Local Excision Versus Radical Resection for Grade 2 Rectal Neuroendocrine Tumors: A Multicenter Propensity Score-Matched Analysis.

BACKGROUND: Studies on grade 2 rectal neuroendocrine tumors are limited, and the optimal treatment for these tumors is not well established. OBJECTIVE: We aimed to compare the oncologic results of local excision versus radical resection for the treatment of grade 2 rectal neuroendocrine tumors. DESIGN: Retrospective multicenter propensity score-matched study to minimize heterogeneity between groups and focus on the differences between surgery strategies. SETTINGS: Seventeen large-scale Chinese medical centers participated in this study. PATIENTS: A total of 144 patients with pathologically confirmed grade 2 rectal neuroendocrine tumors were retrospectively analyzed. MAIN OUTCOME MEASURES: Cancer-specific survival and relapse-free survival were assessed to compare surgery strategies. RESULTS: A total of 144 patients with grade 2 rectal neuroendocrine tumors were enrolled in this study. Twenty-seven patients underwent endoscopic resection, 55 underwent transanal excision, 50 underwent radical resection, and 12 underwent palliative surgery or biopsy for distant metastasis. Of the 50 patients who underwent radical resection, 30 (60.0%) had clinically positive lymph nodes on the basis of the histopathology results. The optimal cutoff value for tumor size to predict cancer-specific survival was 1.5 cm. In patients with grade 2 rectal neuroendocrine tumors of ≤1.5-cm size, there were no significant differences in cancer-specific survival and relapse-free survival between local excision and radical resection groups ( p > 0.05). In patients with grade 2 rectal neuroendocrine tumors of >1.5-cm size, relapse-free survival was significantly lower in the local excision group than in the radical resection group ( p = 0.04). LIMITATIONS: The nature of retrospective reviews and a relatively short follow-up period are limitations of this study. CONCLUSIONS: Grade 2 rectal neuroendocrine tumors have a nonnegligible rate of lymph node metastasis. Local excision is a feasible choice for tumors of ≤1.5 cm size without metastasis, whereas radical resection is more beneficial in those of >1.5 cm size. See Video Abstract . ESCISIN LOCAL VERSUS RESECCIN RADICAL PARA TUMORES NEUROENDOCRINOS RECTALES GRADO ANLISIS MULTICNTRICO CON PUNTUACIN DE PROPENSIN COINCIDENTE: ANTECEDENTES:Los estudios sobre los tumores neuroendocrinos rectales de grado 2 son limitados y el tratamiento óptimo para estos tumores no está bien establecido.OBJETIVO:Comparar los resultados oncológicos de la escisión local versus la resección radical para el tratamiento de tumores neuroendocrinos rectales grado 2.DISEÑO:Estudio multicéntrico retrospectivo emparejado por puntuación de propensión para minimizar la heterogeneidad entre grupos y centrarse en la diferencia entre estrategias quirúrgicas.ESCENARIO:Diecisiete centros médicos chinos de gran tamaño participaron en este estudio.PACIENTES:Se analizaron retrospectivamente un total de 144 pacientes con tumores neuroendocrinos rectales grado 2 patológicamente confirmados.PRINCIPALES MEDIDAS DE RESULTADO:Se evaluaron la supervivencia específica del cáncer y la supervivencia libre de recaída para comparar las estrategias quirúrgicas.RESULTADOS:En este estudio se inscribieron un total de 144 pacientes con tumores neuroendocrinos rectales grado 2. Veintisiete pacientes se sometieron a resección endoscópica, 55 a escisión transanal, 50 a resección radical y 12 a cirugía paliativa o biopsia por metástasis a distancia. De los 50 pacientes que se sometieron a resección radical, 30 (60,0%) tenían ganglios linfáticos clínicamente positivos según los resultados histopatológicos. El valor de corte óptimo para el tamaño del tumor para predecir la supervivencia específica del cáncer fue de 1,5 cm. En pacientes con tumores neuroendocrinos rectales grado 2 ≤ 1,5 cm, no hubo diferencias significativas en la supervivencia específica del cáncer y la supervivencia libre de recaída entre los grupos de escisión local y resección radical ( p >0,05). En pacientes con tumores neuroendocrinos rectales grado 2 > 1,5 cm, la supervivencia libre de recaída fue significativamente menor en el grupo de escisión local que en el grupo de resección radical ( p = 0,04).LIMITACIONES:La naturaleza de la revisión retrospectiva y el período de seguimiento relativamente corto son limitaciones de este estudio.CONCLUSIONES:Los tumores neuroendocrinos rectales grado 2 tienen una tasa no despreciable de metástasis en los ganglios linfáticos. La escisión local es una opción factible para tumores ≤ 1,5 cm sin metástasis, mientras que la resección radical es más beneficiosa en aquellos > 1,5 cm. (Traducción-Dr. Felipe Bellolio ).

