Proteinase K treatment improves RNA recovery from thyroid cells fixed with liquid-based cytology solution

BMC Research Notes

Mitsuyoshi Hirokawa¹  Iwao Sugitani²  Tomoko Ishikawa³  Tomoo Jikuzono⁴  Takashi Inui⁴  Osamu Ishibashi⁴  Aya Horikawa⁴ 

[1] Department of Diagnostic Pathology and Cytology, Kuma Hospital;Department of Endocrine Surgery, Nippon Medical School;Institute for Human Life Innovation, Ochanomizu University;Laboratory of Biological Macromolecules, Department of Applied Life Sciences, Graduate School of Life & Environmental Sciences, Osaka Prefecture University;

关键词: Thyroid cancer;    RNA;    Liquid-based cytology;    Fine-needle aspiration biopsy;    RNA integrity number;   

DOI  :  10.1186/s13104-018-3914-4

来源: DOAJ

【 摘 要 】

Abstract Objective Fine-needle aspiration biopsy (FNAB), an important diagnostic tool given its simplicity, safety, and cost-effectiveness, is fast becoming a popular procedure in the diagnosis of thyroid diseases. Generally, cells isolated from biopsies are transferred directly to microscope slides to prepare smears for cytopathological examination; however, the technical difficulties of this procedure often cause poor reproducibility, which limits the accuracy of diagnostic results. Liquid-based cytology (LBC), in which isolated cells are collected in a fixative solution, is advantageous in that it facilitates the preparation of homogenous cytological specimens. However, LBC has not been applied to molecular diagnoses, such as RNA expression-based diagnosis, mainly because of difficulties in cell recovery and RNA isolation. This study was aimed to improve RNA extraction from papillary cancer-derived K1 cells and thyroid FNAB specimens suspended in LBC solutions. Results K1 cells suspended in CytoRich-Red and CytoRich-Blue, fixatives for LBC, were efficiently recovered by trapping to glass-fiber filters. Importantly, subsequent Proteinase K treatment was essential for efficient RNA extraction from the fixed cells. This finding was also applicable to RNA extraction from CytoRich-Red-fixed thyroid FNAB specimens processed in the same way. Consistently, U6 small nuclear RNA was detected in these RNA samples by reverse transcription-polymerase chain reaction.

【 授权许可】

Unknown