Clinicopathological significance of PTPN12 expression in human breast cancer
Braz. j. med. biol. res
;
45(12): 1334-1340, Dec. 2012. ilus, tab
Article
in English
| LILACS
| ID: lil-659660
ABSTRACT
Protein tyrosine phosphatase non-receptor type 12 (PTPN12) is a recently identified tumor suppressor gene (TSG) that is frequently compromised in human triple-negative breast cancer. In the present study, we investigated the expression of PTPN12 protein by patients with breast cancer in a Chinese population and the relationship between PTPN12 expression levels and patient clinicopathological features and prognosis. Additionally, we explored the underlying down-regulation mechanism from the perspective of an epigenetic alteration. We examined PTPN12 mRNA expression in five breast cancer cell lines using semi-quantitative reverse-transcription PCR, and detected PTPN12 protein expression using immunohistochemistry in 150 primary invasive breast cancer cases and paired adjacent non-tumor tissues. Methylation-specific PCR was performed to analyze the promoter CpG island methylation status of PTPN12. PTPN12 was significantly down-regulated in breast cancer cases (48/150) compared to adjacent noncancerous tissues (17/150; P < 0.05). Furthermore, low expression of PTPN12 showed a significant positive correlation with tumor size (P = 0.047), lymph node metastasis (P = 0.001), distant metastasis (P = 0.009), histological grade (P = 0.012), and survival time (P = 0.019). Additionally, promoter CpG island hypermethylation occurs more frequently in breast cancer cases and breast cancer cell lines with low PTPN12 expression. Our findings suggest that PTPN12 is potentially a methylation-silenced TSG for breast cancer that may play an important role in breast carcinogenesis and could potentially serve as an independent prognostic factor for invasive breast cancer patients.
Full text:
Available
Index:
LILACS (Americas)
Main subject:
Breast Neoplasms
/
DNA Methylation
Type of study:
Prognostic study
Limits:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
Language:
English
Journal:
Braz. j. med. biol. res
Journal subject:
Biology
/
Medicine
Year:
2012
Type:
Article
Affiliation country:
China
Institution/Affiliation country:
Qingdao University/CN
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