Circular RNAs as important players in human gastric cancer.

As one of the most prevalent gastrointestinal diseases, gastric cancer (GC) is the second leading cause of cancer-related deaths worldwide. Since GC has no clinical manifestations in the early stage of the disease, most patients are detected in the later phases of disease and have an unfortunately lower chance of recovery. Circular RNAs (circRNAs), a novel category of non-coding RNAs (ncRNAs), are mainly engaged in the regulation of gene expression at the transcriptional and post-transcriptional levels. Numerous evidences have revealed that circRNAs play key roles in GC as they are involved in cell proliferation, growth, and apoptosis via modulating the expression of some target genes, miRNAs, and proteins. Many studies have addressed the impact of circRNA dysregulation on GC initiation, progression, and invasion via binding to miRNAs or RNA binding proteins. Moreover, changes in circRNA expression are associated with pathological and clinical features of GC highlighting their potentials as diagnostic or prognostic biomarkers in GC. In the current study, the recent findings on the significance of circRNAs in the development and progression of GC are reviewed. We focus on the implications of circRNAs as potential diagnostic or prognostic biomarkers in this malignancy.

Scrib and Dlg1 polarity proteins regulate Ag presentation in human dendritic cells.

We recently reported, for the first time, the expression and regulation of the PDZ polarity proteins Scrib and Dlg1 in human APCs, and also described the viral targeting of these proteins by NS1 of influenza A virus in human dendritic cells (DCs). Scrib plays an important role in reactive oxygen species (ROS) production in Mϕs and uropod formation and migration in T cells, while Dlg1 is important for T cell downstream activation after Ag recognition. Nevertheless, the functions of these proteins in human DCs remain unknown. Here, we knocked-down the expression of both Scrib and Dlg1 in human DCs and then evaluated the expression of co-stimulatory molecules and cytokine production during maturation. We demonstrated that Scrib is necessary for adequate CD86 expression, while Dlg1 is important for CD83 up-regulation and IL-6 production upon maturation, suggesting that Scrib and Dlg1 participate in separate pathways in DCs. Additionally, both proteins are required for adequate IL-12 production after maturation. Furthermore, we showed that the inefficient maturation of DCs induced by Scrib or Dlg1 depletion leads to impaired T cell activation. Our results revealed the previously unknown contribution of Scrib and Dlg1 in human DCs pivotal functions, which may be able to impact innate and adaptive immune response.

Downregulation of TGF-ß1 suppressed proliferation and increased chemosensitivity of ovarian cancer cells by promoting BRCA1/Smad3 signaling.

BACKGROUND: Studies have demonstrated that transforming growth factor beta-1 (TGF-ß1) exhibits oncogenic activity in different types of cancer, including ovarian cancer (OC). However, its regulatory mechanism in OC and whether TGF-ß1 is involved in chemosensitivity regulation remains unclear. Thus, the aim of this study was to investigate the role of TGF-ß1 in OC. METHODS: The OC cell line SKOV3 was employed, and TGF-ß1 overexpression or knockdown vectors were constructed. The cell proliferation of SKOV3 was evaluated with the cell counting kit (CCK8) kit after treatment with different concentrations of cis-platinum. Western blot and protein immunoprecipitation were employed to detect changes in BRCA1 and Smad3 expression and their interactions. Tumor growth in nude mice was evaluated. RESULTS: The results showed that TGF-ß1 knockdown increased chemosensitivity by promoting BRCA1 expression and Smad3 phosphorylation. In vivo studies showed that TGF-ß1 knockdown significantly inhibited the growth of tumors, also by upregulating BRCA1 expression and Smad3 phosphorylation. CONCLUSION: Taken together, our results suggest that TGF-ß1 knockdown inhibits tumor growth and increases chemosensitivity by promotion of BRCA1/Smad3 signaling.

[Combating tumor cells through SIRT3 activation and exercise]. / Combatiendo el metabolismo de las células cancerosas mediante la activación de SIRT3 y el ejercicio físico.

