scholarly journals Relationship between amount of esterase and gene copy number in insecticide-resistant Myzus persicae (Sulzer)

1999 ◽  
Vol 339 (3) ◽  
pp. 737-742 ◽  
Author(s):  
Linda M. FIELD ◽  
Roger L. BLACKMAN ◽  
Chris TYLER-SMITH ◽  
Alan L. DEVONSHIRE
Keyword(s):  
Gene Amplification ◽  
Myzus Persicae ◽  
Copy Number ◽  
Transcriptional Control ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Copy Numbers ◽  
And Function ◽  
Gene Copy Numbers

Overproduction of the insecticide-degrading esterases, E4 and FE4, in peach-potato aphids, Myzus persicae (Sulzer), depends on both gene amplification and transcriptional control, the latter being associated with changes in DNA methylation. The structure and function of the aphid esterase genes have been studied but the determination of their copy number has proved difficult, a common problem with gene amplification. We have now used a combination of pulsed-field gel electrophoresis and quantitative competitive PCR to determine relative esterase gene copy numbers in aphid clones with different levels of insecticide resistance (R1, R2 and R3). There are approx. 4-fold increases between susceptible, R1, R2 and R3 aphids, reaching a maximum of approx. 80 times more genes in R3; this gives proportionate increases in esterase protein relative to susceptible aphids. Thus there is no overexpression of the amplified genes, in contrast with what was thought previously. For E4 genes, the loss of 5-methylcytosine is correlated with a loss of expression, greatly decreasing the amount of enzyme relative to the copy number.

scholarly journals PCNA-associated factor (KIAA0101/PCLAF) overexpression and gene copy number alterations in hepatocellular carcinoma tissues

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Anchalee Tantiwetrueangdet ◽  
Ravat Panvichian ◽  
Pattana Sornmayura ◽  
Surasak Leelaudomlipi ◽  
Jill A. Macoska
Keyword(s):  
Hepatocellular Carcinoma ◽  
Protein Expression ◽  
Gene Amplification ◽  
Copy Number ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Mrna Levels ◽  
Ki 67 ◽  
Copy Numbers ◽  
Gene Copy Numbers

Abstract Background PCNA-associated factor, the protein encoded by the KIAA0101/PCLAF gene, is a cell-cycle regulated oncoprotein that regulates DNA synthesis, maintenance of DNA methylation, and DNA-damage bypass, through the interaction with the human sliding clamp PCNA. KIAA0101/PCLAF is overexpressed in various cancers, including hepatocellular carcinoma (HCC). However, it remains unknown whether KIAA0101/PCLAF overexpression is coupled to gene amplification in HCC. Methods KIAA0101/PCLAF mRNA expression levels were assessed by quantitative real-time PCR (qRT-PCR) in 40 pairs of snap-frozen HCC and matched-non-cancerous tissues. KIAA0101/PCLAF gene copy numbers were evaluated by droplet digital PCR (ddPCR) in 36 pairs of the tissues, and protein expression was detected by immunohistochemistry (IHC) in 81 pairs of formalin-fixed paraffin-embedded (FFPE) tissues. The KIAA0101/PCLAF gene copy number alteration and RNA expression was compared by Spearman correlation. The relationships between KIAA0101 protein expression and other clinicopathological parameters, including Ki-67, p53, and HBsAg protein expression in HCC tissues, were evaluated using Chi-square test. Results Our results demonstrated that KIAA0101/PCLAF mRNA levels were significantly higher in HCC than in the matched-non-cancerous tissues (p < 0.0001). The high KIAA0101/PCLAF mRNA levels in HCC were associated with poor patient survival. The KIAA0101/PCLAF gene was not amplified in HCC, and KIAA0101/PCLAF gene copy numbers were not associated with KIAA0101/PCLAF transcript levels. KIAA0101 protein was overexpressed in the majority of HCC tissues (77.8%) but was not detectable in matched-non-cancerous tissues. Significant correlations between the expression of KIAA0101 protein in HCC tissues and p53 tumor suppressor protein (p = 0.002) and Ki-67 proliferation marker protein (p = 0.017) were found. However, KIAA0101 protein levels in HCC tissues were not correlated with patient age, tumor size, serum AFP level, or the HBsAg expression. Conclusions KIAA0101/PCLAF mRNA and protein overexpression is frequently observed in HCC but without concurrent KIAA0101/PCLAF gene amplification. Significant correlations between the expression of KIAA0101 protein and p53 and Ki-67 proteins were observed in this study. Thus, detection of KIAA0101/PCLAF mRNA/protein might be used, along with the detection of p53 and Ki-67 proteins, as potential biomarkers to select candidate patients for further studies of novel HCC treatment related to these targets.

