Prognostic factors for well-differentiated squamous cell carcinoma in the oral cavity with emphasis on immunohistochemical evaluation

Eosinophils in Oral Disease: A Narrative Review

The prevalence of diseases characterised by eosinophilia is on the rise, emphasising the importance of understanding the role of eosinophils in these conditions. Eosinophils are a subset of granulocytes that contribute to the body's defence against bacterial, viral, and parasitic infections, but they are also implicated in haemostatic processes, including immunoregulation and allergic reactions. They contain cytoplasmic granules which can be selectively mobilised and secrete specific proteins, including chemokines, cytokines, enzymes, extracellular matrix, and growth factors. There are multiple biological and emerging functions of these specialised immune cells, including cancer surveillance, tissue remodelling and development. Several oral diseases, including oral cancer, are associated with either tissue or blood eosinophilia; however, their exact mechanism of action in the pathogenesis of these diseases remains unclear. This review presents a comprehensive synopsis of the most recent literature for both clinicians and scientists in relation to eosinophils and oral diseases and reveals a significant knowledge gap in this area of research.

Eosinophilia in cancer and its regulation by sex hormones

Gender differences in the functionality of the immune system have been attributed, in part, to direct and indirect effects of sex steroids, especially estrogens, on immune cell repertoire and activity. Notable are studies that have defined roles for estrogens in the regulation of the biology of dendritic cells (DCs), macrophages, T cells and natural killer (NK) cells. Although estrogens can modulate eosinophil function, the mechanisms by which this occurs and how it contributes to the pathobiology of different diseases remains underexplored. Furthermore, although the importance of eosinophils in infection is well established, it remains unclear as to how these innate immune cells, which are present in different tumors, impact the biology of cancer cells and/or response to therapeutics. The observation that eosinophilia influences the efficacy of immune checkpoint blockers (ICBs) is significant considering the role of estrogens as regulators of eosinophil function and recent studies suggesting that response to ICBs is impacted by gender. Thus, in this review, we consider what is known about the roles of estrogen(s) in regulating tissue eosinophilia/eosinophil function and how this influences the pathobiology of breast cancer (in particular). This information provides the context for a discussion of how estrogens/the estrogen receptor (ER) signaling axis can be targeted in eosinophils and how this would be expected to influence the activity of standard-of-care interventions and contemporary immunotherapy regimens in cancer(s).

Blood Eosinophils Are Associated with Efficacy of Targeted Therapy in Patients with Advanced Melanoma

Background: Eosinophils appear to contribute to the efficacy of immunotherapy and their frequency was suggested as a predictive biomarker. Whether this observation could be transferred to patients treated with targeted therapy remains unknown. Methods: Blood and serum samples of healthy controls and 216 patients with advanced melanoma were prospectively and retrospectively collected. Freshly isolated eosinophils were phenotypically characterized by flow cytometry and co-cultured in vitro with melanoma cells to assess cytotoxicity. Soluble serum markers and peripheral blood counts were used for correlative studies. Results: Eosinophil-mediated cytotoxicity towards melanoma cells, as well as phenotypic characteristics, were similar when comparing healthy donors and patients. However, high relative pre-treatment eosinophil counts were significantly associated with response to MAPKi (p = 0.013). Eosinophil-mediated cytotoxicity towards melanoma cells is dose-dependent and requires proximity of eosinophils and their target in vitro. Treatment with targeted therapy in the presence of eosinophils results in an additive tumoricidal effect. Additionally, melanoma cells affected eosinophil phenotype upon co-culture. Conclusion: High pre-treatment eosinophil counts in advanced melanoma patients were associated with a significantly improved response to MAPKi. Functionally, eosinophils show potent cytotoxicity towards melanoma cells, which can be reinforced by MAPKi. Further studies are needed to unravel the molecular mechanisms of our observations.

High TGF-β signature predicts immunotherapy resistance in gynecologic cancer patients treated with immune checkpoint inhibition

Various immune signatures predictive of resistance to immune checkpoint inhibitors (ICI) have been described in multiple solid cancers, but still under-investigated in gynecological (GYN) cancer. For 49 GYN cancer patients included in our study, without transcriptome signature, immune-related toxicity was the only clinical predictor of ICI treatment response (p = 0.008). The objective clinical response was the only predictor of progression-free survival (ICI-PFS, p = 0.0008) and overall survival (ICI-OS, p = 0.01). Commonly used ICI marker PD-L1 expression negatively correlated with progression-free survival (ICI-PFS) (p = 0.0019). We performed transcriptome and signaling pathway enrichment analyses based on ICI treatment responses and the survival outcome, and further estimated immune cell abundance using 547 gene markers. Our data revealed that TGF-β regulated signaling pathway was noted to play an important role in immunotherapy failure. Using our 6-genes TGF-β score, we observed longer ICI-PFS associated with lower TGF-β score (8.1 vs. 2.8 months, p = 0.046), which was especially more prominent in ovarian cancer (ICI-PFS 16.6 vs. 2.65 months, p = 0.0012). Further, abundant immunosuppressive cells like T-regulatory cells, eosinophils, and M2 macrophages were associated with shorter ICI-OS and correlated positively with CD274 and CTLA4 expressions. This study provides insight on the potential role of TGF-β in mediating immunotherapy resistance and cross-talking to immunosuppressive environment in GYN cancer. The TGF-β score, if validated in a larger cohort, can identify patients who likely to fail ICI and benefit from targeting this pathway to enhance the response to ICI.

CCL24 Signaling in the Tumor Microenvironment

Chemokines with their network play an important role in cancer growth, metastasis, and host-tumor interactions. Of many chemokines, C-C motif chemokine ligand 24 (CCL24) has been shown to contribute to tumorigenesis as well as inflammatory diseases like asthma, allergies, and eosinophilic esophagitis. CCL24 is expressed in some tumor cells such as colon cancer, hepatocellular carcinoma, and cutaneous T cell lymphoma. CCL24 can be used as a potential biomarker in several cancers including colon cancer, non-small cell cancer, and nasopharyngeal carcinoma as the plasma level of CCL24 is increased. The various functions of CCL24 contribute to the biology of cancer by M2 macrophage polarization, angiogenesis, invasion and migration, and recruitment of eosinophils.

Trial watch: Prognostic and predictive value of the immune infiltrate in cancer

Solid tumors are constituted of a variety of cellular components, including bona fide malignant cells as well as endothelial, structural and immune cells. On one hand, the tumor stroma exerts major pro-tumorigenic and immunosuppressive functions, reflecting the capacity of cancer cells to shape the microenvironment to satisfy their own metabolic and immunological needs. On the other hand, there is a component of tumor-infiltrating leucocytes (TILs) that has been specifically recruited in the attempt to control tumor growth. Along with the recognition of the critical role played by the immune system in oncogenesis, tumor progression and response to therapy, increasing attention has been attracted by the potential prognostic and/or predictive role of the immune infiltrate in this setting. Data from large clinical studies demonstrate indeed that a robust infiltration of neoplastic lesions by specific immune cell populations, including (but not limited to) CD8⁺ cytotoxic T lymphocytes, Th1 and Th17 CD4⁺ T cells, natural killer cells, dendritic cells, and M1 macrophages constitutes an independent prognostic indicator in several types of cancer. Conversely, high levels of intratumoral CD4⁺CD25⁺FOXP3⁺ regulatory T cells, Th2 CD4⁺ T cells, myeloid-derived suppressor cells, M2 macrophages and neutrophils have frequently been associated with dismal prognosis. So far, only a few studies have addressed the true predictive potential of TILs in cancer patients, generally comforting the notion that—at least in some clinical settings—the immune infiltrate can reliably predict if a specific patient will respond to therapy or not. In this Trial Watch, we will summarize the results of clinical trials that have evaluated/are evaluating the prognostic and predictive value of the immune infiltrate in the context of solid malignancies.

