Tracking Monocytes and Macrophages in Tumors With Live Imaging

Visualizing the spatial organization of monocytes, interstitial macrophages, and tissue-specific macrophages in situ

Tissue-resident mononuclear phagocytes (MPs) are an abundant cell population whose localization in situ reflects their identity. To enable assessment of their heterogeneity, we developed the red/green/blue (RGB)-Mac mouse based upon combinations of Cx3cr1 and Csf1r reporter transgenes, providing a complete visualization of their spatial organization in situ. 3D-multi-photon imaging for spatial mapping and spectral cytometry employing the three markers in combination distinguished tissue-associated monocytes, tissue-specific macrophages, and three subsets of connective-tissue-associated MPs, including CCR2+ monocyte-derived cell, CX3CR1+, and FOLR2+ interstitial subsets, associated with distinct sub-anatomic territories. These populations were selectively reduced by blockade of CSF1, CSF2, CCR2, and CX3CR1 and efficiently reconstitute their spatial distribution after transient myelo-ablation, suggesting an autonomous regulatory environment. Our findings emphasize the organization of the MP compartment at the sub-anatomic level under steady-state conditions, thereby providing a holistic understanding of their relative heterogeneity across different tissues.

Understanding tissue-resident macrophages unlocks the potential for novel combinatorial strategies in breast cancer

Tissue-resident macrophages (TRMs) are an integral part of the innate immune system, but their biology is not well understood in the context of cancer. Distinctive resident macrophage populations are identified in different organs in mice using fate mapping studies. They develop from the yolk sac and self-maintain themselves lifelong in specific tissular niches. Similarly, breast-resident macrophages are part of the mammary gland microenvironment. They reside in the breast adipose tissue stroma and close to the ductal epithelium and help in morphogenesis. In breast cancer, TRMs may promote disease progression and metastasis; however, precise mechanisms have not been elucidated. TRMs interact intimately with recruited macrophages, cytotoxic T cells, and other immune cells along with cancer cells, deciding further immunosuppressive or cytotoxic pathways. Moreover, triple-negative breast cancer (TNBC), which is generally associated with poor outcomes, can harbor specific TRM phenotypes. The influence of TRMs on adipose tissue stroma of the mammary gland also contributes to tumor progression. The complex crosstalk between TRMs with T cells, stroma, and breast cancer cells can establish a cascade of downstream events, understanding which can offer new insight for drug discovery and upcoming treatment choices. This review aims to acknowledge the previous research done in this regard while exploring existing research gaps and the future therapeutic potential of TRMs as a combination or single agent in breast cancer.

Leukaemia exposure alters the transcriptional profile and function of BCR::ABL1 negative macrophages in the bone marrow niche

Macrophages are fundamental cells of the innate immune system that support normal haematopoiesis and play roles in both anti-cancer immunity and tumour progression. Here we use a chimeric mouse model of chronic myeloid leukaemia (CML) and human bone marrow (BM) derived macrophages to study the impact of the dysregulated BM microenvironment on bystander macrophages. Utilising single-cell RNA sequencing (scRNA-seq) of Philadelphia chromosome (Ph) negative macrophages we reveal unique subpopulations of immature macrophages residing in the CML BM microenvironment. CML exposed macrophages separate from their normal counterparts by reduced expression of the surface marker CD36, which significantly reduces clearance of apoptotic cells. We uncover aberrant production of CML-secreted factors, including the immune modulatory protein lactotransferrin (LTF), that suppresses efferocytosis, phagocytosis, and CD36 surface expression in BM macrophages, indicating that the elevated secretion of LTF is, at least partially responsible for the supressed clearance function of Ph- macrophages.

The Naples Prognostic Score Is a Useful Tool to Assess Surgical Treatment in Non-Small Cell Lung Cancer

Different prognostic scores have been applied to identify patients with non-small cell lung cancer who have a higher probability of poor outcomes. In this study, we evaluated whether the Naples Prognostic Score, a novel index that considers both inflammatory and nutritional values, was associated with long-term survival. This study presents a retrospective propensity score matching analysis of patients who underwent curative surgery for non-small cell lung cancer from January 2016 to December 2021. The score considered the following four pre-operative parameters: the neutrophil-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, serum albumin, and total cholesterol. The Kaplan-Meier method and Cox regression analysis were performed to evaluate the relationship between the score and disease-free survival, overall survival, and cancer-related survival. A total of 260 patients were selected for the study, though this was reduced to 154 after propensity score matching. Post-propensity Kaplan-Meier analysis showed a significant correlation between the Naples Prognostic Score, overall survival (p = 0.018), and cancer-related survival (p = 0.007). Multivariate Cox regression analysis further validated the score as an independent prognostic indicator for both types of survival (p = 0.007 and p = 0.010, respectively). The Naples Prognostic Score proved to be an easily achievable prognostic factor of long-term survival in patients with non-small cell lung cancer after surgical treatment.

