p53 mutation biases squamocolumnar junction progenitor cells towards dysplasia rather than metaplasia in Barrett's oesophagus.

BACKGROUND: While p53 mutations occur early in Barrett's oesophagus (BE) progression to oesophageal adenocarcinoma (EAC), their role in gastric cardia stem cells remains unclear. OBJECTIVE: This study investigates the impact of p53 mutation on the fate and function of cardia progenitor cells in BE to EAC progression, particularly under the duress of chronic injury. DESIGN: We used a BE mouse model (L2-IL1ß) harbouring a Trp53 mutation (R172H) to study the effects of p53 on Cck2r+ cardia progenitor cells. We employed lineage tracing, pathological analysis, organoid cultures, single-cell RNA sequencing (scRNA-seq) and computational analyses to investigate changes in progenitor cell behaviour, differentiation patterns and tumour progression. Additionally, we performed orthotopic transplantation of sorted metaplastic and mutant progenitor cells to assess their tumourigenic potential in vivo. RESULTS: The p53 mutation acts as a switch to expand progenitor cells and inhibit their differentiation towards metaplasia, but only amidst chronic injury. In L2-IL1ß mice, p53 mutation increased progenitors expansion and lineage-tracing with a shift from metaplasia to dysplasia. scRNA-seq revealed dysplastic cells arise directly from mutant progenitors rather than progressing through metaplasia. In vitro, p53 mutation enhanced BE progenitors' organoid-forming efficiency, growth, DNA damage resistance and progression to aneuploidy. Sorted metaplastic cells grew poorly with no progression to dysplasia, while mutant progenitors gave rise to dysplasia in orthotopic transplantation. Computational analyses indicated that p53 mutation inhibited stem cell differentiation through Notch activation. CONCLUSIONS: p53 mutation contributes to BE progression by increasing expansion and fitness of undifferentiated cardia progenitors and preventing their differentiation towards metaplasia.

Rational Design of 2D Metal Halide Perovskites with Low Congruent Melting Temperature and Large Melt-Processable Window.

Metal halide perovskites (MHPs) have garnered significant attention due to their distinctive optical and electronic properties, coupled with excellent processability. However, the thermal characteristics of these materials are often overlooked, which can be harnessed to cater to diverse application scenarios. We showcase the efficacy of lowering the congruent melting temperature (Tm) of layered 2D MHPs by employing a strategy that involves the modification of flexible alkylammonium through N-methylation and I-substitution. Structural-property analysis reveals that the N-methylation and I-substitution play pivotal roles in reducing hydrogen bond interactions between the organic components and inorganic parts, lowering the rotational symmetry number of the cation and restricting the residual motion of the cations. Additional I···I interactions enhance intermolecular interactions and lead to improved molten stability, as evidenced by a higher viscosity. The 2D MHPs discussed in this study exhibit low Tm and wide melt-processable windows, e.g., (DMIPA)2PbI4 showcasing a low Tm of 98 °C and large melt-processable window of 145 °C. The efficacy of the strategy was further validated when applied to bromine-substituted 2D MHPs. Lowering the Tm and enhancing the molten stability of the MHPs hold great promise for various applications, including glass formation, preparation of high-quality films for photodetection, and fabrication of flexible devices.

Room-Temperature Anisotropic Actuation Driven by a Synergistic Order-Disorder and Displacive Phase Transition in a Ferroelectric Crystal.

Actuating materials convert different forms of energy into mechanical responses. To satisfy various application scenarios, they are desired to have rich categories, novel functionalities, clear structure-property relationships, fast responses, and, in particular, giant and reversible shape changes. Herein, we report a phase transition-driven ferroelectric crystal, (rac-3-HOPD)PbI3 (3-HOPD = 3-hydroxypiperidine cation), showing intriguingly large and anisotropic room-temperature actuating behaviors. The crystal consists of rigid one-dimensional [PbI3] anionic chains running along the a-axis and discrete disk-like cations loosely wrapping around the chains, leaving room for anisotropic shape changes in both the b- and c-axes. The shape change is switched by a ferroelectric phase transition occurring at around room temperature (294 K), driven by the exceptionally synergistic order-disorder and displacive phase transition. The rotation of the cations exerts internal pressure on the stacking structure to trigger an exceptionally large displacement of the inorganic chains, corresponding to a crystal lattice transformation with length changes of +24.6% and -17.5% along the b- and c-axis, respectively. Single crystal-based prototype devices of circuit switches and elevators have been fabricated by exploiting the unconventional negative temperature-dependent actuating behaviors. This work provides a new model for the development of multifunctional mechanically responsive materials.