Tumor associated tissue eosinophilia in oral squamous cell carcinoma: A systematic review and meta-analysis

Background

Oral squamous cell carcinoma (OSCC) still lacks the valid prognosticator for survival. Tumor associated tissue eosinophilia (TATE) have been widely investigated in the literature but still there is no consensus viewpoint on its role as prognostic marker. With this view in mind, a systematic review and meta-analysis of studies that evaluated the overall risk of elevated TATE and survival in OSCC was conducted.

Methodology

A systematic literature search conducted to identify studies that have evaluated TATE in OSCC. Overall survival (OS), Disease Free Survival (DFS) Hazard ratio (HR) with 95% confidence interval) was extracted. HR was extrapolated if direct HR was not given in publication. Studies were pooled and combined hazard ratios (HRs) of High TATE for OS and DFS were calculated.

Results

6 out of 874 articles were found eligible for systematic review and meta-analysis. High TATE was predictor of OS (pooled HR 0.45 (95% CI, 030-0.65, P ​< ​0.0001)) and DFS (pooled HR 2.33 (95% CI, 0.74-7.37)) in OSCC patients.

Conclusion

High TATE positively predicts OS and DFS in OSCC and thus can be regarded as an important survival prognosticator. Standardization of counting and reporting methodology for TATE count is recommended on future cohort studies.

Tumor-associated tissue eosinophilia versus tumor associated blood eosinophilia: A ratio of diagnostic importance in oral squamous cell carcinoma

Introduction

Eosinophils are multifunctional granulocytes, which play a pivotal role in health and disease. Tumor Associated Tissue Eosinophilia (TATE) has long been evaluated in the diagnosis and progression of oral squamous cell carcinomas (OSCCs). However, their association with Tumor Associated Blood Eosinophilia (TABE) in OSCCs is still far fetched. We, therefore, attempted to evaluate their individual roles and to achieve a ratio between TATE and TABE in order to signify its usage in objectifying the diagnosis.

Materials and Methods

TATE was evaluated using H and E stain per 10 high power fields in 33 previously diagnosed cases of OSCC which were retrieved from department archives. TABE values were achieved from complete blood hemogram reports of patients. TATE/TABE ratio was calculated. All the parameters were clinicopathologically correlated and statistically evaluated using SPSS.

Results

TATE represented higher values in well-differentiated squamous cell carcinoma (WDSCC) and poorly differentiated squamous cell carcinoma (PDSCC) and was least in moderately differentiated squamous cell carcinoma (MDSCC), whereas TABE linearly increased from WDSCC to PDSCC. TNM Stage II cases revealed the highest TATE and lowest TABE. TATE/TABE ratio was the highest in WDSCC.

Conclusion

Due to the dual nature of eosinophils in early and late carcinogenesis events, evaluation of only TATE might not be conclusive in determining tumor grade. Hence, in a first of its kind attempt, the TATE/TABE ratio may be suitable to achieve a criterion for the determination of tumor grade and may also help to unfold the underlying biologic events.

Quantitative assessment of CD15 positive tissue eosinophils in Oral Squamous Cell Carcinoma: effects on mast cells and tumor angiogenesis

BACKGROUND

The present study determines to correlate eosinophil, mast cell and microvessel densities with the histopathological grades and clinical staging of Oral Squamous Cell Carcinoma (OSCC) cases, as the potential role of inflammatory mediators within tumor stroma remains debatable.

METHODS

The study sample comprised 60 cases consisting of 40 cases of Well to moderately differentiated OSCC (group 1) and 20 cases of poorly differentiated OSCC (group 2). Immunohistochemistry with anti-CD15 antibody and antifactor VIII antibody; and toluidine blue special stain were employed for the detection of eosinophils, microvessels, and mast cells, respectively.

RESULTS

The mean numbers of eosinophils, mast cells, and microvessels per high power field in group 1 and group 2 were 15.37±11.86 and 12.62±14.30, 6.00±4.84 and 4.51±4.51, 13.96±6.25 and 6.62±2.05, respectively. Eosinophil density had a positive correlation with both mast cell and microvessel density. Also, the correlation of primary tumor size (T status) with microvessel density was found to be statistically significant (P≤0.05).

CONCLUSIONS

The cohesive interpretation of the aforementioned mediators in OSCC suggested that while these variables correlate well with the differentiation of tumor, the quantification did not correlate with the clinical staging of the disease.

Identification of a novel IL-5 signaling pathway in chronic pancreatitis and crosstalk with pancreatic tumor cells

BACKGROUND

While inflammation is associated with pancreatic cancer, the underlying mechanisms leading to cancer initiation are still being delineated. Eosinophils may promote or inhibit tumor growth, although the specific role in pancreatic cancer has yet to be determined. Eosinophil-supporting cytokine interleukin-5 and receptor are likely to have a role, but the significance in the pancreatic cancer microenvironment is unknown.

METHODS

Genetically engineered Akt1^Myr/KRas^G12D and KRas^G12D mice were used to model changes induced by chronic inflammation. Tissue samples were collected to analyze the tumor microenvironment and infiltration of immune cells, whereas serum was collected to analyze cytokine and amylase activity in the inflammatory model. The expression of IL-5R and the effects of IL-5 were analyzed in human and murine tumor cells.

RESULTS

Compound Akt1^Myr/KRas^G12D mice, compared to single KRas^G12D or Akt1^Myr mice, exhibited increased tissue damage after repeat inductions of inflammation, and had accelerated tumor development and metastasis. M2 macrophages and newly identified eosinophils co-localized with fibrotic regions rather than infiltrating into tumors, consistent with immune cell privilege. The majority of eosinophils found in the pancreas of Akt1^Myr/KRas^G12D mice with chronic inflammation lacked the cytotoxic NKG2D marker. IL-5 expression was upregulated in pancreatic cells in response to inflammation, and then diminished in advanced lesions. Although not previously described in pancreatic tumors, IL-5Rα was increased during mouse pancreatic tumor progression and expressed in human pancreatic ductal adenocarcinomas (7 of 7 by immunohistochemistry). IL-5 stimulated tumor cell migration and activation through STAT5 signaling, thereby suggesting an unreported tumor-promoting role for IL-5Rα in pancreatic cancer.

CONCLUSIONS

Chronic inflammation induces increased pancreatic cancer progression and immune cells such as eosinophils are attracted to areas of fibrosis. Results suggest that IL-5 in the pancreatic compartment stimulates increased IL-5Rα on ductal tumor cells to increase pancreatic tumor motility. Collectively, IL-5/IL-5Rα signaling in the mouse and human pancreatic tumors microenvironment is a novel mechanism to facilitate tumor progression. Additional file 1: Video Abstract.

Quantitative analysis of tumor-associated tissue eosinophils and tumor-associated blood eosinophils in oral squamous cell carcinoma

Background:

Stromal response to cancer is usually characterized by intense lymphoplasmacytic infiltrate. However, recently, the attention has shifted to tumor-associated tissue eosinophils (TATE). Tumor-associated blood eosinophils (TABE) are rare in solid cancers; however, carcinoma of the head and neck shows its prevalence.

Aim:

The aim of the study was to investigate the prevalence and relationship of tissue and blood eosinophils in various grades of oral cancer. The purpose of the article is to emphasize the possible clinical and biological significance of eosinophils in patients of oral squamous cell carcinoma (OSCC) so that appropriate therapeutic strategies can be devised accordingly.

