Background: Laryngeal Squamous Cell Carcinoma (LSCC) is a malignant epithelial tumor with poor
prognosis and its incidence rate increased recently. rLj-RGD3, a recombinant protein cloned from the buccal
gland of Lampetra japonica, contains three RGD motifs that could bind to integrins on the tumor cells.
Methods: MTT assay was used to detect the inhibitory rate of viability. Giemsa’s staining assay was used to
observe the morphological changes of cells. Hoechst 33258 and TUNEL staining assay, DNA ladder assay were
used to examine the apoptotic. Western blot assay was applied to detect the change of the integrin signal
pathway. Wound-healing assay, migration, and invasion assay were used to detect the mobility of Hep2
cells. H&E staining assay was used to show the arrangement of the Hep2 cells in the solid tumor tissues.
Results: In the present study, rLj-RGD3 was shown to inhibit the viability of LSCC Hep2 cells in vitro by inducing
apoptosis with an IC50 of 1.23µM. Western blot showed that the apoptosis of Hep2 cells induced by rLj-
RGD3 was dependent on the integrin-FAK-Akt pathway. Wound healing, transwells, and western blot assays
in vitro showed that rLj-RGD3 suppressed the migration and invasion of Hep2 cells by integrin-FAKpaxillin/
PLC pathway which could also affect the cytoskeleton arrangement in Hep2 cells. In in vivo studies,
rLj-RGD3 inhibited the growth, tumor volume, and weight, as well as disturbed the tissue structure of the solid
tumors in xenograft models of BALB/c nude mice without reducing their body weights.
Conclusion: These results suggested that rLj-RGD3 is an effective and safe suppressor on the growth and metastasis
of LSCC Hep2 cells from both in vitro and in vivo experiments. rLj-RGD3 might be expected to become
a novel anti-tumor drug to treat LSCC patients in the near future.