Changes in galectin-7 and cytokeratin-19 expression during the progression of malignancy in thyroid tumors: diagnostic and biological implications

Biomarkers in Cancer Detection, Diagnosis, and Prognosis

Biomarkers are vital in healthcare as they provide valuable insights into disease diagnosis, prognosis, treatment response, and personalized medicine. They serve as objective indicators, enabling early detection and intervention, leading to improved patient outcomes and reduced costs. Biomarkers also guide treatment decisions by predicting disease outcomes and facilitating individualized treatment plans. They play a role in monitoring disease progression, adjusting treatments, and detecting early signs of recurrence. Furthermore, biomarkers enhance drug development and clinical trials by identifying suitable patients and accelerating the approval process. In this review paper, we described a variety of biomarkers applicable for cancer detection and diagnosis, such as imaging-based diagnosis (CT, SPECT, MRI, and PET), blood-based biomarkers (proteins, genes, mRNA, and peptides), cell imaging-based diagnosis (needle biopsy and CTC), tissue imaging-based diagnosis (IHC), and genetic-based biomarkers (RNAseq, scRNAseq, and spatial transcriptomics).

Malignant human thyroid neoplasms associated with blood parasitic (haemosporidian) infection

Investigation of archival cytological material obtained by cytologists during fine-needle aspiration biopsy in follicular, papillary, and medullary human thyroid cancers revealed haemosporidian (blood parasitic) infection. Haemosporidian infection was detected as exo- and intraerythrocytic stages of development in thyrocytes schizogony. The exoerythrocytic stage of development is represented as microschizonts in a thyroid needle biopsy specimen. Probably, blood parasitic infection is the common etiology for these pathologies. All biopsy material in medical laboratories was stained with RomanowskyGiemsa stain. To clarify the localization of nuclei (DNA) of thyrocytes and nuclei (DNA) of haemosporidian infection in cytological material following investigation of the entire set of smears, a selective series of original archival smears was stained (restained) with a Feulgen/Schiff reagent. Staining of smears with RomanowskyGiemsa stain is an adsorption method that enables re-use of the same smears for staining with a Feulgen/Schiff reagent where the fuchsin dye, after DNA hydrolysis by hydrochloric acid, is incorporated into DNA and stains it in redviolet (crimsonlilac) color. An intentionally unstained protoplasm of blood parasitic infection was present as a light band around erythrocyte nuclei. In follicular thyroid cancer, Feulgen staining of thyrocytes revealed nuclear DNA and parasitic DNA (haemosporidium nuclei) as point inclusions and rings and diffusely distributed in the thyrocyte cytoplasm. The thyrocyte cytoplasm and nuclei were vacuolated, with thyrocyte nuclei being deformed, flattened, and displaced to the cell periphery. The erythrocytes, which were initially stained with eosin (orange color), contained haemosporidian nuclei (DNA). In some cases, endoglobular inclusions in thyrocytes and erythrocytes were of the same size. In papillary thyroid cancer, we were able to localize the nuclear DNA of thyrocytes and the parasitic DNA as point inclusions and diffusely distributed in the thyrocyte cytoplasm. Two or more polymorphic nuclei may eccentrically occur in the hyperplastic cytoplasm. Haemosporidian microschizonts occurred circumnuclearly in thyrocytes and as an exoerythrocytic stage in the blood. The erythrocyte cytoplasm contained redviolet polymorphic haemosporidian nuclei (DNA). In medullary thyroid cancer, the hyperplastic cytoplasm of thyrocytes contained eccentrically located nuclei (DNA) of thyrocytes and small haemosporidian nuclei (DNA), which may occupy the whole thyrocyte. There were thyrocytes with vacuolated cytoplasm and pronounced nuclear polymorphism. The size of hyperplastic nuclei was several times larger than that of normal thyrocyte nuclei. The color of stained cytoplasmic and nuclear vacuoles of thyrocytes was less redviolet compared with that of surrounding tissues, which probably indicates the presence of parasitic DNA in them. The haemosporidian nuclear material in erythrocytes is represented by polymorphic nuclei, which may indicate the simultaneous presence of different pathogen species and/or generations in the blood. Intracellular parasitism of haemosporidian infection in thyrocytes (schizogony) associated with three thyroid cancers leads to pronounced cytoplasmic hyperplasia, cytoplasmic vacuolization, and nuclear vacuolization of the thyrocyte, followed by impaired secretory function. Multinucleated thyrocytes with incomplete cytokinesis appear. The absence of lytic death of the affected thyrocytes indicates that the contagium is able to control apoptosis and influence physiological functions of the cell. There is deformation of the nuclei, which leads to a decrease in their size, their flattening and displacement to the cell periphery, with high risk of DNA mutations and deletions in affected cells, reaching a neoplastic level.

The role of cytokeratin 19 levels in the determination of endometriosis stages

OBJECTIVE/AIM

Endometrisosis, one of the most common gynecological disease, is characterized by the presence of endometriotic tissue outside of uterine cavity. The development and the validation of a simple blood biomarker specific and sensitive for endometriosis may facilitate the rapid and the accurate diagnosis of the disease and thus early treatment. Cytokeratin expression changes during epithelial differentiation and this expression is important for the modulation and the control of cell cycle regulation, tumor cell motility and apoptosis. Cytokeratin 19 (CK-19) is expressed in most simple epithelial cells and their malignant counterparts. The aim of this study is to investigate serum CK-19 expression levels in patients with endometriosis and to determine the diagnostic role of CK-19 levels in differentiating various stage of endometriosis.

METHODS

Ctytokeratin-19 expression and level were studied in 70 endometriosis patients and 50 volunteers by ELISA and RT-PCR. ROC analysis was performed by comparing all stages with each other and with the control group.

RESULTS

The CK-19 levels were significantly higher in the endometriosis groups than that of the control group by ELISA and RT-PCR. A significant (p < .05) difference was observed in endometriosis patients according to the stages.

CONCLUSION

Based on our data, it suggests that Cytokeratin-19 may have a potential role in the development of endometriosis.

Tissue architecture delineates field cancerization in BRAFV600E-induced tumor development

Cancer cells hijack developmental growth mechanisms but whether tissue morphogenesis and architecture modify tumorigenesis is unknown. Here, we characterized a new mouse model of sporadic thyroid carcinogenesis based on inducible expression of BRAF carrying a Val600 Glu (V600E) point mutation (BRAFV600E) from the thyroglobulin promoter (TgCreERT2). Spontaneous activation of this Braf-mutant allele due to leaky activity of the Cre recombinase revealed that intrinsic properties of thyroid follicles determined BRAF-mutant cell fate. Papillary thyroid carcinomas developed multicentrically within a normal microenvironment. Each tumor originated from a single follicle that provided a confined space for growth of a distinct tumor phenotype. Lineage tracing revealed oligoclonal tumor development in infancy and early selection of BRAFV600E kinase inhibitor-resistant clones. Somatic mutations were few, non-recurrent and limited to advanced tumors. Female mice developed larger tumors than males, reproducing the gender difference of human thyroid cancer. These data indicate that BRAFV600E-induced tumorigenesis is spatiotemporally regulated depending on the maturity and heterogeneity of follicles. Moreover, thyroid tissue organization seems to determine whether a BRAF-mutant lineage becomes a cancerized lineage. The TgCreERT2;BrafCA/+ sporadic thyroid cancer mouse model provides a new tool to evaluate drug therapy at different stages of tumor evolution.

