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Background: The tumor microenvironment plays a critical role in cancer development, progression, and control. We demonstrated in vitro and in vivo that a bidirectional crosstalk between tumor-associated macrophages and cancer cells via CCR2-CCL2 and CX3CR1-CXCL1 signaling is fundamental for lung cancer growth and metastasis offers new treatment concepts. Aim: Our working hypothesis is to develop a new platform for specific chemokine receptor (CCR2) PET imaging and a range of theranostic applications in lung cancer. For this purpose, we planned to define the CCR2 expression in NSCLC as well as in SCLC, tumor cells as well as immune/inflammatory cells. Material and Methods: This is a multicenter trial with patients from Zentralklinik Bad Berka GmbH (n =100 NSCLC, n=100 SCLC). All patients gave informed consent according to the declaration of Helsinki. FFPE material was available in all cases. CCR2 CXCR4 and CX3CR1 expression was determined by immunohistochemistry with the avidin-biotin-peroxidase-complex. Results: Analyzing 96 NSCLC (47 adenocarcinoma, 49 squamous cell carcinoma) and 45 SCLC tumor samples, we found CXCR4 and CCR2 chemokine receptor expression in tumor, immune and inflammatory cells. In NSCLC, co-expression between CCR2 and CXCR4 staining was very high concerning their expression on tumor cells rising with higher tumor stages, proliferation rate and grading. CCR2 expression in immune cells was restricted to lower stages; the same pattern could be observed in 45 SCLC tumor samples where CCR2 expression on immune cells was found especially in limited disease rather than in metastatic disease; CXCR4 expression in tumor cells was found to be high in all stages of SCLC. To evaluate the therapeutic efficacy of CCR2 antagonism in vivo, we injected LLC1 s.c. into WT mice treated with CCR2 antagonist (RS504393) or vehicle. Notably, tumor growth was significantly inhibited in CCR2 antagonist-treated mice as compared with vehicle-treated mice. Discussion: Our preliminary results show a significant portion of CCR2 positive tumors - NSCLC as well as SCLC which would qualify for a CCR2-based imaging as well as - demonstrated in our mice models - CCR2 inhibitory strategies. This should be evaluated in further preclinical trials. Citation Format: Katalin Nagy-Major, Jörg Sänger, Harshad R. Kulkarni, Peter Fix, Almut Kunze, Amelie Lupp, Reiner Bonnet, Werner Seeger, Richard P. Baum, Patricia Grabowski, Rajkumar Savai. Chemokine receptor signaling as a new tool to improve lung cancer diagnostics and therapy [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 944. doi:10.1158/1538-7445.AM2017-944

Selective High Affinity Ligands (SHALs) are a new class of small molecule targeting agents that can be designed to bind selectively and with high affinity to unique sites located on almost any protein. A series of SHAL-based therapeutics have been developed to target the cell surface antigen HLA-DR10 that is over-expressed on many B-cell derived malignancies. SHALs are created by first identifying subsets of potential ligands, or “recognition elements,” that bind to two or three neighboring unique sites on the surface of the target protein. Bidentate or tridentate SHALs are produced by linking two or three of these recognition ligands together using carbodiimide chemistry and a miniPEG and lysine scaffold. SHAL synthesis is rapid, uses relatively inexpensive, commercially available components, and is very versatile. Multiple forms of the SHAL can be created by combining different recognition elements (ligands) or by attaching a variety of tags (biotin, chelating groups, dyes, inhibitors) to the end of the linker. Using this approach, SH7139 has been developed as a promising therapeutic for treating non-Hodgkin's lymphoma. Previous studies have shown SH7139 to be effective in treating human B-cell lymphoma in a mouse xenograft model at extremely low doses (3.3μg/kg); 70% of the tumors disappeared within 30 days after treatment and did not reoccur during the remainder of the life of the animal. Here we report that a biotinylated derivative of SH7139 can be used as companion diagnostic to prescreen needle aspirates or biopsies from B-cell lymphomas and determine whether or not the tumor is likely to respond to SH7139 therapy. The staining protocol involves detecting the bound biotinylated SHAL using commercially available alkaline phosphatase reagents, and it works equally well with both fixed and unfixed biopsy sections. Biotinylated SH7139 has been used to identify potentially responsive B-cell lymphomas in both canine and human patients. The development of SHAL-based diagnostics in parallel with new SHAL-based therapeutics will help advance individualized therapies and minimize the systemic trauma and valuable time lost by patients given treatments that prove to be ineffective. Our results also suggest this diagnostic may also prove useful in determining whether malignancies over-expressing HLA-DR10 have metastasized and individual lymphoma cells have migrated out of the tumor into surrounding normal tissue. This research was supported, in part, by NIH/NCI SBIR grant 1R43CA159843-01 to Rod Balhorn. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4591. doi:1538-7445.AM2012-4591