Prevalence of gonorrhea and chlamydia in a community clinic for Men who Have Sex with Men in Portugal

Background

Men who have sex with men (MSM) are at greater risk for sexually transmitted infections (STIs). Data on MSM chlamydia and gonorrhea prevalence estimates and associated risk factors is scarce. To our knowledge, this is the first study to describe the prevalence and the determinants of both chlamydia and gonorrhea infections in MSM in Portugal.

Methods

We conducted a cross-sectional study using data from 1,832 visits to CheckpointLX, a community-based center for screening blood-borne viruses and other STIs in MSM.

Results

Overall prevalence of chlamydia or gonorrhea in our sample was 16.05%, with 14.23% coinfection and 40.73% asymptomatic presentation among those testing positive. Anorectal infection was most common for chlamydia (67.26%), followed by urethral (24.78%) and oral (19.47%) infection. Oral infection was most common for gonorrhea (55.63%), followed by anal (51.25%) and urethral (17.50%) infection. In multivariate analyses, young age (U = 94684, p = 0.014), being foreign-born (χ2=11.724, p = 0.003), reporting STI symptoms (χ2=5.316, p = 0.021), inhaled drug use (χ2=4.278, p = 0.039) and having a higher number of concurrent (χ2=18.769, p < 0.001) or total (χ2=5.988, p = 0.050) sexual partners were each associated with higher rates of chlamydia or gonorrhea infection.

Conclusions

Young and migrant MSM are a vulnerable population to STIs, as are those who use inhaled drugs and those with a higher number of concurrent or total sexual partners. Although Portugal has no guidelines on chlamydia and gonorrhea screening, our results point towards a need for greater awareness about the importance of high frequency screening for those at increased risk (i.e. every 3 to 6 months).

Key messages

Higher prevalence was found in young and migrant MSM, those with higher number of concurrent or total sexual partners, and those who use inhaled drugs. There is a need for greater awareness about the importance of high frequency STI screening for MSM at increased risk.

Estudio anatómico de la vascularización peroneal y su importancia clínica para el injerto vascularizado de peroné

Introducción: Desde que Ueba utilizara por primera vez el injerto óseo vascularizado de peroné en 1973, esta técnica se ha usado con éxito como método de reconstrucción de múltiples tipos de defectos óseos. La correcta vascularización del injerto es clave para su supervivencia. El objetivo de este trabajo es describir la vascularización diafisaria y epifisaria proximal del peroné.

Material y método: Se utilizaron 12 especímenes de cadáver criopreservado inyectados con látex negro. Se procedió a su disección, seguida de una técnica de corrosión en solución alcalina para demostrar la distribución de la red vascular del peroné de forma precisa.

Resultados: Observamos que el peroné recibe su irrigación sobre todo de una abundante red de vasos periósticos en la diáfisis y en menor medida de la arteria nutricia. Apreciamos que la epífisis proximal presenta entre 2 y 6 ramos recurrentes, procedentes de las arterias tibial anterior y tronco tibioperoneo.

Conclusión: El aporte vascular perióstico de la diáfisis del peroné es el mayoritario, siendo limitada la vascularización a través de la arteria nutricia. En la epífisis proximal, la presencia de vasos recurrentes accesorios puede ser de relevancia durante la cirugía.

Estudio de las unidades neurofuncionales del flexor carpi ulnaris y su utilidad en las transferencias tendinosas

Objetivos: Este trabajo pretende documentar la inervación intramuscular del flexor carpi ulnaris (FCU), su vascularización, y su consecuente organización en unidades neurofuncionales. Así mismo, se discute la relevancia de dichas unidades en la realización de transferencias tendinosas de este músculo con su tendón dividido. Aunque en algunos centros ya se ha puesto en práctica la idea de dividir el tendón, hay pocos trabajos en la literatura que demuestren fotográficamente el sustrato anatómico subyacente.

Material y métodos: Se tiñeron según la técnica de Sihler 6 FCU extraídos de cadáveres humanos criopreservados. Para estudiar su vascularización, en 5 de ellos se inyectó el árbol arterial con látex negro.

Resultados: En todos los especímenes ambas cabezas del FCU se correspondían con dos unidades neurofuncionales que presentaban una inervación independiente (tipo iii de Taylor). Los 5 especímenes inyectados pertenecían a los tipos ii y iii de Mathes-Nahai.

Conclusiones: La divisibilidad del músculo en 2 unidades neurofuncionales independientes con vascularización e inervación propia permite obtener 2 tendones transferibles a 2 músculos diferentes, optimizándose la transferencia.

Abstract P2-06-11: Wild type N-Ras, overexpressed in basal-like breast cancer, promotes tumor formation by inducing IL8 secretion via JAK2 activation

"Basal-like" breast cancer (BLBC) is a very aggressive subtype of breast cancer. BLBC has very poor prognosis — median time to distant recurrence is just 2.6 years vs. 5 years overall, and survival time from diagnosis of distant metastatic disease is 9 months vs. 22 months. BLBC tumors usually do not express ER, Her2, or progesterone receptor. As such, they cannot be treated by the current targeted therapies, which target these molecules. What drive the formation and progression of BLBCs is largely unclear.

