Content and distribution of macrophages and lymphocytes in solid malignant human tumours

Exosome miRNA-203 promotes M1 macrophage polarization and inhibits prostate cancer tumor progression

Prostate cancer (PCa) is a prevalent malignant neoplasm affecting the male reproductive system globally. However, the diagnostic and therapeutic approaches fall short of meeting the demands posed by PCa. Poor expression of miRNA-203 (miR-203) within PCa tissues and cells implies its potential utility as a diagnostic indicator for PCa. Exosomes (Exo), membranous vesicles released by various cells, are rich reservoirs of miRNAs. However, the presence of miR-203 presents within Exo derived from PCa cells remains unclarified. In this study, Exo was isolated from urine specimens collected from clinical PCa patients and LNCaP cells to detect miR-203 expression. Meanwhile, the impact of overexpressed miR-203 on M0 macrophages (mø) was analyzed. Subsequently, alterations in the proliferative, migratory, and invasive capacities of LNCaP cells were examined within a co-culture system featuring elevated miR-203 levels in both macrophages and LNCaP cells. Furthermore, the repercussions of miR-203 upregulation or inhibition were explored in a murine PCa tumor model. The results revealed that Exo manifested a circular or elliptical morphology, encapsulating a phospholipid bilayer approximately 100 nm in diameter. Notably, Exo readily infiltrated, with both Exo and miR-203-overexpressing Exo prompting macrophage polarization toward the M1 subtype. In the co-culture system, miR-203 exhibited pronounced suppression of LNCaP cell proliferation, migration, and invasion, while concurrently fostering apoptosis as compared with the LNCaP group (Control). In vivo experiments further disclosed that miR-203 greatly inhibited the growth of PCa tumors in nude mice. Markedly heightened expression of M1 macrophage markers such as IL-1β, IL-6, IL-12, CXCL9, and CXCL10 was observed within the tumor microenvironment following miR-203 intervention, as opposed to the model group. However, the introduction of miR-203 antagomir led to a reversal in tumor growth trends. This investigation indicates the presence of miR-203 within the urine of PCa patients and Exo originating from cells, and that miR-203 exerted antitumor effect by facilitating M1 macrophage polarization. Our study furnishes valuable insights into the potential applicability of miR-203 as a diagnostic biomarker and therapeutic target for PCa.

Clinical and prognostic significance of preoperative lymphocyte-monocyte ratio, neutrophil-lymphocyte ratio and neutrophil-monocyte ratio on esophageal squamous cell carcinoma patients

Background

The interaction between tumor cells and inflammatory cells has not been systematically investigated in esophageal squamous cell carcinoma (ESCC). The aim of the present study was to evaluate whether preoperative lymphocyte-monocyte ratio (LMR), neutrophil-lymphocyte ratio (NLR), and neutrophil-monocyte ratio (NMR) could predict the prognosis of ESCC patients undergoing esophagectomy.

Methods

A total of 1,883 patients with histologically diagnosed ESCC who underwent radical esophagectomy from May 2005 to May 2015 were retrospectively reviewed. Besides clinicopathological factors, “Survminer” package in R^® was applied to determine the optimal cut-off point for LMR, NLR and NMR. Meanwhile, we evaluated the prognostic value of LMR, NLR, and PLR using Kaplan-Meier curves and Cox regression models.

Results

The median follow-up was 28.77 months (range, 1.60–247.90 months). The optimal cut-off point of LMR, NLR and NMR is 3.83, 2.06 and 7.21, respectively. Kaplan-Meier survival analysis of patients with low preoperative LMR demonstrated a significant worse prognosis for 5-year OS (P<0.001) than those with high preoperative LMR. The high NLR cohort had lower 5-year OS (P<0.001). No significant difference with 5-year OS was found in NMR (P=0.405). On multivariate analysis, preoperative LMR (P=0.018; HR =0.786, 95% CI: 0.645, 0.959) and NLR (P=0.028; HR =1.247, 95% CI: 1.024, 1.519) were the independent prognostic factors in ESCC patients. Integrating LMR and NLR, we divided the ESCC patients in four groups according to their cut-off points and we found the patients in LMR ≥3.83 and NLR <2.06 group received the best prognosis while the prognosis of patients in LMR<3.83 and NLR ≥2.06 group was the worst. The difference was statistically significant.

Conclusions

Preoperative LMR and NLR better predicts cancer survival in patients with ESCC undergoing esophagectomy, especially under the circumstances of LMR ≥3.83 and NLR <2.06.

The tumor microenvironment: the making of a paradigm

What has been will be again, what has been done will be done again; there is nothing new under the sun

(Ecclesiastes 1:9)

Stephen Paget was the conceptual father of the role played by the Tumor Microenvironment (TME) in tumor progression. The focus of this essay is the developmental phase of the post Paget TME research. Attempts will be made to highlight some of the pioneering work of scientists from the late sixties through the eighties of last century who laid the foundations for the contemporary scientific achievements of TME research but whose ground breaking studies are rarely cited. This review should serve as a small tribute to their great work.

