Impact of endothelial nitric oxide synthase activation on accelerated liver regeneration in a rat ALPPS model.

BACKGROUND: Although the associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) induces more rapid liver regeneration than portal vein embolization, the mechanism remains unclear. AIM: To assess the influence of inflammatory cytokines and endothelial nitric oxide synthase (eNOS) activation on liver regeneration in ALPPS. METHODS: The future liver remnant/body weight (FLR/BW) ratio, hepatocyte proliferation, inflammatory cytokine expression, and activation of the Akt-eNOS pathway were evaluated in rat ALPPS and portal vein ligation (PVL) models. Hepatocyte proliferation was assessed based on Ki-67 expression, which was confirmed using immunohistochemistry. The serum concentrations of inflammatory cytokines were measured using enzyme linked immune-solvent assays. The Akt-eNOS pathway was assessed using western blotting. To explore the role of inflammatory cytokines and NO, Kupffer cell inhibitor gadolinium chloride (GdCl3), NOS inhibitor N-nitro-arginine methyl ester (L-NAME), and NO enhancer molsidomine were administered intraperitoneally. RESULTS: The ALPPS group showed significant FLR regeneration (FLR/BW: 1.60% ± 0.08%, P < 0.05) compared with that observed in the PVL group (1.33% ± 0.11%) 48 h after surgery. In the ALPPS group, serum interleukin-6 expression was suppressed using GdCl3 to the same extent as that in the PVL group. However, the FLR/BW ratio and Ki-67 labeling index were significantly higher in the ALPPS group administered GdCl3 (1.72% ± 0.19%, P < 0.05; 22.25% ± 1.30%, P < 0.05) than in the PVL group (1.33% ± 0.11% and 12.78% ± 1.55%, respectively). Phospho-Akt Ser473 and phospho-eNOS Ser1177 levels were enhanced in the ALPPS group compared with those in the PVL group. There was no difference between the ALPPS group treated with L-NAME and the PVL group in the FLR/BW ratio and Ki-67 labeling index. In the PVL group treated with molsidomine, the FLR/BW ratio and Ki-67 labeling index increased to the same level as in the ALPPS group. CONCLUSION: Early induction of inflammatory cytokines may not be pivotal for accelerated FLR regeneration after ALPPS, whereas Akt-eNOS pathway activation may contribute to accelerated regeneration of the FLR.

Safety and oncological benefits of hepatectomy for hepatocellular carcinoma in octogenarians.

BACKGROUND: The number of octogenarians requiring surgery for hepatocellular carcinoma (HCC) is increasing. However, the safety of hepatectomy in octogenarians remains controversial. The aim of this retrospective study was to determine the effect of age on the short- and long-term outcomes of hepatectomy for HCC to evaluate the safety of hepatectomy for octogenarians. METHODS: Data from a total of 845 patients who underwent initial hepatectomy for HCC between April 1990 and March 2021 were retrospectively reviewed. Patients were categorized based on the age at the time of surgery (<80 years, n = 790; ≥80 years, n = 55), and the short- and long-term postoperative outcomes of the two groups were compared to evaluate whether hepatectomy is appropriate for octogenarian patients. RESULTS: The proportion of octogenarian patients undergoing hepatectomy increased from 2.6% in 1990-1995 to 16.8% in 2016-2020 (P < 0.001), and the overall incidences of anatomical and major hepatectomy have increased. There was no significant difference in the morbidity rate between the octogenarians and the group of patients <80 years old (60.0% vs. 54.4%, P = 0.420), and the 90-day mortality rate was 0% in the octogenarian group. Furthermore, the two groups had similar overall survival and recurrence-free survival rates (P = 0.173 and 0.671, respectively). CONCLUSION: Favorable postoperative outcomes following initial hepatectomy for HCC are achieved in appropriately selected octogenarians.

Small-sized Pulmonary Adenocarcinoma Manifesting Skip-like Transition from Nonsolid Nodule: A Case Report.

