Directed C(sp3)-H Arylation of Free α-Aminophosphonates: Dual Models Exploration via Palladium Catalysis.

In this report, we present the dual activation models for transient directing group-directed and amino-self-directed Pd-catalyzed α-aminophosphonate side-chain C(sp3)-H arylation. Both strategies showed facile, efficient, and single regioselectivity in the reaction between free α-aminophosphonates and aryl iodides. Furthermore, the modification of amino and late-stage functionalization of the C(sp3)-P bond from products indicates potential applications for α-aminophosphonates.

Direct C(sp3)-H Polyfluoroarylation: Access to Polyfluoroaryl Amino Acids via Rh-Catalyzed Selective C-F Bond Cleavage.

A catalytic selective C-F bond alkylation method for polyfluoroarene with glycinates and derivatives in the presence of a DavePhos-ligated Rh catalyst was developed. This method avoids the preactivation of alkylating reagents and provides an efficient and straightforward route to synthesize a series of polyfluoroaryl amino acids via C(sp3)-H functionalization. This reaction proceeds under mild conditions and exhibits high reactivity and excellent chemoselectivities. Meanwhile, the synthetic potential of this method was demonstrated by gram-scale synthesis, and further transformations proved the application value of the products as well.

Transamidation and Decarbonylation of N-Phthaloyl-Amino Acid Amides Enabled by Palladium-Catalyzed Selective C-N Bond Cleavage.

Amides are important functional synthons that have been widely used in the construction of peptides, natural products, and drugs. The C-N bond cleavage provides the direct method for amide conversion. However, amides, especially secondary amides, tend to be chemically inert due to the resonance of the amide bond. Here, we describe an efficient Pd-catalyzed transamidation and decarbonylation of multiamide structure molecules through C-N bond cleavage with excellent chemoselectivity. The transamidation of secondary amides and the decarbonylation of phthalimide provide meaningful tools for the modification of amino acid derivatives. Moreover, further transformations of azidation and C(sp3)-H monoarylation emphasized the potential utility of this selective C-N bond cleavage method.

GHR is involved in gastric cell growth and apoptosis via PI3K/AKT signalling.

Growth hormone receptor (GHR), the cognate receptor of growth hormone (GH), is a membrane bound receptor that belongs to the class I cytokine receptor superfamily. GH binding GHR induces cell differentiation and maturation, initiates the anabolism inside the cells and promotes cell proliferation. Recently, GHR has been reported to be associated with various types of cancer. However, the underlying mechanism of GHR in gastric cancer has not been defined. Our results showed that silence of GHR inhibited the growth of SGC-7901 and MGC-803 cells, and tumour development in mouse xenograft model. Flow cytometry showed that GHR knockout significantly stimulated gastric cancer cell apoptosis and caused G1 cell cycle arrest, which was also verified by Western blot that GHR deficiency induced the protein level of cleaved-PARP, a valuable marker of apoptosis. In addition, GHR deficiency inhibited the activation of PI3K/AKT signalling pathway. On the basis of the results, that GHR regulates gastric cancer cell growth and apoptosis through controlling G1 cell cycle progression via mediating PI3K/AKT signalling pathway. These findings provide a novel understanding for the role of GHR in gastric cancer.

Combined Chibby and ß-Catenin Predicts Clinical Outcomes in Patients with Hepatocellular Carcinoma.

Chibby is an antagonist of ß-catenin and is considered a potential tumor suppressor protein, but the role of Chibby in hepatocellular carcinoma (HCC) has not been characterized. The expression patterns of Chibby and ß-catenin in HCC specimens and paired adjacent noncancerous tissues were measured by Western blotting and immunohistochemistry. The correlations between Chibby expression and clinicopathological parameters were analyzed. Then the biological functions of Chibby were analyzed in vitro. The Chibby protein was significantly downexpressed in human primary HCC tissues compared to that in matched adjacent normal liver tissue and is a risk factor for HCC recurrence and shorter survival. Furthermore, we found that in HCC tissues the high expression of ß-catenin with low expression of Chibby in the nuclei was an independent predictor for disease-free survival (DFS) (p = 0.012) and overall survival (OS) (p = 0.005). Subsequent genetic manipulation in vitro studies revealed that Chibby knockdown induced the expression of ß-catenin and C-myc, cyclin D1 protein, which promoted cell proliferation and invasiveness. In contrast, overexpression of Chibby decreased ß-catenin expression and inhibited the cell proliferation and invasiveness. Our results suggest that low expression of Chibby was associated with advanced tumor-node-metastasis (TNM) stage and poor differentiation. Furthermore, the combination of Chibby and ß-catenin can predict poor prognosis in patients with HCC. Chibby inhibited HCC progression by blocking ß-catenin signaling in vitro. Chibby is a biomarker and may be a potential therapeutic target for HCC.

