Tsuyoshi Notake

Impact of advanced age on the short- and long-term outcomes in patients undergoing hepatectomy for hepatocellular carcinoma: a single-center analysis over a 20-year period

BACKGROUND The purpose of this study was to analyze the influence of age on both the risk of hepatectomy and the prognosis in patients with hepatocellular carcinoma (HCC). METHODS Patients undergoing an initial hepatectomy for HCC were classified into 2 age groups: 75 years or over (n = 113) and less than 75 years (n = 499). RESULTS A zero 90-day mortality was achieved in the elderly. Although the recurrence rate and recurrence sites were almost similar between the 2 groups, the 5-year survival rate in the elderly patients was significantly lower than that in the younger patients (46.0% vs 57.6%; P = .018), possibly because of the higher incidence of deaths from other causes (26.8% vs 10.4%; P = .011) in the elderly. CONCLUSION Selected elderly HCC patients can undergo a hepatectomy safely and can benefit from long-term HCC control comparable with that of their younger counterparts.

IL-15–High-Responder Developing NK Cells Bearing Ly49 Receptors in IL-15−/− Mice

In mice lacking IL-15, NK cell development is arrested at immature stages, providing an opportunity to investigate the earliest developing NK cells that would respond to IL-15. We show in this study that immature NK cells were present in the spleen as well as bone marrow (BM) and contained IL-15–high-responder cells. Thus, mature NK cells were generated more efficiently from IL-15−/− than from control donor cells in radiation BM chimeras, and the rate of IL-15–induced cell division in vitro was higher in NK cells in the spleen and BM from IL-15−/− mice than in those from wild-type mice. Phenotypically, NK cells developed in IL-15−/− mice up to the minor but discrete CD11b–CD27+DX5hiCD51dullCD127dullCD122hi stage, which contained the majority of Ly49G2+ and D+ NK cells both in the spleen and BM. Even among wild-type splenic NK cells, IL-15–induced proliferation was most prominent in CD11b–DX5hi cells. Notably, IL-15–mediated preferential expansion (but not conversion from Ly49– cells) of Ly49+ NK cells was observed in vitro only for NK cells in the spleen. These observations indicated the uneven distribution of NK cells of different developing stages with variable IL-15 responsiveness in these lymphoid organs. Immature NK cells in the spleen may contribute, as auxiliaries to those in BM, to the mature NK cell compartment through IL-15–driven extramarrow expansion under steady-state or inflammatory conditions.

Nomogram predicting long-term survival after the diagnosis of intrahepatic recurrence of hepatocellular carcinoma following an initial liver resection

We appreciate the interest of Drs. Ayubi and Safiri in our study and their insightful comments [1]. We will be able to investigate the validity of our constructed model once the number of events increases in the future. We believe that their comments will help to improve the quality of our future studies greatly. As mentioned in their letter, multivariate results can be biased because of multicollinearity if this phenomenon is not checked during the univariate phase. The multicollinearity among the variables was investigated before their inclusion in the multivariate model, although we did not mention this point in our manuscript [2].

Differential Requirements for IRF-2 in Generation of CD1d-Independent T Cells Bearing NK Cell Receptors

NK cell receptors (NKRs) such as NK1.1, NKG2D, and Ly49s are expressed on subsets of CD1d-independent memory phenotype CD8+ and CD4–CD8– T cells. However, the mechanism for the generation and functions of these NKR+ T cells remained elusive. In this study, we found that CD1d-independent Ly49+ T cells were reduced severely in the spleen, bone marrow, and liver, but not thymus, in mice doubly deficient for IFN regulatory factor-2 (IRF-2) and CD1d, in which the overall memory phenotype T cell population was contrastingly enlarged. Because a large fraction of Ly49+ T cells coexpressed NK1.1 or NKG2D, the reduction of Ly49+ T cells resulted indirectly in underrepresentation of NK1.1+ or NKG2D+ cells. Ly49+ T cell deficiency was observed in IRF-2−/− mice additionally lacking IFN-α/βR α-chain (IFNAR1) as severely as in IRF-2−/− mice, arguing against the involvement of the accelerated IFN-α/β signals due to IRF-2 deficiency. Rather, mice lacking IFN-α/βR alone also exhibited relatively milder Ly49+ T cell reduction, and IL-2 could expand Ly49+ T cells from IFNAR1−/−, but not from IRF-2−/−, spleen cells in vitro. These results together indicated that IRF-2 acted in Ly49+ T cell development in a manner distinct from that of IFN-α/β signals. The influence of IRF-2 deficiency on Ly49+ memory phenotype T cells observed in this study suggested a unique transcriptional program for this T cell population among other NKR+ T and memory phenotype T cells.

