Vascular endothelial growth factor, CD68, and epidermal growth factor receptor expression and survival in patients with Stage II and Stage III colon carcinoma: a role for the host response in prognosis

Directed Mutagenesis for Arginine Substitution of a Phaseolus acutifolius Recombinant Lectin Disrupts Its Cytotoxic Activity

Recently, we reported that a recombinant Tepary bean (Phaseolus acutifolius) lectin (rTBL-1) induces apoptosis in colon cancer cell lines and that cytotoxicity was related to differential recognition of β1-6 branched N-glycans. Sequencing analysis and resolution of the rTBL-1 3D structure suggest that glycan specificity could be strongly influenced by two arginine residues, R103 and R130, located in the carbohydrate binding pocket. The aim of this work was to determine the contribution of these residues towards cytotoxic activity. Two rTBL-1 mutants were produced in Pichia pastoris, biochemically characterized, and cytotoxic effects were evaluated on human colorectal cancer cells (HT-29). Substitution of either of the arginine residues with glutamines resulted in significant reductions in cytotoxic activity, with losses of 1.5 and 3 times for R103 and R130, respectively. Docking analysis showed that the mutations decreased lectin affinity binding to some Epidermal Growth Factor Receptor (EGFR)-related N-glycans. Together, these findings confirm that both of the selected arginine residues (R103 and R130) play a key role in the recognition of tumor cell glycoconjugates by rTBL-1.

Exploring the relationship between ulcerative colitis, colorectal cancer, and prostate cancer

Chronic systemic inflammation caused by diseases such as ulcerative colitis (UC) and Crohn's disease (CD) increases the risk of developing colorectal cancer (CRC). Recent evidence indicates that patients with UC are more susceptible to prostate cancer (PCa), and individuals with PCa may also be at a higher risk of developing CRC. However, these relationships are not well defined. A better understanding of this phenomenon could improve the identification of high-risk populations. In this study, we characterized these relationships with experiments using preclinical mouse models of dextran sulfate sodium (DSS)-induced colitis (DSS-UC) and DSS/azoxymethane (AOM)-induced CRC (DSS/AOM-CRC) in wild-type and conditional transgenic mice of PCa. We showed that DSS-induced UC was more severe in mice with PCa and resulted in the development of CRC in the absence of AOM. We further showed that PCa-free mice that developed DSS-induced UC also showed histological changes in the normal prostate that resembled proliferative inflammatory atrophy. Finally, we used immunohistochemical immune profiling to show that mice with PCa-induced chronic systemic inflammation accumulated Gr1+ myeloid cells in the normal colon and exposure to DSS further enriched these cells in active colitis regions and colon tumors. Our study provides evidence to support a link between systemic chronic inflammation and cancer.

Using a pan-cancer atlas to investigate tumour associated macrophages as regulators of immunotherapy response

The paradigm for macrophage characterization has evolved from the simple M1/M2 dichotomy to a more complex model that encompasses the broad spectrum of macrophage phenotypic diversity, due to differences in ontogeny and/or local stimuli. We currently lack an in-depth pan-cancer single cell RNA-seq (scRNAseq) atlas of tumour-associated macrophages (TAMs) that fully captures this complexity. In addition, an increased understanding of macrophage diversity could help to explain the variable responses of cancer patients to immunotherapy. Our atlas includes well established macrophage subsets as well as a number of additional ones. We associate macrophage composition with tumour phenotype and show macrophage subsets can vary between primary and metastatic tumours growing in sites like the liver. We also examine macrophage-T cell functional cross talk and identify two subsets of TAMs associated with T cell activation. Analysis of TAM signatures in a large cohort of immune checkpoint inhibitor-treated patients (CPI1000 + ) identify multiple TAM subsets associated with response, including the presence of a subset of TAMs that upregulate collagen-related genes. Finally, we demonstrate the utility of our data as a resource and reference atlas for mapping of novel macrophage datasets using projection. Overall, these advances represent an important step in both macrophage classification and overcoming resistance to immunotherapies in cancer.

Immunoexpression of CD44, p16 and VEGF in oral cancer

Objectives

The aim of the present study was to examine the immunoexpression of CD44, p16 and VEGF in oral squamous cell carcinoma (OSCC) and correlate them to clinicopathological parameters and survival outcomes in order to clarify their prognostic impact.

Material and Methods

A total of 68 individuals with OSCC recruited between 2011 and 2015 from two referral centres were enrolled in the study. The samples were placed on silanized glass slides and subjected to immunohistochemistry using anti-p16, anti-CD44 and anti-VEGF antibodies. The H Score was used for p16 and VEGF, while CD44 was scored according to the percentage of stained cells. Chi-square tests and Fisher's exact probability tests were used to compare clinicopathological characteristics according to the immunohistochemical expression, while overall survival and disease-free survival were estimated and compared using the Kaplan-Meier method and log-rank test, respectively. For all hypothesis tests, the level of significance was set at P ≤ 0.05.

Results

No correlation was observed between the expression of tumour VEGF, p16 and CD44, and the clinicopathological characteristics analysed. Patients with high stromal VEGF expression had better disease-free survival than patients with low VEGF expression (P = 0.023).

Conclusion

In summary, P16, CD44 and tumour VEGF did not prove to be good prognostic biomarkers. Stromal VEGF expression is suggested to be a good candidate prognostic biomarker, although additional studies are needed.

IL17RB and IL17REL Expression Are Associated with Improved Prognosis in HPV-Infected Head and Neck Squamous Cell Carcinomas

Changes in the cellular secretome are implicated in virus infection, malignancy, and anti-tumor immunity. We analyzed the association between transcriptional signatures (TS) from 24 different immune and stromal cell types on the prognosis of HPV-infected and HPV-free head and neck squamous carcinoma (HNSCC) patients from The Cancer Genome Atlas (TCGA) cohort. We found that HPV-positive HNSCC patients have tumors with elevated immune cell TS and improved prognosis, which was specifically associated with an increased tumor abundance of memory B and activated natural killer (NK) cell TS, compared to HPV-free HNSCC patients. HPV-infected patients upregulated many transcripts encoding secreted factors, such as growth factors, hormones, chemokines and cytokines, and their cognate receptors. Analysis of secretome transcripts and cognate receptors revealed that tumor expression of IL17RB and IL17REL are associated with a higher viral load and memory B and activated NK cell TS, as well as improved prognosis in HPV-infected HNSCC patients. The transcriptional parameters that we describe may be optimized to improve prognosis and risk stratification in the clinic and provide insights into gene and cellular targets that may potentially enhance anti-tumor immunity mediated by NK cells and memory B cells in HPV-infected HNSCC patients.

EGFR and p38MAPK Contribute to the Apoptotic Effect of the Recombinant Lectin from Tepary Bean (Phaseolus acutifolius) in Colon Cancer Cells

Previous works showed that a Tepary bean lectin fraction (TBLF) induced apoptosis on colon cancer cells and inhibited early colonic tumorigenesis. One Tepary bean (TB) lectin was expressed in Pichia pastoris (rTBL-1), exhibiting similarities to one native lectin, where its molecular structure and in silico recognition of cancer-type N-glycoconjugates were confirmed. This work aimed to determine whether rTBL-1 retained its bioactive properties and if its apoptotic effect was related to EGFR pathways by studying its cytotoxic effect on colon cancer cells. Similar apoptotic effects of rTBL-1 with respect to TBLF were observed for cleaved PARP-1 and caspase 3, and cell cycle G0/G1 arrest and decreased S phase were observed for both treatments. Apoptosis induction on SW-480 cells was confirmed by testing HA2X, p53 phosphorylation, nuclear fragmentation, and apoptotic bodies. rTBL-1 increased EGFR phosphorylation but also its degradation by the lysosomal route. Phospho-p38 increased in a concentration- and time-dependent manner, matching apoptotic markers, and STAT1 showed activation after rTBL-1 treatment. The results show that part of the rTBL-1 mechanism of action is related to p38 MAPK signaling. Future work will focus further on the target molecules of this recombinant lectin against colon cancer.

