Identification of mannose receptor and CD163 as novel biomarkers for colorectal cancer

Chondroitin Sulphate: An emerging therapeutic multidimensional proteoglycan in colon cancer

Chondroitin sulfate (CS) is a sulfated glycosaminoglycan (GAG) that has captured massive attention in the field of drug delivery. As the colon is considered the preferred site for local and systemic delivery of bioactive agents for the treatment of various diseases, colon-targeted drug delivery rose to the surface of research. Amid several tactics to attain colon-targeted drug release, the exploitation of polymers degraded by colonic bacteria holds great promise. Chondroitin sulfate as a biodegradable, biocompatible mucopolysaccharide is known for its anti-inflammatory, anti-osteoarthritis, anti-atherosclerotic, anti-oxidant, and anti-coagulant effects. Besides these therapeutic functions, CS thrived to play a major role in nanocarriers as a matrix material, coat, and targeting ligand. This review focuses on the role of CS in nanocarriers as a matrix material or as a targeting moiety for colon cancer therapy, relating the present applications to future perspectives.

High serum mannose in colorectal cancer: a novel biomarker of lymph node metastasis and poor prognosis

Background

Lymph node status is an important prognostic indicator and it significantly influences treatment decisions for colorectal cancer (CRC). The objective of this study was to evaluate the ability of serum monosaccharides in predicting lymph node metastasis (LNM) and prognosis.

Methods

High performance anion exchange chromatography coupled with pulsed amperometric detector (HPAEC-PAD) was used to quantify serum monosaccharides from 252 CRC patients. Receiver operating characteristic (ROC) curves were used to evaluate predictive performance of parameters. Predictors of LNM were evaluated by univariate and multivariate analyses. The prognostic role of the factors was evaluated by survival analysis.

Results

The levels of serum mannose (Man) and galactose (Gal) were significantly increased in patients with LNM (p <0.0001, p =0.0017, respectively). The area under the curves (AUCs) of Man was 0.8140, which was higher than carcinoembryonic antigen (CEA) (AUC =0.6523). Univariate and multivariate analyses demonstrated histologic grade (G3) (odds ratio [OR] =2.60, p =0.043), histologic grade (mucin-producing subtype) (odds ratio [OR] =3.38, p =0.032), lymphovascular invasion (LVI) (OR =2.42, p <0.01), CEA (>5ng/ml) (OR =1.85, p =0.042) and high Man (OR =2.65, p =0.006) to be independent risk factors of LNM. The survival analysis showed that the high serum Man was independent risk factor for poor prognosis in CRC patients (HR=1.75, p =0.004).

Conclusions

The Man is superior to CEA in prediction of LNM for CRC patients. Man is expected to be a predictor for LNM in CRC. High serum Man is associated with poor prognosis of CRC patients.

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.

Proteomic Discovery of Plasma Protein Biomarkers and Development of Models Predicting Prognosis of High-Grade Serous Ovarian Carcinoma

Ovarian cancer is one of the most lethal female cancers. For accurate prognosis prediction, this study aimed to investigate novel, blood-based prognostic biomarkers for high-grade serous ovarian carcinoma (HGSOC) using mass spectrometry-based proteomics methods. We conducted label-free liquid chromatography-tandem mass spectrometry using frozen plasma samples obtained from patients with newly diagnosed HGSOC (n = 20). Based on progression-free survival (PFS), the samples were divided into two groups: good (PFS ≥18 months) and poor prognosis groups (PFS <18 months). Proteomic profiles were compared between the two groups. Referring to proteomics data that we previously obtained using frozen cancer tissues from chemotherapy-naïve patients with HGSOC, overlapping protein biomarkers were selected as candidate biomarkers. Biomarkers were validated using an independent set of HGSOC plasma samples (n = 202) via enzyme-linked immunosorbent assay (ELISA). To construct models predicting the 18-month PFS rate, we performed stepwise selection based on the area under the receiver operating characteristic curve (AUC) with 5-fold cross-validation. Analysis of differentially expressed proteins in plasma samples revealed that 35 and 61 proteins were upregulated in the good and poor prognosis groups, respectively. Through hierarchical clustering and bioinformatic analyses, GSN, VCAN, SND1, SIGLEC14, CD163, and PRMT1 were selected as candidate biomarkers and were subjected to ELISA. In multivariate analysis, plasma GSN was identified as an independent poor prognostic biomarker for PFS (adjusted hazard ratio, 1.556; 95% confidence interval, 1.073-2.256; p = 0.020). By combining clinical factors and ELISA results, we constructed several models to predict the 18-month PFS rate. A model consisting of four predictors (FIGO stage, residual tumor after surgery, and plasma levels of GSN and VCAN) showed the best predictive performance (mean validated AUC, 0.779). The newly developed model was converted to a nomogram for clinical use. Our study results provided insights into protein biomarkers, which might offer clues for developing therapeutic targets.