PALB2 mutations in breast cancer patients from a multi-ethnic region in northwest China.

BACKGROUND: Germline mutations in PALB2 gene make a small contribution to heritable breast cancer susceptibility. A recent report has revealed that women with mutations in the PALB2 gene were more than nine times as likely to develop breast cancer compared to those without. The aim of this study is to understand the status of PALB2 mutations among Chinese high-risk breast cancer patients in a multi-ethnic region in China. METHODS: 152 patients with hereditary predisposition to breast cancer from the Xinjing region of China were enrolled in the study, and 100 control samples from healthy women were collected in the same locality. We sequenced the coding sequences and flanking intronic regions of PALB2 gene from DNA samples obtained from all subjects by direct sequencing. RESULTS: A total of 4 deleterious PALB2 mutations were identified in 152 breast cancer patients with a prevalence of about 2.6 % (4/152). The PALB2 mutation prevalence was 3.2 % (3/95) in cases with family history of breast cancer. In addition to the four deleterious mutations, we identified nine missense variants in 12 patients, using the prediction Softwares SIFT and PolyPhen, four of which might be disease associated (in 5 patients). Two of the 4 patients with deleterious mutations and 2 of the 5 patients presenting putative deleterious missense mutations had triple-negative breast cancer. No PALB2 mutation carriers were identified in 100 healthy controls. CONCLUSION: PALB2 mutations account for a small, but not negligible, proportion of patients with hereditary predisposition to breast cancer in the Xinjing region of China.

Hepatoma-derived growth factor/nucleolin axis as a novel oncogenic pathway in liver carcinogenesis.

Hepatoma-derived growth factor (HDGF) overexpression is involved in liver fibrosis and carcinogenesis. However, the receptor(s) and signaling for HDGF remain unclear. By using affinity chromatography and proteomic techniques, nucleolin (NCL) was identified and validated as a HDGF-interacting membrane protein in hepatoma cells. Exogenous HDGF elicited the membrane NCL accumulation within 0.5 hour by protein stabilization and transcriptional NCL upregulation within 24 hours. Blockade of surface NCL by antibodies neutralization potently suppressed HDGF uptake and HDGF-stimulated phosphatidylinositol 3-kinase (PI3K)/Akt signaling in hepatoma cells. By using rescectd hepatocellular carcinoma (HCC) tissues, immunohistochemical analysis revealed NCL overexpression was correlated with tumour grades, vascular invasion, serum alpha-fetoprotein levels and the poor survival in HCC patients. Multivariate analysis showed NCL was an independent prognostic factor for survival outcome of HCC patients after surgery. To delineate the role of NCL in liver carcinogenesis, ectopic NCL overexpression promoted the oncogenic behaviours and induced PI3K/Akt activation in hepatoma cells. Conversely, NCL knockdown by RNA interference attenuated the oncogenic behaviours and PI3K/Akt signaling, which could be partially rescued by exogenous HDGF supply. In summary, this study provides the first evidence that surface NCL transmits the oncogenic signaling of HDGF and facilitates a novel diagnostic and therapeutic target for HCC.

[Study on directional separation of picroside II from extract of traditional Chinese medicine by molecularly imprinted technology].

