In vivo imaging and specific targeting of P-glycoprotein expression in multidrug resistant nude mice xenografts with [125I]MRK-16 monoclonal antibody

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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The Lst Sialyltransferase of Neisseria gonorrhoeae Can Transfer Keto-Deoxyoctanoate as the Terminal Sugar of Lipooligosaccharide: a Glyco-Achilles Heel That Provides a New Strategy for Vaccines to Prevent Gonorrhea

mBio ◽

10.1128/mbio.03666-20 ◽

2021 ◽

Vol 12 (2) ◽

Author(s):

Freda E.-C. Jen ◽

Margaret R. Ketterer ◽

Evgeny A. Semchenko ◽

Christopher J. Day ◽

Kate L. Seib ◽

...

Keyword(s):

Monoclonal Antibody ◽

Neisseria Gonorrhoeae ◽

Phase Variation ◽

Multidrug Resistant ◽

Content Type ◽

Acetylneuraminic Acid ◽

New Strategy ◽

Opsonophagocytic Killing ◽

Further Development

ABSTRACT The lipooligosaccharide (LOS) of Neisseria gonorrhoeae plays key roles in pathogenesis and is composed of multiple possible glycoforms. These glycoforms are generated by the process of phase variation and by differences in the glycosyltransferase gene content of particular strains. LOS glycoforms of N. gonorrhoeae can be terminated with an N-acetylneuraminic acid (Neu5Ac), which imparts resistance to the bactericidal activity of serum. However, N. gonorrhoeae cannot synthesize the CMP-Neu5Ac required for LOS biosynthesis and must acquire it from the host. In contrast, Neisseria meningitidis can synthesize endogenous CMP-Neu5Ac, the donor molecule for Neu5Ac, which is a component of some meningococcal capsule structures. Both species have an almost identical LOS sialyltransferase, Lst, that transfers Neu5Ac from CMP-Neu5Ac to the terminus of LOS. Lst is homologous to the LsgB sialyltransferase of nontypeable Haemophilus influenzae (NTHi). Studies in NTHi have demonstrated that LsgB can transfer keto-deoxyoctanoate (KDO) from CMP-KDO to the terminus of LOS in place of Neu5Ac. Here, we show that Lst can also transfer KDO to LOS in place of Neu5Ac in both N. gonorrhoeae and N. meningitidis. Consistent with access to the pool of CMP-KDO in the cytoplasm, we present data indicating that Lst is localized in the cytoplasm. Lst has previously been reported to be localized on the outer membrane. We also demonstrate that KDO is expressed as a terminal LOS structure in vivo in samples from infected women and further show that the anti-KDO monoclonal antibody 6E4 can mediate opsonophagocytic killing of N. gonorrhoeae. Taken together, these studies indicate that KDO expressed on gonococcal LOS represents a new antigen for the development of vaccines against gonorrhea. IMPORTANCE The emergence of multidrug-resistant N. gonorrhoeae strains that are resistant to available antimicrobials is a current health emergency, and no vaccine is available to prevent gonococcal infection. Lipooligosaccharide (LOS) is one of the major virulence factors of N. gonorrhoeae. The sialic acid N-acetylneuraminic acid (Neu5Ac) is present as the terminal glycan on LOS in N. gonorrhoeae. In this study, we made an unexpected discovery that KDO can be incorporated as the terminal glycan on LOS of N. gonorrhoeae by the alpha-2,3-sialyltransferase Lst. We showed that N. gonorrhoeae express KDO on LOS in vivo and that the KDO-specific monoclonal antibody 6E4 can direct opsonophagocytic killing of N. gonorrhoeae. These data support further development of KDO-LOS structures as vaccine antigens for the prevention of infection by N. gonorrhoeae.

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99mTc-Sestamibi, A Sensitive Probe for In Vivo Imaging of P-Glycoprotein Inhibition by Modulators and mdr1 Antisense Oligodeoxynucleotides

Molecular Imaging and Biology ◽

10.1007/s11307-006-0057-0 ◽

2006 ◽

Vol 8 (6) ◽

pp. 333-339 ◽

Cited By ~ 6

Author(s):

Veronika Jekerle ◽

Jing-Hung Wang ◽

Deborah A. Scollard ◽

Raymond M. Reilly ◽

Michael Wiese ◽

...

Keyword(s):

In Vivo Imaging ◽

Antisense Oligodeoxynucleotides ◽

P Glycoprotein ◽

Glycoprotein Inhibition ◽

99Mtc Sestamibi

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24 Specific targeting of uPA activity with a monoclonal antibody neutralizeS uPA-dependent effects in vivo

Apmis ◽

10.1111/j.1600-0463.2008.00abs1165_34.x ◽

2008 ◽

Vol 116 (5) ◽

pp. 428-428

Author(s):

Ida K. Lund ◽

Annika Jögi ◽

Birgitte Rønø ◽

Morten G. Rasch ◽

Leif R. Lund ◽

...

