Therapeutic efficacy of RAS inhibitor trametinib using a juvenile myelomonocytic leukemia patient-derived xenograft model.

Juvenile myelomonocytic leukemia (JMML) is an aggressive pediatric leukemia with few effective treatments and poor outcomes even after stem cell transplantation, the only current curative treatment. We developed a JMML patient-derived xenograft (PDX) mouse model and demonstrated the in vivo therapeutic efficacy and confirmed the target of trametinib, a RAS-RAF-MEK-ERK pathway inhibitor, in this model. A PDX model was created through transplantation of patient JMML cells into mice, up to the second generation, and successful engraftment was confirmed using flow cytometry. JMML PDX mice were treated with trametinib versus vehicle control, with a median survival of 194 days in the treatment group versus 124 days in the control group (p = 0.02). Trametinib's target as a RAS pathway inhibitor was verified by showing inhibition of ERK phosphorylation using immunoblot assays. In conclusion, trametinib monotherapy significantly prolongs survival in our JMML PDX model by inhibiting the RAS pathway. Our model can be effectively used for assessment of novel targeted treatments, including potential combination therapies, to improve JMML outcomes.

Genomic insights into familial adenomatous polyposis: unraveling a rare case with whole APC gene deletion and intellectual disability.

A young patient diagnosed with advanced colon cancer and liver metastasis was found to have familial adenomatous polyposis (FAP) through comprehensive genomic analysis. Whole-genome array comparative genomic hybridization (aCGH) revealed germline deletions at chromosome 5q22.1-22.2 encompassing the entire APC gene. The patient and her son exhibited mild intellectual disability without developmental delay. This case highlights the need for further exploration of the characteristics associated with whole APC deletions. aCGH is a valuable tool for studying FAP and provides a detailed analysis of large deletions.

Cmpd10357 to treat B-cell acute lymphoblastic leukemia.

B-cell acute lymphoblastic leukemia (B-ALL) is the most common type of cancer found in children. Although the overall survival rates are now >80%, 15%-20% of pediatric patients relapse, with survival rates subsequently dropping to 5%-10%. Cmpd10357, 3-amino-5-arylamino-6-chloro-N- (diaminomethylene) pyrazine-2-carboximide, is a highly potent, cell-permeant compound recently shown to have cytotoxic effects on solid tumors, including human breast cancer and high-grade gliomas, independent of their proliferative status. Cmpd10357 demonstrated concentration-dependent cytotoxicity in two human B-ALL cell lines, JM1 and Reh, at half-maximal inhibitory concentrations (IC50) of 3.2 and 3.3 µM, respectively. Cmpd10357, at a dose of 5 mg/kg, significantly prolonged survival in our B-ALL xenograft mouse model, with a median survival time of 49.0 days compared with 45.5 days in the control group (p < 0.05). The cytotoxicity of Cmpd10357 demonstrated caspase-independent, nonapoptotic cancer cell demise associated with the nuclear translocation of apoptosis-inducing factor (AIF). The cytotoxicity of Cmpd10357 in B-ALL cells was inhibited by Necrostatin-1 but not by Necrosulfonamide. These studies suggest that an AIF-mediated, caspase-independent necrosis mechanism of Cmpd10357 in B-ALL could be used in combination with traditional apoptotic chemotherapeutic agents.

A distinct subpopulation of leukemia initiating cells in acute precursor B lymphoblastic leukemia: quiescent phenotype and unique transcriptomic profile.

