Hiroki Furue

Limited but heterogeneous osteogenic response of human bone marrow mesenchymal stem cells to bone morphogenetic protein-2 and serum.

Although there are numerous reports describing the in vivo bone forming capability of recombinant human bone morphogenetic proteins-2 (rhBMP-2), studies have reported limited effects on human mesenchymal stem cells (hMSCs). However, the reasons for these discrepancies are not well understood. The aim of this study was to investigate the responsiveness of hMSCs to osteoinductive signals, focusing on rhBMP-2 and the effect of serum on that responsiveness. Human MSCs from six donors were analysed. When those cells were treated with osteoinduction medium including dexamethasone (Dex), alkaline phosphatase (ALP) activities increased in all cell lines. On the other hand, rhBMP-2-containing medium failed to increase ALP activity. When five different sera were used for cultivation and induction with rhBMP-2, ALP activities increased in two of them, but not in the others. The expression of BMP-2 antagonist noggin was induced in almost all combinations regardless of the responsiveness to rhBMP-2. On the other hand, the expression of follistatin showed significant variations depending on the serum and cell line. However, the expression did not correlate with the responsiveness to rhBMP-2. The results from this study showed limited but heterogeneous osteogenic response of hMSCs to rhBMP-2 and that the results are affected by the choice of serum. This fact should be concerned for the successful and effective clinical application of rhBMP-2.

INVERSE ASSOCIATION BETWEEN TOOTHBRUSHING AND UPPER AERODIGESTIVE TRACT CANCER RISK IN A JAPANESE POPULATION

Oral hygiene is attracting increasing attention as a potential risk factor for cancers. To investigate the association between toothbrushing frequency and upper aerodigestive tract (UADT) cancer, the authors conducted a large‐scale case‐control study.

Opposite impact of NKG2D genotype by lifestyle exposure to risk of aerodigestive tract cancer among Japanese

It was reported that there are 2 haplotypes in natural killer complex (NKC) region. One of them could be divided by NKG2D polymorphism into 2 haplotype alleles (high and low natural killer (NK) cell activity) and were associated with overall cancer risks. However, its impact on a specific cancer is unclear. Therefore, by a case‐control study, we analyzed the association between NKG2D genotype and aerodigestive tract cancer risk. Subjects were 502 aerodigestive tract cancer patients (276 with head and neck, 226 with esophageal) and 1,004 sex‐age matched noncancer controls. Exposures to 2 lifestyle factors, smoking and drinking, were evaluated by a self‐administered questionnaire. The genotype of NKG2D was determined by the TaqMan method, and its impact was assessed by multivariable logistic regression models. Association strength was measured by the odds ratio (OR) and its confidence intervals (CI). An overall analysis revealed no statistically significant association between NKG2D genotype and the risk of aerodigestive tract cancer. However, we found protective effects of G allele among never smokers (OR 0.35; 95% CI 0.15–0.84) and never drinkers (0.42; 0.19–0.94). In contrary, increased risks were observed for G allele among heavy smokers (5.92; 3.23–10.85) and heavy drinkers (4.13; 2.29–7.47). Interactions between NKG2D genotype and lifestyle exposure were statistically significant (interaction p = 0.001 for smoking, 0.005 for drinking). The same trends were observed in both sexes, and in head and neck cancer and esophageal cancer independently. These results suggest an opposite impact of NKG2D genotype by lifestyle exposure to the risk of aerodigestive tract cancer among a Japanese population.

Optimization of hyperthermia and dendritic cell immunotherapy for squamous cell carcinoma.

The aims of this study were to explore the feasibility of a novel combination therapy comprising hyperthermia (HT) and dendritic cell (DC) application for squamous cell carcinoma (SCC), and to optimize the conditions of this therapy. In vitro, the correlation between maturation of DCs by co-culture with SCCVII cells and HT was investigated. DCs did not mature in simple HT (43 °C for 30 min) with SCCVII cells. On the other hand, DC maturation occurred in additional mild HT (mHT: 41 °C for 30 min) with simple HT. To assess whether additional mHT was effective, in vivo combined treatment was performed using tumor-bearing C3H/HeJ mice. A more suppressive effect of tumor growth was observed, and cytotoxic T cell infiltration was significantly increased by adding mHT compared to conventional only simple HT with DCs. These phenomena also occurred in non-treated contralateral tumors as well as treated ones. Our data suggest that the combination of 43 °C preheated simple HT SCCVII tumors and additional 41 °C heat mHT promotes DC maturation, resulting in suppression of tumor growth systemically and lifetime prolongation in mice. A three-step process of additional mHT after local HT and intratumoral immature DC (iDC) injection could be a more effective and novel method for the treatment of SCC.