Endotoxemia and Gastrointestinal Cancers: Insight into the Mechanisms Underlying a Dangerous Relationship

Lipopolysaccharide (LPS), also known as endotoxin, is a component of the membrane of gram-negative bacteria and a well-recognized marker of sepsis. In case of disruption of the intestinal barrier, as occurs with unhealthy diets, alcohol consumption, or during chronic diseases, the microbiota residing in the gastrointestinal tract becomes a crucial factor in amplifying the systemic inflammatory response. Indeed, the translocation of LPS into the bloodstream and its interaction with toll-like receptors (TLRs) triggers molecular pathways involved in cytokine release and immune dysregulation. This is a critical step in the exacerbation of many diseases, including metabolic disorders and cancer. Indeed, the role of LPS in cancer development is widely recognized, and examples include gastric tumor related to Helicobacter pylori infection and hepatocellular carcinoma, both of which are preceded by a prolonged inflammatory injury; in addition, the risk of recurrence and development of metastasis appears to be associated with endotoxemia. Here, we review the mechanisms that link the promotion and progression of tumorigenesis with endotoxemia, and the possible therapeutic interventions that can be deployed to counteract these events.

Impact of thymidine phosphorylase and CD163 expression on prognosis in stage II colorectal cancer

BACKGROUND

Tumor-associated macrophages (TAM) are known to facilitate colorectal cancer (CRC) growth. High macrophage infiltration in thymidine phosphorylase (TYMP) expressing CRC may correspond to poor prognosis. The prognostic impact of the expression CD163, a receptor associated with TAM, and TYMP in stroma, respectively, tumor tissue is not yet established. The aim of this study was to identify the potential associations between TYMP and CD163 expression levels and relapse-free survival (RFS) of patients with stage II CRC, and if microdissection is of importance.

METHODS

Stage II CRC patients, radically resected with relapse (n = 104), were matched to patients with a 5-year relapse-free follow-up (n = 206). Gene expression of TYMP and CD163 was analyzed in snap-frozen tumor tissues and in microdissected formalin-fixed tumor tissues separated into tumor epithelium and stroma.

RESULTS

TYMP expression was high in poorly differentiated tumors, right-sided CRC, and tumors with high microsatellite instability CD163-expressing macrophages near tumor epithelial cells had high expression in poorly differentiated and T4 tumors. High TYMP expression in tumor epithelial cells was in the multivariate analyses associated with shorter relapse-free survival (hazard ratio 1.66; 95% confidence interval: 1.09-2.56; p < 0.05).

CONCLUSIONS

TYMP expression in tumor epithelial cells was associated with RFS and emphasizes the need for tissue microdissection. Additional studies are needed to establish whether TYMP and CD163 could add clinically relevant information to identify high-risk stage II patients that could benefit from adjuvant chemotherapy.

Glycopolymer Engineering of the Cell Surface Changes the Single Cell Migratory Direction and Inhibits the Collective Migration of Cancer Cells

Cancer cell migration is one of the most important processes in cancer metastasis. Metastasis is the major cause of death from most solid tumors; therefore, suppressing cancer cell migration is an important means of reducing cancer mortality. Cell surface engineering can alter the interactions between cells and their microenvironment, thereby offering an effective method of controlling the migration of the cells. This paper reports that modification of the mouse melanoma (B16) cancer cell surface with glycopolymers affects the migration of the cells. Changes in cell morphology, migratory trajectories, and velocity were investigated by time-lapse cell tracking. The data showed that the migration direction is altered and diffusion slows down for modified B16 cells compared to unmodified B16 cells. When modified and unmodified B16 cells were mixed, wound-healing experiments and particle image velocimetry (PIV) analysis showed that the collective migration of unmodified B16 cells was suppressed because of vortexlike motions induced by the modified cells. The work demonstrates the important role of surface properties/modification in cancer cell migration, thereby providing new insights relative to the treatment of cancer metastasis.

