Tumor-infiltrating Treg, MDSC, and IDO expression associated with outcomes of neoadjuvant chemotherapy of breast cancer

Research Progress on the Role of Regulatory T Cell in Tumor Microenvironment in the Treatment of Breast Cancer

The tumor microenvironment (TME) is a complex ecosystem comprised of cancer cells, stromal cells, and immune cells. Analysis of the composition of TME is essential to assess the prognosis of patients with breast cancer (BC) and the efficacy of different regimes. Treg plays a crucial role in the microenvironment of breast cancer subtypes, and its function contributes to the development and progression of BC by suppressing anti-tumor immunity directly or indirectly through multiple mechanisms. In addition, conventional treatments, such as anthracycline-based neoadjuvant chemotherapy, and neo-therapies, such as immune-checkpoint blockades, have a significant impact on the absence of Tregs in BC TME, thus gaining additional anti-tumor effect to some extent. Strikingly, Treg in BC TME revealed the predicted efficacy of some therapeutic strategies. All these results suggest that we can manipulate the abundance of Treg to achieve the ultimate effect of both conventional and novel treatments. In this review, we discuss new insights into the characteristics of Treg in BC TME, the impact of different regiments on Treg, and the possibilities of Treg as a predictive marker of efficacy for certain treatments.

Deep learning model enables the discovery of a novel immunotherapeutic agent regulating the kynurenine pathway

Kynurenine (Kyn) is a key inducer of an immunosuppressive tumor microenvironment (TME). Although indoleamine 2,3-dioxygenase (IDO)-selective inhibitors have been developed to suppress the Kyn pathway, the results were not satisfactory due to the presence of various opposing mechanisms. Here, we employed an orally administered novel Kyn pathway regulator to overcome the limitation of anti-tumor immune response. We identified a novel core structure that inhibited both IDO and TDO. An orally available lead compound, STB-C017 (designated hereafter as STB), effectively inhibited the enzymatic and cellular activity of IDO and TDO in vitro. Moreover, it potently suppressed Kyn levels in both the plasma and tumor in vivo. STB monotherapy increased the infiltration of CD8⁺ T cells into TME. In addition, STB reprogrammed the TME with widespread changes in immune-mediated gene signatures. Notably, STB-based combination immunotherapy elicited the most potent anti-tumor efficacy through concurrent treatment with immune checkpoint inhibitors, leading to complete tumor regression and long-term overall survival. Our study demonstrated that a novel Kyn pathway regulator derived using deep learning technology can activate T cell immunity and potentiate immune checkpoint blockade by overcoming an immunosuppressive TME.

Immunotherapy in Breast Cancer: When, How, and What Challenges?

Breast Cancer (BC) is the second most frequent cause of cancer death among women worldwide and, although there have been significant advances in BC therapies, a significant percentage of patients develop metastasis and disease recurrence. Since BC was demonstrated to be an immunogenic tumor, immunotherapy has broken through as a significant therapy strategy against BC. Over the years, immunotherapy has improved the survival rate of HER2+ BC patients due to the approval of some monoclonal antibodies (mAbs) such as Trastuzumab, Pertuzumab and, recently, Margetuximab, along with the antibody-drug conjugates (ADC) Trastuzumab-Emtansine (T-DM1) and Trastuzumab Deruxtecan. Immune checkpoint inhibitors (ICI) showed promising efficacy in triple-negative breast cancer (TNBC) treatment, namely Atezolizumab and Pembrolizumab. Despite the success of immunotherapy, some patients do not respond to immunotherapy or those who respond to the treatment relapse or progress. The main causes of these adverse events are the complex, intrinsic or extrinsic resistance mechanisms. In this review, we address the different immunotherapy approaches approved for BC and some of the mechanisms responsible for resistance to immunotherapy.

A nomogram-based immunoprofile predicts clinical outcomes for stage II and III human colorectal cancer

An immunoscore for colorectal cancer (CRC) has higher prognostic significance than the TNM staging system. However, the tumor immune microenvironment contains various components that affect clinical prognosis. Therefore, a broader range of immune markers is required to establish an accurate immunoprofile to assess the prognosis of patients with CRC. Using immunohistochemistry combined with multispectral immunohistochemistry and objective assessments, the infiltration of four immune cell types (CD4⁺/CD8⁺/forkhead box p3⁺/CD33⁺ cells), as well as the expression of six co-signaling molecules [programmed cell death 1 (PD1) ligand 1/PD1/T-cell immunoglobulin mucin family member 3/lymphocyte-activating 3/tumor necrosis factor receptor superfamily, member 4/inducible T-cell costimulator] and indoleamine 2,3-dioxygenase 1 were investigated in two independent cohorts of CRC. The patients' overall survival (OS) was evaluated using the Kaplan-Meier method. Using the Cox proportional hazards model, independent prognostic factors of patients were assessed and a nomogram-based immunoprofile system was developed. The predictive ability of the nomogram was determined using a concordance index (C-index) and calibration curve. To facilitate clinical application, a simplified nomogram-based immunoprofile was constructed. Using receiver operating characteristic (ROC) analysis, the predictive accuracy for OS was compared between the immunoprofile and the TNM staging system for patients with stage II/III CRC. According to multivariate analysis for the primary cohort, independent prognostic factors for OS were CD8⁺ tumor-infiltrating lymphocytes, CD33⁺ myeloid-derived suppressor cells and TNM stage, which were included in the nomogram. The C-index of the nomogram for predicting OS was 0.861 (95% CI: 0.796-0.925) for the internal validation and 0.759 (95% CI: 0.714-0.804) for the external validation cohort. The simplified nomogram-based immunoprofile system was able to separate same-stage patients into different risk subgroups, particularly for TNM stage II (P<0.0001) and III (P=0.0002) patients. Pairwise comparison of ROC curves for the immunoprofile and TNM stage systems for patients with stage II/III CRC revealed statistically significant differences (P=0.046) and the Z-statistic value was 1.995. In conclusion, the nomogram-based immunoprofile system provides prognostic accuracy regarding clinical outcomes and is a useful supplement to the TNM staging system for patients with stage II/III CRC.

Characterization of PD-1/PD-L1 immune checkpoint expression in the pathogenesis of musculoskeletal Langerhans cell histiocytosis: A retrospective study

Recent data suggest that programmed cell death -1 (PD-1) and programmed cell death ligand-1 (PD-L1) are involved in the pathogenesis of Langerhans cell histiocytoma (LCH); however, their contributions are not well established. Also, the involvement of PD-1/PD-L1 molecules in musculoskeletal LCH remains particularly unclear. The current study aims to characterize the involvement of PD-1/PD-L1 immune checkpoint system in the pathogenesis of musculoskeletal LCH. PD-1/PD-L1 expression was evaluated in 6 patients, 3 men and 3 women with a mean age of 13.5 years, with musculoskeletal LCH who were treated at Kindai University Hospital and Osaka Women's and Children's Hospital between November 2005 and December 2020. The median follow-up period for all patients with musculoskeletal LCH was 41 months. We surveyed symptoms, number of lesions, treatment modality, and outcomes. Immunostaining for CD4, CD8, PD-1, and PD-L1 was also performed on pathological specimens obtained by biopsy. Multiple lesions were observed in 5 cases, and a single lesion was observed in 1 case. The chief complaint in 5 cases was pain. Four patients underwent spontaneous regression. The other 2 patients received chemotherapy. The outcomes included continuous disease-free (n = 5) and alive with the disease (n = 1). The CD4-, CD8-, PD-1-, and PD-L1-positive rates among all specimens were 100%, 100%, 16.6%, and 83.3%, respectively. The CD4/PD-L1, CD8/PD-L1, and PD-1/PD-L1 positive rates in all the specimens were 83.3%, 83.3%, and 16.6%, respectively. We believe that the PD-1/PD-L1 immune checkpoint molecules may play some role in the microenvironment of musculoskeletal LCH.

Integrative analysis-based identification and validation of a prognostic immune cell infiltration-based model for patients with advanced gastric cancer

BACKGROUNDS

Advanced gastric cancer (GC) remains difficult to conduct individualized prognostic evaluations owing to the highly heterogeneous nature and the low level of immune cell infiltration (ICI) within GC tumors. This study thus sought to develop a model capable of classifying GC patients according to the degree of tumor ICI and gauging prognosis.

