ABSTRACT
Objective:To establish a method based on the iPLEX analysis of MassARRAY mass spectrometry platform to detect multiplex genetic mutations among Chinese lung cancer patients. Methods:We reviewed the related literature and data of lung cancer treatments. We also determined 99 mutation hot spots in 13 target genes, namely, EGFR, KRAS, ALK, FGFR1, FGFR2, FGFR3, PIK3CA, BRAF, PTEN, MET, ERBB2, AKT1, and STK11, which are closely related to the pathogenesis, drug resistance, and metastasis of lung cancer and are associated with relevant transduction pathways. A total of 297 primers comprising 99 paired forward and reverse amplification primers and 99 matched extension primers were designed by using Assay Design in accordance with the mutation label and format requirements of the MassARRAY platform. The detection method was established by analyzing eight cell lines and six lung cancer specimens;the proposed method was then validated through comparisons with a LungCarta kit. The sensitivity and specificity of the proposed method were evaluated by directly sequencing EGFR and KRAS genes in 100 lung cancer cases. Results:The proposed method could detect multiplex genetic mutations in the lung cancer cell lines, and this finding is consistent with that observed using previously reported methods. The proposed method could also detect such mutations in clinical lung cancer specimens;this result is also consistent with that observed by using the LungCarta kit. However, an FGFR2 mutation was detected only by using the proposed method. The measured sensitivity and specificity were 100%and 96.3%, respectively. Conclusion:The proposed MassARRAY technology-based method could detect multiplex genetic mutations among Chinese lung cancer patients. Indeed, the proposed method can be potentially applied to detect mutations in cancer cells.
ABSTRACT
ObjectiveTo investigate the fusion sequence complexity of EML4-ALK in non-small cell lung cancer (NSCLC) patients,and the potential mutation in tyrosine kinase ( TK ) domain of ALK gene.MethodsIn routine practice,a novel echinoderm microtubule-associated protein-like4 and anaplastic lymphoma kinase (EML4-ALK) V3c variant was detected by rapid amplification of cDNA ends-polymerase chain reaction ( RACE-PCR )-sequencing technology in a patient with NSCLC.The further consecutive 39 cases( total of 40 cases)were screened by use of reverse transcription (RT)-PCR for EML4-ALK fusion.Positive PCR products were purified and cloned into T vectors,transformed into DH5a germ cells and colony picked up and sequenced for sequence complexity analysis.Tyrosine kinase domain of ALK was amplified by RT-PCR and sequenced.ResultsThree out of 40 cases had EML4-ALK fusion.One case had six novel variants of EML4-ALK co-existing,termed as V3c ( 64.6％ ),V3d ( 25.0％ ),V3e ( 2.1％ ),V3f (4.2％ ),V3g(2.1％ )and V3h(2.1％ ) variants,whereas without common V3a and V3b variants.In other two positive cases,one was V1 variant,another was concurrent V2,V3a and V3b variants.No mutations were detected in the TK domain of EML4-ALK in any case.ConclusionsSeveral EML-ALK variants could co-exist in a given lung cancer tissue,which suggest that the diversity and sequence complexity of EML4-ALK fusion are exist.Attentions should be paid to screen all the variants in clinic to improve the pick-up rate.