Lymph node ratio and hematological parameters predict relapse-free survival in patients with high grade rectal neuroendocrine neoplasms after radical resection: a multicenter prognostic study.

BACKGROUND: The prognostic nutritional index (PNI), alkaline phosphatase (ALP), and lymph node ratio (LNR) are reportedly related to prognosis. The aim of this study was to elucidate the clinical importance of the LNR and hematological parameters in patients with high grade rectal neuroendocrine neoplasms (HG-RNENs) who were undergoing radical resection. METHODS: We reviewed the medical records of patients with HG-RNENs from 17 large-scale medical centers in China (January 1, 2010-April 30, 2022). A nomogram was constructed by using a proportional hazard model. Bootstrap method was used to draw calibration plots to validate the reproducibility of the model. Concordance index (C-Index), decision curve analysis (DCA), and time-dependent area under the receiver operating characteristic curve (TD-AUC) analysis were used to compare the prognostic predictive power of the new model with American Joint Committee on Cancer (AJCC) TNM staging and European Neuroendocrine Tumor Society (ENETS) TNM staging. RESULTS: A total of 85 patients with HG-RNENs were enrolled in this study. In the 45 patients with HG-RNENs who underwent radical resection, PNI ≤ 49.13 (HR: 3.997, 95% CI: 1.379-11.581, P = 0.011), ALP > 100.0 U/L (HR: 3.051, 95% CI: 1.011-9.205, P = 0.048), and LNR > 0.40 (HR: 6.639, 95% CI: 2.224-19.817, P = 0.0007) were independent predictors of relapse-free survival. The calibration plots suggested that the nomogram constructed based on the three aforementioned factors had good reproducibility. The novel nomogram revealed a C-index superior to AJCC TNM staging (0.782 vs 0.712) and ENETS TNM staging (0.782 vs 0.657). Also, the new model performed better compared to AJCC TNM staging and ENETS TNM staging in DCA and TD-AUC analyses. CONCLUSIONS: LNR, ALP, and PNI were independent prognostic factors in patients with HG-RNENs after radical resection, and the combined indicator had better predictive efficacy compared with AJCC TNM staging and ENETS TNM staging.

A pilot study on prophylactic tube enterostomy for the prevention of anastomotic leakage in patients with high-risk intestinal anastomosis.

BACKGROUND: Anastomotic leakages (ALs) are one of the most serious complications following gastrointestinal anastomosis. Currently, very few operative measures are available for the prevention of ALs. This pilot study aimed to evaluate the safety and efficacy of tube enterostomy (T-E) for the prevention of ALs in patients with high-risk intestinal anastomosis. METHODS: In this retrospective study, demographic data and postoperative outcomes were compared among patients who received T-E and two historical cohorts: one group that underwent primary anastomosis without T-E (non-T-E group) and another that underwent conventional stoma construction without anastomosis (stoma group). The operative procedures were selected according to a scoring system that quantitatively evaluated risk of Als (Zhongnan score). RESULTS: From March 2017 to March 2020, a total of 45 consecutive patients were enrolled in the T-E group. Among these patients, 53.3% (24/45) were diagnosed with Crohn's disease (CD), and 66.7% (30/45) of them underwent emergency surgery. After propensity score matching, the demographic data were comparable among the three groups. One case of AL (2.2%) occurred in the T-E group, while four cases of ALs (8.9%, 4/45) were found in the non-T-E group (p = 0.13). Tube feeding was provided to 33.3% (15/45) of the T-E patients. Major tube-related complications included one tube dislocation (2.2%) and 3 (6.7%) minor leakages after tube withdrawal (treated conservatively). One death occurred in the stoma group. In the subgroup analysis of CD patients, lower rates of ALs and abdominal abscesses were observed in the T-E group than in the non-T-E and stoma subgroups, but the differences were not significant. CONCLUSIONS: T-E seems to be a safe and feasible operative method for the protection of high-risk intestinal anastomosis, can be reversed and can provide enteral feeding with acceptable tube-related complications. Further studies are needed to validate the role of T-E.