One of the main features of cancer is the high rate of cell proliferation and growth. To do this, cancer cells need to redirect their metabolism mainly towards anaerobic glycolysis and an increased mitochondrial glutamine energy metabolism. Sirtuins are cellular proteins with regulatory functions on metabolic pathways, genomic stability, apoptosis, longevity, inflammation, energy metabolism and oxidative stress. Sirtuins have emerged recently as a potential therapeutic option to treat several chronic diseases including cancer. This review summarizes the tumor suppressor function of Sirtuin 3 (SIRT3), highlighting its repressor effect on glycolytic metabolism, promoting mitochondrial metabolism and oxidative stress reduction. SIRT3 activation by exercise is particularly described since it may represent a potent tool for several types of cancer treatment.

Combatiendo el metabolismo de las células cancerosas mediante la activación de SIRT3 y el ejercicio físico / Combating tumor cells through SIRT3 activation and exercise

One of the main features of cancer is the high rate of cell proliferation and growth. To do this, cancer cells need to redirect their metabolism mainly towards anaerobic glycolysis and an increased mitochondrial glutamine energy metabolism. Sirtuins are cellular proteins with regulatory functions on metabolic pathways, genomic stability, apoptosis, longevity, inflammation, energy metabolism and oxidative stress. Sirtuins have emerged recently as a potential therapeutic option to treat several chronic diseases including cancer. This review summarizes the tumor suppressor function of Sirtuin 3 (SIRT3), highlighting its repressor effect on glycolytic metabolism, promoting mitochondrial metabolism and oxidative stress reduction. SIRT3 activation by exercise is particularly described since it may represent a potent tool for several types of cancer treatment.

Stromal expression of JNK1 and VDR is associated with the prognosis of esophageal squamous cell carcinoma.

PURPOSE: Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide, and its outcome is poor. The purpose of this study was to determine the association between JNK1 and vitamin D receptor (VDR) expression and the prognosis of ESCC. METHODS: Immunohistochemical staining was conducted on ESCC tissue microarrays (362 pairs of ESCC and normal esophagus tissues). The epithelial and stromal expression levels of c-jun NH2-terminal kinase 1 (JNK1) and VDR were scored and correlated with the ESCC characteristics. Laser-capture-based quantitative RT-PCR was performed on ESCC tissues. The effects of JNK1 and VDR on ESCC cell proliferation and migration were analyzed in vitro by transient transfection, and protein changes were evaluated by immunoblotting. RESULTS: Both JNK1 and VDR were reduced in ESCC epithelial cells in comparison with the normal esophagus, but the expression of JNK1 and VDR in ESCC stromal tissues, not epithelial cells, was strongly associated with the survival time of ESCC patients. Functional studies showed that increased JNK1 suppressed cancer cell proliferation, mobility, and migration, which were linked to the alterations of VDR and metastasis-associated proteins. CONCLUSION: JNK1 and VDR act as tumor suppressors, and their stromal expression levels are associated with prognosis in esophageal squamous cell carcinoma.

Downregulation of TGF-ß1 suppressed proliferation and increased chemosensitivity of ovarian cancer cells by promoting BRCA1/Smad3 signaling

BACKGROUND: Studies have demonstrated that transforming growth factor beta-1 (TGF-ß1) exhibits oncogenic activity in different types of cancer, including ovarian cancer (OC). However, its regulatory mechanism in OC and whether TGF-ß1 is involved in chemosensitivity regulation remains unclear. Thus, the aim of this study was to investigate the role of TGF-ß1 in OC. METHODS: The OC cell line SKOV3 was employed, and TGF-ß1 overexpression or knockdown vectors were constructed. The cell proliferation of SKOV3 was evaluated with the cell counting kit (CCK8) kit after treatment with different concentrations of cis-platinum. Western blot and protein immunoprecipitation were employed to detect changes in BRCA1 and Smad3 expression and their interactions. Tumor growth in nude mice was evaluated. RESULTS: The results showed that TGF-ß1 knockdown increased chemosensitivity by promoting BRCA1 expression and Smad3 phosphorylation. In vivo studies showed that TGF-ß1 knockdown significantly inhibited the growth of tumors, also by upregulating BRCA1 expression and Smad3 phosphorylation. CONCLUSION: Taken together, our results suggest that TGF-ß1 knockdown inhibits tumor growth and increases chemosensitivity by promotion of BRCA1/Smad3 signaling.

