Background: A major challenge in cervical cancer radiotherapy is tailoring the radiation
doses efficiently to eliminate malignant cells and reduce the side effects in normal tissues. Oncolytic
adenovirus drug H101 was recently tested and approved as a topical adjuvant treatment for several
Objective: This study aimed to evaluate the potential neoadjuvant radiotherapy benefits of H101 by
testing the inhibitory function of H101 in combination with radiation in different cervical cancer
Methods: Human cervical cancer cell lines C33a, SiHa, CaSki, and HeLa were treated with varying
concentrations of H101 alone or in combination with radiation (2 Gy or 4 Gy). Cell viability
and apoptosis were measured at the indicated time intervals. HPV16 E6 and cellular p53 mRNA expression
alteration was measured by qRT-PCR. In situ RNA scope was used to determine HPV E6
status. P53 protein alterations were detected by Western blot.
Results: Cell viability and apoptosis assays revealed that the combination of a high dose of H101
(MOI=1000, 10000) with radiation yielded a synergistic anticancer effect in all tested cervical cancer
cell lines (P<0.05), with the greatest effect achieved in HPV-negative C33a cells (P<0.05).
Low-HPV16-viral-load SiHa cells were more sensitive to the combination therapy than high-HPV16-
viral-load CaSki cells (P<0.05). The combined treatment reduced HPV16 E6 expression and
increased cellular P53 levels compared to those observed with radiation alone in SiHa and CaSki
Conclusion: Oncolytic adenovirus H101 effectively enhances the antitumor efficacy of radiation in
cervical cancer cells and may serve as a novel combination therapy for cervical cancer.