scholarly journals PCNA-associated factor (KIAA0101/PCLAF) overexpression and gene copy number alterations in hepatocellular carcinoma tissues

2020 ◽  
Author(s):  
Anchalee Tantiwetrueangdet ◽  
Ravat Panvichian ◽  
Pattana Sornmayura ◽  
Surasak Leelaudomlipi ◽  
Jill A. Macoska
Keyword(s):  
Hepatocellular Carcinoma ◽  
Protein Expression ◽  
Gene Amplification ◽  
Copy Number ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Mrna Levels ◽  
Ki 67 ◽  
Copy Numbers ◽  
Gene Copy Numbers

Abstract Background: PCNA-associated factor, the protein encoded by the KIAA0101/PCLAF gene, is a cell-cycle regulated oncoprotein that regulates DNA synthesis, maintenance of DNA methylation, and DNA-damage bypass, through the interaction with the human sliding clamp PCNA. KIAA0101/PCLAF is overexpressed in various cancers, including hepatocellular carcinoma (HCC). However, it remains unknown whether KIAA0101/PCLAF overexpression is coupled to gene amplification in HCC.Methods: KIAA0101/PCLAF mRNA expression levels were assessed by quantitative real-time PCR in 40 pairs of snap-frozen HCC and matched-non-cancerous tissues,KIAA0101/PCLAF gene copy numbers were evaluated by droplet digital PCR (ddPCR) in 36 pairs of the tissues, and protein expression was detected by immunohistochemistry (IHC) in 81 pairs of formalin-fixed paraffin-embedded (FFPE) tissues. The KIAA0101/PCLAF gene copy number alteration and RNA expression was compared by Spearman correlation, and the relationship between KIAA0101 protein expression and other clinicopathological parameters was evaluated using Chi-square test.Results: Our results demonstrated that KIAA0101/PCLAF mRNA levels were significantly higher in HCC than in the matched-non-cancerous tissues (p<0.0001), and high KIAA0101/PCLAF mRNA levels in HCC were associated with poor patient survival. The KIAA0101/PCLAF gene was not amplified in HCC and KIAA0101/PCLAF gene copy numbers were not associated with KIAA0101/PCLAF transcript levels. KIAA0101 protein was overexpressed in the majority of HCC tissues (77.8%) but was not be detectable in matched-non-cancerous tissues. Significant correlations between the expression of KIAA0101 protein and p53 tumor suppressor protein (p=0.002), and Ki-67 proliferation marker protein (p=0.017) were found. However, KIAA0101 protein levels were not correlated with patient age, tumor size, or the expression of AFP and HBsAg.Conclusions: KIAA0101/PCLAF mRNA and protein overexpressionis frequently observed in HCC but without concurrent KIAA0101/PCLAF gene amplification. Significant correlations between the expression of KIAA0101 protein and p53 and Ki-67 proteins were observed in this study. Thus, detection of KIAA0101/PCLAF mRNA/protein might be used, along with the detection of p53 and Ki-67 proteins, as potential biomarkers to select candidate patients for further studies of novel HCC treatment related to these targets.