Construction of a DLBCL Prognostic Signature Based on Tumor Microenvironment

BACKGROUNDS

Diffuse large B-cell lymphoma (DLBCL) is a common curable non-Hodgkin's lymphoma. Patients with this disease can be cured after the R-CHOP immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). Nonetheless, most cured patients will relapse again and have dismal prognosis. In this study, we aim to identify a potential biomarker by analyzing gene expression data, and to predict patient's survival rate by constructing a risk model.

METHODS

Firstly, mRNA chip data (GSE87371) and clinical data of DLBCL patients were obtained from Gene Expression Omnibus (GEO). Samples were scored with estimate package. The obtained stromal score (P < 0.05) and ESTIMATE score (P < 0.05) were significantly correlated with the prognosis. Differentially expressed genes (DEGs) screened through the above two scoring methods were intersected and 279 DEGs were obtained. Next, five feature genes (CD163, CLEC4A, COL15A1, GABRB2, IFIT3) were identified by univariate Cox, LASSO and multivariate Cox regression analyses to establish a risk evaluation model. Thereafter, the 5-gene risk model was validated on a validation set. ROC and survival analyses were performed to assess the performance of the model.

RESULTS

Further analysis showed that the risk model was capable of independently determining the prognosis of patients, and a nomogram was sequentially established.

CONCLUSIONS

Authors screened DEGs related to ESTIMATE and stromal scores from GEO database, and established a 5-gene prognostic signature through Cox regression analysis and LASSO analysis. The risk model and nomogram will help individuals accurately predict the prognosis of DLBCL patients.

The Prognostic Value of CD206 in Solid Malignancies: A Systematic Review and Meta-Analysis

Simple Summary

The role of innate immune cells in the tumor microenvironment (TME), more specifically the presence of the tumor associated macrophages (TAMs), is becoming more important in the prognosis and treatment of patients diagnosed with malignancies. The aim of this systematic review and meta-analysis was to assess the potential prognostic value of CD206-expressing TAMs, a subclass of macrophages, which were previously proposed to negatively impact the patient’s prognosis. We identified 27 manuscripts describing the role of CD206 in patient prognosis for 14 different tumor types. Despite a large heterogeneity in the results, we identified a significantly worse overall and disease-free survival for patients with increased CD206-expressing TAMs in the TME. The use of CD206-expressing TAMs could therefore be used as a prognostic marker in patients diagnosed with solid malignancies.

Abstract

An increased presence of CD206-expressing tumor associated macrophages in solid cancers was proposed to be associated with worse outcomes in multiple types of malignancies, but contradictory results are published. We performed a reproducible systematic review and meta-analysis to provide increased evidence to confirm or reject this hypothesis following the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The Embase, Web of Science, and MEDLINE-databases were systematically searched for eligible manuscripts. A total of 27 papers studying the prognostic impact of CD206 in 14 different tumor types were identified. Meta-analyses showed a significant impact on the overall survival (OS) and disease-free survival (DFS). While no significant differences were revealed in progression-free survival (PFS) and disease-specific survival (DSS), a shift towards negative survival was correlated with increased CD206-expresion. As a result of the different tumor types, large heterogeneity was present between the different tumor types. Subgroup analysis of hepatocellular carcinoma and gastric cancers revealed no heterogeneity, associated with a significant negative impact on OS in both groups. The current systematic review displays the increased presence CD206-expressing macrophages as a significant negative prognostic biomarker for both OS and DFS in patients diagnosed with solid cancers. Because a heterogenous group of tumor types was included in the meta-analysis, the results cannot be generalized. These results can, however, be used to further lead follow-up research to validate the specific prognostic value of CD206 in individual tumor types and therapeutic approaches.

Role of tumor-associated macrophages at the invasive front in human colorectal cancer progression

