Nuclear and cytoplasmic expression of survivin in 67 surgically resected pancreatic cancer patients

Pancreatic cancer is one of the most aggressive gastrointestinal cancer with less than 10% long-term survivors. The apoptotic pathway deregulation is a postulated mechanism of carcinogenesis of this tumour. The present study investigated the prognostic role of apoptosis and apoptosis-involved proteins in a series of surgically resected pancreatic cancer patients. All patients affected by pancreatic adenocarcinoma and treated with surgical resection from 1988 to 2003 were considered for the study. Patients' clinical data and pathological tumour features were recorded. Survivin and Cox-2 expression were evaluated by immunohistochemical staining. Apoptotic cells were identified using the TUNEL method. Tumour specimen of 67 resected patients was included in the study. By univariate analysis, survival was influenced by Survivin overexpression. The nuclear Survivin overexpression was associated with better prognosis (P=0.0009), while its cytoplasmic overexpression resulted a negative prognostic factor (P=0.0127). Also, the apoptotic index was a statistically significant prognostic factor in a univariate model (P=0.0142). By a multivariate Cox regression analysis, both the nuclear (P=0.002) and cytoplasmic (P=0.040) Survivin overexpression maintained the prognostic statistical value. This is the first study reporting a statistical significant prognostic relevance of nuclear and cytoplasmic Survivin overexpression in pancreatic cancer. In particular, patients with high nuclear Survivin staining showed a longer survival, whereas patients with high cytoplasmic Survivin staining had a shorter overall survival

ZIC1 Is Downregulated through Promoter Hypermethylation, and Functions as a Tumor Suppressor Gene in Colorectal Cancer

The transcription factor, Zinc finger of the cerebellum (ZIC1), plays a crucial role in vertebrate development. Recently, ZIC1 has also been found to participate in the progression of human cancers, including medulloblastomas, endometrial cancers, and mesenchymal neoplasms. However, the function of ZIC1 in colon cancer progression has not been defined. In this study, we demonstrate ZIC1 to be silenced or significantly downregulated in colon cancer cell lines. These effects were reversed by demethylation treatment with 5-aza-2′-deoxycytidine (Aza). ZIC1 expression is also significantly downregulated in primary colorectal cancer tissues relative to adjacent non-tumor tissues (p = 0.0001). Furthermore, methylation of ZIC1 gene promoter is frequently detected in primary tumor tissues (85%, 34/40), but not in adjacent non-tumor tissues. Ectopic expression of ZIC1 suppresses cell proliferation and induces apoptosis, which is associated with MAPK and PI3K/Akt pathways, as well as the Bcl-xl/Bad/Caspase3 cascade. To identify target candidates of ZIC1, we employed cDNA microarray and found that 337 genes are downregulated and 95 genes upregulated by ectopic expression of ZIC1, which were verified by 10 selected gene expressions by qRT-PCR. Taken together, our results suggest that ZIC1 may potentially function as a tumor suppressor gene, which is downregulated through promoter hypermethylation in colorectal cancers

CONFRONTO DEI VALORI PLASMATICI DELLE METALLOPROTEASI DELLA MATRICE 2,3,9 IN PAZIENTI CON CARCINOMI E FIBROADENOMI MAMMARI.

Il processo di infiltrazione delle cellule tumorali nei tessuti limitrofi prevede il rimaneggiamento dello stroma peritumorale determinato da un’alta attività litica sulla matrice extracellulare da parte del fenotipo neoplastico invasivo. Tra i principali enzimi litici prodotti dalle cellule tumorali e principalmente coinvolti nel processo invasivo ci sono le metalloproteasi della matrice (MMPs). Lo scopo di questo lavoro è quello di confrontare i livelli plasmatici pre-operatori delle MMPs 2, 3, 9 in pazienti affette da carcinomi e fibroadenomi mammari per valutare un’eventuale differenza di espressione delle tre MMPs tra i due gruppi di pazienti. Sono stati quantizzati con ELISA test i valori delle MMPs 2, 3, 9 nel plasma prelevato 24 h prima dell’intervento chirurgico in 50 pazienti con carcinomi ed in 30 pazienti con fibroadenomi mammari. Il valore medio di MMP2 nelle pazienti con carcinoma è risultato essere significativamente superiore a quello nelle pazienti con fibroadenoma, mentre non è stata rivelata una differenza significativa per le altre due MMPs analizzate. Alla luce dei risultati ottenuti è possibile confermare il ruolo fondamentale svolto dalle MMPs nel fenomeno invasivo neoplastico. Inoltre, sulla base dei valori ottenuti per la MMP2, si potrebbe inserire la valutazione di questo enzima come marcatore a fianco ad altri parametri biologici e clinici nell’orientamento prognostico delle lesioni mammarie neoplastiche

Plasma levels of matrix metalloproteinases 2 and 9 correlate with histological grade in breast cancer patients