Survival pathway of cholangiocarcinoma via AKT/mTOR signaling to escape RAF/MEK/ERKpathway inhibition by sorafenib

Cholangiocarcinoma (CCC) is a strongly aggressive malignancy for which surgical resection is the only potential curative therapy. Sorafenib, a multikinase inhibitor of the RAF/MEK/ERK pathway, is a molecular-targeted drug that is approved for hepatocellular carcinoma (HCC) but not for CCC. The differences in signaling pathway characteristics under sorafenib treatment between HCC (HLF, Huh7, PLC/PRF/5) and CCC (RBE, YSCCC, Huh28) cell lines were therefore investigated using cell proliferation, western blotting, and apoptosis analyses. Sorafenib inhibited cell growth significantly less in CCC cells than in HCC cells, with lower suppression of ERK phosphorylation. Significantly decreased AKT Ser473 phosphorylation in HCC cells, and conversely enhanced phosphorylation of AKT Ser473 and mTORC2 in CCC cells, were observed with sorafenib treatment. Disassembly of the mTORC2 complex in RBE cells with siRNA targeting Rictor resulted in the downregulation of AKT Ser473 phosphorylation and enhanced apoptosis presumably via increased FOXO1, which consequently suppressed RBE cell proliferation. Phosphorylation of mTORC1 and autophagy were not influenced by sorafenib in CCC cells. Simultaneous administration of everolimus to suppress activated mTORC1 in RBE cells revealed that combined everolimus and sorafenib treatment under mTORC2 disassembly could enhance growth inhibition through the suppression of both sorafenib- and everolimus-dependent AKT Ser473 phosphorylation in addition to the inhibition of mTORC1 phosphorylation. Prevention of escape by AKT/mTOR signaling from the RAF/MEK/ERK pathway in sorafenib treatment by suppressing mTORC2 activity may lead to promising new approaches in CCC therapy.

Treatment with specific soluble factors promotes the functional maturation of transcription factor-mediated, pancreatic transdifferentiated cells

Pancreatic lineage-specific transcription factors (TFs) display instructive roles in converting adult cells to endocrine pancreatic cells through a process known as transdifferentiation. However, little is known about potential factors capable of accelerating transdifferentiation following transduction to achieve the functional maturation of transdifferentiated cells. In this study, we demonstrated, using adult liver-derived progenitor cells, that soluble factors utilized in pancreatic differentiation protocols of pluripotent stem cells promote functional maturation of TFs-mediated transdifferentiated cells. Treatment with an N2 supplement in combination with three soluble factors (glucagon-like peptide-1 [GLP-1] receptor agonist, notch inhibitor, and transforming growth factor-β [TGF-β] inhibitor) enhanced liver-to-pancreas transdifferentiation based on the following findings: i) the incidence of c-peptide-positive cells increased by approximately 1.2-fold after the aforementioned treatment; ii) the c-peptide expression level in the treated cells increased by approximately 12-fold as compared with the level in the untreated cells; iii) the treated cells secreted insulin in a glucose-dependent manner, whereas the untreated cells did not; and iv) transplantation of treated-transdifferentiated cells into streptozotocin-induced immunodeficient diabetic mice led to the amelioration of hyperglycemia. These results suggest that treatment with specific soluble factors promotes the functional maturation of transdifferentiated cells. Our findings could facilitate the development of new modalities for cell-replacement therapy for patients with diabetes.

Tu1061 Impact of Multiple Tumors or Portal Hypertension on the Results of Second Hepatectomy for Recurrent Hepatocellular Carcinoma: A Single Center Experience

Background & Aims: Roayaie et al. reported a 5-year overall survival (OS) rate of 67% after second hepatectomy for recurrent hepatocellular carcinoma (HCC) in highly selected patients with a single nodule, preserved liver function, and noportal hypertension (PHT). The aim of this study was whether second liver resection can offer survival benefit for patients with multiple HCCs and/or PHT. Methods: We retrospectively studied 101 patients who had undergone second liver resection for recurrent HCC and stratified them into 3 groups according to the number of tumors and the presence of PHT, defined as a platelet count , 100,000/μL and/or the presence of esophageal varices: group A, patients with solitary tumor and no-PHT (n = 45); group B, those with either multiple tumor or PHT (n = 48); and Group C, those with both multiple tumor and PHT (n = 8). Overall survival (OS) and recurrence rate (RR) curves were constructed by the Kaplan-Meier method, and multivariate regression analysis was performed using the Cox proportional hazard model. Results: There was no 30-day mortality. The morbidity rate was comparable among the groups. The 5year OS rates and the 2-year recurrent rates were 67% and 60% in group A, 62%and 55% in group B, and 38% and 88% in group C, respectively, showing no significant differences among the three groups. In a multivariate analysis, neither multiple tumors nor presence of PHT was a predictive factor for poor prognosis. Conclusions: We can extend the indication of second hepatectomy for recurrent HCC, at least, to the patients with either multiple HCCs or PHT.