METHODS

The degree of ICI in GC patients from the GSE15459, GSE57303, and GSE62254 datasets were estimated, and these values were used to group patients via an unsupervised clustering approach, after which ICI cluster-related genes were identified the association with prognosis through Cox and LASSO regression analyses. The primary risk genes were then verified by immunohistochemical staining of GC tumor tissue samples.

RESULTS

570 patients were clustered into three clusters and 289 ICI cluster-related genes were identified. A prognostic model based on the expression of six crucial ICI risk genes (CXCL11, RBPMS2, LOC400043, JCHAIN, CT83, and ORM1) wa constructed. Patients identified as being high risk based upon the model have poorer clinical features and survival outcomes compared to the other patients. Adjuvant intervention was found to be more beneficial for patients expressing high levels of RBPMS2, JCHAIN, or ORM1. Furthermore, patients expressing low levels of JCHAIN or CT83 in GC tumor tissues were verified to exhibit a significantly better prognosis in a CMU cohort.

CONCLUSION

Advanced GC patients were successfully grouped into clusters based on the degree of intratumoral ICI, and a prognostic evaluation model based on 6 ICI risk genes was developed and validated.

Tumor-Infiltrating Cytotoxic T Cells and Tumor-Associated Macrophages Correlate With the Outcomes of Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer

BACKGROUND

Tumor-infiltrating immune cells (TIICs) play a key role in immunoregulatory networks and are related to tumor development. Emerging evidence shows that these cells are associated with sensitivity to chemotherapy and radiotherapy. However, the predictive role of TIICs in the outcomes of neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer (LARC) is unclear.

METHODS

Imaging mass cytometry (IMC) was performed to comprehensively assess the immune status before nCRT in 6 patients with LARC (3 achieved pathological complete response (pCR), 3 did not) with matched clinicopathological parameters. Immunohistochemistry (IHC) for CD8, CD163 and Foxp3 on biopsy samples from 70 patients prior to nCRT and logistic regression analysis were combined to further evaluate its predictive value for treatment responses in an independent validation group.

RESULTS

A trend of increased CD8+ cytotoxic T lymphocytes (CTLs) and decreased CD163+ tumor-associated macrophages (TAMs) and Foxp3+ regulatory T cells (Tregs) in the pCR group was revealed by IMC. In the validation group, CTLs and TAMs were strong predictors of the clinical response to nCRT. High levels of CTLs were positively associated with the pCR ratio (OR=1.042; 95% CI: 1.015~1.070, p=0.002), whereas TAMs were correlated with a poor response (OR=0.969; 95% CI: 0.941~0.998, p=0.036). A high density of TAMs was also associated with an advanced cN stage.

CONCLUSION

CTLs in the tumor microenvironment (TME) may improve the response to nCRT, whereas TAMs have the opposite effect. These results suggest that these cells might be potential markers for the clinical outcomes of nCRT and aid in the clinical decision-making of LARC for improved clinical outcomes.

Myeloid-derived suppressor cells as immunosuppressive regulators and therapeutic targets in cancer

Myeloid-derived suppressor cells (MDSCs) are a heterogenic population of immature myeloid cells with immunosuppressive effects, which undergo massive expansion during tumor progression. These cells not only support immune escape directly but also promote tumor invasion via various non-immunological activities. Besides, this group of cells are proved to impair the efficiency of current antitumor strategies such as chemotherapy, radiotherapy, and immunotherapy. Therefore, MDSCs are considered as potential therapeutic targets for cancer therapy. Treatment strategies targeting MDSCs have shown promising outcomes in both preclinical studies and clinical trials when administrated alone, or in combination with other anticancer therapies. In this review, we shed new light on recent advances in the biological characteristics and immunosuppressive functions of MDSCs. We also hope to propose an overview of current MDSCs-targeting therapies so as to provide new ideas for cancer treatment.

Multi-Omics Reveals the Immunological Role and Prognostic Potential of Mitochondrial Ubiquitin Ligase MARCH5 in Human Breast Cancer

E3 ubiquitin-linked enzyme MARCH5, also known as membrane-associated circular finger 5, is an enzyme encoded by the human MARCH5 gene. The main objective of this study was to visualize the prognosis of MARCH5 in breast cancer and to determine the relationship between MARCH5 expression and tumor immunity. MARCH5 expression was significantly higher in several cancers, including breast cancer (BRCA), compared with corresponding normal tissues. Not only was high MARCH5 expression associated with poorer overall survival, but also MARCH5 expression was positively correlated with the number of tumor-infiltrating immune cells in BRCA malignant tissues. Furthermore, MARCH5 expression showed a strong correlation with various immune markers of BRCA, suggesting its role in regulating tumor immunity. MARCH5 is a useful prognostic biomarker in several cancers, and its expression is highly correlated with tumor immune cell infiltration, and increased MARCH5 expression may serve as a new biomarker for BRCA diagnosis and prognosis.

[Effects of neoadjuvant chemoradiotherapy on infiltrating immune cells in the tumor microenvironment of rectal cancer]

OBJECTIVE

To detect the changes in the number and phenotype of tumor infiltrating immune cells in rectal cancer tissues before and after neoadjuvant concurrent chemoradiotherapy (CRT) and analyze their correlation with the clinicopathological parameters of the patients.

METHODS

The protein expressions of CD3, CD4, CD8, CD56 and Foxp3 in biopsy specimens and postoperative pathological specimens collected from 20 rectal cancer patients before and after neoadjuvant CRT were detected using Elivision^TM Plus immunohistochemistry, and the results were statistically analyzed.

RESULTS

Compared with the measurements before the therapy, neoadjuvant CRT resulted in significant increments in CD3 (21.8% vs 48.8%, P < 0.001), CD4(16.5% vs 42.2%, P < 0.001), CD8(8.3% vs 33.4%, P < 0.001)and CD56(0 vs 7.6%, P=0.012), obvious reduction in Foxp3 expression(26.0% vs 15.3%, P=0.005), but no significant changes in CD4/CD8 ratio of(2.7 vs 5.1).Multivariate analysis showed that the increase of CD3-positive cells(HR=0.16, P=0.028)and CD8-positive cells(HR=0.03, P=0.001)was positively correlated with the disease-free survival of the patients after the operation.

CONCLUSION

Neoadjuvant CRT can significantly increase the proportions of infiltrating immune cells positive for CD3, CD4, CD8 and CD56 and decrease the proportion of Treg lymphocytes in the tumor tissues in patients with rectal cancer.The patients with increased CD3-and CD8-positive T lymphocytes may have longer disease-free survival after the surgery.

Circulating immune biomarkers in peripheral blood correlate with clinical outcomes in advanced breast cancer

Identification of the different elements intervening at the tumor microenvironment seems key to explain clinical evolution in several tumor types. In this study, a set of immune biomarkers (myeloid derived suppressor cells, regulatory T cells, and OX40 + and PD-1 + T lymphocytes counts) in peripheral blood of patients diagnosed with advanced breast cancer were analyzed along of first line antineoplastic therapy. Subsequently, a comparison between groups with clinical benefit versus progression of disease and with a healthy women cohort was executed. Results reflected that patients showed higher basal levels of myeloid derived suppressor cells (35.43, IR = 180.73 vs 17.53, IR = 16.96 cells/μl; p = 0.001) and regulatory T cells (32.05, IR = 29.84 vs 22.61, IR = 13.57 cells/μl; p = 0.001) in comparison with healthy women. Furthermore, an increase in the number of activated T lymphocytes (expressing OX40), a decrease of immune inhibitory cells (MDSCs and Tregs) and inhibited T lymphocytes (expressing PD-1) were observed along the treatment in patients with clinical benefit (p ≤ 0.001). The opposite trend was observed in the case of disease progression. These findings suggest that some critical immune elements can be easily detected and measured in peripheral blood, which open a new opportunity for translational research, as they seem to be correlated with clinical evolution, at least in ABC.

