Evaluation of Double Tract Reconstruction After Total Gastrectomy in Patients with Gastric Cancer: Prospective Randomized Controlled Trial

Background  The double tract (DT) method was compared with the Roux-en-Y (R-Y) method to identify the optimal reconstruction procedure after total gastrectomy for patients with gastric cancer. The DT reconstruction is as simple as the R-Y, and it can be safely performed even after total gastrectomy. However, these have been no studies evaluating the usefulness of DT reconstruction in comparison to R-Y reconstruction. Methods  A group of 44 patients with gastric cancer were intraoperatively randomized for R-Y (n = 23) or DT reconstruction (n = 21) after total gastrectomy (TG). Body weight, food intake, nutritional conditions, and quality of life (QOL) were determined at 3 and 12 months after the operation. This study is registered with ClinicalTrials.gov, no. NCT00746161. Results  Food intake significantly decreased soon after the operation. No differences were observed between the DT and R-Y groups. The body weight decreased throughout the ensuing period (P < 0.05) and thereafter gradually recovered. However, no differences were observed between the two groups. Among the nutritional laboratory parameters, serum prealbumin, retinol-binding protein, total cholesterol, and triglyceride were decreased soon after the operation. The changes of those parameters were not substantially different between the two groups. The postoperative QOL was evaluated, and no differences were observed between those groups. Conclusions  There were no particular advantages in the DT method after TG in comparison to the simple R-Y method in terms of body weight, QOL, and nutritional conditions, suggesting that the DT method might not be recommended after TG for patients with gastric cancer.     

Three Na+/Ca2+ exchanger (NCX) variants are expressed in mouse osteoclasts and mediate calcium transport during bone resorption

The plasma membrane Na(+)/Ca(2+) exchanger (NCX) is a bidirectional transporter that mediates the exchange of Na(+) for Ca(2+) depending on the electrochemical gradients. Mammalian NCXs form a multigene family comprising NCX1, NCX2, and NCX3 isoforms. Although it has been known that NCX1 in rat osteoclasts is coupled with the Na(+)/ H(+) exchanger for regulation of intracellular Ca(2+) concentration ([Ca(2+)](i)), it is unclear what kind of NCX1 variants are expressed and whether the other two NCX isoforms are also present in mouse osteoclasts. To clarify the role of NCXs during bone resorption, we investigated the expression of NCXs, the ion transport via NCXs, and the effects of NCX inhibitors on bone-resorbing activity in mouse osteoclasts. Using RT-PCR, immunocytochemical, and Western blot methods, we detected three splice variants of NCX1 and NCX3, namely NCX1.3, NCX1.41, and NCX3.2. Of these, NCX1.41 is a newly identified splice variant. Low extracellular sodium ([Na(+)](o)) solution increases the intracellular Ca(2+) concentration via NCX transporter in fura-2-loaded osteoclasts. The [Na(+)](o)-free solution-induced [Ca(2+)](i) increase was suppressed by benzyloxyphenyl NCX inhibitors. Bidirectional NCX currents in mouse osteoclasts were recorded using the patch clamp method and could be suppressed with NCX inhibitors. NCX inhibitors also decreased the resorption pit area surrounding osteoclasts in a dose-dependent manner. Furthermore, small interference RNAs targeted against NCX1.3, NCX1.41, and NCX3.2 expressed in mouse osteoclasts suppressed osteoclastic pit formation. These results show that three NCX variants are expressed in mouse osteoclasts and play an important role for Ca(2+) transport and regulation during osteoclastic bone resorption.     