scholarly journals High levels of copy number variation of ampliconic genes across major human Y haplogroups

2017 ◽  
Author(s):  
Danling Ye ◽  
Arslan Zaidi ◽  
Marta Tomaszkiewicz ◽  
Corey Liebowitz ◽  
Michael DeGiorgio ◽  
...  
Keyword(s):  
Copy Number Variation ◽  
Y Chromosome ◽  
Copy Number ◽  
Gene Copy Number ◽  
Gene Families ◽  
Digital Pcr ◽  
Gene Copy ◽  
Copy Numbers ◽  
Number Variation ◽  
Gene Copy Numbers

AbstractDue to its highly repetitive nature, the human male-specific Y chromosome remains understudied. It is important to investigate variation on the Y chromosome to understand its evolution and contribution to phenotypic variation, including infertility. Approximately 20% of the human Y chromosome consists of ampliconic regions which include nine multi-copy gene families. These gene families are expressed exclusively in testes and usually implicated in spermatogenesis. Here, to gain a better understanding of the role of the Y chromosome in human evolution and in determining sexually dimorphic traits, we studied ampliconic gene copy number variation in 100 males representing ten major Y haplogroups world-wide. Copy number was estimated with droplet digital PCR. In contrast to low nucleotide diversity observed on the Y in previous studies, here we show that ampliconic gene copy number diversity is very high. A total of 98 copy-number-based haplotypes were observed among 100 individuals, and haplotypes were sometimes shared by males from very different haplogroups, suggesting homoplasies. The resulting haplotypes did not cluster according to major Y haplogroups. Overall, only three gene families (DATZ, RBMY, TSPY) showed significant differences in copy number among major Y haplogroups, and the haplogroup of an individual could not be predicted based on his ampliconic gene copy numbers. Finally, we found a significant correlation between copy number variation and individual’s height (for three gene families), but not between the former and facial masculinity/femininity. Our results suggest rapid evolution of ampliconic gene copy numbers on the human Y, and we discuss its causes.

Epidermal Growth Factor Receptor in Non–Small-Cell Lung Carcinomas: Correlation Between Gene Copy Number and Protein Expression and Impact on Prognosis

2003 ◽  
Vol 21 (20) ◽  
pp. 3798-3807 ◽  
Author(s):  
Fred R. Hirsch ◽  
Marileila Varella-Garcia ◽  
Paul A. Bunn ◽  
Michael V. Di Maria ◽  
Robert Veve ◽  
...  
Keyword(s):  
Protein Expression ◽  
Copy Number ◽  
Gene Copy Number ◽  
Growth Factor Receptor ◽  
Gene Copy ◽  
Protein Status ◽  
Copy Numbers ◽  
High Gene ◽  
Epidermal Growth ◽  
Gene Copy Numbers

Purpose: The epidermal growth factor receptor (EGFR) is frequently overexpressed in non–small-cell lung carcinoma (NSCLC), and EGFR inhibitors are promising new therapeutic agents. The molecular mechanisms responsible for EGFR overexpression are poorly understood. Materials and Methods: Gene copy number and protein status of EGFR were investigated in microarrayed tumors from 183 NSCLC patients, including squamous cell carcinoma (SCC; 89 patients) and non-SCC (94 patients) histologies. Protein expression was assessed by immunohistochemistry on a scale from 0 to 400 (percentage of positive cells × staining intensity). Gene and chromosome 7 copy numbers were identified by fluorescent in situ hybridization (FISH). Results: EGFR protein overexpression was observed in 62% of the NSCLC (25% scored 201 to 300; 37% scored 301 to 400), more frequently in SCC than non-SCC (82% v 44%; P < .001), and in 80% of the bronchioloalveolar carcinomas. The prevalent FISH patterns were balanced disomy (40%) and trisomy (38%) for EGFR gene and chromosome 7 (40%), whereas balanced polysomy was seen in 13% and gene amplification was seen in 9% of the patients. Gene copy number correlated with protein expression (r = 0.4; P < .001). EGFR overexpression or high gene copy numbers had no significant influence on prognosis. Conclusion: EGFR overexpression is frequent in NSCLC, is most prominent in SCC, and correlates with increased gene copy number per cell. High gene copy numbers per cell showed a trend toward poor prognosis. It will be important to evaluate EGFR gene and EGFR protein status and signal protein expression to properly interpret future clinical trials using EGFR inhibitors.