Study Design:

Thirty histologically confirmed cases of oral squamous cell carcinoma were divided into well, moderate and poorly differentiated carcinoma. Eosinophilic infiltration in the tissue was graded as low, moderate and massive TATE. The number of eosinophils per 100 WBCs was taken as the differential eosinophil count. Blood eosinophilia (BE) >6% was considered to be TABE.

Materials and Methods:

Hematoxylin and eosin-stained tissue sections at 5 μ were evaluated. Prolonged staining in dilute 0.05% aqueous eosin demonstrated eosinophils selectively. Blood smears were stained by Leishman stain.

Statistical Analysis:

Student's t-test, Chi-square test, ANOVA, Newman–Keuls Multiple Comparison Test and Karl Pearson correlation coefficient® method were used.

Results:

The mean TATE value was highest in poorly differentiated carcinoma. TABE was seen only in a few cases and was associated mostly with poorly differentiated OSCC.

Conclusion:

There was a statistically significant correlation between TATE and histological grades of OSCC. Eosinophilia of the peripheral blood is an adverse sign in patients with carcinoma.

Immunoexpression of human leukocyte antigen-DR in actinic cheilitis and lower lip squamous cell carcinoma

The aim of this study was to evaluate the immunoexpression of human leukocyte antigen-DR (HLA-DR) in actinic cheilitis (AC) and lower lip squamous cell carcinoma (LLSCC), and to correlate the findings with clinical (tumor size/extent, regional lymph node metastasis, and clinical stage) and histopathological (grade of epithelial dysplasia and inflammatory infiltrate for AC and histopathological grade of malignancy for LLSCC) parameters. Twenty-four AC and 48 LLSCC cases (24 with regional nodal metastasis and 24 without regional nodal metastasis) were selected. The scores of immunopositive cells for HLA-DR in the epithelial component of the lesions were assessed and the results were analyzed statistically using the nonparametric Mann-Whitney test. Epithelial expression of HLA-DR was observed in only five (20.8%) cases of AC (two low-grade and three high-grade lesions), with a very low median score of immunopositivity. By contrast, expression of HLA-DR was found in most LLSCC (97.9%), with a relatively high median score of positive cells. The score of HLA-DR-positive cells tended to be higher in tumors with regional lymph node metastasis, tumors in advanced clinical stages, and low-grade tumors, but the difference was not statistically significant (p > 0.05). In addition, there was a tendency towards higher expression of HLA-DR in highly/moderately keratinized tumors, and tumors with little/moderate nuclear pleomorphism (p > 0.05). The results suggest a potential role of HLA-DR in lip carcinogenesis, particularly in the development and progression of LLSCC. The expression of this protein can be related to the degree of cell differentiation in these tumors.

Eosinophil-cationic protein - a novel liquid prognostic biomarker in melanoma

BACKGROUND

The role of eosinophils in cancer is not yet completely understood, but patients with eosinophilia show a trend towards longer survival in several types of cancer, including melanoma. However, eosinophil count at initial diagnosis of metastatic melanoma does not predict survival. Since eosinophil cationic protein (ECP) mediates anticancer effects, such as tissue remodelling and cytotoxic activity, we investigated this marker as an early prognostic marker in metastatic melanoma.

METHODS

Serum of 56 melanoma patients was collected at the time of diagnosis of metastatic disease. ECP levels as measured by ELISA were correlated with overall survival (OS) in patients before systemic therapy with immunotherapy or chemotherapy. Statistical analyses were performed using the Log-Rank (Mantel-Cox) test.

RESULTS

The median OS for patients with high serum ECP above 12.2 ng/ml was 12 months (n = 39), compared to 28 months for patients with ECP below this threshold (n = 17; p = 0.0642). In patients with cutaneous melanoma, excluding patients with uveal and mucosal melanoma, the survival difference was even more striking (p = 0.0393). ECP's effect size on OS was observed independently of the consecutive therapy. ECP levels were not correlated with LDH levels.

CONCLUSION

ECP seems to be a novel prognostic serum marker for the outcome of melanoma patients, which is independent of LDH and easy to perform in clinical practice. The striking negative prognostic value of high ECP level is unanticipated and can guide patient management.

Adenosquamous carcinoma of the uterine cervix displaying tumor-associated tissue eosinophilia

Background:

Tumor-associated tissue eosinophilia is defined as an inflammatory response with the marked infiltration of eosinophils within tumor tissues. Tumor-associated tissue eosinophilia has been reported in various organs; however, no studies have examined the detailed cytopathological findings of tumor-associated tissue eosinophilia.

Case Presentation:

A 49-year-old woman presented with lower abdominal and back pain that had started 1 month earlier. A cervical biopsy revealed a diagnosis of non-keratinizing squamous cell carcinoma. A mildly increased number of eosinophils was observed in both cervical cytology and a biopsy. On pelvic computed tomography, a tumor mass measuring up to 5.5 cm in the largest diameter was seen in the uterine cervix. After 1 month, endometrial cytology was performed, and non-keratinizing squamous cell carcinoma together with normal endometrial glands was obtained in a background of marked eosinophil numbers. Tumor cells in an irregular-shaped solid nest had variable-sized hyperchromatic nuclei and light-green-stained cytoplasm. The number of eosinophils was obviously increased. Considering the possibility of tumor-associated tissue eosinophilia, we evaluated a peripheral blood sample and confirmed an increased number of eosinophils. Radical hysterectomy was performed, and the final pathological diagnosis was adenosquamous carcinoma. Although the number of eosinophils decreased after surgery, it increased again at the time of recurrence 1 year later. Chemo-irradiation was performed, but the patient died 1 year and 8 months after the operation.

Conclusion:

Cytopathologists should consider the presence of tumor-associated tissue eosinophilia by focusing on not only tumor cells but also the markedly eosinophilic background. The eosinophil count might be a useful marker of the disease activity.

The Impact of Peritumoral Retraction Clefting & Intratumoral Eosinophils on Overall Survival in Oral Squamous Carcinoma Patients

This retrospective study aimed to investigate the impact of peritumoral retraction clefts (RC) and tumor-associated tissue eosinophilia (TATE) as predictors of overall survival (OS) in oral squamous cell carcinoma (OSCC) patients. Their relationships with tumor-factors were also examined. Eighty-seven OSCC cases (pTNM: I + II/III + IV; 32/55), post-curative surgery, comprised the study cohort. Three observers independently estimated the percent RC semi-quantitatively in the selected tumor sections. Additionally, stromal eosinophils were counted in ten consecutive high-power fields of intratumoral and peritumoral regions to evaluate the corresponding TATE. The percent RC ranged between 0% -90% (Mean ± SD: 16 ± 24%; Median: 5%). The stromal eosinophils were greater in peritumoral as compared to intratumoral region. The events of death and tumor recurrence were reached in 16 (18.4%) and 36 (41%) cases respectively. The 3-years OS was 69% [Median OS: 1880 days; Mean follow up: 471(Range; 36-1880) days]. Increased percent RC exhibited relationship with pathologic stage (pTNM III&IV), primary tumor (pT III&IV), tumor depth > 4 mm and categorical tumor recurrence. Additionally, peritumoral eosinophilic infiltrates increased with increasing tumor depths and muscle invasion. Kaplan-Meier curves revealed significantly reduced OS in OSCC cases exhibiting: increased percent RC (>2.5%), mild -moderate/absent intratumoral TATE (versus intense TATE) or categorical tumor recurrence. In subsequent multivariate tests, all the three variables retained significance. Additionally, intraclass correlation coefficient demonstrated acceptable internal consistency for the observers who estimated percent RC. In conclusion, RC and intratumoral TATE proved to be independent predictors of OS in our OSCC cohort. Additionally, increased percent RC pointed towards aggressive tumor behaviour.