The Combined Utility of HBME-1 and Galectin-3 Immunohistochemistry and BRAF V600E Mutations in the Diagnosis of Papillary Thyroid Carcinoma

Newer diagnostic modalities have revolutionized the pathologist’s approach to diagnosing thyroid malignancies. Molecular characterization of these malignancies has helped circumvent common morphologic diagnostic difficulties by integrating their genotypic, phenotypic, and immunohistochemical features. BRAF V600E mutation has been characterized as highly specific for thyroid carcinoma, especially papillary thyroid carcinoma (PTC); human bone marrow endothelial marker-1 (HBME-1) and galectin-3 are also such markers that are highly specific for PTC. We propose to study HBME-1 and galectin-3 expression and BRAF V600E mutation in thyroid neoplasms and do a comparative analysis to determine whether there is a correlation between BRAF V600E expression and that of HBME-1 and galectin-3. We further propose to analyze the individual and combined diagnosed utility of the above-mentioned ancillary diagnostic techniques.

Functions and Inhibition of Galectin-7, an Emerging Target in Cellular Pathophysiology

Galectin-7 is a soluble unglycosylated lectin that is able to bind specifically to β-galactosides. It has been described to be involved in apoptosis, proliferation and differentiation, but also in cell adhesion and migration. Several disorders and diseases are discussed by covering the aforementioned biological processes. Structural features of galectin-7 are discussed as well as targeting the protein intracellularly or extracellularly. The exact molecular mechanisms that lie behind many biological processes involving galectin-7 are not known. It is therefore useful to come up with chemical probes or tools in order to obtain knowledge of the physiological processes. The objective of this review is to summarize the roles and functions of galectin-7 in the human body, providing reasons why it is necessary to design inhibitors for galectin-7, to give the reader structural insights and describe its current inhibitors.

Towards a Better Understanding of the Relationships between Galectin-7, p53 and MMP-9 during Cancer Progression

It has been almost 25 years since the discovery of galectin-7. This member of the galectin family has attracted interest from many working in the cancer field given its highly restricted expression profile in epithelial cells and the fact that cancers of epithelial origin (carcinoma) are among the most frequent and deadly cancer subtypes. Initially described as a p53-induced gene and associated with apoptosis, galectin-7 is now recognized as having a protumorigenic role in many cancer types. Several studies have indeed shown that galectin-7 is associated with aggressive behavior of cancer cells and induces expression of MMP-9, a member of the matrix metalloproteinases (MMP) family known to confer invasive behavior to cancer cells. It is therefore not surprising that many studies have examined its relationships with p53 and MMP-9. However, the relationships between galectin-7 and p53 and MMP-9 are not always clear. This is largely because p53 is often mutated in cancer cells and such mutations drastically change its functions and, consequently, its association with galectin-7. In this review, we discuss the functional relationships between galectin-7, p53 and MMP-9 and reconcile some apparently contradictory observations. A better understanding of these relationships will help to develop a working hypothesis and model that will provide the basis for further research in the hope of establishing a new paradigm for tackling the role of galectin-7 in cancer.

Diagnostic Value of TROP2 Expression in Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC) represents the most common primary malignant thyroid lesion in all age groups. As diagnosis of PTC could be challenging in some cases and borderline nuclear features could be seen in some benign mimickers, several immunohistochemical markers are proposed to be helpful for making the correct diagnosis. In this study the authors investigated the diagnostic value of transmembrane glycoprotein (TROP2) for differentiating PTC from other thyroid follicular lesions. A total of 155 total thyroidectomy specimens including 84 cases of PTC and 71 cases of non-PTC were investigated. Among non-PTC group, 45 cases were follicular neoplasms and 26 cases were Hashimoto thyroiditis. TROP2 expression was observed in 82 of 84 cases of PTC group. In contrast only 5 cases of non-PTC group, all from Hashimoto thyroiditis specimens, showed positive expression. The sensitivity, specificity, positive predictive value, and negative predictive value of TROP2 for diagnosis of PTC was 98%, 93%, 94%, and 97%, respectively. The authors concluded that high sensitivity and specificity of TROP2 as well as its uniform negative reaction in follicular adenoma and carcinoma makes it a valuable immunohistochemical marker for diagnosis of PTC.

Diagnostic Value of TROP-2 and CK19 Expression in Papillary Thyroid Carcinoma in Both Surgical and Cytological Specimens

Papillary thyroid carcinoma (PTC) represents the most common primary malignant thyroid tumor and its diagnosis is dependent on the presence of classic nuclear features that are sometimes seen in some non-neoplastic and benign lesions. Several immunohistochemical markers are used individually or in combination to help in differentiation of PTC from mimickers. The aim of the current study was to assess the diagnostic value of TROP-2 and cytokeratin 19 (CK19) expression in differentiating PTC from other mimickers both singly and in combination. The current study was carried out on 77 surgical specimens (56 PTC and 21 non-neoplastic cases) and 12 cytological specimens (4 THY2, 6 THY4, and 2 THY5). TROP-2 was negative in 81% of non-neoplastic surgical specimens and in 100% of THY2 cytological specimens while it was positive in 71.4% of PTC surgical specimens and 100% of THY4/THY5 cytological specimens. Sensitivity and specificity of TROP-2 positive expression for diagnosis of PTC in surgical specimens reached 71% and 81%, respectively, while it reached 100% for both in cytological specimens. Cytokeratin 19 showed positive expression in 85.7% of non-neoplastic surgical specimens and in 92.9% of PTC surgical specimens. Cytokeratin 19 showed negative expression in 75% of Thy2 cases while it was positive in all studied Thy4 and Thy5 cases. Sensitivity and specificity of CK19 total estimated score for diagnosis of PTC in surgical specimens were 78.6% and 66.7%, respectively, while it reached 100% and 75% in cytological specimens. Positive TROP-2 and CK19 expression in PTC were associated with lymph node metastasis. TROP-2 is a specific rather than sensitive marker while CK19 is a sensitive rather than specific marker in differentiating PTC from other mimickers in surgical specimens. The diagnostic validity of both markers was superior in diagnosis of classic PTC compared with follicular variant PTC. TROP-2 is superior to CK19 in diagnosis of PTC in cytological specimens. Both TROP-2 and CK19 could be used preoperatively in adjunct to hematoxylin and eosin for more confident diagnosis of thyroid cytology and along with radiology as predictors of lymph node metastasis.

