Juliana Silva Zanetti

Beta 1 integrin predicts survival in breast cancer: a clinicopathological and immunohistochemical study

BackgroundThe main focus of several studies concerned with cancer progression and metastasis is to analyze the mechanisms that allow cancer cells to interact and quickly adapt with their environment. Integrins, a family of transmembrane glycoproteins, play a major role in invasive and metastatic processes. Integrins are involved in cell adhesion in both cell-extracellular matrix and cell-cell interactions, and particularly, β1 integrin is involved in proliferation and differentiation of cells in the development of epithelial tissues. This work aimed to investigate the putative role of β1 integrin expression on survival and metastasis in patients with breast invasive ductal carcinoma (IDC). In addition, we compared the expression of β1 integrin in patients with ductal carcinoma in situ (DCIS).MethodsThrough tissue microarray (TMA) slides containing 225 samples of IDC and 67 samples of DCIS, β1 integrin expression was related with several immunohistochemical markers and clinicopathologic features of prognostic significance.Resultsβ1 integrin was overexpressed in 32.8% of IDC. In IDC, β1 integrin was related with HER-2 (p = 0.019) and VEGF (p = 0.011) expression and it had a significant relationship with metastasis and death (p = 0.001 and p = 0.05, respectively). Kaplan-Meier survival analysis showed that the overexpression of this protein is very significant (p = 0.002) in specific survival (number of months between diagnosis and death caused by the disease). There were no correlation between IDC and DCIS (p = 0.559) regarding β1 integrin expression.ConclusionsConsidering that the expression of β1 integrin in breast cancer remains controversial, specially its relation with survival of patients, our findings provide further evidence that β1 integrin can be a marker of poor prognosis in breast cancer.Virtual slidesThe virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/6652215267393871

Cancer stem cell immunophenotypes in oral squamous cell carcinoma.

BACKGROUND The presence of cancer stem cell (CSC) antigens can be evidenced in some human tumors by phenotypic analysis through immunostaining. This study aims to identify a putative CSC immunophenotype in oral squamous cell carcinoma (OSCC) and determine its influence on prognosis. METHODS The following data were retrieved from 157 patents: age, gender, primary anatomic site, smoking and alcohol intake, recurrence, metastases, histologic classification, treatment, disease-free survival (DFS), and overall survival (OS). An immunohistochemical study for CD44 and CD24 was performed in a tissue microarray of 157 paraffin blocks of OSCCs. RESULTS In univariate analysis, the immunostaining pattern showed significant influences in relation to OS for alcohol intake and treatment, as well as for the CD44(+) and CD44(-) /CD24(-) immunophenotypes. The multivariate test confirmed these associations. CONCLUSIONS Based on our results, the CD44 immunostaining and the absence of immunoexpression of these two investigated markers can be used in combination with other clinicopathologic information to improve the assessment of prognosis in OSCC.

Differential expression of HIF-1α in CD44+CD24-/low breast ductal carcinomas

BackgroundCancer stem cell (CSC) hypothesis postulates that tumors are maintained by a self-renewing CSC population that is also capable of differentiating into non-self-renewing cell populations that constitute the bulk of tumor. Stem cells renewal and differentiation can be directly influenced by the oxygen levels of determined tissues, probably by the reduction of oxidative DNA damage in hypoxic regions, thus leading to a friendlier microenvironment, regarding to clonal expansion and for resistance to chemotherapeutic regimens. Furthermore, there have been strong data indicating a pivotal role of hypoxic niche in cancer stem cells development. There are evidence that hypoxia could drive the maintenance of CSC, via HIF-1α expression, but it still to be determined whether hypoxia markers are expressed in breast tumors presenting CD44+CD24-/low immunophenotype.MethodsImmunohistochemical analysis of CD44+CD24-/low expression and its relationship with hypoxia markers and clinical outcome were evaluated in 253 samples of breast ductal carcinomas. Double-immunolabeling was performed using EnVision Doublestain System (Dako, Carpinteria, CA, USA). Slides were then scanned into high-resolution images using Aperio ScanScope XT and then, visualized in the software Image Scope (Aperio, Vista, CA, USA).ResultsIn univariate analysis, CD44+CD24-/low expression showed association with death due to breast cancer (p = 0.035). Breast tumors expressing CD44+CD24-/low immunophenotype showed relationship with HIF-1α (p = 0.039) and negativity for HER-2 (p = 0.013).ConclusionConsidering that there are strong evidences that the fraction of a tumour considered to be cancer stem cells is plastic depending upon microenvironmental signals, our findings provide further evidence that hypoxia might be related to the worse prognosis found in CD44+CD24-/low positive breast tumors.

