Insights into the volatile flavor and quality profiles of loquat (Eriobotrya japonica Lindl.) during shelf-life via HS-GC-IMS, E-nose, and E-tongue.

Loquat fruits are among the most popular Chinese fruits because of their unique taste and aroma. The quality profiles of these fruits during 18 days of shelf-life at 20 °C were elucidated by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), E-nose, and E-tongue. During shelf-life period, the properties and variations of 43 (20 aldehydes, 7 esters, 6 ketones, 1 alcohol, and 1 furan) volatile flavored compounds were determined by GC-IMS, which showed that the contents of methyl 3-methyl butanoate, ethyl acetate, and dimethyl ketone gradually decrease with prolonged shelf-life time, while (E)-2-heptenal, heptanal, (E)-2-pentenal, 1-penten-3-one 3-pentanone and 2-pentylfuran increase. The PCA based on the signal intensity of GC-IMS and E-nose, revealed that loquat fruits are well distinguished at different shelf-life times. The taste profile alternates as the storage time increases, along with higher pH, and lower amounts of total soluble solids, vitamin C, and total phenolics. The visual plots of GC-IMS, E-nose, and E-tongue had good consistency, and they characterized the aroma characteristics of loquat fruits well during different shelf-life periods. The findings of this research provide a useful understanding of the flavors of loquat fruits during their prolonged shelf-life, and a potential research basis for advancements in the loquat industry.

Hypoxia deactivates epigenetic feedbacks via enzyme-derived clicking proteolysis-targeting chimeras.

Epigenetic mediation through bromodomain and extraterminal (BET) proteins have progressively translated protein imbalance into effective cancer treatment. Perturbation of druggable BET proteins through proteolysis-targeting chimeras (PROTACs) has recently contributed to the discovery of effective therapeutics. Unfortunately, precise and microenvironment-activatable BET protein degradation content with promising tumor selectivity and pharmacological suitability remains elusive. Here, we present an enzyme-derived clicking PROTACs (ENCTACs) capable of orthogonally cross-linking two disparate small-molecule warhead ligands that recognize BET bromodomain-containing protein 4 (BRD4) protein and E3 ligase within tumors only upon hypoxia-induced activation of nitroreductase enzyme. This localized formation of heterobifunctional degraders promotes specific down-regulation of BRD4, which subsequently alters expression of epigenetic targets and, therefore, allows precise modulation of hypoxic signaling in live cells, zebrafish, and living mice with solid tumors. Our activation-feedback system demonstrates compelling superiorities and may enable the PROTAC technology with more flexible practicality and druggable potency for precision medicine in the near future.

Anti-polyphenol oxidase properties of total flavonoids from young loquat fruits: inhibitory activity and mechanism.

This study investigated anti-polyphenol oxidase activity and mechanism of purified total flavonoids (PTF) from young loquat fruits. PTF remarkably inhibited the activity of polyphenol oxidase (PPO) with an IC50 value of 21.03 ± 2.37 µg/mL. Based on enzyme kinetics, PTF was found to be a potent, mixed-type, and reversible inhibitor of PPO. The fluorescence intensity of PPO was quenched by PTF through forming a PTF-PPO complex in a static procedure. Therefore, this study authenticated PTF as an efficient PPO inhibitor, which would contribute to their utilization in food industry.

[Effect of acupuncture on intestinal flora in rats with stress gastric ulcer].

