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.

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.

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.

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.

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.

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.

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.

Formation and Growth of Granular Carbides in Multiple Alloying Wear Resistant Cast Iron Containing RE Through Hot Deformation

The granular carbides formed from hot deformation in multiple alloying wear resistant cast iron were studied through the observation by means of optical microscope, SEM and TEM. The experimental results show that carbides with large size are formed from original short rhabdoid carbides existing in cast, those with small size directly nucleate in the matrix. Carbides with the size between the above are formed from precipitation induced by hot deformation. The bigger the deformation is, the larger the number of microsized granular carbides is. The mechanisms of nucleation and growth of granular carbides and the function of RE were discussed.

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.

Plasmid mediated multiple antibiotic resistance in Escherichia coli isolated from community acquired infection of urinary tract in Aligarh Hospital

This study was to investigate the current trends of multiple drug resistance in bacteria against antibiotics for the proper empirical treatmen.Clinical isolates were collected from community-acquired infection of urinary tract patients in Aligarh India from March 1999 to August 1999.Antibiotic susceptibility test was performed,using the disc diffusion method followed by plasmid isolation by the method of Kado and Liu.Transfer experiments were performed by the method of Lederberg and Cohen.Clinical study revealed that this infection was more common in young women.Various strains of E.coli isolated during the course of study were found to show multiple antibiotic resistance which was further characterized as plasmid-borne drug resistance.This study shows that E.coli may be one of the important causative agents of urinary tract infection(UTI) in young women.

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.

Evaluation of glucose metabolism in women with multiple ovarian follicles

Objective ：To investigate glucose metabolism in women with multiple ovarian follicles （MOF） and explore the relationship between glucose metabolism, insulin resistance and body weight. Methods：We evaluated 46 women with MFO and 30 normal women as controls. All the subjects were given 75g of glucose orally in order to perform the oral glucose tolerance test （OGTT） and insulin releasing test （IRT）, and they were also evaluated for insulin resistance using the insulin resistance index with homeostatic model assessment （HOMA）. Results：The occurrence of impaired glucose tolerance in women with MOF was 10.87%, which was significantly higher than that in the control group （3.33% ,P 〈 0.05）. The rate of insulin resistance was 30.43% in the study group as compared to 10.00% in the control group. The results showed that there was significant difference between the two groups（P 〈 0.05）. The levels of FSH,LH,PRL,E2,T and P between the two groups had no significant difference （P 〉 0.05）. BMI in women with impaired glucose tolerance was correlated positively to insulin resistance （r = 0.567, P 〈 0.05）. Conclusion：Abnormal glucose metabolism was observed in women with unitary multiple ovarian follicles, and this could be attributed to obesity and insulin resistance. Women with MOF and associated obesity should be subjected to OGTT so that their glucose levels can be monitored as a preventive measure.

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.

Stroke Due to Hypercoagulable State Can Mimic Multiple Sclerosis: A Case Report

Introduction: Stroke is the second major cause of mortality worldwide and in several cases, and it may lead to disability. Factor V Leiden is a common genetic thrombophilia, which causes activated protein C (APC) resistance. Hyperhomocysteinemia and factor V Leiden deficiency, two independent coagulopathy factors, can lead to venous and arterial infarctions in multiple small and large arteries and veins anywhere in the body. Case Report: Here, we report a unique case in which both hyperhomocysteinemia and factor V Leiden deficiency are documented together with MTHFR (C677T) (Methylene Tetra Hydro Folate Reductase) gene polymorphism and activated protein C resistance respectively. Conclusion: More interestingly, the mode of presentation in this case highly resembled that of progressive multiple sclerosis;all signs and symptoms slowly progressed without any systemic signs at first few years. Further studies needed to assess current outcomes.

Discontinuous polyostotic fibrous dysplasia with multiple systemic disorders and unique genetic mutations:A case report

BACKGROUND Polyostotic fibrous dysplasia(PFD)is an uncommon developmental bone disease in which normal bone and marrow are replaced by pseudotumoral tissue.The etiology of PFD is unclear,but it is generally thought to be caused by sporadic,post-zygotic mutations in the GNAS gene.Herein,we report the case of a young female with bone pain and lesions consistent with PFD,unique physical findings,and gene mutations.CASE SUMMARY A 27-year-old female presented with unbearable bone pain in her left foot for 4 years.Multiple bone lesions were detected by radiographic examinations,and a diagnosis of PFD was made after a biopsy of her left calcaneus with symptoms including pre-axial polydactyly on her left hand and severe ophthalmological problems such as high myopia,vitreous opacity,and choroidal atrophy.Her serum cortisol level was high,consistent with Cushing syndrome.Due to consanguineous marriage of her grandparents,boosted whole exome screening was performed to identify gene mutations.The results revealed mutations in HSPG2 and RIMS1,which may be contributing factors to her unique findings.CONCLUSION The unique findings in this patient with PFD may be related to mutations in the HSPG2 and RIMS1 genes.

