Alveolus-like organoid from isolated tip epithelium of embryonic mouse lung.

Embryonic lungs were obtained from embryonic day 13.5 ICR mice. The lung-tip epithelium isolated using dispase treatment was embedded in low-growth factor Matrigel, cultured in DMEM/F12 medium containing 0.1% bovine serum albumin, supplemented with insulin, transferrin, and selenium (ITS), with or without fibroblast growth factor 7 (FGF7), and were observed for 14 days. With the addition of FGF7, the tip epithelium grew to form a cyst by culture day 7. Then, tubular tufts-like alveolus appeared around the cyst surface. Reverse transcription-polymerase chain reaction revealed that, with the addition of FGF7, the cultured lung explants expressed alveolar-type 1 cell markers, such as HopX and Aquaporin5, and type 2 cell markers, such as Lamp3 and Surfactant apoproteins (Sftp) C and D. Paraffin-embedded sections were stained with hematoxylin and eosin, and alveolar structures at culture day 14 were composed of squamous and cuboidal epithelial cells. Immunohistochemical studies showed that the squamous epithelial cells were positive for HopX, and the cuboidal epithelial cells were positive for pro-SftpC. Furthermore, transmission electron microscopic observation confirmed that the squamous epithelial cells were alveolar-type 1 cells and the cuboidal cells were type 2 cells, because they had many lamellar inclusion bodies. Embryonic lung-tip epithelium forms an alveolus-like organoid through the self organization with the aid of Matrigel, ITS, and FGF7. This method to make alveolus-like organoid in vitro is easy, reproducible, and economical. This method could have potential to solve many issues in alveolar epithelial cells in normal and pathological conditions.

Glycine regulates proliferation and differentiation of salivary-gland-derived progenitor cells.

Amino acids have various physiological activities that influence processes such as intestinal regeneration, EGF secretion, protein synthesis, and cell growth. Salivary glands are exposed to nutrients that influence their proliferation and regeneration. Glycine is included in saliva in large quantities and reportedly has important roles in antibacterial activities and the inhibition of tumor growth and as a precursor of nucleotide synthesis in cell proliferation. We have investigated the effects of glycine on the proliferation and differentiation of salivary glands by using mouse salivary-gland-derived progenitor (mSGP) cells. In cultures of mSGP cells, cell proliferation is suppressed in the presence of glycine, whereas it is promoted by its removal. Glycine promotes three-dimensional formations of mSGP cells, which are negative for immature markers and positive for differentiation markers. In cell-cycle analysis, cell-cycle progression is delayed at the S-phase by glycine supplementation. Glycine also suppresses the phosphorylation of p42/p44MAPK. These results suggest that glycine suppresses the proliferation and promotes the differentiation of mSGP cells, and that it has inhibitory effects on growth factor signaling and cell-cycle progression. Glycine might therefore be a physiological activator that regulates the proliferation and differentiation of salivary glands.

[Clinical and prognostic significance of protein and gene expression of orotate phosphoribosyltransferase in gastric carcinoma].

Although orotate phosphoribosyltransferase (OPRT EC 2.4.2.10) is a key enzyme related to the first-step activation process of 5-fluorouracil, and therefore it has been shown to be an important enzyme that enables to predict sensitivity to 5-fluorouracil, the clinical and prognostic significance of protein and/or gene expression of OPRT has not been well established in gastric carcinoma. We examined the protein level, and mRNA expression of OPRT in gastric carcinoma tissues and relationships with clinicopathologic factors and prognosis were evaluated. A total of 75 surgically-resected gastric carcinoma tissues were subjected to the study. An enzymelinked immunosorbent assay (ELISA) was used to accurately assess intratumoral OPRT, and gene expressions of OPRT were examined using a real-time PCR method. Survival of patients with gastric carcinoma in relation to OPRT protein levels was analyzed using Kaplan-Meier methods along with log-rank test. The mean value of OPRT was 5.4+/-3.6 ng/mg protein, and it was significantly higher in patients with differentiated-type and invasive-type gastric carcinoma. The prognosis of patients in the high OPRT group was better than for those with low OPRT (p<0.05). There was a significant correlation between OPRT levels measured by ELISA and OPRT mRNA expression (p<0.05). Determination of OPRT levels is a useful tool to predict the biological characteristics of gastric carcinoma and possibly predict sensitivity to fluoropyrimidine-based anticancer chemotherapy,particularly dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine, in patients with gastric carcinoma.

Weekly administration of paclitaxel attenuated rectal stenosis caused by multiple peritoneal recurrence 8 years after the resection of gastric carcinoma.

We report a patient with rectal stenosis caused by peritoneal recurrence 8 years after a curative resection of advanced stage gastric carcinoma; the recurrence was effectively treated with the weekly administration of paclitaxel. The patient was a 66-year-old Japanese woman who was admitted to our hospital complaining of abdominal pain and frequent bowel movements. She had undergone total gastrectomy, due to advanced-stage gastric carcinoma with extensive lymph node metastasis, 8 years before, and had taken an oral anticancer agent, fluoropyrimidine, for 4 years after the operation. Colonofiberscopy performed on admission revealed circumferential rectal stenosis located 10 cm from the anal verge. Barium enema study demonstrated extensive poor expansion of the upper and lower rectum and irregularity of the descending colon. Abdominal computed tomography (CT) scanning revealed wall thickening in the rectum and descending colon. These findings were compatible with rectal stenosis caused by the peritoneal recurrence of gastric carcinoma. Weekly administration of paclitaxel was started. The abdominal symptoms soon disappeared when the second cycle of paclitaxel was completed, and they have not appeared since then. The rectal stenosis was attenuated, as confirmed by imaging analyses. Weekly paclitaxel has been effective for more than 13 months, suggesting that the patient is in a state of tumor dormancy of recurrent gastric carcinoma.