This report shows a case with a rare small-sized lung adenocarcinoma that rapidly progressed from a nonsolid nodule (NSN) to a solid nodule (SON) over a period of just 1 year after a very long-term observation from its first detection. In 2007, the patient was an asymptomatic 52-year-old man at the time of the first detection via chest low-dose computed tomography (CT) screening as part of a periodic medical checkup at our hospital. It revealed an abnormal shadow in another location of the lung field, necessitating a more thorough examination. Then, he visited our outpatient clinic for the first time and a workup examination was performed using thin-section CT (TSCT) images, which incidentally detected a small NSN with a maximum diameter of 1.2 cm in the mid-zone of the left upper lung field. Since it did not disappear in the periodic subsequent workup examinations, the patient was informed of the suspicious early lung adenocarcinoma each time; however, the patient desired to continue watchful waiting. The radiographical properties of the NSN remained almost unchanged until 2019, but in 2020, the inside of the nodule showed a skip-like change to a SON. Finally, because of the unexpectedly fast transition, consent for lobectomy could be obtained. Surgery was then performed, 13 years after its first detection, at an age of 65 years. The pathological findings revealed a 1.2 cm, pT1bN0M0, pStage IA2-adenocarcinoma, which was 90% of the acinar subtype with positive vascular permeation. Management of a NSN, that does not resolve and/or change, must continue watchful waiting, and at the very least continue follow-up with TSCT observation to ensure the safe and appropriate timing of excision using imaging as a marker of transition.

Extramedullary hematopoiesis in gastric wall under early gastric cancer in a man with a myeloproliferative disorder: a case report.

Extramedullary hematopoiesis (EMH) is the proliferation of hematopoietic stem cells outside the bone marrow and often observed in the liver, spleen in association with myeloproliferative disorders. On the other hand, EMH in the gastric wall is extremely rare. We report a rare case of EMH foci coexisting with early gastric cancer, which resulted in severe gastrointestinal bleeding. A 70-year-old male was diagnosed with myelofibrosis 4 years ago and visited our emergency room with a complaint of hematemesis and tarry stools. Upper gastrointestinal endoscopy revealed three early-stage gastric cancers in the lower gastric body and antrum, and biopsy was performed. Persistent bleeding at the biopsy site of the hypogastric lesion led to the consideration of surgical intervention. An open distal gastrectomy was performed. Postoperative histopathological examination revealed the tumor of the lower gastric body had EMH foci associated with myelofibrosis.

Clinical and neonatal outcomes of individually vitrified human sperm with Cryotop and Cell Sleeper.

Technique for preserving limited number of human spermatozoa is important for successful treatment of patients with azoospermia and cryptozoospermia. This study determined whether the non-biological devices (Cryotop and Cell Sleeper) efficiently vitrify small numbers of human spermatozoa. From December 2011 to December 2018, 10 males with very low sperm numbers managed with a single sperm vitrification method. Post-warmed sperm recovery was similar with both devices. Post-warmed sperm motility and fertilization after intracytoplasmic sperm injection were significantly higher in Cryotop group than in Cell Sleeper group (40.0% vs. 22.0%, P < 0.01 and 50.7% vs. 21.7%, P < 0.01, respectively). The pregnancy rate was 15.4% and 2 healthy babies were born in the Cryotop, while 14.3% and 1 baby in the Cell Sleeper, which did not differ between the groups. Both devices have clinical advantages in terms of easy use and safety, and would be performed more efficiently by using devices with different properties.

Survival Outcomes of Gemcitabine Plus S-1 Adjuvant Chemotherapy after Surgical Resection for Advanced Biliary Tract Cancer.

