Caffeine Supplementation and FOXM1 Inhibition Enhance the Antitumor Effect of Statins in Neuroblastoma.

High-risk neuroblastoma exhibits transcriptional activation of the mevalonate pathway that produces cholesterol and nonsterol isoprenoids. A better understanding of how this metabolic reprogramming contributes to neuroblastoma development could help identify potential prevention and treatment strategies. Here, we report that both the cholesterol and nonsterol geranylgeranyl-pyrophosphate branches of the mevalonate pathway are critical to sustain neuroblastoma cell growth. Blocking the mevalonate pathway by simvastatin, a cholesterol-lowering drug, impeded neuroblastoma growth in neuroblastoma cell line xenograft, patient-derived xenograft (PDX), and TH-MYCN transgenic mouse models. Transcriptional profiling revealed that the mevalonate pathway was required to maintain the FOXM1-mediated transcriptional program that drives mitosis. High FOXM1 expression contributed to statin resistance and led to a therapeutic vulnerability to the combination of simvastatin and FOXM1 inhibition. Furthermore, caffeine synergized with simvastatin to inhibit the growth of neuroblastoma cells and PDX tumors by blocking statin-induced feedback activation of the mevalonate pathway. This function of caffeine depended on its activity as an adenosine receptor antagonist, and the A2A adenosine receptor antagonist istradefylline, an add-on drug for Parkinson's disease, could recapitulate the synergistic effect of caffeine with simvastatin. This study reveals that the FOXM1-mediated mitotic program is a molecular statin target in cancer and identifies classes of agents for maximizing the therapeutic efficacy of statins, with implications for treatment of high-risk neuroblastoma. SIGNIFICANCE: Caffeine treatment and FOXM1 inhibition can both enhance the antitumor effect of statins by blocking the molecular and metabolic processes that confer statin resistance, indicating potential combination therapeutic strategies for neuroblastoma. See related commentary by Stouth et al., p. 2091.

Outcomes of patients with malignant duodenal obstruction after receiving self-expandable metallic stents: A single center experience.

OBJECTIVES: Self-expandable metallic stent (SEMS) placement is a safe and effective palliative treatment for malignant gastric outlet obstruction; however, the clinical outcomes of gastric and duodenal stenoses may differ. This study aimed to investigate the clinical efficacy of SEMS placement and the predictors of clinical outcomes, specifically in malignant duodenal obstruction (MDO). METHODS: Between September 2009 and March 2021, 79 patients with MDO who received SEMS placement in our hospital were retrospectively enrolled. Patients were divided into three groups according to the obstruction levels: above-papilla group (type 1), papilla involved group (type 2), and below-papilla group (type 3). The clinical outcomes and predictors of survival and restenosis were analyzed. RESULTS: The technical and clinical success rates were 97.5% and 80.5%, respectively. Among patients who had successful stent placement, stent restenosis occurred in 17 patients (22.1%). The overall median stent patency time was 103 days. The overall median survival time after stent placement was 116 days. There was no difference in the stent patency, or stent dysfunction and procedure-related adverse events among the three groups. A longer length of duodenal stenosis ≥ 4 cm was associated with poor prognosis (hazard ratio [HR] = 1.92, 95% confidence interval [CI] = 1.06-3.49, p = 0.032) and post-stent chemotherapy was associated with lower mortality (HR = 0.33; 95% CI = 0.17-0.63, p = 0.001). CONCLUSION: SEMS is a safe and effective treatment for MDO. Chemotherapy after SEMS implantation improve the survival for these patients and a longer length of stenosis predicts higher mortality.

The effects of whole-body vibration amplitude on glucose metabolism, inflammation, and skeletal muscle oxygenation.