Ras GTPases are best known for mediating growth factor signaling. Oncogenic mutations in the RAS genes, K-RAS in particular, are found in more than 30% of human tumors. Surprisingly, oncogenic RAS mutations are rare in breast cancer. However, we found that wild-type N-RAS is overexpressed in BLBCs, possibly partly via promoter demethylation, but not in other breast cancer subtypes. Repressing N-RAS inhibits transformation and tumor growth, while overexpressing it enhances these processes even in preinvasive BLBC cells. In contrast, in breast cancer cells of other subtypes, repressing N-RAS expression does not affect growth and transforming activities. We identified N-Ras-responsive genes, most of which encode chemokines and cytokines, e.g., IL8. High expression levels of these N-Ras-responsive genes as well as of N-RAS itself in tumors correlate with poor patient outcome. N-Ras, but not K-Ras, induces IL8 by binding and activating the cytoplasmic pool of JAK2; IL8 then acts on both the cancer cells and stromal fibroblasts.

In conclusion, N-Ras drives BLBC by promoting transformation in epithelial cells, which may in turn remodel the tumor microenvironment to create a proinvasive state. Although oncogenic mutations affecting RAS are common in many other human cancers, tumorigenesis in an important subset of breast cancers is driven instead by increasing activity of wild-type N-Ras. Thus, to fully assess the impact of Ras on tumorigenesis, the role of wild-type as well as mutant Ras proteins must be carefully examined.

Citation Format: Zheng Z-Y, Bu W, Tian L, Fan C, Gao X, Zhang X, Yu C, Wang H, Liao Y-H, Li Y, Lewis MT, Edwards D, Zwaka TP, Hilsenbeck SG, Medina D, Perou CM, Creighton CJ, Zhang XH, Chang EC. Wild type N-Ras, overexpressed in basal-like breast cancer, promotes tumor formation by inducing IL8 secretion via JAK2 activation. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-06-11.

Antenatal corticosteroids and perinatal outcomes in infants born at 23-25 weeks of gestation

OBJECTIVES

To evaluate the perinatal results of infants born between 23 and 25.6 weeks of gestation.

METHODS

Medical charts of all women giving birth prematurely (23-25.6 w) from January 2005 to December 2011 were retrospectively reviewed. Cases of malformed infants or deliveries elsewhere were excluded.

RESULTS

198 infants were included. Chorioamnionitis occurred in 86 (43.4%) of the whole group: 26 (86.7%) in the 23-week; 35 (53.8%) in the 24-week and 25 (24.3%) in the 25-week groups. Foetal maturation with antenatal corticosteroids was complete in 119 cases (60.1%): 4 (13.3%) in the 23-week; 35 (53.8%) in the 24-week and 80 (77.7%) in the 25-week groups. Foetal death at birth occurred in 22 cases (11%) and 61 newborns (30.8%) died in the neonatal period. Of the 106 survivors with 2 years complete follow-up, 45 infants (42.4%) did not present sequelae; 16 infants (15.1%) had severe sequelae. A 66.6% (4) of infants born at 23 weeks of gestation did not present sequelae compared with a 32.3% (11) at 24 weeks and 45.4% (30) at 25 weeks.

CONCLUSIONS

The chorioamnionitis rate was higher when gestational age was lower. The foetal maturation rate was higher when gestational age was higher. A low severe sequelae rate was observed in the whole series, particularly in the 23-week group where the rate was lower than expected; however, these results could have been influenced by the small size of the 23-week group.

Cell-virus Interactions with the Polyoma Virus: The Induction of Cell Transformation and Malignancy in vitro

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Assessment and follow-up of muscle injuries in athletes by bioimpedance: preliminary results

Mono-frequency (50 kHz) whole-body and segmental bioimpedance is measured before sport training in 14 high performance athletes. The athletes are classified in two groups according to the team sport: football and basketball. Bioelectrical impedance vector analysis (BIVA) method is used to obtain the individual whole-body impedance and 6 segmental impedance vectors in the main muscular groups in the lower-limbs. The whole-body vector is analyzed in the tolerance ellipses of the reference population. Individual impedance vector components are standardized by the height H of the subject, (R/H and Xc/H) to obtain the impedance vector (Z/H) of each segment. The hypotheses of the study are: 1) Not all the sports have the same pattern of bioimpedance vector by muscle group. 2) In elite well trained athletes their muscle groups are symmetrical (right and left sides), thus each athlete is its own reference for future comparisons. 3) We expect a change in the two components of bioimpedance vector (R/H and Xc/H) in front of a muscle injury. In order to compare the differences between the complex Z/H vector (R/H, Xc/H) we use Hotelling's T2 test. Preliminary results show a significant difference (P < 0.05) in bioimpedance vectors between groups according to the team sport, and also between normal muscle condition and after muscle injury producing hyper-hydration.

Abstract P1-03-12: The First Reproducible Model of Primary Human Ductal Carcinoma In Situ (DCIS) Using the Mouse Intraductal (MIND) Method

Past studies of the molecular mechanisms regulating human DCIS progression to invasion have been limited by a lack of suitable human models. The current models have not utilized primary human DCIS placed in their natural microenvironment, i.e., inside the mammary ducts, and do not mimic the heterogeneity of human DCIS. Previously, we reported the development of a mouse xenograft model using established breast DCIS cell lines, SUM-225 and DCIS.COM by the mouse intraductal (MIND) method. MIND involves injection of human DCIS cells into the primary ducts of immunodeficient mouse mammary glands via the nipple. In this study we demonstrate the reproducible growth of human primary DCIS cells derived from patient biopsy samples using the MIND model. Core biopsies from consenting patients are processed to isolate the epithelial cell component and injected. To date, 69 patients have consented to provide core biopsy tissue and we have received tissue from 38. Of these, 14 samples have been confirmed as positive for DCIS, and 2 as atypical hyperplasia, based on the pathology report of adjacent biopsies. The biopsy samples were heterogeneous with respect to ER, PR, Ki67, Her-2 and histology. A total of 24 mammary glands from immunodeficient mice have been injected with these cells and analyzed for growth by immunofluorescent (IF) with antibodies directed at human-specific cytokeratin-5 and/or 19 and smooth muscle actin.

