Synthesis and antitumor activities of derivatives of the marine mangrove fungal metabolite deoxybostrycin.

Deoxybostrycin (1) is an anthraquinone compound derived from the marine mangrove fungus Nigrospora sp. No. 1403 and has potential to be a lead for new drugs because of its various biological properties. A series of new derivatives (2-22) of deoxybostrycin were synthesized. The in vitro cytotoxicity of all the new compounds was tested against MDA-MB-435, HepG2 and HCT-116 cancer cell lines. Most of the compounds exhibit strong cytotoxicity with IC50 values ranging from 0.62 to 10 µM. Compounds 19, 21 display comparable cytotoxicity against MDA-MB-435 to epirubicin, the positive control. The primary screening results indicate that the deoxybostrycin derivatives might be a valuable source of new potent anticancer drug candidates.

Statistical research on marine natural products based on data obtained between 1985 and 2008.

Since the 1960s, more than 20,000 compounds were discovered from marine organisms. In this paper we performed a quantitative analysis for the novel marine natural products reported between 1985 and 2008. The data was extracted mainly from the reviews of Faulkner and Blunt [1-26]. The organisms producing these marine natural products are divided into three major biological classes: marine microorganisms (including phytoplankton), marine algae and marine invertebrate. The marine natural products are divided into seven classes based on their chemical structure: terpenoids, steroids (including steroidal saponins), alkaloids, ethers (including ketals), phenols (including quinones), strigolactones, and peptides. The distribution and the temporal trend of these classes (biological classes and chemical structure classes) were investigated. We hope this article provides a comprehensive perspective on the research of marine natural products.

[Analysis of Epstein-Barr virus BamH I "f" variant in nodal metastasis of nasopharyngeal carcinoma].

OBJECTIVE: To investigate the Epstein-Barr virus (EBV) BamH I "f" variant in primary nasopharyngeal carcinoma (NPC) and its metastases in lymph nodes (LN). METHODS: In situ hybridization was used to detect EBV-encoded small RNA (EBER) expression in 21 paired paraffin-embedded tissue from primary NPC and their lymph node metastases and 22 primary NPC without lymph node metastasis. PCR and restriction fragment length polymorphism (RFLP) assay were used to detect EBV BamH I "f" variant in all cases of NPCs, lymph node metastases and 50 cases of chronic inflammation of nasopharynx from Canton. RESULTS: All cases of NPCs and their lymph node metastases showed EBER expression, indicating a high EBV-positive rate in Cantonese NPC patients. EBV BamH I "f" variant was found in 11 cases (52.4%, 11/21) of primary NPCs with LN metastasis, 12 cases (57.1%, 12/21) of the LN metastases, and 18 cases (81.8%, 18/22) of primary NPCs without LN metastasis. However, of the 50 cases of chronic inflammation of nasopharynx, only one case (2.1%, 1/47) demonstrated BamH I "f" variant. The frequency of BamH I "f" variant in NPC was therefore dramatically higher than that in chronic inflammation of nasopharynx. It is of note that atypical hyperplasia was observed in a few epithelial cells from the case of chronic inflammation of nasopharynx expressing BamH I "f" variant. CONCLUSIONS: The frequency of EBV BamH I "f" variant in NPC is significantly higher than that in chronic inflammation of nasopharynx. It is the first demonstration that the BamH I "f" variant is also present in the LN metastases of NPC. The frequency of BamH I "f" variant in metastatic NPC of the lymph node is almost equal to that of primary NPCs.

[Mutant thiopurine S-methyltransferase alleles among Jing Chinese in Guangxi province].

OBJECTIVE: To investigate the mutant alleles of thiopurine S-methyltransferase (TPMT) among Jing Chinese. METHODS: Polymerse chain reaction-single strand conformation polymorphism (PCR-SSCP) techniques were developed for assaying exons 5, 7 and 10 of the TPMT gene respectively and were used to detect mutant TPMT alleles among Jing Chinese. RESULTS: Two cases of TPMT*3C (A719G) heterozygotes were identified in 103 Jing Chinese; other deleterious alleles such as TPMT*2 (G238C), TPMT*3A (G460A/A719G) and TPMT*3B (G460A) were not found; 27 cases of silent mutant allele TPMT*1S (T474C) were also identified (5 homozygotes and 22 heterozygotes). CONCLUSION: The PCR-SSCP assay established and adopted in this study was sensitive and reliable, which could be used to detect mutant TPMT alleles. Allele frequency of TPMT*3C is low among Jing Chinese (1.0%), and TPMT*3C appears to be the most prevalent deleterious allele in this population.

Upregulator of cell proliferation predicts poor prognosis in hepatocellular carcinoma and contributes to hepatocarcinogenesis by downregulating FOXO3a.

