Short report: Performance evaluation of the Idylla™ KRAS and EGFR mutation tests on paraffin-embedded cytological NSCLC samples.

BACKGROUND: Quick and reliable testing of EGFR and KRAS is needed in non-small cell lung cancer (NSCLC) to ensure optimal decision-making for targeted therapy. The Idylla™ platform was designed for Formalin-Fixed Paraffin-Embedded (FFPE) tissue sections but recently several studies were published that evaluated its potential for cytological specimens. This study aimed to validate the Idylla™ platform for the detection of EGFR/KRAS mutations in cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. MATERIAL AND METHODS: The KRAS Idylla™ test were performed on 11 specimens with a known KRAS mutation. The EGFR Idylla™ test was performed on 18 specimens with a known primary EGFR mutation and 7 specimens with a primary EGFR-EGFR T790M resistance mutation combination. RESULTS: Concordant KRAS and primary EGFR mutations were detected for both KRAS and primary EGFR mutations. Samples with a total CQ value of < 26 could be considered negative. Samples with a total CQ value of > 26 could not be assessed (probability of false-negative). In specimens with a primary EGFR-EGFR T790M resistance mutation combination, 5/7 cases were not concordant. CONCLUSION: Our results confirm the conclusion of recent reports that the Idylla™EGFR assay is not suitable in a resistance to EGFR TKI setting, also not in our cytological NSCLC samples prepared as cytoblocks using AGAR and paraffin embedding. KRAS and primary EGFR mutations were detected using the Idylla™ assays in virtually all cytological NSCLC samples. This analysis was rapid and time-saving compared to other mutation detection assays and may be useful if the amount of material is insufficient to perform a full set of molecular tests.

Pyrosequencing analysis of EGFR and KRAS mutations in EUS and EBUS-derived cytologic samples of adenocarcinomas of the lung.

INTRODUCTION: Patients with stage IV non-small-cell lung cancer harboring an activating epidermal growth factor receptor (EGFR) mutation are eligible for treatment with EGFR tyrosine kinase inhibitors. With pyrosequencing, low-frequency mutations may be detected more easily even in small diagnostic samples like endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) and endobronchial ultrasound-guided transbronchial needle aspirations (EBUS-TBNA). The diagnostic performance of pyrosequencing in analyzing cytological specimens is compared with the routinely used high-resolution melting (HRM) and Sanger sequencing. METHODS: Patients diagnosed with adenocarcinoma of the lung were selected from a fine needle aspiration and transbronchial needle aspiration specimen database. If formalin-fixed paraffin-embedded tumor blocks were available, mutation analysis was performed for EGFR and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog genes using both pyrosequencing and HRM. When HRM showed abnormalities, Sanger sequencing was used. RESULTS: A total of 126 samples were available for mutation analysis. The analysis success rate for pyrosequencing and HRM were 97% and 93%, respectively. HRM failures were observed in fragmented DNA showing chains of 100 to 200 bp. A significant correlation between length of DNA fragments (100-300 bp versus 300-400 bp) and mean sample age (797 versus 317 days) was found (p < 0.0001), suggesting an influence of sample age on DNA quality. CONCLUSION: Pyrosequencing on cytological blocks, especially older tumor blocks, is feasible with a high diagnostic success rate. Failures in HRM were observed in DNA samples with short fragments related to longer storage times.

Early organ-specific endothelial activation during hemorrhagic shock and resuscitation.

Multiple organ dysfunction syndrome (MODS) is a complication of hemorrhagic shock (HS) and related to high morbidity and mortality. Interaction of activated neutrophils and endothelial cells is considered to play a prominent role in the pathophysiology of MODS. Insight in the nature and molecular basis of endothelial cell activation during HS can assist in identifying new rational targets for early therapeutic intervention. In this study, we examined the kinetics and organ specificity of endothelial cell activation in a mouse model of HS. Anesthetized male mice were subjected to controlled hemorrhage to a MAP of 30 mmHg. Mice were killed after 15, 30, 60, or 90 min of HS. After 90 min of hemorrhagic shock, a group of mice was resuscitated with 6% hydroxyethyl starch 130/0.4. Untreated mice and sham shock mice that underwent instrumentation and 90 min of anesthesia without shock served as controls. Gene expression levels of inflammatory endothelial cell activation (P-selectin, E-selectin, vascular cell adhesion molecule 1, and intercellular adhesion molecule 1) and hypoxia-responsive genes (vascular endothelial growth factor and hypoxia-inducible factor 1alpha) were quantified in kidney, liver, lung, brain, and heart tissue by quantitative reverse-transcription-polymerase chain reaction. Furthermore, we examined a selection of these genes with regard to protein expression and localization using immunohistochemical analysis. Induction of inflammatory genes occurred early during HS and already before resuscitation. Expression of adhesion molecules was significantly induced in all organs, albeit to a different extent depending on the organ. Endothelial genes CD31 and VE-cadherin, which function in endothelial cell homeostasis and integrity, were not affected during the shock phase except for VE-cadherin in the liver, which showed increased mRNA levels. The rapid inflammatory activation was not paralleled by induction of hypoxia-responsive genes. This study demonstrated the occurrence of early and organ-specific endothelial cell activation during hemorrhagic shock, as presented by induced expression of inflammatory genes. This implies that early therapeutic intervention at the microvascular level may be a rational strategy to attenuate MODS.

Telomerase in relation to expression of p53, c-Myc and estrogen receptor in ovarian tumours.

Telomerase activity and its subunits (hTERC, hTERT mRNA) were evaluated in ovarian tumours in relation to the expression of p53, c-Myc and estrogen receptor (ER). Furthermore, relations between telomerase activity, hTERC and hTERT with known clinicopathologic prognostic factors and survival in patients with malignant tumours was investigated. Telomerase activity was determined with TRAP, hTERC and hTERT with RT-PCR, while p53, c-Myc and ER expression with immunohistochemistry. Telomerase activity and hTERT mRNA were more frequently observed in malignant ovarian tumours compared to borderline and benign tumours, whereas hTERC was present in all tumour types. p53 and c-Myc were more frequently detected in malignant compared to borderline and benign tumours. Telomerase activity was positively related to hTERT mRNA, p53 and c-Myc expression, but not to hTERC and ER expression. In malignant tumours, hTERC levels were related to tumour stage, while telomerase activity and hTERT mRNA expression were not related to any clinicopathologic feature. Tumour stage, differentiation grade, residual tumour after first laparotomy and presence of ascites were related to (progression free) survival, whereas telomerase activity or its subunits were not. In conclusion, these data suggest that p53 expression (e.g. p53 mutation) as well as c-Myc expression may have a role in regulation of telomerase activity in ovarian tumours.