Tumor Microenvironment: Key Players in Triple Negative Breast Cancer Immunomodulation

Simple Summary

The tumor microenvironment (TME) is a complicated network composed of various cells, signaling molecules, and extra cellular matrix. TME plays a crucial role in triple negative breast cancer (TNBC) immunomodulation and tumor progression, paradoxically, acting as an immunosuppressive as well as immunoreactive factor. Research regarding tumor immune microenvironment has contributed to a better understanding of TNBC subtype classification. Shall we treat patients precisely according to specific subtype classification? Moving beyond traditional chemotherapy, multiple clinical trials have recently implied the potential benefits of immunotherapy combined with chemotherapy. In this review, we aimed to elucidate the paradoxical role of TME in TNBC immunomodulation, summarize the subtype classification methods for TNBC, and explore the synergistic mechanism of chemotherapy plus immunotherapy. Our study may provide a new direction for the development of combined treatment strategies for TNBC.

Abstract

Triple negative breast cancer (TNBC) is a heterogeneous disease and is highly related to immunomodulation. As we know, the most effective approach to treat TNBC so far is still chemotherapy. Chemotherapy can induce immunogenic cell death, release of damage-associated molecular patterns (DAMPs), and tumor microenvironment (TME) remodeling; therefore, it will be interesting to investigate the relationship between chemotherapy-induced TME changes and TNBC immunomodulation. In this review, we focus on the immunosuppressive and immunoreactive role of TME in TNBC immunomodulation and the contribution of TME constituents to TNBC subtype classification. Further, we also discuss the role of chemotherapy-induced TME remodeling in modulating TNBC immune response and tumor progression with emphasis on DAMPs-associated molecules including high mobility group box1 (HMGB1), exosomes, and sphingosine-1-phosphate receptor 1 (S1PR1), which may provide us with new clues to explore effective combined treatment options for TNBC.

Review of 10 years of research on breast cancer patients: Focus on indoleamine 2,3-dioxygenase

Therapeutic manipulation of the immune system in cancer has been an extensive area of research in the field of oncoimmunology. Immunosuppression regulates antitumour immune responses. An immunosuppressive enzyme, indoleamine 2,3-dioxygenase (IDO) mediates tumour immune escape in various malignancies including breast cancer. IDO upregulation in breast cancer cells may lead to the recruitment of regulatory T (T-regs) cells into the tumour microenvironment, thus inhibiting local immune responses and promoting metastasis. Immunosuppression induced by myeloid derived suppressor cells activated in an IDO-dependent manner may enhance the possibility of immune evasion in breast cancer. IDO overexpression has independent prognostic significance in a subtype of breast cancer of emerging interest, basal-like breast carcinoma. IDO inhibitors as adjuvant therapeutic agents may have clinical implications in breast cancer. This review proposes future prospects of IDO not only as a therapeutic target but also as a valuable prognostic marker for breast cancer.

Nodal status in luminal A invasive breast cancer: relationships with cytotoxic CD8 + and regulatory FOXP3 + cells tumor-associated infiltrate and other prognostic factors

Luminal A breast cancers are generally associated with low metastatic potential and good prognosis. However, there is a proportion of patients, who present with metastases in lymph nodes. The aim of our study was to determine the association between the number of positive lymph nodes and infiltrates of tumor-associated cytotoxic CD8 + (CTLs), regulatory FOXP3 + T cells (Tregs), as well as other prognostic factors. Immunohistochemistry (IHC) for CD8 + and FOXP3 + was performed in 87 formalin-fixed paraffin-embedded primary breast cancer tissues, and cell infiltrate was assessed under light microscope. We observed that node-positive cases were associated with higher numbers of Treg cells and lower CTL/Treg ratio. There was also an inverse correlation between the CTL/Treg ratio and the number of metastatic lymph nodes. Similar relationships were found between the number of metastatic lymph nodes and Treg density or CTL/Treg ratio in pT1 BC. An elevated intratumoral CTL/Treg ratio was associated with pN0 stage. The relationship between lymphovascular invasion (LVI) and Treg density was also noted in node-negative tumors. In addition, more advanced nodal stage was related to LVI, higher pT, and lower PR expression. The numbers of CD8 + and FOXP3 + were also associated with tumor size, histologic grade, PR expression, and mitotic index. The results of our study suggested that the levels of tumor-infiltrating regulatory and cytotoxic cells as well as the balance between them play a role in lymphovascular spread of luminal A breast cancers.

Tumor Immune Microenvironment and Immunosuppressive Therapy in Hepatocellular Carcinoma: A Review

Liver cancer has the fourth highest mortality rate of all cancers worldwide, with hepatocellular carcinoma (HCC) being the most prevalent subtype. Despite great advances in systemic therapy, such as molecular-targeted agents, HCC has one of the worst prognoses due to drug resistance and frequent recurrence and metastasis. Recently, new therapeutic strategies such as cancer immunosuppressive therapy have prolonged patients' lives, and the combination of an immune checkpoint inhibitor (ICI) and VEGF inhibitor is now positioned as the first-line therapy for advanced HCC. Since the efficacy of ICIs depends on the tumor immune microenvironment, it is necessary to elucidate the immune environment of HCC to select appropriate ICIs. In this review, we summarize the findings on the immune microenvironment and immunosuppressive approaches focused on monoclonal antibodies against cytotoxic T lymphocyte-associated protein 4 and programmed cell death protein 1 for HCC. We also describe ongoing treatment modalities, including adoptive cell transfer-based therapies and future areas of exploration based on recent literature. The results of pre-clinical studies using immunological classification and animal models will contribute to the development of biomarkers that predict the efficacy of immunosuppressive therapy and aid in the selection of appropriate strategies for HCC treatment.

Valproic Acid-Like Compounds Enhance and Prolong the Radiotherapy Effect on Breast Cancer by Activating and Maintaining Anti-Tumor Immune Function

Inadequate sustained immune activation and tumor recurrence are major limitations of radiotherapy (RT), sustained and targeted activation of the tumor microenvironment can overcome this obstacle. Here, by two models of a primary rat breast cancer and cell co-culture, we demonstrated that valproic acid (VPA) and its derivative (HPTA) are effective immune activators for RT to inhibit tumor growth by inducing myeloid-derived macrophages and polarizing them toward the M1 phenotype, thus elevate the expression of cytokines such as IL-12, IL-6, IFN-γ and TNF-α during the early stage of the combination treatment. Meanwhile, activated CD8+ T cells increased, angiogenesis of tumors is inhibited, and the vasculature becomes sparse. Furthermore, it was suggested that VPA/HPTA can enhance the effects of RT via macrophage-mediated and macrophage-CD8+ T cell-mediated anti-tumor immunity. The combination of VPA/HPTA and RT treatment slowed the growth of tumors and prolong the anti-tumor effect by continuously maintaining the activated immune response. These are promising findings for the development of new effective, low-cost concurrent cancer therapy.

Coordinated regulation of immune contexture: crosstalk between STAT3 and immune cells during breast cancer progression

Recent insights into the molecular and cellular mechanisms underlying cancer development have revealed the tumor microenvironment (TME) immune cells to functionally affect the development and progression of breast cancer. However, insufficient evidence of TME immune modulators limit the clinical application of immunotherapy for advanced and metastatic breast cancers. Intercellular STAT3 activation of immune cells plays a central role in breast cancer TME immunosuppression and distant metastasis. Accumulating evidence suggests that targeting STAT3 and/or in combination with radiotherapy may enhance anti-cancer immune responses and rescue the systemic immunologic microenvironment in breast cancer. Indeed, apart from its oncogenic role in tumor cells, the functions of STAT3 in TME of breast cancer involve multiple types of immunosuppression and is associated with tumor cell metastasis. In this review, we summarize the available information on the functions of STAT3-related immune cells in TME of breast cancer, as well as the specific upstream and downstream targets. Additionally, we provide insights about the potential immunosuppression mechanisms of each type of evaluated immune cells. Video abstract.

