CCN1 induces apoptosis in esophageal adenocarcinoma through p53-dependent downregulation of survivin.

Many cancer drugs have been developed to control tumor growth by inducing cancer cell apoptosis. However, several intracellular barriers could fail this attempt. One of these barrier is high expression of survivin. Survivin can interfere caspase activation and thereby abort apoptosis. In this study, we found that CCN1 suppressed the survivin expression in tumor cells of esophageal adenocarcinoma (EAC) and thus allowed apoptosis to finish. Furthermore, we demonstrated that this downregulation was dependent on p53 phosphorylation at Ser20, and CCN1 induced EAC cell apoptosis through the activation of p53.

Overexpression of CCN1 in Het1A cells attenuates bile-induced esophageal metaplasia through suppressing non-canonical NFκB activation.

GERD is the most common gastrointestinal diagnosis given during office visit. People who suffer from a long history of GERD eventually develop Barrett's esophagus, a premalignant intestinal metaplasia due to NFκB activation. Previous studies focused on the contribution of TNF-triggered canonical NFκB pathway to this event. In this study, we demonstrated in vitro that it was LTA, rather than TNF, initiated canonical NFκB activation at the beginning of acid/bile attacks, but later it switched to CD40-activated non-canonical pathway, which played a bigger part in esophageal metaplasia. CCN1 attenuated this cellular transformation by suppressing CD40 and its associated proteins involved in non-canonical signaling.

CCN1 sensitizes esophageal cancer cells to TRAIL-mediated apoptosis.

TRAIL is one of the best anti-cancer molecules in our body. It kills a variety of cancer cells that are resistant to conventional chemotherapy, without causing much negative impact on normal cells, because its death receptors are almost exclusively found on cancer cells. However, some cancer cells are not sensitive to TRAIL treatment, even though they express its death receptors. A second molecule is needed to help TRAIL to complete its mission. Finding such molecules now becomes a top priority in cancer research. Our study shows that CCN1 is such a molecule. CCN1 was highly expressed in the esophageal epithelium of the patients suffering from gastroesophageal reflux disease, but faded away as the situation worsened towards adenocarcinoma. Treating the tumor cells with CCN1 resulted in apoptosis, while the same treatment to the normal cells only nourished cell growth. It was TRAIL that mediated this process. Apparently, CCN1 altered the expression profile of TRAIL and its receptors in tumor cells, namely, activating TRAIL and its death receptors and shutting down its decoy receptors. CCN1 and TRAIL worked as a team to put the cancer cells to death, as elimination of either one failed apoptosis.

CCN1 induces a reversible epithelial-mesenchymal transition in gastric epithelial cells.

CCN1 is a matricellular protein that activates many genes related to wound healing and tissue remodeling in fibroblasts, but its effect on epithelial cells remains unclear. This study examined the role of CCN1 in epithelial wound healing using rat gastric epithelial cells and rat stomach ulcer as in vitro and in vivo models, respectively. We found that CCN1 expression is highly upregulated in the epithelial cells adjacent to a wound and remains high until the wound is healed. Upregulation of CCN1 activates a transient epithelial-mesenchymal transition in the epithelial cells at the migrating front and drives wound closure. Once the wound is healed, these epithelial cells and their progeny can resume their original epithelial phenotype. We also found that CCN1-induced E-cadherin loss is not due to transcriptional regulation but rather protein degradation due to the collapse of adherens junctions, which is contributed by beta-catenin translocation. CCN1-activated integrin-linked kinase mediates this process. Finally, our in vivo study showed that locally neutralizing CCN1 drastically impairs wound closure, whereas local injection of recombinant CCN1 protein induces expression of vimentin and smooth muscle alpha-actin in normal gastric mucosal epithelial cells and accelerates re-epithelialization during ulcer healing. In conclusion, our study indicates that CCN1 can induce reversible epithelial-mesenchymal transition, and this feature may have great value for clinical wound healing.

CCN1 is critical for acid-induced esophageal epithelial cell transformation.