Relationship between CD 163 Tumor-Associated Macrophages and Colorectal-Cancer Stem Cell Markers

BACKGROUND: Colorectal-cancer stem cells (CR-CSCs) represent a specific subpopulation of colorectal cancer (CRC) cells, which are characterized by the expression of CD133 and CD166. Tumor-associated macrophages (TAMs), found near CSCs may represent polarized macrophages, which are characterized by CD163 expression. In most tumors, TAMs may promote aggressive tumor development, leading to poor prognoses. AIM: The aim of this study was to determine whether any association exists between CD163 expression in TAMs and CD133 and CD166 expression in CR-CSCs. METHODS: This study used a cross-sectional design that was conducted at the General Hospital and affiliates in Medan, from September 2018 to July 2019. CRC tissues were collected from colonoscopy biopsies and surgical resections performed on CRC patients, who fulfilled all necessary inclusion and exclusion criteria and provided informed consent. Subjects were divided into high- and low-CD163-level groups. We analyzed the expression levels of CD163, CD133, and CD166 using immunohistochemical (IHC) assays. RESULTS: A total of 118 CRC patients were enrolled in this study, of whom 58.5% were male. No significant differences in hemoglobin, leukocyte, or platelet levels were observed between high- and low-level CD163 expression. We didn’t find any significant association of CD163 TAM with CRC histological grade and TNM stagings. Significant associations were found between the CD 163 expression level and the CD133 expression level (p < 0.001) and between the CD 163 expression level and the CD166 expression level (p< 0.001). Increased TAM levels of CD163 was associated with 2.770-fold and 2.616-fold increased risks of elevated CD133 and CD166 levels, respectively. CONCLUSION: An association was found between the expression levels of CD163 in TAMs and the expression levels of CD133 and CD166 in CR-CSCs.

Tumor-Associated Macrophages (TAMs) in Colorectal Cancer (CRC): From Mechanism to Therapy and Prognosis

Colorectal cancer (CRC) is a malignant tumor in the digestive system whose incidence and mortality is high-ranking among tumors worldwide. The initiation and progression of CRC is a complex process involving genetic alterations in cancer cells and multiple factors from the surrounding tumor cell microenvironment. As accumulating evidence has shown, tumor-associated macrophages (TAMs)—as abundant and active infiltrated inflammatory cells in the tumor microenvironment (TME)—play a crucial role in CRC. This review focuses on the different mechanisms of TAM in CRC, including switching of phenotypical subtypes; promoting tumor proliferation, invasion, and migration; facilitating angiogenesis; mediating immunosuppression; regulating metabolism; and interacting with the microbiota. Although controversy remains in clinical evidence regarding the role of TAMs in CRC, clarifying their significance in therapy and the prognosis of CRC may shed new light on the optimization of TAM-centered approaches in clinical care.

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.

Carcinoma origin dictates differential skewing of monocyte function

Macrophages are versatile cells, which phenotype is profoundly influenced by their environment. Pro-inflammatory classically activated or M1 macrophages, and anti-inflammatory alternatively-activated or M2 macrophages represent two extremes of a continuum of functional states. Consequently, macrophages that are present in tumors can exert tumor-promoting and tumor-suppressing activity, depending on the tumor milieu. In this study we investigated how human monocytes-the precursors of macrophages-are influenced by carcinoma cells of different origin. We demonstrate that monocytes, stimulated with breast cancer supernatant, showed increased expression of interleukin (IL)-10, IL-8 and chemokines CCL17 and CCL22, which are associated with an alternatively-activated phenotype. By contrast, monocytes that were cultured in supernatants of colon cancer cells produced more pro-inflammatory cytokines (e.g., IL-12 and TNFα) and reactive oxygen species. Secretome analysis revealed differential secretion of proteins by colon and breast cancer cell lines, of which the proteoglycan versican was exclusively secreted by colon carcinoma cell lines. Reducing active versican by blocking with monoclonal antibodies or shRNA diminished pro-inflammatory cytokine production by monocytes. Thus, colon carcinoma cells polarize monocytes toward a more classically-activated anti-tumorigenic phenotype, whereas breast carcinomas predispose monocytes toward an alternatively activated phenotype. Interestingly, presence of macrophages in breast or colon carcinomas correlates with poor or good prognosis in patients, respectively. The observed discrepancy in macrophage activation by either colon or breast carcinoma cells may therefore explain the dichotomy between patient prognosis and macrophage presence in these different tumors. Designing new therapies, directing development of monocytes toward M1 activated tumor macrophages in cancer patients, may have great clinical benefits.

Tumor-Associated Macrophages in Human Breast, Colorectal, Lung, Ovarian and Prostate Cancers

Tumor-associated macrophages (TAMs) are major innate immune cells that constitute up to 50% of the cell mass of human tumors. TAMs are highly heterogeneous cells that originate from resident tissue-specific macrophages and from newly recruited monocytes. TAMs' variability strongly depends on cancer type, stage, and intratumor heterogeneity. Majority of TAMs are programmed by tumor microenvironment to support primary tumor growth and metastatic spread. However, TAMs can also restrict tumor growth and metastasis. In this review, we summarized the knowledge about the role of TAMs in tumor growth, metastasis and in the response to cancer therapy in patients with five aggressive types of cancer: breast, colorectal, lung, ovarian, and prostate cancers that are frequently metastasize into distant organs resulting in high mortality of the patients. Two major TAM parameters are applied for the evaluation of TAM correlation with the cancer progression: total amount of TAMs and specific phenotype of TAMs identified by functional biomarkers. We summarized the data generated in the wide range of international patient cohorts on the correlation of TAMs with clinical and pathological parameters of tumor progression including lymphatic and hematogenous metastasis, recurrence, survival, therapy efficiency. We described currently available biomarkers for TAMs that can be measured in patients' samples (tumor tissue and blood). CD68 is the major biomarker for the quantification of total TAM amounts, while transmembrane receptors (stabilin-1, CD163, CD206, CD204, MARCO) and secreted chitinase-like proteins (YKL-39, YKL-40) are used as biomarkers for the functional TAM polarization. We also considered that specific role of TAMs in tumor progression can depend on the localization in the intratumoral compartments. We have made the conclusion for the role of TAMs in primary tumor growth, metastasis, and therapy sensitivity for breast, colorectal, lung, ovarian, and prostate cancers. In contrast to other cancer types, majority of clinical studies indicate that TAMs in colorectal cancer have protective role for the patient and interfere with primary tumor growth and metastasis. The accumulated data are essential for using TAMs as biomarkers and therapeutic targets to develop cancer-specific immunotherapy and to design efficient combinations of traditional therapy and new immunomodulatory approaches.

The prognostic and clinicopathological value of tumor-associated macrophages in patients with colorectal cancer: a systematic review and meta-analysis

PURPOSE

There is a growing literature on the significance of tumor-associated macrophages (TAMs) in colorectal cancer (CRC). However, the role of TAMs in predicting the prognosis of CRC remains controversial. The current study aims to determine the prognostic and clinicopathological value of different types and distribution of TAMs in CRC.

METHODS

A comprehensive literature search of PubMed, Embase, and Cochrane Library databases was conducted from the inception to 1 September 2019. The correlations of TAMs with overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and clinicopathological characteristics were analyzed.

