Correlation of Skp2 overexpression to prognosis of patients with nasopharyngeal carcinoma from South China / 癌症

S-phase kinase-associated protein 2 (Skp2), which plays a role in cell cycle regulation, is commonly overexpressed in a variety of human cancers and associated with poor prognosis. However, its role in nasopharyngeal carcinoma (NPC) is not well understood. In this study, we examined the clinical significance of Skp2, with a particular emphasis on overall survival (OS) and disease-free survival (DFS), in NPC cases in South China, where NPC is an epidemic. Additionally, we explored the function of Skp2 in maintaining a cancer stem cell-like phenotype in NPC cell lines. Skp2 expression was assessed for 127 NPC patients using tissue microarrays and immunohistochemistry and analyzed together with clinicopathologic features, OS, and DFS. Skp2 expression was detectable, or positive, in 75.6% of patients. Although there was no correlation between Skp2 and any clinicopathologic factor, Skp2 expression significantly portended inferior OS (P = 0.013) and DFS (P = 0.012). In the multivariate model, Skp2 expression remained significantly predictive of poor OS [P = 0.009, risk ratio (RR) = 4.06] and DFS (P = 0.008, RR = 3.56), and this was also true for clinical stage (P = 0.012 and RR=3.201 for OS; P = 0.002 and RR=1.94 for DFS) and sex (P = 0.016 and RR=0.31 for OS; P = 0.006 and RR = 0.27 for DFS). After Skp2 knockdown, a colony formation assay was used to evaluate the self-renewal property of stem-like cells in the NPC cell lines CNE-1 and CNE-2. The colony formation efficiency in CNE-1 and CNE-2 cells was decreased. In Skp2-transfected CNE-1 and CNE-2 cells, side population (SP) proportion was increased as detected by flow cytometry. Skp2 is an independent prognostic marker for OS and DFS in NPC. Skp2 may play a role in maintaining the cancer stem cell-like phenotype of NPC cell lines.

Study on genetic polymorphisms of CYP2F1 gene in Guangdong population of China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the genetic polymorphism of CYP2F1 gene, a member of CYP450 gene family in the healthy population and the patients with nasopharyngeal carcinoma (NPC) of Guangdong province, and furthermore analyze the relationship between CYP2F1 genetic polymorphism and the risk of developing NPC.</p><p><b>METHODS</b>By direct gene sequencing, all of 10 exons of CYP2F1 gene were detected in 40 peripheral blood specimens of patients with primary NPC. For the genetic polymorphism with high allelic frequency, mismatch PCR-RFLP technique was developed to identify the different frequency between 368 NPC cases and 344 cancer-free controls.</p><p><b>RESULTS</b>There were totally 35 SNPs identified in all of 10 exons and exon-intron junctions of CYP2F1 gene from 40 NPC patients, which included 10 missense mutations and 1 frame shift mutation. The most important mutation was C insertion located in 15-16 bp, which caused the frame shift. The allelic frequency of C insertion was 25%. However, there was no significant difference found between 368 NPC cases and 344 controls in allelic frequency of 15-16 bp C insertion mutation (P>0.05).</p><p><b>CONCLUSION</b>A lot of genetic polymorphism of CYP2F1 gene is found in Guangdong population of China. However, no single genetic polymorphism associated with the individual susceptibility to NPC can be identified. The cooperated operations with multiple genetic polymorphisms of one or more genes may be critical factors contributing to the development and progression of NPC.</p>

Caspase-3 plays a required role in PC12 cell apoptotic death induced by roscovitine / 生理学报

Roscovitine is a specific inhibitor of cyclin-dependent kinases (cdks) cdc2/cyclin B, cdk2/cyclin A, cdk2/cyclin E and cdk5/p35. The studies on the enzyme inhibitory properties and cellular effects of roscovitine revealed that it arrests cells in G(2)/M and G(1)/S phase, inhibits the proliferation of mammalian cells and induces cell death. However, the characteristics of cell death and exact mechanism by which this cdk inhibitor kills transformed cells are unknown. We previously investigated that the roscovitine induces apoptotic death of mitotic PC12 cells. The present study was to identify whether the roscovitine-induced death is related with the specific elements of caspases in pathway of apoptosis. The morphological data of caspase-3 immunofluorocytochemistry double staining with hoechst 33342 indicated that apoptotic nuclei were identified as nuclei with chromatin condensation and nuclear fragmentation, and that caspase-3 active p17 subunit co-existed in PC12 cells treated with roscovitine 50 micromol/L for 4 h. The number of the caspase-3 positive cells increased significantly to about 42%, as compared with the normal control (P<0.001). The data of MTT assay showed that the number of viable cells treated by roscovitine (50 micromol/L) alone for 12 h was 29.03%, of the untreated controls. Both a broad-spectrum caspase inhibitor Z-VAD-FMK (50 mumol/L) and a specific caspase-3 inhibitor Z-DEVD-FMK (100 micromol/L) increased viable PC12 cells to 45.16%, (Z-DEVD-FMK) and 58.06%, (Z-VAD-FMK), respectively, in the presence of roscovitine. Non-erythroid a-spectrin is a cytoskeleted protein that is a substrate of caspase-3 cysteine proteases. To confirm the activity of caspase-3 that produced in roscovitine (50 micromol/L for 12 h)-induced PC12 cell death, activated caspase-3 specific 120 kDa spectrin breakdown products (SBDP) were detected by Western bloting using the mouse anti-non-erythroid a-spectrin monoclonal antibody. The mean relative density of bands corresponding to caspase-3 specific SBDP levels were significantly increased in the cytosolic fractions treated with roscovitine, as compared to the normal control (P<0.001). These results indicate that caspase signals, especially caspase-3 signal are necessary for the progression of proliferating PC12 cell apoptotic death evoked by roscovintine.

