Mutation of the gene PARK2, which encodes an E3 ubiquitin ligase, is the most common cause of early-onset Parkinson's disease. In a search for multisite tumor suppressors, we identified PARK2 as a ...frequently targeted gene on chromosome 6q25.2-q27 in cancer. Here we describe inactivating somatic mutations and frequent intragenic deletions of PARK2 in human malignancies. The PARK2 mutations in cancer occur in the same domains, and sometimes at the same residues, as the germline mutations causing familial Parkinson's disease. Cancer-specific mutations abrogate the growth-suppressive effects of the PARK2 protein. PARK2 mutations in cancer decrease PARK2's E3 ligase activity, compromising its ability to ubiquitinate cyclin E and resulting in mitotic instability. These data strongly point to PARK2 as a tumor suppressor on 6q25.2-q27. Thus, PARK2, a gene that causes neuronal dysfunction when mutated in the germline, may instead contribute to oncogenesis when altered in non-neuronal somatic cells.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Tyrosine phosphorylation plays a critical role in regulating cellular function and is a central feature in signaling cascades involved in oncogenesis. The regulation of tyrosine phosphorylation is ...coordinately controlled by kinases and phosphatases (PTPs). Whereas activation of tyrosine kinases has been shown to play vital roles in tumor development, the role of PTPs is much less well defined. Here, we show that the receptor protein tyrosine phosphatase delta (PTPRD) is frequently inactivated in glioblastoma multiforme (GBM), a deadly primary neoplasm of the brain. PTPRD is a target of deletion in GBM, often via focal intragenic loss. In GBM tumors that do not possess deletions in PTPRD, the gene is frequently subject to cancer-specific epigenetic silencing via promoter CpG island hypermethylation (37%). Sequencing of the PTPRD gene in GBM and other primary human tumors revealed that the gene is mutated in 6% of GBMs, 13% of head and neck squamous cell carcinomas, and in 9% of lung cancers. These mutations were deleterious. In total, PTPRD inactivation occurs in >50% of GBM tumors, and loss of expression predicts for poor prognosis in glioma patients. Wild-type PTPRD inhibits the growth of GBM and other tumor cells, an effect not observed with PTPRD alleles harboring cancer-specific mutations. Human astrocytes lacking PTPRD exhibited increased growth. PTPRD was found to dephosphorylate the oncoprotein STAT3. These results implicate PTPRD as a tumor suppressor on chromosome 9p that is involved in the development of GBMs and multiple human cancers.
Pre‐clinical non‐small cell lung cancer (NSCLC) models are poorly representative of the considerable inter‐ and intra‐tumor heterogeneity of the disease in patients. Primary cell‐based in vitro ...models of NSCLC are therefore desirable for novel therapy development and personalized cancer medicine. Methods have been described to generate rapidly proliferating epithelial cell cultures from multiple human epithelia using 3T3‐J2 feeder cell culture in the presence of Y‐27632, a RHO‐associated protein kinase (ROCK) inhibitor, in what are known as “conditional reprograming conditions” (CRC) or 3T3 + Y. In some cancer studies, variations of this methodology have allowed primary tumor cell expansion across a number of cancer types but other studies have demonstrated the preferential expansion of normal epithelial cells from tumors in such conditions. Here, we report our experience regarding the derivation of primary NSCLC cell cultures from 12 lung adenocarcinoma patients enrolled in the Tracking Cancer Evolution through Therapy (TRACERx) clinical study and discuss these in the context of improving the success rate for in vitro cultivation of cells from NSCLC tumors.
What's new?
Traditionally, the primary culture of human cancer cells has been challenging. A new protocol known as 3T3 + Y has allowed cancer cell cultures to be established across multiple cancer types, but reports are inconsistent for non‐small cell lung cancer (NSCLC). Here, the authors sought to expand tumor cells from surgically resected primary human lung adenocarcinoma tumors within the TRACERx clinical study using 3T3 + Y. Contaminating normal epithelial cells were the predominant cell type in early passage cultures, although KRAS‐mutant tumor cells were cultured in one donor culture. The researchers urge caution in the use of NSCLC primary cell cultures and call for further investigation in 3T3 + Y applications.
Automatic cell detection in histology images is a challenging task due to varying size, shape and features of cells and stain variations across large cohorts. Conventional deep learning methods ...regress the probability of each pixel belonging to the centre of a cell followed by detection of local maxima. We propose a three stage method (MapDe) to improve cell detection. (a) The dot annotations are convolved with a mapping filter to generate artifical labels. (b) A convolutional neural network (CNN) is modified to convolve its output with the same mapping filter. The mapping filter is fixed during training forcing the network to generate better probability maps. (c) Output of the trained CNN is deconvolved to generate points as cell detection. The results show that (1) local maxima performs better cell detection with probability maps generated using fixed convolution filter, (2) the results can be further improved by deconvolving the output with fewer parameters to tune.