TSLP promotes angiogenesis of human umbilical vein endothelial cells by strengthening the crosstalk between cervical cancer cells and eosinophils

Our previous study demonstrated that thymic stromal lymphopoietin (TSLP) secreted by cervical cancer cells promotes angiogenesis and recruitment, and regulates the function of eosinophils (EOS). However, the function of TSLP in the crosstalk between EOS and vascular endothelial cells in cancer lesions remains unknown. The aim of the present study was to investigate the effect of EOS caused by TSLP in in vitro angiogenesis of human umbilical vein endothelial cells (HUVECs). The results of the present study revealed that recombinant human TSLP protein (rhTSLP) increased the secretion of vascular endothelial growth factor (VEGF), but not fibroblast growth factors, in HL-60-eosinophils (HL-60E). Compared with cervical cancer cells (HeLa or CasKi cells) or HL-60E alone, there were increased levels of interleukin (IL)-8 and VEGF in the co-culture system between cervical cancer cells, and HL-60E cells. This effect was strengthened by rhTSLP, but inhibited by inhibiting the TSLP signal with anti-human TSLP or TSLP receptor neutralizing antibodies. The results of the tube formation assays revealed that treatment with the supernatant from cervical cancer cells and/or HL-60E resulted in an increase in angiogenesis in HUVECs, which could be decreased by TSLP or TSLPR inhibitors. The results of the present study suggested that TSLP derived of cervical cancer cells may indirectly stimulate angiogenesis of HUVECs, by upregulating IL-8 and VEGF production, in a co-culture model between cervical cancer cells and EOS, therefore promoting the development of cervical cancer.

Evaluation of myeloid cells (tumor-associated tissue eosinophils and mast cells) infiltration in different grades of oral squamous cell carcinoma

Background:

The multifunctional involvement and infiltration of myeloid cells (tumor-associated tissue eosinophils [TATE] and mast cells) can provide a unique opportunity to define relevant effectors functions that may represent novel, therapeutic options for modulation of tumor onset/growth.

Aim:

Our study aimed to evaluate infiltration of myeloid cells (TATE and Mast cells) infiltration in different grades (WHO grading) of oral squamous cell carcinoma (OSCC).

Materials and Methods:

Total 30 cases of OSCC were selected for this study. Hematoxylin and eosin stain and toluidine blue special stain, to evaluate TATE and the mast cells infiltration, were used. Three-year follow-up of OSCC cases was done.

Result:

Among 30 cases, 63.33% cases of OSCC showed TATE-positive and 36.66% cases showed TATE-negative. Regarding mast cells infiltration, 66.66% OSCC cases showed mast cells positive and 33.33% cases did not show significant mast cells infiltration. We found significant association of TATE and mast cells infiltration in OSCC cases. These myeloid cells infiltration significantly associated with age of patients but did not show any significant association with gender, site, and habit of cases. When we compared these cells infiltration with clinical stages and different histological grades of tumor, we found their infiltration is decreasing, from Stages 1 to Stage 3 of tumor and from well to poorly differentiated carcinoma. We have also found the less infiltration of these myeloid in recurrence cases of OSCC.

Conclusion:

As the infiltration of TATE and mast cells are correlated, along with evaluation of TATE, we should also evaluate the presence of mast cells infiltration in OSCC. The assessment of myeloid cells could become, in the future, useful for therapeutic approaches in this subset of the patient.

Tumour-Associated Tissue Eosinophilia in Oral Squamous Cell Carcinoma- A Boon or a Bane?

INTRODUCTION

The infiltration of tumour stroma by eosinophils, Tumour-Associated Tissue Eosinophilia (TATE) is known to modulate the evolution of Oral Squamous Cell Carcinoma (OSCC). Identification of eosinophils in the inflammatory stroma has been proven to be an important factor in prognostication of malignant tumours including cancers of mouth, oesophagus, larynx, pharynx, breast, lung, intestine and genitourinary tract.

AIM

Our study aimed to assess the role of TATE as a prognosticator in OSCC as visualized by Haematoxylin and Eosin (H&E) and congo red staining.

MATERIALS AND METHODS

Thirty histologically-proven cases of OSCC were retrieved from the archives of Department of Oral Pathology, Manipal College of Dental Sciences, Mangalore, Manipal University, Karnataka, India. Two serial sections of 4μm thickness were made and subjected to routine staining with H&E and modified congo red staining, where eosinophil granules stained red and nuclei stained blue. In 40x magnification, 10 HPF at invasive tumour front were assessed for counting eosinophils by placing a 49 square grid (measuring 0.0289 sq mm).

STATISTICAL ANALYSIS

The TATE was compared with the prognosticators using Mann-Whitney U-test. The grades of carcinoma were correlated with TATE using Kruskal-Wallis test followed by Post-hoc Bonferronis correction. Agreement of the number of eosinophils counted in the two staining techniques (H&E and Congo red) in OSCC was achieved using interclass correlation coefficient, and Friedman's test. A value of p< 0.05 was considered statistically significant.

RESULTS

Our results showed that tissue eosinophil counts were higher in well-differentiated cases of OSCC, cases with lymph node involvement, decreased survival, without margin involvement and in cases that did not recur. H&E stain showed significantly better visualization of eosinophils resulting in higher eosinophil counts than when seen with Congo red (p=0.008).

CONCLUSION

Thus, TATE can be used as a surrogate marker in prediction of survival and recurrence in OSCC. H&E proved to be a better stain for evaluation of eosinophils.

Eosinophil-Associated Gene Pathways but not Eosinophil Numbers are Differentially Regulated between Synchrotron Microbeam Radiation Treatment and Synchrotron Broad-Beam Treatment by 48 Hours Postirradiation

Synchrotron microbeam radiation treatment (MRT) is a preclinical radiotherapy technique with considerable clinical promise, although some of the underlying radiobiology of MRT is still not well understood. In recently reported studies, it has been suggested that MRT elicits a different tumor immune profile compared to broad-beam treatment (BB). The aim of this study was to investigate the effects of synchrotron MRT and BB on eosinophil-associated gene pathways and eosinophil numbers within and around the tumor in the acute stage, 48 h postirradiation. Balb/C mice were inoculated with EMT6.5 mouse mammary tumors and irradiated with microbeam radiation (112 and 560 Gy) and broad-beam radiation (5 and 9 Gy) at equivalent doses determined from a previous in vitro study. After tumors were collected 24 and 48 h postirradiation, RNA was extracted and quantitative PCR performed to assess eosinophil-associated gene expression. Immunohistochemistry was performed to detect two known markers of eosinophils: eosinophil-associated ribonucleases (EARs) and eosinophil major basic protein (MBP). We identified five genes associated with eosinophil function and recruitment (Ear11, Ccl24, Ccl6, Ccl9 and Ccl11) and all of them, except Ccl11, were differentially regulated in synchrotron microbeam-irradiated tumors compared to broad-beam-irradiated tumors. However, immunohistochemical localization demonstrated no significant differences in the number of EAR- and MBP-positive eosinophils infiltrating the primary tumor after MRT compared to BB. In conclusion, our work demonstrates that the effects of MRT on eosinophil-related gene pathways are different from broad-beam radiation treatment at doses previously demonstrated to be equivalent in an in vitro study. However, a comparison of the microenvironments of tumors, which received MRT and BB, 48 h after exposure showed no difference between them with respect to eosinophil accumulation. These findings contribute to our understanding of the role of differential effects of MRT on the tumor immune response.

