Immunohistochemical markers for tumor associated macrophages and survival in advanced classical Hodgkin's lymphoma

Topological importance of CD8+ T-cell enrichment in the tumor microenvironment of classic Hodgkin lymphoma

Classic Hodgkin lymphoma (CHL) histologically consists of Hodgkin Reed-Sternberg (HRS) cells and the tumor microenvironment (TME), but the relationship between TME characteristics and clinical features of CHL remains unclear. We aimed to investigate the effects of the TME structure on the outcomes of patients with CHL. We performed a high-throughput analysis of HRS cells and their topological relationship with the reactive immune cells in the TME. After multiplexed immunofluorescence labeling against CD4, CD8, CD30, CD68, CD163, PD-1, and PD-L1, visual images were analyzed. Phenotypes were assigned to all reactive cells, such as CD4+ and CD8+ T-cells and macrophages. Since the densities of PD1+/CD4+ T-cells, CD8+ T-cells, and PD-L1+ macrophages were significantly higher in the area < 60 μm than in the area < 120 μm from each HRS cell in 45 tissue samples from 34 patients with CHL, we further analyzed the TME-component cells by focusing on the 60 μm radius in the initial samples. TMEs containing > 15 CD8+ T-cells were associated with a significantly better 3-year progression-free survival than those with ≤ 15 CD8+ T-cells (100% vs. 53%, p = 0.006). In comparison with TMEs containing ≤ 15 CD8+ T-cells, TMEs containing > 15 CD8+ T-cells had significantly more PD-L1- macrophages (mean 3 vs. 1 cell, p = 0.015) and fewer PD-1+/CD4+ T-cells (mean 16 vs. 28 cells, p = 0.036). Epstein-Barr virus positivity in HRS cells was significantly associated with a higher number of macrophages in the 60 μm radius area. In conclusion, the TME structure in patients with CHL can differ, enabling precision therapies.

A Phase II, Open-Label, Randomized Trial of Durvalumab With Olaparib or Cediranib in Patients With Mismatch Repair-Proficient Colorectal or Pancreatic Cancer

BACKGROUND

The use of immunotherapy in mismatch repair proficient colorectal cancer (pMMR-CRC) or pancreatic adenocarcinoma (PDAC) is associated with limited efficacy. DAPPER (NCT03851614) is a phase 2, basket study randomizing patients with pMMR CRC or PDAC to durvalumab with olaparib (durvalumab + olaparib) or durvalumab with cediranib (durvalumab + cediranib).

METHODS

PDAC or pMMR-CRC patients were randomized to either durvalumab+olaparib (arm A), or durvalumab + cediranib (arm B). Co-primary endpoints included pharmacodynamic immune changes in the tumor microenvironment (TME) and safety. Objective response rate, progression-free survival (PFS) and overall survival (OS) were determined. Paired tumor samples were analyzed by multiplexed immunohistochemistry and RNA-sequencing.

RESULTS

A total of 31 metastatic pMMR-CRC patients were randomized to arm A (n = 16) or B (n = 15). In 28 evaluable patients, 3 patients had stable disease (SD) (2 patients treated with durvalumab + olaparib and 1 patient treated with durvalumab + cediranib) while 25 had progressive disease (PD). Among patients with PDAC (n = 19), 9 patients were randomized to arm A and 10 patients were randomized to arm B. In 18 evaluable patients, 1 patient had a partial response (unconfirmed) with durvalumab + cediranib, 1 patient had SD with durvalumab + olaparib while 16 had PD. Safety profile was manageable and no grade 4-5 treatment-related adverse events were observed in either arm A or B. No significant changes were observed for CD3+/CD8+ immune infiltration in on-treatment biopsies as compared to baseline for pMMR-CRC and PDAC independent of treatment arms. Increased tumor-infiltrating lymphocytes at baseline, low baseline CD68+ cells and different immune gene expression signatures at baseline were associated with outcomes.

CONCLUSIONS

In patients with pMMR-CRC or PDAC, durvalumab + olaparib and durvalumab + cediranib showed limited antitumor activity. Different immune components of the TME were associated with treatment outcomes.

Mapping the Spatial Dynamics of the CD4+ T Cell Spectrum in Classical Hodgkin Lymphoma

As around 25% to 30% of classical Hodgkin lymphoma (cHL) patients with advanced stages do not respond to standard therapies, the tumor microenvironment of cHL is one avenue that may be explored with the aim of improving risk stratification. CD4+ T cells are thought to be one of the main cell types in the tumor microenvironment. However, few immune signatures have been studied, and many of these lack related spatial data. Thus, our aim is to spatially resolve the CD4+ T cell subtypes that influence cHL outcome, depicting new immune signatures or transcriptional patterns that are in crosstalk with the tumor cells. This study was conducted using the NanoString GeoMx digital spatial profiling technology, based on the selection of distinct functional areas of patients' tissues followed by gene-expression profiling. The goals were to assess the differences in CD4+ T cell populations between tumor-rich and immune-predominant areas defined by different CD30 and PD-L1 expression levels and seek correlations with clinical metadata. Our results depict a complex map of CD4+ T cells with different functions and differentiation states that are enriched at distinct locations, the flux of cytokines and chemokines that could be related to these, and the specific relationships with the clinical outcome.

T cells in testicular germ cell tumors: new evidence of fundamental contributions by rare subsets

BACKGROUND

Immune cell infiltration is heterogeneous but common in testicular germ cell tumors (TGCT) and pre-invasive germ cell neoplasia in situ (GCNIS). Tumor-infiltrating T cells including regulatory T (Treg) and follicular helper T (Tfh) cells are found in other cancer entities, but their contributions to TGCT are unknown.

METHODS

Human testis specimens from independent patient cohorts were analyzed using immunohistochemistry, flow cytometry and single-cell RNA sequencing (scRNA-seq) with special emphasis on delineating T cell subtypes.

RESULTS

Profound changes in immune cell composition within TGCT, shifting from macrophages in normal testes to T cells plus B and dendritic cells in TGCT, were documented. In most samples (96%), the CD4+ T cell frequency exceeded that of CD8+ cells, with decreasing numbers from central to peripheral tumor areas, and to tumor-free, contralateral testes. T cells including Treg and Tfh were most abundant in seminoma compared to mixed tumors and embryonal carcinoma.

CONCLUSION

Despite considerable heterogeneity between patients, T cell subtypes form a key part of the TGCT microenvironment. The novel finding of rare Treg and Tfh cells in human testis suggests their involvement in TGCT pathobiology, with implications for understanding tumor progression, to assess patients' prognosis, and as putative targets for personalized immunotherapy.

BRCA1 mutation promotes sprouting angiogenesis in inflammatory cancer-associated fibroblast of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is an aggressive breast cancer subtype with inferior outcomes owing to its low treatment response and high invasiveness. Based on abundant cancer-associated fibroblasts (CAFs) and frequent mutation of breast cancer-associated 1 (BRCA1) in TNBC, the characteristics of CAFs in TNBC patients with BRCA1 mutation compared to wild-type were investigated using single-cell analysis. Intriguingly, we observed that characteristics of inflammatory CAFs (iCAFs) were enriched in patients with BRCA1 mutation compared to the wild-type. iCAFs in patients with BRCA1 mutation exhibited outgoing signals to endothelial cells (ECs) clusters, including chemokine (C-X-C motif) ligand (CXCL) and vascular endothelial growth factor (VEGF). During CXCL signaling, the atypical chemokine receptor 1 (ACKR1) mainly interacts with CXCL family members in tumor endothelial cells (TECs). ACKR1-high TECs also showed high expression levels of angiogenesis-related genes, such as ANGPT2, MMP1, and SELE, which might lead to EC migration. Furthermore, iCAFs showed VEGF signals for FLT1 and KDR in TECs, which showed high co-expression with tip cell marker genes, including ZEB1 and MAFF, involved in sprouting angiogenesis. Moreover, BRCA1 mutation patients with relatively abundant iCAFs and tip cell gene expression exhibited a limited response to neoadjuvant chemotherapy, including cisplatin and bevacizumab. Importantly, our study observed the intricate link between iCAFs-mediated angiogenesis and chemoresistance in TNBC with BRCA1 mutation.

