Adhesion molecules in cancer biology

Receptor-Mediated Targeted Delivery of Surface-ModifiedNanomedicine in Breast Cancer: Recent Update and Challenges

Breast cancer therapeutic intervention continues to be ambiguous owing to the lack of strategies for targeted transport and receptor-mediated uptake of drugs by cancer cells. In addition to this, sporadic tumor microenvironment, prominent restrictions with conventional chemotherapy, and multidrug-resistant mechanisms of breast cancer cells possess a big challenge to even otherwise optimal and efficacious breast cancer treatment strategies. Surface-modified nanomedicines can expedite the cellular uptake and delivery of drug-loaded nanoparticulate constructs through binding with specific receptors overexpressed aberrantly on the tumor cell. The present review elucidates the interesting yet challenging concept of targeted delivery approaches by exploiting different types of nanoparticulate systems with multiple targeting ligands to target overexpressed receptors of breast cancer cells. The therapeutic efficacy of these novel approaches in preclinical models is also comprehensively discussed in this review. It is concluded from critical analysis of related literature that insight into the translational gap between laboratories and clinical settings would provide the possible future directions to plug the loopholes in the process of development of these receptor-targeted nanomedicines for the treatment of breast cancer.

Nerve growth factor modulates the tumor cells migration in ovarian cancer through the WNT/β-catenin pathway

Nerve growth factor (NGF)/nerve growth factor receptors (NGFRs) axis and canonical WNT/β-catenin pathway have shown to play crucial roles in tumor initiation, progression and prognosis. But little did we know the relationship between them in modulation of tumor progress. In this report, we found that NGF/NGFRs and β-catenin were coexpression in ovarian cancer cell lines, and NGF can decrease the expression level of β-catenin and affect its activities, which may be related to the NGF-induced down-regulation of B-cell CLL/lymphoma 9-like (BCL9L, BCL9-2). Furthermore, NGF can also increase or decrease the downstream target gene expression levels of WNT/β-catenin depending on the cell types. Especially, we created a novel in vitro cell growth model based on a microfluidic device to intuitively observe the effects of NGF/NGFRs on the motility behaviors of ovarian cancer cells. The results showed that the migration area and maximum distance into three dimensional (3D) matrigel were decreased in CAOV3 and OVCAR3 cells, but increased in SKOV3 cells following the stimulation with NGF. In addition, we found that the cell colony area was down-regulated in CAOV3 cells, however, it was augmented in OVCAR3 cells after treatment with NGF. The inhibitors of NGF/NGFRs, such as Ro 08-2750, K252a and LM11A-31,can all block NGF-stimulated changes of gene expression or migratory behavior on ovarian cancer cells. The different results among ovarian cancer cells illustrated the heterogeneity and complexity of ovarian cancer. Collectively, our results suggested for the first time that NGF is functionally linked to β-catenin in the migration of human ovarian cancer cells, which may be a novel therapeutic perspective to prevent the spread of ovarian carcinomas by studying the interaction between NGF/NGFRs and canonical WNT/β-catenin signaling.

FAM3B mediates high glucose-induced vascular smooth muscle cell proliferation and migration via inhibition of miR-322-5p

The proliferation and migration of vascular smooth muscle cells (VSMCs) play an essential role during the development of cardiovascular diseases (CVDs). While many factors potentially contribute to the abnormal activation of VSMCs, hyperglycemia is generally believed to be a major causative factor. On the other hand, FAM3B (named PANDER for its secretory form) is a uniquely structured protein strongly expressed within and secreted from the endocrine pancreas. FAM3B is co-secreted with insulin from the β-cell upon glucose stimulation and regulates glucose homeostasis. In the present study, we sought to determine the roles of FAM3B in the regulation of VSMC physiology, especially under the hyperglycemic condition. We found that FAM3B expression was induced by hyperglycemia both in vivo and in vitro. FAM3B knockdown inhibited, whereas FAM3B overexpression accelerated VSMC proliferation and migration. At the molecular level, FAM3B inhibited miR-322-5p expression, and enforced expression of miR-322-5p antagonized FAM3B-induced VSMC proliferation and migration, suggesting that FAM3B facilitated VSMC pathological activation via miR-322-5p. Taken together, FAM3B mediates high glucose-induced VSMC proliferation and migration via inhibition of miR-322-5p. Thus, FAM3B may therefore serve as a novel therapeutic target for diabetes-related CVDs.