RESULTS

A total of 5,575 patients from 29 studies were included in this meta-analysis. The pooled hazard ratios (HRs) indicated that high density of pan-macrophages in tumor invasive margin (IM) was associated with better OS (HR = 0.57, 95%CI = 0.38-0.85), DFS (HR = 0.32, 95%CI = 0.19-0.52), and CSS (HR = 0.56, 95%CI = 0.41-0.77). Moreover, the high density of pan-macrophages in tumor center (TC) was correlated with better DFS (HR = 0.66, 95%CI = 0.45-0.96). However, high expression of M2 macrophages in TC was associated with poor DFS (HR = 2.42, 95%CI = 1.45-4.07) and CSS (HR = 1.74, 95%CI = 1.24-2.44). High M2 macrophages density in IM was also associated with short DFS (HR = 2.81, 95%CI = 1.65-4.77). In addition, the results showed that high density of pan-macrophages in IM was associated with no tumor metastasis, while high M2 macrophages density in TC was correlated with poor tumor differentiation.

CONCLUSION

High Pan-TAMs density in IM has a positive effect on the prognosis of CRC patients, while high density M2 macrophage infiltration in TC is a strong indicator of poor prognosis.

Tumor-associated macrophage infiltration and prognosis in colorectal cancer: systematic review and meta-analysis

BACKGROUND

Tumor-associated macrophages (TAMs) are key components of colorectal cancer (CRC) microenvironment, but their role in CRC prognosis is not fully defined.

OBJECTIVE

This study aimed to evaluate prognostic value of different types and distribution of TAMs in CRC.

METHODS

Total 27 studies with 6115 patients were searched from PubMed and Embase and analyzed to determine the association between TAMs, including distinct TAM subsets and infiltration location, and CRC survival. The prognostic impact of TAMs on CRC was further stratified by tumor type and mismatch repair system (MMR) status.

RESULTS

A pooled analysis indicated that high density of TAMs in CRC tissue was significantly associated with favorable 5-year overall survival (OS) but not with disease-free survival (DFS). CD 68⁺ TAM subset correlated with better 5-year OS, while neither CD68⁺NOS2⁺ M1 subset nor CD163⁺ M2 subset was correlated with 5-year OS. Increased CD68⁺ TAM infiltration in tumor stroma but not in tumor islet predicted improved 5-year OS. Stratification by tumor type and MMR status showed that in colon cancer or MMR-proficient CRC, elevated TAM density was associated with better 5-year OS.

CONCLUSIONS

High infiltration of CD68⁺ TAMs could be a favorable prognostic marker in CRC. Future therapies stimulating CD68⁺ TAM infiltration may be promising in CRC treatment.

Targeting the Tumor Microenvironment with Fluorescence-Activatable Bispecific Endoglin/Fibroblast Activation Protein Targeting Liposomes

Liposomes are biocompatible nanocarriers with promising features for targeted delivery of contrast agents and drugs into the tumor microenvironment, for imaging and therapy purposes. Liposome-based simultaneous targeting of tumor associated fibroblast and the vasculature is promising, but the heterogeneity of tumors entails a thorough validation of suitable markers for targeted delivery. Thus, we elucidated the potential of bispecific liposomes targeting the fibroblast activation protein (FAP) on tumor stromal fibroblasts, together with endoglin which is overexpressed on tumor neovascular cells and some neoplastic cells. Fluorescence-quenched liposomes were prepared by hydrating a lipid film with a high concentration of the self-quenching near-infrared fluorescent dye, DY-676-COOH, to enable fluorescence detection exclusively upon liposomal degradation and subsequent activation. A non-quenched green fluorescent phospholipid was embedded in the liposomal surface to fluorescence-track intact liposomes. FAP- and murine endoglin-specific single chain antibody fragments were coupled to the liposomal surface, and the liposomal potentials validated in tumor cells and mice models. The bispecific liposomes revealed strong fluorescence quenching, activatability, and selectivity for target cells and delivered the encapsulated dye selectively into tumor vessels and tumor associated fibroblasts in xenografted mice models and enabled their fluorescence imaging. Furthermore, detection of swollen lymph nodes during intra-operative simulations was possible. Thus, the bispecific liposomes have potentials for targeted delivery into the tumor microenvironment and for image-guided surgery.

Tissue Infiltrating Immune Cells as Prognostic Biomarkers in Endometrial Cancer: A Meta-Analysis

Background

The association between tumour-infiltrating immune cells and the prognosis of endometrial cancer (EC) is controversial due to the smaller sample sizes and limited statistical power of the extant studies. We carried out a meta-analysis of the relationship between tumour-infiltrating immune cells and EC survival outcomes.

Methods

A literature search in multiple databases was carried out up to December 2019. Pooled hazard ratio (HRs) and 95% confidence intervals (CIs) were calculated by the Z-test to assess the association between infiltrating immune cells and overall survival (OS), progression-free survival (PFS), relapse-free survival (RFS), disease-specific survival (DSS), and disease-free survival (DFS). A subgroup analysis was performed based on the localisation of immune cells in tumour parenchyma or stroma, immune markers, and the International Federation of Gynecology and Obstetrics stage. Heterogeneity and publication bias between studies were evaluated by Cochran's Q-test and Egger regression test, respectively.

Results

Seventeen studies were included in the analysis. The pooled HR of OS, PFS, DSS, and DFS indicated that a high CD8⁺ T cell density was associated with a favorable prognosis in EC patients. A significant relationship was found between a high density of CD45RO⁺ T cells and a favorable OS in EC patients, but the FoxP3⁺ T cell density was not associated with either OS or RFS. A high TAM density was associated with a worse PFS. However, a sensitivity analysis indicated that the findings of PFS and DSS in CD8⁺ T cell and PFS in TAM were not robust results.

Conclusion

This is the first meta-analysis of the relationship between tumour-infiltrating immune cells and the prognosis of EC. High CD8⁺ and CD45RO⁺ T cell densities in tumours were associated with favorable outcomes in EC patients.

Prognostic value and clinicopathological roles of phenotypes of tumour-associated macrophages in colorectal cancer

BACKGROUND

The role of tumour-associated macrophages (TAMs) in predicting the prognosis of colorectal cancer (CRC) remains controversial. This is especially so because the prognostic significance and clinicopathological relevance of different subtypes of TAMs in the immune microenvironment of CRC have not yet been established.

OBJECTIVE

To assess the clinicopathological and prognostic value of pan-macrophages, M1-macrophages or M2-macrophages in patients with CRC.

METHODS

Comprehensive searched on the Medline/PubMed, Web of Science (WoS) and Google Scholar databases was conducted to identify relevant studies published up to April 2019. The association between overall survival (OS), cancer-specific survival (CSS) or disease-free survival (DFS) and TAMs was analysed by meta-analysis.

RESULTS

A total of 3749 patients from 17 studies were included. The pooled hazard ratios (HRs) indicated that high-density pan-macrophages improved OS (HR 0.67, P = 0.02). The pooled HR for M2-macrophages showed that high M2-macrophages infiltration was significantly associated with shorter OS (HR 2.93, P < 0.0001) and DFS (HR 2.04, P = 0.02). The pooled odds ratios (ORs) revealed that high-density TAMs was associated with high CD8+ T cell infiltration (OR 2.04, P = 0.007), no distant metastasis (NDM) (OR 0.38, P < 0.0001), microsatellite instability-high (MSI-H) (OR 0.38, P = 0.001), no lymph node metastasis (NLNM) (OR 0.54, P = 0.0002) and non-mucinous cancer (OR 0.39, P < 0.00001).

CONCLUSIONS

Unlike other solid tumours, high-density CD68+ macrophage infiltration can be a good prognostic marker for CRC. However, when macrophages act as targets of combination therapy in CRC treatment, this might be more effective for CRC patients with high CD8+ T cell infiltrate, NDM, MSI-H, NLNM and non-mucinous cancer.

