The relevance of miRNAs as promising biomarkers in lip cancer.

OBJECTIVES: This study aimed to analyze the expression of miR-181b, miR-21, miR-31, and miR-345 in actinic cheilitis with and without epithelial dysplasia and lower lip squamous cell carcinomas, and to verify if the deregulated expression of these miRNAs would be indicative of malignant transformation. MATERIALS AND METHODS: The sample was selected from formalin-fixed paraffin-embedded tissues of 19 actinic cheilitis without epithelial dysplasia, 32 actinic cheilitis with epithelial dysplasia, 42 lower lip squamous cell carcinomas, and 10 nonaltered oral mucosa of the lip. The microRNA (miR, miRNA) expression was quantified by real-time RT-PCR and the expression of the selected miRNAs among the groups of actinic cheilitis and lower lip cancer was compared by chi-square. RESULTS: A higher expression of miR-181b, miR-31, and miR-345 was found in actinic cheilitis without epithelial dysplasia in comparison to that in actinic cheilitis with epithelial dysplasia and with lower lip cancer. There were no differences in miR-21 expression between actinic cheilitis and lower lip cancer. Hierarchical clustering analysis showed a tendency for a downregulation of miR-181b, miR-21, miR-31, and miR-345 in most patients with lower lip cancers. CONCLUSIONS: The upregulation of miR-181b, miR-31, and miR-345 expression in actinic cheilitis without epithelial dysplasia and the decrease in the expression of these miRNAs in actinic cheilitis with epithelial dysplasia and in lower lip cancer are potential biomarkers of malignant progression. CLINICAL RELEVANCE: This miRNA signature can help to identify actinic cheilitis with potential to progress to lip cancer.

Osseous Flap of Galea and Periosteum Filled With Mesenchymal Stem Cells, Platelet-Rich Plasma, Bone Dust, and Hyaluronic Acid.

Reconstructive surgery to craniofacial deformities caused by tumor ressections, traumas or congenital malformation are frequent in medicine practice. It aims to provide the patients with better quality of life and functional improvement of speech, breathing, chewing, and swallowing. Many are the techniques described in the literature to recover bone defects. This study evaluated a vascularized galeal and periosteum flap in rabbits, which could possibly substitute the bone graft in reconstructive surgery, especially for facial defects. It involved rabbits, divided into 12 groups, submitted to a surgical procedure to construct the galea and periosteum cranial flap filled with fragments of cranial bone, platelet-rich plasma, mesenchimal stem cells, and hyaluronic acid. The evaluation methods included image examinations and histological analysis.The results demonstrated bone formation with the use of platelet-rich plasma, mesenchimal stem cells, and bone fragments. The use of several enrichment materials of osseous cellular stimulation improved the quality and bone tissue organization. The more enrichment factor used, the better the tissue quality result was.Much research should be done to improve the methods and to analyze if results in human have the same bone formation as it happened in rabbits.

Loss of cytokeratin 10 indicates malignant transformation in actinic cheilitis.

OBJECTIVES: The aim of this study was to investigate the relationship the expression of cytokeratins (CK10 and CK13) and the cell proliferation index determined by Ki-67 of lip squamous cell carcinoma and actinic cheilitis with different degrees of dysplasia. MATERIALS AND METHODS: Forty-five paraffin-embedded actinic cheilitis with and without dysplasia and 20 lip squamous cell carcinoma were analyzed by immunohistochemistry using anti-human anti-CK10, anti-CK13, and anti-Ki-67 antibodies. RESULTS: The majority of actinic cheilitis showed immunopositivity for CK10 and CK13 with decrease or loss of expression in dysplastic areas. In lip squamous cell carcinoma of the lip, heterogeneous expression of CK13 and immunonegativity for CK10 were observed. There was a statistically significant difference between CK10 expression in lip squamous cell carcinoma and in actinic cheilitis with or without dysplasia (p < 0.001). The cell proliferation index was higher in actinic cheilitis with dysplasia and lip squamous cell carcinoma than in actinic cheilitis without epithelial dysplasia. A significant correlation was found between the intensity of the epithelial dysplasia and the cell proliferation index (p < 0.001). CONCLUSION: These results provide evidence that there is a downregulation of CK10 expression in dysplastic areas of patients with actinic cheilitis and in those with lip squamous cell carcinoma (LSCC) and that the index of cell proliferation, determined by Ki-67, is directly correlated with the intensity of the epithelial dysplasia. CLINICAL RELEVANCE: Altogether, these results suggest that CK10 expression and the epithelial cell proliferation index can help to identify malignant transformation in the lip region.