INTRODUCTION: The usefulness of adjuvant chemotherapy in biliary tract cancer (BTC) is poorly reported. This study aimed to evaluate the effectiveness and safety of adjuvant gemcitabine plus S-1 (GS) chemotherapy after curative surgical resection for BTC. METHODS: 225 BTC patients who underwent surgical resection between January 2006 and May 2019 were enrolled in this study. Twenty-seven patients received adjuvant chemotherapy with GS (GS group), whereas 67 patients underwent surgery alone (S group). Twenty-three matching pairs were derived through propensity score (PS) matching analysis. Patients received 12 cycles of adjuvant chemotherapy (70 mg/m2 oral S-1 for 7 consecutive days plus intravenous gemcitabine 1,000 mg/m2 on day 7). The primary end point was recurrence-free survival (RFS). The secondary end points were the 1-, 2-, and 3-year RFS and overall survival (OS) rates, tolerability, and frequency of grade 3/4 toxicity. RESULTS: The completion rate was 81.5%; no treatment-related deaths were observed. Grade 3/4 adverse events were seen in 40.7% of the patients. RFS (3-year RFS rate: 59.3% vs. 39.1%, p = 0.049) and OS (3-year OS rate: 71.7% vs. 53.4%, p = 0.008) were significantly better in the GS group than in the S group among PS-matched pairs. DISCUSSION/CONCLUSION: GS chemotherapy after curative surgery was well tolerated, showed better clinical benefit in the adjuvant setting, and can effectively reduce BTC recurrence.

Laser-assisted hatching on clinical and neonatal outcomes in patients undergoing single vitrified Blastocyst transfer: A propensity score-matched study.

PURPOSE: This study determined the effect of laser-assisted hatching on the clinical and neonatal outcomes of single vitrified blastocyst transfer. METHODS: From June 2014 to March 2018, 289 matched pairs after propensity score matching were analyzed. During the blastocyst warming procedure, a small section of the zona pellucida area in the empty perivitelline space was sliced off using multiple laser beams. The clinical and neonatal outcomes of the laser-treated group and non-treatment control were analyzed. RESULTS: In the laser-assisted hatching group, significantly higher rates of clinical pregnancy (40.8% vs 29.4%, P < .01) and live delivery (34.3% vs 22.5%, P < .01) were observed compared to the control group. Other variables such as the average gestational weeks, the sex of the baby, birthweight, or congenital malformations were found to have no significant differences in neonatal outcomes. Moreover, all babies were singleton live births. CONCLUSIONS: Single vitrified blastocyst transfer treated with laser-assisted hatching increases the live birth rate and has no adverse effects on neonatal outcomes.

Usefulness and limitation of indocyanine green fluorescence for detection of peritoneal recurrence after hepatectomy for hepatocellular carcinoma: a case report.

BACKGROUND: Peritoneal recurrence of hepatocellular carcinoma (HCC) after hepatectomy occurs rarely, accounting for less than 1% of all recurrences. Reported causes of such dissemination include a history of rupture of the original HCC, needle biopsy or puncture treatment, and surgical procedures. There is no consensus on the optimal treatment strategy for peritoneal dissemination. There have been few reports on assisting resection of peritoneal dissemination by using indocyanine green (ICG) fluorescence. CASE PRESENTATION: A 57-year-old man underwent posterior sectionectomy for HCC. Six months later, computed tomography revealed multiple nodules suspected of indicating peritoneal dissemination. Various preoperative imaging studies demonstrated only four nodules, the doubling time of the tumors being rapid at 22 days. The nodules were therefore resected. ICG (0.5 mg/kg) was injected intravenously 2 days before the procedure, enabling identification of the nodules by their brightness in the operative field under near-infrared lighting. A total of eight lesions were detected during the procedure and resected, some of which had not been identified by preoperative imaging studies. We diagnosed peritoneal dissemination of HCC based on the pathological findings and their similarity to those of the original HCC. We concluded that the recurrences were likely attributable to exposure of the tumor to the serosa at the time of the original operation. CONCLUSIONS: Although ICG fluorescence is useful for identifying peritoneal dissemination of HCC, attention should be paid to the difficulty in detecting deep lesions and occurrence of false positives.

Applicability of sentinel lymph node oriented treatment strategy for gallbladder cancer.

