Inhibition of histone methyltransferase EZH2 for immune interception of colorectal cancer in Lynch syndrome
Charles M. Bowen, Fahriye Duzagac, Abel Martel-Martel, Laura Reyes-Uribe, Mahira Zaheer, Jacklyn Thompson, Nan Deng, Ria Sinha, Soham Mazumdar, Melissa W. Taggart, Abhinav K. Jain, Elena Tosti, Winfried Edelmann, Krishna M. Sinha, Eduardo Vilar
Charles M. Bowen, Fahriye Duzagac, Abel Martel-Martel, Laura Reyes-Uribe, Mahira Zaheer, Jacklyn Thompson, Nan Deng, Ria Sinha, Soham Mazumdar, Melissa W. Taggart, Abhinav K. Jain, Elena Tosti, Winfried Edelmann, Krishna M. Sinha, Eduardo Vilar
View: Text | PDF
Research Article Immunology Oncology

Inhibition of histone methyltransferase EZH2 for immune interception of colorectal cancer in Lynch syndrome

Abstract

Colorectal precancers in Lynch syndrome (LS) exhibit a distinct immune profile, presenting unique opportunities for developing immune-interception strategies to prevent carcinogenesis. Epigenetic modulation by EZH2 of immune-related genes is implicated in the carcinogenesis of different cancer types, including colorectal cancer. This study utilizes a mouse model of LS and ex vivo colonic organoids to assess the effects of the EZH2 inhibitor GSK503 on immune regulatory pathways, tumorigenesis, and epigenetic reprogramming. Our findings revealed that GSK503 significantly increased CD4+ and CD8+ T cells in both splenocytes and colonic mucosa of treated mice compared with controls. Additionally, a preventive dose of GSK503 over 9 weeks notably reduced adenoma multiplicity, demonstrating its efficacy as a preventive modality. Single-cell RNA-Seq and molecular analyses showed activation of immune and apoptotic markers, along with a reduction in H3K27 methylation levels in colonic crypts. ChIP sequencing further revealed decreased levels of H3K27me3 and H3K4me1, while levels of the active enhancer marks H3K4me3 and H3K27Ac increased in treated mice. Collectively, these findings indicate that EZH2 inhibition enhances immune responses through epigenetic reprogramming in the genome of LS mice, establishing a promising framework for the clinical development of EZH2 inhibitors as a cancer prevention strategy for LS carriers.

Authors

Charles M. Bowen, Fahriye Duzagac, Abel Martel-Martel, Laura Reyes-Uribe, Mahira Zaheer, Jacklyn Thompson, Nan Deng, Ria Sinha, Soham Mazumdar, Melissa W. Taggart, Abhinav K. Jain, Elena Tosti, Winfried Edelmann, Krishna M. Sinha, Eduardo Vilar

×

Figure 2

EZH2 inhibition reduces colonic polyposis and enriches adaptive immune cellularity in VCMsh2THu mice.

Options: View larger image (or click on image) Download as PowerPoint
EZH2 inhibition reduces colonic polyposis and enriches adaptive immune c...
(A) Flow chart of murine preclinical trial. (B) Polyp multiplicity in mice treated with GSK503 versus control. Colonoscopy data show no significant difference in polyp count at baseline (P = 0.4512) or after 9 weeks (P = 0.1558) but a significant reduction at the 6-week midpoint (P < 0.0001). Necropsy data show a significant decrease in colonic polyp multiplicity (P = 0.0045) in GSK503-treated mice, with no significant difference in small intestine polyps (P = 0.3706). LI, large intestine. Results are from 2 independent trials. (C) Flow cytometry results from the large intestine and small intestine of VCMsh2THu mice from GSK503 preclinical trial (n = 4 control mice, n = 5 treated mice). Light-colored bars represent control mice, and dark-colored bars represent treated mice. Activated CD8+ T cells were significantly increased in both the large intestine (P < 0.0001) and small intestine (P = 0.0055) of GSK503-treated mice. GSK503 significantly increased macrophages (CD68) in the large intestine (P < 0.0001) and small intestine (P = 0.0062). Finally, GSK503 increased total CD8+ T cells (P = 0.0058) and activated CD4+ T cells (P = 0.012) in the large intestine only (N = 3 mice per condition). (D) Immune cell profiling from splenocytes harvested from mice in the preclinical trial (n = 5 mice). Light-colored bars represent control mice (n = 4), and dark-colored bars represent treated mice (n = 5). GSK503 significantly increased total CD8+ cells (P = 0.0103) and activated CD8+ T cells (P < 0.0001), total CD4+ T cells (P = 0.0007), and CD335+ NK cells (P < 0.001) compared with untreated controls (N = 3 mice per condition). (E) Autologous cocultures from 6 mice per treatment group. GSK503 treatment significantly reduced coculture MDO viability compared with that of untreated cocultures (P = 0.012) and organoids alone (P = 0.003). Statistical analyses were performed using Student’s t test (B–D) and 1-way ANOVA with multiple comparisons (E) and are presented as mean ± SEM. *P < 0.05, ** P < 0.01, *** P < 0.001, **** P < 0.0001.