Abstract 2356: Aberrant TIMP-1 secretion by tumor-associated fibroblasts is a major contributor to the selective positive response to nintedanib in lung adenocarcinoma

Abstract

Abstract Adenocarcinoma (ADC) and Squamous Cell Carcinoma (SCC) are the most frequent histologic subtypes of lung cancer, and both are rich in activated/myofibroblast-like tumor-associated fibroblasts (TAFs). Nintedanib is a potent antifibrotic drug that targets the tumor stroma and is clinically approved to treat advanced lung ADC patients owing to the survival benefits observed in the LUME-1 clinical trial in ADC but not SCC patients. Although the mechanism underlying the ADC-selective therapeutic effects of nintedanib remained poorly understood, we have previously reported that nintedanib abrogates the pro-tumoral traits of the secretome of ADC-TAFs but not SCC-TAFs, suggesting that secreted factor(s) in ADC-TAFs may be implicated. In addition, we recently unveiled an ADC-specific tumor-promoting crosstalk between TAFs and cancer cells driven by TIMP-1 and CD63, whereas others have shown that TIMP-1 is a molecular target of nintedanib. However, it remains unknown if TIMP-1 is involved in the ADC-selective benefits of nintedanib. To address this question, we used patient-derived TAFs obtained with the patient’s informed consent and using protocols approved by the Ethics Committee of the Hospital Clinic. We treated TGF-β1-activated ADC-TAFs and SCC-TAFs with nintedanib and determined the content of TIMP-1 in their conditioned medium by ELISA. Moreover, we used cell-based functional assays and tumor xenografts after knocking-down TIMP-1 in TAFs by siRNA to examine how silencing TIMP-1 altered their response to nintedanib. By analyzing TCGA data and the human protein atlas, we found that TIMP-1 is consistently upregulated in ADC compared to SCC tumors both at the mRNA and protein levels. Moreover, TCGA data revealed that TIMP-1 is increased in tumors compared to paired control tissue in ADC but not SCC. In culture, we observed that TIMP-1 secretion was higher in ADC-TAFs than SCC-TAFs, and that this secretion was downregulated by nintedanib to a larger extent in ADC-TAFs compared to SCC-TAFs. In vivo analyses revealed that ADC cells co-injected with fibroblasts silenced for TIMP-1 as in SCC-TAFs into immunocompromised mice exhibited a less invasive growth pattern compared to tumors bearing control fibroblasts. In addition, we observed that the inhibition of the pro-tumoral secretome of ADC-TAFs elicited by nintedanib was abrogated upon knocking-down TIMP-1 in TAFs both in vitro and in vivo. Collectively, these results reveal that the high secretion of TIMP-1 in ADC-TAFs render them more responsive to nintedanib, whereas the low TIMP-1 secretion of SCC-TAFs may be a major contributor to the selective resistance of SCC patients to nintedanib. Moreover, our results identify TIMP-1 as a promising predictive biomarker of nintedanib responses. Citation Format: Paula Duch, Natalia Díaz-Valdivia, Marta Gabasa, Rafael Ikemori, Frank Hilberg, Noemí Reguart, Derek Radisky, Jordi Alcaraz. Aberrant TIMP-1 secretion by tumor-associated fibroblasts is a major contributor to the selective positive response to nintedanib in lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2356.