MET expression during prostate cancer progression.

Area of Science:

• Oncology
• Molecular Biology
• Cancer Research

Background:

• Hepatocyte growth factor receptor MET inhibitors are explored for hormone-refractory prostate cancer (HRPC) metastasis treatment.
• Analyzing MET expression and genetic alterations can aid in stratifying prostate cancer patients for therapy.

Purpose of the Study:

• To investigate MET expression and alterations at protein, DNA, and RNA levels across various stages of prostate cancer progression.

Main Methods:

• Immunohistochemistry for MET protein expression.
• In situ hybridization for MET mRNA levels and DNA copy numbers.
• Analysis in hormone-naive primary prostate cancers, lymph node metastases, HRPC, and bone metastases.

Main Results:

• MET expression was absent in hormone-naive primary prostate cancer and lymph node metastases.
• MET protein and mRNA were detected in 23% and 26% of HRPC resections, respectively, without MET amplification.
• MET protein expression was high in bone metastases (88% hormone-naive, 67% HRPC), with MET polysomy in 61% of evaluable cases.

Conclusions:

• MET is predominantly expressed in HRPC and prostate cancer bone metastases.
• MET expression in late-stage prostate cancer is not linked to MET amplification or polysomy.
• Assessing MET status is crucial for therapeutic stratification in advanced prostate cancer.