Assessment of Naples prognostic score in predicting survival for small cell lung cancer patients treated with chemoradiotherapy

BACKGROUNDS

The Naples prognosis score (NPS) is a novel prognostic biomarker-based immune and nutritional status and that can be used to evaluate prognosis. Our study aimed to investigate the prognostic role of NPS in SCLC patients.

METHODS

Patients treated with chemoradiotherapy were retrospectively analyzed between June 2012 and August 2017. We divided patients into three groups depending on the NPS: group 0, n = 31; group 1, n = 100; and group 2, n = 48, and associations between clinical characteristics and NPS group were analyzed. The univariable and multivariable Cox analyses were used to evaluate the prognostic value of clinicopathological characteristics and laboratory indicators for overall survival (OS) and progression-free survival (PFS).

RESULTS

Data from 179 patients were analyzed. Treatment modality (p < 0.001) and serum CEA (p = 0.03) were significantly different among the NPS groups. The age, sex, smoking status, KPS, Karnofsky performance score (KPS), disease extent, and number of metastatic sites were not correlated with NPS (all p > 0.05). KPS, disease extent, prophylactic cranial irradiation, treatment response and NPS Group were associated with OS. In addition, KPS, disease extent, prophylactic cranial irradiation, treatment response and NPS Group were associated with PFS. Multivariate analysis results showed that NPS was identified as an independent prognostic factor for OS (Group 1: hazard ratio [HR] = 2.704, 95% confidence interval [CI] = 1.403-5.210; p = 0.003; Group 2: HR = 5.154, 95% CI = 2.614-10.166; p < 0.001) and PFS (Group 1: HR = 2.018, 95% CI = 1.014-4.014; p = 0.045; Group 2: HR = 3.339, 95% CI = 1.650-6.756; p = 0.001).

CONCLUSIONS

NPS is related to clinical outcomes in patients with SCLC.

Prognostic value of a modified systemic inflammation score in breast cancer patients who underwent neoadjuvant chemotherapy

BACKGROUND AND PURPOSE

The modified systemic inflammation score (mSIS) system, which is constructed based on the neutrophil to lymphocyte ratio (NLR) and albumin (Alb), has not been applied to evaluate the prognosis of malignant breast cancer patients who underwent neoadjuvant chemotherapy (NAC). The present study aimed to explore the relationship between the mSIS and overall survival (OS), disease-free survival (DFS) and pathological complete response (pCR).

METHODS

A total of 305 malignant breast tumor patients who underwent NAC were incorporated into this retrospective analysis. We determined OS and DFS using K-M survival curves and the log-rank test. The relationship between the mSIS and OS and DFS was evaluated by a Cox regression model. A nomogram was constructed based on Cox regression analysis.

RESULTS

Patients in the mSIS low-risk group had better 5- and 8-year OS rates than those in the mSIS high-risk group (59.8% vs. 77.0%; 50.1% vs. 67.7%; X² = 8.5, P = 0.0035, respectively). Patients in the mSIS (1 + 2 score) + pCR subgroup had the highest 5- and 8-year OS and disease-free survival (DFS) rates (OS: 55.0% vs. 75.7% vs. 84.8, 42.8% vs. 65.7% vs. 79.8%, X² = 16.6, P = 0.00025; DFS: 38.8% vs. 54.7% vs. 76.3%, 33.3% vs. 42.3 vs. 72.1%, X2 = 12.4, P = 0.002, respectively). Based on the mSIS, clinical T stage and pCR results, the nomogram had better predictive ability than the clinical TNM stage, NLR and Alb.

CONCLUSIONS

mSIS is a promising prognostic tool for malignant breast tumor patients who underwent NAC, and the combination of mSIS and pCR is helpful in enhancing the ability to predict a pCR.

