1. Academic Validation
  2. Chemotherapy-induced macrophage CXCL7 expression drives tumor chemoresistance via the STAT1/PHGDH-serine metabolism axis and SAM paracrine feedback to M2 polarization

Chemotherapy-induced macrophage CXCL7 expression drives tumor chemoresistance via the STAT1/PHGDH-serine metabolism axis and SAM paracrine feedback to M2 polarization

  • Cell Death Dis. 2025 May 14;16(1):379. doi: 10.1038/s41419-025-07712-y.
Shuguang Liu # 1 Hui Gong # 2 Peihang Li # 3 Jiahao Hu # 3 Yixuan Li 3 Rou Xu 3 Junchao Cai 4 Shuqi Wang 5 Jiayi Cai 6 Hongmei Ma 1 Xirong Mi 7 Yifan Li 2 Qingbo Zhou 8 Qiming Zhou 9 Weiqiang Yang 10 Riqing Li 11 Libing Song 12 Lishan Fang 13
Affiliations

Affiliations

  • 1 Department of pathology, The Eighth Affiliated Hospital, Sun Yat-Sun University, Shenzhen, China.
  • 2 Shenzhen Nanshan People's Hospital, Shenzhen, China.
  • 3 Medical Research Center, The Eighth Affiliated Hospital, Sun Yat-Sun University, Shenzhen, China.
  • 4 Department of Immunology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
  • 5 Department of Microbiology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
  • 6 Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
  • 7 Shenzhen University Medical School, Shenzhen, Guangdong, China.
  • 8 Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.
  • 9 Shenzhen Nanshan People's Hospital, Shenzhen, China. zqm19771221@163.com.
  • 10 Department of Otolaryngology, Peking University Shenzhen Hospital, Shenzhen, China. 497450210@qq.com.
  • 11 Shenzhen Inspection and Testing Center of Agricultural Product Quality and Safety, Shenzhen, China. liriqing246@163.com.
  • 12 Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China. songlb@sysucc.org.cn.
  • 13 Medical Research Center, The Eighth Affiliated Hospital, Sun Yat-Sun University, Shenzhen, China. fanglsh5@mail.sysu.edu.cn.
  • # Contributed equally.
Abstract

Chemotherapy resistance in colorectal Cancer (CRC) remains a major obstacle in clinical oncology. Analysis of clinical specimens from chemotherapy-resistant patients revealed elevated CXCL7 expression in tumor-associated macrophages (TAMs). Through integrated in vitro and in vivo studies, we demonstrated that chemotherapy induces tumor cell-macrophage crosstalk, leading to CXCL7 upregulation in TAMs. Using a co-culture system, we observed that CXCL7+ macrophages confer chemoresistance to CRC cells. Mechanistic investigations revealed that CXCL7 activates the CXCR2 receptor on tumor cells, triggering interferon signaling and promoting serine metabolism through STAT1-dependent transcriptional upregulation of phosphoglycerate dehydrogenase (PHGDH), the key enzyme in serine biosynthesis. This metabolic reprogramming enhances the paracrine secretion of S-adenosyl methionine (SAM), which drives chemotherapy resistance. Furthermore, CXCL7-mediated the paracrine secretion of SAM in tumor cells, which in turn promotes M2 macrophage polarization and sustains CXCL7 expression in TAMs. Our findings reveal that a CXCL7-SAM feedback loop between tumor cells and macrophages establishes a chemoresistant niche. This interaction represents a promising therapeutic target for overcoming chemoresistance in CRC.

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