Nanoparticle-mediated synergistic chemoimmunotherapy for tailoring cancer therapy: recent advances and perspectives

Nowadays, a potent challenge in cancer treatment is considered the lack of efficacious strategy, which has not been able to significantly reduce mortality. Chemoimmunotherapy (CIT) as a promising approach in both for the first-line and relapsed therapy demonstrated particular benefit from two key gating strategies, including chemotherapy and immunotherapy to cancer therapy; therefore, the discernment of their participation and role of potential synergies in CIT approach is determinant. In this study, in addition to balancing the pros and cons of CIT with the challenges of each of two main strategies, the recent advances in the cancer CIT have been discussed. Additionally, immunotherapeutic strategies and the immunomodulation effect induced by chemotherapy, which boosts CIT have been brought up. Finally, harnessing and development of the nanoparticles, which mediated CIT have expatiated in detail.

Role of immune regulatory cells in breast cancer: Foe or friend?

Breast cancer (BC) is the most common cancer among women between the ages of 20 and 50, affecting more than 2.1 million people and causing the annual death of more than 627,000 women worldwide. Based on the available knowledge, the immune system and its components are involved in the pathogenesis of several malignancies, including BC. Cancer immunobiology suggests that immune cells can play a dual role and induce anti-tumor or immunosuppressive responses, depending on the tumor microenvironment (TME) signals. The most important effector immune cells with anti-tumor properties are natural killer (NK) cells, B, and T lymphocytes. On the other hand, immune and non-immune cells with regulatory/inhibitory phenotype, including regulatory T cells (Tregs), regulatory B cells (Bregs), tolerogenic dendritic cells (tDCs), tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), myeloid-derived suppressor cells (MDSCs), mesenchymal stem cells (MSCs), and regulatory natural killer cells (NKregs), can promote the growth and development of tumor cells by inhibiting anti-tumor responses, inducing angiogenesis and metastasis, as well as the expression of inhibitory molecules and suppressor mediators of the immune system. However, due to the complexity of the interaction and the modification in the immune cells' phenotype and the networking of the immune responses, the exact mechanism of action of the immunosuppressive and regulatory cells is not yet fully understood. This review article reviews the immune responses involved in BC as well as the role of regulatory and inhibitory cells in the pathogenesis of the disease. Finally, therapeutic approaches based on inhibition of immunosuppressive responses derived from regulatory cells are discussed.

Cells of the Immune System in Cardiac Remodeling: Main Players in Resolution of Inflammation and Repair After Myocardial Infarction

The burden of heart failure (HF), developing after myocardial infarction MI, still represents a major issue in clinical practice. Failure of appropriate resolution of inflammation during post-myocardial injury is associated with unsuccessful left ventricular remodeling and underlies HF pathogenesis. Cells of the immune system have been shown to mediate both protective and damaging effects in heart remodeling. This ambiguity of the role of the immune system and inconsistent results of the recent clinical trials question the benefits of anti-inflammatory therapies during acute MI. The present review will summarize knowledge of the roles that different cells of the immune system play in the process of post-infarct cardiac healing. Data on the phenotype, active molecules and functions of the immune cells, based on the results of both experimental and clinical studies, will be provided. For some cellular subsets, such as macrophages, neutrophils, dendritic cells and lymphocytes, an anti-inflammatory activity has been attributed to the specific subpopulations. Activity of other cells, such as eosinophils, mast cells, natural killer (NK) cells and NKT cells has been shown to be highly dependent of the signals created by micro-environment. Also, new approaches for classification of cellular phenotypes based on the single-cell RNA sequencing allow better understanding of the phenotype of the cells involved in resolution of inflammation. Possible perspectives of immune-mediated therapy for AMI patients are discussed in the conclusion. We also outline unresolved questions that need to be solved in order to implement the current knowledge on the role of the immune cells in post-MI tissue repair into practice.

Up-regulation of DGAT1 in cancer tissues and tumor-infiltrating macrophages influenced survival of patients with gastric cancer

Background

Diacylglycerol-acyltransferase 1 (DGAT1) plays an important role in the energy storage and is involved in cancer progression. A growing number of evidences showed that elevated expression of DGAT1 in cancer tissue indicated a poor outcome in cancer patients. However, the relationship between DGAT1 and gastric cancer is still unclear. Thus, Transcriptomic analysis and in vitro experiments were performed to investigate the role of DGAT1 in gastric cancer, as well as the potential therapy target in gastric cancer treatment.

Methods

We screened the public cancer datasets to identify the expression and function of DGAT1 in gastric cancer and tumor infiltrating lymphocytes. Then we testified the DGAT1 expression and function after sodium oleate treatment in AGS and MKN45 cell line. Finally, we analyzed ration of apoptosis, necrosis in gastric cancer cells by using flow cytometry after administration of DGAT1 inhibitor.

Results

Our results showed a highly expression of DGAT1 in gastric cancer tissues (n = 5, p = 0.0004), and tumor-infiltrating macrophages with elevated DGAT1 expression is associated with poor overall survival in gastric cancer patients. In addition, gastric cell lines AGS (n = 3, p < 0.05) and MKN45 (n = 3, p < 0.01) expressed higher level of DGAT1 than human gastric mucosal epithelial cell line GES-1. Administration of DGAT1 inhibitor effectively suppressed functional factors expression and induced cell death in MKN45.

Conclusion

The findings of this research provide an in-depth insight into the potential role and influences involved in DGAT1 in the gastric cancer patients. And higher expression of DGAT1 leads to lower overall survival (OS) rate in patients with poorly differentiated gastric cancer. Our findings suggest a potential role for DGAT1 in the gastric cancer progression and inhibiting DGAT1 might be a promising strategy in gastric cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07976-5.

Interferon Regulatory Factor 4 Regulates the Development of Polymorphonuclear Myeloid-Derived Suppressor Cells Through the Transcription of c-Myc in Cancer

The accumulation of myeloid-derived suppressor cells (MDSCs) is one of the major obstacles to achieve an appropriate anti-tumor immune response and successful tumor immunotherapy. MDSCs in tumor-bearing hosts are primarily polymorphonuclear (PMN-MDSCs). However, the mechanisms regulating the development of MDSCs remain poorly understood. In this report, we showed that interferon regulatory factor 4 (IRF4) plays a key role in the development of PMN-MDSCs, but not monocytic MDSCs. IRF4 deficiency caused a significant elevation of PMN-MDSCs and enhanced the suppressive activity of PMN-MDSCs, increasing tumor growth and metastasis in mice. Mechanistic studies showed that c-Myc was up-regulated by the IRF4 protein. Over-expression of c-Myc almost abrogated the effects of IRF4 deletion on PMN-MDSCs development. Importantly, the IRF4 expression level was negatively correlated with the PMN-MDSCs frequency and tumor development but positively correlated with c-Myc expression in clinical cancer patients. In summary, this study demonstrated that IRF4 represents a novel regulator of PMN-MDSCs development in cancer, which may have predictive value for tumor progression.

Clinical Perspectives in Addressing Unsolved Issues in (Neo)Adjuvant Therapy for Primary Breast Cancer

The treatment of primary breast cancer has evolved over the past 50 years based on the concept that breast cancer is a systemic disease, with the escalation of adjuvant and neoadjuvant therapies and de-escalation of breast cancer surgery. Despite the development of these therapies, recurrence with distant metastasis during the 10 years after surgical treatment is observed, albeit infrequently. Recent advances in genomic analysis based on circulating tumor cells and circulating tumor DNA have enabled the development of targeted therapies based on genetic mutations in residual tumor cells. A paradigm shift involving the application of neoadjuvant chemotherapy (NAC) has enabled the prediction of treatment response and long-term prognoses; additional adjuvant chemotherapy targeting remaining tumor cells after NAC improves survival. The activation of antitumor immunity by anticancer agents may be involved in the eradication of residual tumor cells. Elucidation of the manner in which antitumor immunity is induced by anticancer agents and unknown factors, and the overcoming of drug resistance via the targeted eradication of residual tumor cells based on genomic profiles, will inevitably lead to the achievement of 0% distant recurrence and a complete cure for primary breast cancer.