The perceptions of medical researchers on qualitative methodologies / Percepción de los investigadores médicos en metodologías cualitativas / Percepção de pesquisadores médicos sobre metodologias qualitativas

We aimed to verify doctor's perception of the qualitative research method, via a qualitative study of interviews with questions on the academic profile of doctors and on the methodology. We interviewed 42 professionals, of which 18 had experience with the qualitative method and 24 with the quantitative method. The results showed that knowledge on the qualitative method was virtually nil among "quantitative researchers", who did not value qualitative research, although some of those realized that it would be important to be more accepting in clinical practice. Others only considered the method as subsidiary to quantitative. The majority considered qualitative methods as lacking academic structure, taking too long to conduct empirical studies, and being difficult to publish. All of them criticized the misuse of the method, and the "quantitatives" pointed out the problem of being unable to reproduce. We concluded that widening the use of the qualitative method by doctors requires investment from the beginning of the academic career and participation in qualitative research projects.

El objetivo es verificar la percepción de médicos sobre el método de investigación cualitativa. Se trata de un estudio cualitativo por medio de entrevistas con preguntas sobre el perfil de los médicos y sobre el método. Entrevistamos a 42 profesionales, 18 con experiencia en el método cualitativo y 24 con el cuantitativo. Los resultados mostraron que el conocimiento sobre lo cualitativo es casi nulo entre los "cuantitativistas", que no valoran la investigación cualitativa, aunque algunos se dan cuenta de que sería importante tener un enfoque más amplio en la práctica clínica. Otros la ven como subsidiaria a lo cuantitativo. Sus dificultades para utilizar ese abordaje son: falta de formación, cantidad de tiempo que exigen y problemas de publicación. Todos han criticado el mal uso del método. Los "cuantitativistas" han destacado como fragilidad, la no reproductibilidad. Llegamos a la conclusión de que para ampliar el uso de los abordajes cualitativos entre los médicos es importante invertir en su formación desde el inicio del curso y la participación en proyectos de investigación cualitativa.

Objetivamos verificar a percepção de médicos sobre o método qualitativo de pesquisa. Estudo qualitativo por meio de entrevistas com questões sobre o perfil acadêmico do médico e perguntas abertas a respeito do método. Entrevistamos 42 profissionais, sendo 18 com experiência no método qualitativo e 24 com o quantitativo. Os resultados evidenciaram que o conhecimento sobre o qualitativo é quase nulo entre os pesquisadores "quantitativistas", os quais não valorizam a pesquisa qualitativa, embora alguns percebam que seria importante ter uma postura mais compreensiva na prática clínica. Outros só a veem como subsidiária ao quantitativo. As principais dificuldades da maioria são: falta de formação, tempo longo despendido nos estudos empíricos e dificuldade de publicação. Todos os entrevistados criticaram o mau uso do método, e os "quantitativistas" ressaltaram, como problema, sua não reprodutibilidade. Concluímos que ampliar o uso do método qualitativo por médicos exige investimento na formação desde o início da graduação e participação em projetos de pesquisa qualitativa.

Pulmonary lymphangioleiomyomatosis: literature update.

Pulmonary lymphangioleiomyomatosis is an uncommon disease of unknown etiology characterized by the proliferation of abnormal smooth muscle cells in the lungs, leading to parenchymal destruction and progressive respiratory failure. The natural history of this disease remains poorly understood, primarily seen in women of childbearing age. The diagnosis can be difficult because symptoms are nonspecific and very similar to other respiratory diseases like asthma, emphysema and bronchitis. Lymphangioleiomyomatosis may not be diagnosed until a pneumothorax, chylothorax, interstitial lung disease or angiomyolipomas are discovered. The recent advances in genetic and molecular research provide new hope to discover the intricate mechanism of disease and evaluate new therapies. Internists, primary care physicians and pulmonologists should be aware of this condition in order to avoid delay in the diagnosis and institute appropriate therapy. The clinical features, pathophysiology, molecular genetics and medical treatment will be reviewed.

