scholarly journals A forward genetic screen reveals novel independent regulators of ULBP1, an activating ligand for natural killer cells

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Benjamin G Gowen ◽  
Bryan Chim ◽  
Caleb D Marceau ◽  
Trever T Greene ◽  
Patrick Burr ◽  
...  

Recognition and elimination of tumor cells by the immune system is crucial for limiting tumor growth. Natural killer (NK) cells become activated when the receptor NKG2D is engaged by ligands that are frequently upregulated in primary tumors and on cancer cell lines. However, the molecular mechanisms driving NKG2D ligand expression on tumor cells are not well defined. Using a forward genetic screen in a tumor-derived human cell line, we identified several novel factors supporting expression of the NKG2D ligand ULBP1. Our results show stepwise contributions of independent pathways working at multiple stages of ULBP1 biogenesis. Deeper investigation of selected hits from the screen showed that the transcription factor ATF4 drives ULBP1 gene expression in cancer cell lines, while the RNA-binding protein RBM4 supports ULBP1 expression by suppressing a novel alternatively spliced isoform of ULBP1 mRNA. These findings offer insight into the stress pathways that alert the immune system to danger.

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 641
Author(s):  
Kaitlin M. Branch ◽  
Erica C. Garcia ◽  
Yin Maggie Chen ◽  
Matthew McGregor ◽  
Mikayla Min ◽  
...  

Breast cancer is the leading cause of cancer deaths among women worldwide. There are many known risk factors for breast cancer, but the role of infectious disease remains unclear. Human cytomegalovirus (HCMV) is a widespread herpesvirus that usually causes little disease. Because HCMV has been detected in breast tumor biopsy samples and is frequently transmitted via human breast milk, we investigated HCMV replication in breast tumor cells. Four human breast cancer cell lines with different expression profiles for the key diagnostic markers of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), were infected with a bacterial artificial chromosome-derived HCMV clinical strain TB40/E tagged with green fluorescent protein (GFP). Fluorescence microscopy confirmed that all four breast cancer cell lines supported virus entry. RNA was isolated from infected cells and the expression of immediate early (UL123), early (UL54), and late (UL111A) genes was confirmed using PCR. Viral proteins were detected by immunoblotting, and viral progeny were produced during the infection of breast tumor cells, as evidenced by subsequent infection of fibroblasts with culture supernatants. These results demonstrate that breast tumor cells support productive HCMV infection and could indicate that HCMV replication may play a role in breast cancer progression.


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 480-480
Author(s):  
Anirban P Mitra ◽  
Andrea Kokorovic ◽  
Tanner Miest ◽  
Vikram M Narayan ◽  
Debasish Sundi ◽  
...  

480 Background: Members of the forkhead transcription factor (FOX) family are important mediators of embryonic development and are known to be altered in a variety of cancers. The functional role of FOXF1 in bladder tumorigenesis and progression has not been clearly characterized thus far. This study investigated the clinical implications of differential FOXF1 expression in bladder cancer, and potential mechanisms by which its alteration can lead to tumor metastasis. Methods: Whole genome expression profiling was performed on paired primary tumors and nodal metastases from a radical cystectomy discovery cohort using Illumina HT12 v3-4 BeadChip arrays to identify FOXF1 as a top differentially expressed gene. Prognostic role of differential FOXF1 expression was validated on two independent cystectomy cohorts. Differential FOXF1 expression was also evaluated in murine orthotopic xenografts. Small interfering RNA was used to knock down FOXF1 in RT112 and UC6 bladder cancer cell lines to develop an in vitro model for assessment of metastatic potential. Next-generation sequencing and hierarchical clustering analysis were used to identify differentially altered genes secondary to FOXF1 knockdown. 186 biologically curated pathways were interrogated with internal validation to elucidate the downstream biologic mechanisms of metastasis. Results: In the discovery cohort, FOXF1 was a top differentially expressed gene with 3.6-fold lower expression in nodal metastases than paired primary tumors (n = 33, p < 0.001). Multivariable analyses in two validation cohorts (total n = 128) indicated that FOXF1 underexpression was associated with worse cancer-specific (p = 0.046) and overall survival (p = 0.006). Murine orthotopic xenografts (n = 13) established from human bladder cancer cell lines (UC3, UC6, UC14) showed FOXF1 underexpression in metastatic deposits compared with primary tumors (p = 0.004). Hierarchical clustering identified 40 differentially expressed genes between FOXF1-knockdown bladder cancer cell lines and their corresponding controls. Biological pathway interrogation showed differential enrichment for genes associated with mitogen-activated protein kinase signaling, focal adhesion and other carcinogenic pathways in FOXF1-knockdown cells compared with controls (normalized enrichment score ≥ 1.3). Conclusions: We identify and characterize FOXF1 as a novel regulatory molecule that potentially drives bladder cancer metastasis. This may be modulated through alterations in intracellular signaling and cellular adhesion. FOXF1 may serve as a prognostic biomarker that can identify patients at impending risk for metastasis who may benefit from more aggressive management.