Label-free metabolic imaging for sensitive and robust monitoring of anti-CD47 immunotherapy response in triple-negative breast cancer

Background

Immunotherapy is revolutionizing cancer treatment from conventional radiotherapies and chemotherapies to immune checkpoint inhibitors which use patients’ immune system to recognize and attack cancer cells. Despite the huge clinical success and vigorous development of immunotherapies, there is a significant unmet need for a robust tool to identify responders to specific immunotherapy. Early and accurate monitoring of immunotherapy response is indispensable for personalized treatment and effective drug development.

Methods

We established a label-free metabolic intravital imaging (LMII) technique to detect two-photon excited autofluorescence signals from two coenzymes, NAD(P)H (reduced nicotinamide adenine dinucleotide (phosphate) hydrogen) and FAD (flavin adenine dinucleotide) as robust imaging markers to monitor metabolic responses to immunotherapy. Murine models of triple-negative breast cancer (TNBC) were established and tested with different therapeutic regimens including anti-cluster of differentiation 47 (CD47) immunotherapy to monitor time-course treatment responses using the developed metabolic imaging technique.

Results

We first imaged the mechanisms of the CD47-signal regulatory protein alpha pathway in vivo, which unravels macrophage-mediated antibody-dependent cellular phagocytosis and illustrates the metabolism of TNBC cells and macrophages. We further visualized the autofluorescence of NAD(P)H and FAD and found a significant increase during tumor growth. Following anti-CD47 immunotherapy, the imaging signal was dramatically decreased demonstrating the sensitive monitoring capability of NAD(P)H and FAD imaging for therapeutic response. NAD(P)H and FAD intravital imaging also showed a marked decrease after chemotherapy and radiotherapy. A comparative study with conventional whole-body bioluminescence and fluorescent glucose imaging demonstrated superior sensitivity of metabolic imaging. Flow cytometry validated metabolic imaging results. In vivo immunofluorescent staining revealed the targeting ability of NAD(P)H imaging mainly for tumor cells and a small portion of immune-active cells and that of FAD imaging mainly for immunosuppressive cells such as M2-like tumor-associated macrophages.

Conclusions

Collectively, this study showcases the potential of the LMII technique as a powerful tool to visualize dynamic changes of heterogeneous cell metabolism of cancer cells and immune infiltrates in response to immunotherapy thus providing sensitive and complete monitoring. Leveraged on ability to differentiate cancer cells and immunosuppressive macrophages, the presented imaging approach provides particularly useful imaging biomarkers for emerged innate immune checkpoint inhibitors such as anti-CD47 therapy.

Antibody-based in vivo leukocyte label for two-photon brain imaging in mice

Significance: To study leukocyte-endothelial interactions in a living system, robust and specific leukocyte labeling techniques are needed for in vivo two-photon microscopy of the cerebral microvasculature. Aim: We tested fluorophore-conjugated anti-CD45.2 monoclonal antibodies (mAb) to optimize dosing and two-photon imaging parameters for leukocyte labeling in healthy mice and a venous microstroke model. Approach: We retro-orbitally injected anti-CD45.2 mAb at 0.04, 0.4, and 2    mg / kg into BALB/c mice and used flow cytometry to analyze antibody saturation. Leukocyte labeling in the cortical microvasculature was examined by two-photon imaging. We also tested the application of CD45.2 mAb in a pathological leukocyte-endothelial adhesion model by photothrombotically occluding cortical penetrating venules. Results: We found that 0.4    mg / kg of anti-CD45.2 antibody intravenously was sufficient to label 95% of circulating leukocytes. There was no depletion of circulating leukocytes after 24 h at the dosages tested. Labeled leukocytes could be observed as deep as 550    μ m from the cortical surface. The antibody reliably labeled rolling, crawling, and adherent leukocytes in venules around the stroke-affected tissues. Conclusion: We show that the anti-CD45.2 mAb is a robust reagent for acute labeling of leukocytes during in vivo two-photon microscopy of the cortical microvasculature.