In leukemia, a distinct subpopulation of cancer-initiating cells called leukemia stem cells (LSCs) is believed to drive population expansion and tumor growth. Failing to eliminate LSCs may result in disease relapse regardless of the amount of non-LSCs destroyed. The first step in targeting and eliminating LSCs is to identify and characterize them. Acute precursor B lymphoblastic leukemia (B-ALL) cells derived from patients were incubated with fluorescent glucose analog 2-(N-(7-Nitrobenz-2-oxa-1, 3-diazol-4-yl) Amino)-2-Deoxyglucose (NBDG) and sorted based on NBDG uptake. Cell subpopulations defined by glucose uptake were then serially transplanted into mice and evaluated for leukemia initiating capacity. Gene expression profiles of these cells were characterized using RNA-Sequencing (RNA-Seq). A distinct population of NBDG-low cells was identified in patient B-ALL samples. These cells are a small population (1.92% of the entire leukemia population), have lower HLA expression, and are smaller in size (4.0 to 7.0 µm) than the rest of the leukemia population. All mice transplanted with NBDG-low cells developed leukemia between 5 and 14 weeks, while those transplanted with NBDG-high cells did not develop leukemia (p ≤ 0.0001-0.002). Serial transplantation of the NBDG-low mouse model resulted in successful leukemia development. NBDG-medium (NBDG-med) populations also developed leukemia. Interestingly, comprehensive molecular characterization of NBDG-low and NBDG-med cells from patient-derived xenograft (PDX) models using RNA-Seq revealed a distinct profile of 2,162 differentially-expressed transcripts (DETs) (p<0.05) with 70.6% down-regulated in NBDG-low cells. Hierarchical clustering of DETs showed distinct segregation of NBDG-low from NBDG-med and NBDG-high groups with marked transcription expression alterations in the NBDG-low group consistent with cancer survival. In conclusion, A unique subpopulation of cells with low glucose uptake (NBDG-low) in B-ALL was discovered. These cells, despite their quiescence characteristics, once transplanted in mice, showed potent leukemia initiating capacity. Although NBDG-med cells also initiated leukemia, gene expression profiling revealed a distinct signature that clearly distinguishes NBDG-low cells from NBDG-med and the rest of the leukemia populations. These results suggest that NBDG-low cells may represent quiescent LSCs. These cells can be activated in the appropriate environment in vivo, showing leukemia initiating capacity. Our study provides insight into the biologic mechanisms of B-ALL initiation and survival.

Novel Patient Metastatic Pleural Effusion-Derived Xenograft Model of Renal Medullary Carcinoma Demonstrates Therapeutic Efficacy of Sunitinib.

BACKGROUND: Renal medullary carcinoma (RMC) is a rare but aggressive tumor often complicated by early lung metastasis with few treatment options and very poor outcomes. There are currently no verified RMC patient-derived xenograft (PDX) mouse models established from metastatic pleural effusion (PE) available to study RMC and evaluate new therapeutic options. METHODS: Renal tumor tissue and malignant PE cells from an RMC patient were successfully engrafted into 20 NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice. We evaluated the histopathological similarity of the renal tumor and PE PDXs with the original patient renal tumor and PE, respectively. We then evaluated the molecular integrity of the renal tumor PDXs between passages, as well as the PE PDX compared to two generations of renal tumor PDXs, by microarray analysis. The therapeutic efficacy of sunitinib and temsirolimus was tested in a serially-transplanted generation of 27 PE PDX mice. RESULTS: The pathologic characteristics of the patient renal tumor and patient PE were retained in the PDXs. Gene expression profiling revealed high concordance between the two generations of renal tumor PDXs (RMC-P0 vs. RMC-P1, r=0.865), as well as between the first generation PE PDX and each generation of the renal tumor PDX (PE-P0 vs. RMC-P0, r=0.919 and PE-P0 vs. RMC-P1, r=0.843). A low number (626) of differentially-expressed genes (DEGs) was seen between the first generation PE PDX and the first generation renal tumor PDX. In the PE-P1 xenograft, sunitinib significantly reduced tumor growth (p<0.001) and prolonged survival (p=0.004) compared to the vehicle control. CONCLUSIONS: A metastatic PE-derived RMC PDX model was established and shown to maintain histologic features of the patient cancer. Molecular integrity of the PDX models was well maintained between renal tumor and PE PDX as well as between two successive renal tumor PDX generations. Using the PE PDX model, sunitinib demonstrated therapeutic efficacy for RMC. This model can serve as a foundation for future mechanistic and therapeutic studies for primary and metastatic RMC.

