Laminaria Japonica Polysaccharides effectively inhibited the growth of nasopharyngeal carcinoma cells in vivo and in vitro study

Aims: Laminaria Japonica Polysaccharides (LJP) is a kind of plant polysaccharide isolated from Laminaria Japonica Aresch. LJP has a variety of biological activity, including anti-tumor, improving immune function, anti radiation and others. This study observed the biological activity of LIP in vitro and in vivo on human nasopharyngeal carcinoma(NPC), and the possible anticancer mechanism was explored. Methods: Nasopharyngeal poorly differentiated squamous cell carcinoma cell lines CNE2 and HONE1 were used for the study. MIT method was used to detect the proliferation of HONE1 and CNE2 treated with gradient concentrations of LJP. The apoptosis of HONE1 treated with LJP was detected by annexin V-FITC/PI double staining method. HONE1 was used to establish subcutaneous implanted tumor model in nude mice. The changes of transplanted tumor volume and body weight of nude mice in each group were observed and recorded. The changes of the ultrastructure of transplanted tumor were observed by transmission electron microscope (TEM). Results: MIT results showed that LIP has inhibitory effect on proliferation of both HONE1 and CNE2, and the effects were dosage-dependent; results of flow cytometry (FCM) analysis showed that, LJP could efficient induce apoptosis in HONE1, and apoptosis rate increased with the increase of LJP concentration. In vivo experiments, the inhibition rate was 33.7% (P < 0.05) and 47% (P < 0.01) in middle and high dose LJP group, respectively. TEM results suggested that the cancer cells in the transplanted tumor tissue treated with middle and high dose LIP presented unique apoptosis changes. Conclusions: LIP can effectively inhibit the growth of NPC cells. And it may be achieved by inducing apoptosis of NPC cells.