Advanced oxidation protein products trigger apoptosis and block epithelial-to-mesenchymal transition in crypt epithelial cells.

Advanced oxidation protein products (AOPPs) are uremic toxins. The present study aimed to investigate the effects of AOPPs on the epithelial mesenchymal transition (EMT) and apoptosis of rat crypt epithelial cells, and to assess the signaling pathways involved. The oxidized rat serum albumin was obtained by sodium hypochlorite modification as AOPPs, and the rat serum albumin (RSA) without sodium hypochlorite modification was set as the control. Different concentrations of AOPPs or RSA were incubated with rat crypt epithelial cells (IEC-6 cells). After culturing for 48 and 72 h, apoptosis was detected by flow cytometry. IEC-6 cells were divided into three groups: A normal group, an AOPPs group and an RSA group. Three groups of cells were collected following treatment for 2 h, and the phosphorylation levels of Akt and p65 NF-κB were detected by western blotting. After 72 h of treatment, the cells were collected and the apoptotic rate was detected by flow cytometry. The expression of EMT-related proteins was detected by reverse transcription-quantitative polymerase chain reaction and western blotting. The apoptotic rate of IEC-6 cells increased with the concentration of AOPPs, and the apoptotic rate of the AOPPs group was higher than that of the RSA group. The expression of fibronectin, snail, slug and collagen I in the AOPPs group was lower than that in the RSA group, while the expression of E-cadherin was not significantly different between the two groups. In addition, the expression of fibronectin, snail, slug and collagen I genes in the AOPPs-treated group was equal to or lower than that in the normal group. Compared with the normal group, the Akt phosphorylation level was decreased and the p65 phosphorylation level was increased in the AOPPs- or RSA-treated groups. Compared with the AOPPs-treated group, Akt and p65 phosphorylation levels in RSA-treated group were slightly higher. In conclusion, AOPPs trigger apoptosis and inhibit the EMT of rat crypt epithelial cells, which may be associated with the inhibition of Akt phosphorylation and the promotion of p65 phosphorylation.

Uncaria alkaloids reverse ABCB1-mediated cancer multidrug resistance.

The overexpression of ATP-binding cassette (ABC) transporters is the main cause of cancer multidrug resistance (MDR), which leads to chemotherapy failure. Uncaria alkaloids are the major active components isolated from uncaria, which is a common Chinese herbal medicine. In this study, the MDR-reversal activities of uncaria alkaloids, including rhynchophylline, isorhynchophylline, corynoxeine, isocorynoxeine (Icory), hirsutine and hirsuteine, were screened; they all exhibited potent reversal efficacy when combined with doxorubicin. Among them, Icory significantly sensitized ABCB1-overexpressing HepG2/ADM and MCF-7/ADR cells to vincristine, doxorubicin and paclitaxel, but not to the non-ABCB1 substrate cisplatin. Noteworthy, Icory selectively reversed ABCB1-overexpressing MDR cancer cells but not ABCC1- or ABCG2-mediated MDR. Further mechanistic study revealed that Icory increased the intracellular accumulation of doxorubicin in ABCB1-overexpressing cells by blocking the efflux function of ABCB1. Instead of inhibiting ABCB1 expression and localization, Icory acts as a substrate of the ABCB1 transporter by competitively binding to substrate binding sites. Collectively, these results indicated that Icory reversed ABCB1-mediated MDR by suppressing its efflux function, and it would be beneficial to increase the efficacy of these types of uncaria alkaloids and develop them to be selective ABCB1-mediated MDR-reversal agents.

[Research progress in pharmacological effects of Uncaria Hook on Alzheimer disease models].

The most common neurodegenerative disease, Alzheimer disease (AD) constitutes the majority of all senile dementia cases. Extending life expectancy contributes to the increased incidence of AD, which is a serious threat to the quality of life of the elderly. The etiology and pathogenesis of AD are not absolutely clear. There are various kinds of hypotheses, such as abnormal phosphorylation of tau proteins, amyloid-beta protein toxicity, gene mutation, degeneration of cholinergic system, neuroinflammation, oxidative stress. Based on the above-mentioned theories, lots of studies of Uncaria Hook have been conducted in Alzheimer disease models. In this paper, we reviewed the latest research of Uncaria Hook on Alzheimer disease models to provide reference for further development of Uncaria Hook's medicinal potential.

