Interactions between polycyclic aromatic hydrocarbons and genetic variants in the cGAS-STING pathway affect the risk of colorectal cancer.

The cGAS-STING pathway plays an essential role in the activation of tumor immune cells. Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants with potential carcinogenicity, and their exposure is associated with the development of colorectal cancer. However, the impacts of genetic factors in the cGAS‒STING pathway and gene‒environment interactions on colorectal cancer remain understudied. We used logistic regression models and interaction analysis to evaluate the impact of genetic variants on colorectal cancer risk and gene‒environment interactions. We analysed the expression patterns of candidate genes based on the RNA-seq data. Molecular biology experiments were performed to investigate the impact of PAHs exposure on candidate gene expression and the progression of colorectal cancer. We identified the susceptibility locus rs3750511 in the cGAS‒STING pathway, which is associated with colorectal cancer risk. A negative interaction between TRAF2 rs3750511 and PAHs exposure was also identified. Single-cell RNA-seq analysis revealed significantly elevated expression of TRAF2 in colorectal cancer tissues compared with normal tissues, especially in T cells. BPDE exposure increased TRAF2 expression and the malignant phenotype of colorectal cancer cells. The treatment also further increased the expression of the TRAF2 downstream gene NF-κB and decreased the expression of Caspase8. Our results suggest that the genetic variant of rs3750511 affects the expression of TRAF2, thereby increasing the risk of colorectal cancer through interaction with PAHs. Our study provides new insights into the influence of gene‒environment interactions on the risk of developing colorectal cancer.

Multidimensional Fragmentomics Enables Early and Accurate Detection of Colorectal Cancer.

Colorectal cancer is frequently diagnosed in advanced stages, highlighting the need for developing approaches for early detection. Liquid biopsy using cell-free DNA (cfDNA) fragmentomics is a promising approach, but the clinical application is hindered by complexity and cost. This study aimed to develop an integrated model using cfDNA fragmentomics for accurate, cost-effective early-stage colorectal cancer detection. Plasma cfDNA was extracted and sequenced from a training cohort of 360 participants, including 176 patients with colorectal cancer and 184 healthy controls. An ensemble stacked model comprising five machine learning models was employed to distinguish patients with colorectal cancer from healthy controls using five cfDNA fragmentomic features. The model was validated in an independent cohort of 236 participants (117 patients with colorectal cancer and 119 controls) and a prospective cohort of 242 participants (129 patients with colorectal cancer and 113 controls). The ensemble stacked model showed remarkable discriminatory power between patients with colorectal cancer and controls, outperforming all base models and achieving a high area under the receiver operating characteristic curve of 0.986 in the validation cohort. It reached 94.88% sensitivity and 98% specificity for detecting colorectal cancer in the validation cohort, with sensitivity increasing as the cancer progressed. The model also demonstrated consistently high accuracy in within-run and between-run tests and across various conditions in healthy individuals. In the prospective cohort, it achieved 91.47% sensitivity and 95.58% specificity. This integrated model capitalizes on the multiplex nature of cfDNA fragmentomics to achieve high sensitivity and robustness, offering significant promise for early colorectal cancer detection and broad patient benefit. Significance: The development of a minimally invasive, efficient approach for early colorectal cancer detection using advanced machine learning to analyze cfDNA fragment patterns could expedite diagnosis and improve treatment outcomes for patients. See related commentary by Rolfo and Russo, p. 3128.

Cholangiocytes of cirrhotic rats are more tolerant to ischemia than normal rats: a role for abnormal hepatic arteriovenous communications?