Whole-body vibration (WBV) is an exercise mimetic that elicits beneficial metabolic effects. This study aims to investigate the effects of WBV amplitude on metabolic, inflammatory, and muscle oxygenation responses. Forty women and men were assigned to a high (HI; n = 20, Age: 31 ± 6 y) or a low-amplitude group (LO; n = 20, Age: 33 ± 6 y). Participants engaged in 10 cycles of WBV [1 cycle =1 min of vibration followed by 30 s of rest], while gastrocnemius muscle oxygen consumption (mVO2 ) was assessed using near-infrared spectroscopy (NIRS). Blood samples were collected PRE, POST, 1H, 3Hs, and 24H post-WBV and analyzed for insulin, glucose, and IL-6. In the LO group, Homeostatic Model Assessment for Insulin Resistant (HOMA-IR) at 3 h (0.7 ± 0.2) was significantly lower compared to PRE (1.1 ± 0.2; p = 0.018), POST (1.3 ± 0.3; p = 0.045), 1H (1.3 ± 0.3; p = 0.010), and 24H (1.4 ± 0.2; p < 0.001). In addition, at 24H, HOMA-IR was significantly lower in the LO when compared to the HI group (LO: 1.4 ± 0.2 vs. HI: 2.2 ± 0.4; p = 0.030). mVO2 was higher (p = 0.003) in the LO (0.93 ± 0.29 ml/min/100 ml) when compared to the HI group (0.63 ± 0.28 ml/min/100 ml). IL-6 at 3H (LO: 13.2 ± 2.7 vs. HI: 19.6 ± 4.0 pg·ml-1 ; p = 0.045) and 24H (LO: 4.2 ± 1.1 vs. HI: 12.5 ± 3.1 pg·ml-1 ; p = 0.016) was greater in the HI compared to the LO group. These findings indicate that low-amplitude WBV provides greater metabolic benefits compared to high-amplitude WBV.

Outcomes of patients with malignant esophagogastric junction obstruction receiving metallic stents: A single-center experience.

BACKGROUND: Malignancies-related esophagogastric junction (EGJ) obstruction is usually diagnosed in inoperable status with poor clinical outcomes. Metallic stent placement at EGJ could improve dysphagia for these patients. However, studies regarding the outcomes in these patients receiving metallic stents are still limited. This study aimed to investigate the outcomes of metallic stent placement in malignant EGJ obstruction. METHODS: Forty-one patients with inoperable malignant EGJ obstruction receiving metallic stent placement were retrospectively enrolled. The clinical outcomes between different stents and deployment techniques were analyzed. RESULTS: The overall technical success rate was 97.6% and clinical success rate was 92.1%. The median overall survival time was 77 (4-893) days, and the patency time was 71 (4-893) days, respectively. Poststent radiotherapy significantly prolonged survival and stent patency. Between patients receiving uncovered or partially covered metal stents, there was no difference in procedure-related complications, survival time, and stent patency time. Moreover, the clinical outcomes in patients receiving duodenal stents for malignant EGJ obstruction are not inferior to those receiving esophageal stents. CONCLUSION: This study provides crucial information for endoscopists to establish individualized stenting strategies for malignant EGJ obstruction.

Endoscopic management of malignant gastric outlet obstruction.

Malignant gastric outlet obstruction (MGOO) is a late complication of advanced malignancies, mostly occurring due to gastrointestinal cancers or external compression outside the lumen. It causes nausea, vomiting, poor appetite, weight loss, and decreased quality of life. In the past, surgical bypass was the gold standard for the management of MGOO. However, the introduction of self-expandable metallic stent (SEMS) provides several advantages over surgical bypass, including earlier oral intake, rapid symptom relief, less invasiveness, and shorter hospital stays; therefore, it has replaced surgical bypass as the mainstream management approach in most situations. Although SEMS placement is a safe and effective way for palliation of MGOO, stent dysfunction with obstruction or migration limits the utilization and increases repeated intervention. Endoscopic ultrasound-guided gastroenterostomy with lumen-apposing metal stent has emerged as an alternative way to bypass the obstruction site and restore the oral intake of patients. Although a lower stent dysfunction rate was reported, further prospective studies are warranted to validate its effectiveness and safety.

Unique Genetic Characteristics and Clinical Prognosis of Female Patients with Lung Cancer Harboring RET Fusion Gene.

OBJECTIVES: Since no report on the genetic characteristics of RET fusions in female patients with lung cancer is available, this study revealed the genetic and prognostic characteristics of female patients with lung cancer harboring RET fusion gene for the first time. MATERIALS AND METHODS: The molecular portfolios of 1,652 patients with lung cancer who underwent targeted next-generation sequencing for screening candidate oncogenic drivers in their histological specimens from January 2016 to December 2018 were investigated in this study. RESULTS: RET fusions were identified in 23 cases, 15 females [2.2% (15/685)] and eight males [0.9% (8/902)]. The most common fusions were KIF5B-RET in females [80% (12/15)] and CCDC6-RET in males [50% (4/8)], along with some rare RET fusions, including SLC39A8-RET, ITIH2-RET, FYCO1-RET and SLC25A36-RET in females, and MIR3924-RET, ZBTB41-RET and ITGA8-RET in males. Interestingly, the highly positive, moderate positive, and negative rates of PD-L1 staining in females were 33.3%, 8.3% and 58.3%, respectively; whereas those in males were 0%, 57.1% and 42.9%. Additionally, the progression-free survival (PFS) of stage IV patients was comparatively shorter in females, shown by the medians of 4.0 months in females and 6.0 months in males (P = 0.029). A 43-year-old female patient with metastatic lung adenocarcinoma, who harbored KIF5B-RET fusion and had highly positive PD-L1 staining, received nivolumab as second-line treatment. A partial response was achieved and remained for more than five months. CONCLUSION: Unique genetic characteristics and poor prognosis are found in female patients with lung cancer harboring RET fusion gene. Immune checkpoint inhibitors are a potential option for patients with high expression of PD-L1.