Diagnostic accuracy of CD44V6 for osteosarcoma: a meta-analysis

Background

Recently, more and more evidences have revealed the association between CD44V6 and osteosarcoma (OS), but whether it can be used as a clinical biomarker is still unknown. The purpose of this study is to assess the diagnostic value of CD44V6 in OS by conducting a meta-analysis.

Methods

All relevant electronic literatures were collected from seven international databases together with three Chinese databases up to April 23, 2016. Eligible studies were selected through multiple search strategies and the quality was assessed by QUADAS. Data was extracted from studies according to the key statistics index. All analyses were performed using STATA 12 and Meta-DiSc 1.4 statistical software.

Results

According to the exclusion and inclusion criteria, 8 literatures were retrieved, accounting for 463 cases and 188 controls. For discriminating OS from benign bone tumor or healthy controls, the area under the receiver operating characteristic curve (AUC) was 0.91 (95 % CI 0.88–0.93). Overall, the results showed pooled sensitivity of 0.743 (95 % CI 0.606–0.844) and specificity of 0.897 (95 % CI 0.818–0.945), respectively. Substantial heterogeneity was detected in this study (I² = 90 %). The publication bias was assessed by using Deeks’ asymmetry test (p = 0.795). No evidence of heterogeneity from threshold effects was detected by the Spearman correlation coefficient (−0.506, p = 0.201). Meta-regression was performed to mining the source of heterogeneity, and subgroup analysis showed that neither the cut-off values nor the control groups were the source of heterogeneity.

Conclusions

The present results suggest that promoted CD44V6 expression levels are associated with OS and CD44V6 may be used as a diagnostic marker for OS.

Amphiregulin enhances intercellular adhesion molecule-1 expression and promotes tumor metastasis in human osteosarcoma

Osteosarcoma is a common, high malignant, and metastatic bone cancer. Amphiregulin (AREG) has been associated with cancer cellular activities. However, the effect of AREG on metastasis activity in human osteosarcoma cells has yet to be determined. We determined that AREG increases the expression of intercellular adhesion molecule-1 (ICAM-1) through PI3K/Akt signaling pathway via its interaction with the epidermal growth factor receptor, thus resulting in the enhanced cell migration of osteosarcoma. Furthermore, AREG stimulation increased the association of NF-κB to ICAM-1 promoter which then up-regulated ICAM-1 expression. Finally, we observed that shRNA silencing of AREG decreased osteosarcoma metastasis in vivo. Our findings revealed a relationship between osteosarcoma metastatic potential and AREG expression and the modulating effect of AREG on ICAM-1 expression.

Protective Effect of Curcumin on Carbapenem-Resistant Escherichia coli–Induced Lung Injury in Rats

