Immunohistochemical expression of E-cadherin in metastatic brain tumors

Protective role of Decylubiquinone against secondary melanoma at lung in B16F10 induced mice by reducing E-cadherin expression and ameliorating ROCKII-Limk1/2-Cofiliin mediated metastasis

Melanoma is one of the most consequential skin cancer with a rising death incidences. Silent but belligerent nature of metastatic sprouting is the leading cause of melanoma related mortality. Invasion of metastatic cells and re-expression of E-Cadherin play the crucial role in the establishment of secondary tumor at distal sites. Thus, manipulation of tumor cell invasion in parallel to regulation of E-Cadherin expression can be considered as potential anti-metastatic strategy. Evidences suggested key role of reactive oxygen species associated ROCK activities in the modulation of metastatic invasion via F-actin stabilization. Here, we first-time report Decylubiquinone, a dietary Coenzyme Q₁₀ analog, as an effective attenuator of pulmonary metastatic melanoma in C57BL/6 mice. Current study depicted detailed molecular interplay associated with Decylubiquinone mediated phosphorylation of ROCKII at Tyr722 along with reduced phosphorylation of ROCKII Ser1366 leading to suppression of Limk1/2-Cofilin-F-actin stabilization axis that finally restricted B16F10 melanoma cell invasion at metastatic site. Analysis further deciphered the role of HNF4α as its nuclear translocation modulated E-Cadherin expression, the effect of reactive oxygen species dependent ROCKII activity in secondarily colonized B16F10 melanoma cells at lungs. Thus unbosoming of related signal orchestra represented Decylubiquinone as a potential remedial agent against secondary lung melanoma.

Lung cancer-associated brain metastasis: Molecular mechanisms and therapeutic options

BACKGROUND

Lung cancer is the most common cause of cancer-related mortality in humans. There are several reasons for this high rate of mortality, including metastasis to several organs, especially the brain. In fact, lung cancer is responsible for approximately 50% of all brain metastases, which are very difficult to manage. Understanding the cellular and molecular mechanisms underlying lung cancer-associated brain metastasis brings up novel therapeutic promises with the hope to ameliorate the severity of the disease. Here, we provide an overview of the molecular mechanisms underlying the pathogenesis of lung cancer dissemination and metastasis to the brain, as well as promising horizons for impeding lung cancer brain metastasis, including the role of cancer stem cells, the blood-brain barrier, interactions of lung cancer cells with the brain microenvironment and lung cancer-driven systemic processes, as well as the role of growth factor/receptor tyrosine kinases, cell adhesion molecules and non-coding RNAs. In addition, we provide an overview of current and novel therapeutic approaches, including radiotherapy, surgery and stereotactic radiosurgery, chemotherapy, as also targeted cancer stem cell and epithelial-mesenchymal transition (EMT)-based therapies, micro-RNA-based therapies and other small molecule or antibody-based therapies. We will also discuss the daunting potential of some combined therapies.

CONCLUSIONS

The identification of molecular mechanisms underlying lung cancer metastasis has opened up new avenues towards their eradication and provides interesting opportunities for future research aimed at the development of novel targeted therapies.

Immunohistochemical Expression Profiles of Cell Adhesion Molecules, Matrix Metalloproteinases and their Tissue Inhibitors in Central and Peripheral Neoplastic Foci of Feline Mammary Carcinoma

Feline mammary carcinoma (FMC) is a common cancer with high metastatic potential and high mortality rate. Loss of cell-cell interactions and degradation of the extracellular matrix by proteinases enhances tumour invasion and metastasis. Peripheral neoplastic foci (PNF) are defined as the presence of discrete tumour cell clusters, splitting off from central neoplastic foci (CNF) and lodging around these CNF. PNF therefore locate at the tumour-host interface at the site of invasion. The aim of this study was to evaluate immunohistochemically the expression of cell adhesion molecules (e-cadherin [CDH-1], syndecan 1 [SDC-1] and nectin-2), matrix metalloproteinases (matrix metalloproteinase [MMP]-2, MMP-7 and MMP-9) and their tissue inhibitors (tissue inhibitor of matrix metalloproteinase [TIMP]-1 and TIMP-2) together with the cellular proliferation marker, Ki67, in CNF and PNF of FMCs of different clinical stages and histological grades. Compared with control sections from areas of mammary gland hyperplasia, lower expression of MMP-7 and TIMP-2 was observed in all stages. Increased expression of TIMP-1 was observed in PNF in early-stage disease with no metastasis, while marked expression of CDH-1 and Ki67 occurred in late-stage FMC. In addition, the expression of MMP-2, MMP-9 and TIMP-1 in PNF of tumours with high histological grade (grade III) was higher than in low-grade tumours. The observed divergent protein expression in PNF could potentially form the basis of acting as novel markers in FMC. Potential markers may include the expression of TIMP-1 in PNF in early stage lesions, the expression of CDH-1 and Ki67 in late stages and the expression of MMP-2, MMP-9 and TIMP-1 in high-grade tumours.

