Role of HGF in epithelial–stromal cell interactions during progression from benign breast disease to ductal carcinoma in situ

Introduction

Basal-like and luminal breast cancers have distinct stromal–epithelial interactions, which play a role in progression to invasive cancer. However, little is known about how stromal–epithelial interactions evolve in benign and pre-invasive lesions.

Methods

To study epithelial–stromal interactions in basal-like breast cancer progression, we cocultured reduction mammoplasty fibroblasts with the isogenic MCF10 series of cell lines (representing benign/normal, atypical hyperplasia, and ductal carcinoma in situ). We used gene expression microarrays to identify pathways induced by coculture in premalignant cells (MCF10DCIS) compared with normal and benign cells (MCF10A and MCF10AT1). Relevant pathways were then evaluated in vivo for associations with basal-like subtype and were targeted in vitro to evaluate effects on morphogenesis.

Results

Our results show that premalignant MCF10DCIS cells express characteristic gene expression patterns of invasive basal-like microenvironments. Furthermore, while hepatocyte growth factor (HGF) secretion is upregulated (relative to normal, MCF10A levels) when fibroblasts are cocultured with either atypical (MCF10AT1) or premalignant (MCF10DCIS) cells, only MCF10DCIS cells upregulated the HGF receptor MET. In three-dimensional cultures, upregulation of HGF/MET in MCF10DCIS cells induced morphological changes suggestive of invasive potential, and these changes were reversed by antibody-based blocking of HGF signaling. These results are relevant to in vivo progression because high expression of a novel MCF10DCIS-derived HGF signature was correlated with the basal-like subtype, with approximately 86% of basal-like cancers highly expressing the HGF signature, and because high expression of HGF signature was associated with poor survival.

Conclusions

Coordinated and complementary changes in HGF/MET expression occur in epithelium and stroma during progression of pre-invasive basal-like lesions. These results suggest that targeting stroma-derived HGF signaling in early carcinogenesis may block progression of basal-like precursor lesions.     

Excess breast cancer risk in first degree relatives of CHEK211100delC positive familial breast cancer cases

AimThe CHEK211100delC mutation confers a relative risk of two for breast cancer (BC) in the general population. This study aims to explore the excess cancer risk due to the CHEK211100delC mutation within a familial non-BRCA1/2 breast cancer setting.Patients and MethodsCancer incidences were compared between first degree relatives of 107 familial breast cancer patients positive for the CHEK211100delC mutation (CHEK2 positive families) and first degree relatives of 314 familial breast cancer patients without the CHEK211100delC mutation (CHEK2 negative families). All families were derived from the same pool of familial non-BRCA1/2 breast cancer families (n = 2554). Medical information of 2188 first degree relatives of these families was analysed for cancer risk. CHEK211100delC status of relatives was unknown.ResultsIncreased breast cancer risk (hazard ratio (HR) 2.0 (95% confidence interval (CI): 1.4–2.7), p < 0.001) was observed in sisters of CHEK211100delC positive index cases compared to sisters of CHEK211100delC negative index cases. HR was 1.6 (95% CI: 1.0–2.4) for mothers of CHEK2 positive versus negative index cases (p = 0.041). For second primary breast cancers HR was increased in CHEK211100delC positive index cases (HR 2.1, 95% CI: 1.3–3.3, p = 0.003) and their sisters (HR 2.6, 95% CI: 1.1–6.1, p = 0.025).ConclusionThere is an excess breast cancer risk in first degree relatives of CHEK211100delC positive non-BRCA1/2 familial breast cancer patients compared to non-CHEK211100delC familial breast cancer relatives.Genotyping for the CHEK211100delC mutation in a familial breast cancer setting contributes to optimal clinical surveillance in countries in which this mutation is prevalent. Carriers and female relatives are eligible for stringent breast surveillance programs.     

