Suppression of P-gp induced multiple drug resistance in a drug resistant gastric cancer cell line by overexpression of Fas

AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved by FACS.The sensitivity of gastriccancer cells to apoptosis was determined by invitro apoptosis assay.The drug sensitization ofcells to several anti-tumor drugs was observedby MTT assay.Immunochemical method wasused to show expression of P-gp and Topo Ⅱ ingastric cancer cells.RESULTS Comparing to SGC7901 and pBK-SGC7901/VCR,fas-SGC7901/VCR showeddecreasing G2 cells and increasing S cells,theG2 phase fraction of pBK-SGC7901/VCR wasabout 3.0 times that of fas-SGC7901/VCR,but Sphase fraction of fas-SGC7901/VCR was about1.9 times that of pBK-SGC7901/VCR,indicatingS phase arrest of fas-SGC7901/VCR.FACS alsosuggested apoptosis of fas-SGC7901/VCR,fas-SGC7901/VCR was more sensitive to apoptosisinducing agent VM-26 than pBK-SGC7901/VCR.MTT assay showed increased sensitization offas-SGC7901/VCR to DDP,MMC and 5-FU,butsame sensitization to VCR according to pBK-SGC7901/VCR.SGC7901,pBK-SGC7901/ VCRand fas-SGC7901/VCR had positively stainedTopo Ⅱ equally.P-gp staining in pBK- SGC7901/VCR was stronger than in SG07901,but there was little staining of P-gp in fas.SGC7901/VCR.CONCLUSION fas gene transduction couldreverse the MDR of human drug-resistant gastriccancer cell SGC7901/VCR to a degree,possiblybecause of higher sensitization to apoptosis anddecreased expression of P-gp.

Novel mechanism of drug resistance to proteasome inhibitors in multiple myeloma

Multiple myeloma(MM) is a cancer caused by uncontrolled proliferation of antibody-secreting plasma cells in bone marrow, which represents the second most common hematological malignancy. MM is a highly heterogeneous disease and can be classified into a spectrum of subgroups based on their molecular and cytogenetic abnormalities. In the past decade, novel therapies, especially, the first-in-class proteasome inhibitor bortezomib, have been revolutionary for the treatment of MM patients. Despite these remarkable achievements, myeloma remains incurable with a high frequency of patients suffering from a relapse, due to drug resistance. Mutation in the proteasome β5-subunit(PSMB5) was found in a bortezomib-resistant cell line generated via long-term coculture with increasing concentrations of bortezomib in 2008, but their actual implication in drug resistance in the clinic has not been reported until recently. A recent study discovered four resistance-inducing PSMB5 mutations from a relapsed MM patient receiving prolonged bortezomib treatment. Analysis of the dynamic clonal evolution revealed that two subclones existed at the onset of disease, while the other two subclones were induced. Protein structural modeling and functional assays demonstrated that all four mutations impaired the binding of bortezomib to the 20 S proteasome, conferring different degrees of resistance. The authors further demonstrated two potential approaches to overcome drug resistance by using combination therapy for targeting proteolysis machinery independent of the 20 S proteasome.

Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens

Objective:To evaluate the antibacterial properties ot Allium sativum(garlic) cloves and Zingiber officinale(ginger) rhizomes against multi-drug resistant clinical pathogens causing nosocomial infection.Methods:The cloves of garlic and rhizomes of ginger were extracted with 95%(v/v) ethanol.The ethanolic extracts were subjected to antibacterial sensitivity test against clinical pathogens.Results:Anti-bacterial potentials of the extracts of two crude garlic cloves and ginger rhizomes were tested against five gram negative and two gram positive multi-drug resistant bacteria isolates.All the bacterial isolates were susceptible to crude extracts of both plants extracts.Except Enterobacter sp.and Klebsiella sp.,all other isolates were susceptible when subjected to ethanolic extracts of garlic and ginger.The highest inhibition zone was observed with garlic(19.4S mm) against Pseudomonas aeruginosa(P.aeruginosa).The minimal inhibitory concentration was as low as 67.00 μg/mL against P.aeruginosa.Conclusions:Natural spices of garlic and ginger possess effective anti-bacterial activity against multi-drug clinical pathogens and can be used for prevention of drug resistant microbial diseases and further evaluation is necessary.