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.

Pathogenic Variation and Occurrence of Multiple Resistance-Breaking <i>Rice yellow mottle virus</i>Strains in Tanzania

Rice yellow mottle virus (RYMV) is a major biotic constraint for rice production in Africa. The resistance-breaking ability of Tanzanian RYMV strains and phylotypes (S4lm (Tz526), S4lv (Tz516), S4ug (Tz508), S5 (Tz429, Tz445), S6c (Tz486) and S6w (Tz539)) were tested by inoculating rice cultivars with RYMV1 resistant alleles (Gigante (rymv1-2), Tog12387 (rymv1-3), Tog5681 (rymv1-3), Tog5438 (rymv1-4), Tog5672 (rymv1-4+rymv2) and Tog5674 (rymv 1-5)) in a screen house. The results revealed multiple resistance-breaking strains and phylotypes on resistant cultivars Gigante, Tog12387, Tog5438 and Tog5681. However, the resistance breakdown was highly variable depending on the strain used, and disease severity ranged from 11% - 75.3%. The virulence potential of RYMV phylotype S4lm (Tz526) was similar to phylotype S6w (Tz539). The impact of strains and phylotypes on yield and its components in rice cultivars revealed highly significant differences (P ≤ 0.001). The lowest percent plant height reduction (2.8%), number of tillers per plant (2.5%), 1000 grain weight (2.7%), spikelet sterility (3.5%) and yield (5%) was recorded in rice cultivar Gigante inoculated with RYMV phylotype S6c (Tz486). Phylotype S6c (Tz486) despite being less virulent compared to other strains, its virus titer in rice cultivar Gigante (1.833) was higher than S5 (Tz429, Tz445) inoculated on Tog5674 (0.171, 0.207) and S6w (Tz539) inoculated on Tog5681 (0.283). The resistant-breaking strain S5 (Tz445) multiplied in resistant rice cultivar Tog5674 without inducing visible symptoms but showed positive reaction to ELISA with low virus titer. The strain S5 overcame wide range of resistant alleles including rymv1-2, rymv1-3, rymv1-4 and rymv1-5 resistance, with exception of rymv1-4 + rymv2. The current results gave a new perspective for future identification of resistance-breaking mutations through sequencing of the RYMV genome in infected rice cultivars and mutagenesis of an infectious viral clone useful for future RYMV resistant breeding programs.

Biologically-Effective-Dose of Tolpyralate and Tolpyralate plus Atrazine for Control of Multiple-Herbicide-Resistant Waterhemp [<i>Amaranthus tuberculatus</i>(Moq.) J. D. Sauer] in Corn

The biologically-effective-dose of tolpyralate, a new 4-hydroxyphenyl-pyruvate dioxygenase (HPPD)-inhibitor, applied alone or tank-mixed with atrazine, for the control of multiple-herbicide-resistant (MHR) waterhemp [Amaranthus tuberculatus (Moq.) J. D. Sauer] has not been studied in corn. Seven field experiments were conducted during a three-year period (2018, 2019, 2020) in Ontario, Canada with MHR waterhemp to determine: 1) the dose-response of MHR waterhemp to tolpyralate and tolpyralate plus atrazine, and 2) the relative efficacy of tolpyralate and tolpyralate plus atrazine to post-emergence corn herbicides, dicamba/atrazine (500/1000 g·ha−1) and mesotrione + atrazine (100 + 280 g·ha−1). Tolpyralate + atrazine (120 + 4000 g·ha−1) caused 13% corn injury at one site two weeks after application (WAA), which was observed as transient foliar chlorosis and bleaching of new leaves. At 12 WAA, the predicted dose of tolpyralate for 50% control of MHR waterhemp at Cottam and on Walpole Island was 8 and 2 g·ha−1, respectively;the predicted dose of tolpyralate + atrazine for 50% control of MHR waterhemp at Cottam and on Walpole Island was 5 + 160 and 1 + 21 g·ha−1, respectively. The difference in predicted dose at the two sites is likely due to differences in MHR density and resistance profile. Applied at the registered rate, tolpyralate (30 g·ha−1) and tolpyralate + atrazine (30 + 1000 g·ha−1) controlled MHR waterhemp similar to dicamba/atrazine and mesotrione + atrazine across sites. This study demonstrates that tolpyralate + atrazine, applied POST, provides season-long control of MHR waterhemp in corn.