Expression of CD163, interleukin-10, and interferon-gamma in oral squamous cell carcinoma: mutual relationships and prognostic implications

Comprehensive survival analysis of oral squamous cell carcinoma patients undergoing initial radical surgery

OBJECTIVE

This study was designed to evaluate the five-year overall survival (OS) rate and postoperative survival time of patients diagnosed with oral squamous cell carcinoma (OSCC), as well as examine the clinical and pathological factors influencing survival outcomes in OSCC patients.

METHODS

Data were collected from OSCC patients who underwent their first radical surgical intervention in the Department of Maxillofacial Surgery at the First Affiliated Hospital of Chongqing Medical University between April 2014 and December 2016. Follow-up was conducted until March 2022.

RESULTS

The study included a total of 162 patients. The observed 5-year OS rate was 59.3%. Approximately 45.7% of OSCC patients experienced postoperative recurrence or metastasis, with a 5-year overall disease-free survival rate of 49.4%. There was no significant difference in the impact of sex, age, smoking, alcohol consumption, primary tumour location, depth of invasion or primary tumour size on the 5-year survival rate (p > 0.05). Univariate analysis revealed that clinical stage (Hazard Ratio = 2.239, p = 0.004), perineural invasion (PNI) (Hazard Ratio = 1.712, p = 0.03), lymph node metastasis (pN) (Hazard Ratio = 2.119, p = 0.002), pathological differentiation (Hazard Ratio = 2.715, p < 0.001), and recurrence or metastasis (Hazard Ratio = 10.02, p < 0.001) were significant factors influencing survival. Multivariate analysis further indicated that pathological differentiation (Hazard Ratio = 2.291, p = 0.001), PNI (Hazard Ratio = 1.765, p = 0.031) and recurrence or metastasis (Hazard Ratio = 9.256, p < 0.001) were independent risk factors of survival. Intriguingly, 11 OSCC patients were diagnosed with oesophageal squamous cell carcinoma (ESCC) within 1-4 years following surgery.

CONCLUSION

The survival prognosis of OSCC patients is significantly associated with clinical stage, PNI, lymph node metastasis, pathological differentiation, and recurrence or metastasis. Pathological differentiation, PNI and recurrence or metastasis are independent risk factors affecting survival. Routine clinical screening for ESCC may be recommended for OSCC patients with a history of alcohol consumption and tobacco use.

Analysis of the effect of CCR7 on the microenvironment of mouse oral squamous cell carcinoma by single-cell RNA sequencing technology

BACKGROUND

Studies have shown that CCR7, an important inflammatory factor, can promote the proliferation and metastasis of oral squamous cell carcinoma (OSCC), but its role in the tumor microenvironment (TME) remains unclear. This paper explores the role of CCR7 in the TME of OSCC.

METHODS

In this work, we constructed CCR7 gene knockout mice and OSCC mouse models. Single-cell RNA sequencing (scRNA-seq) and bioinformatics were used to analyze the differences in the OSCC microenvironment between three CCR7 gene knockout mice (KO) and three wild-type mice (WT). Immunohistochemistry, immunofluorescence staining, and flow cytometry were used to analyze the expression of key genes in significantly different cell types between the KO and WT groups. An in vitro experiment was used to verify the effect of CCR7 on M2 macrophage polarization.

RESULTS

In the mouse OSCC models, the tumor growth rate in the KO group was significantly lower than that in the WT group. Eight main cell types (including tumor cells, fibroblasts, macrophages, granulocytes, T cells, endothelial cells, monocytes, and B cells) were identified by Seurat analysis. The scRNA-seq results showed that the proportion of tumor cells was lower, but the proportion of inflammatory cells was significantly higher in the KO group than in the WT group. CellPhoneDB analysis results indicated a strong interaction relationship between tumor cells and macrophages, T cells, fibroblasts, and endothelial cells. Functional enrichment results indicated that the expression level of the Dusp1 gene in the KO group was generally higher than that in the WT group in various cell types. Macrophage subclustering results indicated that the proportion of M2 macrophages in the KO group was lower than that in the WT group. In vitro experimental results showed that CCR7 can promote M2 macrophage polarization, thus promoting the proliferation, invasion and migration of OSCC cells.

CONCLUSIONS

CCR7 gene knockout can significantly inhibit the growth of mouse oral squamous cell carcinoma by promoting the polarization of M2 macrophages.

Evaluation of the presence of Th1 response through T-bet and IFN-gamma immunohistochemical expression in lower lip and oral tongue squamous cell carcinomas

INTRODUCTION

Evaluate the immunohistochemical expression of T-bet and IFN-γ in lower lip (LLSCC) and oral tongue squamous cell carcinoma (OTSCC), verifying the presence of Th1 responses in lesions with different clinical conditions.

METHODS AND MATERIALS

Thirty OTSCC and 30 LLSCC were analyzed by immunohistochemistry. T-bet was quantitatively assessed by parenchyma cell and stroma quantification, and IFN-γ was semi-quantitatively analyzed: 1:0-25%; 2:26-50%; 3:51-75%; 4:> 75% immunopositive cells. Histological differentiation degrees were categorized as well differentiated (WD), moderately differentiated (MD), or poorly differentiated (PD).

RESULTS

OTSCC presented the highest number of T-bet+, parenchyma (p: 0.006), stroma (p: 0.156), parenchyma/stroma (p: 0.015), with no relationship to histological malignancy grade. IFN-γ higher concentrations in LLSCC were detected in parenchyma, stroma and in parenchyma/stroma (p: 0.000), as well as greater immunoreactivity in WD and MD (p: 0.001). In OTSCC, a positive and statistically significant correlation was observed between T-bet+ in parenchyma and IFN-γ in stroma(r: 0.388; p: 0.034), in addition to a statistically significant positive correlation between T-bet in parenchyma compared to stroma(r: 0.411; p: 0.024) and for IFN-γ in both parenchyma and stroma(r: 0.775; p: 0.000) in LLSCC. Higher T-bet+ was observed in OTSCCs, although higher IFN-γ was detected in LLSCCs.

CONCLUSION

Thus, we suggest that, even though LLSCC presented lower T-bet+, the favorable microenvironment in these lesions led to an expressive activation of IFN-γ by T-bet+, considerably acting on Th1 differentiation and in antitumor activity, which, admittedly, present less aggressive behavior, reinforcing once again the important role of this cytokine and its use in strategy to fight cancer.

Cytokine network imbalance in children with B-cell acute lymphoblastic leukemia at diagnosis

Immune imbalance has been proved to be involved in the pathogenesis of hematologic neoplasm. However, little research has been reported altered cytokine network in childhood B-cell acute lymphoblastic leukemia (B-ALL) at diagnosis. Our study aimed to evaluate the cytokine network in peripheral blood of newly diagnosed pediatric patients with B-ALL. Serum levels of interleukin (IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF), interferon (IFN)-γ, and IL-17A in 45 children with B-ALL and 37 healthy control children were measured by cytometric bead array, while the level of transforming growth factor-β1 (TGF-β1) in the serum was measured by enzyme-linked immunosorbent assay. Patients showed a significant increase in IL-6 (p < 0.001), IL-10 (p < 0.001), IFN-γ (p = 0.023) and a significant reduction in TGF-β1 (p = 0.001). The levels of IL-2, IL-4, TNF and IL-17A were similar in the two groups. Higher concentrations of pro-inflammatory cytokines were associated with febrile in patients without apparent infection by using unsupervised machine learning algorithms. In conclusion, our results indicated a critical role for aberrant cytokine expression profiles in the progression of childhood B-ALL. Distinct cytokine subgroups with different clinical features and immune response have been identified in patients with B-ALL at the time of diagnosis.