Liposome-mediated Functional Expression of Multiple Drug Resistance Gene in Human Bone Marrow CD34^+ Cells

Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34+ cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.0l). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34+ cells.

Enhanced Precision Therapy of Multiple Myeloma Through Engineered Biomimetic Nanoparticles with Dual Targeting

Multiple myeloma(MM)is the second most prevalent hematological malignancy.Current MM treatment strategies are hampered by systemic toxicity and suboptimal therapeutic efficacy.This study addressed these limitations through the development of a potent MM-targeting chemotherapy strategy,which capitalized on the high binding affinity of alendronate for hydroxyapatite in the bone matrix and the homologous targeting of myeloma cell membranes,termed T-PB@M.The results from our investigations highlight the considerable bone affinity of T-PB@M,both in vitro and in vivo.Additionally,this material demonstrated a capability for drug release triggered by low pH conditions.Moreover,T-PB@M induced the generation of reactive oxygen species and triggered cell apoptosis through the poly(ADP-ribose)polymerase 1(PARP1)-Caspase-3-B-cell lymphoma-2(Bcl-2)pathway in MM cells.Notably,T-PB@M preferentially targeted bone-involved sites,thereby circumventing systemic toxic side effects and leading to prolonged survival of MM orthotopic mice.Therefore,this designed target-MM nanocarrier presents a promising and potentially effective platform for the precise treatment of MM.

Identification of TNFRSF1A as a novel regulator of carfilzomib resistance in multiple myeloma

Multiple myeloma(MM)is a hematological tumor with high mortality and recurrence rate.Carfilzomib is a new-generation proteasome inhibitor that is used as the first-line therapy for MM.However,the development of drug resistance is a pervasive obstacle to treating MM.Therefore,elucidating the drug resistance mechanisms is conducive to the formulation of novel therapeutic therapies.To elucidate the mechanisms of carfilzomib resistance,we retrieved the GSE78069 microarray dataset containing carfilzomib-resistant LP-1 MM cells and parental MM cells.Differential gene expression analyses revealed major alterations in the major histocompatibility complex(MHC)and cell adhesion molecules.The upregulation of the tumor necrosis factor(TNF)receptor superfamily member 1A(TNFRSF1A)gene was accompanied by the downregulation of MHC genes and cell adhesion molecules.Furthermore,to investigate the roles of these genes,we established a carfilzomib-resistant cell model and observed that carfilzomib resistance induced TNFRSF1A overexpression and TNFRSF1A silencing reversed carfilzomib resistance and reactivated the expression of cell adhesion molecules.Furthermore,TNFRSF1A silencing suppressed the tumorigenesis of MM cells in immunocompetent mice,indicating that TNFRSF1A may lead to carfilzomib resistance by dampening antitumor immunity.Furthermore,our results indicated that TNFRSF1A overexpression conferred carfilzomib resistance in MM cells and suppressed the expression of MHC genes and cell adhesion molecules.The suppression of MHC genes and cell adhesion molecules may impair the interaction between immune cells and cancer cells to impair antitumor immunity.Future studies are warranted to further investigate the signaling pathway underlying the regulatory role of TNFRSF1A in MM cells.

