Objective: Malignant tumor cells were found with an abnormal cell cycle. Previous in vivo experiment had confirmed the Feiyanning’s intervention effect on checkpoint signaling of G₁/S in the cell cycle. This study was to further observe the expressions of nucleosome conformation-regulating factors intervened by Feiyanning decoction in S phase.
Methods: Lewis lung carcinoma models of C57BL/6 mice were established. Sixty mice were randomly divided into four groups: normal control group, model control group, Feiyanning group, and cisplatin group. There were 15 mice in each group. Tumor weight and tumor inhibition rate were observed. In addition, the cell cycle distribution was detected by flow cytometry and the proliferation index was calculated. Furthermore, mRNA and protein expressions of H3-K56, regulator of Ty1 transposition 109 (Rtt109), antisilencing function 1 (Asf1) and E2F1 were analyzed by real-time polymerase chain reaction and Western blot methods, respectively.
Results: The tumor weights of mice in the Feiyanning group and the cisplatin group were lower than those in the model group (P<0.01), with tumor inhibition rates of 27.92% and 42.50%, respectively. Cancer cell proliferation index and proportion of cancer cell population in S phase in the Feiyanning group were significantly lower than those in the cisplatin group (P<0.01). The mRNA and protein levels of H3-K56, Rtt109, Asf1, E2F1 in the Feiyanning group were lower than those in the model group (P<0.05).
Conclusion: Feiyanning plays a role in intervening in the abnormal cell cycle by nucleosome conformation-regulating factors and thus inhibits the lung cancer cell proliferation.

Key words: carcinoma, Lewis lung, nucleosomes, cell cycle, drugs, Chinese herbal, mice