M3 mAChR-mediated IL-8 expression through PKC/NF-κB signaling pathways

Objective

M3 muscarinic acetylcholine receptor (mAChR) plays an important role in the regulation of cytokine production in inflammatory diseases. In this study, we explored the precise role of M3 mAChR under stimulation with agonist in IL-8 expression and of the signaling pathway involved in this process.

Materials and methods

Recombinant U2OS cells stably expressing M3 mAChR as a model system were stimulated by carbachol to evaluate the role of M3 mAChR in the expression of IL-8.

Results

Activation of M3 mAChR with carbachol increased both IL-8 mRNA and protein expression in a concentration-dependent manner. Elevated IL-8 expression was completely antagonized by atropine, 4-DAMP and tiotropium. M3 mAChR-mediated IL-8 expression was almost completely inhibited by the NF-κB inhibitor BAY11-7082 and, to a lesser extent, by U0126, SB203580, and SP600125, which are inhibitors for ERK1/2, p38, and JNK, respectively. Furthermore, M3 mAChR-mediated NF-κB activation and IL-8 expression were simultaneously attenuated by the PKC inhibitor calphostin C, whereas PMA, a PKC activator, mimicked the effects of carbachol, inducing IL-8 expression.

Conclusions

Our findings offer insights into the specific and critical role of M3 mAChR in regulating inflammatory response and indicate M3 mAChR/PKC/NF-κB signaling axis driven by endogenous acetylcholine as a potential therapeutic targets for inflammatory diseases.     

The Histopathologic, Pharmacologic and Urodynamic Results of Mesenchymal Stem Cell’s Injection into the Decompensated Rabbit’s Bladder

Objectives

We researched the survival of bone marrow-derived mesenchymal stem cells (MSCs) and the results of MSCs’ injected into decompensated bladders in a rabbit model.

Methods

Partial bladder neck obstruction (PBNO) and subsequent decompensation of the bladder was achieved by wrapping the bladder neck with autologous rectus fascia. In the first aspect of the experiment 18 rabbits underwent MSC injection into the decompensated bladder to prove the survivability of injected MSCs. For this purpose MSCs were isolated, transfected with Green Fluorescent Protein (GFP), and injected into the detrusor layer. Once viability was assessed in the first phase, an additional 10 rabbits underwent PBNO in the second phase. Five of these animals underwent subsequent MSC injection (group 3, stem cell) and 5 did not (group 2, obstruction). Both groups were compared to 5 controls (group 1). Urodynamics were performed in all groups. After the animals were sacrificed the groups were compared via morphometric analysis, contractile response to carbachol and KCl, and muscarinic receptor type analysis.

Results

On morphometric analysis, collagenous area rates were 43, 53 and 37 % in group 1, 2 and 3, respectively. There was no statistically significant difference between groups in terms of bladder weight, bladder capacity and vesical pressure. The contractile effects of KCl and muscarinic agonist carbachol were significantly higher in groups 1 and 3 than group 2. The response to carbachol was antagonized by muscarinic M₁ and M₃ receptor antagonist pirenzepine and abolished by muscarinic M₃ receptor antagonist 4-DAMP in all groups.

Conclusions

The injection of MSCs decreased the collagenous area, increased detrusor contractility. Functional M₃ receptors were also expressed in MSCs-injected bladder smooth muscle as well as in control group.     

Dietary grape polyphenol resveratrol increases mammary tumor growth and metastasis in immunocompromised mice

Background

Resveratrol, a polyphenol from grapes and red wine has many health beneficial effects, including protection against cardiovascular and neurodegenerative diseases and cancer. However, our group and others have provided evidence for a dual cancer promoting or inhibitory role for resveratrol in breast cancer, dependent on estrogenic or antiestrogenic activities. Moreover, much of the inhibitory effects of resveratrol have been reported from studies with high non-physiological concentrations.

Methods

We investigated the effects of a range of concentrations (0.5, 5, 50 mg/kg body weight) of resveratrol on mammary tumor development post-initiation, using immunocompromised mice.

