Anti-invasive activities of experimental chemotherapeutic agents
1Department of Radiotherapy and Nuclear Medicine, University Hospital, Ghent, Belgium.
Abstract:
We have discussed a number of agents that affect invasion and we have grouped them according to their most probable targets. This strategy is based on the following hypothesis. Invasion is the result of cellular responses to extracellular signals. Candidate signals are components of the extracellular matrix, which are rendered inactive by the flavonoid (+)-catechin (see Section III). Signals are recognized by receptors on the plasma membrane, possibly glycoproteins, that may lose their recognition function through alteration of the oligosaccharide side chains by inhibitors of protein glycosylation (see Section IV) and possibly also by alkyllysophospholipids (see Section V). Synthetic oligopeptides reflecting sequences from cell-binding domains of extracellular matrix molecules are also effective tools for blocking specific receptors (see Section VI). GTP-binding proteins (G proteins) act as signal transducers and can be inactivated by pertussis toxin (see Section VII). An intriguing aspect of both alkyllysophospholipids and pertussis toxin is that they can either inhibit the invasion of constitutively invasive cells or induce invasion of constitutively noninvasive cells. Without doubt, cellular responses implicated in invasion are many-fold. Discussed here are cell motility and directional migration with inhibition through dipyridamole and its analogs and through microtubule inhibitors, respectively (see Section VIII). Alternative hypotheses and alternative strategies for the dissection of the invasion process do exist, and alternative cellular and molecular mechanisms of action may explain the anti-invasive activity of the agents discussed earlier. The latter are mentioned in each section. It is the authors' opinion that the possibilities for exploiting the battery of anti-invasive agents have by no means been exhausted. Introducing researchers to experiments that may lead to an understanding of the mechanisms of invasion and metastasis and to new rationales for cancer treatment has been the purpose of our review.
Insights
Researchers explored agents targeting cellular responses to extracellular signals to inhibit invasion. Agents like (+)-catechin, glycosylation inhibitors, and pertussis toxin show potential in understanding and treating cancer metastasis.
Area of Science:
- Biochemistry
- Cell Biology
- Pharmacology
Background:
- Cellular invasion is a critical process in cancer metastasis.
- Extracellular signals and cellular responses mediate invasion.
- Understanding these mechanisms is key for developing anti-cancer therapies.
Purpose of the Study:
- To review agents that inhibit cellular invasion by targeting specific molecular pathways.
- To explore the hypothesis that invasion results from cellular responses to extracellular signals.
- To provide a basis for new anti-cancer treatment strategies.
Main Methods:
- Categorization of anti-invasion agents based on their molecular targets.
- Discussion of flavonoids, protein glycosylation inhibitors, and oligopeptides.
- Analysis of signal transduction inhibitors like pertussis toxin and their effects on cell invasion.
Main Results:
- (+)-Catechin inactivates extracellular matrix components.
- Inhibitors of protein glycosylation and alkyllysophospholipids alter receptor function.
- Pertussis toxin and alkyllysophospholipids can modulate invasion in different cell types.
- Dipyridamole analogs and microtubule inhibitors affect cell motility and migration.
Conclusions:
- Multiple agents targeting various steps of the invasion process have been identified.
- The anti-invasive potential of these agents offers promising avenues for cancer treatment.
- Further research is warranted to fully exploit these agents for therapeutic development.