BACKGROUND: To assess whether cholangiocytes of rats with liver cirrhosis are more tolerant to ischemic changes than normal rats, and whether this is due to arteriovenous fistulas. METHODS: Ninety-eight Sprague-Dawley rats were divided into the normal group (n = 30) and the cirrhosis group (n = 68), and then each group was divided into controls and those with bile duct ischemia. At 0 h, 6 h, 3 d, and 14 d after the induction of bile duct ischemia, the liver of each rat was removed and stained with toluidine blue to compare cholangiocyte morphology. Cholangiocyte apoptosis was evaluated by a deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Expression of VEGF, HIF1, NF-kB(p65) was assessed by quantitative analysis of the products of reverse-transcriptase polymerase chain reaction. Resin casts were used to reproduce the intrahepatic vasculature of cirrhotic rats, and the presence of communications between the portal vein and hepatic artery was assessed with stereomicroscopy. RESULTS: Rats with liver cirrhosis were more tolerant than normal rats 6 h after bile duct ischemia (P < 0.05); at 3 and 14 d after the ischemic insult, there was no significant difference between the cirrhotic rats and normal rats. Levels of expression of VEGF, HIF1, and NF-kB(p65) genes, either in normal rats or cirrhotic rats, were significantly elevated compared with those in the control group (∗, ∗∗P < 0.05), but a lower extent changes appeared in the cirrhotic rats (∗∗∗P < 0.05). Several communications could be observed between the portal vein and hepatic artery. CONCLUSION: Cholangiocytes of cirrhotic rats appear to be more tolerant to ischemia of bile duct than non-cirrhotic rats. This may be due to the protective role of arterioportal fistulas.

Low miR-1273a expression predicts poor prognosis of colon cancer and facilitates tumor cell proliferation, migration, and invasion.

MicroRNAs (miRNAs) have been indicated to be frequently dysregulated in various cancers and promising biomarkers for colon cancer. The present study aimed to assess the prognostic significance and biological function of miR-1273a in colon cancer. The expression levels of miR-1273a was estimated using quantitative real-time polymerase chain reaction. Kaplan-Meier survival curves and Cox regression analysis were used to evaluate the prognostic value of miR-1273a in patients of colon cancer. The effects of miR-1273a on cell proliferation, migration, and invasion were investigated by cell experiments. The expression of miR-1273a was downregulated in colon cancer tissues and tumor cell lines compared with the normal controls (all P<0.001). The aberrant expression of miR-1273a was associated with vascular invasion (P=0.005), differentiation (P=0.023), lymph node metastasis (P=0.021), and TNM stage (P=0.004). The patients with low miR-1273a expression had low overall survival compared with the patients with high miR-1273a expression (log-rank P=0.002). miR-1273a was detected to be an independent prognostic biomarker for patients. Furthermore, the results of cell experiments revealed that miR-1273a downregulation promoted, while miR-1273a upregulation suppressed the cell proliferation, migration, and invasion. In conclusion, all data indicated that a downregulated expression of miR-1273a predicted poor prognosis for colon cancer and enhanced tumor cell proliferation, migration, and invasion. Thus, we suggest that methods to promote miR-1273a expression may serve as novel therapeutic strategies in colon cancer.

Characteristics of the medical malpractice cases against orthopedists in China between 2016 and 2017.

