Purpose: Period2 (PER2) is associated with the occurrence and development of nasopharyngeal carcinoma (NPC); however, its mechanism(s) of action underlying NPC carcinogenesis remains unclear. Method: In this study, differentially expressed proteins were identified via proteomics. The cells were infected with Lentivirus and divided into two groups: normal control group (Control) and PER2 overexpression Lentivirus-infected group (PER2-OE). Western blot was used to detect ERK and p-ERK expression in the two groups. Immunohistochemistry was used to further detect PER2 and p-ERK expression in human NPC samples, and the correlations between PER2, p-ERK and clinical NPC characteristics were analysed. Result: Statistical analysis revealed that MAPK3 (ERK) was among the top 20 differentially expressed proteins, PER2 overexpression and control samples were significantly different (P<0.05). The western blot results showed that PER2 overexpression downregulated p-ERK protein expression. Significant differences (P < 0.05) were observed in the proportions of cells which expressed PER2 and p-ERK between NPC tissues and normal nasopharyngeal mucosa samples. Conclusion: Overexpression of PER2 downregulated the expression of p-ERK. In NPC tissues, PER2 protein was expressed at low levels, whereas p-ERK protein was highly expressed, and these trends are closely related to the occurrence and development of NPC.

The authors have declared no competing interest.

This work was supported by the Natural Science Foundation of Ningxia Province [grant number 2019AAC03210],Granted by: Hailiang Li Ningxia Medical University [grant number XM20211041],Granted by: Zhijuan Zhang Natural Science Foundation of Ningxia Province [grant number 2019AAC03215],Granted by: Li Hou Key Research and Development Program of Ningxia [grant number 2022BEG03105],Granted by: Li Hou. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

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