Abstract 4209
Background
Vimentin (Vim) is one of the mesenchymal markers, that are often upregulated in cancer cells during epithelial-mesenchymal transition (EMT) – a process endowing tumor cells with invasiveness, pro-metastatic potential and, arguably, cancer stem cells (CSC) properties. It is normally seen in cytoplasm, but cell surface Vim was also detected on cells with CSC characteristics. Vim expression may be used as a surrogate marker of EMT in tumor tissue samples from patients and aid in prognosis evaluation. We aimed to characterize Vim expression in prostate cancer (PCa) using our method of semiquantitative staining assessment.
Methods
Vim expression was assessed in 48 cases of PCa using immunohistochemistry with primary rabbit polyclonal antibodies (ThermoFischer, 1:1000). UnoView Rabbit Detection Kit was used for visualization. Specificity of staining was confirmed by another antibody (mouse monoclonal, DAKO, 1:200) in selected cases. To assess Vim expression semiquantitatively we proposed a weighed staining index (WSI) that takes into account the proportion of stained cells as well as the ratios of staining intensities and can be applied to different cellular compartments staining separately. It combines advantages of simple ad oculus semiquantitative staining evaluation and obtaining numerical characteristics of marker expression.
Results
Median WSI for membranous staining was 5 (0 – 52) (7, if cases without expression were excluded), for cytoplasmic – 20.5 (0 – 64) (22.5, if cases without expression were excluded). In 2 (4.2%) cases marker expression was absent in both membrane and cytoplasm. WSI in PCa was significantly higher for cytoplasmic staining. However, in 3 (6.25%) cases WSI for membranous staining was higher than that for cytoplasmic. Significant correlation was found between WSI for cytoplasmic and membranous staining (Spearman test, r = 0.51, p < 0,05). However, no correlation was found between WSI for both compartments and E-cadherin expression (as assessed by average staining intensity score – a method similar to WSI – using Aperio software previously).
Conclusions
Vim expression as a sign of EMT in the tumor is present in 95.8% cases of PCa and is more prevalent in cytoplasm. WSI is a useful tool to assess Vim (and possibly other markers) expression.
Clinical trial identification
Legal entity responsible for the study
M. Puchinskaya.
Funding
Belarusian Republican Foundation for Fundamental Research.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3887 - First Real Life Data on Durvalumab after definitive concomitant ChemoRadiotherapy (cCRT) in unresectable Stage (St) III Non-Small Cell Lung Cancer (NSCLC) in France: Analysis of 591 patients (pts) enrolled in the French cohort (c) Temporary Authorization of Use (ATU)
Presenter: Virginie Avrillon
Session: Poster Display session 1
Resources:
Abstract
682 - EGFR Inhibitor Versus Chemotherapy as Adjuvant Treatment for Locally-advanced EGFR-mutant Non-Small Cell Lung Cancer
Presenter: Peng Xie
Session: Poster Display session 1
Resources:
Abstract
2509 - Afatinib in EGFR TKI-naïve patients with EGFR mutation-positive (EGFRm+) NSCLC: interim analysis of a Phase IIIb, multi-national, open-label study
Presenter: Filippo de Marinis
Session: Poster Display session 1
Resources:
Abstract
3300 - First-line ceritinib versus chemotherapy in patients (pts) with advanced ALK rearranged (ALK+) non-small cell lung cancer (NSCLC): ASCEND-4 Asian subgroup analysis
Presenter: Daniel SW Tan
Session: Poster Display session 1
Resources:
Abstract
2653 - A combined analysis of two Phase IIIb studies of afatinib in EGFR TKI-naïve patients (pts) with EGFR mutation-positive (EGFRm+) NSCLC
Presenter: Filippo de Marinis
Session: Poster Display session 1
Resources:
Abstract
3663 - Impact of plasma EGFR mutation fractions on response to first generation tyrosine-kinase inhibitor in treatment of naïve non-small cell lung cancer patients
Presenter: Xiaohong Wang
Session: Poster Display session 1
Resources:
Abstract
5921 - Definition of an afatinib trough concentration threshold in the treatment of NSCLC
Presenter: Stephane Bouchet
Session: Poster Display session 1
Resources:
Abstract
2852 - A Phase Ib Trial of Neoadjuvant Chemoradiotherapy and Durvalumab(MEDI4736) for Potentially Resectable stage III Non-Small Cell Lung Cancer (NSCLC)
Presenter: Beung chul AHN
Session: Poster Display session 1
Resources:
Abstract
3273 - Low expression of Notch1 and combined Notch1/HES1 are associated with adverse survival factor for limited stage small cell lung cancer
Presenter: Jinsoo Lee
Session: Poster Display session 1
Resources:
Abstract
5141 - Mutational profiling of tumor tissue and sequential plasma illustrates emergent clones during treatment in late stage small cell lung cancer (SCLC)
Presenter: Stephanie Yaung
Session: Poster Display session 1
Resources:
Abstract