Genetic Profiling Reveals Cross-Contamination and Misidentification of 6 Adenoid Cystic Carcinoma Cell Lines: ACC2, ACC3, ACCM, ACCNS, ACCS and CAC2

Adenoid cystic carcinoma (ACC) is the second most common malignant neoplasm of the salivary glands. Most patients survive more than 5 years after surgery and postoperative radiation therapy. The 10 year survival rate, however, drops to 40%, due to locoregional recurrences and distant metastases. Improving long-term survival in ACC requires the development of more effective systemic therapies based on a better understanding of the biologic behavior of ACC. Much preclinical research in this field involves the use of cultured cells and, to date, several ACC cell lines have been established. Authentication of these cell lines, however, has not been reported. We performed DNA fingerprint analysis on six ACC cell lines using short tandem repeat (STR) examinations and found that all six cell lines had been contaminated with other cells. ACC2, ACC3, and ACCM were determined to be cervical cancer cells (HeLa cells), whereas the ACCS cell line was composed of T24 urinary bladder cancer cells. ACCNS and CAC2 cells were contaminated with cells derived from non-human mammalian species: the cells labeled ACCNS were mouse cells and the CAC2 cells were rat cells. These observations suggest that future studies using ACC cell lines should include cell line authentication to avoid the use of contaminated or non-human cells

The regulation of oncogenic Ras/ERK signalling by dual-specificitymitogen activated protein kinase phosphatases (MKPs)

AbstractDual-specificity MAP kinase (MAPK) phosphatases (MKPs or DUSPs) are well-established negative regulators of MAPK signalling in mammalian cells and tissues. By virtue of their differential subcellular localisation and ability to specifically recognise, dephosphorylate and inactivate different MAPK isoforms, they are key spatiotemporal regulators of pathway activity. Furthermore, as they are transcriptionally regulated as downstream targets of MAPK signalling they can either act as classical negative feedback regulators or mediate cross talk between distinct MAPK pathways. Because MAPKs and particularly Ras/ERK signalling are implicated in cancer initiation and development, the observation that MKPs are abnormally regulated in human tumours has been interpreted as evidence that these enzymes can either suppress or promote carcinogenesis. However, definitive evidence of such roles has been lacking. Here we review recent work based on the use of mouse models, biochemical studies and clinical data that demonstrate key roles for MKPs in modulating the oncogenic potential of Ras/ERK signalling and also indicate that these enzymes may play a role in the response of tumours to certain anticancer drugs. Overall, this work reinforces the importance of negative regulatory mechanisms in modulating the activity of oncogenic MAPK signalling and indicates that MKPs may provide novel targets for therapeutic intervention in cancer

Authentication of the R06E Fruit Bat Cell Line

Fruit bats and insectivorous bats are believed to provide a natural reservoir for a wide variety of infectious diseases. Several lines of evidence, including the successful isolation of infectious viruses, indicate that Marburg virus and Ravn virus have found a major reservoir in colonies of the Egyptian rousette (Rousettus aegyptiacus). To facilitate molecular studies on virus-reservoir host interactions and isolation of viruses from environmental samples, we established cell lines from primary cells of this animal. The cell lines were given to several laboratories until we realized that a contamination with Vero cells in one of the cultures had occurred. Here we describe a general diagnostic procedure for identification of cross-species contamination with the focus on Vero and Rousettus cell lines, and summarize newly discovered properties of the cell lines that may pertain to pathogen discovery

IGRhCellID: integrated genomic resources of human cell lines for identification

Cell line identification is emerging as an essential method for every cell line user in research community to avoid using misidentified cell lines for experiments and publications. IGRhCellID (http://igrcid.ibms.sinica.edu.tw) is designed to integrate eight cell identification methods including seven methods (STR profile, gender, immunotypes, karyotype, isoenzyme profile, TP53 mutation and mutations of cancer genes) available in various public databases and our method of profiling genome alterations of human cell lines. With data validation of 11 small deleted genes in human cancer cell lines, profiles of genomic alterations further allow users to search for human cell lines with deleted gene to serve as indigenous knock-out cell model (such as SMAD4 in gene view), with amplified gene to be the cell models for testing therapeutic efficacy (such as ERBB2 in gene view) and with overlapped aberrant chromosomal loci for revealing common cancer genes (such as 9p21.3 homozygous deletion with co-deleted CDKN2A, CDKN2B and MTAP in chromosome view). IGRhCellID provides not only available methods for cell identification to help eradicating concerns of using misidentified cells but also designated genetic features of human cell lines for experiments

