Role of AP-1 family members in lymphomagenesis

Constitutive activation of the nuclear factor-KB (NF-KB) transcriptional pathway is the main characteristic of the activated B-cell-like (ABC) subtype of diffuse large B- cell lymphoma (DLBCL). This has been attributed to oncogenic mutations in the CARMA1, CD79A/B, MyD88 or RNF31 signaling proteins, which control NF-kB activation at different levels. Since several of these mutations lead to a state that mimics chronically antigen receptor-stimulated B-cells, and since the antigen receptor also triggers other transcription pathways, these might be important in ABC DLBCL malignancy too. In this study we analyzed whether abnormal expression and activity of members of the AP-1 transcription factor family could contribute to the pathogenesis of ABC DLBCL. Here, we identified activation of Jun as well as ATF members of the dimeric AP-1 transcription factor family, as a hallmark of ABC but not of germinal center B- cell-like (GCB) DLBCL cell lines. ABC DLBCL cell lines harbored an upregulated expression of c-Jun, JunB, JunD and ATF3 proteins. We could show that the upregulation of c-Jun, JunB and ATF3 was dependent on constitutive BCR and MyD88 signaling. Since AP-1 transcription factors need to dimerize to be active, Jun binding partners were investigated and we could demonstrate the presence of several ATF/Jun heterodimers (including c-Jun/ATF2, c-Jun/ATF3, c-Jun/ATF7, JunB/ATF2, JunB/ATF3, JunB/ATF7, JunD/ATF2, JunD/ATF3 and JunD/ATF7 heterodimers). The disruption of ATF/Jun heterodimers by A-Fos, a dominant negative form of Jun members, was toxic to ABC but not to GCB DLBCL cell lines. Finally, ATF3 immunohistochemistry on DLBCL patient samples revealed that samples classified as non-GCB had more intense and preferentially nuclear staining of ATF3, which could be of diagnostic relevance since the histological classification of the ABC and GCB DLBCL subtypes is difficult in clinical practice. In conclusion, we could show that ABC DLBCL are not only addicted to NF-KB signaling, but also to signaling by some members of the AP-1 transcription factor family. Thus, the AP-1 pathway might be a promising therapeutic target for the treatment of ABC DLBCL. Additionally, monitoring ATF3 levels could improve the diagnosis of ABC DLBCL by IHC. -- L'activation constitutive du facteur de transcription NF-KB est l'une des caractéristiques principales des lymphomes B du type ABC-DLBCL. Cette addiction est dépendante de mutations oncogéniques de CARMA1, CD79A/B, MyD88 et RNF31 qui contrôlent NF-KB à différents niveaux. Etant donné que la plupart de ces mutations mène à un état d'activation chronique du récepteur des cellules B (BCR) et que le BCR active d'autres voies de signalisation, d'autres facteurs de transcription pourraient être impliqués dans la lymphomagénèse des ABC-DLBCL. Dans cette étude, nous nous sommes demandé si les membres de la famille du facteur de transcription AP-1 contribuaient à la pathogénèse de ce type de lymphome. Dans des lignées cellulaires de lymphomes du type ABC-DLBCL en comparaison avec le type GCB-DLBCL, nous avons pu identifier une activation anormale de plusieurs membres de la famille Jun et ATF, deux sous-familles du facteur de transcription AP-1. Les lignées cellulaires dérivées de lymphomes du type ABC-DLBCL surexpriment les facteurs de transcription c-Jun, JunB, JunD et ATF3. Leur surexpression dépend de l'activation constitutive de la voie du BCR et de MyD88. Etant donné qu'AP-1 requiert la formation de dimères pour être actif, nous nous sommes intéressés aux partenaires d'interactions de c-Jun, JunB et JunD et avons pu montrer la formation de plusieurs hétérodimères Jun/ATF (incluant les hétérodimères c-Jun/ATF2, c-Jun/ATF3, c-Jun/ATF7, JunB/ATF2, JunB/ATF3, JunB/ATF7, JunD/ATF2, JunD/ATF3 et JunD/ATF7). Lorsque l'on empêche la formation de ces hétérodimères avec A-Fos, un dominant négatif des membres Jun, la survie des lignées cellulaires du type ABC-DLBCL est diminuée, tandis que les lignées cellulaires GCB-DLBCL ne sont pas affectées. Pour finir, des immunohistochimies (IHC) pour ATF3 sur des échantillons de patients classifiés comme GCB et non-GCB ont pu montrer une coloration d'ATF3 nucléaire et beaucoup plus intense que les échantillons du type GCB. Ainsi, ATF3 pourrait être potentiellement utile en clinique pour différencier le sous type non-GCB des GCB. En conclusion, nous avons pu montrer que les lymphomes du type ABC- DLBCL ne présentent pas uniquement une addiction à NF-KB, mais également de certains membres de la famille de facteur de transcription AP-1. Par conséquent, AP- 1 pourrait être une cible thérapeutique prometteuse pour le développement de futures stratégies. En outre, la détermination des niveaux d'ATF3 par IHC pourraient améliorer le diagnostic des patients du type ABC DLBCL.

