scholarly journals Multidrug resistance P-glycoprotein monoclonal antibody JSB-1 crossreacts with pyruvate carboxylase.

1995 ◽  
Vol 43 (12) ◽  
pp. 1187-1192 ◽  
Author(s):  
V V Rao ◽  
D C Anthony ◽  
D Piwnica-Worms

Multidrug resistance (MDR) is associated with overexpression of a 170 KD plasma membrane P-glycoprotein (P-gp), a putative energy-dependent efflux transporter that reduces intracellular accumulation of chemotherapeutic agents. For detection of P-gp expression in normal and malignant tissues, an MDR1-specific monoclonal antibody (MAb) JSB-1 has been used extensively. In this report we show that MAb JSB-1 crossreacts with a protein of M(r) approximately 130,000 present in rat liver mitochondrial inner membrane/matrix fractions. Peptide mapping and microsequencing identify this protein as pyruvate carboxylase (PC), an abundant mitochondrial enzyme. MAb JSB-1 also crossreacts with purified PC from bovine liver. Under immunoblotting conditions, this crossreactivity is partially abolished by pre-incubation of MAb JSB-1 with a 1000-fold molar excess of MAb C494 epitope-specific peptide (PNTLEGN), indicating that the epitope of MAb JSB-1 may either overlap with or be in close proximity to that of MAb C494. Immunohistochemical cross-reactivity was also demonstrated in cryosections of human skeletal muscle, a tissue known not to express P-gp. MAb JSB-1 strongly immunostained Type 1 fibers, the subtype known to contain abundant mitochondria. Use of MAb JSB-1 for detection of MDR1 P-gp expression should be approached with caution.

2009 ◽  
Vol 2009 ◽  
pp. 1-11
Author(s):  
Ji Cao ◽  
Lei Zhang ◽  
Qing Ye ◽  
Xinglu Zhou ◽  
Jianshu Lou ◽  
...  

Overexpression of multidrug resistance proteins P-glycoprotein (P-gp, MDR1) causes resistance of the tumor cells against a variety of chemotherapeutic agents. 3-(1-methyl-1H-indol-3-yl)-1-phenyl-4-(1-(3-(piperidin-1-yl)propyl)-1H-pyrazolo[3,4-b]pyridine-3-yl)-1H-pyrrole-2,5-dione (YQ36) is a novel analogue of bisindolylmaleimide, which has been reported to overcome multidrug resistance. Here, we dedicated to investigate the anticancer activity of YQ36 on KB/VCR cells. The results revealed that YQ36 exhibited great antiproliferative activity on three parental cell lines and MDR1 overexpressed cell lines. Moreover, the hypersensitivity of YQ36 was confirmed on the base of great apoptosis induction and unaltered intracellular drug accumulation in KB/VCR cells. Further results suggested that YQ36 could not be considered as a substrate of P-gp, which contributed to its successfully escaping from the efflux mediated by P-gp. Interestingly, we observed that YQ36 could accumulate in nucleus and induce DNA damage. YQ36 could also induce the activation of caspase-3, imposing effects on the mitochondrial function. Collectively, our data demonstrated that YQ36 exhibited potent activities against MDR cells, inducing DNA damage and triggering subsequent apoptosis via mitochondrial pathway.


Author(s):  
Lothar Esser ◽  
Suneet Shukla ◽  
Fei Zhou ◽  
Suresh V. Ambudkar ◽  
Di Xia

P-glycoprotein (P-gp) is a polyspecific ATP-dependent transporter linked to multidrug resistance in cancers that plays important roles in the pharmacokinetics of a large number of drugs. The drug-resistance phenotype of P-gp can be modulated by the monoclonal antibody UIC2, which specifically recognizes human P-gp in a conformation-dependent manner. Here, the purification, sequence determination and high-resolution structure of the Fab fragment of UIC2 (UIC2/Fab) are reported. Purified UIC2/Fab binds human P-gp with a 1:1 stoichiometry. Crystals of UIC2/Fab are triclinic (space groupP1), with unit-cell parametersa= 40.67,b= 44.91,c= 58.09 Å, α = 97.62, β = 99.10, γ = 94.09°, and diffracted X-rays to 1.6 Å resolution. The structure was determined by molecular replacement and refined to 1.65 Å resolution. The asymmetric unit contains one molecule of UIC2/Fab, which exhibits a positively charged antigen-binding surface, suggesting that it might recognize an oppositely charged extracellular epitope of P-gp.