The efficacy of the submucosal injection of lidocaine during endoscopic submucosal dissection for colorectal neoplasms: a multicenter randomized controlled study.

BACKGROUND: Endoscopic submucosal dissection (ESD) is currently a common procedure although it requires a long procedural time. We conducted a prospective study to determine the efficacy and safety of lidocaine injection for shortening the procedural time and relieving bowel peristalsis during ESD. METHODS: A multicenter randomized controlled study was conducted in three hospitals. Ninety-one patients who underwent colorectal ESD were enrolled. Patients were randomly divided into two groups using the envelope method: the lidocaine group and saline group. The primary endpoint was the procedural time, and the secondary endpoints were the procedural time in each part of the colon and the grade of bowel peristalsis and the incidence and amounts of antispasmodic drugs use and adverse events. RESULTS: The patients' demographics were not markedly different between the two groups. The mean procedural time in the lidocaine group was not markedly different from that in the saline group. In contrast, at the proximal site, the procedural time in the lidocaine group (57 min) was significantly shorter in the saline group (80 min). The grade of bowel peristalsis in the lidocaine group (0.67) was significantly lower than in the saline group (1.17). Antispasmodic drug use was significantly rarer in the lidocaine group than in the saline group. The incidence of adverse events was not markedly different between the two groups. CONCLUSIONS: Local lidocaine injection is a feasible option for preventing bowel peristalsis, particularly in the proximal colon, leading to a reduced procedural time for ESD and decreased antispasmodic drug use. University Hospital Medical Information Network Center (UMIN number: 000022843).

Probiotic­derived ferrichrome inhibits the growth of refractory pancreatic cancer cells.

Pancreatic cancer is associated with a poor prognosis due to challenges in early detection, severe progression of the primary tumor, metastatic lesions, and resistance to antitumor agents. However, previous studies have indicated a relationship between the microbiome and pancreatic cancer outcomes. Our previous study demonstrated that ferrichrome derived from Lactobacillus casei, a probiotic bacteria, exhibited tumor­suppressive effects in colorectal and gastric cancer, and that the suppressive effects were stronger than conventional antitumor agents, such as 5­fluorouracil (5­FU) and cisplatin, suggesting that certain probiotics exert antitumorigenic effects. However, whether or not probiotic­derived molecules, including ferrichrome, exert a tumor­suppressive effect in other gastrointestinal tumors, such as pancreatic cancer, remains unclear. In the present study, it was demonstrated that probiotic­derived ferrichrome inhibited the growth of pancreatic cancer cells, and its tumor­suppressive effects were further revealed in 5­FU­resistant pancreatic cancer cells in vitro and in vivo in a mouse xenograft model. Ferrichrome inhibited the progression of cancer cells via dysregulation of the cell cycle by activating p53. DNA fragmentation and cleavage of poly (ADP­ribose) polymerase were induced by ferrichrome treatment, suggesting that ferrichrome induced apoptosis in pancreatic cancer cells. A transcriptome analysis revealed that the expression p53­associated mRNAs was significantly altered by ferrichrome treatment. Thus, the tumor­suppressive effects of probiotics may mediated by probiotic­derived molecules, such as ferrichrome, which may have applications as an antitumor drug, even in refractory and 5­FU­resistant pancreatic cancer.

Autofluorescence Imaging Reflects the Nuclear Enlargement of Tumor Cells as well as the Cell Proliferation Ability and Aberrant Status of the p53, Ki-67, and p16 Genes in Colon Neoplasms.