Quantitative Evaluation of Tumour--Associated Tissue Eosinophilia and Cyclo-oxegenase-2 Gene in Oral Cancer Patients with Assessment of Long Term Outcomes

Various histopathological parameters have been extensively studied for prognostication of oral cancer but the focus is now getting diverted towards the role of inflammatory mediators in cancer progression. The present study was undertaken to evaluate two such components of the inflammatory milieu, tumor-associated tissue eosinophilia (TATE) as well as Cyclo-oxygenase-2 (COX-2) gene expression, quantitatively in oral squamous cell carcinoma (OSCC) patients in relation to treatment outcomes and patterns of recurrence. A total of forty five patients with primary OSCC matching our inclusion criteria were selected for the study and followed up over a five year period. TATE was evaluated from the invasive front of the tumor using Haematoxylin and eosin (H & E) stained sections of histopathological specimens and graded as mild, moderate or intense. COX-2 gene expression was obtained from specimens using the reverse transcriptase--polymerase chain reaction (RT-PCR) method. A statistically significant association was observed between degree of TATE and locoregional recurrence (P < 0.001). The expression of COX-2 gene ranged from 0.4326 to 0.9998 and a higher mean COX-2 score was recorded in samples with intense degree of TATE followed by moderate and mild TATE. (P < 0.001). Using the t-test, the difference in mean COX-2 was found to be statistically significant (P < 0.001) between patients who developed locoregional recurrence and those who did not. The analysis of TATE may provide an indication of future recurrence at the time of diagnosis of OSCC. Also, the increased expression of COX-2 gene in OSCC strongly suggests its possible use as a chemopreventive/chemotherapeutic target.

Myeloid Cells as Targets for Therapy in Solid Tumors

It is well established that cancer development ensues based on reciprocal interactions between genomically altered neoplastic cells and diverse populations of recruited "host" cells co-opted to support malignant progression. Among the host cells recruited into tumor microenvironments, several subtypes of myeloid cells, including macrophages, monocytes, dendritic cells, and granulocytes contribute to tumor development by providing tumor-promoting factors as well as a spectrum of molecules that suppress cytotoxic activities of T lymphocytes. Based on compelling preclinical data revealing that inhibition of critical myeloid-based programs leads to tumor suppression, novel immune-based therapies and approaches are now entering the clinic for evaluation. This review discusses mechanisms underlying protumorigenic programming of myeloid cells and discusses how targeting of these has potential to attenuate solid tumor progression via the induction and of mobilization CD8 cytotoxic T cell immunity.

The infiltration and functional regulation of eosinophils induced by TSLP promote the proliferation of cervical cancer cell

Cervical cancer is often associated with eosinophil (EOS) infiltration, but the source and the role of EOS are still largely unknown. Our previous work has established that thymic stromal lymphopoietin (TSLP) can stimulate the growth of cervical cancer cell in an autocrine manner. Here, we report that EOS infiltration of the lesion site increased gradually with the progression of cervical cancer. The increase in TSLP secretion in HeLa and SiHa cells induced by hypoxia led to a high level of chemokine CCL17 production by HeLa and SiHa cells, and recruited more EOS to the cancer lesion. In addition, TSLP derived from HeLa and SiHa cells promoted proliferation, up-regulated the levels of anti-inflammatory cytokines (IL-10, IL-4, IL-5 and IL-13), and decreased the expression of CD80 and CD86 of EOS. Such educated EOS significantly promoted proliferation and restricted the apoptosis of cervical cancer cells, which was associated with the up-regulation of Ki-67, PCNA and Bcl-2, and the down-regulation of Fas and FasL in HeLa and SiHa cells. These results suggest that a high level of TSLP in cancer lesions mediated by hypoxia is an important regulator of the progression of cervical cancer by recruiting and licensing tumor-associated EOS to promote the growth of the cervical cancer cell itself. This provides a scientific basis on which potential therapeutic strategies could be targeted to cervical cancer, especially for patients with massive infiltrations of EOS.

Tumour associated tissue eosinophilia as a predictor of locoregional recurrence in oral squamous cell carcinoma

Objectives: The increasing global burden of oral cancer has driven much of the focus of research to the determination of reliable prognostic markers which may have significant effects on survival and the control of post-treatment morbidity. This study was undertaken to evaluate tumour associated tissue eosinophilia (TATE) quantitatively in oral cancer specimens and observe for its possible association with tumour stage, patterns of locoregional recurrence and overall prognosis. Study Design: 14 patients undergoing surgical resection for primary oral squamous cell carcinoma (OSCC) were subjected to grey scale ultrasonography (USG) to assess tumour dimensions. The findings were compared with the cTNM stage initially documented. TATE was evaluated along the invasive tumour front (ITF) using H & E stained sections of histopathological specimens for 10 continuous high power fields (HPF) and graded as mild, moderate or intense. Patients were followed up over 5 years and observed for patterns of recurrence. Results: Loco regional recurrence was significantly associated with intense degree of TATE. (p<0.001) cTNM stage as well as USG stage did not correlate with the degree of TATE with p=0.419 and 0.772 respectively. None of the patients with mild/ moderate dysplasia developed locoregional recurrence within the period of follow up. Conclusions: Analysis of TATE in OSCC patients may provide an early indication of future locoregional recurrence. Identification of an appropriate biopsy site representing the ITF where TATE analysis can be performed may be a simple, inexpensive method of obtaining valuable prognostic information at the time of diagnosis.

Key words:Tumour associated tissue eosinophilia, oral cancer, prognosis.

Eosinophils and cancer

Eosinophils have long been known to infiltrate tumors, and in most cases, this is associated with an improved prognosis. However, the reasons behind this infiltration and the mechanism of action of the eosinophil have remained elusive. In this article, we explore the biology of eosinophils and examine their function in homeostasis and disease states, specifically focusing on what is currently known about the association of the eosinophil with cancer.

Eosinophil cytokines, chemokines, and growth factors: emerging roles in immunity

Eosinophils derive from the bone marrow and circulate at low levels in the blood in healthy individuals. These granulated cells preferentially leave the circulation and marginate to tissues, where they are implicated in the regulation of innate and adaptive immunity. In diseases such as allergic inflammation, eosinophil numbers escalate markedly in the blood and tissues where inflammatory foci are located. Eosinophils possess a range of immunomodulatory factors that are released upon cell activation, including over 35 cytokines, growth factors, and chemokines. Unlike T and B cells, eosinophils can rapidly release cytokines within minutes in response to stimulation. While some cytokines are stored as pre-formed mediators in crystalloid granules and secretory vesicles, eosinophils are also capable of undergoing de novo synthesis and secretion of these immunological factors. Some of the molecular mechanisms that coordinate the final steps of cytokine secretion are hypothesized to involve binding of membrane fusion complexes comprised of soluble N-ethylmaleimide sensitive factor attachment protein receptors (SNAREs). These intracellular receptors regulate the release of granules and vesicles containing a range of secreted proteins, among which are cytokines and chemokines. Emerging evidence from both human and animal model-based research has suggested an active participation of eosinophils in several physiological/pathological processes such as immunomodulation and tissue remodeling. The observed eosinophil effector functions in health and disease implicate eosinophil cytokine secretion as a fundamental immunoregulatory process. The focus of this review is to describe the cytokines, growth factors, and chemokines that are elaborated by eosinophils, and to illustrate some of the intracellular events leading to the release of eosinophil-derived cytokines.

