Overexpression of group II phospholipase A2 in human breast cancer tissues is closely associated with their malignant potency.
Membrane-associated phospholipase A2 (M-PLA2) is an enzyme that hydrolyses the sn-2 fatty acyl ester bond of phosphoglycerides. We measured M-PLA2 concentration in tissue extracts from 325 human breast cancers using a specific radioimmunoassay recently developed. Correlation analyses between the tissue concentration of M-PLA2 and clinicopathological factors showed that the enzyme level was significantly higher in patients with distant metastasis than in those without. In addition, M-PLA2 concentration was significantly higher in scirrhous carcinoma than in other histological types. No significant association was found between M-PLA2 concentration and age, menstrual status, tumour size, histological grade, vessel involvement or oestrogen receptor (ER) and progesterone receptor (PR) status. The expression of M-PLA2 mRNA was examined in a fibroadenoma, a stage IV breast cancer and its metastatic site of skin. Northern blot analysis showed a clear hybridisation band corresponding to M-PLA2 mRNA in both primary breast cancer and its metastatic site, while the fibroadenoma expressed a faint band corresponding to M-PLA2 mRNA. Breast cancer patients with high M-PLA2 concentrations exhibited significantly shorter disease-free and overall survival than those with low M-PLA2 concentration at the cut-off point of 5 ng 100 mg-1 protein, which was determined in a separate study. In multivariate analysis, M-PLA2 was found to be an independent prognostic factor for disease recurrence and death in human breast cancer. The possible significance of M-PLA2 expression in human breast cancer tissue is discussed.
Yamashita
S
S
Department of Surgery II, Kumamoto University Medical School, Japan.
Yamashita
J
J
Ogawa
M
M
D000367:Age Factors; D000704:Analysis of Variance; D015152:Blotting, Northern; D001943:Breast Neoplasms / Q000201:enzymology / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D015870:Gene Expression; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D010741:Phospholipases A / Q000032:analysis / Q000096:biosynthesis*; D054467:Phospholipases A2; D011379:Prognosis; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone / Q000032:analysis; D016019:Survival Analysis; D013997:Time Factors
D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D010741:Phospholipases A; D054467:Phospholipases A2