2007 ◽  
Vol 29 (4) ◽  
pp. 289-299
Author(s):  
Robert E. Page ◽  
Andrés J. P. Klein-Szanto ◽  
Samuel Litwin ◽  
Emmanuelle Nicolas ◽  
Raid Al-Jumaily ◽  
...  

Background: Proprotein convertases (PCs) are serine proteases that after restricted proteolysis activate many proteins that play a crucial role in cancer such as metalloproteinases, growth factors and growth factor receptors, adhesion molecules, and angiogenic factors. Although the expression of several PCs is increased in many tumors, their expression in primary ovarian tumors has not been studied in detail. We sought to determine if there was an association between the expression of the ubiquitously expressed PCs, furin, PACE-4, PC-5 and PC-7, and ovarian tumor progression. Methods: We assessed their expression by RT-PCR, Real-time PCR, Western blot, and immunohistochemistry using cells derived from normal human ovarian surface epithelium (HOSE) and cancer cell lines as well as ovarian epithelial cancer specimens (45 RT-PCR/Real-time PCR, and 120 archival specimens for Immunohistochemistry). Results: We found that furin expression was restricted to the cancer cell lines. In contrast, PACE-4 and PC-7 showed expression only in normal HOSE cells lines. Furthermore, furin was predominantly expressed in primary tumors from patients who survived for less than five years. The other PCs are either expressed in the group of survivors (PC-7 and PACE4) or expressed in low amounts (PC-5). Conclusions: Our studies point to a clear relationship between furin and ovarian cancer. In addition, these results show that furin exhibits the closest association with ovarian cancer among the ubiquitously expressed PCs, arguing against the redundancy of these proteases. In summary, furin may constitute a marker for ovarian tumor progression and could contribute to predict the outcome of this disease.


2019 ◽  
Author(s):  
Neetha Nanoth Vellichirammal ◽  
Abrar Albahrani ◽  
Jasjit K. Banwait ◽  
You Li ◽  
Babu Guda

2019 ◽  
Author(s):  
Neetha Nanoth Vellichirammal ◽  
Abrar Albahrani ◽  
Jasjit K. Banwait ◽  
You Li ◽  
Babu Guda

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 644 ◽  
Author(s):  
Ghani ◽  
Dendo ◽  
Watanabe ◽  
Yamada ◽  
Yoshimatsu ◽  
...  

The success rate of establishing human cancer cell lines is not satisfactory and the established cell lines often do not preserve the molecular and histological features of the original tissues. In this study, we developed a novel culture method which can support proliferation of almost all primary epithelial ovarian cancer cells, as well as primary normal human oviductal epithelial cells. Cancer cells from fresh or frozen specimens were enriched by the anti-EpCAM antibody-conjugated magnetic beads, plated on Matrigel-coated plate and cultivated under the optimized culture conditions. Seventeen newly established ovarian cancer cell lines, which included all four major histotypes of ovarian cancer, were confirmed to express histotype-specific markers in vitro. Some of the cell lines from all the four histotypes, except mucinous type, generated tumors in immune-deficient mice and the xenograft tumor tissues recapitulated the corresponding original tissues faithfully. Furthermore, with poorly tumorigenic cell lines including mucinous type, we developed a novel xenograft model which could reconstruct the original tissue architecture through forced expression of a set of oncogenes followed by its silencing. With combination of the novel culture method and cell-derived xenograft system, virtually every epithelial ovarian cancer can be reconstituted in mice in a timely fashion.


