Galectin-3: a useful biomarker for differential diagnosis of brain tumors

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).

Fibroblasts Derived From Vestibular Schwannoma Express Protumorogenic Markers

BACKGROUND AND AIM

Vestibular schwannomas (VSs), despite being histologically benign, cause significant morbidity because of their challenging intracranial location and the propensity for growth. The role of the stroma and particularly fibroblasts, in the progression of VS, is not completely understood. This study examines the profile of fibroblasts in VS.

METHODS

Seventeen patients undergoing surgical excision of VS were recruited into the study. Reverse transcription with quantitative polymerase chain reaction (RT-qPCR) was performed on VS tissue samples and fibroblast-associated molecules examined. Immunofluorescence and immunohistochemistry in VS tissue were used to study the expression of fibroblast markers CD90 and podoplanin in situ. Fibroblast cultures were established from VS, and RT-qPCR analysis was performed on a panel of fibroblast markers on VS and control tissue fibroblasts.

RESULTS

Several fibroblast-associated molecules including members of galectin family and matrix metalloproteinases were found to be expressed in VS tissue on RT-qPCR analysis. In situ, expression of CD90 and podoplanin was observed in VS tissue both on immunohistochemistry and immunofluorescence. RT-qPCR analysis of fibroblasts from VS and control vestibular neuroepithelium (NE) showed a higher expression of several molecules of the galectin and matrix metalloproteinases family on VS fibroblasts compared with NE fibroblasts.

CONCLUSION

This work examines fibroblasts from VS and shows qualitative differences from NE fibroblasts on RT-qPCR. Further understanding of the fibroblast function in the progression of VS will potentially unveil new targets to manage VS growth.

Glycan-Lectin Interactions as Novel Immunosuppression Drivers in Glioblastoma

Despite diagnostic and therapeutic improvements, glioblastoma (GB) remains one of the most threatening brain tumor in adults, underlining the urgent need of new therapeutic targets. Lectins are glycan-binding proteins that regulate several biological processes through the recognition of specific sugar motifs. Lectins and their ligands are found on immune cells, endothelial cells and, also, tumor cells, pointing out a strong correlation among immunity, tumor microenvironment and vascularization. In GB, altered glycans and lectins contribute to tumor progression and immune evasion, shaping the tumor-immune landscape promoting immunosuppressive cell subsets, such as myeloid-derived suppressor cells (MDSCs) and M2-macrophages, and affecting immunoeffector populations, such as CD8⁺ T cells and dendritic cells (DCs). Here, we discuss the latest knowledge on the immune cells, immune related lectin receptors (C-type lectins, Siglecs, galectins) and changes in glycosylation that are involved in immunosuppressive mechanisms in GB, highlighting their interest as possible novel therapeutical targets.

Underestimated Prediabetic Biomarkers: Are We Blind to Their Strategy?

Type 2 Diabetes (T2D) is currently one of the fastest growing health challenging, a non-communicable disease result of the XXI century lifestyle. Given its growing incidence and prevalence, it became increasingly imperative to develop new technologies and implement new biomarkers for early diagnosis in order to promote lifestyle changes and thus cause a setback of the disease. Promising biomarkers have been identified as predictive of T2D development; however, none of them have yet been implemented in clinical practice routine. Moreover, many prediabetic biomarkers can also represent potential therapeutical targets in disease management. Previous studies have identified the most popular biomarkers, which are being thoroughly investigated. However, there are some biomarkers with promising preliminary results with limited associated studies; hence there is still much to be understood about its mechanisms and associations in T2D pathophysiology. This work identifies and discusses the promising results of Galectin-3, Ophthalmate and Fetuin-A.

Increased LGALS3 expression independently predicts shorter overall survival in patients with the proneural subtype of glioblastoma