Beta-catenin Status in P?aediatric Medulloblastomas: correlation of immunohistochemical expression with mutational status, genetic profiles, and clinical characteristics.

Medulloblastoma is the most frequent malignant paediatric brain tumour. The activation of the Wnt/beta-catenin pathway occurs in 10-15% of medulloblastomas and has been recently described as a marker for favourable patient outcome. We report a series of 72 paediatric medulloblastomas evaluated for beta-catenin protein expression, CTNNB1 mutations, and comparative genomic hybridization. Gene expression profiles were also available in a subset of 40 cases. Immunostaining of beta-catenin showed extensive nuclear staining (>50% of the tumour cells) in six cases and focal nuclear staining (<10% of cells) in three cases. The other cases either exhibited a signal strictly limited to the cytoplasm (58 cases) or were negative (five cases). CTNNB1 mutations were detected in all beta-catenin extensively nucleopositive cases. The expression profiles of these cases documented strong activation of the Wnt/beta-catenin pathway. Remarkably, five out of these six tumours showed a complete loss of chromosome 6. In contrast, cases with focal nuclear beta-catenin staining, as well as tumours with negative or cytoplasmic staining, never demonstrated CTNNB1 mutation, Wnt/beta-catenin pathway activation or chromosome 6 loss. Patients with extensive nuclear staining were significantly older at diagnosis and were in continuous complete remission after a mean follow-up of 75.7 months (range 27.5-121.2 months) from diagnosis. All three patients with focal nuclear staining of beta-catenin died within 36 months from diagnosis. Altogether, these data confirm and extend previous observations that CTNNB1-mutated tumours represent a distinct molecular subgroup of medulloblastomas with favourable outcome, indicating that therapy de-escalation should be considered. International consensus on the definition criteria of this distinct medulloblastoma subgroup should be achieved.

Comparison of microsatellite instability and chromosomal instability in predicting survival of patients with T3N0 colorectal cancer.

BACKGROUND: At least 2 apparently independent mechanisms, microsatellite instability (MSI) and chromosomal instability, are implicated in colorectal tumorigenesis. Their respective roles in predicting clinical outcomes of patients with T3N0 colorectal cancer remain unknown. METHODS: Eighty-eight patients with a sporadic T3N0 colon or rectal adenocarcinoma were followed up for a median of 67 months. For chromosomal instability analysis, Ki-ras mutations were determined by single-strand polymerase chain reaction, and p53 protein staining was studied by immunohistochemistry. For MSI analysis, DNA was amplified by polymerase chain reaction at 7 microsatellite targets (BAT25, BAT26, D17S250, D2S123, D5S346, transforming growth factor receptor II, and BAX). RESULTS: Overall 5-year survival rate was 72%. p53 protein nuclear staining was detected in 39 patients (44%), and MSI was detected in 21 patients (24%). MSI correlated with proximal location (P <.001) and mucinous content (P <.001). In a multivariate analysis, p53 protein expression carried a significant risk of death (relative risk = 4.0, 95% CI = 1.6 to 10.1, P =.004). By comparison, MSI was not a statistically significant prognostic factor for survival in this group (relative risk = 2.2, 95% CI = 0.6 to 7.3, P =.21). CONCLUSIONS: p53 protein overexpression provides better prognostic discrimination than MSI in predicting survival of patients with T3N0 colorectal cancer. Although MSI is associated with specific clinicopathologic parameters, it did not predict overall survival in this group. Assessment of p53 protein expression by immunocytochemistry provides a simple means to identify a subset of T3N0 patients with a 4-times increased risk for death.