Inhibitor of growth 1 (ING1) acts at early steps of multiple DNA repair pathways.

ING proteins are tumor suppressors involved in the regulation of gene transcription, cell cycle arrest, apoptosis, and senescence. Here, we show that ING1b expression is upregulated by several DNA-damaging agents, in a p53-independent manner. ING1b stimulates DNA repair of a variety of DNA lesions requiring activation of multiple DNA repair pathways. Moreover, Ing1(-/-) cells showed impaired genomic DNA repair after H2O2 and neocarzinostatin treatment and this defect was reverted by overexpression of ING1b. Two tumor-derived ING1 mutants failed to promote DNA repair highlighting the physiological importance of the integrity of the PHD domain for ING1b DNA repair activity and suggesting a role in the prevention of tumor progression. Ing(-/-) cells showed higher basal levels of γ-H2AX and, upon DNA damage, γ-H2AX increase was greater and with faster kinetics compared to wild-type cells. Chromatin relaxation by Trichostatin A led to an exacerbated damage signal in both types of cells, but this effect was dependent on Ing1 status, and more pronounced in wild-type cells. Our results suggest that ING1 acts at early stages of the DNA damage response activating a variety of repair mechanisms and that this function of ING1 is targeted in tumors.

Lack of the matricellular protein SPARC (secreted protein, acidic and rich in cysteine) attenuates liver fibrogenesis in mice.

INTRODUCTION: Secreted Protein, Acidic and Rich in Cysteine (SPARC) is a matricellular protein involved in many biological processes and found over-expressed in cirrhotic livers. By mean of a genetic approach we herein provide evidence from different in vivo liver disease models suggesting a profibrogenic role for SPARC. METHODS: Two in vivo models of liver fibrosis, based on TAA administration and bile duct ligation, were developed on SPARC wild-type (SPARC(+/+)) and knock-out (SPARC(-/-)) mice. Hepatic SPARC expression was analyzed by qPCR. Fibrosis was assessed by Sirius Red staining, and the maturation state of collagen fibers was analyzed using polarized light. Necroinflammatory activity was evaluated by applying the Knodell score and liver inflammatory infiltration was characterized by immunohistochemistry. Hepatic stellate cell activation was assessed by α-SMA immunohistochemistry. In addition, pro-fibrogenic genes and inflammatory cytokines were measured by qPCR and/or ELISA. Liver gene expression profile was analyzed in SPARC(-/-) and SPARC(+/+) mice using Affymetrix Mouse Gene ST 1.0 array. RESULTS: SPARC expression was found induced in fibrotic livers of mouse and human. SPARC(-/-) mice showed a reduction in the degree of inflammation, mainly CD4+ cells, and fibrosis. Consistently, collagen deposits and mRNA expression levels were decreased in SPARC(-/-) mice when compared to SPARC(+/+) mice; in addition, MMP-2 expression was increased in SPARC(-/-) mice. A reduction in the number of activated myofibroblasts was observed. Moreover, TGF-ß1 expression levels were down-regulated in the liver as well as in the serum of TAA-treated knock-out animals. Ingenuity Pathway Analysis (IPA) analysis suggested several gene networks which might involve protective mechanisms of SPARC deficiency against liver fibrogenesis and a better established machinery to repair DNA and detoxify from external chemical stimuli. CONCLUSIONS: Overall our data suggest that SPARC plays a significant role in liver fibrogenesis. Interventions to inhibit SPARC expression are suggested as promising approaches for liver fibrosis treatment.

In vitro cytokine expression in in situ-like areas of malignant neoplasia.