MET Gene High Copy Number (Amplification/Polysomy) Identified in Melanoma for Potential Targeted Therapy

2021 ◽  
Author(s):  
Nisha S Ramani ◽  
Ajaykumar C Morani ◽  
Shengle Zhang
Keyword(s):  
Targeted Therapy ◽  
Gene Amplification ◽  
Copy Number ◽  
Kinase Inhibitors ◽  
Gene Copy Number ◽  
Tissue Microarrays ◽  
High Copy Number ◽  
Gene Copy ◽  
Aberrant Expression ◽  
Mesenchymal Epithelial Transition Factor

Abstract Objectives Aberrant expression of the mesenchymal epithelial transition factor (MET) gene has been observed in several malignancies, and drugs targeting the MET gene have been implicated in clinical trials with promising results. Hence, MET is a potentially targetable oncogenic driver. We explored the frequency of MET gene high copy number in melanomas and carcinomas. Methods The study group included 135 patients. Tissue microarrays were constructed with 19 melanomas and 116 carcinomas diagnosed from 2010 to 2012. We screened MET gene copy number by fluorescence in situ hybridization analysis using probes for MET gene and CEP7 as control. Results We found MET gene amplification in 2 (11%) of 19 melanoma cases, whereas 5 (26%) of 19 melanoma cases showed polysomy. For carcinomas, there was no MET gene amplification identified. However, 8 (7%) of 116 cases showed polysomy. Conclusions In our study, MET gene amplification was identified in 11% of melanomas and is relatively concordant with few reported studies. However, about 26% of the additional melanoma cases showed MET gene polysomy, which has not been reported as per our knowledge. If these results are validated with further orthogonal studies, more of the melanoma cases could potentially benefit from targeted therapy with MET tyrosine kinase inhibitors.

Solid-phase minisequencing confirmed by FISH analysis in determination of gene copy number

1995 ◽  
Vol 96 (3) ◽  
Author(s):  
Maris Laan ◽  
Kristiina Gr�n-Virta ◽  
Armi Salo ◽  
Pertti Aula ◽  
Leena Peltonen ◽  
...  
Keyword(s):  
Copy Number ◽  
Solid Phase ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Fish Analysis

scholarly journals Photo-Induced Electron Transfer Real-Time PCR for Detection ofPlasmodium falciparum plasmepsin 2Gene Copy Number

2018 ◽  
Vol 62 (8) ◽  
Author(s):  
Samaly Santos Souza ◽  
Mariangela L'Episcopia ◽  
Carlo Severini ◽  
Venkatachalam Udhayakumar ◽  
Naomi W. Lucchi
Keyword(s):  
Electron Transfer ◽  
Real Time ◽  
Real Time Pcr ◽  
Copy Number ◽  
Gene Copy ◽  
Content Type ◽  
Copy Numbers ◽  
Ofplasmodium Falciparum ◽  
Photo Induced Electron Transfer ◽  
Gene Copy Numbers

ABSTRACTPiperaquine is an important partner drug used in artemisinin-based combination therapies (ACTs). An increase in theplasmepsin 2and3gene copy numbers has been associated with decreased susceptibility ofPlasmodium falciparumto piperaquine in Cambodia. Here, we developed a photo-induced electron transfer real-time PCR (PET-PCR) assay to quantify the copy number of theP. falciparumplasmepsin 2gene (PfPM2) that can be used in countries whereP. falciparumis endemic to enhance molecular surveillance.

