Miglustat, a glucosylceramide synthase inhibitor, mitigates liver fibrosis through TGF-ß/Smad pathway suppression in hepatic stellate cells.

Transforming growth factor (TGF)-ß/Smad pathway is implicated in the pathogenesis of liver fibrosis, a condition characterized by excessive deposition of extracellular matrix (ECM) proteins such as collagen in response to chronic inflammation. It has been reported that ceramide regulates collagen production through TGF-ß/Smad pathway activation. In this study, we examined whether miglustat, an inhibitor of glucosylceramide synthase, can suppress liver fibrosis by reducing TGF-ß/Smad pathway activity. Human hepatic stellate cells (HHSteCs) were cultured with TGF-ß and multiple miglustat concentrations to examine dose-dependent effects on the expression levels of ECM-related genes and Smad proteins. To evaluate the efficacy of miglustat for fibrosis mitigation, C57BL/6 mice were treated with carbon tetrachloride (CCl4) for 4 weeks to induce liver fibrosis, followed by combined CCl4 plus miglustat for a further 2 weeks. To examine if miglustat can also prevent fibrosis, mice were treated with CCl4 for 2 weeks, followed by CCl4 plus miglustat for 2 weeks. Miglustat dose-dependently downregulated expression of α-smooth muscle actin and ECM components in TGF-ß-treated HHSteCs. Both phosphorylation and nuclear translocation of Smad2 and Smad3 were also suppressed by miglustat treatment. Sirius-Red staining and hydroxyproline assays of model mouse liver samples revealed that miglustat reduced fibrosis, an effect accompanied by decreased expression of ECM. Our findings suggest that miglustat can both prevent and reverse liver fibrosis by inhibiting TGF-ß/Smad pathway.

Multicenter Retrospective Analysis of Original versus Modified FOLFIRINOX in Metastatic Pancreatic Cancer: Results of the NAPOLEON Study.

INTRODUCTION: Original FOLFIRINOX (oFFX) is more toxic than other regimens for patients with metastatic pancreatic cancer (mPC); therefore, a modified FFX (mFFX) regimen with a reduced dosage has been used in Japanese clinical practice. However, very few studies have compared these two regimens. METHODS: This study was conducted as part of a multicenter retrospective study of 318 patients with mPC across 14 centers in Japan (NAPOLEON study). To control for potential bias and confounders, we conducted a propensity score-adjusted analysis of patient characteristics and clinical outcomes. RESULTS: oFFX and mFFX were administered to 48 and 54 patients. More patients with younger age and poorer performance status were included in the oFFX group. The overall survival (OS; median, 11.6 vs. 11.3 months; hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.60-1.40; p = 0.67), progression-free survival (PFS) (median, 6.3 vs. 5.7 months; HR, 0.85; 95% CI, 0.56-1.28; p = 0.44), and overall response rate (29 vs. 26%, p = 0.71) were not significantly different for the oFFX and mFFX groups. Thrombopenia and liver dysfunction were significantly more frequent with oFFX than with mFFX. The median received dose intensity of CPT-11 was higher with oFFX than with mFFX (299 vs. 270 mg/m2/week, p < 0.01). The propensity score-adjusted analysis revealed no statistically significant differences in OS and PFS between the two groups. CONCLUSION: In our data, there was no significant difference in efficacy between mFFX and oFFX, and mFFX has fewer adverse events.

Scoring model with serum albumin and CA19-9 for metastatic pancreatic cancer in second-line treatment: results from the NAPOLEON study.

