Effect of low dose fractionated radiation on reversing cisplatin resistance in ovarian carcinoma via VEGF and mTOR

Objective To investigate the mechanism of low-dose fractionated radiation on reversing cisplatin resistance in ovarian carcinoma via vascular endothelial growth factor(VEGF) and mammalian target of rapamycin(mTOR) in vivo.Methods Human cisplatin-resistant ovarian carcinoma cells(SKOV3/DDP) were injected into nude mice to establish ovarian cancer xenografts. The mice were randomly divided into three groups: a control group, a low-dose fractionated radiation(LDRFT) group, and a conventional-dose radiation group. Each group was exposed to 0 cGy, 50 cGy, and 200 cGy radiation, respectively, for 4 weeks, up to a total of 8.0 Gy. Mice in the LDFRT group were irradiated twice daily with 6 hour intermissions on day 1 and 2 of every week for a total of 4 weeks. Conventional-dose group mice were given a single 200 cGy radiation dose on the first day each week for a total of 4 weeks. Maximum horizontal and vertical diameters of the tumors were measured every other day and used to create a tumor growth curve. After 4 weeks of irradiation, we dissected the tumor tissue and calculated the tumor inhibition rate. RT-PCR detected the expression of VEGF and m TOR, and Western blots detected the expression of corresponding proteins.Results Both LDRFT and conventional-dose radiation inhibited the growth of tumor cells, and growth of tumors in the two radiation groups compared with growth in the control group were significantly different(P < 0.05). The rate of tumor inhibition in the LDFRT group(37.5603%) was lower than in the conventionaldose group(47.4446%), but there was no significant difference(P 0.05). Compared with the other two groups, the m RNA expression of VEGF was significantly lower in the LDFRT group(P < 0.05), but there was no obvious difference between the conventional-dose and control groups. There was no obvious difference in the m RNA expression of m TOR among the three groups, but the expression of the protein p-m TOR was lower in the LDFRT group(P < 0.05), as confirmed by Western blotting.Conclusion LDFRT is as effective at inhibiting the growth of tumor cells as conventional-dose radiation. In addition, LDFRT could deregulate the expression of VEGF and p-m TOR, and may therefore play a vital role in reversing cisplatin resistance in ovarian cancer.

Identification of potential immune-related prognostic biomarkers of lung cancer using gene co-expression network analysis

Objective The objective of this study was to identify new carcinogenetic hub genes and develop the integration of differentially expressed genes to predict the prognosis of lung cancer.Methods GSE139032 microarray data packages were downloaded from the Gene Expression Omnibus for planning,testing,and review of data.We identified KRT6C,LAMC2,LAMB3,KRT6A,and MYEOV from a key module for validation.Results We found that the five genes were related to a poor prognosis,and the expression levels of these genes were associated with tumor stage.Furthermore,Kaplan-Meier plotter showed that the five hub genes had better prognostic values.The mean levels of methylation in lung adenocarcinoma(LUAD)were significantly lower than those in healthy lung tissues for the hub genes.However,gene set enrichment analysis(GSEA)for single hub genes showed that all of them were immune-related.Conclusion Our findings demonstrated that KRT6C,LAMC2,LAMB3,KRT6A,and MYEOV are all candidate diagnostic and prognostic biomarkers for LUAD.They may have clinical implications in LUAD patients not only for the improvement of risk stratification but also for therapeutic decisions and prognosis prediction.

Effects of Different Seedling Raising Methods on Seedling Growth of Two Kinds of Fritillaria

[Objectives] To reveal the effects of film mulching and open ground seedling raising on the differences between Fritillaria przewalskii Maxim. and Fritillaria pallidiflora Schrenkf., find the optimal seedling raising method, and provide scientific basis for standard seedling raising technique and protecting wild resources of Fritillaria. [Methods] This experiment counted the seedling emergence number and calculated the seedling emergence indicator and the yield. [Results] The results showed that under the condition of film mulching and open ground seedling raising, the changes of Fritillaria seedlings showed an "S" curve, conforming to the Logistic equation, and the rapid growth period appeared 5-13 d after seedling emergence. Compared with the open ground seedling raising, the seedlings of F. przewalskii Maxim. and F. pallidiflora Schrenkf. raised through film mulching emerged 2-4 d earlier, and the yield increased by 56.8% and 21.71%, respectively, and the individual quality was excellent. [Conclusions] The film mulching of F. przewalskii Maxim. and F. pallidiflora Schrenkf. has great significance to protect the wild resources of Fritillaria in Eryin Mountain Area. It is recommended to adopt the film mulching method for Fritillaria seedling raising, to reduce the yield decline due to lodging, and adopt sun-shading net covering after sowing.