Curcumin has remarkable anti-inflammatory and antioxidant properties. The aim of this study was to investigate the protective effects of curcumin on a rat model of carbapenem-resistant Escherichia coli–induced acute lung injury (ALI). Thirty-two rats were randomly allocated to 4 groups to induce an ALI: negative control group (rats not infected with E coli with no antibiotic treatment), positive control group (rats infected with E coli with no antibiotic treatment), imipenem group (rats infected with E coli that received intraperitoneal injection of imipenem), and the imipenem+curcumin group (rats infected with E coli that received intraperitoneal injection of imipenem and were fed on curcumin).The rats were killed, and lung tissues samples were harvested for biochemical analyses and histopathologic examination. Total antioxidant status (TAS), total oxidant status (TOS), tumor necrosis factor α (TNFα), and interleukin-6 (IL6) were measured. TOS increased in the positive control group (P < 0.001) and decreased in the imipenem and imipenem+curcumin groups (P < 0.001 and P < 0.001, respectively). TAS decreased in the positive control group (P = 0.005). Imipenem treatment did not increase TAS, but the imipenem+curcumin group increased TAS (P = 0.014). TNFα and IL6 increased in the positive control group compared with the negative control group (P < 0.001 and P = 0.010, respectively). Imipenem decreased TNFα (P < 0.001), but did not decrease IL6 (P = 0.418). Imipenem+curcumin decreased TNFα (P < 0.001); this decrease was more pronounced compared with the imipenem group (P = 0.008). IL6 decreased in the curcumin group compared with the positive control group (P = 0.011). Curcumin combined with imipenem can be an alternative therapeutic agent to overcome the resistance of E coli strains.

Mechanistic Insight into Receptor-Mediated Delivery of Cationic-β-Cyclodextrin:Hyaluronic Acid-Adamantamethamidyl Host:Guest pDNA Nanoparticles to CD44(+) Cells

Targeted delivery is a key element for improving the efficiency and safety of nonviral vectors for gene therapy. We have recently developed a CD44 receptor targeted, hyaluronic acid-adamantamethamidyl based pendant polymer system (HA-Ad), capable of forming complexes with cationic β-cyclodextrins (CD-PEI(+)) and pDNA. Complexes formed using these compounds (HA-Ad:CD-PEI(+):pDNA) display high water solubility, good transfection efficiency, and low cytotoxicity. Spatial and dynamic tracking of the transfection complexes by confocal microscopy and multicolor flow cytometry techniques was used to evaluate the target specificity, subcellular localization, and endosomal escape process. Our data shows that cells expressing the CD44 receptor undergo enhanced cellular uptake and transfection efficiency with HA-Ad:CD-PEI(+):pDNA complexes. This transfection system, comprised noncovalent assembly of cyclodextrin:adamantamethamidyl-modified hyaluronic acid via host:guest interactions to condense pDNA, is a potentially useful tool for targeted delivery of nucleic acid therapeutics.

Role of the recently identified dysadherin in E-cadherin adhesion molecule downregulation in head and neck cancer

Dysadherin is a cancer-related cell membrane glycoprotein, recently identified, playing an important role in tumor progression and metastasis. In the present minireview article, we are focusing on the role of dysadherin in E-cadherin downregulation, the various expression patterns of the molecule in head and neck cancer as well as its potential role as a molecular target for future applications in diagnosis, clinical routine and prognosis of the disease.

PMA-induced up-regulation of TBX3 is mediated by AP-1 and contributes to breast cancer cell migration

The T-box transcription factor TBX3 provides an important link between embryonic development and cancer. TBX3 mediates limb, mammary gland and heart development and, in humans, mutations resulting in haplo-insufficiency of TBX3 lead to ulnar-mammary syndrome. Importantly, the de-regulation of TBX3 gene expression has been linked to several cancers, where it acts to suppress senescence and promotes proliferation and tumour invasion. Despite the negative impact of de-regulated TBX3 expression as seen by developmental defects and cancer, surprisingly little is known about the regulation of the TBX3 gene. In the present paper, we show that the phorbol ester PMA increases TBX3 protein and mRNA levels in a protein kinase C-dependent manner via the AP-1 (activator protein 1) transcription factors c-Jun and JunB. Furthermore, these AP-1 factors are shown to mediate the activation of the TBX3 gene by binding a non-consensus PMA-response element in the TBX3 promoter in vitro and in vivo. We also demonstrate that TBX3 contributes to the PMA-induced migration previously observed for the MCF-7 breast epithelium cancer cell line. Our present results reveal a previously unidentified pathway that up-regulates TBX3 expression and provides additional evidence that increased levels of TBX3 contribute to metastasis.