Paracoccidioidomycosis in patients with lymphoma and review of published literature.

This paper describes four new cases of lymphomas, two Hodgkin lymphomas and two non-Hodgkin lymphomas in patients with paracoccidioidomycosis. All had mycosis diagnosed before lymphomas with Paracoccidioides brasiliensis demonstrated in several lymph nodes, as seen in the disseminated form of the disease. When lymphoma was diagnosed, one patient was under regular paracoccidioidomycosis treatment and in clinic-serological remission for this disease, another was under regular treatment but with clinic-serological mycosis activity, one had abandoned paracoccidioidomycosis treatment 6 years earlier, and the other had not yet received any kind of antifungal drugs. Three patients received treatment for lymphomas with one remaining in remission until now, one achieving tumor remission which relapsed years later, and one having only residual lymphoma in bone marrow for a decade but clinically well. All three experienced paracoccidioidomycosis clinical remission, however, serology became negative just in one. Similar previously described cases were reviewed: five Hodgkin lymphomas, three non-Hodgkin lymphomas, and one described only as "lymphoma" without specifying type; a summary of their findings is presented. Finally, there is also a brief discussion on the possible pathophysiological mechanisms involved in the concomitance of these two disorders.

Tissue-engineered blood vessel substitute by reconstruction of endothelium using mesenchymal stem cells induced by platelet growth factors.

BACKGROUND: Cardiovascular diseases remain leaders as the major causes of mortality in Western society. Restoration of the circulation through construction of bypass surgical treatment is regarded as the gold standard treatment of peripheral vascular diseases, and grafts are necessary for this purpose. The great saphenous vein is often not available and synthetic grafts have their limitations. Therefore, new techniques to produce alternative grafts have been developed and, in this sense, tissue engineering is a promising alternative to provide biocompatible grafts. This study objective was to reconstruct the endothelium layer of decellularized vein scaffolds, using mesenchymal stem cells (MSCs) and growth factors obtained from platelets. METHODS: Fifteen nonpregnant female adult rabbits were used for all experiments. Adipose tissue and vena cava were obtained and subjected to MSCs isolation and tissue decellularization, respectively. MSCs were subjected to differentiation using endothelial inductor growth factor (EIGF) obtained from human platelet lysates. Immunofluorescence, histological and immunohistochemical analyses were employed for the final characterization of the obtained blood vessel substitute. RESULTS: The scaffolds were successfully decellularized with sodium dodecyl sulfate. MSCs actively adhered at the scaffolds, and through stimulation with EIGF were differentiated into functional endothelial cells, secreting significantly higher quantities of von Willebrand factor (0.85 µg/mL; P < .05) than cells cultivated under the same conditions, without EIGF (0.085 µg/mL). Cells with evident morphologic characteristics of endothelium were seen at the lumen of the scaffolds. These cells also stained positive for fascin protein, which is highly expressed by differentiated endothelial cells. CONCLUSIONS: Taken together, the use of decellularized bioscaffold and subcutaneous MSCs seems to be a potential approach to obtain bioengineered blood vessels, in the presence of EIGF supplementation.

Association of insulin-like growth factor II mrna-binding protein 3 (IMP3) expression with prognostic and morphological factors in endometrial cancer.

