Related Experiment Video

Updated: May 17, 2026

Detection of Toxin Translocation into the Host Cytosol by Surface Plasmon Resonance
10:41

Detection of Toxin Translocation into the Host Cytosol by Surface Plasmon Resonance

Published on: January 3, 2012

Saponins modulate the intracellular trafficking of protein toxins

Alexander Weng1, Mayank Thakur, Benedicta von Mallinckrodt

  • 1Institut für Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charité - Universitätsmedizin Berlin, Germany. alexander.weng@charite.de

Journal of Controlled Release : Official Journal of the Controlled Release Society
|October 16, 2012
PubMed

Insights

Certain saponins from Saponaria officinalis L. enhance the cytosolic delivery of saporin, a toxin used in anti-tumor therapies. This saponin-mediated release from late endosomes and lysosomes improves toxin efficacy against cancer cells.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Pharmacology

Background:

  • Type I ribosome-inactivating proteins like saporin are crucial toxin components in targeted anti-tumor therapies.
  • Efficient delivery of these toxins into the tumor cell cytosol is essential for their cytotoxic effect but remains a significant challenge.
  • The plant Saponaria officinalis L. biosynthesizes both saporin and saponins, suggesting a potential biological interaction.

Purpose of the Study:

  • To investigate the role of saponins from Saponaria officinalis L. in mediating the cytosolic release of saporin.
  • To identify the specific intracellular compartments involved in saponin-mediated saporin release.
  • To explore the potential application of saponins in enhancing the efficacy of saporin-based anti-tumor toxins.

Main Methods:

  • Utilized saporin and characterized saponins in cell culture and in vivo tumor models.
  • Investigated intracellular trafficking and release mechanisms using microscopy and biochemical assays.
  • Analyzed the pH-dependency of saponin-saporin interactions and their effect on endosomal/lysosomal compartments.
  • Assessed the efficacy of the combined treatment in a syngeneic tumor model.

Main Results:

  • Demonstrated that specific saponins facilitate the release of saporin from late endosomes and lysosomes into the cytosol.
  • Showed that this release occurs without compromising plasma membrane integrity.
  • Identified endosomal acidification as a critical requirement for saponin-mediated saporin release.
  • Confirmed a pH-dependent association between saponins and saporin.
  • Validated the in vivo applicability of this strategy in a syngeneic tumor model.

Conclusions:

  • Saponins from Saponaria officinalis L. can effectively enhance the cytosolic delivery of saporin, a key toxin in targeted cancer therapy.
  • The mechanism involves pH-dependent release from late endosomes and lysosomes, improving therapeutic payload delivery.
  • This finding presents a promising strategy for optimizing the efficacy of saporin-based anti-tumor agents.

More Related Videos

Live Imaging Assay for Assessing the Roles of Ca2+ and Sphingomyelinase in the Repair of Pore-forming Toxin Wounds18:25

Live Imaging Assay for Assessing the Roles of Ca2+ and Sphingomyelinase in the Repair of Pore-forming Toxin Wounds

Published on: August 25, 2013

Analysis of Endocytic Uptake and Retrograde Transport to the Trans-Golgi Network Using Functionalized Nanobodies in Cultured Cells11:05

Analysis of Endocytic Uptake and Retrograde Transport to the Trans-Golgi Network Using Functionalized Nanobodies in Cultured Cells

Published on: February 21, 2019

Related Concept Videos

Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
Bacterial Toxins01:12

Bacterial Toxins

Bacterial toxins are sophisticated virulence factors that enable pathogenic bacteria to interact with, invade, and damage host tissues. These toxins fall broadly into two types: protein exotoxins, which are secreted into the environment and target specific host receptors, and lipopolysaccharide endotoxins, which are structural components of the bacterial outer membrane released primarily during bacterial lysis or membrane shedding. Exotoxins generally act more selectively, binding to cell...
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters01:16

Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters

The pharmacogenetics of drug transporters is increasingly recognized as a critical factor influencing interindividual variability in drug absorption, distribution, and elimination. These membrane-bound proteins regulate drugs' movement across cellular barriers by actively pumping them out (efflux) or facilitating their uptake (influx). Among the major transporter families, ATP-binding cassette (ABC) and solute carrier (SLC) transporters play particularly prominent roles. Genetic polymorphisms...
Fusion of Secretory Vesicles with the Plasma Membrane01:26

Fusion of Secretory Vesicles with the Plasma Membrane

Proteins and neurotransmitters in secretory vesicles can be released from a cell upon vesicle docking, priming, and fusion with the plasma membrane. Vesicles are docked and primed in preparation for the quick exocytosis of their contents in response to a stimulus. The fusion process is mainly carried out by a SNAP Receptor or SNARE complex, consisting of synaptobrevin, syntaxin-1, and SNAP-25.
In 1993, Jim Rothman proposed that the antiparallel pairing of vesicular and transmembrane SNAREs, or...
Overview of Secretory Vesicles01:33

Overview of Secretory Vesicles

Secretory vesicles, also known as dense core vesicles (DCVs), are membrane-bound vesicles that transport secretory proteins, such as hormones or neurotransmitters. Regulated secretory vesicles transport proteins from the trans-Golgi network to the exterior of the cell. Proteins present in regulated secretory vesicles are required to be rapidly exocytosed in large amounts upon a specific stimulus.
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Introduction to Membrane Traffic01:44

Introduction to Membrane Traffic

The ER, Golgi apparatus, endosomes, and lysosomes work in tandem to modify, sort, and package proteins and lipids. An integrated membrane trafficking network facilitates the back and forth shuttling of molecules within different organelles in the same cell or across the cell membrane.
The transport of soluble and membrane proteins is mediated by transport vesicles that collect cargo from one cellular compartment and deliver it to another by fusing with the target organelle membrane. The Rab...