Analysen der beiden cis-regulierenden Sequenzelemente translational control element (TCE) und cytoplasmic polyadenylation element (CPE) in der Drosophila-Spermatogenese

Ein essentieller Bestandteil in dem Mechanismus der Translationskontrolle sind RNA-Pro­tein-Wechselwirkungen. Solche Interaktionen konnten in Translationssystemen an zwei unabhängigen cis-regulierenden Elementen durch in vitro-Bindungsanalysen mit individu­ellen rekombinanten Proteinen dokumentiert werden. Im Fall des translational control elements (TCE), welches ein konserviertes Sequenz-Ele­ment in der Mst(3)CGP-Genfamilie darstellt, wird eine negative Translationskontrolle durch die Bindung der Proteine CG3213, CG12470, CG1898, dFMR1, Exuperantia und Orb2 an diese Sequenz vermittelt (Stinski, 2011). Neben den in Bindungsstudien positiv getesteten Kandidaten dFMR1 und Orb2 (Stinski, 2011) wurde in der vorliegenden Dis­sertation CG3213 als weiterer direkter Bindungspartner an das TCE dokumentiert. Ein Abgleich der genomweiten Zusammenstellung von Proteininteraktionen in der Datenbank InterologFinder lieferte zwei weitere potentielle Kandidaten: CG34404 und CG3727. Al­lerdings schließen Northern-Analysen und das Proteinexpressionsmuster eine zentrale Rolle in der Drosophila-Spermatogenese für diese nahezu aus. In Kolokalisationsstudien einiger TCE-Komplex-Kandidaten mit CG3213 als Referenz konnten eindeutige Überein­stimmungen der Fluoreszenzmuster mit CG12470 in der postmeiotischen Phase be­schrieben werden, wohingegen mit Orb2 (postmeiotisch) und CG1898 (prämeiotisch) nur eine geringe Kolokalisation erkannt wurde. Punktstrukturen in den Verteilungsmustern sowohl von CG3213 als auch von CG12470 ließen sich nicht mit ER- und mitochondrien­spezifischen Markern korrelieren. Im Anschluss der Meiose konnte eine deutliche Intensitätserhöhung des CG3213-Proteins beobachtet werden, was eventuell durch eine veränderte Translationseffizienz zustande kommen könnte. Exuperantia (Exu) stellt einen bekannten Regulator für eine Reihe von translationskontrollierten mRNAs dar (Wang und Hazelrigg, 1994). Die Quantifizierungen der CG3213-mRNA in exu-mutantem Hintergrund bestätigen, dass auch die Transkript­menge der CG3213-mRNA durch Exu reguliert wird, was die obige Interpretation stützen würde. Für das zweite cis-regulierende Element, das cytoplasmic polyadenylation element (CPE), konnte eine direkte Bindung mit dem CPEB-Homolog in Drosophila (Orb2) gezeigt wer­den, welches auch eine Komponente des mst87F-RNP-Komplexes ist. Ein vermuteter Interaktionspartner dieses CPEBs ist Tob, weshalb die Verteilung beider Proteine in einem Kombinationsstamm verglichen wurde. In dem teilweise übereinstimmenden Fluoreszenz­muster ist Tob an den distalen Spermatidenenden auffallend konzentriert. Das gesamte Tob-Muster jedoch legt eine Verteilung in den Mitochondrien nahe, wie die MitoTracker®-Färbung belegt. Somit wurde erstmals ein Mitglied der Tob/BTG-Genfamilie in der Droso­phila-Spermatogenese mit Mitochondrien in Verbindung gebracht. Die Lokalisierung die­ser Proteine ist bislang unklar, jedoch konnte eine Kernlokalisation trotz der N-terminalen NLS-Sequenz mit Hilfe einer Kernfärbung ausgeschlossen werden.