Gossypol decreases tumor necrosis factor-α-induced intercellular adhesion molecule-1 expression via suppression of NF-κB activity

Gossypol is a yellowish polyphenolic compound originally from cotton plant, which has been shown to exert a potential for anti-cancer and anti-inflammatory effects. However, its molecular mechanism is not thoroughly understood on breast cancer cells known to highly express intercellular adhesion molecule-1 (ICAM-1) for their adhesion and metastasis. This study aims to investigate the effect of gossypol on tumor necrosis factor (TNF)-α-stimulated ICAM-1 via nuclear factor-kappa B (NF-κB) activity. Gossypol was shown to inhibit TNF-α-induced ICAM-1 expression and U937 cell adhesion to MDA-MB-231 and MCF-7 cells. Additionally, TNF-α-induced MDA-MB-231 cell invasion was blocked in the presence of gossypol. Chromatin immunoprecipitation analysis demonstrated that gossypol blocks NF-κB binding on the ICAM-1 promoter regions. Additionally, TNF-α-induced NF-κB activation was completely suppressed in the presence of gossypol. Gossypol did not directly suppress the binding of NF-κB to the DNA but rather inhibited the nuclear translocation of p65 and p50 via phosphorylation and degradation of IκB. We also found that gossypol suppresses NF-κB activation induced by a wide variety of agents, including taxol, okadaic acid, and phorbol myristate acetate. Taken together, gossypol effectively inhibited TNF-α-induced ICAM-1 expression via the suppression of NF-κB activation and in vitro adhesion and invasion in human breast cancer cells.

Curcumin alone and in combination with augmentin protects against pulmonaryinflammation and acute lung injury generated during Klebsiella pneumoniae B5055-induced lung infection in BALB/c mice

Acute lung injuries due to acute lung infections remain a major cause ofmortality. Thus a combination of an antibiotic and a compound with immunomodulatoryand anti-inflammatory activities can help to overcome acute lung infection-inducedinjuries. Curcumin derived from the rhizome of turmeric has been used fordecades and it exhibits anti-inflammatory, anti-carcinogenic, immunomodulatoryproperties by downregulation of various inflammatory mediators. Keeping theseproperties in mind, we investigated the anti-inflammatory properties of curcuminin a mouse model of acute inflammation by introducing Klebsiella pneumoniae B5055 into BALB/c mice via the intranasal route. Intranasal instillationof bacteria in this mouse model of acute pneumonia-induced inflammation resultedin a significant increase in neutrophil infiltration in the lungs along withincreased production of various inflammatory mediators [i.e. malondialdehyde (MDA),myeloperoxidase (MPO), nitric oxide (NO), tumour necrosisfactor (TNF)-α] in the lung tissue. The animalsthat received curcumin alone orally or in combination with augmentin, 15 daysprior to bacterial instillation into the lungs via the intranasal route, showeda significant (P <0.05) decrease in neutrophil influxinto the lungs and a significant (P <0.05) decreasein the production of MDA, NO, MPO activity and TNF-α levels.Augmentin treatment alone did not decrease the MDA, MPO, NO and TNF-α levels significantly (P >0.05) as compared tothe control group. We therefore conclude that curcumin ameliorates lung inflammationinduced by K. pneumoniae B5055 without significantly (P <0.05) decreasing the bacterial load in the lung tissue whereasaugmentin takes care of bacterial proliferation. Hence, curcumin can be usedas an adjunct therapy along with antibiotics as an anti-inflammatory or animmunomodulatory agent in the case of acute lung infection.

