PI3k and Stat3: Oncogenes that are Required for Gap Junctional, Intercellular Communication

Area of Science:

• Cellular biology
• Oncology
• Molecular signaling

Background:

• Gap junctional intercellular communication (GJIC) is crucial for cell-to-cell signaling.
• Oncogenic transformation, particularly by activated Src, disrupts GJIC.
• The role of downstream signaling pathways in regulating GJIC during oncogenesis is complex.

Purpose of the Study:

• To investigate the dual role of oncogenes, specifically activated Src, in regulating GJIC.
• To elucidate the involvement of Ras, PI3k, and Stat3 pathways in Src-mediated GJIC modulation.
• To explore the potential link between GJIC regulation and cell survival pathways.

Main Methods:

• Utilizing oncogene-transformed cells (Src) and non-transformed cells (fibroblasts, epithelial cells, lung carcinoma lines).
• Employing pathway-specific inhibitors for Ras, PI3k, and Stat3.
• Assessing GJIC levels through communication assays.

Main Results:

• Activated Src inhibits GJIC in a Ras-dependent manner.
• Inhibition of PI3k or Stat3 impairs GJIC in non-transformed cells, while their activation enhances it.
• Activated Src exhibits a dual role: inhibiting GJIC via Ras and activating it via PI3k/Stat3, with inhibition dominating.

Conclusions:

• Oncogenic Src differentially regulates GJIC through distinct pathways (Ras vs. PI3k/Stat3).
• The PI3k and Stat3 pathways, linked to cell survival, may activate GJIC.
• Interruption of GJIC by oncogenes might confine apoptosis, preserving tissue integrity.