OBJECTIVE: To observe the effect of acupuncture at "Baihui" (GV 20), "Zhongwan" (CV 12) and "Zusanli" (ST 36) on intestinal flora in rats with stress gastric ulcer (SGU) , and to explore the mechanism of acupuncture promoting SGU recovery. METHODS: Thirty-one SPF SD rats were randomly divided into a control group (7 rats), a model control group (8 rats), an acupuncture group (8 rats) and a medication group (8 rats). The rats in the model group, acupuncture group and medication group were selected to applied the improved restraint water-immersion stress method to establish the SGU model. After modeling, the rats in the control group and model group were fixed and restrained for 20 min every day for a total of 5 days; the rats in the acupuncture group were intervented with acupuncture at "Baihui" (GV 20), "Zhongwan" (CV 12) and "Zusanli" (ST 36), once a day, 20 min each time, and twisting needle for 30 s every 5 min for a total of 5 days; the rats in the medication group were gavaged by solution of omeprazole enteric-coated tablet (200 mg/mL), 2 mL for each rat, once a day. Guth method was used to calculate the gastric mucosal damage index (GMDI), HE staining was used to observe the pathological changes of gastric mucosa, and 16SrDNA identification was used to detect the structural abundance of intestinal flora. RESULTS: Compared with the control group, the GMDI of rats in the model group was increased (P<0.01), the gastric mucosal pathological changes were significant, and the intestinal flora richness index Chao1, Observed species and diversity index Shannon were all decreased (P<0.05), the diversity index Simpson was increased (P<0.05). Compared with the model group, the GMDI of rats in the acupuncture group and medication group was reduced (P<0.01, P<0.05), the gastric mucosal damage degree was reduced, and the intestinal flora richness index Chao1, Observed species and diversity index Shannon were all increased (P<0.05) and the diversity index Simpson decreased (P<0.05). Compared with the medication group, the GMDI of rats in the acupuncture group was reduced (P<0.01), the recovery of gastric mucosal injury was better than that of the medication group. CONCLUSION: Acupuncture can effectively improve gastric mucosal injury of SGU, and the mechanism may be related to increasing the diversity of intestinal flora and promoting the correction of the disordered intestinal flora.

[Effect of acupuncture on serum inflammatory cytokines and intestinal flora in rats with stress-induced gastric ulcer].

OBJECTIVE: To investigate the effect of acupuncture on serum inflammatory cytokines and intestinal flora in rats with stress-induced gastric ulcer (SGU), and to explore the mechanism of acupuncture in the treatment of SGU. METHODS: Sprague-Dawley rats were randomly divided into blank, model, acupuncture, and medication groups, with 7 rats in each group. Restraint water-immersion stress was used to establish the model of SGU. The rats in the acupuncture group were given acupuncture at "Zhongwan"(CV12) and bilateral "Zusanli"(ST36) for 20 min, once a day for 5 days, and those in the medication group were given 2 mL solution of Omeprazole enteric-coated tablets (0.2 mg/kg) by gavage, once a day for 5 days. The Guth method was used to calculate the gastric mucosa damage index, HE staining was used to observe the histopathological changes of the gastric mucosa, ELISA was used to measure the serum levels of interleukin-4 (IL-4) and interleukin-6 (IL-6), and 16S rDNA sequencing method was used to observe the change in intestinal flora. RESULTS: Compared with the blank group, the model group had a significant increase in gastric mucosa damage index (P<0.01), markedly pathological changes of the gastric mucosa shown by HE staining, a significant reduction in the content of serum IL-4 (P<0.01), and a significant increase in the content of serum IL-6 (P<0.01), as well as a significant reduction in Bacteroidetes and Firmicutes at the phylum level. Compared with the model group, the acupuncture group and the medication group had a significant reduction in gastric mucosa damage index (P<0.01, P<0.05). HE staining showed reduced pathological changes of the gastric mucosa, as well as a significant increase in the content of serum IL-4 (P<0.01, P<0.05) and a significant reduction in the content of serum IL-6 (P<0.01, P<0.05). As for the intestinal flora, there was a significant increase in Bacteroidetes. Compared with the medication group, the gastric mucosa damage index was decreased （P<0.05），the content of serum IL-4 was significantly increased （P<0.05）, while the content of serum IL-6 significantly decreased (P<0.05) in the acupuncture group. CONCLUSION: Acupuncture at CV12 and ST36 can down-regulate the content of serum IL-6, up-regulate the content of serum IL-4, maintain the relative homeostasis of inflammatory cytokines, and regulate the community structure of intestinal flora, and thus help to repair the damage of gastric mucosa.

Dolastatin 15 from a Marine Cyanobacterium Suppresses HIF-1α Mediated Cancer Cell Viability and Vascularization.

