ROS Synthesis and Accumulation during Wound-induced Sesquiterpene Biosynthesis in Aquilaria sinensis Callus / 中国药学杂志

OBJECTIVE: To explore the response intensity of reactive oxygen species(ROS) components including H2O2, O-2 and OH- in the course of wound-induced sesquiterpenes formation in Aquilaria sinensis callus. METHODS: The synthesis of sesquiterpenes in wounded callus was analyzed by using GG-MS technique. Total ROS distribution in cells was observed by fluorescence microscope after H2DCF fluorescent probe staining. The H2O2, O-2 and OH- contents were measured according to biochemical reaction principle. RESULTS: Two sesquitterpenes were synthesized and accumulated in the wounded cells. As a signal molecule, ROS burst and accumulated in the process of wound-induced sesquiterpenes formation, DCF fluorescence was observed to increase gradually. DCF fluorescence reached peak at 3 d and then began to decrease. The response of H2O2 and O-2 to injury took place earlier than those of OH-, H2O2 and O-2 reached the maximum value at 3 d and then decreased, while OH- reached the maximum value at 5 d. CONCLUSION: All ROS components respond to injury stimulation as signaling molecules, and the difference in response intensity of each component can synergistically regulate defense response to promote the synthesis of sesquiterpenes in A.sinensis callus.

Overexpression of catalytic subunit M2 in patients with ovarian cancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The formation and growth of tumors are related to the synthesis of the DNA. The enzyme ribonucleotide reductase (RR) is an enzyme that regulates the total rate of DNA synthesis and thus plays a pivotal role in cell growth. Catalytic subunit M2 (RRM2) is the main unit modulating the ribonucleotide reductase enzymatic activity. This study aimed to investigate the expression of RRM2 mRNA and protein in patients with ovarian cancer and its relevance to diagnosis and clinical outcome of the patients.</p><p><b>METHODS</b>RRM2 mRNA levels and protein expression were detected in 98 ovarian specimens with immunohistochemistry and real-time quantitative polymerase chain reaction (PCR). Expression of the RRM2 protein and correlation of the RRM2 gene expression with clinical pathological features were analyzed. The Kaplan-Meier test was used for evaluating RRM2 expression and time to progression and survival. The Cox proportional model was used to analyze the risk factors in prognosis of patients.</p><p><b>RESULTS</b>Positive RRM2 immunostaining was found in 43 of 62 (69.4%) patients with epithelial ovarian cancer, 10 of 15 (66.7%) patients with borderline neoplasm, 4 of 15 (26.7%) patients with benign growths, and none of the normal group. The RRM2 mRNA levels were significantly over expressed in epithelial ovarian cancer (1.722 ± 0.639) and borderline ovarian neoplasms (1.365 ± 0.615), compared to the normal group (0.678 ± 0.446) and benign group (0.828 ± 0.545). Patients with ovarian caner in clinical FIGO-stages III-IV presented higher RRM2 gene expression than those in clinical FIGO-stages I-II. Furthermore, the survival of patients with low RRM2 mRNA level was significantly better than patients with high levels (P < 0.05). By Cox proportional risk model analysis, the risk of mortality of patients with high level expression of RRM2 mRNA was 2.553 times greater than those with low expression.</p><p><b>CONCLUSION</b>RRM2 expression closely correlates with the development of ovarian tumor and may serve as a novel predictive marker for diagnosis and prognosis of the disease.</p>

A meta-analytic review of ERCC1/MDR1 polymorphism and chemosensitivity to platinum in patients with advanced non-small cell lung cancer / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Platinum-based regimens are used as standard first-line chemotherapy in non-small cell lung cancer (NSCLC) patients. To study if pharmacogenetic approach may allow a tailored selection of platinum chemotherapy for advanced NSCLC, we performed a meta-analysis to compare chemosensitivity to platinum with different ERCC1 C118T/ MDR1 C3435T single-nucleotide polymorphism (SNP).</p><p><b>METHODS</b>Relevant studies were identified by searching the PubMed, Embase, Cochrane, OVID, Springer, EBSCO and CNKI databases. Inclusion criteria were patients with advanced NSCLC who received platinum-based chemotherapy, an evaluated polymorphism of ERCC/MDR1 and overall response rate. We excluded duplicate publications, letters and review articles. The RevMan 4.2 and STATA 11 package were used to do comprehensive quantitative assessment.</p><p><b>RESULTS</b>A total of 11 studies were included in this meta-analysis. For studies evaluating ERCC1 C118T, test for heterogeneity was done (χ(2) = 13.41, P = 0.1), and the odds ratio (OR) for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 1.50 (95% CI 1.09 - 2.06, P = 0.01). In four studies evaluating MDR1 polymorphism, test for heterogeneity was also done (χ(2) = 3.22, P = 0.36), and the OR for the wild-type C/C genotype versus the heterozygous C/T and T/T genotypes was 2.30 (95% CI 1.44 - 3.68, P = 0.0005).</p><p><b>CONCLUSIONS</b>The results indicated that platinum-based chemotherapy sensitivity was significantly associated with polymorphism of ERCC1 C118T and MDR1 C3435T SNP. In further perspective studies, the ERCC1/MDR1 SNPs might serve as simple and less invasive biomarkers for personalized chemotherapy with platinum-based anticancer drugs.</p>

Exogenous hydrogen sulfide delays the senescence of human umbilical vein endothelial cells by lessening oxidative stress / 生理学报

The present study was aimed to investigate the effect of pretreatment with hydrogen sulfide (H2S) on human umbilical vein endothelial cells (HUVECs) senescence and the underlying mechanism. Cultured HUVECs at twelfth and fourth passages were taken as old and young groups, respectively. Sodium hydrosulfide (NaHS, donor of H2S) group was treated with NaHS from fourth to twelfth passage. The cell senescence was determined by senescence-associated β-galactosidase (SA β-gal) staining. DAPI fluorescent dye was used to detect cellular apoptosis. Western blot was used to analyze the expression levels of xanthine oxidase (XOD), manganese-superoxide dismutase (Mn-SOD) and the subunits p67(phox) of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in the HUVECs. Colorimetric method was used to detect SOD activity and cellular hydrogen peroxide (H2O2) level. The results showed that, compared with young group, the old group exhibited higher SA β-gal positive rate and cellular apoptosis, while NaHS pretreatment decreased SA β-gal positive rate and cellular apoptosis. Compared with the young group, the old group showed increased expression levels of XOD and p67(phox), as well as lower Mn-SOD expression level. With the pretreatment of NaHS, the up-regulations of XOD and p67(phox) levels and down-regulation of Mn-SOD level were inhibited. Compared with the young group, the old group showed lower SOD activity and higher H2O2 level, whereas NaHS pretreatment reversed the changes of SOD activity and H2O2 level. These results suggest that H2S delays senescence of HUVECs through lessening oxidative stress.