BACKGROUND: Patients with metastatic pancreatic cancer refractory to first-line chemotherapy (CTx) have few treatment options. It is unclear what kind of patients could be brought about survival benefit by 2nd-line CTx after refractory to gemcitabine + nab-PTX (GnP) or FOLFIRINOX. METHODS: This analysis was conducted as part of a multicenter retrospective study of GnP or FOLFIRINOX in patients with metastatic pancreatic cancer. Excluding censored cases, 156 and 77 patients, respectively, received second-line chemotherapy (CTx) and best supportive care (BSC). Using prognostic factors for post-discontinuation survivals (PDSs) at the first-line determination in multivariate analysis, we developed a scoring system to demonstrate the benefit of second-line CTx. RESULTS: The second-line CTx group had a median PDS of 5.2 months, whereas the BSC group had a median PDS of 2.7 months (hazard ratio 0.42; 95% confidence interval [CI] 0.31-0.57; p < 0.01). According to the Cox regression model, serum albumin levels below 3.5 g/dL, and CA19-9 levels above 1000 U/mL were independent prognostic factors (p < 0.01). Serum albumin (≥ and < 3.5 g/dL allotted to scores 0 and 1) and CA19-9 (< and ≥ 1000 U/mL allotted to scores 0 and 1) at first-line determination were used to develop the scoring system. The PDSs of patients with scores of 0 and 1 were significantly better than those of the BSC group; however, there was no significant difference between the PDSs of patients with score 2 and the BSC group. CONCLUSION: The survival advantage of second-line CTx, was observed in patients with scores of 0 and 1 but not in those with score 2.

Prognostic nomogram for patients with unresectable pancreatic cancer treated with gemcitabine plus nab-paclitaxel or FOLFIRINOX: A post-hoc analysis of a multicenter retrospective study in Japan (NAPOLEON study).

BACKGROUND: No reliable nomogram has been developed until date for predicting the survival in patients with unresectable pancreatic cancer undergoing treatment with gemcitabine plus nab-paclitaxel (GnP) or FOLFIRINOX. METHODS: This analysis was conducted using clinical data of Japanese patients with unresectable pancreatic cancer undergoing GnP or FOLFIRINOX treatment obtained from a multicenter study (NAPOLEON study). A Cox proportional hazards model was used to identify the independent prognostic factors. A nomogram to predict 6-, 12-, and 18-month survival probabilities was generated, validated by using the concordance index (C-index), and calibrated by the bootstrapping method. And then, we attempted risk stratification for survival by classifying the patients according to the sum of the scores on the nomogram (total nomogram points). RESULTS: A total of 318 patients were enrolled. A prognostic nomogram was generated using data on the Eastern Cooperative Oncology Group performance status, liver metastasis, serum LDH, serum CRP, and serum CA19-9. The C-indexes of the nomogram were 0.77, 0.72 and 0.70 for 6-, 12-, and 18-month survival, respectively. The calibration plot showed optimal agreement at all points. Risk stratification based on tertiles of the total nomogram points yielded clear separations of the survival curves. The median survival times in the low-, moderate-, and high-risk groups were 15.8, 12.8 and 7.8 months (P<0.05), respectively. CONCLUSIONS: Our nomogram might be a convenient and inexpensive tool to accurately predict survival in Japanese patients with unresectable pancreatic cancer undergoing treatment with GnP or FOLFIRINOX, and will help clinicians in selecting appropriate therapeutic strategies for individualized management.

Effects of ceramide kinase knockout on lipopolysaccharide-treated sepsis-model mice: Changes in serum cytokine/chemokine levels and increased lethality.

Ceramide, a central molecule of sphingolipid metabolism, is phosphorylated to ceramide-1-phosphate (C1P) by ceramide kinase (CerK). The CerK/C1P pathway regulates many cellular functions, but its roles in immune/inflammation-related (IIR) diseases in vivo are not well known. Sepsis is an acute systemic inflammatory disease accompanied by damage/dysfunction in multiple organs. In the present study, we investigated the effects of CerK knockout on the onset/progression of sepsis-related events in lipopolysaccharide (LPS)-treated sepsis-model mice. In CerK-null mice, the lethality at 48 h after i.v. injection of LPS was significantly increased compared with that in wild-type (WT) mice. The increased lethality by CerK knockout was reproduced in mice treated with i.p. injections of LPS. Changes in serum levels of 23 IIR molecules, including cytokines and chemokines, were measured. In WT mice, levels of these molecules increased 4 and/or 20 h after i.v. injection of LPS. Although the basal levels of IIR molecules were not affected, LPS-induced increases in interleukin-17 (IL-17), C-C motif chemokine ligands (CCL-2 and CCL-11), and tumor necrosis factor-α were significantly up-regulated, whereas IL-2 levels were slightly down-regulated by CerK knockout. Putative mechanisms for the CerK/C1P pathway-mediated regulation of IIR molecules and increased lethality in LPS-treated mice are discussed.