The role of tumor hypoxia in MUC1-positive breast carcinomas

Mucin 1 (MUC1) is a glycoprotein that is expressed on apical cell membranes in a variety of normal tissues. MUC1 is involved in cell signaling, inhibition of cell–cell and cell matrix adhesion, apoptosis, proliferation, and transcription. Hypoxia is an important factor that promotes cancer metastasis and stimulates angiogenesis and tumor progression. Hypoxia inducible factor 1 (HIF-1α) and carbonic anhydrase IX (CAIX) are two molecules that are involved in this process. The role of hypoxia in MUC1+ invasive ductal breast carcinomas is not well established. In this study, the expression of MUC1 was correlated with the hypoxia-associated markers HIF-1α and CAIX, as well as several immunohistochemical markers and clinicopathologic features of prognostic significance in 243 invasive ductal carcinomas. MUC1 was overexpressed in 37.0% of patients and correlated with the expression of estrogen receptor (p = 0.0001), progesterone receptor (p = 0.0001), HIF-1α (p = 0.006), VEGF (p = 0.024), and p53 (p = 0.025). In breast cancer, MUC1 expression has been associated with increased degradation of inhibitor of NF-κB (IκBα), driving NF-κB to the nucleus and blocking apoptosis and promoting cell survival. We analyzed NF-κB expression in MUC1+ breast carcinoma and found a very significant relationship between these proteins (p = 0.0001). Our findings indicate that MUC1 may play a role in the regulation of hormone receptors by increasing the inactivation of p53 and targeting NF-κB to the nucleus. Our data also support the notion that activation of HIF-1α in MUC1+ breast carcinomas may modulate VEGF expression, allowing a metabolic adaptation to hypoxia.

Significance of topoisomerase IIIβ expression in breast ductal carcinomas: strong associations with disease-specific survival and metastasis.

Topoisomerases are ubiquitous nuclear enzymes that regulate DNA structure in eukaryotic cells. The role of topoisomerase IIIβ, the newest member of the topoisomerase family, in the clinical outcome of breast cancer is still poorly understood. This study aims to investigate the immunoexpression of topoisomerase IIIβ in breast cancer and its relationships with clinicopathologic features and immunohistochemical markers of prognostic significance in breast pathology. Using tissue microarrays containing 171 cases of primary invasive breast cancer, we analyzed the immunoexpression of topoisomerase IIIβ, estrogen receptor, progesterone receptor, HER-2, BRCA-1, p53, and Ki67. Immunostaining for topoisomerase IIIβ was found in 33.9% of breast carcinomas, and immunopositivity was correlated with distant metastasis (P = .036) and death (P = .006). Decreased expression of topoisomerase IIIβ correlated with low expression of Ki67 (P < .001) and negativity for HER-2 (P < .001), BRCA-1 (P = .001), and p53 (P < .001). In the multivariate analysis, topoisomerase IIIβ expression was a significant predictor of survival (hazard ratio, 3.006 [95% confidence interval, 1.582-5.715]; P = .001). In conclusion, topoisomerase IIIβ expression can be a useful marker in assessing the prognosis of patients with breast cancer and is an independent predictor of survival.