The molecular biology of lung cancer brain metastasis: an overview of current comprehensions and future perspectives

Brain metastases occur in 20-40% of patients with advanced malignancies and lung cancer is one of the most common causes of brain metastases. The occurrence of brain metastases is associated with poor prognosis and high morbidity in patients with advanced lung cancer, even after intensive multimodal therapy. Progress in treating brain metastases has been hampered by a lack of model systems, a lack of human tissue samples, and the exclusion of brain metastatic patients from many clinical trials. While the biology of brain metastasis is still poorly understood, it is encouraging to see more efforts are beginning to be directed toward the study of brain metastasis. During the multi-step process of metastasis, functional significance of gene expressions, changes in brain vasculature, abnormal secretion of soluble factors and activation of autocrine/paracrine signaling are considered to contribute to the brain metastasis development. A better understanding of the mechanism of this disease will help us to identify the appropriate therapeutic strategies, which leads to circumvent brain metastases. Recent findings on the biology of lung cancer brain metastases and translational leads identified by molecular studies are discussed in this review.

Brain metastases from lung cancer show increased expression of DVL1, DVL3 and beta-catenin and down-regulation of E-cadherin

The susceptibility of brain to secondary formation from lung cancer primaries is a well-known phenomenon. In contrast, the molecular basis for invasion and metastasis to the brain is largely unknown. In the present study, 31 brain metastases that originated from primary lung carcinomas were analyzed regarding over expression of Dishevelled-1 (DVL1), Dishevelled-3 (DVL3), E-cadherin (CDH1) and beta-catenin (CTNNB1). Protein expressions and localizations were analyzed by immunohistochemistry. Genetic alterations of E-cadherin were tested by polymerase chain reaction (PCR)/loss of heterozygosity (LOH). Heteroduplex was used to investigate mutations in beta-catenin. DVL1 and DVL3 showed over expression in brain metastasis in 87.1% and 90.3% of samples respectively. Nuclear staining was observed in 54.8% of cases for DVL1 and 53.3% for DVL3. The main effector of the Wnt signaling, beta-catenin, was up-regulated in 56%, and transferred to the nucleus in 36% of metastases. When DVL1 and DVL3 were up-regulated the number of cases with nuclear beta-catenin significantly increased (p=0.0001). Down-regulation of E-cadherin was observed in 80% of samples. Genetic analysis showed 36% of samples with LOH of the CDH1. In comparison to other lung cancer pathologies, the diagnoses adenocarcinoma and small cell lung cancer (SCLC) were significantly associated to CDH1 LOH (p=0.001). Microsatellite instability was detected in one metastasis from adenocarcinoma. Exon 3 of beta-catenin was not targeted. Altered expression of Dishevelled-1, Dishevelled-3, E-cadherin and beta-catenin were present in brain metastases which indicates that Wnt signaling is important and may contribute to better understanding of genetic profile conditioning lung cancer metastasis to the brain.

Predictive biochemical-markers for the development of brain metastases from lung cancer: clinical evidence and future directions

BACKGROUND

Brain metastases are a common complication of patients with lung cancer and lung cancer is one of the most common causes of brain metastases. The occurrence of brain metastases is associated with poor prognosis and high morbidity, even after intensive multimodal therapy. Therefore, identifying lung cancer patients with who are at high risk of developing brain metastases and applying effect intervention is important to reduce or delay the incidence of brain metastases. Biochemical-markers may meet an unmet need for following patients' mechanisms of brain metastases.