1998 ◽  
Vol 46 (1) ◽  
pp. 127-134 ◽  
Author(s):  
Udo Schumacher ◽  
Elizabeth Adam

Alterations in mucin expression have been detected in many clinically relevant cancers and, in particular, the polymorphic epithelial mucin, encoded by the MUC1 gene, has attracted considerable attention. We investigated its expression in human breast, colon, ovarian, lung, and skin cancer cells and their metastases grown in severe combined immunodeficient ( scid) mice using three different monoclonal antibodies (HMFG-1, HMFG-2, and SM3). Four of five breast cancer cell lines, three of five colon cancer cell lines, two of three small-cell carcinoma of the lung cell lines, and A 431 cells all expressed the MUC1 gene product. Neuraminidase predigestion often enhanced HMFG-1 immunoreactivity, which was more widespread and stronger than SM3 immunoreactivity. A considerable heterogeneity of MUC1 gene product expression was observed in the same tumors grown in different mice. The binding pattern between single-cell/small-cell clusters (up to 10 cells) and larger cell number aggregates varied. The results indicate that the MUC1 gene expression both in primary tumors and metastases is not tightly controlled within a particular tumor cell line. Because of this heterogeneous antigen expression in vivo, it appears impossible to target all metastatic deposits by a single monoclonal antibody directed against the MUC1 gene product.


2018 ◽  
Author(s):  
K. Yu ◽  
B. Chen ◽  
D. Aran ◽  
J. Charalel ◽  
A. Butte ◽  
...  

AbstractCancer cell lines are commonly used as models for cancer biology. While they are limited in their ability to capture complex interactions between tumors and their surrounding environment, they are a cornerstone of cancer research and many important findings have been discovered utilizing cell line models. Not all cell lines are appropriate models of primary tumors, however, which may contribute to the difficulty in translating in vitro findings to patients. Previous studies have leveraged public datasets to evaluate cell lines as models of primary tumors, but they have been limited in scope to specific tumor types and typically ignore the presence of tumor infiltrating cells in the primary tumor samples. We present here a comprehensive pan-cancer analysis utilizing approximately 9,000 transcriptomic profiles from The Cancer Genome Atlas and the Cancer Cell Line Encyclopedia to evaluate cell lines as models of primary tumors across 22 different tumor types. After adjusting for tumor purity in the primary tumor samples, we performed correlation analysis and differential gene expression analysis between the primary tumor samples and cell lines. We found that cell-cycle pathways are consistently upregulated in cell lines, while no pathways are consistently upregulated across the primary tumor samples. In a case study, we compared colorectal cancer cell lines with primary tumor samples across the colorectal subtypes and identified three colorectal cell lines that were derived from fibroblasts rather than tumor epithelial cells. Lastly, we propose a new set of cell lines panel, the TCGA-110, which contains the most representative cell lines from 22 different tumor types as a more comprehensive and informative alternative to the NCI-60 panel. Our analysis of the other tumor types are available in our web app (http://comphealth.ucsf.edu/TCGA110) as a resource to the cancer research community, and we hope it will allow researchers to select more appropriate cell line models and increase the translatability of in vitro findings.


2018 ◽  
Vol 2 (S1) ◽  
pp. 36-37
Author(s):  
Nicolas Seranio ◽  
Louise Aguarin ◽  
Jay F. Dorsey ◽  
John P. Christodouleas ◽  
Gary D. Kao

OBJECTIVES/SPECIFIC AIMS: Bladder cancer patients being considered for immune checkpoint blockade are often judged on immunohistochemical staining for the checkpoint target protein PD-L1 in the original surgery or biopsy sample. However, sampling error or the clinical evolution of most patients’ cancer can render the original PD-L1 assessment no longer accurate. In contrast, circulating tumor cells (CTCs) allow serial noninvasive sampling of the current tumor status throughout a patient’s clinical course including those with the highest metastatic potential. We therefore sought to develop a method for quantifying PD-L1 expression in CTCs towards addressing inherent limitations of current UC management. METHODS/STUDY POPULATION: This work utilizes both cancer cell lines as well as patient samples. Positive and negative control cancer cell lines were assessed via “industry standard” antibodies for PD-L1 expression via Western blots and immunofluorescence, and a threshold-based method was developed for reliable quantification. PDL-1 expression was additionally verified via interferon-mediated up-regulation. CTCs isolated from bladder cancer patient samples via a density centrifugation method were then assessed for PD-L1 via the same antibodies. RESULTS/ANTICIPATED RESULTS: We will show preliminary preclinical and clinical data that validates the sensitivity and specificity of our assay. A case study will be presented that illustrate the potential useful of the novel approach we describe and which should be complementary to current clinical practices. In a patient with metastatic bladder cancer, this method effectively detected the PD-L1 expression in CTCs taken at a time coincident to when the patient derived an excellent response to the PD-L1 checkpoint inhibitor Pembrolizumab. DISCUSSION/SIGNIFICANCE OF IMPACT: This work highlights the potential utility of CTCs in the management of bladder cancer. It may be the case that this assay in conjunction with current methods of patient selection for immunotherapy may allow for better response prediction than either method alone.


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