Lipoplexes targeting the CD44 hyaluronic acid receptor for efficient transfection of breast cancer cells

Lipoplexes containing a hyaluronic acid-dioleoylphosphatidylethanolamine (HA-DOPE) conjugate were designed to target the CD44 receptor on breast cancer cells. Cationic liposomes composed of a mixture of [2-(2,3-didodecyloxypropyl)hydroxyethyl]ammonium bromide (DE) and dioleoylphosphatidylethanolamine (DOPE) with or without HA-DOPE were prepared, characterized, and used to form a complex with plasmid DNA pCMV-luc. Lipoplexes displayed a negative zeta potential and a mean diameter between 250-300 nm. Cytotoxicity and transfection efficiency of the lipoplexes were determined on the MDA-MB-231and MCF-7 breast cancer cell lines. Cytotoxicity was not modified by the presence of HA-DOPE. However HA-DOPE increased the level of transfection on CD44-expressing MDA-MB-231 cells compared to the MCF-7 line, which expresses very low levels of CD44. The transfection on the MDA-MB-231 cells was highly inhibited by anti-CD44 Hermes-1 antibody but not by the nonspecific anti-ErbB2 antibody. In conclusion, cationic liposomes containing the HA-DOPE conjugate mediated good transfection on CD44 expressing cell lines in culture.

Sialilated β1,6 branched N-oligosaccharides modulate adhesion, chemotaxis and motility of melanoma cells: Effect on invasion and spontaneous metastasis properties

B16BL6 cells, selected specifically for invasive characteristics from B16F10 mouse melanoma cells, displayed greater ability to metastasize to lungs and produced larger colonies than the parent cells, when injected intravenously. When the two cell lines were compared for surface beta1,6-branched N-oligosaccharides by flow cytometry using Leuco-Phyto-Heam-Agglutinin, B16BL6 were found to express significantly higher levels. Inhibition of the oligosaccharide expression, by treatment of the cells with swainsonine or antisense-N-acetyl glucosaminyl-transferase-V, significantly reduced metastasis and invasion (>50%). Further, inhibition of oligosaccharides on the molecules like beta1 integrin (one of the major carriers) caused 30-45% reduction in their adherence to extra-cellular-matrix components especially collagen IV and laminin, and chemotaxis towards fibronectin and matrigel. The inhibition also decreased haptotaxis by approximately 50% to fibronectin but surprisingly was enhanced towards laminin by approximately 75%. The cells on which the expression of these oligosaccharides was inhibited failed to exhibit the characteristic spontaneous metastasis and adhesion properties of B16BL6 cells. In none of the cases, however, the secretion of matrix-metallo-proteases correlated with oligosaccharide expression. Sialylation of surface oligosaccharides was found to be accompanied by even higher motility and adherence to the substrates. These results strongly support an important role of cell surface beta1,6-linked N-oligosaccharides, especially the sialylated derivatives, in the processes that influence invasion and metastasis.

Breast cancer biomarkers

Substantial progress has been made over the past three decades in our understanding of the epidemiology, clinical course and basic biology of breast cancer. This chapter considers the existing ancillary tests and emerging molecular markers in breast cancer prognosis assessment and the prediction of response of breast cancer to treatment of the disease.

The influence of epidermal growth factor receptor and tumor differentiation on the response to accelerated radiotherapy of squamous cell carcinomas of the head and neck in the randomized DAHANCA 6 and 7 study

BACKGROUND AND PURPOSE

Reduction of the overall treatment time of radiotherapy has increased locoregional control and disease specific survival in squamous cell carcinomas of the head and neck (HNSCC), but the response is heterogeneous. EGFr is often overexpressed in HNSCC and has been related to the repopulation taking place during radiotherapy. The aim of the current study was to address the influence of EGFr and histopathological differentiation when the overall treatment time of radiotherapy was moderately reduced.

PATIENTS AND METHODS

Eight hundred and three patients with representative pretreatment tissue samples from the randomized DAHANCA 6 and 7 study of 5 vs. 6 fx/wk of radiotherapy. EGFr was visualized using immunohistochemistry and separated into high and low expression before correlation with clinical data.