CCN1 is a matricellular protein involved in both wound healing and cancer cell invasion. Increased CCN1 expression has been associated with the development of Barrett's esophagus and the increased risk of progression to esophageal adenocarcinoma. In both cases, acid reflux is a major contributor. Low pH has been shown to induce CCN1 gene expression in esophageal epithelial cells. Here we demonstrated that both CCN1 and low pH could cause esophageal epithelial cell transformation, including loss of E-cadherin, disruption of cell-cell junctions, and expression of mesenchymal markers. Furthermore, knockdown of CCN1 through RNA interference sufficiently attenuated acid-driven cell phenotypic changes, while over-expression of CCN1 exacerbated these effects, indicating a critical role of CCN1 in acid-induced esophageal epithelial cell transformation. Given the pivotal role of low pH in gastro-esophageal reflux disease and its progression towards esophageal adenocarcinoma, our study identified CCN1 as a key molecule mediating this process.

Casein Kinase I epsilon positively regulates the Akt pathway in breast cancer cell lines.

The Akt pathway is very important in both development and cancer. Here we show that, expression of Casein Kinase I epsilon (CKIepsilon) causes up-regulation of the Akt pathway despite normal protein expression of the pathway inhibitor phosphate and tensin homologue deleted on chromosome ten (PTEN). Conversely, we show that a CKIepsilon/delta-specific inhibitor can inhibit Akt phosphorylation at both Thr308 and Ser473 and drastically reduce phosphorylation of the Akt target Glycogen Synthase Kinase 3beta (GSK3beta). These conclusions were confirmed between MCF7 cells transiently transfected with CKIepsilon and Hs578T cells which already express endogenous CKIepsilon. The results suggest that CKIepsilon is a new positive regulator of the Akt pathway. Here we propose that, rather than inhibiting PTEN function, CKIepsilon positively regulates Akt possibly by inhibiting Protein Phosphatase 2A (PP2A).

Comparison of manual & automated analysis methods for corneal endothelial cell density measurements by specular microscopy.

PURPOSE: To determine the reliability of corneal endothelial cell density (ECD) obtained by automated specular microscopy versus that of validated manual methods and factors that predict such reliability. METHODS: Sharp central images from 94 control and 106 glaucomatous eyes were captured with Konan specular microscope NSP-9900. All images were analyzed by trained graders using Konan CellChek Software, employing the fully- and semi-automated methods as well as Center Method. Images with low cell count (input cells number <100) and/or guttata were compared with the Center and Flex-Center Methods. ECDs were compared and absolute error was used to assess variation. The effect on ECD of age, cell count, cell size, and cell size variation was evaluated. RESULTS: No significant difference was observed between the Center and Flex-Center Methods in corneas with guttata (p=0.48) or low ECD (p=0.11). No difference (p=0.32) was observed in ECD of normal controls <40 yrs old between the fully-automated method and manual Center Method. However, in older controls and glaucomatous eyes, ECD was overestimated by the fully-automated method (p=0.034) and semi-automated method (p=0.025) as compared to manual method. CONCLUSION: Our findings show that automated analysis significantly overestimates ECD in the eyes with high polymegathism and/or large cell size, compared to the manual method. Therefore, we discourage reliance upon the fully-automated method alone to perform specular microscopy analysis, particularly if an accurate ECD value is imperative.

Comparison of manual & automated analysis methods for corneal endothelial cell density measurements by specular microscopy / Comparación de los métodos de análisis manual y automatizado para medir la densidad celular endotelial corneal mediante microscopio especular

Purpose: To determine the reliability of corneal endothelial cell density (ECD) obtained by automated specular microscopy versus that of validated manual methods and factors that predict such reliability. Methods:Sharp central images from 94 control and 106 glaucomatous eyes were captured with Konan specular microscope NSP-9900. All images were analyzed by trained graders using Konan CellChek Software, employing the fully- and semi-automated methods as well as Center Method. Images with low cell count (input cells number <100) and/or guttata were compared with the Center and Flex-Center Methods. ECDs were compared and absolute error was used to assess variation. The effect on ECD of age, cell count, cell size, and cell size variation was evaluated. Results:No significant difference was observed between the Center and Flex-Center Methods in corneas with guttata (p = 0.48) or low ECD (p = 0.11). No difference (p = 0.32) was observed in ECD of normal controls < 40 yrs old between the fully-automated method and manual Center Method. However, in older controls and glaucomatous eyes, ECD was overestimated by the fully-automated method (p = 0.034) and semi-automated method (p = 0.025) as compared to manual method. Conclusion: Our findings show that automated analysis significantly overestimates ECD in the eyes with high polymegathism and/or large cell size, compared to the manual method. Therefore, we discourage reliance upon the fully-automated method alone to perform specular microscopy analysis, particularly if an accurate ECD value is imperative