Results

Our findings suggest promotion of mammary tumor growth and metastasis by resveratrol at all concentrations tested in tumors derived from the low metastatic estrogen receptor (ER)α(-), ERβ(+) MDA-MB-231 and the highly metastatic ER(-) MDA-MB-435 cancer cell lines. Additionally, the activity of the migration/invasion regulator Rac, which we have previously shown to be regulated by resveratrol in vitro, was measured in tumors from resveratrol treated mice. Our results show a significant induction of tumoral Rac activity and a trend in increased expression of the Rac downstream effector PAK1 and other tumor promoting molecules following resveratrol treatment.

Conclusion

Taken together, our findings implicate low concentrations of resveratrol in potential promotion of breast cancer. Therefore, this study illuminates the importance of further delineating resveratrol’s concentration dependent effects, particularly in breast cancer, before it can be tested in the clinic or used as a dietary supplement for breast cancer patients.     

A genome-wide association study of breast and prostate cancer in the NHLBI's Framingham Heart Study

Background

Cutaneous Malignant Melanoma causes over 75% of skin cancer-related deaths, and it is clear that many factors may contribute to the outcome. Matrix Metalloproteinases (MMPs) play an important role in the degradation and remodeling of the extracellular matrix and basement membrane that, in turn, modulate cell division, migration and angiogenesis. Some polymorphisms are known to influence gene expression, protein activity, stability, and interactions, and they were shown to be associated with certain tumor phenotypes and cancer risk.

Methods

We tested seven polymorphisms within the MMP-9 gene in 1002 patients with melanoma in order to evaluate germline genetic variants and their association with progression and known risk factors of melanoma. The polymorphisms were selected based on previously published reports and their known or potential functional relevance using in-silico methods. Germline DNA was then genotyped using pyrosequencing, melting temperature profiles, heteroduplex analysis, and fragment size analysis.

Results

We found that reference alleles were present in higher frequency in patients who tend to sunburn, have family history of melanoma, higher melanoma stage, intransit metastasis and desmoplastic melanomas among others. However, after adjustment for age, sex, phenotypic index, moles, and freckles only Q279R, P574R and R668Q had significant associations with intransit metastasis, propensity to tan/sunburn and primary melanoma site.

Conclusion

This study does not provide strong evidence for further investigation into the role of the MMP-9 SNPs in melanoma progression.     

Enhanced activation of matrix metalloproteinase-9 correlates with the degree of papillary thyroid carcinoma infiltration

Aim

To determine whether matrix metalloproteinase-9 (MMP-9) may be a useful adjunctive tool for predicting unfavorable biological behavior of papillary thyroid carcinoma (PTC) by evaluating the expression profile and proteolytic activity of MMP-9 in PTC by different techniques and correlating the findings with clinicopathological prognostic factors.

Methods

Immunohistochemical localization of MMP-9 was analyzed with antibodies specific for either total or active MMP-9. Activation ratios of MMP-9 were calculated by quantifying gel zymography bands. Enzymatic activity of MMP-9 was localized by in situ zymography after inhibiting MMP-2 activity.

Results

Immunostaining of total and active MMP-9 was observed in tumor tissue and occasionally in non-neoplastic epithelium. Only active MMP-9 was significantly associated with extrathyroid invasion, lymph-node metastasis, and the degree of tumor infiltration (P < 0.001, P = 0.004, and P < 0.001, respectively). Gelatin zymography revealed a correlation between the MMP-9 activation ratio and nodal involvement, extrathyroid invasion, and the degree of tumor infiltration. In situ zymography showed that gelatinases exerted their activity in tumor parenchymal and stromal cells. Moreover, after application of MMP-2 inhibitor, the remaining gelatinase activity, corresponding to MMP-9, was highest in cancers with the most advanced degree of tumor infiltration.