Macrophages are an essential component of antitumor activity; however, the role of tumor‐associated macrophages (TAMs) in colorectal cancer (CRC) remains controversial. Here, we elucidated the role of TAMs in CRC progression, especially at the early stage. We assessed the TAM number, phenotype, and distribution in 53 patients with colorectal neoplasia, including intramucosal neoplasia, submucosal invasive colorectal cancer (SM‐CRC), and advanced cancer, using double immunofluorescence for CD68 and CD163. Next, we focused on the invasive front in SM‐CRC and association between TAMs and clinicopathological features including lymph node metastasis, which were evaluated in 87 SM‐CRC clinical specimens. The number of M2 macrophages increased with tumor progression and dynamic changes were observed with respect to the number and phenotype of TAMs at the invasive front, especially at the stage of submucosal invasion. A high M2 macrophage count at the invasive front was correlated with lymphovascular invasion, low histological differentiation, and lymph node metastasis; a low M1 macrophage count at the invasive front was correlated with lymph node metastasis. Furthermore, receiver operating characteristic curve analysis revealed that the M2/M1 ratio was a better predictor of the risk of lymph node metastasis than the pan‐, M1, or M2 macrophage counts at the invasive front. These results suggested that TAMs at the invasive front might play a role in CRC progression, especially at the early stages. Therefore, evaluating the TAM phenotype, number, and distribution may be a potential predictor of metastasis, including lymph node metastasis, and TAMs may be a potential CRC therapeutic target.

A study of the correlation between M2 macrophages and lymph node metastasis of colorectal carcinoma

Background

Lymph node metastasis is a major prognostic sign of colorectal carcinoma and an important indicator for individualized treatment. M2 macrophages play a key role in carcinogenesis and tumor development by enhancing invasiveness and promoting lymph node metastasis. The purpose of this study was to investigate the effect of CD163-positive M2 macrophages on lymph node metastasis in colorectal carcinoma.

Methods

Postoperative lymph node tissues were obtained from 120 patients with colorectal carcinoma who underwent radical surgery in the First Affiliated Hospital of Jinzhou Medical University between December 2019 and May 2020. We detected the expression of the CD163 protein in lymph nodes using immunohistochemistry. Furthermore, the relationships between M2 macrophages identified by expression of CD163 and lymph node metastasis were analyzed using the independent sample t-test and Chi-square test.

Results

M2 macrophages were increased in metastatic lymph nodes and non-metastatic lymph nodes adjacent to the cancer. The M2 macrophage count was higher in patients with macro-metastases than in patients with micro-metastases.

Conclusions

The presence of M2 macrophages represents an important indicator for lymph node metastasis in colorectal carcinoma and may be a potential marker for its prediction. Thus, M2 macrophage localization might offer a new target for the comprehensive treatment of colorectal carcinoma.

Immunosuppressive Phenotype of Esophagus Tumors Stroma

Background

Tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) contribute significantly to the development of immunosuppressive properties of a tumor. In this study, we performed immunohistochemical analysis of immune cells of esophageal tumors stroma.

Methods

Paraffin-embedded tissue specimens from 48 esophageal squamous cell carcinoma (ESCC) patients were retrospectively collected for immunohistochemical analysis of stromal cells. For staining of macrophages, CD68, CD163, CD206, PU.1, and iNOS were used. For T cell detection, CD8, CD3, and FOXP3 were used. Also, we performed staining for PD-L1 that can be expressed on TAMs and tumor cells. Clinicopathological and survival data were collected and analyzed using the χ² and Fisher exact tests, Kaplan–Meier curves, and the log-rank test. The correlation analysis was performed with Spearman's rank correlation coefficient.

Results

We found that FOXP3 expression was associated with age (p = 0.042) and iNOS expression was associated with the disease stage (p = 0.044). In addition, FOXP3 and CD163 appeared to be markers of good prognosis (HR = 0.4420, p = 0.0325, and HR = 0.4447, p = 0.0456, respectively). Significant association between PU.1+ and CD68+ macrophages (r = 0.833; p ≤ 0.001) and between PU.1+ and CD163+ macrophages (r = 0.500; p ≤ 0.001) was established; positive association between PU.1 and CD206 expression was also observed (r = 0.250; p = 0.043).

Conclusions

Large amounts of CD163+ macrophages and FOXP3+ Т cells appear to be markers of good prognosis of ESCC. The number of PU.1+ macrophages strongly correlates with the number of CD68+ macrophages; therefore, usage of PU.1 as a potential macrophage marker can be recommended for esophageal tumors.

