Results: 5

1.
Figure 4

Figure 4. PTEN protein expression by immunohistochemistry is highly correlated with PTEN genomic loss by FISH. From: PTEN Protein Loss by Immunostaining: Analytic Validation and Prognostic Indicator for a High Risk Surgical Cohort of Prostate Cancer Patients.

In Case A, PTEN protein is highly expressed in malignant glands, corresponding to a normal PTEN/CEP10 ratio by FISH, with retention of PTEN (red) and CEP10 (green) FISH signals in malignant cells. In Case B, PTEN protein is markedly decreased in malignant glands, with a corresponding PTEN/CEP10 ratio of 0.18. Malignant cells show homozygous loss of the PTEN (red) signal in malignant cells, with retention of the CEP10 (green signal).

Tamara L. Lotan, et al. Clin Cancer Res. ;17(20):6563-6573.
2.
Figure 5

Figure 5. PTEN protein loss by immunohistochemistry is associated with poor clinical outcomes in a surgical cohort of high risk prostate cancer patients. From: PTEN Protein Loss by Immunostaining: Analytic Validation and Prognostic Indicator for a High Risk Surgical Cohort of Prostate Cancer Patients.

(A) The Kaplan-Meier curve shows a significant decrease in metastasis-free survival for patients with PTEN protein loss by immunohistochemistry (p= 0.03). (B) The Kaplan-Meier curve for disease-specific survival shows a non-significant decrease in prostate-cancer specific survival in patients with PTEN protein loss (p = 0.06).

Tamara L. Lotan, et al. Clin Cancer Res. ;17(20):6563-6573.
3.
Figure 3

Figure 3. PTEN protein loss by immunohistochemistry is highly correlated with prostate cancer pathologic stage and grade. From: PTEN Protein Loss by Immunostaining: Analytic Validation and Prognostic Indicator for a High Risk Surgical Cohort of Prostate Cancer Patients.

(A) PTEN protein is more frequent in higher pathologic stage tumors (p=0.003 by Pearson’s chi square test). (B) PTEN protein loss is more common in higher Gleason grade tumors (p=0.0001 by Pearson’s chi square test). (C) PTEN protein loss is least common in benign prostate tissues and PIN and most common in metastatic prostate tumors (p=0.001 by Pearson’s chi square test).

Tamara L. Lotan, et al. Clin Cancer Res. ;17(20):6563-6573.
4.
Figure 1

Figure 1. PTEN protein expression by immunohistochemistry in isogenic cell line controls with and without somatic PTEN gene loss. From: PTEN Protein Loss by Immunostaining: Analytic Validation and Prognostic Indicator for a High Risk Surgical Cohort of Prostate Cancer Patients.

(A) Wildtype HCT116 and (D) DLD-1 colon cancer cells, and (G) MCF-10A breast epithelial cells show PTEN protein expression by immunohistochemistry, while the same cell lines with homozygous PTEN deletion by somatic homologous recombination (PTEN KO), show absent PTEN protein (B, E, H). (C, F) HCT116 and DLD-1 cells with PTEN deletion transiently transfected with CMV-PTEN show high PTEN protein expression in a subset of cells. (I) MCF10A cells with hemizygous deletion of PTEN show levels of PTEN immunostaining intermediate between wildtype and cells with homozygous PTEN deletion.

Tamara L. Lotan, et al. Clin Cancer Res. ;17(20):6563-6573.
5.
Figure 2

Figure 2. PTEN protein expression by immunohistochemistry in human prostate specimens. From: PTEN Protein Loss by Immunostaining: Analytic Validation and Prognostic Indicator for a High Risk Surgical Cohort of Prostate Cancer Patients.

(A) Typical cancer case with uniform retained PTEN protein expression in all malignant glands. (B) Typical cancer case with PTEN protein loss in malignant glands, while adjacent benign glands (arrow) retain PTEN protein expression. (C) Some tumors showed only weak PTEN protein positivity (left panel) but were still readily distinguishable from cases with total PTEN protein loss (right panel). (D) Intra-tumoral heterogeneity for PTEN protein expression is evident in this tumor specimen, where malignant glands with PTEN loss and PTEN protein retention are intermingled. Note the presence of cells with and without PTEN expression within a single malignant gland (arrow). (E) High grade prostatic intraepithelial neoplasia (PIN) with PTEN loss in most of the involved gland, while PTEN protein is retained in a minority of luminal cells (arrow) and all basal cells (arrowhead). An adjacent benign gland expresses PTEN. (F) PTEN protein loss in lymph node metastasis of prostatic carcinoma. While the cytoplasm is negative, some glands show a small amount of staining at the apical plasma membrane (arrow), a finding of uncertain significance.

Tamara L. Lotan, et al. Clin Cancer Res. ;17(20):6563-6573.

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