Conclusions

This is the first report suggesting that the evaluation of active MMP-9 by immunohistochemistry and determination of its activation ratio by gelatin zymography may be a useful adjunct to the known clinicopathological factors in predicting tumor behavior. Most important, in situ zimography with an MMP-2 inhibitor for the first time demonstrated a strong impact of MMP-9 activity on the degree of tumor infiltration during PTC progression.Papillary thyroid carcinoma (PTC) is the most common malignancy of the thyroid, with a rapid global rise in incidence in the recent decades. Despite its generally indolent behavior, a small proportion of PTC patients develop more aggressive forms of the disease. Several clinical and histopathological parameters, such as sex, age, histologic grade, and tumor stage have been reported as useful in improving prognostic stratification (1). However, the prognosis of tumor behavior for individual patients with thyroid cancer can vary greatly, partly due to the marked clinical heterogeneity among such patients, even within a particular histologic group. Therefore, it is important to understand the molecular mechanisms responsible for cancer development, progression, and metastasis, and to establish novel strategies for predicting biological behavior of thyroid cancer and for clinical management of patients.In cancer research, much interest has been devoted to alterations in expression grade and activity of various matrix metalloproteinases (MMPs) and their corresponding inhibitors (2). MMPs are a family of zinc-dependent endopeptidases with the capacity to degrade extracellular matrix proteins and basement membranes (3), and are therefore strongly implicated in multiple stages of cancer progression. Among the MMPs, a subset called gelatinases, consisting of MMP-2 (gelatinase A) and MMP-9 (gelatinase B), has gained the most attention in studies on the acquisition of invasive and metastatic tumor properties, as they degrade collagen IV, the major component of the basement membrane (4,5). Their proteolytic activity is regulated at various levels, including expression, balance between amounts of enzymes and their inhibitors, pericellular localization, and most importantly, latent form activation. Namely, gelatinases are secreted as inactive proenzymes and are activated after cleavage of the pro-peptide domain of the molecule (6). MMP-9 is of special interest because its basal expression is normally low, whereas it is highly expressed in most human cancers in response to various growth factors and cytokines (7,8). It has been shown that MMP-9-deficient mice exhibit impaired metastasis formation and tumor growth (9). In this respect, up-regulation of MMP-9 expression in various types of human cancers contributes to tumor progression, invasion, and metastasis (10-13).There is much evidence demonstrating that MMP-9 is overexpressed in various tumor types when compared to normal tissue (14-16). On the other hand, this protein has not been widely investigated in thyroid tumors and there are still some controversies regarding its usefulness as a marker for diagnosis or prognosis of these tumors (17-21). Moreover, the ratio of active-to-total MMP-9 and the precise localization of enzymatic activity in thyroid tissue have not yet been investigated. To localize MMP-9 expression in PTC and corresponding non-tumor tissue, we used two commercial antibodies that recognize either both pro-active and active or only active form of MMP-9 for immunohistochemistry. To our knowledge, active form of MMP-9 has not been immunohistochemically evaluated on thyroid tissue sections previously. We also used gelatin zymography, which is a sensitive, quantifiable assay to analyze pro-active and active form of MMP-9, and sensitive dye-quenched gelatin (DQ-gelatin) in situ zymography with a selective MMP-2 inhibitor to localize the gelatinase activity corresponding to MMP-9 in tissue. Thus, we explored the expression profiles, activation ratio, and localization of MMP-9 activity in tissue sections of papillary thyroid carcinomas and correlated the findings with clinicopathological prognostic factors with the aim of determining whether MMP-9 may be a useful adjunctive tool for predicting unfavorable biological behavior of PTC.     

Lack of MMP-9 expression is a marker for poor prognosis in Dukes’ B colorectal cancer

Background

Matrix metalloproteinases (MMPs) play a role in cancer progression by degrading extracellular matrix and basement membranes, assisting in tumour neovascularization and in supporting immune response in cancer.

Methods

We studied the prognostic value of immunohistochemical expression of MMP-2, MMP-8, and MMP-9 in a series of 619 colorectal cancer patients using tissue microarray specimens.

Results

Of the samples, 56% were positive for MMP-2, 78% for MMP-8, and 60% for MMP-9. MMP-9 associated with low WHO grade (p?<?0.001). In univariate analysis of Dukes’ B tumours, MMP-9 negativity associated with poor survival (p?=?0.018), and MMP-9 positivity was an independent prognostic marker in multivariate analysis of these tumours (p?=?0.034).

Conclusion

Negative MMP-9 expression can predict poor prognosis in Dukes’ B colorectal tumours and may prove useful for identifying patients, who should be offered adjuvant treatment.