Risk factors for anastomotic leak and postoperative morbidity after right hemicolectomy for colon cancer: results from a prospective, multi-centre, snapshot study in China.

BACKGROUND: Right hemicolectomy is the standard treatment for right-sided colon cancer. There is variation in the technical aspects of performing right hemicolectomy as well as in short-term outcomes. It is therefore necessary to explore best clinical practice following right hemicolectomy in expert centres. METHODS: This snapshot study of right hemicolectomy for colon cancer in China was a prospective, multicentre cohort study in which 52 tertiary hospitals participated. Eligible patients with stage I-III right-sided colon cancer who underwent elective right hemicolectomy were consecutively enrolled in all centres over 10 months. The primary endpoint was the incidence of postoperative 30-day anastomotic leak. RESULTS: Of the 1854 patients, 89.9 per cent underwent laparoscopic surgery and 52.3 per cent underwent D3 lymph node dissection. The overall 30-day morbidity and mortality were 11.7 and 0.2 per cent, respectively. The 30-day anastomotic leak rate was 1.4 per cent. In multivariate analysis, ASA grade > II (P < 0.001), intraoperative blood loss > 50 ml (P = 0.044) and D3 lymph node dissection (P = 0.008) were identified as independent risk factors for postoperative morbidity. Extracorporeal side-to-side anastomosis (P = 0.031), intraoperative blood loss > 50 ml (P = 0.004) and neoadjuvant chemotherapy (P = 0.004) were identified as independent risk factors for anastomotic leak. CONCLUSION: In high-volume expert centres in China, laparoscopic resection with D3 lymph node dissection was performed in most patients with right-sided colon cancer, and overall postoperative morbidity and mortality was low. Further studies are needed to explore the optimal technique for right hemicolectomy in order to improve outcomes further.

Chitinase 3-like 1 overexpression aggravates hypoxia-reoxygenation injury in IEC-6 cells by inhibiting the PI3K/AKT signalling pathway.

Intestinal ischaemia-reperfusion (I/R) is a common clinical pathology with high incidence and mortality rates. However, the mechanisms underlying intestinal I/R injury remain unclear. In this study, we investigated the role and mechanism of chitinase 3-like 1 (CHI3L1) during intestinal I/R injury. Therefore, we analysed the expression levels of CHI3L1 in the intestinal tissue of an intestinal I/R rat model and explored its effects and mechanism in a hypoxia-reoxygenation (H/R) IEC-6 cell model. We found that intestinal I/R injury elevated CHI3L1 levels in the serum, ileum and duodenum, whereas H/R enhanced CHI3L1 expression in IEC-6 cells. The H/R-induced inhibition of proliferation and apoptosis was alleviated by CHI3L1 knockdown and aggravated by CHI3L1 overexpression. In addition, CHI3L1 knockdown alleviated, and CHI3L1 overexpression aggravated, the H/R-induced inflammatory response and oxidative stress. Mechanistically, CHI3L1 overexpression weakened the activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway, suppressed the nuclear translocation of Nrf2, and promoted the nuclear translocation of nuclear factor κB (NF-κB). Moreover, CHI3L1 knockdown had the opposite effect on the PI3K/AKT pathway, Nrf2, and NF-κB. Moreover, the PI3K inhibitor LY294002 blocked the effect of CHI3L1 knockdown on the H/R-induced inhibition of proliferation, apoptosis, inflammatory response and oxidative stress. In conclusion, CHI3L1 expression was induced during intestinal I/R and H/R injury in IEC-6 cells, and CHI3L1 overexpression aggravated H/R injury in IEC-6 cells by inhibiting the PI3K/AKT signalling pathway. Therefore, CHI3L1 may be an effective target for controlling intestinal I/R injury.