Chemical investigation of a benthic marine cyanobacterium yielded the anticancer agent dolastatin 15, originally isolated from a mollusk. Dolastatin 15 is a microtubule-destabilizing agent with analogues undergoing clinical evaluation. Profiling against a panel of isogenic HCT116 colorectal cancer cells showed remarkable differential cytotoxicity against the parental cells over isogenic cells lacking HIF or other key players in the pathway, including oncogenic KRAS and VEGF. Dolastatin 15 displayed an antivascularization effect in human endothelial cells and in zebrafish vhl mutants with activated Hif, thus signifying its clinical potential as a treatment for solid tumors with an angiogenic component. Global transcriptome analysis with RNA sequencing suggested that dolastatin 15 could affect other major cancer pathways that might not directly involve tubulin or HIF. The identification of the true producer of a clinically relevant agent is important for sustainable supply, as is understanding the biosynthesis, and future genetic manipulation of the biosynthetic gene cluster for analogue production.

Optimization of extraction of loquat flowers polyphenolics and its antioxidant and anti-polyphenol oxidase properties.

In this study, the conditions of extraction of loquat flowers polyphenolics were optimized through response surface methodology (RSM). Proper extraction conditions were: solid to liquid ratio 1 g per 50 mL and ethanol concentration 50% at 61°C for 9 min. Furthermore, the antioxidant and anti-polyphenol oxidase (PPO) activity of purified total polyphenolics (PTP) were investigated. PTP displayed strong antioxidant activity with IC50 values of 126.3 ± 8.9, 162.4 ± 6.3 and 94.97 mg ascorbic acid equivalent/g dry weight (mg AAE/d.w.) for ABTS, DPPH, and FRAP assays. In addition, PTP has a substantial inhibitory activity on PPO (IC50 = 115 ± 9.2 µg/mL). From the kinetics analysis, it was proved to be a reversible and mixed-type inhibitor of PPO with KI and KIS values of 76.77 µg/mL and 227.86 µg/mL, respectively. Further, the molecular mechanism underlying the inhibition of PPO by PTP was investigated by molecular docking techniques. The results showed that PTP units could form interaction with the catalytic pocket of PPO through the interaction with amino acid residues in the enzyme active center. The antioxidant activities of PTP together with its effect on PPO activity provide a strong starting point for their practical usage in the food industry.

[Moxibustion improved gastric ulcer by reducing contents of corticotrophin-releasing hormone and adrenocorticotropic hormone in serum and hypothalamus-pituitary tissues in rats with stress-induced gastric ulcer].

OBJECTIVE: To observe the effect of moxibustion of "Zhongwan" (CV12) and "Zusanli" (ST36) on histopathological changes of the gastric mucosa and contents of corticotropin-releasing hormone(CRH) and adrenocorticotrophic hormone(ACTH) in the serum, hypothalamus and pituitary tissues in rats with stress-induced gastric ulcer(SGU), so as to reveal its mechanisms underlying improvement of SGU. METHODS: A total of 28 male SD rats were randomly divided into blank control, model, moxibustion, and medication groups, with 7 rats in each group. The SGU model was established by water immersion restraint stress for 3 h. Moxibustion was applied to "Zhongwan"(CV12) and bilateral "Zusanli" (ST36) for 20 min, once a day for 5 days, and rats of the medication group were treated by gavage of Omeprazole enteric-coated tablets (0.2 mg/kg) once a day for 5 days. The gastric mucosal damage index (ulcer index, UI) was measured to assess the injury severity according to Guth's me-thods. Histopathological changes of the gastric mucosa were determined by H．E. staining. The contents of CRH in serum and hypothalamus and ACTH in serum and pituitary gland tissue were assayed by using ELISA. RESULTS: Outcomes of H．E. staining showed gastric mucosal epithelia defect, disordered arrangement of glands, obvious mucosal hyperemia and edema, exudation of a large number of red blood cells, swelling of mucosal cells with necrosis of nuclei in the model group. These situations were relatively milder in the moxibustion and medication groups. After modeling, the UI, and the contents of CRH in the serum and hypotha-lamus, and ACTH in the serum and pituitary tissue were significantly increased in comparison with the blank control group (P<0.01). Following the intervention, the UI, and contents of CRH in the serum and hypothalamus, and ACTH in the serum and pituitary were all down-regulated in both medication and moxibustion groups relevant to the model group (P<0.05, P<0.01). The therapeutic effect of moxibustion was notably superior to that of medication in down-regulating serum CRH and ACTH (P<0.05). No significant differences were found between the medication and moxibustin interventions in lowering the UI, hypothalamic CRH and pituitary ACTH levels (P>0.05)．. CONCLUSION: Moxibustion can relieve gastric mucosal injury induced by stress in water immersion restraint stress rats, which may be associated with its effects in down-regulating the levels of CRH and ACTH in se-rum, hypothalamus and pituitary tissues (inhibition of activities of hypothalamic-pituitary-adrenocortical axis)．.

