Chemoprevention of Low-Molecular-Weight Citrus Pectin (LCP) in Gastrointestinal Cancer Cells.

BACKGROUND & AIMS: Low-molecular-weight citrus pectin (LCP) is a complex polysaccharide that displays abundant galactosyl (i.e., sugar carbohydrate) residues. In this study, we evaluated the anti-tumor properties of LCP that lead to Bcl-xL -mediated dampening of apoptosis in gastrointestinal cancer cells. METHODS: We used AGS gastric cancer and SW-480 colorectal cancer cells to elucidate the effects of LCP on cell viability, cell cycle and apoptosis in cultured cells and tumor xenografts. RESULTS: Significantly decreased cell viabilities were observed in LCP treated AGS and SW-480 cells (P<0.05). Cell cycle-related protein expression, such as Cyclin B1, was also decreased in LCP treated groups as compared to the untreated group. The AGS or SW-480 cell-line tumor xenografts were significantly smaller in the LCP treated group as compared the untreated group (P<0.05). LCP treatment decreased Galectin-3 (GAL-3) expression levels, which is an important gene in cancer metastasis that results in reversion of the epithelial-mesenchymal transition (EMT), and increased suppression of Bcl-xL and Survivin to promote apoptosis. Moreover, results demonstrated synergistic tumor suppressor activity of LCP and 5-FU against gastrointestinal cancer cells both in vivo and in vitro. CONCLUSIONS: LCP effectively inhibits the growth and metastasis of gastrointestinal cancer cells, and does so in part by down-regulating Bcl-xL and Cyclin B to promote apoptosis, and suppress EMT. Thus, LCP alone or in combination with other treatments has a high potential as a novel therapeutic strategy to improve the clinical therapy of gastrointestinal cancer.

[Variability of human cytomegalovirus UL144 gene in low-passage clinical isolates analyzed by HMA-SSCP].

BACKGROUND: Human cytomegalovirus (HCMV) infection is an important infectious agent that results in neonatal disease and congenital deformity. HCMV infection may affect in many organs. The different symptoms and tissue tropism of HCMV infection perhaps resulted from the genetic polymorphism of HCMV. HCMV UL144 open reading frames encode a homologue of the tumor necrosis factor receptor. It seems important to study the strain-specific variability of UL144 sequence in low-passage clinical isolates and to discuss if the variability related to the clinical HCMV infection. METHODS: HCMV-UL144 gene was amplified by PCR assay in 65 low-passage clinical isolates and urine from 7 healthy children who were HCMV-DNA positive by quantitative PCR. All the positive PCR products were analyzed by Heteroduplex mobility assay and single-stranded conformation polymorphism (HMA-SSCP) and 32 of them were sequenced. RESULTS: Fifty-five isolates and 5 urine specimens were HCMV-UL144 positive by PCR. Sequencing and HMA-SSCP analysis showed that significant strain-specific variability was present in the UL144 ORFs. Comparing UL144 sequences and the corresponding symptoms showed that genotype 2 did not exist in megacolon isolates. And genotype 1 and 3 were the major types among microcephaly and jaundice isolates respectively. CONCLUSION: HCMV-UL144 existed in almost all the low passage isolates. HMA-SSCP assay is an easy and effective method to detect the genetype of HCMV-UL144 sequence. The characteristic of sequences in different isolates showed that UL144 gene may play an important role in HCMV infection.

Sequence variability of human cytomegalovirus UL144 open reading frame in low-passage clinical isolates.

OBJECTIVE: To explore the relationship between human cytomegalovirus (HCMV) UL144 sequence variability and clinical disease. METHODS: HCMV UL144 open reading frame (ORF) was amplified by PCR assay in 72 low-passage isolates [65 congenitally infective children and 7 healthy children who were HCMV-DNA positive by quantitative PCR (qPCR)]. All positive PCR products were analyzed by heteroduplex mobility assay and single-stranded conformation polymorphism (HMA-SSCP) and 32 of them were sequenced. RESULTS: Fifty-five patient isolates and five healthy children isolates were HCMV-UL144 positive by PCR. Sequencing and HMA-SSCP analysis showed that significant strain-specific variability was present in the UL144 ORF. Phylogenetic analysis indicated that the nucleotide sequences could be separated into 3 major genotypes. Comparing between UL144 sequences and the corresponding symptoms showed that genotype 2 did not exist in megacolon isolates. And genotype 1 and 3 were the major types among microcephaly and jaundice isolates respectively. CONCLUSIONS: HCMV-UL144 existed in most of low passage isolates and sequences were hypervariable. The UL144 ORF and its predicted product with the high level of sequence variability in different kinds of isolates suggest that UL144 ORF might play a role in HCMV infectivity and subsequent diseases.

[Effects of low oxygen-modified atmosphere packaging on browning and lignification of peeled bamboo shoots].

The browning and lignification of peeled bamboo shoots (Phyllostachys praecox f. prevelnalis) under modified atmosphere packaging (MAP) with a combination of 2% O(2)+5% CO(2)+93% N(2) in 0.04 mm polyethylene bag during storage at 10 degrees C were investigated. The results indicated malondialdehyde (MDA) content of bamboo shoots under MAP with low O(2) atmosphere was lower than that in the control during early storage, the activities of peroxidase (POD) and phenylalanine ammonia-lyse (PAL) were significantly inhibited (P<0.05 and P<0.01, respectively), and the browning of bamboo shoots under MAP with low O2 atmosphere was eventually significantly prevented (P<0.01) and cellulose and lignin contents were significantly decreased (P<0.05). The browning of bamboo shoots was probably caused by POD and PAL activities, and the increase in POD and PAL activities might account for the lignification of bamboo shoots.