High tumour islet macrophage infiltration correlates with improved patient survival but not with EGFR mutations, gene copy number or protein expression in resected non-small cell lung cancer

The purpose of this study was to investigate the prognostic value of tumour-associated macrophages with a focus on micro-anatomical localisation and determine whether molecular changes of the epidermal growth factor receptor (EGFR) are related to macrophage infiltration in resected non-small cell lung cancer (NSCLC). One hundred and forty-four patients were included in this study. Immunohistochemistry was used to identify CD68+ macrophages in the tumour islet and surrounding stroma. Epidermal growth factor receptor mutations were studied by direct sequencing. The EGFR gene copy number and protein expression were analysed by fluorescence in situ hybridisation and immunohistochemistry. Patients with a high tumour islet macrophage density survived longer than did the patient with a low tumour islet macrophage density (5-year overall survival rate was 63.9 vs 38.9%, P=0.0002). A multivariate Cox proportional hazard analysis revealed that the tumour islet macrophage count was an independent prognostic factor for survival (hazard ratio 0.471, 95% confidence interval 0.300-0.740). However, EGFR mutations, gene copy number, and protein expression were not related to the macrophage infiltration. In conclusion, tumour islet macrophage infiltration was identified as a strong favourable independent prognostic marker for survival but not correlated with the molecular changes of the EGFR in patients with resected NSCLC.

The Δ32 allele distribution of the CCR5 gene and its relationship with certain cancers in a Turkish population

OBJECTIVE

In the present study, we determined the frequency of delta32 allele distribution and its relationship with various carcinomas in a Turkish population.

DESIGN AND METHODS

We determined the allelic frequency of CCR5-delta32 in 267 healthy individuals as well as 39 breast, 34 laryngeal, 30 thyroid and 20 brain carcinomas in a Turkish population using polymerase chain reaction (PCR).

RESULTS

The frequency of mutant delta32 alleles in the Turkish population was 2.18%. The population was in the Hardy-Weinberg equilibrium. The frequency of the mutant allele was the highest in patients with breast carcinoma (3.85%) among all the carcinomas studied, but there was no statistically significant relationship (P = 0.334).

CONCLUSION

The frequency of the delta32 allele detected in the Turkish population was slightly lower in comparison with the previous reports. The frequency of heterozygote genotypes remained an independent risk factor for the development of breast cancer (odd ratio = 1.628; confidence intervals = 0.442-5.992) as well as other cancers examined in this study.

Immunophenotyping of tumor-infiltrating mononuclear cells in ovarian carcinoma

Infiltrating mononuclear cells play an important role in many types of cancer. The aim of this work was to determine the immunologic characteristics of mononuclear cellular infiltrate in ovarian cancer as compared to benign ovarian tumors. Paraffin-embedded tissues obtained from 52 ovarian carcinomas and 21 benign ovarian neoplasms were examined immunohistochemically to demonstrate suppressor/cytotoxic T cells and macrophages by using CD8 and CD68 monoclonal antibodies, respectively. The mean percentage of CD8+ cells was much higher in the malignant than in the benign group (P=0.00009). Similarly, the mean level of CD68+ cells was significantly higher in carcinomas than in benign cases (P=0.006). There was a significant negative correlation between the percentage of CD8+ cells and CD68+ cells in the malignant group (P=0.000002). Conversely, no correlation could be obtained between the values of these two cell types in the benign lesions. In the malignant group, although the percentages of CD8+ cells and CD68+ cells were not related to tumor differentiation, they were significantly related to tumor type. CD8+ cells were significantly higher in the serous (P=0.02), and CD68+ cells were higher in the mucinous carcinomas (P=0.0005). CD8+ T cells and macrophages constitute a major component of the infiltrating mononuclear cells in ovarian carcinoma. Their frequency seems to be related to the tumor type rather than the degree of tumor differentiation.

Chemokines and their role in tumor growth and metastasis

Chemokines are a superfamily of pro-inflammatory polypeptide cytokines that selectively attract and activate different cell types. Many patho-physiological conditions require the participation of chemokines, including inflammation, infection, tissue injury, allergy, cardiovascular diseases, as well as malignant tumors. Chemokines activate cells through their binding to shared or unique cell surface receptors which belong to the seven-transmembrane, G-protein-coupled Rhodopsin superfamily. The role of chemokines in malignant tumors is complex: while some chemokines may enhance innate or specific host immunity against tumor implantation, others may favor tumor growth and metastasis by promoting tumor cell proliferation, migration or neovascularization in tumor tissue. In this review, the authors summarize some of the recent advances in chemokine research and emphasis is made on the effect of chemokines in tumor growth and metastasis.

