Rafael Malagoli Rocha

Pericyte Depletion Results in Hypoxia-Associated Epithelial-to-Mesenchymal Transition and Metastasis Mediated by Met Signaling Pathway

The functional role of pericytes in cancer progression remains unknown. Clinical studies suggest that low numbers of vessel-associated pericytes correlated with a drop in overall survival of patients with invasive breast cancer. Using genetic mouse models or pharmacological inhibitors, pericyte depletion suppressed tumor growth but enhanced metastasis. Pericyte depletion was further associated with increased hypoxia, epithelial-to-mesenchymal transition (EMT), and Met receptor activation. Silencing of Twist or use of a Met inhibitor suppressed hypoxia and EMT/Met-driven metastasis. In addition, poor pericyte coverage coupled with high Met expression in cancer cells speculates the worst prognosis for patients with invasive breast cancer. Collectively, our study suggests that pericytes within the primary tumor microenvironment likely serve as important gatekeepers against cancer progression and metastasis.

Glut1 and Glut3 as potential prognostic markers for oral squamous cell carcinoma

We associated clinical-pathological features of 142 OSCC with the expression pattern of GLUT1 and GLUT3 in order to estimate their prognostic value. Methods: Clinical-pathological features and overall survival data of 142 patients with Oral Squamous Cell Carcinoma (OSCC) were retrospectively reviewed from A.C.Camargo hospital records. A tissue microarray (TMA) was built for the immunohistochemical (IHC) analysis of GLUT 1 and GLUT 3. IHC results were evaluated according to the staining pattern and number of positive cells. Results: GLUT 1 was over expressed in 50.3% of OSSC cases showing membrane staining pattern. However, nuclear expression was observed in 49.7% of the analyzed cases. GLUT 3 over expression was detected in 21.1% of OSCC cases. The pattern of GLUT 1 expression showed significant association with alcohol consumption (p = 0.004). Positive cell membrane GLUT 3 protein expression was associated with advanced clinic-staging of tumours (p = 0.005) as well as with vascular embolization (p = 0.005). Positive expression of GLUT 3 was associated with unfavorable free-disease survival (p = 0.021). Conclusion: GLUT1 and GLUT3 protein expression evaluated by immunohistochemistry are, significantly, indicators of poor prognosis outcome in oral squamous cell carcinoma, probably due to the enhanced glycolytic metabolism of more aggressive neoplastic cells.

Digital slides: present status of a tool for consultation, teaching, and quality control in pathology.

In the last few years, telepathology has benefited from the progress in the technology of image digitalization and transmission through the world web. The applications of telepathology and virtual imaging are more current in research and morphology teaching. In surgical pathology daily practice, this technology still has limits and is more often used for case consultation. In the present review, we intend to discuss its applications and challenges for pathologists and scientists. Much of the limitations of virtual imaging for the surgical pathologist reside in the capacity of storage of images, which so far has hindered the more widespread use of this technology. Overcoming this major drawback may revolutionize the surgical pathologists activity and slide storing.

GLUT1 expression in malignant tumors and its use as an immunodiagnostic marker

OBJECTIVE: To analyze glucose transporter 1 expression patterns in malignant tumors of various cell types and evaluate their diagnostic value by immunohistochemistry. INTRODUCTION: Glucose is the major source of energy for cells, and glucose transporter 1 is the most common glucose transporter in humans. Glucose transporter 1 is aberrantly expressed in several tumor types. Studies have implicated glucose transporter 1 expression as a prognostic and diagnostic marker in tumors, primarily in conjunction with positron emission tomography scan data. METHODS: Immunohistochemistry for glucose transporter 1 was performed in tissue microarray slides, comprising 1955 samples of malignant neoplasm from different cell types. RESULTS: Sarcomas, lymphomas, melanomas and hepatoblastomas did not express glucose transporter 1. Forty-seven per cent of prostate adenocarcinomas were positive, as were 29% of thyroid, 10% of gastric and 5% of breast adenocarcinomas. Thirty-six per cent of squamous cell carcinomas of the head and neck were positive, as were 42% of uterine cervix squamous cell carcinomas. Glioblastomas and retinoblastomas showed membranous glucose transporter 1 staining in 18.6% and 9.4% of all cases, respectively. Squamous cell carcinomas displayed membranous expression, whereas adenocarcinomas showed cytoplasmic glucose transporter 1 expression. CONCLUSION: Glucose transporter 1 showed variable expression in various tumor types. Its absence in sarcomas, melanomas, hepatoblastomas and lymphomas suggests that other glucose transporters mediate the glycolytic pathway in these tumors. The data suggest that glucose transporter 1 is a valuable immunohistochemical marker that can be used to identify patients for evaluation by positron emission tomography scan. The function of cytoplasmic glucose transporter 1 in adenocarcinomas must be further examined.