Culture of mature trophoblastic giant cells from bovine placentomes

The mostly binucleate trophoblast giant cells (TGC) found in bovine placentomes, in addition to synthesizing and releasing hormones play an important role in fetal development and maternal adaptation to pregnancy. Placentomes from early gestation were collected, and for isolation of mature TGC, three cellular disaggregation methods, mechanical (MECH), enzymatic by trypsin (TRYP) or collagenase (COLL) were compared to each other. Further on, the cell survival in culture medium (DMEM) supplemented with either 10% fetal calf serum (FCS) or 10% serum replacement (SR) on culture plates free of any substrate was evaluated over a period of 90 days by trypan blue exclusion. The cells were further characterized by HOECHST 33342 nuclear staining, and immunocytochemical staining with monoclonal antibodies against vimentim and cytokeratin. A mean total rate of TGC survival of 82.56% was recorded. Statistical analysis showed significantly higher survival rates after enzymatic disaggregation with COLL (86.23%) than following MECH (80.38%) or TRYP (80.91%) treatment. Supplementation of DMEM with FCS resulted in significantly higher cellular survival rates (87.13%) when compared to the addition of SR (77.73%). Analysis of the influence of both, disaggregation method and medium supplementation on TGC survival revealed statistically significant differences between the following groups: MECH-SR (71.09%) was significantly lower than all other groups; TRYP-SR (78.03%) was significantly different from all other groups; TRYP-FCS (83.43%) and COLL-SR (84.08%) were significantly lower than MECH-FCS (89.98%) which together with COLL-FCS (88.25%) showed the highest cellular survival rate. In summary, our results show that TGC isolated from early gestation placentomes may be viable for more than 90 days of culture. However, whether these TGC produce placental lactogen throughout this period has yet to be determined. (c) 2006 Elsevier B.V. All rights reserved.

Estudo da imunoexpressão dos transportadores de glicose 1 e 3 em carcinomas epidermóides de lábio inferior e sua relação com parâmetros clínico-patológicos

The Epidermoid Carcinoma (EC) is the most common lesions located in the region of the head and neck and, despite advances in treatment modalities, the prognosis is still poor. The malignant cells show an increase in glucose uptake, process mediated by glucose transporters (GLUTs). Increased expression of GLUT 1 and GLUT 3 is related to the aggressive behavior of this lesion. The aim of this study was to evaluate, through immunohistochemistry, the expression of GLUTs 1 and 3 in EC of the lower lip. The sample consisted of 40 cases of EC of the lower lip, of which 20 had regional lymph node metastasis and the remaining 20 with absence of metastasis. The percentages of immunostained cells in front of tumor invasion and in the center of tumor were evaluated. These results were related to the presence and absence of lymph node metastasis, TNM classification and histological grading. The percentage of cytoplasmic/membranous expression of GLUT 1 ranged from 77.35% to 100%, while for GLUT 3 this value ranged from 0.79% to 100%. As for nuclear staining for GLUT 1, this percentage ranged from 0 to 0.42%, however. GLUT 3 showed only one case with nuclear staining. Despite the significant expression of tumor cells related to the proteins studied, we observed no statistically significant relationship between the variables and the antibodies analyzed, regardless of the region evaluated. However, there was a moderate positive correlation between cytoplasmic/membranous immunoexpressions of GLUT 1 in invasion front and in the tumor center (r = 0.679, p <0.001). Similarly, moderate positive correlation was found between the nuclear immunoexpressions of GLUT 1 in the invasion front and in the tumor center (r = 0.547, p <0.001). For GLUT 3, was also observed a moderate statistically significant positive correlation between cytoplasmic/membranous expression in tumor invasion front and in tumor center (r = 0.589, p <0.001). We also observed that the immunoreactivity for GLUT 1 was higher than GLUT 3 expression in invasion front (p <0.001) and tumor center (p <0.001). From these results, this study suggests that tumor hypoxia is a remarkable characteristic of the EC of the lower lip and GLUT 1 may be primarily responsible for glucose uptake into the interior of the malignant cells

Detecção do vírus Epstein-Barr (EBV) em adenocarcinomas gástricos procedentes dos estados do Ceará e de São Paulo