Table 1. Summary of grewlh of human primary biopsies in (tie MIND xenograft

The average number of cells recovered per mg of tissue are shown in Table 1. Biopsies diagnosed as normal yielded only 91±34 cells/mg compared with most DCIS cases that showed an average cell number of 971 per mg tissue. Our results indicate that human DCIS and hyperplasia cells from biopsy samples are capable of growing within the NOD-SCID IL2Rgammanull (NSG) mouse mammary ducts. NSG mice mammary ducts are more suitable hosts for the growth of human primary DCIS cells, compared to SCID-Beige. Furthermore, the higher number of cells recovered following digestion predicted the positive DCIS growth rate. DCIS cells formed single and multi-layered epithelium inside the ducts and were heterogeneous with respect to the expression of human specific cytokeratins. The MIND xenografts recapitulated the patient's original DCIS as evidenced by IF staining for the biomarkers ER and Her-2 in the primary human biopsies and MIND xenografts. These results provide the first reproducible model of primary human DCIS for studying the temporal processes of early breast cancer progression. Future experiments will characterize the cellular basis for the subtypes of DCIS and delineate the distinct molecular and cellular mechanisms of early breast cancer invasion, and cancer stem cell growth and self-renewal.

Genes Regulating the Progression of Human Ductal Carcinoma In Situ to Invasive Breast Cancer

Rationale: The progression of human ductal carcinoma in situ (DCIS) to invasive breast cancer (IBC) represents a major potentially life-threatening event. Our understanding of this process is rudimentary. Improved understanding could lead to better ability to predict and new therapeutic strategies to prevent progression, which would be major contributions to health care. Objectives: To identify genes involved in regulating the progression of human DCIS to IBC, and to confirm their involvement utilizing relevant in vitro and in vivo model systems. Methods: Gene expression profiles were evaluated in five complimentary cohorts of human DCIS and IBC (total n=59 in each category) using cDNA microarray technology. Supervised statistical comparisons were used to identify differentially expressed genes in each cohort. The genes were distilled to top priority candidates by the following vetting strategy: (1) expression changed in same direction in 2 or more cohorts; and (2) they possessed known biological functions which might reasonably be involved in regulating tumor invasion; and (3) they had not been studied in the context of breast cancer invasion. Initial studies have focused on candidate invasion-suppressor genes (down-regulated in IBC vs. DCIS). A human DCIS-like cell line (DCIS.COM) was stably transduced with shRNAi against the genes (3-5 hairpins each) and evaluated in vitro and in vivo for changes in invasion-related behaviors vs. controls (growth and migration in 2D and 3D cell cultures, invasion in 3D culture, and a human-in-mouse [HIM} DCIS xenograft model). The latter is a novel method we developed where cells are injected into the nipple duct of intact mammary glands of immune-compromised mice. They initially grow as DCIS which progress to IBC at varying rates depending on the cells. Results: Two novel invasion-suppressor genes (CSTA and FAT1) were identified based on demonstrating significantly increased growth, migration, and invasion in the assays described. In particular, shCSTA (n=22) and shFAT1 (n=22) HIM DCIS xenografts progressed to large IBCs by 10 weeks or less, significantly (P&lt;.0001) greater than observed in controls (n=26) (67%, 64%, vs. 26%, respectively). Conclusions: We have identified two genes (CSTA and FAT1) whose normal functions appear to suppress the progression of human DCIS to IBC. These results could lead to new therapeutic strategies to prevent or suppress progression.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6141.

Molecular studies in the GJB2 gene (Cx26) among a deaf population from Bogotá, Colombia: results of a screening program

OBJECTIVE

We conducted a pilot screening program to define the prevalence of non-syndromic deafness and establish the frequency of mutations in the GJB2 gene (Cx26) in a population of children with congenital deafness in Bogotá, Colombia.

METHOD

From a cohort of 731 children in 8 institutions for the deaf, we identified 322 (44%) with presumed non-syndromic deafness. These were invited to a more detailed evaluation, but 46 chose not to participate. The remaining 276 individuals received a complete ophthalmological evaluation that was normal in 205 (74.3%) and showed salt and pepper retinopathy in 55 (19.9%) and other ocular abnormalities in 16 (5.8%). A comprehensive medical history, and a detailed physical examination were performed in the 205 children with normal ocular exam. Of these, 93 were found to have acquired deafness and/or associated anomalies and 112 (15.3% of the initial 731 children), non-syndromic deafness. The GJB2 gene was sequenced in these 112 individuals.

RESULTS

Based on family history, 59.8% (67/112) of these cases had autosomal recessive non-syndromic sensorineural hearing loss and the remaining 40.2% (45/112) were sporadic, without apparent known cause. We identified three mutations in the GJB2 gene: 35delG, S199F, and 167delT, all of which have been previously reported in the literature, the variant M34T, and the polymorphism V27I. S199F was the most frequent mutation (17.9%), followed by 35delG (17.0%) and 167delT (0.4%). The mutations in the GJB2 gene were present in 50.7% of the autosomal recessive group and in 33.3% of the sporadic cases.

