Targeting mTOR dependency in pancreatic cancer

Area of Science:

• Oncology
• Molecular Biology
• Cancer Genetics

Background:

• Pancreatic cancer is a major cause of cancer mortality with limited treatment options.
• Activating KRAS mutations drive pancreatic tumor initiation, while other pathway dysregulations promote progression.
• PTEN loss accelerates Kras(G12D)-driven pancreatic ductal adenocarcinoma (PDAC) in mice, correlating with high mTOR signaling.

Purpose of the Study:

• To investigate the dependence of KRAS PTEN-driven pancreatic tumors on mTOR signaling.
• To compare the response to mTOR inhibition in KRAS PTEN tumors versus KRAS P53 tumors.
• To identify potential patient subsets responsive to mTOR inhibition in human PDAC.

Main Methods:

• Utilized a murine model of Kras(G12D)/PTEN-null pancreatic ductal adenocarcinoma (PDAC).
• Administered mTOR inhibitors to assess tumor response, including proliferative arrest and regression.
• Compared responses between KRAS PTEN and KRAS P53 mouse models.
• Analyzed gene expression and PTEN status in human PDAC samples.

Main Results:

• KRAS PTEN pancreatic tumors demonstrated significant dependence on mTOR signaling.
• mTOR inhibition resulted in proliferative arrest and tumor regression in these models.
• KRAS P53 pancreatic tumors did not respond to mTOR inhibition.
• Approximately 20% of human PDAC cases showed low PTEN expression and gene signatures similar to murine KRAS PTEN tumors.

Conclusions:

• Pancreatic tumors with KRAS and PTEN alterations are uniquely sensitive to mTOR inhibition.
• Targeted anti-mTOR therapies show potential clinical benefit for specific human PDAC subsets.
• Genomic profiling of human tumors can guide personalized treatment strategies for pancreatic cancer.