Biopharmacetical Product Research Department, Genetic Engineering and Biotechnology Research Institute, City of Scientific Research and Technology Applications, New Borg El-Arab City, 21934, Alexandria, Egypt.
Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Tanta University, Tanta, 31527, Egypt.
Microb Cell Fact. 2018 Feb 21;17(1):29. doi: 10.1186/s12934-018-0877-z.
The direct link between inflammatory bowel diseases and colorectal cancer is well documented. Previous studies have reported that some lactic acid bacterial strains could inhibit colon cancer progression however; the exact molecules involved have not yet been identified. So, in the current study, we illustrated the tumor suppressive effects of the newly identified Lactobacillus acidophilus DSMZ 20079 cell-free pentasaccharide against colon cancer cells. The chemical structure of the purified pentasaccharide was investigated by MALDI-TOF mass spectrum, 1D and 2D Nuclear Magnetic Resonance (NMR). The anticancer potentiality of the purified pentasaccharide against both Human colon cancer (CaCo-2) and Human breast cancer (MCF7) cell lines with its safety usage pattern were evaluated using cytotoxicity, annexin V quantification and BrdU incorporation assays. Also, the immunomodulatory effects of the identified compound were quantified on both LPS-induced PBMC cell model and cancer cells with monitoring the immunophenotyping of T and dendritic cell surface marker. At molecular level, the alteration in gene expression of both inflammatory and apoptotic pathways were quantified upon pentasaccharide-cellular treatment by RTqPCR.
The obtained data of the spectroscopic analysis, confirmed the structure of the newly extracted pentasaccharide; (LA-EPS-20079) to be: α-D-Glc (1→2)][α-L-Fuc(1→4)] α-D-GlcA(1→2) α-D-GlcA(1→2) α-D-GlcA. This pentasaccharide, recorded safe dose on normal mammalian cells ranged from 2 to 5 mg/ml with cancer cells selectivity index, ranged of 1.96-51.3. Upon CaCo-2 cell treatment with the non-toxic dose of LA-EPS-20079, the inhibition percentage in CaCo-2 cellular viability, reached 80.65 with an increase in the ratio of the apoptotic cells in sub-G0/G1 cell cycle phase. Also, this pentasaccharide showed potentialities to up-regulate the expression of IKbα, P53 and TGF genes.
The anticancer potentialities of LA-EPS-20079 oligosaccharides against human colon cancer represented through its regulatory effects on both apoptotic and NF-κB inflammatory pathways.
炎症性肠病与结直肠癌之间存在直接联系，这一点已有充分的文献记载。先前的研究报告称，某些乳酸杆菌菌株可以抑制结肠癌的进展，但是，涉及的确切分子尚未确定。因此，在本研究中，我们说明了新鉴定的嗜酸乳杆菌 DSMZ 20079 无细胞五糖对结肠癌细胞的肿瘤抑制作用。通过 MALDI-TOF 质谱、1D 和 2D 核磁共振（NMR）研究了纯化五糖的化学结构。使用细胞毒性、Annexin V 定量和 BrdU 掺入测定法评估了纯化五糖对人结肠癌（CaCo-2）和人乳腺癌（MCF7）细胞系的抗癌潜力及其安全使用模式。此外，通过监测 LPS 诱导的 PBMC 细胞模型和癌细胞的免疫表型，量化了鉴定化合物的免疫调节作用。在分子水平上，通过 RTqPCR 量化了细胞处理后炎症和凋亡途径基因表达的变化。
光谱分析获得的数据证实了新提取的五糖（LA-EPS-20079）的结构为：α-D-Glc（1→2）][α-L-Fuc（1→4）]α-D-GlcA（1→2）α-D-GlcA（1→2）α-D-GlcA。该五糖在正常哺乳动物细胞中的安全剂量记录为 2 至 5mg/ml，对癌细胞的选择性指数范围为 1.96-51.3。在用非毒性剂量的 LA-EPS-20079 处理 CaCo-2 细胞后，CaCo-2 细胞活力的抑制率达到 80.65%，同时 G0/G1 细胞周期阶段的凋亡细胞比例增加。此外，该五糖显示出通过调节凋亡和 NF-κB 炎症途径对人结肠癌具有潜在作用。
LA-EPS-20079 低聚糖对人结肠癌细胞的抗癌潜力通过其对凋亡和 NF-κB 炎症途径的调节作用来体现。