Discovery of human antibodies to cell surface antigens by capture lift screening of phage-expressed antibody libraries

An assay for the rapid identification and cloning of antibody fragments (Fabs) reactive with cell surface antigens was established and used to identify Fabs selectively reactive with tumor cell surface antigens. The Fabs were produced by a phage expression system and screened by a modified plaque lift approach in which nitrocellulose filters were coated with an anti-immunoglobulin reagent and blocked with bovine serum albumin prior to application to the phage-infected bacterial lawn. Subsequently, capture lifts were incubated with biotinylated antigen and reactive Fabs were identified with streptavidin conjugates. This screening method, termed capture lift, results in the immobilization of greater quantities of Fab and decreases the binding of unrelated host proteins, resulting in a more sensitive plaque lift assay. The capture lift permits the simultaneous analysis of thousands of antibody clones and, more importantly, can be used with crude detergent-solubilized cell extracts, permitting the discovery of Fabs which bind integral membrane proteins present in heterogeneous mixtures of antigens. Optimal conditions were identified utilizing phage-expressed BR96 Fab and a horseradish peroxidase conjugate of Lewis Y, a soluble cross-reactive antigen. Subsequently, it was demonstrated that the assay was functional with postnuclear detergent extracts isolated from surface-biotinylated tumor cells expressing the BR96 tumor antigen. Purification of the target antigen was not required. To demonstrate the application of the capture lift assay for the discovery of Fabs reactive with novel cell surface antigens a phage-expressed human antibody library constructed from tumor-infiltrating B lymphocytes was screened. Multiple antibody clones which reacted with detergent-solubilized biotinylated surface antigens were identified. Upon further characterization a portion of these displayed selectivity for tumor cells, as demonstrated by the binding of Fab to fixed and live tumor cells but not normal fibroblasts.

Human tumour-associated macrophages differentiate into osteoclastic bone-resorbing cells

Macrophages are commonly found within osteolytic secondary carcinomas in bone, but the manner in which these cells contribute to malignant bone resorption is uncertain. Macrophages isolated from primary breast carcinomas were co-cultured for up to 21 days with UMR 106 rat osteoblast-like cells on bone slices and glass coverslips in the presence and absence of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] and human macrophage colony stimulating factor (M-CSF). Cell cultures were then assessed for the presence of phenotypic markers of macrophage and osteoclast differentiation. Isolated cells were negative for osteoclast markers including tartrate-resistant acid phosphatase (TRAP), vitronectin receptor (VNR), and the ability to carry our lacunar bone resorption, but were positive for CD11b and CD14, macrophage markers which are not present on osteoclasts. In 21-day co-cultures of breast carcinoma tumour-associated macrophages (TAMs) and UMR 106 cells, incubated in the presence of 1,25(OH)2D3 and M-CSF, numerous TRAP- and VNR-positive multinucleated cells capable of extensive lacunar resorption were formed. Contact with UMR 106 cells and the presence of 1,25(OH)2D3 and M-CSF were absolute requirements for differentiation of human breast carcinoma TAMs into mature functional osteoclasts. TAM-osteoclast differentiation may represent an important cellular mechanism of osteolysis in metastatic skeletal carcinomas.

In vitro analysis of cancer prevention by a mycobacterial antigen complex and of cancer-promoted inhibition of immune reactions

The antigen complex A60 of Mycobacterium bovis bacillus Calmette-Guérin protected mice against experimental tuberculous infection, and prevented cancer development after challenge with EMT 6 cells. Although humoral and cellular immune reactions elicited by A60 in vivo remained unaffected in cases of tumor rejection, they were suppressed in the case of neoplastic growth. In the present work, these in vivo observations were analyzed by in vitro techniques. Activated macrophages played a major role, and cytolytic T lymphocytes a minor role, in A60-promoted cancer cell cytolysis leading to tumor rejection. In vitro, EMT 6 cells weakly inhibited the proliferation of A60-specific B lymphocytes and strongly inhibited the functions of activated macrophages. However, the collapse of both humoral and cellular immune reactions during the course of cancer development was also accompanied by an inhibitory action of EMT 6 cells on the multiplication and functions of A60-specific T lymphocytes. Tumor-dependent repression of macrophage activation was therefore due to both a direct action of tumor cells on macrophages and an indirect one via inhibition of macrophage-activating T cell functions. On the other hand, tumor-induced collapse of the anti-A60 Ig synthesis was mainly due to inhibition of B-cell-activating T cells, with a weaker direct effect of tumor cells on B lymphocytes. Consequently, A60 and tumor cells exert opposite effects on the immune system at several levels.

Photofrin accumulation in malignant and host cell populations of various tumours

Photofrin accumulation in malignant and host cell populations of various tumours was studied by flow cytometry analysis of cells dissociated from the tumour tissue. The transplantable mouse tumour models included in this analysis were sarcomas EMT6, RIF, KHT and FsaN, Lewis lung carcinoma, SCCVII squamous cell carcinoma (SCC) and slowly growing moderately differentiated AT17 SCC. An example of spontaneous mouse adenocarcinoma was also examined. Staining with specific monoclonal antibodies was used to identify the various cell populations present in these tumours. The main characteristic of Photofrin cellular accumulation was a very high photosensitiser content found exclusively in a subpopulation of tumour-associated macrophages (TAMs). Photosensitiser levels similar to or lower than in malignant cells were observed in the remaining TAMs and other tumour-infiltrating host cells. Photofrin accumulation in malignant cells was not equal in all tumour models, but may have been affected by tumour blood perfusion/vascularisation. Results consistent with the above findings were obtained with SCC of buccal mucosa induced by 9,10-dimethyl-1,2-benzanthracene in Syrian hamsters. The TAM subpopulation that accumulates by far the highest cellular Photofrin levels in tumours is suggested to be responsible for the tumour-localised photosensitiser fluorescence.