PD-L1 immunohistochemistry assay optimization to provide more comprehensive pathological information in classic Hodgkin lymphoma

Overexpression of PD-L1 can be a predictive marker for anti-PD-1 therapeutic efficacy in classic Hodgkin lymphoma (CHL); however, harmonization of different IHC assays remains to be accomplished, and interpretations of PD-L1 immunostaining results remain controversial in CHL. In this study, we sought to optimize the PD-L1 immunohistochemistry (IHC) assay in CHL. All tests were performed on a tumour tissue microarray established from 54 CHL cases. Three IHC antibodies (405.9A11, SP142, 22C3) for detecting PD-L1 expression were compared semi quantitatively with the RNAscope assay (No. 310035, ACD), and the difference in the expression in background immune cells (ICs) between assays and the associations of expression levels with densities of TILs/TAMs were also analysed. 405.9A11 demonstrated best specificity in HRS cells and best sensitivity in ICs. Positive expression of PD-L1 was more frequent in ICs (85.2%) than in HRS cells (48.1%). Different subgroups of background ICs, including tumour-associated macrophages (TAMs), were assessed and scored for CD4, CD8, FOXP3, and CD163 expression. PD-L1 expression on ICs was the factor most associated with the density of TAMs. 405.9A11 provided the most convincing PD-L1 expression results. Pathologists should report PD-L1 expression in a combined manner, including both the status of HRS cells and the percentage of PD-L1-positive ICs.

Analysis of scRNA-seq and bulk RNA-seq demonstrates the effects of EVI2B or CD361 on CD8+ T cells in osteosarcoma

Osteosarcoma (OS) is a common primary malignant tumor of the bone in children and adolescents. The five-year survival rate is estimated to be ~70% based on the currently available treatment modalities. It is well known that tumor-infiltrating immune cells (TIICs) that are the most important components in the tumor microenvironment can exert a killing effect on tumor cells. Therefore, in the present study, 85 RNA-sequencing OS samples were categorized into high- and low-immune score groups with ESTIAMATE. Based on the immune score groups, 474 differentially expressed genes (DEGs) were acquired using the LIMMA package of R language. Subsequently, 86 DEGs were taken through univariate COX regression analysis, of which 14 were screened out by least absolute shrinkage and selection operator regression analysis. Furthermore, multivariate COX regression analysis was performed to obtain 4 DEGs. Finally, ecotropic virus integration site 2B (EVI2B) or CD361 gene was screened out via Kaplan-Meier analysis. In addition, CIBERSORT algorithm was used to evaluate the proportion of 22 kinds of TIICs in OS. Correlation analysis revealed that the high expression level of EVI2B can elevate the infiltrated proportion of CD8⁺ T cells. Moreover, analysis of single cell RNA-sequencing transcriptome datasets and immunohistochemical staining uncovered that EVI2B was mainly expressed on CD8⁺ T cells and that EVI2B could promote the expression of granzyme A and K of CD8⁺ T cells to exhibit a potent killing effect on tumor cells. Therefore, EVI2B was identified as a protective immune-related gene and contributed to good prognosis in OS patients.

The Need for Standardization in Next-Generation Sequencing Studies for Classic Hodgkin Lymphoma: A Systematic Review

Classic Hodgkin lymphoma (cHL) constitutes a B cell-derived neoplasm defined by a scarce tumoral population, termed Hodgkin and Reed–Sternberg (HRS) cells, submerged into a histologically heterogeneous microenvironment. The paucity of HRS cells has historically hampered genetic studies, rendering the identification of the recurrent genetic lesions and molecular pathways deregulated in this lymphoma difficult. The advent of high-throughput sequencing methods such as next-generation sequencing (NGS) could sensibly optimize the identification of the mutational landscape of cHL. However, there is no current consensus either in the design of panels for targeted NGS or in its most relevant clinical applications. In this work, we systematically review the current state of NGS studies of cHL, stressing the need for standardization both in the candidate genes to be analyzed and the bioinformatic pipelines. As different institutions have developed and implemented their own customized NGS-based protocols, to compare and systematically review the major findings of this ongoing research area could be of added value for centers that routinely perform diagnostic, monitoring and genotyping strategies in cHL samples. The results of this systematic review should contribute to the interdepartmental harmonization and achievement of a consensus in the current clinical applications of NGS studies of cHL.

ATG16L1 is a Potential Prognostic Biomarker and Immune Signature for Osteosarcoma: A Study Based on Bulk RNA and Single-Cell RNA-Sequencing

Background

Osteosarcoma is a common solid malignancy of the bone in children and adolescents, and its metastasis and recurrence are the principal causes of poor treatment outcomes.

Methods

Autophagy-related genes were used to cluster osteosarcoma patients by consensus clustering analysis using the GSE21257 database. Differentially expressed genes (DEGs) were identified by limma package. Multiple-gene risk signature was constructed using least absolute shrinkage and selection operator (LASSO) analysis and Cox regression analyses. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to determine gene expression levels. Then, single-cell RNA-sequencing dataset GSE152048 were used to identify the correlation between the DEGs and effector molecules expressed in specific tumor-infiltrating immune cells.

Results

Two clusters were identified in the consensus clustering analysis, which were confirmed by principal component analysis. Limma analysis revealed that 15 genes were related, and 9 genes were screened using protein-protein interaction network and LASSO regression analysis. Cox regression analyses identified 5 genes. Combined with survival analysis, only the autophagy related 16 like 1 gene (ATG16L1) was significant. The results of qRT-PCR showed low expression levels of ATG16L1 in tumor cells group. Immune infiltration analysis revealed significantly lower expression of CD8⁺ T cells in the high ATG16L1 gene expression group. ScRNA-seq revealed that in the ATG16L1⁺CD8⁺ T cell group, the expression of GZMB was lower, whereas the expression of ITGA1 was higher. These results showed that ATG16L1 is an immune-related gene, which is associated with poor prognosis in patients with osteosarcoma.

Conclusion

ATG16L1 is a potential prognostic biomarker and immune signature and may be a therapeutic target for osteosarcoma.

Potential role of tumor-associated macrophages and CD163/CD68 ratio in mycosis fungoides and Sézary syndrome in correlation with serum sCD163 and CCL22

Currently, there are no curative treatment options for mycosis fungoides (MF) and Sézary syndrome (SS) other than stem cell transplant. Understanding the interplay between tumor cells and tumor microenvironment could aid in the development of new therapies. Tumor-associated macrophages (TAMs) mostly have M2 phenotype that promotes tumor progression. This study investigated CD68+ and CD163+ TAMs as well as CD163/CD68 ratio in skin lesions from different stages of MF, large-plaque parapsoriasis, and SS. Moreover, we analyzed serum levels of sCD163 and CCL22 in correlation with TAMs count and CD163/CD68 ratio. CD68+ and CD163+ TAMs count significantly increased as the disease progressed. CD163/CD68 ratio was highest at MF tumor stage and SS indicating M2 polarization with disease progression. Significant positive correlations were detected between serum levels of sCD163 and CCL22 and CD68+ and CD163+ TAMs count and CD163/CD68 ratio. We concluded that TAMs play an important role in MF progression. High CD163/CD68 ratio in tumor stage MF and SS indicates M2 polarization of TAMs with tumor progression. CD163/CD68 ratio should be considered in assessing TAMs rather than total TAMs count. Also, sCD163 and CCL22 serum levels reflect M2 load and thus could be used as markers to assess disease progression.

