Generation of affibody molecules specific for HPV16 E7 recognition

Area of Science:

• Oncology
• Molecular Biology
• Biotechnology

Background:

• Cervical cancer, a leading gynecologic malignancy, is primarily caused by high-risk human papillomavirus (HPV) infection.
• Persistent expression of HPV oncogenes E6 and E7 is crucial for cervical cancer development.
• In vivo detection of these oncoproteins is vital for accurate cancer diagnosis.

Purpose of the Study:

• To screen and evaluate HPV16 E7-binding affibody molecules for molecular imaging of HPV-induced cervical cancer.
• To assess the specificity and affinity of selected affibody molecules for HPV16 E7 oncoprotein.
• To investigate the in vivo tumor-targeting and imaging capabilities of an E7-specific affibody.

Main Methods:

• Phage-displayed peptide library screening to identify HPV16 E7-binding affibody molecules.
• Biosensor binding assays to determine affibody affinity and specificity.
• In vitro co-localization studies in HPV-positive and HPV-negative cancer cells.
• In vivo tumor imaging in mice using a Dylight755-conjugated affibody (ZHPV16E7384).

Main Results:

• Four affibody molecules (Z HPV16 E7127, Z HPV16E7301, Z HPV16E7384, Z HPV16E7745) demonstrated high affinity and specificity for HPV16 E7.
• Affibodies co-localized with E7 protein exclusively in HPV16-positive SiHa and CaSki cells.
• Dylight755-conjugated ZHPV16E7384 showed rapid, high-contrast retention in HPV16-derived tumors in vivo.
• Tumor accumulation was observed as early as 30 minutes and persisted up to 24 hours post-injection, with no signal in HPV-negative or HPV18-derived tumors.

Conclusions:

• E7-specific affibody molecules are effective probes for molecular imaging of HPV-induced cancers.
• The developed affibodies offer high specificity and sensitivity for detecting HPV16-positive tumors.
• These findings highlight the potential of affibody-based imaging for diagnosing and monitoring cervical cancer.