Leukemic progenitor cells enable immunosuppression and post-chemotherapy relapse via IL-36-inflammatory monocyte axis

Bone Marrow Endothelial Progenitor Cells remodelling facilitates normal hematopoiesis during Acute Myeloid Leukemia Complete Remission

Although acute myeloid leukemia (AML) affects hematopoietic stem cell (HSC)-supportive microenvironment, it is largely unknown whether leukemia-modified bone marrow (BM) microenvironment can be remodeled to support normal hematopoiesis after complete remission (CR). As a key element of BM microenvironment, endothelial progenitor cells (EPCs) provide a feasible way to investigate BM microenvironment remodeling. Here, we find reduced and dysfunctional BM EPCs in AML patients, characterized by impaired angiogenesis and high ROS levels, could be partially remodeled after CR and improved by N-acetyl-L-cysteine (NAC). Importantly, HSC-supporting ability of BM EPCs is partially recovered, whereas leukemia-supporting ability is decreased in CR patients. Mechanistically, the transcriptome characteristics of leukemia-modified BM EPCs return to near-normal after CR. In a classic AML mouse and chemotherapy model, BM vasculature and normal hematopoiesis are reversed after CR. In summary, we provide further insights into how leukemia-modified BM microenvironment can be remodeled to support normal hematopoiesis after CR, which can be further improved by NAC.

Prognostic value of Interleukin-36s in cancers: A systematic review and meta-analysis

BACKGROUND

Interleukin-36s (IL-36s) are a category of inflammatory cytokines and an increasing number of studies over the past decade have found that different kinds of IL-36s play different roles in cancers. This systematic review and meta-analysis aimed to evaluate the prognostic value of IL-36s in different cancer types.

METHOD

Two reviewers independently searched in PubMed, Cochrane Library and EMBASE up to December 13, 2022. We extracted the hazard ratio (HR) and the confidence intervals (CIs) of the related prognostic outcomes and analyzed the pooled HR.

RESULTS

We included 12 studies including 1925 patients. In all, six studies including IL-36α, five including IL-36γ and one including IL-36β. A high expression of IL-36α was associated with better overall survival (OS) (HR = 0.48, 95 %CI: 0.37-0.62, P < 0.001) of cancer patients. The expression of IL-36γ was not related with cancers. Further, subgroup analysis showed that the expression of IL-36γ had no correlation with the OS of colorectal cancer (CRC) and non‑small cell lung cancer (NSCLC) patients. Interestingly, a high expression of IL-36γ played contrasting prognostic roles in hepatocellular carcinoma (HCC) (HR = 0.43, 95 %CI: 0.27-0.69, P < 0.001) patients and gastric cancer (GC) (HR = 1.58, 95 %CI: 1.33-1.87, P < 0.001) patients. The only IL-36β related study showed the expression of IL-36β was not correlated with the prognosis of CRC patients (P > 0.05).

CONCLUSION

IL-36α, IL-36β and IL-36γ possibly play different roles in different cancers. High expression of IL-36α may be associated with good prognostic value in cancer patients, especially in CRC patients. The association between cancers prognosis and expression of IL-36β or IL-36γ needs further evaluation. These conclusions need more clinical prognostic data for confirmation.

Effects of the Anti-Tumor Agents Trabectedin and Lurbinectedin on Immune Cells of the Tumor Microenvironment

Immune cells in the tumor micro-environment (TME) establish a complex relationship with cancer cells and may strongly influence disease progression and response to therapy. It is well established that myeloid cells infiltrating tumor tissues favor cancer progression. Tumor-Associated Macrophages (TAMs) are abundantly present at the TME and actively promote cancer cell proliferation and distant spreading, as well as contribute to an immune-suppressive milieu. Active research of the last decade has provided novel therapeutic approaches aimed at depleting TAMs and/or at reprogramming their functional activities. We reported some years ago that the registered anti-tumor agent trabectedin and its analogue lurbinectedin have numerous mechanisms of action that also involve direct effects on immune cells, opening up new interesting points of view. Trabectedin and lurbinectedin share the unique feature of being able to simultaneously kill cancer cells and to affect several features of the TME, most notably by inducing the rapid and selective apoptosis of monocytes and macrophages, and by inhibiting the transcription of several inflammatory mediators. Furthermore, depletion of TAMs alleviates the immunosuppressive milieu and rescues T cell functional activities, thus enhancing the anti-tumor response to immunotherapy with checkpoint inhibitors. In view of the growing interest in tumor-infiltrating immune cells, the availability of antineoplastic compounds showing immunomodulatory effects on innate and adaptive immunity deserves particular attention in the oncology field.