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

Eosinophils in Colorectal Cancer: Emerging Insights into Anti-Tumoral Mechanisms and Clinical Implications

Eosinophils are myeloid effector cells whose main homing is the gastrointestinal tract. There, they take part in type I and type II immune responses. They also contribute to other non-immunological homeostatic functions like mucus production, tissue regeneration, and angiogenesis. In colorectal cancer (CRC), eosinophils locate in the center of the tumor and in the front of invasion and play an anti-tumoral role. They directly kill tumor cells by releasing cytotoxic compounds and eosinophil extracellular traps or indirectly by activating other immune cells via cytokines. As CRC progresses, the number of infiltrating eosinophils decreases. Although this phenomenon is not fully understood, it is known that some changes in the microenvironmental milieu and microbiome can affect eosinophil infiltration. Importantly, a high number of intratumoral eosinophils is a favorable prognostic factor independent from the tumor stage. Moreover, after immunotherapy, responding patients usually display eosinophilia, so eosinophils could be a good biomarker candidate to monitor treatment outcomes. Finally, even though eosinophils seem to play an interesting anti-tumoral role in CRC, much more research is needed to fully understand their interactions in the CRC microenvironment. This review explores the multifaceted roles of eosinophils in colorectal cancer, highlighting their anti-tumoral effects, prognostic significance, and potential as a biomarker for treatment outcomes.

The exploration of new biomarkers for oral cancer through the ceRNA network and immune microenvironment analysis

The competitive endogenous RNA (ceRNA) and tumor-penetrating immune cells may be related to the prognosis of oral cancer. However, few studies have focused on the correlation between ceRNAs and immune cells. Thus, we developed a method based on a ceRNA network and tumor-infiltrating immune cells to elucidate the molecular pathways that may predict prognosis in patients with oral cancer. Download RNAseq expression data of oral cancer and control samples from the Cancer Genome Atlas (TCGA), obtain differentially expressed genes and establish a ceRNA network. The cox analysis and lasso regression analysis were used to screen key RNAs to establish a prognostic risk assessment model, and draw a 1.3.5-year forecast nomogram. Then the CIBERSORT algorithm was used to screen important tumor immune infiltrating cells associated with oral cancer. Another prognostic predictive model related to immune cells was established. Finally, co-expression analysis was applied to explore the relationship between key genes in the ceRNA network and important immune cells. Multiple external data sets are used to test the expression of key biomarkers. We constructed prognostic risk models of ceRNA and immune cells, which included 9 differentially expressed mRNAs and 2 types of immune cells. It was discovered from the co-expression analysis that a pair of important biomarkers were associated with the prognosis of oral cancer. T cells regulatory and CGNL1 (R = 0.39, P < .001) showed a significant positive correlation. External data set validation also supports this result. In this study, we found that some crucial ceRNAs (GGCT, TRPS1, CGNL1, HENMT1, LCE3A, S100A8, ZNF347, TMEM144, TMEM192) and immune cells (T cells regulatory and Eosinophils) may be related to the prognosis of oral cancer.

Apprising Diagnostic and Prognostic Biomarkers in Cutaneous Melanoma—Persistent Updating

The incidence of melanoma, a very aggressive skin cancer, has increased over the past few decades. Although there are well-established clinical, dermoscopic and histopathological criteria, the diagnosis is often performed late, which has important implications on the patient’s clinical outcome. Unfortunately, melanoma is one of the most challenging tumors to diagnose because it is a heterogeneous neoplasm at the clinical, histopathological, and molecular level. The use of reliable biomarkers for the diagnosis and monitoring of disease progression is becoming a standard of care in modern medicine. In this review, we discuss the latest studies, which highlight findings from the genomics, epitranscriptomics, proteomics and metabolomics areas, pointing out different genes, molecules and cells as potential diagnostic and prognostic biomarkers in cutaneous melanoma.

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.

Evaluation of Eosinophilic Cationic Protein as a Marker of Alveolar and Cystic Echinococcosis

Echinococcosis is a neglected zoonotic disease and a worldwide public health problem caused by infection with the larval stages of taeniid cestodes of the genus Echinococcus. In vitro studies have demonstrated a protoscolecidal effect of eosinophilic cationic protein (ECP), a granule protein of eosinophilic granulocytes, against E. granulosus. Therefore, the main objective of this study was to evaluate ECP as a biomarker in the treatment of alveolar echinococcosis (AE) and cystic echinococcosis (CE). Data were collected retrospectively from the Vienna Echinococcosis Cohort over 7 years until December 2020. Altogether, 32 patients (16 AE and 16 CE) were included. In the selected patients, serum ECP values were compared before and after the beginning of an operative and/or benzimidazole (BMZ) therapy. Mean ECP serum levels before intervention were significantly (p < 0.05) elevated at 34.0 ± 22.9 μg/L in AE patients and at 38.6 ± 19.9 μg/L in CE patients compared to the control group. After the intervention, mean ECP levels decreased significantly (p < 0.05) to 20.4 ± 14.6 μg/L in AE patients and to 22.4 ± 8.3 μg/L in CE patients. Furthermore, ECP showed a significant (p < 0.05) correlation of k = 0.56 with PET–CTI. Based on the significant decrease after operative and/or BMZ treatment and the correlation with clinical markers such as PET–CTI, it is recommended to investigate ECP more intensively as a marker of AE and CE in prospective studies with larger cohorts.