The distribution of lymphocyte subpopulations in normal and acanthotic ovine skin

The prevalence and distribution of lymphocyte subpopulations in normal and acanthotic ovine skin were investigated using monoclonal antibody immunocytochemistry. CD8+ cells were predominant in the epidermis of both normal and acanthotic skin, but were CD8+ cells, CD4+ cells and T19+ cells infrequent in normal epidermis. Within the dermis of normal skin, there were significantly greater numbers of CD4+ and T19+ cells situated around the superficial dermal vessels than in any other region examined. The majority of the CD8+ cells adjoined vessels, but the proportion that did not was greater for CD8+ than for CD4+ or T19+ cells. The CD4+ and CD8+ subsets were represented equally in adnexa. T cells were of memory phenotype. B cells and naive T cells, both of which express the CD45RA antigen, were rarely seen and tended to be associated with vessels in both normal and acanthotic skin. None of the T19+ cells (which are gamma delta+) resembled the dendritic gamma delta cells seen in murine epidermis. Acanthotic skin was strikingly different to normal skin. There was a greater abundance of T cells, particularly CD4+ cells, in acanthotic epidermis and the numbers of CD8+ and T19+ cells, and to a greater extent CD4+ cells, were greater at the dermal-epidermal junction. There were more CD4+ and CD8+ cells in the superficial dermal stroma of acanthotic skin. Within the dermis of acanthotic skin, T cells were concentrated near vessels but the apportioning of T cells between stromal/adnexal and vessel-associated sites differed from normal. Such observations suggest that migration away from perivascular sites and into the stroma may be controlled separately for subregions of skin and for each T cell subset. The role of this altered nonrandom migration of T cells in skin chronically exposed to ultra violet radiation is uncertain.

Alteration of the immune response during cancer development and prevention by administration of a mycobacterial antigen

It has been shown previously that A60, an antigen complex of Mycobacterium bovis BCG, triggers humoral and cellular immune reactions in vivo and lymphocyte-dependent macrophage activation in vitro. In the present work, the ability of A60 to prevent murine tumour development, in conjunction or not with irradiated isologous cancer cells, was explored with Taper liver tumour (TLT), a mammary-derived neoplasm (EMT6), and Lewis lung carcinoma (3LL). Repeated injections of A60 prior to challenge reduced the incidence of EMT6 and 3LL solid tumours and increased life span. This effect was enhanced by simultaneous administration of gamma-irradiated cancer cells (80-100% suppression of EMT6 and 3LL tumour growth). In mice developing or rejecting tumours, the status of humoral and cellular immunity was evaluated by A60-based immunoassays. Tumor development was accompanied by a rapid decrease of both anti-A60 IgG titre in blood and A60-triggered delayed hypersensitivity reactions. Moreover, A60-induced T lymphocyte proliferation and macrophage-dependent autologous cancer cell cytolysis declined progressively during the course of tumour growth. In case of successful immunotherapy, a pattern similar to that of unchallenged controls was observed. Our results suggest that A60 promotes cancer rejection via tumour infiltration by lymphocytes and macrophages activated by A60-specific T lymphocytes. An increased processing of tumour-specific antigens and activation of tumour-infiltrating lymphocytes is induced by administration of irradiated cancer cells in conjunction with A60.

Association of different macrophage phenotypes with infiltrating and non-infiltrating areas of tumor-host interface in colorectal carcinoma

At the tumor-host interface (interface) of well differentiated tubulary or tubulopapillary colorectal carcinomas infiltrative, poorly demarcated and non-infiltrative, well bordered areas alternate. The composition of the inflammatory infiltrate within the desmoplastic stroma of the central tumor part and the interface was analyzed, particularly emphasizing differences between infiltrative and non-infiltrative areas of the interface. Of particular interest was the distribution of the following recently identified, functionally different human macrophage phenotypes: the 27E10-positive phenotype, an inflammatory macrophage, the 25F9-positive phenotype, a mature, resident macrophage and the RM3/1-positive phenotype, associated with anti-inflammatory function. It was found that macrophages were the dominating cells in the inflammatory infiltrate of both central tumor part and interface and that the number of B-cells and NK-cells were negligible. The 27E10-positive phenotype revealed a strong association with infiltrative areas at the interface, whereas the resident macrophage together with the RM3/1 was associated with sharply bordered tumor areas dominating within the tumor stroma, particularly in carcinomas with marked desmoplastic stroma response. These findings suggest that different macrophage phenotypes, localized in different regions of the carcinoma, have different effects on tumor cells.

