early dissemination and rapid growth. We here analyze gene expression profile of 23 clinical SCLC samples. EZH2 was found to be highly expressed in SCLC samples compared to 42 normal tissues including the normal lung, and other PRC2 members, SUZ12 and EED, were also highly expressed in SCLC. To obtain target genes of PRC2 in SCLC, H3K27me3 mark was mapped in three SCLC cell lines, Lu130, H209 and DMS53, and compared to normal small airway epithelial cells (SAEC). Whereas H3K27me3(+) genes in SAEC were significantly overlapped with PRC-target genes in ES cells (P=1.7x10-31), genes with H3K27me3 in SCLC cell lines but not in SAEC were not significantly overlapped with PRC-target genes in ES cells (P=0.64). These genes with H3K27me3 specifically in SCLC cell lines but not in SAEC showed decreased expression, not only in SCLC cell lines but also in clinical SCLCs, and showed enrichment of GO-terms such as plasma membrane (P=8.1x10-21) and cell adhesion (P=1.7x10-8). Introduction of JUB, a gene showing specific H3K27me3 modification and the strongest repression in the three SCLC cell lines, resulted in repression of cellular growth in DMS53. In clinical SCLC cases, lower JUB level correlated to shorter survival (P=0.002), or a set of PRC target genes (JUB, EPHB4) and marker genes of classic type SCLC (GRP, ASCL1) correlated to shorter survival (P=0.0001) and classified SCLC into two groups with distinct prognosis. Growth of SCLC cell lines was repressed when treated with 3-Deazaneplanocin A, an inhibitor against PRC2. It is suggested that high expression of PRC2 in SCLC contributed to repression of genes including non-PRC-target genes in ES cells, and that the gene repression may play a role in genesis of SCLC.
Project description:SUMMARY Non-Hispanic Black/African American (Black/AA) men in the United States have disproportionally higher incidence and mortality rates of lung cancer compared to non-Hispanic White (NHW) men. Biological factors are believed to play critical roles in driving the disparities. Nevertheless, large-scale genomic studies fail to identify significant somatic differences in lung cancer driver genes contributing to the disparities. Elevated expression of protein arginine methyltransferases (PRMTs) correlating with poorer prognosis is observed in many cancer types. Here, we observed a higher PRMT6 expression in lung cancer of Black/AA men compared to NHW men. PRMT6 formed a heteromer complex with PRMT1 to catalyze arginine methylation of interleukin enhancer-binding factor 2 essential for cell proliferation. Disrupting PRMT1/PRMT6 heteromer complex by a competitive peptide reduced cell proliferation in non-small cell lung cancer cell lines and lung cancer patient-derived organoids. This work implicates that PRMT1/PRMT6 heteromer complex contributes to poorer lung cancer outcomes in Black/AA men vs. NHW men that could serve as a target to eliminate cancer health disparities.
Project description:Aberrant differentiation, driven by activation of normally silent tissue-specific genes, results in a switch of cell identity and often leads to cancer progression. The underlying genetic and epigenetic events are largely unexplored. Here, we report ectopic activation of the hepatobiliary-, intestinal- and neural-specific gene one cut homeobox 2 (ONECUT2) in various subtypes of lung cancer. ONECUT2 expression was associated with poor prognosis of RAS-driven lung adenocarcinoma. ONECUT2 overexpression promoted the malignant growth and invasion of A549 lung cancer cells in vitro, as well as xenograft tumorigenesis and bone metastases of these cells in vivo. Integrative transcriptomics and epigenomics analyses suggested that ONECUT2 promoted the trans-differentiation of lung cancer cells by preferentially targeting and regulating the activity of bivalent chromatin domains through modulating Polycomb Repressive Complex 2 (PRC2) occupancy. Our findings demonstrate that ONECUT2 is a lineage-specific and context-dependent oncogene in lung adenocarcinoma and suggest that ONECUT2 is a potential therapeutic target for these tumors.
Project description:The introduction of new therapies against particular genetic mutations in non-small cell lung cancer is a promising avenue for improving the survival of these patients, but the target population is small. There is a need to uncover new potential actionable genetic lesions and non-conventional cancer pathways, such as RNA editing, are worthy to explore. Herein we show that the adenosine-to-inosine editing enzyme ADAR1 undergoes gene amplification in non-small cancer cell lines and primary tumors in association with higher levels of the corresponding mRNA and protein. From a growth and invasion standpoint, the depletion of ADAR1 expression in amplified cells reduces their tumorigenic potential in cell culture and mice models, whereas its overexpression causes the opposite effects. From a functional perspective, ADAR1 overexpression enhances the editing frequencies of target transcripts such as NEIL1 and miR-381. In the clinical setting, patients with early stage lung cancer, but harboring ADAR1 gene amplification, show poor outcome. Overall, our results indicate a role for ADAR1 as a lung cancer oncogene undergoing gene amplification-associated activation that affect downstream RNA editing patterns and patient prognosis.
