The following is a summary of ”Intratumor mycobiome promotes lung cancer progression via myeloid-derived suppressor cells,” published in the November 2023 issue of Cancer Cell by Liu et al.

There was a significant gap in knowledge on the involvement of the intratumor mycobiome as live microorganisms in the course of cancer, even though polymorphic microbiomes have emerged as features characteristic of cancer. 

Using fungi-enriched DNA extraction and deep shotgun metagenomic sequencing, researchers could identify enriched tumor-resident Aspergillus sydowii in patients diagnosed with lung adenocarcinoma (LUAD). 

Using three distinct syngeneic lung cancer mouse models, they showed that A. sydowii plays a role in lung tumor growth through IL-1β-mediated proliferation and activation of mesenchymal stromal cells (MSCs). This activity led to the suppression of cytotoxic T lymphocyte cells and the accumulation of PD-1⁺ CD8⁺ T lymphocytes. Through the β-glucan/Dectin-1/CARD9 pathway, the process was facilitated by the release of IL-1β. 

Enhanced A. sydowii is related to immunosuppression and poor patient outcomes, according to the findings of an analysis of human samples. Even though it had a low biomass, their data indicated that the intratumor mycobiome contributes to the advancement of lung cancer. The mycobiome might be targeted at the strain level to improve the prognosis for patients with LUAD.

Source: sciencedirect.com/science/article/abs/pii/S153561082300288X