CONCLUSIONS

Our pilot study showed that 15.3% of institutionalized deaf children in Bogotá have non-syndromic deafness and among them, the frequency of the S199F mutation was higher than reported in previous studies, whereas the frequency of the 35delG is similar to Caucasian populations. The fact that the S199F mutation was the most frequent allele in our study confirms the fact that the prevalence of GJB2 mutations depends on the ethnic origin. We emphasize the need to follow a strict protocol to identify bona fide cases of non-syndromic deafness among individuals with congenital hearing loss in order to identify the molecular basis of this condition.

How to manage post stapedotomy reparative granuloma

Different techniques for restoration of hearing in patients with conductive hearing loss due to otosclerosis have been developed with excellent hearing improvement in most of the cases. However, nowadays complications and failures still compromise expected results and necessitate revision surgery.

OBJECTIVE

This article aims to report the management of reparative granuloma after stapes surgery.

CASE REPORT

A case of poststapedotomy sudden sensory hearing loss is described. A reparative granuloma was found and removed during revision surgery. All the symptoms including hearing and tinnitus returned to normal. This patient did not present vertigo.

CONCLUSION

Hypothesis to explain this evolution is exposed. Reparative granuloma is an emergency and needs as soon as possible a revision surgery.

Genetic counseling in Usher syndrome: linkage and mutational analysis of 10 Colombian families

Usher Syndrome (US), an autosomal recessive disease, is characterized by retinitis pigmentosa (RP), vestibular dysfunction, and congenital sensorineural deafness. There are three recognized clinical types of the disorder. In order to improve genetic counseling for affected families, we conducted linkage analysis and DNA sequencing in 10 Colombian families with confirmed diagnosis of US (4 type I and 6 type II). Seventy-five percent of the US1 families showed linkage to locus USH1B, while the remaining 25% showed linkage to loci USH1B and USH1C. Among families showing linkage to USH1B we found two different mutations in the MYO7A gene: IVS42-26insTTGAG in exon 43 (heterozygous state) and R634X (CGA-TGA) in exon 16 (homozygous state). All six US2 families showed linkage to locus USH2A. Of them, 4 had c.2299delG mutation (1 homozygote state and 3 heterozygous); in the remaining 2 we did not identify any pathologic DNA variant. USH2A individuals with a 2299delG mutation presented a typical and homogeneous retinal phenotype with bilateral severe hearing loss, except for one individual with a heterozygous 2299delG mutation, whose hearing loss was asymmetric, but more profound than in the other cases. The study of these families adds to the genotype-phenotype characterization of the different types and subtypes of US and facilitates genetic counseling in these families. We would like to emphasize the need to perform DNA studies as a prerequisite for genetic counseling in affected families.

Inhibition of mammary tumorigenesis by estrogen and progesterone in genetically engineered mice

Estrogen and progesterone play a critical role in normal and neoplastic development of the mammary gland. A long duration of estrogen and progesterone exposure is associated with increased breast cancer risk, and a short duration of the same doses of these hormones is associated with a reduced breast cancer risk. The protective effects of estrogen and progesterone have been extensively studied in animal models. Several studies have demonstrated that these hormones induce persistent and long-lasting alterations in gene expression in the mammary epithelial cells. In the experiments discussed herein, the protective effect of estrogen and progesterone is shown to occur in genetically engineered mice (the p53-null mammary gland). The protective effect is associated with a decrease in cell proliferation. The effects of hormones seem to manifest as a delay in premalignant progression. In the nontumor-bearing glands of hormone-treated mice, premalignant foci are present at the time the control glands are actively developing mammary tumors. If the hormone-treated cells are transplanted from the treated host to the untreated host, the cells resume their predetermined tumorigenic potential. The protective effect reflects both host-mediated factors (either stroma-determined or systemic factors) and mammary epithelial intrinsic changes. If normal, untreated p53 cells are transplanted into a host that has been previously treated with a short dose of hormones, the cells exhibit a significant delay in tumorigenesis. The relative contributions of host-mediated factors and mammary cell intrinsic factors remain to be determined. Current studies are moving this research area from the biological to the molecular realm and from the rodent models to human studies and offer the potential for directing prevention efforts at specific molecular targets.

Expression of heregulin by mouse mammary tumor cells: role in activation of ErbB receptors

The inappropriate activation of one or more members of the ErbB family of receptor tyrosine kinases [ErbB-1 (EGFR), ErbB-2, ErbB-3, ErbB-4] has been linked with oncogenesis. ErbB-2 is frequently coexpressed with ErbB-3 in breast cancer cells and in the presence of the ligand heregulin (HRG) the ErbB-2/ErbB-3 receptors form a signaling heterodimer that can affect cell proliferation and apoptosis. The major goal of the present study was to determine whether endogenous HRG causes autocrine/paracrine activation of ErbB-2/ErbB-3 and contributes to the proliferation of mammary epithelial tumor cells. Tyrosine-phosphorylated (activated) ErbB-2 and ErbB-3 receptors were detected in the majority of extracts from tumors that had formed spontaneously or as a result of oncogene expression. HRG-1 transcripts and protein were found in the epithelial cells of most of these mouse mammary tumors. Various mouse mammary cell lines also contained activated ErbB-2/ErbB-3 and HRG transcripts. A approximately 50 kDa C-terminal fragment of pro-HRG was detected, which indicates that the HRG-1 precursor is readily processed by these cells. It is likely that the secreted mature HRG activated the ErbB-2/3 receptors. Addition of an antiserum against HRG to the mammary epithelial tumor cell line TM-6 reduced ErbB-3 Tyr-phosphorylation. Treatment with HRG-1 siRNA oligonucleotides or infection with a retroviral construct to stably express HRG siRNA effectively reduced HRG protein levels, ErbB-2/ErbB-3 activation, and the rate of proliferation, which could be reversed by the addition of HRG. The cumulative findings from these experiments show that coexpression of the HRG ligand contributes to activation of ErbB-2/Erb-3 in mouse mammary tumor cells in an autocrine or paracrine fashion.