METHODS

Data for this review were identified by searches of Pubmed and Cochrane databases, and references from relevant articles using the search terms "lung cancer" and "brain metastasis". Meeting abstracts, unpublished reports and review articles were not considered.

RESULTS

Clinical results for pathological and circulating markers including cancer molecular subtypes, miRNA, single nucleotide polymorphisms, and other markers are presented. However, these biochemical-markers are not yet established surrogate assessments for prediction of brain metastases.

CONCLUSIONS

Biochemical-markers reported allowed physicians to identify which patients with lung cancer are at high risk for brain metastases. Prospective randomized clinical studies are needed to further assess the utility of these biochemical-markers.

Role of the blood-brain barrier in the formation of brain metastases

The majority of brain metastases originate from lung cancer, breast cancer and malignant melanoma. In order to reach the brain, parenchyma metastatic cells have to transmigrate through the endothelial cell layer of brain capillaries, which forms the morphological basis of the blood-brain barrier (BBB). The BBB has a dual role in brain metastasis formation: it forms a tight barrier protecting the central nervous system from entering cancer cells, but it is also actively involved in protecting metastatic cells during extravasation and proliferation in the brain. The mechanisms of interaction of cancer cells and cerebral endothelial cells are largely uncharacterized. Here, we provide a comprehensive review on our current knowledge about the role of junctional and adhesion molecules, soluble factors, proteolytic enzymes and signaling pathways mediating the attachment of tumor cells to brain endothelial cells and the transendothelial migration of metastatic cells. Since brain metastases represent a great therapeutic challenge, it is indispensable to understand the mechanisms of the interaction of tumor cells with the BBB in order to find targets of prevention of brain metastasis formation.

E-cadherin as a predictive marker of brain metastasis in non-small-cell lung cancer, and its regulation by pioglitazone in a preclinical model

It remains unclear whether patients with non-small-cell lung cancer (NSCLC) develop brain metastasis during or after standard therapy. We attempted to identify biological markers that predict brain metastasis, and investigated how to modulate expression of such markers. A case-control study of patients who were newly diagnosed with NSCLC and who had developed brain metastasis during follow-up was conducted between 2004 and 2009. These patients were compared with a control group of patients who had NSCLC but no evidence of brain metastasis. Immunohistochemical analysis of expression of Ki-67, p53, Bcl-2, Bax, vascular endothelial growth factor, epidermal growth factor receptor, caspase-3, and E-cadherin was conducted. The methylation status of the genes for O(6)-methylguanine-DNA-methyltransferase, tissue inhibitor of matrix metalloproteinase (TIMP)-2, TIMP-3, and death-associated protein-kinase was also determined, by use of a methylation-specific polymerase chain reaction. A significantly increased risk of developing brain metastasis was associated with the presence of primary tumors with low E-cadherin expression in patients with NSCLC. We also investigated the effects of pioglitazone, a peroxisome proliferator-activated receptor γ-activating drug, in tumor-bearing mouse models. We found that E-cadherin expression was proportional to pioglitazone exposure time. Interestingly, pioglitazone pretreatment before cancer cell inoculation prevented loss of E-cadherin expression and reduced expression of MMP9 and fibronectin, compared with the control group. E-cadherin expression could be a predictor of brain metastasis in patients with NSCLC. Preventive treatment with pioglitazone may be useful for modulating E-cadherin expression.

Immunohistochemical Expression of DCUN1D1 in Non-small Cell Lung Carcinoma: Its Relation to Brain Metastasis

PURPOSE

Non-small cell lung carcinoma (NSCLC) comprises 75-85% of all lung cancers, and approximately 25% of all NSCLC patients develop brain metastasis. There are no reliable markers for predicting in which patients this metastasis will occur. DCUN1D1, also known as squamous cell carcinoma-related oncogene, is associated with tumor progression and poor outcomes in NSCLC. The objective of this study was to investigate the role of DCUN1D1 expression in cases of brain metastasis due to NSCLC.

MATERIALS AND METHODS

Primary tumor samples from a total of 71 cases of NSCLC, either with (n=40) or without (n=31) brain metastasis, were evaluated for DCUN1D1 expression by immunohistochemistry analysis.