BACKGROUND: Autofluorescence imaging (AFI) is useful for diagnosing colon neoplasms, but what affects the AFI intensity remains unclear. This study investigated the association between AFI and the histological characteristics, aberrant methylation status, and aberrant expression in colon neoplasms. METHODS: Fifty-three patients with colorectal neoplasms who underwent AFI were enrolled. The AFI intensity (F index) was compared with the pathological findings and gene alterations. The F index was calculated using an image analysis software program. The pathological findings were assessed by the tumor crypt density, cell densities, and N/C ratio. The aberrant methylation of p16, E-cadherin, Apc, Runx3, and hMLH1 genes was determined by a methylation-specific polymerase chain reaction. The aberrant expression of p53 and Ki-67 was evaluated by immunohistochemical staining. RESULTS: An increased N/C ratio, the aberrant expression of p53, Ki-67, and the altered methylation of p16 went together with a lower F index. The other pathological findings and the methylation status showed no association with the F index. CONCLUSIONS: AFI reflects the nuclear enlargement of tumor cells, the cell proliferation ability, and the altered status of cell proliferation-related genes, indicating that AFI is a useful and practical method for predicting the dysplastic grade of tumor cells and cell proliferation.

White coat status is a predictive marker for post-esophageal endoscopic submucosal dissection stricture: a retrospective study.

BACKGROUND: Steroid therapy is primarily used to prevent esophageal stricture after endoscopic submucosal dissection (ESD). However, esophageal stricture can still occur after preventive therapy, and the effect of preventive steroid therapy cannot be predicted before stricture formation. This study aimed to clarify the risk factors for esophageal stricture after preventive steroid therapy. METHODS: This was a retrospective study conducted at three institutions. From January 2011 to February 2018, 28 large-sized SENs in 26 patients who had a mucosal defect that involved more than three-quarters of the esophageal circumference were enrolled. We classified white coats on artificial ulcers after esophageal ESD into three groups (thin, moderately thick, thick) based on endoscopic images obtained on postoperative day 7. RESULTS: The white coat status on the artificial ulcer after ESD was a significant risk factor for post-ESD stricture (p < 0.05). The stricture rates in patients with thin, moderately thick and thick white coats were 10.0, 36.4 and 85.7%, respectively. When thin and moderately thick white coats were combined, the stricture rate was 23.8%. The rate of stricture in lesions with thick white coats was significantly higher than that in patients with thin white coats or thin to moderately thick white coats (p < 0.05). The multivariate analysis revealed that the white coat status was an independent factor related to esophageal stricture (odds ratio 13.70, 95% confidence interval 1.22-154.0; p = 0.034). CONCLUSIONS: The thickness of the white coat is a useful marker for predicting the risk of post-ESD stricture and the effectiveness of preventive steroid therapy.

The Incidence and Risk Factors of Venous Thromboembolism in Patients with Inflammatory Bowel Disease: A Prospective Multicenter Cohort Study.

BACKGROUND: Venous thromboembolism (VTE) has been shown to be more frequent in inflammatory bowel disease (IBD) than in the general population in Western studies. However, the actual state of VTE in Asian IBD remains poorly understood. AIMS: To reveal the incidence of VTE in IBD patients in Japan. METHODS: Eighty-five patients admitted to 3 gastroenterology centers were registered from 2013 to 2018. The incidence of VTE in patients with IBD (n = 42) was prospectively compared to that among patients with other digestive diseases (n = 43). The presence of VTE was surveyed using contrast-enhanced computed tomography and/or ultrasonography at admission and at 1-2 weeks after admission. The patient characteristics and laboratory data of IBD patients with or without VTE were compared to determine the risk factors for VTE. RESULTS: The incidence of VTE with IBD was 16.7%, which was significantly more frequent than with other digestive diseases (2.3%; p = 0.0296). In IBD patients, VTE was detected in 6 of 22 patients with ulcerative colitis (27.2%) but in only 1 of 20 patients with Crohn's disease (5.0%). VTE was diagnosed at admission in 4 IBD patients and 2 weeks after admission in 3 IBD patients. The risk factors of VTE in IBD were the presence of an indwelling central venous catheter, a low level of total protein, a low activated partial thromboplastin time, and a high level of fibrinogen degradation products. CONCLUSION: VTE was frequently detected in Japanese IBD patients both at and after admission. Adequate screening and prophylaxis for VTE is deemed necessary in IBD.