2019 ◽  
Vol 442 ◽  
pp. 91-103 ◽  
Author(s):  
Albert A. De Vera ◽  
Pranav Gupta ◽  
Zining Lei ◽  
Dan Liao ◽  
Silpa Narayanan ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li-rui Sun ◽  
Qiu-shi Guo ◽  
Wei Zhou ◽  
Min Li

AbstractChinese herbal medicine is widely used because it has a good safety profile and few side effects. However, the risk of adverse drug reactions caused by herb-drug interactions (HDIs) is often overlooked. Therefore, the task of identifying possible HDIs and elucidating their mechanisms is of great significance for the prevention and treatment of HDI-related adverse reactions. Since extract from Dioscorea bulbifera L. rhizomes (DB) can cause various degrees of liver damage, it is speculated that HDIs may occur between DB extract and chemicals metabolized or excreted by the liver. Our study revealed that the cardiotoxicity of pirarubicin (THP) was increased by co-administration of DB, and the expression of P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (Mrp2) in the liver was inhibited by DB extract, which led to the accumulation of THP in heart tissue. In conclusion, there are risks of the co-administration of DB extract and THP. The mechanism of HDIs can be better revealed by targeting the efflux transporters.


1987 ◽  
Vol 7 (2) ◽  
pp. 718-724
Author(s):  
K L Deuchars ◽  
R P Du ◽  
M Naik ◽  
D Evernden-Porelle ◽  
N Kartner ◽  
...  

The overexpression of a plasma membrane glycoprotein, P-glycoprotein, is strongly correlated with the expression of multidrug resistance. This phenotype (frequently observed in cell lines selected for resistance to a single drug) is characterized by cross resistance to many drugs, some of which are used in cancer chemotherapy. In the present study we showed that DNA-mediated transformants of mouse LTA cells with DNA from multidrug-resistant hamster cells acquired the multidrug resistance phenotype, that the transformants contained hamster P-glycoprotein DNA sequences, that these sequences were amplified whereas the recipient mouse P-glycoprotein sequences remained at wild-type levels, and that the overexpressed P-glycoprotein in these cells was of hamster origin. Furthermore, we showed that the hamster P-glycoprotein sequences were transfected independently of a group of genes that were originally coamplified and linked within a 1-megabase-pair region in the donor hamster genome. These data indicate that the high expression of P-glycoprotein is the only alteration required to mediate multidrug resistance.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 593 ◽  
Author(s):  
Jaeok Lee ◽  
Song Wha Chae ◽  
LianJi Ma ◽  
So Yeon Lim ◽  
Sarah Alnajjar ◽  
...  

P-glycoprotein (P-gp) is known to be involved in multidrug resistance (MDR) and modulation of pharmacokinetic (PK) profiles of substrate drugs. Here, we studied the effects of synthesized ferulic acid (FA) derivatives on P-gp function in vitro and examined PK alteration of paclitaxel (PTX), a well-known P-gp substrate drug by the derivative. Compound 5c, the FA derivative chosen as a significant P-gp inhibitor among eight FA candidates by in vitro results, increased PTX AUCinf as much as twofold versus the control by reducing PTX elimination in rats. These results suggest that FA derivative can increase PTX bioavailability by inhibiting P-gp existing in eliminating organs.


2020 ◽  
Vol 52 (11) ◽  
pp. 1202-1214
Author(s):  
Lejia Qiu ◽  
Zhaoxia Ma ◽  
Xiaoran Li ◽  
Yizhang Deng ◽  
Guangling Duan ◽  
...  