[Bowel Sounds Detection Method and Experiment Based on Multi-feature Combination].

Bowel sounds is an important indicator to monitor and reflect intestinal motor function, and traditional manual auscultation requires high professional knowledge and rich clinical experience of doctors. In addition, long-time auscultation is time-consuming and laborious， which may lead to misjudgment caused by subjective error. To solve the problem, firstly, the wavelet transform is used to preprocess the bowel sounds signal for noise reduction and enhancement. Secondly, three typical features of intestinal sound were extracted. According to the combination of these features, a three-stage decision was designed to carry out multi-parameter and multi-feature joint threshold detection. This algorithm realized the detection of bowel sound signal and the location of its start and end points, making it possible that the complete bowel sound signal was extracted effectively. In this study, a large number of clinical data and label of bowel sounds were collected, and a new effective evaluation method was proposed to verify the proposed method. The accuracy rate is 83.51%. Results of this study will provide systematic support and theoretical guarantee for the diagnosis of intestinal diseases and the monitoring of postoperative intestinal function recovery of patients.

Direct Evidence of Active SARS-CoV-2 Replication in the Intestine.

BACKGROUND: Currently, there is no direct evidence to prove the active replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the intestinal tract and relevant pathological changes in the colon and rectum. We investigated the presence of virions and pathological changes in surgical rectal tissues of a patient with clinically confirmed coronavirus disease 2019 (COVID-19) with rectal adenocarcinoma. METHODS: The clinical data were collected during hospitalization and follow-up of this patient. Quantitative reverse transcriptase-polymerasechain reaction (RT-PCR) was performed on the rectal tissue specimens obtained from surgical resection, succus entericus and intestinal mucosa of ileostomy, and rectal mucosa during follow-up after recovery. Ultrathin sections of surgical samples were observed for SARS-CoV-2 virions using electron microscopy. Histopathological examination was performed using hematoxylin-eosin stain. Immunohistochemical analysis and immunofluorescence were carried out on rectal tissues to evaluate the distribution of SARS-CoV-2 antigen and immune cell infiltrations. RESULTS: The patient had fever and cough on day 3 postoperatively, was diagnosed with COVID-19 on day 7, and was discharged from the hospital on day 41. RNA of SARS-CoV-2 was detected in surgically resected rectal specimens but not in samples collected 37 days after discharge. Notably, coincident with rectal tissues of surgical specimens testing nucleic acid positive for SARS-CoV-2, typical coronavirus virions in rectal tissue were observed under electron microscopy. Moreover, abundant lymphocytes and macrophages (some were SARS-CoV-2 positive) infiltrating the lamina propria were found with no significant mucosal damage. CONCLUSIONS: We first report the direct evidence of active SARS-CoV-2 replication in a patient's rectum during the incubation period, which might explain SARS-CoV-2 fecal-oral transmission.

miR-128 participates in the pathogenesis of chronic constipation by regulating the p38α/M-CSF inflammatory signaling pathway.