In the current study, we tried to study the expression of LGALS3 and LGALS3BP, their potential as prognostic markers and the possible genetic/epigenetic mechanisms underlying their dysregulation in different subtypes of glioblastoma (GBM). An in silico retrospective study was performed using large online databases. Results showed that LGALS3 and LGALS3BP were upregulated at both RNA and protein levels in GBM tissue and were generally associated with shorter overall survival (OS) in GBM patients. However, in subgroup analysis, we only found the association in proneural subtype. The copy number alterations did not necessarily lead to LGALS3/LGALS3BP dysregulation. In the proneural subtype of GBM patients, hypermethylation of the two CpG sites (cg19099850 and cg17403875) was associated with significantly lower expression of LGALS3. In univariate and multivariate analysis, LGALS3 expression independently predicted shorter OS in the proneural subtype of GBM (HR: 1.487, 95% CI: 1.229‐1.798, P < 0.001), after adjustment of age, gender, IDH1 mutations, temozolomide chemotherapy, radiotherapy and LGALS3BP expression. In comparison, LGALS3BP lost the prognostic value in multivariate analysis. Based on these findings, we infer that LGALS3 expression serves as an independent biomarker of shorter OS in the proneural subtype of GBM, the expression of which might be regulated in an epigenetic manner.

Galectin-3 and cancer stemness

Over the last few decades galectin-3, a carbohydrate binding protein, with affinity for N-acetyllactosamine residues, has been unique due to the regulatory roles it performs in processes associated with tumor progression and metastasis such as cell proliferation, homotypic/heterotypic aggregation, dynamic cellular transformation, migration and invasion, survival and apoptosis. Structure-function association of galectin-3 reveals that it consists of a short amino terminal motif, which regulates its nuclear-cytoplasmic shuttling; a collagen α-like domain, susceptible to cleavage by matrix metalloproteases and prostate specific antigen; accountable for its oligomerization and lattice formation, and a carbohydrate-recognition/binding domain containing the anti-death motif of the Bcl2 protein family. This structural complexity permits galectin-3 to associate with numerous molecules utilizing protein-protein and/or protein-carbohydrate interactions in the extra-cellular as well as intracellular milieu and regulate diverse signaling pathways, a number of which appear directed towards epithelial-mesenchymal transition and cancer stemness. Self-renewal, differentiation, long-term culturing and drug-resistance potential characterize cancer stem cells (CSCs), a small cell subpopulation within the tumor that is thought to be accountable for heterogeneity, recurrence and metastasis of tumors. Despite the fact that association of galectin-3 to the tumor stemness phenomenon is still in its infancy, there is sufficient direct evidence of its regulatory roles in CSC-associated phenotypes and signaling pathways. In this review, we have highlighted the available data on galectin-3 regulated functions pertinent to cancer stemness and explored the opportunities of its exploitation as a CSC marker and a therapeutic target.

Evaluation of biologically active substances promoting the development of or protecting against endometrial cancer

Introduction

Adipose tissue is considered an endocrine organ and produces a number of biologically active substances.

Aims

To consider the role that four adipokines – leptin, omentin-1, vaspin, and galectin-3 – play in the diagnosis of endometrium cancer and to investigate the association between serum concentrations of adipose tissue metabolism products and the diagnostics and prognosis in endometrial cancer.

Patients and methods

The study included 168 patients with body mass index (BMI) >20 kg/m² admitted due to post-menopausal bleeding.

Results

A receiver operating characteristic curves test was performed to determine the diagnostic values of the proteins tested. For leptin and galectin-3 the area under the curve (AUC) values were 0.79/0.68, while for vaspin and omentin-1 the AUC values were 0.82/0.86 for all study patients. The final model identified the following independent risk factors: glucose concentration, BMI, waist circumference, leptin, and vaspin concentrations. Diagnostic values of leptin and galectin-3 with regard to differentiation between high (Fédération Internationale de Gynécologie Obstétrique [FIGO] III and IV) and low (FIGO I and II) stages of clinical tumor advancement and prediction of tumor grading (G1 vs G3) based on the AUC curve were 0.82/0.70 and 0.80/0.74. The AUC values for vaspin and omentin-1 with respect to differentiation between histopathological advancement and grading were 0.86/0.81 and 0.83/0.77, respectively. Significantly lower values of mean omentin-1 and vaspin concentrations were also demonstrated in cases of lymphatic vessel invasion, lymph node metastases, or deep endometrial infiltration (p=0.002, p=0.01, p=0.003, respectively).

Conclusion

It appears that elevated concentrations of leptin, vaspin, and omentin-1 may indicate the presence of endometrial cancer. Furthermore, leptin serum level and vaspin appear to be useful tools in the assessment of clinical staging of endometrial cancer.

