Identification of Candidate Biomarkers for EGFR-T790M Drug-resistant Gene Mutation in Advanced Lung Adenocarcinoma / 中国肺癌杂志

BACKGROUND@#Osimertinib is approved by Food and Drug Administration for patients with advanced non-small cell lung cancer carrying EGFR-T790M mutations. Osimertinib therapy was missed in many patients who were unable to perform biopsy due to occult lesion progression or weak body. In this study. We hope that some proteins associated with predicting EGFR-T790M resistance could be screened from the serum to provide help for clinical medication. The aim of this study is to explore the protein associated with EGFR-T790M drug resistance gene and provide help for clinical medication.@*METHODS@#In this study, 36 patients with advanced lung adenocarcinoma treated by gefitinib were included. After the disease progression of the patients, biopsy was performed. 18 patients in the EGFR-T790M mutation group and 18 patients in the non-EGFR-T790M mutation group were detected by the ARMS method. Serum of patients with drug resistance was collected, and proteins related to EGFR-T790M resistance were screened by isotopic marker relative and absolute quantitative marker combined with two-dimensional liquid chromatography tandem mass spectrometry proteomics technology.@*RESULTS@#Seventeen different proteins were screened out, including 6 up-regulated proteins and 11 down-regulated proteins associated with EGFR-T790M gene mutation, which were mainly involved in 31 biological processes, 7 cell components and 26 molecular functions. Twelve enrichment pathways were identified, among which the highest enrichment index was the coagulation cascade pathway.@*CONCLUSIONS@#Seventeen proteins associated with EGFR-T790M resistance were found, and proteins involved in the coagulation cascade pathway are expected to be biomarkers associated with predicting EGFR-T790M resistance mutations.

Real-World Analysis of the Efficacy of Rebiopsy and EGFR Mutation Test of Tissue and Plasma Samples in Drug-Resistant Non-Small Cell Lung Cancer

PURPOSE: Standard treatment for cases of non-small cell lung cancer (NSCLC) exhibiting acquired drug resistance includes tumor rebiopsy, epidermal growth factor receptor (EGFR) mutation testing (e.g., for T790M mutations), and the subsequent administration of third-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs). However, rebiopsies are typically invasive, costly, and occasionally not feasible. Therefore, the present study aimed to assess rebiopsy procedures by analyzing real-world data collected by the ASTRIS study of patients with resistant NSCLC. MATERIALS AND METHODS: The present study used statistical models to evaluate data collected by the ASTRIS trial (NCT02474355) conducted at Yonsei Cancer Center, including the rebiopsy success rate, incidence of T790M mutations in collected tissue and plasma samples, and association of administered osimertinib treatment efficacy. RESULTS: In a total of 188 screened patients, 112 underwent rebiopsy. An adequate tumor specimen was obtained in 95 of these patients, the greatest majority of whom (43.8%) were subjected to bronchoscopy. T790M mutations were detected in 53.3% of successfully EGFR-tested rebiopsy samples. A total of 88 patients received osimertinib treatment, and the objective response rate and median progression-free survival time was 44.3% and 32.7 weeks, respectively, among the treated patients overall, but 57.8% and 45.0 weeks, and 35.2% and 20.4 weeks among patients who exhibited T790M-positive tissue (n=45) and plasma (n=54) samples, respectively. CONCLUSION: Approximately 60% of patients in the analyzed real-world cohort were eligible for tissue rebiopsy upon NSCLC progression. Osimertinib activity was higher in patients in whom T790M mutations were detected in tissues rather than in plasma samples.