Outcomes of enteral metallic stent in patients with pancreatic carcinoma and gastric outlet obstruction: A single center experience.

BACKGROUND: Duodenal obstruction is uncommon in patients with pancreatic cancer. However, the obstruction rate is increasing as a result of advancements in chemotherapy and target therapy. This study aimed to investigate the effect of self-expandable metal stent placement on outcomes of patients with duodenal obstruction secondary to pancreatic carcinoma. METHODS: Twenty-nine consecutive inoperable patients with pancreatic cancer and gastric outlet obstruction who received metallic stent placement in our hospital between September 2009 and October 2017 were enrolled for analysis. RESULTS: Fifteen male patients and 14 female patients receiving stent placement with a median age of 68 years (range, 50-85 years) were included. The technical and clinical success rates of the procedure were 100% and 89.7%, respectively. The Gastric Outlet Obstruction Scoring System scores were significantly improved at day 1 (1.14 ± 0.51) and days 7 (2.21 ± 0.9) after the implantation compared to those prior to the procedure (0.38 ± 0.49) (p < 0.001). Aspiration pneumonia and bleeding developed in 1 patient (3.4%) after the procedure. Stent dysfunction developed in 6 of 29 patients (20.6%). The median stent patency time was 109 days (range, 10-314 days). The median survival time was 114 days (range, 15-323 days). Post-stent chemotherapy predicted better survival (hazard ratio: 0.2, 95% confidence interval: 0.08-0.51, p = 0.001). CONCLUSION: Metallic stent placement is an effective treatment for patients with inoperable pancreatic cancer leading to gastric outlet obstruction. Chemotherapy may be considered following stent placement.

Non-canonical Raf-1/p70S6K signalling in non-small-cell lung cancer.

Lung cancer is the leading cause of cancer-related death globally, with non-small-cell lung cancer (NSCLC) being the predominant subtype. Overall survival remains low for NSCLC patients, and novel targets are needed to improve outcome. Raf-1 is a key component of the Ras/Raf/MEK signalling pathway, but its role and downstream targets in NSCLC are not completely understood. Our previous study indicated a possible correlation between Raf-1 levels and ribosomal protein S6 kinase (p70S6K) function. In this study, we aimed to investigate whether p70S6K is a downstream target of Raf-1 in NSCLC. Raf-1 was silenced in NSCLC cell lines by using small hairpin RNA, and Raf-1 and p70S6K protein levels were measured via Western blot. p70S6K was then overexpressed following Raf-1 knock-down; then, cell proliferation, apoptosis and the cell cycle in NSCLC cell lines were examined. Tumour xenografts with NSCLC cells were then transplanted for in vivo study. Tumours were measured and weighed, and Raf-1 and p70S6K expression, cell proliferation and apoptosis were examined in tumour tissues by Western blot, Ki-67 staining and TUNEL staining, respectively. When Raf-1 was silenced, p70S6K protein levels were markedly decreased in the A549 and H1299 NSCLC cell lines. A significant decrease in NSCLC cell proliferation, a profound increase in apoptosis and cell cycle arrest were observed in vitro following Raf-1 knock-down. Overexpression of p70S6K after Raf-1 depletion effectively reversed these effects. Xenograft studies confirmed these results in vivo. In conclusion, Raf-1 targets p70S6K as its downstream effector to regulate NSCLC tumorigenicity, making Raf-1/p70S6K signalling a promising target for NSCLC treatment.

Glycine decarboxylase is a transcriptional target of MYCN required for neuroblastoma cell proliferation and tumorigenicity.