Keyword(s):

Monoclonal Antibody ◽

Specific Targeting

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A New Strategy for Glioblastoma Treatment: In Vitro and In Vivo Preclinical Characterization of Si306, a Pyrazolo[3,4-d]Pyrimidine Dual Src/P-Glycoprotein Inhibitor

Cancers ◽

10.3390/cancers11060848 ◽

2019 ◽

Vol 11 (6) ◽

pp. 848 ◽

Cited By ~ 10

Author(s):

Anna Lucia Fallacara ◽

Claudio Zamperini ◽

Ana Podolski-Renić ◽

Jelena Dinić ◽

Tijana Stanković ◽

...

Keyword(s):

Kinase Inhibitors ◽

Multidrug Resistant ◽

Cellular Level ◽

Cns Tumors ◽

Significant Activity ◽

Src Tyrosine Kinase ◽

P Glycoprotein ◽

New Strategy

Overexpression of P-glycoprotein (P-gp) and other ATP-binding cassette (ABC) transporters in multidrug resistant (MDR) cancer cells is responsible for the reduction of intracellular drug accumulation, thus decreasing the efficacy of chemotherapeutics. P-gp is also found at endothelial cells’ membrane of the blood-brain barrier, where it limits drug delivery to central nervous system (CNS) tumors. We have previously developed a set of pyrazolo[3,4-d]pyrimidines and their prodrugs as novel Src tyrosine kinase inhibitors (TKIs), showing a significant activity against CNS tumors in in vivo. Here we investigated the interaction of the most promising pair of drug/prodrug with P-gp at the cellular level. The tested compounds were found to increase the intracellular accumulation of Rho 123, and to enhance the efficacy of paclitaxel in P-gp overexpressing cells. Encouraging pharmacokinetics properties and tolerability in vivo were also observed. Our findings revealed a novel role of pyrazolo[3,4-d]pyrimidines which may be useful for developing a new effective therapy in MDR cancer treatment, particularly against glioblastoma.

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Hybridoma producing monoclonal antibody F4 which specifically binds to multidrug resistant P-glycoprotein and assays for detection of P-glycoprotein

Enzyme and Microbial Technology ◽

10.1016/s0141-0229(97)89238-1 ◽

1997 ◽

Vol 21 (1) ◽

pp. 72

Keyword(s):

Monoclonal Antibody ◽

Multidrug Resistant ◽

P Glycoprotein

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Assessment of the in vitro and in vivo properties of a 99mTc-labeled inhibitor of the multidrug resistant gene product P-glycoprotein

Nuclear Medicine and Biology ◽

10.1016/s0969-8051(99)00107-9 ◽

2000 ◽

Vol 27 (2) ◽

pp. 135-141 ◽

Cited By ~ 8

Author(s):

R Bergmann ◽

P Brust ◽

M Scheunemann ◽

H.-J Pietzsch ◽

S Seifert ◽

...

Keyword(s):

Gene Product ◽

Multidrug Resistant ◽

Resistant Gene ◽

P Glycoprotein

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Baicalin-induced Cytotoxicity and Apoptosis in Multidrug-resistant MC3/5FU Mucoepidermoid Carcinoma Cell Line

Letters in Drug Design & Discovery ◽

10.2174/157018081210151012121717 ◽

2019 ◽

Vol 16 (12) ◽

pp. 1339-1347 ◽

Cited By ~ 1

Author(s):

Xiaofang Xu ◽

Qihong Li ◽

Kaitao Yu ◽

Ghulam Murtaza ◽

Bin Liu

Keyword(s):

Flow Cytometry ◽

Multidrug Resistance ◽

Nude Mice ◽

Multidrug Resistant ◽

Clinical Findings ◽

Hoechst 33342 ◽

Protein Levels ◽

Transmission Electron

Background: Multidrug Resistance (MDR) is a serious hindrance to cancer chemotherapy and profoundly influences the clinical findings. Many Traditional Chinese Medicines (TCM) have been tested with the aim of developing effective resistance modulators or anticancer drugs to overcome the MDR of human cancers. Methods: The anticancer effect of baicalin on multidrug-resistant MC3/5FU (5-fluorouracil) cells was investigated by MTT test and xenografts in nude mice. Cell apoptosis was studied by transmission electron microscopy, Hoechst-33342 staining, DNA fragmentation detection, and flow cytometry. RT-PCR and Rhodamine 123 efflux assay was also used to detect its effect on ABC drug transporter proteins, ABCB1 (P-glycoprotein, P-gp) and ABCC1 (multidrug resistance protein 1, MRP1). Results: The results indicate that there was no significant effect of baicalin on ABC transporters expression or efflux function, although it induced potent growth inhibition in MC3/5FU cells. Flow cytometry, Hoechst 33342 staining and transmission electron microscope revealed that baicalin caused MC3/5FU cell death through the induction of apoptosis. It is demonstrated that baicalininduced apoptosis could be mediated by up-regulation of Bax and caspase-3 protein levels and downregulation of Bcl-2 protein levels. In addition, daily intraperitoneal injection of baicalin (100 and 200 mg/kg) for 2 weeks significantly inhibited the growth of MC3/5FU cells xenografts in nude mice. Conclusion: Our results suggest that baicalin possesses considerable cytotoxic activity in multidrug resistance MC3/5FU cells in vitro and in vivo.

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