Objective: Endometrial cancer (EC) is a heterogeneous disease with recurrence rates ranging from 15 to 20%. The discrimination of cases with a worse prognosis aims, in part, to reduce the length of surgical staging in cases with a better prognosis. This study aimed to evaluate the association between Insulin-like growth factor II mRNA-binding protein 3 (IMP3) expression and prognostic and morphological factors in EC. Methods: This retrospective, cross-sectional, analytical study included 79 EC patients - 70 endometrioid carcinoma (EEC) and 9 serous carcinoma (SC) - and 74 benign endometrium controls. IMP3 expression was evaluated by immunohistochemistry-based TMA (Tissue Microarray), and the results were associated with morphological and prognostic factors, including claudins 3 and 4, estrogen and progesterone receptors, TP53, and KI67. Results: IMP3 expression was significantly higher in SC compared to EEC in both extent (p<0.001) and intensity (p=0.044). It was also significantly associated with worse prognostic factors, including degree of differentiation (p=0.024, p<0.001), staging (p<0.001; p<0.001) and metastasis (p=0.002; p<0.001). IMP3 expression was also significant in extent (p=0.002) in endometrial tumors compared with controls. In addition, protein TP53 and KI67 showed significant associations in extent and intensity, respectively. Conclusion: IMP3 expression was associated with worse prognostic factors studied. These findings suggest that IMP3 may be a potential biomarker for EC poorer prognosis.

Chromosomal imbalances exclusively detected in invasive front area are associated with poor outcome in laryngeal carcinomas from different anatomical sites.

Laryngeal squamous cell carcinoma (LSCC) is a malignant neoplasm exhibiting aggressive phenotype, high recurrence rate, and risk of developing second primary tumors. Current evidence suggests that cells in the invasive front of carcinomas have different molecular profiles compared to those in superficial areas. This study aimed to identify candidate genes in the invasive front and superficial cells from laryngeal carcinomas that would be useful as molecular markers. Invasive front and tumor surface cells of 32 LSCC were evaluated by high-resolution comparative genomic hybridization. Both CCND1 copy number gains and cyclin D1 protein expression were evaluated to confirm gains of 11q13.3. Losses of 3q26.2-q29 and 18q23 were confirmed by loss of heterozygosity analysis. The most frequent chromosomal alterations observed only in invasive front cells involved gains of 1p, 4q, and 9p and losses of 3p, 11p, 12p, 13q, 17q, 18p, 19q, 20q, 21q, and Xp. Gains of 11q13 were detected in both components from glottis and supraglottis but only in invasive front cells from transglottic tumors. Fluorescence in situ hybridization confirmed gains of CCND1/CPE11 in a subset of cases. In supraglottic tumors, cyclin D1 positivity was associated with distant metastasis (P = 0.0018) and with decreased disease-free survival (P = 0.042). Loss of heterozygosity at 3q26.2 and 18q23 were associated with lymph node involvement (P = 0.055) and worsened prognosis, respectively. In conclusion, this study revealed regions that could be targeted in the search for molecular markers in LSCC. Cyclin D1 may be useful as a prognostic marker in supraglottic tumors.

Comparative study of the behavior of p53 immunoexpression in smoking associated lesions: Reinke's edema and laryngeal carcinoma.

OBJECTIVE: To assess the behavior of the immunoexpression of protein p53 in Reinke's edema and laryngeal squamous cell carcinoma. STUDY DESIGN: retrospective. METHODS: we recovered the histological paraffin blocks of patients who were subjected to Reinke's edema and laryngeal squamous cell carcinoma surgery in 2000-2011. The paraffin blocks were cut into 3-µm sections; the specimens were prepared in silanized slides (one slide for each paraffin block) and subjected to immunohistochemical reaction according to the Avidin Biotin Peroxidase method. Monoclonal primary anti-p53 antibodies were used at 1:50 dilution. Slides were examined under a light microscope at different magnitudes and results were interpreted based on the degree of brown staining in the nuclei of epithelial cells and in the extent of the fragment by using a semi-quantitative score from 0 to 3. RESULTS: 67 slides of Reinke's edema and 60 slides of laryngeal squamous cell carcinoma were included. Scores 2 and 3 for staining of the nuclei of epithelial cells were recorded for 46 slides of Reinke's edema (68.65%) and for 57 slides of laryngeal squamous cell carcinoma (95%). As to the extent of the fragment, scores 2 and 3 were recorded for 74% slides of Reinke's edema and for 95% slides of carcinomas. CONCLUSION: the positive immunoexpression for protein p53, positive in 95% carcinomas and 74% Reinke's edemas, makes us aware of the possible preneoplastic condition of the latter lesion. Further studies are needed to identify and reveal the genetic changes that lead to these results.