Chronic constipation (CC) is a gastrointestinal disorder that adversely affects the quality of life. MicroRNAs are involved in the pathogenesis of functional gastrointestinal disorders. This study aims to investigate the molecular mechanism of microRNA-128 in CC. Here, we successfully constructed a murine model of CC based on morphine and rhubarb. The expression of stem cell factor (SCF) and neuron-specific enolase (NSE) was low in the models. Using miRNA array and bioinformatic analysis, we predicted and confirmed the expression of miR-128 and its downstream target genes in CC model. Compared with the control group, CC group showed a significant downregulation of miR-128 and upregulation of p38α and macrophage colony-stimulating factors (M-CSFs). Moreover, we observed elevated inflammatory cytokine and decreased anti-inflammatory cytokine levels in colonic tissues. Furthermore, coculture assays indicated that regulating expression of miR-128 in colonic epithelial cells induced the secretion of IL-6 and TNF-α by macrophages. In conclusion, our study demonstrated that miR-128 regulated the p38α/M-CSF signaling pathway to promote chronic inflammatory responses and changes in the immune microenvironment of the colon, thereby offering potential insights into the pathogenesis of CC and therapeutic targets for its treatment.NEW & NOTEWORTHY In this study, we constructed a murine model and identified a novel signaling mechanism involved in the chronic constipation progression. Our findings on the role of miR-128/p38α/M-CSF axis provide new insights into the treatment of chronic constipation.

Quantitative Analysis of Intramucosal Mast Cells in Irritable Bowel Syndrome: A Comparison With Inflammatory Bowel Disease in Remission.

GOAL: We aimed to study the density of intramucosal mast cells in histologically normal colonic mucosa biopsied from patients with a clinical diagnosis of irritable bowel syndrome (IBS). BACKGROUND: Mast cell activation has been thought to implicate in the pathogenesis of inflammatory bowel disease (IBD). Whether it serves a role in the pathogenesis of IBS remains controversial. STUDY: A total of 127 colonoscopic mucosal biopsies were immunohistochemically stained, including 51 IBS, 66 IBD, and 10 normal control samples. Intact mast cells were quantified in 3 high power fields (HPF) in areas showing the highest density. RESULTS: CD117 was sensitive in detecting mast cells in colonic mucosa. The mast cell counts in all biopsies ranged from 2 to 60 per HPF (mean=17.5±7.2). The density of intramucosal mast cells were similar among IBS, IBD and normal control groups (P=0.6733). IBD in remission versus IBS (17.1±8.0 vs. 18.1±7.0; P=0.4804), Crohn disease versus ulcerative colitis (17.1±10.4 vs. 17.2±5.2; P=0.9463), IBS with diarrhea versus without diarrhea (19.5±6.3 vs. 16.8±6.9; P=0.1404). Forty biopsies (31.5%) showing ≥20 mast cells per HPF appeared to equally distribute among various disease groups (P=0.7283). CONCLUSIONS: There is no significant difference in the number of intramucosal mast cells between IBS and IBD that show normal colonic biopsies. In IBS patients, the number of intramucosal mast cell does not correlate with symptoms. The mast cell count (≥20/HPF) is not a reliable criterion for the diagnosis of IBS or for the distinction between patients with IBS and those with IBD in remission.

Correlation of Musashi-1, Lgr5, and pEGFR expressions in human small intestinal adenocarcinomas.

Recent studies have revealed that Musashi-1 and Lgr5 (leucine-rich-repeat-containing G-protein-coupled receptor 5) were putative stem cell genes. The epidermal growth factor receptor (EGFR) has also been extensively studied; it was known as an oncogenic driver in cancers. Overexpressions of Musashi-1, EGFR, and Lgr5 have been reported in some tumor tissues and cell lines. In this study, we used immunohistochemical analysis to investigate the expression pattern of Musashi-1, Lgr5, and pEGFR in 38 small intestinal adenocarcinomas (SIAs) resection specimens, 20 matched normal specimens and tried to analyze the correlations among them. The positive rate of Musashi-1, Lgr5, and pEGFR in SIAs, respectively, was 71 % (27/38), 55 % (21/38), and 45 % (17/38). Compared with the adjacent normal small intestinal mucosa, Musashi-1, Lgr5, and pEGFR protein were overexpressed in SIAs (P< 0.05). Furthermore, Musashi-1 and Lgr5 expressions were significantly correlated with the depth of wall invasion (P = 0.0011, P = 0.0017, respectively). Musashi-1 expression was closely correlated with Lgr5 (P = 0.015, r = 0.392). However, pEGFR expression was not associated with age, gender, tumor size, differentiation, depth of invasion, lymphatic metastasis, TNM stage, and pEGFR expression was not correlated with Musashi-1 or Lgr5 (P > 0.05, r = 0.064; P > 0.05, r = 0.307, respectively). Thus, we suggest that Musashi-1, Lgr5, and pEGFR are overexpressed in human SIAs and may play roles in human SIA carcinogenesis and progression.