RESULTS

Tumors with high EGFr (84%) responded better to moderately accelerated radiotherapy, than carcinomas with low EGFr, using locoregional control as endpoint and a similar pattern was seen, stratifying by well/moderate vs. poor tumor differentiation. Therefore, a combined parameter was constructed showing a more prominent separation of response: tumors with high EGFr and well/moderate differentiation did benefit from moderate acceleration of treatment regarding locoregional control, HR 0.54 (0.37-0.78), whereas such an effect was not seen in tumors with low EGFr and/or poor differentiation, HR 0.8 (0.51-1.25). These results reflected the disease specific survival as well and were confirmed in multivariable analyses.

CONCLUSIONS

Moderately accelerated fractionation is superior to conventional treatment in HNSCC but the response is heterogeneous and may be predicted by high expression of EGFr and well/moderate tumor differentiation.

Expression of integrins and E-cadherin in squamous cell carcinomas of the head and neck

Integrins and cadherins are cell adhesion molecules suggested to play an important role in malignant progression and tumour differentiation. Our aim was to characterise the pattern of expression and the relations between integrin beta1, beta4, beta6 and E-cadherin and the different histopathological features important when judging tumour differentiation, using a well-defined scoring system. Formalin-fixed paraffin-embedded pre-irradiation biopsies from 85 patients with head and neck squamous cell carcinomas (HNSCC) were stained and evaluated for the expression of integrin beta1, beta4 and beta6 and E-cadherin. The integrins were upregulated in carcinomas compared to the adjacent mucosa and E-cadherin was downregulated. However, differences were found within the tumour: Expression of E-cadherin was lost and the three integrins were upregulated at the tumour borders, compared to central parts of the tumour biopsy. Expression of the integrins did not correlate with tumour or histopathological parameters, whereas expression of E-cadherin was correlated with high degree of keratinisation, high nuclear maturation and few mitoses - factors that characterise well-differentiated carcinomas -and E-cadherin can therefore be considered as a marker of differentiation. Furthermore, loss of adhesion expressed by low E-cadherin and integrin beta4 correlated with the presence of nodal metastases at the time of diagnosis.

Butyrate inhibits leukocyte adhesion to endothelial cells via modulation of VCAM-1

BACKGROUND

Leukocyte recruitment to areas of inflammation depends on Integrin-VCAM/ICAM interaction. Blocking the vascular cell adhesion molecule (VCAM-1) and the intracellular adhesion molecule (ICAM-1) may have therapeutic benefit for the inflammatory component of bowel disease. Notably, the induction of ICAM and VCAM is mediated by a nuclear factor kappaB (NF-kappaB)-dependent mechanism. We investigated whether the anti-inflammatory properties of butyrate are mediated via the modulation of VCAM and ICAM on human endothelial cells.

METHODS

VCAM-1 and ICAM-1 expression on human endothelial cells upon tumor necrosis factor-alpha (TNF-alpha) stimulation was assessd by FACS analysis. A monocyte adhesion assay was performed to evaluate the relevance of a modulated CAM-expression. Electrophoretic mobility shift assays were applied to investigate NF-kappaB activation.

RESULTS

The observed butyrate-associated inhibition of monocyte adhesion to endothelial cells is associated with an inhibition of NF-kappaB activation in human endothelial cells. In this context, the observed suppression of the TNF-alpha induced VCAM-1 expression is likely to play an essential role.

CONCLUSIONS

Butyrate inhibits VCAM-1 mediated leukocyte adhesion to human endothelial cells. This inhibition may contribute to the anti-inflammatory effects of butyrate in patients with distal ulcerative colitis.

