Significance of Alternatively Activated Macrophages in Intrahepatic Cholangiocarcinoma

Strategic Insights -

In a groundbreaking study from Kumamoto, Japan, researchers investigated the role of tumor-associated macrophages (TAMs) in intrahepatic cholangiocarcinoma (ICC), a type of liver cancer. The study found that CD163-positive macrophages, a marker of M2 macrophages, were positively correlated with angiogenesis, immunosuppression, and poor clinical prognosis in ICC patients. Notably, patients with high counts of CD163-positive macrophages showed poor disease-free survival. The study also demonstrated that tumor cell supernatant induced Stat3 activation and macrophage polarization toward the M2 phenotype in an in vitro study using ICC cell lines and human macrophages.

Key Takeaways:

  • The study found a positive correlation between CD163-positive macrophages and angiogenesis, immunosuppression, and poor clinical prognosis in ICC patients.
  • Patients with high counts of CD163-positive macrophages showed poor disease-free survival, while the macrophage density was not correlated with overall survival.
  • Tumor cell supernatant induced Stat3 activation and macrophage polarization toward the M2 phenotype in an in vitro study using ICC cell lines and human macrophages.
  • The tumor cell supernatant from HuCCT1 cell line most strongly induced Stat3 activation and production of cytokines and bioactive molecules, including IL-10, VEGF-A, TGF-beta, and MMP-2.
  • Down-regulation of Stat3 by siRNA significantly suppressed the production of IL-10 and VEGF-A.
  • The study suggests that TAMs contribute to cancer progression via Stat3 activation, and CD163 is useful for evaluating M2 TAMs and predicting clinical prognosis in ICC patients.

Statistics:

  • The study analyzed tissue samples from 39 patients with intrahepatic cholangiocarcinoma (ICC).
  • The number of CD68-positive and CD163-positive macrophages was positively correlated with the numbers of vessels and regulatory T cells (p=0.0426).
  • The macrophage density was not correlated with overall survival.
  • The tumor cell supernatant from HuCCT1 cell line induced the production of 14.6 pg/mL IL-10, 2.5 pg/mL VEGF-A, and 0.5 pg/mL TGF-beta.

Sources:

  • H. Hasita et al. (2010). Significance of alternatively activated macrophages in patients with intrahepatic cholangiocarcinoma. Cancer Science, 101(8), 1913-9.
  • Cancer Gene Therapy