CD163 as a Biomarker in Colorectal Cancer: The Expression on Circulating Monocytes and Tumor-Associated Macrophages, and the Soluble Form in the Blood

The macrophage-associated molecule CD163 has been reported as a prognostic biomarker in different cancer types, but its role in colorectal cancer (CRC) is unclear. We studied CD163 in the tumor microenvironment and circulation of patients with CRC in relation to clinicopathological parameters. An enzyme-linked immunosorbent assay (ELISA) was used to measure the serum sCD163 levels and multiparameter flow cytometry was used to study the peripheral blood monocytes and their CD163 expression in CRC patients (N = 78) and healthy donors (N = 50). The distribution of tumor-associated macrophages (TAMs) was studied in primary colorectal tumors with multiplex immunofluorescence. We showed that CRC patients with above-median sCD163 level had a shorter overall survival (OS, p = 0.035) as well as disease-free survival (DFS, p = 0.005). The above-median sCD163 remained significantly associated with a shorter DFS in the multivariate analysis (p = 0.049). Moreover, a shorter OS was observed in CRC patients with an above-median total monocyte percentage (p = 0.007). The number and phenotype of the stromal and intraepithelial TAMs in colorectal tumors were not associated with clinical outcome. In conclusion, sCD163 and monocytes in the circulation may be potential prognostic biomarkers in CRC patients, whereas TAMs in the tumor showed no association with clinical outcome. Thus, our results emphasize the importance of the innate systemic immune response in CRC disease progression.

Mannose shows antitumour properties against lung cancer via inhibiting proliferation, promoting cisplatin‑mediated apoptosis and reducing metastasis

It has been reported that mannose exerts antitumour effects against certain types of cancer. The present study was designed to evaluate whether mannose exerted potential anticancer effects on A549 and H1299 non-small cell lung cancer (NSCLC) cells in vitro, which has not been reported previously. A Cell Counting Kit-8 cell viability assay was used to assess the antiproliferative effects of mannose on NSCLC cells. Flow cytometry-based methods were used to evaluate the effects of mannose on the cell cycle distribution and cisplatin-mediated apoptosis of NSCLC cells. Transwell migration and invasion assays were conducted to examine whether mannose could inhibit the invasive abilities of NSCLC cells. The effects of mannose on the PI3K/AKT and ERK signalling pathways were explored through western blot analysis assessing the expression of phosphorylated (p)-AKT and p-ERK1/2. It was found that mannose showed potential anticancer effects against NSCLC cells in vitro by inhibiting proliferation, inducing G0/G1 cell cycle arrest, promoting cisplatin-induced apoptosis and decreasing the invasive abilities. These data indicate the potential anticancer properties of mannose and suggest the application of mannose-based therapies to treat NSCLC.

Mannose Suppresses the Proliferation and Metastasis of Lung Cancer by Targeting the ERK/GSK-3β/β-Catenin/SNAIL Axis

INTRODUCTION

It has been found that mannose exerts antitumoural properties in vitro and in animal models. Whether mannose has potential anti-proliferative and anti-metastatic properties against non-small-cell lung cancer (NSCLC) is still unclear.

METHODS

Here, we performed ex vivo experiments and established a nude mouse model to evaluate the anticancer effects of mannose on NSCLC cells and its effects on the ERK/GSK-3β/β-catenin/SNAIL axis. A CCK-8 assay was conducted to evaluate the effects of mannose on lung cancer cells (A549 and HCC827) and normal lung cells (HPAEpiC). Transwells were used to examine the motility of cancer cells. qRT-PCR was used to evaluate the effects of mannose on the mRNA expression of β-catenin. Western blotting was conducted to explore the effects of mannose on the ERK/GSK-3β/β-catenin/SNAIL axis and nuclear accumulation of β-catenin. An animal model was established to evaluate the antitumoural effect of mannose on hepatic metastasis in vivo.

RESULTS

In this study, we found that mannose inhibited the proliferation of A549 and HCC827 cells in vitro both time- and dose-dependently. However, it exerted only a slight influence on the viability of normal lung cells in vitro. Moreover, mannose also inhibited the migrating and invading capacity of NSCLC cells in vitro. Using Western blotting, we observed that mannose reduced SNAIL and β-catenin expression and ERK activation and promoted phospho-GSK-3β expression. The ERK agonist LM22B-10 promoted the metastatic ability of NSCLC cells and increased SNAIL and β-catenin expression in cancer cells, which could be reversed by mannose. Furthermore, ERK-mediated phosphorylation of the β-catenin-Tyr654 residue might participate in the nuclear accumulation of β-catenin and its transcriptional function. The results from animal experiments showed that mannose effectively reduced hepatic metastasis of A549 cells in vivo. Furthermore, mannose inhibited ERK/GSK-3β/β-catenin/SNAIL in tumour tissues obtained from nude mice.

DISCUSSION

Collectively, these findings suggest that mannose exerts anti-metastatic activity against NSCLC by inhibiting the activation of the ERK/GSK-3β/β-catenin/SNAIL axis, which indicates the potential anticancer effects of mannose.

