Increased functional cell surface expression of CFTR and ΔF508-CFTR by the anthracycline doxorubicin

Maitra, Rangan; Shaw, Collin M.; Stanton, Bruce A.; Hamilton, Joshua W.

doi:10.1152/ajpcell.2001.280.5.c1031

Cited by 32 publications

(20 citation statements)

References 22 publications

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“…The addition of glycerol and incubation at a reduced temperature are conditions that promote, in cultured cells, the correct processing of membrane proteins trapped in the ER or Golgi. [54][55][56] In an initial experiment, the effects of glycerol alone, incubation at 28°C alone, or glycerol and 28°C in combination on wild-type BSEP, R948C (c.2842CϾT), and E297G (c. 890AϾG) were assessed. Fig.…”

Section: Resultsmentioning

confidence: 99%

Missense mutations and single nucleotide polymorphisms in ABCB11 impair bile salt export pump processing and function or disrupt pre-messenger RNA splicing #

et al. 2009

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The gene encoding the human bile salt export pump (BSEP), ABCB11, is mutated in several forms of intrahepatic cholestasis. Here we classified the majority (63) of known ABCB11 missense mutations and 21 single-nucleotide polymorphisms (SNPs) to determine whether they caused abnormal ABCB11 pre-messenger RNA splicing, abnormal processing of BSEP protein, or alterations in BSEP protein function. Using an in vitro minigene system to analyze splicing events, we found reduced wild-type splicing for 20 mutations/SNPs, with normal mRNA levels reduced to 5% or less in eight cases. The common ABCB11 missense mutation encoding D482G enhanced aberrant splicing, whereas the common SNP A1028A promoted exon skipping. Addition of exogenous splicing factors modulated several splicing defects. Of the mutants expressed in vitro in CHO-K1 cells, most appeared to be retained in the endoplasmic reticulum and degraded. A minority had BSEP levels similar to wild-type. The SNP variant A444 had reduced levels of protein compared with V444. Treatment with glycerol and incubation at reduced temperature overcame processing defects for several mutants, including E297G. Taurocholate transport by two assessed mutants, N490D and A570T, was reduced compared with wild-type. Conclusion: This work is a comprehensive analysis of 80% of ABCB11 missense mutations and singlenucleotide polymorphisms at pre-mRNA splicing and protein processing/functional levels. We show that aberrant pre-mRNA splicing occurs in a considerable number of cases, leading to reduced levels of normal mRNA. Thus, primary defects at either the protein or the mRNA level (or both) contribute significantly to BSEP deficiency. These results will help to develop mutation-specific therapies for children and adults suffering from intrahepatic cholestasis due to BSEP deficiency. (HEPATOLOGY 2009;49:553-567.)

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Section: Resultsmentioning

confidence: 99%

Missense mutations and single nucleotide polymorphisms in ABCB11 impair bile salt export pump processing and function or disrupt pre-messenger RNA splicing #

et al. 2009

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“…Such mechanisms are currently known for the p-glycoprotein only. For example, Ihnat et al 49 and Maitra et al 50 reported that mitomycin C induces decreased p-glycoprotein expression. The effects vary among different cell lines and are detectable between 24 and 96 hours after treatment with drugs, a fact which is in agreement with the observations made in the present study.…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, mitomycin C induces cross-linking on promoters of inducible genes. 50,51 Comparable relationships could be associated with the inducible genes for MRP 1 and 3. The differential effects of MRP 1 and MRP 3 are possibly related to different basal expression levels of MRP 1 (ubiquitary) and MRP 3 (selective, predominantly in the liver) in adenocarcinoma cells as a consequence of different functionality.…”

Section: Discussionmentioning

confidence: 99%

The exposure of cancer cells to hyperthermia, iron oxide nanoparticles, and mitomycin C influences membrane multidrug resistance protein expression levels

Franke¹,

Kettering²,

Lange³

et al. 2013

IJN

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Purpose:The presence of multidrug resistance-associated protein (MRP) in cancer cells is known to be responsible for many therapeutic failures in current oncological treatments. Here, we show that the combination of different effectors like hyperthermia, iron oxide nanoparticles, and chemotherapeutics influences expression of MRP 1 and 3 in an adenocarcinoma cell line. Methods: BT-474 cells were treated with magnetic nanoparticles (MNP; 1.5 to 150 µg Fe/cm 2 ) or mitomycin C (up to 1.5 µg/cm 2 , 24 hours) in the presence or absence of hyperthermia (43°C, 15 to 120 minutes). Moreover, cells were also sequentially exposed to these effectors (MNP, hyperthermia, and mitomycin C). After cell harvesting, mRNA was extracted and analyzed via reverse transcription polymerase chain reaction. Additionally, membrane protein was isolated and analyzed via sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. Results: When cells were exposed to the effectors alone or to combinations thereof, no effects on MRP 1 and 3 mRNA expression were observed. In contrast, membrane protein expression was influenced in a selective manner. The effects on MRP 3 expression were less pronounced compared with MRP 1. Treatment with mitomycin C decreased MRP expression at high concentrations and hyperthermia intensified these effects. In contrast, the presence of MNP only increased MRP 1 and 3 expression, and hyperthermia reversed these effects. When combining hyperthermia, magnetic nanoparticles, and mitomycin C, no further suppression of MRP expression was observed in comparison with the respective dual treatment modalities. Discussion: The different MRP 1 and 3 expression levels are not associated with de novo mRNA expression, but rather with an altered translocation of MRP 1 and 3 to the cell membrane as a result of reactive oxygen species production, and with shifting of intracellular MRP storage pools, changes in membrane fluidity, etc, at the protein level. Our results could be used to develop new treatment strategies by repressing mechanisms that actively export drugs from the target cell, thereby improving the therapeutic outcome in oncology.