Immunohistochemical Markers of Thyroid Tumors Significance and Diagnostic Applications

Immunohistochemical markers of thyroid tumors can be divided into two major categories: those related to the cell types and those related to the type of pathology. The most important markers in the first category are thyroglobulin and TTF-1 for follicular cells, and calcitonin, CEA, and chromogranin for C cells. Markers in the second category are primarily directed at papillary carcinoma and include cytokeratin 19, high-molecular weight keratin (identifiable with antibody 34βE12), S-100 protein, HBME-1, galectin 3, and p27kip1. At the practical level, cell type-related markers are much more useful than disease-related markers. Markers said to be of prognostic value in medullary carcinomas are calcitonin, bcl-2, and N-myc.

Galectin Targeted Therapy in Oncology: Current Knowledge and Perspectives

The incidence and mortality of cancer have increased over the past decades. Significant progress has been made in understanding the underpinnings of this disease and developing therapies. Despite this, cancer still remains a major therapeutic challenge. Current therapeutic research has targeted several aspects of the disease such as cancer development, growth, angiogenesis and metastases. Many molecular and cellular mechanisms remain unknown and current therapies have so far failed to meet their intended potential. Recent studies show that glycans, especially oligosaccharide chains, may play a role in carcinogenesis as recognition patterns for galectins. Galectins are members of the lectin family, which show high affinity for β-galactosides. The galectin–glycan conjugate plays a fundamental role in metastasis, angiogenesis, tumor immunity, proliferation and apoptosis. Galectins’ action is mediated by a structure containing at least one carbohydrate recognition domain (CRD). The potential prognostic value of galectins has been described in several neoplasms and helps clinicians predict disease outcome and determine therapeutic interventions. Currently, new therapeutic strategies involve the use of inhibitors such as competitive carbohydrates, small non-carbohydrate binding molecules and antibodies. This review outlines our current knowledge regarding the mechanism of action and potential therapy implications of galectins in cancer.

Galectin-7 in Epithelial Homeostasis and Carcinomas

Galectins are small unglycosylated soluble lectins distributed both inside and outside the cells. They share a conserved domain for the recognition of carbohydrates (CRD). Although galectins have a common affinity for β-galatosides, they exhibit different binding preferences for complex glycans. First described twenty years ago, galectin-7 is a prototypic galectin, with a single CRD, able to form divalent homodimers. This lectin, which is mainly expressed in stratified epithelia, has been described in epithelial tissues as being involved in apoptotic responses, in proliferation and differentiation but also in cell adhesion and migration. Most members of the galectins family have been associated with cancer biology. One of the main functions of galectins in cancer is their immunomodulating potential and anti-angiogenic activity. Indeed, galectin-1 and -3, are already targeted in clinical trials. Another relevant function of galectins in tumour progression is their ability to regulate cell migration and cell adhesion. Among these galectins, galectin-7 is abnormally expressed in various cancers, most prominently in carcinomas, and is involved in cancer progression and metastasis but its precise functions in tumour biology remain poorly understood. In this issue, we will focus on the physiological functions of galectin-7 in epithelia and present the alterations of galectin-7 expression in carcinomas with the aim to describe its possible functions in tumour progression.

Expression of Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16 in cervical dysplasia

AIM

Cervical intraepithelial neoplasia (CIN) is commonly divided into three grades. Guidelines increasingly recommend surgery only in CIN 3 lesions. We investigated markers to evaluate differences in CIN 2 and 3 lesions as well as possible predictors for regression/progression in CIN 2 lesions.

MATERIALS & METHODS

Biopsies (n = 128) of healthy cervical tissue and CIN 1-3 were stained for Sialyl Lewis a, Sialyl Lewis x, Lewis y, Gal-3, Gal-7, STMN1 and p16.

RESULTS

We observed significant differences between CIN 2 and 3 lesions for Sialyl Lewis a, Sialyl Lewis x, Gal-3, Gal-7, STMN1 and p16. Expression of Sialyl Lewis a was significantly higher in CIN 2 patients who progressed during follow-up.

CONCLUSION

Significant differences in marker expression support the differentiation of CIN 2 and 3. Lewis a may help to predict progression/regression in CIN 2 patients.

Clinical significance of galectin-7 in vulvar squamous cell carcinoma

The present study reports the role of galectin-7 (Gal-7) expression in vulvar squamous cell carcinoma (VSCC) and its correlation with clinicopathological variables. Gal-7 expression was immunohistochemically detected in the paraffin-embedded sections of 20 normal vulvar biopsy samples and 50 VSCC specimens. Expression was also detected in 10 normal vulvar biopsy samples and 10 VSCC specimens by western blotting. In addition, the methylation status of the promoter of the Gal-7 gene was determined in 30 VSCC specimens and 20 samples of normal vulvar tissue by methylation-specific polymerase chain reaction. Gal-7 expression was found to be significantly downregulated in the VSCC tissues compared with the normal vulvar tissues (P<0.05). Downregulation of Gal-7 was correlated with advanced clinical stage, poor tumor differentiation and regional lymph node metastasis (P<0.05). Furthermore, methylation of the Gal-7 gene promoter was significantly reduced in the vulvar normal tissues compared with the VSCC tissues (P=0.023), while increased Gal-7 promoter methylation was correlated with advanced clinical stage, poor tumor differentiation and regional lymph node metastasis (P<0.05). There was no association between patient age and Gal-7 promoter methylation. Together, these results suggested that Gal-7 has a negative impact in patients with VSCC, with malignant potential correlating with Gal-7 promoter methylation.

Galectin expression in cancer diagnosis and prognosis: A systematic review

Galectins are a family of proteins that bind to specific glycans thereby deciphering the information captured within the glycome. In the last two decades, several galectin family members have emerged as versatile modulators of tumor progression. This has initiated the development and preclinical assessment of galectin-targeting compounds. With the first compounds now entering clinical trials it is pivotal to gain insight in the diagnostic and prognostic value of galectins in cancer as this will allow a more rational selection of the patients that might benefit most from galectin-targeted therapies. Here, we present a systematic review of galectin expression in human cancer patients. Malignant transformation is frequently associated with altered galectin expression, most notably of galectin-1 and galectin-3. In most cancers, increased galectin-1 expression is associated with poor prognosis while elevated galectin-9 expression is emerging as a marker of favorable disease outcome. The prognostic value of galectin-3 appears to be tumor type dependent and the other galectins require further investigation. Regarding the latter, additional studies using larger patient cohorts are essential to fully unravel the diagnostic and prognostic value of galectin expression. Furthermore, to better compare different findings, consensus should be reached on how to assess galectin expression, not only with regard to localization within the tissue and within cellular compartments but also regarding alternative splicing and genomic variations. Finally, linking galectin expression and function to aberrant glycosylation in cancer cells will improve our understanding of how these versatile proteins can be exploited for diagnostic, prognostic and even therapeutic purposes in cancer patients.