Tumor-associated macrophage heterogeneity is driven by tissue territories in breast cancer

Tissue-resident macrophages adapt to local signals within tissues to acquire specific functions. Neoplasia transforms the tissue, raising the question as to how the environmental perturbations contribute to tumor-associated macrophage (TAM) identity and functions. Combining single-cell RNA sequencing (scRNA-seq) with spatial localization of distinct TAM subsets by imaging, we discover that TAM transcriptomic programs follow two main differentiation paths according to their localization in the stroma or in the neoplastic epithelium of the mammary duct. Furthermore, this diversity is exclusively detected in a spontaneous tumor model and tracks the different tissue territories as well as the type of tumor lesion. These TAM subsets harbor distinct capacity to activate CD8+ T cells and phagocyte tumor cells, supporting that specific tumor regions, rather than defined activation states, are the major drivers of TAM plasticity and heterogeneity. The distinctions created here provide a framework to design cancer treatment targeting specific TAM niches.

Prognostic significance of Naples prognostic score in non-small-cell lung cancer patients with brain metastases

Aims: The authors aimed to evaluate the prognostic value of Naples prognostic score (NPS) in advanced non-small-cell lung cancer patients with brain metastases. Materials & methods: A total of 186 consecutive advanced non-small-cell lung cancer patients were retrospectively analyzed. Kaplan-Meier survival analysis and Cox proportional regression models were used to assess the significance of NPS in overall survival and disease-free survival. Results: Multivariate Cox proportional regression analysis revealed that NPS was a significant independent predictive indicator for overall survival (hazard ratio: 1.897; 95% CI: 1.184-3.041; p = 0.008) and disease-free survival (hazard ratio: 2.169; 95% CI: 1.367-3.44; p = 0.001). Conclusion: NPS was a powerful prognostic indicator for outcome in advanced non-small-cell lung cancer patients with brain metastases.

Microbial Colonization and Inflammation as Potential Contributors to the Lack of Therapeutic Success in Oral Squamous Cell Carcinoma

This review discusses the microenvironment of evolving and established conventional oral squamous cell carcinoma, by far the most common oral cancer. The focus of this paper is mainly on the more recent data that describe the role of microorganisms, host-microbial interactions, and in particular, the contributions of cell-surface toll-like receptors on immune system cells and on normal and malignant epithelial cells to their functions that support carcinogenesis. Because carcinomas arising at various host surfaces share much in common, additional information available from studies of other carcinomas is included in the discussion. Accumulating evidence reveals the complex toll-like receptor-mediated tumor-supporting input into many aspects of carcinogenesis via malignant cells, stromal immune cells and non-immune cells, complicating the search for effective treatments.

Evaluation of Predictive Values of Naples Prognostic Score in Patients with Unresectable Stage III Non-Small Cell Lung Cancer

Background

Naples prognosis score (NPS) is a new prognostic score according to host inflammatory and nutritional state, and it could be useful for predicting tumor prognosis based on albumin level, total cholesterol level, neutrophil-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio. This study aimed to evaluate the clinical significance of Naples prognostic score (NPS) in stage III non-small cell lung cancer patients (NSCLC).

Patients and Methods

In this study, 206 patients diagnosed with locally advanced NCCLC receiving chemoradiotherapy were retrospectively reviewed from January 2013 to January 2017. The included patients were divided into 3 groups according to NPS (group 0, group 1, and group 2), and the associations of the NPS with clinical characteristics and outcomes were evaluated among the groups. Survival curves for the NPS were analyzed using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazards regression model to evaluate the prognostic value of overall survival (OS) and progression-free survival (PFS).

Results

The median follow-up time of this study was 37.0 (range, 13-59) months. The median OS was 27 months in group 0, 23 months in group 1, and 21 months in group 2, and median PFS was 15, 12 and 13 in group 0, group 1 and group 2, respectively. Age was significantly different among the 3 groups. The NPS was superior to other host inflammatory and nutritional indexes for prognostic risk stratification. In the multivariate analysis, NPS was identified as an independent prognostic indicator for OS and PFS (all P<0.05).

Conclusion

The NPS system is considered to be a useful predictor of outcomes in patients with stage III NSCLC.

Visualizing murine breast and melanoma tumor microenvironment using intravital multiphoton microscopy

Intravital multiphoton imaging of the tumor milieu allows for the dissection of intricate and dynamic biological processes in situ. Herein, we present a step-by-step protocol for setting up an experimental cancer imaging model that has been optimized for solid tumors such as breast cancer and melanoma implanted in the flanks of mice. This protocol can be utilized for dissecting tumor-immune cell dynamics in vivo or other tumor-specific biological questions.

