Crucial involvement of the CCL3‐CCR5 axis‐mediated fibroblast accumulation in colitis‐associated carcinogenesis in mice

Abstract

Patients with inflammatory bowel diseases often develop colon carcinoma. Combined treatment of azoxymethane (AOM) and dextran sulfate sodium (DSS) recapitulates colitis‐associated cancer in mice. AOM/DSS‐induced tumor formation was reduced in CCL3‐ or its specific receptor, CCR5‐deficient mice despite the presence of a massive infiltration of inflammatory cells. However, AOM/DSS‐induced type I collagen‐positive fibroblast accumulation in the colon was reduced in CCL3‐ or CCR5‐deficient mice. This was associated with depressed expression of heparin‐binding epidermal growth factor‐like growth factor (HB‐EGF), which is expressed mainly by fibroblasts. Moreover in vitro, CCL3 induced fibroblasts to proliferate and to enhance HB‐EGF expression. Furthermore, CCR5 blockade reduced tumor formation together with reduced fibroblast accumulation and HB‐EGF expression, even when administered after the development of multiple colon tumors. Thus, CCL3‐CCR5‐mediated fibroblast accumulation may be required, in addition to leukocyte infiltration, to induce full‐blown colitis‐associated carcinogenesis. Our studies shed light on a therapeutic potential of CCR5 antagonist for patients with colitis‐associated cancer.

Gemcitabine-induced CXCL8 expression counteracts its actions by inducing tumor neovascularization

“…Total RNA was isolated and was reverse transcribed to cDNA as previously described [14]. The resultant cDNA was amplified to detect human CXCR1 and CXCR2 mRNA by using the specific sets of the primers, 5'-CCCCTGTATGCTAGAAACTGAGAC-3' (CXCR1 forward), 5'-CCAGCAGCCAAGACAAACAAAC-3' (CXCR1 reverse), 5'-CATGGGCAACAATACAGCAA-3' (CXCR2 forward) and 5'-TGAGGAC-GACAGCAAAGATG-3' (CXCR2 reverse) with 30 cycles consisting of 94 C for 30 s, 55 C for 30 s and 68 C for 1 min, and with a final extension at 68 C for 5 min.…”

“…GAPDH was used as a positive control. Quantitative (q)RT-PCR for CXCL8 was performed using the sets of the primers, 5'-TGGCAGCCTTCCTGATTTCT-3' (forward) and 5'-TTTCTGTGTTGGC GCAGTGT-3' (reverse) and mRNA amounts were normalized to the amounts of GAPDH as relative expression values as described previously [14].…”

“…Tumor volume (mm 3 ) ¼ (the longest diameter) (mm) Â (the shortest diameter) 2 (mm)/2. At the indicated time points after the injection, tumors were removed for immunohistochemical analysis using anti-human CXCL8, anti-mouse CD31 (Abcam, Cambridge, UK), or anti-mouse Ly6G antibody (BD Biosciences) as previously described [14]. All animal experiments were performed in compliance with the Guidelines for the Care and Use of Laboratory Animals of Kanazawa University.…”

High-dose cyclophosphamide induces specific tumor immunity with concomitant recruitment of LAMP1/CD107a-expressing CD4-positive T cells into tumor sites

“…CCR5-deficient (CCR5 -/-) mice were backcrossed with BALB/c mice for more than eight8 generations [12]. CD45.1 BALB/c congenic mice were obtained from the Jackson Laboratories (Bar Harbor, ME).…”

“…qRT-PCR was done performed to quantify the chemokine mRNA of chemokines as previously described [12]. Hypoxanthine phosphoribosyltransferase (HPRT) or Naito 8 glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was amplified as an internal control.…”