Picroside II, separated from Chinese herbal medicine, is an active compound with neroprotective activity. Molecularly imprinted polymers (MIPs) have high affinity toward template molecules synthesized by molecularly imprinted technology for its specific combined sites, which can overcome the shortcomings of traditional separation methods, such as complex operation and low efficiency. In this paper, MIPs were prepared by precipitation polymerization with picroside II as the template molecule, 1-vinylimidazole (1-Vinyl) as functional monomer, ethylene glycol dimethacrylate (EDMA) as cross-linker. The morphology of MIPs was characterized by scanning electronmicroscope (SEM) and its static adsorption capacity was measured by the scatchard equation. The results showed that picroside II MIPs have spherical shape, and most of them are uniform in size. Furthermore, the maximum binding capacity (Q(max)) of MIPs is 3.02 mg x g(-1), higher than that of non-imprinted polymers (NIPs). This result indicated that picroside II MIPs with good morphology and high targeted affinity toward the template molecules can be prepared by precipitation polymerization, which can be used to separate picroside II and its analogies from extract of Chinese herbal medicine. In addition, this method has the advantages of good environment and simple operation, which might offer a novel method for the efficient separation of picroside II in the traditional herbal medicines.

[Study on the law of compatibility in three categorized formulas for tonifying Shen Yang: Shenqi pill, Yougui pill, and Yougui drink based on rough set].

OBJECTIVE: To evaluate the efficacy of three categorized formulas for tonifying Shen yang, i.e. Shenqi Pill (SP), Yougui Pill (YP), and Yougui Drink (YD) based on rough set, thus exploring the law of compatibility between the core herbs and the edge herbs as well as the law of compatibility between the yang-tonifying herbs and the yin-tonifying herbs in the core herbs. METHODS: The rats were divided into the normal group, the Shen-yang deficiency model group, and the original prescription group, the core herbs group, and the edge herbs group of this three categorized formulas for tonifying Shen yang, 11 groups altogether. Thyroxine (T4), cortisol (CORT), and testosterone (T) were detected respectively. The decision rules model based on rough set was set up, the interactions between various herbs were analyzed according to the decision rules. RESULTS: There were synergies between yam and cinnamon, yam and aconite, as well as yam and wolfberry. Poria alisma, Cortex Moutan, and oriental waterplantain tuber had no effect themselves, but they had synergistic effects with the core herbs in SP. Angelica had a certain effect itself, but its functions were different to different core herbs in YP. Licorice had no effect itself, and it was antagonistic with the core herbs in YD. CONCLUSIONS: The compatibility of core herbs of categorized formula for tonifying Shen yang should focus on benefiting both yin and yang, as well as mutual rooting of yin-yang. Appropriate edge herbs should be chosen for compatibility according to different core herbs. The decision rules model based on rough set has a good prospect in exploring the law of compatibility of the categorized formulas.

[Comparative study on two polymerization methods for preparing ginsenoside Rg1 molecularly imprinted polymer separating materials].

To obtain ginsenoside Rg1 molecularly imprinted polymer (MIP) separating materials with high selectivity, enrichment and adsorption performance through directional separation of ginsenoside Rg1 and analogues. In this study, MIPs were respectively prepared by precipitation polymerization and surface imprinted polymerization. Their adsorption performances were compared. The results showed that ginsenoside Rg1 MIPs prepared by the above two methods had a high adsorption performance to template molecules, with the maximum apparent adsorbing capacity of up to 27.74, 46. 80 mg x g(-1), respectively. Moreover, MIPs prepared by surface imprinted polymerization showed higher adsorption capacity than that by precipitation polymerization. The experimental results indicated that as for ginsenoside Rg1 with higher polarity, MIPs prepared by surface imprinted polymerization showed higher selectivity and adsorption performance, which provides provide important reference for preparing imprinted polymers with good adsorption performance with active molecules with strong polarity.

Viral kinetics of enterovirus 71 in human abdomyosarcoma cells.