Future of immunotherapy in pancreas cancer and the trials, tribulations and successes thus far

Pancreas ductal adenocarcinoma (PDAC) has a dismal prognosis with a 5-year survival rate of 10%. Currently, chemotherapy remains the standard of care for systemic treatment. Immunotherapy with checkpoint inhibitors unfortunately has not been found to be effective in the treatment of PDAC to date, likely due to the highly desmoplastic and immunosuppressive tumor microenvironment (TME). Treatment targeting pathways against the immunosuppressive mechanisms of PDAC are of mounting interest to improve outcomes in PDAC. In this review, we discuss prior efforts and the current state of immunotherapy in PDAC. We will also review the emerging targets and treatments with significant clinical potential for the treatment of PDAC such as: CD40 pathway, the adenosine pathway, the CXCR4/CXCL12 axis, the CCR2/CCL2 axis, IDO pathway, and others.

Development of a predictive model utilizing the neutrophil to lymphocyte ratio to predict neoadjuvant chemotherapy efficacy in early breast cancer patients

Neutrophils and lymphocytes are key regulators of breast cancer (BC) development and progression. Neutrophil to lymphocyte ratio (NLR) values have been found to offer clear prognostic utility when evaluating BC patients. In this study, we sought to determine whether BC patient baseline NLR values are correlated with pathological complete response (pCR) following neoadjuvant chemotherapy (NCT) treatment. In total, 346 BC patients underwent NCT at our hospital from January 1, 2014 to October 31, 2019, and data pertaining to these patients were retrospectively analyzed. Correlations between clinicopathological characteristics and pCR rates were assessed via multivariate logistic regression analyses. A predictive scoring model was used to gauge the likelihood of pCR based upon regression coefficient (β) values for each significant variable identified through these analyses. NLR cut-off values suitable for identifying patients likely to achieve pCR following NCT treatment were calculated using receiver operating characteristic (ROC) curves. All patients in the present study were females with a median age of 48 years old (range 22–77). An optimal NLR cut-off value of 1.695 was identified and was associated with respective sensitivity and specificity values of 63.6% and 45.5%. We found that higher NLR values were significantly associated with younger age, premenopausal status, and non-pCR status. Logistic regression analyses indicated that NLR, tumor size, hormone receptor (HR) status, and Ki-67 expression were all independent predictors of pCR. The area under the curve (AUC) for the resultant predictive scoring model was 0.705, and this model was assessed via K-fold cross-validation (k = 10) and bootstrapping validation, yielding respective AUC values of 0.68 and 0.694. Moreover, the incorporation of NLR into this predictive model incrementally improved its overall prognostic value relative to that of a model not incorporating NLR (AUC = 0.674). BC patients with a lower baseline NLR are more likely to exhibit pCR following NCT treatment, indicating that NLR may be a valuable biomarker for BC patient prognostic evaluation and treatment planning. Overall, our results demonstrate that this NLR-based predictive model can efficiently predict NCT efficacy in early BC patients with a high degree of accuracy.

The immune contexture and Immunoscore in cancer prognosis and therapeutic efficacy

The international American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumour-node-metastasis (TNM) staging system provides the current guidelines for the classification of cancer. However, among patients within the same stage, the clinical outcome can be very different. More recently, a novel definition of cancer has emerged, implicating at all stages a complex and dynamic interaction between tumour cells and the immune system. This has enabled the definition of the immune contexture, representing the pre-existing immune parameters associated with patient survival. Even so, the role of distinct immune cell types in modulating cancer progression is increasingly emerging. An immune-based assay named the 'Immunoscore' was defined to quantify the in situ T cell infiltrate and was demonstrated to be superior to the AJCC/UICC TNM classification for patients with colorectal cancer. This Review provides a broad overview of the main immune parameters positively or negatively shaping cancer development, including the Immunoscore, and their prognostic and predictive value. The importance of the immune system in cancer control is demonstrated by the requirement for a pre-existing intratumour adaptive immune response for effective immunotherapies, such as checkpoint inhibitors. Finally, we discuss how the combination of multiple immune parameters, rather than individual ones, might increase prognostic and/or predictive power.

IDO Expression in Cancer: Different Compartment, Different Functionality?

Indoleamine 2,3-dioxygenase 1 (IDO1) is a cytosolic haem-containing enzyme involved in the degradation of tryptophan to kynurenine. Although initially thought to be solely implicated in the modulation of innate immune responses during infection, subsequent discoveries demonstrated IDO1 as a mechanism of acquired immune tolerance. In cancer, IDO1 expression/activity has been observed in tumor cells as well as in the tumor-surrounding stroma, which is composed of endothelial cells, immune cells, fibroblasts, and mesenchymal cells. IDO1 expression/activity has also been reported in the peripheral blood. This manuscript reviews available data on IDO1 expression, mechanisms of its induction, and its function in cancer for each of these compartments. In-depth study of the biological function of IDO1 according to the expressing (tumor) cell can help to understand if and when IDO1 inhibition can play a role in cancer therapy.

Targeting Myeloid-Derived Suppressor Cells in Cancer Immunotherapy

Simple Summary

Myeloid-Derived Suppressor Cells (MDSCs) have been regarded as the main promoters of cancer development in recent years. They can protect tumor cells from being eliminated by neutralizing the anti-tumor response mediated by T cells, macrophages and dendritic cells (DCs). Therefore, different treatment methods targeting MDSCs, including chemotherapy, radiotherapy and immunotherapy, have been developed and proven to effectively inhibit tumor expansion. Herein, we summarize the immunosuppressive role of MDSCs in the tumor microenvironment and some effective treatments targeting MDSCs, and discuss the differences between different therapies.

Abstract

Myeloid-derived suppressor cells (MDSCs), which are activated under pathological conditions, are a group of heterogeneous immature myeloid cells. MDSCs have potent capacities to support tumor growth via inhibition of the antitumoral immune response and/or the induction of immunosuppressive cells. In addition, multiple studies have demonstrated that MDSCs provide potential therapeutic targets for the elimination of immunosuppressive functions and the inhibition of tumor growth. The combination of targeting MDSCs and other therapeutic approaches has also demonstrated powerful antitumor effects. In this review, we summarize the characteristics of MDSCs in the tumor microenvironment (TME) and current strategies of cancer treatment by targeting MDSCs.

1-MT inhibits the invasion of CBP-resistant ovarian cancer cells via down-regulating IDO expression and re-activating immune cells function

Background

The indoleamine 2, 3-dioxygenase (IDO) inhibitor 1-methyl-tryptophan (1-MT) is currently being used in clinical trials in patients with relapsed or refractory solid tumors by inhibiting tumor immune escape. A greater understanding of IDO activity is required to begin to understand the molecular mechanism by which drugs work. This study was conducted to investigate of the clinical significance of 1-methyl-tryptophan (1-MT) in treating carboplatin-resistant (CBP-resistant) ovarian cancer and its mechanism of action.

Methods

Using a medium dose, intermittent treatment method, a clinically relevant CBP-resistant human ovarian cancer cell line (SKOV3/CBP) was established. SKOV3/CBP cells were treated with normal serum (control) or 1-MT (0.25 ng/mL) for 4 h (SKOV3/CBP + 1-MT). Cell proliferation, invasion and IDO expression in SKOV3, SKOV3/CBP and SKOV3/CBP + 1-MT cells were determined by MTT assays, Matrigel invasion chambers assays and ELISAs, respectively. The half-maximal inhibitory concentration (IC₅₀) and resistance index (RI) were also calculated. The killing ability of the NK cells and CD8+ T cells co-cultured with SKOV3, SKOV3/CBP and SKOV3/CBP + 1-MT cells were determined by LDH activity assays and the INF-γcounting method.

Results

The SKOV3/CBP cell line displayed an increased IC₅₀ compared to the SKOV3 cell line (P < 0.05) under CBP treatment. Treatment with 1-MT significantly decreased the IC₅₀ and RI of SKOV3/CBP cells. Furthermore, 1-MT treatment not only reduced the invasion ability, but also suppressed IDO expression in the drug-resistant SKOV3/CBP + 1-MT cell line as compared to the SKOV3/CBP cell line. Furthermore, 1-MT enhanced the killing ability of NK cells and the amount of INF-γsecreted from CD8+ T cells which were co-cultured with the SKOV3/CBP cell line.

Conclusion

Our data suggested that 1-MT inhibits the invasion of CBP-resistant ovarian cancer cells via down-regulation of IDO expression which leads to re-activation of immune cell function. We provide a conceptual foundation for the clinical development of 1-MT as an anti-tumor immunomodulator for chemotherapy resistant ovarian cancer patients.