Tankyrase Regulates Neurite Outgrowth through Poly(ADP-ribosyl)ation-Dependent Activation of ß-Catenin Signaling.

Poly(ADP-ribosyl)ation is a post-translational modification of proteins by transferring poly(ADP-ribose) (PAR) to acceptor proteins by the action of poly(ADP-ribose) polymerase (PARP). Two tankyrase (TNKS) isoforms, TNK1 and TNK2 (TNKS1/2), are ubiquitously expressed in mammalian cells and participate in diverse cellular functions, including wnt/ß-catenin signaling, telomere maintenance, glucose metabolism and mitosis regulation. For wnt/ß-catenin signaling, TNKS1/2 catalyze poly(ADP-ribosyl)ation of Axin, a key component of the ß-catenin degradation complex, which allows Axin's ubiquitination and subsequent degradation, thereby activating ß-catenin signaling. In the present study, we focused on the functions of TNKS1/2 in neuronal development. In primary hippocampal neurons, TNKS1/2 were detected in the soma and neurites, where they co-localized with PAR signals. Treatment with XAV939, a selective TNKS1/2 inhibitor, suppressed neurite outgrowth and synapse formation. In addition, XAV939 also suppressed norepinephrine uptake in PC12 cells, a rat pheochromocytoma cell line. These effects likely resulted from the inhibition of ß-catenin signaling through the stabilization of Axin, which suggests TNKS1/2 enhance Axin degradation by modifying its poly(ADP-ribosyl)ation, thereby stabilizing wnt/ß-catenin signaling and, in turn, promoting neurite outgrowth and synapse formation.

[Wasted Anti-Cancer Agents Due to Cancellations after Dispensing].

At our hospital, anti-cancer drug administration is managed using a regimen-ordering system, and orders for the outpatient department and hospital wards have to be placed by 15:00 and 14:00 the day before they are required. On the day of treatment, the doctor examines the patient, confirms the test results, and places the final order for treatment on the patient's electronic medical record. In response, the pharmacist adjusts the anti-cancer drug preparation, and treatment is provided in the outpatient setting or in a ward. Although drug costs have increased due to the widespread use of immunotherapy, there have been cases where a drug was wasted after the required amount was adjusted on the day of treatment or drugs were discarded altogether, which pose serious problems. From April 2016 to March 2021, the total number of cases of drug wastage following placement of the final treatment order and drug disposal were 146 and 84, respectively, and the total associated economic loss was 5.81 million yen. The main causes were pre-confirmation mistakes and patients' physical condition on the day of treatment; some cancellations caused by patient-related factors were unavoidable. The current status of drug disposal is reported to the hospital director every 6 months, and the doctor-in-charge is interviewed regarding the reason for the wastage. In cases involving the disposal of large quantities of drugs(≥100,000 yen), the department manager and medical office manager are contacted, and an incident report is submitted. In 2021, drugs worth 2.03 million yen were discarded between April and September, which is worth serious consideration. It is essential to understand the reasons for drug wastage, pay attention to expensive regimens, and take appropriate measures at each facility.

Amyloid Beta-Peptide 25-35 (Aß25-35) Induces Cytotoxicity via Multiple Mechanisms: Roles of the Inhibition of Glucosylceramide Synthase by Aß25-35 and Its Protection by D609.