The Relationship Between Colonic Macrophages and MicroRNA-128 in the Pathogenesis of Slow Transit Constipation.

BACKGROUND: Recent evidence suggests that colonic macrophages and microRNAs play important roles in motor activity in the gastrointestinal tract. However, there are almost no data concerning colonic macrophages and microRNAs in slow transit constipation. AIM: The purpose of this study was to investigate colonic macrophages and microRNA-128 expression in the pathogenesis of slow transit constipation in colon tissues. METHODS: Full-thickness colonic specimens from patients undergoing surgery for slow transit constipation, due to refractoriness to other therapeutic interventions (n = 25), were compared to controls (n = 25), and the number of colonic macrophages (as evaluated by specific monoclonal antibodies) was counted. Gene expression analysis of microRNA-128 was performed by microRNA microarray and qRT-PCR. Lastly, bioinformatics analysis, coupled with luciferase reporter assays, was used to investigate the mRNA transcript(s) targeted by microRNA-128. RESULTS: Compared to controls, 20 of 25 slow transit constipation patients (80 %) had significantly higher numbers of macrophages in colonic specimens, coupled with down-regulation of microRNA-128. Linear regression analyses showed a significant negative correlation between macrophage number and microRNA-128 expression level. Among 83 bioinformatically predicated candidates, mitogen-activated protein kinase 14 (p38α) was validated to be a direct target of microRNA-128 in human intestinal epithelial cells. CONCLUSIONS: This study presents evidence for the negative correlation of macrophage number and microRNA-128 expression, in slow transit constipation patients, representing a possible mechanism of impaired gastrointestinal motility.

[A prospective multicenter clinical trial of extralevator abdominoperineal excision for locally advanced low rectal cancer].

OBJECTIVE: To demonstrate the feasibility of extralevator abdominoperineal excision (ELAPE) for locally advanced low cancer in China. METHODS: A prospective multicenter clinical trial was carried out by 7 general hospitals across China from August 2008 to October 2011. A total of 102 patients underwent ELAPE for primary locally advanced low rectal cancer. There were 60 male and 42 female patients. The patients' characteristics, complications and prognosis were recorded. RESULTS: All patients underwent the ELAPE procedure successfully. The median operating time was 180 minutes (range 110-495 minutes) and median intraoperative blood loss was 200 ml (range 50-1000 ml). The rates of sexual dysfunction, perineal complications, urinary retention, and chronic perineal pain were 40.5%, 23.5%, 18.6% and 13.7%, respectively. Chronic perineal pain was associated with coccygectomy (12 months postoperatively, t = 8.06, P < 0.01), and the pain might gradually ease over time. Reconstruction of pelvic floor with biologic mesh was associated with lower rate of perineal dehiscence (χ(2) = 13.502, P = 0.006) and overall perineal wound complications (χ(2) = 5.836, P = 0.016) compared with primary closure. A positive circumferential margin (CRM) was demonstrated in 6 (5.9%) patients, and intraoperative perforations occurred in 4 (3.9%) patients. All CRM involvement and intraoperative perforation located at anteriorly and anterolaterally. The local recurrence was 4.9% at a median follow-up of 35 months (range, 18-58 months). CONCLUSIONS: ELAPE performed in the prone position for low rectal cancer leads to a reduction in CRM involvement, intraoperative perforations, and local recurrence, but it might result in a little high rate of perineal wound related complications. Reconstruction of pelvic floor with biologic mesh might lower the rate of perineal wound complications.

CRISPR/Cas9 screening: unraveling cancer immunotherapy's 'Rosetta Stone'.