Retinoic acid receptor α facilitates human colorectal cancer progression via Akt and MMP2 signaling.

Purpose: Retinoic acid α (RARα) is overexpressed in various tumors and facilitates cancer progression. Although RARα has been shown to facilitate colorectal cancer (CRC) progression, more efforts to characterize mechanisms of RARα in CRC are needed in order to develop better target-based drugs for tumor therapy. Methods: RARα expression in CRC was assessed by IHC. EdU, QPCR, Western blotting, dual-luciferase reporter assay and ChIP were performed to explore the role of RARα in CRC and the mechanism involoved. Results: Here, we show an overexpression of RARα in 73.5% (i.e., 25 of 34 human CRC specimens). RARα knockdown decreased cell proliferation, migration, and invasion. Such phenotypic manifestations can be correlated to lowered activation of Akt and expression of PCNA (proliferating cell nuclear antigen) as well as MMP2 (matrix metallopeptidase). Mechanistically, RARα facilitates CRC growth through Akt signaling activation to cause levels of PCNA to be upregulated. Furthermore, RARα promotes migration and invasion of CRC cells by directly recruiting the MMP2 promoter to enhance the expression of MMP2. Conclusions: These findings demonstrate that CRC carcinogenesis is promoted by RARα via an enhanced Akt signaling and by increasing MMP2 transcription. CRC therapy can examine the use of RARα as a prospective molecular target.

[Effect of Electroacupuncture on Cerebro-cortex Caspase-3 Expression and Blood Lipid Levels in Hyperlipemia Rats with Cerebral Ischemia].

OBJECTIVE: To observe the effect of electroacupuncture (EA) stimulation of "Fenglong" (ST 40), "Sanyinjiao" (SP 6) plus manual acupuncture (MA) stimulation of "Shuigou" (GV 26) and "Baihui" (GV 20) on Caspase-3 protein expression in the cerebral cortex of rats with hyperlipemia and cerebral ischemia(HL-CI),so as to reveal its mechanisms underlying improvement of HL-CI. METHODS: Forty-five rats were randomly divided into normal control,sham operation,model,EA group I(EA+MA was given for 14 days, i.e., 7 days before CI, and 7 days more after HL-CI)and EA group Ⅱ (EA+MA was given for only 7 days after HL-CI),with 9 rats being in each group. The HL-CI model was established by feeding the animals with high fat forage for 6 weeks and then making an occlusion of the unilateral middle cerebral artery by regional application of quantitative paper adsorbing 50% FeCl3 solution (10 µL). Rats of the sham operation group were treated with the same procedures only without application of FeCl3 solution. For rats of the EA group I,EA (1-3 mA, 2 Hz/100 Hz) was applied to bilateral acupoints SP 6 and ST 40 (for 20 min),and MA stimulation applied to GV 26 and GV 20. EA was conducted once daily for 7 days after 6 weeks' high fat fo-rage feeding, and EA+MA intervention was conducted once daily for 7 days after CI modeling. For rats in the EA group Ⅱ, EA+MA was applied to the same 4 acupoints once a day for 7 days only after CI modeling. The neurological impairment was assessed by Zea Longa's scoring. The blood sample was taken from the abdominal aorta for measuring the contents of serum cholesterol (CHO),triglyceride (TG) and high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Pathological changes of the cerebral cortex were observed after H.E. staining, and the expression of cerebro-cortex Caspase-3 was analyzed by immunohistochemistry. RESULTS: Following modeling,the neurological score,CHO, TG and LDL-C contents, and the number of Caspase-3 positive cells as well as Caspase-3 immunoactivity level were significantly increased in the model group(P<0.05), while serum HDL-C level was obviously decreased(P<0.05). After the treatment,the increased neurological score, CHO, TG and LDL-C contents, and the number of Caspase-3 positive cells and Caspase-3 immunoactivity level were considerably decreased in the EA group I and Ⅱ(P<0.05)while the decreased HDL-C level was notably increased relevant to the model group(P<0.05). The effects of the EA group I were notably superior to those of EA group Ⅱ in down-regulating the neurological score,CHO, TG and LDL-C levels and the expression of Caspase-3 protein(P<0.05). No significant differences were found between the normal control and sham operation groups in the neurological scores 20 min and 7 days after modeling and Caspase-3 expression levels (P>0.05). H.E. staining showed a reduction of the apoptotic cells and inflammatory cells in both EA group I and Ⅱ. CONCLUSIONS: Both EA and EA+MA interventions can improve neurological function in HL-CI rats,which may be related to their effects in adjusting the levels of serum lipids and down-regulating the expression of cell apoptosis-related Caspase-3 protein in the ischemic cortex. Moreover, the cerebral ischemia injury may be lightened by EA-lowering hyperlipemia first.