Sphingolipids (SLs), such as ceramide, glucosylceramide (GlcCer), and sphingomyelin, play important roles in the normal development/functions of the brain and peripheral tissues. Disruption of SL homeostasis in cells/organelles, specifically up-regulation of ceramide, is involved in multiple diseases including Alzheimer's disease (AD). One of the pathological features of AD is aggregates of amyloid beta (Aß) peptides, and SLs regulate both the formation/aggregation of Aß and Aß-induced cellular responses. Up-regulation of ceramide levels via de novo and salvage synthesis pathways is reported in Aß-treated cells and brains with AD; however, the effects of Aß on ceramide decomposition pathways have not been elucidated. Thus, we investigated the effects of the 25-35-amino acid Aß peptide (Aß25-35), the fundamental cytotoxic domain of Aß, on SL metabolism in cells treated with the fluorescent nitrobenzo-2-oxa-1,3-diazole-labeled C6-ceramide (NBD-ceramide). Aß25-35 treatment reduced the formation of NBD-GlcCer mediated by GlcCer synthase (GCS) without affecting the formation of NBD-sphingomyelin or NBD-ceramide-1-phosphate, and reduced cell viability. Aß25-35-induced responses decreased in cells treated with D609, a putative inhibitor of sphingomyelin synthases. Aß25-35-induced cytotoxicity significantly increased in GCS-knockout cells and pharmacological inhibition of GCS alone demonstrated cytotoxicity. Our study revealed that Aß25-35-induced cytotoxicity is at least partially mediated by the inhibition of GCS activity.

A multicenter propensity score analysis of FOLFIRINOX vs gemcitabine plus nab-paclitaxel administered to patients with metastatic pancreatic cancer: results from the NAPOLEON study.

PURPOSE: Fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX, FFX) and gemcitabine plus nab-paclitaxel (GnP) are considered standard treatments for patients with metastatic pancreatic cancer. Direct comparisons are not available that establish which is optimal. METHODS: We conducted a propensity score-adjusted analysis of patients with metastatic pancreatic cancer to identify the therapeutic advantages of these standard therapies. We used clinical data as part of a multicenter retrospective study of patients with unresectable or recurrent pancreatic cancer treated with FFX or GnP (NAPOLEON study). RESULTS: FFX and GnP were initially administered to 102 and 153 patients, respectively. The GnP group comprised more patients of advanced age, worse performance status, lower body mass index, recurrence, and lower albumin concentrations. Median overall survival (OS) and progression-free survival (PFS) were 11.5 months and 5.8 months in the FFX group and 11.1 months and 5.9 months in the GnP group, respectively. Propensity score-adjusted analysis indicated that the administration of FFX or GnP was not independently associated with OS (adjusted hazard ratio [HR] 1.06; 95% confidence interval [CI] 0.76-1.47; P = 0.73). Similarly, the difference in PFS was not significant between groups (adjusted HR 0.93; 95% CI 0.68-1.26; P = 0.62). Gastrointestinal disorders were more common in the FFX group, whereas the frequencies of hematological, nervous system, and skin disorders were higher in the GnP group. CONCLUSION: The efficacies of FFX and GnP were comparable, although safety profiles differed and should be considered in selecting treatment.

Impact of single-heterozygous UGT1A1 on the clinical outcomes of irinotecan monotherapy after fluoropyrimidine and platinum-based combination therapy for gastric cancer: a multicenter retrospective study.

