Analysis of protein biomarkers in human clinical tumor samples: critical aspects to success from tissue acquisition to analysis

Dystroglycan in human fetal membranes decreases in later gestation and with spontaneous membrane rupture

BACKGROUND/AIMS

The transmembrane protein dystroglycan (DG) is known to anchor the cell membrane to the extracellular matrix, and is susceptible to cleavage by matrix metalloproteinases. This study tested the hypothesis that changes in DG abundance in fetal membranes (FM) occur late in gestation, with spontaneous rupture of membranes (SROM), and during labor.

METHODS

FM were collected from a prospective cohort consisting of four groups of patients (term labor, term unlabored, preterm labor, and preterm unlabored). FM were subjected to immunohistochemical staining using antibodies specific for α- and β-DG subunits, and staining intensity was graded by a blinded pathologist.

RESULTS

α- and β-DG staining was significantly decreased at term and after SROM (p < 0.05), but not in the presence of labor.

CONCLUSIONS

Decreased DG intensity was seen in FM of patients at term and with SROM, but no change was observed with labor.

High-throughput, automated quantification of white matter neurons in mild malformation of cortical development in epilepsy

INTRODUCTION

In epilepsy, the diagnosis of mild Malformation of Cortical Development type II (mMCD II) predominantly relies on the histopathological assessment of heterotopic neurons in the white matter. The exact diagnostic criteria for mMCD II are still ill-defined, mainly because findings from previous studies were contradictory due to small sample size, and the use of different stains and quantitative systems. Advance in technology leading to the development of whole slide imaging with high-throughput, automated quantitative analysis (WSA) may overcome these differences, and may provide objective, rapid, and reliable quantitation of white matter neurons in epilepsy. This study quantified the density of NeuN immunopositive neurons in the white matter of up to 142 epilepsy and control cases using WSA. Quantitative data from WSA was compared to two other systems, semi-automated quantitation, and the widely accepted method of stereology, to assess the reliability and quality of results from WSA.

RESULTS

All quantitative systems showed a higher density of white matter neurons in epilepsy cases compared to controls (P = 0.002). We found that, in particular, WSA with user-defined region of interest (manual) was superior in terms of larger sampled size, ease of use, time consumption, and accuracy in region selection and cell recognition compared to other methods. Using results from WSA manual, we proposed a threshold value for the classification of mMCD II, where 78% of patients now classified with mMCD II were seizure-free at the second post-operatively follow up.

CONCLUSION

This study confirms the potential role of WSA in future quantitative diagnostic histology, especially for the histopathological diagnosis of mMCD.

Primary tumor vascularity, HIF-1α and VEGF expression in vulvar squamous cell carcinomas: their relationships with clinicopathological characteristics and prognostic impact

BACKGROUND

Increased vascularity is a crucial event in the tumor progression and has prognostic significance in various cancers. However, the ultimate role of angiogenesis in the pathogenesis and clinical outcome of vulvar carcinoma patients is still not settled.

METHODS

Tumor vascularity using CD34 stained slides measured by Chalkley counting method as well as hypoxia-inducible factor (HIF)-1α and vascular endothelial growth factor (VEGF) immunoexpression was examined in 158 vulvar squamous cell carcinomas. Associations between vascular Chalkley count, HIF-1α and VEGF expression and clinicopathological factors and clinical outcome were evaluated.

RESULTS

High CD34 Chalkley count was found to correlate with larger tumor diameter (P = 0.002), deep invasion (P < 0.001) and HIF-1α (P = 0.04), whereas high VEGF expression correlate significantly with poor tumor differentiation (P = 0.007). No significant association between CD34 Chalkley counts and VEGF expression and disease-specific survival was observed. High HIF-1α expression showed better disease specific survival in both univariate and multivariate analyses (P = 0.001).

CONCLUSIONS

A significant association between high tumor vascularity and larger tumor size as well as deeper tumor invasion suggests an important role of angiogenesis in the growth and progression of vulvar carcinomas. HIF-1α expression in vulvar carcinomas was a statistically independent prognostic factor.