RESUMO
AIM: To investigate the expression of receptor-binding cancer antigen expressed on SiSo cells (RCAS1) in metastatic lymph nodes from gastrointestinal cancer. METHODS: Metastatic lymph nodes from gastrointestinal cancer were detected for RCAS1 by immunohistochemical staining and mRNA in situ hybridization. RESULTS: A total of 102 metastatic lymph nodes from bile duct, gastric, colon and pancreatic cancer were investigated for RCAS1 expression. The immunoreactivity of RCAS1 was identified in 100% of metastatic lymph nodes. Both local and distant metastatic lymph nodes showed RCAS1 expression. On the contrary, specimens of non-cancerous lymph nodes were negative for RCAS1. The result of mRNA in situ hybridization was also confirmed by the finding of immunohistochemical staining. RCAS1 mRNA was detected in all tumor cells that metastasized to lymph nodes. CONCLUSION: All metastatic lymph nodes express RCAS1 in tumor cells at both mRNA levels, and RCAS1 that should be used as a complementary factor for identification of metastatic lymph nodes from gastrointestinal cancers.
Assuntos
Antígenos de Neoplasias/metabolismo , Neoplasias Gastrointestinais/imunologia , Antígenos de Neoplasias/genética , Sequência de Bases , Linhagem Celular Tumoral , Neoplasias Gastrointestinais/genética , Neoplasias Gastrointestinais/secundário , Humanos , Hibridização In Situ , Metástase Linfática , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Neoplásico/genética , RNA Neoplásico/metabolismo , Homologia de Sequência do Ácido NucleicoRESUMO
Although there is a specific antitumor immune response in the body, colorectal cancer cells progressively develop. This fact indicated that the cancer cells could have a variety of mechanisms to evade or escape the immune system. HLA-G is identified to inhibit the recognition of NK-cell in various kinds of cancers. This study investigated the expression of HLA-G in colorectal cancer. Eighty five specimens of colorectal cancer, carcinoma in situ and adenomatous polyp were examined by immunohistochemistry and RT-PCR for the detection of human leukocyte antigen (HLA)-G The expression of HLA-G was not found in all colorectal specimens (85/85) both protein level and transcription level, suggesting that the expression of HLA-G is not a possible immune evasion mechanism of colorectal cancer cell.
Assuntos
Neoplasias Colorretais/metabolismo , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Pólipos Adenomatosos/metabolismo , Carcinoma in Situ/metabolismo , Antígenos HLA-G , Humanos , Imuno-Histoquímica , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
BACKGROUND: Isopentenyl diphosphate (IPP), a common biosynthetic precursor to the labdane diterpene forskolin, has been biosynthesised via a non-mevalonate pathway. Geranylgeranyl diphosphate (GGPP) synthase is an important branch point enzyme in terpenoid biosynthesis. Therefore, GGPP synthase is thought to be a key enzyme in biosynthesis of forskolin. Herein we report the first confirmation of the GGPP synthase gene in Coleus forskohlii Briq. RESULTS: The open reading frame for full-length GGPP synthase encodes a protein of 359 amino acids, in which 1,077 nucleotides long with calculated molecular mass of 39.3 kDa. Alignments of C. forskohlii GGPP synthase amino acid sequences revealed high homologies with other plant GGPP synthases. Several highly conserved regions, including two aspartate-rich motifs were identified. Transient expression of the N-terminal region of C. forskohlii GGPP synthase-GFP fusion protein in tobacco cells demonstrated subcellular localization in the chloroplast. Carotenoid production was observed in Escherichia coli harboring pACCAR25DeltacrtE from Erwinia uredovora and plasmid carrying C. forskohlii GGPP synthase. These results suggested that cDNA encoded functional GGPP synthase. Furthermore, C. forskohlii GGPP synthase expression was strong in leaves, decreased in stems and very little expression was observed in roots. CONCLUSION: This investigation proposed that forskolin was synthesised via a non-mevalonate pathway. GGPP synthase is thought to be involved in the biosynthesis of forskolin, which is primarily synthesised in the leaves and subsequently accumulates in the stems and roots.