The role of interferon-gamma and its receptors in gastrointestinal cancers

Gastrointestinal malignancies are the most prevalent type of cancer around the world. Even though numerous studies have evaluated gastrointestinal malignancies, the actual underlying mechanism is still unknown. These tumors have a poor prognosis and are frequently discovered at an advanced stage. Globally, there is an increase in the incidence and mortality of gastrointestinal malignancies, including those of the stomach, esophagus, colon, liver, and pancreas. Growth factors and cytokines are signaling molecules that are part of the tumor microenvironment and play a significant role in the development and spread of malignancies. IFN-γ induce its effects by activation of intracellular molecular networks. The main pathway involved in IFN-γ signaling is the JAK/STAT pathway, which regulates the transcription of hundreds of genes and mediates various biological responses. IFN-γ receptor is composed of two IFN-γR1 chains and two IFN-γR2 chains. Binding to IFN-γ, causes the intracellular domains of IFN-γR2 to oligomerize and transphosphorylate with IFN-γR1 which activates downstream signaling components: JAK1 and JAK2. These activated JAKs phosphorylate the receptor, creating binding sites for STAT1. STAT1 is then phosphorylated by JAK, resulting in the formation of STAT1 homodimers (gamma activated factors or GAFs) that translocate to the nucleus and regulate gene expression. The balance between positive and negative regulation of this pathway is crucial for immune responses and tumorigenesis. In this paper, we evaluate the dynamic roles of IFN- γ and its receptors in gastrointestinal cancers and present evidence that inhibiting IFN- γ signaling may be an effective treatment strategy.

Prognostic Role of CD68+ and CD163+ Tumour-Associated Macrophages and PD-L1 Expression in Oral Squamous Cell Carcinoma: A Meta-Analysis

Background: Oral squamous cell carcinoma (OSCC) is a common malignant cancer in humans. An abundance of tumour associated macrophages (TAMs) create an immunosuppressive tumour microenvironment (TME). TAM markers (CD163 and CD68) are seen to serve as prognostic factors in OSCC. PD-L1 has seen to widely modulate the TME but its prognostic significance remains controversial. The aim of this meta-analysis is to evaluate the prognostic role of CD163⁺, CD68⁺ TAMs and PD-L1 in OSCC patients. Methods: Searches in PubMed, Scopus and Web of Science were performed; 12 studies were included in this meta-analysis. Quality assessment of included studies was performed according to REMARK guidelines. Risk of bias across studies was investigated according to the rate of heterogeneity. Meta-analysis was performed to investigate the association of all three biomarkers with overall survival (OS). Results: High expression of CD163⁺ TAMs were associated with poor overall survival (HR = 2.64; 95% Cl: [1.65, 4.23]; p < 0.0001). Additionally, high stromal expression of CD163⁺ TAMs correlated with poor overall survival (HR = 3.56; 95% Cl: [2.33, 5.44]; p < 0.00001). Conversely, high CD68 and PD-L1 expression was not associated with overall survival (HR = 1.26; 95% Cl: [0.76, 2.07]; p = 0.37) (HR = 0.64; 95% Cl: [0.35, 1.18]; p = 0.15). Conclusion: In conclusion, our findings indicate CD163⁺ can provide prognostic utility in OSCC. However, our data suggests CD68⁺ TAMs were not associated with any prognostic relevance in OSCC patients, whereas PD-L1 expression may prove to be a differential prognostic marker dependent on tumour location and stage of progression.

Investigating the factors proposed in oral lichen planus malignant transformation: A literature review

Background and Aims

Lichen planus is a chronic inflammatory disease that affects about 1% of the world's population. The World Health Organization has included oral lichen planus among potentially malignant disorders. Identification of reliable biomarkers for the diagnosis of malignant transformation may play a unique role in the development of standard screening and improvement of follow-up in patients with oral precancerous lesions. It is currently assumed that the molecular pathways controlling growth, maturation, proliferation, and apoptosis in epithelial cells may play an important role in the process of transformation into malignancy.

Methods

The search was done in PubMed, Scopus, Google Scholar, Embase, and Cochrane databases from 1960 to 2022.

Results

Based on the inclusion criteria, 23 articles were included.

Conclusion

In this review of articles, 34 different biomarkers that have been investigated in studies for the possibility of malignant transformation in OLP have been studied. Among all the risk factors related to malignant transformation, most studies have been done on the role of cytokines and tumor suppressors, in fact, the chronicity of the lesion which is the result of the reaction between the repair and the inflammatory response and the responses accompanied by the secretion of cytokines, may play a major role in the malignant transformation of OLP.

Precancerous Lesions of the Head and Neck Region and Their Stromal Aberrations: Piecemeal Data

Head and neck squamous cell carcinomas (HNSCCs) develop through a series of precancerous stages from a pool of potentially malignant disorders (PMDs). Although we understand the genetic changes that lead to HNSCC, our understanding of the role of the stroma in the progression from precancer to cancer is limited. The stroma is the primary battleground between the forces that prevent and promote cancer growth. Targeting the stroma has yielded promising cancer therapies. However, the stroma at the precancerous stage of HNSCCs is poorly defined, and we may miss opportunities for chemopreventive interventions. PMDs already exhibit many features of the HNSCC stroma, such as inflammation, neovascularization, and immune suppression. Still, they do not induce cancer-associated fibroblasts or destroy the basal lamina, the stroma's initial structure. Our review aims to summarize the current understanding of the transition from precancer to cancer stroma and how this knowledge can reveal opportunities and limitations for diagnostic, prognostic, and therapeutic decisions to benefit patients. We will discuss what may be needed to fulfill the promise of the precancerous stroma as a target to prevent progression to cancer.

Tumor-Associated Macrophages Promote Metastasis of Oral Squamous Cell Carcinoma via CCL13 Regulated by Stress Granule

M2 tumor-associated macrophages (TAMs) have been a well-established promoter of oral squamous cell carcinoma (OSCC) progression. However, the mechanisms of M2 TAMs promoting OSCC metastasis have not been elucidated clearly. This study illustrated the regulatory mechanisms in which M2 TAMs enhance OSCC malignancy in a novel point of view. In this study, mass spectrometry was utilized to analyze the proteins expression profile of M2 type monocyte-derived macrophages (MDMs-M2), whose results revealed the high expression of G3BP1 in M2 macrophages. RNA sequencing analyzed the genome-wide changes upon G3BP1 knockdown in MDMs-M2 and identified that CCL13 was the most significantly downregulated inflammatory cytokines in MDMs-M2. Co-immunoprecipitation and qualitative mass spectrometry were used to identify the proteins that directly interacted with endogenous G3BP1 in MDMs-M2. Elevated stress granule (SG) formation in stressed M2 TAMs enhanced the expression of CCL13, which promoted OSCC metastasis both in vitro and in vivo. For mechanisms, we demonstrated SG formation improved DDX3Y/hnRNPF-mediated CCL13 mRNA stability, thus enhancing CCL13 expression and promoting OSCC metastasis. Collectively, our findings demonstrated for the first time the roles of CCL13 in improving OSCC metastasis and illustrated the molecular mechanisms of CCL13 expression regulated by SG, indicating that the SG-CCL13 axis can be the potential targets for TAM-navigated tumor therapy.