Functional evaluation of tumor-infiltrating mononuclear cells. Detection of endogenous interferon-gamma and tumor necrosis factor-alpha in human colorectal adenocarcinomas

Quantitative evaluation of the levels of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) in the extracts of tumors and their corresponding normal tissues resected from 43 patients with colorectal adenocarcinoma was done using solid-phase, sandwich radioimmunoassay. The levels of both IFN-gamma and TNF-alpha detected in the tumor tissues were higher than those in the corresponding normal colorectal tissues obtained from each patient. A significant negative correlation was observed between the level of IFN-gamma and TNF-alpha in each tumor extract. The decrease of the level of IFN-gamma in the tumor correlated with the advance of clinical stage, and the levels of IFN-gamma of the patients with distant metastases were significantly lower than those of the patients without distant metastases. However, an increase in the level of TNF-alpha correlated not only with an enlarged diameter but also with the extent of the primary tumor. Immunohistochemical staining of IFN-gamma and TNF-alpha producing cells in tumor tissues showed that IFN-gamma was mainly produced by CD4+ CD8- T-lymphocytes and TNF-alpha was mainly produced by CD11c+ cells with macrophage-like morphology. These results suggest that CD4+ T-lymphocytes that produce IFN-gamma might play an important role in the antitumor response against cancer progression in human colorectal adenocarcinomas.

Distribution of Photofrin between tumour cells and tumour associated macrophages

Photofrin levels in cells derived from SCCVII tumours, excised from mice that previously received the drug, were measured using a fluorescence activated cell sorter (FACS). Concomitantly, in the same cells the FACS was used to measure fluorescein isothiocyanate (FITC) fluorescence that originated from FITC-conjugated antimouse IgG added to the cell suspension before sorting. This later measurement enabled discrimination between IgG negative tumour malignant cells and IgG positive host cells (primarily macrophages). In addition, cellular Photofrin content in 'tumour' and 'host' cells sorted by FACS was determined by chemical extraction. The measurements were performed for the time intervals 1-96 h post Photofrin administration. The data showed consistently higher Photofrin levels in the 'host cells', i.e., tumour associated macrophages (TAM), than in 'tumour' cells. On a per cell basis, at any time point studied there was a minimum of 1.7 times more Photofrin in 'host' than in 'tumour cells', while at 4-12 h postadministration, ratios of up to 3.0 times were observed. This corresponds to ratio values greater than 9, when based on Photofrin content per micrograms cell protein.

Characterization and frequency distribution of lymphoreticular infiltrates in axillary lymph node metastases of invasive ductal carcinoma of the breast

One hundred and seventy-five axillary lymph nodes containing metastatic deposits from 46 invasive ductal carcinomas of the breast were evaluated histologically and immunohistologically. The study yielded the following results: (1) tumor-infiltrating lymphoreticular cells preferentially accumulated in the stromal bands; the tumor foci generally showed a considerably lower degree of infiltration; (2) in most cases, monocytes/macrophages (Mono 1+) represented the overwhelming majority of tumor-infiltrating cells; (3) next in frequency were T-lymphocytes (Leu-1+), especially CD4+ lymphocytes (Leu-3a+), while CD8+ lymphocytes (Leu-2a+) mostly occurred only in moderate numbers; (4) B-lymphocytes (To15+), plasma cells, natural killer cells (Leu-7+), tissue mast cells, and T-accessory reticulum cells (OKT 6+) were observed mostly in low or very low numbers, while eosinophils were nearly absent and B-accessory reticulum cells (Ki-M4+) were totally absent from the lymphoreticular infiltrates. Definite conclusions regarding the functional properties of the tumor-infiltrating cells cannot be drawn from an immunohistologic analysis in situ alone, but the preferred localization of most tumor-infiltrating cells in the stroma does not support an intensive interaction between the host defenses and the metastatic tumor.

Lymphoreticular infiltrates in adenocarcinoma of the large intestine

Twenty-two invasive adenocarcinomas of the large intestine were investigated histologically and immunohistologically to determine the localisation and composition of the tumor-infiltrating lymphoreticular cells: The lymphoreticular cells were consistently more frequent in the intervening stroma than in the tumor foci. Monocytes/macrophages (Mono 1+), helper/inducer cells (Leu-3 a+), and T lymphocytes (Leu-1+) were mostly observed in large numbers, thus constituting the great majority of tumor-infiltrating cells. In most tumors, the suppressor/cytotoxic T lymphocytes (Leu-2a+), plasma cells, eosinophils, and tissue mast cells occurred in moderate numbers. T-accessory cells bearing the CD 1 surface-antigen (Leu-6+) were generally detected in low, or even very low numbers, while B lymphocytes (TO 15+) and natural killer cells (Leu-7+) were nearly, and dendritic reticulum cells (KiM 4+) were totally absent from the lymphoreticular infiltrates. Though an immunohistological in situ analysis of tumor-infiltrating cells allows only limited conclusions concerning their functional properties, the often dense and polymorphic infiltrates might reflect a relatively intensive interaction between the specific and non-specific host defense and the malignant tumor.