OBJECTIVE: The goal of the present study was to investigate the potential correlation between the expression level of upregulator of cell proliferation (URGCP/URG4) and the prognosis of hepatocellular carcinoma (HCC), and to examine the biological function of URGCP/URG4 in the progression of HCC, to better understand its underlying molecular mechanism in hepatic tumorigenesis. DESIGN: URGCP/URG4 expression was analyzed in 15 HCC cell lines, in 278 archived paraffin-embedded HCC sections, and in 10 pairs of fresh HCC tumor and para-tumor non-cancerous tissues using immunohistochemistry (IHC) and Western blotting analysis (WB). The effect of URGCP/URG4 on cell proliferation and tumorigenesis was examined in vitro and in vivo. WB and luciferase reporter analyses were performed to identify the effects of URGCP/URG4-overexpression or -knockdown on expression of cell cycle regulators and transcriptional activity of FOXO3a. RESULTS: IHC results revealed an upregulation of URGCP/URG4 in all HCC cell lines and fresh HCC samples as compared with normal liver cells and para-tumor tissues, respectively. URGCP/URG4 was also expressed at a high level in 122 of the 278 (43.8%) archived HCC specimens. The expression level of URGCP/URG4 was significantly correlated with clinical staging and poor patient survival of HCC in the study cohort, and in various clinical subgroups. Strikingly, ectopic expression of URGCP/URG4 induced proliferation and anchorage-independent growth of HCC cells, while silencing of URGCP/URG4 had the opposite effect. Furthermore, URGCP/URG4 overexpression in HCC cells increased cellular entry into the G1/S transitional phase, associated with downregulation of p27(Kip1) and p21(Cip1) and upregulation of cyclin D1. These effects were accompanied by enhanced Akt activity and reduced FOXO3a transcriptional activity. CONCLUSIONS: URGCP/URG4 plays an important role in promoting proliferation and tumorigenesis of HCC and may represent a novel prognostic biomarker and therapeutic target for this disease.

Surveillance and genome analysis of human bocavirus in patients with respiratory infection in Guangzhou, China.

Human bocavirus (HBoV) is a novel parvovirus associated with respiratory tract diseases and gastrointestinal illness in adult and pediatric patients throughout the world. To investigate the epidemiological and genetic variation of HBoV in Guangzhou, South China, we screened 3460 throat swab samples from 1686 children and 1774 adults with acute respiratory infection symptoms for HBoV between March 2010 and February 2011, and analyzed the complete genome sequence of 2 HBoV strains. Specimens were screened for HBoV by real-time PCR and other 6 common respiratory viruses by RT-PCR or PCR. HBoV was detected in 58 (1.68%) out of 3460 samples, mostly from pediatric patients (52/58) and inpatient children (47/58). Six adult patients were detected as HBoV positive and 5 were emergency cases. Of these HBoV positive cases, 19 (32.76%) had co-pathogens including influenza virus (n = 5), RSV (n = 5), parainfluenza (n = 4), adenovirus (n = 1), coronavirus (n = 7). The complete genome sequences of 2 HBoVs strains (Genbank no. JN794565 and JN794566) were analyzed. Phylogenetic analysis showed that the 2 HBoV strains were HBoV1, and were most genetically close to ST2 (GenBank accession number DQ0000496). Recombination analysis confirmed that HBoV strain GZ9081 was an intra-genotype recombinant strain among HBoV1 variants.

[Correlation of Epstein-Barr virus-encoded latent membrane protein 1 (LMP1) to fascin and phosphorylated Stat3 in nasopharyngeal carcinoma].

BACKGROUND & OBJECTIVE: Latent membrane protein 1 (LMP1) of Epstein-Barr (EB) virus is an important oncogene. Fascin is an actin cross-linking protein involved in cell migration and adhesion. Phosphorylated signal transducer and activator of transcription 3 (pStat3) is a member of STATs family, which is closely related to tumorigenesis. This study was to investigate expressions of LMP1, Fascin and pStat3 in nasopharyngeal carcinoma (NPC) tissues and lymph node metastases of NPC, thus to explore their correlations to the initiation and progression of NPC. METHODS: Expressions of EBV-encoded small RNA (EBER), LMP1, Fascin, pStat3, p53, Ki-67 and Bcl-2 were detected in 43 NPC tissues (21 with and 22 without lymph node metastases) and 21 corresponding lymph node metastases using in situ hybridization or immunohistochemistry (IHC). Data were statistically analyzed. Expressions of pStat3 and Fascin were measured in the NPC cell line CNE1 transfected with LMP1-expressing plasmid using Western blot. RESULTS: Positive EBER expression was detected in all 43 NPC tissues and 21 lymph node metastases in NPC. The expression rates of LMP1, Fascin, pStat3, p53, Ki-67, and Bcl-2 were 69.8% (30/43), 93.0% (40/43), 72.1% (31/43), 90.7% (39/43), 88.4% (38/43) and 88.4% (38/43)in 43 NPC tissues, respectively. LMP1 expression was positively correlated with the expression level of Fascin, pStat3, p53, Ki-67 and Bcl-2 in 43 NPC cases(P < 0.05). LMP1 was found in 10 out of 21 (46.7%) lymph node metastases in NPC. In addition, LMP1 expression dramatically increased pStat3 and Fascin in CNE1 cells. CONCLUSIONS: LMP1 is expressed in lymph node metastatases in NPC. The expression of LMP1 is positively correlated with Fascin, pStat3 and the proliferation index of tumor cells. Moreover, LMP1 up-regulates pStat3 and Fascin in NPC cells.