Challenges in the stratification of breast tumors for tailored therapies

Studying the molecular stratification of breast carcinoma is a real challenge considering the extreme heterogeneity of these tumors. Many patients are now treated following recommendation established at several NIH and St Gallen consensus conferences. However a significant fraction of these breast cancer patients do not need adjuvant chemotherapies while other patients receive inefficacious therapies. High density gene expression arrays have been designed to attempt to establish expression profiles that could be used as prognostic indicators or as predictive markers for response to treatment. This review is intended to discuss the potential value of these new indicators, but also the current weaknesses of these new genomic and bioinformatic approaches. The combined analysis of transcriptomic and genomic alteration data from relatively large numbers of well annotated tumor specimens may offer an opportunity to overcome the current difficulties in validating recently published non overlapping gene lists as prognostic or therapeutic indicators. There is also hope for identifying and deciphering signal transduction pathways driving tumor progression with newly developed algorithms and semi quantitative parameters obtained in simplified in vitro or in vivo models for specific transduction pathways.

Anti-tumor activity of partially HLA-matched irradiated blood mononuclear cells in patients with advanced malignancies

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Background: We previously demonstrated the safety and efficacy of HLA-haploidentical blood mononuclear cells (MNCs) administered in the absence of preparative therapy to patients with metastatic renal cell carcinoma (RCC) (J Clin Oncol 21:3785–91.2003). The efficacy of this therapy is evaluated further in patients with advanced malignancies. Methods: Patients with advanced malignancies who had HLA- haploidentical donors were enrolled. Donors underwent 12–15 L leukapheresis. MNCs were processed by irradiation (25 Gy) and immediately infused. Disease evaluation was undertaken every 8 weeks. Repeat infusions were given every 8 weeks until disease progression. Results: 30 patients with diverse diagnoses, including 9 patients with a hematological malignancy were treated. Three of 13 patients with RCC had disease response, and 1 of 2 patients with melanoma had a mixed response. A patient with imatinib mesylate-refractory chronic myelogenous leukemia (CML) had a transient response. A patient with refractory acute myelogenous leukemia (AML) had disease response in conjunction with therapy. Treatment was associated with minimal toxicity and radiographic responses in patients with RCC did not occur until after 2–3 treatments. Host CD8+ cells reactive with the Pr-1 peptide of proteinase 3 were induced in association with disease response in a patient with AML. Additional studies identifying disease targets and mechanisms by which infusion of irradiated HLA-haploidentical cells are associated with disease response are ongoing. Conclusions: Disease response is seen with irradiated allogeneic MNCs administered outside the context of hematopoietic stem-cell transplantation. Evidence for anti-tumor activity is seen in isolated patients with RCC, melanoma, CML and AML. The temporal nature of the response in RCC in combination with the very limited survival of the infused cells raises the possibility of induction of a host-mediated anti-tumor effect. This hypothesis is supported by induction of host CD8+ T cells reactive with a tumor-associated peptide in a patient with AML. Given the lack of toxicity, broad availability of related haploidentical donors and the relative low financial cost, this form of cellular therapy should be developed further.

No significant financial relationships to disclose.

PAK1 hyperactivation is sufficient for mammary gland tumor formation

Emerging data suggest that p21-activated kinase 1 (Pak1), a downstream signaling molecule of the small GTPases, growth factors, and lipid signaling, is upregulated or hyperactivated in human breast cancer. Until now, however, no direct causative role had been found for Pak1 in mammary tumor formation. We therefore sought to identify the role that Pak1 plays in mammary gland tumorigenesis. Our results showed that in a transgenic mouse model, overexpression of catalytically active Pak1 leads to the development of malignant mammary tumors and to a variety of other breast lesions, including focal solid nodules, ductal hyperplasia, and mini-intraductal neoplasm and adenoma. We also found that Pak1 hyperactivation increases the stimulation of downstream proliferative signaling effectors MEK1/2 and p38-MAPK in mammary tumor epithelial cells. Moreover, in our study, we detected expression of estrogen receptor-alpha expression and progesterone receptor expression during early stages of the lesions, but their expression was lost during the cells' transition to malignant invasive tumors. Finally, we found that consistent with a role in breast tumor progression, Pak1 expression and its nuclear accumulation was increased progressively during the transition from ductal hyperplasia to ductal carcinoma in situ to adenocarcinoma in widely used multistep polyoma-middle T-antigen transgenic mice. Together, these findings provide the first direct evidence that Pak1 deregulation may be sufficient for the formation of mammary gland tumors.

