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

Abstract

Abbreviations: PLIN2, perilipin 2; ADRP, adipose differentiation related protein; FFPE, formalin-fixed paraffinembedded; DCIS, ductal carcinoma in situ; ADH, atypical ductal hyperplasia; IHC, immunohistochemistry CorrespondenceBoth 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. K E Y W O R D S breast cancer, immunohistochemistry, lipid droplets, Oil-red O, perilipin 2

The clinicopathological significance of the adipophilin and fatty acid synthase expression in salivary duct carcinoma

“…In this study, ADP-positive expression was related to a high Ki-67 labeling index, a representative marker of cellular proliferation. This relationship was also reported in lung and breast cancer [9,13]. Third, in SDC, the expression of ADP may reflect the activation of hypoxic signaling, and this activation may lead to an aggressive phenotype and a poor prognosis.…”

“…The percentage of Ki-67-positive cells was determined by counting at least 1000 tumor cells, and then recorded as the Ki-67 labeling index (LI). Ki-67 LI values of < 40% and ≥ 40% were classified as Ki-67-low and Ki-67-high, respectively [9]. The HER2 status and the results of immunohistochemical staining of AR, FOXA1, Ki-67, and p53, which were previously reported by our group, were compared to the ADP and FASN expression [4,27,29].…”

“…ADP prevents the efflux of intracellular lipid droplets and increases the intracellular lipid level [8]. Immunohistochemically, ADP is a diagnostic marker of apocrine differentiation in breast cancer, and lipid-storage cancers such as sebaceous carcinoma and secretory carcinoma of the salivary glands [9][10][11][12]. Furthermore, the ADP expression was recently found to be a poor prognosticator in various malignant tumors, including pulmonary, pancreatic, colonic, and renal cell carcinomas, and Burkitt lymphoma [13][14][15][16][17].…”

“…Furthermore, the ADP expression was recently found to be a poor prognosticator in various malignant tumors, including pulmonary, pancreatic, colonic, and renal cell carcinomas, and Burkitt lymphoma [13][14][15][16][17]. In breast cancer, ADP is related to the ER expression, HER2 status, and the classification based on the biomarker immunoprofiling [9].…”

“…The ADP expression of foamy macrophages in the tubular lumen ( Fig. 2a) and the FASN expression of the adipose tissue were used as an internal positive control [9,10]. Thirty-five cases (23.8%) and 112 cases (76.2%) were classified into the ADP-negative and ADP-positive groups, respectively (mean ADP expression value 13.5%) ( Figs.…”