Detection of P-glycoprotein in ovarian cancer: a molecular marker associated with multidrug resistance.

1985 ◽  
Vol 3 (3) ◽  
pp. 311-315 ◽  
Author(s):  
D R Bell ◽  
J H Gerlach ◽  
N Kartner ◽  
R N Buick ◽  
V Ling

A multidrug resistance phenotype is frequently observed in animal and human cell lines selected for in vitro resistance to a single chemotherapeutic agent. Overexpression of a highly conserved cell-surface glycoprotein (P-glycoprotein) is consistently associated with this phenotype in these mutant lines. A monoclonal antibody against P-glycoprotein was used to examine tumor samples from five patients with advanced ovarian cancer for evidence of P-glycoprotein overexpression. High levels of P-glycoprotein were detected in samples from two patients suggesting that a multidrug resistance mutation may also occur in ovarian cancer. This finding has broad implications for the understanding of nonresponse to chemotherapy in a variety of human neoplasms, and may provide a rational explanation for failure of chemotherapy in treatment of advanced ovarian cancer.

1987 ◽  
Vol 5 (9) ◽  
pp. 1452-1460 ◽  
Author(s):  
J H Gerlach ◽  
D R Bell ◽  
C Karakousis ◽  
H K Slocum ◽  
N Kartner ◽  
...  

Overexpression of an immunologically conserved, cell-surface glycoprotein (P-glycoprotein) is consistently associated with multidrug resistance in cell lines in vitro. A preliminary survey of specimens from 12 solid tumor types in our laboratories indicates significant overexpression of P-glycoprotein in some sarcomas. When tested by immunoblotting with monoclonal antibodies directed against P-glycoprotein; tumors from six of 25 sarcoma patients displayed elevated levels of P-glycoprotein. Three of the sarcoma patients exhibiting P-glycoprotein had not previously been exposed to chemotherapy, implying that overexpression of this marker and possible concomitant multidrug resistance may not depend only on selection during prior drug treatments. The P-glycoprotein overexpression in the sarcoma specimens is evidence for the presence of multidrug resistant cells in these tumors; thus, our data suggest that this mode of resistance may have clinical significance in sarcoma patients.


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

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.


Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 303 ◽  
Author(s):  
Jitka Viktorová ◽  
Simona Dobiasová ◽  
Kateřina Řehořová ◽  
David Biedermann ◽  
Kristýna Káňová ◽  
...  

Silychristin A is the second most abundant compound of silymarin. Silymarin complex was previously described as an antioxidant with multidrug resistance modulation activity. Here, the results of a classical biochemical antioxidant assay (ORAC) were compared with a cellular assay evaluating the antioxidant capacity of pure silychristin A and its derivatives (anhydrosilychristin, isosilychristin and 2,3-dehydrosilychristin A). All the tested compounds acted as antioxidants within the cells, but 2,3-dehydro- and anhydro derivatives were almost twice as potent as the other tested compounds. Similar results were obtained in LPS-stimulated macrophages, where 2,3-dehydro- and anhydrosilychristin inhibited NO production nearly twice as efficiently as silychristin A. The inhibition of P-glycoprotein (P-gp) was determined in vitro, and the respective sensitization of doxorubicin-resistant ovarian carcinoma overproducing P-gp was detected. Despite the fact that the inhibition of P-gp was demonstrated in a concentration-dependent manner for each tested compound, the sensitization of the resistant cell line was observed predominantly for silychristin A and 2,3-dehydrosilychristin A. However, anhydrosilychristin and isosilychristin affected the expression of both the P-gp (ABCB1) and ABCG2 genes. This is the first report showing that silychristin A and its 2,3-dehydro-derivative modulate multidrug resistance by the direct inhibition of P-gp, in contrast to anhydrosilychristin and isosilychristin modulating multidrug resistance by downregulating the expression of the dominant transmembrane efflux pumps.


2020 ◽  
Vol 17 (10) ◽  
pp. 1270-1282
Author(s):  
Ximeng Shi ◽  
Yuyu Zhao ◽  
Licheng Zhou ◽  
Huanhuan Yin ◽  
Jianwen Liu ◽  
...  

Background: P-glycoprotein (P-gp) has been regarded as an important factor in the multidrug resistance (MDR) of tumor cells within the last decade, which can be solved by inhibiting Pgp to reverse MDR. Thus, it is an effective strategy to develop inhibitor of P-gp. Objective: In this study, the synthesis of a series of derivatives had been carried out by bioisosterism design on the basis of Dimethyl Cardamonin (DMC). Subsequently, we evaluated their reversal activities as potential P-glycoprotein (P-gp)-mediated Multidrug Resistance (MDR) agents. Methods: Dimethyl cardamonin derivatives were synthesized from acetophenones and the corresponding benzaldehydes in the presence of 40% KOH by Claisen-Schmidt reaction. Their cytotoxicity and reversal activities in vitro were assessed with MTT. Moreover, the compound B4 was evaluated by Doxorubicin (DOX) accumulation, Western blot and wound-healing assays deeply. Results and Conclusion: The results showed that compounds B2, B4 and B6 had the potency of MDR reversers with little intrinsic cytotoxicity. Meanwhile, these compounds also demonstrated the capability to inhibit MCF-7 and MCF-7/DOX cells migration. Besides, the most compound B4 was selected for further study, which promoted the accumulation of DOX in MCF-7/DOX cells and inhibited the expressionof P-gp at protein levels. Conclusion: The above findings may provide new insights for the research and development of Pgp- mediated MDR reversal agents.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Qing Xia ◽  
Zhi-Yong Wang ◽  
Hui-Qing Li ◽  
Yu-Tao Diao ◽  
Xiao-Li Li ◽  
...  