     

Balanced and unbalanced solutions modulate the release of Matrix Metalloproteinase-9 (MMP-9) from neutrophils in response to inflammatory stimuli: an in vitro study

Objectives and design

We investigated the effect of balanced (BS) and unbalanced (UBS) solutions in the absence or presence of hydroxyethyl starch (HES) on neutrophil functionality, evaluating the release of matrix metalloproteinase (MMP)-9, myeloperoxidase (MPO), and MMP-8.

Materials and methods

Neutrophils were isolated by gradient centrifugation and dextran sedimentation and incubated in BS or UBS without or with HES, in the absence or presence of Interleukin-8 (IL-8) or Lipopolysaccharide (LPS). MMP-9, MPO, and MMP-8 were assayed by commercially available ELISA kits.

Results

There was not any influence of volume replacement solutions on the release of the enzymes from resting neutrophils. After IL-8 stimulation, the release of MMP-9 was higher in BS than in UBS or RPMI-1640, whereas HES enhanced its release regardless of the composition. After LPS stimulation, the release of MMP-9 was higher in both UBS and BS than RPMI-1640, but HES brought its release back to physiological conditions. No difference was found in the release of MPO and MMP-8 after stimulation with IL-8 or LPS.

Conclusion

Volume replacement solutions might have an impact on the release of MMP-9 depending on the inflammatory milieu, suggesting that the use of balanced or unbalanced solutions is not a neutral choice.     

Nuclear medicine technologists are able to accurately determine when a myocardial perfusion rest study is necessary

Background

Adjuvant! Online ( http://www.adjuvantonline.com) is an Internet-based software program that allows clinicians to make predictions about the benefits of adjuvant therapy and 10-year survival probability for early-stage breast cancer patients. This model has been validated in Western countries such as the United States, United Kingdom, Canada, Germany, and Holland. The aim of our study was to investigate the performance and accuracy of Adjuvant! Online in a cohort of Taiwanese breast cancer patients.

Methods

Data on the prognostic factors and clinical outcomes of 559 breast cancer patients diagnosed at the National Cheng Kung University Hospital in Tainan between 1992 and 2001 were enrolled in the study. Comprehensive demographic, clinical outcome data, and adjuvant treatment data were entered into the Adjuvant! Online program. The outcome prediction at 10 years was compared with the observed and predicted outcomes using Adjuvant! Online.

Results

Comparison between low- and high-risk breast cancer patient subgroups showed significant differences in tumor grading, tumor size, and lymph node status (p?<?0.0001). The mean 10-year predicted death probability in 559 patients was 19.44%, and the observed death probability was 15.56%. Comparison with the Adjuvant! Online-predicted breast cancer-specific survival (BCSS) showed significant differences in the whole cohort (p?<?0.001). In the low-risk subgroup, the predicted and observed outcomes did not differ significantly (3.69% and 3.85%, respectively). In high-risk patients, Adjuvant! Online overestimated breast cancer-specific survival (p?=?0.016); the predicted and observed outcomes were 21.99% and 17.46%, respectively.

Conclusions

Adjuvant! Online accurately predicted 10-year outcomes and assisted in decision making about adjuvant treatment in low-risk breast cancer patients in our study, although the results were less accurate in the high-risk subgroup. Development of a prognostic program based on a national database should be considered, especially for high-risk breast cancer patients in Taiwan.     

NOV/CCN3 attenuates inflammatory pain through regulation of matrix metalloproteinases-2 and -9

Background

Sustained neuroinflammation strongly contributes to the pathogenesis of pain. The clinical challenge of chronic pain relief led to the identification of molecules such as cytokines, chemokines and more recently matrix metalloproteinases (MMPs) as putative therapeutic targets. Evidence points to a founder member of the matricial CCN family, NOV/CCN3, as a modulator of these inflammatory mediators. We thus investigated the possible involvement of NOV in a preclinical model of persistent inflammatory pain.

Methods

We used the complete Freund's adjuvant (CFA)-induced model of persistent inflammatory pain and cultured primary sensory neurons for in vitro experiments. The mRNA expression of NOV and pro-inflammatory factors were measured with real-time quantitative PCR, CCL2 protein expression was assessed using ELISA, MMP-2 and -9 activities using zymography. The effect of drugs on tactile allodynia was evaluated by the von Frey test.