Novel agents and new therapeutic approaches for treatment of multiple myeloma

This review summarizes the therapeutic strategies and the drugs actually in development for the management of myeloma patients. Multiple myeloma is caused by the expansion of monoclonal plasma cells and secretion of M-protein(immunoglobulins, Bence Jones protein and free light chains). Multiple myeloma still remains an incurable disease with a high incidence rate in the elderly, despite the introduction of several new therapeutic agents(bortezomib, lenalidomide and thalidomide) which have changed its natural history. The high heterogeneity of this disease leads to large differences in clinical responses to treatments. Thus, the choice of the best treatment is a difficult issue. However, the introduction of new drugs has made it possible to achieve high response rates and good quality respons-es with long-term disease control. Interactions between tumor cells and their bone marrow microenvironment play a pivotal role in the development, maintenance, and progression of myeloma, inducing also drug resistance. These knowledges have improved treatment options, leading to the approval of new drugs which not only target the malignant cell itself, but also its microenvironment. These agents are in preclinical/early clinical evaluation and they appear to further improve disease control, but their use is still not approved outside of clinical trials.

A REVIEW ON TRADITIONAL CHINESE MEDICINE IN PREVENTION AND TREATMENT OF MULTIPLE SCLEROSIS

Multiple sclerosis(MS),a diseaseaffecting the central nervous system,ischaracterized by patches of demyelinationand sclerosis of gliosis desseminatedthroughout the white matter of brain andspinal cord.In 1968,Charcot firstdescribed its clinical and pathologicalcharacteristics.Its incidence is very high,especially in Europe and America.Thereis no epidemic data of this

Should mast cells be considered therapeutic targets in multiple sclerosis?

Mast cells are immune cells of the myeloid lineage that are found throughout the body,including the central nervous system.They perform many functions associated with innate and specific immunity,angiogenesis,and vascular homeostasis.Moreover,they have been implicated in a series of pathologies(e.g.,hypersensitivity reactions,tumors,and inflammatory disorders).In this review,we propose that this cell could be a relevant therapeutic target in multiple sclerosis,which is a central nervous system degenerative disease.To support this proposition,we describe the general biological properties of mast cells,their contribution to innate and specific immunity,and the participation of mast cells in the various stages of multiple sclerosis and experimental autoimmune encephalomyelitis development.The final part of this review is dedicated to an overview of the available mast cells immunomodulatory drugs and their activity on multiple sclerosis and experimental autoimmune encephalomyelitis,including our own experience related to the effect of ketotifen fumarate on experimental autoimmune encephalomyelitis evolution.

Association of Human Herpesvirus 6 and 8 in Relapsing Remitting Multiple Sclerosis Type during Exacerbation

Multiple Sclerosis (MS) is a chronic demyelinating disease of the CNS with assumed autoimmune etiology. Human herpes viruses have probable effects on relapsing-remitting MS pathogenesis presumably through molecular mimicry and/or bystander mechanisms. In this study we probed the possible contribution of the two herpes viruses, human herpesvirus 6 (HHV-6) and human herpesvirus 8 (HHV-8), in clinically definite multiple sclerosis (CDMS) pa-tients-relapsing remitting type (RRMS) during clinical exacerbations. All patients had no history of immune modulating or suppressing drugs intake in the last 6 months. The peripheral blood samples, from CDMS patients (n = 20) (13F/7M, age (y) = 30.3 ± 3.21) and other immune mediated neurological disorders (OIND) (11F/9M, age = 25.2 ± 12.1), (My-asthenia Gravis, Guillain Barré Syndrome, ischemic stroke in adolescent and young adult with no clear risk factors), as a control group, had been enrolled within 15 months (January-2007-- March -2008). We investigated the existence of specific deoxyribonucleic acid (DNA) sequences belonging to HHV-6 and HHV-8, using polymerase chain reaction (PCR) in the isolated peripheral blood mononuclear cells (PBMCs) and in plasma. PCR demonstrated HHV-6 DNA in 7 cases (35%), HHV-8 sequences in only one cases (5%) in PBMCs from 20 relapsed CDMS patients;all HHV-6 posi-tive cases showed positive plasma results, while the blood samples from 20 OIND patients showed negative results ex-cept one case (5%) out of 9 cases of GBS was positive for HHV-8 in PBMCs. We consequently concluded that there is considerable evidence in this study that proposed the roles of HHV-6 and HHV-8 in MS pathogenesis and clinical ex-acerbation.

