Devil in the detail: MET overexpression fails as surrogate marker for MET exon 14 splice site mutations in NSCLC.
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SUBMITTER: Strickland MR
PROVIDER: S-EPMC7791198 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:PurposeMET exon 14 skipping is one of the rare mutations in non-small cell lung cancer (NSCLC), involving its pathogenesis and progression. The performances of several MET inhibitors in clinical trials have been validated based on NGS, immunohistochemistry (IHC), and gene copy number assessments. Thus, a detailed understanding of the relationship between these markers and prognosis is required.MethodsThis study has recruited patients (n = 17) with MET exon 14 skipping mutation and initially screened genes (n = 10) by polymerase chain reaction (PCR) from 257 specimens of NSCLC, including small biopsies and surgical resection. Further, the IHC analysis detected MET overexpression and recorded the score using the MetMAb trial (rial ( recruited patients (n = 17) with MET exstainings). Finally, the fluorescence in situ hybridization (FISH) resulted in the MET amplification with a MET copy number initially screened genes (n = 10) by p.ResultsPCR results indicated strong MET staining ( 3+) in more than 50% of tumor cells. Among the recruited 17 cases of MET exon 14 skipping, 9 cases presented MET amplification, and 10 cases with MET overexpression. These attributes were not correlated to the clinicopathological characteristics and overall survival. In addition, 4 cases showed gene amplification, and 3 cases presented polyploidy condition. The correlation analysis showed a significant relationship between MET amplification and MET overexpression (Pearson's r2 = 0.4657, P < 0.005).ConclusionTogether, these findings indicated a significant correlation between MET overexpression and MET amplification in NSCLC patients but no correlation to prognosis.
| S-EPMC10318750 | biostudies-literature
Project description:Targeted therapies for MET exon 14-skipping (METΔex14)-driven lung cancers have generated some promising results but response rates remain below that seen for other kinase-driven cancers. One strategy for improving treatment outcomes is to employ rational combination therapies to enhance the suppression of tumour growth and delay or prevent the emergence of resistance. To this end, we profiled the transcriptomes of MET-addicted lung tumours and cell lines and identified the RAS-mitogen-activated protein kinase (MAPK) pathway as a critical effector required for METΔex14-dependent growth. Ectopic expression of MET in an isogenic cell line model showed that overexpression of the mutant MET receptor led to higher levels of MAPK phosphorylation and nuclear import, resulting in increased expression and phosphorylation of nuclear MAPK targets. In comparison, other known MET effectors were unaffected. Inhibition of this pathway by KRAS knockdown in MET-addicted cells in vitro led to decreased viability in only the METΔex14-mutant cells. Conversely, decoupling RAS-MAPK axis, but not other effector pathways, from MET activity via the introduction of constitutively active mutants conferred resistance to MET inhibitors in vitro. Our results suggest that aberrant hyperactivity of the MET receptor caused by the exon 14-skipping mutation does not uniformly upregulate all known downstream effectors, rather gaining a predilection for aberrantly activating and subsequently relying on the RAS-MAPK pathway. These findings provide a rationale for the co-targeting of the RAS-MAPK pathway alongside MET to prolong therapeutic response and circumvent resistance to improve patient survival.
| S-EPMC8946549 | biostudies-literature
Project description:Background The aim of the present study was to summarize the clinical and pathological characteristics of 11 non-small cell lung cancer (NSCLC) patients with mesenchymal-epithelial transition factor exon 14 skipping (METex14). Methods From 2018 to 2021, medical records of 763 NSCLC patients were reviewed and 11 patients carrying METex14 were identified from the Affiliated Hospital of Guangdong Medical University. Their clinical data were subsequently examined for pathological and related clinical information including symptom and diagnosis, imaging and follow-up. Results The METex14 cohort includes 9 males and 2 females and the age range was 69–85 years, with a median age of 77 years. Of the patients one is diagnosed with stage IVB lung adenosquamous carcinoma, 7 with lung adenocarcinoma (1 with stage IIIA and 6 with stage IV), and 3 with stage IV lung sarcomatoid carcinoma. 3 reached stable disease until the end of follow-up and 4 died within a year due to multiple metastases. In 4 cases, the patients received selective MET inhibitor treatment all lived longer than 7 months. There were 4 heterozygous point mutations and 1 deletion of the MET gene in this cohort, as follows: c.G3028T (p.D1010Y); c.G3028A (p.D1010N); c.G3005C (p.V1002A); c.3022C>G and MET c.3021_3028+20del (E14). Conclusions According to the data that we collected, the incidence of NSCLC carrying METex14 is low and male outnumber female in our sample pool. Selective target therapy had better prognosis than multitargeted tyrosine kinase inhibitor (TKI) such as crizotinib or standard therapy.
