Thymidylate synthase (TS) gene expression in patients with ALK positive (+) non-small cell lung cancer (NSCLC): Implications for therapy.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 7582-7582 ◽  
Author(s):  
David R. Gandara ◽  
Eric Huang ◽  
Sonal Desai ◽  
Philip C. Mack ◽  
Laurel Beckett ◽  
...  

7582 Background: ALK+ NSCLC represents a molecular target-defined patient population highly responsive to the ALK inhibitor crizotinib. Previous reports have also suggested increased sensitivity of ALK+ NSCLC to the chemotherapeutic agent pemetrexed. Thymidylate synthase (TS) is a candidate predictive biomarker for pemetrexed activity. Here we report analysis of the Response Genetics Inc. (RGI) database for this association and implications for therapy. Methods: ALK fusion was identified by a novel RT-PCR assay (Danenberg et al: ASCO 2010). For TS, RNA from microdissected formalin-fixed paraffin-embedded tumors was analyzed as previously described, reported as the ratio of gene expression to β-actin. For reference, a TS level <2.33 is the cutpoint for sensitivity. Results: TS levels were available from 63 ALK+ patients and 1,698 ALK- control lung adenocarcinoma patients. All ALK+ patients had adenocarcinomas without EGFR or KRAS mutations. Median age: 59.0 (range 33-88), gender (male/female) 32/31 (51%/49%). Median TS RNA level in ALK+ patients was 2.02, range (0.55-19.44), and in ALK- patients was 3.32 (0.36-53.51), p<0.0001 (Mann-Whitney test). The majority of ALK+ patients (N=43, 68%) had a TS level <2.33 cutpoint, compared to only 32% of ALK- patients (N=551, p<0.0001). Conclusions: This analysis demonstrates relatively low TS gene expression in ALK+ patient tumors as determined by RT-PCR. These data provide a mechanism of action supportive of pemetrexed sensitivity for ALK+ NSCLC. [Table: see text]

BMC Cancer ◽  
2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Michal Marczyk ◽  
Chunxiao Fu ◽  
Rosanna Lau ◽  
Lili Du ◽  
Alexander J. Trevarton ◽  
...  

Abstract Background Utilization of RNA sequencing methods to measure gene expression from archival formalin-fixed paraffin-embedded (FFPE) tumor samples in translational research and clinical trials requires reliable interpretation of the impact of pre-analytical variables on the data obtained, particularly the methods used to preserve samples and to purify RNA. Methods Matched tissue samples from 12 breast cancers were fresh frozen (FF) and preserved in RNAlater or fixed in formalin and processed as FFPE tissue. Total RNA was extracted and purified from FF samples using the Qiagen RNeasy kit, and in duplicate from FFPE tissue sections using three different kits (Norgen, Qiagen and Roche). All RNA samples underwent whole transcriptome RNA sequencing (wtRNAseq) and targeted RNA sequencing for 31 transcripts included in a signature of sensitivity to endocrine therapy. We assessed the effect of RNA extraction kit on the reliability of gene expression levels using linear mixed-effects model analysis, concordance correlation coefficient (CCC) and differential analysis. All protein-coding genes in the wtRNAseq and three gene expression signatures for breast cancer were assessed for concordance. Results Despite variable quality of the RNA extracted from FFPE samples by different kits, all had similar concordance of overall gene expression from wtRNAseq between matched FF and FFPE samples (median CCC 0.63–0.66) and between technical replicates (median expression difference 0.13–0.22). More than half of genes were differentially expressed between FF and FFPE, but with low fold change (median |LFC| 0.31–0.34). Two out of three breast cancer signatures studied were highly robust in all samples using any kit, whereas the third signature was similarly discordant irrespective of the kit used. The targeted RNAseq assay was concordant between FFPE and FF samples using any of the kits (CCC 0.91–0.96). Conclusions The selection of kit to purify RNA from FFPE did not influence the overall quality of results from wtRNAseq, thus variable reproducibility of gene signatures probably relates to the reliability of individual gene selected and possibly to the algorithm. Targeted RNAseq showed promising performance for clinical deployment of quantitative assays in breast cancer from FFPE samples, although numerical scores were not identical to those from wtRNAseq and would require calibration.


2016 ◽  
Vol 70 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Carla Thomas ◽  
Cleo Robinson ◽  
Ben Dessauvagie ◽  
Benjamin Wood ◽  
Greg Sterrett ◽  
...  

AimBreast carcinoma proliferative activity, histological grade and commercial molecular tests are all important in prognostication and treatment. There is a particular need for improved, standardised techniques for subclassification of grade 2 breast cancers into low-risk and high-risk prognostic groups. In this study we investigated whether gene expression profiling of five proliferation genes was feasible using breast cancer tissue in a clinical setting and whether these profiles could enhance pathological assessment.MethodsExpression of five proliferation gene mRNAs; Ki-67, STK 15, CCNB1, CCND1 and MYBL2, was quantified in 27 breast carcinomas and compared with Ki-67 proliferation index (PI) and Nottingham mitotic score.ResultsExpression of Ki-67, STK15 and MYBL2 mRNA showed moderate Spearman's correlation with Ki-67 PI (p<0.01), but CCND1 and CCNB1 showed weak, non-significant correlation. Individual gene expression did not associate with mitotic score but combined mRNA expression correlated with both Ki-67 PI (p=0.018) and mitotic score (p=0.03; 0.007).ConclusionsThis study confirms mRNA analysis in breast carcinoma formalin-fixed, paraffin-embedded samples is feasible and suggests gene expression profiling, using a small set of five proliferation genes, has potential in aiding histological grading or assessment of proliferative activity of breast cancers. To fully evaluate the clinical applicability of this approach, a larger cohort study with long-term follow-up data is required.