Immune Cells in Head-and-Neck Tumor Microenvironments

Head-and-neck cancers constitute a heterogeneous group of aggressive tumors with high incidence and low survival rates, collectively being the sixth most prevalent cancer type globally. About 90% of head-and-neck cancers are classified as squamous cell carcinomas (HNSCC). The innate and adaptive immune systems, indispensable for anti-cancer immune surveillance, largely define the rates of HNSCC emergence and progression. HNSCC microenvironments harbor multiple cell types that infiltrate the tumors and interact both with tumor cells and among themselves. Gradually, tumor cells learn to manipulate the immune system, either by adapting their own immunogenicity or through the release of immunosuppressive molecules. These interactions continuously evolve and shape the tumor microenvironment, both structurally and functionally, facilitating angiogenesis, proliferation and metastasis. Our understanding of this evolution is directly related to success in the development of advanced therapies. This review focuses on the key mechanisms that rule HNSCC infiltration, featuring particular immune cell types and their roles in the pathogenesis. A close focus on the tumor-immunity interactions will help identify new immunotherapeutic targets in patients with HNSCC.

The ‘Danse Macabre’—Neutrophils the Interactive Partner Affecting Oral Cancer Outcomes

Over the past few decades, tremendous advances in the prevention, diagnosis, and treatment of cancer have taken place. However for head and neck cancers, including oral cancer, the overall survival rate is below 50% and they remain the seventh most common malignancy worldwide. These cancers are, commonly, aggressive, genetically complex, and difficult to treat and the delay, which often occurs between early recognition of symptoms and diagnosis, and the start of treatment of these cancers, is associated with poor prognosis. Cancer development and progression occurs in concert with alterations in the surrounding stroma, with the immune system being an essential element in this process. Despite neutrophils having major roles in the pathology of many diseases, they were thought to have little impact on cancer development and progression. Recent studies are now challenging this notion and placing neutrophils as central interactive players with other immune and tumor cells in affecting cancer pathology. This review focuses on how neutrophils and their sub-phenotypes, N1, N2, and myeloid-derived suppressor cells, both directly and indirectly affect the anti-tumor and pro-tumor immune responses. Emphasis is placed on what is currently known about the interaction of neutrophils with myeloid innate immune cells (such as dendritic cells and macrophages), innate lymphoid cells, natural killer cells, and fibroblasts to affect the tumor microenvironment and progression of oral cancer. A better understanding of this dialog will allow for improved therapeutics that concurrently target several components of the tumor microenvironment, increasing the possibility of constructive and positive outcomes for oral cancer patients. For this review, PubMed, Web of Science, and Google Scholar were searched for manuscripts using keywords and combinations thereof of “oral cancer, OSCC, neutrophils, TANs, MDSC, immune cells, head and neck cancer, and tumor microenvironment” with a focus on publications from 2018 to 2021.

Genetic Changes Driving Immunosuppressive Microenvironments in Oral Premalignancy

Oral premalignant lesions (OPLs) are the precursors to oral cavity cancers, and have variable rates of progression to invasive disease. As an intermediate state, OPLs have acquired a subset of the genomic alterations while arising in an oral inflammatory environment. These specific genomic changes may facilitate the transition to an immune microenvironment that permits malignant transformation. Here, we will discuss mechanisms by which OPLs develop an immunosuppressive microenvironment that facilitates progression to invasive cancer. We will describe how genomic alterations and immune microenvironmental changes co-evolve and cooperate to promote OSCC progression. Finally, we will describe how these immune microenvironmental changes provide specific and unique evolutionary vulnerabilities for targeted therapies. Therefore, understanding the genomic changes that drive immunosuppressive microenvironments may eventually translate into novel biomarker and/or therapeutic approaches to limit the progression of OPLs to potential lethal oral cancers.

Oral Squamous Cell Carcinoma Contributes to Differentiation of Monocyte-Derived Tumor-Associated Macrophages via PAI-1 and IL-8 Production

Tumor-associated macrophages (TAMs) promote cancer cell proliferation and metastasis, as well as anti-tumor immune suppression. Recent studies have shown that tumors enhance the recruitment and differentiation of TAMs, but the detailed mechanisms have not been clarified. We thus examined the influence of cancer cells on the differentiation of monocytes to TAM subsets, including CD163+, CD204+, and CD206+ cells, in oral squamous cell carcinoma (OSCC) using immunohistochemistry, flow cytometry, and a cytokine array. Furthermore, we investigated the effect of OSCC cells (HSC-2, SQUU-A, and SQUU-B cells) on the differentiation of purified CD14+ cells to TAM subsets. The localization patterns of CD163+, CD204+, and CD206+ in OSCC sections were quite different. The expression of CD206 on CD14+ cells was significantly increased after the co-culture with OSCC cell lines, while the expressions of CD163 and CD204 on CD14+ cells showed no change. High concentrations of plasminogen activator inhibitor-1 (PAI-1) and interleukin-8 (IL-8) were detected in the conditioned medium of OSCC cell lines. PAI-1 and IL-8 stimulated CD14+ cells to express CD206. Moreover, there were positive correlations among the numbers of CD206+, PAI-1+, and IL-8+ cells in OSCC sections. These results suggest that PAI-1 and IL-8 produced by OSCC contribute to the differentiation of monocytes to CD206+ TAMs.

DNA methylation in oral squamous cell carcinoma: from its role in carcinogenesis to potential inhibitor drugs

DNA methylation is one of epigenetic changes most frequently studied nowadays, together with its relationship with oral carcinogenesis. A group of enzymes is responsible for methylation process, known as DNA methyltransferases (DNMT). Although essential during embryogenesis, DNA methylation pattern alterations, including global hypomethylation or gene promoter hypermethylation, can be respectively associated with chromosomal instability and tumor suppressor gene silencing. Higher expression of DNA methyltransferases is a common finding in oral cancer and may contribute to inactivation of important tumor suppressor genes, influencing development, progression, metastasis, and prognosis of the tumor. To control these alterations, inhibitor drugs have been developed as a way to regulate DNMT overexpression, and they are intended to be associated with ongoing chemo- and radiotherapy in oral cancer treatments. In this article, we aimed to highlight the current knowledge about DNA methylation in oral cancer, including main hyper/hypomethylated genes, DNMT expression and its inhibitor treatments.

Pro-Tumorigenic Macrophage Infiltration in Oral Squamous Cell Carcinoma and Possible Macrophage-Aimed Therapeutic Interventions

In Oral Squamous Cell Carcinomas (OSCC), as in other solid tumors, stromal cells strongly support the spread and growth of the tumor. Macrophages in tumors (tumor-associated macrophages or “TAMs”), can swing between a pro-inflammatory and anti-tumorigenic (M1-like TAMs) state or an anti‐inflammatory and pro-tumorigenic (M2-like TAMs) profile depending on the tumor microenvironment cues. Numerous clinical and preclinical studies have demonstrated the importance of macrophages in the prognosis of patients with different types of cancer. Here, our aim was to review the role of M2-like TAMs in the prognosis of patients with OSCC and provide a state of the art on strategies for depleting or reprogramming M2-like TAMs as a possible therapeutic solution for OSCC. The Clinical studies reviewed showed that higher density of CD163+ M2-like TAMs associated with worse survival and that CD206+ M2-TAMs are involved in OSCC progression through epidermal growth factor (EGF) secretion, underlining the important role of CD206 as a marker of OSCC progression and as a therapeutic target. Here, we provide the reader with the current tools, in preclinical and clinical stage, for depleting M2-like TAMs, re-educating them towards M1-like TAMs, and exploiting TAMs as drug delivery vectors.

