Loss of Kmt2c/d promotes gastric cancer and confers vulnerability to mTORC1 and PD-1 inhibition
Naitao Wang, Dan Li, Tao Zhang, Mohini R. Pachai, Dana M. Schoeps, Yudi Bao, Woo Hyun Cho, Makhzuna N. Khudoynazarova, Kae Kristoff, Marion Liu, Laura Tang, Yelena Y. Janjigian, Ping Chi, Yu Chen
Naitao Wang, Dan Li, Tao Zhang, Mohini R. Pachai, Dana M. Schoeps, Yudi Bao, Woo Hyun Cho, Makhzuna N. Khudoynazarova, Kae Kristoff, Marion Liu, Laura Tang, Yelena Y. Janjigian, Ping Chi, Yu Chen
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Research Article Gastroenterology Genetics Oncology

Loss of Kmt2c/d promotes gastric cancer and confers vulnerability to mTORC1 and PD-1 inhibition

Abstract

Based on the observation that loss-of-function mutations of KMT2C and KMT2D (KMT2C/D) are enriched and co-occur in gastric adenocarcinoma, we developed genetically engineered mouse models (GEMMs) to conditionally knock out Kmt2c and Kmt2d in gastric epithelial cells. We observed that Kmt2c/d loss led to nuclear dysplasia, cellular crowding, and expansion of cells with mixed gastric lineage markers. When combined with Pten deletion, Kmt2c/d loss drove rapid development of muscle-invasive gastric adenocarcinoma as early as 3 weeks after Cre-mediated gene deletion. The adenocarcinoma exhibited decreased expression of gastric lineage markers and increased expression of intestinal differentiation markers, phenocopying human intestinal-type gastric adenocarcinoma. Bioinformatic integration of single-cell RNA-seq of our GEMMs and human gastric cancer datasets showed coclustering of normal and of cancerous gastric epithelial cells. Kmt2c/d knockout in gastric epithelium reduced protein synthesis but upregulated transcription of ribosomal proteins, rendering the cells hypersensitive to mTOR complex 1 (mTORC1) inhibitors. Additionally, Kmt2c/d knockout increased MHC class I molecule expression and enhanced antigen presentation. Combination of mTORC1 inhibition and anti–programmed cell death 1 immunotherapy markedly suppressed tumor growth in immune-competent mice. Together, these findings reveal the role of Kmt2c/d loss in gastric cancer initiation and suggest potential therapeutic strategies for KMT2C/D-deficient gastric cancer.

Authors

Naitao Wang, Dan Li, Tao Zhang, Mohini R. Pachai, Dana M. Schoeps, Yudi Bao, Woo Hyun Cho, Makhzuna N. Khudoynazarova, Kae Kristoff, Marion Liu, Laura Tang, Yelena Y. Janjigian, Ping Chi, Yu Chen

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Figure 8

Combination of rapamycin and anti–PD-1 suppresses growth of TPCD cells in vivo.

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Combination of rapamycin and anti–PD-1 suppresses growth of TPCD cells i...
(A and B) Representative bright-field images of organoid from TP and TPCD groups. Scale bar, 1 mm. Cells were seeded in Matrigel (500 cells per blob, 50 μL), then treated from day 2 for 10 days. Organoid culture medium and inhibitors were refreshed every 4 days. Cell growth was measured using the CellTiter-Glo luminescent reagent. Data are presented as mean ± SD (n = 3) and analyzed with 2-tailed t test. (C) Schematic illustration showing the induction and treatment of stomach cancer in TPCD mice. Vehicle or rapamycin treatment started 3 days after the first dose of tamoxifen. (D) Kaplan-Meier plots showing the survival of mice treated with vehicle or rapamycin. (E) Stomach weight in TPCD mice treated with vehicle (n = 13 mice) or rapamycin (n = 10 mice). Data are presented as mean ± SD and analyzed with 2-tailed t test. (F) Statistics of invasive lesions in TPCD mice treated with vehicle (n = 13 mice) or rapamycin (n = 10 mice). Invasion sites were determined using IHC of α–smooth muscle actin (α-SMA). Data are presented as mean ± SD and analyzed with 2-tailed t test. (G) Representative H&E and IHC of α-SMA in vehicle- or rapamycin-treated TPCD mice. Scale bar, 200 μm.#3, third mouse. (H and I) Allografts and growth curves of TPCD tumors treated with rapamycin (5 mg/kg/d) or anti–PD-1 (8 mg/kg, twice a week) in C57BL/6 mice (n = 8 grafts per condition). Treatment started 2 weeks after injection of cells into the mammary fat pad. Data are presented as mean ± SEM and analyzed with 2-tailed t test at endpoint. (J) Statistics of TPCD tumor weight in C57BL/6 mice. Data are presented as mean ± SD and analyzed with 2-tailed t test.