scholarly journals Correlation of MET-Receptor Overexpression with MET Gene Amplification and Patient Outcome in Malignant Mesothelioma

2021 ◽  
Vol 22 (23) ◽  
pp. 12868
Author(s):  
Eric Santoni-Rugiu ◽  
Maya Jeje Schuang Lü ◽  
Jan Nyrop Jakobsen ◽  
Linea Cecilie Melchior ◽  
Jesper Ravn ◽  
...  
Keyword(s):  
Malignant Mesothelioma ◽  
Gene Copy Number ◽  
Copy Number Gain ◽  
Gene Copy ◽  
Met Receptor ◽  
Standard Chemotherapy ◽  
Met Amplification ◽  
Lower Response Rate ◽  
Significant Difference

Thanks to clinically newly introduced inhibitors of the mesenchymal–epithelial transition (MET) receptor tyrosine-kinase, MET-gene copy number gain/amplification (MET-GCNG/GA) and increased expression of the MET protein are considered very promising therapeutic targets in lung cancer and other malignancies. However, to which extent these MET alterations occur in malignant mesothelioma (MM) remains unclear. Thus, we investigated by well-established immunohistochemistry and fluorescence in situ hybridization methods, the frequency of these alterations in specimens from 155 consecutive MMs of different subtypes obtained from pleural or peritoneal biopsies and pleurectomies. Thirty-three benign reactive mesothelial proliferations (RMPs) were used as controls. MET-protein upregulation was observed in 35% of all MM-cases, though restricted to predominantly epithelioid MMs. We detected low-/intermediate-level MET-GCNG/GA in 22.2% of MET-overexpressing MMs (7.8% of whole MM-cohort) and no MET-GCNG/GA in the other 77.8%, suggesting other upregulating mechanisms. In contrast, 100% of RMPs exhibited no MET-upregulation or MET-GCNG/-GA. Neither MET exon 14 skipping mutations nor MET-fusions were detected as mechanisms of MET overexpression in MM using RNA next-generation sequencing. Finally, in two cohorts of 30 MM patients with or without MET overexpression (MET-positive/-negative) that were matched for several variables and received the same standard chemotherapy, the MET-positive cases showed a significantly lower response rate, but no significant difference in progression-free or overall survival. Our results imply that MET overexpression occurs in a substantial fraction of predominantly epithelioid MMs, but correlates poorly with MET-amplification status, and may impact the likelihood of response to mesothelioma standard chemotherapy. The predictive significance of MET-IHC and -FISH for possible MET-targeted therapy of MM remains to be elucidated.

scholarly journals Comprehensive Genomic Profiling of Circulating Cell-Free DNA Distinguishes Focal MET Amplification from Aneuploidy in Diverse Advanced Cancers

2021 ◽  
Vol 28 (5) ◽  
pp. 3717-3728
Author(s):  
Yuichi Kumaki ◽  
Steve Olsen ◽  
Mitsukuni Suenaga ◽  
Tsuyoshi Nakagawa ◽  
Hiroyuki Uetake ◽  
...  
Keyword(s):  
Copy Number ◽  
Gene Copy Number ◽  
Copy Number Gain ◽  
Small Cell ◽  
Gene Copy ◽  
Genomic Profiling ◽  
Single Nucleotide Variants ◽  
Advanced Cancer Patients ◽  
Met Amplification ◽  
Comprehensive Genomic Profiling