The Role of Macrophages in Oral Squamous Cell Carcinoma

Oral cancer is a common malignancy worldwide, with high disease-related death rates. Oral squamous cell carcinoma (OSCC) accounts for more than 90% of oral tumors, with surgical management remaining the treatment of choice. However, advanced and metastatic OSCC is still incurable. Thus, emphasis has been given lately in understanding the complex role of the oral tumor microenvironment (TME) in OSCC progression, in order to identify novel prognostic biomarkers and therapeutic targets. Tumor associated macrophages (TAMs) constitute a major population of the OSCC TME, with bipolar role in disease progression depending on their activation status (M1 vs. M2). Here, we provide an up to date review of the current literature on the role of macrophages during oral oncogenesis, as well as their prognostic significance in OSCC survival and response to standard treatment regimens. Finally, we discuss novel concepts regarding the potential use of macrophages as targets for OSCC immunotherapeutics and suggest future directions in the field.

Prognostic significance and targeting tumor-associated macrophages in cancer: new insights and future perspectives

Macrophages are phagocytic sentinel cells of the immune system that are central to both innate and adaptive immune responses and serve as the first line of defense against pathogenic insults to tissues. In the tumor microenvironment, tumor-derived factors induce monocyte polarization towards a pro-tumor phenotype. The pro-tumor macrophages regulate key steps in tumorigenicity including tumor growth, angiogenesis, immune suppression, and metastasis. Macrophage infiltration in solid tumors correlates with poor prognosis and resistance to chemotherapy in most cancers. Here in this review, we will shed light on tumor-associated macrophages (TAMs) in regulating tumorigenicity and TAMs as a prognostic biomarker. Also, we will review the recent advances in targeting TAMs to increase the prognosis of cancer patients.

New Insights Into Oral Squamous Cell Carcinoma: From Clinical Aspects to Molecular Tumorigenesis

Oral squamous cell carcinoma (SCC) is a prevalent malignant disease worldwide, especially so in Taiwan. Early- or even preclinical-stage detection is critical for reducing morbidity and mortality from oral SCC. Epidemiological and genome association studies are useful for identifying clinicopathological risk factors for preventive, diagnostic, and therapeutic approaches of oral SCC. For advanced oral SCC, effective treatments are critical to prolonging survival and enhancing quality of life. As oral SCC is characteristic of regional invasion with lymph node metastases, understanding the aggressive features of oral SCC, particularly in lymphangiogenesis, is essential for determining effective treatments. Emerging evidence has demonstrated that the tumor microenvironment (TME) plays a pivotal role in tumor growth, invasion, and metastases. Recent clinical successes in immune checkpoint inhibitors either alone or combined with chemotherapy have also supported the therapeutic value of immunotherapy in oral SCC. This review summarizes critical advances in basic knowledge of oral SCC from the perspective of clinicopathological risk factors, molecular tumorigenesis, and the TME. We also highlight our recent investigations on the microbiome, genome association studies, lymphangiogenesis, and immunomodulation in oral SCC. This review may provide new insights for oral SCC treatment by systematically interpreting emerging evidence from various preclinical and clinical studies.

Tumor-associated macrophages: Harbingers of aggressiveness in oral squamous cell carcinoma

BACKGROUND

The significance of the tumor microenvironment (TME) as a modulator of tumor behavior was acknowledged by Hanahan and Weinberg in 2011 as the emerging hallmarks and enabling characteristics of the hallmarks of cancer. Subsequently, the role of inflammation, in conferring aggressiveness to a tumor, was regarded as a fundamental process in the evolution of the TME. Tumor-associated macrophages (TAMs) are distinctly polarized inflammatory cells and key shapers of a protumorigenic microenvironment.

AIMS

The aim of the study was to evaluate the distribution of TAMs and the expression of CD-163 as a marker to evince tumor aggressiveness, in oral squamous cell carcinoma (OSCC).

SETTINGS AND DESIGN

A retrospective institutional study was approved by the institutional ethics committee, and random sampling was carried out. Cases fulfilling the inclusion criteria were subjected to S(site), T(tumor), N( node), M( metastasis), P(pathology) STNMP staging along with immunohistochemical evaluation of CD-163.

METHODS

Samples for this study included 58 archival cases of OSCC. Demographic details were recorded, and the STNMP stage ascertained, following which, each case was reevaluated histopathologically for the invasive front. Cases with sufficient stroma and demonstrating the invasive front were further subjected to immunohistochemical evaluation of CD-163 for TAMs. The density of CD-163-positive cells was assessed by three pathologists, independently, in a double-blinded evaluation using Image-J©.

STATISTICAL ANALYSIS

Descriptive data were evaluated and analyzed statistically using Spearman's/Pearson's correlation tests based on the distribution of data.

RESULTS

The density of TAMs was noted to be directly proportional to the STNMP stage. In addition, a strong positive, statistically significant correlation was noted between the density of TAMs and tumor size, nodal status and STNMP stage.

CONCLUSION

The crucial role of the tumor microenvironment must be considered when evaluating OSCC. TAMs prove to be a reliable marker for assessing tumor aggressiveness and could aid in improved prognostication of OSCC, while also being potential targets for therapy.

Tumor Microenvironment and Immunotherapy Response in Head and Neck Cancer

The tumor microenvironment (TME) encompasses cellular and non-cellular components which play an important role in tumor evolution, invasion, and metastasis. A complicated interplay between tumor cells and adjacent TME cells, such as stromal cells, immune cells, inflammatory cells, and cytokines, leads to severe immunosuppression and the proliferation of cancer cells in several solid tumors. An immunosuppressive TME has a significant impact on treatment resistance and may guide response to immunotherapy. In head and neck cancer (HNC), immunotherapeutic drugs have been incorporated in everyday clinical practice. However, despite an exceptional rate of durable responses, only a low percentage of patients respond. In this review, we will focus on the complex interactions occurring in this dynamic system, the TME, which orchestrate key events that lead to tumor progression, immune escape, and resistance. Furthermore, we will summarize current clinical trials that depict the TME as a potential therapeutic target for improved patient selection.

Water-Pipe Smoking Exposure Deregulates a Set of Genes Associated with Human Head and Neck Cancer Development and Prognosis

Water-pipe smoking (WPS) is becoming the most popular form of tobacco use among the youth, especially in the Middle East, replacing cigarettes rapidly and becoming a major risk of tobacco addiction worldwide. Smoke from WPS contains similar toxins as those present in cigarette smoke and is linked directly with different types of cancers including lung and head and neck (HN) carcinomas. However, the underlying molecular pathways and/or target genes responsible for the carcinogenic process are still unknown. In this study, human normal oral epithelial (HNOE) cells, NanoString PanCancer Pathways panel of 770 gene transcripts and quantitative real-time polymerase chain reaction (qRT-PCR) analysis were applied to discover differentially expressed genes (DEG) modulated by WPS. In silico analysis was performed to analyze the impact of these genes in HN cancer patient’s biology and outcome. We found that WPS can induce the epithelial–mesenchymal transition (EMT: hallmark of cancer progression) of HNOE cells. More significantly, our analysis of NanoString revealed 23 genes deregulated under the effect of WPS, responsible for the modulation of cell cycle, proliferation, migration/invasion, apoptosis, signal transduction, and inflammatory response. Further analysis was performed using qRT-PCR of HNOE WPS-exposed and unexposed cells supported the reliability of our NanoString data. Moreover, we demonstrate those DEG to be upregulated in cancer compared with normal tissue. Using the Kaplan–Meier analysis, we observed a significant association between WPS-deregulated genes and relapse-free survival/overall survival in HN cancer patients. Our findings imply that WPS can modulate EMT as well as a set of genes that are directly involved in human HN carcinogenesis, thereby affecting HN cancer patients’ survival.