Development of ulcerative colitis in a patient with multiple sclerosis following treatment with interferonβ 1a

To alert clinicians to a potential novel adverse drug effect of interferonβ la, we herein report a patient with relapsing-remitting multiple sclerosis who developed ulcerative colitis following treatment with interferonβ la. Ulcerative colitis persisted despite discontinuation of interferonβ la treatment and switching the patient to glatiramer acetate. Tacrolimus （FK506）, 6-mercaptopurine, and prednisolone were required to induce remission. Both ulcerative colitis and multiple sclerosis were eventually well controlled using this regimen. Our report underscores that caution should be exercised when prescribing immunostimulatory agents in patients with inflammatory bowel disease （IBD） and challenges current efforts to stimulate innate immunity as a novel therapeutic concept for IBD.

The Role of 1q21 Gain on the Prognosis of Multiple Myeloma

Multiple myeloma(MM)is a clonal expansion of malignant plasma cells,and comprises approximately 10%of hematologic malignancies.Although various therapeutic agents and strategies,such as immunomodulatory agents,proteasome inhibitors,monoclonal antibodies and hematopoietic stem cell transplantation(HSCT)have been evaluated,MM remains largely incurable.It is therefore important to further explore the risk factors for disease progression,and to design trials aimed at improving the patient outcomes.Previous studies have considered the presence of a gain in 1q21 as a risk factor for a poorer overall survival.Gain of 1q21 is one of the most common chromosomal aberrations in MM,being detected by fluorescence in situ hybridization in 36%to 47%of newly-diagnosed patients,as well as 52%and 62%patients with relapsed MM.Although a series of reports identified 1q21 gain in MM as a significant and independent poor prognostic factor,other studies failed to demonstrate any prognostic value.Thus,the prognostic value of 1q21 gain in MM remains controversial.We reviewed the current knowledge about 1q21 gain and its value for the clinical management of MM.

A step-by-step multiple stimuli-responsive metal-phenolic network prodrug nanoparticles for chemotherapy

Currently,chemotherapy is the main clinical therapy of tumors.Depressingly,most chemotherapeutic drugs such as doxorubicin and paclitaxel(PTX)have poor water solubility,leading to low bioavailability and serious side effects.Till now,although a variety of nanoparticulate drug delivery systems have been designed to ameliorate the above disadvantage of chemotherapy drugs,their application is still severely limited due to the complex preparation,poor stability,low drug loading,and premature drug release.Herein,a metal phenolic network-based drug delivery system with superior stability,satisfactory drug loading capacity,good biocompatibility,reduced undesired premature release,and excellent anti-tumor ability has been established for achieving step-by-step multiple stimuli-responsive drug delivery.Firstly,the redox-responsive dimeric paclitaxel(diPTX)prodrug was synthesized.Then diPTX@Fe&tannic acid(diPTX@Fe&TA)complex nanoparticles with satisfactory PTX loading capacity were obtained by deposition of Fe&TA network complex on the nanocore of diPTX rapidly with a simple method.The diPTX@Fe&TA nanoparticles have a hydrodynamic diameter of 152.6±1.2 nm,long-term colloidal stability,and high PTX loading content of 24.7%.Besides,diPTX@Fe&TA could expose to the acidic lysosomal environment and the reduction cytoplasmic environment continuously,resulting in the sequential release of diPTX and PTX when it was phagocytosed by tumor cells.Meanwhile,PTX showed almost no release under physiological condition(pH 7.4),which effectively inhibited the undesirable premature release of PTX.More importantly,diPTX@Fe&TA could suppress the growth of tumor effectively in vivo,along with negligible toxicity for organs.This work developed a simple and novel approach for the construction of a stepwise multiple stimuli-responsive drug delivery system with superior stability and satisfactory drug loading capacity to inhibit tumor growth effectively.

