Laser Pressure Cell Transfer Method: A New Microdissection Technique for Frozen Sections

Laser microdissection is a method for the procurement of targeted cells from a tissue section, and its use enables one to analyze both nucleic acid and protein from procured cells. However, contamination by cells other than the target cells and damage to mRNA are problems that have been encountered. We have developed a laser pressure cell transfer method that is similar to the laser pressure catapulting method, but it has some advantages with regard to ease of the handling of an original thin film, the procedure for the preparation before laser microdissection, and the use of toluidine blue stain. We demonstrated that the quality of total RNA extracted from procured cells using the laser pressure cell transfer method was excellent for subsequent analysis, and this method could obtain clear morphological images of targeted cells before and after laser microdissection. Furthermore, as trial research for this method, we examined the expression profile of various transcriptional products related to invasive and metastatic potential using surgical materials of oral squamous cell carcinoma (OSCC). Lymph node metastasis tended to be often seen in cases that express VEGF, VEGFC and CD44s (2 of 3 cases) and in cases that express vimentin, keratin 19 and osteopontin (2 of 3 cases). These findings indicate that there may be a close relationship between those molecules in OSCC. This technique seems to be significantly better than the laser microdissection method currently available for obtaining clear morphological images, preserving the form of procured targeted cells, procuring mRNAs efficiently, and preserving them.