Targeting of CD163+ Macrophages in Inflammatory and Malignant Diseases

The macrophage is a key cell in the pro- and anti-inflammatory response including that of the inflammatory microenvironment of malignant tumors. Much current drug development in chronic inflammatory diseases and cancer therefore focuses on the macrophage as a target for immunotherapy. However, this strategy is complicated by the pleiotropic phenotype of the macrophage that is highly responsive to its microenvironment. The plasticity leads to numerous types of macrophages with rather different and, to some extent, opposing functionalities, as evident by the existence of macrophages with either stimulating or down-regulating effect on inflammation and tumor growth. The phenotypes are characterized by different surface markers and the present review describes recent progress in drug-targeting of the surface marker CD163 expressed in a subpopulation of macrophages. CD163 is an abundant endocytic receptor for multiple ligands, quantitatively important being the haptoglobin-hemoglobin complex. The microenvironment of inflammation and tumorigenesis is particular rich in CD163+ macrophages. The use of antibodies for directing anti-inflammatory (e.g., glucocorticoids) or tumoricidal (e.g., doxorubicin) drugs to CD163+ macrophages in animal models of inflammation and cancer has demonstrated a high efficacy of the conjugate drugs. This macrophage-targeting approach has a low toxicity profile that may highly improve the therapeutic window of many current drugs and drug candidates.

The Immune Microenvironment in Head and Neck Squamous Cell Carcinoma: on Subsets and Subsites

PURPOSE

To understand why some patients respond to immunotherapy but many do not, a clear picture of the tumor microenvironment (TME) of head and neck squamous cell carcinoma (HNSCC) is key. Here we review the current understanding on the immune composition per HNSCC subsite, the importance of the tumor's etiology and the prognostic power of specific immune cells.

RECENT FINDINGS

Large cohort data are mostly based on deconvolution of transcriptional databases. Studies focusing on infiltrate localization often entail small cohorts, a mixture of HNSCC subsites, or focus on a single immune marker rather than the interaction between cells within the TME. Conclusions on the prognostic impact of specific immune cells in HNSCC are hampered by the use of heterogeneous or small cohorts. To move forward, the field should focus on deciphering the immune composition per HNSCC subsite, in powered cohorts and considering the molecular diversity in this disease.

Targeting tumor-associated macrophages in head and neck squamous cell carcinoma

In head and neck squamous cell carcinoma (HNSCC), tumor-associated macrophages (TAMs) are associated with a poorer prognosis. TAMs, derived from inflammatory monocyte, play a critical role in regulating tumor progression. Generally, TAMs promote tumor progression and suppress immune response via both innate and adaptive immune mechanisms. However, as the double-blade sword, TAMs retain the potential pro-inflammatory ability to inhibit tumor progression. By depleting the immunosuppressive function or evoking anti-tumor ability, therapeutic strategies targeting TAMs show promising preclinical and clinical effects. Now, macrophage-centered therapeutic approaches are entering the clinical arena. In this review, we discuss the immunosuppressive role of TAMs in the tumor microenvironment and the therapeutic approaches targeting macrophages which offer promise in improving HNSCC outcome.

Prognostic value of HLA class I expression in patients with oral squamous cell carcinoma

Human leukocyte antigen (HLA) class Ⅰ molecules play a central role in anticancer immunity, but their prognostic value in oral squamous cell carcinoma (OSCC) remains unclear. We examined HLA class I expression in 2 distinct tumor compartments, namely, the tumor center and invasive front, and evaluated the association between its expression pattern and histopathological status in 137 cases with OSCC. Human leukocyte antigen class Ⅰ expression was graded semiquantitatively as high, low, and negative. At the invasive front of the tumor, HLA class I expression was high in 72 cases (52.6%), low in 44 cases (32.1%), and negative in 21 cases (15.3%). The HLA class I expression in the tumor center was high in 48 cases (35.0%), low in 58 cases (42.4%), and negative in 31 cases (22.6%). The 5‐year overall survival and disease‐specific survival rates were good in cases with high HLA class I expression at the invasive front; however, there was no significant difference in survival based on HLA class I expression in the tumor center. In addition, high HLA class I expression was correlated with high CD8⁺ T cell density, whereas negative HLA class I expression was correlated with low CD8⁺ T cell density at the invasive front. These results suggest that it is easier for CD8⁺ T cells to recognize presented peptides in the case of high HLA class Ⅰ expression at the tumor invasive front and could be a prognostic factor for OSCC.

RACK1 promotes cancer progression by increasing the M2/M1 macrophage ratio via the NF-κB pathway in oral squamous cell carcinoma

Receptor for activated C kinase 1 (RACK1) has been shown to promote oral squamous cell carcinoma (OSCC) progression, and RACK1 expression levels have been negatively correlated with prognosis in patients with OSCC. Here, we investigated the impact of RACK1 OSCC expression on the recruitment and differentiation of tumor-associated macrophages. High RACK1 expression in OSCC cells correlated with increased M2 macrophage infiltration in tumor samples from a clinical cohort study. Moreover, the combination of RACK1 expression and the M2/M1 ratio could successfully predict prognosis in OSCC. OSCC cells with high RACK1 expression inhibited the migration of THP-1 cells, promoted M2-like macrophage polarization in vitro, and increased the proportion of M2-like macrophages in a xenograft mouse model. Moreover, both M1- and M2-like macrophage polarization-associated proteins were induced in macrophages cocultured with RACK1-silenced cell supernatant. A mechanistic study revealed that the expression and secretion of C-C motif chemokine 2 (CCL2), C-C motif chemokine 5 (CCL5), interleukin-6 (IL-6), and interleukin-1 (IL-1) are closely related to RACK1 expression. In addition, blocking nuclear factor-kappa B (NF-κB) could promote M2-like macrophage polarization. These results indicate that RACK1 and the M2/M1 ratio are predictors of a poor prognosis in OSCC. RACK1 promotes M2-like polarization by regulating NF-κB and could be used as a potential therapeutic target for antitumor immunity.

CD163+ macrophages infiltration correlates with the immunosuppressive cytokine interleukin 10 expression in tongue leukoplakia

Objective

Accumulating evidence suggests that macrophages are involved in the immunoediting of oral squamous cell carcinoma but the role of macrophages in oral carcinogenesis is unclear. We aimed to clarify the role of macrophages in oral leukoplakia, which is the most common oral potentially malignant disorder from immunotolerance viewpoint.

Materials and methods

The study included 24 patients who underwent surgical resection for tongue leukoplakia. The relationships between macrophage markers and clinicopathological factors were assessed. Conditioned medium was harvested from the CD163+ human monocytic leukaemia cell line, THP-1. The phenotypic alteration of human oral keratinocytes by the conditioned medium treatment was assessed using quantitative reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. Moreover, the clinical samples were evaluated using immunohistochemistry.

Results

Tongue leukoplakia tissues with high CD163+ macrophage infiltration were associated with significantly higher degrees of epithelial dysplasia, abnormal Ki-67 expression and cytokeratin13 loss when compared with the tissues with low CD163+ macrophage infiltration. In vitro, CD163+ THP-1 conditioned medium induced immunosuppressive molecules, especially interleukin-10 (IL-10) in human oral keratinocytes. The IL-10 expression levels showed significant positive correlations with not only the numbers of FOXP3+ regulatory T cells but also that of CD163+ macrophages.