Insights into pathological mechanisms of missense mutations in C-terminal domains of von Willebrand factor causing qualitative or quantitative von Willebrand disease

The carboxyl-terminal domains of von Willebrand factor, D4-CK, are cysteine-rich implying that they are structurally important. In this study we characterized the impact of five cysteine missense mutations residing in D4-CK domains on the conformation and biosynthesis of von Willebrand factor. These variants were identified as heterozygous in type 1 (p.Cys2619Tyr and p.Cys2676Phe), type 2A (p.Cys2085Tyr and p.Cys2327Trp) and as compound heterozygous in type 3 (p.Cys2283Arg) von Willebrand disease. Transient expression of human cell lines with wild-type or mutant von Willebrand factor constructs was performed. The mutated and wild-type recombinant von Willebrand factors were quantitatively and qualitatively assessed and compared. Storage of von Willebrand factor in pseudo-Weibel-Palade bodies was studied with confocal microscopy. The structural impact of the mutations was analyzed by homology modeling. Homozygous expressions showed that these mutations caused defects in multimerization, elongation of pseudo-Weibel-Palade bodies and secretion of von Willebrand factor. Co-expressions of wild-type von Willebrand factor and p.Cys2085Tyr, p.Cys2327Trp and p.Cys2283Arg demonstrated defective multimer assembly, suggesting a new pathological mechanism for dominant type 2A von Willebrand disease due to mutations in D4 and B domains. Structural analysis revealed that mutations p.Cys2283Arg, p.Cys2619Tyr and p.Cys2676Phe disrupted intra-domain disulfide bonds, whereas p.Cys2327Trp might affect an inter-domain disulfide bond. The p.Cys2327Trp variant is distinguished from the other mutants by an electrophoretic mobility shift of the multimer bands. The results highlight the importance of cysteine residues within the carboxyl-terminal of von Willebrand factor on structural conformation of the protein and consequently multimerization, storage, and secretion of von Willebrand factor.     

Normal and abnormal thymus in childhood: MR imaging

Magnetic resonance (MR) imaging studies of 47 children without thymic disease were compared with those of 14 children with proved thymic abnormalities (eg, lymphoma, leukemia, hyperplasia) to evaluate the spectrum of MR features of the normal and abnormal thymus and to determine the best indicators of thymic disease. In healthy children younger than 5 years of age, the thymus had a quadrilateral shape and biconvex lateral contours. Older children and adolescents had a triangular thymus with straight lateral margins. The thymus appeared homogeneous with a signal intensity slightly greater than that of muscle on T1-weighted images and close to that of fat on T2-weighted images. Qualitative evaluation of gross thymic morphology (size, shape, margins, and signal intensity) usually was sufficient for distinguishing between the normal and abnormal thymus. The abnormal thymus generally was enlarged, multilobular, or inhomogeneous because of the presence of cystic degeneration, hemorrhage, septations, fibrosis, or calcification on pathologic sections. In patients with lymphoma, the presence of associated lymphadenopathy also was helpful in distinguishing the normal from the abnormal thymus.     

Predominance of herpes simplex virus type 1 from patients with genital herpes in Nova Scotia

The epidemiology of genital herpes is changing with evidence to suggest an increasing incidence of herpes simplex virus type 1 (HSV-1) infections. The results of 6529 HSV genital cultures taken between April 1998 and December 2001 were reviewed. overall, HSV-1 was recovered more often than HSV-2; 1213 versus 1045. This trend was particularly striking in young women 30 years of age or less, in whom 70.8% of isolates were HSV-1. In men of the same age range, 45% of isolates were HSV-1. The proportion of women with HSV-1 declined from 73.7% in those younger than 31 years of age to 4.5% in those older than 60 years of age.These observations have important implications. The decline in the relative proportion of HSV-1 isolates from young adults may be the result of changing sexual practices, changing susceptibility or increased exposure to HSV-1 during vaginal intercourse. In this setting HSV-2 vaccines may be less likely to produce the desired reduction in the overall prevalence of genital herpes infections.Key Words: Genital herpes, Herpes simplex virus type-1Many factors have contributed to the changing epidemiology of sexually transmitted diseases (STDs) in the past decade. Changes in sexual practices, improved diagnosis and more effective treatments have dramatically reduced the incidence of chlamydia, gonorrhea and syphilis (1). On the other hand, in many countries the incidence of genital herpes (GH) infections has not declined. In the United States, the number of physician office visits for GH has increased markedly since 1966 (1). There are likely several reasons why significant declines have not been observed: the period of infectivity may extend over many years, GH may be less effectively prevented by condom use, diagnosis of subclinical infections is technically difficult, and no curative treatments are available. Many patients have numerous asymptomatic recurrences and are unable to identify periods of increased infectivity.There is evidence that the relative prevalence of herpes simplex virus type 1 (HSV-1) and HSV-2 genital infections may be changing. Recent studies from Scandinavia and the United States suggest that HSV-1 infections are increasingly prevalent (2-5). We reviewed the results of genital cultures performed at our hospital over a 30-month period to determine whether this is also the case in Nova Scotia.     

