Aberrant expression of anaplastic lymphoma kinase in lung adenocarcinoma: Analysis of circulating free tumor RNA using one-step reverse transcription-polymerase chain reaction

Abstract

Lung adenocarcinoma patients harboring anaplastic lymphoma kinase (ALK) gene rearrangements respond well to approved ALK inhibitors. However, to date, limited evidence is available regarding whether using circulating free tumor mRNA to identify aberrant ALK expression is possible, and its feasibility remains to be clearly addressed. The present study evaluated ALK expression by a one-step reverse transcription‑polymerase chain reaction (PCR) assay on the circulating free tumor mRNA from 12 lung adenocarcinoma patients. Additionally, the present study tested for ALK rearrangements by fluorescence in situ hybridization (FISH) and immunohistochemistry. A molecular genetic characterization was performed on tumor tissues and plasma samples. Aberrant ALK expression was detected in 2/12 patients using mRNA purified from plasma specimens and the results agreed with the FISH and immunohistochemistry findings of solid biopsy samples. The detection of aberrant ALK expression on circulating free tumor RNA may be feasible using a one‑step real‑time PCR assay and may be particularly helpful when a solid biopsy sample is not available.

Oncogenic Alterations in Histologically Negative Lymph Nodes Are Associated with Prognosis of Patients with Stage I Lung Adenocarcinoma

“…Oncogenic alterations of EGFR, ALK, ROS1, RET, KRAS, BRAF, HER2, NRAS, and PIK3CA were detected by fluorescence quantitative PCR in tumor samples using Stratagene Mx3000P™ and AmoyDx Multi-Gene Mutations Detection Kit (Amoy Diagnostics, Xiamen, China). Fusions of ALK, ROS1 and RET genes were identified by mRNA-based methods using specific primers and fluorescent probes in a one-step RT-PCR [13] and point mutations in EGFR, KRAS, BRAF, NRAS, HER2, and PIK3CA genes were identified using the ADxamplification refractory mutation system (ARMS) as previously described [14]. Only the canonical oncogenic mutations such as EGFR L858R/19Del/T790M, KRAS G12C/A/V/R, BRAF V600E, NRAS G12C/R/V/A, PIK3CA E545K, HER2 20ins etc.…”