Conceptual Development of Immunotherapeutic Approaches to Gastrointestinal Cancer

Gastrointestinal (GI) cancer is one of the common causes of cancer-related death worldwide. Chemotherapy and/or immunotherapy are the current treatments, but some patients do not derive clinical benefits. Recently, studies from cancer molecular subtyping have revealed that tumor molecular biomarkers may predict the immunotherapeutic response of GI cancer patients. However, the therapeutic response of patients selected by the predictive biomarkers is suboptimal. The tumor immune-microenvironment apparently plays a key role in modulating these molecular-determinant predictive biomarkers. Therefore, an understanding of the development and recent advances in immunotherapeutic pharmacological intervention targeting tumor immune-microenvironments and their potential predictive biomarkers will be helpful to strengthen patient immunotherapeutic efficacy. The current review focuses on an understanding of how the host-microenvironment interactions and the predictive biomarkers can determine the efficacy of immune checkpoint inhibitors. The contribution of environmental pathogens and host immunity to GI cancer is summarized. A discussion regarding the clinical evidence of predictive biomarkers for clinical trial therapy design, current immunotherapeutic strategies, and the outcomes to GI cancer patients are highlighted. An understanding of the underlying mechanism can predict the immunotherapeutic efficacy and facilitate the future development of personalized therapeutic strategies targeting GI cancers.

M2 macrophage infiltration into tumor islets leads to poor prognosis in non-small-cell lung cancer

Background: Lung cancer is the leading cause of cancer-related death worldwide. Although the macrophages can affect the development of tumor, the contribution of macrophages to the prognosis of non-small-cell lung cancer (NSCLC) is still controversial. Moreover, anti-PD-1 therapy can redirect macrophages from an M2 to an M1 phenotype, suggesting that tumor PD-L1 may affect the prognostic role of macrophages. Therefore, in this study, we aimed to display a macrophage landscape to clarify the function of macrophages, considering the localization and polarization of the macrophages, and evaluate the effect of M2 macrophages and tumor PD-L1 in combination on the prognosis of NSCLC. Methods: We performed multiplex quantitative immunofluorescence staining of pan-cytokeratin (CK), CD68, CD163, PD-L1, and DAPI on one tissue specimen simultaneously from 137 NSCLC patients. Results: M2 macrophages, involved marginM2 (M2 macrophages in tumor stroma), and centralM2 (M2 macrophages infiltrating into tumor islets) increased as the tumor stage increased. More macrophages were found in lung squamous cell carcinoma (LUSC) patients, patients with wild-type EGFR, and smokers than in patients with lung adenocarcinoma (LUAD), patients with EGFR mutations, and non-smokers. Infiltration of centralM2 was an independent prognostic factor of poor overall survival (OS) and disease-free survival (DFS) for NSCLC patients (P<0.05), which was superior to total macrophages and total M2 macrophages. Moreover, patients with centralM2^lessPD-L1^- tumors showed the best OS and DFS, while the patients with centralM2^morePD-L1⁺ tumors showed the worst OS and DFS, and the two groups with centralM2^lessPD-L1⁺ and centralM2^morePD-L1^- were in the middle (P=0.002, 0.034, respectively). Conclusion: Tumor islet-infiltrating M2 macrophages influence the prognosis of NSCLC patients. The analysis of M2 macrophages and tumor PD-L1 in combination may enhance the accuracy of prognostic prediction. This study provides a new understanding of macrophages in the development of NSCLC through the analysis of macrophage landscape.

Prognostic significance of inflammatory cell response in patients with colorectal cancer

Cancer cells are characterized by a low antigenic immunogenicity, a rapid growth and an immunosuppressive effect on the extracellular matrix. These properties induce a weak immune response in colorectal cancer (CRC) carcinogenesis. It is therefore crucial to determine the composition of the inflammatory mass, including neutrophils, macrophages and eosinophils in the tumor tissue of patients with CRC, and to analyze other clinicopathological parameters. The present study included 144 patients diagnosed with CRC. Tissue samples obtained from routine histopathological diagnosis were stained with hematoxylin and eosin. Inflammatory cells were assessed in the invasive front and in the center of the tumor by light microscopy under a high-power magnification. The percentage of neutrophils in the invasive front was significantly higher compared with that in the center of the tumor mass (P<0.01). Macrophages and eosinophils were present in the invasive front and in the center of tumor mass in most cases. The presence of neutrophils, macrophages and eosinophils was correlated with various clinicopathological features. Patients with macrophages present in the center of tumor mass had longer disease-free survival time (P=0.041). In conclusion, the present study demonstrated that the inflammatory cell infiltrate served a significant role in the immune response of patients with CRC. It should be noted that the presence of macrophages localized in the stroma of the central part of the primary tumor mass was associated with the survival time of patients with CRC.

Macrophages in Colorectal Cancer Liver Metastases

Tumor-associated macrophages (TAMs) provide a nurturing microenvironment for metastasis and are concomitantly key determinants of the efficacy of anticancer strategies. TAM represent an extremely heterogeneous population in terms of cell morphology, functions, and tissue localization. Colorectal liver metastases (CLM) display a high heterogeneity, responsible for a wide array of clinical presentations and responsiveness to treatments. In the era of precision medicine, there is a critical need of reliable prognostic markers to improve patient stratification, and, for their predominance in metastatic tissues, TAMs are emerging as promising candidates.

Role of VEGF, CD105, and CD31 in the Prognosis of Colorectal Cancer Cases

INTRODUCTION

Colorectal cancer (CRC) incidence is increasing globally. It is ranked as the second most common cancer in women and the third most in men. Angiogenesis plays a significant role in the development and spread of colorectal cancer. Angiogenesis has been proposed as a prognostic marker in a variety of human neoplasms. In this regard, markers of angiogenic endothelial cells are emerging as targets for cancer therapy.

AIM OF THE WORK

The aim of this study is to evaluate the prognostic impact of tumor angiogenesis assessed by microvessel density (MVD) counting using CD31 and CD105 along with VEGF immunostaining in colorectal cancer patients.

METHODS

VEGF, CD31, and CD105 expressions were evaluated using immunohistochemical staining in 50 patients with colorectal cancer. The relationship between their expressions and clinicopathological factors and outcome of patients were analyzed.

RESULTS

The VEGF expression (70% of the cases) correlated significantly with larger tumor size, higher grade, and advanced tumor stage (p = 0.006, p < 0.001, p < 0.001), respectively. The mean MVD was 24.2 ± VMD by CD105 (p = 0.10.65 019 for CD105, 19.2 ± 8.41 for CD31, respectively. MVD by CD31 (p = 0.023)) and was significant predictive factors for overall survival. Furthermore, the VEGF expression (p = < 0.001) was a significant predictive factor for DFS. There was a statistically significant association between the recurrence rates with both VEGF and CD105 (p < 0.001) but not significant with CD31.

CONCLUSION

CRC patients with high VEGF, CD105, and CD31 expression showed poor prognosis. The immunohistochemical markers could be used for stratification of patients into low-risk and high-risk groups.

Tumour-Associated Macrophages (TAMs) in Colon Cancer and How to Reeducate Them

Tumour-associated macrophage (TAM) serves as the site in which most inflammatory cells coreside. It plays an important role in determining the progression and metastasis of a tumour. The characteristic of TAM is largely dependent on the stimuli present in its tumour microenvironment (TME). Under this environment, however, M2 macrophages are found to be in abundance compared to M1 macrophages which later promote tumour progression. Numerous studies have elucidated the relationship between TAM and the progression of tumour; hence, TAM has now been the subject of interest among researchers for anticancer therapy. This review discusses the role of TAM in colorectal cancer (CRC) and some of the potential candidates that could reeducate TAM to fight against CRC. It is with hope that this review will serve as the foundation in understanding TAM in CRC and helping other researchers to select the most suitable candidate to reeducate TAM that could assist in enhancing the tumouricidal activity of M1 macrophage and eventually repress the development of CRC.