Multidrug resistance (MDR) is the major obstacle in chemotherapy, which involves multiple signaling pathways. Diallyl trisulfide (DATS) is the main sulfuric compound in garlic. In the present study, we aimed to explore whether DATS could overcome P-glycoprotein-(P-gp-)mediated MDR in K562/A02 cells, and to investigate whether NF-κB suppression is involved in DATS-induced reversal of MDR. MTT assay revealed that cotreatment with DATS increased the response of K562/A02 cells to adriamycin (the resistance reversal fold was 3.79) without toxic side effects. DATS could enhance the intracellular concentration of adriamycin by inhibiting the function and expression of P-gp, as shown by flow cytometry, RT-PCR, and western blot. In addition, DATS resulted in more K562/A02 cell apoptosis, accompanied by increased expression of caspase-3. The expression of NF-κB/p65 (downregulation) was significantly linked to the drug-resistance mechanism of DATS, whereas the expression of IκBαwas not affected by DATS. Our findings demonstrated that DATS can serve as a novel, nontoxic modulator of MDR, and can reverse the MDR of K562/A02 cells in vitro by increasing intracellular adriamycin concentration and inducing apoptosis. More importantly, we proved for the first time that the suppression of NF-κB possibly involves the molecular mechanism in the course of reversion by DATS.


2019 ◽  
Vol 11 (16) ◽  
pp. 2095-2106 ◽  
Author(s):  
Alexander A Titov ◽  
Mauro Niso ◽  
Modesto de Candia ◽  
Maxim S Kobzev ◽  
Alexey V Varlamov ◽  
...  

Aim: Enamino 3-benzazecine compounds, incorporating the C6-C8 allene system, were synthesized and evaluated in vitro as inhibitors of P-glycoprotein (P-gp) and/or multidrug resistance-associated protein 1 (MRP1), two efflux pumps mainly connected with multidrug resistance (MDR) in cancer cells. Results & methodology: Most of the synthesized compounds were selective P-gp inhibitors in Calcein-AM uptake assay. Structure–activity relationships (SARs) pointed out that CO2Me derivatives are more potent than acetyl derivatives, and 10,11-dimethoxy compounds are five to tenfold more potent inhibitors than the respective unsubstituted compounds, and that the P-gp inhibition potency is mainly related to volume parameters. Conclusion: Nanomolar P-gp inhibitors, such as 23 (IC50 = 4.2 nM), restored the antiproliferative activity of doxorubicin in multidrug-resistant cells. The observed activities showed that 3-benzazecine-based compounds may be promising MDR reversers.


2017 ◽  
Vol 95 (5) ◽  
pp. 580-585 ◽  
Author(s):  
Yuzhu Wang ◽  
Jian Cui ◽  
Yuxuan Dai ◽  
Yuxiang Wu ◽  
Wenlong Huang ◽  
...  

Multidrug resistance (MDR) is one of the major obstacles confronted in cancer chemotherapy; this obstacle is mainly due to the overexpression of P-glycoprotein (P-gp). Co-administration of anticancer drugs and P-gp inhibitors is a promising approach to overcome MDR. WYX-5, a novel P-gp inhibitor, shows a notable reversal effect with low cytotoxicity in vitro. In this paper, the reversal mechanism and safety of the MDR modulator WYX-5 were explored in vitro, and evaluated for its pharmacokinetics and effects on adriamycin (ADM) metabolism in vivo. The results suggest that WYX-5 is a potent P-gp inhibitor with EC50 in nanomole range (EC50 = 204.3 ± 20.2 nmol·L−1), relative safety (therapeutic index = 446.4), which performs as a substrate of P-gp and retrains its function. Further, WYX-5 (5 mg·kg−1) had relatively ideal pharmacokinetic properties (T1/2 = 6.448 h, F = 96.05%) without interactions with ADM metabolism in vivo. In conclusion, WYX-5 may be a promising candidate for MDR cancer combined-chemotherapy research.


2012 ◽  
Vol 32 (6) ◽  
pp. 559-566 ◽  
Author(s):  
Yan Xu ◽  
Feng Zhi ◽  
Guangming Xu ◽  
Xiaolei Tang ◽  
Sheng Lu ◽  
...  

MDR (multidrug-resistance) represents a major obstacle to successful cancer chemotherapy and is usually accomplished by overexpression of P-gp (P-glycoprotein). Much effort has been devoted to developing P-gp inhibitors to modulate MDR. However, none of the inhibitors on the market have been successful. 1416 [1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (phenoprolamine hydrochloride)] is a new VER (verapamil) analogue with a higher IC50 for blocking calcium channel currents than VER. In the present paper, we examined the inhibition effect of 1416 on P-gp both in vitro and in vivo. 1416 significantly enhanced cytotoxicity of VBL (vinblastine) in P-gp-overexpressed human multidrug-resistant K562/ADM (adriamycin) and KBV cells, but had no such effect on the parent K562 and KB cells. The MDR-modulating function of 1416 was further confirmed by increasing intracellular Rh123 (rhodanmine123) content in MDR cells. Human K562/ADM xenograft-nude mice model verified that 1416 potentiates the antitumour activity of VBL in vivo. RT-PCR (reverse transcriptase-PCR) and FACS analysis demonstrated that the expression of MDR1/P-gp was not affected by 1416 treatment. All these observations suggest that 1416 could be a promising agent for overcoming MDR in cancer chemotherapy.


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