INTRODUÇÃO: O vírus Epstein-Barr (EBV) está associado a cerca de 10% dos adenocarcinomas gástricos, representando mais de 50 mil casos por ano no mundo. Apesar dos estudos realizados em várias partes do mundo, alguns aspectos clinicopatológicos permanecem controversos. OBJETIVOS: O presente estudo teve como objetivo analisar as características clinicopatológicas de casos de adenocarcinomas gástricos procedentes dos estados de São Paulo e Ceará, correlacionando-os com a detecção de EBV. MATERIAIS E MÉTODOS: Foram obtidos 192 casos de adenocarcinomas gástricos de hospitais dos estados de São Paulo e do Ceará, dos quais 160 foram submetidos à técnica de RNA-hibridização in situ para detecção de EBV. RESULTADOS: Dos 160 casos, 11 (6,9%) foram EBV-positivo, exibindo intensa marcação nuclear em células tumorais. Destes, dois casos também apresentaram linfócitos infiltrados marcados. Não encontramos marcação em tecido normal ou pré-neoplásico. São Paulo e Ceará apresentaram as frequências 3/60 (5%) e 8/100 (8%), respectivamente, e maior relação do EBV com indivíduos do sexo masculino, de idade avançada, com tumores do tipo intestinal, de estadiamento elevado e grau pouco a moderadamente diferenciado. Os casos do Ceará exibiram aumento relativo de tumores EBV(+) localizados na cárdia, enquanto os casos de São Paulo demonstraram aumento naqueles localizados no corpo gástrico. CONCLUSÃO: A frequência de tumores EBV(+) do presente estudo situa-se nos valores descritos na literatura mundial. Entre os achados, um deles não encontra paralelo na literatura mundial e refere-se ao elevado percentual de tumores EBV(+) no corpo gástrico observado nos casos de São Paulo.

Labeling index in pituitary adenomas evaluated by means of MIB-1: is there a prognostic role? A critical review

Objective: The present article presents an overview of the literature, and analyses the methods and the primary questions related to assessment of proliferation index using the Ki-67/MIB-1 labeling index in pituitary adenomas. Although atypical adenomas are characterized by their atypical morphological features by an elevated mitotic index, a Ki-67 (MIB-1) labeling index greater than 3% and extensive nuclear staining for p53, use of the proliferation index (LI) of pituitary adenomas in assessing the degree of tumor aggressiveness is a controversial topic in the literature, and there are disparate results involving many studies.Methods: A review of literature was carried out to correlate the role of Ki-67 LI and its correlation with clinical findings, tumor size, invasiveness, recurrence, adenoma subtype, adenoma doubling time, and pituitary carcinomas is addressed. Results: The prognosis cannot be predicted on the basis of the Ki-67 LI alone. Although there is no direct relation between Ki-67 LI and some of these variables and controversial data were found regarding some topics, our review justify the use of Ki-67 in the analysis of pituitary adenomas as an additional information for clinical decision.Conclusion: Although assessment of proliferative may be helpful in predicting subsequent tumor recurrence or invasiveness, there are many other important and as yet unidentified factors pituitary tumors. It is clear that further research is needed to clarify these molecular mechanisms to predict those with a potentially poor clinical outcome.

Evaluation epidermal p53 immunostaining by digital image analysis

Digital techniques have been developed and validated to assess semiquantitatively immunohistochemical nuclear staining. Currently visual classification is the standard for qualitative nuclear evaluation. Analysis of pixels that represents the immunohistochemical labeling can be more sensitive, reproducible and objective than visual grading. This study compared two semiquantitative techniques of digital image analysis with three techniques of visual analysis imaging to estimate the p53 nuclear immunostaining. Methods: Sixty-three sun-exposed forearm-skin biopsies were photographed and submitted to three visual analyses of images: the qualitative visual evaluation method (0 to 4 +), the percentage of labeled nuclei and HSCORE. Digital image analysis was performed using ImageJ 1.45p; the density of nuclei was scored per ephitelial area (DensNU) and the pixel density was established in marked suprabasal epithelium (DensPSB). Results: Statistical significance was found in: the agreement and correlation among the visual estimates of evaluators, correlation among the median visual score of the evaluators, the HSCORE and the percentage of marked nuclei with the DensNU and DensPSB estimates. DensNU was strongly correlated to the percentage of p53-marked nuclei in the epidermis, and DensPSB with the HSCORE. Conclusion: The parameters presented herein can be applied in routine analysis of immunohistochemical nuclear staining of epidermis. © 2012 John Wiley & Sons A/S.