BACKGROUND: It is unclear whether the UGT1A1 status, single heterozygous (SH) or wild type (WT), is associated with the efficacy and toxicity of irinotecan monotherapy in advanced gastric cancer (AGC). We investigated the association between clinical outcomes (efficacy and safety) and UGT1A1 status in patients who received irinotecan monotherapy. METHODS: We evaluated AGC patients who received irinotecan monotherapy between January 2011 and December 2017. Efficacy was assessed according to overall survival (OS) and progression-free survival (PFS). Toxicity was graded using the Common Toxicity Criteria for Adverse Events (version 4.0). RESULTS: A total of 100 patients were evaluated (62 and 38 patients with UGT1A1 WT and SH, respectively). In the WT and SH groups, the irinotecan dose was reduced in 19 (30.6%) and 18 (47.2%) patients (p = 0.135), respectively; treatment was delayed due to adverse events (AEs) in 19 (30.6%) and 13 (34.2%) patients (p = 0.826), respectively; the median PFS was 3.15 and 3.25 months (HR, 0.734; 95% CI 0.465-1.158; p = 0.184), respectively; and the median OS was 10.4 and 7.26 months (HR, 1.137; 95% CI 0.752-1.721; p = 0.543), respectively. Severe hematological AEs (Grade ≥ 3) were significantly more frequent in the SH group than in the WT group (63% vs. 36%; p = 0.008), while severe non-hematological AEs was not significantly different (16.0% vs. 6.5%; p = 0.173). CONCLUSION: There was no significant difference in the efficacy of irinotecan monotherapy between UGT1A1 WT and UGT1A1 SH, but UGT1A1 SH was associated with a high frequency of severe hematological toxicity.

[Trends in Outpatient Chemotherapy for Thoracic Oncology].

We conducted a survey of the outpatient pharmacotherapy we administered from April 2016 to March 2019 to understand trends in chemotherapy for respiratory thoracic malignancies, such as lung cancer. Over the 3-year period, 19,408 were treated in the outpatient chemotherapy department. Of these, 1,270(6.5%)had respiratory thoracic malignancies. The total number of patients and the number of patients with thoracic malignancies(%) were 5,815 and 320(5.5%); 6,344 and 434(6.8%); and 7,247 and 516(7.1%)in FY2016, FY2017 and FY2018, respectively. This shows that both increased during the study period. Each patient was treated in the chemotherapy department multiple times, and treatment for thoracic malignancies was initiated in 161 patients. The female:male ratio was 27%:73%, and the patients' median age(range)was 68 years(range: 36-84 years). Lung cancer was the most common disease(91%), followed by malignant pleural mesothelioma(5%), thymoma(2%), thymic carcinoma(1%), and synovial sarcoma(1%). The most common histological type of lung cancer was adenocarcinoma(67%), followed by squamous cell carcinoma(17%), small cell carcinoma( 7%), and others(9%). Outpatient chemotherapy was introduced as a first-line, second-line, and third-line or later treatment in 46%, 28%, and 22% of cases, respectively. While the number of patients increased, the number of new patients with thoracic malignancies decreased from 58 in FY2016 to 52 in FY2017 and 51 in FY2018. Conversely, the number of visits to the chemotherapy department by each new patient almost doubled from 5.5 in FY2016 to 8.5 in FY2017 and 10.1 in FY2018. The proportion of patients for which immunotherapy was included in the induction treatment regimen increased from 28% and 24% in FY2016 and FY2017, respectively, to 39% in FY2018. The increase in the use of outpatient chemotherapy for respiratory thoracic malignancies was due to the increase in the proportion of patients undergoing immunotherapy and the number of visits to the chemotherapy department per patient. It is important to implement measures to help prolong and increase the use of outpatient pharmacotherapy for respiratory thoracic malignancies by cooperating with surrounding medical institutions and increasing the number of beds available.

Forkhead box protein A1 confers resistance to transforming growth factor-ß-induced apoptosis in breast cancer cells through inhibition of Smad3 nuclear translocation.

Transforming growth factor-ß (TGF-ß) induces apoptosis of normal epithelial cells, such as mammary epithelium. Although breast cancer progression associates with acquisition of resistance to TGF-ß-induced apoptosis, the molecular mechanisms underlying this resistance are largely unknown. Here, we show that forkhead box protein A1 (FOXA1), which is known as a pioneer transcription factor, suppresses TGF-ß-induced apoptosis of estrogen receptor-positive breast cancer cells. FOXA1 is found to inhibit nuclear translocation of Smad3, a key transcription factor downstream of TGF-ß signaling, through suppression of the binding of Smad3 to the nuclear import receptor importin7. Furthermore, RNA sequencing analyses show that knockdown of FOXA1 upregulates Smad3-mediated proapoptotic gene expression. These results demonstrate that FOXA1 as a potent survival factor that suppresses TGF-ß-induced apoptosis by inhibiting Smad3 signaling in estrogen receptor-positive breast cancer cells. Thus, we provide evidence for the first time that FOXA1 localizing to the cytoplasm negatively regulates Smad3-induced apoptosis in TGF-ß-mediated signal transduction.