The CCAAT/enhancer-binding protein beta-2 isoform (CEBPβ-2) upregulates galectin-7 expression in human breast cancer cells

Galectin-7 is considered a gene under the control of p53. However, elevated expression of galectin-7 has been reported in several forms of cancer harboring an inactive p53 pathway. This is especially true for breast cancer where galectin-7 expression is readily expressed in a high proportion in basal-like breast cancer tissues, conferring cancer cells with increased resistance to cell death and metastatic properties. These observations suggest that other transcription factors are capable of inducing galectin-7 expression. In the present work, we have examined the role of CCAAT/enhancer-binding protein beta (C/EBPβ) in inducing expression of galectin-7. C/EBP proteins have been shown to contribute to breast cancer by upregulating pro-metastatic genes. We paid particular attention to C/EBPβ-2 (also known as LAP2), the most transcriptionally active of the C/EBPβ isoforms. Our results showed that ectopic expression of C/EBPβ-2 in human breast cancer cells was sufficient to induce expression of galectin-7 at both the mRNA and protein levels. In silico analysis further revealed the presence of an established CEBP element in the galectin-7 promoter. Mutation of this binding site abolished the transcriptional activity of the galectin-7 promoter. Chromatin immunoprecipitation analysis confirmed that C/EBPβ-2 binds to the endogenous galectin-7 promoter. Analysis of galectin-7 protein expression in normal epithelia and in breast carcinoma by immunohistochemistry further showed the expression pattern of C/EBPβ closely micmicked that of galectin-7, most notably in mammary myoepithelial cells and basal-like breast cancer where galectin-7 is preferentially expressed. Taken together, our findings suggest that C/EBPβ is an important mediator of galectin-7 gene activation in breast cancer cells and highlight the different transcriptional mechanisms controlling galectin-7 in cancer cells.

Utility of immunohistochemical markers in diagnosis of follicular cell derived thyroid lesions

Differentiating the follicular derived lesions can be challenging. Although immunohistochemistry is generally accepted as a useful ancillary technique in the diagnosis, controversy exists regarding the best marker or combination of markers to distinguish each lesion from its mimics. In this study, we aimed at evaluating multiple markers to compare their sensitivity and usefulness, and to find out if a combination of the evaluated markers can be of additional value in discriminating thyroid lesions. The study included two groups of follicular derived thyroid lesions; benign group (Grave's disease, nodular goiter, Hashimoto's and adenoma) and malignant group (papillary, follicular carcinoma, well differentiated tumors of unknown malignant potential and follicular tumour of unknown malignant potential). Immunohistochemical evaluation of CD56, HBME-1, Gaectin-3 and CK19 were done. The sensitivity, specificity for each marker and their combination were calculated. Each marker was sensitive and specific for certain lesion but the sensitivity and specificity was increased when use combination of markers. Although no single marker is completely sensitive and specific for follicular thyroid lesions, the combination of CD56, HBME-1, Gaectin-3 and CK19 attains high sensitivity and specificity in diagnosis.

Ras inhibition boosts galectin-7 at the expense of galectin-1 to sensitize cells to apoptosis

Galectins are a family of β-galactoside-binding lectins that exert diverse extracellular and intracellular effects. Galectin-7 and galectin-1 show opposing effects on proliferation and survival in different cell types. Galectin-7 is a p53-induced gene and an enhancer of apoptosis, whereas galectin-1 induces tumorigenicity and resistance to apoptosis in several types of cancers. We show here that in cells derived from neurofibromin-deficient (Nf1^−/−) malignant peripheral nerve sheath tumors (MPNSTs), Ras inhibition by S-trans,trans-farnesylthiosalicylic-acid (FTS; Salirasib) shifts the pattern of galectin expression. Whereas FTS decreased levels of both active Ras and galectin-1 expression, it dramatically increased both the mRNA and protein expression levels of galectin-7. Galectin-7 accumulation was mediated through JNK inhibition presumably resulting from the observed induction of p53, and was negatively regulated by the AP-1 inhibitor JDP2. Expression of galectin-7 by itself decreased Ras activation in ST88-14 cells and rendered them sensitive to apoptosis. This observed shift in galectin expression pattern together with the accompanying shift from cell proliferation to apoptosis represents a novel pattern of Ras inhibition by FTS. This seems likely to be an important phenomenon in view of the fact that both enhanced cell proliferation and defects of apoptosis constitute major hallmarks of human cancers and play a central role in the resistance of MPNSTs to anti-cancer treatments. These findings suggest that FTS, alone or in combination with chemotherapy agents, may be worth developing as a possible treatment for MPNSTs.

Expression and functions of galectin-7 in human and murine melanomas

The identification of galectin-7 as a p53-induced gene and its ability to induce apoptosis in many cell types support the hypothesis that galectin-7 has strong antitumor activity. This has been well documented in colon cancer. However, in some cases, such as breast cancer and lymphoma, its high expression level correlates with aggressive subtypes of cancer, suggesting that galectin-7 may have a dual role in cancer progression. In fact, in breast cancer, overexpression of galectin-7 alone is sufficient to promote metastasis to the bone and lung. In the present work, we investigated the expression and function of galectin-7 in melanoma. An analysis of datasets obtained from whole-genome profiling of human melanoma tissues revealed that galectin-7 mRNA was detected in more than 90% of biopsies of patients with nevi while its expression was more rarely found in biopsies collected from patients with malignant melanoma. This frequency, however, was likely due to the presence of normal epidermis tissues in biopsies, as shown our studies at the protein level by immunohistochemical analysis. Using the experimental melanoma B16F1 cell line, we found that melanoma cells can express galectin-7 at the primary tumor site and in lung metastasis. Moreover, we found that overexpression of galectin-7 increased the resistance of melanoma cells to apoptosis while inducing de novo egr-1 expression. Overexpression of galectin-7, however, was insufficient to modulate the growth of tumors induced by the subcutaneous injection of B16F1 cells. It also failed to modulate the dissemination of B16F1 cells to the lung.

Cytokeratin 19 immunoreactivity in the diagnosis of papillary thyroid carcinoma

Context:

The diagnosis of papillary thyroid carcinoma (PTC) is based on nuclear features. These features may be present in focal areas in benign thyroid diseases and follicular adenoma (FA), leading to diagnostic difficulty.

Aims:

To evaluate the expression and pattern of the distribution of cytokeratin 19 (CK19) in PTC and compare its reactivity with other neoplastic and non-neoplastic conditions to assess its potential as a useful marker for PTC.

Materials and Methods:

Twenty two cases of papillary carcinoma (usual type, follicular and diffuse sclerosing variant), eight follicular adenomas, eight multinodular goiters (MNG) were collected for a period of two years and six months. Sections were taken from thyroidectomy specimens fixed in 10% buffered neutral formalin. Hematoxylin and eosin staining and immunohistochemical staining for CK19 were done using standard protocol. Results were semiquantitatively scored as follows: 1+ (<5% positively stained cells), 2+ (5-25%), 3+ (25-75%) and 4+ (>75%), and then analyzed.