Single-cell transcriptomics reveals heterogeneous progression and EGFR activation in pancreatic adenosquamous carcinoma

Pancreatic adenosquamous carcinoma (PASC) - a rare pathological pancreatic cancer (PC) type - has a poor prognosis due to high malignancy. To examine the heterogeneity of PASC, we performed single-cell RNA sequencing (scRNA-seq) profiling with sample tissues from a healthy donor pancreas, an intraductal papillary mucinous neoplasm, and a patient with PASC. Of 9,887 individual cells, ten cell subpopulations were identified, including myeloid, immune, ductal, fibroblast, acinar, stellate, endothelial, and cancer cells. Cancer cells were divided into five clusters. Notably, cluster 1 exhibited stem-like phenotypes expressing UBE2C, ASPM, and TOP2A. We found that S100A2 is a potential biomarker for cancer cells. LGALS1, NPM1, RACK1, and PERP were upregulated from ductal to cancer cells. Furthermore, the copy number variations in ductal and cancer cells were greater than in the reference cells. The expression of EREG, FCGR2A, CCL4L2, and CTSC increased in myeloid cells from the normal pancreas to PASC. The gene sets expressed by cancer-associated fibroblasts were enriched in the immunosuppressive pathways. We demonstrate that EGFR-associated ligand-receptor pairs are activated in ductal-stromal cell communications. Hence, this study revealed the heterogeneous variations of ductal and stromal cells, defined cancer-associated signaling pathways, and deciphered intercellular interactions following PASC progression.

Whole-slide image analysis of the tumor microenvironment identifies low B-cell content as a predictor of adverse outcome in patients with advanced-stage classical Hodgkin lymphoma treated with BEACOPP

Asubset of patients with advanced-stage classical Hodgkin lymphoma (cHL) relapse or progress following standard treatment. Given their dismal prognosis, identifying this group of patients upfront represents an important medical need. While prior research has identified characteristics of the tumor microenvironment, which are associated with cHL outcomes, biomarkers that are developed and validated in this high-risk group are still lacking. Here, we applied wholeslide image analysis (WSI), a quantitative, large-scale assessment of tumor composition that utilizes conventional histopathology slides. We conducted WSI on pre-treatment biopsies from 340 patients with advanced-stage cHL enrolled in the HD12 and HD15 trials of the German Hodgkin Study Group (GHSG), and tested our results in a validation cohort of 147 advanced-stage cHL patients within the GHSG HD18 trial. All patients were treated with BEACOPP-based regimens. By quantifying T cells, B cells, Hodgkin and Reed-Sternberg cells and macrophages with WSI, 80% of all cells in the tumor tissue were identified. Crucially, low B-cell count was associated with significantly reduced progression-free survival and overall survival, while the content of T cells, macrophages and Hodgkin and Reed-Sternberg cells was not associated with the risk of progression or relapse in the study cohort. We further validated low Bcell content as a prognostic factor for progression-free survival and overall survival in the validation cohort and demonstrated the good interobserver agreement of WSI. WSI may represent a key tool for risk stratification of advanced-stage cHL and can easily be added to the standard diagnostic histopathology work-up.

PD-1 and LAG-3 Checkpoint Blockade: Potential Avenues for Therapy in B-Cell Lymphoma

The dependence of cancer on an immunotolerant tumor microenvironment (TME) is well established. Immunotherapies that overcome tumor-induced immune suppression have been central to recent advancements in oncology. This is highlighted by the success of agents that interrupt PD-1 mediated immune suppression in a range of cancers. However, while PD-1 blockade has been paradigm-shifting in many malignancies, the majority of cancers show high rates of primary resistance to this approach. This has led to a rapid expansion in therapeutic targeting of other immune checkpoint molecules to provide combination immune checkpoint blockade (ICB), with one such promising approach is blockade of Lymphocyte Activation Gene 3 (LAG-3). Clinically, lymphoproliferative disorders show a wide spectrum of responses to ICB. Specific subtypes including classical Hodgkin lymphoma have demonstrated striking efficacy with anti-PD-1 therapy. Conversely, early trials of ICB have been relatively disappointing in common subtypes of Non-Hodgkin lymphoma. In this review, we describe the TME of common lymphoma subtypes with an emphasis on the role of prominent immune checkpoint molecules PD-1 and LAG3. We will also discuss current clinical evidence for ICB in lymphoma and highlight key areas for further investigation where synergistic dual checkpoint blockade of LAG-3 and PD-1 could be used to overcome ICB resistance.

CD68-positive tumour associated macrophages, PD-L1 expression, and EBV latent infection in a high HIV-prevalent South African cohort of Hodgkin lymphoma patients

A higher proportion of CD68-positive tumour associated macrophages (TAMs) has been associated with poorer outcomes in HIV-negative patients with Hodgkin lymphoma (HL), but whether this is true in HIV-positive patients with HL is not known. In this study, we investigated the number of CD68-positive TAMs and expression of programmed cell death-ligand 1 (PD-L1) in lymph node specimens from HL patients and correlated expression with clinical features (HIV status, disease severity and survival) and histopathological features (EBV latent positivity and subtype of HL). We stained archived lymph node specimens from 77 patients diagnosed with HL for CD68 and PD-L1. Stains were graded as: CD68 low (≤25%), CD68 high (>25%), PD-L1 low (≤50%), and PD-L1 high (>50%). Expression levels were correlated with the clinical and histopathological features using bivariate and multivariate analyses. Survival was analysed by overall and progression-free survival. Thirty-four of the 77 included patients (44%) were HIV-positive. EBV latency was detected in 97% of HIV-positive HL patients and in 14% of HIV-negative HL patients. A high CD68 score was associated with lower median haemoglobin levels (9.4 vs 11.4 g/dL; p=0.02), platelet numbers (262 vs 424 cells ×10⁹/L; p=0.01), and lymphocyte numbers (0.99 vs 1.70 cells ×10⁹/L, p=0.01) and a trend towards advanced disease (international prognostic score ≥4; hazard ratio 2.4; confidence interval 0.89-6.47; p=0.08). HIV status did not affect CD68 or PD-L1 expression. A higher proportion of CD68-positive TAMs was found in samples that were EBV-positive. HIV positivity and EBV negativity correlated with poorer survival. CD68 and PD-L1 expression were not predictive of survival. High CD68 expression was associated with EBV positivity but not HIV positivity and did not predict adverse outcomes. PD-L1 expression was unaffected by HIV status or EBV positivity and did predict adverse outcomes.

Relationship of Tumor-Associated Macrophage Population Detected by CD68 PG-M1, CD68 KP1, and CD163 with Latent EBV Infection and Prognosis in Classical Hodgkin Lymphoma

OBJECTIVE

To evaluate the quantity of tumor-associated macrophages (TAMs) in cases of Hodgkin Lymphoma of classical type (cHL), and to reveal possible associations between TAM intensity and latent Epstein-Barr virus (EBV) infection, overall survival, progression-free survival, prognostic indices, and clinicopathological parameters.

MATERIALS AND METHODS

A total 46 cases of cHL with complete clinical records were selected and re-evaluated histopathologically. Staining for CD68 (PG-M1; KP1 clones) and CD163 was evaluated and the cut-off values were defined. Also, all cases were evaluated using the chromogen in situ hybridization (CISH) method with EBER (Epstein-Barr virus-encoded RNA) probes for the presence of possible EBV infection.

RESULTS

It was found that high expression levels of PG-M1 and high International Prognostic Scores (IPS) were associated with shortened overall survival (p=0.047, p=0.013). Cases with 2 or less areas of nodal region involvement were observed to have longer progression-free survival period (p=0.043). Higher expression levels of CD68 PG-M1, CD68 KP1, and CD163 were found to show significant associations with the presence of some clinical parameters such as the presence of B symptoms, spleen involvement, and the presence of EBV infection.

CONCLUSIONS

Our findings suggest that increase of PG-M1+ TAM is associated with shortened overall survival, while higher expressions of all immunohistochemical markers are statistically significantly associated with the presence of EBV infection and clinical parameters mentioned above. These findings indicate that highlighting the TAM rate via macrophage markers in cases of cHL could be helpful in determining the prognostic risk groups and the relevant results should be mentioned in pathology reports.

Macrophages in Osteosarcoma Immune Microenvironment: Implications for Immunotherapy

Osteosarcoma is a malignant primary bone tumor commonly occurring in children and adolescents. The treatment of local osteosarcoma is mainly based on surgical resection and chemotherapy, whereas the improvement of overall survival remains stagnant, especially in recurrent or metastatic cases. Tumor microenvironment (TME) is closely related to the occurrence and development of tumors, and macrophages are among the most abundant immune cells in the TME. Due to their vital roles in tumor progression, macrophages have gained increasing attention as the new target of tumor immunotherapy. In this review, we present a brief overview of macrophages in the TME and highlight the clinical significance of macrophages and their roles in the initiation and progression of osteosarcoma. Finally, we summarize the therapeutic approaches targeting macrophage, which represent a promising strategy in osteosarcoma therapies.