PTTG is a Secretory Protein in Human Pituitary Adenomas and in Mouse Pituitary Tumor Cell Lines

The pituitary tumor-transforming gene (PTTG) is a homolog of yeast Securin, which arrests the activation of Separin to induce sister chromatid separation in the transition from metaphase to anaphase. Pituitary tumor-transforming gene is also known to induce angiogenesis during pituitary tumorigenesis. It has not been clarified whether PTTG functions as a cytoplasmic or a nuclear protein. Our immunohistochemical study indicated that PTTG is localized in the cytoplasm of pituitary tumor cells. In the present study, confocal laser scanning microscopy (CLSM) analysis of human pituitary adenomas and immunoelectron microscopy of the mouse pituitary cell line, AtT-20, demonstrated the localization of PTTG in the Golgi apparatus and vesicles. Secreted PTTG was detected by immunoblotting from culture medium of mouse pituitary tumor cell lines. Our results suggested that PTTG is a secretory protein produced by pituitary tumor cells. In addition, PTTG may exert autocrine and/or paracrine functions as a newly proposed important pathway for the action of PTTG.     

The induced RNA‐binding protein,HuR, targets 3′‐UTR region of IL‐6 mRNA and enhances its stabilization in periodontitis

RNA‐binding proteins (RBPs) regulate mRNA stability by binding to the 3′‐untranslated region (UTR) region of mRNA. Human antigen‐R (HuR), one of the RBPs, is involved in the progression of diseases, such as rheumatoid arthritis, diabetes mellitus and some inflammatory diseases. Interleukin (IL)‐6 is a major inflammatory cytokine regulated by HuR binding to mRNA. Periodontal disease (PD) is also an inflammatory disease caused by elevations in IL‐6 following an infection by periodontopathogenic bacteria. The involvement of HuR in the progression of PD was assessed using in‐vitro and in‐vivo experiments. Immunohistochemistry of inflamed periodontal tissue showed strong staining of HuR in the epithelium and connective tissue. HuR mRNA and protein level was increased following stimulation with Porphyromonas gingivalis (Pg), one of the periodontopathogenic bacteria, lipopolysacchride (LPS)‐derived from Pg (PgLPS) and tumour necrosis factor (TNF)‐α in OBA‐9, an immortalized human gingival epithelial cell. The luciferase activity of 3′‐UTR of IL‐6 mRNA was increased by TNF‐α, Pg and PgLPS in OBA‐9. Luciferase activity was also increased in HuR‐over‐expressing OBA‐9 following a bacterial stimulation. Down‐regulation of HuR by siRNA resulted in a decrease in mRNA expression and production of IL‐6. In contrast, the over‐expression of HuR increased IL‐6 mRNA expression and production in OBA‐9. The HuR inhibitor, quercetin, suppressed Pg‐induced HuR mRNA expression and IL‐6 production in OBA‐9. An oral inoculation with quercetin also inhibited bone resorption in ligature‐induced periodontitis model mice as a result of down‐regulation of IL‐6. These results show that HuR modulates inflammatory responses by regulating IL‐6.     

VEGF-A induces tumor and sentinel lymph node lymphangiogenesis and promotes lymphatic metastasis

The mechanisms of tumor metastasis to the sentinel lymph nodes are poorly understood. Vascular endothelial growth factor (VEGF)-A plays a principle role in tumor progression and angiogenesis; however, its role in tumor-associated lymphangiogenesis and lymphatic metastasis has remained unclear. We created transgenic mice that overexpress VEGF-A and green fluorescent protein specifically in the skin, and subjected them to a standard chemically-induced skin carcinogenesis regimen. We found that VEGF-A not only strongly promotes multistep skin carcinogenesis, but also induces active proliferation of VEGF receptor-2-expressing tumor-associated lymphatic vessels as well as tumor metastasis to the sentinel and distant lymph nodes. The lymphangiogenic activity of VEGF-A-expressing tumor cells was maintained within metastasis-containing lymph nodes. The most surprising finding of our study was that even before metastasizing, VEGF-A-overexpressing primary tumors induced sentinel lymph node lymphangiogenesis. This suggests that primary tumors might begin preparing their future metastatic site by producing lymphangiogenic factors that mediate their efficient transport to sentinel lymph nodes. This newly identified mechanism of inducing lymph node lymphangiogenesis likely contributes to tumor metastasis, and therefore, represents a new therapeutic target for advanced cancer and/or for the prevention of metastasis.