Hamadan University of Medical Sciences Avicenna Journal of Dental Research 2423-7582 16 2 2024 06 29 Herpes Simplex Virus Type 1 Infection Up-regulates miR-221-5P in Oral Squamous Cell Carcinoma 83 89 10.34172/ajdr.1780 EN Fatemeh Alipour https://orcid.org/0000-0001-9688-1671 Noushin Jalayer Naderi https://orcid.org/0000-0002-7356-3205 Ronak Bakhtiari https://orcid.org/0000-0002-3778-5732 Journal Article 10.34172/ajdr.1780 2024 01 24 2024 04 30 Background: Herpes simplex virus type 1 (HSV-1) infection contributes to oral carcinoma, but its carcinogenic role has not been elucidated yet. MicroRNAs (miRNAs) are involved in carcinogenesis. The aim of the present study was to examine the effect of HSV-1 infection on the expression of miR-29c, miR-221-5P, miR-21-5P, and miR-96-5P in patients with oral squamous cell carcinoma (OSSC). Methods: Twenty-five cases of OSCC and 25 samples of normal oral mucosa were examined in this study. The SYBR real-time polymerase chain reaction (RT-PCR) was completed to confirm the presence of HSV-1. The expressions of miR-29c, miR-221-5P, miR-21-5P, and miR-96-5P were measured using RT-PCR. Results: The expression of miR-221-5P was significantly higher in OSCC with HSV-1 infection compared to non-infected cases (P=0.007). The expressions of miR-29c, miR-21-5P, and miR-96-5P were not significantly different between OSCCs with HSV-1 infection and controls (P=0.27, P=0.66, and P=0.23, respectively). Conclusion: HSV-1 infection had an up-regulation effect on miR-221-5P in OSCC. This finding proposes a novel mechanism for HSV-1 infection in the development of OSCC.