BACKGROUND: Double-stranded RNA-specific adenosine deaminase 1 (ADAR1) binds to double-stranded RNA and catalyzes the deamination of adenosine (A) to inosine (I). The functional mechanism of ADAR1 in non-small cell lung cancer (NSCLC) remains incompletely understood. This study aimed to investigate the prognostic significance of ADAR1 in NSCLC and to elucidate its potential role in regulating tumor cell proliferation and migration. METHODS: Data from The Cancer Genome Atlas (TCGA) and cBioPortal were analyzed to assess the correlation between high ADAR1 expression and clinicopathological features as well as prognosis in lung cancer. We performed Western blot (WB), cell proliferation assays, Transwell invasion/migration assays, and nude mouse xenograft modeling to examine the phenotypic changes and molecular mechanisms induced by ADAR1 knockdown. Furthermore, the ADAR1 p150 overexpression model was utilized to validate the proposed mechanism. RESULTS: ADAR1 expression was significantly elevated in lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) tissues compared with adjacent non-tumor tissues (LUAD: P=3.70×10-15, LUSC: P=0.016). High ADAR1 expression was associated with poor prognosis (LUAD: P=2.03×10-2, LUSC: P=2.81×10-2) and distant metastasis (P=0.003). Gene Set Enrichment Analysis (GSEA) indicated that elevated ADAR1 was associated with mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway activation, matrix metalloproteinase-9 (MMP-9) expression, and cell adhesion. ADAR1 and MMP-9 levels showed a strongly positive correlation (P=6.45×10-34) in 10 lung cancer cell lines, highest in H1581. Knockdown of ADAR1 in H1581 cells induced a rounded cellular morphology with reduced pseudopodia. Concomitantly, it suppressed cell proliferation, invasion, migration, and in vivo tumorigenesis. It also suppressed ERK phosphorylation and downregulated cellular Finkel-Biskis-Jinkins murine osteosarcoma viral oncogene homolog (c-FOS), MMP-9, N-cadherin, and Vimentin. Conversely, ADAR1 p150 overexpression in PC9 cells enhanced ERK phosphorylation and increased c-FOS and MMP-9 expression. CONCLUSIONS High ADAR1 expression is closely associated with poor prognosis and distant metastasis in NSCLC patients. Mechanistically, ADAR1 may promote proliferation, invasion, migration, and tumorigenesis in lung cancer cells via the ERK/c-FOS/MMP-9 axis.
Humans ; Lung Neoplasms/physiopathology* ; Adenosine Deaminase/genetics* ; Matrix Metalloproteinase 9/genetics* ; Cell Proliferation ; Carcinoma, Non-Small-Cell Lung/physiopathology* ; Cell Movement ; Animals ; Mice ; RNA-Binding Proteins/genetics* ; Female ; Male ; Cell Line, Tumor ; Proto-Oncogene Proteins c-fos/genetics* ; Middle Aged ; MAP Kinase Signaling System ; Gene Expression Regulation, Neoplastic ; Mice, Nude ; Extracellular Signal-Regulated MAP Kinases/genetics*

BACKGROUND: The switch/sucrose nonfermentable chromatin-remodeling (SWI/SNF) complex is a pivotal chromatin remodeling complex, and the genomic alterations (GAs) of the SWI/SNF complex are observed in several cancer types, correlating with multiple biological features of tumor cells. However, their role in liver metastasis of non-small cell lung cancer (NSCLC) remains unclear. Our study aims to investigate the role and potential mechanisms underlying NSCLC liver metastasis induced by the GAs of SWI/SNF complex. METHODS: The GAs of SWI/SNF complex in NSCLC cell lines (H1299, H23 and H460) were identified by whole-exome sequencing (WES). ARID1A knockout H1299 cell was constructed with the CRISPR/Cas9 technology. The mouse model of liver metastasis from NSCLC was established to simulate lung cancer liver metastasis and observe the metastasis rate under different gene mutation conditions. RNA sequencing and Western blot were conducted for differential gene expression analysis. Immunohistochemistry (IHC) analysis was used to assess protein expression levels of SWI/SNF-regulated target molecules in mouse liver metastases. RESULTS: WES analysis revealed intracellular gene mutations. The animal experiments demonstrated a correlation between the GAs of SWI/SNF complex and a higher liver metastasis rate in immunodeficient mice. Transcriptome sequencing and Western blot analysis showed upregulated expression of ALDH1A1 and APOBEC3B in SWI/SNF-mut cells, particularly in ARID1A-deficient H460 and H1299 sgARID1A cells. IHC staining of mouse liver metastases further demonstrated elevated expression of ALDH1A1 in the H460 and H1299 sgARID1A group. CONCLUSIONS This study underscores the critical role of the GAs of SWI/SNF complex, such as ARID1A and SMARCA4, in promoting liver metastasis of lung cancer cells. The GAs of SWI/SNF complex may promote liver-specific metastasis by upregulating ALDH1A1 and APOBEC3B expression, providing novel insights into the molecular mechanisms underlying lung cancer liver metastasis.
Animals ; Mice ; Carcinoma, Non-Small-Cell Lung/genetics* ; Lung Neoplasms/genetics* ; Mutation ; Liver Neoplasms/genetics*

Background and objective Uridine-diphosphoglucuronosyl transferase 1A1 (UGT1A1),UGT1A1 *28 polymorphism can reduce UGT1A1 enzymatic activity,which may lead to severe toxicities in patients who receive irinotecan.This study tries to build a fragment analysis method to detect UGT1A1 *28 polymorphism.Methods A total of 286 blood specimens from the lung cancer patients who were hospitalized in Guangdong General Hospital between April 2014 to May 2015 were detected UGT1A1*28 polymorphism by fragment analysis method.Results Comparing with Sanger sequencing,precision and accuracy of the fragment analysis method were 100％.Of the 286 patients,236 (82.5％ harbored TA6/6 genotype,48 (16.8％) TA 6/7 genotype and 2 (0.7％) TA7/7 genotype.Conclusion Our data suggest hat the fragment analysis method is robust for detecting UGT1A1 *28 polymorphism in clinical practice.It's simple,time-saving,and easy-to-carry.

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.

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.