[Advance in studies on neuroprotective mechanism of Uncariae Ramulus Cum Uncis].

The Uncariae Ramulus Cum Uncis is a commonly used traditional Chinese medicine. In recent years, many studies have revealed its prominent neuroprotection function. The active ingredients in Uncariae Ramulus Cum Uncis could protect the nervous system in a multi-path and multi-target manner. Uncariae Ramulus Cum Uncis shows the neuroprotective effect by resisting oxidation, scavenging free radicals, modulating neurotransmitters and their related receptors, regulating the inflammatory factors and their related pathways, attenuating neuron apoptosis, reducing intracellular Ca2+ overloads and mitigating neurodegeneration. In this paper, the authors summarized the advance in studies on neuroprotective mechanisms of Uncariae Ramulus Cum Uncis.

[Pattern of lymph node metastasis and extent of lymphadenectomy for distal gastric cancer].

OBJECTIVE: To analyze lymph node (LN) metastasis patterns and determine the appropriate extent of LN dissection in distal-third gastric cancer. METHODS: Clinical data of 545 patients with distal third gastric cancer undergoing radical operation in the Fujian Provincial Hospital between 2001 and 2010 were analyzed retrospectively. The metastasis rate for each LN station was analyzed stratified by the depth of tumor invasion. RESULTS: The incidence of LN metastasis in this cohort was 38.2% (208/545). LN metastasis rate in mucosal cancer was 2.0% (2/99) and involved LNs were limited to station 1 LN stations. LN metastasis rate in submucosal cancer was 18.9% (18/95), significantly higher than that in mucosal cancer (P<0.01). The metastasis rates to groups No.7, 8 and 9 in station 2 were 5.3% (5/94), 3.2% (3/94), and 1.1% (1/89) respectively. In addition, 3 cases (3.2%) had metastasis in station 2 outside the range of groups 7, 8 and 9 including groups No.1, 11p and 12. Gastric cancer invading the muscularis propria or deeper layers showed an significant increased rate of metastasis (P<0.01). CONCLUSION: D1 dissection seems to be sufficient for mucosal cancer. Standard D2 dissection should be performed for cancers of the muscularis propria or deeper. For submucosal cancer, an extended D1+ dissection is required for complete removal of metastatic nodes.

Discovery and validation of prognostic markers in gastric cancer by genome-wide expression profiling.

AIM: To develop a prognostic gene set that can predict patient overall survival status based on the whole genome expression analysis. METHODS: Using Illumina HumanWG-6 BeadChip followed by semi-supervised analysis, we analyzed the expression of 47,296 transcripts in two batches of gastric cancer patients who underwent surgical resection. Thirty-nine samples in the first batch were used as the training set to discover candidate markers correlated to overall survival, and thirty-three samples in the second batch were used for validation. RESULTS: A panel of ten genes were identified as prognostic marker in the first batch samples and classified patients into a low- and a high-risk group with significantly different survival times (P = 0.000047). This prognostic marker was then verified in an independent validation sample batch (P = 0.0009). By comparing with the traditional Tumor-node-metastasis (TNM) staging system, this ten-gene prognostic marker showed consistent prognosis results. It was the only independent prognostic value by multivariate Cox regression analysis (P = 0.007). Interestingly, six of these ten genes are ribosomal proteins, suggesting a possible association between the deregulation of ribosome related gene expression and the poor prognosis. CONCLUSION: A ten-gene marker correlated with overall prognosis, including 6 ribosomal proteins, was identified and verified, which may complement the predictive value of TNM staging system.

[Analysis of prognostic factors in lymph node-negative advanced gastric cancer patients].

OBJECTIVE: To investigate the prognostic factors of lymph node-negative advanced gastric cancer patients in order to guide adjunctive therapy and surveillance tragedy. METHODS: A total of 236 advanced gastric cancer patients with no less than 12 retrieved lymph nodes and without lymph node metastasis from Fujian Provincial Hospital between 1998 and 2008 were collected retrospectively. Univariate and multivariate prognostic analysis were performed. RESULTS: Two hundred and twenty-four patients(94.9%) were followed up and 5-year overall and disease-free survival rates were 75.2% and 66.4% respectively. Univariate prognostic analysis showed that depth of infiltration, Lauren histotype and retrieved lymph nodes were associated with 5-year overall survival(all P<0.05). Multivariate prognostic analysis testified that depth of infiltration was independent prognostic predictor(P<0.05). Recurrent rates of T2 and T3 patients were 5.8%(8/138) and 14.0%(12/86),5-year overall survival rates were 82.5% and 59.0%, 5-year disease-free survival rates were 70.4% and 52.2% respectively. These differences were all statistically significant (all P<0.05). CONCLUSIONS: T2N0 gastric cancer patients have a better prognosis than T3N0 patients. Depth of infiltration should be considered to stratify lymph node-negative gastric cancer patients for an adjunctive treatment and follow-up scheduling.