Immunofluorescent assessment of tumour infiltrating cells in laryngeal carcinoma. Application of monoclonal antibodies

In order to gain some insight into host cell accumulations within primary tumour, frozen sections from surgical specimens of laryngeal carcinoma were subjected to indirect immunofluorescence using a panel of monoclonal antibodies against various human lymphocyte subsets as well as macrophages. In addition, polyclonal antibodies against Ig were used in order to trace B cells. Numerous host cell infiltrates seen at the tumour periphery were composed of T4 (helper) lymphocytes and macrophages. Lymphocytes of OKT8 (suppressor/cytotoxic) and Leu-7 (NK cells) series were intermingled with tumour cells in the case of scanty infiltrates. Infiltrating cells were also linked to the presence of metastases in regional lymph nodes. OKT4-positive abundant infiltrates were usually accompanied by uninvolved nodes, while scanty ones with OKT8 specificity were relatively frequently seen in the patients with evidence of nodal metastases. These differences were not statistically significant, however, B cells as well as plasma cells were infrequently observed and were encountered both in tumour samples with intensive cellular infiltrates as well as in those with scanty ones.

Inflammatory infiltrates of experimental mammary cancers

The purpose of this review was to summarize observations on the type and function of inflammatory infiltrates of mouse mammary tumors and to speculate on the underlying mechanisms and the significance of infiltrates to mammary tumor biology. Although the major conclusion is that much more work is needed, certain themes seem to be emerging. The number of infiltrating cells can be very high but is unrelated to biological behavior of the tumors. What seems to be important is the relative contributions of inflammatory cell subsets. In the case of T-cell subsets and NK cells, the infiltrates from tumors of long-term cell lines so far seem uninformative. The general characteristics are similar to those of infiltrates from rapidly proliferating, normal mammary tissues. These characteristics do not correlate with diverse biological behavior or malignant potential. A more informative model appears to be one in which the development of tumors from preneoplastic tissue can be observed. Here our attention is currently focused on NK cells. By contrast, the correlation between activated TAM and metastatic behavior suggests that our transplantable MMT lines may be biologically relevant in the study of infiltrating macrophages. We are especially interested in the role of TAM in the generation of tumor cell variability. Overall, our data indicate that the host infiltrate is another manifestation of both inter- and intra-tumor heterogeneity and, as such, is not simply a response to, but, rather, a part of the tumor ecosystem. Unraveling the cellular and molecular mechanisms that govern the inflammatory cell component of tumors should provide insight into the types of cellular interactions that result in tumor development and progression.

Lymphoreticular infiltrates in invasive ductal breast cancer. A histological and immunohistological study

Fifty-two invasive ductal breast cancers were investigated histologically and immunohistologically to assess localization and composition of the lymphoreticular infiltrates. The tumour-infiltrating cells were mainly located in the intervening stroma, whereas tumour foci often exhibited lower numbers of lymphoreticular cells. Macrophages (Mono 1+ and KiM 6+) and helper/inducer cells bearing the T4 surface antigen (Leu-3a+) regularly constituted the majority of the tumour-infiltrating lymphoreticular cells. In more than 80% of cases large numbers of macrophages were found, and many T4 cells occurred in about 60%. Next in frequency were the T lymphocytes (Leu-1+) which were mostly observed in high (46%), or in moderate (39%) numbers. In about 2/3 of the cases moderate numbers of T8 (suppressor/cytotoxic) lymphocytes (Leu-2a+) were detected. B lymphocytes (T0 15+) and natural killer cells (Leu-7+) were generally encountered in very low numbers, while eosinophilic granulocytes were virtually absent from the lymphoreticular infiltrates. Tissue mast cells and plasma cells were present in very low numbers in about one half of the tumours but cases with low, moderate or - rarely - even high numbers of infiltrating cells also occurred. It must be emphasized that an in situ histomorphological analysis of the cellular part of the stromal reaction of invasive ductal breast cancers allows only limited conclusions concerning the functional properties of the tumour-infiltrating lymphoreticular cells. From the present study, macrophages and T4 cells but also T8 lymphocytes might be of significance in immunooncological reactions "against" clinically detectable stages of invasive breast cancer.

Role of macrophage in the defense against intestinal cancers

The capability of activated macrophages to kill tumor cells in vitro is now well documented. The tumoricidal activation of macrophages against intestinal tumor cells by different agents is described and the main hypothesis on the mechanisms of tumor cell killing in vitro are discussed. These in vitro results suggest that the macrophage can constitute an efficient effector cell in the defense against intestinal tumors. The distribution and ratio of macrophages in normal intestine and intestinal tumors is described. At the moment, potent activators of macrophages studied in vivo on experimental and human intestinal tumors give poor results or even enhance the growth of tumors. Macrophages may also interfere with the specific immune response in two directions by enhancing the immune response or decreasing it by elaboration of mediators such as prostaglandins.