Tumor-associated macrophages in classical Hodgkin lymphoma: hormetic relationship to outcome

Commonly attributed to the prevalence of M2 macrophages, tumor-associated macrophages (TAM) are linked to poor outcome in Hodgkin lymphoma (HL). MYC is supposed to control the expression of M2-specific genes in macrophages, and deficiency in MYC-positive macrophages inhibits tumor growth in mouse models. To verify this hypothesis for HL, seventy-six samples were subjected to immunohistochemical double staining using CD68 or CD163 macrophage-specific antibodies and a reagent detecting MYC. For each cell population, labelled cells were grouped according to low, intermediate and high numbers and related to disease-free survival (DFS) and overall survival (OS). MYC+ cells accounted for 21% and 18% of CD68+ and CD163+ cells, respectively. Numbers of MYC- macrophages were significantly higher in EBV+ cases while no differences were observed for MYC+ macrophages between EBV+ and EBV- cases. Cases with highest numbers of macrophages usually showed worst DFS and OS. In most scenarios, intermediate numbers of macrophages were associated with better outcome than very low or very high numbers. Our observations are reminiscent of the "hormesis hypothesis" and suggest that a relative lack of TAM may allow HL growth while macrophages display an inhibitory effect with increasing numbers. Above a certain threshold, TAM may again support tumor growth.

Prognostic Impact of Tumor-Associated Macrophages on Survival Is Checkpoint Dependent in Classical Hodgkin Lymphoma

Tumor microenvironment and immune escape affect pathogenesis and survival in classical Hodgkin lymphoma (cHL). While tumor-associated macrophage (TAM) content has been associated with poor outcomes, macrophage-derived determinants with clinical impact have remained undefined. Here, we have used multiplex immunohistochemistry and digital image analysis to characterize TAM immunophenotypes with regard to expression of checkpoint molecules programmed cell death ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO-1) from the diagnostic tumor tissue samples of 130 cHL patients, and correlated the findings with clinical characteristics and survival. We show that a large proportion of TAMs express PD-L1 (CD68⁺, median 32%; M2 type CD163⁺, median 22%), whereas the proportion of TAMs expressing IDO-1 is lower (CD68⁺, median 5.5%; CD163⁺, median 1.4%). A high proportion of PD-L1 and IDO-1 expressing TAMs from all TAMs (CD68⁺), or from CD163⁺ TAMs, is associated with inferior outcome. In multivariate analysis with age and stage, high proportions of PD-L1⁺ and IDO-1⁺ TAMs remain independent prognostic factors for freedom from treatment failure (PD-L1⁺CD68⁺/CD68⁺, HR = 2.63, 95% CI 1.17–5.88, p = 0.019; IDO-1⁺CD68⁺/CD68⁺, HR = 2.48, 95% CI 1.03–5.95, p = 0.042). In contrast, proportions of PD-L1⁺ tumor cells, all TAMs or PD-L1⁻ and IDO-1⁻ TAMs are not associated with outcome. The findings implicate that adverse prognostic impact of TAMs is checkpoint-dependent in cHL.

Identification of a novel monocytic phenotype in Classic Hodgkin Lymphoma tumor microenvironment

Classic Hodgkin lymphoma (CHL) characteristically shows few malignant cells in a microenvironment comprised of mixed inflammatory cells. Although CHL is associated with a high cure rate, recent studies have associated poor prognosis with absolute monocyte count in peripheral blood and increased monocyte/macrophages in involved lymph nodes. Thus, the role of monocytic infiltration and macrophage differentiation in the tumor microenvironment of CHL may be more relevant than absolute macrophage numbers to defining prognosis in CHL patients and potentially have therapeutic implications. Most studies identify tumor-associated macrophages (TAMs) using markers (e.g., CD68) expressed by macrophages and other mononuclear phagocytes, such as monocytes. In contrast, Class A Scavenger Receptor (SR-A/CD204) is expressed by tissue macrophages but not monocytic precursors. In this study, we examined SR-A expression in CHL (n = 43), and compared its expression with that of other macrophage markers. We confirmed a high prevalence of mononuclear cells that stained with CD68, CD163, and CD14 in CHL lymph nodes. However, SR-A protein expression determined by immunohistochemistry was limited to macrophages localized in sclerotic bands characteristic of nodular sclerosis CHL. In contrast, SR-A protein was readily detectable in lymph nodes with metastatic tumor, extra-nodal CHL, T cell/histiocyte-rich large B cell lymphoma, and resident macrophages in non-malignant tissues, including spleen, lymph node, liver and lung. The results of SR-A protein expression paralleled the expression of SR-A mRNA determined by quantitative RT-PCR. These data provide evidence that tumor-infiltrating monocyte/macrophages in CHL have a unique phenotype that likely depends on the microenvironment of nodal CHL.

Immunohistochemical phenotyping of T cells, granulocytes, and phagocytes in the muscle of cancer patients: association with radiologically defined muscle mass and gene expression

BACKGROUND

Inflammation is a recognized contributor to muscle wasting. Research in injury and myopathy suggests that interactions between the skeletal muscle and immune cells confer a pro-inflammatory environment that influences muscle loss through several mechanisms; however, this has not been explored in the cancer setting. This study investigated the local immune environment of the muscle by identifying the phenotype of immune cell populations in the muscle and their relationship to muscle mass in cancer patients.

METHODS

Intraoperative muscle biopsies were collected from cancer patients (n = 30, 91% gastrointestinal malignancies). Muscle mass was assessed histologically (muscle fiber cross-sectional area, CSA; μm²) and radiologically (lumbar skeletal muscle index, SMI; cm²/m² by computed tomography, CT). T cells (CD4 and CD8) and granulocytes/phagocytes (CD11b, CD14, and CD15) were assessed by immunohistochemistry. Microarray analysis was conducted in the muscle of a second cancer patient cohort.

RESULTS

T cells (CD3+), granulocytes/phagocytes (CD11b+), and CD3-CD4+ cells were identified. Muscle fiber CSA (μm²) was positively correlated (Spearman's r = > 0.45; p = < 0.05) with the total number of T cells, CD4, and CD8 T cells and granulocytes/phagocytes. In addition, patients with the smallest SMI exhibited fewer CD8 T cells within their muscle. Consistent with this, further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively associated (Pearson's r = ≥ 0.5; p = <0.0001) with key genes within muscle catabolic pathways for signaling (ACVR2B), ubiquitin proteasome (FOXO4, TRIM63, FBXO32, MUL1, UBC, UBB, UBE2L3), and apoptosis/autophagy (CASP8, BECN1, ATG13, SIVA1).

CONCLUSION

The skeletal muscle immune environment of cancer patients is comprised of immune cell populations from the adaptive and innate immunity. Correlations of T cells, granulocyte/phagocytes, and CD3-CD4+ cells with muscle mass measurements indicate a positive relationship between immune cell numbers and muscle mass status in cancer patients. Further exploration with gene correlation analyses suggests that the presence of CD8 T cells is negatively correlated with components of muscle catabolism.

Co-Expression Network Analysis Identified Gene Signatures in Osteosarcoma as a Predictive Tool for Lung Metastasis and Survival

Osteosarcoma (OS) is the most common primary bone tumor, whose poor prognosis is mainly due to lung metastasis. The aim of this study is to build a practical and valid diagnostic test that can predict the risk of OS metastasis and progression. We performed weighted gene co-expression network analysis (WGCNA) on GSE21257 from the Gene Expression Omnibus (GEO) database, which contains microarray data of biopsies from OS patients. In these modules, the highest association was found between the blue module and metastasis stage (r = -0.52) by Pearson's correlation analysis. Based on Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression, we derived eight clinically significant genes and constructed an eight-gene signature for metastasis status. It showed great efficacy to distinguish metastasis from non-metastasis (AUC = 0.886) and the results were validated in The Cancer Genome Atlas (TCGA) database. Functional enrichment analysis of hub genes showed that their biological processes focused on immune-related pathways, suggesting the important roles of immune cells, immune pathways and the tumor microenvironment in metastasis development. In conclusion, we discovered an efficient gene signature with great efficacy to distinguish metastasis status, which may help improve early diagnosis and treatment, enhancing the clinical outcomes of OS patients. Besides we created an effective protocol to seek for several hub genes in high-throughput data by combining WGCNA and LASSO Cox regression.