High-risk human papillomavirus in oral squamous cell carcinoma of young patients

The aim of this study was to investigate a possible relation between oral squamous cell carcinoma (SCC), the presence of high‐risk human papillomavirus (HR‐HPV) DNA and p16 expression in young patients. Paraffin‐embedded tumor blocks from 47 oral SCC of young (≤40‐year old) patients were evaluated. The presence of HPV DNA in tumor specimens was analyzed by polymerase chain reaction (PCR) using GP5+/GP6+ generic primers (L1 region) followed by dot blot hybridization for HPV typing. When necessary, the HPV16 positivity was confirmed by PCR HPV16 E7‐specific primers. Cases involving young patients were compared with 67 oral SCC from patients ≥50‐year old (controls). Demographic and clinical data were collected to analyze patient outcomes. p16ink4 expression was evaluated by immunostaining of tissue microarrays. HPV16 was detected in 22 (19.2%) cases; 15 (68.2%) young and 7 (31.8%) control patients, a statistically significant difference (p = 0.01). In 1 (1.7%) young group specimen, HPV DNA 16 and 18 was detected. p16 expression was observed in 11 (25.6%) cases from the young group and in 11 (19.6%) controls (p = 0.48). Association between HPV and p16 was verified, and it was statistically significant (p = 0.002). The higher prevalence of high‐risk HPV types, especially HPV16, may be a contributing factor to oral carcinogenesis in younger individuals.

Repair of oxidative DNA damage, cell-cycle regulation and neuronal death may influence the clinical manifestation of Alzheimer's disease.

Alzheimer’s disease (AD) is characterized by progressive cognitive decline associated with a featured neuropathology (neuritic plaques and neurofibrillary tangles). Several studies have implicated oxidative damage to DNA, DNA repair, and altered cell-cycle regulation in addition to cell death in AD post-mitotic neurons. However, there is a lack of studies that systematically assess those biological processes in patients with AD neuropathology but with no evidence of cognitive impairment. We evaluated markers of oxidative DNA damage (8-OHdG, H2AX), DNA repair (p53, BRCA1, PTEN), and cell-cycle (Cdk1, Cdk4, Cdk5, Cyclin B1, Cyclin D1, p27Kip1, phospho-Rb and E2F1) through immunohistochemistry and cell death through TUNEL in autopsy hippocampal tissue samples arrayed in a tissue microarray (TMA) composed of three groups: I) “clinical-pathological AD” (CP-AD) - subjects with neuropathological AD (Braak≥IV and CERAD = B or C) and clinical dementia (CDR≥2, IQCODE>3.8); II) “pathological AD” (P-AD) - subjects with neuropathological AD (Braak≥IV and CERAD = B or C) and without cognitive impairment (CDR 0, IQCODE<3.2); and III) “normal aging” (N) - subjects without neuropathological AD (Braak≤II and CERAD 0 or A) and with normal cognitive function (CDR 0, IQCODE<3.2). Our results show that high levels of oxidative DNA damage are present in all groups. However, significant reductions in DNA repair and cell-cycle inhibition markers and increases in cell-cycle progression and cell death markers in subjects with CP-AD were detected when compared to both P-AD and N groups, whereas there were no significant differences in the studied markers between P-AD individuals and N subjects. This study indicates that, even in the setting of pathological AD, healthy cognition may be associated with a preserved repair to DNA damage, cell-cycle regulation, and cell death in post-mitotic neurons.

Prognostic impact of the cancer stem cell related markers ALDH1 and EZH2 in triple negative and basal-like breast cancers.