OBJECTIVES: The myoepithelial cells exert important effects regulating the transition of an in situ to an invasive carcinoma. This cell has been associated with a tumour suppressor phenotype due to its ability to inhibit tumour growth as well as its immunomodulatory role in cancer behaviour. DESIGN: In order to correlate the cancer cell growth and the role of cytokines in regulating the neoplastic process, we have attempted to simulate an in vitro model of tumorigenesis, which mimics a situation where in situ neoplastic cells of carcinoma are surrounded by benign myoepithelial cells from pleomorphic adenoma. To certify the formation of in situ-like neoplasic areas, the cells were immunostained with vimentin and AE1/AE3, markers for tumoral benign myoepithelial cells and squamous cell carcinoma lineage, respectively. We investigated the correlation of the cancer cell growth with the releasing of IL-4, IL-6 and IL-10 associated with the immune response. The cytokines levels were evaluated using ELISA. RESULTS: In in situ neoplastic areas, IL-6 amounts were higher released when compared with IL-4 and IL-10, in all studied periods. Interestingly, the peak of IL-6 release fits with the predominance of malignant cells in the culture. CONCLUSIONS: The present results demonstrated that, in this in vitro condition, the myoepithelial cells were not able to suppress the tumour cell proliferation even with high secretion of IL-4 by benign myoepithelial cells which at the beginning is supposed to act as an anti-tumour agent. In addition, these cells favoured the tumour growth by excessive production of IL-6 and IL-10.

Oxidative stress activates the c-Abl/p73 proapoptotic pathway in Niemann-Pick type C neurons.

Niemann-Pick type C (NPC) is a neurodegenerative disease characterized by the intralysosomal accumulation of cholesterol leading to neuronal apoptosis. We have previously reported the activation of the c-Abl/p73 proapoptotic pathway in the cerebellum of NPC mice; however, upstream signals underlying the engagement of this pathway remain unknown. Here, we investigate the possible role of oxidative stress in the activation of c-Abl/p73 using different in vitro and in vivo NPC models. Our results indicate a close temporal correlation between the appearance of nitrotyrosine (N-Tyr; a post-translational tyrosine modification caused by oxidative stress) and the activation of c-Abl/p73 in NPC models. To test the functional role of oxidative stress in NPC, we have treated NPC neurons with the antioxidant NAC and observed a dramatic decrease of c-Abl/p73 activation and a reduction in the levels of apoptosis in NPC models. In conclusion, our data suggest that oxidative stress is the main upstream stimulus activating the c-Abl/p73 pathway and neuronal apoptosis in NPC neurons.

Impact of mutations in kisspeptin and neurokinin B signaling pathways on human reproduction.

The involvement of kisspeptin and neurokinin in B pathways in the reproductive axis was first suspected by linkage analysis in consanguineous families with isolated hypogonadotropic hypogonadism (IHH). Since then, several loss-of-function mutations affecting the kisspeptin receptor and neurokinin B and its receptor were associated with sporadic and familial IHH without olfactory abnormalities or other associated developmental alterations. Clinical manifestations were indistinguishable in individuals with mutations affecting these pathways. Micropenis and cryptorchidism were common findings among male patients. Response to acute GnRH stimulation varied from blunted to normal, and many affected males and females were successfully treated for infertility with either exogenous gonadotropins or long term pulsatile GnRH infusion. More recently, rare activating mutations of the kisspeptin and its receptor were identified in children with idiopathic central precocious puberty, supporting the crucial role of this system in the human pubertal onset. Kisspeptin is a potent excitatory regulator of the GnRH secretion, whereas the role of neurokinin B in the neuroendocrine control of the reproductive axis is still poorly understood. Interestingly, kisspeptin and neurokinin B are coexpressed in the arcuate nucleus in the mammalian hypothalamus, suggesting that these systems are closely related and potential partners of the regulation of the reproductive axis.

Role of Scrib and Dlg in anterior-posterior patterning of the follicular epithelium during Drosophila oogenesis.