Clustered regularly interspaced palindromic repeats (CRISPR)-based technology, a powerful toolset for the unbiased functional genomic screening of biological processes, has facilitated several scientific breakthroughs in the biomedical field. Cancer immunotherapy has advanced the treatment of numerous malignancies that previously had restricted treatment options or unfavorable outcomes. In the realm of cancer immunotherapy, the application of CRISPR/CRISPR-associated protein 9 (Cas9)-based genetic perturbation screening has enabled the identification of genes, biomarkers, and signaling pathways that govern various cancer immunoreactivities, as well as the development of effective immunotherapeutic targets. In this review, we summarize the advances in CRISPR/Cas9-based screening for cancer immunotherapy and outline the immunotherapeutic targets identified via CRISPR screening based on cancer-type classification.

Identification of the molecular subtypes and signatures to predict the prognosis, biological functions, and therapeutic response based on the anoikis-related genes in colorectal cancer.

BACKGROUND: Tumors that resist anoikis, a programmed cell death triggered by detachment from the extracellular matrix, promote metastasis; however, the role of anoikis-related genes (ARGs) in colorectal cancer (CRC) stratification, prognosis, and biological functions remains unclear. METHODS: We obtained transcriptomic profiles of CRC and 27 ARGs from The Cancer Genome Atlas, the Gene Expression Omnibus, and MSigDB databases, respectively. CRC tissue samples were classified into two clusters based on the expression pattern of ARGs, and their functional differences were explored. Hub genes were screened using weighted gene co-expression network analysis, univariate analysis, and least absolute selection and shrinkage operator analysis, and validated in cell lines, tissues, or the Human Protein Atlas database. We constructed an ARG-risk model and nomogram to predict prognosis in patients with CRC, which was validated using an external cohort. Multifaceted landscapes, including stemness, tumor microenvironment (TME), immune landscape, and drug sensitivity, between high- and low-risk groups were examined. RESULTS: Patients with CRC were divided into C1 and C2 clusters. Cluster C1 exhibited higher TME scores, whereas cluster C2 had favorable outcomes and a higher stemness index. Eight upregulated hub ARGs (TIMP1, P3H1, SPP1, HAMP, IFI30, ADAM8, ITGAX, and APOC1) were utilized to construct the risk model. The qRT-PCR, Western blotting, and immunohistochemistry results were consistent with those of the bioinformatics analysis. Patients with high risk exhibited worse overall survival (p < 0.01), increased stemness, TME, immune checkpoint expression, immune infiltration, tumor mutation burden, and drug susceptibility compared with the patients with low risk. CONCLUSION: Our results offer a novel CRC stratification based on ARGs and a risk-scoring system that could predict the prognosis, stemness, TME, immunophenotypes, and drug susceptibility of patients with CRC, thereby improving their prognosis. This stratification may facilitate personalized therapies.

Metabolic Recoding of NSUN2-Mediated m5C Modification Promotes the Progression of Colorectal Cancer via the NSUN2/YBX1/m5C-ENO1 Positive Feedback Loop.

The RNA modification, 5-methylcytosine (m5C), has recently gained prominence as a pivotal post-transcriptional regulator of gene expression, intricately intertwined with various tumorigenic processes. However, the exact mechanisms governing m5C modifications during the onset and progression of colorectal cancer (CRC) remain unclear. Here, it is determined that the m5C methyltransferase NSUN2 exhibits significantly elevated expression and exerts an oncogenic function in CRC. Mechanistically, NSUN2 and YBX1 are identified as the "writer" and "reader" of ENO1, culminating in the reprogramming of the glucose metabolism and increased production of lactic acid in an m5C-dependent manner. The accumulation of lactic acid derived from CRC cells, in turn, activates the transcription of NSUN2 through histone H3K18 lactylation (H3K18la), and induces the lactylation of NSUN2 at the Lys356 residue (K356), which is crucial for capturing target RNAs. Together, these findings reveal an intriguing positive feedback loop involving the NSUN2/YBX1/m5C-ENO1 signaling axis, thereby bridging the connection between metabolic reprogramming and epigenetic remodeling, which may shed light on the therapeutic potential of combining an NSUN2 inhibitor with immunotherapy for CRC.

Molecular alterations of EGFR in small intestinal adenocarcinoma.