Eosinophils as Major Player in Type 2 Inflammation: Autoimmunity and Beyond

Eosinophils are a subset of differentiated granulocytes which circulate in peripheral blood and home in several body tissues. Along with their traditional relevance in helminth immunity and allergy, eosinophils have been progressively attributed important roles in a number of homeostatic and pathologic situations. This review aims at summarizing available evidence about eosinophils functions in homeostasis, infections, allergic and autoimmune disorders, and solid and hematological cancers.Their structural and biological features have been described, along with their physiological behavior. This includes their chemokines, cytokines, granular contents, and extracellular traps. Besides, pathogenic- and eosinophilic-mediated disorders have also been addressed, with the aim of highlighting their role in Th2-driven inflammation. In allergy, eosinophils are implicated in the pathogenesis of atopic dermatitis, allergic rhinitis, and asthma. They are also fundamentally involved in autoimmune disorders such as eosinophilic esophagitis, eosinophilic gastroenteritis, acute and chronic eosinophilic pneumonia, and eosinophilic granulomatosis with polyangiitis. In infections, eosinophils are involved in protection not only from parasites but also from fungi, viruses, and bacteria. In solid cancers, local eosinophilic infiltration is variably associated with an improved or worsened prognosis, depending on the histotype. In hematologic neoplasms, eosinophilia can be the consequence of a dysregulated cytokine production or the result of mutations affecting the myeloid lineage.Recent experimental evidence was thoroughly reviewed, with findings which elicit a complex role for eosinophils, in a tight balance between host defense and tissue damage. Eventually, emerging evidence about eosinophils in COVID-19 infection was also discussed.

Tumour-associated tissue eosinophilia (TATE) in oral squamous cell carcinoma: a comprehensive review

Oral squamous cell carcinoma is the most common head and neck malignancy, characterised by high invasive capacity, lymph node metastasis, and high recurrence rate. Among the morphological features of oral cancer, the tumour-associated tissue eosinophilia has gained growing interest in the last years. Eosinophils are a minor subpopulation of leukocytes, representing 1-3% of all circulating white blood cells. The presence of high levels of eosinophils is associated with several diseases, but their role in cancer pathophysiology is controversial. In particular, an uncertain and contradictory relationship exists between the exact role of tumour-associated tissue eosinophilia and oral cancer development. Many studies have shown that tumour-associated tissue eosinophilia increases both in the progression of oral potentially malignant disorders as well as in the grade and stage progression of oral cancer. Despite this, both negative and positive prognostic outcomes have been associated with eosinophil infiltration. The heterogeneous results may be partially due both to several methodological inconsistencies and to an incorrect interpretation of the physiological role of eosinophils. Therefore, further studies to elucidate the contribution of eosinophil infiltration are needed, focusing on the existence of eosinophil subpopulations regulated by the cancer immune microenvironment. Furthermore, the correct reporting of prognostic marker research is encouraged, in order to ensure the reproducibility and the comparability of the results from different studies.

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.

Tumor infiltrating lymphocytes: The regulator of melanoma evolution

Melanoma is the most severe type of skin cancer and its incidence has increased in the last decades. In the United States, it is the 6th most common cancer in both men and women. Prognosis for patients with melanoma depends on the stage of the disease at the time of diagnosis and it can be influenced by the immunologic response. Melanoma has been historically considered an immunogenic malignancy. It often contains great amount of immune cells (different subsets of T-cells, dendritic cells, macrophages, neutrophils, mast cells, B lymphocytes), which may reflect a continuous intercommunication between host and tumor. It is not established if tumor-infiltrating lymphocytes (TILs) are induced by tumor cells or by other components of the microenvironment or when they are a host direct immunologic reaction. It has been observed that in many cases, the presence of a dense TIL is associated with good prognosis. The pattern and activation state of the cells which constitute TIL is variable and modulates the clinical outcome. An important step in the understanding of tumor immunobiology is the analysis of the populations and subsets of immune cells that form TIL. Besides its prognostic significance, after approval of cytotoxic T lymphocyte antigen 4, programmed cell death-1 and programmed death-1 ligand antibodies for the treatment of melanoma, the assessment of immune infiltrate composition has become even more captivating, as it could provide new target molecules and new biomarkers for predicting the effect of the treatment and disease outcome in patients treated with immunotherapy. In this review we discuss current state of knowledge in the field of immune cells that infiltrate melanoma, resuming the potential of TIL components to become prognostic markers for natural evolution, for response to drugs or valuable targets for new medication.