Flow cytometry for assessment of the tumor microenvironment in pediatric Hodgkin lymphoma

BACKGROUND

The role of flow cytometry in diagnosis and management of Hodgkin lymphoma (HL) remains limited. As knowledge emerges of the tumor microenvironment in this disease, various methods are being evaluated in its study. This study examines the microenvironment using flow cytometry to assess differences between subtypes and clinicopathologic correlates.

PROCEDURE

A retrospective cross-sectional study was performed analyzing the tumor immunophenotype, by flow cytometry, for 31 children with classical HL. Correlation was made with patient information, including outcome.

RESULTS

The makeup of the tumor microenvironment varies across subtype of HL, with T cells predominating in nodular sclerosis (NS), and similar proportions of B and T cells in mixed cellularity (MC). CD4 cells predominate in NS, whereas CD8 more so in MC subtype. The rate of continuous complete remission is significantly higher in the MC subgroup. Last, the proportion of HLA-DR/CD38 copositive lymphocytes was an independent prognostic factor for relapse/refractoriness.

CONCLUSIONS

This study indicates that flow cytometry can be used to examine the tumor microenvironment in HL and that percentage of HLA-DR/CD38 copositive lymphocytes may be a biomarker for relapse and refractoriness in pediatric HL.

Essential genes of the macrophage response to Staphylococcus aureus exposure

Background

Although significant advances have been made in understanding the mechanisms of macrophage response to Staphylococcus aureus infection, the molecular details are still elusive. Identification of the essential genes and biological processes of macrophages that are specifically changed at different durations of S. aureus exposure is of great clinical significance.

Methods

We aimed to identify the significantly changed genes and biological processes of S. aureus-exposed macrophages. We systematically analyzed the macrophage gene expression profile GSE 13670 database with 8 h, 24 h or 48 h S. aureus infection. The results were further confirmed by western blot and quantitative polymerase chain reaction (qPCR) analyses.

Results

After 8 h of S. aureus infection, the expression of 624 genes was significantly changed. Six hundred thirteen differentially expressed genes (DEGs) were identified after 24 h of S. aureus infection. Two hundred fifty-three genes were significantly changed after 48 h of S. aureus infection. STAT1 was consistently up-regulated in these three treatments. TP53, JAK2, CEBPA, STAT3, MYC, CTNNB1 and PRKCA were only identified in the 8 h or 24 h S. aureus infection groups. CTNNB1 and PRKCA were for the first time identified as potential essential genes in S. aureus infection of macrophages. In the Gene Ontology (GO) term analysis, the defense response was shown to be the most significantly changed biological process among all processes; KEGG pathway analysis identified the JAK-STAT signaling pathway involved in early infection.

Conclusions

Our systematic analysis identified unique gene expression profiles and specifically changed biological processes of the macrophage response to different S. aureus exposure times.

Analysis of the mutational landscape of classic Hodgkin lymphoma identifies disease heterogeneity and potential therapeutic targets

Defining the mutational landscape of classic Hodgkin lymphoma is still a major research goal. New targeted next-generation sequencing (NGS) techniques may identify pathogenic mechanisms and new therapeutic opportunities related to this disease. We describe the mutational profile of a series of 57 cHL cases, enriched in Hodgkin and Reed-Sternberg (HRS) cells.

Overall, the results confirm the presence of strong genomic heterogeneity. However, several variants were consistently detected in genes related to relevant signaling pathways, such as GM-CSF/IL-3, CBP/EP300, JAK/STAT, NF-kappaB, and numerous variants of genes affecting the B-cell receptor (BCR) pathway, such as BTK, CARD11, BCL10, among others. This unexpectedly high prevalence of mutations affecting the BCR pathway suggests some requirement for active BCR signaling for cHL cell viability. Additionally, incubation of a panel of cHL cellular models with selective BTK inhibitors in vitro constrains cell proliferation and causes cell death. Our results indicate new pathogenic mechanisms and therapeutic opportunities in this disease.

LAMPs: Shedding light on cancer biology

Lysosomes are important cytoplasmic organelles whose critical functions in cells are increasingly being understood. In particular, despite the long-standing accepted concept about the role of lysosomes as cellular machineries solely assigned to degradation, it has been demonstrated that they play active roles in homeostasis and even in cancer biology. Indeed, it is now well documented that during the process of cellular transformation and cancer progression lysosomes are changing localization, composition, and volume and, through the release of their enzymes, lysosomes can also enhance cancer aggressiveness. LAMPs (lysosome associated membrane proteins) represent a family of glycosylated proteins present predominantly on the membrane of lysosomes whose expression can vary among different tissues, suggesting a separation of functions. In this review we focus on the functions and roles of the different LAMP family members, with a particular emphasis on cancer progression and metastatic spread. LAMP proteins are involved in many different aspects of cell biology and can influence cellular processes such as phagocytosis, autophagy, lipid transport, and aging. Interestingly, for all the five members identified so far (LAMP1, LAMP2, LAMP3, CD68/Macrosialin/LAMP4, and BAD-LAMP/LAMP5), a role in cancer has been suggested. While this is well documented for LAMP1 and LAMP2, the involvement of the other three proteins in cancer progression and aggressiveness has recently been proposed and remains to be elucidated. Here we present different examples about how LAMP proteins can influence and support tumor growth and metastatic spread, emphasizing the impact of each single member of the family.

Thioredoxin-1, chemokine (C-X-C motif) ligand-9 and interferon-γ expression in the neoplastic cells and macrophages of Hodgkin lymphoma: clinicopathologic correlations and potential prognostic implications

Expression of thioredoxin-1 (TXN) and CXCL9 is not restricted to THRLBCL macrophages, but may be observed in histiocytes and neoplastic (HRS) cells of EBV + mixed cellularity (MC) classical Hodgkin lymphoma (cHL) and nodular lymphocyte predominant HL. We aimed to validate and extend the above observations in 174 cHL patients evaluating the immunohistochemical expression of TXN, CXCL9 and IFN-γ. HRS-cell CXCL9 expression was higher in latent membrane protein-1 (LMP1)+, MC and Stage IV. TXN and CXCL9 expression by cHL histiocytes was more frequent in LMP1+, MC and older patients (only for CXCL9). TXN expression by HRS cells (≥80%) was independently associated with better failure-free survival. In conclusion, markers of TCHRLBCL histiocytes (TXN, CXCL9), as well as IFN-γ are also expressed by histiocyte subsets and neoplastic cells of cHL. The expression of some of them is more prominent in EBV + MC, but not restricted to this subtype. The prognostic implication of TXN needs further evaluation.

Meta-analysis of the prognostic and clinical value of tumor-associated macrophages in adult classical Hodgkin lymphoma

BACKGROUND

The prognostic significance of tumor-associated macrophages (TAM) in adult classical Hodgkin lymphoma (cHL) remains controversial. Here, we report a meta-analysis of the association of CD68 and CD163 infiltration on the clinical outcome of adult cHL.

METHODS

A comprehensive search to identify relevant articles was performed in PubMed, Embase, and Google Scholar on January 31, 2016. Using the fixed effect or random effects model of DerSimonian and Laird, hazard ratios (HR) or odds ratios (OR) with 95 % confidence intervals (CIs) were used as the effect size estimate.

