Development of a novel ALK rearrangement screening test for non-small cell lung cancers

PLoS One. 2021 Sep 24;16(9):e0257152. doi: 10.1371/journal.pone.0257152. eCollection 2021.

Abstract

Approximately 5-7% of non-small cell lung cancer (NSCLC) cases harbor an anaplastic lymphoma kinase (ALK) fusion gene and may benefit from ALK inhibitor therapy. To detect ALK fusion genes, we developed a novel test using reverse transcription polymerase chain reaction (RT-PCR) for the ALK kinase domain (KD). Since ALK expression is mostly silenced in the adult with the exception of neuronal tissue, the normal lung tissue, mesothelial lining, and inflammatory cells are devoid of ALK transcript, making ALK KD RT-PCR an ideal surrogate test for ALK fusion transcripts in lung or pleural effusion. The test was designed with a short PCR product (197 bp) to work for both malignant pleural effusion (MPE) and formalin-fixed, paraffin-embedded (FFPE) NSCLC samples. Using ALK IHC as a reference, the sensitivity of the test was 100% for both MPE and FFPE. The specificity was 97.6% for MPE and 97.4% for FFPE. Two false positive cases were found. One was a metastatic brain lesion which should be avoided in the future due to intrinsic ALK expression in the neuronal tissue. The other one resulted from ALK gene amplification. Due to potential false positivity, subsequent confirmation tests such as fluorescence in situ hybridization or multiplex PCR would be preferable. Nevertheless, the test is simple and inexpensive with no false negativity, making it a desirable screening test. It also offers an advantage over multiplex RT-PCR with the capability to detect novel ALK fusions. Indeed through the screening test, we found a novel ALK fusion partner (sperm antigen with calponin homology and coiled-coil domains 1 like gene, SPECC1L) with increased sensitivity to crizotinib in vitro. In summary, a novel RNA-based ALK KD analysis was developed for ALK rearrangement screening in MPE and FFPE specimens of NSCLC. This simple inexpensive test can be implemented as routine diagnostics.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Anaplastic Lymphoma Kinase / genetics*
  • Base Sequence
  • Carcinoma, Non-Small-Cell Lung / drug therapy
  • Carcinoma, Non-Small-Cell Lung / enzymology*
  • Carcinoma, Non-Small-Cell Lung / genetics*
  • Cell Cycle Proteins / genetics
  • Cell Proliferation / drug effects
  • Cohort Studies
  • Crizotinib / pharmacology
  • Crizotinib / therapeutic use
  • DNA, Neoplasm / genetics
  • Early Detection of Cancer*
  • ErbB Receptors / genetics
  • Female
  • Formaldehyde
  • Gene Rearrangement*
  • HEK293 Cells
  • Humans
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / enzymology*
  • Lung Neoplasms / genetics*
  • Male
  • Microtubule-Associated Proteins / genetics
  • Middle Aged
  • Paraffin Embedding
  • Pleural Effusion, Malignant / enzymology
  • Pleural Effusion, Malignant / genetics
  • Serine Endopeptidases / genetics
  • Tissue Fixation

Substances

  • Cell Cycle Proteins
  • DNA, Neoplasm
  • Microtubule-Associated Proteins
  • Formaldehyde
  • Crizotinib
  • Anaplastic Lymphoma Kinase
  • EGFR protein, human
  • ErbB Receptors
  • EML4 protein, human
  • Serine Endopeptidases

Associated data

  • figshare/10.6084/m9.figshare.15090201

Grants and funding

This manuscript was supported by research grants MOST 110-2320-B-006-026 from the Ministry of Science and Technology, TAIWAN; NCKUH-11008004, NCKUH-11008014 and NCKUH-11008018 from the National Cheng Kung University Hospital, Tainan, TAIWAN.