Conclusions

In tongue leukoplakia, CD163+ macrophages infiltration correlates with immunosuppressive cytokine IL-10 expression.

The prognostic role of tumour-infiltrating lymphocytes in oral squamous cell carcinoma: A meta-analysis

It has been suggested that tumour-infiltrating lymphocytes (TILs) are associated with the progression of oral squamous cell carcinoma (OSCC). However, the prognostic value of TILs is inconclusive due to the heterogeneity of immune cells within the tumour microenvironment. In this meta-analysis, we aimed to assess the prognostic value of TILs in OSCC. The PubMed, Cochrane, Embase, Scopus and Web of Science databases were searched up to April 20, 2019, and 33 studies were ultimately included in this meta-analysis. Our pooled meta-analysis showed that high infiltration of CD8⁺ TILs, CD45RO⁺ TILs and CD57⁺ TILs favoured better overall survival (OS). However, high infiltration of CD68⁺ macrophages and CD163⁺ macrophages was associated with poor prognosis in OSCC. These findings suggest that CD8⁺ TILs, CD45RO⁺ TILs, CD57⁺ TILs, CD68⁺ macrophages and CD163⁺ macrophages might serve as novel prognostic factors and therapeutic targets in OSCC.

Prognostic Significance of Tumor-Associated Macrophage Content in Head and Neck Squamous Cell Carcinoma: A Meta-Analysis

Background: Head and neck squamous cell carcinoma (HNSCC) exists within a microenvironment rich in immune cells. Macrophages are particularly abundant in and around tumor tissue, and have been implicated in the growth, malignancy, and persistence of HNSCC (1). However, current literature reports variable degrees of association between the density of tumor-associated macrophages (TAMs) and clinicopathologic markers of disease (2, 3). These inconsistent findings may be a result of differences in approach to TAM detection. Authors have measured total TAMs in tumor tissue, while others have stained tumor samples for individual subtypes of TAMs, which include pro-inflammatory (M1-like) and immunosuppressive (M2-like). Our aim is to more clearly define the prognostic significance of the phenotypes of tumor-associated macrophages in HNSCC. Methods: We conducted a meta-analysis of the existing publications investigating the relationship between TAMs (total and M2-like subtype) and T stage, nodal involvement, vascular invasion, lymphatic invasion, and tumor differentiation (Figure 1). A total of 12 studies were included. Forest plots and risk ratios were generated to report overall effect. Results: Higher density of both total and M2-like subtype of TAMs in the tumor microenvironment is associated with advanced T stage, increased rates of nodal positivity, presence of vascular invasion, and presence of lymphatic invasion (p < 0.0001; Figures 2-9). There is no significant association between TAM density, either total or M2-like subtype, and tumor differentiation (Figures 10, 11). Conclusions: Increased density of TAMs, including those of the M2-like phenotype, correlate with poor clinicopathologic markers in HNSCC. Our findings warrant additional investigation into the subpopulations of TAMs, the mechanisms behind their recruitment and differentiation, and the associated influence of each phenotype on tumor growth and invasion. A greater understanding of TAM dynamics in HNSCC is critical for directing further research and employing TAM-targeted adjunct therapies.

Prognostic significance of CD68+ and CD163+ tumor associated macrophages in head and neck squamous cell carcinoma: A systematic review and meta-analysis

OBJECTIVE

Tumor associated macrophages (TAMs) are among the most abundant cells of the tumor microenvironment. Several studies have been performed to investigate whether TAM markers, namely CD68 and CD163, could serve as prognostic factors in patients with squamous cell carcinoma of the head and neck (SCCHN). The aim of this systematic review and meta-analysis was to synthetize the available evidence of the literature about the role of CD68+ and CD163+ TAMs as prognostic factors in SCCHN.

MATERIALS AND METHODS

This systematic review was performed according to the guidelines reported in the Cochrane Handbook and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Meta-analysis of overall survival, disease-free survival and progression-free survival was performed using the inverse of variance test. A random- or a fixed- effect model was used on the basis of the presence of heterogeneity. Risk of bias assessment and subgroup analysis were also performed.

RESULTS

High stromal expression of CD163+ TAMs correlated with both poor overall survival (HR, 2.26; 95% CI: [1.47, 3.47]; P < 0.001) and progression-free survival (HR, 2.29; 95% CI: [1.11, 4.71]; P = 0.03). Conversely, abundance of CD68+ TAMs was not associated with overall survival (HR, 1.25; 95% CI: [0.86, 1.80]; P = 0.24) and disease-free survival (HR, 2.06; 95% CI: [0.84, 5.05]; P = 0.11).

CONCLUSIONS

Findings from this study revealed that whilst IHC analysis of the generic macrophage marker CD68+ has no prognostic utility in patients with SCCHN, the M2-like marker CD163+ predicts poor prognosis. Our data suggest that assessment of CD163+ TAMs in SCCHN has potential for future clinical use. Further well-standardized studies should be performed to confirm these results.

Molecular subtyping reveals immune alterations associated with progression of bronchial premalignant lesions

Bronchial premalignant lesions (PMLs) are precursors of lung squamous cell carcinoma, but have variable outcome, and we lack tools to identify and treat PMLs at risk for progression to cancer. Here we report the identification of four molecular subtypes of PMLs with distinct differences in epithelial and immune processes based on RNA-Seq profiling of endobronchial biopsies from high-risk smokers. The Proliferative subtype is enriched with bronchial dysplasia and exhibits up-regulation of metabolic and cell cycle pathways. A Proliferative subtype-associated gene signature identifies subjects with Proliferative PMLs from normal-appearing uninvolved large airway brushings with high specificity. In progressive/persistent Proliferative lesions expression of interferon signaling and antigen processing/presentation pathways decrease and immunofluorescence indicates a depletion of innate and adaptive immune cells compared with regressive lesions. Molecular biomarkers measured in PMLs or the uninvolved airway can enhance histopathological grading and suggest immunoprevention strategies for intercepting the progression of PMLs to lung cancer.

Tissue-infiltrating immune cells as prognostic markers in oral squamous cell carcinoma: a systematic review and meta-analysis

Background

Various immune cells have been suggested as prognostic markers for cancer patients. In this article, we present a systematic review and meta-analysis of studies assessing the prognostic value of tissue-infiltrating immune cells in oral cancer and discuss the reporting quality of these studies.

Methods

We performed a systematic literature search and included studies using immunohistochemistry and survival analysis to assess the prognostic value of tumour-infiltrating T cells, B cells, macrophages, dendritic cells, mast cells and natural killer cells in oral cancer. We performed meta-analysis of studies providing necessary statistical data and investigated the studies’ adherence to the REporting recommendations for tumour MARKer prognostic studies (REMARK) guidelines.

Results

Of the 1960 articles identified, 33 were eligible for this systematic review and 8 were included in the meta-analysis. CD163+ M2 macrophages and CD57+ natural killer cells were the most promising predictors of survival in oral cancer patients. Many studies lacked important information on their design and conduct.

Conclusion

Deficiencies in the reporting of study design and conduct make it difficult to draw reliable conclusions about the suggested markers. The prognostic value of CD163+ M2 macrophages and CD57+ natural killer cells should be validated in large, standardised studies.