BACKGROUND: This study aimed to identify the most frequent reasons for orthopedic medical malpractice, gain insight into the related patient demographics and clinical characteristics, and identify the independent factors associated with it. METHODS: We collected and analyzed the demographic and injury characteristics, hospital levels and treatments, medical errors, and orthopedist's degree of responsibility for the patients who were subject to orthopedic medical malpractice at our institution. Univariate and multivariate analyses were performed to identify the factors associated with the orthopedist's degree of responsibility in the medical malpractice cases. RESULTS: We included 1922 cases of medical malpractice in the final analysis. There were 1195 and 727 men and women, respectively (62.2% and 37.8%, respectively). Of the total patients, 1810, 1038, 1558, 1441, and 414 patients (94.2%, 54.0%, 81.1%, 75.0%, and 21.5%, respectively) were inpatients, had closed injuries, underwent surgery, were trauma cases, and had preoperative comorbidities, respectively. Most medical malpractice cases were in patients with fractures and spinal degenerative disease (1229 and 253 cases; 63.9% and 13.2%, respectively), and occurred in city-level hospitals (1006 cases, 52.3%), which were located in the eastern part of china (1001, 52.1%), including Jiangsu and Zhejiang (279 and 233 cases, 14.52% and 52.1%, respectively). Between 2016 and 2017, the orthopedist's degree of responsibility in medical malpractice claims were deemed as full, primary, equal, secondary, and minor in 135, 654, 77, 716, and 340 orthopedists (7.0%, 34.0%, 4.0%, 37.3%, and 17.7%). Most medical errors made by orthopedists in cases of medical malpractice were related to failure to supervise or monitor cases, improper performance of procedures, and failure to instruct or communicate with the patient (736, 716, and 423 cases; 38.3%, 37.3%, and 22.0%, respectively). The multivariate analysis found that patients with preoperative comorbidities, who sustained humerus injuries, who were aged ≥65 years, who were treated by doctors who failed to supervise or monitor them, and who were treated at the provincial and city level hospitals were more likely to claim that the orthopedist bore a serious degree of responsibility in the medical malpractice case. CONCLUSIONS: Our results provide detailed information on the plaintiff demographics, clinical characteristics, and factors associated with medical malpractice. Medical malpractice is related to poor treatment outcomes. The first preventative measure that is required is a comprehensive improvement in the medical staff quality, mainly through medical ethics cultivation, and professional ability and technique training. Additionally, failure to supervise or monitor cases was the leading cause of medical malpractice and one of the factors that led to orthopedists bearing an equal and higher responsibility for medical malpractice. Orthopedists should improve patient supervision, especially when treating older patients and those with preoperative comorbidities and humerus injuries.

PRMT5 functionally associates with EZH2 to promote colorectal cancer progression through epigenetically repressing CDKN2B expression.

Background: Protein arginine methyltransferase 5 (PRMT5) is a type II arginine methyltransferase that symmetrically di-methylates arginine residues on both histone and non-histone protein substrates. Accumulating evidence suggests that PRMT5 exerts its oncogenic properties in a wide spectrum of human malignancies. However, the underlying mechanisms by which PRMT5 contributes to the progression of colorectal cancer (CRC) remain to be defined. Methods: Western blot and real-time PCR were used to analyze the expression of CDKN2B. Co-immunoprecipitation (Co-IP), immunofluorescence and GST pulldown assays were employed to investigate the interaction between PRMT5 and EZH2. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays were performed to validate CDKN2B as a direct target of PRMT5/EZH2. DNA methylation status at the CpG islands of promoter region of CDKN2B gene was analyzed by bisulfite sequencing. The effect of PRMT5/EZH2 on malignant phenotypes was examined through in vitro and in vivo assays. PRMT5 and EZH2 protein expression levels in CRC tissues were analyzed by immunohistochemistry (IHC) staining. Results: We observed that PRMT5-deficient CRC cells exhibit proliferation defects in vitro. PRMT5 was identified as a major transcriptional repressor of CDKN2B (p15INK4b) for determining CRC progression. Mechanistically, PRMT5-mediated histone marks H4R3me2s and H3R8me2s were predominantly deposited at the promoter region of CDKN2B gene in CRC cells. Knockdown of PRMT5 in CRC cells decreased the accumulation of H4R3me2s and H3R8me2s marks and reduced the CpG methylation level of CDKN2B promoter, then re-activated CDKN2B expression. Strikingly, silencing of CDKN2B partially abrogated the proliferation defects caused by PRMT5 depletion in vitro and in vivo. Furthermore, we proved that PRMT5 interacted with Enhancer of zeste homolog 2 (EZH2), leading to enhanced EZH2 binding and H3K27me3 deposition together with decreased transcriptional output of CDKN2B gene. Importantly, we found that the combined interventions exerted a synergistic inhibitory effect of combined treatment with PRMT5i (GSK591) and EZH2i (GSK126) on the growth of CRC cells/xenografts in vitro and in vivo. Moreover, PRMT5 and EZH2 were found to be significantly elevated and associated with poor prognosis in CRC patients. Conclusion: PRMT5 functionally associates with EZH2 to promote CRC progression through epigenetically repressing CDKN2B expression. Thus, our findings raise the possibility that combinational intervention of PRMT5 and EZH2 may be a promising strategy for CRC therapy.