[Systematic Evaluation and Meta-analysis on Acupuncture for Peptic Ulcer].

OBJECTIVE: To systematically evaluate the clinical efficacy of acupuncture for peptic ulcer. METHODS: Randomized controlled trials of acupuncture for peptic ulcer were searched from China National Knowledge Infrastructure (CNKI), WanFang Database, Chinese Scientific and Technological Journals (VIP), China Biomedicine (CBM), PubMed and the Cochrane Library from the establishment time of databases to September, 2016. Data extraction and quality evaluation were implemented for the literature which met the inclusive criteria. The RevMan 5.3 software was used to make Meta-analysis. RESULTS: Sixteen papers including 1 570 patients of peptic ulcer were included. The results of Meta-analysis showed that there was no statistical significance between acupuncture and western medicine in the effective rate, the healing rate of ulcer area and the HP negative rate (all P>0.05); the recurrence rate of acupuncture was significantly lower than that of western medicine[RR=0.35, 95%CI (0.14, 0.84), P<0.05]. Acupuncture plus western medicine was significantly different from simple western medicine in the effective rate, the healing rate of ulcer area and the recurrence rate[RR=1.20,95% CI (1.04, 1.38), P=0.01; RR=1.29, 95% CI (1.06, 1.58), P=0.01;RR=0.27, 95% CI (0.16, 0.45), P<0.00001]. The analysis of evidence grade (GRADE) pre-sented that the healing rate of ulcer area and the HP negative rate of acupuncture were "low grade", and others were "extremely low grade". CONCLUSIONS: Acupuncture combined with western medicine has some advantages for peptic ulcer compared with the conventional western medicine, which needs further confirmation due to the lower evidence grade. Larger samples, randomized controlled trials with high quality are highly recommended.

Multidimensional Screening Platform for Simultaneously Targeting Oncogenic KRAS and Hypoxia-Inducible Factors Pathways in Colorectal Cancer.