The incidence and risk factors of venous thromboembolism in Japanese inpatients with inflammatory bowel disease: a retrospective cohort study.

BACKGROUND/AIMS: Venous thromboembolism (VTE) is a major extraintestinal manifestation in inflammatory bowel disease (IBD), regarded as an independent risk factor for VTE according to reports from Western countries. However, the incidence and risk factors of VTE in Asian IBD patients are not fully understood. We aimed to reveal the incidence and risk factors of VTE in Japanese IBD inpatients. METHODS: The incidence of VTE in inpatients with IBD (n=340), gastrointestinal cancers (n=557), and other gastrointestinal diseases (n=569) treated at our hospital from 2009 to 2013 was retrospectively investigated. The characteristics and laboratory data of IBD inpatients with and without VTE were compared in univariate and multivariate analyses. Clinical courses of VTE in IBD were surveyed. RESULTS: VTE was detected in 7.1% of IBD inpatients, significantly higher than in gastrointestinal cancer inpatients (2.5%) and inpatients with other gastrointestinal diseases (0.88%). The incidence of VTE in ulcerative colitis (UC) patients (16.7%) was much higher than that in those with Crohn's disease (3.6%). In the univariate analysis, the risk factors were an older age, central venous catheter, prednisolone, surgery, low serum albumin, high serum C-reactive protein and D-dimer. According to a multivariate analysis, >50 years of age and surgery were the only risk factors. The in-hospital mortality rate of IBD inpatients with VTE was 4.2%. CONCLUSIONS: The incidence of VTE with IBD, especially UC, was found to be high compared with other digestive disease, which was almost equivalent to that of Western countries. The efficacy of prophylaxis needs to be investigated in Asian IBD patients.

Takayasu's arteritis associated with eosinophilic gastroenteritis, possibly via the overactivation of Th17.

BACKGROUND: Takayasu's arteritis (TA) is a large-vessel vasculitis pathologically characterized by granulomatous necrotizing vasculitis with giant cells. Although the cause of TA is still unclear, genetic factors as well as immunological abnormalities, particularly the overactivation of Th1 and Th-17, are considered to play important roles in the pathogenesis of this disease. Eosinophilic gastroenteritis (EGE) is a type of refractory inflammation in which numerous eosinophils infiltrate the inflammatory area. It is known that the overactivation of Th2 is associated with the pathogenesis of EGE, although the cause of EGE is still unclear. The immunological abnormalities in TA are therefore thought to be different from those in EGE. To date, no cases of complication of TA and EGE have been reported. CASE PRESENTATIONS: An 18 year-old female was diagnosed with EGE and treated with prednisolone. At 6 months after completion of the treatment, the patient experienced chest pain, and was diagnosed with TA. TH1 and TH17 immunity are thought to be involved with TA, while TH2 are considered to be involved with EGE. In this case, the expression of IL-17 mRNA in the colon mucosa greatly decreased after prednisolone treatment for EGE. CONCLUSIONS: This is the first report of TA complicated with EGE, and the overactivation of TH17 is considered to be associated with the pathogenesis of these two diseases.

An elevated expression of serum exosomal microRNA-191, - 21, -451a of pancreatic neoplasm is considered to be efficient diagnostic marker.

