Expression of MET and SOX2 genes in non-small cell lung carcinoma with EGFR mutation

Abstract

Abstract. Non-small cell lung carcinoma (NSCLC) is a leading cause of cancer-related deaths. Aberrance of the two oncogenes MET and SOX2 are frequently encountered in NSCLC. Exons 18 through 21 of the EGFR gene were screened and MET and SOX2 immunostaining was conducted to analyze the immunohistological staining of MET and SOX2 and the EGFR mutation status. One hundred and fifty tissue samples were examined including 57 squamous cell carcinomas (SCCs), 80 adenocarcinomas (ADCs), 9 adenosquamous carcinomas (ADSCs) and 4 large cell carcinomas (LCCs). The 32 NSCLCs harboring an EGFR mutation included 28 ADCs, 3 SCCs and 1 ADSC. A higher level of SOX2 expression appeared in NSCLCs without the EGFR mutation compared to those with EGFR mutation (χ 2 =9.02, P=0.0027). Of the 28 ADCs, 24 (85.7%) with an EGFR mutation showed low level of SOX2 expression. ADCs with deletion in exon 19 overexpressed MET and showed low levels of SOX2. SOX2 expression was inversely correlated to the expression of MET in NSCLC and mainly present in non-mutated NSCLC (r=-0.42, P<0.0001). There was a tendency for SOX2 to be expressed in SCCs and particularly in the part of SCC among ADSCs, whereas MET was mainly expressed in the part of ADC among ADSCs and ADCs. High level of MET and SOX2 expression were respectively demonstrated in ADCs and SCCs; MET activation was accompanied with exon 19 deletion in ADCs. EGFR and MET coordinate to drive tumorigenesis. Detection of the activation of MET and EGFR may be used for targeted drug therapy.

SOX2 expression is an early event in a murine model of EGFR mutant lung cancer and promotes proliferation of a subset of EGFR mutant lung adenocarcinoma cell lines

“…For example, whereas HCC827 cells had high SOX2 expression, MET-amplified HCC827 GR5 cells that were made resistant to EGFR TKIs had low levels of SOX2. Interestingly, MET expression has been inversely correlated with SOX2 expression in human EGFR mutant lung cancers [22]. Therefore, acquisition of MET amplification might confer SOX2 independence and might be a negative predictor of SOX2 expression in EGFR mutant NSCLC.…”

Differential expression of CRKL and AXL genes in lung adenocarcinoma subtypes according to the epidermal growth factor receptor and anaplastic lymphoma kinase gene status

“…The primers were designed as follows: exon 18, forward 5'-CAACCAAGCTCTCTTGAGGATC-3' and reverse 5'-CCCAGCCCAGAGGCCTGT-3'; exon 19, forward 5'-GCA GCATGTGGCACCATCTC-3' and reverse 5'-AGAGCCATG GACCCCCACAC-3'; exon 20, forward 5'-CACACTGAC GTGCCTCTCC-3' and reverse 5'-AGCAGGTACTGGGAG CCAAT-3'; and exon 21, forward 5'-TCTGTCCCTCACAGC AGGGTCT-3' and reverse 5'-GCTGGCTGACCTAAAGCC ACC-3'. Amplification and sequencing of the exon fragments were performed as previously described (23). The PCR products were sequenced in the sense and antisense directions.…”

“…Genomic DNA was extracted from 50-100 mg tumor tissue scraped off formalin-fixed and paraffin-embedded blocks according to the previously described protocol (23). Briefly, PCR for exons 18 through 21 was performed with 100 ng template DNA in a 50-µl volume containing 0.75 U HotStarTaq DNA polymerase (Fermentas International Inc., Ontario, Canada), 5 µl PCR buffer, 0.8 µM deoxyribonucleotide triphosphate, 0.5 µM of each primer and different concentrations of MgCl 2 , depending on the various markers.…”

Expression level of CRKL and AXL combined with exon 19 deletion in EGFR and ALK status confer differential prognosis of lung adenocarcinoma subtypes

“…Genomic DNA was extracted from 50-100-mg tumor tissues obtained from formalin-fixed and paraffin-embedded blocks. The procedures followed a previously described protocol (27). PCR for exons 18-21 was performed using 100 ng template DNA in 50 µl volumes containing 0.75 U Hotstart Taq DNA polymerase (Fermentas; Thermo Fisher Scientific, Inc., Pittsburgh, PA, USA), 5 µl PCR buffer, 0.8 µM dNTP (Fermentas; Thermo Fisher Scientific, Inc.), 0.5 µM of each primer (Sangon Biotech Co., Ltd., Shanghai, China), and various concentrations of MgCl 2 , depending on varied markers.…”

“…The primers were designed by Sangon Biotech Co., Ltd. as follows: Exon 18 forward, 5'-CAA CCA AGC TCT CTT GAG GATC-3' and reverse, 5'-CCC AGC CCA GAG GCC TGT-3'; exon 19 forward, 5'-GCA GCA TGT GGC ACC ATCTC-3' and reverse, 5'-AGA GCC ATG GAC CCC CACAC-3'; exon 20 forward, 5'-CAC ACT GAC GTG CCT CTCC-3' and reverse, 5'-AGC AGG TAC TGG GAG CCAAT-3'; and exon 21 forward, 5'-TCT GTC CCT CAC AGC AGG GTCT-3' and reverse, 5'-GCT GGC TGA CCT AAA GCC ACC-3'. The amplification and sequencing of exon fragments were performed as previously described (27). PCR products were sequenced in sense and antisense directions.…”