The Effect of Different Immunization Cycles of a Recombinant Mucin1-Maltose-Binding Protein Vaccine on T Cell Responses to B16-MUC1 Melanoma in Mice

We explored the effect of a recombinant mucin1-maltose-binding protein vaccine, including immunization cycles of recombinant mucin1-maltose-binding protein (MUC1-MBP) and CpG 2006 on T cell responses to human MUC1-overexpressing mouse melanoma B16 cells (B16-MUC1) melanoma in mice. We found that the vaccine had a significant antitumor effect, with the most obvious tumor-suppressive effect being observed in mice immunized five times. After more than five immunizations, the tumor inhibition rate decreased from 81.67% (five immunizations) to 43.67% (eight immunizations). To study the possible mechanism, Mucin-1(MUC1)-specific antibodies, IFN-γ secretion by lymphocytes, and cytotoxic T lymphocyte (CTL) cytotoxicity were measured by enzyme-linked immunosorbent assay (ELISA) and a real-time cell analyzer (RTCA). T cell subsets and immunosuppressive cells in the mouse spleen and tumor microenvironment were analyzed by FACS. These results showed that five immunizations activated MUC1-specific Th1 and CTL and reduced the ratio of myeloid-derived suppressor cells (MDSCs) and Th17 in mice more significantly than eight immunizations, indicating that excessive frequency of the immune cycle leads to the increased numbers of immunosuppressive cells and decreased numbers of immunostimulatory cells, thereby inhibiting antitumor immune activity. This data provide an experimental foundation for the clinical application of a recombinant MUC1-MBP vaccine.

Abscopal Effect Following Radiation Therapy in Cancer Patients: A New Look from the Immunological Point of View

Abscopal effect, a radiobiology term meaning “away from target”, was practically unheard of just ten years ago. This effect describes the elimination and cure of a non-treated tumor when another part of the body is irradiated. Successful treatment of cancer in patients with multiple metastatic foci has sporadically been reported. Abscopal effect after radiotherapy has been introduced as the key factor which induced an anticancer response in these metastatic lesions. Moreover, not receiving chemotherapy is reported to have a role in cancer regression after radiotherapy. Given this consideration, it can be hypothesized that standard radiotherapy doses, which usually classified as high-dose, may cause cancer cells to expose or release their sequestered antigens that had been previously masked. Furthermore, radiotherapy can decrease the suppressive effect of regulatory T cells which usually down modulate immune responses against cancers. Moreover, some data show that low dose total-body irradiation (TBI) alone (without standard localized high dose radiotherapy) may cause suppression of distant metastasis of tumor cells. Induction of a “whole body abscopal effect” can be involved in suppression of distant metastasis. Here we discuss whether cancer treatments could be more successful if immune system is boosted, not destroyed by the treatments such as chemotherapy

Tryptophan Catabolism as Immune Mechanism of Primary Resistance to Anti-PD-1

Background: Clinical trials showed that only a subset of patients benefits from immunotherapy, suggesting the need to identify new predictive biomarker of resistance. Indoleamine-2,3-dioxygenase (IDO) has been proposed as a mechanism of resistance to anti-PD-1 treatment, and serum kynurenine/tryptophan (kyn/trp) ratio represents a possible marker of IDO activity. Methods: Metastatic non-small cell lung cancer (NSCLC), renal cell carcinoma (RCC), and head and neck squamous cell carcinoma (HNSCC) treated with nivolumab as second-line treatment were included in this prospective study. Baseline serum kyn and trp levels were measured by high-performance liquid chromatography to define the kyn/trp ratio. The χ2-test and t-test were applied to compare frequencies and mean values of kyn/trp ratio between subgroups with distinct clinical/pathological features, respectively. Median baseline kyn/trp ratio was defined and used as cutoff in order to stratify the patients. The association between kyn/trp ratio, clinical/pathological characteristics, response, progression-free survival (PFS), and overall survival (OS) was analyzed. Results: Fifty-five patients were included. Mean baseline serum kyn/trp ratio was significantly lower in female than in male patients (0.048 vs. 0.059, respectively, p = 0.044) and in patients with lung metastasis than in others (0.053 vs. 0.080, respectively, p = 0.017). Mean baseline serum kyn/trp ratio was significantly higher in early progressor patients with both squamous and non-squamous NSCLC (p = 0.003) and with a squamous histology cancer (19 squamous NSCLC and 14 HNSCC, p = 0.029). The median value of kyn/trp ratio was 0.06 in the overall population. With the use of median value as cutoff, patients with kyn/trp ratio > 0.06 had a higher risk to develop an early progression (within 3 months) to nivolumab with a trend toward significance (p = 0.064 at multivariate analysis). Patients presenting a baseline kyn/trp ratio ≤0.06 showed a longer PFS [median 8 vs. 3 months; hazard ratio (HR): 0.49; 95% confidence interval (CI) 0.24-1.02; p = 0.058] and a significantly better OS than did those with a kyn/trp ratio > 0.06 (median 16 vs. 4 months; HR: 0.39; 95% CI 0.19-0.82; p = 0.013). Conclusion: Serum kyn/trp ratio could have both prognostic and predictive values in patients with solid tumor treated with immunotherapy, probably reflecting a primary immune-resistant mechanism regardless of the primary tumor histology. Its relative weight is significantly related to gender, site of metastasis, NSCLC, and squamous histology, although these suggestive data need to be confirmed in larger studies.

Tumor-induced neurogenesis and immune evasion as targets of innovative anti-cancer therapies

Normal cells are hijacked by cancer cells forming together heterogeneous tumor masses immersed in aberrant communication circuits that facilitate tumor growth and dissemination. Besides the well characterized angiogenic effect of some tumor-derived factors; others, such as BDNF, recruit peripheral nerves and leukocytes. The neurogenic switch, activated by tumor-derived neurotrophins and extracellular vesicles, attracts adjacent peripheral fibers (autonomic/sensorial) and neural progenitor cells. Strikingly, tumor-associated nerve fibers can guide cancer cell dissemination. Moreover, IL-1β, CCL2, PGE2, among other chemotactic factors, attract natural immunosuppressive cells, including T regulatory (Tregs), myeloid-derived suppressor cells (MDSCs), and M2 macrophages, to the tumor microenvironment. These leukocytes further exacerbate the aberrant communication circuit releasing factors with neurogenic effect. Furthermore, cancer cells directly evade immune surveillance and the antitumoral actions of natural killer cells by activating immunosuppressive mechanisms elicited by heterophilic complexes, joining cancer and immune cells, formed by PD-L1/PD1 and CD80/CTLA-4 plasma membrane proteins. Altogether, nervous and immune cells, together with fibroblasts, endothelial, and bone-marrow-derived cells, promote tumor growth and enhance the metastatic properties of cancer cells. Inspired by the demonstrated, but restricted, power of anti-angiogenic and immune cell-based therapies, preclinical studies are focusing on strategies aimed to inhibit tumor-induced neurogenesis. Here we discuss the potential of anti-neurogenesis and, considering the interplay between nervous and immune systems, we also focus on anti-immunosuppression-based therapies. Small molecules, antibodies and immune cells are being considered as therapeutic agents, aimed to prevent cancer cell communication with neurons and leukocytes, targeting chemotactic and neurotransmitter signaling pathways linked to perineural invasion and metastasis.

Immunohistochemical Features of Indoleamine 2,3-Dioxygenase (IDO) in Various Types of Lymphoma: A Single Center Experience

Indolamine-2,3-dioxygenase (IDO) is an intracellular enzyme that catalyzes amino acid tryptophan to L-kynurenine. IDO is overexpressed in various cancers and several IDO inhibitors have been assessed in multiple clinical trials. If an IDO inhibitor is to be commercialized, IDO immunohistochemistry will be an important method. In this study, 80% (28/35) of mature T- and natural killer (NK)-cell neoplasms showed positivity for IDO protein (score 1: five, score 2: one, score 3: seven, score 4: fifteen). In addition, 29.9% (23/77) of mature B-cell lymphomas showed positivity for IDO protein (score 1: three, score 2: tewelve, score 3: four, score 4: four). In mature B-cell lymphomas, 95.7% (22/23) of IDO positive cases were diffuse B-cell lymphomas. Our study includes various types of lymphoma that were previously unreported and shows various patterns of IDO stain according to the type. When the results are accumulated, IDO immunohistochemistry will be a useful tool to diagnose lymphomas and to predict their prognosis.