RESULTS

DCUN1D1 expression was detected in 16 patients (23%) and tended to correlate with T classification (15% of T1-2 tumors vs. 30% of T3-4 tumors, p=0.083). DCUN1D1 expression was significantly associated with tumor stage. It was observed in none of the patients with stage I disease, 10% of those with stage II disease, and 29% with stage III disease (p=0.009). In addition, 14 of 16 DCUN1D1-positive patients resulted in brain metastasis (p=0.01). The odds ratio of brain metastasis for patients with DCUN1D1 expression was 3.112 (p=0.009).

CONCLUSION

DCUN1D1 expression may play a role in tumor progression and development of brain metastasis in patients with NSCLC. Evaluation of DCUN1D1 expression may provide assistance in identifying those patients who are at higher risk for brain metastasis.

Immunohistochemical assessment of primary breast tumors and metachronous brain metastases, with particular regard to differences in the expression of biological markers and prognosis

In this study, we conducted an immunohistochemical analysis of primary breast tumors and metachronous brain metastases to compare the differences in the expression of biological markers between the two. Carcinoma tissues from primary breast tumors and metachronous brain metastases collected from 21 patients were examined immunohistochemically for the expression status of the estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor (HER)-2, Ki-67, bcl-2 and p53, and the results were compared. In addition, the relationships between the expression of these factors and prognosis were evaluated. There were no significant differences in the frequencies of ER-, PgR-, HER-2-, bcl-2- or p53-positivity between the primary breast tumors and metachronous brain metastases. While the Ki-67 labeling index (LI) was high in both the primary breast tumors and brain metastases, it was significantly higher in the brain metastases than in the corresponding primary breast tumors (P=0.003). With regard to the prognosis, breast cancer patients who showed ER-positivity in the primary tumors showed significantly longer survival after primary diagnosis (P=0.0076). Furthermore, breast cancer patients who exhibited ER-positivity, bcl-2-positivity or p53-negativity in the primary tumors showed significantly longer intervals from primary diagnosis to the detection of the brain metastases. Of all the markers, only the Ki-67 LI was significantly higher in the brain metastases than in the primary breast tumors. We confirmed that the tumor characteristics were worse in the metachronous brain metastases.

The expression of three genes in primary non-small cell lung cancer is associated with metastatic spread to the brain

PURPOSE

Brain metastases affect 25% of patients with non-small cell lung cancer (NSCLC). We hypothesized that the expression of genes in primary NSCLC tumors could predict brain metastasis and be used for identification of high-risk patients, who may benefit from prophylactic therapy.

EXPERIMENTAL DESIGN

The expression of 12 genes was measured by real-time quantitative reverse transcriptase PCR in 142 frozen NSCLC tissue samples. Univariate and multivariate Cox regression analysis was used to analyze the correlation between gene expression and the occurrence of brain metastasis. Immunohistochemistry on independent samples was used to verify the findings.

RESULTS

A score based on the expression levels of three genes, CDH2 (N-cadherin), KIFC1, and FALZ, was highly predictive of brain metastasis in early and advanced lung cancer. The probability of remaining brain metastasis-free at 2 years after diagnosis was 90.0+/-9.5% for patients with stage I/stage II tumors and low score compared with 62.7+/-12% for patients with high score (P<0.01). In patients with more advanced lung cancer, the brain metastasis-free survival at 24 months was 89% for patients with low score compared with only 37% in patients with high score (P<0.02). These results were confirmed by immunohistochemical detection of N-cadherin in independent cohort of primary NSCLC.

CONCLUSIONS

The expression levels of three genes in primary NSCLC tumors may be used to identify patients at high risk for brain metastasis who may benefit from prophylactic therapy to the central nervous system.

E-cadherin-β-catenint complex expression and clinicopathologic properties in esophageal carcinoma patients and their relationship with the prognosis

AIM: To investigate the expression of E-cadherin (E-cad) and β-catenint (β-cat) complex in esophageal carcinoma (EC) tissue and the clinicopathologic properties in EC patients and to further explore their relationship with the prognosis.

METHODS: The data of 67 EC patients undergoing radical esophagectomy from 1998 to 2001 were reviewed and analyzed. The expression of E-cad and β-cat in the resected esophageal carcinoma tissue was detected using immunohistochemical technique. The prognostic factors were analyzed by Kaplan-Meier univariate and Cox multivariate survival analyses.

