Immune Responses Raised in an Experimental Colon Carcinoma Model Following Oral Administration of Lactobacillus casei

Abstract

The role of dietary probiotic strains on host anti-cancer immune responses against experimental colon carcinoma was investigated. We have previously shown that Lactobacillus casei administration led to tumor growth suppression in an experimental colon cancer model. Here, we investigated the underlying immune mechanisms involved in this tumor-growth inhibitory effect. BALB/c mice received daily live lactobacilli per os prior to the establishment of a syngeneic subcutaneous CT26 tumor. Tumor volume, cytokine production, T cell differentiation and migration, as well as tumor cell apoptosis were examined to outline potential immunomodulatory effects following L. casei oral intake. Probiotic administration in mice resulted in a significant increase in interferon gamma (IFN-γ), Granzyme B and chemokine production in the tumor tissue as well as enhanced CD8+ T cell infiltration, accompanied by a suppression of tumor growth. Cytotoxic activity against cancer cells was enhanced in probiotic-fed compared to control mice, as evidenced by the elevation of apoptotic markers, such as cleaved caspase 3 and poly (ADP-ribose) polymerase 1 (PARP1), in tumor tissue. Oral administration of Lactobacillus casei induced potent Th1 immune responses and cytotoxic T cell infiltration in the tumor tissue of tumor-bearing mice, resulting in tumor growth inhibition. Thus, the microorganism may hold promise as a novel dietary immunoadjuvant in raising protective anti-cancer immune responses.

Linking Obesity with Colorectal Cancer: Epidemiology and Mechanistic Insights

“…Lactobacillus casei is a genus of Lactobacillus . Oral administration of Lactobacillus casei enhanced CD8 + T cell infiltration and inhibited colon carcinoma growth in tumor-bearing mice [ 148 ]. These data indicate that potential probiotic bacteria and beneficial metabolites are promising therapeutic agents for treating obesity and CRC.…”

Modulation of Anti-Tumour Immune Responses by Probiotic Bacteria

“…These chemokines play an important role in the trafficking and infiltration of T cells to tumours. Cytotoxic activity in tumours through IFN-γ and granzyme B, as well as cancer cell apoptosis, were also enhanced following oral administration of L. casei [113]. These studies show that probiotic bacteria affect and modulate different stages in the cancer-immunity cycle (Figure 1).…”

Isolation of a Lactobacillus paracasei Strain with Probiotic Attributes from Kefir Grains

“…In this line, the preliminary cytotoxic effects of viable L. casei ATCC 393 at concentrations of 10 8 or 10 9 CFU/mL against HT-29 and CT-26 (a Mus musculus colon carcinoma cell line) [ 40 ] were also demonstrated in vivo. In greater detail, BALB/c mice carrying a syngeneic subcutaneous CT26 tumor that were administered with 10 9 CFU/mL of L. casei exhibited a reduction of tumor weight and volume that was accompanied by the induction of pro-inflammatory and pro-apoptotic events, in situ [ 42 ]. The translation of these findings to the clinic for the treatment of malignancies remains a challenge, however specific probiotic strains show beneficial effect by preventing perioperative infections [ 43 ] or by alleviating the gastrointestinal symptoms caused by chemotherapeutic drugs in colon cancer patients [ 44 ].…”