Colorectal tumor risks could be reduced by polyphenol-rich diets that inhibit cell growth. Here, apple polyphenols were studied for effects on the survival of colon adenoma (LT97) and ...carcinoma-derived (HT29) cell lines. Three apple extracts (AEs) from harvest years 2002−2004 were isolated (AE02, AE03, and AE04) and fermented in vitro with human fecal flora. Extracts and fermentation products were analyzed for polyphenols with HPLC. The cells were treated with AEs (0−850 μg/mL) or fermented AEs (F-AEs, 0−9%), and survival was measured by DNA staining. All AEs contained high amounts of polyphenols (311−534 mg/g) and reduced cell survival (in LT97 > HT29). AE03 was most potent, possibly because it contained more quercetin compounds. Fermentation of AEs resulted in an increase of short chain fatty acids, and polyphenols were degraded. The F-AEs were ∼3-fold less bioactive than the corresponding AEs, pointing to a loss of chemoprotective properties through fermentation. Keywords: Antiproliferative activity; apple polyphenols; colon cancer chemoprevention; fermentation; colon cell line
Tracking the Evolution of Non–Small-Cell Lung Cancer Jamal-Hanjani, Mariam; Wilson, Gareth A; McGranahan, Nicholas ...
New England journal of medicine/The New England journal of medicine,
06/2017, Letnik:
376, Številka:
22
Journal Article
Recenzirano
Odprti dostop
Distinct genes are mutated in different regions of a single patient’s tumor. Point mutations seem to have less adverse effect on relapse-free survival than copy-number heterogeneity. Chromosome ...instability appears to be an important adverse prognostic factor.
Lung cancer is the leading cause of cancer-related death worldwide,
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with non–small-cell lung cancer (NSCLC) being the most common type. Large-scale sequencing studies have revealed the complex genomic landscape of NSCLC
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and genomic differences between lung adenocarcinomas and lung squamous-cell carcinomas.
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However, in-depth exploration of NSCLC intratumor heterogeneity (which provides the fuel for tumor evolution and drug resistance) and cancer genome evolution has been limited to small retrospective cohorts.
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Therefore, the clinical significance of intratumor heterogeneity and the potential for clonality of driver events to guide therapeutic strategies have not yet been defined.
Tracking Non–Small-Cell Lung Cancer . . .
ADAPTeR is a prospective, phase II study of nivolumab (anti-PD-1) in 15 treatment-naive patients (115 multiregion tumor samples) with metastatic clear cell renal cell carcinoma (ccRCC) aiming to ...understand the mechanism underpinning therapeutic response. Genomic analyses show no correlation between tumor molecular features and response, whereas ccRCC-specific human endogenous retrovirus expression indirectly correlates with clinical response. T cell receptor (TCR) analysis reveals a significantly higher number of expanded TCR clones pre-treatment in responders suggesting pre-existing immunity. Maintenance of highly similar clusters of TCRs post-treatment predict response, suggesting ongoing antigen engagement and survival of families of T cells likely recognizing the same antigens. In responders, nivolumab-bound CD8+ T cells are expanded and express GZMK/B. Our data suggest nivolumab drives both maintenance and replacement of previously expanded T cell clones, but only maintenance correlates with response. We hypothesize that maintenance and boosting of a pre-existing response is a key element of anti-PD-1 mode of action.
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•115 pre- and post-nivolumab multiregion tumor samples in a prospective phase II study•Maintenance of pre-treatment expanded TCR clones associates with response•Expanded CD8+ T cells upregulate GZMB/K in responders•HERV expression reflects tumor purity and indirectly correlates with response
ADAPTeR is a phase II study of nivolumab (anti-PD-1) in treatment-naive patients with metastatic clear cell renal cell carcinoma. Through multi-omic analysis of multiregion tumor biopsies taken pre- and post-treatment, Au et al. evaluate genomic and tumor immune microenvironment features underpinning anti-PD-1 response and resistance using bulk and single-cell approaches.
DNA damage checkpoints are critical for preventing tumorigenesis and regulating the response of cells to genotoxic agents. It is believed that the coordinated actions of a number of effectors ...underlie proper checkpoint function. The kinase Chk2, p21, and 14-3-3σ have each been shown to be independent effectors of the G2 DNA damage checkpoint. However, the relative roles of these proteins remain unclear. To help elucidate this question, we have perturbed each of these 3 genes in combination in human cells. We show that Chk2 depletion causes markedly increased sensitivity to DNA damage in p21-/-, 14-3-3σ-/- cells but not in cells lacking only one or none of these genes. This greater sensitivity was due to an increase in apoptosis following DNA damage and not due to exacerbation of G2 checkpoint defects. Pharmacologic inhibition of Chk2 in p21-/-, 14-3-3σ-/- cells also resulted in greater sensitivity to DNA damage. Our data indicates that p21 and 14-3-3σ synergize as molecular determinants of sensitivity to DNA damage following Chk2 inhibition, and Chk2 modulates the biological rheostat that determines whether a cancer cell undergoes arrest versus death after treatment with a chemotherapeutic agent. These findings have implications for the targeting of Chk2 in human cancers.
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