Master Regulators of Epithelial-Mesenchymal Transition and WNT Signaling Pathways in Juvenile Nasopharyngeal Angiofibromas.

Juvenile nasopharyngeal angiofibroma (JNA) is a rare fibrovascular benign tumor showing an invasive growth pattern and affecting mainly male adolescents. We investigated the role of epithelial-mesenchymal transition (EMT) and WNT signaling pathways in JNA. Gene expression profiles using nine JNA paired with four inferior nasal turbinate samples were interrogated using a customized 2.3K microarray platform containing genes mainly involved in EMT and WNT/PI3K pathways. The expression of selected genes (BCL2, CAV1, CD74, COL4A2, FZD7, ING1, LAMB1, and RAC2) and proteins (BCL2, CAV1, CD74, FZD7, RAF1, WNT5A, and WNT5B) was investigated by RT-qPCR (28 cases) and immunohistochemistry (40 cases), respectively. Among 104 differentially expressed genes, we found a significantly increased expression of COL4A2 and LAMB1 and a decreased expression of BCL2 and RAC2 by RT-qPCR. The immunohistochemistry analysis revealed a low expression of BCL2 and a negative to moderate expression of FZD7 in most samples, while increased CAV1 and RAF1 expression were detected. Moderate to strong CD74 protein expression was observed in endothelial and inflammatory cells. A significant number of JNAs (78%) presented reduced WNT5A and increased WNT5B expression. Overall, the transcript and protein profile indicated the involvement of EMT and WNT pathways in JNA. These candidates are promising druggable targets for treating JNA.

p53 and p21 expression in bone marrow clots of megaloblastic anemia patients.

The pathogenesis of megaloblastic hemopathies (MH) is centered on the deficiency of vitamin B12 and folic acid with interruption of erythrocyte maturation. This study researched the participation of p53 and p21 in the pathophysiology of the disease. A retrospective study enrolled 95 patients with histopathologic diagnosis by biopsy or bone marrow clot (BMB/BMC), with clinical review and immunohistochemical study in tissue microarray (TMA) for p53 and p21, detailing their marking location. All patients had BMC and only 11 had BMB. The CMO was a differential of this study and it allowed an expanded sample. In the TMA, 63.7% (58/91) of the samples were immunopositive for p53; and 35.2% (31/88) were immunopositive for p21. Nuclear staining, divergent from the literature, was observed in 17.3% (10/58) among those p53+ and in 38.7% (12/31) among those p21+. The pattern of immunostaining showed non-significant differences (P=0.474) regarding morphologic and clinical aspects. The positivity for both may indicate an effective balance between apoptosis and anti-apoptotic action. Excessive inhibition of apoptosis would contribute to high global cellularity, but without functional maturation effectiveness. In conclusion, there is p21 and/or p53 immunoexpression in most cases of this study and there is no clear association between immunoexpression pattern and patient outcome. Unlike the literature, we also found a percentage of nuclear immunostaining, but the finding was not statistically significant. Combination of p21 and p53 results created different possibilities of pathologic interpretation for MH, reinforcing the importance of studies similar to this one.

Increased DSG2 plasmatic levels identified by transcriptomic-based secretome analysis is a potential prognostic biomarker in laryngeal carcinoma.