Results

NOV was expressed in neurons of both dorsal root ganglia (DRG) and dorsal horn of the spinal cord (DHSC). After intraplantar CFA injection, NOV levels were transiently and persistently down-regulated in the DRG and DHSC, respectively, occurring at the maintenance phase of pain (15 days). NOV-reduced expression was restored after treatment of CFA rats with dexamethasone. In vitro, results based on cultured DRG neurons showed that siRNA-mediated inhibition of NOV enhanced IL-1??- and TNF-??-induced MMP-2, MMP-9 and CCL2 expression whereas NOV addition inhibited TNF-??-induced MMP-9 expression through ??₁ integrin engagement. In vivo, the intrathecal delivery of MMP-9 inhibitor attenuated mechanical allodynia of CFA rats. Importantly, intrathecal administration of NOV siRNA specifically led to an up-regulation of MMP-9 in the DRG and MMP-2 in the DHSC concomitant with increased mechanical allodynia. Finally, NOV intrathecal treatment specifically abolished the induction of MMP-9 in the DRG and, MMP-9 and MMP-2 in the DHSC of CFA rats. This inhibitory effect on MMP is associated with reduced mechanical allodynia.

Conclusions

This study identifies NOV as a new actor against inflammatory pain through regulation of MMPs thus uncovering NOV as an attractive candidate for therapeutic improvement in pain relief.     

Quality of Life in Women with Localised Breast Cancer or Malignant Melanoma 2 Years After Initial Treatment: a Comparison

Background

Two thirds of female breast cancer patients and more than 80 % of malignant melanoma patients are diagnosed with localised disease and good prognosis with a 5-year relative survival of more than 90 % in Germany.

Purpose

This study was conducted to present quality of life (QoL) data from a German population-based cohort of female breast cancer and melanoma patients without recurrence for approximately 2 years after initial diagnosis.

Methods

In 2003–2004, patients with localised breast cancer and melanoma were recruited from the Munich Cancer Registry (Upper Bavaria, Germany) to answer QoL questionnaires. Differences between breast cancer and melanoma patients were investigated with regard to age and aspects of communication with their medical caregivers.

Results

One thousand three hundred and four breast cancer and 348 melanoma patients were included. Breast cancer patients were about 7 years older and had significantly lower QoL and higher symptom scores than melanoma patients. Communication needs were generally similar in both groups; however, breast cancer patients experienced more empathy from their medical caregivers. In breast cancer patients, communication was an independent factor for all QoL functioning scores.

Conclusions

Even when faced with a similarly good prognosis, breast cancer patients have a worse QoL than melanoma patients 2 years after diagnosis. An explanation may be more distinctive surgery and systemic therapy, older patients with comorbidities and misunderstood risk communication in breast cancer patients that may stoke anxiety and fears. Further reasons could be unceasing public discussion about breast cancer and its instrumentalisation for political purposes.     

Contribution of Cyclophilin A to the Regulation of Inflammatory Processes in Rheumatoid Arthritis

Introduction

Previous studies show that cyclophilin A (CypA) acts as a strong chemotactic cytokine to neutrophils, eosinophils, and monocytes in rheumatoid arthritis (RA).

Methods

In this study, monocytes were stimulated by purified CypA and the production of matrix metalloproteinase (MMPs), the cell invasion and the release of inflammatory cytokines were detected respectively by gelatin zymography, invasion assay, and cytometric bead array FCM.

Results

The elevated level of inflammatory cytokine IL-8 was also detected. Results showed that CypA significantly promoted the invasion of THP-1 cells and increased the production of MMP-2 and MMP-9, which displayed a biphasic concentration dependency. In vivo experiments found that the cartilage erosion scores in CypA injection group were significantly higher than those in control group (P?<?0.05).

Conclusion

Our findings suggest that CypA significantly enhances the secretion of MMP-2 and MMP-9, the cell invasion, and the inflammatory cytokines production of monocytes. Our findings may shed some new light on the inflammatory process and the degradation of cartilage and bone in RA.     