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.

Eosinophil peroxidase over-expression predicts the clinical outcome of patients with primary lung adenocarcinoma

Eosinophil peroxidase (EPO), a heme protein abundantly expressed in eosinophils, involves in the catalysis of cytotoxic oxidants associated with the pathogenesis of cancer, asthma, and allergic inflammatory disorders. To date, its roles in the pathogenesis of lung cancer are still not known. We determined the expression of EPO in the lung adenocarcinoma tissues and the normal adjacent lung tissues using Real-time PCR and Western blotting analysis, respectively. Also, EPO protein expression in 90 lung adenocarcinoma (AD) samples were confirmed with immunohistochemistry (IHC) using tissue microarrays. Meanwhile, we investigated the association between EPO and the clinicopathological characteristics and disease prognosis in the pulmonary adenocarcinoma patients, which demonstrated that EPO mRNA and protein were significantly higher in lung AD tissues that those of the adjacent normal lung tissues (P<0.05). EPO overexpression was significantly correlated with pathologic-tumour nodes metastasen stage (p-TNM stage, P=0.017) and lymph node metastasis (P=0.027). Patients with EPO overexpression showed shorter survival time than those with low EPO levels (P=0.017), according to the Kaplan-Meier survival curve. Furthermore, a multivariate Cox regression model was utilized to analyze the prognostic factors, which indicated that N stage (HR=0.965, 95% CI=0.328-1.359, P=0.008), p-TNM Stage (HR=3.127, 95% CI =2.463-5.015, P=0.021) and high EPO protein expression (HR=3.145, 95% CI=2.016-5.519, P=0.018) were independent factors for the prognosis of lung AD. In conclusion, increased EPO expression could be used as a biomarker for lung AD patients with poor prognosis.

Quantitative Analysis of Tumor-associated Tissue Eosinophilia in Recurring Bladder Cancer

The relatively high incidence of recurrence of bladder cancer is a serious problem in clinical practice. At present, there are no objective microscopic criteria for evaluation of the tendency for local relapse. Besides the phenotypic properties of the tumor parenchymal cells, possible signs in regard to recurrence could also be derived from the peculiarities of the tumor stroma. The stromal reaction, manifested by inflammatory infiltration in the tumor is considered to influence the biological behavior of tumors. Also, a relationship has been reported between the number of eosinophils and the survival of patients. The aim of the present study is to analyze tumor-associated tissue eosinophilia (TATE) and to compare TATE density in the initial foci of age and gender-matched 156 cases of recurrent and non-recurrent bladder cancers; the tumors that have relapsed within six months after removal and contained statistically significant greater numbers of eosinophils in primary cancer sites. These results suggest that TATE may be one of the probable prognostic signs for local relapse of urothelial cancer.

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.

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.

Role of tissue eosinophils in oral Leukoplakia: A pilot study

CONTEXT

Tissue eosinophilia in oral squamous cell carcinoma has been well - recognized. Studies have reported both favorable and unfavorable prognoses associated with tissue eosinophils in oral squamous cell carcinoma. However, the role of eosinophils in the development of tumor is still unclear.

AIMS

The present study was an attempt to elucidate the potential role of tissue eosinophils in oral leukoplakia, a potentially malignant lesion.

SETTINGS AND DESIGN

To count eosinophils in tissues of normal subjects and oral leukoplakia cases. To compare tissue eosinophil count (TEC) between normal and oral leukoplakia cases. To compare TEC between dysplastic and non-dysplastic cases of oral leukoplakia and to correlate with degree of epithelial dysplasia.

MATERIALS AND METHODS

A total of 85 cases (59 cases of oral leukoplakia and 26 normal oral tissues) constituted the study material. Tissue eosinophils were counted in 10 different high- power fields.

STATISTICAL ANALYSIS USED

Non-parametric tests (Mann-Whitney U-test, Kruskal-Wallis test, Mann-Whitney post hoc analysis and Spearman's correlation statistics).

RESULTS

Mean eosinophil count (MEC) in oral leukoplakia cases was significantly more when compared to normal subjects. MEC in dysplastic cases of oral leukoplakia was significantly more when compared to those without epithelial dysplasia (Mann-Whitney U-test). Furthermore, MEC was directly proportional to the degree of epithelial dysplasia (Spearman's correlation statistics).