Prognosis significance of indoleamine 2, 3-dioxygenase, programmed death ligand-1 and tumor-infiltrating immune cells in microenvironment of breast cancer

INTRODUCTION

The immune microenvironment plays an increasingly important role in predicting the prognosis of multiple tumors and selecting patients for immunotherapy trials. We studied the expression of indoleamine 2, 3-dioxygenase (IDO) and programmed death ligand-1 (PD-L1), detected the proportion of tumor-infiltrating immune cells (TIIs), and further analyzed the association of these immunological characteristics with the clinicopathological parameters and prognosis of breast cancer patients.

METHODS

Immunohistochemical staining for IDO, PD-L1, CD4, CD8, Foxp3, CD20, CD56 and CD68 expression in breast cancer tissues was carried out. IDO and PD-L1 expression were scored by extent in tumor cells. TIIs expressing CD4, CD8, Foxp3, CD20, CD56 or CD68 were evaluated by positive count. Clinicopathological characteristics and follow-up were recorded.

RESULTS

The frequencies of IDO-high-expressing and PD-L1-expressing tissue were 33.77% and 24.68%, respectively. The co-expression of IDO and PD-L1 was identified in 16/77 (20.78%) of cases. IDO high expression, CD4⁺ T cells and CD56⁺ cells were most frequently observed in patients with tumor-draining lymph nodes(TDLNs) metastasis. Immune cells were more common in non-luminal breast cancer than in luminal breast cancer. In survival analysis, PFS were not associated with high levels of IDO and PD-L1, nor were TIIs. However, CD20 and CD68 were significant risk factors for prognostic after adjusting covariates by COX regression. IDO^highFoxp3^highT patients had a tendency with shorter progression-free survival.

CONCLUSIONS

Although we found a limited prognostic effect of TIIs on survival in breast cancer patients, IDO combined with TIIs can help to evaluate the prognosis of patients.

A CT-based radiomics signature for evaluating tumor infiltrating Treg cells and outcome prediction of gastric cancer

Background

Tumor infiltrating regulatory T (TITreg) cells are highly infiltrated in gastric cancer (GC) and associated with worse prognosis of GC patients. We aim to develop and validate a radiomics signature for evaluation of TITreg cells and outcome prediction of GC patients.

Methods

A total of 165 GC patients from three independent cohorts were enrolled in this retrospective study. The abundance of TITreg cells were evaluated by using multispectral immunohistochemical analysis and CIBERSORT algorithm. The radiomics features were extracted by using PyRadiomics software and the radiomics signature was generated by using the least absolute shrinkage and selection operator (LASSO) logistic regression model. The receiver operator characteristic (ROC) curves were applied to assess the performance of radiomics signature for estimating TITreg cells. Univariable and multivariable Cox regression analysis were used for identifying risk factor of overall survival (OS). The prognostic value of the radiomics signature and the TITreg cells were evaluated by using the Kaplan-Meier method and log-rank test.

Results

Six robust features were selected for building the radiomics signature. The radiomics signature showed good ability for estimating TITreg in the training, validation and testing cohort, with area under the curve (AUC) of 0.884, 0.869 and 0.847, respectively. Multivariable Cox regression analysis showed that the radiomics signature was an independent risk factor of unfavorable OS of GC patients.

Conclusions

The proposed CT-based radiomics signature is a promising non-invasive biomarker of TITreg cells and outcome prediction of GC patients.

Bioinformatics Identified 17 Immune Genes as Prognostic Biomarkers for Breast Cancer: Application Study Based on Artificial Intelligence Algorithms

An increasing body of evidence supports the association of immune genes with tumorigenesis and prognosis of breast cancer (BC). This research aims at exploring potential regulatory mechanisms and identifying immunogenic prognostic markers for BC, which were used to construct a prognostic signature for disease-free survival (DFS) of BC based on artificial intelligence algorithms. Differentially expressed immune genes were identified between normal tissues and tumor tissues. Univariate Cox regression identified potential prognostic immune genes. Thirty-four transcription factors and 34 immune genes were used to develop an immune regulatory network. The artificial intelligence survival prediction system was developed based on three artificial intelligence algorithms. Multivariate Cox analyses determined 17 immune genes (ADAMTS8, IFNG, XG, APOA5, SIAH2, C2CD2, STAR, CAMP, CDH19, NTSR1, PCDHA1, AMELX, FREM1, CLEC10A, CD1B, CD6, and LTA) as prognostic biomarkers for BC. A prognostic nomogram was constructed on these prognostic genes. Concordance indexes were 0.782, 0.734, and 0.735 for 1-, 3-, and 5- year DFS. The DFS in high-risk group was significantly worse than that in low-risk group. Artificial intelligence survival prediction system provided three individual mortality risk predictive curves based on three artificial intelligence algorithms. In conclusion, comprehensive bioinformatics identified 17 immune genes as potential prognostic biomarkers, which might be potential candidates of immunotherapy targets in BC patients. The current study depicted regulatory network between transcription factors and immune genes, which was helpful to deepen the understanding of immune regulatory mechanisms for BC cancer. Two artificial intelligence survival predictive systems are available at https://zhangzhiqiao7.shinyapps.io/Smart_Cancer_Survival_Predictive_System_16_BC_C1005/ and https://zhangzhiqiao8.shinyapps.io/Gene_Survival_Subgroup_Analysis_16_BC_C1005/. These novel artificial intelligence survival predictive systems will be helpful to improve individualized treatment decision-making.

IMMUNEPOTENT CRP plus doxorubicin/cyclophosphamide chemotherapy remodel the tumor microenvironment in an air pouch triple-negative breast cancer murine model

In 1889, Steven Paget postulated the theory that cancer cells require a permissive environment to grow. This permissive environment is known as the tumor microenvironment (TME) and nowadays it is evident that the TME is involved in the progression and response to therapy of solid cancer tumors. Triple-negative breast cancer is one of the most lethal types of cancer for women worldwide and chemotherapy remains the standard treatment for these patients. IMMUNEPOTENT CRP is a bovine dialyzable leukocyte extract with immunomodulatory and antitumor properties. The combination of chemotherapy and IMMUNEPOTENT CRP improves clinical parameters of breast cancer patients. In the current study, we aimed to evaluate the antitumor effect of doxorubicin/cyclophosphamide chemotherapy plus IMMUNEPOTENT CRP and its impact over the tumor microenvironment in a triple-negative breast cancer murine model. We evaluated CD8⁺, CD4⁺, T regulatory cells, memory T cells, myeloid-derived suppressor cells, CD71⁺, innate effector cells and molecules such as α-SMA, VEGF, CTLA-4, PD-L1, Gal-3, IDO, IL-2, IFN-γ, IL-12, IL-6, MCP-1, and IL-10 as part of the components of the TME. Doxorubicin/cyclophosphamide + IMMUNEPOTENT CRP decreased tumor volume, prolonged survival, increased infiltrating and systemic CD8⁺ T cells and decreased tumor suppressor molecules (such as PD-L1, Gal-3, and IL-10 among others). In conclusion, we suggest that IMMUNEPOTENT CRP act as a modifier of the TME and the immune response, potentiating or prolonging anti-tumor effects of doxorubicin/cyclophosphamide in a triple-negative breast cancer murine model.

Spatiotemporal Changes in Checkpoint Molecule Expression

Immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 blockade, have led to therapeutic breakthrough in patients with advanced malignancy, covering the lung, breast, gastrointestinal, head and neck, urinary system, lymphoma, and solid tumor harboring MSI/dMMR. In certain cancer types, the expression level of immune checkpoint molecule will be required if the immune-based approaches are considered, especially the PD-L1 expression. However, in other types, survival benefit has been proven regardless of PD-L1 expression. It raises a question of how to select patients for immune therapy and whether the expression of immune checkpoint molecules will be optimal biomarkers. Before answering this question, a comprehensive map for the expression of immune checkpoint molecules is needed. In this chapter, we describe our current knowledge on the spatiotemporal changes in the expression of checkpoint molecules. We discuss the different frequencies of expression depending on tumor types and stages, the different patterns between primary and metastatic tumors, as well as the change of expression before and after treatment. The expression of PD-L1 has been most studied, but the threshold that separate "positive" and "negative" PD-L1 expressions and the consistency of testing platform remain under debate. Better understanding on the tumor microenvironment and expression of checkpoint molecules will help to identify patients who will benefit from checkpoint blockade therapy.