Amplification (amp) of MET can be observed in cases of focal gene copy number gain, such as MET-driven amp, or with a gain of chromosome 7, such as aneuploidy. Several studies have shown that only high-level focal MET amp (MET/CEP7 ratio ≥5) is oncogenic, with such tumors responding to targeted therapy. However, there are few reports on how to distinguish between focal amplification and aneuploidy using next-generation sequencing (NGS). A total of 1025 patients with advanced solid tumors (typically pre-treated) were tested with a non-invasive comprehensive cfDNA NGS panel (Guardant360) from July 2014 to June 2019. Since bioinformatics upgrades of Guardant360 were undergoing in September 2018, focal MET amp was determined by our independent algorithm using the cohorts tested before September 2018 (291 patients), and validation was performed in the remaining cohort (734 patients). MET alterations (alts) associated with aberrant signaling were found in 110 patients (10.7%) among nine different cancer types, most commonly in non-small cell (12.2%, 62/510) and small cell (33.3%, 3/9) lung cancers, gastroesophageal cancer (19.4%, 7/36), and prostate adenocarcinoma (15.6%; 5/32). Among 291 patients tested before September 2018, 37 (12.7%) had MET alts. Among these, 24 (64.9%) had amps, 5 (13.5%) had exon 14 skipping, and 13 (35.1%) had single nucleotide variants (SNVs). Co-alterations, such as amp + SNVs, were found in four samples (10.8%). Among 24 MET amps, 29.2% (7/24) were focal according to our algorithm. MET copy number was significantly higher with focal amp compared to non-focal amp (mean copy number 3.26 vs. 2.44, respectively, p = 0.00304). In 734 patients tested after September 2018, our definition of focal MET amp was detected in 4.2% (31/734). Overall, focal amplification based on our algorithm was 3.7% (=38/1025). This study describes an approach to distinguish focal and non-focal MET amplification using comprehensive genomic profiling of cfDNA in advanced cancer patients. Focal MET amp accounted for ~30% of all MET amp, which was found in 3.7% of patients with diverse cancers and was associated with a higher plasma copy number. Clinical studies are warranted to assess the clinical utility of targeted therapies for tumors with focal MET amplification detected by NGS of cfDNA.

scholarly journals Insulin-like Growth Factor Receptor 1 (IGF1R) Gene Copy Number Is Associated With Survival in Operable Non–Small-Cell Lung Cancer: A Comparison Between IGF1R Fluorescent In Situ Hybridization, Protein Expression, and mRNA Expression

2010 ◽  
Vol 28 (13) ◽  
pp. 2174-2180 ◽  
Author(s):  
Rafal Dziadziuszko ◽  
Daniel T. Merrick ◽  
Samir E. Witta ◽  
Adelita D. Mendoza ◽  
Barbara Szostakiewicz ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Protein Expression ◽  
Squamous Cell ◽  
Copy Number ◽  
Gene Copy Number ◽  
Growth Factor Receptor ◽  
Gene Copy ◽  
Cell Versus

PurposeThe purpose of this study was to characterize insulin-like growth factor-1 receptor (IGF1R) protein expression, mRNA expression, and gene copy number in surgically resected non–small-cell lung cancers (NSCLC) in relation to epidermal growth factor receptor (EGFR) protein expression, patient characteristics, and prognosis.Patients and MethodsOne hundred eighty-nine patients with NSCLC who underwent curative pulmonary resection were studied (median follow-up, 5.3 years). IGF1R protein expression was evaluated by immunohistochemistry (IHC) with two anti-IGF1R antibodies (n = 179). EGFR protein expression was assessed with PharmDx kit. IGF1R gene expression was evaluated using quantitative reverse transcription polymerase chain reaction (qRT-PCR) from 114 corresponding fresh-frozen samples. IGF1R gene copy number was assessed by fluorescent in situ hybridization using customized probes (n = 181).ResultsIGF1R IHC score was higher in squamous cell carcinomas versus other histologies (P < .001) and associated with stage (P = .03) but not survival (P = .46). IGF1R and EGFR protein expression showed significant correlation (r = 0.30; P < .001). IGF1R gene expression by qRT-PCR was higher in squamous cell versus other histologies (P = .006) and did not associate with other clinical features nor survival (P = .73). Employing criteria previously established for EGFR copy number, patients with IGF1R amplification/high polysomy (n = 48; 27%) had 3-year survival of 58%, patients with low polysomy (n = 87; 48%) had 3-year survival of 47% and patients with trisomy/disomy (n = 46; 25%) had 3-year survival of 35%, respectively (P = .024). Prognostic value of high IGF1R gene copy number was confirmed in multivariate analysis.ConclusionIGF1R protein expression is higher in squamous cell versus other histologies and correlates with EGFR expression. IGF1R protein and gene expression does not associate with survival, whereas high IGF1R gene copy number harbors positive prognostic value.

scholarly journals Top-level MET gene copy number gain defines a subtype of poorly differentiated pulmonary adenocarcinomas with poor prognosis