BACKGROUND: Proper patterning of the follicle cell epithelium over the egg chamber is essential for the Drosophila egg development. Differentiation of the epithelium into several distinct cell types along the anterior-posterior axis requires coordinated activities of multiple signaling pathways. Previously, we reported that lethal(2)giant larvae (lgl), a Drosophila tumor suppressor gene, is required in the follicle cells for the posterior follicle cell (PFC) fate induction at mid-oogenesis. Here we explore the role of another two tumor suppressor genes, scribble (scrib) and discs large (dlg), in the epithelial patterning. RESULTS: We found that removal of scrib or dlg function from the follicle cells at posterior terminal of the egg chamber causes a complete loss of the PFC fate. Aberrant specification and differentiation of the PFCs in the mosaic clones can be ascribed to defects in coordinated activation of the EGFR, JAK and Notch signaling pathways in the multilayered cells. Meanwhile, the clonal analysis revealed that loss-of-function mutations in scrib/dlg at the anterior domains result in a partially penetrant phenotype of defective induction of the stretched and centripetal cell fate, whereas specification of the border cell fate can still occur in the most anterior region of the mutant clones. Further, we showed that scrib genetically interacts with dlg in regulating posterior patterning of the epithelium. CONCLUSION: In this study we provide evidence that scrib and dlg function differentially in anterior and posterior patterning of the follicular epithelium at oogenesis. Further genetic analysis indicates that scrib and dlg act in a common pathway to regulate PFC fate induction. This study may open another window for elucidating role of scrib/dlg in controlling epithelial polarity and cell proliferation during development.

WW-domain-containing oxidoreductase is associated with low plasma HDL-C levels.

Low serum HDL-cholesterol (HDL-C) is a major risk factor for coronary artery disease. We performed targeted genotyping of a 12.4 Mb linked region on 16q to test for association with low HDL-C by using a regional-tag SNP strategy. We identified one SNP, rs2548861, in the WW-domain-containing oxidoreductase (WWOX) gene with region-wide significance for low HDL-C in dyslipidemic families of Mexican and European descent and in low-HDL-C cases and controls of European descent (p = 6.9 x 10(-7)). We extended our investigation to the population level by using two independent unascertained population-based Finnish cohorts, the cross-sectional METSIM cohort of 4,463 males and the prospective Young Finns cohort of 2,265 subjects. The combined analysis provided p = 4 x 10(-4) to 2 x 10(-5). Importantly, in the prospective cohort, we observed a significant longitudinal association of rs2548861 with HDL-C levels obtained at four different time points over 21 years (p = 0.003), and the T risk allele explained 1.5% of the variance in HDL-C levels. The rs2548861 resides in a highly conserved region in intron 8 of WWOX. Results from our in vitro reporter assay and electrophoretic mobility-shift assay demonstrate that this region functions as a cis-regulatory element whose associated rs2548861 SNP has a specific allelic effect and that the region forms an allele-specific DNA-nuclear-factor complex. In conclusion, analyses of 9,798 subjects show significant association between HDL-C and a WWOX variant with an allele-specific cis-regulatory function.

ATM allelic variants associated to hereditary breast cancer in 94 Chilean women: susceptibility or ethnic influences?

Besides BRCA1 and BRCA2, two genes accounting for a small proportion of breast cancer cases, ATM has been widely proposed as a low-penetrance susceptibility gene. Several nucleotide changes have been proposed to be associated with breast cancer, still remaining a high controversy in this sense. We screened the ATM gene in 94 breast cancer patients selected from 78 high-risk families, not presenting a mutation in BRCA1 or BRCA2. We found three novel allelic variants: IVS64 + 51delT and p.L752L, not showing association with hereditary breast cancer, and p.L694L found in one family in two breast cancer patients. Two amino acid substitutions p.S707P and p.F858L, previously reported to be associated with breast cancer, were present in our study in cases and controls, lacking of association with breast cancer. A positive association of c.5557G>A (p.D1853N) was found (OR 2.52, P = 0.008), when analyzed alone and in combination with an intronic variant IVS24-9delT (OR 3.97; P = 0.0003). We postulate that our discrepancies with other reports related to the associated ATM alleles to hereditary breast cancer, as well as discrepancies in the literature between other groups, could be explained by the diversity in the ethnic origins of families gathered in a sole study, and the selection of the control group. In relation to this issue, and based on genetic markers, we found that the Chilean group of breast cancer families in this study has a stronger European genetic component than our control sample selected randomly from the Chilean population.