Colorectal cancer (CRC) is a genetic disease, due to progressive accumulation of mutations in oncogenes and tumor suppressor genes. Large scale genomic sequencing projects revealed >100 mutations in any individual CRC. Many of these mutations are likely passenger mutations, and fewer are driver mutations. Of these, activating mutations in RAS proteins are essential for cancer initiation, progression, and/or resistance to therapy. There has been significant interest in developing drugs targeting mutated cancer gene products or downstream signaling pathways. Due to the number of mutations involved and inherent redundancy in intracellular signaling, drugs targeting one mutation or pathway have been either ineffective or led to rapid resistance. We have devised a strategy whereby multiple cancer pathways may be simultaneously targeted for drug discovery. For proof-of-concept, we targeted the oncogenic KRAS and HIF pathways, since oncogenic KRAS has been shown to be required for cancer initiation and progression, and HIF-1α and HIF-2α are induced by the majority of mutated oncogenes and tumor suppressor genes in CRC. We have generated isogenic cell lines defective in either oncogenic KRAS or both HIF-1α and HIF-2α and subjected them to multiplex genomic, siRNA, and high-throughput small molecule screening. We have identified potential drug targets and compounds for preclinical and clinical development. Screening of our marine natural product library led to the rediscovery of the microtubule agent dolastatin 10 and the class I histone deacetylase (HDAC) inhibitor largazole to inhibit oncogenic KRAS and HIF pathways. Largazole was further validated as an antiangiogenic agent in a HIF-dependent manner in human cells and in vivo in zebrafish using a genetic model with activated HIF. Our general strategy, coupling functional genomics with drug susceptibility or chemical-genetic interaction screens, enables the identification of potential drug targets and candidates with requisite selectivity. Molecules prioritized in this manner can easily be validated in suitable zebrafish models due to the genetic tractability of the system. Our multidimensional platform with cellular and organismal components can be extended to larger scale multiplex screens that include other mutations and pathways.

[Effects of Direct Moxibustion of "Ganshu"(BL 18) on the Contents of T cells in Peripheral Blood in Rats with Precancerous Lesion of Primary Hepatocellular Carcinoma].

OBJECTIVE: To observe the effect of moxibustion stimulation of "Ganshu"(BL 18) region on contents of T cells in the peripheral blood in rats with Diethylnitrosamine (DEN)-induced hepatocellular carcinoma (HCC), so as to explore its effective in improving immunoregulatory function. METHODS: Seventy male Wistar rats were randomly divided into control group (n=10), model group(n=15), direct moxibustion-15 s group(n=15), direct moxibustion-30 s group (n=15) and ginger-separated moxibustion group(n=15). The primary HCC precancerous lesion model was established by intraperitoneal injection of DEN (50 mg/kg), once every 3 days for 10 weeks. Moxibustion was applied to bilateral "Ganshu"(BL 18) for about 15 min (3 moxa-cones), or 30 min (six moxa-cones), with or without ginger-slice separation, once every other day for 10 consecutive weeks. The contents of T cells of CD 3+, CD 4+, CD 8+ and CD 4+/CD 8+ ratio in the peripheral blood were detected with Flow Cytometey(FCM), pathological changes of liver were observed by light microscope after hematoxylin-eosin(HE) stain. RESULTS: Compared to the control group, the contents of blood CD 3+ and CD 4+ T cells and ratio of CD 4+/CD 8+ were significantly down-regulated, while that of CD 8+T cells was obviously increased in the model group(P<0.05,P<0.01). After moxibustion intervention, the decreased CD 3+ and CD 4+T cells and CD 4+/CD 8+ levels and the increased CD 8+T cell contents were reversed in all the 3 moxibustion groups (P<0.05, P<0.01), except CD 3+ in the ginger-separated moxibustion group (P>0.05). There were no significant differences among the three moxibustion groups in the CD 3+, CD 4+, CD 8+ and CD 4+/CD 8+ levels (P>0.05). In addition, the pathological changes of liver tissue as central vein deviation or absence, disordered arrangement of hepatic cords, narrowing of the hepatic sinusoid, hyperplasia of collagen fibers, formation of tuberosis, unevenness of liver cells with nuclear anachromasis and higher heteromorphism, and macronucleus oncocytes in primary HCC rats were not observed or milder after moxibustion intervention. CONCLUSIONS: Direct moxibustion and ginger-separated moxibustion can improve pathological changes of hepatic cells in rats with HCC, which may be associated with its actions in raising blood CD 3+ and CD 4+ T cell contents and reducing CD 8+ T levels to improve immune function.

XIAP gene downregulation by small interfering RNA inhibits proliferation, induces apoptosis, and reverses the cisplatin resistance of ovarian carcinoma.