Composition and Clinical Impact of the Immunologic Tumor Microenvironment in Oral Squamous Cell Carcinoma

Immunotherapy shows promising results and revolutionizes treatment of oral squamous cell carcinoma (OSCC). The immunologic microenvironment might have prognostic/predictive implications. Morphologic immunologic parameters (inflammatory infiltrate, stromal content, and budding activity [BA] [potentially indicating epithelial-mesenchymal transition]) were evaluated in 66 human primary therapy-naive OSCCs. Intraepithelial/stromal tumor-infiltrating lymphocytes (TILs; CD3⁺/CD4⁺/CD8⁺/CD4⁺FOXP3⁺/IL-17A⁺) were quantified, and ratios were calculated. HLA class I in tumor cells was evaluated immunohistochemically. mRNA in situ hybridization to detect IFN-γ was performed. Analysis was performed within invasive front (IF) and tumor center (TCe). Decreased HLA expression was associated with low TIL density, pronounced stromal content, and high BA; IFN-γ in TILs was correlated with high-density TILs; and IFN-γ in tumor cells was correlated with absence of BA (p < 0.05). Heterogeneity of parameters (TCe/IF) was rare. Low density of stromal CD4⁺FOXP3⁺ TILs within TCe and IF was identified as an independent prognostic factor for poor overall, disease-specific, and disease-free survival (p ≤ 0.011). Refining prognostication in OSCC with high-density CD4⁺FOXP3⁺ infiltrate within TCe and/or IF, high FOXP3:CD4 ratio was significantly correlated with favorable outcome in this subgroup. Furthermore, high-stromal CD8:CD4 ratio was found to be an independent favorable prognostic factor. In summary, immunologic parameters were closely intertwined. Morphologic correlates of epithelial-mesenchymal transition were associated with downregulation of HLA and decreased inflammation. Heterogeneity was infrequent. Low-density stromal CD4⁺FOXP3⁺ infiltrate within TCe and IF was an independent poor prognostic factor. Stratification of cases with high-density CD4⁺FOXP3⁺ TILs by FOXP3:CD4 ratio enables refinement of prognostication of this subgroup. CD8:CD4 ratio was identified as an independent prognostic factor.

Evaluation of the mRNA expression levels of integrins α3, α5, β1 and β6 as tumor biomarkers of oral squamous cell carcinoma

Integrin signaling may modulate several different functions involved in cell migration, invasion, proliferation and motility, and is a potential candidate biomarker for oral cancer. In the present study, a total of four integrin genes were evaluated as potential biomarkers of oral squamous cell carcinoma (OSCC). Gene expression was determined using the reverse transcription-quantitative polymerase chain reaction in 55 OSCC and 55 matched normal oral tissues. The performance of individual and combined biomarkers was analyzed by receiver operating characteristic (ROC) analysis based on the relative mRNA expression (OSCC vs. matched oral tissue from the tumor-free margin), which was calculated using the ΔΔCq value (ΔCq of OSCC-ΔCq of oral tissue from the tumor-free margin of the same patient). In the individual ROC analysis, the areas under the ROC curve (AUCs) of relative mRNA expression (ΔΔCq) of integrin subunit α3 (ITGA3), integrin subunit α5 (ITGA5), integrin subunit β1 (ITGB1) and integrin subunit β6 (ITGB6) in all tumor locations were 0.724, 0.698, 0.640 and 0.657, respectively. For locations 2 (tongue/mouth part) and 3 (edentulous ridge), their individual AUC values were 0.840, 0.765, 0.725 and 0.763, respectively. In the cumulative ROC analysis, ITGA3, ITGA5 and ITGB1 genes exhibited the highest combined AUC values (0.809 and 0.871 for all locations and locations 2 and 3 combined, respectively) compared with other biomarker combinations. In conclusion, the results of the present study identified that higher mRNA expressions of ITGA3, ITGA5, ITGB1 and ITGB6 genes are suitable for OSCC diagnosis biomarkers. Cumulative ROC analysis indicated an improved overall performance compared with the best individual integrin biomarker of OSCC.

The prognostic significance of carcinoma-associated fibroblasts and tumor-associated macrophages in nasopharyngeal carcinoma

Purpose

Tumor stroma cells play an important role in the carcinogenesis and progression of cancer. The aim of the present investigation was to explore the predictive role of carcinoma-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs) in nasopharyngeal carcinoma (NPC).

Patients and methods

The densities of CAFs and TAMs were measured by immunohistochemistry staining for α-smooth muscle actin (α-SMA), CD68, and CD163 in two sets of tissue microarrays including 260 pretreatment NPC tissues, that is, a training test comprising of 152 patients and a validation set comprising of 108 patients. Chi-square tests were performed for comparisons among the groups. Survival rates were estimated by using the Kaplan–Meier method and compared with log-rank tests. Cox proportional hazards models were used to identify significant independent variables.

Results

Patients older than 50 years showed a lower expression of CD68, and there was a positive relationship between the densities of CAFs and CD163⁺ TAMs (p=0.001). In the multivariate analysis of the training test, both α-SMA and CD163 were independent prognostic factors for overall survival and progression-free survival (all p<0.05). Based on the expression levels of α-SMA and CD163, patients were categorized into three groups: high-risk, intermediate-risk, and low-risk groups according to both high, either high, and both low, respectively. Survival analysis and Cox multivariate analysis showed that the risk groups based on α-SMA and CD163 expression were independent predictors for the survival of patients with NPC in the training test, which was also confirmed by the validation test.

Conclusion

A patient’s risk group based on the level of CD163⁺ TAMs and CAFs was an independent predictor of survival, which may facilitate patient counseling and individualized treatment.

Macrophages and prognosis of oral squamous cell carcinoma: A systematic review

Oral Squamous Cell Carcinoma (OSCC) presents a tumor microenvironment rich in inflammatory cells. Depending on the stimulus, macrophages can polarize in M1 or M2 profile, where M1 acts as proinflammatory and antitumor, and M2 is anti-inflammatory and shows protumor activity. Several studies have shown that macrophages are important to the prognosis of patients with different types of cancer. Our aim was to conduct a systematic review to evaluate the role of macrophages in the prognosis of OSCC patients. A search in the Pubmed, Scopus, and ISI Web of Knowledge database was performed, and it was included only studies that evaluated the importance of macrophages in the prognosis of OSCC patients. From initial 286 articles, 14 fully attended the inclusion criteria. In the majority of the articles, it was evaluated only CD68, a panmacrophage marker, or CD163, a M2 marker. Only one article evaluated the M1 marker, CD11c. Besides, 5 articles analyzed the presence of macrophages in different areas of the tumor. Higher concentrations of CD68 and CD163 were associated with worse survival. In conclusion, macrophages are important to OSCC patients' prognosis; however, it is necessary to address in which tumor region the presence of polarized macrophage is more important to the outcome.

Small-molecule studies identify CDK8 as a regulator of IL-10 in myeloid cells

Enhancing production of the anti-inflammatory cytokine interleukin-10 (IL-10) is a promising strategy to suppress pathogenic inflammation. To identify new mechanisms regulating IL-10 production, we conducted a phenotypic screen for small molecules that enhance IL-10 secretion from activated dendritic cells. Mechanism-of-action studies using a prioritized hit from the screen, BRD6989, identified the Mediator-associated kinase CDK8, and its paralog CDK19, as negative regulators of IL-10 production during innate immune activation. The ability of BRD6989 to upregulate IL-10 is recapitulated by multiple, structurally differentiated CDK8 and CDK19 inhibitors and requires an intact cyclin C-CDK8 complex. Using a highly parallel pathway reporter assay, we identified a role for enhanced AP-1 activity in IL-10 potentiation following CDK8 and CDK19 inhibition, an effect associated with reduced phosphorylation of a negative regulatory site on c-Jun. These findings identify a function for CDK8 and CDK19 in regulating innate immune activation and suggest that these kinases may warrant consideration as therapeutic targets for inflammatory disorders.