2005 ◽  
Vol 53 (8) ◽  
pp. 963-969 ◽  
Author(s):  
Stephen B. Hunter ◽  
Vijay Varma ◽  
Bahig Shehata ◽  
J.D.L. Nolen ◽  
Cynthia Cohen ◽  
...  

Apolipoprotein D (apoD) expression has been shown to correlate both with cell cycle arrest and with prognosis in several types of malignancy, including central nervous system astrocytomas and medulloblastomas. ApoD expression was investigated by real-time quantitative RT-PCR using RNA extracted from 68 formalin-fixed, paraffin-embedded brain specimens. Glyceraldehyde phosphate dehydrogenase was used as an internal control. Quantitation was achieved on all specimens. Sixteen poorly infiltrating WHO grade I glial neoplasms (i.e., pilocytic astrocytomas and gangliogliomas) showed an average 20-fold higher apoD expression level compared with the 20 diffusely infiltrating glial neoplasms (i.e., glioblastoma, anaplastic astrocytoma, oligodendrogliomas; p=0.00004). A small number of exceptions (i.e., two high-expressing glioblastomas and three low-expressing gangliogliomas) were identified. Analyzed as individual tumor groups, poorly infiltrating grade I pilocytic astrocytomas and gangliogliomas differed significantly from each tumor type within the diffusely infiltrating higher-grade category ( p<0.05 for each comparison) but not from each other ( p>0.05). Conversely, each individual tumor type within the diffusely infiltrating category differed significantly from both pilocytic astrocytomas and gangliogliomas ( p<0.05) but did not vary from other infiltrating tumors ( p>0.05). Ependymomas, non-infiltrating grade II neoplasms, expressed levels of apoD similar to or lower than levels expressed by the diffusely infiltrating gliomas. Ten medulloblastomas with survival longer than 3 years averaged slightly higher apoD expression than four fatal medulloblastomas; however, this result was not statistically significant and individual exceptions were notable. In 17 of the medulloblastomas, MIB-1 proliferation rates quantitated by image cytometry did not correlate with apoD expression. In addition, apoD expression was 5-fold higher in the slowly proliferating grade I glial neoplasms compared with non-proliferating normal brain tissue ( p=0.01), suggesting that apoD expression is not simply an inverse measure of proliferation. ApoD expression measured by quantitative RT-PCR may be useful in the differential diagnosis of primary brain tumors, particularly pilocytic astrocytomas and gangliogliomas.


2019 ◽  
Author(s):  
Christopher A. Hilker ◽  
Aditya V. Bhagwate ◽  
Jin Sung Jang ◽  
Jeffrey G Meyer ◽  
Asha A. Nair ◽  
...  

AbstractFormalin fixed paraffin embedded (FFPE) tissues are commonly used biospecimen for clinical diagnosis. However, RNA degradation is extensive when isolated from FFPE blocks making it challenging for whole transcriptome profiling (RNA-seq). Here, we examined RNA isolation methods, quality metrics, and the performance of RNA-seq using different approaches with RNA isolated from FFPE and fresh frozen (FF) tissues. We evaluated FFPE RNA extraction methods using six different tissues and five different methods. The reproducibility and quality of the prepared libraries from these RNAs were assessed by RNA-seq. We next examined the performance and reproducibility of RNA-seq for gene expression profiling with FFPE and FF samples using targeted (Kinome capture) and whole transcriptome capture based sequencing. Finally, we assessed Agilent SureSelect All-Exon V6+UTR capture and the Illumina TruSeq RNA Access protocols for their ability to detect known gene fusions in FFPE RNA samples. Although the overall yield of RNA varied among extraction methods, gene expression profiles generated by RNA-seq were highly correlated (>90%) when the input RNA was of sufficient quality (≥DV200 30%) and quantity (≥ 100 ng). Using gene capture, we observed a linear relationship between gene expression levels for shared genes that were captured using either All-Exon or Kinome kits. Gene expression correlations between the two capture-based approaches were similar using RNA from FFPE and FF samples. However, TruSeq RNA Access protocol provided significantly higher exon and junction reads when compared to the SureSelect All-Exon capture kit and was more sensitive for fusion gene detection. Our study established pre and post library construction QC parameters that are essential to reproducible RNA-seq profiling using FFPE samples. We show that gene capture based NGS sequencing is an efficient and highly reproducible strategy for gene expression measurements as well as fusion gene detection.


2021 ◽  
Vol 4 (1) ◽  
pp. 61-65
Author(s):  
Elahe Esmaeili ◽  
◽  
Sara Ghaffarpour ◽  
Alireza Sadeghipour ◽  
Tooba Ghazanfari ◽  
...  

Background: Finding a sample of healthy tissue is a critical challenge in research studies. Non-pathological Tissue adjacent to the tumor (NAT) specimens is usually used as the control in several studies. However, little is known about the similarity of NAT to healthy tissues. Here, we compared the expression of Matrix Metalloproteinase 2 (MMP-2) and its inhibitor, Tissue Inhibitors of MMP (TIMP)-1 as extracellular matrix remodeling factors in NAT and autopsy lung tissue. Materials and Methods: RNA of 7 NAT and 6 Formalin-Fixed Paraffin-Embedded (FFPE) lung autopsies from healthy people as the control group was extracted, and cDNA was synthesized. The gene expression levels of MMP-2 and TIMP-1 were evaluated by real-time PCR. Results: There were no significant differences in the expression of MMP-2, TIMP-1, or their ratio between the two groups. Conclusion: The results showed that NAT could be used as healthy controls in lung tissue studies for MMP-2 and TIMP-1.


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