RESULTS

Twenty-two eligible studies with a total of 2959 patients were identified. Our analysis indicated that a high density of CD68⁺ TAMs in the tumor microenvironment of adult cHL predicted poor overall survival (OS) (HR: 2.41; 95 % CI, 1.92-3.03), shorter progression-free survival (PFS) (HR: 1.78; 95 % CI, 1.45-2.18), and poor disease-specific survival (HR: 2.71; 95 % CI, 1.38-5.29). High density of CD163⁺ TAMs in the tumor microenvironment of adult cHL also predicted poor OS (HR: 2.75; 95 % CI, 1.58-4.78) and poor PFS (HR: 1.66; 95 % CI, 1.22-2.27). In addition, we demonstrated that a high density of either CD68⁺ or CD163⁺ TAMs was associated with the presence of Epstein-Barr virus in neoplastic cells (OR_CD68: 3.13; 95 % CI, 2.02-4.84; OR_CD163: 2.88; 95 % CI, 1.55-5.34). A high density of either CD68⁺ or CD163⁺ TAMs tend to be associated with a more advanced clinical stage (OR_CD68: 1.25; 95 % CI, 0.93-1.67; OR _CD163: 1.19; 95 % CI, 0.86-1.63), B-symptoms (OR_CD68: 1.35; 95 % CI, 0.90-2.01; OR_CD163: 2.19; 95 % CI, 0.96-5.03), higher International Prognostic Factors Project Score (OR_CD68: 1.20; 95 % CI, 0.67-2.15; OR_CD163: 2.00; 95 % CI, 0.92-4.35), and bulky disease (OR_CD68: 1.47; 95 % CI, 0.88-2.47; OR_CD163: 1.19; 95 % CI, 0.72-1.96).

CONCLUSIONS

Our analyses suggest that a high density of either CD68⁺ or CD163⁺ TAMs is a robust predictor of adverse outcomes in adult cHL. Increased TAMs should be taken into account to further improve prognostic stratification and the planning of appropriate therapeutic strategies.

Diagnostic and predictive biomarkers for lymphoma diagnosis and treatment in the era of precision medicine

Lymphomas are a group of hematological malignancies derived from lymphocytes. Lymphomas are clinically and biologically heterogeneous and have overlapping diagnostic features. With the advance of new technologies and the application of efficient and feasible detection platforms, an unprecedented number of novel biomarkers have been discovered or are under investigation at the genetic, epigenetic, and protein level as well as the tumor microenvironment. These biomarkers have enabled new clinical and pathological insights into the mechanisms underlying lymphomagenesis and also have facilitated improvements in the diagnostic workup, sub-classification, outcome stratification, and personalized therapy for lymphoma patients. However, integrating these biomarkers into clinical practice effectively and precisely in daily practice is challenging. More in-depth studies are required to further validate these novel biomarkers and to assess other parameters that can affect the reproducibility of these biomarkers such as the selection of detection methods, biological reagents, interpretation of data, and cost efficiency. Despite these challenges, there are many reasons to be optimistic that novel biomarkers will facilitate better algorithms and strategies as we enter a new era of precision medicine to better refine diagnosis, prognostication, and rational treatment design for patients with lymphomas.

Prognostic Biomarkers for Hodgkin Lymphoma

The prognosis of patients with classical Hodgkin lymphoma following chemo- and radiotherapy has been excellent during the last 4 decades. However, the development of secondary malignancies is of major concern. Therefore, the reduction of radiotherapy application is a major objective of ongoing clinical trials. De-escalation of treatment may increase the risk of relapses and thus may lead to reappearance of prognostic factors. Prognostic biomarkers might help to identify patients who are at increased risk of relapse. This review summarizes the current knowledge about potential prognostic biomarkers for patients with classical Hodgkin lymphoma.

Logic Learning Machine and standard supervised methods for Hodgkin's lymphoma prognosis using gene expression data and clinical variables

This study evaluates the performance of a set of machine learning techniques in predicting the prognosis of Hodgkin's lymphoma using clinical factors and gene expression data. Analysed samples from 130 Hodgkin's lymphoma patients included a small set of clinical variables and more than 54,000 gene features. Machine learning classifiers included three black-box algorithms ( k-nearest neighbour, Artificial Neural Network, and Support Vector Machine) and two methods based on intelligible rules (Decision Tree and the innovative Logic Learning Machine method). Support Vector Machine clearly outperformed any of the other methods. Among the two rule-based algorithms, Logic Learning Machine performed better and identified a set of simple intelligible rules based on a combination of clinical variables and gene expressions. Decision Tree identified a non-coding gene ( XIST) involved in the early phases of X chromosome inactivation that was overexpressed in females and in non-relapsed patients. XIST expression might be responsible for the better prognosis of female Hodgkin's lymphoma patients.

CD68+ cell count, early evaluation with PET and plasma TARC levels predict response in Hodgkin lymphoma

Early response evaluation with [¹⁸F]fluordeoxyglucose (FDG) positron emission tomography after 2 cycles of chemotherapy (interim PET) has been indicated as the strongest predictor for outcome in classical Hodgkin lymphoma (HL). We studied the prognostic role of the number of tumor‐infiltrating CD68+ cells and of the plasma levels of TARC (thymus and activation‐regulated chemokine) in the context of interim PET in 102 patients with classical HL treated with Adriamycin, Bleomycin, Vinblastine, Dacarbazine (ABVD). After 2 ABVD cycles, interim PET according to Deauville criteria was negative (score 0–3) in 85 patients and positive (score 4–5) in 15 patients (2 patients technically not evaluable). TARC levels were elevated in 89% of patients at diagnosis, and decreased after 2 cycles in 82% of patients. Persistently elevated TARC levels in 18% of patients were significantly associated with a positive PET result (P = 0.007). Strong predictors for progression‐free survival (PFS) were a negative interim PET (85% vs. 28%, P < 0.0001) and CD68+ cell counts <5% (89% vs. 67%, P = 0.006), while TARC levels at diagnosis and at interim evaluation had no prognostic role. In multivariate analysis, interim PET, CD68+ cell counts and presence of B‐symptoms were independently associated with PFS. We conclude that although TARC levels are a biomarker for early response evaluation, they cannot substitute for interim PET as outcome predictor in HL. The evaluation of CD68 counts and B‐symptoms at diagnosis may help to identify low‐risk patients regardless positive interim PET.

Prognostic value of lymphocyte/monocyte ratio in advanced Hodgkin lymphoma: correlation with International Prognostic Score and tumor associated macrophages

We studied the prognostic significance of the absolute lymphocyte/monocyte count ratio (ALC/AMC), its contribution to the prognostic value of the International Prognostic Score (IPS), and evaluated if ALC/AMC could serve as a proxy for the frequency of CD68 + tumor-associated macrophages (TAMs) in 101 patients with advanced Hodgkin lymphoma (HL). The receiver operating characteristic (ROC) curve identified best cut-off values of 2.0 for ALC/AMC and 25% for CD68 + TAM. Patients with ALC/AMC < 2, IPS > 2 and > 25% CD68 + TAM had an inferior overall survival (OS) and event-free survival (EFS). Spearman's test also uncovered a significant correlation between the ALC/AMC and TAM. Multivariate analysis identified ALC/AMC < 2, IPS > 2 and > 25% CD68 + TAM as poor prognostic factors of OS and EFS. After evaluating ALC/AMC and IPS, we stratified patients into three progressively-worse-outcome groups (low-risk: 0 risk factors; intermediate: 1 risk factor; high: 2 risk factors). Our study encourages the combination of ALC/AMC with IPS, for refining risk prediction in advanced HL patients.

Cancer immunotherapy: Strategies for personalization and combinatorial approaches

The results of recent clinical trials using novel immunotherapy strategies such as immune checkpoint blockade and adoptive T-cell therapy approaches including CAR T-cell therapy have clearly established immunotherapy as an important modality for the treatment of cancer besides the traditional approaches of surgery, radiotherapy, and chemotherapy or targeted therapy. However, to date immunotherapy has been shown to induce durable clinical benefit in only a fraction of the patients. The use of combination strategies is likely to increase the number of patients that might benefit from immunotherapy. Indeed, over the last decade, the characterization of multiple immune resistance mechanisms used by the tumor to evade the immune system and the development of agents that target those mechanisms has generated a lot of enthusiasm for cancer immunotherapy. But a critical issue is to determine how best to combine such agents. This review will focus on novel immunotherapy agents currently in development and discuss strategies to develop and personalize combination cancer immunotherapy strategies.