BACKGROUND AND AIMS: Molecular testing for epidermal growth factor receptor (EGFR) mutations has recently become a standard practice for the management of patients with non-squamous none small cell lung cancer. Primary small intestine adenocarcinoma (SIA) is an uncommon malignancy, and EGFR mutation in the cancer has not been well characterized due to its rarity. METHODS: A micro-tissue array with 53 SIAs and 24 surgically resected primary non-ampullary SIAs were studied. EGFR mutations were analyzed by DNA sequencing in 24 cases with formalin-fixed paraffin-embedded blocks. All 77 cases were examined by immunohistochemistry (IHC) using antibodies specific for the EGFR E746-A750 deletion in exon 19 (DEL), L858R point mutation in exon 21 (L858R), and total EGFR. EGFR amplifications were detected by fluorescence in situ hybridization. RESULTS: A positive reaction of DEL-specific, L858R-specific, and total EGFR antibodies was detected in seven (9.1%), 5 (6.5%) and 35 (45.5%) of 77 SIAs by IHC, respectively. Positive reaction of the three antibodies was not significantly correlated with patient's age, gender, differentiation, and stage. EGFR gene amplification was assayed in 77 SIAs in micro-tissue array. Of 24 SIA samples that had DNA sequencing, two (8.3%) harbored exon 19 deletion and one (4.2%) harbored L858R point mutation. Only one case with EGFR amplification and two cases with polysomy were shown. CONCLUSIONS: Our findings suggested that mutations and amplification in EGFR genes are minor events, and most of SIAs may be unsuitable to EGFR-TKIs treatment.

m6A and m5C modification of GPX4 facilitates anticancer immunity via STING activation.

Cancer immunotherapy is arguably the most rapidly advancing realm of cancer treatment. Glutathione peroxidase 4 (GPX4) has emerged as the vital enzyme to prevent lipid peroxidation and maintain cellular redox homeostasis. However, the mechanism of GPX4 in the regulation of cancer immunotherapy of colon adenocarcinoma (COAD) are incompletely understood. In pan-cancer analysis, we found that GPX4 showed remarkably upregulated expression and exhibited significant association with overall survival in multiple cancer types, especially COAD. Furthermore, upregulated GPX4 expression was positively correlated with increased immune cells infiltration and enhanced expression of immunomodulators. Mechanistically, RBM15B- and IGFBP2-mediated N6-methyladenosine (m6A) modification and NSUN5-mediated 5-methylcytosine (m5C) modification of GPX4 facilitated anticancer immunity via activation of cyclic GMP-AMP synthase (cGAS)-stimulator of interferon (STING) signaling by maintaining redox homeostasis in COAD. The risk model and nomogram model constructed based on the GPX4-derived genes further confirmed the prognostic and treatment-guiding value of GPX4. In all, our study demonstrated that m6A and m5C modification of GPX4 may be a promising target for cancer immunotherapy via activating the cGAS-STING signaling pathway in COAD.

Degree of transverse colon ptosis: an alternative surrogate for evaluation of slow transit constipation.

Background: Although transverse colon ptosis (TCP) is commonly diagnosed in patients with constipation, it has not attracted significant attention in the evaluation of constipation. Herein, we assessed the correlation between TCP-related radiological parameters and the severity of slow transit constipation (STC). Methods: This study was a single-center retrospective cohort study, with participants enrolled between 2012 and 2020 in Zhongnan Hospital of Wuhan University, China. STC was diagnosed according to Rome IV criteria and results of colonic transit test (CTT); healthy volunteers were also recruited as controls. All participants were examined using abdominal X-rays (AXRs) to acquire the radiological parameters related to TCP. Among these parameters, the degree of TCP (DTCP) was defined as the vertical distance from the top of the splenic flexure to the lowest point of the reverse colon. The Wexner Constipation Score and Hospital Anxiety and Depression Scale were used to assess clinical severity. After multivariable linear regression, the correlations between radiological parameters and severity of STC were investigated. We also explored the differences in radiological parameters between the operation and the conservative group. Results: The study included 139 patients with STC and 125 healthy people in as the normal control (NC). Patients with STC probably had larger DTCPs than those in the NC group (242.27±25.86 vs. 93.00±32.57 mm; P<0.001). Pearson correlation analysis showed that TCP-related parameters were consistent with the symptom severity of STC [e.g., parameter DTCP was strongly correlated with Wexner Constipation Score, with a ß coefficient (95% CI) of 8.63 (8.24-9.02), P<0.001]. Multivariable linear regression models showed that patients with a larger DTCP were more likely to undergo surgery (23.67; 95% CI: 1.40-45.94; P=0.04). Conclusions: TCP-related parameters, especially the DTCP, may serve as novel and feasible alternative indices for the assessment of STC. However, the potential value of DTCP in assisting the evaluation of STC needs to be confirmed in study with a larger sample size.