Monitoring EGFR T790M mutations by Blocker PCR in plasma of advanced non-small-cell lung cancer patients with EGFR-TKI acquired resistance / 复旦学报（医学版）

Objective To evaluate the feasibility of Blocker PCR assays in monitoring T790M mutations in plasma of non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) acquired resistance.Methods Blocker PCR assays were employed to identify mutations in plasma for 127 advanced NSCLC with acquired EGFR-TKI resistance.In addition,the paired tumor re-biopsy or PE samples were obtained to analyze EGFR mutations.Meanwhile,we evaluated the detection accuracy of Blocker PCR assays in comparison with the next generation sequencing (NGS).Results Among the 127 patients,40.15％ (51/127) EGFR T790M was detected in the plasma,78.44％ (40/51) coexisted with an EGFR activating mutation.Additionally,54.54 ％ (6/11) EGFR T790M was identified in re-biopsy tissues,while 43.75 ％ (14/32) were detected in the plasma.Furthermore,the concordance rate of Blocker PCR and NGS in identifying EGFR sensitizing mutations and EGFR T790M mutations was 100％.Conclusions Blocker PCR is a highly sensitive and reliable method in monitoring EGFR T790M mutations in the plasma of NSCLC patients with EGFR-TKI acquired resistance.

The research on the change of chemosensitivity of geiftinib-resistant lung adenocarcinoma cell caused byEGFR-T790M mutation / 中国癌症杂志

Background and purpose:Chemotherapy is an alternative treatment option, which could still get a therapeutic effect, when the EGFR-TKI treatment of non-small cell lung cancer failed. Studies have shown that RR, TYMS, ERCC1 and TUBB3 have respectively relationship with chemosensitivity of gemcitabine, pemetrexed, platinum-based drugs and microtubule-based chemotherapy drugs.The expression levels of these molecular markers can predict the sensitivity of these chemotherapy drugs. The patients with RRMI, TS, ERCC1 and TUBB3 higher expression have reduced chemosensitivity, and lower expression have increased sensitivity. The purpose of this study was to explore the sensitivity of tumor cell lines with acquired resistance to geiftinib caused byEGFR-T790M mutation to cisplatin, gemcitabine, pemetrexed, vinorelbine, paclitaxel and docetaxel.Methods:MTT assay was used to detect the IC50 values of cisplatin, gemcitabine, vinorelbine, paclitaxel and docetaxel, pemetrexed to PC9 and PC9/GR cells, and to explore the chemosensitivity of lung adenocarcinoma cells to these chemotherapy drugs; Luminex method was used respectively to detect the expression levels of ERCC1 mRNA, TUBB3 mRNA, TS mRNA, and RRM1 mRNA in PC9 and PC9/GR cells. Western blot was used to detect the protein expression levels of ERCC1, TUBB3, TS and RRM1 in PC9 and PC9/GR cells.Results: The IC50 values of cisplatin, gemcitabine and pemetrexed to PC9/GR cells were signiifcantly higher than those to PC9 cells (P<0.05), while the IC50 values of vinorelbine, paclitaxe and docetaxel to PC9/GR cells were signiifcantly decreased (P<0.05). Luminex method showed the expressions of ERCC1 mRNA, TS mRNA and RRM1 mRNA in PC9/GR cells were signiifcantly increased than those in PC9 cells (P<0.05), while the expression of TUBB3 mRNA was signiifcantly decreased (P<0.05). Western blot method showed the expressions of TUBB3, TS and RRM1 protein in PC9/GR cells were signiifcantly increased than those in PC9 cells (P<0.05), while TUBB3 protein expression in PC9/GR cells was signiifcantly decreased (P<0.05). Western blot method analysis result showed that the expressions of TUBB3, TS and RRM1 protein in PC9/GR cells were significantly increased than those in PC9 cells (P<0.05), while TUBB3 protein expression in PC9/GR cells was signiifcantly decreased (P<0.05). Conclusion:The chemosensitivity of lung adenocarcinoma with EGFR-T790M mutation is changed. It has decreased sensitivity to cisplatin, gemcitabine, pemetrexed and increased sensitivity to vinorelbine, paclitaxel and docetaxel. The reason of the change of chemosensitivity of geiftinib-resistant lung adenocarcinoma cell maybe related to the changes of ERCC1 mRNA, RRM1 mRNA and TS mRNA and their protein expressions.