BACKGROUND: Utility of the sentinel lymph node (SLN) biopsy in some malignancies has been reported, however, research on that of gallbladder cancer (GBC) is rare. The aim of this study is to investigate whether the concept of SLN is applicable to T2/3 GBC. METHODS: A total of 80 patients who underwent resection for gallbladder cancer were enrolled in this study. Patients with GBC were stratified into two groups based on the location of tumor, peritoneal-side (T2p or 3p) and hepatic-side (T2h or 3h) groups. We evaluated the relationship between cystic duct node (CDN) and downstream lymph node (LN) status. CDN was defined as a SLN in this study. RESULTS: Thirty-eight patients were classified into T2, including T2p (n = 18) and T2h (n = 20), and 42 patients into T3, including T3p (n = 22) andT3h (n = 20). The incidence of LN metastasis was significantly higher in hepatic-side than peritoneal-side in both T2 and T3 (P = 0.036 and 0.009, respectively). In T2, 14 T2p had negative CDN and downstream LN, however, three T2h had negative CDN and positive downstream LNs (defined as a skipped LN metastasis) (P = 0.043). In T3, patients with skipped LN metastasis were significantly higher in T3h (n = 11) than those in T3p (n = 2) (P<0.001). There was no recurrence of the local lymph node. Disease-free survival in the T2p and T3p were significantly better than those in the T2h and T3h (P = 0.005 and 0.025, respectively). CONCLUSION: The concept of SLN can be applicable to T2p GBC, where the downstream LNs dissection can be omitted.

Safety and Oncological Benefit of Hepatopancreatoduodenectomy for Advanced Extrahepatic Cholangiocarcinoma with Horizontal Tumor Spread: Shinshu University Experience.

BACKGROUND: Although hepatopancreatoduodenectomy (HPD) is the only means of achieving R0 resection of widespread extrahepatic cholangiocarcinoma, its safety and oncological benefit remain controversial because of its inherent high risk of mortality and morbidity. OBJECTIVE: The aim of this study was to retrospectively analyze short- and long-term outcomes and evaluate the safety and oncological benefit of this advanced procedure. METHODS: The study cohort comprised 37 consecutive patients who had undergone major HPD. Portal vein embolization was performed before surgery in 20 (54%) patients with future remnant liver volume < 35%. RESULTS: The median operative time and blood loss were 866 min and 1000 mL, respectively. Concomitant vascular resection was performed in five patients (14%). The overall morbidity and mortality rates were 100% and 5.4% (n = 2), respectively. Nineteen patients (51%) had major (Clavien-Dindo grade III or higher) complications, the most common being intra-abdominal infection (49%) and post-hepatectomy liver failure (46%, grade B/C: 32%/5%), followed by postoperative pancreatic fistula (30%, grade B/C). R0 resection was achieved in 31 patients (84%). The 1-, 3-, and 5-year overall survival (OS) rates were 83%, 48%, and 37%, respectively. In patients with R0 resection, 5-year OS was comparable between patients who had undergone major HPD and major hepatectomy alone (41% vs. 40%, p = non-significant). CONCLUSIONS: HPD is a valid treatment option for extensive cholangiocarcinoma, offering long-term survival benefit at the cost of relatively high but acceptable morbidity and mortality rates. HPD is advocated in selected patients provided that it is considered possible to achieve R0 resection.

Impact of Remnant Carcinoma in Situ at the Ductal Stump on Long-Term Outcomes in Patients with Distal Cholangiocarcinoma.

BACKGROUND: The management of positive ductal margins with carcinoma in situ (R1-CIS) after resection is controversial. The aim of this study was to evaluate the impact of R1-CIS on survival in patients who underwent resection for distal cholangiocarcinoma. METHODS: We enrolled 121 consecutive patients with distal cholangiocarcinoma. Poor prognostic factors were investigated by multivariable analysis, and we performed a stratified analysis to evaluate the impact of R1-CIS on survival in patients with or without prognostic factors. RESULTS: Multivariable analysis identified node-positive status as the prognostic factor (P = 0.003). Stratified by lymph node status, overall survival (OS) in the R0 group was significantly better than that in the R1-CIS group in node-negative patients (57.1% vs 30.0%; P < 0.050). Although OS was comparable between the two groups in node-positive patients (5-year OS: 22.2% vs 20.0%, respectively; P = not significant). Furthermore, OS in patients in whom R0 was achieved by additional resection was significantly better than that in patients with R1-CIS (5-year OS: 66.7% vs 30.0%, respectively; P < 0.050). CONCLUSIONS: Remnant CIS is associated with a poor prognosis in patients with node-negative distal cholangiocarcinoma. Every effort should be made to achieve negative bile duct margins.