p53 promotes peroxisomal fatty acid ß-oxidation to repress purine biosynthesis and mediate tumor suppression.

The metabolic pathways through which p53 functions as a potent tumor suppressor are incompletely understood. Here we report that, by associating with the Vitamin D receptor (VDR), p53 induces numerous genes encoding enzymes for peroxisomal fatty acid ß-oxidation (FAO). This leads to increased cytosolic acetyl-CoA levels and acetylation of the enzyme 5-Aminoimidazole-4-Carboxamide Ribonucleotide Formyltransferase/IMP Cyclohydrolase (ATIC), which catalyzes the last two steps in the purine biosynthetic pathway. This acetylation step, mediated by lysine acetyltransferase 2B (KAT2B), occurs at ATIC Lys 266, dramatically inhibits ATIC activity, and inversely correlates with colorectal cancer (CRC) tumor growth in vitro and in vivo, and acetylation of ATIC is downregulated in human CRC samples. p53-deficient CRCs with high levels of ATIC is more susceptible to ATIC inhibition. Collectively, these findings link p53 to peroxisomal FAO, purine biosynthesis, and CRC pathogenesis in a manner that is regulated by the levels of ATIC acetylation.

STING is a cell-intrinsic metabolic checkpoint restricting aerobic glycolysis by targeting HK2.

Evasion of antitumour immunity is a hallmark of cancer. STING, a putative innate immune signalling adaptor, has a pivotal role in mounting antitumour immunity by coordinating innate sensing and adaptive immune surveillance in myeloid cells. STING is markedly silenced in various human malignancies and acts as a cell-intrinsic tumour suppressor. How STING exerts intrinsic antitumour activity remains unclear. Here, we report that STING restricts aerobic glycolysis independent of its innate immune function. Mechanistically, STING targets hexokinase II (HK2) to block its hexokinase activity. As such, STING inhibits HK2 to restrict tumour aerobic glycolysis and promote antitumour immunity in vivo. In human colorectal carcinoma samples, lactate, which can be used as a surrogate for aerobic glycolysis, is negatively correlated with STING expression level and antitumour immunity. Taken together, this study reveals that STING functions as a cell-intrinsic metabolic checkpoint that restricts aerobic glycolysis to promote antitumour immunity. These findings have important implications for the development of STING-based therapeutic modalities to improve antitumour immunotherapy.

ERK and USP5 govern PD-1 homeostasis via deubiquitination to modulate tumor immunotherapy.

The programmed cell death protein 1 (PD-1) is an inhibitory receptor on T cells and plays an important role in promoting cancer immune evasion. While ubiquitin E3 ligases regulating PD-1 stability have been reported, deubiquitinases governing PD-1 homeostasis to modulate tumor immunotherapy remain unknown. Here, we identify the ubiquitin-specific protease 5 (USP5) as a bona fide deubiquitinase for PD-1. Mechanistically, USP5 interacts with PD-1, leading to deubiquitination and stabilization of PD-1. Moreover, extracellular signal-regulated kinase (ERK) phosphorylates PD-1 at Thr234 and promotes PD-1 interaction with USP5. Conditional knockout of Usp5 in T cells increases the production of effector cytokines and retards tumor growth in mice. USP5 inhibition in combination with Trametinib or anti-CTLA-4 has an additive effect on suppressing tumor growth in mice. Together, this study describes a molecular mechanism of ERK/USP5-mediated regulation of PD-1 and identifies potential combinatorial therapeutic strategies for enhancing anti-tumor efficacy.