Epithelial organoids and mononuclear phagocytes from DMBA-induced mammary tumors of the rat secrete collagenase in vitro

The production of collagenase has been examined in primary cultures of multicellular epithelial organoids and of stromal cells isolated from DMBA-induced mammary tumors of the rat. Plastic culture dishes and dishes coated with collagen fibrils were used to study the effect of such a substrate on collagenase release. Cultures of 51-micron epithelial organoids consisted of cuboidal cells and a myoepithelial-like cell type which formed a continuous layer under the cuboidal cells. A transient low production of collagenase with an apparent molecular weight (MW) of 72 kD was detected on both substrates. Upon separation by trypsin only cuboidal cells released collagenase. Cultures of 27-micron organoids contained only few myoepithelial-like cells. On plastic, they formed dense monolayers of cuboidal cells and released more collagenase than the greater aggregates. On collagen fibrils, these organoids formed cords and ridges and collagenase production was about 4- to 6-fold higher. These results indicate that collagenase release is influenced by the nature of the interaction of cuboidal cells with the substrate on which they grow. Similar organoids prepared from virgin mammary glands failed to secrete collagenase on either substrate. Primary cultures of stromal cells derived from tumor tissues comprised one basic cell type that expressed a series of properties characteristic for monocytes/macrophages. These cultures were capable of producing collagenase with an apparent MW of 56 kD. Collagenase with a similar size was detected in the extracts of 51 from 65 mammary tumors.

Lymphoid infiltration and prognosis in colorectal carcinoma

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Biological significance of interstitial collagenase in DMBA-induced mammary tumors of the rat

In this review the production of interstitial collagenase in DMBA-induced mammary tumors of the rat has been examined. Cell sorting and cell cultures have given us the opportunity to relate the release of collagenase to a specific cell type. By means of FITC-fluorescence and monospecific antibodies (S. Sakamoto, Harvard University, Boston) it was further possible to localize collagenase in vitro and in vivo. The most outstanding characteristic is that collagenase is produced both by cuboidal, epithelial cell and by macrophages in vitro but not by myoepithelial-like cells. On the other hand, synthesis of collagenase in vivo was detected in some stromal cells, possibly macrophages, but not in neoplastic cuboidal cells. This observation has been related to the inability of cuboidal cells to interact with stromal, fibrillar collagen in vivo since tumor cells are arranged in glandular-like structures bordered by myoepithelial cells and a basement membrane. In vitro, fibrillar rat tail tendon collagen was found to be a potent stimulator of collagenase production by cuboidal cells. Collagenase stimulation by interstitial collagen therefore suggests a plausible mechanism for the degradation of collagen fibrils during local invasion by mammary tumor cells.

Macrophages in cancer metastases and their relevance to metastatic growth

The dissemination of malignant cells throughout the body to form secondary growths is a highly complex process dependent upon both host and tumor cell properties. One potential defensive system which could influence the outcome of metastasis is the mononuclear phagocyte system. Although macrophages have been observed in essentially all primary and metastatic tumors examined regardless of histologic type or anatomic location, the biological significance of these observations is far from clear. What is clear, however, is that in most cases the effects of macrophages on tumor cells are not sufficient to alter progressive growth. Therefore, the presence of macrophages within metastases does not necessarily signify a protective host defensive response. On the other hand, macrophage-induced regression of established metastases can occur in vivo under certain conditions in which tumor-bearing mice are treated systemically with macrophage-activating agents. When mice bearing metastases are treated with macrophage-activating agents contained within liposomes, metastasis-associated macrophages are activated to the tumoricidal state and the metastatic lesions are simultaneously eradicated. Such a process of macrophage activation may have implications in determining successful approaches to the therapy of disseminated cancer.

In situ analysis of the inflammatory cell infiltrates in colon carcinomas and in the normal colon wall

Inflammatory cells (lymphocytes, plasma cells, macrophages, mast cells and polymorphonucleated cells) forming infiltrates in the stroma of ten colon carcinomas were analysed in situ and compared with the cells of the normal colon wall. The cancer stroma contained a larger proportion of lymphocytes, while the number of IgA-containing plasma cells was markedly reduced compared to the normal colon mucosa from the resection edge. In both tissues the number of macrophages was much higher than the study of H & E stained routine preparations would suggest. The peritumoural cell infiltrates consisted of 47% lymphocytes, 19% plasma cells, 15% macrophages (including monocytes) and 5% granulated mast cells, while 15% of all inflammatory cells were polymorphonucleated (PMN). Necrotic areas of the tumours were dominated by a larger number of PMN and macrophages. Compared to the normal colon wall, the significant differences in cell composition and the accumulation of mononuclear cells (MC) at the cancer borders indicate that populations of cells are selectively attracted to the tumour site, although the factors responsible for the local cell reaction in cancer are still unknown.