Statistical Analysis and Results:

All 22 (100%) papillary carcinomas showed diffuse and strong (3+ and 4+) CK19 expression. Six out of eight (75%) FAs and four out of eight (50%) MNG were positive for CK19, but it was of weaker intensity (1+ and 2+) and focal in distribution.

Conclusion:

Focal CK19 staining may be found in benign disease, but diffuse and strong positivity is characteristic of PTC, which can be used in the diagnosis of PTC in lesions of equivocal morphological appearances.

Galectin-1, -3, -7 expressions in congenital and acquired pediatric cholesteatomas compared to external auditory canal skin

OBJECTIVES

There is a classical distinction based on clinical criteria between acquired and congenital cholesteatomas. To determine if these two types of lesions show different immunohistochemical features, we have studied the expression patterns of three distinctive galectins (animal lectins implied especially in cellular proliferation and apoptosis) in both types of cholesteatomas and compared it to their expression patterns in external auditory canal skin.

METHODS

Our study is based on nine acquired and eight congenital cholesteatomas, obtained from children during ear surgery. Six specimens of normal adult auditory meatal skin served as control. Specimens were analyzed by immunohistochemistry using monoclonal antibodies with galectin-1 and galectin-3, and a polyclonal antibody with galectin-7.

RESULTS

We did not observe any differences in the galectin distribution pattern between congenital and acquired pediatric cholesteatomas. Compared to the control group, cholesteatomas present some particular features. There was no expression of galectin-1 and a lower expression of galectin-3 in the epithelium. Furthermore, we observed a preferentially nuclear distribution of galectin-7 in cholesteatomas, whereas it is essentially cytoplasmic in the control group.

CONCLUSION

The data reported in this study suggest, on the basis of a lesser marked galectin-3 in cholesteatomas epithelium compared with an external auditory canal skin, that an immature keratinocytes population is at the origin of these lesions and that galectin-3 and galectin-7 play a part in the capacity as apoptosis modulators. Our study does not establish a difference in the galectin expressions of congenital and acquired cholesteatomas, but it constitutes however an additional argument in favor of the "undifferentiated" origin of keratinocytes in cholesteatomas.

Comparison of proliferating cell nuclear antigen, thyroid transcription factor-1, Ki-67, p63, p53 and high-molecular weight cytokeratin expressions in papillary thyroid carcinoma, follicular carcinoma, and follicular adenoma

The searching of the reliable and repeatable immunohistochemical markers in the differential diagnosis of the thyroid's differentiated follicular epithelial neoplasms has been continuing. Recently, the studies have majored on immunohistochemical markers such as high-molecular weight cytokeratin (HMW-CK), galectin-3, cytokeratin 19, and p27. We aimed to evaluate the differences of the expressions of the proliferating cell nuclear antigen (PCNA), thyroid transcription factor-1 (TTF-1), Ki-67, p63, p53, and HMW-CK among the papillary thyroid carcinomas (PTCs), follicular carcinomas (FCs), and follicular adenomas (FAs). Thirty-nine patients with the diagnoses of the PTC, FC, and FA in the archives of the Izmir Tepecik Training and Research Hospital Pathology Laboratory registries in between 2004 and 2009 were included in the study. Immunohistochemical stains for PCNA, TTF-1, Ki-67, p63, p53, and HMW-CK were applied. The results were analyzed statistically by using Statistical Package for the Social Sciences (SPSS) for Windows 16.0 program (SPSS Inc., IBM, Somers, New York, USA). In all 3 groups, all tumors showed PCNA and TTF-1 positivity. Ki-67 proliferation index varied in a wide range in all groups. Although it was not statistically significant, 19 of 39 tumors (7 PTCs, 2 FCs, and 10 FAs) were stained with p63. The results of the immunoreactivity seen in PTCs with p53 (41.2%) and HMW-CK (52.9%) were statistically significant. The tumors in the other 2 groups (FC and FA) showed no reactivity with HMW-CK. Although the differential diagnosis of the thyroid follicular neoplasms are based on the histologic and cytomorphological criteria, p53 and HMW-CK positivity might be undertaken in favor of the diagnosis of the PTC.

The role of oxidative stress in neuromelanin synthesis in PC12 cells

Previous research has indicated that neuromelanin (NM) is involved in the pathogenesis of Parkinson's disease (PD). Increased reactive oxygen species (ROS) generation in PD sufferers is thought to be related to enhanced tyrosine hydroxylase (TH) activity and NM production. However, few reports have confirmed this hypothesis. In this study, PC12 cells of all experiments were exposed to 50 μmol/L levodopa (l-DOPA) to generate a model for NM synthesis. Meanwhile, PC12 cells were treated with glucose oxidase (GO) at different concentrations to generate oxidative stress. Finally, cell viability, TH activity, and NM generation in PC12 cells were measured. The results showed that GO dose-dependently stimulated oxidative stress generation in PC12 cells. Moderate increases in oxidative stress enhanced the viability of PC12 cells. However, an excessive level of oxidative stress can lead to the degeneration of PC12 cells. Notably, in the surviving PC12 cells, ROS significantly increased the TH activity, and the NM production was also upregulated. Thus, oxidative stress may upregulate the synthesis of NM, which may be a result of the increased TH activity observed in response to the elevated ROS in l-DOPA-treated PC12 cells.

Advances in cellular therapy for the treatment of thyroid cancer

Up to now, there are no curative therapies available for the subset of metastasized undifferentiated/anaplastic thyroid carcinomas. This review describes the possible use of immunocompetent cells which may help to restore the antitumor immune recognition for treating an existing tumor or preventing its recurrence. The most prominent experimental strategy is the use of dendritic cells (DCs) which are highly potent in presenting tumor antigens. Activated DCs subsequently migrate to draining lymph nodes where they present antigens to naïve lymphocytes and induce cytotoxic T cells (CTL). Alternatively to DC therapy, adoptive cell transfer may be performed by either using natural killer cells or ex vivo maturated CTLs. Within this review article we will focus on recent advances in the understanding of anti-tumor immune responses, for example, in thyroid carcinomas including the advances which have been made for the identification of potential tumor antigens in thyroid malignancies.

Identification of galectin-7 as a potential biomarker for esophageal squamous cell carcinoma by proteomic analysis

Background

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignancies. Early diagnosis is critical for guiding the therapeutic management of ESCC. It is imperative to find more effective biomarkers of ESCC.

Methods

To identify novel biomarkers for esophageal squamous cell carcinoma (ESCC), specimens from 10 patients with ESCC were subjected to a comparative proteomic analysis. The proteomic patterns of ESCC samples and normal esophageal epithelial tissues (NEETs) were compared using two-dimensional gel electrophoresis. And differentially expressed proteins were identified using MALDI-TOF-MS/MS. For further identification of protein in selected spot, western blotting and immunohistochemistry were employed.