[Systematic analysis of cis-nested gene pairs in the human genome].

In the genome one gene, whose entire or the most part of the sequence localizes in an intronic or UTR region of another larger gene, is called nested gene. A nested gene pair consists of a host and a nested gene. Here, we conducted a systematic scanning and analysis to identify all cis-nested gene pairs and their structural features in the human genome. Meanwhile, we also explored possible mechanism for evolution of nested gene and the relationship between the host and the cis-nested gene (denoted as nested gene in short). Our analysis indicated that evolution of nested gene pair probably arose from the transposition, de novo mutation, and the mutations occurred in transcription start or termination sites. The change in transcription starting or ending site could be a unique mechanism driving evolution of nested gene pair. Gene Ontology analysis indicated the gene products of the nested gene and its host counterpart have no functional correlation.

[The contribution of gene conversion at the same chromosome to the HLA diversity].

HLA is the most polymorphic gene family in human genome, which is imperative for human to face numerous heterogeneous bio-molecules. Previous studies on the formation of HLA polymorphism have been focused on gene crossover. Here, we investigated the contribution of gene conversion, which is an important mechanism to generate polymorphism at shaping different patterns of HLA-DRB genes. Analysis of all known HLA-DRB haplotypes and alleles demonstrated that this was a highly polymorphic gene family. Using Ester Betran's algorithm, 32 gene conversion regions were identified. The minimal conversion tract was as short as 2 bp, and the maximum interval between two furthest SNPs was 204 bp. Moreover, gene conversion occurred more frequently in certain regions (71-75, 18-221) of various alleles, suggesting that these segments were conversion hotspots. Further analysis showed that the conversion regions of 71-75 and 205-217 appeared to correlate with populations of Oriental and Caucasian, respectively, indicating that conversion hotspots might be population specific.

[Contents mensuration of total alkaloid in Uncaria rhynchophylla by acid dye colorimetry].

OBJECTIVE: To investigate the method of determination of total alkaloids Uncaria rhynchophylla. METHODS: The Contents of total Alkaloid were determined by Acid dye Colorimetry. RESULTS: Acid dye color conditions: pH3.6 buffer 5.0 ml, bromocresol green liquid 5.0 ml; chloroform extraction three times, each time was exeracted for 2 minutes, put it aside for at least 5 minutes for the determination of the best method. Rhynchophylline 6.018 microg - 108.324 microg in the linear range, Recoveriys rate was 97.19%, RSD was 1.34% (n = 6). CONCLUSION: The method is simple, highly sensitive and reproducible.

Neighboring-nucleotide effects on the mutation patterns of the rice genome.

DNA composition dynamics across genomes of diverse taxonomy is a major subject of genome analyses. DNA composition changes are characteristics of both replication and repair machineries. We investigated 3,611,007 single nucleotide polymorphisms (SNPs) generated by comparing two sequenced rice genomes from distant inbred lines (subspecies), including those from 242,811 introns and 45,462 protein-coding sequences (CDSs). Neighboring-nucleotide effects (NNEs) of these SNPs are diverse, depending on structural content-based classifications (genome-wide, intronic, and CDS) and sequence context-based categories (A/C, A/G, A/T, C/G, C/T, and G/T substitutions) of the analyzed SNPs. Strong and evident NNEs and nucleotide proportion biases surrounding the analyzed SNPs were observed in 1-3 bp sequences on both sides of an SNP. Strong biases were observed around neighboring nucleotides of protein-coding SNPs, which exhibit a periodicity of three in nucleotide content, constrained by a combined effect of codon-related rules and DNA repair mechanisms. Unlike a previous finding in the human genome, we found negative correlation between GC contents of chromosomes and the magnitude of corresponding bias of nucleotide C at -1 site and G at +1 site. These results will further our understanding of the mutation mechanism in rice as well as its evolutionary implications.