Related Experiment Video
Updated: Feb 9, 2026
06:34
A Tailored HPLC Purification Protocol That Yields High-purity Amyloid Beta 42 and Amyloid Beta 40 Peptides, Capable of Oligomer Formation
Published on: March 27, 2017
12.5K
Amyloid-beta Interactions with ABC Transporters and Resistance Modifiers
Joseph Molnar1, Imre Ocsovszki2, Rozalia Pusztai3
1Department of Medical Microbiology and Immunobiology, University of Szeged, Szeged, Hungary molnar.jozsef@med.u-szeged.hu.
Anticancer Research
|June 1, 2018
Summary
Amyloid-beta complexes with ABC transporter inhibitors reduced multidrug resistance in tumor cells by inhibiting efflux pumps. This suggests a potential link between reduced membrane transport and lower cancer incidence in Alzheimer's disease.
Area of Science:
- Biochemistry
- Oncology
- Neuroscience
Background:
- Multidrug resistance (MDR) in cancer is mediated by ATP-binding cassette (ABC) transporters, hindering chemotherapy efficacy.
- Similar ABC transporters are involved in clearing amyloid deposits in Alzheimer's disease (AD).
Purpose of the Study:
- To investigate the effects of amyloid-beta complexes with ABC transporter inhibitors on MDR tumor cells.
- To assess the potential of these complexes in reversing multidrug resistance and inducing apoptosis.
Main Methods:
- Rhodamine-123 accumulation was used to measure efflux pump activity in treated MDR cells.
- Annexin-V and propidium iodide staining assessed apoptosis induction.
- Flow cytometry (PARTEC FACScan) analyzed cellular fluorescence.
Main Results:
- Disiloxanes and memantine complexed with amyloid-beta 1-42 decreased ABC transporter activity in MDR tumor cells.
- Amyloid-beta complexes moderately increased early apoptosis.
- No significant changes were observed in late apoptosis or total viable cell count.
Conclusions:
- Amyloid-beta and its complexes inactivate tumor cell efflux pumps, leading to amyloid accumulation.
- Reduced membrane transport activity may contribute to the observed lower cancer incidence in Alzheimer's disease patients.
Related Concept Videos
01:31ABC Transporters: Exporter
6.7K
ATP-binding cassette or ABC transporter is the largest superfamily of integral membrane proteins. The transporters have transmembrane-binding domains (TMDs) and nucleotide-binding domains (NBDs). The TMDs are specific to their substrates, whereas the NBDs are similar to engines that complete ATP hydrolysis to complete the substrate transport. They can be full transporters consisting of two TMDs and NBDs, half transporters with one TMD and NBD, while some encoded with a single TMD or NBD are...
6.7K
01:27ABC Transporters: Importer
3.5K
ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants.
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types:
3.5K
03:03Amyloid Fibrils
12.0K
Amyloid fibrils are aggregates of misfolded proteins. Under most circumstances, misfolded proteins are either refolded by chaperone proteins or degraded by the proteasome. However, in the case of a mutation or a disease, these proteins can accumulate to form large clusters and often further assemble to form elongated fibers, called fibrils.
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
12.0K
03:03Amyloid Fibrils
6.5K
6.5K
01:19Facilitated Transport
149.7K
The chemical and physical properties of plasma membranes cause them to be selectively permeable. Since plasma membranes have both hydrophobic and hydrophilic regions, substances need to be able to transverse both regions. The hydrophobic area of membranes repels substances such as charged ions. Therefore, such substances need special membrane proteins to cross a membrane successfully. In facilitated transport, also known as facilitated diffusion, molecules and ions travel across a...
149.7K
01:47Primary Active Transport
199.9K
In contrast to passive transport, active transport involves a substance being moved through membranes in a direction against its concentration or electrochemical gradient. There are two types of active transport: primary active transport and secondary active transport. Primary active transport utilizes chemical energy from ATP to drive protein pumps that are embedded in the cell membrane. With energy from ATP, the pumps transport ions against their electrochemical gradients—a direction...
199.9K