Elevated DLL3 in stomach cancer by tumor-associated macrophages enhances cancer-cell proliferation and cytokine secretion of macrophages

Jian-Bin Ye; Jun-Jie Wen; Dan-Lin Wu; Bing-Xin Hu; Mei-Qun Luo; Yan-Qing Lin; Yun-Shan Ning; Yan Li

doi:10.1093/gastro/goab052

Elevated DLL3 in stomach cancer by tumor-associated macrophages enhances cancer-cell proliferation and cytokine secretion of macrophages

Gastroenterol Rep (Oxf). 2021 Nov 25:10:goab052. doi: 10.1093/gastro/goab052. eCollection 2022.

Authors

Jian-Bin Ye¹, Jun-Jie Wen¹, Dan-Lin Wu¹, Bing-Xin Hu¹, Mei-Qun Luo¹, Yan-Qing Lin¹, Yun-Shan Ning^{1

2}, Yan Li¹

Affiliations

¹ School of Laboratory Medicine and Biotechnology, Southern Medical University, Guangzhou, Guangdong, P.R. China.
² Service Union Medicine, Southern Medical University, Zhuhai, Guangdong, P.R. China.

Abstract

Background: The notch signal pathway is important in the development of both tumor-associated macrophages (TAMs) and stomach cancer, but how Notch signaling affects TAMs in stomach cancer is barely understood.

Methods: The expressions of Notch1, Notch2, Notch3, Notch4, hes family bHLH transcription factor 1 (Hes1), and delta-like canonical Notch ligand 3 (DLL3) were detected by Western blot and the expressions of interleukin (IL)-10, IL-12, and IL1-β were detected using enzyme-linked immunosorbent assay after the co-culture of macrophages and stomach-cancer cells. The proliferation and migration of cancer cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and scratch assay, respectively, and the cell cycle was detected using Annexin V/propidium iodide assay. The protein interactions with DLL3 were detected using co-immunoprecipitation and mass spectrometry.

Results: The co-culture of macrophages and stomach-cancer cells MKN45 and BGC823 could enhance cell proliferation accompanied by the activation of Notch1/Notch2 signaling and upregulation of DLL3. Notch signaling gamma-secretase inhibitor (DAPT) blocked this process. The overexpression of DLL3 in stomach-cancer cells could promote the proliferation of cancer cells, enhance the activation of Notch1/Notch2 signaling, induce the expression of IL-33, lead to the degradation of galectin-3-binding protein (LG3BP) and heat shock cognate 71 kDa protein (HSPA8), and result in elevated IL-1β, IL-12, and IL-10 secretion by macrophages. Higher expression of DLL3 or IL-33 could lead to a lower survival rate based on University of California, Santa Cruz Xena Functional Genomics Explorer and The Cancer Genome Atlas data set.

Conclusions: This is evidence that DLL3 regulates macrophages in stomach cancer, suggesting that DLL3 may be a novel and potential target for stomach-cancer therapy.

Keywords: DLL3; Notch signaling; cytokines; macrophages; proliferation; stomach cancer.