Roles of nibrin and AtM/ATR kinases on the G2 checkpoint under endogenous or radio-induced DNA damage.

Checkpoint response to DNA damage involves the activation of DNA repair and G2 lengthening subpathways. The roles of nibrin (NBS1) and the ATM/ATR kinases in the G2 DNA damage checkpoint, evoked by endogenous and radio-induced DNA damage, were analyzed in control, A-T and NBS lymphoblast cell lines. Short-term responses to G2 treatments were evaluated by recording changes in the yield of chromosomal aberrations in the ensuing mitosis, due to G2 checkpoint adaptation, and also in the duration of G2 itself. The role of ATM/ATR in the G2 checkpoint pathway repairing chromosomal aberrations was unveiled by caffeine inhibition of both kinases in G2. In the control cell lines, nibrin and ATM cooperated to provide optimum G2 repair for endogenous DNA damage. In the A-T cells, ATR kinase substituted successfully for ATM, even though no G2 lengthening occurred. X-ray irradiation (0.4 Gy) in G2 increased chromosomal aberrations and lengthened G2, in both mutant and control cells. However, the repair of radio-induced DNA damage took place only in the controls. It was associated with nibrin-ATM interaction, and ATR did not substitute for ATM. The absence of nibrin prevented the repair of both endogenous and radio-induced DNA damage in the NBS cells and partially affected the induction of G2 lengthening.

Caveolae and caveolae-like membrane domains in cellular signaling and disease: identification of downstream targets for the tumor suppressor protein caveolin-1.

Caveolae are small, flask-shaped invaginations of the plasma membrane present on a large number of mammalian cells. Recent results obtained with knock-out mice for the gene caveolin-1 demonstrate that expression of caveolin-1 protein is essential for caveolae formation in vivo. Caveolae are implicated in a wide variety of cellular events including transcytosis, cholesterol trafficking and as cellular centers important in coordinating signalling events. Caveolae share this role and the property of detergent insolubility with plasma membrane assemblies rich in glycosphingolipids and cholesterol, often called lipid rafts, but preferably referred to here as caveolae-like membrane domains. Due to such widespread presence and usage in cellular function, caveolae and related domains are implicated in human diseases, including cancer. In particular, the protein caveolin-1 is suggested to function as a tumor suppressor protein. Evidence demonstrating such a role for caveolin-1 in human colon carcinoma cells will be discussed together with data from microarray experiments seeking to identify caveolin-1 target genes responsible for such behavior.

Caveolae and caveolae-like membrane domains in cellular signaling and disease: identification of downstream targets for the tumor suppressor protein caveolin-1

Caveolae are small, flask-shaped invaginations of the plasma membrane present on a large number of mammalian cells. Recent results obtained with knock-out mice for the gene caveolin-1 demonstrate that expression of caveolin-1 protein is essential for caveolae formation in vivo. Caveolae are implicated in a wide variety of cellular events including transcytosis, cholesterol trafficking and as cellular centers important in coordinating signalling events. Caveolae share this role and the property of detergent insolubility with plasma membrane assemblies rich in glycosphingolipids and cholesterol, often called lipid rafts, but preferably referred to here as caveolae-like membrane domains. Due to such widespread presence and usage in cellular function, caveolae and related domains are implicated in human diseases, including cancer. In particular, the protein caveolin-1 is suggested to function as a tumor suppressor protein. Evidence demonstrating such a role for caveolin-1 in human colon carcinoma cells will be discussed together with data from microarray experiments seeking to identify caveolin-1 target genes responsible for such behavior