High levels of DJ-1 protein and isoelectric point 6.3 isoform in sera of breast cancer patients.
Bottom Line: Higher DJ-1 levels were significantly associated with advanced clinical grade, according to the TNM classification, negative hormone receptor status, and high Ki-67 labeling index, of biopsied materials; samples showed low DJ-1 protein expression despite upregulated DJ-1 mRNA.Conversely, in the 6 non-cancerous cases, isoforms other than the pI 6.3 isoform were highly expressed, and there was a significant difference in the isoform pattern between breast cancer cases and controls (P = 0.00025).These data indicate that high levels of DJ-1, probably of isoform at pI 6.3, is a candidate serum marker of breast cancer.
Affiliation: Department of Pathology, National Defense Medical College, Saitama, Japan.Show MeSH
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Mentions: The mean level of DJ-1 in the breast cancer group was 42.7 ng/mL, whereas the mean level of DJ-1 in the non-cancerous group was 28.3 ng/mL; serum levels of DJ-1 were significantly different between the breast cancer and non-cancerous groups (P = 0.019) (Fig.1a). Table1 shows the association between DJ-1 levels and the pathological TNM classification in the breast cancer group. Significantly higher levels of DJ-1 were detected in cases with tumor sizes >5 cm, or where there was evidence of direct invasion to the chest wall or skin, irrespective of tumor size (T3 or T4), than in cases with tumor sizes ≤5 cm (T1 or T2) (P < 0.0001). The presence of both lymph node metastasis (P = 0.00017) and distant metastasis (P < 0.0001) were associated with significantly increased serum levels of DJ-1. These data suggest that serum levels of DJ-1 are elevated in the presence of cancer and correlate with the extent of clinical cancer. Table2 shows the association between biologic markers and DJ-1 levels. Higher levels of DJ-1 were significantly detected in negative estrogen receptor status (P = 0.012), negative progesterone receptor status (P = 0.013), and high Ki-67 labeling index (P = 0.022); however, DJ-1 levels did not correlate with HER2 status.
Affiliation: Department of Pathology, National Defense Medical College, Saitama, Japan.