Abstract Gastric cancer is a common malignancy worldwide. The occurrence of multidrug resistance (MDR) is the major obstacle for effective gastric cancer chemotherapy. In this study, the in-depth molecular mechanism of the DJ-1-induced MDR in SGC7901 gastric cancer cells was investigated. The results showed that DJ-1 expression level was higher in MDR variant SGC7901/VCR cells than that in its parental SGC7901 cells. Moreover, DJ-1 overexpression conferred the MDR phenotype to SGC7901 cells, while DJ-1 knockdown in SGC7901/VCR cells induced re-sensitization to adriamycin, vincristine, cisplatin, and 5-fluorouracil. These results suggested that DJ-1 mediated the development of MDR in SGC7901 gastric cancer cells. Importantly, further data revealed that the activation of PI3k/Akt and Nrf2 signaling pathway were required for the DJ-1-induced MDR phenotype in SGC7901 gastric cancer cells. Meanwhile, we found that PI3k/Akt pathway was activated probably through DJ-1 directly binding to and negatively regulating PTEN, consequently resulting in Nrf2 phosphorylation and activation, and thereby inducing Nrf2-dependent P-glycoprotein (P-gp) and Bcl-2 expressions in the DJ-1-mediated MDR of SGC7901 gastric cancer cells. Overall, these results revealed that activating PTEN/PI3K/Akt/Nrf2 pathway and subsequently upregulating P-gp and Bcl-2 expression could be a critical mechanism by which DJ-1 mediates the development of MDR in SGC7901 gastric cancer cells. The new findings may be helpful for understanding the mechanisms of MDR in gastric cancer cells, prompting its further investigation as a molecular target to overcome MDR.


Blood ◽  
1992 ◽  
Vol 79 (2) ◽  
pp. 473-476 ◽  
Author(s):  
L Campos ◽  
D Guyotat ◽  
E Archimbaud ◽  
P Calmard-Oriol ◽  
T Tsuruo ◽  
...  

Abstract To evaluate the clinical value of the expression of multidrug resistance P-glycoprotein (P-170) on the surface of acute nonlymphoblastic leukemia (ANLL) cells, we analyzed specimens from 150 newly diagnosed patients for staining with MRK16, a monoclonal antibody (MoAb) that binds to an external epitope of P-170. Other surface markers (CD13, CD14, CD15, and CD34) were studied by the same technique. A marker was considered positive when 20% or more cells were stained. Of 150 samples, 71 were P-170-positive. These cases did not differ from P-170-negative cases with regard to age, sex, initial white blood cell (WBC) counts, or French-American-British (FAB) type (except for M3 ANLL, which were more frequently negative). However, leukemias arising from previous myelodysplastic syndrome (MDS) and therapy- induced leukemias were more frequently P-170-positive. CD34 and P-170 expression were significantly associated. All patients were treated by intensive chemotherapy. Complete remission (CR) rates were significantly lower in P-170-positive (23/71, 32%) than in P-170- negative cases (64/79, 81%) (P less than 10(-5)). CD34 positivity was also associated with a low remission rate (P less than 10(-5)). Survival was shorter for P-170- and CD34-positive patients (P less than 10(-5)). The prognostic value of both markers was confirmed in multivariate analysis. CR duration was also shorter for P-170-positive cases, but the difference is less significant (P = .05). It is concluded that P-170 analysis may be an important tool for predicting the outcome of intensive chemotherapy in ANLL patients.


1994 ◽  
Vol 81 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Jurgen Carl Walther Kiwit ◽  
Anja Hertel ◽  
Alexander E. Matuschek

✓ Resistance to multiple drugs is often observed in malignant gliomas. The authors used a microtiter tetrazolium test to analyze primary in vitro chemoresistance and chemosensitivity of 15 early cultures of human malignant glioma exposed to 50 µg/ml (1,4-amino-2-methyl-5-pyrimidinyl)-methyl-3-(2-chloroethyl)-3-nitrosourea (ACNU), 50 µg/ml cisplatin, 1 µg/ml vincristine, or combinations of these chemotherapeutic agents. Primary chemoresistance was observed in 87% of tumors for ACNU, in 87% for cisplatin, and in 83% for vincristine. All tumors were examined for expression of multidrug-resistant p-glycoprotein, a transport protein of 170,000 D, by means of immunohistochemical staining with the JSB-1 antibody on paraffinized tumor sections. Eight of 15 specimens (53%) showed positive staining for the monoclonal antibody. Primary chemoresistance was overcome by addition of the calcium antagonists verapamil or nimodipine to the cultures if the original tumor expressed p-glycoprotein (p < 0.01 for verapamil, p < 0.05 for nimodipine). In tumors not expressing p-glycoprotein, addition of calcium antagonists to the cell cultures did not influence primary chemoresistance. It is concluded from these data that addition of calcium antagonists to the adjuvant chemotherapy of malignant gliomas might overcome primary chemoresistance in tumors expressing the multidrugresistant phenotype.


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