Project description:The progression of noninvasive ductal carcinoma in situ to invasive ductal carcinoma for patients with breast cancer results in a significantly poorer prognosis and is the precursor to metastatic disease. In this work, we have identified insulin-like growth factor–binding protein 2 (IGFBP2) as a potent adipocrine factor secreted by healthy breast adipocytes that acts as a barrier against invasive progression. In line with this role, adipocytes differentiated from patient-derived stromal cells were found to secrete IGFBP2, which significantly inhibited breast cancer invasion. This occurred through binding and sequestration of cancer-derived IGF-II. Moreover, depletion of IGF-II in invading cancer cells using small interfering RNAs or an IGF-II–neutralizing antibody ablated breast cancer invasion, highlighting the importance of IGF-II autocrine signaling for breast cancer invasive progression. Given the abundance of adipocytes in the healthy breast, this work exposes the important role they play in suppressing cancer progression and may help expound upon the link between increased mammary density and poorer prognosis.
Project description:Rho-GTPases are small GTP-binding proteins that contribute to the epithelial-to-mesenchymal transition by regulating several cellular processes including organization of the actin cytoskeleton, cell motility, transcription, and cell proliferation. Overexpression of RhoC-GTPases (RhoC) in breast cancer has been implicated in poor disease prognosis due to increased cancer cells invasion, migration, and motility, which warranted its consideration as a therapeutic target for inhibiting breast cancer metastasis. Using silencing RNA (siRNA) molecules to knockdown RhoC expression is a promising approach to inhibit breast cancer metastases.
Project description:Aberrant overexpression or activation of EGFR drives the development of non-small cell lung cancer (NSCLC) and acquired resistance to EGFR tyrosine kinase inhibitors (TKIs) by secondary EGFR mutations or c-MET amplification/activation remains as a major hurdle for NSCLC treatment. We previously identified WDR4 as a substrate adaptor of Cullin 4 ubiquitin ligase and an association of WDR4 high expression with poor prognosis of lung cancer. Here, using an unbiased ubiquitylome analysis, we uncover PTPN23, a component of the ESCRT complex, as a substrate of WDR4- based ubiquitin ligase. WDR4-mediated PTPN23 ubiquitination leads to its proteasomal degradation, thereby suppressing lysosome trafficking and degradation of wild type EGFR, EGFR mutant, and c-MET. Through this mechanism, WDR4 sustains EGFR and c-MET signaling to promote NSCLC proliferation, migration, invasion, stemness, and metastasis. Clinically, PTPN23 is downregulated in lung cancer and its low expression correlates with WDR4 high expression and poor prognosis. Targeting WDR4-mediated PTPN23 ubiquitination by a peptide that competes with PTPN23 for binding WDR4 promotes EGFR and c-MET degradation to block the growth and progression of EGFR TKI-resistant NSCLC. These findings identify a central role of WDR4/PTPN23 axis in EGFR and c-MET trafficking and a potential therapeutic target for treating EGFR TKI-resistant NSCLC.
Project description:Patient-derived tumor xenografts (PDXs) increasingly are being used as preclinical models to study human cancers and to evaluate novel therapeutics, as they reflect clinical cancers more closely than established tumor cell lines. With >100 PDXs established from resected non-small cell lung carcinomas (NSCLC), we reported previously that xenograftability correlates significantly with poorer patient prognosis. In this study, genomic, transcriptomic, and proteomic profiling of 36 PDXs showed greater similarity in somatic alterations between PDX and primary tumors than with cell lines, using publicly available data on the latter. A higher number of somatic alterations among 865 frequently altered genes in the PDX tumors was associated with better overall patient survival (HR=0.15, p=0.00015) compared to patients with corresponding PDXs characterized by a lower number of alterations; this was validated with the TCGA lung cancer patient dataset (HR=0.28, p=0.000022). These passenger-like alterations, identified in PDXs, link cell-cell signaling and adhesion to patient prognosis. Total RNAs from xenograftswere amplified by DASL kit and hybridized to Illumina HT12v4 chip