For complete details on the use of this protocol for intravital imaging of breast cancer, please refer to Tikoo et al. (2021a), and for intravital imaging of melanoma, please refer to Tikoo et al. (2021b).

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Detailed protocol for setting up high-resolution intravital imaging of murine tumors

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3D printing of custom stage inserts for tumor stabilization

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Procedures for cannulation of blood vessels

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Surgical preparation and tissue stabilization for imaging tumor milieu in vivo

Efficacy of Neoadjuvant Single or Dual Anti-HER-2 Therapy Combined with Chemotherapy in Patients with HER-2-Positive Breast Cancer: A Single-Center Retrospective Study

Background:

Studies have shown that neoadjuvant anti-HER-2 therapy and chemotherapy can increase pathologic complete response (pCR) rate in HER-2-positive breast cancer patients and improve prognosis. However, data from Chinese patients are limited. Therefore, we conducted a single-center retrospective study to evaluate the effects of neoadjuvant single or dual anti-HER-2 therapy and chemotherapy in Chinese HER-2-positive breast cancer patients and to explore the prognostic indicators of pCR and progression-free survival (PFS).

Methods:

We included patients with HER-2-positive breast cancer treated with neoadjuvant anti-HER-2 therapy and chemotherapy at the First Affiliated Hospital of Chongqing Medical University in China from January 2016 to July 2020. We analyzed the relationship between patient characteristics and the pCR rate or PFS.

Results:

Forty-seven patients with HER-2-positive breast cancer receiving neoadjuvant anti-HER-2 therapy and chemotherapy were included. Univariate analysis suggested that compared with patients receiving neoadjuvant single anti-HER-2 therapy, patients receiving neoadjuvant dual anti-HER-2 therapy tended to have a higher pCR rate and better PFS. Patients who achieved pCR also tended to have longer PFS. Multivariate analysis indicated that patients with greater systemic inflammation response index (SIRI) reduction (>0.54) during neoadjuvant treatment (NAT) and patients with a lower T stage were more likely to achieve pCR. Patients aged ≤60 years with lower Ki-67 had longer PFS.

Conclusion:

Greater SIRI reduction during NAT was an independent influencing factor for pCR. Patients receiving neoadjuvant dual anti-HER-2 therapy and chemotherapy tended to have higher pCR rates and longer PFS. Patients who achieved pCR also tended to have longer PFS.

Imaging resident and recruited macrophage contribution to Wallerian degeneration

Wallerian degeneration (WD) is a process of autonomous distal degeneration of axons upon injury. Macrophages (MPs) of the peripheral nervous system (PNS) are the main cellular agent controlling this process. Some evidence suggests that resident PNS-MPs along with MPs of hematogenous origin may be involved, but whether these two subsets exert distinct functions is unknown. Combining MP-designed fluorescent reporter mice and coherent anti–Stokes Raman scattering (CARS) imaging of the sciatic nerve, we deciphered the spatiotemporal choreography of resident and recently recruited MPs after injury and unveiled distinct functions of these subsets, with recruited MPs being responsible for efficient myelin stripping and clearance and resident MPs being involved in axonal regrowth. This work provides clues to tackle selectively cellular processes involved in neurodegenerative diseases.

Multi-Modal Multi-Spectral Intravital Microscopic Imaging of Signaling Dynamics in Real-Time during Tumor-ImmuneInteractions

Intravital microscopic imaging (IVM) allows for the study of interactions between immune cells and tumor cells in a dynamic, physiologically relevant system in vivo. Current IVM strategies primarily use fluorescence imaging; however, with the advances in bioluminescence imaging and the development of new bioluminescent reporters with expanded emission spectra, the applications for bioluminescence are extending to single cell imaging. Herein, we describe a molecular imaging window chamber platform that uniquely combines both bioluminescent and fluorescent genetically encoded reporters, as well as exogenous reporters, providing a powerful multi-plex strategy to study molecular and cellular processes in real-time in intact living systems at single cell resolution all in one system. We demonstrate that our molecular imaging window chamber platform is capable of imaging signaling dynamics in real-time at cellular resolution during tumor progression. Importantly, we expand the utility of IVM by modifying an off-the-shelf commercial system with the addition of bioluminescence imaging achieved by the addition of a CCD camera and demonstrate high quality imaging within the reaches of any biology laboratory.