[Efforts toward Venous Access of Anti-Cancer Drug by Nurses].

Our hospital has an established outpatient chemotherapy room, and medical doctors have accessed veins for infusion so far. We trialed venous access by nurses for the purpose of managing safe and proper cancer chemotherapy, reducing the work of doctors, and reducing patient waiting time. A questionnaire was conducted in June 2013, and nurses secured routes at 19 facilities(58%)of the 33 national university hospitals. In November of the same year, the working group was established, and from September 2016 to March 2017, lectures, practical skills, a paper test, and a practical test were conducted; successful applicants were approved as in-hospital certified nurses. From April 2017, we started intravenous injection of anti-cancer drugs by nurses in outpatient chemotherapy rooms and always waiting for doctor in chemotherapy room. There have been many favorable reports of reduced pain and less route failure from patients, and issues, such as extravasation and dyspnea, have not occurred yet. The doctors who were interrupting their work by 29 minutes(20 minutes to and from the patient for a 9-minute procedure)could concentrate on their own tasks. However, patient waiting time increased from 14 minutes to 21 minutes because the amount of work for nurses increased. In the future, reducing the burden on nurses, for example, by increasing the number of nurses, is warranted.

Src Acts as an Effector for Ku70-dependent Suppression of Apoptosis through Phosphorylation of Ku70 at Tyr-530.

Src-family tyrosine kinases are widely expressed in many cell types and participate in a variety of signal transduction pathways. Despite the significance of Src in suppression of apoptosis, its mechanism remains poorly understood. Here we show that Src acts as an effector for Ku70-dependent suppression of apoptosis. Inhibition of endogenous Src activity promotes UV-induced apoptosis, which is impaired by Ku70 knockdown. Src phosphorylates Ku70 at Tyr-530, being close to the possible acetylation sites involved in promotion of apoptosis. Src-mediated phosphorylation of Ku70 at Tyr-530 decreases acetylation of Ku70, whereas Src inhibition augments acetylation of Ku70. Importantly, knockdown-rescue experiments with stable Ku70 knockdown cells show that the nonphosphorylatable Y530F mutant of Ku70 reduces the ability of Ku70 to suppress apoptosis accompanied by augmentation of Ku70 acetylation. Our results reveal that Src plays a protective role against hyperactive apoptotic cell death by reducing apoptotic susceptibility through phosphorylation of Ku70 at Tyr-530.

First-line chemotherapy with S-1 alone or S-1 plus cisplatin for elderly patients with advanced gastric cancer: a multicenter propensity score matched study.

BACKGROUND: Fluoropyrimidine and platinum combination is the standard treatment for advanced or recurrent gastric cancer (AGC). However, fluoropyrimidine monotherapy is commonly used for elderly patients with AGC because of its good tolerability. METHODS: In this multicenter retrospective study, we collected clinical data of AGC patients aged 70 years or older, treated with S-1 alone or S-1 plus cisplatin (SP) as the first-line treatment between January 2009 and December 2011. Propensity score matched cohorts (PSMC) were used for reducing the confounding effects to compare efficacy and safety between the two treatment groups. Cox regression analysis was performed to clarify the prognostic factors. RESULTS: PSMC (n = 109 in each group) were selected from among 444 eligible patients (S-1 group, 210; SP group, 234); the S-1 group included more patients deemed unfit for intensive chemotherapy than the SP group (e.g., higher age, poorer PS, poor renal function). In the PSMC, patients' characteristics were comparable between groups, except the male ratio (S-1 group, 64.2%; SP group, 77.1%; p = 0.04). No significant differences were observed in either overall survival [hazard ratio (HR) 0.93, p = 0.63] or progression-free survival (HR 1.09, p = 0.61). Severe adverse events (AEs) and hospitalization due to AEs were more frequent in the SP group than in the S-1 group (p < 0.001 each). CONCLUSION: Our findings do not support the survival benefit of SP over S-1 in elderly patients with AGC. We are now conducting a prospective comparative study to optimize treatment strategy and explore applicability of the geriatric assessment for these patients.