Preoperative C-reactive protein-to-albumin ratio predicts long-term outcomes in extrahepatic cholangiocarcinoma patients.

BACKGROUND: Systemic inflammation may have prognostic value in some malignancies and association with lymph node metastasis. This study aimed to evaluate the impact of systemic inflammatory biomarkers on long-term and oncological outcomes as well as to assess the association between biomarkers with lymph node metastasis in extrahepatic cholangiocarcinoma patients. METHODS: We enrolled 271 consecutive patients who underwent surgical resection for extrahepatic cholangiocarcinoma. Poor prognostic factors were compared to identify the biomarkers that were most associated with overall survival (OS) and disease-free survival (DFS) using receiver operating characteristic curves and multivariable analysis. Furthermore, we evaluated the relationship between biomarkers and lymph node metastasis. RESULTS: Four and two biomarkers were predictive for OS and DFS, respectively, among which, the C-reactive protein-to-albumin ratio (CAR) had the highest area under the curve values (OS: 0.631, DFS: 0.624). Multivariable analysis showed that a high CAR was an independent prognostic factor for both OS and DFS (P = .002 and P < .001, respectively). Although a high CAR was not significantly correlated with lymph node metastasis (P = .645), carbohydrate antigen 19-9 showed a significant correlation (P < .001). CONCLUSIONS: Preoperative CAR is the most accurate prognostic factor for OS and DFS in extrahepatic cholangiocarcinoma patients and is independent of lymph node metastasis.

Effect of equilibration time on clinical and neonatal outcomes in human blastocysts vitrification.

PURPOSE: Prolonged exposure to equilibration solutions may be detrimental to an embryo's developmental potential, whereas a shorter exposure may affect the penetration of cryoprotectants into blastomeres. The purpose of this study was to evaluate the effects of different equilibration times on the clinical and neonatal outcomes of human blastocyst vitrification. METHODS: This is a retrospective study based on data collected between November 2008 and November 2015. A total of 192 blastocysts (80 non-expanded and 112 expanded) obtained from 167 patients were analyzed. The blastocysts were divided into two groups according to their equilibration time: 8-11 minutes or 12-15 minutes. The clinical and neonatal outcomes of warmed blastocysts were evaluated. RESULTS: The survival, implantation, and live birth rates of non-expanded blastocysts were not different between the two groups, but they significantly improved for the expanded blastocysts in the 12-15 minutes group compared to the 8-11 minutes group. The results were similar for the neonatal outcomes after vitrified embryo transfer, when partitioned by equilibration time and blastocyst stage at vitrification. CONCLUSIONS: For the non-expanded blastocysts, a shortened equilibration time (8-11 minutes) is sufficient for effective vitrification.

Left-sided portal hypertension caused by idiopathic splenic vein stenosis improved by splenectomy: a case report.

BACKGROUND: Splenic vein stenosis and occlusion, which are known causes of left-sided portal hypertension, often occur secondary to trauma, pancreatitis, or invasion or compression by pancreatic tumors. However, few reports have described idiopathic splenic vein stenosis. CASE PRESENTATION: A 70-year-old man was referred to our hospital for examination of isolated gastric varices. He had no history of liver disease, pancreatitis, or abdominal trauma. Computed tomography revealed stenosis of almost the entire length of the splenic vein, and development of gastric fundal and short gastric varices. No inflammatory changes or neoplastic lesions of the pancreas were observed in any imaging study. The patient was diagnosed with left-sided portal hypertension caused by idiopathic splenic vein stenosis, and splenectomy was performed. The postoperative course was smooth, and improvement of the gastric varices was shown by upper gastrointestinal endoscopy at 3 months after the operation. CONCLUSIONS: Idiopathic splenic vein stenosis is an extremely rare cause of left-sided portal hypertension. Splenectomy is one of the most effective treatments for left-sided portal hypertension caused by idiopathic splenic vein stenosis.

