Podoplanin, alpha-Smooth Muscle Actin or S100A4 Expressing Cancer-Associated Fibroblasts Are Associated with Different Prognosis in Colorectal Cancers

The interactions between the tumor microenvironment and tumor cells determine the behavior of the primary tumors. Whether cancer-associated fibroblasts (CAF) have a tumor progressive or a protective role likely depends on the type of tumor cells and the CAF subpopulation. In the present study, we analyzed the prognostic significance of CAF subpopulations in colorectal cancer (CRC). CAF phenotypes were analyzed in 302 CRC patients by using antibodies against podoplanin (PDPN), alpha-smooth muscle actin (alpha-SMA), and S100A4. The relationship between the CAF phenotypes and 11 clinicopathological parameters were evaluated and their prognostic significance was analyzed from the disease-free and overall survival times. We observed that at the tumor invasive front, PDPN CAFs were present in 40% of the cases, and S100A4 or alpha-SMA CAFs were detected in all the cases. PDPN/S100A4 and alpha-SMA/S100A4 dual-stained CAFs were observed in 10% and 40% of the cases, respectively. The PDPN+ CAFs were associated with 6 favorable clinicopathological parameters and prolonged disease-free survival time. The PDPN-/alpha-SMA(high) CAFs were associated with 6 aggressive clinicopathological parameters and tended to exhibit shorter disease-free survival time. On the other hand, the PDPN-/S100A4(high) CAFs were associated with 2 tumor progression parameters, but not with disease prognosis. The PDPN+ CAF phenotype is distinct from the alpha-SMA or S100A4 CAFs in that it is associated with less aggressive tumors and a favorable prognosis, whereas the PDPN-/alpha-SMA(high) or PDPN-/S100A4(high) CAFs are associated with tumor progression in CRC. These findings suggest that CAFs can be a useful prognostic biomarker or potential targets of anti-cancer therapy in CRC.

Significance of smooth muscle/anti-actin autoantibodies in celiac disease / Significado de los anticuerpos anti-músculo liso/anti-actina en la enfermedad celíaca

BACKGROUND/AIM: Smooth muscle antibody (SMA) specific for the protein actin, a major component of the cytoskeleton of epithelial cells, is one of the most prevalent non-organ specific autoantibodies in the serum of celiac disease (CD) patients. Our aim was to explore the clinical relevance of the presence of IgA type anti-actin antibody (AAA) and SMA in a series of patients with CD. METHODS: We evaluated frozen serum samples collected at diagnosis from 92 adult patients with CD and 52 control individuals in whom CD was excluded. Patients were re-evaluated a median time of 5 yr after treatment. IgA type AAA was detected using a modified commercial ELISA assay and IgA SMA was detected using indirect immunofluorescence on primate esophagus substrate. RESULTS: At diagnosis, samples from CD patients had significantly higher AAA values than controls (p<0.00001). While all active CD patients had serum AAA values over the cut-off for healthy controls, we observed a very significant reduction of these antibodies after treatment (p>0.0001). AAA had a highly significant correlation with both, tissue, transglutaminase (r=0.62) and antigliadin (r=0.60, p<0.00001) antibodies as well as the severity of the intestinal injury (p<0.05). SMA was detected in sera of 35 consecutive CD patients. At diagnosis, SMA positive patients had significantly higher values of AAA (p<0.0002), increased number of autoimmune disorders (p<0.04), delayed menarche (p<0.04), lower hemoglobin levels (p<0.01), increased fecal a-I antitrypsin clearance (p<0.01) and more severe diarrhea (p<0.06). We also detected a trend to more severe complications at follow-up (p=0.059). CONCLUSIONS: Based on our findings we suggest that the presence of increased IgA AAA serum levels is a highly sensitive marker of the disturbed architecture of intestinal epithelial cells of CD patients with a potential relevance to diagnosis and follow-up. The presence of SMA seems to define a distinct subset of CD patients with ...

Introduccion/objetivo: El anticuerpo anti-musculo liso (SMA) dirigido contra la proteína actina, un componente mayor del citoesqueleto de las células epiteliales, es el anticuerpo no-órgano específico más prevalente en enfermedad celíaca (EC). Nuestro objetivo fue explorar la importancia clínica de los anticuerpos anti-actina (AAA) y SMA en una serie de pacientes con EC. Métodos: Evaluamos 92 muestras serológicas de pacientes celíacos adultos recolectadas al momento del diagnóstico y la de 52 individuos controles no celíacos. Los pacientes fueron re-evaluados luego de un tiempo medio de 5 años en tratamiento. Evaluamos AAA tipoIgA mediante ELISA empleando un equipo commercial modificado y SMA IgA por inmunofluorescencia indirecta sobre sustrato de esófago de mono. Resultados: Al momento del diagnóstico, los pacientes celíacos tuvieron valores de AAA significativamente más elevados que los controles (p<0.00001). Todos los pacientes con EC activa presentaron niveles de AAA por encima del valor de corte determinado para el grupo control sano y se evidenció una reducción significativa de los nivelesluego del tratamiento (p>0.0001). Los AAA presentaron una correlación significativa con los anticuerpos anti-transglutaminasa tisular (r=0.62) y anti-gliadina (r=0.60) (p<0.00001), de igual modo que con la severidad del daño intestinal (p<0.05). Al momento del diagnóstico, se detectó SMA en el suero de 35 pacientes no controles. Los pacientes SMA positivos tuvieron valores significativamente mayores de AAA (p<0.002), un incremento del número de enfermedades autoinmunes asociadas (p<0.04), menarca tardía (p<0.04), niveles bajos de hemoglobina (p<0.01), incremento del clearance de a-1 antitripsina fecal (p<0.01) y mayor severidad de la diarrea (p<0.06).En ellos se evidenció una tendencia al desarrollo de complicaciones más severas durante el seguimiento (p=0.059). Conclusiones: Sugerimos que la presencia de un valor sérico aumentado de AAA tipo IgA...