Low-dose fractionated radiation reverses cisplatin resistance in ovarian cancer cells via PI3K/AKT/GSK-3β signaling

Objective To investigate whether low-dose fractionated radiation(LDFRT) could enhance cisplatin sensitivity in drug-resistant human ovarian cancer cells SKOV3/DDP, and to further explore the underlying mechanism.Methods SKOV3/DDP ovarian cancer cells were divided into three groups as follows: control, LDFRT, and conventional-dose radiation groups. Cells from all three groups were treated with different concentrations of cisplatin(0, 1.25, 2.5, 5, 10, and 20 μg/m L) for 48 h. The proliferation inhibition rate was investigated using the cell counting kit 8(CCK8). The rate of apoptosis was determined by flow cytometry(FCM). Protein levels of AKT, P-AKT, GSK-3β, P-GSK-3β, P21, cyclin D1, and P27 were examined by Western blotting. Results As expected, LDFRT significantly reduced the half-maximal inhibitory concentration(IC50) of cisplatin and promoted apoptosis in SKOV3/DDP cells. Moreover, in the LDFRT group, protein levels of P-AKT, P-GSK-3β, and cyclin D1 were markedly decreased, those of P21 and P27 were greatly increased, and total AKT and GSK-3β levels showed no significant difference compared to those in both the control and conventional-dose radiation groups.Conclusion LDFRT sensitizes resistant SKOV3/DDP ovarian cancer cells to cisplatin through inactivation of PI3 K/AKT/GSK-3β signaling.

Field-based evidence for the enrichment of intrinsic antibiotic resistome stimulated by plant-derived fertilizer in agricultural soil

Animal manures have been demonstrated to enhance antibiotic resistance in agricultural soils.However,little is known about the effects of plant-derived fertilizer on soil antibiotic resistome.Herein,metagenomic sequencing was used to investigate the effects of a plantderived fertilizer processed from sugarcane and beet on soil antibiotic resistance genes(ARGs)in a soybean field along crop growth stages.ARG profiles in the soils amended by plant-derived fertilizer were compared with those in the soils amended by chicken manure.The abundance and diversity of total ARGs in the soils amended by plant-derived fertilizer were significantly(P<0.05)elevated at the sprout stage,to a level comparable to that in the manured soils.Whereas,unlike chicken manure mainly introducing manure-borne ARGs to soil,the plant-derived fertilizer was indicated to mainly enrich multidrug resistance genes in soil by nourishing indigenous bacteria.ARGs with abundances in amended soils significantly(P<0.05)higher than in unamended soils at the sprout stage of soybean were considered as enriched ARGs.Decrease in the abundance of the enriched ARGs was observed in both the amended soils from the sprout to the harvest.Network analysis further identified Proteobacteria and Bacteroidetes as the primary bacterial taxa involved in the temporal variation of the enriched ARGs in the soils amended by plant-derived fertilizer,while in manured soils were Firmicutes and Actinobacteria.As revealed by multivariate statistical analyses,variation of the enriched ARGs in the soils amended by plant-derived fertilizer was majorly attributed to the response of co-occurred bacteria to depleting nutrients,which was different from the failed establishment of manure-borne bacteria in the manured soils.Our study provided field-based evidence that plant-derived fertilizer stimulated the intrinsic antibiotic resistome,and proposed attention to the un-perceived risk since some clinically relevant ARGs originate and evolve from natural resistome.

Peptidomimetic-liganded gold nanoclusters for controlled iron delivery and synergistic suppression of tumor growth

A novel peptidomimetic-liganded gold nanocluster(CDp-AuNC)is proposed for the synergistic suppression of tumor growth.Taking advantages of the multi-capabilities offered by the surface ligands,including iron chelation,glutathione peroxidases-1(GPx-1)binding,and tumor cells recognition,CDp-AuNCs are able to function as the nanocarriers to deliver iron in a controlled manner for the ferroptosis therapy and as the inhibitors for GPx-1 to induce the apoptosis of tumor cells.The Fe2+@CDp-AuNC nanocomplexes are fabricated through a facile self-assembly method.The experimental data verify that the nanocomplexes are internalized specifically by tumor cells with high efficiency.The acidic microenvironment in endosomes triggers the collapse of the nanocomplexes and thereby releases Fe2+to induce ferroptosis and CDp-AuNCs to inhibit the enzyme activity of GPx-1.Benefiting from the H_(2)O_(2)-depleted pathway inhibition and ferroptosis acceleration,the intracellular reactive oxygen species(ROS)level could be enhanced significantly.As a consequence,the apoptosis/ferroptosis of 4T1 cells as well as the tumor elimination in vivo are observed after treatment with the Fe2+@CDp-AuNC nanocomplexes at a relatively low dose.The facile iron loading method,simple construction procedure,and outstanding tumor suppression performance,provide CDp-AuNCs great application promise.More importantly,the strategy of peptidomimetic ligands design provides a transferable approach to building multifunctional nanomaterials.