Abstract 4664: CXCL14 and CXCR7 expression are upregulated in human squamous lung cancers

Purposes Lung squamous cell carcinoma (SQCC) is the second-largest histological subtype of non-small cell lung cancer, but relatively few biomarkers are available compared to adenocarcinoma. Recently, chemokines and their receptors have been suggested to play important roles in the initiation or progression of cancers. In this study we examined the expression of chemokines and their receptors in human lung SQCC. Methods For mRNA expression of chemokines their receptors study, tumors and their matched normal lung specimens were collected from fresh frozen samples of 10 patients. For immunohistochemistry (IHC) study, formalin-fixed paraffine-embedded samples of 35 patients with primary lung SQCC were collected. All samples were from patients who were subjected to curative surgical resection at Dongnam Institute of Radiological and Medical Sciences. The mRNA was extracted by Quiagen RNeasy kit and the human RT2ProfilerPCR arrays for Chemokines/Receptors (SA Biosciences) was employed to determine the mRNA expression. Also, IHC was used to demonstrate their protein expression. Results The expression profiles of 84 chemokines and their related genes were compared across the tumors and their matched normal lung tissues. Among them, mRNA expression levels of CXCL14 (p=0.000) and CXCR7 (p=0.025) were significantly upregulated in tumor. CXCL14 and CXCR7 protein expression by IHC were detected in 25 (71%, p=0.000) and 21 (60%, p=0.000) of 35 cases for tumor, respectively. However, normal lung tissues showed no protein expression for CXCL14 and CXCR7. We also analyzed the correlation between clinicopathologic features (age, stage, tumor size, lymph node involvement, lymphovascular and perineural invasion and differentiation of tumor) and protein expression of CXCL14 and CXCR7. Although not significant, CXCL14 protein expression was more detected in the advanced stage (stage I/II, 60% vs III/IV, 90%) (p=0.120), lymphatic invasion (Yes, 82% vs No, 41%) (p=0.146) and perineural invasion (Yes, 100% vs No, 57%) (p=0.067). CXCR7 protein expression was significantly higher in advanced stage (stage I/II, 11/24, 46% vs III/IV, 10/10, 100%) (p=0.005) and lymphatic invasion (Yes, 13/16, 81% vs No, 8/18, 44%) (p=0.039). Conclusions This study demonstrated that mRNA expression level of CXCL14 and CXCR7 were significantly higher in SQCC compared to those in normal tissue. CXCR7 protein expression was detected significantly higher in advanced stage and lymphatic invasion. Our results indicated that CXCL14 and CXCR7 might play important roles in carcinogenesis and further study to elucidate their role in SQCC is required. Citation Format: YoonHee Choi, Soo Young Chung, Yoo Sang Yoon, Jae Hyun Kim, Ha-young Lee, Kyung A Kwon, Bong-Gun Seo, Hee Sam Na, Sung Sook Lee. CXCL14 and CXCR7 expression are upregulated in human squamous lung cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4664. doi:10.1158/1538-7445.AM2017-4664