according to the manufacturer’s instructions. Briefly, serial section slides of 5 μm were obtained from the paraffin-embedded specimens. After regular de-paraffin and re-hydration, the slides were placed in an antigen
retrieval solution (pH 6.0) and heated in a microwave oven for 10 min at 95°C. Next, the slides were incubated in a 3% hydrogen peroxide-methanol solution for 10 min to remove endogenous peroxidase. IHC staining was performed as follows: nonspecific binding was blocked with 10% goat serum; the slide was incubated for 1 h with primary antibodies, followed by incubation for 30 min with a biotin-labeled secondary antibody; and subsequently the slide was incubated for 30 min with horseradish peroxidase-labeled streptavidin. Ro 61-8048 Color was developed using DAB, and the slide was counterstained with hematoxylin. Finally, the slides were mounted and coverslipped with resinene. Negative control slides were stained with PBS instead of the primary antibodies.
Breast cancer slides were used as a positive control. VEGF-C, VEGF-D, and Flt-4 positive cells showed brown-yellow particles in their cytoplasm. According to the method described by Jüttner et al., the samples were classified as follows: – (no positive cell), + (0–5% positive cell), ++ (5–50% positive cell), +++ (>50% positive cell). Among these, ++ and +++ samples MM-102 were determined to have a positive expression. LVD and FVD were determined according to the methods previously described by Weidner et al. . Protein kinase N1 Briefly, the slides were scanned on a low-power microscope and areas with the highest positively stained vessel density, called hot spots, were identified. The number of positively stained lymphatic vessels in five high-power fields in the selected areas was counted. LVD and FVD were determined as the mean value of vessel counts. Statistical Analysis All statistical calculations were performed using SPSS (version
13.0, Chicago, IL USA). LVDs and FVDs were expressed as means ± SD. The statistical methods used included the t-test, the one-way ANOVA test, and the Chi-square test. Differences were considered to be statistically significant when P < 0.05. Results Expression of VEGF-C, VEGF-D and Flt-4 in cervical cancer tissue The IHC signals of VEGF-C, VEGF-D, and their receptor Flt-4 were mostly localized in the cytoplasm of the cancer cell in the examined cervical carcinoma samples and the positively stained cells showed a brown-yellow color in the cytoplasm. The positive rates were 57.7% (56 out of 97) for VEGF-C, 60.8% (59 out of 97) for VEGF-D, and 52.6% (51 out of 97) for Flt-4 (Figure 1A). Figure 1 The expression of VEGF-C (A), VEGF-D (B), and Flt-4 (C) in cervical carcinoma tissues. A. IHC detection of VEGF-C (→) ×400; B. IHC detection of VEGF-D (→) ×400; and C. IHC detection of Flt-4 (→) ×400.