Safety and Efficacy of Mesenchymal Stem Cells for Radiation-Induced Xerostomia: A Randomized, Placebo-Controlled Phase 1/2 Trial (MESRIX).

BACKGROUND: Salivary gland hypofunction and xerostomia are major complications to head and neck radiotherapy. This trial assessed the safety and efficacy of adipose tissue-derived mesenchymal stem cell (ASC) therapy for radiation-induced xerostomia. PATIENT AND METHODS: This randomized, placebo-controlled phase 1/2 trial included 30 patients, randomized in a 1:1 ratio to receive ultrasound-guided transplantation of ASCs or placebo to the submandibular glands. Patients had previously received radiotherapy for a T1-2, N0-2A, human papillomavirus-positive, oropharyngeal squamous cell carcinoma. The primary outcome was the change in unstimulated whole salivary flow rate, measured before and after the intervention. All assessments were performed one month prior (baseline) and one and four months following ASC or placebo administration. RESULTS: No adverse events were detected. Unstimulated whole salivary flow rates significantly increased in the ASC-arm at one (33%; P = .048) and four months (50%; P = .003), but not in the placebo-arm (P = .6 and P = .8), compared to baseline. The ASC-arm symptom scores significantly decreased on the xerostomia and VAS questionnaires, in the domains of thirst (-22%, P = .035) and difficulties in eating solid foods (-2%, P = .008) after four months compared to baseline. The ASC-arm showed significantly improved salivary gland functions of inorganic element secretion and absorption, at baseline and four months, compared to the placebo-arm. Core-needle biopsies showed increases in serous gland tissue and decreases in adipose and connective tissues in the ASC-arm compared to the placebo-arm (P = .04 and P = .02, respectively). MRIs showed no significant differences between groups in gland size or intensity (P < .05). CONCLUSIONS: ASC therapy for radiation-induced hypofunction and xerostomia was safe and significantly improved salivary gland functions and patient-reported outcomes. These results should encourage further exploratory and confirmatory trials.

Comparative study of the human ficolins reveals unique features of Ficolin-3 (Hakata antigen).

The ficolins and mannose-binding lectin (MBL) are collagen-like defence proteins that serve as recognition molecules in lectin complement pathway. Differential features that may indicate diverse functions of these proteins are poorly understood. In this study we compared important biological features of the ficolins and MBL. We investigated the tissue distribution of the FCN1-3 and the MBL2 genes encoding the ficolins and MBL by quantitative PCR. Recombinant proteins were produced and structural and biological characteristics were investigated and compared. Our main findings were that FCN3 mRNA was highly expressed in the liver and lung compared with the other genes revealing the lung as the tissue with the highest FCN3 expression pattern. Ficolin-3 revealed higher complement activating capacity compared with Ficolin-2, MBL and Ficolin-1 and was highly resistant to bacterial collagenase treatment, which is different from the other ficolins and MBL. We discovered several unique properties of Ficolin-3 showing that FCN3 is the most highly expressed gene in liver and lung among the lectin complement pathway initiators. Moreover, Ficolin-3 has a high complement activating potential and is the only collagenase proteolytic resistant molecule among the lectin complement pathway initiators.