Increased immune cell infiltration in patient-derived tumor explants treated with Traniplatin: an original Pt(iv) pro-drug based on Cisplatin and Tranilast

Elevated intra-tumoral immune infiltrate is associated with an improved prognosis in cancer of distinct origins. Traniplatin (TPT) is a novel platinum(iv) pro-drug based on Cisplatin (CDDP) and the marketed drug Tranilast. When compared in vitro to Cisplatin, TPT showed increased cytotoxic activity against colon and lung cancer cells but decreased activity against immune cells. In addition, TPT efficiency was evaluated in tumor explants derived from colorectal cancer samples from patients subjected to intended curative surgery. TPT induced strong intra-tumoral cytotoxic activity yet was associated with an elevated presence of immune cell infiltrate, suggesting a reduced cytotoxic activity against immune cells in colorectal cancer.

Multiparametric analysis of colorectal cancer immune responses

Colorectal cancer (CRC) is a heterogeneous disease, with a diverse and plastic immune cell infiltrate. These immune cells play an important role in regulating tumour growth - progression or elimination. Some populations of cells have a strong correlation with disease-free survival, making them useful prognostic markers. In particular, the infiltrate of CD3+ and CD8+ T cells into CRC tumours has been validated worldwide as a valuable indicator of patient prognosis. However, the heterogeneity of the immune response, both between patients with tumours of different molecular subtypes, and within the tumour itself, necessitates the use of multiparametric analysis in the investigation of tumour-specific immune responses. This review will outline the multiparametric analysis techniques that have been developed and applied to studying the role of immune cells in the tumour, with a focus on colorectal cancer. Because much of the data in this disease relates to T cell subsets and heterogeneity, we have used T cell populations as examples throughout. Flow and mass cytometry give a detailed representation of the cells within the tumour in a single-cell suspension on a per-cell basis. Imaging technologies, such as imaging mass cytometry, are used to investigate increasing numbers of markers whilst retaining the spatial and structural information of the tumour section and the infiltrating immune cells. Together, the analyses of multiple immune parameters can provide valuable information to guide clinical decision-making in CRC.

Irradiated VEGF164-modified tumor cell vaccine protected mice from the parental tumor challenge

Vascular endothelial growth factor (VEGF) is an important regulating molecule of angiogenesis in tumor formation and progression. Cancer cells always secrete VEGF to stimulate angiogenesis that facilitate growth and invasion of the tumor. In this study, we established a VEGF164 overexpressing LL/2 lung cancer cell model and found that the postirradiated VEGF164-modified tumor cells protected the host against the challenge with LL/2 wild-type tumor cells. Histochemical assay showed that there were large areas of tumor necrosis with macrophage infiltration in the mice vaccinated with the VEGF164-modified tumor vaccine. T-cells isolated from the vaccinated mice showed cytotoxicity against the parental tumor cells in a dose-dependent manner. Meanwhile, sera from the mice vaccinated with LL/2-VEGF164 showed higher titers of antibodies against parental tumor cells compared with the nonvaccinated groups. Our results indicated that VEGF164-modified tumor vaccine could modulate host antitumor immune response and hold therapeutic potential for cancer.

Prognostic role of tumour-associated macrophages and macrophage scavenger receptor 1 in prostate cancer: a systematic review and meta-analysis

Recent studies suggested that the tumour associated macrophages may be associated with prostate cancer outcome. A meta-analysis was performed to evaluate the prognostic value of tumor associated macrophages and macrophage scavenger receptor 1, marker for a subset of macrophages, by pooled hazard ratio and 95% confidence intervals from qualified studies following a systemic search. The results indicate that higher infiltration of tumor associated macrophages predicts poor overall survival (HR=1.57, 95%CI: 1.15-1.98), but not biochemical recurrence (HR=1.01, 95%CI: 0.98-1.04) or recurrence-free survival (HR=1.03, 95%CI: 0.05-2.01). In contrast, elevated level of macrophage scavenger receptor 1 was significantly associated with better recurrence-free survival (HR=3.26, 95%CI: 1.22-5.29). Thus, our analysis confirmed the prognostic value of these markers in prostate cancer outcome. We also discussed potential causes of the controversies in the literature and future research directions.

EGFR in Tumor-Associated Myeloid Cells Promotes Development of Colorectal Cancer in Mice and Associates With Outcomes of Patients

BACKGROUND & AIMS

Inhibitors of the epidermal growth factor receptor (EGFR) are the first-line therapy for patients with metastatic colorectal tumors without RAS mutations. However, EGFR inhibitors are ineffective in these patients, and tumor level of EGFR does not associate with response to therapy. We screened human colorectal tumors for EGFR-positive myeloid cells and investigated their association with patient outcome. We also performed studies in mice to evaluate how EGFR expression in tumor cells and myeloid cells contributes to development of colitis-associated cancer and ApcMin-dependent intestinal tumorigenesis.

METHODS

We performed immunohistochemical and immunofluorescent analyses of 116 colorectal tumor biopsies to determine levels of EGFR in tumor and stroma; we also collected information on tumor stage and patient features and outcomes. We used the Mann-Whitney U and Kruskal-Wallis tests to correlate tumor levels of EGFR with tumor stage, and the Kaplan-Meier method to estimate patients' median survival time. We performed experiments in mice lacking EGFR in intestinal epithelial cells (Villin-Cre; Egfrf/f and Villin-CreERT2; Egfrf/f mice) or myeloid cells (LysM-Cre; Egfrf/f mice) on a mixed background. These mice were bred with ApcMin/+ mice; colitis-associated cancer and colitis were induced by administration of dextran sodium sulfate (DSS), with or without azoxymethane (AOM), respectively. Villin-CreERT2 was activated in developed tumors by administration of tamoxifen to mice. Littermates that expressed full-length EGFR were used as controls. Intestinal tissues were collected; severity of colitis, numbers and size of tumors, and intestinal barrier integrity were assessed by histologic, immunohistochemical, quantitative reverse transcription polymerase chain reaction, and flow cytometry analyses.

RESULTS

We detected EGFR in myeloid cells in the stroma of human colorectal tumors; myeloid cell expression of EGFR associated with tumor metastasis and shorter patient survival time. Mice with deletion of EGFR from myeloid cells formed significantly fewer and smaller tumors than the respective EGFR-expressing controls in an ApcMin/+ background as well as after administration of AOM and DSS. Deletion of EGFR from intestinal epithelial cells did not affect tumor growth. Furthermore, tamoxifen-induced deletion of EGFR from epithelial cells of established intestinal tumors in mice given AOM and DSS did not reduce tumor size. EGFR signaling in myeloid cells promoted activation of STAT3 and expression of survivin in intestinal tumor cells. Mice with deletion of EGFR from myeloid cells developed more severe colitis after DSS administration, characterized by increased intestinal inflammation and intestinal barrier disruption, than control mice or mice with deletion of EGFR from intestinal epithelial cells. EGFR-deficient myeloid cells in the colon of DSS-treated LysM-Cre; Egfrf/f mice had reduced expression of interleukin 6 (IL6), and epithelial STAT3 activation was reduced compared with controls. Administration of recombinant IL6 to LysM-Cre; Egfrf/f mice given DSS protected them from weight loss and restored epithelial proliferation and STAT3 activation, compared with administration of DSS alone to these mice.