Assessment of tissue eosinophilia as a prognosticator in oral epithelial dysplasia and oral squamous cell carcinoma-an image analysis study

Association of tissue eosinophilia with oral squamous cell carcinoma has shown variable results ranging from favourable to unfavourable or even having no influence on prognosis. Also, very few studies have been done to know the role of eosinophils in premalignancy. So the present study investigated role of eosinophilic infiltration in oral precancer and cancer and its possible use as a prognosticator. 60 histopathologically proven cases (20 cases each of metastatic and nonmetastatic oral squamous cell carcinoma and oral leukoplakia with dysplasia of various grades) were included. Congo red is used as a special stain for eosinophils. Each specimen slide was viewed under high power in 10 consecutive microscopic fields for counting of eosinophils. As a result, a significant increase in eosinophil count was found in oral carcinomas compared to dysplasia. Nonmetastatic cases showed higher counts than metastatic carcinomas. So, it is concluded that eosinophilia is a favourable histopathological prognostic factor in oral cancer. Moreover, higher eosinophil counts in carcinoma group compared to dysplasia group proved that they might have a role in stromal invasion thus suggesting that quantitative assessment of tissue eosinophilia should become a part of the routine histopathological diagnosis for oral precancer and OSCC.

IgE-based immunotherapy of cancer: challenges and chances

Passive immunotherapy with monoclonal antibodies is an indispensable cornerstone of clinical oncology. Notably, all FDA-approved antibodies comprise the IgG class, although numerous research articles proposed monoclonal antibodies of the IgM, IgG, IgA and IgE classes directed specifically against tumor-associated antigens. In particular, for the IgE isotype class, several recent studies could demonstrate high tumoricidic efficacy. Therefore, this review specifically highlights the latest developments toward IgE-based immunotherapy of cancer. Possible mechanisms and safety aspects of IgE-mediated tumor cell death are discussed with special focus on the attracted immune cells. An outlook is given on how especially comparative oncology could contribute to further developments. Humans and dogs have a highly comparable IgE biology, suggesting that translational AllergoOncology studies in patients with canine cancer could have predictive value for the potential of IgE-based anticancer immunotherapy in human clinical oncology.

Eosinophils in human oral squamous carcinoma; role of prostaglandin D2

Eosinophils are often predominant inflammatory leukocytes infiltrating oral squamous carcinoma (OSC) sites. Prostaglandins are secreted by oral carcinomas and may be involved in eosinophil infiltration. The objective of this study was to determine the factors contributing to eosinophil migration and potential anti-neoplastic effects on OSC. Eosinophil degranulation was evaluated by measuring release of eosinophil peroxidase (EPO). Eosinophil chemotaxis towards OSC cells was assessed using artificial basement membrane. Eosinophil infiltration was prominent within the tissue surrounding the OSC tumor mass. We observed growth inhibition of the OSC cell line, SCC-9, during co-culture with human eosinophils, in vitro, which correlated with EPO activity that possesses growth inhibitory activity. The PGD₂ synthase inhibitor, HQL-79, abrogated migration towards SCC-9. Our data suggest that OSC-derived PGD₂ may play an important role via CRTH2 (the PGD₂ receptor on eosinophils) in eosinophil recruitment and subsequent anti-tumor activity through the action of eosinophil cationic proteins.

Outcome analysis of patients with well-differentiated oral cavity squamous cell carcinoma

The prognosis of well-differentiated oral cavity squamous cell carcinoma (OSCC) is better than less-well-differentiated neoplasms. The aim of this retrospective study was to identify prognostic factors in patients with well-differentiated OSCC. The 5-year outcomes of 467 patients with well-differentiated OSCC who underwent radical surgery and neck dissection were analyzed. In the entire cohort, the presence of pathological node metastases (pN+ vs. pN0) was an independent predictor of 5-year outcomes. In pN0 patients, tumor depth (≥8 mm) was the only independently prognostic factor for 5-year survival rates on multivariable analysis (disease-free survival [DFS], P=0.001, hazard ratio [HR]=2.634, 95% confidence interval [95% CI]=1.496-4.636; disease-specific survival [DSS], P<0.001, HR=6.794, 95% CI=2.364-19.525). In pN+ patients, level IV/V neck nodal metastases (DFS, P<0.001, HR=47.483, 95% CI=8.942-252.122; DSS, P<0.001, HR=14.301, 95% CI=5.337-38.323), and ≥3 positive nodes (DFS, P=0.037, HR=2.107, 95% CI=1.047-4.242; DSS, P=0.044, HR=2.093, 95% CI=1.020-4.295) were independently associated with 5-year outcomes. Our results suggest that a tailored treatment approach in well-differentiated OSCC patients should take into account the presence of either pN0 or pN+ disease.

Immune suppression in head and neck cancers: a review

Head and neck squamous cell carcinomas (HNSCCs) are the sixth most common cancer in the world. Despite significant advances in the treatment modalities involving surgery, radiotherapy, and concomitant chemoradiotherapy, the 5-year survival rate remained below 50% for the past 30 years. The worse prognosis of these cancers must certainly be link to the fact that HNSCCs strongly influence the host immune system. We present a critical review of our understanding of the HNSCC escape to the antitumor immune response such as a downregulation of HLA class I and/or components of APM. Antitumor responses of HNSCC patients are compromised in the presence of functional defects or apoptosis of T-cells, both circulating and tumor-infiltrating. Langerhans cells are increased in the first steps of the carcinogenesis but decreased in invasive carcinomas. The accumulation of macrophages in the peritumoral areas seems to play a protumoral role by secreting VEGF and stimulating the neoangiogenesis.

The role of eosinophils and eosinophil cationic protein in oral cancer: a review

Eosinophils are multifunctional leukocytes implicated in the pathogenesis of numerous inflammatory processes, such as allergies and parasitic infections. Increased number of these cells has been described in many human cancers, including oral squamous cell carcinoma, and its presence related to favourable as well as unfavourable prognosis. Although the exact role of eosinophils in tumours is not yet defined, the anti-tumour activity of these rare granulocytes has been associated with the release of their cytotoxic proteins, especially the eosinophil cationic protein, a single polypeptide chain with a molecular mass ranging from 15 to 22kDa encoded by the RNSE3 gene located on chromosome 14q11.2. Functional studies have implicated ECP in numerous processes, such as tissue remodelling in allergic inflammation; however its most striking function is the cytotoxic activity. The aim of this review is to summarise the role and functions of eosinophils and their granule-derived products in oral malignant tumours and the clinical value of the tumour-associated tissue eosinophilia for patients' prognosis.

Covalent linking of proteins and cytokines to suture: Enhancing the immune response of head and neck cancer patients

BACKGROUND

The immune system of advanced stage head and neck cancer patients is frequently suppressed. Poor immune function has been correlated with poor clinical outcome. Immunotherapeutic strategies have been previously attempted in an effort to enhance immune function and improve survival. Previous studies have shown surgical suture can be transformed into an immune stimulant capable of activating the T lymphocytes of cancer patients. The development of a process for covalently linking proteins and cytokines to suture could have enormous potential for the in vivo manipulation of the immune system.

HYPOTHESIS

We hypothesize proteins and cytokines can be covalently linked to surgical suture while preserving their functional properties.

STUDY DESIGN

Prospective study testing normal donor and head and neck squamous cell carcinoma (HNSCC) patient lymphocytes.