Frequency of CHEK2*1100delC in New York breast cancer cases and controls

Background

The 1100delC CHEK2 allele has been associated with a 1.4–4.7 fold increased risk for breast cancer in women carrying this mutation. While the frequency of 1100delC was 1.1–1.4% in healthy Finnish controls, the frequency of this allele in a North American control population and in North American breast cancer kindreds remains unclear.

Methods

We genotyped 1665 healthy New York volunteers and 300 cases of breast cancer for the CHEK2*1100delC.

Results

The overall frequency of the 1100delC was 3/300 (1.0%) among all cases with either a family history of breast cancer (n = 192) or a personal history of breast cancer (n = 108, of which 46 were bilateral, 46 unilateral, and 16 were male breast cancer cases), compared to a frequency of 5/1665 (0.3%) in healthy controls (p = 0.1). There was no difference in allele frequency among Ashkenazi and non-Ashkenazi controls.

Conclusion

The relatively low breast cancer penetrance of this allele, along with the low population frequency, will limit the clinical applicability of germline testing for CHEK2*1100delC in North American kindreds.     

Evaluation of in vivo labelled dendritic cell migration in cancer patients

Background

Dendritic Cell (DC) vaccination is a very promising therapeutic strategy in cancer patients. The immunizing ability of DC is critically influenced by their migration activity to lymphatic tissues, where they have the task of priming naïve T-cells. In the present study in vivo DC migration was investigated within the context of a clinical trial of antitumor vaccination. In particular, we compared the migration activity of mature Dendritic Cells (mDC) with that of immature Dendritic Cells (iDC) and also assessed intradermal versus subcutaneous administration.

Methods

DC were labelled with ^99mTc-HMPAO or ¹¹¹In-Oxine, and the presence of labelled DC in regional lymph nodes was evaluated at pre-set times up to a maximum of 72 h after inoculation. Determinations were carried out in 8 patients (7 melanoma and 1 renal cell carcinoma).

Results

It was verified that intradermal administration resulted in about a threefold higher migration to lymph nodes than subcutaneous administration, while mDC showed, on average, a six-to eightfold higher migration than iDC. The first DC were detected in lymph nodes 20–60 min after inoculation and the maximum concentration was reached after 48–72 h.

Conclusions

These data obtained in vivo provide preliminary basic information on DC with respect to their antitumor immunization activity. Further research is needed to optimize the therapeutic potential of vaccination with DC.     

Lifestyle Changes in Women at Genetic Risk of Breast Cancer: an Observational Study

Background

Lifestyle influences breast cancer risk. Women at increased familial risk may benefit from modifying behaviour, but it is not known to what extent they do so.

Purpose

This study aims to measure changes that UK (Scottish) women make in response to increased familial risk of breast cancer and attitudes to a risk-reduction trial.

Methods

A questionnaire, completed by 140 “breast cancer family” clinic patients, generated data on habitual diet, alcohol consumption and exercise, changes made after learning of breast cancer risk and attitudes to possible further changes. Subgroups of patients were defined by criteria likely to influence changes in behaviour. Between-group differences were analysed by Fisher's exact test and overall correlations by linear regression.

Results

Thirty-six subjects (26 %) reported no behavioural change but, overall, around 25 % of diet, exercise and alcohol items had been changed. Women perceiving their lifetime cancer risk to be high (>50 %) and those who were obese (BMI >25) had made significantly more changes than others. Younger women (<40 years) and those with daughters had made fewer changes. Almost all suggested elements of a risk-reduction trial were strongly supported.

Conclusions

Scottish women at increased risk of breast cancer have scope for protective changes in lifestyle and support a risk-reduction trial. The needs of younger women and of those with daughters should be addressed in its design.     

GenDrux: A biomedical literature search system to identify gene expression-based drug sensitivity in breast cancer

Background

This paper describes the development of a web-based tool, GenDrux, which extracts and presents (over the Internet) information related to the disease-gene-drug nexus. This information is archived from the relevant biomedical literature using automated methods. GenDrux is designed to alleviate the difficulties of manually processing the vast biomedical literature to identify disease-gene-drug relationships. GenDrux will evolve with the literature without additional algorithmic modifications.