Evaluation of the effect of piezo-intracytoplasmic sperm injection on the laboratory, clinical, and neonatal outcomes.

PURPOSE: Limited research has been published on the effect of piezo-assisted intracytoplasmic sperm injection (P-ICSI). We evaluated the effect of P-ICSI on the laboratory, clinical, and neonatal outcomes. METHODS: This retrospective study was based on the data collected between April 2011 and October 2016. Total 1348 mature oocytes from 145 patients were analyzed. Laboratory, clinical, and neonatal outcomes of those given conventional intracytoplasmic sperm injection (C-ICSI) and those administered P-ICSI were examined. RESULTS: P-ICSI showed significantly more favorable results, with a survival rate of 97.0% (C-ICSI: 94.1%, P < .010) and a fertilization rate of 83.5% (C-ICSI: 70.6%, P < .001). There were no differences in the blastocyst development rate, implantation rate, miscarriage rate, live birth rate, gestational age, birth weight, proportion of male neonates, cesarean section rate, and congenital abnormalities between the two patient groups. CONCLUSIONS: Our comparison of P-ICSI with C-ICSI showed that P-ICSI significantly improved the survival and fertilization.

Effect on clinical and neonatal outcomes of blastocelic microsuction prior to vitrification.

PURPOSE: Microsuction (MS) is a technique for mechanically emptying fluid from blastocele using a microneedle. In this study, we evaluated the improvement in clinical and neonatal outcomes of vitrified blastocyst transfer programs when MS of blastocelic fluid was used before vitrification. METHODS: This was a retrospective study based on data collected between March 2014 and August 2016. A total of 317 blastocysts obtained from 211 patients were analyzed. The blastocelic fluid of expanded blastocysts was aspirated completely, and blastocysts were collapsed prior to vitrification. Clinical and neonatal outcomes of warmed blastocysts were compared. RESULTS: The survival rate of the MS blastocyst was significantly higher compared with the nontreatment control (98.7% vs 89.3%, OR: 9.34, 95% CI: 2.35-36.8, P < 0.01). The rates of implantation and live birth were higher in the MS group than in the control group, but the differences were not significant. There were no differences in gestational age, birthweight, proportion of male babies, rates of cesarean section, and congenital abnormalities. CONCLUSION: The MS procedure improved blastocyst survival and had little effect on further embryo development after warming.

Impact of age on groin hernia profiles observed during laparoscopic transabdominal preperitoneal hernia repair.

BACKGROUND: How increasing age affects the characteristics of groin hernia remains uncertain. This study evaluated the association between age and the type of groin hernia, especially with respect to its multiplicity, observed during laparoscopic transabdominal preperitoneal (TAPP) hernia repair. METHODS: We retrospectively evaluated 634 consecutive patients with primary groin hernia who underwent laparoscopic TAPP repair between October 2000 and June 2017. Patients were stratified into 4 age groups: < 60 years, 60-69 years, 70-79 years, and 80 years or older. RESULTS: The incidence of occult contralateral hernia and multiple ipsilateral hernias increased significantly with each increasing age group: 7.3%, 10.4%, 12.7%, and 20.8% for occult contralateral hernia (p = 0.005), and 5.6%, 9.2%, 16.8%, and 21.7% for multiple ipsilateral hernias (p < 0.001), respectively. Univariate analyses showed that an older age (age ≥ 70 years) was the only factor significantly associated with the presence of multiple groin hernias (odds ratio, 2.69; 95% confidence interval, 1.89-3.81; p < 0.001). In patients with multiple ipsilateral hernias, the prevalent form in men was a pantaloons hernia, with an incidence of about 70% across all age groups, whereas in women it was groin hernias, with one component being a femoral hernia, an obturator hernia, or both. CONCLUSIONS: The multiple occurrence of groin hernias, either unilaterally or bilaterally, was a clinical feature in the elderly.

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-ß [TGF-ß] 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.

Survival pathway of cholangiocarcinoma via AKT/mTOR signaling to escape RAF/MEK/ERK pathway 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.