Mutation and amplification of RIT1 gene in hepatocellular carcinoma / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To explore the mutation and amplification of RIT1 gene and their correlation with carcinogenesis of hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>The polymerase chain reactioindirect sequencing method was used for detecting the mutations in the sequence of all 6 exons in the RIT1 gene of 50 HCC tissues and paratumor tissues. And the amplification of RIT1 gene was examined by fluorescence quantitative polymerase chain reaction method.</p><p><b>RESULTS</b>A nucleotide 241 G --> C substitution in exon 5 of RIT1 gene was detected in one patient's HCC tissue, but not in paratumor tissue; this 241 G --> C substitution leads to Glu81Gln amino acid alteration in the conservative domain binding GTP. A nucleotide G --> C substitution in 5'-UTR (-21 bp from initial codon) was detected in all of the 50 HCC tissues and paratumor tissues, and 2- to 297-fold amplification of RIT1 gene was detected in 11 of 43 qualified cases, the amplification frequency being 25.6%.</p><p><b>CONCLUSION</b>Gene amplification is one of the main activating ways of RIT1 gene in HCC, and its amplification might be correlated with HCC carcinogenesis, while point mutation might be not.</p>

Studies on heart-protecting musk pH-dependent gradient-release pellets / 药学学报

<p><b>AIM</b>To prepare heart-protecting musk pH-dependent gradient-release pellets and investigate the drug release in vitro and in vivo.</p><p><b>METHODS</b>The pH-dependent gradient-release pellet system was prepared by using HPMC, Eudragit L-30D-55 and Eudragit L100-Eudragit S100 (1:5) combinations as coater. The release of borneol and total ginsenoside from pH-dependent gradient-release pellets were determined according to the method of Pharmacopoeia of the People's Republic of China (2000) in the simulated gastrointestinal pH conditions. The gastrointestinal transit and disintegration of pellets was investigated by using gamma-scintigraphic trace in volunteers. The pharmacokinetics of borneol of heart-protecting musk pH-dependent gradient-release pellets was studied in 6 healthy volunteers by GC methods.</p><p><b>RESULTS</b>The f2 value of release data of borneol and total ginsenoside of the heart-protecting musk pH-dependent gradient-release pellets was 79.6 in the simulated gastrointestinal pH conditions. The gamma-scintigraphic trace evaluation demonstrated that the pellets coated with HPMC, Eudragit L-30D-55 or Eudragit L100-Eudragit S100 (1:5) combinations can disintegrate in stomach, duodenum and jejunum or ileum. The gastrointestinal transit time of pellets was about 5 hours in fasted state and about 6 hours in fed state. The concentration-time curves of borneol of heart-protecting musk pills fit in two-compartment model. The pharmacokinetics data showed that borneol had a short time of absorption and elimination. The mean residence time (MRT) of borneol of heart-protecting musk pills was 2.61 hours. The plasma concentration of borneol of heart-protecting musk sustained-release capsule which consisted of three kinds of pellets coated with HPMC, Eudragit L-30D-55 or Eudragit L100-Eudragit S100 (1:5) combinations was steadier than those of heart-protecting musk pills, its Cmax was lower than and Tmax was near to those of heart-protecting musk pills, its MRT was 4.0 hours, and its relative bioavailability was 96%.</p><p><b>CONCLUSION</b>The lipidsoluble borneol and watersoluble total ginsenoside of heart-protecting musk pH-dependent gradient-release pellets can release simultaneously while sustained-releasing in vitro. The heart-protecting musk pH-dependent gradient-release pellets had the characteristics of pH-dependent gradient-releasing and disintegration while transiting in gastrointestinal tract. A characteristic of gradient sustained-release was shown in the concentration-time curves of borneol of heart-protecting musk sustained-release capsule in volunteers.</p>

Study on the preparation of venenum bufonis beta-cyclodextrin inclusion complexes / 中国中药杂志

<p><b>OBJECTIVE</b>To study the preparation of Venenum Bufonis beta-cyclodextrin inclusion complexes.</p><p><b>METHOD</b>An optimal condition was established by the uniform design. Under the optimal conditions the Venenum Bufonis beta-cyclodextrin inclusion complexes were prepared with 5 different methods.</p><p><b>RESULT</b>The ball grinding method was superior to other four methods. The bufadienolide inclusion rate of Venenum Bufonis beta-cyclodextrin prepared with ball grinding method was 85.42%.</p><p><b>CONCLUSION</b>Ball grinding method is the best method for the preparation of Venenum Bufonis beta-cyclodextrin inclusion complexes.</p>