A simple biological imaging system for detecting viable human circulating tumor cells.

Area of Science:

• Oncology
• Virology
• Biotechnology

Background:

• Circulating tumor cells (CTCs) in peripheral blood indicate poor prognosis and treatment response.
• Current methods for CTC detection lack sensitivity for viable cells.
• A need exists for a sensitive assay to specifically detect viable CTCs.

Purpose of the Study:

• To develop a novel, sensitive assay for detecting viable circulating tumor cells (CTCs).
• To establish a simple ex vivo method for enumerating viable human CTCs in peripheral blood.

Main Methods:

• Development of a replication-selective adenovirus (OBP-401) expressing GFP, regulated by the telomerase promoter.
• Implementation of a 3-step ex vivo method: red blood cell lysis, OBP-401 addition, and fluorescence microscopy.
• Utilizing OBP-401's tumor-specific replication and GFP expression for signal amplification in viable CTCs.

Main Results:

• OBP-401 successfully detected viable human CTCs in peripheral blood.
• The virus-based method demonstrated a high signal-to-background ratio due to amplified GFP expression in infected tumor cells.
• The assay allows for precise enumeration of CTCs.

Conclusions:

• TelomeScan (OBP-401) provides a simple, visual, and sensitive method for detecting and enumerating viable CTCs.
• This virus-based approach holds potential as a prognostic factor and surrogate marker for treatment response in cancer.
• Further validation of this method could significantly impact clinical cancer management.