OBJECTIVES: The tumor secretome deconvolution is a promising strategy to identify diagnostic and prognostic biomarkers. Here, transcriptomic-based secretome analysis was performed aiming to discover laryngeal squamous cell carcinomas (LSCC) biomarkers from potentially secreted proteins (PSPs). MATERIAL AND METHODS: The tumor expression profile (35 LSCC biopsies compared with surrounding normal tissues - SN) revealed 589 overexpressed genes. This gene list was used for secretome analysis based on laryngeal tumors and related secretome databases. RESULTS: Forty-nine (Laryngeal tumor secretome database) and 50 (Human Protein Atlas and Cancer Secretome Database) PSPs presented an association with worse overall survival. Specifically, DSG2 overexpression was strongly correlated with poor survival and distant metastasis. DSG2 increased expression was confirmed in the LSCC dataset (LSCC = 111; SN = 12) from TCGA. A significant association between shorter survival and DSG2 overexpression was also detected. In an independent cohort of cases, we analyzed and confirmed high protein levels of DSG2 in plasma from LSCC patients. CONCLUSION: A set of PSPs including the circulating DSG2, were associated with shorter overall survival in LSCC. DSG2 overexpression was also correlated with distant metastasis. The high plasmatic protein levels of DSG2 suggest its potential to be tested in liquid biopsies and applied as prognostic biomarker of LSCC.

Effects of cyclosporine on ischemia-reperfusion injuries in rat kidneys. An experimental model.

PURPOSE: To assess Cyclosporine A (CsA) therapy at an intraperitoneal dose of 15 mg.kg -1 in a rodent model of non-septic renal ischemia. METHODS: Twenty male Wistar rats were randomized to receive CsA therapy or none therapy before undergoing 30 minutes of renal ischemia followed by reperfusion. Additionally, 10 rats were randomized to undergo the same surgical procedure of the aforementioned animals with neither ischemia nor CsA therapy. Twelve hours after kidney ischemia, the left kidneys were evaluated for histological injury according to Park's criteria. Serum creatinine (Cr), urea nitrogen (Ur) and sodium levels were obtained at different times of the experimental protocol. RESULTS: Rodents in the CsA group showed negative results (p<0.05) in serum variables (Cr: 0.41±0.05mg/dL vs . 4.17±1.25mg/dL; Ur: 40.90±3.98mg/dL vs . 187.70±22.93mg/dL) even the non CsA or control group (Cr: 0.35±0.07mg/dL vs . 3.80±1.20mg/dL; Ur: 40.10±4.70mg/dL vs . 184.50±49.80mg/dL). The negative results were also verified in histological evaluation, CsA group had 50% in the very severe grade of lesion, 10% in the severe and 40% in the moderate to severe whereas the control group had 90% in the very severe grade. CONCLUSION: CsA was incapable of preventing the deleterious effects of ischemia-reperfusion injury in rat kidneys.

Integrated miRNA and mRNA expression analysis uncovers drug targets in laryngeal squamous cell carcinoma patients.

OBJECTIVES: The current treatment of laryngeal squamous cell carcinoma (LSCC) is based on radical surgery and radiotherapy resulting in high morbidity. Chemoradiotherapy has been used as alternative to organ sparing; however, several advanced cases presented resistance to treatment, which contributes to a high risk of recurrence and mortality. Coding RNAs and miRNAs have potential to be used as biomarkers or targets for cancer therapy. MATERIALS AND METHODS: In this study, 36 LSCC and 5 non-neoplastic control samples were investigated using miRNA and mRNA large-scale expression analysis and a cross-validation was performed using the TCGA database (116 LSCC and 12 surrounding normal tissues). RESULTS: The large-scale profiling revealed the involvement of 28 miRNAs and 817 genes differentially expressed in LSCC. An integrative analysis comprising predicted and experimentally validated miRNA/mRNA interactions (negatively correlated), resulted in 28 miRNAs and 543 mRNAs. Decreased expression of miR-199b was significantly associated with shorter disease-free survival in LSCC (internal and TCGA datasets). The expression levels of selected miRNAs (miR-199b-5p, miR-29c-3p, miR-204-5p, miR-125b-5p and miR-92a-3p) and genes (COL3A1, COL10A1, ERBB4, HMGA2, HLF, TOP2A, MMP3, MMP13, MMP10 and PPP1R3) were confirmed as altered in LSCC by RT-qPCR. Additionally, a drug target prediction analysis revealed drug combinations based on miRNA and mRNA expression, pointing out novel alternatives to optimize the LSCC treatment. CONCLUSION: Collectively, these findings provide new insights in the LSCC transcriptional deregulation and potential drug targets.