Immune cells mediate the causal pathway linking circulating complements to cancer: A Mendelian randomization study.

BACKGROUND: The role of complement in cancer remains controversial. Whether immune cells and inflammatory factors mediate the pathway from complement to cancer has not been fully elucidated. METHODS: We conducted bidirectional Mendelian randomization (MR) analysis to explore the causal association between complement components and cancer. Meta-analysis was conducted to enhance the robustness of the results. We further explored the mediation roles of immune cells and inflammatory factors in these associations. RESULTS: Our study identified causal associations between 11 complement components and 12 types of cancer. Furthermore, we identified five immune cells as potential mediators: BAFF-R on IgD + CD38- naive B cell mediated 7.434% of the increased risk for liver cancer from C3; CD4 on CD39 + activated CD4 regulatory T cell mediated 12.384% of the increased risk for biliary tract cancer from CD93; CD25 + + CD45RA + CD4 not regulatory T cell and Basophil %CD33dim HLA DR- CD66b- mediated 7.721% and 7.986% of the increased risk of colorectal cancer from MASP1, respectively; CD45RA on resting CD4 regulatory T cell mediated 11.444% of the increased risk of skin cancer from MASP1. CONCLUSION: This study revealed the causal relationships between complement components and certain cancers, with five immune cells as potential mediators.

Unveiling Chirality Transfer between Chiral Centers and Metal Halides in Chiral Organic-Inorganic Hybrid Metal Halides.

Chirality transfer refers to the process in which chiral cations compel the crystallization of the inorganic component into the Sohncke group. Enhancing the chirality of the inorganic component in chiral organic-inorganic hybrid metal halides (OIHMHs) through chirality transfer, aimed at improving chiroptical and spintronic properties, remains challenging due to the complexity of the underlying mechanism. To investigate this, we propose a novel concept─chirality transfer coefficient─as a means of quantifying the strength of chirality transfer in OIHMHs. A comparative study of OIHMHs with varying dimensionality, metal ions, and chiral centers was conducted to elucidate this mechanism. By analyzing factors such as hydrogen bonding, the number of chiral centers, dimensionality, helical geometry, and structural distortions, we found that chirality transfer is influenced by a combination of structural dimensions and the number of chiral centers. Importantly, our findings reveal that 0D, and 1D OIHMHs, particularly 1D with a zigzag chain configuration, exhibit stronger chirality transfer than their 2D counterparts. Moreover, in 2D OIHMHs, a reduction in the number of chiral centers enhances chirality transfer. However, no direct correlation was observed between chirality transfer and spin splitting. These insights contribute to a more comprehensive understanding of chirality transfer mechanisms and provide a strategic approach for enhancing the chirality transfer and associated physical properties in OIHMHs.

Unveiling Chiral Perovskite CD Signal Scaling: Discerning Authentic and Counterfeit Signals through Sample-State Analysis.

Circular dichroism (CD) spectroscopy is a well-known and powerful technique widely used for distinguishing chiral enantiomers based on their differential absorbance of the right and left circularly polarized light. With the increasing demand for solid-state chiral optics, CD spectroscopy has been extended to elucidate the chirality of solid-state samples beyond the traditional solution state. However, due to the sample preparation differential, the CD spectra of the same compound measured by different researchers may not be mutually consistent. In this study, we employ solution, powder, thin-film, and single-crystal samples to explore the challenges associated with CD measurements and distinguish between genuine and fake signals. Rational fabrication of the solid-state samples can effectively minimize the macroscopic anisotropic nature of the samples and thereby mitigate the influence of linear dichroism (LD) and linear birefringence (LB) effects, which arise from anisotropy-induced differences in the absorbances and refractive indices. The local anisotropic and overall isotropic features of the high-quality thin-film sample achieve an optically isotropic state, which exhibits superior CD signal repeatability at the front and back sides at different angles by rotating the sample along the light path. In addition, sample thickness-induced CD signal overload and absorption saturation pose more severe challenges than the LBLD-induced amplified CD signal but are rarely focused on. The CD signal overload in the deep UV region leads to the presence of fake signals, while absorption saturation results in a complete loss of the CD signal. These findings help obtain accurate CD signals by a well-fabricated optically isotropic sample to avoid LDLB and optimize the sample thickness to avoid fake signals and no signals.