CSF1R Protein Expression in Reactive Lymphoid Tissues and Lymphoma: Its Relevance in Classical Hodgkin Lymphoma

Tumour-associated macrophages (TAMs) have been associated with survival in classic Hodgkin lymphoma (cHL) and other lymphoma types. The maturation and differentiation of tissue macrophages depends upon interactions between colony-stimulating factor 1 receptor (CSF1R) and its ligands. There remains, however, a lack of consistent information on CSF1R expression in TAMs. A new monoclonal antibody, FER216, was generated to investigate CSF1R protein distribution in formalin fixed tissue samples from 24 reactive lymphoid tissues and 187 different lymphoma types. We also analysed the distribution of CSF1R+, CD68+ and CD163+ macrophages by double immunostaining, and studied the relationship between CSF1R expression and survival in an independent series of 249 cHL patients. CSF1R+ TAMs were less frequent in B-cell lymphocytic leukaemia and lymphoblastic B-cell lymphoma than in diffuse large B-cell lymphoma, peripheral T-cell lymphoma, angioimmunoblastic T-cell lymphoma and cHL. HRS cells in cHL and, with the exception of three cases of anaplastic large cell lymphoma, the neoplastic cells in NHLs, lacked detectable CSF1R protein. A CSF1R+ enriched microenvironment in cHL was associated with shorter survival in an independent series of 249 cHL patients. CSF1R pathway activation was evident in the cHL and inactivation of this pathway could be a potential therapeutic target in cHL cases.

Role of tumor-associated macrophages in hematological malignancies

The tumor microenvironment consists of many non-tumor cells such as leukocytes, endothelial cells, and fibroblasts, and phenotypic changes in a tumor microenvironment are believed to be involved in tumor progression and resistance to anticancer treatments. In hematological malignancies, tumor-associated macrophages (TAMs) that have infiltrated lymphoma or leukemia tissues may be involved in tumor progression, and many researchers have studied phenotypic changes in TAMs. This review article summarizes the publications related to TAMs in hematological malignancies, with an emphasis on CD163(+) protumoral TAMs, which seem to be associated with disease progression. Cell-cell interactions between protumoral TAMs and lymphoma or leukemia cells may play an important role in lymphoma or leukemia microenvironments. Although detailed molecular mechanisms of these cell-cell interactions have not yet been clarified, phenotypic characterization of TAMs is thought to be a useful approach for evaluating clinical prognosis. In addition, targeting TAMs may be a new strategy for treating malignant hematological diseases.

Overexpression of Semaphorin4D indicates poor prognosis and prompts monocyte differentiation toward M2 macrophages in epithelial ovarian cancer

Previously, we demonstrated overexpression of semaphorin4D (SEMA4D, CD100) to be closely related to tumor angiogenesis in epithelial ovarian cancers (EOCs). However, the function and expression of SEMA4D in the EOC microenvironment has yet to be clarified in detail. In this study, we confirmed that overexpression of SEMA4D in primary tumors and ascites was related to low differentiation, platinum resistance and a refractory status (P<0.05), while high M2 macrophage count and percentage were evident in EOC patients with advanced FIGO stage and platinum resistance (P<0.05), using immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), and fluorescence-activated cell sorting (FACS), respectively. The data showed correlations of SEMA4D expression and M2 macrophage counts in primary tumors and M2 macrophage percentage in ascites (r=0.281 and 0.355, each P<0.05). In the Cox proportional hazard mode, SEMA4D expression was an independent indicator of overall survival (OS) and progression-free survival (PFS) for EOC patients. Furthermore, higher expression of SEMA4D in ovarian cancer cell lines (SKOV3, A2780, and SW626) and their supernatants were found than that in a human primary cultured ovarian cell and its supernatant by reversed transcript PCR (RT-PCR), Western blotting and ELISA, respectively. Interestingly, peripheral blood monocytes (MOs) tended towards the M2-polarized macrophage phenotype (CD163high) in vitro after human recombined soluble SEMA4D protein stimulation. These findings suggest that SEMA4D might possibly serve as a reliable tool for early and accurate prediction of EOC poor prognosis and could playan important role in promoting tumor dissemination and metastasis in the EOC microenvironment. Thus SEMA4D and its role in macrophage polarization in EOC warrants further study.

The classical Hodgkin lymphoma tumor microenvironment: macrophages and gene expression-based modeling

Despite the high cure rate in classical Hodgkin lymphoma (CHL), more accurate tailoring of upfront treatment is required to maximize cure while avoiding unnecessary short- and long-term treatment side effects. To this end, the unique tumor microenvironment of CHL has been searched extensively for prognostic biomarkers. Beyond targeted immunohistochemistry (IHC) studies, gene expression profiling (GEP) of diagnostic whole tissue biopsies has allowed a de novo approach to biomarker discovery. Among numerous candidate biomarkers, an association between the number of tumor-associated macrophages in the microenvironment and outcomes after ABVD (doxorubicin + bleomycin + vinblastine + dacarbazine) chemotherapy emerged, and multiple subsequent studies have validated this biological relationship using IHC. These studies have also defined key aspects for macrophage interrogation, including the characteristics of the CD68 and CD163 antibodies, appropriate scoring methodologies, and the identification of specific patient populations in which macrophage IHC may not be prognostic. The GEP studies also led to the development of gene expression-based prognostic models for advanced-stage CHL, with new technologies allowing reliable gene expression quantitation using RNA from routinely produced formalin-fixed paraffin-embedded biopsies. The bridge to predictive biomarkers that can be used reliably to inform upfront treatment selection requires further studies to demonstrate that these biomarkers can identify robustly, at diagnosis, patients at high risk of treatment failure with ABVD and that this risk may be overcome using alternative treatments.

Macrophages and dendritic cells as actors in the immune reaction of classical Hodgkin lymphoma

BACKGROUND

The inflammatory infiltrate plays a pivotal role in classical Hodgkin lymphoma (cHL). Here, we focussed on the role of macrophages (MΦ) and dendritic cells (DC).

METHODS

MΦ and DC infiltration was investigated in 106 cHL specimens using immunohistochemistry and cytokine expression was analyzed in a subset by real-time PCR. Human peripheral blood-derived monocytes, DC, MΦ stimulated with GM-CSF (MΦGM-CSF, pro-inflammatory MΦ-1-model) or M-CSF (MΦM-CSF, immunomodulatory MΦ-2-model) were incubated with cHL cell line (L1236, HDLM2) supernatants (SN). DC maturation or MΦ polarization were investigated by flow cytometry. Furthermore, the impact of DC or MΦ on cHL cell proliferation was analyzed by BrdU/CFSE assay.

RESULTS

In cHL tissues mature myeloid (m)DC and MΦ predominated. High numbers of CD83+ mDC and low numbers of CD163+ MΦ were associated with improved disease specific survival. In numerous cHL specimens increased levels of both pro- and anti-inflammatory cytokines and of IL13 and GM-CSF were observed compared to reactive lymphadenopathies. Maturation of DC and induction and maintenance of an immunomodulatory MΦ phenotype were promoted by SN derived from cHL cell lines. TNFα neutralization in SN resulted in a significant inhibition of mDC maturation. DC and pro-inflammatory MΦ inhibited the proliferation of cHL cells.

CONCLUSION

Adopting an immunomodulatory phenotype is a potential mechanism for how MΦ promote immune evasion in cHL. Mature DC, in contrast, might participate in antitumoral immunity.

CD68 staining correlates with the size of residual mass but not with survival in classical Hodgkin lymphoma

The prognostic role of CD68 tumor-associated macrophages in classic Hodgkin lymphoma (cHL) remains controversial. We stained diagnostic biopsies and scored for CD68 using the PGM1 antibody among 98 consecutive patients with cHL from our center followed over a median of 45 months for progression-free survival (PFS). Among 79 patients we assessed interim and post-treatment positron emission tomography-computed tomography (PET-CT). Residual mass (RM) size was based on the greatest diameter of the largest mass seen in post-treatment imaging, and percent reduction was calculated by comparing RM size with its greatest pretreatment diameter. We found a significant association between CD68 positivity and absolute size of initial disease mass (p = 0.014) and residual mass at the end of therapy (p = 0.006) but no association was observed with interim PET-CT results or PFS. Our findings suggest that macrophages may influence tumor size by altering the microenvironment. This study does not support a prognostic role of CD68 positivity in predicting survival.