AIM: To characterise the viral kinetics of enterovirus 71 (EV71). METHODS: In this study, human rhabdomyosarcoma (RD) cells were infected with EV71 at different multiplicity of infection (MOI). After infection, the cytopathic effect (CPE) was monitored and recorded using a phase contrast microscope associated with a CCD camera at different time points post viral infection (0, 6, 12, 24 h post infection). Cell growth and viability were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in both EV71 infected and mock infected cells at each time point. EV71 replication kinetics in RD cells was determined by measuring the total intracellular viral RNA with real-time reverse-transcription polymerase chain reaction (qRT-PCR). Also, the intracellular and extracellular virion RNA was isolated and quantified at different time points to analyze the viral package and secretion. The expression of viral protein was determined by analyze the levels of viral structure protein VP1 with Western blotting. RESULTS: EV71 infection induced a significant CPE as early as 6 h post infection (p.i.) in both RD cells infected with high ratio of virus (MOI 10) and low ratio of virus (MOI 1). In EV71 infected cells, the cell growth was inhibited and the number of viable cells was rapidly decreased in the later phase of infection. EV71 virions were uncoated immediately after entry. The intracellular viral RNA began to increase at as early as 3 h p.i. and the exponential increase was found between 3 h to 6 h p.i. in both infected groups. For viral structure protein synthesis, results from western-blot showed that intracellular viral protein VP1 could not be detected until 6 h p.i. in the cells infected at either MOI 1 or MOI 10; and reached the peak at 9 h p.i. in the cells infected with EV71 at both MOI 1 and MOI 10. Simultaneously, the viral package and secretion were also actively processed as the virus underwent rapid replication. The viral package kinetics was comparable for both MOI 1 and MOI 10 infected groups. It was observed that at 3 h p.i, the intracellular virions obviously decreased, thereafter, the intracellular virions began to increase and enter into the exponential phase until 12 h p.i. The total amounts of intracellular virons were decreased from 12 to 24 h p.i. Consistent with this result, the increase of virus secretion occurred during 6 to 12 h p.i. CONCLUSION: The viral kinetics of EV71 were established by analyzing viral replication, package and secretion in RD cells.

Three fatal cases of pandemic 2009 influenza A virus infection in Shenzhen are associated with cytokine storm.

China had taken strict measures for pandemic 2009 H1N1 infection with enhanced surveillance and hospital isolation since April 2009. In Shenzhen, over 1200 confirmed cases of H1N1 infection were identified. Three young patients died of severe pneumonia. Among them, two boys developed neurological complications. Cytokine storm seemed an important cause.

Colorectal mesenchymal tumors - from smooth muscle tumors to stromal tumors.

Colorectal mesenchymal tumors are rare. Therefore, distinguishing between gastrointestinal stromal (GIST) and smooth muscle tumors is important. This study aimed to delineate the immunophenotype and prognostic factors of 75 colorectal mesenchymal tumors. Fifty-three GIST and 22 smooth muscle tumor specimens were included from 1986 to 2007. Forty of 53 GIST were initially diagnosed as smooth muscle tumors and re-diagnosed as CD117 (+) GIST. Immunohistochemical studies were performed with antibodies of CD117, CD34, smooth muscle actin (SMA), desmin, S-100, Ki-67 and PCNA for clinicopathologic and prognostic correlation. In comparison, colorectal GIST exhibited a larger tumor size (P<0.001), higher mitotic count (P<0.001), higher cellularity (P<0.001), less spindle cell type (P=0.004), higher nuclear pleomorphism (P=0.004), and a higher NIH risk (P<0.001) than that of smooth muscle tumors. Positive immunoreactivities of GIST to a panel of antibodies were 88.6% to CD34, 28.3% to SMA, 1.8% to S-100 and 15.1% to desmin. For 75 mesenchymal tumors, survival analyses revealed that older patients (P=0.006), with a large tumor size (P<0.001), high mitotic count (P<0.001), increased NIH risk (P<0.001), non-spindle cell type (P<0.001), high cellularity (P=0.015), high cell pleomorphism (P<0.001), positive Ki-67 (P<0.001), high PCNA (P<0.001) and GIST (P=0.001) had a shorter disease-free survival than that of comparative groups. When the analyses concentrated on 53 GIST, the cell type and cellularity were no longer viable prognostic factors. The tumor mitotic count was the only independent prognostic factor for either mesenchymal tumors or GIST. In conclusion, GIST exhibited heterogeneous characteristics and was significantly larger, more mitotic and a poorer prognostic factor than smooth muscle tumor. The mitotic count is still the most valuable prognostic factor for colorectal mesenchymal tumors after KIT.

Elevated p21 expression is associated with poor prognosis of rectal stromal tumors after resection.