CONCLUSIONS

Increased expression of EGFR in myeloid cells from the colorectal tumor stroma associates with tumor progression and reduced survival time of patients with metastatic colorectal cancer. Deletion of EGFR from myeloid cells, but not intestinal epithelial cells, protects mice from colitis-induced intestinal cancer and ApcMin-dependent intestinal tumorigenesis. Myeloid cell expression of EGFR increases activation of STAT3 and expression of survivin in intestinal epithelial cells and expression of IL6 in colon tissues. These findings indicate that expression of EGFR by myeloid cells of the colorectal tumor stroma, rather than the cancer cells themselves, contributes to tumor development.

Tumor-Associated Macrophage Infiltration in Colorectal Cancer Liver Metastases is Associated With Better Outcome

BACKGROUND

Tumor-associated macrophages (TAMs) support growth in most human cancers, with the notable exception of colorectal adenocarcinoma, in which TAM infiltration of primary tumors is correlated with a better outcome. The importance of TAMs in colorectal liver metastases (CLM) is unknown.

METHODS

Using a tissue microarray of CLM resected at their institution from 1998 to 2000, the authors quantified immune marker expression by immunohistochemistry (IHC) using Metamorph Image Analysis software. Findings showed that CD68, CD3, CD4, CD8, FoxP3, and MHC-I were correlated with overall survival (OS) and disease-free survival (DFS).

RESULTS

Tumor cores from 158 patients were analyzed. The median follow-up period was 117 months for survivors (n = 39). The univariate analysis showed a significant positive association between DFS and CD4⁺ (p = 0.025) and CD68⁺ (p = 0.007). The findings showed a significant positive correlation of OS with CD4⁺ (p = 0.042), whereas the correlation with CD68⁺ was not significant (p = 0.17). Cutoffs were determined to dichotimize each marker for the highest log-rank statistic. Patients with CD4^high had a median OS of 115 months and DFS of 41 months (p = 0.007 compared with 40 and 16 months, respectively, for patients with CD4^low (p = 0.022). Patients with CD68^high had a median OS of 50 months and a median DFS of 25 months (p = 0.67) compared with 43 and 15 months (p = 0.028). In the multivariate analysis of factors affecting DFS, high CD68 was associated with longer DFS (hazard ratio [HR], 0.63, 95% confidence interval [CI], 0.43-0.94; p = 0.02), independently of clinicopathologic variables and CD4.

CONCLUSIONS

High TAM infiltration in resected CLM is associated with better outcome, independently of known clinicopathologic and immune predictors. This suggests that TAM depletion, which is being tested clinically in other cancers, may be detrimental in CLM.

Stromal CCR6 drives tumor growth in a murine transplantable colon cancer through recruitment of tumor-promoting macrophages

Interactions between the inflammatory chemokine CCL20 and its receptor CCR6 have been implicated in promoting colon cancer; however, the mechanisms behind this effect are poorly understood. We have previously demonstrated that deficiency of CCR6 is associated with decreased tumor macrophage accumulation in a model of sporadic intestinal tumorigenesis. In this study, we aimed to determine the role of stromal CCR6 expression in a murine syngeneic transplantable colon cancer model. We show that deficiency of host CCR6 is associated with decreased growth of syngeneic CCR6-expressing colon cancers. Colon cancers adoptively transplanted into CCR6-deficient mice have decreased tumor-associated macrophages without alterations in the number of monocytes in blood or bone marrow. CCL20, the unique ligand for CCR6, promotes migration of monocytes in vitro and promotes accumulation of macrophages in vivo. Depletion of tumor-associated macrophages decreases the growth of tumors in the transplantable tumor model. Macrophages infiltrating the colon cancers in this model secrete the inflammatory mediators CCL2, IL-1α, IL-6 and TNFα. Ccl2, Il1α and Il6 are consequently downregulated in tumors from CCR6-deficient mice. CCL2, IL-1α and IL-6 also promote proliferation of colon cancer cells, linking the decreased macrophage migration into tumors mediated by CCL20-CCR6 interactions to the delay in tumor growth in CCR6-deficient hosts. The relevance of these findings in human colon cancer is demonstrated through correlation of CCR6 expression with that of the macrophage marker CD163 as well as that of CCL2, IL1α and TNFα. Our findings support the exploration of targeting the CCL20-CCR6 pathway for the treatment of colon cancer.

Prognostic and Predictive Significance of Stromal Fibroblasts and Macrophages in Colon Cancer

Colon cancer development and malignant progression are driven by genetic and epigenetic alterations in tumor cells and by factors from the tumor microenvironment. Cancer cells become reliant on the activity of specific oncogenes and on prosurvival and proliferative signals they receive from the abnormal environment they create and reside in. Accordingly, the response to anticancer therapy is determined by genetic and epigenetic changes that are intrinsic to tumor cells and by the factors present in the tumor microenvironment. Recent advances in the understanding of the involvement of the tumor microenvironment in tumor progression and therapeutic response are optimizing the application of prognostic and predictive factors in colon cancer. Moreover, new targets in the tumor microenvironment that are amenable to therapeutic intervention have been identified. Because stromal cells are with rare exceptions genetically stable, the tumor microenvironment has emerged as a preferred target for therapeutic drugs. In this review, we discuss the role of stromal fibroblasts and macrophages in colon cancer progression and in the response of colon cancer patients to therapy.

Immune cell interplay in colorectal cancer prognosis

The immune response to colorectal cancer has proven to be a reliable measure of patient outcome in several studies. However, the complexity of the immune response in this disease is not well understood, particularly the interactions between tumour-associated cells and cells of the innate and adaptive immune system. This review will discuss the relationship between cancer associated fibroblasts and macrophages, as well as between macrophages and T cells, and demonstrate how each population may support or prevent tumour growth in a different immune environment.

A Comprehensive Proteomics Analysis Reveals a Secretory Path- and Status-Dependent Signature of Exosomes Released from Tumor-Associated Macrophages

Exosomes are 30-120 nm-sized membrane vesicles of endocytic origin that are released into the extracellular environment and play roles in cell-cell communication. Tumor-associated macrophages (TAMs) are important constituents of the tumor microenvironment; thus, it is critical to study the features and complex biological functions of TAM-derived exosomes. Here, we constructed a TAM cell model from a mouse macrophage cell line, Ana-1, and performed comparative proteomics on exosomes, exosome-free media, and cells between TAMs and Ana-1. Proteomic analysis between exosome and exosome-free fractions indicated that the functions of exosome dominant proteins were mainly enriched in RNA processing and proteolysis. TAM status dramatically affected the abundances of 20S proteasome subunits and ribosomal proteins in their exosomes. The 20S proteasome activity assay strongly indicated that TAM exosomes possessed higher proteolytic activity. In addition, Ana-1- and TAM-derived exosomes have different RNA profiles, which may result from differential RNA processing proteins. Taken together, our comprehensive proteomics study provides novel views for understanding the complicated roles of macrophage-derived exosomes in the tumor microenvironment.

The delicate balance of macrophages in colorectal cancer; their role in tumour development and therapeutic potential

Most tumours are heavily infiltrated by immune cells. This has been correlated with either a good or a bad patient prognosis, depending on the (sub) type of immune cells. Macrophages represent one of the most prominent leukocyte populations in the majority of tumours. Functions of macrophages range from cytotoxicity, to stimulation of tumour growth by secretion of cytokines, growth and angiogenic factors, or suppressing immune responses. In most tumours macrophages are described as cells with immune suppressing, and wound healing properties, which aids tumour development. Yet, increasing evidence shows that macrophages are potent inhibitors of tumour growth in colorectal cancer. Macrophages in this respect show high plasticity. The presence of high macrophage numbers in the tumour may therefore become advantageous, if cells can be reprogrammed from tumour promoting macrophages into potent effector cells. Enhancing cytotoxic properties of macrophages by microbial products, pro-inflammatory cytokines or monoclonal antibody therapy are promising possibilities, and are currently tested in clinical trials.

