thymalfasin and Colonic-Neoplasms

Heated intraperitoneal chemotherapy (HIPEC) is currently implemented in the treatment of peritoneal metastases from colorectal carcinoma (PM-CRC) origin. However, recurrence is common and the effectiveness of HIPEC has been questioned. The aim of this study was to evaluate the use of thymosin alpha 1 (Tα1), an immunomodulatory molecule, as an adjuvant to HIPEC treatment.. We developed an experimental model of HIPEC by the induction of PM-CRC in C57BL mice and intra-abdominal perfusion of mitomycin C (MMC). Mice were treated with Tα1 at 0.6 mg/kg for 5 days after HIPEC. Clinical and immunological parameters were compared between HIPEC and HIPEC + Tα1 groups.. Treatment with Tα1 increased overall survival of mice compared to HIPEC treatment alone and sham-treated animals (16.1 ± 0.8 vs. 14.1 ± 0.6 and 11.8 ± 0.8, respectively, p = 0.02). Tα1 had no direct anti-tumor effect, as seen by lack of inhibition of tumor cell proliferation. Tα1 treatment induced a T helper (Th) 1 immune response in tumor metastases as evidenced by a significant increase of the Th1-specific markers IFN-γ and T-bet (1.21 ± 0.3 vs. 0.52 ± 0.08, p < 0.05; 0.88 ± 0.04 vs. 0.64 ± 0.14, p < 0.05, respectively). This Th1 skew was accompanied by increased CD8. Tα1 augments the effect of HIPEC by the induction of a Th1 anti-tumor immune response. Further experiments should evaluate Tα1 and other novel immunomodulators in order to exploit the immunological opportunities created by HIPEC.

Topics: Animals; Carcinoma; Chemotherapy, Adjuvant; Colonic Neoplasms; Colorectal Neoplasms; Combined Modality Therapy; Hyperthermia, Induced; Hyperthermic Intraperitoneal Chemotherapy; Mice; Mice, Inbred C57BL; Models, Theoretical; Peritoneal Neoplasms; Thymalfasin

Increasing evidence showed invariant NKT cells (iNKT cell) are an attractive candidate for cancer immunotherapy, but its role in colorectal cancer treatment was still unclear. Here we reported iNKT cells exerted moderate cytotoxic effect against colorectal cancer cells (CRC cells) with the stimulation of α-Galcer, and the mutual recognition between CRC and iNKT cells could be greatly enhanced by Thymosinα1 (TA), which resulted in stronger killing efficiency both in vitro and in vivo. TA is widely used as an immune adjuvant for cancer therapy, but how it works on cancer cells still remains unclear. We found TA could upregulate CD80, B7H2 and CD1d expression on CRC cells. However, neutralization assay revealed iNKT cells' activation depended on CD1d expression rather than CD80 or B7H2. Moreover, colon cancer stem cells expressed higher CD1d level, which accounted for their greater sensitization to iNKT cells. Mechanistically, inhibition of Erk/MAPK pathway greatly attenuated the upregulation of CD1d by TA. Taken together, depending on Erk/MAPK pathway, TA promoted the activation and cytotoxicity of iNKT cells via upregulating CD1d expression on CRC cells, which indicated a novel immunotherapeutic strategy of iNKT cells against CRC.

Topics: Animals; Antigens, CD1d; Antineoplastic Agents; Apoptosis; Blotting, Western; Cell Proliferation; Coculture Techniques; Colonic Neoplasms; Female; Flow Cytometry; Fluorescent Antibody Technique; Humans; Immunoenzyme Techniques; Mice; Mice, Inbred NOD; Mice, SCID; Natural Killer T-Cells; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thymalfasin; Thymosin; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

To investigate the effects of thymosin alpha1 (Talpha1) on the differentiation, maturation and function of tumor lysate-pulsed dendritic cells (LyDCs) in vitro, and to study the antitumor effects on tumor models of the nude mice bearing colon cancer in vivo.. Immature DCs (imDCs) were prepared routinely from human peripheral blood mononuclear cells. The LyDCs were prepared from the imDCs loaded with lysate of HT-29 tumor cell line. The phenotypes of imDCs and LyDCs pre- or post-stimulated by Talpha1 were analyzed by flow cytometry. Autologous T cells were cocultured with LyDCs in the presence or absence of Talpha1 2 days later. IL-12 secretion of LyDCs and IFN-gamma secretion of the activated T cells in the supernatants were measured by ELISA. The in vitro cytotoxicity of antigen specific cytotoxic T lymphocytes (CTLs) induced by LyDCs which were treated with Talpha1 was evaluated by MTT assay. A humanized nude mice model bearing colon cancer was established. The in vivo antitumor activity was evaluated in the humanized nude mice after the treatment with LyDCs plus Talpha1 or LyDCs alone.. The expression levels of HLA-DR, CD80, CD86 and CD83 in imDCs and LyDCs were markedly up-regulated after the stimulation with Talpha1 respectively (P<0.01). The levels of IL-12 and IFN-gamma were also significantly increased in the presence of Talpha1 (P<0.05 and P<0.01, respectively). Cytotoxicity induced by LyDCs treated with Talpha1 was significantly enhanced (P<0.01) as compared with LyDCs in vitro. The humanized cellular immunity was successfully established in the nude mice model. On the 58 th day after the inoculation of tumor cells, the inhibitory rate of tumor growth was significantly higher in the group treated with LyDCs plus Talpha1 than that in the group treated with LyDCs alone (60.41% and 37.20%, respectively; P<0.01).. Talpha1 can induce the functional maturation of DCs and enhance the immune response of CD4+Th1 arm and cytotoxicity induced by LyDCs. Talpha1 has a synergistic antitumor effect. It might be a promising adjuvant candidate for DC-based immunotherapy of gastrointestinal carcinomas.

Topics: Animals; Antineoplastic Agents; Cell Extracts; Cell Line, Tumor; Cell Proliferation; Colonic Neoplasms; Dendritic Cells; Female; Humans; Immunotherapy; Interferon-gamma; Interleukin-12; Mice; Mice, Nude; T-Lymphocytes, Cytotoxic; Thymalfasin; Thymosin