PI3K and mTOR signaling pathways in cancer: new data on targeted therapies

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Deregulation of phosphoinositide 3-kinase (PI3K) and mammalian target of rapamycin (mTOR) signaling pathways is common in cancer, promoting tumor growth and survival.
• mTOR functions in two complexes, mTORC1 and mTORC2, with distinct structures and substrate specificities. Constitutive mTORC1 activation mechanisms are not fully understood.
• Complex crosstalk exists between PI3K and mTOR pathways, involving shared substrates, feedback loops, and direct activation.

Purpose of the Study:

• To review recent advancements in second-generation mTOR inhibitors.
• To evaluate the anti-cancer potential of novel inhibitors targeting both mTORC1 and mTORC2.
• To explore inhibitors that also target class IA PI3K.

Main Methods:

• Review of recent scientific literature and preclinical data.
• Analysis of novel catalytic mTOR inhibitors.
• Evaluation of inhibitor activity against cancer cells.

Main Results:

• First-generation mTOR inhibitors (e.g., rapamycin) primarily target mTORC1 and exhibit cytostatic effects.
• Second-generation mTOR inhibitors target both mTORC1 and mTORC2.
• Some new inhibitors demonstrate dual activity against mTOR and class IA PI3K, showing potential in cancer models.

Conclusions:

• Second-generation mTOR inhibitors targeting both mTORC1 and mTORC2 represent a promising therapeutic strategy in oncology.
• Dual PI3K/mTOR inhibitors may offer enhanced anti-tumor efficacy.
• Further investigation into these novel inhibitors is warranted for their clinical application in cancer treatment.