Abstract

N-glycolyl GM3 ganglioside (NeuGcGM3) expression in lung carcinomas using formalin-fixed and paraffin-embedded (FFPE) samples has been recently demonstrated. In the present work, it was confirmed the tissue expression of NeuGcGM3 in lung carcinomas by mean of two different mAbs, P3 (anti-NeuGc-containing gangliosides and sulfated glycolipids) and 14F7 (a highly specific for NeuGcGM3) using FFPE samples. In addition, it was reported the tissue expression of NeuGcGM3 in frozen lung carcinoma sections, also supported by the chemical extraction of this ganglioside with organic solvents such as: ethanol, methanol and chloroform/methanol. Moreover, the murine, chimeric and humanized versions of 14F7 mAb showed a similar pattern of immunostaining in this kind of samples. It was also demonstrated that formalin fixation prevent the damage and/or extraction of the antigenic determinant recognized by 14F7 mAb. Consequently, the detection of NeuGcGM3 in frozen samples and their FFPE counterparts was comparable. Our data seems to be in agreement with the potential use of chimeric and/or humanized versions of 14F7 mAb for the passive immunotherapy of lung carcinoma expressing NeuGcGM3. The reactivity of 14F7 murine mAb in FFPE tissues permits to consider it as a useful tool in the selection of patients for specific therapies.