RESULTS: The univariate Kaplan-Meier analysis showed that age, the degree of tumor differentiation, depth of invasion, lymph node metastasis and the expression of E-cad and β-cat complex were very important prognostic factors for EC patients. The multivariate analysis demonstrated that the degree of tumor differentiation and depth of invasion, lymph node metastasis were independent prognostic factors (P = 0.039, 0.006, 0.020), Risk degree were 2.675, 3.077, 2.958 while E-cad-β-cat could not be used as independent prognostic factors for EC patients.

CONCLUSION: Both the expression of E-cad - β-cat complex and clinicopathologic properties are very important for prognosis of EC patients. The clinicopathologic properties could be used as independent markers for predicting the prognosis. The degree of tumor differentiation is the most important prognostic factor.

Utility of tissue-specific transcription factors thyroid transcription factor 1 and Cdx2 in determining the primary site of metastatic adenocarcinomas to the brain

CONTEXT

Brain metastases of adenocarcinoma of unknown primary pose a diagnostic dilemma to the surgical pathologist. Although the most common source in these cases is the lung, determining a primary source is difficult on routinely stained slides. Immunohistochemical stain panels including differential cytokeratins, hormone receptors, and breast-specific proteins are commonly used in these cases. Recently, attention has turned to tissue-specific transcription factors, such as thyroid transcription factor 1 (TTF-1) and Cdx2, in the appraisal of metastatic adenocarcinomas.

OBJECTIVE

To characterize the previously unpublished immunohistochemical expression of the relatively new tissue-specific transcription factor Cdx2 in metastatic adenocarcinomas to the brain.

DESIGN

We reviewed the surgical pathology files of the H. Lee Moffitt Cancer Center and Research Institute, Tampa, Fla, and retrieved 38 consecutive cases of metastatic adenocarcinoma (22 pulmonary, 10 breast, 6 gastrointestinal [2 esophagus/gastroesophageal junction, 4 colorectal]) to the brain with confirmation of the primary site by chart review and histologic evaluation. Sections were immunohistochemically stained with antibodies to TTF-1, Cdx2, and cytokeratins 7 and 20 by standard methods.

RESULTS

Specificities and positive predictive values for Cdx2 and TTF-1 equaled 100% for metastatic gastrointestinal and pulmonary adenocarcinomas, respectively. The negative predictive value of Cdx2 was also very high at 97%.

CONCLUSIONS

Cdx2 is a specific and valuable tool for the surgical pathologist when faced with the common problem of metastatic adenocarcinoma of unknown primary. In conjunction with TTF-1, cytokeratin 7, and cytokeratin 20, Cdx2 can accurately differentiate the most common sources of metastatic adenocarcinoma to the brain.

Brain microenvironment promotes the final functional maturation of tumor-specific effector CD8+ T cells

During the priming phase of an antitumor immune response, CD8(+) T cells undergo a program of differentiation driven by professional APCs in secondary lymphoid organs. This leads to clonal expansion and acquisition both of effector functions and a specific adhesion molecule pattern. Whether this program can be reshaped during the effector phase to adapt to the effector site microenvironment is unknown. We investigated this in murine brain tumor models using adoptive transfer of tumor-specific CD8(+) T cells, and in spontaneous immune responses of patients with malignant glioma. Our data show proliferation of Ag-experienced tumor-specific T cells within the brain parenchyma. Moreover, CD8(+) T cells further differentiated in the brain, exhibiting enhanced IFN-gamma and granzyme B expression and induction of alpha(E)(CD103)beta(7) integrin. This unexpected integrin expression identified a subpopulation of CD8(+) T cells conditioned by the brain microenvironment and also had functional consequences: alpha(E)(CD103)beta(7)-expressing CD8(+) T cells had enhanced retention in the brain. These findings were further investigated for CD8(+) T cells infiltrating human malignant glioma; CD8(+) T cells expressed alpha(E)(CD103)beta(7) integrin and granzyme B as in the murine models. Overall, our data indicate that the effector site plays an active role in shaping the effector phase of tumor immunity. The potential for local expansion and functional reprogramming should be considered when optimizing future immunotherapies for regional tumor control.

