SESSION TITLE: Biomarkers in Lung Cancer
SESSION TYPE: Original Investigation Slide
PRESENTED ON: Sunday, October 27, 2013 at 10:45 AM - 11:45 AM
PURPOSE: It is increasingly recognized that interaction of cancer cells, macrophages, and inflammatory response in the tumor micro-environment may facilitate cancer cell invasion and metastasis. However the specific molecular mechanisms are not well defined. Triggering receptor expressed on myeloid cells 1 (TREM-1) is a member of the super immunoglobulin family expressed on a select group of monocyte macrophage and neutrophils. TREM-1 amplifies toll like receptor (TLR) induced inflammatory response. We have previously shown that TREM-1 accentuates inflammatory response by inhibiting apoptosis of macrophages thus prolonging their survival. Based on these data we hypothesize that TREM-1 expression in tumor associated macrophages (TAM) is an important regulator of lung cancer progression. To address this we determined the expression of TREM-1 in human NSCLC specimens.
METHODS: Tumor and normal lung specimens from patients who underwent surgical resection for NSCLC were obtained from clinical and translational research institute at University of Florida. TREM-1 expression was determined by using immunohistochemistry and confocal microscopy. Macrophage specificity was determined by CD68 staining. TREM-1 expression was also confirmed by quantitative real time polymerase chain reaction (RT-PCR) from tumor tissue.
RESULTS: Immunostaining and confocal microscopy showed that TREM-1 was highly expressed in macrophages in the tumor tissue as confirmed by CD68 staining. Tumor tissue showed an increase in TREM-1 mRNA expression. TREM-1 was not detected in macrophages from normal lung tissue.
CONCLUSIONS: Our data shows that TREM-1 is highly expressed in NSCLC and not detected in normal lung tissue. Expression of TREM-1 in tumors is specifically seen in TAM's. Thus expression of TREM-1 in tumors may play a key role in the biology and progression of NSCLC.
CLINICAL IMPLICATIONS: Detection of TREM-1 may serve as an important biomarker in lung cancer progression. Future studies are needed to define the role of modulation of TREM-1 in NSCLC.
DISCLOSURE: The following authors have nothing to disclose: Hiren Mehta, Zhihong Yuan, K. Mohammed, N. Nasreen, Vipul Patel, Peruvemba Sriram, Ruxana Sadikot
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