Results

Twelve proteins were up-regulated and fifteen proteins were down-regulated in the ESCC samples compared with the NEET samples. Up-regulation of galectin-7 was further confirmed by western blotting and immunohistochemistry. Furthermore, immunohistochemical staining of galectin-7 was performed on a tissue microarray containing ESCC samples (n = 50) and NEET samples (n = 10). The expression levels of galectin-7 were markedly higher in the ESCC samples than in the NEET samples (P = 0.012). In addition, tissue microarray analysis also showed that the expression level of galectin-7 was related to the differentiation of ESCC.

Conclusions

The present proteomics analysis revealed that galectin-7 was highly expressed in ESCC tissues. The alteration in the expression of galectin-7 was confirmed using a tissue microarray. These findings suggest that galectin-7 could be used as a potential biomarker for ESCC.

Overexpression of galectin-7, a myoepithelial cell marker, enhances spontaneous metastasis of breast cancer cells

Galectins are members of a family of beta-galactosides-binding proteins that have recently emerged as novel modulators in different aspects of cancer. The expression of galectins in tumors and/or the tissue surrounding them has been well documented. Since galectin-7 expression has been associated with epithelial tissues and varies significantly in various types of cancer, we have investigated for the first time its role in breast cancer. Using two preclinical mouse models, high levels of galectin-7 expression in breast cancer cells drastically increased their ability to metastasize to lungs and bones. Significant increases in the number of pulmonary metastases and osteolytic lesions were induced by overexpression of galectin-7 compared with control cells. In human tissues, galectin-7 was specifically found in myoepithelial cells of normal human breast tissue, but not in luminal cells. Its expression was severely altered in breast carcinoma, many samples showing greater than 70% of galectin-7 positive cells. High expression levels of galectin-7 were restricted to high-grade breast carcinomas, including HER2 overexpressing and basal-like groups. In HER2 overexpressing cases, galectin-7 expression was associated with lymph node axillary metastasis. Taken together, our results indicate that galectin-7 may represent a potential target for both specific detection and therapeutic inhibition of metastatic breast cancer.

Increased galectin-7 gene expression in lymphoma cells is under the control of DNA methylation

Recent studies have reported that elevated levels of galectin-7 in different types of cancer. The mechanisms underlying its abnormal regulation in cancer cells remain, however, unknown. Here, we have examined the relationship between galectin-7 and p53, a gene previously associated with upregulation of galectin-7. While RNA and protein analyses revealed a consistent and irreversible upregulation of galectin-7 throughout progression of lymphoma, no correlation with p53 was found. In fact, most of the lymphoma cell lines expressing high levels of galectin-7 did not express any detectable level of p53, although expressed p21(Waf1/Cip1) gene following doxorubicin treatment, indicating that p53 was functional in these cells. Methylation-specific polymerase chain reaction (MS-PCR) analyses rather suggested that galectin-7 expression was associated with changes in DNA methylation. This conclusion was supported by data using demethylating agent 5-aza-dC. Furthermore, disruption of the DNA methylases dnmt1 and dnmt3a induced galectin-7. Collectively, our data suggest that abnormal expression of galectin-7 in lymphoma cells is not dependent on p53, but is rather associated with DNA hypomethylation.

Molecular phenotyping of thyroid tumors identifies a marker panel for differentiated thyroid cancer diagnosis

BACKGROUND

Currently, a large proportion of individuals undergo thyroidectomy as a diagnostic procedure for cancer. The objective of this work was to evaluate the molecular phenotype of differentiated thyroid cancer (DTC) and benign thyroid lesions to identify molecular markers that allow for accurate thyroid cancer diagnosis.

METHODS

Tissue microarrays consisting of 100 benign and 105 malignant thyroid lesions, plus 24 lymph node samples, were stained for a panel of 57 molecular markers. Significant associations between marker staining and tumor pathology (DTC versus benign) were determined using contingency table and Mann-Whitney U (MU) tests. A Random Forests classifier algorithm was also used to identify useful/important molecular classifiers.

RESULTS

Of the 57 diagnostic markers evaluated 35 (61%) were significantly associated with a DTC diagnosis after multiple testing correction. Of these, in DTC compared with benign thyroid tumors, 8 markers were downregulated and 27 upregulated. The most significant markers for DTC diagnosis were: Galectin-3, Cytokeratin 19, Vascular Endothelial Growth Factor, Androgen Receptor, p16, Aurora-A, and HBME-1. Using the entire molecular marker panel, a Random Forests algorithm was able to classify tumors as DTC or benign with an estimated sensitivity of 87.9%, specificity of 94.0%, and an accuracy of 91.0%.

CONCLUSION

Evaluation of the DTC and benign thyroid tumor molecular phenotype has allowed for identification of a marker panel, composed of both established and novel markers, useful for thyroid cancer diagnosis. These results suggest that further study of the molecular profile of thyroid tumors is warranted, and a diagnostic molecular marker panel may potentially improve patient selection for thyroid surgery.

Serum galectin-1 and galectin-3 levels in benign and malignant nodular thyroid disease

BACKGROUND

Since the histological expression of galectins is increased in thyroid carcinoma, determination of their serum levels may provide useful preoperative information. The goal of this study was to determine if a difference in galectin serum levels could be detected between benign and malignant nodular thyroid diseases.

DESIGN

Using validated ELISAs, the concentrations of several galectins were prospectively measured in serum samples from 30 healthy individuals and preoperatively in 90 patients with thyroid disease. Seventy-one patients had multiple thyroid nodules (MTN), 13 patients had a single thyroid nodule (STN), and 6 patients had Graves' disease. Nine of 71 patients with MTN had fine-needle aspiration biopsy (FNAB) of their nodules and in 7 patients a "benign" diagnosis was made, in 0 patient a "malignant" diagnosis was made, and in 2 patients a "suspicious" diagnosis was made. Six of 13 patients with STN had FNAB of their nodules and in 2 patients a "benign" diagnosis was made, in 3 patients a "malignant" diagnosis was made, and in 1 patient a "suspicious" diagnosis was made.

RESULTS

Thyroid disease was associated with higher levels of galectins-1 and -3 compared to normal subjects. Using a threshold value of 3.2 ng/mL as a cut-off point, the measurement of serum galectin-3 separated micro- and macropapillary thyroid carcinoma (PAP_CA) from patients with nonmalignant thyroid disease with 74% specificity, 73% sensitivity, 57% positive predictive value, and 85% negative predictive value. Elevated serum galectin-3 concentrations (>3.2 ng/mL) detected 87% of macropapillary thyroid carcinomas and 67% of micropapillary thyroid carcinomas.