Relationship between B-Cell-specific moloney murine leukemia virus integration site 1 (BMI-1) and homologous recombination regulatory genes in invasive ductal breast carcinomas

B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) is a Polycomb group protein that is able to induce telomerase activity, enabling the immortalization of epithelial cells. Immortalized cells are more susceptible to double-strand breaks (DSB), which are subsequently repaired by homologous recombination (HR). BRCA1 is among the HR regulatory genes involved in the response to DNA damage associated with the RAD51 protein, which accumulates in DNA damage foci after signaling H2AX, another important marker of DNA damage. Topoisomerase IIIß (topoIIIß) removes HR intermediates before chromosomal segregation, preventing damage to cellular DNA structure. In breast carcinomas positive for BMI-1 the role of proteins involved in HR remains to be investigated. The aim of this study was to evaluate the association between BMI-1 and homologous recombination proteins. Using tissue microarrays containing 239 cases of primary breast tumors, the expression of Bmi-1, BRCA-1, H2AX, Rad51, p53, Ki-67, topoIIIß, estrogen receptors (ER), progesterone receptors (PR), and HER-2 was analyzed by immunohistochemistry. We observed high Bmi-1 expression in 66 cases (27.6%). Immunohistochemical overexpression of BMI-1 was related to ER (p=0.004), PR (p<0.001), Ki-67 (p<0.001), p53 (p=0.003), BRCA-1 (p= 0.003), H2AX (p=0.024) and topoIIIß (p<0,001). Our results show a relationship between the expression of BMI-1 and HR regulatory genes, suggesting that Bmi-1 overexpression might be an important event in HR regulation. However, further studies are necessary to understand the mechanisms in which Bmi-1 could regulate HR pathways in invasive ductal breast carcinomas.

CHK2 Immunohistochemical Expression in Colon Cancer and its Relation with Clinicopathological Features and Outcome in Metastatic ColonCancer Patients

Background: The DNA damage checkpoint pathway has been of interest to the field of cancer biology, since checkpoint defects result in the accumulation of altered genetic information, a central feature of carcinogenesis. Little is known about the role that CHK2 (checkpoint kinase 2) gene plays in colorectal cancer tumorigenesis. The purpose of this study was to evaluate CHK2 expression in metastatic colon cancer and correlate it with clinicopathological features and patient survival. Methods: Tissues of primary tumors were obtained from 58 patients with metastatic colon cancer. The tissue microarray immunohistochemistry was the technique used to evaluate CHK2 expression. Statistical analysis used was SPSS17; p-value was set at <0.050. The relationship between the CHK2 immunohistochemical expression and the patients’ clinical and pathological features as well as survival data was reported. Results: CHK2 expression was positive in 69% of the cases. CHK2 expression was associated with lymph node status (p=0.012) and survival (p=0.034). Negative CHK2 expression increased the chance of lymph node involvement (Odds ratio: 10.23, p=0.03). The global survival time of CHK2-negative patients was higher (72 versus 59 months); the same trend emerged for progression-free survival time (19 versus 13 months). The survival curves differed depending on CHK2 expression in patients with or without lymph node involvement; survival was lower in CHK2-positive. A larger number of deaths occurred in CHK2-positive. Multivariate regression analysis identified performance status ECOG (p=0.01), synchronous metastasis (p=0.037), tumor cell differentiation (p=0.029) and CHK2 expression (p=0.020) as independent factors for overall survival. Conclusions: This study demonstrated that positive CHK2 expression in colon cancer indicates aggressiveness and impacts negatively patient survival and outcome. On the other hand, a negative expression indicates dissemination to lymph nodes.

Câncer de mama: de perfis moleculares a células tronco

RESUMO: O câncer de mama e a neoplasia maligna mais incidente entre a populacao feminina. A maioria dos tumores de mama sao resultados de alteracoes geneticas e epigeneticas que podem mudar a morfologia e a funcao das celulas. A tumorigenese do câncer de mama e sua progressao sao resultantes do acumulo dessas alteracoes geneticas que leva a transicao gradual do tecido normal para o maligno. Alem dessas alteracoes, acredita-se que o câncer pode se originar de uma unica celula que adquire a capacidade de se proliferar indefinidamente. Essas celulas compartilham algumas caracteristicas com as celulas tronco do tecido adulto normal, por isso muitas vezes sao denominadas celulas tronco tumorais. Estudos recentes correlacionaram a expressao de marcadores de celulas tronco com os subtipos moleculares de câncer de mama (luminal, basal e HER2 positivos). Essa correlacao permite um estudo mais aprofundado da fisiopatogenia dos perfis moleculares do câncer de mama e o desenvolvimento de novas abordagens terapeuticas. Palavras- chave: Câncer. Mama. Celulas tronco. Prognostico. Perfil molecular.