Abstract 3947: Atypical chemokine receptor ACKR3 expression is associated with aggressive behavior and poor prognosis in gastric cancer

• Published in: Cancer research (Chicago, Ill.) Ill.), 2016-07, Vol.76 (14_Supplement), p.3947-3947
• Main Authors: Kim, Nayoung, Baek, Seung-Woo, Ryu, Hyewon, Choi, Yoon Seok, Song, Ik Chan, Yun, Hwan Jung, Jo, Deog Yeon, Kim, Samyong, Lee, Hyo Jin
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2016-3947

Chemokine and their receptors are key mediators of normal physiology and a large number of pathologic conditions such as cancer, and this family of receptors is the emerging therapeutic target in the field of cancer treatment. ACKR3 is an atypical chemokine receptor first cloned from a dog cDNA library as the orphan receptor and was initially named Receptor Dog cDNA 1 (RDC1). Shortly after demonstrating that RDC1 binds with its ligand, stromal cell-derived factor-1α (SDF-1α) and interferon-inducible T-cell α chemoattractant (I-TAC), RDC1 was officially deorphanized. Accumulating evidence of recent studies have suggested that expression of ACKR3 is augmented in most of tumor cells as compared to their normal counterparts and is involved in cell proliferation, survival, migration, invasion during the initiation and progression of cancer. However, there is little information regarding their expression and clinical relevance in gastric cancer. The expression status of ACKR3 was investigated in 221 specimens of primary gastric cancer using immunohistochemistry. The correlation of ACKR3 expression with the clinicopathological features and survival outcomes was analyzed as well. Immunohistochemical staining of gastric cancer tissue sections revealed diverse cytoplasmic and membrane staining patterns for ACKR3. One hundred-fourteen cases (51.6%) showed low ACKR3 expression according to an arbitrary scoring system (grade 0-1; grade 0, n = 26; grade 1, n = 88), and one hundred-seven cases (48.4%) showed high expression (grade 2-3; grade 2, n = 58; grade 3, n = 49). There were no significant differences in age, gender, histology, tumor location, lymphatic and venous invasion among the two groups. However, high CXCR7 expression in cancer cells tended to be associated with proportion of tumor size greater than 5 cm (P = 0.055) and was significantly correlated with depth of tumor invasion (P < 0.001), lymph node metastasis (P = 0.042), and higher stage (P = 0.002). Furthermore, patients with high ACKR3 expression showed worse overall survival rate of 47% compared to 56% in patients with low ACKR3 expression. In conclusion, ACKR3 is differentially expressed in gastric cancer cells, and high expression of ACKR3 is associated with aggressive tumor behavior and poor survival in patients with gastric cancer, suggesting that ACKR3 plays an important role during gastric cancer progression. Citation Format: Nayoung Kim, Seung-Woo Baek, Hyewon Ryu, Yoon Seok Choi, Ik Chan Song,