CONCLUSIONS

TEC may be used as an adjunct to predict the malignant transformation of dysplastic cases of oral leukoplakia. Eosinophilic infiltration in oral dysplastic cases should prompt a thorough evaluation for invasiveness, especially when features of invasion are absent or suspected in smaller biopsy specimens. Use of TEC as a prognostic indicator demands larger sample size and mandates long-term follow-up.

T cells in tumor microenvironment

Tumors progress in a specific area, which supports its development, spreading or shrinking in time with the presence of different factors that effect the fate of the cancer cells. This specialized site is called "tumor microenvironment" and has a composition of heterogenous materials. The immune cells are also residents of this stromal, cancerous, and inflammatory environment, and their types, densities, or functional differences are one of the key factors that mediate the fate of a tumor. T cells as a vital part of the immune system also are a component of tumor microenvironment, and their roles have been elucidated in many studies. In this review, we focused on the immune system components by focusing on T cells and detailed T helper cell subsets in tumor microenvironment and how their behaviors affect either the tumor or the patient's outcome.

Primary esophageal sclerosing mucoepidermoid carcinoma with “tissue eosinophilia”

Mucoepidermoid carcinoma (MEC) is a rare primary esophageal malignancy. It is characterized by poor clinical recognition, pre-operative diagnostic challenges and a lack of standardized therapeutic guidelines. We report the clinicopathological features of a hitherto unreported variant of esophageal MEC, sclerosing MEC with “tissue eosinophilia”, in a mid-esophageal location in a 51-year-old female. The diagnosis of the initial biopsy was challenging, because of the small size, poor orientation and inadequate representation of the MEC components. Recognition of the resectability of the tumor prompted surgical resection and enabled a demonstration of the low grade foci containing intermediate cells, mucin pools and the hitherto undescribed presence of stromal sclerosis and tissue eosinophils in esophageal MEC. Heightened clinicopathological awareness of esophageal MEC facilitated a definitive diagnosis and patient management. Increased recognition and global documentation of esophageal sclerosing MEC with “tissue eosinophilia” is necessary to improve the understanding and diagnosis of this malignancy in this location and to improve management guidelines.

Chromophobe renal cell carcinoma associated with eosinophilia: A report of three cases

Eosinophilia is typically associated with allergic reactions, parasitic infestations, certain forms of vasculitis, the use of certain medications and hematologic malignancies. In addition to eosinophilia associated with gastrointestinal tumors, lung cancer and thyroid carcinoma in solid malignancies, there are a limited number of cases describing peripheral hypereosinophilia in urologic tumors. The present study reports three cases of eosinophilia in patients with chromophobe renal cell carcinoma (CRCC) and investigates the association between excessive eosinophilia and the recurrence and prognosis of renal carcinoma. This is the first report of CRCC associated with excessive eosinophilia. Eosinophilia following tumor resectioning may indicate a poor prognosis, tumor recurrence and rapid disease progression.

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.

In silico prediction and in vitro characterization of multifunctional human RNase3

Human ribonucleases A (hRNaseA) superfamily consists of thirteen members with high-structure similarities but exhibits divergent physiological functions other than RNase activity. Evolution of hRNaseA superfamily has gained novel functions which may be preserved in a unique region or domain to account for additional molecular interactions. hRNase3 has multiple functions including ribonucleolytic, heparan sulfate (HS) binding, cellular binding, endocytic, lipid destabilization, cytotoxic, and antimicrobial activities. In this study, three putative multifunctional regions, ³⁴RWRCK³⁸ (HBR1), ⁷⁵RSRFR⁷⁹ (HBR2), and ¹⁰¹RPGRR¹⁰⁵ (HBR3), of hRNase3 have been identified employing in silico sequence analysis and validated employing in vitro activity assays. A heparin binding peptide containing HBR1 is characterized to act as a key element associated with HS binding, cellular binding, and lipid binding activities. In this study, we provide novel insights to identify functional regions of hRNase3 that may have implications for all hRNaseA superfamily members.

Eosinophil cationic protein: overview of biological and genetic features

The eosinophil cationic protein (ECP) is a small polypeptide that originates from activated eosinophil granulocytes. A wide range of stimuli has been shown to induce the secretion of ECP. The gene that encodes the human ECP is located on chromosome 14, and the protein shares the overall three-dimensional structure and the RNase active-site residues with other proteins in the RNase A superfamily. Several single-nucleotide polymorphisms in the human ECP gene have been currently described. ECP has many biological functions, including an immunoregulatory function, the regulation of fibroblast activity, and the induction of mucus secretion in the airway. Additionally, the protein is a potent cytotoxic molecule and has the capacity to kill mammalian and nonmammalian cells. The purpose of this article was to review the known biological and genetic characteristics of ECP that contribute to the understanding of this protein's role in the development and progression of a wide variety of diseases.