Development of anticancer gene vaccine interact with human papillomavirus oncoprotein inhibition

Area of Science:

• Molecular Biology
• Virology
• Oncology

Background:

• Adeno-associated virus (AAV) Rep 78 protein is known to inhibit oncogene and viral gene promoters, including human papillomavirus (HPV) type 16 E6.
• Previous studies focused on biochemical aspects of Rep 78, leaving its effect on HPV 16 E6 promoter activity in cervical carcinoma cells uncharacterized.

Purpose of the Study:

• To investigate the effects of Rep 78 gene-mediated inhibition of HPV 16 E6 promoter activity in various human cervical carcinoma cell lines.
• To assess the impact of Rep 78 transfection on cervical cancer cell growth and HPV 16 E6 DNA levels.

Main Methods:

• Adeno-associated virus (AAV)-mediated Rep 78 gene was cloned into a pEGFP-N1 vector and transfected into cervical carcinoma cells (CaSki, HeLa, HeLaS3, HT3, QGU).
• Transfection efficiency was monitored, and Rep 78 mRNA and protein expression levels were analyzed.
• HPV 16 E6 DNA levels and cell growth inhibition were measured post-transfection.

Main Results:

• Rep 78 transfection efficiency varied (approximately 30-60%).
• CaSki cells showed significantly higher Rep 78 expression and decreased HPV 16 E6 DNA levels on day 1 post-transfection.
• Rep 78 transfection resulted in only 10-15% growth inhibition in CaSki cells, with no significant effect on other tested cell lines.

Conclusions:

• While Rep 78 can be efficiently expressed and reduces HPV 16 E6 DNA, it does not significantly inhibit the growth of various cervical cancer cell lines in the short term.
• Long-term expression of Rep 78 may be a necessary strategy for effective gene therapy in cervical carcinoma using AAV vectors.