Results

GenDrux, a pilot system, is developed in the domain of breast cancer and can be accessed at http://www.microarray.uab.edu/drug_gene.pl. GenDrux can be queried based on drug, gene and/or disease name. From over 8,000 relevant abstracts from the biomedical literature related to breast cancer, we have archived a corpus of more than 4,000 articles that depict gene expression-drug activity relationships for breast cancer and related cancers. The archiving process has been automated.

Conclusions

The successful development, implementation, and evaluation of this and similar systems when created may provide clinicians with a tool for literature management, clinical decision making, thus setting the platform for personalized therapy in the future.     

Connexin-43 upregulation in micrometastases and tumor vasculature and its role in tumor cell attachment to pulmonary endothelium

Background

The modulation of gap junctional communication between tumor cells and between tumor and vascular endothelial cells during tumorigenesis and metastasis is complex. The notion of a role for loss of gap junctional intercellular communication in tumorigenesis and metastasis has been controversial. While some of the stages of tumorigenesis and metastasis, such as uncontrolled cell division and cellular detachment, would necessitate the loss of intercellular junctions, other stages, such as intravasation, endothelial attachment, and vascularization, likely require increased cell-cell contact. We hypothesized that, in this multi-stage scheme, connexin-43 is centrally involved as a cell adhesion molecule mediating metastatic tumor attachment to the pulmonary endothelium.

Methods

Tumor cell attachment to pulmonary vasculature, tumor growth, and connexin-43 expression was studied in metastatic lung tumor sections obtained after tail-vein injection into nude mice of syngeneic breast cancer cell lines, overexpressing wild type connexin-43 or dominant-negatively mutated connexin-43 proteins. High-resolution immunofluorescence microscopy and Western blot analysis was performed using a connexin-43 monoclonal antibody. Calcein Orange Red AM dye transfer by fluorescence imaging was used to evaluate the gap junction function.

Results

Adhesion of breast cancer cells to the pulmonary endothelium increased with cancer cells overexpressing connexin-43 and markedly decreased with cells expressing dominant-negative connexin-43. Upregulation of connexin-43 was observed in tumor cell-endothelial cell contact areas in vitro and in vivo, and in areas of intratumor blood vessels and in micrometastatic foci.

Conclusion

Connexin-43 facilitates metastatic 'homing' by increasing adhesion of cancer cells to the lung endothelial cells. The marked upregulation of connexin-43 in tumor cell-endothelial cell contact areas, whether in preexisting 'homing' vessels or in newly formed tumor vessels, suggests that connexin-43 can serve as a potential marker of micrometastases and tumor vasculature and that it may play a role in the early incorporation of endothelial cells into small tumors as seeds for vasculogenesis.     

An Exploratory Analysis of Fear of Recurrence among African-American Breast Cancer Survivors

Background

Fear of recurrence (FOR) is a psychological concern that has been studied extensively in cancer survivors but has not been adequately examined in African-American breast cancer survivors.

Purpose

This exploratory study describes the extent and nature of FOR in African-American breast cancer survivors. FOR is examined in relation to socio-demographic characteristics, treatment-related characteristics, psychological distress, and quality of life (QOL).

Methods

Participants completed questionnaires assessing FOR, psychological distress, QOL, and demographic and treatment characteristics. Pearson r correlations, t tests, and ANOVAs were used to determine the association between FOR and demographic and treatment-related characteristics. Hierarchical multiple regression models were performed to investigate the degree to which FOR dimensions account for the variance in QOL and psychological distress.

Results

Fifty-one African-American breast cancer survivors participated in this study. The mean age of participants was 64.24 (SD?=?12.3). Overall fears as well as concerns about death and health were rated as low to moderate. Role worries and womanhood worries were very low. Inverse relationships were observed between age and FOR dimensions. FOR was positively correlated with measures of psychological distress and negatively correlated with QOL. FOR significantly accounted for a portion of the variance in QOL and distress after controlling for other variables.

Conclusions

This study suggests that African-American women in this sample demonstrated some degree of FOR. Results indicate that FOR among African-American breast cancer survivors decreases with age and time since diagnosis and co-occurs with psychological distress as well as diminished quality of life.