Modeling human breast cancer metastasis in mice: maspin as a paradigm

Breast cancer is the most common cancer detected in women, accounting for nearly one out of every three cancers diagnosed in the United States. Most cancer patients do not die from the primary tumor but die due to metastasis. Therefore, the study of metastasis is of most importance both to the clinician and patient. In the past, animal models have been used in breast cancer research and mammary gland biology. Our group has also established several animal models to address the function of a novel tumor suppressor gene maspin in breast tumor progression. Maspin was initially isolated from normal mammary epithelial cells. Its expression was down regulated in breast tumors. To test the protective role of maspin overexpression in mammary tumor progression, we crossed maspin overexpression transgenic mice (WAP-maspin) with a strain of oncogenic WAP-SV40 T antigen mice. The bitransgenic mice had reduced tumor growth rate and metastasis. Maspin overexpression increased the rate of apoptosis of both preneoplastic and carcinomatous mammary epithelial cells. Maspin reduced tumor growth through a combination of reduced angiogenesis and increased apoptosis. In a separate animal experiment, maspin overexpressing mammary tumor cells (TM40D) were implanted into the fat pad of syngeneic mice. TM40D tumor cells were very invasive and metastatic. However, both primary tumor growth and metastasis were significantly blocked in TM40D cells that overexpress maspin as a consequence of plasmid or retrovirus infection. These evidences demonstrate that maspin function to inhibit primary tumor growth as well as invasion and metastasis. Elucidating the molecular mechanism of maspin action will shed light on our understanding of breast cancer invasion and metastasis.

Se-methylselenocysteine: a new compound for chemoprevention of breast cancer

Selenium compounds have attracted renewed interest as chemopreventive agents for human cancer on the basis of the pioneering intervention study by Clark and co-workers. The rodent mammary gland has been used extensively as a model for examining the chemopreventive activities of inorganic and organic selenium compounds. This review summarizes the rationale and results for use of a new organic selenium compound, Se-methylselenocysteine, which exhibits greater efficacy as a chemopreventive agent than several previously used selenium compounds in experimental models of breast cancer and has potential for use in human populations.

Mechanisms of hormonal prevention of breast cancer

Reproductive history is a consistent risk factor for human breast cancer. Epidemiological studies have repeatedly demonstrated that early age of first pregnancy is a strong protective factor against breast cancer and provides a physiologically operative model to achieve a practical mode of prevention. In rodents, the effects of full-term pregnancy can be mimicked by a three-week exposure to low doses of estrogen and progesterone. Neither hormone alone is sufficient to induce protection. The cellular and molecular mechanisms that underlie hormone-induced refractoriness are largely unresolved. Our recent studies have demonstrated that an early cellular response that is altered in hormone-treated mammary cells is the initial proliferative burst induced by the chemical carcinogen methylnitrosourea. The decrease in proliferation is also accompanied by a decrease in the ability of estrogen receptor-positive cells to proliferate. RNA expression of several mammary cell-cycle-related genes is not altered in hormone-treated mice; however, immunohistochemical assays demonstrate that the protein level and nuclear compartmentalization of the p53 tumor suppressor gene are markedly upregulated as a consequence of hormone treatment. These results support the hypothesis that hormone stimulation, at a critical period in mammary development, results in cells with persistent changes in the intracellular regulatory loops governing proliferation and response to DNA damage. A corollary to this hypothesis is that the genes affected by estrogen and progesterone are independent of alveolar differentiation-specific genes. Suppressive subtractive hybridization-PCR methods have identified several genes that are differentially expressed as a consequence of prior estrogen and progesterone treatment. Future experiments are aimed at determining the mechanisms of hormone-induced upregulation of p53 protein expression as part of the overall goal of identifying and functionally characterizing the genes responsible for the refractory phenotype.

Wnt-1 and int-2 mammary oncogene effects on the beta-catenin pathway in immortalized mouse mammary epithelial cells are not sufficient for tumorigenesis

Development of strategies for prevention of breast cancer development requires an understanding of the effects of mammary oncogenes on mammary cells at early stages in neoplastic transformation. As mammary oncogenes wnt-1 and int-2 affect different signal transduction pathways, we investigated their effects on established mouse mammary epithelial cell lines (MMECLs) reflecting early stages in tumorigenesis. Normal interactions between beta-catenin and E-cadherin were abrogated in all three immortalized MMECLs and the cells lacked beta-catenin-mediated transactivation activity, detectable using a reporter assay, suggesting that alterations in cell adhesion may be very early events in mammary tumorigenesis. Immortalized FSK4 and EL12 cells and hyperplastic TM3 cells were stably transfected with expression vectors encoding wnt-1 or int-2 or the control vector, and drug-selected pooled cells from each line were confirmed by reverse transcription-polymerase chain reaction to express the transfected oncogene; this expression persisted in the cells analysed in vitro and in vivo. Resultant phenotypic changes depended both on the oncogene and the target mammary cell line. In FSK4 cells, expression of wnt-1 or int-2 resulted in proliferative changes in vitro, including reduced contact inhibition, increased beta-catenin expression, and decreased p53 transcriptional activity, but neither oncogene conferred upon those cells the ability to produce tumors in vivo. EL12 cells were highly refractory to the effects of both oncogenes, with the only measurable changes being increased E-cadherin levels induced by both oncogenes and increased proliferation of the int-2-transfected cells in the absence of serum. Parental TM3 cells were phenotypically similar to wnt-1- or int-2-transfected FSK4 cells and displayed an increased rate of proliferation in vitro and markedly increased tumorigenicity in vivo following transfection with int-2 but not with wnt-1. These results suggest that wnt-1 signaling is redundant in the hyperplastic TM3 cells and indicate that wnt-1-induced effects in the immortalized FSK4 and EL12 cells were not sufficient to mediate a tumorigenic phenotype. This study showed that the wnt-1 and int-2 oncogenes have similar but distinguishable effects on immortalized MMECLs and that the genetic background of the mammary cells greatly influences the consequences of oncogene expression at early stages of cell transformation.

