Journal Article

Exopolysaccharides extracted from Parachlorella kessleri inhibit colon carcinoma growth in mice via stimulation of host antitumor immune responses

Nakashima, Arashi, Ishiguro, Susumu, Robertson, Dana, Holt, Hayley, Uppalapati, Deepthi, Turner, Katie, Goldsmith, Zachary, Tamura, Masaaki, Hodge, Jacob

2017

Overview

The newly purified extracellular polysaccharides (exopolysaccharides) from Parachlorella kessleri (PCEPS) were evaluated on their antitumor and immunomodulatory effects in cell culture and mouse colon carcinoma peritoneal dissemination model. In two-dimensional cell culture, the PCEPS treatment inhibited cell growth of both murine and human colon carcinoma cells in a dose- and time-dependent manner. In contrast, the growth of mouse splenocytes (SPLs) and bone marrow cells (BMCs) were stimulated by the treatment with PCEPS. The treatment with PCEPS also increased specific subpopulations of the cells in BMCs: antigen presenting cells (CD19+ B cells, 33D1+ dendritic cells and CD68+ macrophage) and CD8+ cytotoxic T cells. In three-dimensional spheroid culture, spheroid growth of CT26 cells co-cultured with HL-60 human neutrophilic promyeloblasts and Jurkat cells (human lymphoblasts), but not THP-1 human monocyte/macrophage was significantly attenuated by PCEPS treatment. In a mouse CT26 colon carcinoma peritoneal dissemination model, intraperitoneal injection of PCEPS (10 mg/kg, twice per week) significantly attenuated the growth of CT26 colon carcinoma in syngeneic mice. The present study suggests that PCEPS inhibits colon carcinoma growth via direct cell growth inhibition and a stimulation of the host antitumor immune responses. Taken together, the current study suggests that exopolysaccharides derived from Parachlorella kessleri contain significant bioactive materials that inhibit colon carcinoma growth.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Algae / Analysis / Anatomy & physiology / Animals / Anticancer properties / Antigen-presenting cells / Antineoplastic Agents - therapeutic use / Binding sites / Biocompatibility / Biology and Life Sciences / Biomedical materials / Bone marrow / Bone Marrow Cells - drug effects / Care and treatment / Cell cycle / Cell Line, Tumor / Chlorella - chemistry / Chlorophyta / Chromatography / Colon / Colon cancer / Colonic Neoplasms - drug therapy / Colorectal cancer / Development and progression / Dose-Response Relationship, Drug / Female / Green algae / Humans / Immune response / Immune system / Immunologic Factors - therapeutic use / Inhibition / Kinases / Lung cancer / Lymphocytes / Lymphocytes T / Macrophages / Medical prognosis / Medicine and Health Sciences / Mice / Mice, Inbred BALB C / Monocytes / Mortality / Neutrophils / Physiological aspects / Physiology / Plant Extracts - therapeutic use / Polysaccharides / Polysaccharides - therapeutic use / Research and Analysis Methods / Saccharides / Spleen - cytology / Spleen - drug effects / Stem cells / Stimulation / Subpopulations / Two dimensional models / Umbilical cord / Veterinary colleges / Veterinary medicine