Avaliação da expressão proteica de PTEN, MDM2, P53 e AR em lesões proliferativas da próstata canina

Pós-graduação em Medicina Veterinária - FCAV

Photobiological effect of low-level laser irradiation in bovine embryo production system

The objectives of this study were to evaluate the effect of low-level laser irradiation (LLLI) on bovine oocyte and granulosa cells metabolism during in vitro maturation (IVM) and further embryo development. Cumulus-oocytes complexes (COCs) were subjected (experimental group) or not (control group) to irradiation with LLLI in a 633-nm wavelength and 1 J/cm2 fluency. The COCs were evaluated after 30 min, 8, 16, and 24 h of IVM. Cumulus cells were evaluated for cell cycle status, mitochondrial activity, and viability (flow cytometry). Oocytes were assessed for meiotic progression status (nuclear staining), cell cycle genes content [real-time polymerase chain reaction (PCR)], and signal transduction status (western blot). The COCs were also in vitro fertilized, and the cleavage and blastocyst rates were assessed. Comparisons among groups were statistically performed with 5% significance level. For cumulus cells, a significant increase in mitochondrial membrane potential and the number of cells progressing through the cycle could be observed. Significant increases on cyclin B and cyclin-dependent kinase (CDK4) levels were also observed. Concerning the oocytes, a significantly higher amount of total mitogen-activated protein kinase was found after 8 h of irradiation, followed by a decrease in all cell cycle genes transcripts, exception made for the CDK4. However, no differences were observed in meiotic progression or embryo production. In conclusion, LLLI is an efficient tool to modulate the granulosa cells and oocyte metabolism

p300/CBP tyrosine phosphorylation in response to dna damage activated by c-Abl tyrosine kinase

The nuclear signaling that is triggered in response to DNA damage entails the recruitment and assembly of repair proteins and the induction of genes involved in the activation of cell cycle checkpoint, apoptosis or senescence. The extensive changes in chromatin structure underlying these processes suggest that chromatin-modifying enzymes could be relevant targets of DNA damage-activated signaling. The acetyltransferases p300 and CBP participate in DNA damage-activated responses, including local histone hyperacetylation, cell cycle regulation, and co-activation of DNA damage activated proteins, such as p53, p73 and BRCA1. However, the link between DNA damage and p300/CBP activation has not been identified.We have detected p300 tyrosine phosphorylation in response to DNA damage. We show that the DNA damage-activated cAbl tyrosine kinase enters the nuclei of cells exposed to genotoxic agents and phosphorylates p300 on a tyrosine residue within the bromodomain that is conserved in p300, CBP and many other bromodomain-containing proteins. Antibodies against tyrosine phosphorylated p300/CBP show a DNA damage-inducible nuclear staining, suggesting that p300 tyrosine phosphorylation is an event linking DNA damage and chromatin modifications.

Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) is closely associated with the chondrocyte nucleus in human articular cartilage

OBJECTIVE: Insulin-like growth factor-I (IGF-I) is critically involved in the control of cartilage matrix metabolism. It is well known that IGF-binding protein-3 (IGFBP-3) is increased during osteoarthritis (OA), but its function(s) is not known. In other cells, IGFBP-3 can regulate IGF-I action in the extracellular environment and can also act independently inside the cell; this includes transcriptional gene control in the nucleus. These studies were undertaken to localize IGFBP-3 in human articular cartilage, particularly within cells. DESIGN: Cartilage was dissected from human femoral heads derived from arthroplasty for OA, and OA grade assessed by histology. Tissue slices were further characterized by extraction and assay of IGFBPs by IGF ligand blot (LB) and by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry (IHC) for IGF-I and IGFBP-3 was performed on cartilage from donors with mild, moderate and severe OA. Indirect fluorescence and immunogold-labeling IHC studies were included. RESULTS: LBs of chondrocyte lysates showed a strong signal for IGFBP-3. IHC of femoral cartilage sections at all OA stages showed IGF-I and IGFBP-3 matrix stain particularly in the top zones, and closely associated with most cells. A prominent perinuclear/nuclear IGFBP-3 signal was seen. Controls using non-immune sera or antigen-blocked antibody showed negative or strongly reduced stain. In frozen sections of human ankle cartilage, immunofluorescent IGFBP-3 stain co-localized with the nuclear 4',6-diamidino-2-phenyl indole (DAPI) stain in greater than 90% of the cells. Immunogold IHC of thin sections and transmission electron immunogold microscopy of ultra-thin sections showed distinct intra-nuclear staining. CONCLUSIONS: IGFBP-3 in human cartilage is located in the matrix and within chondrocytes in the cytoplasm and nuclei. This new finding indicates that the range of IGFBP-3 actions in articular cartilage is likely to include IGF-independent roles and opens the door to studies of its nuclear actions, including the possible regulation of hormone receptors or transcriptional complexes to control gene action.

