Prognostic Role of Monocytic Myeloid-Derived Suppressor Cells in Advanced Non-Small-Cell Lung Cancer: Relation to Different Hematologic Indices

Functional Flow Cytometry to Predict PD-L1 Conformational Changes

The programmed cell death protein 1/programmed cell death protein ligand 1 (PD-1/PD-L1) axis is one of the most widely recognized targets for cancer immunotherapy. Importantly, PD-L1 conformational changes can hinder target binding when living cells are used. Antibody affinity, equilibrium binding, association and dissociation rates, and other affinity-related constants are fundamental to ensure target saturation. Here, PD-L1 changes in conformation and their potential impact on PD-L1 function and mutation are explored. Specifically, we present detailed flow cytometry procedures to analyze PD-L1 reactivity in myeloid-derived suppressor cells (MDSCs). This approach can also be used to study the contribution of protein conformational changes in living cells. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Sample preparation for PD-L1+ myeloid-derived suppressor cells detection by flow cytometry Basic Protocol 2: Protocol preparation, sample acquisition, and gating strategy for flow cytometric screening of PD-L1+ myeloid-derived suppressor cells in patients with lung cancer Support Protocol 1: Bioinformatic tools for the analysis of flow cytometric data.

Regulation of T cells by myeloid-derived suppressor cells: emerging immunosuppressor in lung cancer

Myeloid-derived suppressor cells (MDSCs), major components maintaining the immune suppressive microenvironment in lung cancer, are relevant to the invasion, metastasis, and poor prognosis of lung cancer, through the regulation of epithelial-mesenchymal transition, remodeling of the immune microenvironment, and regulation of angiogenesis. MDSCs regulate T-cell immune functions by maintaining a strong immunosuppressive microenvironment and promoting tumor invasion. This raises the question of whether reversing the immunosuppressive effect of MDSCs on T cells can improve lung cancer treatment. To understand this further, this review explores the interactions and specific mechanisms of different MDSCs subsets, including regulatory T cells, T helper cells, CD8 + T cells, natural killer T cells, and exhausted T cells, as part of the lung cancer immune microenvironment. Second, it focuses on the guiding significance confirmed via clinical liquid biopsy and tissue biopsy that different MDSC subsets improve the prognosis of lung cancer. Finally, we conclude that targeting MDSCs through action targets or signaling pathways can help regulate T-cell immune functions and suppress T-cell exhaustion. In addition, immune checkpoint inhibitors targeting MDSCs may serve as a new approach for enhancing the efficiency of immunotherapy and targeted therapy for lung cancer in the future, providing better comprehensive options for lung cancer treatment.

The prognostic effects of circulating myeloid-derived suppressor cells in non-small cell lung cancer: systematic review and meta-analysis

Immunotherapy is the main standard treatment for non-small cell lung cancer (NSCLC) patients. Immune suppressive cells in tumor microenvironment can counteract its efficacy. Myeloid-derived suppressor cells (MDSCs) include two major subsets: polymorphonuclear (PMN-MDSCs) and monocytic (M-MDSCs). Many studies explored the prognostic impact of these cell populations in NSCLC patients. The aim of this systematic review is to select studies for a meta-analysis, which compares prognosis between patients with high vs low circulating MDSC levels. We collected hazard ratios (HRs) and relative 95% confidence intervals (CIs) in terms of progression-free survival (PFS) or recurrence-free survival (RFS), and overall survival (OS). Among 139 studies retrieved from literature search, 14 eligible studies (905 NSCLC patients) met inclusion criteria. Low circulating MDSC levels favor a better PFS/RFS (HR = 1.84; 95% CI = 1.28-2.65) and OS (HR = 1.78; 95% CI = 1.29-2.46). The subgroup analysis based on MDSC subtypes (total-, PMN-, and M-MDSCs) obtained a statistical significance only for M-MDSCs, both in terms of PFS/RFS (HR = 2.67; 95% CI = 2.04-3.50) and OS (HR = 2.10; 95% CI = 1.61-2.75). NSCLC patients bearing high M-MDSC levels in peripheral blood experience a worse prognosis than those with low levels, both in terms of PFS/RFS and OS. This finding suggests that detecting and targeting this MDSC subset could help to improve NSCLC treatment efficacy.

Mean platelet volume/platelet count ratio in combination with tumor markers in colorectal cancer: a retrospective clinical study

BACKGROUND

Mean platelet volume (MPV) is a marker of platelet activation, which is usually negatively correlated with platelet count (PC). The ratio of MPV to PC (MPV/PC) has an essential role in the diagnosis of multiple malignancies. However, only a few studies investigated the value of MPV/PC in colorectal cancer (CRC) and the combination of MPV/PC with tumor markers in CRC. This retrospective clinical study aimed to evaluate the diagnostic value of MPV/PC and tumor markers (CA72-4, CA125, CA199) used alone or in combination in CRC.

METHODS

200 patients with CRC and 317 patients with colorectal benign polypus pathologically diagnosed during 2019/01/04 to 2022/06/30 were included. Hematological and pathological parameters of the above patients were collected, data were analyzed with Student's t-test, one-way ANOVA or Kruskal-Wallis H test and receiver operating characteristic (ROC) curve, and ROC curve was used to evaluate the diagnostic value of tumor markers and MPV/PC used alone or in combination in CRC.