Loading mitomycin C inside long circulating hyaluronan targeted nano-liposomes increases its antitumor activity in three mice tumor models

The frequent overexpression of the hyaluronan receptors CD44 and RHAMM in cancer cells opens the door for targeting by the naturally-occurring high-M(r) hyaluronan. This is the first time effective in vivo tumor targeting is reported for mitomycin C (MMC) loaded inside nano-sized hyaluronan-liposomes (denoted tHA-LIP). The severe adverse effects of free MMC made it a rational candidate for an effective targeted carrier. In vitro, loading MMC inside tHA-LIP increased drug potency 100-fold, in cells overexpressing, but not in cells underexpressing, hyaluronan receptors. Both types of liposomes were non-toxic and reduced MMC-related toxicity in healthy C57BL/6 mice. In 3 tumor models, BALB/c bearing C-26 solid tumors; C57BL/6 bearing B16F10.9 or (separately) D122 lung metastasis, tHA-LIP were long-circulating, 7-fold and 70-fold longer than nt-LIP and free MMC, respectively. tHA-LIP-mediated MMC accumulation in tumor-bearing lungs was 20% of injected dose, compared to 0.6% and 4% with free drug and nt-LIP, respectively. Tumor-free lungs showed low accumulation, irrespective of drug formulation. Key indicators of therapeutic responses, tumor progression, metastatic burden and survival, were superior (p < 0.001) in animals receiving MMC-loaded tHA-LIP, no treatment, MMC-loaded nt-LIP and free drug. In conclusion, tHA-LIP perform as tumor-targeted carriers, with promising prospects for treatment of tumors overexpressing hyaluronan receptors.

Structural insight into the mechanisms of targeting and signaling of focal adhesion kinase

Focal adhesion kinase (FAK) is a nonreceptor tyrosine kinase whose focal adhesion targeting (FAT) domain interacts with other focal adhesion molecules in integrin-mediated signaling. Localization of activated FAK to focal adhesions is indispensable for its function. Here we describe a solution structure of the FAT domain bound to a peptide derived from paxillin, a FAK-binding partner. The FAT domain is composed of four helices that form a "right-turn" elongated bundle; the globular fold is mainly maintained by hydrophobic interactions. The bound peptide further stabilizes the structure. Certain signaling events such as phosphorylation and molecule interplay may induce opening of the helix bundle. Such conformational change is proposed to precede departure of FAK from focal adhesions, which starts focal adhesion turnover.

Methylation of the E-cadherin gene in bladder neoplasia and in normal urothelial epithelium from elderly individuals

Decreased expression of the epithelial cell adhesion protein E-Cadherin occurs in several forms of human epithelial-derived cancers, including bladder cancers. We investigated the possibility that aberrant methylation of the CpG island flanking the 5' transcriptional start site of the e-cadherin gene is responsible for the decreased expression of this gene in bladder cancer, similar to the relationship previously seen between e-cadherin methylation and gene expression in other types of human cancers. Using methylation-specific polymerase chain reaction, we found methylation of this CpG island in 20 of 47 cases (43%) of bladder neoplasms ranging from low-grade papillary neoplasms to advanced, invasive cancers. When methylation status was compared to immunochemical staining for E-Cadherin, we found significantly diminished levels of E-Cadherin expression in 14 of 15 cases (93%) with methylation of the gene. We also found decreased expression of E-Cadherin, although to a somewhat lesser extent, in a high percentage (77%) of the cases without methylation of the gene. Although these data suggest a relationship between e-cadherin CpG island methylation and decreased gene expression, it evident that other mechanisms also contribute to decreased expression of this gene in bladder neoplasia. Remarkably, we also found low levels of e-cadherin methylation in urothelial cells from three of nine (33%) histologically normal bladders, with all three of the normal bladder samples with methylated e-cadherin being from individuals older than 70 years of age. Thus, methylation of the e-cadherin CpG island may occur normally in this tissue with aging as well as in low-grade papillary neoplasms, and is not specific to cancer in the bladder. This finding of methylation in normal urothelial cells from elderly individuals is provocative with respect to a possible link between aging and increased risk for bladder cancer, but it suggests limitations on the usefulness of using methylation of e-cadherin as a molecular marker for detection of bladder cancer.