METHOD

Polyester suture was acid hydrolyzed followed by reacting with 1-ethyl-3(-3-dimethylamino propyl carbodiimide) (EDAC) to create a suture-EDAC intermediate. Next, selected proteins (horseradish peroxidase [HRP] or bovine serum albumin [BSA]) or cytokines (interleukin [IL]-2 or interferon [IFN]-gamma) were reacted with the suture-EDAC intermediate to test the covalent linkage of the selected protein or cytokine to suture. Functional activity of the linked proteins was measured spectrophotometrically. The linking of cytokines to suture was tested by stimulating normal donor peripheral blood lymphocytes (PBL) or HNSCC patients' lymphocytes. The functional activity was confirmed by proliferation, enzyme linked immunoadsorbent assay (ELISA), and phenotype expression of T cells. RESULTS The conditions for optimally linking a protein to polyester suture were defined using HRP as a model protein. HRP retained its enzymatic activity. The optimal conditions for linking IL-2 or IFN-gamma were defined. The covalently linked cytokines retained their immune enhancing properties for stimulating PBL and lymph node lymphocytes (LNL) from HNSCC patients to proliferate, generate a TH1 immunologic profile of cytokines (IL-2, IL-12, IFN-gamma), and stimulate T lymphocytes.

CONCLUSION

This is the first report to demonstrate that cytokines can be covalently linked to surgical sutures and retain their immune-stimulating properties. Proteins linked to suture also retained their enzymatic activity. The clinical implications of functionally active cytokines or proteins linked to surgical suture may be very significant in the future for manipulating the immune system in vivo or enhancing wound healing.

Eosinophils and oral squamous cell carcinoma: a short review

The eosinophil cell has been related as a prognostic indicator for cancers. However, its exact function in tumour behaviour is still not clearly defined. In the oral cavity the presence of eosinophils can be a favourable prognostic indicator as well as it may be associated with a poor prognosis. In this short review, we briefly summarize the role of the eosinophils in the general context of immunoregulation and its relation to oral squamous cell carcinoma.

Prognostic significance of stromal eosinophilic infiltration in oral squamous cell carcinoma

Tumor-associated tissue eosinophilia (TATE) has been described in many sites, including head and neck. The aim of this study was to investigate the prevalence and possible role of TATE as a prognostic factor in oral squamous cell carcinoma (OSCC). Seventy-six consecutive patients with a diagnosis of OSCC were evaluated, and the number of eosinophils was obtained in 3 different areas in the tumor. The possible role of TATE as a prognostic factor in OSCC was investigated with respect to tumor differentiation; perineural, vascular, and muscular invasion (histopathologic parameters); and locoregional metastasis (clinical parameter). Tumor-associated tissue eosinophilia was low in most cases in 3 different areas. The mean eosinophil count was higher in the invasive front of tumor than intratumoral stroma and stroma subjacent the surface epithelium. The relations between TATE and tumor differentiation; perineural, vascular, and muscular invasion; and locoregional metastasis were not statistically significant (P > 0.05). Tumor-associated tissue eosinophilia has no correlation with prognostic parameters in OSCC.

Eosinophil-rich squamous carcinoma of the oral cavity: a study of 13 cases and delineation of a possible new microscopic entity

We report 13 cases of squamous cell carcinoma (SCC) of the oral cavity characterized by a prominent eosinophilic infiltration of the stroma. All patients were adults, 10 men and 3 women (aged 54 to 92 years; median, 71 years). They presented with tumors of the gingiva (5 cases), tongue (3 cases), palatine tonsil (2 cases), palate (2 cases), and mucosal aspect of lip (1 case). Metastatic involvement of regional lymph nodes was seen in 5 cases. The metastatic foci were associated with heavy eosinophilia as well. No patient had an abnormal eosinophil count in blood. Microscopically, the clusters of eosinophils were characteristically noticed in intimate admixture with the advancing edge of squamous carcinoma, either as nests or small tumor cords. The pattern of eosinophilic infiltration was comparable, regardless of tumor site or grade. Data from our series indicate that SCC with a reactive inflammatory infiltrate rich in eosinophils is consistently associated with stromal invasion. This observation may be useful in dealing with small tissue fragments where subepithelial stromal invasion cannot be easily assessed by conventional criteria. In addition, our data seem to confirm that eosinophil-rich SCC, although associated with metastatic involvement of cervical lymph node, seems to pursue a less aggressive course if compared with ordinary SCC.

Eotaxin-2 and colorectal cancer: a potential target for immune therapy

PURPOSE

To study the production of chemokines by colorectal hepatic metastases.

EXPERIMENTAL DESIGN

Biopsies of resected colorectal hepatic metastases and nonneoplastic adjacent liver tissue were screened for chemokines using protein arrays and results were confirmed by ELISA and immunohistochemistry.

RESULTS

Two chemokines, eotaxin-2 and MCP-1, were found at elevated levels within the tumor biopsy compared with adjacent liver. The relative increase in expression from tumor was much higher for eotaxin-2 than MCP-1, with 10 of 25 donors having a >100-fold increase in expression compared with 0 of 24 donors for MCP-1. In a parallel analysis, eotaxin-2 was also found at elevated levels in the tumor region of primary colorectal cancer biopsies. Immunohistochemical staining indicated that carcinoembryonic antigen-positive tumor cells stained strongly for eotaxin-2, implicating these cells as the predominant source of the chemokine. In vitro studies confirmed that several colorectal tumor lines produce eotaxin-2 and that secretion of this chemokine could be depressed by IFN-gamma and enhanced by the Th2-type cytokines interleukin-4 and interleukin-13. Jurkat T cells were engineered to express the receptor for eotaxin-2 (CCR3). These cells effectively migrated in response to eotaxin-2 protein, suggesting that immune cells gene modified to express a chemokine receptor may have improved abilities to home to tumor.

CONCLUSIONS

Taken together, these observations confirm eotaxin-2 as a chemokine strongly associated with primary and metastatic tumors of colorectal origin. Furthermore, the importance of this result may be a useful tool in the development of targeted therapeutic approaches to colorectal tumors.

Eosinophilic granulocytes and damage-associated molecular pattern molecules (DAMPs): role in the inflammatory response within tumors

The development of a tumor over many years typically leads to reciprocal alternations in the host and the tumor, enabling tumor growth paradoxically in the setting of substantial necrosis and inflammation. When evaluating a tumor, it is important to assess 3 elements: (1) the quantity and quality of tumor-associated leukocytes, (2) their state of activation, and (3) tumor microenvironment. Peripheral blood eosinophilia and tumor-associated tissue eosinophilia are frequently associated with some tumor types and also found after immunotherapy with IL-2, IL-4, granulocyte-macrophage colony-stimulating factor, and antibody to CTLA-4. Within several tumor types including gastrointestinal tumors, tumor-associated tissue eosinophilia is associated with a significantly better prognosis. The converse is true in other tumor types such as differentiated oral squamous cell carcinoma. On the basis of the emergent data, tumor-associated eosinophils have at least 2 dominant nonoverlapping activities: (1) destructive effector functions potentially limiting tumor growth as well as causing recruitment and activation of other leukocytes, (2) immunoregulative and remodeling activities which suppress immune response and promote tumor proliferation. The mechanism by which eosinophils in particular are recruited into tumor tissue is largely unknown. Candidates for causing eosinophil chemotaxis into tumor tissue are the released damage-associated molecular pattern molecules (DAMPs) including the nuclear protein high mobility group box 1. High mobility group box 1 is released upon necrotic cell death and secreted by many cells, particularly during periods of nutrient, hypoxic, or oxidant stress. This overview on eosinophil biology in the context of cancer and necrosis, introduces intriguing and novel strategies targeting eosinophils to enable more effective biologic therapy for cancer patients.