OBJECTIVE: XIAP is one of the most important members of the inhibitors of apoptosis family. It is upregulated in various malignancies, including human ovarian carcinomas, it promotes invasion, metastasis, growth, and survival of malignant cells, and it also confers resistance to some chemotherapeutic drugs. We observed the effect of XIAP gene RNA interference (RNAi) on the proliferation, apoptosis, tumorigenicity, and chemosensitivity of the human ovarian carcinoma cells A2780/cp70. STUDY DESIGN: We used a human U6 promoter-driven DNA template approach to induce short hairpin RNA-triggered RNAi to block XIAP gene expression in the human ovarian cancer cell line A2780/cp70. A corresponding site-mutated vector was constructed as a negative control (pSilencer 2.1-NC). The expression of XIAP mRNA and protein among the stable transfected cells and the untransfected ones was detected by RT-PCR and Western blotting. The cell growth was examined and drug sensitivity was assayed using the MTT assay. Cell apoptosis was measured by flow cytometry and the tumorigenicity by using nude mice. RESULTS: Three stable transfected cell lines: A2780/cp70-s2, A2780/cp70-NC, and A2780/cp70-neo were established. The expression levels of XIAP gene mRNA and protein in A2780/cp70-s2 were 63.3% and 60.8%, lower than in A2780/cp70-NC, A2780/cp70-neo, and untransfected A2780/cp70 cells. The cell proliferation of A2780/cp70-s2 was reduced by up to 62.2+/-1.9%. Compared with the other cell lines, the changes in apoptotic rate in A2780/cp70-s2 was 31.1+/-1.3%, obviously increasing (P<0.05). The knockdown of XIAP retards tumorigenicity in nude mice and after 21 days the average tumor weight of the A2780/cp70-s2 group was lower by 1.62+/-0.11g (P<0.05). And the survival index in A2780/cp70-s2 cells was markedly reduced with the addition of 1 microM and 10 microM cisplatinum, respectively (P<0.05). CONCLUSIONS: XIAP gene RNAi inhibited the proliferation of ovarian carcinoma cells and caused cells to be more sensitive to cisplatin through the reduction of its mRNA and protein. These results suggest that XIAP is an ovarian cancer-related gene and that XIAP is a potential target for therapeutic anti-cancer drugs.

Inhibition of multi-drug resistance of ovarian carcinoma by small interfering RNA targeting to MRP2 gene.

AIMS: To investigate the inhibiting mechanism of multi-drug resistance (MDR) using expression vectors of short hairpin RNA (shRNA) in a MDR human ovarian cancer cell line (A2780/cp70). METHODS: Two shRNA expression vectors were constructed and introduced into A2780/cp70 cells. Expression of MRP2 mRNA was assessed by RT-PCR, and Mrp2 expression was determined by Western blot and immunocytochemistry. Apoptosis and sensitization of the cells to cisplatinum were quantified by flow cytometry and methyl-thiazol-tetrazolium (MTT) assays. Cellular cisplatinum accumulation was assayed by laser scanning confocal microscopy (LSCM). RESULTS: In A2780/cp70 cells transfected with MRP2-A and MRP2-B shRNA expression vectors, RT-PCR showed that MRP2 mRNA expression was reduced by 41.8% (P < 0.05), 30.9% (P < 0.01) (transient transfection) and 39.6% (P < 0.05), 29.4% (P < 0.01) (stable transfection), respectively. Western blot and immunocytochemistry showed that Mrp2 expression was significantly and specifically inhibited. Resistance against cisplatinum was decreased from 173- to 119-fold (P < 0.05), 64-fold (P < 0.01) (transient transfection) and to 117-fold (P < 0.05), 60-fold (P < 0.01) (stable transfection). Furthermore, shRNA vectors significantly enhanced the cellular cisplatinum accumulation. The combination of shRNA vectors and cisplatinum significantly induced the apoptosis of cells. CONCLUSIONS: shRNA expression vectors effectively reduce MRP2 expression and can restore the sensitivity of drug-resistant cancer cells to conventional chemotherapeutic agents.

[Inhibition of ovarian cancer growth by small interfering RNA targeting X-linked inhibitor of apoptosis gene].

