Diet-induced obesity accelerates oral carcinogenesis by recruitment and functional enhancement of myeloid-derived suppressor cells

Cell Death Dis. 2021 Oct 14;12(10):946. doi: 10.1038/s41419-021-04217-2.

Abstract

Although obesity has been associated with an increased risk and aggressiveness of many types of carcinoma, whether it promotes squamous cell carcinoma remains unclear. To reveal the role of obesity in oral squamous cell carcinoma (OSCC) initiation and development, we used 4NQO-induced OSCC model mice to examine the impact of dietary obesity on carcinogenesis. The results showed that high-fat diet (HFD)-induced obesity significantly promoted the incidence of OSCC and altered the local immune microenvironment with the expansion of CD11b+Gr1+ myeloid-derived suppressor cells (MDSCs). The underlying mechanism that induced an immunosuppressive local microenvironment in obesity was the recruitment of MDSCs through the CCL9/CCR1 axis and enhancement of MDSC immunosuppressive function via intracellular fatty acid uptake. Furthermore, clinical samples verified the increase in infiltrated CD33+ (a marker of human MDSCs) cells in obese OSCC patients, and data from the TCGA dataset confirmed that CD33 expression was positively correlated with local adipocytes in OSCC. Survival analysis showed that enrichment of adipocytes and high expression of CD33 were associated with poor prognosis in OSCC patients. Strikingly, depletion of MDSCs significantly ameliorated HFD-promoted carcinogenesis in 4NQO-induced model mice. These findings indicate that obesity is also an important risk factor for OSCC, and cancer immunotherapy, especially targeting MDSCs, may exhibit greater antitumor efficacy in obese patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Nitroquinoline-1-oxide
  • Adipocytes / metabolism
  • Animals
  • Antigens, Ly
  • CD11b Antigen / metabolism
  • Carcinogenesis / pathology*
  • Chemokines, CC
  • Diet, High-Fat
  • Disease Models, Animal
  • Humans
  • Immunosuppression Therapy
  • Macrophage Inflammatory Proteins
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Models, Biological
  • Mouth Neoplasms / etiology*
  • Mouth Neoplasms / pathology*
  • Myeloid-Derived Suppressor Cells / pathology*
  • Obesity / complications*
  • Quinolones
  • Receptors, CCR1 / metabolism
  • Sialic Acid Binding Ig-like Lectin 3 / metabolism
  • Signal Transduction
  • Survival Analysis
  • Tongue / metabolism
  • Tongue / pathology
  • Tumor Microenvironment / drug effects

Substances

  • 4-nitroquinolone-1-oxide
  • Antigens, Ly
  • CD11b Antigen
  • Ccl9 protein, mouse
  • Ccr1 protein, mouse
  • Chemokines, CC
  • Ly6G antigen, mouse
  • Macrophage Inflammatory Proteins
  • Quinolones
  • Receptors, CCR1
  • Sialic Acid Binding Ig-like Lectin 3
  • 4-Nitroquinoline-1-oxide