Significance of neo-angiogenesis and immuno-surveillance cells in squamous cell carcinoma of the tongue

Background

Neo-angiogenesis is an essential process in physiological and pathological conditions. However, it is a complex process. Several studies demonstrated that intra-tumoural microvessel number is a significant predictor of metastasis and clinical outcome in many tumours, including oral malignancies. The immuno-surveillance cells, mast cells and eosinophils are implicated in the biological behaviour of tumours. Nevertheless, their function in tissues is uncertain. Mast cells are involved in homeostatic regulation of blood vessels as well as host defence. In some malignancies, high mast cell density has been found to correlate with favourable prognosis. However, others reported unfavourable associations. Tumour associated tissue eosinophilia is a well-known phenomena. It has been associated with good and poor prognosis. However, the role of eosinophils in tumours remains controversial. Therefore, this study was designed to investigate the prognostic value of microvessel, mast cell and eosinophil densities in the context of clinico-pathological parameters and survival in squamous cell carcinoma of the tongue.

Materials and Methods

Anti-CD105 and anti-tryptase monoclonal antibodies were utilized to highlight and count microvessels and mast cells respectively in 81 cases of tongue squamous cell carcinoma. Eosinophils were demonstrated using carbol chromotrope histochemical stain. The densities were counted per mm2 and correlated with patients’ outcome and other clinico-pathological parameters using non-parametric tests and student's t-test. Clinically, the cases were divided into 4 main groups depending on survival time, lymph-node or distant metastasis.

Results

The 5 year survival was significantly lower in patients with a low mast cell density than those with a high density (p=0.006, Kruskal-Wallis test). The survival group-A demonstrated significantly higher mast cell and microvessel numbers than group-D (p=0.007, student's t-test) respectively. Patients with well- differentiated squamous cell carcinoma had significantly higher numbers of mast cells when compared to patients with poorly differentiated squamous cell carcinoma (p<0.05, student's t-test). The lymph node involvement correlation between the survival group-A and survival group-D was also significant (p=0.001, Mann-Whitney U test).

Conclusion

Data from this study indicates that accumulating mast cells in tumours play a part in inhibiting tumour progression and is potentially angiogenic in tumours.

Tumour-associated tissue eosinophilia as a prognostic factor in oral squamous cell carcinomas

AIMS

Tumour-associated tissue eosinophilia has been described in many sites, including head and neck. The mechanism of eosinophil recruitment and its role in tumours has not yet been defined, and its presence has been related to a favourable as well as unfavourable prognosis. The aim of this study was to evaluate the influence of tumour-associated tissue eosinophilia on the prognosis of 125 oral squamous cell carcinoma patients.

METHODS AND RESULTS

The number of eosinophils was obtained by morphometric analysis and ranged from 0 to 392 per mm2. Tumour-associated tissue eosinophilia was classified according to intensity as mild, moderate, or intense and correlated statistically to the intensity of the mononuclear inflammatory infiltrate as well as to the location of the eosinophilic inflammatory infiltrate. The multivariate analysis demonstrated that intense tumour-associated tissue eosinophilia is an independent favourable prognostic factor for oral squamous cell carcinomas.

CONCLUSION

These findings suggest an anti-tumoral role of eosinophils not as yet well understood that should be better investigated.

Eotaxin (CCL11) induces in vivo angiogenic responses by human CCR3+ endothelial cells

Chemokines are attractants and regulators of cell activation. Several CXC family chemokine members induce angiogenesis and promote tumor growth. In contrast, the only CC chemokine, reported to play a direct role in angiogenesis is monocyte-chemotactic protein-1. Here we report that another CC chemokine, eotaxin (also known as CCL11), also induced chemotaxis of human microvascular endothelial cells. CCL11-induced chemotactic responses were comparable with those induced by monocyte-chemotactic protein-1 (CCL2), but lower than those induced by stroma-derived factor-1alpha (CXCL12) and IL-8 (CXCL8). The chemotactic activity was consistent with the expression of CCR3, the receptor for CCL11, on human microvascular endothelial cells and was inhibited by mAbs to either human CCL11 or human CCR3. CCL11 also induced the formation of blood vessels in vivo as assessed by the chick chorioallantoic membrane and Matrigel plug assays. The angiogenic response induced by CCL11 was about one-half of that induced by basic fibroblast factor, and it was accompanied by an inflammatory infiltrate, which consisted predominantly of eosinophils. Because the rat aortic sprouting assay, which is not infiltrated by eosinophils, yielded a positive response to CCL11, this angiogenic response appears to be direct and is not mediated by eosinophil products. This suggests that CCL11 may contribute to angiogenesis in conditions characterized by increased CCL11 production and eosinophil infiltration such as Hodgkin's lymphoma, nasal polyposis, endometriosis, and allergic diathesis.

Eosinophil ablation and tumor development

Tissue eosinophilia in squamous cell carcinoma has long been recognized; however, the role of eosinophils in tumor development remains unclear. Studies have reported both favorable and unfavorable prognoses for patients with tumors exhibiting tumor-associated tissue eosinophilia (TATE). This study seeks to elucidate the potential role of the eosinophil in squamous cell carcinoma development and provide an experimental model for future studies. The carcinogen-induced hamster oral cancer model was found to fulfill these objectives. Eosinophils progressively infiltrate into this carcinogen-induced oral cancer model. We now demonstrate that TATE is completely abolished by the use of an anti-interleukin-5 monoclonal antibody (mAb) preparation, TRFK-5. Clinical observations revealed that TRFK-5-treated hamsters exhibited smaller tumor burden and delayed onset of tumor development. The results suggest that anti-interleukin-5 antibody treatment may delay and/or inhibit tumor development, and that eosinophils may have a tumor-promoting role.

HLA-DR expression is a significant prognostic factor in laryngeal cancer. A morphometric study

HLA-DR antigen expression in tumour cells was investigated in 68 laryngeal carcinomas. The tissue sections were studied by a morphometric method using a computer image analysis system. Although the highest number of HLA-DR-positive cells was observed in the groups with the lowest clinical stage, these differences did not reach statistical significance. Analysis of survival showed a significantly different survival time of patients classified as HLA-DR positive (10% and more HLA-DR+tumour cells) compared to those classified as HLA-DR negative. There were no significant differences in survival times between patients with glottic and extraglottic cancers, or between patients with various grades of histological malignancy.

Increased mast cell density in invasive melanoma

Mast cell participation in immune responses, tumor progression, and vascularization has been studied extensively in vitro. In situ investigation of mast cells in routinely processed tissues is hampered by difficulty in reliable detection of mast cells. We studied the tissue density of mast cells using a morphometric point-counting technique in 1 microm-thick, Giemsa-stained, tissue sections from epon-embedded samples of skin biopsies. This technique has been demonstrated to be an accurate and reproducible method for determining mast cell density. Mast cell density in 15 cases of invasive melanoma was compared to that of 9 cases of benign melanocytic nevi and 4 cases of melanoma in situ. Mast cell density was greatest in invasive melanoma (mean density = 0.61 vol.%). The mean density of mast cells in nevi and in situ melanoma was 0.33 and 0.5 respectively. Six of 15 cases of melanoma had mast cell densities > 0.6, whereas mast cell density did not exceed 0.6 in any cases of melanoma in situ or benign melanocytic nevi (p < 0.02). Our findings confirm an increase in mast cell tissue density in some cases of invasive melanoma when compared to mast cell density in benign nevi and in situ melanoma.