Caracterização do anticorpo contra as formas globular e filamentosa da actina na hepatite auto-imune / Characterization of the antibodies against globular and filamentous forms of actn in autoimmune hepatitis

Os objetivos do presente estudo foram: determinar a freqüência de anticorpos contra a actina G (AG) e actina F (AF) na hepatite auto-imune tipo 1 e em controles; correlacionar a positividade desses anticorpos com o anticorpo anti-microfilamento (AMF); comparar AG e AF em experimentos de adsorção de soros. 250 soros (65 HAI-1 e 185 controles) foram testados por imunofluorescência indireta e por ELISA in house e disponível comercialmente. Reatividade contra AG e AF ocorreu em, respectivamente, 40 por cento e 58,5 por cento dos pacientes com HAI-1 com o ELISA in house. Com o ELISA comercial, 93,7 por cento dos soros foram reativos para AF. Em todos os grupos controles, houve elevada freqüência de positividade para AG e AF. Não houve correlação entre as reatividades contra AG e AF e os títulos do AMF e tanto a AG quanto a AF neutralizaram o padrão do AMF/The aims of this study were: to assess the frequency of antibodies to G-actin and F-actin (GA and FA) in autoimmune hepatitis type1 and controls; to correlate the positivity of those antibodies to the reactivity to antimicrofilaments antibodies (AMF); to compare GA and FA in serum absorption experiments. 250 sera (65 AIH-1 and 185 controls) were tested by indirect immunofluorescence reaction and by ELISA developed in house and commercially purchased. Reactivity to GA and FA, respectively, was detected in 40 por cent and 58.5 por cent of AIH-1 patients by the in house ELISA. By the commercial ELISA, 93.7 por cent were reactivity to FA. All control groups had a high frequency of positivity to both FA and GA. There was no significant correlation between the reactivities to GA and FA and the titers of AMF and both GA and FA neutralized the AMF patter...

Isolation and identification of actin-binding proteins in Plasmodium falciparum by affinity chromatography

The invasion of the erythrocyte by Plasmodium falciparum depends on the ability of the merozoite to move through the membrane invagination. This ability is probably mediated by actin dependent motors. Using affinity columns with G-actin and F-actin we isolated actin binding proteins from the parasite. By immunoblotting and immunoprecipitation with specific antibodies we identified the presence of tropomyosin, myosin, a-actinin, and two different actins in the eluate corresponding to F-actin binding proteins. In addition to these, a 240-260 kDa doublet, different in size from the erythrocyte spectrin, reacted with an antibody against human spectrin. All the above mentioned proteins were metabolically radiolabeled when the parasite was cultured with 35S-methionine. The presence of these proteins in P. falciparum is indicative of a complex cytoskeleton and supports the proposed role for an actin-myosin motor during invasion.

Investigacion de anticuerpos antiactina en hepatitis aguda por virus A en niños / Investigation of anti-actin antibodies in acute viral hepatitis A in children

El virus de la Hepatitis A ha sido propuesto como un posible disparador de hepatitis autoinmune tipo I. Nosostros previamente hemos relatado la presencia de anticuerpos anti-actina en hepatitis A prolongada. En el momento actual la tasa de presencia de anticuerpos antiactina en hepatitis A aguda no complicada es desconocida. Objetivo: evaluar la incidencia y persistencia de anticuerpos antiactina en niños con hepatitis A aguda. Material y métodos: se estudiaron 38 pacientes, 21 mujeres y 17 varones, con una edad media de 6,5 años (margem 2-13). Todos los niños tenían IgM positiva para virus de hepatitis A. Se realizaron controles clínicos y de laboratorio (AST/ALT, gammaglobulina, gammaGT) al comienzo, primer, tercero y quito mes. Los anticuerpos antiactina, anticuerpos a antígenos nucleares (FAN) y antimicrosomas de hígadoriñón (anti-LKM) fueron estudiados con igual frecuencia, hasta volverse negativos. Los anticuerpos anti-actina fueron determinados por imunofluorescencia indirecta en cortes de riñón, hígado y estómago de rata, siendo considerados positivos de sueros con títulos iguales o mayores de 1/40. Resultados: en 18 pacientes (47,3 por ciento) el Ac. anti-actina fue positivo en la primera determinación (títulos 1/40 y 1/80). En 4 pacientes (12,9 por ciento) estos anticuerpos permanecieron positivos durante un mes. Sólo un paciente (2,94 por ciento) tenía el anticuerpo antiactina positivo al tercer mes. Todos los niños eram negativos 5 meses luego del comienzo de la enfermedad. Los FAN y anti-LKM fueron negativos en todos los casos. Conclusiones: 1) Estos datos demuestran la presencia de anticuerpos anti-actina en niños con hepatitis A no complicada. 2) Los anticuerpos permanecieron positivos por un corto período de tiempo. 3) Los títulos fueron menores que en la hepatitis autoinmune tipo I. 4) Estos resultados sugieren que los anticuerpos anti-actina podrían ser la expresión de una estimulación no específica de linfocitos B