Non-radioactive imaging strategies for in vivo immune cell tracking

In vivo tracking of administered cells chosen for specific disease treatment may be conducted by diagnostic imaging techniques preceded by cell labeling with special contrast agents. The most commonly used agents are those with radioactive properties, however their use in research is often impossible. This review paper focuses on the essential aspect of cell tracking with the exclusion of radioisotope tracers, therefore we compare application of different types of non-radioactive contrast agents (cell tracers), methods of cell labeling and application of various techniques for cell tracking, which are commonly used in preclinical or clinical studies. We discuss diagnostic imaging methods belonging to three groups: (1) Contrast-enhanced X-ray imaging, (2) Magnetic resonance imaging, and (3) Optical imaging. In addition, we present some interesting data from our own research on tracking immune cell with the use of discussed methods. Finally, we introduce an algorithm which may be useful for researchers planning leukocyte targeting studies, which may help to choose the appropriate cell type, contrast agent and diagnostic technique for particular disease study.

Pretreatment Systemic Inflammation Response Index in Patients with Breast Cancer Treated with Neoadjuvant Chemotherapy as a Useful Prognostic Indicator

Background and Objective

Systemic inflammation response index (SIRI=N×M/L), based on neutrophil (N), monocyte (M), and lymphocyte (L) counts, is used to predict the survival of patients with malignant tumors and can fully evaluate the balance between host immune and inflammatory condition. The present study is aimed to evaluate the potential prognostic significance of SIRI in patients with breast cancer undergoing neoadjuvant chemotherapy.

Subjects and Methods

A total of 262 breast cancer patients treated with neoadjuvant chemotherapy were enrolled in this retrospective study. The optimal cutoff value of SIRI by receiver operating characteristic curve stratified patients into low SIRI (<0.85×10⁹/L) group and high SIRI (≥0.85×10⁹/L) group. The associations between breast cancer and clinicopathological variables by SIRI were determined by chi-square test or Fisher’s exact test. Kaplan–Meier plots and log-rank test were used to evaluate the clinical outcomes of disease-free survival (DFS) and overall survival (OS). Univariate and multivariate Cox proportional hazards regression models were used to analyze the prognostic value of SIRI. The toxicity of neoadjuvant chemotherapy was evaluated by the National Cancer Institute Common Toxicity Criteria (NCICTC).

Results

The results were shown that SIRI had prognostic significance by optimal cutoff value of 0.85×10⁹/L on DFS and OS in univariate and multivariate Cox regression survival analyses. Compared with patients who had high SIRI, patients with low SIRI had longer DFS and OS (41.27 vs 30.45 months, HR: 1.694, 95% CI: 1.128–2.543, P=0.011; 52.86 vs 45.75 months, HR: 1.288, 95% CI: 0.781–3.124, P=0.002, respectively). The patients with low SIRI had better 3-, 5-, and 10-year rates of DFS and OS than those with high SIRI. The common toxicities after neoadjuvant chemotherapy were hematologic and gastrointestinal reaction, and the SIRI had no significance on toxicities of all enrolled patients, excepted diarrhea. In patients without neural invasion, those with low SIRI had better prognosis and lower recurrence rates than those with high SIRI.

Conclusion

Pretreatment SIRI with the advantage of repeatable, convenient, and non-invasive is a useful prognostic indicator for breast cancer patients who received neoadjuvant chemotherapy and is a promising biomarker for breast cancer on treatment strategy decisions.

Pre-treatment systemic immune-inflammation index is a useful prognostic indicator in patients with breast cancer undergoing neoadjuvant chemotherapy