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“…São eles os poliálcoois, como glicerol, sorbitol e mio -inositol; as aminas como betaína e N -óxido de trimetilamina (TMAO), além de solventes como dimetil sulfóxido -DMSO e D2O (6,17) . Além destas, outras drogas também aumentam a disponibilidade da CFTR -ΔF508 madura no cistoplasma como a doxorrubicinaDox (um derivado antraciclico) e os derivados por substituição do benzo [c] quinolizinio (MBP) (61,63) (66 , 67) .…”

Section: -Reguladores Da Migração Citoplasmáticaunclassified

Canais Iônicos E Fibrose Cística

Coutinho¹,

Figueiredo²,

Tintino³

et al. 2014

Rev. Interf. FLS

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_________________________________________________________________________________ RESUMOIntrodução: A Fibrose Cística (FC) é uma doença autossômica recessiva letal, que acomete preferencialmente crianças brancas. Objetivo: Descrever e discutir os mecanismos moleculares envolvidos na FC. Materiais e métodos: Artigos obtidos nos bancos de dados internacionais SCIELO, PUBMED, BIOLINE, DOAJ e HIGHWIRE que tratam dos mecanismos moleculares envolvidos na FC. Resultados e discussões: Decorre de mutações no gene que codifica a proteína "regulador de condutância transmembrana da fibrose cística" (CFTR). Esta contribui para a regulação do fluxo iônico nas superfícies apicais das células epiteliais, e é um canal de cloreto. A fisiopatologia da FC envolve o bloqueio da secreção do cloreto através da membrana apical das células epiteliais glandulares, resultando em seu acúmulo intracelular, acompanhado do influxo de sódio e água para este compartimento. Como consequência, ocorre desidratação da superfície celular com formação de secreções espessas -características da doença. O diagnóstico é baseado na clínica, demonstração laboratorial de concentrações elevadas de cloreto no suor e análise genética. O tratamento inclui: fluidificação das vias aéreas, antibioticoterapia, broncodilatadores, suporte nutricional e reposição enzimas. Na tentativa de aumentar o efluxo epitelial de Cl -ou inibir o influxo do Na + , alvos moleculares podem ser atacados por diferentes drogas como reguladores de migração citoplasmática, ativadores da expressão gênica, entre outros, para o primeiro, e inativação dos ENaC (amilorida ou benzamil) ou inibição do influxo de sódio (ouabaína, digoxina ou loperamida). Considerações Finais: Novas modalidades terapêuticas e a detecção precoce da FC por genotipagem podem melhorar o prognóstico e a qualidade de vida dos afetados. Palavras -chave:Fibrose Cística, Canalopatias, CFTR, EnaC, F508. ABSTRACTIntroduction: Cystic Fibrosis (CF) is a lethal autossomic recessive disease occurring mainly in white kids. Objective: Describe and discuss the molecular mechanisms involved in the CF. Material and methods: article obtained from the international databanks SCIELO, PUBMED, BIOLINE, DOAJ and HIGHWIRE about the molecular mechanisms of CF. Results and discussions: Its due mutations on the gene of cystic fibrosis Transmembrane conductance regulator (CFTR). This protein contributes for the regulation of the ionic flow in the apical surfaces of the epithelial cells, and is a chloride canal. The physiopathology of the CF involves the blockade of the chloride secretion through the apical membrane of the epithelial cells, resulting in intracellular accumulation, followed by the sodium and water influx. As consequence will occur a dehidratation of the cellular surface with thick secretion. The diagnosis is based on the clinic, the laboratorial identification of high concentrations of chloride in the sweat and genetic analysis. The treatment includes: rehidratation of the airway, antibiothicotherapy, nutritional support and en...

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Increased functional cell surface expression of CFTR and ΔF508-CFTR by the anthracycline doxorubicin

Cited by 32 publications

References 22 publications

Missense mutations and single nucleotide polymorphisms in ABCB11 impair bile salt export pump processing and function or disrupt pre-messenger RNA splicing #

Missense mutations and single nucleotide polymorphisms in ABCB11 impair bile salt export pump processing and function or disrupt pre-messenger RNA splicing #

The exposure of cancer cells to hyperthermia, iron oxide nanoparticles, and mitomycin C influences membrane multidrug resistance protein expression levels

Canais Iônicos E Fibrose Cística

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