Depletion of M2-like tumor-associated macrophages delays cutaneous T-cell lymphoma development in vivo

Macrophages have key roles in tumor development and invasion in several human cancers, but little is known about their pathogenic role in cutaneous T-cell lymphoma (CTCL). Herein, we used PCR arrays to profile the expression of inflammatory cytokines in 12 patients with mycosis fungoides (MF), the most common variant of CTCL. Compared with normal controls, MF skin displayed increased mRNA levels of macrophage-related cytokines. Moreover, we detected CD163, a reliable marker of tumor-associated macrophages, in the tumor microenvironment of MF biopsies. To demonstrate that macrophages had a role in CTCL tumorigenesis, we xenografted human CTCL tumor cells in immunocompromised mice and compared tumor development using clodronate-containing liposomes to deplete macrophages in mice. Mice treated with clodronate-containing liposomes show markedly less tumor growth compared with mice treated with phosphate-buffered saline-containing liposomes (P<0.001). We also noted a strong correlation between macrophage depletion and decreased expression of vascular marker, CD31, and lymphatic marker, podoplanin, suggesting a role for macrophages in angiogenesis. In vitro, clodronate-containing liposomes killed activated murine M2 macrophages, but not Hut78 cells, demonstrating selective ability to induce apoptosis in macrophages. Our data indicate that macrophages have a critical role in the progression of Hut78 cell tumor formation in skin, thus providing a new therapeutic strategy for CTCL.

Human leukocyte antigen-DR expression on flow cytometry and tumor-associated macrophages in diffuse large B-cell lymphoma treated by rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone therapy: retrospective cohort study

Loss of human leukocyte antigen (HLA)-DR expression may be related to a poor prognosis of diffuse large B-cell lymphoma (DLBCL), and tumor-associated macrophages (TAMs) may influence tumor progression. We retrospectively reviewed 36 patients with newly diagnosed DLBCL who received R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) therapy at Kanagawa Cancer Center in Japan from 2004 to 2010. HLA-DR expression by lymphoma cells was evaluated using flow cytometry, and TAMs in lymphoma tissue were detected by immunohistochemistry for CD68 as a marker of macrophages and CD163 as a marker of M2 TAMs. Three-year overall survival was, respectively, 100% versus 69.6% in the HLA-DR "bright" and "not bright" groups (p = 0.012). Patients from the HLA-DR "not bright" group with strong CD163 expression had a much worse prognosis than other patients. The HLA-DR status shown by flow cytometry can be used to predict the prognosis of patients with DLBCL receiving R-CHOP therapy and prognostic accuracy can be increased by also assessing TAMs.

CD163 immunohistochemistry is superior to CD68 in predicting outcome in classical Hodgkin lymphoma

OBJECTIVES

In recent years, research has increasingly focused on the microenvironment of classical Hodgkin lymphoma (CHL) as a predictor of treatment outcome. The focus of this study was to assess the interobserver reproducibility in interpreting macrophage-associated immunohistochemistry (IHC) for CD68 and CD163 in a retrospective cohort of 88 patients with CHL.

METHODS

Staining results were correlated with clinical outcome in all patients and those with a high international prognostic score (IPS).

RESULTS

The intraclass correlation (ICC) for the five hematopathologists interpreting the IHC was stronger for CD163 (0.70) than for CD68 (0.50). Using a cutoff of 25% mean macrophage reactivity and including all patients, a statistically significant difference in overall survival (OS) was seen only for CD163 (P = .0006) and not for CD68 (P = .414). Patients with a mean CD163 reactivity of 25% or more had a median OS of 71 months vs 101 months for patients with less than 25% reactivity. CD163 retained statistical significance in multivariate analysis. In patients with advanced-stage CHL with high IPS, OS was also significantly worse for those with a mean CD163 reactivity of 25% or higher.

CONCLUSIONS

Our study confirms previous reports of a prognostic role of tumor-infiltrating macrophages in CHL, but only for CD163. Although most of the literature supports an increasing role of macrophage IHC as a predictor of clinical outcome, successful clinical translation will require a standardized method and reporting system.

CD163 expression was associated with angiogenesis and shortened survival in patients with uniformly treated classical Hodgkin lymphoma

Background

Recent studies have reported the prognostic value of tissue-associated magrophages (TAMs) in classical Hodgkin lymphoma (cHL). In addition, TAMs are implicated in the tumor angiogenesis. In this study, we examined the prognostic relevance of TAMs in relation to vascular endothelial growth factor (VEGF) expression and angiogenesis in uniformly treated cases of cHL.

Methods

Diagnostic tissue from 116 patients with ABVD-treated cHL was evaluated retrospectively by immunohistochemical analysis for CD68, CD163 and VEGF expression and for CD31 expression as a measure of microvessel density (MVD).

Results

High CD163 expression (≥35% of cellularity) correlated with VEGF expression (Pearson’s Chi-square test, P = 0.008) and MVD (Spearman correlation coefficient 0.310, P<0.001). High CD163 expression was associated with inferior event-free survival (EFS, P = 0.005) and overall survival (OS, P<0.001) in univariate analysis. In multivariate analysis, high CD163 expression was strongly associated with inferior EFS (P = 0.043) and OS (P = 0.008). Patients with high MVD had a lower OS than those with low MVD, but the difference was not significant (P = 0.071, respectively). While high expression of CD68 was also associated with inferior EFS (P = 0.007), it showed no correlation with VEGF or MVD.

Conclusions

Our data confirms that CD163 expression provides independent prognostic information in cHL. The correlation of CD163 with VEGF expression and MVD suggests the role of CD163-positive cells in tumor angiogenesis of cHL.

Clinical significance of macrophage heterogeneity in human malignant tumors

The fact that various immune cells, including macrophages, can be found in tumor tissue has long been known. With the recent introduction of the novel concept of macrophage differentiation into a classically activated phenotype (M1) and an alternatively activated phenotype (M2), the role of tumor-associated macrophages (TAMs) is gradually beginning to be elucidated. Specifically, in human malignant tumors, TAMs that have differentiated into M2 macrophages act as “protumoral macrophages” and contribute to the progression of disease. Based on recent basic and preclinical research, TAMs that have differentiated into protumoral or M2 macrophages are believed to be intimately involved in the angiogenesis, immunosuppression, and activation of tumor cells. In this paper, we specifically discuss both the role of TAMs in human malignant tumors and the cell–cell interactions between TAMs and tumor cells.

The prognostic impact of tumour-associated macrophages and Reed-Sternberg cells in paediatric Hodgkin lymphoma

BACKGROUND

Tumour-associated macrophages (TAM) are associated with treatment failure in adults with Hodgkin lymphoma (HL). Equivalent data in paediatric HL are sparse. We aimed to determine the prognostic significance of TAM and Reed-Sternberg (RS) cells in paediatric HL.

METHODS

All children aged 0-18 with HL between 1980 and 2009 with available diagnostic biopsy material were identified. A treatment failure-enriched cohort was assembled. Demographic, disease and outcome data were abstracted. Tissue microarrays with duplicate cores were constructed from diagnostic biopsy material and stained with immunohistochemical markers for TAM (CD68, CD163) and RS (CD30). A high score was defined as >5% positive cells relative to overall cellularity in any core. The association of candidate variables with event-free survival (EFS) was determined using Cox proportional hazards.

RESULTS

The final study cohort comprised 96 patients with a median age of 14 years (interquartile range 11-15). Agreement on scores between cores from the same biopsy revealed weighted kappas of 0.60, 0.68 and 0.73 for CD30, CD68 and CD163 respectively, indicating moderate tumour heterogeneity. In univariate analysis, a high CD30 score was significantly associated with treatment failure (hazard ratio (HR) 2.27; 95th confidence interval 1.01-5.11; p<0.05). High CD68 and CD163 scores were not associated with EFS.

CONCLUSIONS

Unlike adult HL, a higher percentage of RS cells was associated with poor outcome, while a higher percentage of TAM was not. Adult HL findings may not extend to paediatric HL. Cooperative group trials of paediatric HL should prospectively determine the association of different components of the tumour microenvironment with outcome.