The role of galectin-3 in the tumorigenesis and progression of pituitary tumors

Galectin-3 (Gal-3), a β-galactoside-binding protein, has been implicated in cell proliferation, cell adhesion, and the progression and metastasis of various types of cancer. The present study investigated the involvement of Gal-3 in the tumorigenesis and progression of pituitary tumors using three rat pituitary tumor cell lines. Following transfection with Gal-3 expression and interference vectors, the impact of Gal-3 on proliferation, apoptosis and migration of pituitary tumor cells was been investigated. Meanwhile, BCL2 associated X, apoptosis regulator (Bax), caspase-3 and matrix metalloproteinase 7 (MMP7) protein expression levels were analyzed by western blotting. The results of the present study revealed that Gal-3 expression in GH3 and GH4C1 cells was higher than in RC-4B/C cells. Furthermore, Gal-3 was demonstrated to promote the proliferation and migration of GH3 and GH4C1 cells, and inhibit cell apoptosis. Caspase-3 and MMP7 protein expression was also increased by Gal-3, while Bax expression was decreased. These results suggested that Gal-3 serves an important function in the tumorigenesis and development of pituitary tumors, and it may be a useful target for the treatment of pituitary tumors in the future.

Serum Anti-Gal-3 Autoantibody is a Predictive Marker of the Efficacy of Platinum-Based Chemotherapy against Pulmonary Adenocarcinoma

BACKGROUND

Identification of predictive markers for the efficacy of platinum-based chemotherapy is necessary to improve the quality of the life of cancer patients.

MATERIALS AND METHODS

We detected proteins recognized by autoantibodies in pretreated sera from patients with lung adenocarcinoma (AC) evaluated as showing progressive disease (PD) or a partial response (PR) after cisplatin-based chemotherapy by proteomic analysis. Then, the levels of the candidate autoantibodies in the pretreated serum were validated by dot-blot analysis for 22 AC patients who received platinum-based chemotherapy, and the expression of identified proteins was immunohistochemically analyzed in 40 AC biopsy specimens.

RESULTS

An autoantibody against galectin-3 (Gal-3) was detected in pretreated sera from an AC patient with PD. Serum IgG levels of anti-Gal-3 autoantibody were significantly higher in patients evaluated with PD than in those with PR and stable disease (SD) (p = 0.0084). Furthermore, pretreated biopsy specimens taken from patients evaluated as showing PD following platinum- based chemotherapy showed a tendency to have a higher positive rate of Gal-3 than those with PR and SD (p = 0.0601).

CONCLUSIONS

These results suggest that serum IgG levels of anti-Gal-3 autoantibody may be useful to predict the efficacy of platinum-based chemotherapy for patients with lung AC.

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.

Glioblastoma with oligodendroglial component represents a subgroup of glioblastoma with high prevalence of IDH1 mutation and association with younger age

Glioblastoma with an oligodendroglial component (GBMO) is recognized as a subgroup of glioblastoma (GBM); however, the molecular and clinicopathological characteristics of GBMO are obscure. We evaluated the methylation status of MGMT, IDH1/2 mutation, deletions of 1p and 19q and expression of IDH1, p53, p16, CD151, and galectin3 proteins in 42 GBMOs (32 primary and 10 secondary tumors). Our aims were to correlate our molecular findings with clinicopathologic features, and to compare molecular-to-clinical correlations in the 42 GBMOs with the corresponding correlations in 45 GBMs. GBMO was subdivided into two subgroups according to the predominant cell component comprising >50 % of tumors: the astrocytic predominant type (GBMO-A) and oligodendroglioma predominant type (GBMO-O). Methylation of MGMT, IDH1/2 mutation, and co-deletion of 1p and 19q were found in 31.0, 26.2, and 17.9 % of patients with GBMO, respectively. Clinicopathological and molecular characteristics did not differ significantly between GBMO-A and GBMO-O. However, patients with GBMO-O experienced better outcomes than patients with GBMO-A (p = 0.007). On multivariate analysis the predominant cell type was an independent prognostic factor in overall survival [hazard ratio 4.2 (95 % confidence interval 1.4-12.8), p = 0.011]. When compared to patients with classic GBM, those with GBMO were younger (49.21 vs. 57.47, p = 0.003) and more frequently had tumors with IDH1 mutation (23.8 vs. 4.4 %, p = 0.009). Survival was similar in patients with GBMO and with classic GBM. Based on these results, GBMO may represent a subgroup of GBM that is associated with IDH1 mutation and younger age, although similar to classic GBM in prognosis.