Reliable LC3 and p62 autophagy marker detection in formalin fixed paraffin embedded human tissue by immunohistochemistry

Autophagy assures cellular homeostasis, and gains increasing importance in cancer, where it impacts on carcinogenesis, propagation of the malignant phenotype and development of resistance. To date, its tissue-based analysis by immunohistochemistry remains poorly standardized. Here we show the feasibility of specifically and reliably assessing the autophagy markers LC3B and p62 (SQSTM1) in formalin fixed and paraffin embedded human tissue by immunohistochemistry. Preceding functional experiments consisted of depleting LC3B and p62 in H1299 lung cancer cells with subsequent induction of autophagy. Western blot and immunofluorescence validated antibody specificity, knockdown efficiency and autophagy induction prior to fixation in formalin and embedding in paraffin. LC3B and p62 antibodies were validated on formalin fixed and paraffin embedded cell pellets of treated and control cells and finally applied on a tissue microarray with 80 human malignant and non-neoplastic lung and stomach formalin fixed and paraffin embedded tissue samples. Dot-like staining of various degrees was observed in cell pellets and 18/40 (LC3B) and 22/40 (p62) tumors, respectively. Seventeen tumors were double positive for LC3B and p62. P62 displayed additional significant cytoplasmic and nuclear staining of unknown significance. Interobserver-agreement for grading of staining intensities and patterns was substantial to excellent (kappa values 0.60 - 0.83). In summary, we present a specific and reliable IHC staining of LC3B and p62 on formalin fixed and paraffin embedded human tissue. Our presented protocol is designed to aid reliable investigation of dysregulated autophagy in solid tumors and may be used on large tissue collectives.

Androgen receptor status is highly conserved during tumor progression of breast cancer

BACKGROUND With the advent of new and more efficient anti-androgen drugs targeting androgen receptor (AR) in breast cancer (BC) is becoming an increasingly important area of investigation. This would potentially be most useful in triple negative BC (TNBC), where better therapies are still needed. The assessment of AR status is generally performed on the primary tumor even if the tumor has already metastasized. Very little is known regarding discrepancies of AR status during tumor progression. To determine the prevalence of AR positivity, with emphasis on TNBCs, and to investigate AR status during tumor progression, we evaluated a large series of primary BCs and matching metastases and recurrences. METHODS AR status was performed on 356 primary BCs, 135 matching metastases, and 12 recurrences using a next-generation Tissue Microarray (ngTMA). A commercially available AR antibody was used to determine AR-status by immunohistochemistry. AR positivity was defined as any nuclear staining in tumor cells ≥1 %. AR expression was correlated with pathological tumor features of the primary tumor. Additionally, the concordance rate of AR expression between the different tumor sites was determined. RESULTS AR status was positive in: 87 % (307/353) of primary tumors, 86.1 % (105/122) of metastases, and in 66.7 % (8/12) of recurrences. TNBC tested positive in 11.4 %, (4/35) of BCs. A discrepant result was seen in 4.3 % (5/117) of primary BC and matching lymph node (LN) metastases. Three AR negative primary BCs were positive in the matching LN metastasis, representing 17.6 % of all negative BCs with lymph node metastases (3/17). Two AR positive primary BCs were negative in the matching LN metastasis, representing 2.0 % of all AR positive BCs with LN metastases (2/100). No discrepancies were seen between primary BC and distant metastases or recurrence (n = 17). CONCLUSIONS Most primary (87 %) and metastasized (86.1 %) BCs are AR positive including a significant fraction of TNBCs (11.4 %). Further, AR status is highly conserved during tumor progression and a change only occurs in a small fraction (4.1 %). Our study supports the notion that targeting AR could be effective for many BC patients and that re-testing of AR status in formerly negative or mixed type BC's is recommended.