RESULTS

The MPV/PC in CRC group was significantly lower than the control group (P < 0.0001). Among the three tumor markers, higher CA125 was correlated with distant metastasis and lower differentiation (P < 0.05), increased CA72-4 indicated positive nerve invasion (P = 0.0174), and elevated CA199 was associated with lymphatic metastasis and positive vascular invasion (P < 0.05). For subgroups regarding tumor anatomical location, both CA125 and CA199 were higher in colon cancer group than rectum cancer group (P = 0.0322, P = 0.0094). MPV/PC was associated with tumor infiltration, regional lymph node metastasis, differentiation and nerve invasion (P < 0.05) and the combination of MPV/PC with the three tumor markers produced a larger AUC with higher sensitivity, specificity and Yuden index than MPV/PC or the three tumor markers used alone to distinguish between CRC and colorectal polyps.

CONCLUSION

Preoperative MPV/PC in peripheral blood of patients with CRC was lower than the control group. Meanwhile, the combined detection of tumor markers with MPV/PC can improve the diagnostic value of CRC, revealing the potential of MPV/PC as a promising screening tool in CRC early diagnosis.

LncRNAs has been identified as regulators of Myeloid-derived suppressor cells in lung cancer

Lung tumours are widespread pathological conditions that attract much attention due to their high incidence of death. The immune system contributes to the progression of these diseases, especially non-small cell lung cancer, resulting in the fast evolution of immune-targeted therapy. Myeloid-derived suppressor cells (MDSCs) have been suggested to promote the progression of cancer in the lungs by suppressing the immune response through various mechanisms. Herein, we summarized the clinical studies on lung cancer related to MDSCs. However, it is noteworthy to mention the discovery of long non-coding RNAs (lncRNAs) that had different phenotypes and could regulate MDSCs in lung cancer. Therefore, by reviewing the different phenotypes of lncRNAs and their regulation on MDSCs, we summarized the lncRNAs' impact on the progression of lung tumours. Data highlight LncRNAs as anti-cancer agents. Hence, we aim to discuss their possibilities to inhibit tumour growth and trigger the development of immunosuppressive factors such as MDSCs in lung cancer through the regulation of lncRNAs. The ultimate purpose is to propose novel and efficient therapy methods for curing patients with lung tumours.

Hematologic dysfunction in cancer: Mechanisms, effects on antitumor immunity, and roles in disease progression

With the major advances in cancer immunology and immunotherapy, it is critical to consider that most immune cells are short-lived and need to be continuously replenished from hematopoietic stem and progenitor cells. Hematologic abnormalities are prevalent in cancer patients, and many ground-breaking studies over the past decade provide insights into their underlying cellular and molecular mechanisms. Such studies demonstrate that the dysfunction of hematopoiesis is more than a side-effect of cancer pathology, but an important systemic feature of cancer disease. Here we review these many advances, covering the cancer-associated phenotypes of hematopoietic stem and progenitor cells, the dysfunction of myelopoiesis and erythropoiesis, the importance of extramedullary hematopoiesis in cancer disease, and the developmental origins of tumor associated macrophages. We address the roles of many secreted mediators, signaling pathways, and transcriptional and epigenetic mechanisms that mediate such hematopoietic dysfunction. Furthermore, we discuss the important contribution of the hematopoietic dysfunction to cancer immunosuppression, the possible avenues for therapeutic intervention, and highlight the unanswered questions and directions for future work. Overall, hematopoietic dysfunction is established as an active component of the cancer disease mechanisms and an important target for therapeutic intervention.

Host-Related Factors as Targetable Drivers of Immunotherapy Response in Non-Small Cell Lung Cancer Patients

Despite some significant therapeutic breakthroughs leading to immunotherapy, a high percentage of patients with non-small cell lung cancer (NSCLC) do not respond to treatment on relapse, thus experiencing poor prognosis and survival. The unsatisfying results could be related to the features of the tumor immune microenvironment and the dynamic interactions between a tumor and immune infiltrate. Host-tumor interactions strongly influence the course of disease and response to therapies. Thus, targeting host-associated factors by restoring their physiologic functions altered by the presence of a tumor represents a new therapeutic approach to control tumor development and progression. In NSCLC, the immunogenic tumor balance is shifted negatively toward immunosuppression due to the release of inhibitory factors as well as the presence of immunosuppressive cells. Among these cells, there are myeloid-derived suppressor cells, regulatory T cells that can generate a tumor-permissive milieu by reprogramming the cells of the hosts such as tumor-associated macrophages, tumor-associated neutrophils, natural killer cells, dendritic cells, and mast cells that acquire tumor-supporting phenotypes and functions. This review highlights the current knowledge of the involvement of host-related factors, including innate and adaptive immunity in orchestrating the tumor cell fate and the primary resistance mechanisms to immunotherapy in NSCLC. Finally, we discuss combinational therapeutic strategies targeting different aspects of the tumor immune microenvironment (TIME) to prime the host response. Further research dissecting the characteristics and dynamic interactions within the interface host-tumor is necessary to improve a patient fitness immune response and provide answers regarding the immunotherapy efficacy, with the aim to develop more successful treatments for NSCLC.