title: Exopolysaccharides extracted from Parachlorella kessleri inhibit colon carcinoma growth in mice via stimulation of host antitumor immune responses.
abstract: 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.
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Susumu
authors.initials: S
authors.lastname: Ishiguro
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Deepthi
authors.initials: D
authors.lastname: Uppalapati
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Goldsmith
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Dana
authors.initials: D
authors.lastname: Robertson
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Jacob
authors.initials: J
authors.lastname: Hodge
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Hayley
authors.initials: H
authors.lastname: Holt
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Arashi
authors.initials: A
authors.lastname: Nakashima
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Katie
authors.initials: K
authors.lastname: Turner
authors.affiliation: Departments of Anatomy & Physiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, United States of America.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Tamura
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001854:Bone Marrow Cells / Q000187:drug effects; D045744:Cell Line, Tumor; D002708:Chlorella / Q000737:chemistry*; D000460:Chlorophyta; D003110:Colonic Neoplasms / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D010936:Plant Extracts / Q000627:therapeutic use*; D011134:Polysaccharides / Q000627:therapeutic use*; D013154:Spleen / Q000166:cytology / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D007155:Immunologic Factors; D010936:Plant Extracts; D011134:Polysaccharides