Tumor-Associated Macrophage (TAM) and Angiogenesis in Human Colon Carcinoma

AIM:

This study aimed to clarify how macrophages affect prognosis in cancer colon and their association with tumor angiogenesis.

MATERIAL AND METHODS:

Forty four biopsies of colon carcinoma and 15 of benign adenomatous polyps were investigated for macrophages infiltration and microvessels density using immunohistochemistry and image morphometric analysis. Macrophages and blood vessels were stained immunohistochemically by CD68 and F-VIII markers respectively. The morphometric analysis was carried out on the immunohistochemically stained slides using the Leica Qwin 500 Image Analyzer. Both of macrophages infiltration and microvessels density were correlated with histological tumor grade, stage and lymph node metastases and were correlated with each others.

RESULTS:

Macrophage infiltration was significantly higher in malignant cases than in benign polyps. High macrophage infiltration and hypervascularity were significantly correlated with T-staging and lymph nodes metastasis. A significant correlation was found between macrophage infiltration and microvessels densitie in malignant tumors where hypervascularity was significantly correlated with high macrophages infiltration.

CONCLUSION:

The significant correlation between macrophage infiltration and tumor angiogenesis suggests an interaction between macrophages and cancer cells stimulating microvessels formation, tumor invasion and metastasis in colon cancer. We recommend that macrophages infiltration should be evaluated to investigate their clinical value in development of individualized therapeutic regimens for management of colon carcinoma.

The prognostic significance of tumor epidermal growth factor receptor (EGFR) expression change after neoadjuvant chemoradiation in patients with rectal adenocarcinoma

Aim of the study

The aim of this retrospective study was to determine the prognostic impact of epidermal growth factor receptor (EGFR) expression changes during neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer.

Material and methods

Fifty patients with locally advanced rectal cancer were evaluated. All the patients were administered the total dose of 44 Gy. Capecitabine has been concomitantly administered in the dose 825 mg/m² in two daily oral administrations. Surgery was indicated 4–8 weeks from the chemoradiotherapy completion. Epidermal growth factor receptor expression in the pretreatment biopsies and in the resected specimens was assessed with immunohistochemistry.

Results

All of 50 patients received radiotherapy without interruption up to the total planned dose. In 30 patients sphincter-saving surgery was performed, 20 patients underwent amputation of the rectum. Downstaging was described in 30 patients. Four patients have had complete pathologic remission. Twenty-six patients have had partial remission, the disease was stable in 15 patients. Progression was reported in 5 patients. The median disease-free survival was 64.9 months, median overall survival was 76.4 months. Increased EGFR expression was found in 12 patients (26.1%). A statistically significantly shorter overall survival (p < 0.0001) and disease-free survival (p < 0.0001) was found in patients with increased expression of EGFR compared with patients where no increase in the expression of EGFR during neoadjuvant chemoradiotherapy was observed.

Conclusions

The overexpression of EGFR during neoadjuvant chemoradiotherapy for locally advanced rectal adenokarcinoma associated with significant shorter overall survival and disease free survival.

Epithelial and stromal cell urokinase plasminogen activator receptor expression differentially correlates with survival in rectal cancer stages B and C patients

Urokinase plasminogen activator receptor (uPAR) has been proposed as a potential prognostic factor for colorectal cancer (CRC) patient survival. However, CRC uPAR expression remains controversial, especially regarding cell types where uPAR is overexpressed (e.g., epithelium (uPAR^E) or stroma-associated cells (uPAR^S)) and associated prognostic relevance. In this study, two epitope-specific anti-uPAR monoclonal antibodies (MAbs) could discriminate expression of uPAR^E from uPAR^S and were used to examine this association with survival of stages B and C rectal cancer (RC) patients. Using immunohistochemistry, MAbs #3937 and R4 were used to discriminate uPAR^E from uPAR^S respectively in the central and invasive frontal regions of 170 stage B and 179 stage C RC specimens. Kaplan-Meier and Cox regression analyses were used to determine association with survival. uPAR expression occurred in both epithelial and stromal compartments with differential expression observed in many cases, indicating uPAR^E and uPAR^S have different cellular roles. In the central and invasive frontal regions, uPAR^E was adversely associated with overall stage B survival (HR = 1.9; p = 0.014 and HR = 1.5; p = 0.031, respectively) reproducing results from previous studies. uPAR^S at the invasive front was associated with longer stage C survival (HR = 0.6; p = 0.007), reflecting studies demonstrating that macrophage peritumoural accumulation is associated with longer survival. This study demonstrates that different uPAR epitopes should be considered as being expressed on different cell types during tumour progression and at different stages in RC. Understanding how uPAR^E and uPAR^S expression affects survival is anticipated to be a useful clinical prognostic marker of stages B and C RC.

In vivo molecular imaging of gastric cancer in human-murine xenograft models with confocal laser endomicroscopy using a tumor vascular homing peptide

The early detection of premalignant lesions and cancers are very important for improving the survival of patients with gastric malignancies. Confocal laser endomicroscopy (CLE) is a novel imaging tool for achieving real-time microscopy during the ongoing endoscopy at subcellular resolution. In the present study, to evaluate the feasibility of real-time molecular imaging of GEBP11 by CLE in gastric cancer, CLE was performed on two types of tumor-bearing mice models, as well as surgical specimens of patients with gastric cancer, after the application of GEBP11. A whole-body fluorescent imaging device was first used to screen for the strongest specific fluorescent signal in xenograft models. Next, the tumor sites, as well as human tissues, were scanned with CLE. After this, targeted specimens were obtained for fluorescence microscopy and histology. We confirmed that GEBP11 could specifically bind to co-HUVECs by means of CLE in cell experiments. Thereafter, a specific signal was observed in both subcutaneous and orthotopic xenograft models in vivo after the injection of FITC-GEBP11 via tail vein, whereas the group injected with FITC-URP showed no fluorescent signals. In human tissues, a specific signal of GEBP11 was observed in 26/28 neoplastic specimens and in 8/28 samples of non-neoplastic specimens from the patients (p < 0.01). The findings from ex vivo immunofluorescence microscopy of cryostat sections correlated well with that obtained by CLE. These findings indicate that the peptide, GEBP11, might be a potential candidate for the molecular imaging of gastric cancer.

Upregulation of stromal cell-derived factor 1α expression is associated with the resistance to neoadjuvant chemoradiotherapy of locally advanced rectal cancer: angiogenic markers of neoadjuvant chemoradiation

The ability to achieve pathologic downstaging after neoadjuvant chemoradiotherapy (NCRT) is correlated with improved survival in locally advanced rectal cancer (LARC). However, there is no effective predictive markers. In this study, the expression of angiogenic markers was evaluated in pre-treatment biopsies and corresponding post-treatment resection specimens, and were correlated to histopathological tumour characteristics and response. Fifty-five patients with stage II/III rectal cancer treated with 5-fluorouracil (5-FU)-based NCRT were studied. All patients were administered NCRT followed by surgical resection. Immunohistochemical staining for angiogenic markers [hypoxia-inducible factor 1α (HIF‑1α), vascular endothelial growth factor (VEGF), stromal cell‑derived factor 1α (SDF-1α) and placental growth factor (PlGF)] was performed on specimens obtained before NCRT and after surgery. Expression of VEGF, PlGF and HIF-1α protein was downregulated after NCRT in the rectal cancer tissues (P<0.001, P=0.001 and P=0.044, respectively). However, SDF-1α was upregulated after NCRT (P<0.001). Moreover, upregulated expression of SDF-1α (P=0.016) and positive PlGF staining (P=0.001) after NCRT were significantly associated with resistance to NCRT. On multivariate analysis, positive PlGF staining after NCRT was found to be independently associated with resistance to NCRT (P=0.013). Our data suggest that SDF-1α and PlGF should be evaluated as new targets for NCRT in LARC.