CONCLUSIONS

Serum levels of galectins-1 and -3 are relatively high in patients with thyroid malignancy but there is considerable overlap in serum galectin-3 concentrations between those with benign and malignant nodular thyroid disease and, to a lesser extent, between those with and without nodular thyroid disease.

Galectins: structure, function and therapeutic potential

Galectins are a family of animal lectins that bind beta-galactosides. Outside the cell, galectins bind to cell-surface and extracellular matrix glycans and thereby affect a variety of cellular processes. However, galectins are also detectable in the cytosol and nucleus, and may influence cellular functions such as intracellular signalling pathways through protein-protein interactions with other cytoplasmic and nuclear proteins. Current research indicates that galectins play important roles in diverse physiological and pathological processes, including immune and inflammatory responses, tumour development and progression, neural degeneration, atherosclerosis, diabetes, and wound repair. Some of these have been discovered or confirmed by using genetically engineered mice deficient in a particular galectin. Thus, galectins may be a therapeutic target or employed as therapeutic agents for inflammatory diseases, cancers and several other diseases.

What is New on Thyroid Cancer Biomarkers

Thyroid cancer harbours in about 5% of thyroid nodules. The majority of them are well-differentiated cancers originating from the follicular epithelium, and are subdivided into papillary and follicular carcinomas. Undifferentiated carcinomas and medullary thyroid carcinomas arising from C cells are less common.

Although most thyroid nodules are benign, distinguishing thyroid cancer from benign lesions is crucial for an appropriate treatment and follow-up. The fine needle aspiration cytology (FNAC) allows the diagnosis of nature of thyroid nodules in the majority of cases. However, FNAC has some limitations, particularly in the presence of follicular lesions which can appear dubious in rare instances even at histology.

In an effort to improve diagnostic accuracy and offer new prognostic criteria, several immunohistochemical and molecular markers have been proposed. However, most of them have to be validated on large series before being used in routine practice.

Galectins as modulators of tumor progression in head and neck squamous cell carcinomas

Head and neck squamous cell carcinomas (HNSCCs) remain a significant cause of morbidity worldwide. Biological therapies able to induce and/or upregulate antitumor immune responses could represent a complementary approach to conventional treatments for patients with HNSCC because, despite advances in surgery, radiotherapy, and chemotherapy, the overall survival rates for these patients have not changed over recent decades. Galectins are involved in the control of cell proliferation, cell death, and cell migration and in the modulation of various functions of the immune system. In this context, galectin-1 is known to protect HNSCCs from the immune system. The present review details the involvement of galectins in HNSCC biology and suggests a number of approaches to reduce the levels of expression of galectin-1 in HNSCCs, with the aim of improving the efficiency of HNSCC immunotherapy.

Galectin-7 in Lymphoma: Elevated Expression in Human Lymphoid Malignancies and Decreased Lymphoma Dissemination by Antisense Strategies in Experimental Model

Galectin-7 is found mainly in stratified squamous epithelia as well as in various other types of cancer cells. As with other members of the galectin family, the expression of galectin-7 has been shown to negatively regulate the development of some tumors while correlating with the progression of other tumor types. For example, up-regulation of galectin-7 is associated with rat mammary carcinomas and with progression to T-cell malignancy. Here, we provide evidence indicating that galectin-7 functions as an important molecule in the dissemination of lymphoma cells in vivo. We found that stable transfection of lymphoma cells with a plasmid encoding antisense galectin-7 cDNA significantly inhibited the dissemination and invasion of lymphoma cells to peripheral organs, thereby increasing the survival of mice. We also found that inhibition of galectin-7 in aggressive lymphoma cells correlated with a decreased invasion of tumor cells in target organs and a reduced expression of matrix metalloproteinase-9, a gene associated with a poor prognosis in non-Hodgkin's lymphoma. We finally examined the expression of galectin-7 in 50 specimens of different mature B-cell neoplasms and found high galectin-7 expression levels in a significant proportion of mature B-cell neoplasms but not in normal B cells. Taken together, these findings suggest that galectin-7 is a potential therapeutic target in the treatment of lymphoid malignancies.

Galectin 7 (p53-Induced Gene 1): A New Prognostic Predictor of Recurrence and Survival in Stage IV Hypopharyngeal Cancer

BACKGROUND

Eighty percent of hypopharyngeal squamous cell carcinoma patients have advanced stages (III and IV) of the disease, and biological markers are required to predict high-risk head and neck squamous cell carcinoma patients in need of highly aggressive treatments after surgery to improve the survival rate. We analyzed the potential prognostic value of galectin 7 in a series of 81 stage IV hypopharyngeal SCCs because galectin 7 is an emerging marker involved in the epidermal development of pluristratified epithelia and in epidermal cell migration.

METHODS

The immunohistochemical expression of galectin 7 was determined on a series of 81 stage IV hypopharyngeal SCCs and was compared with that of galectins 1 and 3.

RESULTS

High levels of galectin 7 expression were associated with rapid recurrence rates and dismal prognoses in these 81 stage IV hypopharyngeal SCCs, a feature not observed with galectin 3 and one observed weakly, if at all, with galectin 1.

CONCLUSIONS

These data suggest that the immunohistochemical determination of galectin 7 expression in the case of high-risk hypopharyngeal cancers is a meaningful tool to identify patients who should benefit from aggressive postsurgical adjuvant therapy after surgery, including not only radiotherapy, but also chemotherapy.

Nuclear presence of adhesion-/growth-regulatory galectins in normal/malignant cells of squamous epithelial origin

Cellular activities in the regulation of growth or adhesion/migration involve protein (lectin)-carbohydrate recognition at the cell surface. Members of the galectin family of endogenous lectins additionally bind distinct intracellular ligands. These interactions with protein targets explain the relevance of their nuclear and cytoplasmic presence. Expression profiling for galectins and accessible binding sites is a histochemical approach to link localization with cellular growth properties. Non-cross-reactive antibodies for the homodimeric (proto-type) galectins-1, -2 and -7 and the chimera-type galectin-3 (Gal-3) as well as the biotinylated lectins were tested. This analysis was performed with the FaDu squamous carcinoma cell line and long-term cultured human and porcine epidermal cells as models for malignant and normal cells of squamous cell epithelial origin. A set of antibodies was added for phenotypic cell characterization. Strong nuclear and cytoplasmic signals of galectins and the differential reactivity of labeled galectins support the notion of their individual properties. The length of the period of culture was effective in modulating marker expression. Cytochemical expression profiling is a prerequisite for the selection of distinct proteins for targeted modulation of gene expression as a step toward functional analysis.

ECM1 and TMPRSS4 Are Diagnostic Markers of Malignant Thyroid Neoplasms and Improve the Accuracy of Fine Needle Aspiration Biopsy

OBJECTIVE

The objective of this study was to determine whether genes that regulate cellular invasion and metastasis are differentially expressed and could serve as diagnostic markers of malignant thyroid nodules.