Effect of the gut microbiota and their metabolites on postoperative intestinal motility and its underlying mechanisms.

Gut microbiota is closely related to human health and disease because, together with their metabolites, gut microbiota maintain normal intestinal peristalsis. The use of antibiotics or opioid anesthetics, or both, during surgical procedures can lead to dysbiosis and affect intestinal motility; however, the underlying mechanisms are not fully known. This review aims to discuss the effect of gut microbiota and their metabolites on postoperative intestinal motility, focusing on regulating the enteric nervous system, 5-hydroxytryptamine neurotransmitter, and aryl hydrocarbon receptor.

Structural Descriptors to Correlate Pb Ion Displacement and Broadband Emission in 2D Halide Perovskites.

2D hybrid lead halide perovskites exhibit versatile photoluminescent behaviors for narrowband to broadband emissions (BBEs) and have become attractive candidates for potential applications such as solid-state lighting. Establishing the relationship between the perovskite structural distortion and BBE is key but challenging in designing and optimizing the perovskite luminophores. Conventional attention is given to analyzing the intra-octahedron distortion of the [PbX6]4- (X = halide) unit that has not yet provided a clear structure-luminescence relationship. Herein, we introduce a descriptor, Pb displacement, to describe the inter-octahedron distortion to clarify the structure-emission relationship. The displacement of adjacent Pb centers represents the lattice distortion, which determines the broadband/narrowband emission instead of the octahedron distortion itself. We find a kite-type quadrilateral rule in (001) type 2D perovskites, that is, the degree to which the four octahedral central ions deviate from a square relates to the BBE. The kite-type arrangement of the Pb ions usually corresponds to the BBEs due to the large structure distortions. In contrast, the square-type arrangement of the Pb ions corresponds to the narrowband emissions because of the small distortions. The distortion descriptor magnifies the distortion scale, making it larger than the conventional one for the intra-octahedron distortion, which matches the general concept of excitons based on the scale of the crystal lattice. Therefore, the set of structural descriptors is better to correlate the perovskite structures and emission properties.

hsa-miR-875-5p inhibits tumorigenesis and suppresses TGF-ß signalling by targeting USF2 in gastric cancer.

BACKGROUND: Gastric cancer (GC) is one of the most common malignancies, and an increasing number of studies have shown that its pathogenesis is regulated by various miRNAs. In this study, we investigated the role of miR-875-5p in GC. METHODS: The expression of miR-875-5p was detected in human GC specimens and cell lines by miRNA qRT-PCR. The effect of miR-875-5p on GC proliferation was determined by Cell Counting Kit-8 (CCK-8) proliferation and 5-ethynyl-2'-deoxyuridine (EdU) assays. Migration and invasion were examined by transwell migration and invasion assays as well as wound healing assays. The interaction between miR-875-5p and its target gene upstream stimulatory factor 2(USF2) was verified by dual luciferase reporter assays. The effects of miR-875-5p in vivo were studied in xenograft nude mouse models. Related proteins were detected by western blot. RESULTS: The results showed that miR-875-5p inhibited the proliferation, migration and invasion of GC cells in vitro and inhibited tumorigenesis in vivo. USF2 was proved to be a direct target of miR-875-5p. Knockdown of USF2 partially counteracted the effects of miR-875-5p inhibitor. Overexpression of miR-875-5p could inhibit proliferation, migration and invasion and suppress the TGF-ß signalling pathway by downregulating USF2. CONCLUSIONS: MiR-875-5p can inhibit the progression of GC by directly targeting USF2. And in the future, miR-875-5p is expected to be a potential target for GC diagnosis and treatment.