Trafficking of Acetyl-C16-Ceramide-NBD with Long-Term Stability and No Cytotoxicity into the Golgi Complex.

The Golgi complex plays a prominent role in the modification and sorting of lipids and proteins, and is a highly dynamic organelle that is dispersed and rearranged before and after mitosis. Several reagents including 4-nitrobenzo-2-oxa-1,3-diazole-labeled C6-ceramide (NBD-C6-ceramide, a ceramide having an NBD-bound C6-N-acyl chain) and Golgi-specific proteins that emit fluorescence are used as Golgi markers. In the present study, we synthesized a new ceramide analog, acetyl-C16-ceramide-NBD (a ceramide having an acetylated C-1 hydroxyl group, C16-N-acyl chain, and NBD-bound C15-sphingosine), and showed that it preferentially accumulated in the Golgi complex without cytotoxicity for over 24 h. Pathways for cellular uptake and interorganelle trafficking of acetyl-C16-ceramide-NBD were investigated. Acetyl-C16-ceramide-NBD was transported to the Golgi complex via ceramide transport proteins. In contrast to NBD-C6-ceramide, acetyl-C16-ceramide-NBD was resistant to ceramide metabolic enzymes such as sphingomyelin synthase and glucosylceramide synthase. Because of its weaker cytotoxicity and resistance to ceramide metabolic enzymes, the localization of the Golgi complex could be observed in acetyl-C16-ceramide-NBD-labeled cells before and after mitosis.

The Truncated Isoform of the Receptor Tyrosine Kinase ALK Generated by Alternative Transcription Initiation (ALKATI) Induces Chromatin Structural Changes in the Nucleus in a Kinase Activity-Dependent Manner.

Anaplastic lymphoma kinase (ALK) is a receptor-type tyrosine kinase that promotes cell growth upon stimulation with ligands such as midkine and pleiotrophin. Recently, a truncated isoform of ALK was identified in a variety of tumors. This isoform is expressed from a novel ALK transcript initiated from a de novo alternative transcription initiation (ATI) site in ALK intron 19 (referred to as ALKATI). ALKATI, which consists of only the intracellular kinase domain, localizes to the nucleus as well as the cytoplasm. However, its nuclear role is unknown. In this study, we determined that ALKATI promoted chromatin structural changes in the nucleus in a kinase activity-dependent manner. We found that expression of ALKATI increased the level of the heterochromatin marker Lys9 tri-methylated histone H3. In addition, we demonstrated that ALKATI phosphorylated the nuclear protein A-kinase anchoring protein 8 (AKAP8) and altered its subcellular localization from the insoluble fraction to the soluble fraction. These results suggest that ALKATI induces chromatin structural changes and heterochromatinization through phosphorylation of AKAP8 in the nucleus.

FOXA1 Induces E-Cadherin Expression at the Protein Level via Suppression of Slug in Epithelial Breast Cancer Cells.