Resistance to methotrexate due to gene amplification in a patient with acute leukemia.

1984 ◽  
Vol 2 (1) ◽  
pp. 16-20 ◽  
Author(s):  
M D Carman ◽  
J H Schornagel ◽  
R S Rivest ◽  
S Srimatkandada ◽  
C S Portlock ◽  
...  
Keyword(s):  
Gene Amplification ◽  
Copy Number ◽  
Cdna Probe ◽  
Leukemia Cell ◽  
Gene Copy Number ◽  
Leukemia Cell Line ◽  
Gene Copy ◽  
Acute Myelocytic Leukemia ◽  
Human Leukemia ◽  
Dot Blot

A patient is described with acute myelocytic leukemia refractory to conventional therapy, who also became highly resistant to methotrexate (MTX) after repeated courses of this drug. Leukemia cells from this patient were found to contain an elevated level of dihydrofolate reductase (DHFR) activity, with no change in the affinity of the enzyme for MTX. A sensitive "dot blot" assay revealed a fourfold increase in the gene copy number of DHFR. Southern blot analysis with a human DHFR cDNA probe confirmed this increase in the gene copy number, and demonstrated a similar restriction pattern with Eco R1, Hind III, and Pst 1 as seen with a highly amplified human leukemia cell line, K562. Additional DHFR fragments were detected, not seen in the K562 blot, suggesting the presence of pseudogenes, or a result of gene rearrangements occurring as part of the amplification process. Resistance to MTX in this patient was therefore ascribed to gene amplification and overproduction of DHFR.

Gene copy number of epidermal growth factor receptor (EGFR) by fluorescent in situ hybridization (FISH) in head and neck squamous cell carcinomas (HNSCC) is closely correlated with EGFR protein levels assessed by automated quantitative protein analysis (AQUA)

2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 6023-6023
Author(s):  
P. Weinberger ◽  
A. Psyrri ◽  
P. Kountourakis ◽  
T. Rampias ◽  
C. Sasaki ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Protein Expression ◽  
Protein Content ◽  
Gene Amplification ◽  
Copy Number ◽  
Gene Copy Number ◽  
Gene Copy ◽  
Egfr Gene ◽  
Protein Levels

6023 Background: EGFR overexpression correlates with recurrence and with treatment resistance in HNSCC. The mechanisms of EGFR protein overexpression are poorly understood. Nonetheless, previous investigators have not demonstrated a correlation between EGFR gene copy number and protein content, using conventional immunohistochemistry (IHC). The aim of this study was to evaluate the relationship of EGFR gene copy number and protein expression utilizing fluorescence in situ hybridization (FISH) and AQUA, a novel, immunohistochemical method of automated quantitative in situ proteomic analysis which permits subcellular localization. Methods: A tissue microarray composed of 137 HNSCC treated with (chemo)radiation was constructed and analyzed for EGFR copy number by FISH (Vysis/Abbot) and EGFR protein expression (DAKO antibody) using AQUA analysis of EGFR staining scored on a scale of 0–255 and by conventional IHC. Agreement was assessed using kappa. Results: Sixteen (15%) of one-hundred six tumors with FISH results demonstrated EGFR high polysomy and/or gene amplification (FISH+). AQUA demonstrated a range of 3.6–102.2; protein levels assessed by AQUA in the FISH amplified cases were significantly higher (p =0.008) than in the FISH non- amplified ones. Using the EGFR 75th percentile as a cut-off, AQUA and FISH showed significant agreement (percentage of overall agreement 82%, kappa=0.458, p=0.003). To the contrary there was no concordance between FISH and conventional IHC results in this series. Conclusions: The discrepancy between EGFR gene amplification rate and protein expression by IHC reported previously may be due to the limitations and nonquantitative nature of conventional IHC. EGFR protein content correlates with gene copy number if protein content is quantitated and automatically analyzed, as with AQUA. No significant financial relationships to disclose.

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