Oxygen/Glucose Deprivation and Reperfusion Cause Modifications of Postsynaptic Morphology and Activity in the CA3 Area of Organotypic Hippocampal Slice Cultures

Brain ischemia leads to overstimulation of N-methyl-D-aspartate (NMDA) receptors, referred as excitotoxicity, which mediates neuronal cell death. However, less attention has been paid to changes in synaptic activity and morphology that could have an important impact on cell function and survival following ischemic insult. In this study, we investigated the effects of reperfusion after oxygen/glucose deprivation (OGD) not only upon neuronal cell death, but also on ultrastructural and biochemical characteristics of postsynaptic density (PSD) protein, in the stratum lucidum of the CA3 area in organotypic hippocampal slice cultures. After OGD/reperfusion, neurons were found to be damaged; the organelles such as mitochondria, endoplasmic reticulum, dendrites, and synaptic terminals were swollen; and the PSD became thicker and irregular. Ethanolic phosphotungstic acid staining showed that the density of PSD was significantly decreased, and the thickness and length of the PSD were significantly increased in the OGD/reperfusion group compared to the control. The levels of PSD proteins, including PSD-95, NMDA receptor 1, NMDA receptor 2B, and calcium/calmodulin-dependent protein kinase II, were significantly decreased following OGD/reperfusion. These results suggest that OGD/reperfusion induces significant modifications to PSDs in the CA3 area of organotypic hippocampal slice cultures, both morphologically and biochemically, and this may contribute to neuronal cell death and synaptic dysfunction after OGD/reperfusion.

Differential expression of extracellular matrix-related genes in rare variants of meningioma

Secretory, clear cell, and rhabdoid meningiomas are rare variants of meningiomas characterized by unique histologies and behaviors. Extracellular matrix proteins provide a morphologic structure and influence the biologic behavior of tumors. However, the effects of extracellular matrix proteins on morphologies and biologic behaviors of secretory meningioma, clear cell meningioma, and rhabdoid meningioma have not been established. We evaluated the expression of matrix metalloproteinase 2, matrix metalloproteinase 9, galectin-3, fibronectin, and collagen IV in a series of those rare variants of meningioma and verified their clinicopathologic significance. A total 51 cases included 12 secretory meningiomas, 9 clear cell meningiomas, and 30 rhabdoid meningiomas. Extracellular matrix proteins showed different expression patterns according to the histologic subtypes, and messenger RNA levels were well correlated with immunoexpressions. Secretory meningiomas showed high expressions of fibronectin and galectin-3. Clear cell meningiomas showed high expression of matrix metalloproteinase 2, matrix metalloproteinase 9, and collagen IV. Rhabdoid meningiomas showed high expressions of matrix metalloproteinase 9, galectin-3, and fibronectin. Clinically, high expression of matrix metalloproteinase 9 was associated with tumor recurrence (P < .001) and local invasion at the time of diagnosis (P = .018) among the extracellular matrix-related proteins, and was also associated with shorter recurrence-free survival (P = .025) in the patients with rhabdoid meningioma. In conclusion, the differential expressions of extracellular matrix-related genes according to the histologic subtypes appear to be involved in biologic behavior and clinical outcome, and high matrix metalloproteinase 9 expression is associated with recurrences in rhabdoid meningiomas.

Achieving CNS axon regeneration by manipulating convergent neuro-immune signaling

After central nervous system (CNS) trauma, axons have a low capacity for regeneration. Regeneration failure is associated with a muted regenerative response of the neuron itself, combined with a growth-inhibitory and cytotoxic post-injury environment. After spinal cord injury (SCI), resident and infiltrating immune cells (especially microglia/macrophages) contribute significantly to the growth-refractory milieu near the lesion. By targeting both the regenerative potential of the axon and the cytotoxic phenotype of microglia/macrophages, we may be able to improve CNS repair after SCI. In this review, we discuss molecules shown to impact CNS repair by affecting both immune cells and neurons. Specifically, we provide examples of pattern recognition receptors, integrins, cytokines/chemokines, nuclear receptors and galectins that could improve CNS repair. In many cases, signaling by these molecules is complex and may have contradictory effects on recovery depending on the cell types involved or the model studied. Despite this caveat, deciphering convergent signaling pathways on immune cells (which affect axon growth indirectly) and neurons (direct effects on axon growth) could improve repair and recovery after SCI. Future studies must continue to consider how regenerative therapies targeting neurons impact other cells in the pathological CNS. By identifying molecules that simultaneously improve axon regenerative capacity and drive the protective, growth-promoting phenotype of immune cells, we may discover SCI therapies that act synergistically to improve CNS repair and functional recovery.