Epithelial-to-mesenchymal transition (EMT) is an important process during embryonic development and tumor progression by which adherent epithelial cells acquire mesenchymal properties. Forkhead box protein A1 (FOXA1) is a transcriptional regulator preferentially expressed in epithelial breast cancer cells, and its expression is lost in mesenchymal breast cancer cells. However, the implication of this biased expression of FOXA1 in breast cancer is not fully understood. In this study, we analyzed the involvement of FOXA1 in EMT progression in breast cancer, and found that stable expression of FOXA1 in the mesenchymal breast cancer MDA-MB-231 cells strongly induced the epithelial marker E-cadherin at the mRNA and protein levels. Furthermore, stable expression of FOXA1 was found to reduce the mRNA and protein expression of Slug, a repressor of E-cadherin expression. FOXA1 knockdown in the epithelial breast cancer MCF7 cells reduced E-cadherin protein expression without decreasing its mRNA expression. In addition, FOXA1 knockdown in MCF7 cells up-regulated Slug mRNA and protein expression. Notably, similar to FOXA1 knockdown, stable expression of Slug in MCF7 cells reduced E-cadherin protein expression without decreasing its mRNA expression. Taken together, these results suggest that although FOXA1 can induce E-cadherin mRNA expression, it preferentially promotes E-cadherin expression at the protein level by suppressing Slug expression in epithelial breast cancer, and that the balance of this FOXA1-Slug axis regulates EMT progression.

Anti-cancer Effects of MW-03, a Novel Indole Compound, by Inducing 15-Hydroxyprostaglandin Dehydrogenase and Cellular Growth Inhibition in the LS174T Human Colon Cancer Cell Line.

Increases in the expression of prostaglandin E2 (PGE2) are widely known to be involved in aberrant growth in the early stage of colon cancer development. We herein demonstrated that the novel indole compound MW-03 reduced PGE2-induced cAMP formation by catalization to an inactive metabolite by inducing 15-hydroxyprostaglandin dehydrogenase through the activation of peroxisome proliferator-activated receptor-γ. MW-03 also inhibited colon cancer cell growth by arresting the cell cycle at the S phase. Although the target of MW-03 for cell cycle inhibition has not yet been identified, these dual anti-cancer effects of MW-03 itself and/or its leading compound(s) on colon cancer cells may reduce colon cancer development and, thus, have potential as a novel treatment for the early stage of this disease.

Hepatitis C Virus Infection Increases c-Jun N-Terminal Kinase (JNK) Phosphorylation and Accentuates Hepatocyte Lipoapoptosis.

BACKGROUND Hepatitis C virus (HCV) infection and metabolic diseases including nonalcoholic steatohepatitis (NASH) exhibit a complex interplay. Although free fatty acid-mediated apoptosis is a prominent feature of NASH, the impact of HCV infection on hepatocyte lipotoxicity has remained largely unexplored. The study aimed at identifying whether infection by HCV affected the apoptotic pathway in hepatocytes during fatty acid assault. MATERIAL AND METHODS OR6 cells, which are derived from human hepatocellular carcinoma Huh-7 cells and harbor a full-length HCV RNA genome replication system, were treated with palmitate. Apoptosis was examined by 4',6-diamidino-2-phenylindole staining. Activation and expression of JNK, Bim, cIAP-1, and Mcl-1 were examined by immunoblotting. mRNA expression of CHOP, a major player in endoplasmic reticulum stress-mediated apoptosis, was assessed by real-time PCR. RESULTS Palmitate-induced hepatocyte apoptosis was significantly enhanced in OR6 cells compared to cured cells, in which the HCV genome had been eradicated by treatment with interferon-α. Although basal expression of CHOP mRNA was enhanced in OR6 cells compared to cured cells, it was similarly upregulated in both cell lines following palmitate treatment. Notably, palmitate-induced JNK phosphorylation was accentuated in OR6 cells compared to cured cells. Inhibition of JNK with SP600125 attenuated palmitate-induced apoptosis. Palmitate-mediated upregulation of BH3-only protein Bim, which acts downstream of JNK, was also enhanced in OR6 cells compared to cured cells. In contrast, Mcl-1 and cIAP-1 were equally reduced in OR6 cells and cured cells following palmitate treatment. CONCLUSIONS These findings suggest that during lipoapoptosis, HCV infection may enhance hepatocyte toxicity by increasing JNK phosphorylation.