Genomic amplification of the oncogene MYCN is a major driver in the development of high-risk neuroblastoma, a pediatric cancer with poor prognosis. Given the challenge in targeting MYCN directly for therapy, we sought to identify MYCN-dependent metabolic vulnerabilities that can be targeted therapeutically. Here, we report that the gene encoding glycine decarboxylase (GLDC), which catalyzes the first and rate-limiting step in glycine breakdown with the production of the one-carbon unit 5,10-methylene-tetrahydrofolate, is a direct transcriptional target of MYCN. As a result, GLDC expression is markedly elevated in MYCN-amplified neuroblastoma tumors and cell lines. This transcriptional upregulation of GLDC expression is of functional significance, as GLDC depletion by RNA interference inhibits the proliferation and tumorigenicity of MYCN-amplified neuroblastoma cell lines by inducing G1 arrest. Metabolomic profiling reveals that GLDC knockdown disrupts purine and central carbon metabolism and reduces citrate production, leading to a decrease in the steady-state levels of cholesterol and fatty acids. Moreover, blocking purine or cholesterol synthesis recapitulates the growth-inhibitory effect of GLDC knockdown. These findings reveal a critical role of GLDC in sustaining the proliferation of neuroblastoma cells with high-level GLDC expression and suggest that MYCN amplification is a biomarker for GLDC-based therapeutic strategies against high-risk neuroblastoma.

Metabolic Reprogramming by MYCN Confers Dependence on the Serine-Glycine-One-Carbon Biosynthetic Pathway.

MYCN amplification drives the development of neuronal cancers in children and adults. Given the challenge in therapeutically targeting MYCN directly, we searched for MYCN-activated metabolic pathways as potential drug targets. Here we report that neuroblastoma cells with MYCN amplification show increased transcriptional activation of the serine-glycine-one-carbon (SGOC) biosynthetic pathway and an increased dependence on this pathway for supplying glucose-derived carbon for serine and glycine synthesis. Small molecule inhibitors that block this metabolic pathway exhibit selective cytotoxicity to MYCN-amplified cell lines and xenografts by inducing metabolic stress and autophagy. Transcriptional activation of the SGOC pathway in MYCN-amplified cells requires both MYCN and ATF4, which form a positive feedback loop, with MYCN activation of ATF4 mRNA expression and ATF4 stabilization of MYCN protein by antagonizing FBXW7-mediated MYCN ubiquitination. Collectively, these findings suggest a coupled relationship between metabolic reprogramming and increased sensitivity to metabolic stress, which could be exploited as a strategy for selective cancer therapy. SIGNIFICANCE: This study identifies a MYCN-dependent metabolic vulnerability and suggests a coupled relationship between metabolic reprogramming and increased sensitivity to metabolic stress, which could be exploited for cancer therapy.See related commentary by Rodriguez Garcia and Arsenian-Henriksson, p. 3818.

Histone demethylase KDM6B has an anti-tumorigenic function in neuroblastoma by promoting differentiation.

Induction of differentiation is a therapeutic strategy in high-risk neuroblastoma, a childhood cancer of the sympathetic nervous system. Neuroblastoma differentiation requires transcriptional upregulation of neuronal genes. How this process is regulated at epigenetic levels is not well understood. Here we report that the histone H3 lysine 27 demethylase KDM6B is an epigenetic activator of neuroblastoma cell differentiation. KDM6B mRNA expression is downregulated in poorly differentiated high-risk neuroblastomas and upregulated in differentiated tumors, and high KDM6B expression is prognostic for better survival in neuroblastoma patients. In neuroblastoma cell lines, KDM6B depletion promotes cell proliferation, whereas KDM6B overexpression induces neuronal differentiation and inhibits cell proliferation and tumorgenicity. Mechanistically, KDM6B epigenetically activates the transcription of neuronal genes by removing the repressive chromatin marker histone H3 lysine 27 trimethylation. In addition, we show that KDM6B functions downstream of the retinoic acid-HOXC9 axis in inducing neuroblastoma cell differentiation: KDM6B expression is upregulated by retinoic acid via HOXC9, and KDM6B is required for HOXC9-induced neuroblastoma cell differentiation. Finally, we present evidence that KDM6B interacts with HOXC9 to target neuronal genes for epigenetic activation. These findings identify a KDM6B-dependent epigenetic mechanism in the control of neuroblastoma cell differentiation, providing a rationale for reducing histone H3 lysine 27 trimethylation as a strategy for enhancing differentiation-based therapy in high-risk neuroblastoma.

Transcriptional Regulation of Stem Cell and Cancer Stem Cell Metabolism.

PURPOSE OF REVIEW: Metabolism is increasingly recognized as a major player in control of stem cell function and fate. How stem cell metabolism is established, maintained, and regulated is a fundamental question of biology and medicine. In this review, we discuss major metabolic programs in stem cells and cancer stem cells, with a focus on key transcription factors that shape the stem cell metabolic phenotype. RECENT FINDINGS: Cancer stem cells primarily use oxidative phosphorylation for energy generation, in contrast to normal stem cells, which rely on glycolytic metabolism with the exception of mouse embryonic stem cells. Transcription factors control the metabolic phenotype of stem cells by modulating the expression of enzymes and thus the activity of metabolic pathways. It is evident that HIF1α and PGC1α function as master regulators of glycolytic and mitochondrial metabolism, respectively. SUMMARY: Transcriptional regulation is a key mechanism for establishing specific metabolic programs in stem cells and cancer stem cells.

