The significance of lipid accumulation in breast carcinoma cells through perilipin 2 and its clinicopathological significance.

Both systemic and intratumoral lipid metabolism have been recently reported to play pivotal roles in both tumor development and progression in various human malignancies including breast cancer. However, its details have remained largely unknown in breast cancer patients. Therefore, in this study, we focused on perilipin 2, which is involved in constituting the intracellular lipid composition. Perilipin 2 was first immunolocalized in 105 cases of breast cancer. The status of perilipin 2 immunoreactivity was significantly positively associated with histological grade, Ki-67 labeling index and HER2 status and negatively with estrogen receptor status of these patients. Subsequent in vitro study also revealed that its mRNA expression in triple negative breast carcinoma cells was higher than cells of other subtypes. We then examined the correlation between perilipin 2 immunoreactivity and intracellular lipid droplet evaluated by Oil-red O stating in 13 cases of breast carcinoma tissues. A significantly positive correlation was detected between the status of perilipin 2 and Oil-red O staining. These findings above did indicate that perilipin 2 could represent the status of intracellular lipid droplets in surgical pathology specimens of breast cancer and perilipin 2 was also associated with its more aggressive biological phenotypes.