Galectin-3 expression: a useful tool in the differential diagnosis of posterior fossa tumors in children

OBJECTIVE

Galectin-3 (Gal-3) is a glycan-binding protein highly expressed in several tumors, including brain neoplasms. This protein has been demonstrated to be correlated with adverse prognosis in some tumor types. However, the role of Gal-3 in pediatric posterior fossa tumors (PPFTs) has not yet been fully addressed. The goals of this study were to evaluate Gal-3 expression in a series of PPFTs and verify whether this expression is related to patient outcome.

MATERIAL AND METHODS

Gal-3 expression was analyzed by immunohistochemistry in 42 cases of surgically resected primary PPFTs. Surgeries were performed in our institution from January 2003 to December 2006. Tumor samples consisted of 21 pilocytic astrocytomas (PAs), 13 medulloblastomas, 4 ependymomas, 2 diffuse cerebellar astrocytomas, and 2 atypical teratoid/rhabdoid tumors (AT/RTs).

RESULTS

All PAs and ependymomas strongly showed Gal-3 expression, whereas no immunostaining was observed in medulloblastomas and diffuse astrocytomas. In AT/RTs, Gal-3 expression was conspicuous but heterogeneous, being mainly observed in rhabdoid cells. Concerning the Gal-3 expressing tumors, no relationship was observed between the degree of expression and patient survival. Gal-3 was strongly expressed in reactive astrocytes, normal endothelial cells, and macrophages in the adjacent non-neoplastic brain parenchyma. Interestingly, the endothelial cells in the tumor bulk of PAs lacked Gal-3 expression.

CONCLUSIONS

Gal-3 is differentially expressed in PPFTs, but its expression shows no correlation with patient outcome. However, the evaluation of Gal-3 is helpful in establishing a differential diagnosis among PPFTs, especially between PAs and diffuse astrocytomas, and in some circumstances between medulloblastomas and AT/RTs.

Galectin-3 exerts cytokine-like regulatory actions through the JAK-STAT pathway

Galectin-3, a β-galactoside-binding lectin, has been proposed to have multifaceted functions in various pathophysiological conditions. However, the characteristics of galectin-3 and its molecular mechanisms of action are still largely unknown. In this study, we show that galectin-3 exerts cytokine-like regulatory actions in rat and mouse brain-resident immune cells. Both the expression of galectin-3 and its secretion into the extracellular compartment were significantly enhanced in glia under IFN-γ-stimulated, inflamed conditions. After exposure to galectin-3, glial cells produced high levels of proinflammatory mediators and exhibited activated properties. Notably, within minutes after exposure to galectin-3, JAK2 and STAT1, STAT3, and STAT5 showed considerable enhancement of tyrosine phosphorylation; thereafter, downstream events of STAT signaling were also significantly enhanced. Treatment of the cells with pharmacological inhibitors of JAK2 reduced the galectin-3-stimulated increases of inflammatory mediators. Using IFN-γ receptor 1-deficient mice, we further found that IFN-γR 1 might be required for galectin-3-dependent activation of the JAK-STAT cascade. However, galectin-3 significantly induced phosphorylation of STATs in glial cells from IFN-γ-deficient mice, suggesting that IFN-γ does not mediate activation of STATs. Collectively, our findings suggest that galectin-3 acts as an endogenous danger signaling molecule under pathological conditions in the brain, providing a potential explanation for the molecular basis of galectin-3-associated pathological events.