The systemic immune‐inflammation index (SII = N × P/L) based on neutrophil (N), platelet (P) and lymphocyte (L) counts is used to predict the survival of patients with malignant tumours and can fully reflect the balance between host inflammatory and immune status. This study is conducted to explore the potential prognostic significance of SII in patients with breast cancer undergoing neoadjuvant chemotherapy (NACT). A total of 262 patients with breast cancer received NACT were enrolled in this study. According to the receiver operating characteristic curve, the optimal cut‐off value of SII was divided into two groups: low SII group (<602 × 10⁹/L) and high SII group (≥602 × 10⁹/L). The associations between breast cancer and clinicopathological variables by SII were determined by chi‐squared test or Fisher's exact test. The Kaplan‐Meier plots and log‐rank test were used to determine clinical outcomes of disease‐free survival (DFS) and overall survival (OS). The prognostic value of SII was analysed by univariate and multivariate Cox proportional hazards regression models. The toxicity of NACT was accessed by National Cancer Institute Common Toxicity Criteria (NCICTC). According to univariate and multivariate Cox regression survival analyses, the results showed that the value of SII had prognostic significance for DFS and OS. The patients with low SII value had longer DFS and OS than those with high SII value (31.11 vs 40.76 months, HR: 1.075, 95% CI: 0.718‐1.610, P = .006; 44.47 vs 53.68 months, HR: 1.051, 95% CI: 0.707‐1.564, P = .005, respectively). The incidence of DFS and OS in breast cancer patients with low SII value was higher than that in those patients with high SII value in 3‐, 5‐ and 10‐year rates. The common toxicities after NACT were haematological and gastrointestinal reaction, and there were no differences by SII for the assessment of side effects of neoadjuvant chemotherapy. Meanwhile, the results also proved that breast cancer patients with low SII value and high Miller and Payne grade (MPG) survived longer than those breast cancer with high SII value and low MPG grade. In patients without lymph vessel invasion, these breast cancer patients with low SII value had better prognosis and lower recurrence rates than those with high SII value. Pre‐treatment SII with the advantage of reproducible, convenient and non‐invasive was a useful prognostic indicator for breast cancer patients undergoing neoadjuvant chemotherapy and is a promising biomarker for breast cancer on treatment strategy decisions.

Transcription factor MafB is a marker of tumor-associated macrophages in both mouse and humans

The transcription factor MafB is specifically expressed in macrophages. We have recently demonstrated that MafB is expressed in anti-inflammatory alternatively activated M2 macrophages in vitro. Tumor-associated macrophages (TAMs) are a subset of M2 type macrophages that can promote immunosuppressive activity, induce angiogenesis, and promote tumor cell proliferation. To examine whether MafB express in TAMs, we analyzed green fluorescent protein (GFP) expression in Lewis lung carcinoma tumors of MafB-GFP knock-in heterozygous mice. FACS analysis demonstrated GFP fluorescence in cells positive for macrophage-markers (F4/80, CD11b, CD68, and CD204). Moreover, quantitative RT-PCR analysis with F4/80⁺GFP⁺ and F4/80⁺GFP^- sorted cells showed that the GFP-positive macrophages express IL-10, Arg-1, and TNF-α, which were known to be expressed in TAMs. These results indicate that MafB is expressed in TAMs. Furthermore, immunostaining analysis using an anti-MAFB antibody revealed that MAFB is expressed in CD204-and CD68-positive macrophages in human lung cancer samples. In conclusion, MafB can be a suitable marker of TAMs in both mouse and human tumor tissues.

Ontogeny of Tumor-Associated Macrophages

Tumor-associated macrophages (TAM) represent the main immune cell population of the tumor microenvironment in most cancer. For decades, TAM have been the focus of intense investigation to understand how they modulate the tumor microenvironment and their implication in therapy failure. One consensus is that TAM are considered to exclusively originate from circulating monocyte precursors released from the bone marrow, fitting the original dogma of tissue-resident macrophage ontogeny. A second consensus proposed that TAM harbor either a classically activated M1 or alternatively activated M2 polarization profile, with almost opposite anti- and pro-tumoral activity respectively. These fundamental pillars are now revised in face of the latest discoveries on macrophage biology. Embryonic-derived macrophages were recently characterized as major contributors to the pool of tissue-resident macrophages in many tissues. Their turnover with macrophages derived from precursors of adult hematopoiesis seems to follow a regulation at the subtissular level. This has shed light on an ever more complex macrophage diversity in the tumor microenvironment than once thought and raise the question of their respective implication in tumor development compared to classical monocyte-derived macrophages. These recent advances highlight that TAM have actually not fully revealed their usefulness and deserve to be reconsidered. Understanding the link between TAM ontogeny and their various functions in tumor growth and interaction with the immune system represents one of the future challenges for cancer therapy.