Fucoxanthin may inhibit cervical cancer cell proliferation via downregulation of HIST1H3D

OBJECTIVE: To investigate the role of fucoxanthin, reported to have significant anticancer effects, and histone Cluster 1 H3 Family Member D (HIST1H3D; implicated in tumorigenesis) in cervical cancer. METHODS: The half maximal inhibitory concentration (IC50) of fucoxanthin against HeLa and SiHa cervical cancer cells was determined. Differentially expressed genes (DEGs) in SiHa cells treated with IC50 fucoxanthin were screened by high-throughput techniques and subjected to signal enrichment. Following identification of HIST1H3D as a candidate gene, HIST1H3D-knockdown models were created via transfection with a short hairpin HIST1H3D payload. Impacts on cell proliferation, cell-cycle distribution, colony formation, and apoptosis were studied. RESULTS: The fucoxanthin IC50 was 1 445 and 1 641 µM (Hela and SiHa cells, respectively). Chip results revealed 2 255 DEGs, including 943 upregulated and 1 312 downregulated genes, in fucoxanthin-treated versus untreated SiHa cells. Disease and function analysis indicated that these DEGs are primarily associated with cancer and organismal injuries and abnormalities, and online integrated pathway analysis showed that the DEGs were mainly enriched in p53 signalling. HIST1H3D was significantly downregulated in response to fucoxanthin. Inhibition of HIST1H3D mRNA significantly reduced cell proliferation and colony formation, significantly augmented the percentage of apoptotic HeLa and SiHa cells, and cells were arrested in G(0)/G(1) cell cycle phase. CONCLUSION: The results suggest that HIST1H3D may be an oncogene in cervical carcinogenesis and a potential fucoxanthin target in treating cervical cancer.