Abstract B025: IL6 signaling in pre-malignant obese endometrium and endometrial cancer
Authors: Zhang Qian , Melendez Brenda , Su Xiaoping , Bowen Mikayla , Celestino Joseph , Yates Melinda Sue , Lu Karen 
Published: March 2024

Objective: Obesity associated chronic inflammatory status plays a role in the increased endometrial cancer incidences, IL-6 is one of those inflammatory molecules. To explore the potential of targeting pro-inflammation factors for endometrial cancer prevention, using multi-platform and multi-model analysis, we investigated IL6 and its associated signaling in pre-malignant endometrium and low-grade endometrial cancer. Methods: Illumina microarray and Nanostring nCounter® Pancancer Immune profiling panel gene expression profiling was performed on pre-malignant obese endometrium from diet induced obese Wistar rats, and endometrium from obese patients, lean endometrium was used as control. Clariom D assay was performed on RNA extracted from the gland and stroma of human obese endometrial carcinoma (OEC) and obese normal endometrium (ONE). IPA, nSolver, Transcriptome Analysis Console (TAC), and CIBERSORTx were used for data analysis. Ishikawa cells were 2D and 3D cultured, or 3D co-cultured with endometrial stroma cell line SHT290. Western blot was used for testing cell signal activity. Results: Pronounced IL-6 signaling (Z-score:2.3333, p=2.48E-02) was shown in pre-malignant obese endometrium of diet induced obese rats compared with lean littermates: NF-kB signaling (Z-score:2.714, p=3.47E-02), STAT3 signaling (Z-score:2.53, p=6.56E-04), and tumor microenvironment pathway (Z-score: 3.441, p=6.81E-05) were enhanced; PTEN signaling (Z-score:-1.997, p=2.76E-03) was attenuated. IL6R (FC=1.64, p=0.017), MMP2 (FC=1.938, p=0.026), IL1R2 (FC=1.75, p&lt;0.0001), and CCL2 (FC=2.251, p=0.002) expression were increased. IL6 induced stronger STAT3 signaling, and weaker activation of MAPK signaling in Ishikawa cells 3D co-cultured with stroma cells, compared with 3D cultured Ishikawa cells without stroma cells. No IL-6 induced activation of MAPK signaling was observed with activation of Stat3 signaling in 2D-cultured Ishikawa cells. In pre-malignant obese endometrium from patients with high serum IL-6 levels, attenuated pro-inflammation signaling was seen compared with that from patients with low serum IL6 level: expression of IL1A (FC=-2.21, p=0.001), IRF8 (FC=-1.83, p=0.012), GAGE1 (FC=-3.49, p=0.028), and LBP (FC=-2.03, p=0.038) were decreased. Compared with pre-malignant obese endometrium, more regulatory T cell (Tregs, 0.1276 vs 0.077, p=0.04), and less eosinophils (0.003 vs 0.022, p=0.028) in the stroma, and more neutrophils (0.0145 vs. 0, p=0.02) in the tumor glands were observed in obese EC, implicating immuno-suppression in OEC. Conclusion: Due to the elevated systemic pro-inflammation status, pre-malignant obese endometrium demonstrated activated IL-6 signaling. IL-6 induced cell signaling varied by cellular microenvironment. In pre-malignant endometrium from obese women with high systemic IL-6 level, attenuated inflammation signaling was observed compared to those with low serum IL6 levels. Immuno-suppression was implicated in obese EC.

Citation Format: Qian Zhang, Brenda Melendez, Xiaoping Su, Mikayla Bowen, Joseph Celestino, Melinda Sue Yates, Karen Lu. IL6 signaling in pre-malignant obese endometrium and endometrial cancer [abstract]. In: Proceedings of the AACR Special Conference on Endometrial Cancer: Transforming Care through Science; 2023 Nov 16-18; Boston, Massachusetts. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(5_Suppl):Abstract nr B025.