Cells bearing Fc receptors in human malignant solid tumours

Fc-receptor-bearing cells forming EA rosettes with antibody-coated human erythrocytes (Ripley) were studied in cell suspensions and in purified preparations of mononuclear cells (MC) from 20 human malignant tumours. The EA rosettes were studied in preparations made by cytocentrifugation and the rosette-forming cells identified by their nonspecific-esterase activity and phagocytic capacity. Fc receptors were found on 16 +/- 20% of all cells in the primary cell suspensions. Significantly more tumour-infiltrating lymphocytes had detectable Fc receptors normal control subjects (14 +/- 6%). There was a significant correlation between the proportion of lymphocytes lacking T and B markers (null cells) and the proportion of lymphocytes with Fc receptors. Fc receptors were also found on most tumour-infiltrating macrophages, on some T lymphocytes and polymorphonuclear cells and on a smaller percentage of the tumour cells. The significance of the Fc receptor and its usefulness as a marker of "host infiltration" into the tumours is discussed.

Role of autologous lymphocyte cytotoxicity in colonic neoplasia

The T-lymphocyte mediated killing of autologous carcinoma colon cells was investigated. There was no change in the incidence of activity with advanced disease, age, or nutritional status of the patient and no difference could be demonstrated in lymphocytes extracted from blood, draining lymph nodes, or the tumour itself. Nevertheless. T-lymphocyte activity did appear to be specific for the patients's own tumour, as it was rarely observed with allogeneic tumours. There was also no correlation with lymphocyte natural killer activity. The in vitro studies demonstrated patient specific T-lymphocyte activity in 23 of 47 patients with carcinoma of the colon, but the results do not correlate with clinical and pathological findings.

The local cell response to human lung carcinomas

Non-malignant inflammatory cells were studied in tissue sections and cell suspensions from 21 human lung carcinomas. The different cell types were identified and quantified by means of histochemical and immunohistochemical methods. All tumours were surrounded and to a lesser degree also infiltrated by lymphocytes, macrophages, plasma cells containing IgG, IgA, or IgM, and a small number of mast cells. No evident signs of cell necrosis were present in association with these mononuclear cell infiltrates. Central tumour necroses were dominated by large numbers of neutrophils and macrophages, a reaction considered to be secondary to ischemic necroses in rapidly expanding tumours. The weakest mononuclear cell infiltrates were found in tumours with extensive necrotic areas. Of the tumour lymphocytes 3-67% (mean 37%) were T-lymphocytes, 4-32% (mean 19%) were B-lymphocytes. The relation between these markers did not always correlate with the findings in peripheral blood: low percentages of T-lymphocytes were found in some tumours even when the percentage of T-lymphocytes in peripheral blood was within the normal range. The demonstration of both T-lymphocytes and macrophages in and around the tumour tissue may reflect a local immune response against the neoplastic cells, while the presence of plasma cells in all tumours supports the theory that the tumour also induces a local production of immunoglobulin which may interfere with the cellular immunity.

T lymphocytes in malignant, non-lymphoid human tumours detected by esterase technique

The alpha-naphthyl acetate esterase (ANAE) method, leading to distinct brownish-red dots in the cytoplasm of T lymphocytes, was used to identify these cells in cryostat sections from eighteen malignant tumours. Esterase-positive lymphocytes were found in all tumours, the highest number in the peritumoural stroma. The reliability of the method was tested on lymph nodes, on fixed E-rosetting lymphocytes and on cryostat sections from peripheral blood lymphocytes.

In situ identification of inflammatory cells in malignant, non-lymphoid human tumours

Inflammatory cells (the term is considered to include lymphocytes, plasma cells, macrophages, mast cells and PMN) were identified and quantitated in sections from human carcinomas. Two types of cellular infiltrates are described. In the stroma surrounding the cancer tissue (peritumoural) and, to a lesser degree, also within the malignant tissue (intratumoural), lymphocytes, plasma cells, macrophages and mast cells dominated, whilst numerous polymorph nucleated cells (PMN) and aggregates of macrophages characterized central tumour necroses. The demonstration of both T-lymphocytes and macrophages in and around the cancer tissue supports the view that a local immune reaction is initiated by the tumour, and the consistent finding of IgG, IgA and IgM plasma cells at the borders of the carcinomas, indicates that plasma cells are also part of an immune response at the tumour site. This view is further supported by the demonstration of an increased proportion of IgG containing plasma cells in the stroma of colon tumours, compared with normal mucosa.

Review: prostaglandins and cancer

This paper reviews work on the role of prostaglandins in cancer. A substantial body of evidence demonstrates elevated amounts of E series of prostaglandins in human and experimental tumors. Blockade of prostaglandin synthesis in vitro or in vivo results in inhibition of tumor growth. Involvement of prostaglandins is implicated in the actions of tumor promoters like phorbol and polycyclic aromatic hydrocarbon carcinogens. Symptoms like hypercalcemia, osteolysis and tumor metastasis are discussed where disordered synthesis and/or action of prostaglandins and related substances might have a role in the altered metabolism associated with neoplasia.