Aims: We assessed the expression of ALDH1 and EZH2, cancer stem cell (CSC) related markers, in triple negative and basal-like breast cancers, investigating their association with clinicopathological features and outcome. Methods: Clinicopathological data were obtained from 140 cases of triple negative breast cancer. A tissue microarray was constructed and immunohistochemistry for ER, PR, HER2, ALDH1, EZH2, CK5, CK14, EGFR, p63, caveolin, and p53 was performed. Tumour cell and stromal expression of ALDH1 were evaluated. Multivariate analysis was conducted, including all significant variables. Results: The majority of triple negative breast cancers were invasive ductal carcinomas of no special type (NST) (116/140). Tumour cells exhibited cytoplasmic expression of ALDH1 in 26 of 140 cases, while stromal expression was detected in 117 of 140 cases. Tumour cell expression did not correlate with any of the parameters. Conversely, stromal expression was associated with better overall survival (p=0.044). Assessment by Cox Regression Model showed a HR of 2.80 (HR = 1/0.357 = 2.80; 95%CI 0.178–0.714; p = 0.004) for breast cancer death when ALDH1 was not found in the stromal compartment of tumours, independent of age, histological type/grade, nodal status, stage, relapse, and expression of basal markers. High EZH2 expression was noted in 120 of 140 triple negative breast cancers and was not associated with other variables. Basal-like cancers comprised 75% (105/140) of triple negative breast cancers. Interestingly, we found association between EZH2 and CK14 expression (p = 0.041). Conclusions: ALDH1 expression is frequent in tumour-associated stromal cells of triple negative breast cancer and is associated with better outcome. Tumour microenvironment should be considered when studying prognostic impact of CSCs in breast cancer.

Polybromo‐1 (PBRM1), a SWI/SNF complex subunit is a prognostic marker in clear cell renal cell carcinoma

To analyse the immunohistochemical and mRNA expression of SWI/SNF (SWItch/Sucrose NonFermentable) complex subunit polybromo‐1 (PBRM1) in clear cell renal cell carcinoma (ccRCC) and its impact on clinical outcomes.

Penile Cancer: Epidemiology and Treatment

Penile cancer is an aggressive disease, with major psychological and social impact. The etiological factors are poor genital hygiene, the presence of phimosis, viral infection, ultraviolet radiation, smoking, balanitis xerotic obliterans, and chronic lichen. Identifying prognostic factors is important to select patients at risk for lymph node metastasis and avoid unneeded lymphadenectomy. The presence of lymph node metastasis is currently the strongest prognostic factor but its evaluation is imperfect using clinical and laboratorial methods. The treatment for invasive penile cancer is based on the treatment of primary tumor, usually with amputation and regional lymphadenectomy, treatments that have a high morbidity rate.

Epithelial-mesenchymal transition-like events in vulvar cancer and its relation with HPV

Background:Epithelial-to-mesenchymal transition (EMT) still remains an obscure event in vulvar squamous cell carcinoma (VSCC).Methods:Immunohistochemistry (IHC) expression of E-cadherin, β-catenin, Snail, Slug, Twist and Vimentin was analysed in 87 VSCC, controlled for human papillomavirus (HPV) positivity, considering tumour front and central tumour as different morphological categories from the same tumour.Results:Lower β-catenin and higher Vimentin expression was associated with invasive front when compared with the central tumour (P=0.013 and P⩽0.001, respectively). Higher expression of E-cadherin in central tumour was significantly related to absence of vascular and perineural invasion, lower invasion depth and ⩽2 lymph node involvement. Loss of β-catenin and high Slug, Snail and Twist expression was associated with HPV-negative tumours. Moreover, β-catenin lower expression associated with gain in Slug expression predicts a subgroup with worst outcome (P=0.001). Lower expression of β-catenin in both central tumour and invasive front correlated with lower overall survival (P=0.021 and P=0.011, respectively). Also, multivariate analysis showed that lower β-catenin expression was independently associated with poorer outcome (P=0.044).Conclusion:Human papillomavirus-related tumours show better prognosis and outcome; besides, they do not progress through EMT phenomenon. Immunohistochemical analysis of β-catenin in invasive tumour front is a key issue for establishing prognosis of vulva cancer.