Advancing drug delivery to articular cartilage:From single to multiple strategies

Articular cartilage(AC) injuries often lead to cartilage degeneration and may ultimately result in osteoarthritis(OA) due to the limited self-repair ability. To date, numerous intra-articular delivery systems carrying various therapeutic agents have been developed to improve therapeutic localization and retention, optimize controlled drug release profiles and target different pathological processes. Due to the complex and multifactorial characteristics of cartilage injury pathology and heterogeneity of the cartilage structure deposited within a dense matrix, delivery systems loaded with a single therapeutic agent are hindered from reaching multiple targets in a spatiotemporal matched manner and thus fail to mimic the natural processes of biosynthesis, compromising the goal of full cartilage regeneration. Emerging evidence highlights the importance of sequential delivery strategies targeting multiple pathological processes. In this review, we first summarize the current status and progress achieved in single-drug delivery strategies for the treatment of AC diseases. Subsequently, we focus mainly on advances in multiple drug delivery applications, including sequential release formulations targeting various pathological processes, synergistic targeting of the same pathological process, the spatial distribution in multiple tissues, and heterogeneous regeneration. We hope that this review will inspire the rational design of intraarticular drug delivery systems(DDSs) in the future.

PIMD:An Integrative Approach for Drug Repositioning Using Multiple Characterization Fusion

The accumulation of various types of drug informatics data and computational approaches for drug repositioning can accelerate pharmaceutical research and development.However,the integration of multi-dimensional drug data for precision repositioning remains a pressing challenge.Here,we propose a systematic framework named PIMD to predict drug therapeutic properties by integrating multi-dimensional data for drug repositioning.In PIMD,drug similarity networks(DSNs)based on chemical,pharmacological,and clinical data are fused into an integrated DSN(iDSN)composed of many clusters.Rather than simple fusion,PIMD offers a systematic way to annotate clusters.Unexpected drugs within clusters and drug pairs with a high iDSN similarity score are therefore identified to predict novel therapeutic uses.PIMD provides new insights into the universality,individuality,and complementarity of different drug properties by evaluating the contribution of each property data.To test the performance of PIMD,we use chemical,pharmacological,and clinical properties to generate an iDSN.Analyses of the contributions of each drug property indicate that this iDSN was driven by all data types and performs better than other DSNs.Within the top 20 recommended drug pairs,7 drugs have been reported to be repurposed.The source code for PIMD is available at https://github.com/Sepstar/PIMD/.

Drug resistance and minimal residual disease in multiple myeloma

Great progress has been made in improving survival in multiple myeloma(MM)patients over the last 30 years.New drugs have been introduced and complete responses are frequently seen.However,the majority of MM patients do experience a relapse at a variable time after treatment,and ultimately the disease becomes drug-resistant following therapies.Recently,minimal residual disease(MRD)detection has been introduced in clinical trials utilizing novel therapeutic agents to measure the depth of response.MRD can be considered as a surrogate for both progression-free and overall survival.In this perspective,the persistence of a residual therapy-resistant myeloma plasma cell clone can be associated with inferior survivals.The present review gives an overview of drug resistance in MM,i.e.,mutation ofβ5 subunit of the proteasome;upregulation of pumps of efflux;heat shock protein induction for proteasome inhibitors;downregulation of CRBN expression;deregulation of IRF4 expression;mutation of CRBN,IKZF1,and IKZF3 for immunomodulatory drugs and decreased target expression;complement protein increase;sBCMA increase;and BCMA down expression for monoclonal antibodies.Multicolor flow cytometry,or next-generation flow,and next-generation sequencing are currently the techniques available to measure MRD with sensitivity at 10-5.Sustained MRD negativity is related to prolonged survival,and it is evaluated in all recent clinical trials as a surrogate of drug efficacy.