p53 is a potential mediator of pregnancy and hormone-induced resistance to mammary carcinogenesis

Full-term pregnancy early in reproductive life is protective against breast cancer in women. Pregnancy also provides protection in animals against carcinogen-induced breast cancer, and this protection can be mimicked by using the hormones estrogen and progesterone. The molecular mechanisms that form the basis for this protective effect have not been elucidated. On the basis of our results, we propose a cell-fate hypothesis. At a critical period in adolescence the hormonal milieu of pregnancy affects the developmental fate of a subset of mammary epithelial cells and its progeny, which results in persistent differences in molecular pathways between the epithelial cells of hormone-treated and mature virgin mammary glands. These changes in turn dictate the proliferative response to carcinogen challenge and include a block in carcinogen-induced increase in mammary epithelial cell proliferation and an increased and sustained expression of nuclear p53 in the hormone-treated mammary gland. This hormone-induced nuclear p53 is transcriptionally active as evidenced by increased expression of mdm2 and p21 (CIP1/WAF1). Importantly, exposure to perphenazine, a compound that induces mammary gland differentiation but does not confer protection, does not induce p53 expression, indicating that p53 is not a differentiation marker. The proliferative block and induction of p53 are operative in both rats and mice, results that support the generality of the proposed hypothesis.

Campylobacter fetus diagnosis: direct immunofluorescence comparing chicken IgY and rabbit IgG conjugates

In Argentina Bovine Genital Campylobacteriosis is routinely diagnosed by direct immunofluorescence test. Generally, the hyperimmune sera used for this test are obtained from rabbits and less often from goats. In this work, a chicken egg yolk immunoglobulin (IgY) extract was conjugated and its ability to detect campylobacters with the regular conjugate prepared with rabbit sera was comparatively evaluated. Both conjugates were independently evaluated by two laboratories, named "Azul" (Lab A) and "Balcarce" (Lab B). Animals were immunised with formalin inactivated Campylobacter (C.) fetus cells. Chicken IgY and rabbit IgG were conjugated with fluorescein isothiocyanate and used to comparatively examine strains of C. fetus subspp., other Campylobacter spp. and different bacterial species. Both conjugates had a high percentage rate of detection for C. fetus. IgY had less background due to unspecific fluorescence than IgG. IgY is a cheap, bloodless and very productive method. IgY can replace mammal immunoglobulins for C. fetus diagnosis.

Early exposure of the rat mammary gland to estrogen and progesterone blocks co-localization of estrogen receptor expression and proliferation

An early single full-term pregnancy induces a long-lasting protective effect against mammary tumor development in humans and rodents. This protective effect can be mimicked in rats by short-term administration of estrogen and progesterone hormones prior to carcinogen administration. The hormones of pregnancy are able to induce a proliferative block upon carcinogen challenge that is not observed in the age-matched virgin. We wished to determine whether carcinogen is needed to induce a paracrine-to-autocrine shift of proliferation in steroid receptor positive cells or if such a cell population already exists in the age-matched virgin mammary gland. Here we show that estrogen receptor positive (ER+) proliferating cells are rare in the developing mammary gland of the virgin rat but represent the majority of the proliferating cells in the mature (96-day-old) mammary gland of the virgin rat. As the majority of the proliferating cells before carcinogen challenge were ER positive, the ER+ proliferating cells in the mature mammary gland may represent the target cells for carcinogen-induced transformation. Importantly, prior exposure of the mammary gland to pregnancy levels of estrogen/progesterone blocked this positive association. This ability to block the proliferation of the ER+ cells may be one factor by which pregnancy induces protection against breast cancer.

Blocking tumor growth, invasion, and metastasis by maspin in a syngeneic breast cancer model

Maspin is a unique serine protease inhibitor of which the down-regulation is associated with the development of breast cancers. In vitro, recombinant maspin inhibits tumor cell migration and invasion. Overexpression of maspin in transgenic mice is protective against tumor progression. Additionally, maspin acts as an angiogenesis inhibitor in rat cornea model and in a xenograft tumor model. To additionally prove that maspin is directly involved in the suppression of tumor growth and metastasis, we tested maspin in a new syngeneic mammary tumor model, TM40D. This model involves the implantation of TM40D mammary tumor cells orthotopically to the mammary gland; tumors grew within the gland and then become invasive and metastatic to other organs. Here we demonstrate that TM40D cells in implanted mammary glands are highly invasive. Overall, a 75% rate of invasion and metastasis was observed in this model. However, both primary tumor growth and metastasis were significantly blocked in TM40D cells that overexpress maspin as a consequence of plasmid or retrovirus infection. Maspin-transfected tumors tended to have tumor encapsulation and less necrosis, which were associated with better prognosis and lower invasiveness. Thus, maspin can block primary tumor growth as well as invasion and metastasis. These data support the concept that maspin has a strong protective role against tumor progression.