Objetivo: Determinar la fiabilidad de la densidad celular endotelial corneal (ECD) obtenida mediante microscopio especular automático frente a métodos manuales validados y factores predictivos de la fiabilidad. Métodos: Se capturaron imágenes nítidas de 94 controles y 106 ojos glaucomatosos con un microscopio especular Konan NSP-9900. Todas las imágenes fueron analizadas por examinadores expertos mediante el software Konan CellChek, utilizando los métodos automatizado total, semiautomático y de centrado. Se compararon las imágenes con bajo recuento celular (número de células <100) y/o córnea guttata con el método de centrado y centrado flexible. Se compararon las ECD, utilizándose el error absoluto para valorar la variación. Se evaluó el efecto de la ECD sobre la edad, el recuento celular, el tamaño celular y la variación del tamaño celular. Resultados: No se observó diferencia significativa entre los métodos de centrado y centrado flexible en las córneas con guttata (p = 0,48) o baja ECD (p = 0,11). No se observó diferencia (p = 0,32) en cuanto a ECD en los controles normales < 40 años entre el método totalmente automatizado y el método de centrado manual. Sin embargo, en los controles mayores y en los ojos glaucomatosos, la ECD fue sobreestimada por el método totalmente automatizado (p = 0,034) y el método semiautomático (p = 0,025), en comparación al método manual. Conclusión: Nuestros hallazgos muestran que los análisis automatizados sobreestiman considerablemente la ECD en los ojos con alto polimegatismo y/o gran tamaño celular, en comparación al método manual. Por tanto, no recomendamos confiar en el método totalmente automatizado por sí solo para realizar estudios mediante microscopio especular, particularmente en casos en que la precisión del valor de ECD sea imperativo

CCN1 Induces ß-Catenin Translocation in Esophageal Squamous Cell Carcinoma through Integrin α11.

Aims. Nuclear translocation of ß-catenin is common in many cancers including esophageal squamous cell carcinoma (ESCC). As a mediator of Wnt signaling pathway, nuclear ß-catenin can activate many growth-related genes including CCN1, which in turn can induce ß-catenin translocation. CCN1, a matricellular protein, signals through various integrin receptors in a cell-dependent manner to regulate cell adhesion, proliferation, and survival. Its elevation has been reported in ESCC as well as other esophageal abnormalities such as Barrett's esophagus. The aim of this study is to examine the relationship between CCN1 and ß-catenin in ESCC. Methods and Results. The expression and correlation between CCN1 and ß-catenin in ESCC tissue were examined through immunohistochemistry and further analyzed in both normal esophageal epithelial cells and ESCC cells through microarray, functional blocking and in situ protein ligation. We found that nuclear translocation of ß-catenin in ESCC cells required high level of CCN1 as knockdown of CCN1 in ESCC cells reduced ß-catenin expression and translocation. Furthermore, we found that integrin α(11) was highly expressed in ESCC tumor tissue and functional blocking integrin α(11) diminished CCN1-induced ß-catenin elevation and translocation. Conclusions. Integrin α(11) mediated the effect of CCN1 on ß-catenin in esophageal epithelial cells.

Serum response factor: look into the gut.

Serum response factor (SRF) is a transcription factor that regulates many genes involved in cellular activities such as proliferation, migration, differentiation, angiogenesis, and apoptosis. Although it has only been known for about two decades, SRF has been studied extensively. To date, over a thousand SRF studies have been published, but it still remains a hot topic. Due to its critical role in mesoderm-derived tissues, most of the SRF studies focused on muscle structure/function, cardiovascular development/maintenance, and smooth muscle generation/repair. Recently, SRF has received more attention in the digestive field and several important discoveries have been made. This review will summarize what we have learned about SRF in the gastrointestinal tract and provide insights into possible future directions in this area.

Potential of casein kinase I in digestive cancer screening.

Casein kinase I is a group of ubiquitous Serine/Threonine kinases that have been implicated in both normal cellular functions and several pathological conditions including Alzheimer's disease and cancer. Recent findings in colon and pancreatic cancer have brought tremendous attention to these molecules as potential therapeutic targets in treatment of digestive cancers. In this review, we summarize up to date what is known about this family of kinases and their involvement in carcinogenesis and other pathological conditions. Our emphasis is on their implications in digestive cancers and their potential for cancer screening and therapy.