BACKGROUND AND OBJECTIVES: The pathogenic role of alteration of cell-cycle proteins in rectal stromal tumors (GISTs) remains unclear. This study aimed to elucidate the prognostic role of p21 to compare with p53, PCNA, and Ki-67 in rectal GISTs. METHODS: Forty-nine surgically resected CD117 (+) rectal GISTs were enrolled from 1986 to 2006. Immunohistochemical studies were performed with antibodies of p21, p53, PCNA, and Ki-67. RESULTS: The labeling index (LI) of immunoreactivities range from 0% to 65% for p53, 0% to 60% for p21, 0% to 67% for Ki-67, and 30% to 93% for PCNA. LI of four markers were positively correlated (P < 0.05). LI of four markers were also positively correlated with tumor mitosis and tumor size (P < 0.05). Tumors with high p53, p21, or Ki-67 LI were associated with increased NIH risk, non-spindle cell type, and high cell pleomorphism (P < 0.05). Survival analyses demonstrated that large tumor size (P = 0.012), high tumor mitosis (P < 0.001), increased NIH risk (P = 0.003), high cell pleomorphism (P = 0.004), high p53 LI (P = 0.005), high p21 LI (P = 0.009), high PCNA LI (P = 0.001), and high Ki-67 LI (P = 0.042) were poor prognostic factors for disease-specific survival. CONCLUSIONS: Elevated p21 expression is associated with poor prognosis of rectal stromal tumors after resection.

Interaction with Ppil3 leads to the cytoplasmic localization of Apoptin in tumor cells.

Apoptin, a small protein encoded by chicken anemia virus (CAV), induces cell death specifically in cancer cells. In normal cells, Apoptin remains in the cytoplasm; whereas in cancerous cells, it migrates into the nucleus and kills the cell. Cellular localization appears to be crucial. Through a yeast two-hybrid screen, we identified human Peptidyl-prolyl isomerase-like 3 (Ppil3) as one of the Apoptin-associated proteins. Ppil3 could bind Apoptin directly, and held Apoptin in cytoplasm even in tumor cells. We then demonstrated that the nuclearcytoplasmic distribution of Apoptin is related to the expression level of intrinsic Ppil3. Moreover, extrinsic modifying of Ppil3 levels also resulted in nuclearcytoplasmic shuffling of Apoptin. The Apoptin P109A mutant, located between the putative nuclear localization and export signals, could significantly impair the function of Ppil3. Our results suggest a new direction for the localization mechanism study of Apoptin in cells.

The abnormalities in the p53/p21WAF1 pathway have a significant role in the pathogenesis and progression of gastrointestinal stromal tumors.

To elucidate the prognostic role and relationship of the p53/p21/PCNA pathway in gastrointestinal stromal tumors (GISTs), a total of 167 resected gastric and small intestinal CD117-positive stromal tumor specimens were collected from January 1987 to December 2000. Immunohistochemical studies were performed on the paraffin sections with antibodies of p53, p21/WAF1, proliferating cell nuclear antigen (PCNA) and Ki-67. The immunoreactivity of four markers was recorded by labeling index (LI, %) for clinicopathologic and survival correlation. The labeling index was 0-83% for p53, 0-81% for p21/WAF1, 0-33% for Ki-67 and 12-92% for PCNA. Completely negative immunostaining (LI<1%) was found in 54.5% of p53, 25.8% of p21/WAF1 and 44.3% of Ki-67. The LI of four markers strongly correlate with each other (p<0.05). Furthermore, the LI of all four markers positively correlate to microscopic tumor mitotic counts (p<0.05). Only the LI of p53 and PCNA positively correlate to tumor sizes. Tumors with non-spindle cell type (versus spindle cell) and high cellular pleomorphism (versus low) exhibited a higher p53, p21/WAF1 and PCNA LI (p<0.05). Increased NIH risk significantly correlates to increased p53, PCNA and Ki-67 (p<0.05) LI. Survival analysis indicated that a large tumor size (> or =5 cm, p=0.003), increased tumor mitosis (> or =5/50 HPF, p<0.001), high NIH risk (p<0.001), non-spindle cell type (p=0.024), high p53 LI (p<0.001), high p21/WAF1 LI (p=0.007), high Ki-67 LI (p<0.001) and high PCNA LI (p<0.001) were prognostic factors for poor disease-free survival. Independent factors are tumor size, NIH risk, p53 and p21/WAF1 LI. We demonstrated the first evidence of the linear relationship and prognostic role of the p53/p21/PCNA pathway in gastrointestinal stromal tumors. Abnormalities of the p53/p21WAF1 pathway lead to increased proliferating states, thereby triggering the progression of GISTs.