Bulk Mn2+ Doped 1D Hybrid Lead Halide Perovskite with Highly Efficient, Tunable and Stable Broadband Light Emissions.

Mn2+ doped colloidal three-dimensional (3D) lead halide perovskite nanocrystal (PNC) has attracted intensive research attention; however, the low exciton binding energy and fatal optical instability of 3D PNC seriously hinder the optoelectronic application. Therefore, it remains significant to explore new stable host perovskite with strongly bound exciton to realize more desirable luminescent property. In this work, we utilized bulk one-dimensional (1D) hybrid perovskite of [AEP]PbBr5 ⋅ H2 O (AEP=N-aminoethylpiperazine) as structural platform to rationally optimize the luminescent property by a controllable Mn2+ doping strategy. Significantly, the series of Mn2+ -doped 1D [AEP]PbBr5 ⋅ H2 O show enhanced energy transfer efficiency from the strongly bound excitons of host material to 3d electrons of Mn2+ ions, resulting in tunable broadband light emissions from weak yellow to strong red spectral range with highest photoluminescence quantum yield up to 28.41 %. More importantly, these Mn2+ -doped 1D perovskites display ultrahigh structural and optical stabilities in humid atmosphere, water and high temperature exceeding the conventional 3D PNC. Combined highly efficient, tunable and stable broadband light emissions enable Mn2+ -doped 1D perovskite as excellent down-converting phosphor showcasing the potential application in white light emitting diode. This work not only provides a profound understanding of low-dimensional perovskites but also opens a new way to rationally design high-performance broadband light emitting perovskites for solid-state lighting and displaying devices.

Ultrasonic surgical and electrosurgical system (USES) with conventional ultrasonic scalpel (CUS) in gastrectomy: a retrospective cohort study.

BACKGROUND: Harmonic ACE +7 Shears with Advanced Hemostasis is an upgraded ultrasonic device, an ultrasonic surgical and electrosurgical system (USES). The study aimed to evaluate the economic and clinical effectiveness of the USES compared with the conventional ultrasonic scalpel (CUS) in gastrectomy. METHODS: We conducted a single-center, retrospective cohort study using the electronic medical records in China. We collected intraoperative and postoperative data from gastric cancer patients who underwent the endoscope-assisted distal gastrectomy from 2018 to June 30, 2019. Procedure-related costs were estimated. We used linear regression by controlling a set of covariates to assess the effect of USES on outcomes. RESULT: Out of 87 eligible patients, the USES group (40 patients) and CUS group (47 patients) were comparable in terms of age, medical history and stages of cancer. Compared with the CUS, the USES saved 4.27 hemoclips per person (95% CI 0.57-7.97, p < 0.05) and 34.18 ml intraoperative blood per person (95% CI 8.74-59.62 ml, p < 0.05), respectively. Postoperative length of stay (LOS) was shorter in the USES group (7.90 ± 1.95 vs. 9.26 ± 2.81 days) but the difference was not statistically significant (p = 0.05). CONCLUSIONS: The USES group was associated with fewer hemoclips use and intraoperative blood loss in patients undergoing laparoscopic gastrectomy at comparable costs.

Risk factors for periappendiceal adhesions in acute appendicitis: a retrospective comparative study.