Is there a role for fibronectin upon true histiocytic lymphoma progression?

Cell interaction with extracellular matrix is a crucial event for various biological processes, including tumor progression. Although not exclusively, these interactions are frequently mediated by bidirectional signaling receptors known as integrins. Using a human histiocytic lymphoma-derived cell line (U-937), we evaluated the effects of ECM proteins and their integrin-type receptors in the regulation of cell attachment, proliferation, migration and survival. Fibronectin induces higher cell attachment in vitro when compared to laminin. Fibronectin also promotes a decrease in cell migration but do not modulate cell proliferation and death. Pre-incubation of U-937 cells with VLA-5 antagonistic peptides inhibited attachment of the cells to fibronectin-coated substrates. In a second vein, we observed that lymph node specimens obtained from diagnosed patient for true histiocytic lymphoma had greater deposition of fibronectin (but not laminin) around malignant clones. These results suggest that fibronectins play a relevant role in the establishment and progression of true histiocytic lymphoma cells.

Autopsy Patients With Obesity or Metabolic Syndrome as Basic Cause of Death: Are There Pathological Differences Between These Groups?

BACKGROUND: The objectives of this study were the evaluation of pathological characteristics of patients with obesity or metabolic syndrome (MS) as basic cause of death, associating the autopsy findings with some clinical aspects and the abdominal adipose panicle thickness. METHODS: A total of 88 autopsy cases were studied, divided into 2 groups based on the main cause of death: group 1 (n = 15) obesity and group 2 (n = 73) MS. Clinical summaries of autopsy requests, macroscopic findings, and histologic sections were reviewed. RESULTS: The definition of obesity as the basic cause of death is associated with larger thickness of the abdominal adipose panicle, being 8.5 cm (P = .001) the best measurement, according to the receiver operating characteristic curve. Hypertensive cardiopathy (P = .001), ischemic cardiopathy (P = .003), coronary (P = .008)/systemic (P = .005) atherosclerosis, and arterial (P = .014)/arteriolar (P = .027) nephrosclerosis are associated with the diagnosis of MS. Steatohepatitis is associated with the diagnosis of obesity (P = .030); however, its association with the thickness of the abdominal adipose panicle is not statistically significant (P = .211). CONCLUSIONS: In the context of an obese patient in autopsy, pathologist may use the information about abdominal adipose panicle associated with heart, kidney, and liver findings, even macroscopic ones, to decide the basic cause death between obesity and MS.

Fas-ligand and caspase-3 positivity in three cases of histiocytic sarcoma: a different etiopathogenic pathway?

Histiocytic sarcoma (HS) is a rare malignant neoplasia of hematopoietic origin and unknown etiology. We studied three patients with histiocytic sarcoma reviewing the morphological and immunohistochemical aspects. We evaluated in particular, if apoptosis may be unbalanced in this disease. All cases have morphological and immunohistochemical features consistent with the diagnosis of histiocytic sarcoma. The markers CD163, CD68, vimentin, lysozyme, and S-100 were positive in all cases. Similarly, the three samples were positive for Fas-ligand and Caspase-3. It is well-known that neoplasms may induce increased levels of Fas-ligand with the blockade of the apoptosis process. In the context of HS, the increased Fas-ligand expression represents a new area for research. Indeed, it is linked to proinflammatory stimulus and, maybe with the association of an infection.