Galectin-3 is a candidate biomarker for amyotrophic lateral sclerosis: discovery by a proteomics approach

The discovery of biomarkers for neurodegenerative diseases will have a major impact on the efficiency of therapeutic clinical trials and may be important for understanding basic pathogenic mechanisms. We have approached the discovery of protein biomarkers for amyotrophic lateral sclerosis (ALS) by profiling affected tissues in a relevant animal model and then validating the findings in human tissues. Ventral roots from SOD1(G93A) "ALS" mice were analyzed by label-free quantitative mass spectrometry, and the resulting data were compared with data for matched samples from nontransgenic littermates and transgenic mice carrying wild-type human SOD1 (SOD1(WT)). Of 1299 proteins, statistical inference of the data in the three groups identified 14 proteins that were dramatically altered in the ALS mice compared with the two control groups. The protein galectin-3 emerged as a lead biomarker candidate on the basis of its differential expression as assessed by immunoblot and immunocytochemistry in SOD1(G93A) mice as compared to controls and because it is a secreted protein that could potentially be measured in human biofluids. Spinal cord tissue from ALS patients also exhibited increased levels of galectin-3 when compared to controls. Further measurement of galectin-3 in cerebrospinal fluid samples showed that ALS patients had approximately twice as much galectin-3 as normal and disease controls. These results provide the proof of principle that biomarker identification in relevant and well-controlled animal models can be translated to human disease. The challenge is to validate our biomarker candidate proteins as true biomarkers for ALS that will be useful for diagnosis and/or monitoring disease activity in future clinical trials.

Brain sweet brain: importance of sugars for the cerebral microenvironment and tumor development

The extracellular matrix (ECM) in the brain tissue is a complex network of glycoproteins and proteoglycans that fills the intercellular space serving as scaffolding to provide structural framework for the tissue and regulate the behavior of cells via specific receptors - integrins. There is enormous structural diversity among proteoglycans due to variation in the core protein, the number of glycosaminoglycans chains, the extent and position of sulfation. The lectican family of proteoglycans interacts with growth factors, hyaluronan and tenascin forming a complex structure that regulates neuronal plasticity and ion homeostasis around highly active neurons. In this review, we will discuss the latest insights into the roles of brain glycoproteins as modulators of cell adhesion, migration, neurite outgrowth and glial tumor invasion.

Galectins as cancer biomarkers

Galectins are a group of proteins that bind β-galactosides through evolutionarily conserved sequence elements of the carbohydrate recognition domain (CRD). Proteins similar to galectins can be found in very primitive animals such as sponges. Each galectin has an individual carbohydrate binding preference and can be found in cytoplasm as well as in the nucleus. They also can be secreted through non-classical pathways and function extracellularly. Experimental and clinical data demonstrate a correlation between galectin expression and tumor progression and metastasis, and therefore, galectins have the potential to serve as reliable tumor markers. In this review, we describe the expression and role of galectins in different cancers and their clinical applications for diagnostic use.

In pursuit of prognostic factors in children with pilocytic astrocytomas

OBJECTIVE

This study described a 23-year experience in the treatment of children with pilocytic astrocytomas (piloA) with the aim of identifying putative clinical, histopathological, and/or immunohistochemical features that could be related to the outcome of these patients.

METHODS

Clinical data of 31 patients under 18 years of age with piloA were obtained from 1984 to 2006.

RESULTS

The mean age at the time of surgery was 7.8 +/- 4.2 years (1 to 17 years), and the mean follow-up was 5.7 +/- 5.4 years (1 to 20 years). The most common site of tumor formation was the cerebellum (17), followed by brainstem (4), optic chiasmatic hypothalamic region (4), cerebral hemisphere (3), cervical spinal cord (2), and optic nerve (1). Gross total resection (GTR) was achieved in 23 (74.1%), mainly in those with tumors located in the cerebellum and cerebral hemispheres (P = 0.02). The global mortality rate was 6.4%. Nine patients were reoperated. Rosenthal fibers, eosinophilic granular bodies, microvascular proliferation, and lymphocytic infiltration were observed in most cases. The mean Ki-67LI was 4.4 +/- 4.5%. In all cases, Gal-3 expression in tumor cells was observed with variable staining pattern.

CONCLUSIONS

Aside from GTR, no other clinical, histopathological, or immunohistochemical features were found to be related to the prognosis. We postulate that strict follow-up is recommended if piloA is associated with high mitotic activity/Ki67-LI, or if GTR cannot be achieved at surgery. Tumor recurrence or progression of the residual lesion should be strictly observed. In some aspects, childhood piloA remains an enigmatic tumor.