Sulfated modification of hyaluronan tetrasaccharide enhances its antitumor activity on human lung adenocarcinoma A549 cells in vitro and in vivo

Abstract

Hyaluronan (HA) is a glycosaminoglycan polymer involved in cell phenotype change, inflammation modulation, and tumor metastasis progression. HA oligosaccharides have a higher solubility and drug-forming ability than polysaccharides. HA tetrasaccharide was reported as the smallest fragment required for inhibiting triple-negative breast cancer, but the anti-tumor activity of HA tetrasaccharide (HA4) and its sulfated derivatives in lung cancer is still unknown. In this study, HA4 was prepared via HA degradation by chondroitinase ABC (CSABC), while its sulfated derivatives were prepared by sulfur pyridine trioxide complex in N, N-dimethylformamide (DMF). Then, the anti-tumor activity was detected via MTT assay and xenograft tumor experiments, while the expression level change of apoptosis genes was analyzed by qRT-PCR. Electrospray mass spectrometry (ESI-MS) analysis showed several HA4 sulfated derivatives, GlcA2GlcNAc2 (SO3H)n contains 0-6 sulfation groups, which mainly contain 3-6, 2-3, and 0-1 sulfation groups were classified as HA4S1, HA4S2, and HA4S3, respectively. After the addition of 1.82 mg/mL HA4, HA4S1, HA4S2, and HA4S3, the cell viability of A549 cells was reduced to 81.2 %, 62.1 %, 50.3 %, and 65.9 %, respectively. Thus, HA4S2 was chosen for further measurement, the qRT-PCR results showed it significantly up-regulated the expression of genes in the apoptosis pathway. Moreover, HA4S2 exhibited stronger antitumor activity than HA4 in vivo and the tumor inhibition rate reached 36.90 %. In summary, this study indicated that the CSABC enzyme could effectively degrade HA into oligosaccharides, and sulfation modification was an effective method to enhance the antitumor activity of HA tetrasaccharides.

Keywords: Antitumor; Apoptosis; Hyaluronan; Sulfation modification; Tetrasaccharide.