Matrix metalloproteinases (MMPs) are proteolytic enzymes involved in the process of tumor invasion and metastasis that are found throughout tissues and also in the plasma. The aim of this study was to investigate whether the evaluation of plasma concentrations of MMPs 2, 3 and 9 may have clinical significance in breast cancer. Therefore, sera obtained from 80 patients with breast neoplasia (50 carcinomas and 30 fibroadenomas) were collected before and 96 h after surgery and the concentrations of MMPs 2, 3 and 9 were quantified using an enzyme-linked immunosorbent assay (ELISA). The mean expression level of MMP 2 was significantly higher in carcinoma compared with that in fibroadenoma patients, while there was no significant difference for MMPs 3 and 9. In addition, the group of carcinoma patients was analyzed in order to compare the mean values for each MMP obtained before and after surgery. However, the differences between pre- and post-surgery values for all three MMPs were not statistically significant. Furthermore, the plasma levels of each MMP were correlated with certain clinicopathological parameters of the tumors and we observed a significant and direct correlation between the concentrations of MMPs 2 and 9 and tumor histological grade. These data suggest that the quantification of plasma MMP 2 and MMP 9 levels may provide additional clinical information of the tumor and it is, therefore, a possible prognostic index for breast cancer

Comparison of extracellular matrix and apoptotic markers between benign lesions and carcinomas in human breast

The expression of the extracellular matrix-related genes, such as fibronectin, laminin and tenascin C, and apoptosis-related genes, such as bax, bcl2 and survivin, was evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and by immunohistochemistry in normal breast tissue and benign and malignant breast tumors and then correlated to several clinical parameters: estrogen and progesterone receptors, Ki67, ErbB2, tumor size, lymph node status and grading. Seventy-three breast tissue samples were examined. After RNA extraction, an RT-PCR was performed to detect fibronectin, laminin, tenascin C, bax, bcl2 and survivin gene expression. Thirty-two samples were evaluated also by immunohistochemistry at the protein level to detect fibronectin, laminin, tenascin C, bax and survivin. We found a significant correlation (P=0.025) between fibronectin gene expression and lymph node status, and a significant negative correlation (P=0.049) between laminin gene expression and Ki67. In addition, we found a statistically significant increase in survivin transcription in malign tumors compared to fibroadenomas (P=0.024). The negative correlation between laminin transcription and Ki67 could suggest that laminin impacts negatively on tumor proliferation, and the positive correlation between fibronectin and lymph node status may lead to consider fibronectin as predictive of long distance metastasis

SUMOylation of tissue transglutaminase as link between oxidative stress and inflammation

Cystic fibrosis (CF) is a monogenic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. CF is characterized by chronic bacterial lung infections and inflammation, and we have previously reported that tissue transglutaminase (TG2), a multifunctional enzyme critical to several diseases, is constitutively up-regulated in CF airways and drives chronic inflammation. Here, we demonstrate that the generation of an oxidative stress induced by CFTR-defective function leads to protein inhibitor of activated STAT (PIAS)y-mediated TG2 SUMOylation and inhibits TG2 ubiquitination and proteasome degradation, leading to sustained TG2 activation. This prevents peroxisome proliferator-activated receptor (PPAR)gamma and IkBalpha SUMOylation, leading to NF-kappaB activation and to an uncontrolled inflammatory response. Cellular homeostasis can be restored by small ubiquitin-like modifier (SUMO)-1 or PIASy gene silencing, which induce TG2 ubiquitination and proteasome degradation, restore PPARgamma SUMOylation, and prevent IkBalpha cross-linking and degradation, thus switching off inflammation. Manganese superoxide dismutase overexpression as well as the treatment with the synthetic superoxide dismutase mimetic EUK-134 control PIASy-TG2 interaction and TG2 SUMOylation. TG2 inhibition switches off inflammation in vitro as well as in vivo in a homozygous F508del-CFTR mouse model. Thus, TG2 may function as a link between oxidative stress and inflammation by driving the decision as to whether a protein should undergo SUMO-mediated regulation or degradation. Targeting TG2-SUMO interactions might represent a new option to control disease evolution in CF patients as well as in other chronic inflammatory diseases, neurodegenerative pathologies, and cancer

A novel chemotaxis assay in 3-d collagen gels by time-lapse microscopy

Contains fulltext : 111018.pdf (publisher's version ) (Open Access)The directional cell response to chemical gradients, referred to as chemotaxis, plays an important role in physiological and pathological processes including development, immune response and tumor cell invasion. Despite such implications, chemotaxis remains a challenging process to study under physiologically-relevant conditions in-vitro, mainly due to difficulties in generating a well characterized and sustained gradient in substrata mimicking the in-vivo environment while allowing dynamic cell imaging. Here, we describe a novel chemotaxis assay in 3D collagen gels, based on a reusable direct-viewing chamber in which a chemoattractant gradient is generated by diffusion through a porous membrane. The diffusion process has been analysed by monitoring the concentration of FITC-labelled dextran through epifluorescence microscopy and by comparing experimental data with theoretical and numerical predictions based on Fick's law. Cell migration towards chemoattractant gradients has been followed by time-lapse microscopy and quantified by cell tracking based on image analysis techniques. The results are expressed in terms of chemotactic index (I) and average cell velocity. The assay has been tested by comparing the migration of human neutrophils in isotropic conditions and in the presence of an Interleukin-8 (IL-8) gradient. In the absence of IL-8 stimulation, 80% of the cells showed a velocity ranging from 0 to 1 microm/min. However, in the presence of an IL-8 gradient, 60% of the cells showed an increase in velocity reaching values between 2 and 7 microm/min. Furthermore, after IL-8 addition, I increased from 0 to 0.25 and 0.25 to 0.5, respectively, for the two donors examined. These data indicate a pronounced directional migration of neutrophils towards the IL-8 gradient in 3D collagen matrix. The chemotaxis assay described here can be adapted to other cell types and may serve as a physiologically relevant method to study the directed locomotion of cells in a 3D environment in response to different chemoattractants