Identification and validation of S100A7 associated with lung squamous cell carcinoma metastasis to brain

To identify potential markers associated with non-small cell lung cancer (NSCLC) metastasis to brain, comparative proteome analysis on two lung squamous cell carcinoma (SCC) cell lines, NCI-H226 and H226Br (the brain metastatic cell line of NCI-H226), was performed using two-dimensional electrophoresis (2-DE) followed by a tandem mass spectrometer with a matrix-assisted laser desorption/ionization (MALDI) source. Twenty differential proteins were identified, of which 6 proteins were up-regulated in H226Br cell compared with NCI-H226 cells, whereas 14 proteins were down-regulated. S100A7 and 14-3-3sigma, two of candidate proteins significantly upregulated and downregulated in H226Br cell, were selected to verify the liability of the differential proteins by Western blot. The results were in accordance with 2-D data. To determine whether S100A7 overexpression is actually associated with SCC metastasis to brain, S100A7 protein was testified in 10 brain metastasis tissues from NSCLC, 38 primary NSCLC tissues including half matched local positive lymph nodes, 5 primary brain tumors and 2 non-cancer brain tissues by immunohistochemistry. Of particular interest to us was that the positive staining of S100A7 could be found in 3/5 (60%) brain metastases tissue from SCC and 8/21 (38%) the primary lung SCC tissues, while no positive staining was observed in the brain metastases tissue from Ad (n=5), the primary adenocarcinoma (Ad) tissues (n=17), the primary brain tumors (n=5), all local positive lymph nodes from the primary NSCLC (n=19) and non-cancer brain tissues (n=2). These findings suggest that S100A7 expression is closely associated with SCC metastasis to brain and may be a potential biomarker for monitoring the development of SCC.

E-cadherin and beta-catenin reduction influence invasion but not proliferation and survival in canine malignant mammary tumors

E-Cadherin and beta-catenin are known for their role in tumor invasion, but both proteins also exert an influence on tumor proliferation. This study, performed on canine mammary tumors, aimed to analyze the influence of E-cadherin (E-cad) and beta-catenin (beta-cat), immunohistochemically assessed singly and in combination (E-cad/beta-cat), on survival and their relationship with several proliferation indices (AgNOR index, MIB1 index, mitotic index). Immunohistochemistry was carried out on 60 formalin-fixed, paraffin wax-embedded specimens of canine mammary malignancies. The labeling was defined as preserved when prevalent on cell membranes of more than 75% of cells and reduced in other forms of expression (i.e., membranous less than 75%, cytoplasmic, and negative). E-cad, beta-cat, and E-cad/beta-cat were preserved respectively in 22, 12, and 11 out of 60 cases. Immunohistochemical expression of the two proteins in the same tumors was significantly correlated (P = 0.0001; R = 0.57). Survival analysis revealed no difference in outcome comparing the preserved versus reduced cases (E-cad, P = 0.31; beta-cat, P = 0.29; E-cad/beta-cat P = 0.36). Grouping cases for histologic invasiveness, the expression of E-cad or beta-cat and E-cad/beta-cat showed a progressive reduction that paralleled an increase in invasiveness from noninfiltrating to stage-II tumors (E-cad, P < 0.001; beta-cat, P < 0.05; E-cad/beta-cat, P < 0.05). No significant difference was obtained comparing mitotic index, MIB 1 index, and AgNOR index by analysis of variance between the cases grouped for preserved or reduced E-cad, beta-cat, and E-cad/beta-cat variables. In conclusion, reduced expression of E-cad, beta-cat, or E-cad/beta-cat was significantly associated with the progression from noninfiltrating to highly infiltrating tumors but not with proliferation or survival.

Pathobiology of brain metastases

Brain metastasis is a major cause of systemic cancer morbidity and mortality. Many factors participate in the development and maintenance of brain metastases. The survival of the metastasis depends upon crucial interactions between tumour cells and the brain microenvironment during its development at the new site. This review focuses on the pathobiological mechanisms involved in the establishment and regulation of brain metastases. Developments in molecular biology have vastly expanded our knowledge about the mechanisms of invasion, proliferation, metastatic cell signalling, and angiogenesis in brain metastases. Advances in this understanding of the pathobiology of brain metastasis may lead to novel targeted treatment paradigms and a better prognosis for patients with brain metastatic disease.