Platelet factor-4 variant chemokine CXCL4L1 inhibits melanoma and lung carcinoma growth and metastasis by preventing angiogenesis.

The platelet factor-4 variant, designated PF-4var/CXCL4L1, is a recently described natural non-allelic gene variant of the CXC chemokine platelet factor-4/CXCL4. PF-4var/CXCL4L1 was cloned, and the purified recombinant protein strongly inhibited angiogenesis. Recombinant PF-4var/CXCL4L1 was angiostatically more active (at nanomolar concentration) than PF-4/CXCL4 in various test systems, including wound-healing and migration assays for microvascular endothelial cells and the rat cornea micropocket assay for angiogenesis. Furthermore, PF-4var/CXCL4L1 more efficiently inhibited tumor growth in animal models of melanoma and lung carcinoma than PF-4/CXCL4 at an equimolar concentration. For B16 melanoma in nude mice, a significant reduction in tumor size and the number of small i.t. blood vessels was obtained with i.t. applied PF-4var/CXCL4L1. For A549 adenocarcinoma in severe combined immunodeficient mice, i.t. PF-4var/CXCL4L1 reduced tumor growth and microvasculature more efficiently than PF-4/CXCL4 and prevented metastasis to various organs better than the angiostatic IFN-inducible protein 10/CXCL10. Finally, in the syngeneic model of Lewis lung carcinoma, PF-4var/CXCL4L1 inhibited tumor growth equally well as monokine induced by IFN-gamma (Mig)/CXCL9, also known to attract effector T lymphocytes. Taken together, PF-4var/CXCL4L1 is a highly potent antitumoral chemokine preventing development and metastasis of various tumors by inhibition of angiogenesis. These data confirm the clinical potential of locally released chemokines in cancer therapy.

Vedolizumab Induces Long-term Mucosal Healing in Patients With Crohn's Disease and Ulcerative Colitis.

INTRODUCTION: Vedolizumab has proven efficacy in inflammatory bowel disease [IBD], but long-term mucosal healing in Crohn's disease [CD], as well as the incidence of colorectal neoplasia in IBD, among patients treated with vedolizumab have not been studied. We aimed to document mucosal healing and to explore the risk of colorectal neoplasia with vedolizumab maintenance therapy. METHODS: Surveillance colonoscopy was prospectively scheduled for patients with longstanding ulcerative coltis [UC] or CD at a tertiary referral centre, in the open-label extension phase (vedolizumab 300 mg intravenously [IV] every 4 weeks) of the Gemini studies [GEMINI LTS, study number NCT00790933]. Mayo score ≤ 1 or ulcer disappearance [in CD] was defined as mucosal healing. Targeted biopsies were graded for inflammation and dysplasia. RESULTS: Of 68 patients [29 CD/39 UC] treated for ≥ 1 year [median 3.2 years, range 1.1-6.1], 58 [24 CD/34 UC] were endoscopically monitored. Durable endoscopic healing corrected by non-responder imputation was found in 7/24, 29% [CD] and 17/34, 50% [UC]. Combined histological and mucosal healing was observed in 5/24 [CD] and 11/34 [UC] of those with endoscopic healing. Low-grade dysplasia was detected in 10% of patients and high-grade dysplasia in the resection specimen of one patient with biopsy-proven low-grade dysplasia. CONCLUSIONS: Long-term endoscopic and histological healing was observed in a proportion of patients treated with vedolizumab long-term. The dysplasia risk with vedolizumab deserves further study.