Patients' preference of valacyclovir once-daily suppressive therapy versus twice-daily episodic therapy for recurrent genital herpes: a randomized study

BACKGROUND: Valacyclovir is effective for suppressive and episodic treatment of recurrent genital herpes. Few data on patients' treatment strategy preferences are available. GOAL: The goal was to assess patients' preference, satisfaction, and quality of life with suppressive versus episodic treatment of recurrent genital herpes. STUDY DESIGN: This was a multicenter, open-label, randomized, two-arm, crossover 48-week study involving 225 patients with genital herpes. RESULTS: Suppressive valacyclovir therapy was preferred to episodic valacyclovir treatment by 72% of patients (P < 0.001). Overall treatment satisfaction and quality of life were significantly greater during suppressive therapy (P < 0.001 and P = 0.002, respectively). The risk of recurrence during the first 24 weeks was reduced by 78% with suppressive therapy (P < 0.001). Significantly fewer patients experienced recurrences during suppressive treatment than with episodic treatment (P < 0.001). Valacyclovir was well tolerated. CONCLUSIONS: Suppressive valacyclovir was preferred to episodic therapy by most patients. Suppressive therapy was associated with increased treatment satisfaction, and decreased risk and lower frequency of recurrences.     

Acetylcholine-induced production of reactive oxygen species in adult rabbit ventricular myocytes is dependent on phosphatidylinositol 3- and Src-kinase activation and mitochondrial K(ATP) channel opening

Acetylcholine (ACh), like ischemic preconditioning (PC), protects against infarction and is dependent on generation of reactive oxygen species (ROS). To investigate the mechanism by which ACh causes ROS production, isolated adult rabbit cardiomyocytes underwent a timed incubation in reduced MitoTracker Red, which is oxidized to a fluorescent form after exposure to ROS. The mitochondrial ATP-sensitive potassium (mK(ATP)) channel opener diazoxide (50 microM) increased fluorescence by 47 +/- 9% (P = 0.007), indicating that opening of mK(ATP) leads to ROS generation, and that increase was blocked by the mK(ATP) blocker 5-hydroxydecanoate (5HD, 1 mM); 250 microM ACh caused a similar increase in ROS generation (+45 +/- 6% for all experiments, P < 0.001). ACh-induced ROS production was prevented by (1) blockade of muscarinic surface receptors with 100 microM atropine (-6 +/- 2%, P = n.s.) or 250 nM 4-DAMP (+5 +/- 13%, P = n.s.), indicating that ACh's effect was receptor mediated; (2) closing K(ATP) channels with either the non-selective channel closer glibenclamide (50 microM) (-1.2 +/- 17%, P = n.s.) or the selective mK(ATP) closer 5HD (-1.8 +/- 9%, P = n.s.), indicating that increased ROS production involved opening of mK(ATP); (3) blockade of mitochondrial electron transport chain with 200 nM myxothiazol (-4 +/- 9%, P = n.s.), indicating ROS came from the mitochondria; (4) addition of 100 nM wortmannin (-13 +/- 12%, P = n.s.), indicating that phosphatidylinositol 3-(PI3)-kinase was involved; and (5) blockade of Src-kinase with 1 microM PP2 (-2 +/- 5%, P = n.s.), indicating the involvement of an Src-kinase. These results support the hypothesis that occupation of muscarinic surface receptors by ACh causes activation of PI3- and Src-kinases that then open mK(ATP) resulting in mitochondrial ROS generation and triggering of the preconditioned state.     

Endovascular repair of an infrarenal abdominal aortic aneurysm with a dominant middle mesenteric artery: A case report

The middle mesenteric artery is a rare anomalous mesenteric vessel that may supply variable segments of the colon. Occlusion of this artery during endovascular aortic aneurysm repair may bear a significant risk of bowel ischemia. We report the successful interventional treatment of a patient with a 5.3 cm infrarenal abdominal aortic aneurysm, sparing a dominant middle mesenteric artery.