Overcoming drug resistance by targeting protein homeostasis in multiple myeloma

Multiple myeloma(MM)is a plasma cell disorder typically characterized by abundant synthesis of clonal immunoglobulin or free light chains.Although incurable,a deeper understanding of MM pathobiology has fueled major therapeutical advances over the past two decades,significantly improving patient outcomes.Proteasome inhibitors,immunomodulatory drugs,and monoclonal antibodies are among the most effective anti-MM drugs,targeting not only the cancerous cells,but also the bone marrow microenvironment.However,de novo resistance has been reported,and acquired resistance is inevitable for most patients over time,leading to relapsed/refractory disease and poor outcomes.Sustained protein synthesis coupled with impaired/insufficient proteolytic mechanisms makes MM cells exquisitely sensitive to perturbations in protein homeostasis,offering us the opportunity to target this intrinsic vulnerability for therapeutic purposes.This review highlights the scientific rationale for the clinical use of FDA-approved and investigational agents targeting protein homeostasis in MM.

Bias in multiple-treatments meta-analysis： a case on comparative efficacy and tolerability of 15 antipsychotic drugs for schizophrenia

Multiple-treatments meta-analysis is thought to be a feasible method to compare the efficacy and safety among different treatments, especially when there was no head-to-head research among some treatments. But sometimes some conclusions are inconsistent with the clinical experience. Recently, we read a multiple-treatment meta-analysis finished by Stefen Leucht et al, which was published in Lancet） The authors summarized the results of the RCT studies on 15 antipsychotics commonly used in practice; they also horizontally compared the efficacy and safety profile by the recta-analysis. We believe that the results provide more solid evidence for the rational usage of antipsychotics to the psychiatrists, also for the government to distribute health resources in a more reasonable way.

Mouse tumor susceptibility genes identify drug combinations for multiple myeloma

Long-term genetic studies utilizing backcross and congenic strain analyses coupled with positional cloning strategies and functional studies identified Cdkn2a,Mtor,and Mndal as mouse plasmacytoma susceptibility/resistance genes.Tumor incidence data in congenic strains carrying the resistance alleles of Cdkn2a and Mtor led us to hypothesize that drug combinations affecting these pathways are likely to have an additive,if not synergistic effect in inhibiting tumor cell growth.Traditional and novel systems-level genomic approaches were used to assess combination activity,disease specificity,and clinical potential of a drug combination involving rapamycin/everolimus,an Mtor inhibitor,with entinostat,an histone deacetylase inhibitor.The combination synergistically repressed oncogenic MYC and activated the Cdkn2a tumor suppressor.The identification of MYC as a primary upstream regulator led to the identification of small molecule binders of the G-quadruplex structure that forms in the NHEIII region of the MYC promoter.These studies highlight the importance of identifying drug combinations which simultaneously upregulate tumor suppressors and downregulate oncogenes.

Prediction of multiple drug resistance phenotype in cancer cell lines using gene expression profiles and phylogenetic trees

When microarray gene expression data are used to predict multiple drug resistance(MDR)phenotypes for anticancer drugs,the normalization strategy and the quality of the selected signature genes are usually the main causes of inconsistency among different experiments.A stable statistical drug response prediction model is urgently required in oncology.In this study,the microarray gene expression data of multiple cancer cell lines with MDR was analyzed.For each probe-set,the expression value was defined as present/absent(1/0)and was classified into a gene set defined with protein domain organization(PDO).After employing the gene content method of phylogenetic analysis,a phylogenetic model(cell tree)for MDR phenotype prediction was built at the PDO gene set level.The results indicate that classification of cancer cell lines is predominantly affected by both the histopa-thological features and the MDR phenotype(paclitaxel and vinblastine).When applying this model to predict the MDR phenotype of independent samples,the phylogenetic model performs better than signature gene models.Although the utility of our procedure is limited due to sample heterogeneity,it still has potential application in MDR research,especially for hematological tumors or established cell lines.