A Critical Role for FBXW8 and MAPK in Cyclin D1 Degradation and Cancer Cell Proliferation

Cyclin D1 regulates G1 progression. Its transcriptional regulation is well understood. However, the mechanism underlying cyclin D1 ubiquitination and its subsequent degradation is not yet clear. We report that cyclin D1 undergoes increased degradation in the cytoplasm during S phase in a variety of cancer cells. This is mediated by phosphorylation at Thr286 through the activity of the Ras/Raf/MEK/ERK cascade and the F-box protein FBXW8, which is an E3 ligase. The majority of FBXW8 is expressed in the cytoplasm during G1 and S phase. In contrast, cyclin D1 accumulates in the nucleus during G1 phase and exits into the cytoplasm in S phase. Increased cyclin D1 degradation is linked to association with FBXW8 in the cytoplasm, and enhanced phosphorylation of cyclin D1 through sustained ERK1/2 signaling. Depletion of FBXW8 caused a significant accumulation of cyclin D1, as well as sequestration of CDK1 in the cytoplasm. This resulted in a severe reduction of cell proliferation. These effects could be rescued by constitutive nuclear expression of cyclin D1-T286A. Thus, FBXW8 plays an essential role in cancer cell proliferation through proteolysis of cyclin D1. It may present new opportunities to develop therapies targeting destruction of cyclin D1 or its regulator E3 ligase selectively

Dual-specificity MAP kinase phosphatases in health and disease

Source at https://doi.org/10.1016/j.bbamcr.2018.09.002.It is well established that a family of dual-specificity MAP kinase phosphatases (MKPs) play key roles in the regulated dephosphorylation and inactivation of MAP kinase isoforms in mammalian cells and tissues. MKPs provide a mechanism of spatiotemporal feedback control of these key signalling pathways, but can also mediate crosstalk between distinct MAP kinase cascades and facilitate interactions between MAP kinase pathways and other key signalling modules. As our knowledge of the regulation, substrate specificity and catalytic mechanisms of MKPs has matured, more recent work using genetic models has revealed key physiological functions for MKPs and also uncovered potentially important roles in regulating the pathophysiological outcome of signalling with relevance to human diseases. These include cancer, diabetes, inflammatory and neurodegenerative disorders. It is hoped that this understanding will reveal novel therapeutic targets and biomarkers for disease, thus contributing to more effective diagnosis and treatment for these debilitating and often fatal conditions

PHLDA1 Mediates Drug Resistance in Receptor Tyrosine Kinase-Driven Cancer

Development of resistance causes failure of drugs targeting receptor tyrosine kinase (RTK) networks and represents a critical challenge for precision medicine. Here, we show that PHLDA1 downregulation is critical to acquisition and maintenance of drug resistance in RTK-driven cancer. Using fibroblast growth factor receptor (FGFR) inhibition in endometrial cancer cells, we identify an Akt-driven compensatory mechanism underpinned by downregulation of PHLDA1. We demonstrate broad clinical relevance of our findings, showing that PHLDA1 downregulation also occurs in response to RTK-targeted therapy in breast and renal cancer patients, as well as following trastuzumab treatment in HER2+ breast cancer cells. Crucially, knockdown of PHLDA1 alone was sufficient to confer de novo resistance to RTK inhibitors and induction of PHLDA1 expression re-sensitized drug-resistant cancer cells to targeted therapies, identifying PHLDA1 as a biomarker for drug response and highlighting the potential of PHLDA1 reactivation as a means of circumventing drug resistance.This work was supported by Cancer Research UK (C16420/A12995), the Barry Reed Research Fund (576/2334 SPF1001), Breast Cancer Now (2012 November PR052), the CRUK/DH Barts Experimental Cancer Medicine Centre (C16420/A15583), and by a Cancer Research UK Centre Grant to Barts Cancer Institute (C16420/A18066)