Concomitant p53 and PTEN immunoexpression to predict the risk of malignancy in endometrial polyps.

The aim of this retrospective cross-sectional study was to assess the usefulness of phosphase and tensin homolog deleted on chromosome 10 (PTEN) and p53 protein immunoexpression in predicting the risk of malignancy in endometrial polyps. The study was conducted at tertiary public hospital, university teaching center, and private practice clinic.A total of 159 patients with endometrial polyps who underwent hysteroscopic polypectomy between January 2010 to December 2014 were included. p53 and PTEN immunoexpression were assessed in histologic endometrial polyp samples. Patients were allocated into 2 groups: group A, endometrial polyps without atypia (120), and group B, endometrial polyps with atypia (39), which were subdivided into A1 (80) and B1 (21) = p53-/PTEN+ immunostaining; A2 (20) and B2 (11) = p53+/PTEN+; A3 (14) and B3 (4) = p53+/PTEN-; A4 (6) and B4 (3) = p53-/PTEN-.There was no significant difference between groups regarding clinical and epidemiologic parameters, except for age. Neoplasia incidence within groups was higher when at least 1 marker was abnormally stained (in group A, P = .0089, odds ratio [OR] = 13.94 [1.62; 120.27]; in group B, P = .0255, OR 12.73 [1.38; 117.27]). Overall neoplasia incidence was higher in group B than in group A (20.5% vs 5.8%; P = .0113). Malignant neoplasia was found more frequently in patients with p53+ (P = .0006, OR = 7.67 [2.30; 25.54]) and PTEN- (P = .0043; OR = 5.43 [1.77; 16.61]).Immunohistochemical analysis using p53 and PTEN as markers, either alone or concomitantly, can be useful to predict malignant transformation in cases of endometrial polyps.

Immunohistochemical expression of hormone receptors, Ki-67, endoglin (CD105), claudins 3 and 4, MMP-2 and -9 in endometrial polyps and endometrial cancer type I.

OBJECTIVE: The aim of this study was to investigate the malignant potential of endometrial polyps (EP) by assessing the immunoexpressions of both estrogen receptor (ER) and progesterone receptor (PR), Ki-67 cell proliferation index, neovascularization network (endoglin - CD105), cellular adhesion molecules (claudins 3 and 4), and extracellular matrix proteins (MMP-2 and -9) in both EP and endometrioid adenocarcinoma (type I) in comparison with the normal endometrium. STUDY DESIGN: This is a cross-sectional comparative study. Patients were identified from the database of Botucatu Medical School, São Paulo State University (BMS-UNESP) Clinical Pathology Laboratory. SETTING: The study was conducted using a convenience sample of patients attending the Sectors of Gynecologic Endoscopy and Family Planning and Gynecologic Oncology of the Department of Gynecology and Obstetrics of BMS-UNESP, Brazil. PATIENTS: A total of 90 women were allocated into the following three groups: EP without atypia (EP, n=30), endometrioid endometrial cancer (EC, n=30), and normal endometrium (control, n=30). METHODS: Epidemiological and clinical data were obtained by reviewing medical records. Adenocarcinoma and control cases were assessed using the tissue microarray technique. The immunoexpressions of ER, PR, Ki-67, CD105, claudins 3 and 4, and MMP-2 and -9 were assessed in paraffin blocks containing sections of the largest polyploid lesion fragment and tissue microarray recipient blocks. MAJOR RESULTS: Compared to the control group, significant differences in the expression of ER (P<0.001), PR (P<0.05), Ki-67 (P<0.001), CD105 (P<0.001), and claudin 3 (P<0.001) were observed in EP and EC. No significant differences were found between EP and EC (P≥0.05). MMP-2 and -9 expression were nearly absent in all groups. CONCLUSION: The malignant potential of EP could not be determined through the immunohistochemical parameters used in this study. No MMP-2 or -9 expression was observed in any endometrial tissue sample. Further studies are necessary for a better understanding of the biomolecular mechanisms underlying endometrial carcinogenesis.