[Genetic polymorphism of the thiopurine S-methyltransferase of healthy Han Chinese].

BACKGROUND & OBJECTIVE: Several mutations in the thiopurine S-methyltransferase(TPMT) gene have been identified to correlate with a low activity or deficiency phenotype. The distribution of TPMT activity in Chinese and Caucasian populations is different, and the molecular basis has not yet to be determined. This study was designed to investigate the type and frequency of four kinds of mutant TPMT alleles of healthy Han Chinese. METHODS: TPMT genotypes were determined in 225 healthy Han Chinese. Allele-specific PCR (ASPCR) and PCR-restriction fragment length polymorphism (RFLP) were used for analysis of G238C (TPMT*2), G460A and A719G (TPMT*3A,*3B,*3C). RESULTS: TPMT*2, TPMT*3B, and TPMT*3A were not detected in 225 healthy Han Chinese, and only six TPMT*3C heterozygotes were identified. The average TPMT activity of those TPMT*3C heterozygotes was (9.62+/-3.58) U/ml RBC. The frequency of TPMT mutant alleles was 1.33%(6/450) in healthy Han Chinese. CONCLUSION: The frequency of the known mutant TPMT alleles in Han Chinese population is low, and TPMT*3C appears to be the most prevalent among the known mutant TPMT allele in this population.

Phenotyping and genotyping study of thiopurine S-methyltransferase in healthy Chinese children: a comparison of Han and Yao ethnic groups.

AIMS: Ethnicity is an important variable influencing drug response. Thiopurine S-methyltransferase (TPMT) plays an important role in the metabolism of thiopurine drugs. Previous population studies have identified ethnic variations in both phenotype and genotype of TPMT, but limited information is available within Chinese population that comprises at least 56 ethnic groups. The current study was conducted to compare both phenotype and genotype of TPMT in healthy Han and Yao Chinese children. METHODS: TPMT activity was measured in healthy Chinese children by a HPLC assay (n = 213, 87 Han Chinese and 126 Yao Chinese). Allele-specific polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism (RFLP) were used to determine the frequency of TPMT mutant alleles (TPMT*2, TPMT*3 A, TPMT*3B and TPMT*3C) in these children. RESULTS: There was no significant difference in the mean TPMT activity between Han and Yao Chinese children. A unimodal distribution of TPMT activity in Chinese children was found and the mean TPMT activity was 13.32 +/- 3.49 U ml(-1) RBC. TPMT activity was not found to differ with gender, but tended to increase with age in Yao Chinese children. TPMT*2, TPMT*3B and TPMT*3A were not detected, and only one TPMT*3C heterozygote (Han child) was identified in 213 Chinese children. Erythrocyte TPMT activity of this TPMT*3C heterozygote was 12.36 U ml(-1) RBC. The frequency of the known mutant TPMT alleles was 0.2%[1/426] in Chinese children. CONCLUSION: The frequency distribution of RBC TPMT activity was unimodal. The frequency of the known mutant TPMT alleles in Chinese Children is low and TPMT*3C appears to be the most prevalent among the tested mutant TPMT alleles in this population.

Gene mutation of thiopurine S-methyltransferase in Uygur Chinese.

OBJECTIVE: This study was to investigate the gene mutation of thiopurine S-methyltransferase (TPMT) in Uygur Chinese. METHODS: Polymerase chain reaction-based methods were used to analyze three commonly reported inactivating mutations-G238C, G460A and A719G. RESULTS: One TPMT*3A heterozygote and five TPMT*3C heterozygotes were found in 160 Uygur Chinese subjects, and allele frequencies of TPMT*3A and TPMT*3C were 0.3% and 1.6%, respectively. CONCLUSION: TPMT*3C is a common mutant allele in Uygur Chinese, while TPMT*3A is a rare mutant allele in Uygur Chinese.