SUMMARY AND BACKGROUND DATA

Patients whose thyroid nodules have indeterminate or suspicious cytologic features on fine needle aspiration (FNA) biopsy require thyroidectomy because of a 20% to 30% risk of thyroid cancer. Cell invasion and metastasis is a hallmark of malignant phenotype; therefore, genes that regulate these processes might be differentially expressed and could serve as diagnostic markers of malignancy.

METHODS

Differentially expressed genes (2-fold higher or lower) in malignant versus benign thyroid neoplasms were identified by extracellular matrix and adhesion molecule cDNA array analysis and confirmed by real-time quantitative polymerase chain reaction (PCR). The area under the receiver operating characteristic (AUC) curve was calculated to determine diagnostic accuracy of gene expression level cutoffs established by logistic regression analysis.

RESULTS

By cDNA array analysis, ADAMTS8, ECM1, MMP8, PLAU, SELP, and TMPRSS4 were upregulated, and by quantitative PCR, ECM1, SELP, and TMPRSS4 mRNA expression was higher in malignant (n = 57) than in benign (n = 38) thyroid neoplasms (P< 0.002). ECM1 and TMPRSS4 mRNA expression levels were independent predictors of a malignant thyroid neoplasm (P < 0.003). The AUC was 0.956 for ECM1 and 0.926 for TMPRSS4. Combining both markers improved their diagnostic use (AUC 0.985; sensitivity, 91.7%; specificity, 89.8%; positive predictive value, 85.7%; negative predictive value, 82.8%). ECM1 and TMPRSS4 expression analysis improved the diagnostic accuracy of FNA biopsy in 35 of 38 indeterminate or suspicious results. The level of ECM1 mRNA expression was higher in TNM stage I differentiated thyroid cancers than in stage II and III tumors (P < or = 0.031).

CONCLUSIONS

ECM1 and TMPRSS4 are excellent diagnostic markers of malignant thyroid nodules and may be used to improve the diagnostic accuracy of FNA biopsy. ECM1 is also a marker of the extent of disease in differentiated thyroid cancers.

Toward functional glycomics by localization of tissue lectins: immunohistochemical galectin fingerprinting during diethylstilbestrol-induced kidney tumorigenesis in male Syrian hamster

The current study focused on galectins (-1, -3, -4, -7, and -8) and deliberately performed immunohistochemical fingerprinting to explore their complexity in a context of experimental renal carcinogenesis. The diethylstilbestrol (DES)-induced renal tumors in male Syrian hamster kidney (SHKT) represent a unique animal model for the study of estrogen-dependent renal malignancies. Kidney sections of DES-treated hamsters (3 days to 11 months of DES exposure) were analyzed by immunohistochemistry using a panel of non-crossreactive antibodies raised against galectins-1, -3, -4, -7, and -8. Levels of expression were quantitatively determined by using computer-assisted microscopy on immunostained tissue sections. Except for galectin-4, all above mentioned galectins were expressed in kidney tumors. Small clusters of galectin-1-positive, most likely preneoplastic cells at the corticomedullary junction were already evident 1 week after DES administration. Galectin-1 and -3 expression was apparently associated with the first steps of the neoplastic transformation, because small tumorous buds were found to be positive after 1 month of treatment. In contrast, galectins-7 and -8 were detected in large tumors and medium-sized tumors, respectively, thereby indicating an involvement in later stages of DES-induced SHKT. Galectins-1, -3, -7, and -8 were also detected by immunofluorescence staining in the HKT-1097 cell line established from SHKT, thus illustrating the stability of galectin expression in tumor cells. Our data document the presence and differential regulation of galectins in the course of renal tumorigenesis in the model of DES-induced SHKT.

Tumor suppressor gene allelic loss profiles of the variants of papillary thyroid carcinoma

Papillary thyroid carcinoma (PTCa) is a relatively common, indolent tumor that usually has an excellent prognosis. While the diagnosis of conventional PTCa is relatively straightforward, encapsulated tumors with follicular growth pattern and unusual or incomplete cytologic features of papillary carcinoma can be diagnostically challenging. Encapsulated, noninvasive tumors are particularly controversial as the differential diagnosis includes a nonneoplastic nodule, a benign follicular adenoma, and papillary carcinoma. In this study, we performed molecular genotyping to identify loss of heterozygosity of tumor suppressor genes in conventional PTCa and in several different morphologic variants, including follicular variant, tall cell variant, and oncocytic variant. Our data demonstrate that conventional PTCas have the lowest frequency of allelic loss (7%), as compared with follicular, oncocytic, and tall cell variants (19%, 34%, and 20%, respectively). Frequency of allelic loss increased with increasing size of the tumors, but did not correlate with age, gender, extrathyroidal extension, or lymph node metastases. Though it is unlikely that these results will enable the distinction between different variants of papillary carcinoma, the finding of significant rates ofallelic loss in the variants of PTCa provides additional evidence of malignancy and may be useful in distinguishing encapsulated tumors from nonneoplastic or benign nodules.

Atypical adenomatous hyperplasia of lung: its incidence and analysis of clinical, glycohistochemical and structural features including newly defined growth regulators and vascularization

BACKGROUND

Adenomatous hyperplasia of the peripheral lung has been suggested to be a preneoplastic lesion leading to peripherally localized lung carcinomas. The paucity of data about cellular and vascular characteristics of this lesion in comparison to normal lung prompted this investigation.

MATERIAL AND METHODS

We describe results of two investigations comprising 75 cases and 70 cases, respectively, with atypical adenomatous hyperplasia (AAH) of the lung, respectively: (a) a prospective study part with thorough analysis of surgical lung specimens (lobes and lungs) for light microscopical detection of the lesion; and (b) a retrospective study part with immuno- and lectin histochemical analysis of AAH and non-neoplastic lung parenchyma monitoring expression of growth-related markers and changes in vascularization patterns. Sections of the individual cases were examined by an image-analyzing system including automated measurement of staining intensities and structure analysis.

RESULTS

The prospective study part revealed an incidence of AAH in 2/31 cases with squamous cell carcinoma and in 5/32 cases with adenocarcinomas. No relation to pT- or pN stages was detectable, high grade AAHs were seen to be close to the tumor lesions (<2 cm distance) and those with low grade at greater distances. Statistically significantly increased levels of expression of anti-apoptotic bcl-2, macrophage migration inhibitory factor (MIF) capable to suppress p53 activities, heparin-binding lectin, interleukin-2, galectin-1 and of binding sites for the endogenous lectins galectins-1, -3 and -7 were determined. In addition, alveolar-lining cells, which express these markers, formed spatial clusters, which harbor different levels of structural entropy. AAH displayed an increased level of vascularization characterized by regular size and increased number of newly formed vessels.

INTERPRETATION

The prospective and retrospective study parts point to a close association of AAH with peripherally localized adenocarcinoma of the lung. AAH is characterized by pronounced alteration of expression of several growth-related markers and probably non-reversible changes in vascularization.