Immunohistochemical assessment of PD-L1 expression using three different monoclonal antibodies in triple negative breast cancer patients.

BACKGROUND: PD-L1 receptor expression in breast cancer tissue can be assessed with different anti-human PD-L1 monoclonal antibodies. The performance of three specific monoclonal antibodies in a head-to-head comparison is unknown. In addition, a potential correlation of PD-L1 expression and clinico-pathological parameters has not been investigated. METHODS: This was a retrospective study on tissue samples of patients with histologically confirmed triple negative breast cancer (TNBC). PD-L1 receptors were immune histochemically stained with three anti-human PD-L1 monoclonal antibodies: 22C3 and 28-8 for staining of tumor cell membranes (TC) and cytoplasm (Cyt), SP142 for immune cell staining (IC). Three different tissue samples of each patient were evaluated separately by two observers in a blinded fashion. The percentage of PD-L1 positive tumor cells in relation to the total number of tumor cells was determined. For antibodies 22C3 and 28-8 PD-L1 staining of 0 to < 1% of tumor cells was rated "negative", 1-50% was rated "positive" and > 50% was rated "strong positive". Cyt staining was defined as "negative" when no signal was observed and as "positive", when any positive signal was observed. For IC staining with SP142 all samples with PD-L1 expression ≥ 1% were rated as "positive". Finally, the relationship between PD-L1 expression and clinico-pathological parameters was analyzed. RESULTS: Tissue samples from 59 of 60 enrolled patients could be analyzed. Mean age was 55 years. Both the monoclonal antibodies 22C3 and 28-8 had similar properties, and were positive for both TC in 13 patients (22%) and for Cyt staining in 24 patients (40.7%). IC staining with antibody SP142 was positive in 24 patients (40.7%), who were also positive for Cyt staining. The differences between TC and Cyt staining and TC and IC staining were significant (p = 0.001). Cases with positive TC staining showed higher Ki67 expression compared to those with negative staining, 40 vs 30%, respectively (p = 0.05). None of the other clinico-pathological parameters showed any correlation with PDL1 expression. CONCLUSIONS: Antibodies 22C3 and 28-8 can be used interchangeably for PD-L1 determination in tumor cells of TNBC patients. Results for Cyt staining with 22C3 or 28-8 and IC staining with SP142 were identical. In our study PD-L1 expression correlates with Ki67 expression but not with OS or DFS.

The impact of cigarette smoking on protamines 1 and 2 transcripts in human spermatozoa.

This study was conducted to evaluate the relation between cigarette smoking, semen quality and ratios of protamine mRNAs in smokers and non-smokers. Spermatozoa from 123 men and 64 smokers and 59 non-smokers whose female partners attended an assisted reproduction and andrology laboratory were evaluated. Protamine mRNA was extracted from purified sperm, reverse-transcribed and subjected to real-time quantitative PCR using specific primer pairs for protamine 1 (PRM1) and protamine 2 (PRM2). The main outcomes showed that PRM1 mRNA levels in smokers were significantly lower (p = 0.05) than that of non-smokers. Additionally, PRM2 mRNA levels in smokers were significantly lower (p = 0.001) than that of non-smokers. PRM1/PRM2 mRNA ratios in non-smokers samples show significant differences (p = 0.001) compared with those in smokers. PRM1/PRM2 mRNA ratios were negatively and significantly correlated (p = 0.001) with semen volume, sperm count and normal sperm morphology. We concluded that sperm quality and sperm protamine mRNAs were negatively affected by smoking, and these data will serve as new evidence for the hazardous effect of smoking on male fertility. Additionally, protamine transcripts ratios may serve as a marker for male fertility.

Surface topography and wetting modifications of PEEK for implant applications.

Polyetheretherketone (PEEK) is considered as a substitute for metallic implant materials due to its extremely low elastic modulus (3-4 GPa). Despite its good mechanical properties, PEEK exhibits a slow integration with the bone tissue due to its relatively inert surface and low biocompatibility. We introduced a dual modification method, which combines the laser and plasma surface treatments to achieve hierarchically patterned PEEK surfaces. While the plasma treatment leads to nanotopography, the laser treatment induces microstructures over the PEEK surface. On the other hand, plasma and laser treatments induce inhomogeneity in the surface chemistry in addition to the tailored surface topography. Therefore, we coated the structured PEEK surfaces with a thin alumina layer by pulsed laser deposition (PLD) to get identical surface chemistry on each substrate. Such alumina-coated PEEK surfaces are used as a model to investigate the effect of the surface topography on the wetting independent from the surface chemistry. Prepared surfaces bring advantages of enhanced wetting, multiscaled topography, proven biocompatibility (alumina layer), and low elastic modulus (PEEK as substrate), which together may trigger the use of PEEK in bone and other implant applications.