Metallic Stent Expansion Rate at Day One Predicts Stent Patency in Patients with Gastric Outlet Obstruction.

BACKGROUND AND AIMS: Self-expandable metallic stent insertion has been a mainstream treatment for relieving the obstructive symptoms of malignant gastric outlet obstruction (MGOO), a late-stage complication of gastrointestinal malignancies. This study aims to investigate the predictive value of stent expansion rates in clinical outcomes in patients with MGOO. METHODS: Eighty-seven patients with inoperable MGOO receiving metallic stents were reviewed retrospectively from April 2010 to December 2014. Clinical outcomes, predictors of stent patency, and survival were analyzed. RESULTS: The technical and clinical success rates were 100 and 94.3%, respectively. The median stent patency time was 114 days (range 13-570 days). The median survival time was 133 days (range 13-1145 days). Stent dysfunctions occurred in 28 patients (32.2%), with restenosis accounting for the majority (82%). The stent expansion rate ≥75% at Day 1 predicted the stent patency [hazard ratio (HR) 0.12, P = 0.04]. However, it did not correlate with survival. Non-gastric cancer origins (HR 2.41, P = 0.002) and peritoneal carcinomatosis (HR 2.54, P = 0.001) correlated with poor survival. However, post-stent chemotherapy (HR 0.55, P = 0.03) was related to better outcome. The comparison of clinical outcomes of first and second stent insertions showed no significant difference in the stent expansion rate either at Day 0 and Day 1 (P = 0.97 and P = 0.57). CONCLUSIONS: Self-expandable metallic stent insertion is a safe and effective treatment for relieving the obstructive symptoms. The stent expansion rate ≥75% at Day 1 is a novel stent-related predictor of stent patency.

Transcriptional Profiling Reveals a Common Metabolic Program in High-Risk Human Neuroblastoma and Mouse Neuroblastoma Sphere-Forming Cells.

High-risk neuroblastoma remains one of the deadliest childhood cancers. Identification of metabolic pathways that drive or maintain high-risk neuroblastoma may open new avenues of therapeutic interventions. Here, we report the isolation and propagation of neuroblastoma sphere-forming cells with self-renewal and differentiation potential from tumors of the TH-MYCN mouse, an animal model of high-risk neuroblastoma with MYCN amplification. Transcriptional profiling reveals that mouse neuroblastoma sphere-forming cells acquire a metabolic program characterized by transcriptional activation of the cholesterol and serine-glycine synthesis pathways, primarily as a result of increased expression of sterol regulatory element binding factors and Atf4, respectively. This metabolic reprogramming is recapitulated in high-risk human neuroblastomas and is prognostic for poor clinical outcome. Genetic and pharmacological inhibition of the metabolic program markedly decreases the growth and tumorigenicity of both mouse neuroblastoma sphere-forming cells and human neuroblastoma cell lines. These findings suggest a therapeutic strategy for targeting the metabolic program of high-risk neuroblastoma.

KDM4C and ATF4 Cooperate in Transcriptional Control of Amino Acid Metabolism.

The histone lysine demethylase KDM4C is often overexpressed in cancers primarily through gene amplification. The molecular mechanisms of KDM4C action in tumorigenesis are not well defined. Here, we report that KDM4C transcriptionally activates amino acid biosynthesis and transport, leading to a significant increase in intracellular amino acid levels. Examination of the serine-glycine synthesis pathway reveals that KDM4C epigenetically activates the pathway genes under steady-state and serine deprivation conditions by removing the repressive histone modification H3 lysine 9 (H3K9) trimethylation. This action of KDM4C requires ATF4, a transcriptional master regulator of amino acid metabolism and stress responses. KDM4C activates ATF4 transcription and interacts with ATF4 to target serine pathway genes for transcriptional activation. We further present evidence for KDM4C in transcriptional coordination of amino acid metabolism and cell proliferation. These findings suggest a molecular mechanism linking KDM4C-mediated H3K9 demethylation and ATF4-mediated transactivation in reprogramming amino acid metabolism for cancer cell proliferation.

Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction: A Comparison Between 2 Brands of Stents.

Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P = 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P = 0.01). Cancer with gastric origin (HR: 0.25, P = 0.045) and poststent chemotherapy (HR: 0.38, P = 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P = 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group.