| S-EPMC9091003 | biostudies-literature
Project description:IntroductionThe MET inhibitor tepotinib demonstrated durable clinical activity in patients with advanced MET exon 14 (METex14) skipping NSCLC. We report detailed analyses of adverse events of clinical interest (AECIs) in VISION, including edema, a class effect of MET inhibitors.Patients and methodsIncidence, management, and time to first onset/resolution were analyzed for all-cause AECIs, according to composite categories (edema, hypoalbuminemia, creatinine increase, and ALT/AST increase) or individual preferred terms (pleural effusion, nausea, diarrhea, and vomiting), for patients with METex14 skipping NSCLC in the phase II VISION trial.ResultsOf 255 patients analyzed (median age: 72 years), edema, the most common AECI, was reported in 69.8% (grade 3, 9.4%; grade 4, 0%). Median time to first edema onset was 7.9 weeks (range: 0.1-58.3). Edema was manageable with supportive measures, dose reduction (18.8%), and/or treatment interruption (23.1%), and rarely prompted discontinuation (4.3%). Other AECIs were also manageable and predominantly mild/moderate: hypoalbuminemia, 23.9% (grade 3, 5.5%); pleural effusion, 13.3% (grade ≥ 3, 5.1%); creatinine increase, 25.9% (grade 3, 0.4%); nausea, 26.7% (grade 3, 0.8%), diarrhea, 26.3% (grade 3, 0.4%), vomiting 12.9% (grade 3, 1.2%), and ALT/AST increase, 12.2% (grade ≥ 3, 3.1%). GI AEs typically occurred early and resolved in the first weeks.ConclusionTepotinib was well tolerated in the largest trial of a MET inhibitor in METex14 skipping NSCLC. The most frequent AEs were largely mild/moderate and manageable with supportive measures and/or dose reduction/interruption, and caused few withdrawals in this elderly population.
| S-EPMC10068910 | biostudies-literature
Project description:MET mutations leading to exon 14 skipping (METΔex14) are strong molecular drivers for non-small-cell lung cancer (NSCLC). Capmatinib is a highly potent, selective oral MET inhibitor that showed clinically meaningful efficacy and a manageable safety profile in a global phase II study (GEOMETRY mono-1, NCT02414139) in patients with advanced METΔex14-mutated/MET-amplified NSCLC. We report results of preplanned analyses of 45 Japanese patients according to MET status (METΔex14-mutated or MET-amplified) and line of therapy (first- [1L] or second-/third-line [2/3L]). The starting dose was 400 mg twice daily. The primary endpoint was the objective response rate (ORR) assessed by a blinded independent review committee. A key secondary endpoint was duration of response (DOR). Among METΔex14-mutated patients, in the 1L group, one patient achieved partial response (DOR of 4.24 months) and the other had stable disease. In the 2/3L group, the ORR was 36.4% (95% confidence interval [CI] 10.9%-69.2%), median DOR was not evaluable, and progression-free survival was 4.70 months. One patient (2/3L group) showed partial resolution of brain lesions per independent neuroradiologist review. In MET-amplified patients with a MET gene copy number of ≥10, the ORR was 100% (2/2 patients) in the 1L group and 45.5% (5/11 patients) in the 2/3L group, with DOR of 8.2 and 8.3 months, respectively. Common treatment-related adverse events among the 45 Japanese patients were blood creatinine increased (53.3%), nausea (35.6%), and oedema peripheral (31.1%); most were grade 1/2 severity. In conclusion, capmatinib was effective and well tolerated by Japanese patients with METΔex14/MET-amplified NSCLC, consistent with the overall population.
| S-EPMC8019204 | biostudies-literature
Project description:BackgroundHigh frequency of MNNG HOS transforming (MET) exon 14 skipping mutation (MET exon 14Δ) has been reported in pulmonary sarcomatoid carcinomas (PSCs). However, the frequencies differ greatly. Our study aims to investigate the frequency of MET alterations and the correlations among MET exon 14Δ, amplification, and protein overexpression in a large cohort of PSCs. MET exon 14Δ, amplification, and protein overexpression were detected in 124 surgically resected PSCs by using Sanger sequencing, fluorescent in situ hybridization (FISH), and immunohistochemistry (IHC) respectively. MET exon 14Δ was identified in 9 (7.3%) of 124 cases, including 6 pleomorphic carcinomas, 2 spindle cell carcinomas and 1 carcinosarcoma. MET amplification and protein overexpression were detected in 6 PSCs (4.8%) and 25 PSCs (20.2%), respectively. MET amplification was significantly associated with overexpression (P < 0.001). However, MET exon 14Δ has no correlation with MET amplification (P = 0.370) and overexpression (P = 0.080). Multivariable analysis demonstrated that pathologic stage (hazard ratio [HR], 2.78; 95% confidence interval [CI], 1.28-6.01; P = 0.010) and MET amplification (HR, 4.71; 95% CI, 1.31-16.98; P = 0.018) were independent prognostic factors for poor median overall survival (mOS). MET alterations including MET exon 14Δ and amplification should be recommended as routine clinical testing in PSCs patients who may benefit from MET inhibitors. MET IHC appears to be an efficient screen tool for MET amplification in PSCs.