Myeloid-driven mechanisms as barriers to antitumor CD8+ T cell activity

The adaptive immune system is essential for host defense against pathogenic challenges, and a major constituent is the CD8⁺ cytotoxic T cell. Ordinarily, CD8⁺ T cells are endowed with a unique ability to specifically recognize and destroy their targets. However, in cases where disease emerges, especially in cancer, the efficacy of the CD8⁺ T cell response is frequently counterbalanced in a 'tug-of-war' by networks of tumor-driven mechanisms of immune suppression. As a result, antitumor CD8⁺ T cell activity is hampered, which contributes to clinical manifestations of disease. It is now well-recognized that prominent elements of that network include myeloid-derived suppressor cells (MDSC) and macrophages which assume tumor-supportive phenotypes. Both myeloid populations are thought to arise as consequences of chronic inflammatory cues produced during the neoplastic process. Numerous preclinical studies have now shown that inhibiting the production, trafficking and/or function of these immune suppressive myeloid populations restore antitumor CD8⁺ T cell responses during both immune surveillance or in response to immune-targeted interventions. Correlative studies in cancer patients support these preclinical findings and, thus, have laid the foundation for ongoing clinical trials in patients receiving novel agents that target such myeloid elements alone or in combination with immunotherapy to potentially improve cancer patient outcomes. Accordingly, this review focuses on how and why it is important to study the myeloid-T cell interplay as an innovative strategy to boost or reinvigorate the CD8⁺ T cell response as a critical weapon in the battle against malignancy.

Chemoresistance was correlated with elevated expression and activity of indoleamine 2,3-dioxygenase in breast cancer

BACKGROUND

Indoleamine 2,3-dioxygenase (IDO) catalyses degradation of the essential amino acid tryptophan leading to the production of immunosuppressive kynurenine and tryptophan exhausting. IDO expression and activity contribute to aggressive tumor growth, inferior therapeutic gain and poor prognosis. The aim of this study was to explore the association between chemoresistance and IDO expression, activity in breast cancer METHODS: Immunohistochemistry was applied for evaluating IDO expression in biopsy tissues. Serum IDO activity was examined via High-performance liquid chromatography (HPLC). Western blots (WB), HPLC and Real-time PCR (RT-PCR) were used to analyze IDO protein, IDO enzyme activity and IDO gene expression in original and paclitaxel-resistant cells respectively. Logistic regression and survival analysis were applied to explore the association between chemoresistance and IDO expression, activity in breast cancer.

RESULTS

IDO expression in tumor tissues was associated with serum IDO activity (P = 0.004). Both IDO expression in tumor and serum activity were associated with clinical tumor stage, node stage and estrogen receptor (ER) status (all P < 0.05); clinical response and pathologic complete response (pCR) to NAC were both related to IDO expression and activity prior NAC (all P < 0.05). Multivariate analysis showed IDO activity before NAC was the only independent factor affected pCR (P = 0.032). ROC curves showed that the IDO expression and activity had discriminative ability for predicting the clinical response and pCR. In the prognostic analysis, patients with high IDO expression had significantly impaired overall survival (5 year survival rate: 53.57% vs 80.00%) and progression-free survival (5 year survival rate: 46.43% vs 72.00%, P = 0.031 and P = 0.046). In vitro, significantly increased IDO protein, IDO mRNA expression and IDO enzyme activity in paclitaxel-resistant cells were demonstrated in comparing of sensitive cells.

CONCLUSION

IDO expression and activity associated with advanced breast cancer, poor response to neoadjuvant chemotherapy and prognosis. IDO expression and activity were significantly increased in paclitaxel-resistant breast cancer cells.

Beyond PD-1/PD-L1 Inhibition: What the Future Holds for Breast Cancer Immunotherapy

Cancer immunotherapy has altered the management of human malignancies, improving outcomes in an expanding list of diseases. Breast cancer - presumably due to its perceived low immunogenicity - is a late addition to this list. Furthermore, most of the focus has been on the triple negative subtype because of its higher tumor mutational load and lymphocyte-enriched stroma, although emerging data show promise on the other breast cancer subtypes as well. To this point the clinical use of immunotherapy is limited to the inhibition of two immune checkpoints, Programmed Cell Death Protein 1 (PD-1) and Cytotoxic T-lymphocyte-associated Protein 4 (CTLA-4). Consistent with the complexity of the regulation of the tumor - host interactions and their lack of reliance on a single regulatory pathway, combinatory approaches have shown improved efficacy albeit at the cost of increased toxicity. Beyond those two checkpoints though, a large number of co-stimulatory or co-inhibitory molecules play major roles on tumor evasion from immunosurveillance. These molecules likely represent future targets of immunotherapy provided that the promise shown in early data is translated into improved patient survival in randomized trials. The biological role, prognostic and predictive implications regarding breast cancer and early clinical efforts on exploiting these immune-related therapeutic targets are herein reviewed.

Immunotherapy in breast cancer: Current status and future directions

Breast cancer, one of the leading causes of death in women in the United States, challenges therapeutic success in patients due to tumor heterogeneity, treatment resistance, metastasis and disease recurrence. Knowledge of immune system involvement in normal breast development and breast cancer has led to extensive research into the immune landscape of breast cancer and multiple immunotherapy clinical trials in breast cancer patients. However, poor immunogenicity and T-cell infiltration along with heightened immunosuppression in the tumor microenvironment have been identified as potential challenges to the success of immunotherapy in breast cancer. Oncodrivers, owing to their enhanced expression and stimulation of tumor cell proliferation and survival, present an excellent choice for targeted immunotherapy development in breast cancer. Loss of anti-tumor immune response specific to oncodrivers has been reported in breast cancer patients as well. Dendritic cell vaccines have been tested for their efficacy in generating anti-tumor T-cell response against specific tumor-associated antigens and oncodrivers and have shown improved survival outcome in patients. Here, we review the current status of immunotherapy in breast cancer, focusing on dendritic cell vaccines and their therapeutic application in breast cancer. We further discuss future directions of breast cancer immunotherapy and potential combination strategies involving dendritic cell vaccines and existing chemotherapeutics for improved efficacy and better survival outcome in breast cancer.

Combination of peripheral neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio is predictive of pathological complete response after neoadjuvant chemotherapy in breast cancer patients

The immune system seems to play a fundamental role in breast cancer responsiveness to chemotherapy. We investigated two peripheral indicators of immunity/inflammation, i.e. neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR), in order to reveal a possible relationship with pathological complete response (pCR) in patients with early or locally advanced breast cancer treated with neoadjuvant chemotherapy (NACT). We retrospectively analyzed 373 consecutive patients affected by breast cancer and candidates to NACT. The complete blood cell count before starting NACT was evaluated to calculate NLR and PLR. ROC curve analysis determined threshold values of 2.42 and 104.47 as best cut-off values for NLR and PLR, respectively. The relationships between NLR/PLR and pCR, along with other clinical-pathological characteristics, were evaluated by Pearson's χ 2 or Fisher's exact test as appropriate. Univariate and multivariate analyses were performed using a logistic regression model. NLR and PLR were not significantly associated with pCR if analyzed separately. However, when combining NLR and PLR, patients with a NLR^low/PLR^low profile achieved a significantly higher rate of pCR compared to those with NLR^high and/or PLR^high (OR 2.29, 95% CI 1.22-4.27, p 0.009). Importantly, the predictive value of NLR^low/PLR^low was independent from common prognostic factors such as grading, Ki67, and molecular subtypes. The combination of NLR and PLR may reflect patients' immunogenic phenotype. Low levels of both NLR and PLR may thus indicate a status of immune system activation that may predict pCR in breast cancer patients treated with NACT.