The local inflammatory response in colorectal cancer - Type, location or density? A systematic review and meta-analysis

INTRODUCTION

The host anti-tumour inflammatory response is a strong prognostic indicator, and tumour infiltrating lymphocytes (TILs) are believed to have a complimentary role alongside TNM assessment in dictating future management. However, there is wide disagreement regarding the most efficacious and cost-effective method of assessment.

METHODS

A comprehensive literature search was performed of EMBASE, MedLine and PubMed as well as an assessment of references to identify all relevant studies relating to the assessment of the peri-tumoural inflammatory response or TILs and prognosis in colorectal cancer (CRC). A meta-analysis was performed of 67 studies meeting the REMARK criteria using RevMan software.

RESULTS

Intratumoural assessment of both CD3 and CD8 in CRC were significant for disease-free survival (DFS) (combined HRs 0.46; 95%CI: 0.39-0.54 and 0.54; 95%CI: 0.45-0.65), as well as overall survival (OS) and disease-specific survival (DSS). The same was true for assessment of CD3 and CD8 at the invasive margin (DFS: combined HRs 0.45; 95%CI: 0.33-0.61 and 0.51; 95%CI: 0.41-0.62). However, similar fixed effects summaries were also observed for H&E-based methods, like Klintrup-Makinen grade (DFS: HR 0.62; 95%CI: 0.43-0.88). Furthermore, inflammatory assessments were independent of MSI status.

CONCLUSION

The evidence suggests that it is the density of a co-ordinated local inflammatory infiltrate that confers survival benefit, rather than any individual immune cell subtype. Furthermore, the location of individual cells within the tumour microenvironment does not appear to influence survival. The authors advocate a standardised assessment of the local inflammatory response, but caution against emphasizing the importance of any individual immune cell subtype.

Elevated CD163+/CD68+ Ratio at Tumor Invasive Front is Closely Associated with Aggressive Phenotype and Poor Prognosis in Colorectal Cancer

Background: The interaction and crosstalk between tumor-associated macrophages (TAMs) and epithelial-mesenchymal transition (EMT) has been demonstrated to play a critical role in the progression and metastasis of multiple cancers. However, the roles of the M2-polarized TAMs in different tumor location in EMT and prognosis of colorectal cancer (CRC) have not been elucidated. Therefore, the present study was designed to set up a reliable ratio of CD163+/CD68+ to assess M2-polarized TAMs infiltration in the tumor center (TC) and tumor invasive front (TF) and to further evaluate their prognostic value and biological effects on tumor cells in CRC. Methods: TAMs markers (CD68 and CD163) and EMT markers (E-cadherin and Vimentin) expression were evaluated by immunohistochemistry in 81 patients with CRC. Circulating tumor cells (CTCs) of peripheral blood from above patients was also isolated. The correlation of CD163+/CD68+ ratio in different locations, EMT and CTCs counts were further analyses. Kaplan-Meier and the model analyses of univariate Cox proportional hazards were utilized to compare the survival of patients with high CD163+/CD68+ ratio with those with low CD163+/CD68+ ratio. Furthermore, the effects of the M2-polarized TAMs on growth, migration and invasion of CRC cells were explored in vivo and in vitro co-culture system. Results: The results showed that the level of CD163+/CD68+ ratio in TF was significant higher than that in TC, and higher CD163+/CD68+TF ratio were closely correlated with enhanced lymphovascular invasion, tumor invasion and TNM stage. Interestingly, higher CD163+/CD68+TF ratio were also significantly associated with EMT program and CTCs counts. Meanwhile, Kaplan-Meier analysis showed that CD163+/CD68+TF was associated with both recurrence-free survival (RFS) and overall survival (OS) of patients with CRC. Multivariate Cox regression analyses demonstrated that CD163+/CD68+TF remained an independent prognostic factor for RFS and OS. Further receiver operating characteristic (ROC) curve analysis found that CD163+/CD68+TF was a better prognosticator compared with CD68+TF and CD163+TF for CRC patients. What's more, M2-polarized TAMs secreted TGF-β to facilitate the EMT, growth, proliferation and invasion of CRC cells by in vivo and in vitro experiments. Conclusions: Our studies preliminarily elucidated the prognostic value of CD163+/CD68+ ratio in different tumor locations and the biological functions of M2-polarized TAMs in CRC progression via TGF-β.