Protocol for PTEN expression by immunohistochemistry in formalin-fixed paraffin-embedded human breast carcinoma - PubMed (original) (raw)

Protocol for PTEN expression by immunohistochemistry in formalin-fixed paraffin-embedded human breast carcinoma

Rita A Sakr et al. Appl Immunohistochem Mol Morphol. 2010 Jul.

Abstract

The PI3K/PTEN pathway plays a major role in carcinogenesis. Dysregulation of this pathway occurs frequently in breast cancer, and loss of PTEN expression is emerging as a potentially important mechanism of resistance to the widely used anti-HER2 therapy, trastuzumab. However, assays for loss of PTEN expression have suffered from lack of consistency. Here, we describe an automated and reliable protocol for PTEN protein expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue that can be easily incorporated into clinical trials.

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Figures

FIGURE 1

FIGURE 1

Cell lines: positive PTEN staining in MCF7 breast cell line (A) and negative staining in MDA-MB-468 (B). FFPE breast tissues: positive PTEN staining in ductal carcinoma in situ (C); negative PTEN staining in ductal carcinoma in situ (D); positive PTEN staining in invasive carcinoma (E); negative PTEN staining in invasive carcinoma (F) with normal ductal epithelium and stroma serving as positive internal control. FFPE indicates formalin-fixed paraffin-embedded.

FIGURE 2

FIGURE 2

Semi-quantitative scoring: (A) score 0 = staining undetectable in tumor cells but present in surrounding normal ductal epithelial and stromal cells; (B) score 1 = staining weaker than surrounding normal ductal epithelial and stromal cells; (C) score 2 = staining equal to that of surrounding normal ductal epithelial and stromal cells.

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References

    1. Li J, Yen C, Liaw D, et al. PTEN, a putative protein tyrosine phosphatase gene mutated in human brain, breast, and prostate cancer. Science. 1997;275:1943–1947. - PubMed
    1. Steck PA, Pershouse MA, Jasser SA, et al. Identification of a candidate tumour suppressor gene, MMAC1, at chromosome 10q23.3 that is mutated in multiple advanced cancers. Nat Genet. 1997;15:356–362. - PubMed
    1. Parsons R. Human cancer, PTEN and the PI-3 kinase pathway. Semin Cell Dev Biol. 2004;15:171–176. - PubMed
    1. Rhei E, Kang L, Bogomolniy F, et al. Mutation analysis of the putative tumor suppressor gene PTEN/MMAC1 in primary breast carcinomas. Cancer Res. 1997;57:3657–3659. - PubMed
    1. Garcia JM, Silva J, Pena C, et al. Promoter methylation of the PTEN gene is a common molecular change in breast cancer. Genes Chromosomes Cancer. 2004;41:117–124. - PubMed

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