| S-EPMC7492996 | biostudies-literature
Project description:BackgroundMET amplification or METex14 skipping mutations are uncommon oncogenic events in NSCLC patients. Clinicopathological characteristics, concurrent gene alterations, and prognosis of MET TKIs in these patients are yet to be elucidated.MethodsWe retrospectively analyzed the genomic profiles of 43 MET amplifications or 31 METex14 skipping mutations in NSCLC patients with no previous treatment with EGFR TKIs. Survival outcomes were analyzed in evaluable patients receiving MET TKI treatment: MET amplification cohort (n = 29) and METex14 skipping mutation cohort (n = 29).ResultsAmong evaluable patients, a shorter PFS was observed in the MET amplification cohort than in the METex14 skipping mutation cohort (7.0 months vs. 11.0 months, P = 0.043). Concurrent mutations in both cohorts resulted in a statistically significant shorter PFS (MET amplification: 3.5 months versus 8.0 months, P = 0.038, METex14 skipping mutation: 7.0 versus NR months, P = 0.022). However, a statistically significant OS (17.0 months versus 20.0 months, P = 0.044) was only observed in the MET amplification cohort. TP53, the most common concurrent mutation in both cohorts, was associated with worse survival outcomes as compared to the wild type. The MET amplification cohort with a concurrent PIK3CA mutation exhibited primary resistance to MET TKIs and showed disease progression (80%).ConclusionMET TKIs could be a better treatment option for patients with METex14 skipping mutations. Concurrent mutations may deteriorate the PFS of MET TKIs in NSCLC patients with MET amplification or METex14 skipping mutations. PIK3CA mutations may confer primary resistance to MET TKIs in patients with MET amplification.
| S-EPMC8264054 | biostudies-literature
Project description:Recently, MET exon 14 deletion (METex14del) has been postulated to be one potential mechanism for MET protein overexpression. We screened for the presence of METex14del transcript by multiplexed fusion transcript analysis using nCounter assay followed by confirmation with quantitative reverse transcription PCR with correlation to MET protein expression by immunohistochemistry (IHC) and MET amplification by fluorescence in situ hybridization (FISH). We extracted RNAs from 230 patients enrolled onto the prospective molecular profiling clinical trial (NEXT-1) (NCT02141152) between November 2013 and August 2014. Thirteen METex14del cases were identified including 3 gastric cancer, 4 colon cancer, 5 non-small cell lung cancer, and one adenocarcinoma of unknown primary. Of these 13 METex14del cases, 11 were MET IHC 3+ and 2 were 2+. Only one out of the 13 METex14del cases was MET amplified (MET/CEP ratio > 2.0). Growths of two (gastric, colon) METex14del+ patient tumor derived cell lines were profoundly inhibited by both MET tyrosine kinase inhibitors and a monoclonal antibody targeting MET. In conclusion, METex14del is a unique molecular aberration present in gastrointestinal (GI) malignancies corresponding with overexpression of MET protein but rarely with MET amplification. Substantial growth inhibition of METex14del+ patient tumor derived cell lines by several MET targeting drugs strongly suggests METex14del is a potential actionable driver mutation in GI malignancies.
| S-EPMC4695055 | biostudies-literature
Project description:PurposeMET tyrosine kinase inhibitors (TKIs) can achieve modest clinical outcomes in MET exon 14-altered lung cancers, likely secondary to primary resistance. Mechanisms of primary resistance remain poorly characterized and comprehensive proteomic analyses have not previously been performed.Experimental designWe performed hybrid capture-based DNA sequencing, targeted RNA sequencing, cell-free DNA sequencing, selected reaction monitoring mass spectrometry (SRM-MS), and immunohistochemistry on patient samples of MET exon 14-altered lung cancers treated with a MET TKI. Associations between overall response rate (ORR), progression-free survival (PFS), and putative genomic alterations and MET protein expression were evaluated.ResultsSeventy-five of 168 MET exon 14-altered lung cancers received a MET TKI. Previously undescribed (zygosity, clonality, whole-genome duplication) and known (copy-number focality, tumor mutational burden, mutation region/type) genomic factors were not associated with ORR/PFS (P > 0.05). In contrast, MET expression was associated with MET TKI benefit. Only cases with detectable MET expression by SRM-MS (N = 15) or immunochemistry (N = 22) responded to MET TKI therapy, and cancers with H-score ≥ 200 had a higher PFS than cancers below this cutoff (10.4 vs. 5.5 months, respectively; HR, 3.87; P = 0.02).ConclusionsIn MET exon 14-altered cancers treated with a MET TKI, a comprehensive analysis of previously unknown and known genomic factors did not identify a genomic mechanism of primary resistance. Instead, MET expression correlated with benefit, suggesting the potential role of interrogating the proteome in addition to the genome in confirmatory prospective trials.
| S-EPMC7854494 | biostudies-literature
Project description:MET exon 14 alterations are a diverse group of mutations, many of which disrupt splice acceptor or donor sites leading to exon 14 skipping, impaired receptor degradation, and oncogenic transformation. These alterations are clinically targetable with MET-directed therapy. Clin Cancer Res; 22(12); 2832-4. ©2016 AACRSee related article by Tong et al., p. 3048.
| S-EPMC4911276 | biostudies-literature