Role of tumour-associated macrophages in oral squamous cells carcinoma progression: an update on current knowledge

BACKGROUND

Oral squamous cell carcinoma (OSCC) accounts over 90% of malignant neoplasms of the oral cavity. This pathological entity is associated to a high mortality rate that has remained unchanged over the past decades. Tumour-associated macrophages (TAMs) are believed to have potential involvement in OSCC progression. However, the molecular networks involved in communication between stroma and cancer cells have not yet been fully elucidated.

MAIN BODY

The role of M2 polarized cells in oral carcinogenesis is supported by a correlation between TAMs accumulation into OSCC stroma and poor clinical outcome. Signalling pathways such as the NF-κB and cytokines released in the tumour microenvironment promote a bidirectional cross-talk between M2 and OSCC cells. These interactions consequently result in an increased proliferation of malignant cells and enhances aggressiveness, thus reducing patients' survival time.

CONCLUSIONS

Here, we present a comprehensive review of the role of interleukin (IL)-1, IL-4, IL-6, IL-8, IL-10 and the receptor tyrosine kinase Axl in macrophage polarization to an M2 phenotype and OSCC progression. Understanding the molecular basis of oral carcinogenesis and metastatic spread of OSCC would promote the development of targeted treatment contributing to a more favourable prognosis.

New Mechanisms of Tumor-Associated Macrophages on Promoting Tumor Progression: Recent Research Advances and Potential Targets for Tumor Immunotherapy

The majority of basic and clinical studies have shown a protumor function of tumor-associated macrophages (TAMs), which represent a large proportion of matrix cells. TAMs promote tumorigenesis, and their number is related to the malignancy degree and poor prognosis of many kinds of tumors. Macrophage plasticity makes it possible to change the tumor microenvironment and remodel antitumor immunity during cancer immunotherapy. Increasing numbers of studies have revealed the effects of TAMs on the tumor microenvironment, for example, via promotion of tumor growth and tumorigenesis and through an increase in the number of cancer stem cells or via facilitation of angiogenesis, lymphangiogenesis, and metastasis. Investigators also proposed tumor-immunological treatments targeting TAMs by inhibiting TAM recruitment and differentiation, by regulating TAM polarization, and by blocking factors and pathways associated with the protumor function of TAMs. This comprehensive review presents recent research on TAMs in relation to prediction of poor outcomes, remodeling of the tumor immune microenvironment, and immunological targeted therapies.

Strong inflammatory response and Th1-polarization profile in children with acute lymphoblastic leukemia without apparent infection

Children with acute lymphoblastic leukemia (ALL) often present fever. Febrile states are usually associated with infectious processes that generate an inflammatory response involving various molecules, including cytokines. However, an inflammatory response may also occur in the absence of infection. We hypothesized that the levels of inflammatory cytokines are increased in children with ALL without apparent infection. The serum levels of 13 cytokines in 99 patients with ALL and 48 non-oncological patients without apparent infection were measured using multiplex analyte profiling technology (Luminex®). The concentration of circulating pro-inflammatory cytokines associated with fever was similar between patients with ALL and fever at diagnosis and those without fever. The levels of tumor necrosis factor α, interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1) and IL-10 were higher in patients with ALL vs. the control group (P<0.05). Moreover, the levels of the T helper 1 (interferon‑γ and IL-12) cytokines were higher in patients with ALL vs. the control group. Transforming growth factor β was lower in patients with ALL vs. the control group (P<0.05). The levels of IL-1β, IL-2, IL-4, IL-13, and IL-17 were similar in the two groups. Our results indicate that the circulating levels of seven of the important studied cytokines are elevated in patients with newly diagnosed ALL without apparent infection, reflecting a strong and deregulated inflammatory state in this disease, with a Th1-polarization profile.

Positive expression of NANOG, mutant p53, and CD44 is directly associated with clinicopathological features and poor prognosis of oral squamous cell carcinoma

Background

In order to predict long-term prognosis and define individual treatment modalities for patients with oral squamous cell carcinoma (OSCC), more reliable tumor biomarkers are needed during the pretreatment workup period. The present study aimed to identify more reliable immunohistochemical tumor prognostic markers in the pretreatment biopsy specimens of patients with OSCC.

Methods

We selected 57 patients who were diagnosed with primary OSCC through histopathological analysis. Pretreatment biopsy specimens were immunohistochemically analyzed for the transcription factor NANOG, cancer stem cell marker CD44, and mutant tumor protein 53 (mutant p53). The immunostaining patterns were assessed for their association with the clinicopathological features of OSCC and overall survival rates.

Results

Late tumor stage, positive neck node metastasis, and high-grade differentiation were associated with significantly poorer survival rates. Enhanced expression of NANOG and mutant p53 positivity were significantly associated with clinically late-stage tumors, positive neck node metastasis, histologically high-grade tumors, and poor overall survival rates. OSCCs with strong co-detection of NANOG and mutant p53 were linked to significantly lower survival rates than those with both weak NANOG expression and p53 negativity. Increased expression of CD44 had a limited correlation with unfavorable clinicopathological features.

Conclusion

High expression of NANOG and positive expression of mutant p53 in the pretreatment biopsy specimens of patients with OSCC were associated with poor survival rates and unfavorable clinicopathological features. These results demonstrate that NANOG, mutant p53, and CD44 could be used as immunohistochemical markers in the pretreatment specimens of OSCC. In particular, analysis for co-expression of NANOG and mutant p53 should be made highly available as a tool for prognosis and selecting individual treatment modalities.

Tumor-associated macrophages in oral premalignant lesions coexpress CD163 and STAT1 in a Th1-dominated microenvironment

BACKGROUND

Tumor-associated macrophages (TAMs) are implicated in the growth, invasion and metastasis of various solid tumors. However, the phenotype of TAMs in premalignant lesions of solid tumors has not been clarified. In the present study, we identify the phenotype of TAMs in leukoplakia, an oral premalignant lesion, by immunohistochemical analysis and investigate the involvement of infiltrated T cells that participate in the polarization of TAMs.

METHODS

The subjects included 30 patients with oral leukoplakia and 10 individuals with normal mucosa. Hematoxylin and eosin slides were examined for the histological grades, and immunohistochemical analysis was carried out using antibodies against CD68 (pan-MΦ), CD80 (M1 MΦ), CD163 (M2 MΦ), CD4 (helper T cells: Th), CD8 (cytotoxic T cells), CXCR3, CCR5 (Th1), CCR4 (Th2), signal transducer and activator of transcription (STAT1), phosphorylated STAT1 (pSTAT1) and chemokine CXCL9. The differences in the numbers of positively stained cells among the different histological grades were tested for statistical significance using the Kruskal-Wallis test. Correlations between different types of immune cells were determined using Spearman's rank analysis.

RESULTS

An increase in the rate of CD163(+) TAM infiltration was observed in mild and moderate epithelial dysplasia, which positively correlated with the rate of intraepithelial CD4(+) Th cell infiltration. Although CCR4(+) cells rarely infiltrated, CXCR3(+) and CCR5(+) cells were observed in these lesions. Cells positive for STAT1 and chemokine CXCL9, interferon- (IFN)-induced gene products, and pSTAT1 were also observed in the same lesions. Double immunofluorescence staining demonstrated that the cells that were positive for CD163 were also positive for STAT1.

CONCLUSIONS

CD163(+) TAMs in oral premalignant lesions coexpress CD163 and STAT1, suggesting that the TAMs in oral premalignant lesions possess an M1 phenotype in a Th1-dominated micromilieu.