PURPOSE: Acute appendicitis usually requires immediate surgical treatment, but appendectomies were difficult for some patients with severe periappendiceal adhesions. We investigated risk factors of intraoperative adhesions to help surgeons make better treatment plans for appendicitis. METHODS: We retrospectively analyzed 186 cases diagnosed with acute appendicitis and underwent surgery in Shandong Provincial Hospital affiliated to Shandong First Medical University between January 2018 and December 2019. According to the degree of intraoperative adhesions, they were divided into mild, moderate and severe groups. Then, we analyzed a number of preoperative factors contributed to adhesions, suppuration and perforation during appendectomy in 186 patients. RESULTS: Contrast to the moderate group (MoG) and the mild group (MiG), the severe degree of adhesions group (SG) had a higher intraoperative perforation and suppuration rate, a greater likelihood of conversion to open and more postoperative complications. Multivariable logistic regression analysis showed that recurrent appendicitis and high neutrophil percentage were independently associated with periappendiceal adhesions. The preoperative ultrasonography (US) revealed periappendiceal fluid and high neutrophil percentage were independently associated with appendix suppuration. A high preoperative neutrophil percentage was independently associated with appendix perforation. CONCLUSIONS: Recurrent appendicitis and preoperative high neutrophil percentage were risk factors of periappendiceal adhesions; preoperative US revealed periappendiceal fluid and high neutrophil percentage were risk factors of appendix suppuration; and a high preoperative neutrophil percentage was a risk factor of appendix perforation.

Fibroblast growth factor receptor-like-1: a new therapeutic target and unfavorable prognostic indicator for rectal adenocarcinoma.

Fibroblast growth factor receptor-like-1 (FGFRL1) is important to cell motility and links with tumorigenic potential in various types of cancers. To investigate the biological function and underlying mechanism of FGFRL1 in rectal adenocarcinoma, we conducted this study. TCGA and Oncomine databases were used to analyze FGFRL1 expression and its association with clinical characteristics or overall survival (OS) in rectal adenocarcinoma patients. siRNA strategy was implemented to knockdown FGFRL1 expression in rectal adenocarcinoma cells. CCK8, colony formation, wound healing, and transwell assays were implemented to measure cell behaviors. qRT-PCR and western blot were utilized to identify mRNA and protein expression levels. FGFRL1 was significantly increased in rectal adenocarcinoma tissue samples, either colon or rectum. High-regulation of FGFRL1 expression induced poorer outcome of rectal adenocarcinoma patients. Downregulation of FGFRL1 inhibited the proliferation, colony formation, migration, and invasion of SW837 cells. The MAPK pathway-related proteins, phosphorylation of MEK and ERK, were also decreased after si-FGFRL1 transfection. These findings demonstrated that FGFRL1, acting as a potential inducator, may promote the progression of rectal adenocarcinoma via activating the MAPK signaling pathway.

Improving Broadband White-Light Emission Performances of 2D Perovskites by Subtly Regulating Organic Cations.

Recently, 2D organic-inorganic hybrid lead halide perovskites have attracted intensive attention in solid-state luminescence fields such as single-component white-light emitters, and rational optimization of the photoluminescence (PL) performance through accurate structural-design strategies is still significant. Herein, by carefully choosing homologous aliphatic amines as templates, isotypical perovskites [DMEDA]PbCl4 (1, DMEDA=N,N-dimethylethylenediamine) and [DMPDA]PbCl4 (2, DMPDA=N,N-dimethyl-1,3-diaminopropane) having tunable and stable broadband bluish white emission properties were rationally designed. The subtle regulation of organic cations leads to a higher degree of distortion of the 2D [PbCl4 ]2- layers and enhanced photoluminescence quantum efficiencies (<1 % for 1 and 4.9 % for 2). The broadband light emissions could be ascribed to self-trapped excitons on the basis of structural characterization, time-resolved PL, temperature-dependent PL emission, and theoretical calculations. This work gives a new guidance to rationally optimize the PL properties of low-dimensional halide perovskites and affords a platform to probe the structure-property relationship.

Dexamethasone on postoperative gastrointestinal motility: A placebo-controlled, double-blinded, randomized controlled trial.

