Cancer mutations and targeted drugs can disrupt dynamic signal encoding by the Ras-Erk pathway.

Area of Science:

• Cellular signaling
• Molecular biology
• Cancer research

Background:

• The Ras-Erk pathway transmits signals from the cell surface to the nucleus.
• Signal dynamics, including duration and frequency of Erk activity, are crucial for determining cell fates.
• Accurate temporal information transmission is essential for proper cellular decision-making.

Purpose of the Study:

• To investigate how oncogenic B-Raf mutations and B-Raf inhibitors affect the dynamic transmission of Ras-Erk signaling.
• To understand how disruptions in signal transmission can lead to altered cell proliferation and fate decisions.
• To demonstrate the utility of optogenetic profiling in dissecting signaling pathway dysfunction.

Main Methods:

• Utilized optogenetic profiling to precisely control and measure Ras-Erk pathway activity.
• Applied short pulses of input Ras activity to assess temporal information transmission.
• Analyzed downstream transcriptional changes and cell fate outcomes.

Main Results:

• Both oncogenic B-Raf mutations and B-Raf inhibitors distorted the temporal transmission of Ras activity.
• Short input pulses were converted into abnormally prolonged Erk activity outputs.
• These dynamic signaling alterations promoted aberrant cell proliferation and altered cell fates.

Conclusions:

• Dysfunctional dynamic signal transmission, not solely constitutive signaling, can drive cell proliferation and contribute to cancer.
• Optogenetic profiling is a powerful tool for dissecting the mechanisms of signaling dysfunction in disease.
• Understanding signal dynamics is critical for comprehending cell fate determination and disease pathogenesis.