Related Experiment Video

Updated: Jul 7, 2026

Identification of EGFR and RAS Inhibitors using Caenorhabditis elegans
08:12

Identification of EGFR and RAS Inhibitors using Caenorhabditis elegans

Published on: October 5, 2020

Inhibition of the Ras-Net (Elk-3) pathway by a novel pyrazole that affects microtubules

Christine Wasylyk1, Hong Zheng, Christelle Castell

  • 1Institut de Génétique et de Biologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique/Institut National de la Sante et de la Recherche Medicale/Université Louis Pasteur, Illkirch Cedex, France. boh@igbmc.u-strasbg.fr

Cancer Research
|March 5, 2008
PubMed

Insights

A novel pyrazole, XRP44X, inhibits Ras-Erk signaling and microtubule polymerization, impacting cell growth and potentially offering new cancer treatments.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Pharmacology

Background:

  • Net (Elk-3/SAP-2/Erp) is a transcription factor regulated by Ras-extracellular signal-regulated kinase (Erk) signaling.
  • This pathway is crucial for wound healing, angiogenesis, and tumor development.

Purpose of the Study:

  • To identify small molecules inhibiting Ras activation of Net transcriptional activity.
  • To investigate the mechanism of action and potential therapeutic applications of identified compounds.

Main Methods:

  • A cell-based screen was employed to identify inhibitors of Ras-Net signaling.
  • XRP44X's effects on Net phosphorylation, tubulin binding, cytoskeleton, and cellular processes were analyzed.
  • Comparisons were made with Combretastin-A4, vincristine, docetaxel, and nocodazole.

Main Results:

  • A novel pyrazole, XRP44X, was identified as an inhibitor of Net phosphorylation upstream of Ras.
  • XRP44X binds to tubulin's colchicine site, leading to microtubule depolymerization and altered cell morphology.
  • XRP44X inhibited cell growth, cell cycle progression, and aortal sprouting, similar to other tubulin-binding agents.

Conclusions:

  • XRP44X effectively inhibits key signaling pathways (Ras-Erk) and cytoskeletal dynamics.
  • This compound connects pathways involved in cell transformation, suggesting potential for cancer therapy development.

Related Concept Videos

Drugs that Destabilize Microtubules01:10

Drugs that Destabilize Microtubules

Microtubules are dynamic structures and can be regulated by microtubule targeting agents (MTAs). Microtubule destabilizing drugs are a class of MTAs that destabilize and prevent microtubules' polymerization. Both natural and synthetic chemicals can be found under this class of drugs. Vincristine and vinblastine, two vinca alkaloids, and colchicine were among the first to be discovered. These drugs can affect cells in various ways, either by inducing a change in cell morphology, preventing...
Drugs that Stabilize Microtubules01:15

Drugs that Stabilize Microtubules

Microtubules are dynamic structures that undergo cycles of catastrophe and rescue. The microtubules play a central role in cell division by forming the spindle apparatus for segregating the chromosomes. This makes them ideal targets for regulating dividing cells in tumors and malignant cancer cells. Microtubule stabilizing drugs help stabilize the microtubule formation and promote its polymerization. Paclitaxel was the first microtubule stabilizing agent used as anticancer drug in chemotherapy...
Destabilization of Microtubules01:45

Destabilization of Microtubules

The destabilization of microtubules can occur during different stages of the microtubule lifecycle, such as nucleation or elongation. It can take place at either end of the microtubule or in the microtubule lattices as a whole. The lifespan of individual microtubules within a cell varies according to the cell type and stage of the cell cycle. During interphase, the lifespan of the microtubule is about 30 minutes, while during cell division, it is about 15 minutes. In axonal microtubules of...
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...