BACKGROUND AND AIM: Following abdominal surgery, patients usually experience a transient episode of impaired gastrointestinal motility. This study aimed to determine whether a single preoperative dose of dexamethasone can promote the recovery of gastrointestinal function in patients following elective gastrointestinal surgery. METHODS: In this single-center, two-arm, parallel, randomized controlled trial, we studied 126 patients (aged 18-80 years) who underwent elective open or laparoscopic bowel surgery for malignant or benign pathology. At the induction of anesthesia, a treatment group (n = 64) received a single dose of 8-mg intravenous dexamethasone, and a control group (n = 62) received normal saline. RESULTS: Intravenous administration of 8-mg dexamethasone significantly decreased the time to return of flatus by an average of approximately 8 h (P < 0.05). Abdominal distension was significantly reduced on the third day after surgery in the dexamethasone group (P < 0.05), and the time to tolerance of a liquid diet was shorter in the dexamethasone group (P < 0.01). There were no significant differences in other secondary outcomes, including postoperative pain, complication rates, length of hospital stay, or time to first defecation, between the two groups. CONCLUSIONS: A single intravenous dose of 8-mg dexamethasone at induction of anesthesia significantly decreases the time to return of flatus, improves abdominal distension at 72 h, and promotes tolerance of a liquid diet. Although further studies are required to confirm our results, we recommend that dexamethasone should be used more widely in gastrointestinal surgery.

Mutational landscape of gastric cancer and clinical application of genomic profiling based on target next-generation sequencing.

BACKGROUND: Gastric cancer (GC) is a leading cause of cancer deaths, and an increased number of GC patients adopt to next-generation sequencing (NGS) to identify tumor genomic alterations for precision medicine. METHODS: In this study, we established a hybridization capture-based NGS panel including 612 cancer-associated genes, and collected sequencing data of tumors and matched bloods from 153 gastric cancer patients. We performed comprehensive analysis of these sequencing and clinical data. RESULTS: 35 significantly mutated genes were identified such as TP53, AKAP9, DRD2, PTEN, CDH1, LRP2 et al. Among them, 29 genes were novel significantly mutated genes compared with TCGA study. TP53 is the top frequently mutated gene, and tends to mutate in male (p = 0.025) patients and patients whose tumor located in cardia (p = 0.011). High tumor mutation burden (TMB) gathered in TP53 wild-type tumors (p = 0.045). TMB was also significantly associated with DNA damage repair (DDR) genes genotype (p = 0.047), Lauren classification (p = 1.5e-5), differentiation (1.9e-7), and HER2 status (p = 0.023). 38.31% of gastric cancer patients harbored at least one actionable alteration according to OncoKB database. CONCLUSIONS: We drew a comprehensive mutational landscape of 153 gastric tumors and demonstrated utility of target next-generation sequencing to guide clinical management.

Case report of ascending colon cancer and multiple jejunal GISTs in a patient with neurofibromatosis type 1 (NF1).

BACKGROUND: NF1(Neurofibromatosis type 1) is an autosomal dominant genetic disorder. Patients with NF1 have an increased risk of developing benign or malignant tumours, such as gastrointestinal stromal tumours (GISTs). However, the coexistence of NF1, GIST and colon cancer is very rare, and few cases have been reported in the literature. CASE PRESENTATION: We admitted a case of a 64-year-old man with type 1 neurofibromatosis, GISTs, and ascending colon cancer. This case was characterized by café-au-lait macules, discrete cutaneous neurofibromas, nodular neurofibromas, multiple jejunal tumours, and ascending colon cancer. Laparoscopic exploration revealed ascending colon cancer and multiple jejunal tumours. Laparoscopic right hemicolectomy and local excision of the jejunal tumours were performed successfully. The pathological results confirmed moderate differentiated adenocarcinoma of the ascending colon with multiple jejunal GISTs (low risk, very low risk). Moreover, the immunohistochemistry results of multiple jejunal GISTs suggest that NF1 is positive. Whole-exome sequencing (WES) of colon cancer revealed mutations in more than 20 genes, including KRAS, PIK3CA, APC, SMAD4, etc. The results of whole-exome sequencing (WES) of jejunal GISTs revealed an NF1 mutation and no KIT or PDGFR gene mutation. CONCLUSION: We report a rare case of simultaneous NF1, GIST and colon adenocarcinoma. For patients with NF1, benign and/or malignant tumours are often combined. Therefore, these patients should undergo regular physical examinations so that early detection and early treatment can be achieved.