2020 ◽  
Vol 9 (3) ◽  
pp. 603-616 ◽  
Author(s):  
Tobias Raphael Overbeck ◽  
Dana Alina Cron ◽  
Katja Schmitz ◽  
Achim Rittmeyer ◽  
Wolfgang Körber ◽  
...  
Keyword(s):  
Copy Number ◽  
Poor Prognosis ◽  
Gene Copy Number ◽  
Copy Number Gain ◽  
Gene Copy ◽  
Poorly Differentiated ◽  
Gene Copy Number Gain

scholarly journals Effects of Long-Term Storage on the Detection of Proteins, DNA, and mRNA in Tissue Microarray Slides

2011 ◽  
Vol 59 (12) ◽  
pp. 1113-1121 ◽  
Author(s):  
Christina Karlsson ◽  
Mats G. Karlsson
Keyword(s):  
Gene Copy Number ◽  
Tissue Microarrays ◽  
Storage Conditions ◽  
Gene Copy ◽  
Histological Techniques ◽  
Long Term Storage ◽  
Term Storage ◽  
Formalin Fixed

Storage of tissue slides has been claimed to induce dramatically reduced antigen detection particularly for immunohistochemistry (IHC). With tissue microarrays, the necessity to serially cut blocks in order to obtain as much material as possible is obvious. The presumed adverse effect of storage might hamper such an approach. The authors designed an experimental setting consisting of four different storage conditions with storage time of tissue slides of up to 1 year. Detection of proteins, DNA, and mRNA was performed using IHC and in situ hybridization techniques. Slight but significant changes in IHC occurred over time. The most important factor is the primary antibody used: four showed no significant changes, whereas limited decreases in 8 antibodies could be detected by image analysis. Whether the antigen was nuclear or cytoplasmic/membranous did not matter. No major differences between different storage conditions could be shown, but storage at 4C was overall the best procedure. Furthermore, gene copy number aberrations, chromosomal translocations, and the presence of mRNA could be detected on slides stored up to 1 year. In conclusion, in tissues optimally formalin fixed and using modern histological techniques, only minute changes in tissue antigenicity are induced by long-term storage.

scholarly journals In situ analysis of FGFR2 mRNA and comparison with FGFR2 gene copy number by dual-color in situ hybridization in a large cohort of gastric cancer patients

2017 ◽  
Vol 21 (3) ◽  
pp. 401-412 ◽  
Author(s):  
Yasutoshi Kuboki ◽  
Christoph A. Schatz ◽  
Karl Koechert ◽  
Sabine Schubert ◽  
Janine Feng ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
In Situ Hybridization ◽  
Cancer Patients ◽  
Copy Number ◽  
Gene Copy Number ◽  
In Situ Analysis ◽  
Gene Copy ◽  
Fgfr2 Gene ◽  
Gastric Cancer Patients

scholarly journals Estimation of total bacteria by real-time PCR in patients with periodontal disease

2016 ◽  
Vol 144 (1-2) ◽  
pp. 10-14 ◽  
Author(s):  
Gavrilo Brajovic ◽  
Branka Popovic ◽  
Miljan Puletic ◽  
Marija Kostic ◽  
Jelena Milasin
Keyword(s):  
Periodontal Disease ◽  
Real Time ◽  
Copy Number ◽  
Quantitative Estimation ◽  
Periodontal Diseases ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Additional Tool ◽  
Significant Difference ◽  
Total Bacteria

Introduction. Periodontal diseases are associated with the presence of elevated levels of bacteria within the gingival crevice. Objective. The aim of this study was to evaluate a total amount of bacteria in subgingival plaque samples in patients with a periodontal disease. Methods. A quantitative evaluation of total bacteria amount using quantitative real-time polymerase chain reaction (qRT-PCR) was performed on 20 samples of patients with ulceronecrotic periodontitis and on 10 samples of healthy subjects. The estimation of total bacterial amount was based on gene copy number for 16S rRNA that was determined by comparing to Ct values / gene copy number of the standard curve. Results. A statistically significant difference between average gene copy number of total bacteria in periodontal patients (2.55.107) and healthy control (2.37.106) was found (p=0.01). Also, a trend of higher numbers of the gene copy in deeper periodontal lesions (>7 mm) was confirmed by a positive value of coefficient of correlation (r=0.073). Conclusion. The quantitative estimation of total bacteria based on gene copy number could be an important additional tool in diagnosing periodontitis.

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