Immortalization of human prostate epithelial cells by HPV 16 E6/E7 open reading frames

Area of Science:

• Oncology
• Cell Biology
• Molecular Biology

Background:

• Prostate cancer pathogenesis remains unclear, hindering research progress.
• A significant limitation in prostate cancer research is the scarcity of effective in vitro models.
• This study addresses the need for better models by developing an immortalized human prostate epithelial cell line.

Purpose of the Study:

• To immortalize a human prostate epithelial cell line for use as an in vitro model.
• To investigate the characteristics of the immortalized cell line for prostate cancer research.
• To establish a model for studying early-stage prostate cancer development.

Main Methods:

• Primary human prostate epithelial cells were infected with a retrovirus containing HPV 16 E6 and E7.
• Techniques included PCR, Southern hybridization, Western blot, telomeric repeat amplification protocol assay, 2D gel electrophoresis, and cytogenetic analysis.
• Characterization focused on HPV integration, prostatic acid phosphatase expression, telomerase activity, cytokeratins, and karyotype.

Main Results:

• The immortalized cell line, HPr-1, demonstrated indefinite proliferation (over 80 passages), unlike normal cells.
• HPr-1 cells maintained morphological and biochemical similarities to normal prostate epithelial cells but exhibited telomerase activity.
• Cytogenetic analysis revealed a male karyotype with clonal abnormalities and double minutes in HPr-1 cells.

Conclusions:

• HPr-1 cells expressed prostatic markers (acid phosphatase, cytokeratins K8/K18), confirming their prostate epithelial origin.
• The HPr-1 cell line showed no tumor formation in nude mice or colony formation in soft agar, indicating benign behavior.
• The HPr-1 cell line serves as an in vitro model representing early prostate neoplastic progression.