Sphingomyelin Phosphodiesterase 3 Enhances Cytodifferentiation of Periodontal Ligament Cells

Sphingomyelin phosphodiesterase 3 ( Smpd3), which encodes neutral sphingomyelinase 2 (nSMase2), is a key molecule for skeletal development as well as for the cytodifferentiation of odontoblasts and alveolar bone. However, the effects of nSMase2 on the cytodifferentiation of periodontal ligament (PDL) cells are still unclear. In this study, the authors analyzed the effects of Smpd3 on the cytodifferentiation of human PDL (HPDL) cells. The authors found that Smpd3 increases the mRNA expression of calcification-related genes, such as alkaline phosphatase (ALPase), type I collagen, osteopontin, Osterix (Osx), and runt-related transcription factor (Runx)-2 in HPDL cells. In contrast, GW4869, an inhibitor of nSMase2, clearly decreased the mRNA expression of ALPase, type I collagen, and osteocalcin in HPDL cells, suggesting that Smpd3 enhances HPDL cytodifferentiation. Next, the authors used exome sequencing to evaluate the genetic variants of Smpd3 in a Japanese population with aggressive periodontitis (AgP). Among 44 unrelated subjects, the authors identified a single nucleotide polymorphism (SNP), rs145616324, in Smpd3 as a putative genetic variant for AgP among Japanese people. Moreover, Smpd3 harboring this SNP did not increase the sphingomyelinase activity or mRNA expression of ALPase, type I collagen, osteopontin, Osx, or Runx2, suggesting that this SNP inhibits Smpd3 such that it has no effect on the cytodifferentiation of HPDL cells. These data suggest that Smpd3 plays a crucial role in maintaining the homeostasis of PDL tissue.

Early results of multicenter phase II trial of perioperative oxaliplatin and capecitabine without radiotherapy for high-risk rectal cancer: CORONA I study

BACKGROUNDS

Perioperative introduction of developed chemotherapy into the treatment strategy for locally advanced rectal cancer (LARC) may be a promising option. However, the most prevalent treatment for high-risk LARC remains preoperative chemoradiotherapy (CRT) in Western countries.

PATIENTS AND METHODS

A phase II trial was undertaken to evaluate safety and efficacy of perioperative XELOX without radiotherapy (RT) for patients with high-risk LARC. Patients received 4 cycles of XELOX before and after surgery, respectively. Primary endpoint was disease-free survival.

RESULTS

We enrolled 41 patients between June 2012 and April 2014. The completion rate of the preoperative XELOX was 90.3%. Twenty-nine patients (70.7%) could start postoperative XELOX, 15 of these patients (51.7%) completed 4 cycles. Allergic reaction to oxaliplatin was experienced by 5 patients (17.2%) during postoperative XELOX. One patient received additional RT after preoperative XELOX. Consequently, the remaining 40 patients underwent primary resection. Major complications occurred in 6 of 40 patients (15.0%). Pathological complete response (pCR) rate was 12.2%, and good tumor regression was exhibited in 31.7%. N down-staging (cN+ to ypN0) and T down-staging were detected in 56.7% and 52.5%, respectively. Clinical T4 tumor was a predictor of poor pathological response (p < 0.001).

CONCLUSIONS

We could show the favorable pCR rate after preoperative XELOX alone. However, the T and N down-staging rate was likely to be insufficient. When tumor regression is essential for curative resection, the use of preoperative CRT is likely to be recommended. For patients with massive LN metastasis, the additional Bev to NAC might be a promising option.

Nucleotide Sequence of the Gene for an Alkaline Endoglucanase from an AlkalophilicBacillusand Its Expression inEscherichia coliandBacillus subtilis

The gene for an alkaline endoglucanase from the alkalophilic Bacillus sp. KSM-64 was cloned into the HindIII site of pBR322 and expressed in Escherichia coli HB101. The nucleotide sequence of a 4.1-kb region of the HindIII insert had two open reading frames, ORF-1 and ORF-2. The protein deduced from ORF-1 was composed of 244 amino acids with an M(r) of 27,865. Subcloning analysis proved that the alkaline endoglucanase was encoded by ORF-2 (822 amino acids with an M(r) of 91,040). Upstream from ORF-2, there were three consensus like sequences of the sigma A-type promoter of Bacillus subtilis, a putative Shine-Dalgarno sequence (AGGAGGT), and a catabolite repression operator-like sequence (TGTAAGCGGTTAACC). The HindIII insert was subcloned into a shuttle vector, pHY300PLK, and the encoded alkaline endoglucanase gene was highly expressed both in E. coli and B. subtilis. One of the three promoter-like sequences in ORF-2 could be suitable for high levels of enzyme expression in both host organisms.

Contrast inversion of the h-BN nanomesh investigated by nc-AFM and Kelvin probe force microscopy

Single sheets of hexagonal boron nitride (h-BN) on transition metals provide a model system for layered insulating materials as well as a functional substrate for molecules and metal clusters. The progress in the understanding of h-BN layers on transition metals was mainly driven by scanning tunnelling microscopy (STM) and photoelectron spectroscopy (PES) measurements within the last decade, while direct measurements of mechanical and electrical properties are still rare. Our investigations of the two-dimensional (2D) h-BN nanomesh on a Rh(111) substrate by high-resolution noncontact atomic force microscopy (nc-AFM) reveal a complex surface structure including a frequently observed contrast inversion. Detailed 2D force spectroscopy measurements are revealing towards a mechanical elastic deformation of the h-BN monolayer caused by the tip-sample interaction. Furthermore, Kelvin probe force microscopy (KPFM) and spectroscopy measurements show local work function variations of the nanomesh, proving the results obtained by PES but additionally providing detailed local information.