BACKGROUND: Pancreatic cancer is associated with an extremely poor prognosis, so new biomarkers that can detect the initial stages are urgently needed. The significance of serum microRNA (miR) levels in pancreatic neoplasm such as pancreatic cancer and intraductal papillary mucinous neoplasm (IPMN) diagnosis remains unclear. We herein evaluated the usefulness of miRs enclosed in serum exosomes (ExmiRs) as diagnostic markers. METHODS: The ExmiRs from patients with pancreatic cancer (n = 32) or IPMN (n = 29), and patients without neoplasms (controls; n = 22) were enriched using ExoQuick-TC™. The expression of ExmiRs was evaluated using a next-generation sequencing analysis, and the selected three miRs through this analysis were confirmed by a quantitative real-time polymerase chain reaction. RESULTS: The expression of ExmiR-191, ExmiR-21 and ExmiR-451a was significantly up-regulated in patients with pancreatic cancer and IPMN compared to the controls (p < 0.05). A receiver operating characteristic curve analysis showed that the area under the curve and the diagnostic accuracy of ExmiRs were 5-20% superior to those of three serum bulky circulating miRs (e.g.; ExmiR-21: AUC 0.826, accuracy 80.8%. Circulating miR-21: AUC 0.653, accuracy 62.3%). In addition, high ExmiR-451a was associated with mural nodules in IPMN (p = 0.010), and high ExmiR-21 was identified as a candidate prognostic factor for the overall survival (p = 0.011, HR 4.071, median OS of high-ExmiR-21: 344 days, median OS of low-ExmiR-21: 846 days) and chemo-resistant markers (p = 0.022). CONCLUSIONS: The level of three ExmiRs can thus serve as early diagnostic and progression markers of pancreatic cancer and IPMN, and considered more useful markers than the circulating miRs (limited to these three miRs).

Ferrichrome identified from Lactobacillus casei ATCC334 induces apoptosis through its iron-binding site in gastric cancer cells.

Ferrichrome is known to be a siderophore, but it was recently identified as a tumor-suppressive molecule derived from Lactobacillus casei ATCC334 ( L. casei). In the present study, we investigated the effects of ferrichrome in gastric cancer cells. Cell lines and xenograft models treated with ferrichrome demonstrated growth suppression. The expression levels of cleaved poly (adenosine diphosphate-ribose) polymerase, and cleaved caspase-9 were increased by ferrichrome treatment. Although the tumor-suppressive effects of ferrichrome were almost completely diminished by the iron chelation, the reduction in the intracellular iron by ferrichrome did not correlate with its tumor-suppressive effects. An exhaustive docking simulation indicated that iron-free ferrichrome can make stable conformations with various mammalian molecules, including transporters and receptors. In conclusion, probiotic-derived ferrichrome induced apoptosis in gastric cancer cells. The iron binding site of ferrichrome is the structure responsible for its tumor suppressive function.

Quantification of autofluorescence imaging can accurately and objectively assess the severity of ulcerative colitis.

BACKGROUND AND AIMS: No endoscopic examination has been able to evaluate severity of ulcerative colitis (UC) by quantification. This prospective study investigated the efficacy of quantifying autofluorescence imaging (AFI) to assess the severity of UC, which captures the fluorescence emitted from intestinal tissue and then quantifies the intensity using an image-analytical software program. MATERIALS AND METHODS: Eleven endoscopists separately evaluated 135 images of conventional endoscopy (CE) and AFI from a same lesion. A CE image corresponding to Mayo endoscopic subscore 0 or 1 was defined as being inactive. The fluorescence intensities of AFI were quantified using an image-analytical software program (F index; FI). Active inflammation was defined when Matts' histological grade was 2 or more. A cut-off value of the FI for active inflammation was determined using a receiver operating characteristic (ROC) analysis. The inter-observer consistency was calculated by unweighted kappa statistics. RESULTS: The correlation coefficient for the FI was inversely related to the histological severity (r = -0.558, p < 0.0001). The ROC analysis showed that the optimal cut-off value for the FI for active inflammation was 0.906. The average diagnostic accuracy of the FI was significantly higher than those of the CE (84.7 vs 78.5 %, p < 0.01). The kappa values for the inter-observer consistency of CE and the FI were 0.60 and 0.95 in all participants, 0.53 and 0.97 in the less-experienced endoscopists group and 0.67 and 0.93 in the expert group, respectively. CONCLUSIONS: The quantified AFI is considered to be an accurate and objective indicator that can be used to assess the activity of ulcerative colitis, particularly for less-experienced endoscopists.