Expression and prognostic role of molecular markers in 99 KIT-positive gastric stromal tumors in Taiwanese.

AIM: To elucidate the prognostic role and relationship of three molecular markers such as tumor suppressor gene p53, proliferating cell nuclear antigen (PCNA) and Ki-67 in gastric stromal tumor. METHODS: A total of 108 surgically resected gastric smooth muscle tumor specimens were collected from January 1987 to December 1999. Immunohistochemical studies were performed on the paraffin sections of 99 of 108 CD117-positive tumors with antibodies of p53, PCNA, and Ki-67. Immunoreactivity of three molecular markers was recorded by labeling index (LI, %) and was analyzed for clinicopathologic and survival correlation. RESULTS: Of the 99 cases, immunostaining revealed that 52 patients (52.5%) had p53, and 37 patients (37.3%) had Ki-67 immunoreactivity (defined as >10% of LI). All patients (100%) had PCNA immunoreactivity ranging from 12% to 93% of LI, divided into high or low by median. Statistics revealed that LI of three markers positively correlate to each other (P<0.01) and to microscopic tumor mitotic counts (P<0.001). By combination, patients with >=2 markers (positive or high) in tumors had early tumor recurrence (P<0.001) and unfavorable outcome (P<0.001). Univariate analysis indicated that patients with tumor size >5 cm (P=0.003), tumor mitosis >5/50 HPF (P<0.001), p53 immunoreactivity (P=0.001), Ki-67 immunoreactivity (P=0.026), high PCNA LI (P=0.015) and male gender (P=0.036) were six predictors for early disease recurrence. Subsequent multivariate analysis revealed that mitotic counts, tumor size, and p53 immunoreactivity were three independent prognostic factors for both disease free and overall survival of patients. By combination of three independent prognostic factors for grouping, we found higher tumor recurrence rate (P<0.001) and shorter survival (P<0.001) existed in groups with increasing factors. CONCLUSION: We first provide the prognostic value and linkage of three molecular markers in GISTs. The combination of three factors (p53, tumor size, and tumor mitosis) provides a more powerful prediction of prognosis than any single factor does.

Clinicopathological characteristics and prognosis of patients with small intestinal stromal tumors.

BACKGROUND AND PURPOSE: Gastrointestinal stromal tumors (GISTs) involving the small intestine are less common than those involving the stomach, and data on small intestinal stromal tumors (SISTs) are more limited. This study investigated the clinicopathological characteristics and prognostic factors of SISTs and compared them with those of gastric stromal tumors (GSTs). METHODS: A total of 82 surgically resected and pathologically diagnosed smooth muscle tumors of small bowel in patients treated from January 1986 to December 2000 were included. Immunohistochemical studies were performed on these tumors with antibodies of CD117, CD34, smooth muscle actin (SMA), desmin and S-100. The results were analyzed and compared with 74 cases of GSTs diagnosed and treated from January 1986 to December 1997. RESULTS: Among the 82 small intestine tumors, 71 were CD117-positive (86.6%) and were classified as SISTs. Of the 71 SISTs, 70.4% were immunoreactive to CD34, 88.7% to SMA, 46.5% to S-100, but none to desmin. Survival analysis demonstrated that tumor size < 5 cm (p = 0.021), mitosis number < 5/50 high-power field (p < 0.001), SMA-positive (p = 0.027), non-epithelioid cell type (p = 0.005) and tumor with skeinoid fibers (p = 0.010) predicted longer disease-free survival after operation. Multivariate analysis revealed that mitotic number (p = 0.001), cell morphology (p = 0.031) and tumor size (p = 0.004) were independent prognostic factors. In comparison to GSTs, SISTs exhibited significantly lower rates of CD34, but significantly higher rates of SMA and S-100 immunoreactivity. CONCLUSIONS: SISTs exhibited a different immunophenotype from GSTs. SMA reactivity is a predictor of benign clinical behavior in SISTs. Tumor mitotic numbers, tumor size, and cell type were independent prognostic factors for patients with SISTs after operation.