OBJECTIVE: To construct an RNA interference vector to down-regulate X-linked inhibitor of apoptosis (XIAP) gene and study the RNA interference effect on the cell cycle and growth of ovarian cancer. METHODS: Oligonucleotides of 64 base pairs for hairpin RNA targeting XIAP were designed, chemically synthesized, annealed, and cloned into the pSUPER vector. After identification by restriction digestion, the correct vectors were transiently transfected into SKOV3 cells, a human ovarian cancer cell line. The XIAP mRNA was detected by RT-PCR. The proteins were detected by western blot and indirect immunofluorescence staining. Flow cytometry (FCM) analysis and methyl thiazolyl tetrazolium (MTT) assay method were applied to measure cell cycle, cell growth and sensitiveness to cisplatin. RESULTS: SKOV3 cells had a high level expression of XIAP. The vector of RNA interference, which can interfere with XIAP gene was successfully constructed. After transient transfection, the expression of XIAP protein was significantly decreased in SKOV3 cells and the value of relative density was 3584 +/- 124, 2138 +/- 65, 1973 +/- 80 and 110 +/- 12, respectively (P = 0.0334). At the same time, the expression of XIAP mRNA was decreased accordingly and the value of relative density was 6674 +/- 274, 4532 +/- 107, 2322 +/- 57 and 1864 +/- 78, respectively (P = 0.0127). The FCM results showed that, the vector could increase the number of cells in G(1) phase compared with parent cells and compared with the cells transfected with pSUPER (P < 0.05); the number in S phase decreased compared with parent cells and compared with the cells transfected with pSUPER (P < 0.05). MTT results showed that pSUPER-siXIAP could inhibit the growth and proliferation of SKOV3 cells in a time-dependent manner, and inhibit the tumor cell growth. CONCLUSIONS: We successfully constructed an expressing hairpin RNA against the XIAP vector. The vector can effectively silence XIAP gene, increase the number of cells in G(1) phase, and slow down the growth of tumor cells. This may be a useful therapeutic strategy for XIAP over-expressing ovarian carcinomas.

[Effect of gestrinone on growth and apoptosis in isolated ectopic endometrium cells in vitro].

OBJECTIVE: To investigate the effects of gestrinone on growth and apoptosis, as well as the expression of phosphatase and tension homologue deleted on chromosome 10 (PTEN) in isolated ectopic endometrium cells in vitro and the underlying mechanisms. METHODS: Ectopic endometrium cells were cultured and exposed to gestrinone of different doses of 0, 10(-6) and 10(-4) mol/L respectively. The inhibition of the cells during 48 hours was determined by methylthiazolyl tetrazolium (MTT) assay, and the cell growth curve was made. Gestrinone was administered to the cells and at 24 hours the morphological changes were observed by transmission electron microscopy and the apoptosis rate, cell cycle and PTEN expression were monitored by flow cytometry (FCM) at the same time. RESULTS: Gestrinone at different concentrations could inhibit the growth and proliferation of ectopic endometrium cells in a dose- and time-dependent manner. The inhibition rate of cell growth after exposed to gestrinone for 8, 16, 24, 32, 40 and 48 h was 99.6%, 87.3%, 79.8%, 62.3%, 51.7% and 44.2% in the 10(-6) mol/L group, and 99.2%, 77.1%, 69.6%, 51.1%, 33.7% and 23.6% in the 10(-4) mol/L group (P < 0.05), and cell growth curve was changed accordingly. After 24 hour exposure to gestrinone from 10(-6) to 10(-4) mol/l, apoptotic changes of cells were observed under transmission electron microscope. FCM showed that after the exposure to gestrinone, the apoptotic rate of ectopic endometrium cells was 1.3% in 10(-6) mol/L group and 15.0% in 10(4) mol/L group. It was significantly increased when compared with the 0 mol/L group, the apoptotic rate of which was 0% (P < 0.05). The level of PTEN expression of the ectopic endometrium cells was 60.6% after treated with 0 mol/L gestrinone, while in 10(-6) and 10(-4) mol/l groups the level of PTEN expression was increased to 75.3% and 85.7%, significantly higher than that of the 0 mol/L group (P < 0.05). CONCLUSION: Gestrinone can significantly inhibit the growth and proliferation of ectopic endometrium cells, and this effect was related to increase of PTEN expression.