Nuclear factor-kappaB (NF-kappaB) regulates proliferation and branching in mouse mammary epithelium

The nuclear factor-kappaB (NF-kappaB) family of transcription factors has been shown to regulate proliferation in several cell types. Although recent studies have demonstrated aberrant expression or activity of NF-kappaB in human breast cancer cell lines and tumors, little is known regarding the precise role of NF-kappaB in normal proliferation and development of the mammary epithelium. We investigated the function of NF-kappaB during murine early postnatal mammary gland development by observing the consequences of increased NF-kappaB activity in mouse mammary epithelium lacking the gene encoding IkappaBalpha, a major inhibitor of NF-kappaB. Mammary tissue containing epithelium from inhibitor kappaBalpha (IkappaBalpha)-deficient female donors was transplanted into the gland-free mammary stroma of wild-type mice, resulting in an increase in lateral ductal branching and pervasive intraductal hyperplasia. A two- to threefold increase in epithelial cell number was observed in IkappaBalpha-deficient epithelium compared with controls. Epithelial cell proliferation was strikingly increased in IkappaBalpha-deficient epithelium, and no alteration in apoptosis was detected. The extracellular matrix adjacent to IkappaBalpha-deficient epithelium was reduced. Consistent with in vivo data, a fourfold increase in epithelial branching was also observed in purified IkappaBalpha-deficient primary epithelial cells in three-dimensional culture. These data demonstrate that NF-kappaB positively regulates mammary epithelial proliferation, branching, and functions in maintenance of normal epithelial architecture during early postnatal development.

Short-term exposure to estrogen and progesterone induces partial protection against N-nitroso-N-methylurea-induced mammary tumorigenesis in Wistar--Furth rats

The lifetime protective effect of a full term pregnancy for breast cancer is a reproducible and consistent finding in human beings and in rodent models. The duration of pregnancy necessary to confer protection has yielded contradictory results. As the administration of estrogen and progesterone mimics the full-term pregnancy effect on conferring protection, we examined whether short-term exposure to estrogen and progesterone confers protection against N-nitroso-N-methylurea-induced mammary carcinogenesis in Wistar--Furth rats. The results reported herein show that treatment of rats with estrogen or progesterone alone for 21 days does not confer protection, but a 10-day exposure to the same concentrations of estrogen and progesterone induced a partial protective effect. The significance of these results are discussed in terms of the contradictory results in the literature and the role of morphological differentiation in conferring the protective effect.

Cyclin-dependent kinase (cdk) inhibitors/cdk4/cdk2 complexes in early stages of mouse mammary preneoplasia

The level of circulating ovarian hormones (estrogen and progesterone) alone or in combination with pituitary hormones have a potent mitogenic impact in the normal mammary gland, and they also play a pivotal role in the development and progression of mammary carcinoma. The differential effects of hormones on the molecular components of cyclin-dependent kinase (cdk) complexes in mammary epithelium of the hormone-dependent ductal outgrowth line, EL11, and the hormone-independent alveolar outgrowth line, TM2L, were the focus of this study. The two outgrowth lines, which represent early stages in mammary hyperplasia, were compared with normal mammary gland at different hormonal conditions: control, hormone stimulated by pituitary isograft, and hormone depleted by ovariectomy. Hormonal stimulation by a pituitary isograft resulted in DNA synthesis and lobuloalveolar development of normal mammary ducts, DNA synthesis but no lobuloalveolar development in the EL11 ductal outgrowth, and no changes either in DNA synthesis or in lobuloalveolar morphology in the TM2L outgrowth. The levels of cdk4- and cyclin D1-associated kinase activities were correlated with cell proliferation in only the alveolar phenotypes (i.e., in only hormonally stimulated normal virgin gland and in alveolar mammary outgrowth), whereas cyclin D2-dependent kinase activity was correlated with cell proliferation in only the alveolar preneoplasia. p16(INK4a) and p21(Cip1) protein levels were decreased at the earliest stages of preneoplasia, i.e., at immortalization, and were independent from changes in cyclin D1, which occurred later in preneoplasia. Although all cdk inhibitors changed in concordance with hormonal status reflected by proliferation levels, p27(Kip1) was the only cdk inhibitor that was up-regulated at the earliest stages of preneoplasia and may have a unique role in blocking alveolar differentiation in response to the loss of one or more of the cell cycle-negative regulators. We hypothesize that up-regulation of p27(Kip1) prevents immortalized ductal outgrowths (EL11) from progressing to the neoplastic state, even under hormonal stimulation.

Methylseleninic acid, a potent growth inhibitor of synchronized mouse mammary epithelial tumor cells in vitro

Selenium compounds have been shown to be effective chemopreventive agents in several animal models and in cultured cells in vitro. It has been proposed that compounds able to generate monomethyl Se have an increased potential to inhibit cell growth. To test this hypothesis, methylseleninic acid (MSeA) and other compounds that could generate methylselenol rapidly were compared with Se compounds that do not generate monomethyl Se, using a well-characterized synchronized TM6 mouse mammary epithelial tumor model in vitro. MSeA at a low micromolar concentration inhibited TM6 growth after 10- to 15-min treatment times. Cells resumed growth after 24 hr but remained sensitive to the fresh addition of monomethyl Se-generators. Dimethyl selenide (DMSe), a putative metabolite of methylselenol, was inactive. Cells treated with 5 microM MSeA were arrested in G1. The effects of 5 microM MSeA on gene expression were evaluated using the Atlas mouse cDNA expression array. A 10-min exposure with MSeA caused a 2- to 3-fold change in the expression of three genes: laminin receptor 1 (decreased), integrin beta (decreased), and Egr-1 (increased). The results provide experimental support for the hypothesis that monomethylated forms of Se are the critical effector molecules in Se-mediated growth inhibition in vitro.

Mechanisms of suberoylanilide hydroxamic acid inhibition of mammary cell growth

The mechanism of suberoylanilide hydroxamic acid in cell growth inhibition involved induction of pRb-2/p130 interaction and nuclear translocation with E2F-4, followed by significant repression in E2F-1 and PCNA nuclear levels, which led to inhibition in DNA synthesis in mammary epithelial cell lines.