Assessment of vascular endothelial growth factor in formalin fixed, paraffin embedded colon cancer specimens by means of a well-based reverse phase protein array

BACKGROUND

Vascular endothelial growth factor (VEGF) is a critical pro-angiogenic factor, found in a number of cancers, and a target of therapy. It is typically assessed by immunohistochemistry (IHC) in clinical research. However, IHC is not a quantitative assay and is rarely reproducible. We compared VEGF levels in colon cancer by IHC and a quantitative immunoassay on proteins isolated from formalin fixed, paraffin embedded tissues.

RESULTS

VEGF expression was studied by means of a well-based reverse phase protein array (RPPA) and immunohistochemistry in 69 colon cancer cases, and compared with various clinicopathologic factors. Protein lysates derived from formalin fixed, paraffin embedded tissue contained measurable immunoreactive VEGF molecules. The VEGF expression level of well differentiated colon cancer was significantly higher than those with moderately and poorly differentiated carcinomas by immunohistochemistry (P = 0.04) and well-based RPPA (P = 0.04). VEGF quantification by well-based RPPA also demonstrated an association with nodal metastasis status (P = 0.05). In addition, the normalized VEGF value by well-based RPPA correlated (r = 0.283, P = 0.018). Furthermore, subgroup analysis by histologic type revealed that adenocarcinoma cases showed significant correlation (r = 0.315, P = 0.031) between well-based RPPA and IHC.

CONCLUSIONS

The well-based RPPA method is a high throughput and sensitive approach, is an excellent tool for quantification of marker proteins. Notably, this method may be helpful for more objective evaluation of protein expression in cancer patients.

VPAC1 overexpression is associated with poor differentiation in colon cancer

Vasoactive intestinal peptide (VIP) is a neurotransmitter that primarily functions as a vasodilator. VIP plays its role through binding to its receptors known as VIP/pituitary adenylate cyclase-activating peptide receptors (VPACs). In this study, we examined the expression of VPAC1 in human colon cancer tissues, analyzed the relationship between VPAC1 expression and cancer malignancy, and explored the possible mechanisms using immunohistochemistry and immunofluorescence double staining. The results showed that (1) poorly differentiated colon cancers have significantly higher VPAC1 expression than well-differentiated colon cancers do (p < 0.01); (2) phospho-epithelial growth factor receptor (EGFR) overexpression/activation in the cytoplasm of cancer cells is related to VPAC1 overexpression; (3) blood vessels surrounding colon cancer have significantly more VPAC1-positive than normal colon mucosa does; (4) tumor-associated macrophages (TAMs) of colon cancer have a higher level of VPAC1 expression than macrophages in normal colon mucosa do. These data suggest that VPAC1 overexpression is associated with poorer differentiation of colon cancer, which is likely caused by subsequent EGFR activation in cancer cells. In addition, VPAC1 overexpression in both blood vessels and macrophages in tumors may also play an important role in the development of aggressive cancer.

Can vascular endothelial growth factor and microvessel density be used as prognostic biomarkers for colorectal cancer? A systematic review and meta-analysis

Background. Vascular endothelial growth factor (VEGF) and microvessel density (MVD) are associated with greater incidence of metastases and decreased survival. Whether they can be used as prognostic indicators of colorectal cancer (CRC) is still controversial. Methods. The authors performed a meta-analysis using the results of a literature search of databases of PubMed and EMBASE, and the references of articles included in the analysis. Meta-analysis was performed using random effects model and hazard ratios (HRs) and 95% confidence intervals (CIs) as effect measures. Results. Twenty studies contributed to the analysis of VEGF, of which 16 were used for overall survival (OS) and 9 for disease-free survival (DFS). High VEGF levels has a relationship with unfavorable survival (OS: HR = 1.98, 95% CI: 1.30–3.02; DFS: HR = 2.10, 95% CI: 1.26–3.49) and a 4.22-fold increase in the rate of distant metastases. Analysis was performed on 18 studies for MVD; the results showed that patients with high MVD expression in tumors appeared to have poorer overall survival (HR = 1.39, 95% CI: 1.22–1.58) and were at a greater risk of having unfavorable clinical characteristics related to prognosis. Corresponding results were obtained from quantitative and/or qualitative analysis of clinicopathological. Conclusions. The meta-analysis demonstrates that VEGF and MVD can be used as prognostic biomarkers for CRC patients.

Immune escape mechanisms in colorectal cancer pathogenesis and liver metastasis

Over the past decade, growing evidence indicates that the tumor microenvironment (TME) contributes with genomic/epigenomic aberrations of malignant cells to enhance cancer cells survival, invasion, and dissemination. Many factors, produced or de novo synthesized by immune, stromal, or malignant cells, acting in a paracrine and autocrine fashion, remodel TME and the adaptive immune response culminating in metastasis. Taking into account the recent accomplishments in the field of immune oncology and using metastatic colorectal cancer (mCRC) as a model, we propose that the evasion of the immune surveillance and metastatic spread can be achieved through a number of mechanisms that include (a) intrinsic plasticity and adaptability of immune and malignant cells to paracrine and autocrine stimuli or genotoxic stresses; (b) alteration of positional schemes of myeloid-lineage cells, produced by factors controlling the balance between tumour-suppressing and tumour-promoting activities; (c) acquisition by cancer cells of aberrant immune-phenotypic traits (NT5E/CD73, CD68, and CD163) that enhance the interactions among TME components through the production of immune-suppressive mediators. These properties may represent the driving force of metastatic progression and thus clinically exploitable for cancer prevention and therapy. In this review we summarize results and suggest new hypotheses that favour the growing impact of tumor-infiltrating immune cells on tumour progression, metastasis, and therapy resistance.

The status of targeted agents in the setting of neoadjuvant radiation therapy in locally advanced rectal cancers

Radiotherapy has a longstanding and well-defined role in the treatment of resectable rectal cancer to reduce the historically high risk of local recurrence. In more advanced borderline or unresectable cases, where the circumferential resection margin (CRM) is breached or threatened according to magnetic resonance imaging (MRI), despite optimized local multimodality treatment and the gains achieved by modern high quality total mesorectal excision (TME), at least half the patients fail to achieve sufficient downstaging with current schedules. Many do not achieve an R0 resection. In less locally advanced cases, even if local control is achieved, this confers only a small impact on distant metastases and a significant proportion of patients (30-40%) still subsequently develop metastatic disease. In fact, distant metastases have now become the predominant cause of failure in rectal cancer. Therefore, increasing the intensity and efficacy of chemotherapy and chemoradiotherapy by integrating additional cytotoxics and biologically targetted agents seems an appealing strategy to explore-with the aim of enhancing curative resection rates and improving distant control and survival. However, to date, we lack validated biomarkers for these biological agents apart from wild-type KRAS. For cetuximab, the appearance of an acneiform rash is associated with response, but low levels of magnesium appear more controversial. There are no molecular biomarkers for bevacizumab. Although some less invasive clinical markers have been proposed for bevacizumab, such as circulating endothelial cells (CECS), circulating levels of VEGF and the development of overt hypertension, these biomarkers have not been validated and are observed to emerge only after a trial of the agent. We also lack a simple method of ongoing monitoring of 'on target' effects of these biological agents, which could determine and pre-empt the development of resistance, prior to radiological and clinical assessessments or even molecular imaging. These shortcomings probably explain our current relative lack of success in the arena of combining these agents with chemoradiation.