RESUMEN
Glycosaminoglycans undergo significant structural alterations in cancer, namely in terms of their sulfation pattern and hydrodynamic size. Numerous studies have focused on this issue, and have demonstrated that glycosaminoglycans play a crucial role in cancer growth and invasion. However, the majority of the enzymes involved in glycosaminoglycan alterations have yet to be examined in detail. The present study focused on the expression of chondroitin-synthesizing enzymes in colorectal cancer. Specimens from healthy controls and cancer patients were subjected to RT-PCR analysis after RNA isolation, and to Western blotting after sequential extraction. The results indicated that chondroitin polymerizing factor and glucuronyltransferase gradually increased with cancer stage, and were expressed at much higher levels in adenomas compared to adjacent normal tissue. The opposite profile was obtained for chondroitin synthase I. Chondroitin synthase III was present at low levels in all the samples examined; however, its expression was higher in the samples from the cancer patients than in those from the healthy controls. It can therefore be concluded that, among the various factors regulating the structure of glycosaminoglycans in cancer, the differential expression of chondroitin-synthesizing enzymes is of the most significance.
Asunto(s)
Neoplasias Colorrectales/enzimología , Glucuronosiltransferasa/metabolismo , N-Acetilgalactosaminiltransferasas/metabolismo , Anciano , Anciano de 80 o más Años , Western Blotting , Sulfatos de Condroitina/metabolismo , Neoplasias Colorrectales/genética , Dermatán Sulfato/metabolismo , Femenino , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Glucuronosiltransferasa/genética , Humanos , Masculino , Persona de Mediana Edad , N-Acetilgalactosaminiltransferasas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: Hyaluronidases belong to a class of enzymes that degrade, predominantly, hyaluronan. These enzymes are known to be involved in physiological and pathological processes, such as tumor growth, infiltration and angiogenesis, but their exact role in tumor promotion or suppression is not clear yet. Advanced colorectal cancer is associated with elevated amounts of hyaluronan of varying size. The aim of the present study was therefore to illuminate the importance of hyaluronidases in colon carcinoma progression. METHODS: The patients' samples (macroscopically normal and cancerous) were subjected to sequential extraction with PBS, 4 M GdnHCl and 4 M GdnHCl --1% Triton X-100. The presence of the various hyaluronidases in the extracts was examined by zymography and western blotting. Their expression was also examined by RT-PCR. RESULTS: Among hyaluronidases examined, Hyal-1, -2, -3 and PH-20 were detected. Their activity was higher in cancerous samples. Hyal-1 and Hyal-2 were overexpressed in cancerous samples, especially in advanced stages of cancer. Both isoforms were mainly extracted with PBS. Hyal-3 was observed only in the third extract of advanced stages of cancer. PH-20 was abundant in all three extracts of all stages of cancer. The expression of only Hyal-1 and PH-20 was verified by RT-PCR. CONCLUSION: A high association of hyaluronidases in colorectal cancer was observed. Each hyaluronidase presented different tissue distribution, which indicated the implication of certain isoforms in certain cancer stages. The results provided new evidence on the mechanisms involved in the progression of colorectal cancer.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Moléculas de Adhesión Celular/metabolismo , Colon/enzimología , Neoplasias Colorrectales/enzimología , Hialuronoglucosaminidasa/metabolismo , Recto/enzimología , Anciano , Anciano de 80 o más Años , Western Blotting , Moléculas de Adhesión Celular/genética , Colon/patología , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/patología , Progresión de la Enfermedad , Femenino , Proteínas Ligadas a GPI/genética , Proteínas Ligadas a GPI/metabolismo , Humanos , Hialuronoglucosaminidasa/genética , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , ARN Mensajero/genética , Recto/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tasa de SupervivenciaRESUMEN
The glycosaminoglycans are implicated in many processes important in the growth and progression of malignant tumors. In the present study glycosaminoglycans were purified from healthy, macroscopically normal and cancerous specimens of different anatomic sites and different stages of cancer and analyzed by FACE after chondroitinases and sulfatases digestion. The cancerous samples contained increased levels of 6-sulfated unsaturated disaccharides compared to macroscopically normal and healthy samples, the increase being stage-related. The differences in sulfation were found to be related to the anatomic site and the stage of cancer. RT-PCR analysis of 4-sulfotransferase mRNA revealed its presence in decreasing amounts as the stage of the cancer increased. Furthermore, the percent content of hyaluronan disaccharides was elevated in macroscopically normal samples compared to the cancerous, and in addition, it was much more elevated than that of healthy samples. Haluronan levels increase with stage in cancerous tissues. Therefore, it could be concluded that the glycosaminoglycans in colorectal cancer are biosynthetically directed to contribute in different ways depending on the cancer stage and anatomical site.