Human lung microvascular endothelial cells as potential alternatives to human umbilical vein endothelial cells in bio-3D-printed trachea-like structures.

BACKGROUND: We have been trying to produce scaffold-free structures for airway regeneration using a bio-3D-printer with spheroids, to avoid scaffold-associated risks such as infection. Previous studies have shown that human umbilical vein endothelial cells (HUVECs) play an important role in such structures, but HUVECs cannot be isolated from adult humans. The aim of this study was to identify alternatives to HUVECs for use in scaffold-free structures. METHODS: Three types of structure were compared, made of chondrocytes and mesenchymal stem cells with HUVECs, human lung microvascular endothelial cells (HMVEC-Ls), and induced pluripotent stem cell (iPSC)-derived endothelial cells. RESULTS: No significant difference in tensile strength was observed between the three groups. Histologically, some small capillary-like tube formations comprising CD31-positive cells were observed in all groups. The number and diameters of such formations were significantly lower in the iPSC-derived endothelial cell group than in other groups. Glycosaminoglycan content was significantly lower in the iPSC-derived endothelial cell group than in the HUVEC group, while no significant difference was observed between the HUVEC and HMVEC-L groups. CONCLUSIONS: HMVEC-Ls can replace HUVECs as a cell source for scaffold-free trachea-like structures. However, some limitations were associated with iPSC-derived endothelial cells.

Prognostic influence of the liver hanging maneuver for patients with hepatobiliary malignancies who underwent hepatic resections.

BACKGROUND: Prognostic influences of hepatic transection by an anterior approach using the liver hanging maneuver (LHM) has not been fully clarified. METHODS: We examined 233 patients who underwent major hepatectomy with the LHM (n = 75; hepatocellular carcinoma (HCC) in 35, colorectal liver metastasis (CLM) in 10, intrahepatic cholangiocarcinoma (ICC) in 14 and perihilar bile duct carcinoma (BDC) in 16) or without it (n = 158; HCC in 78, CLM in 21, ICC in 31 and BDC in 28). RESULTS: In HCC patients, cancer-positive margin rate, blood loss, transection time and prevalence of posthepatectomy ascites in the LHM group were significantly lower than those in the non-LHM group (p < 0.05). In CLM, transection time in the LHM group was significantly lower than that in the non-LHM group (p < 0.05). In BDC patients, amount of blood loss, transection time and prevalence of ascites in the LHM group were significantly lower than those in the non-LHM group (p < 0.05). In CLM patients, tumor recurrence rate in the non-LHM group was significantly higher than that in the LHM group and disease-free survival in the LHM group was significantly better than that in the non-LHM group in CLM patients and, however, this difference was not observed in a large CLM exceeding 5 cm. However, significant differences of posthepatectomy disease-free and overall survivals were not observed in HCC, ICC and BDC patients. CONCLUSIONS: Although advantages of LHM improving surgical records in major anatomical liver resections were clarified, oncological advantages in the long-term survival of LHM was still uncertain in the hepatobiliary malignancies.

Relationship between period of survival and clinicopathological characteristics in patients with colorectal liver metastasis.

AIM: Cancer death in the early period after hepatectomy still occurs in patients with colorectal liver metastasis (CLM). We examined the relationship between clinicopathological parameters and survival periods in 130 CLM patients who underwent hepatectomy. PATIENTS/METHODS: Patients were divided into four groups: Group 1 (5-year survivors without tumor relapse), Group 2 (survivors at 2-5 years), Group 3 (cancer death at 2-5 years), and Group 4 (cancer death within 2 years). RESULTS: A short surgical margin was frequent in Group 4 compared to Group 1 (31 vs. 78%, P<0.05). Primary node-positive status, absence of fibrous pseudo-capsular formation, higher Clinical Risk Score, and tumor recurrence within 12 months were frequent in Group 4 (P<0.05). Multivariate analysis revealed a short surgical margin (HR; 3.5) and early tumor relapse (HR; 5.9) as independently significant related parameters (P<0.05). CONCLUSIONS: Sufficient surgical margins and careful follow-up for early tumor relapse may be important for improving postoperative outcomes for CLM patients.

Enhanced methyltransferase activity of SMYD3 by the cleavage of its N-terminal region in human cancer cells.

Histone methylation is involved in the regulation of gene expression and DNA replication through alteration of chromatin structure. We earlier showed that SMYD3, a histone H3-lysine 4-specific methyltransferase, is frequently upregulated in human colorectal, liver and breast cancer compared to their matched non-cancerous cells, and that its activity is associated with the growth of these tumors. In the present study, we found that human cancer cells express both the full-length and a cleaved form of SMYD3 protein. Amino acid sequence analysis uncovered that the cleaved form lacks the 34 amino acids in the N-terminal region of the full-length protein. Interestingly, the cleaved protein and mutant protein containing substitutions at glycines 15 and 17, two highly conserved amino acids in the N-terminal region, revealed a higher histone methyltransferase (HMTase) activity compared to the full-length protein. Furthermore, the N-terminal region is responsible for the association with heat shock protein 90alpha (HSP90alpha). These data indicate that the N-terminal region plays an important role for the regulation of its methyltransferase activity and suggest that a structural change of the protein through the cleavage of the region or interaction with HSP90alpha may be involved in the modulation. These findings may help for a better understanding of the mechanisms that modulate the HMTase activity of SMYD3, and contribute to the development of novel anticancer drugs targeting SMYD3 methyltransferase activity.