FBXW7 and Its Downstream NOTCH Pathway Could be Potential Indicators of Organ-Free Metastasis in Colorectal Cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally. Metastasis is associated with a poor prognosis, yet the underlying molecular mechanism(s) remained largely unknown. In this study, a total of 85 CRC patients were included and the primary tumor lesions were evaluated by next-generation sequencing using a targeted panel for genetic aberrations. Patients were sub-divided according to their metastasis pattern into the non-organ metastases (Non-OM) and organ metastases (OM) groups. By comparing the genetic differences between the two groups, we found that mutations in FBXW7 and alterations in its downstream NOTCH signaling pathway were more common in the Non-OM group. Moreover, correlation analysis suggested that FBXW7 mutations were independent of other somatic alterations. The negative associations of alterations in FBXW7 and its downstream NOTCH signaling pathway with CRC organ metastasis were validated in a cohort of 230 patients in the TCGA CRC dataset. Thus, we speculated that the genomic alterations of FBXW7/NOTCH axis might be an independent negative indicator of CRC organ metastases.

circANKS1B regulates FOXM1 expression and promotes cell migration and invasion by functioning as a sponge of the miR-149 in colorectal cancer.

Background: Circular RNAs (circRNAs) and microRNAs (miRNAs) play key roles in the development of human cancers. CircANKS1B has been reported to be increased in breast cancer. Methods: Real-time polymerase chain reaction (real-time PCR) assay was used to measure expressions of circANKS1B, ANKS1B, and FOXM1. Western blot assay was employed to examine the protein level of FOXM1 and Slug. The abilities of cell migration and invasion were measured by wound-healing and transwell assays. The interaction between circANKS1B and miR-149 was confirmed by site-directed mutagenesis and luciferase assays. Results: The expression of circANKS1B was up-regulated in colorectal cancer tissues and cells. Additionally, circANKS1B increased the expression of FOXM1. Furthermore, the enhancement of CRC cell migration and invasion by circANKS1B was dependent on FOXM1. However, previous studies have shown that miR-149 can directly target FOXM1 and act as tumor suppressor in CRC. Consequently, our results showed that miR-149 could directly bind to circANKS1B and FOXM1. The inhibition of circANKS1B could reduce FOXM1 and Slug protein levels, thus suppressing CRC cell migration and invasion. Conclusion: Taken together, circANKS1B promotes colorectal cancer cell migration and invasion by acting as a molecular sponge of miR-149 to modulate FOXM1 and Slug protein levels.

TIMP1 mRNA in tumor-educated platelets is diagnostic biomarker for colorectal cancer.

Platelets have been shown to promote the growth of tumors, including colorectal cancer. The RNA profile of tumor-educated platelets has the possibility for cancer diagnosis. We used RNA sequencing to identified the gene expression signature in platelets from colorectal cancer patients and healthy volunteers. We then verified the selected biomarkers from the RNA sequencing in a two-step case-control study using quantitative reverse-transcription polymerase chain reaction. We found that TIMP1 mRNA levels are higher in platelets from colorectal cancer patients than in platelets from healthy volunteers and patients with inflammatory bowel diseases. Additionally, TIMP1 mRNA expressed in platelets from colorectal cancer patients can be carried into colorectal cancer cells, where it promotes tumor growth in vivo and in vitro. These findings show that the TIMP1 mRNA in platelets is a potential independent diagnostic biomarker for colorectal cancer, and that platelets can carry RNAs into colorectal cancer cells to promote colorectal cancer development.

Effects of neuritin on the differentiation of bone marrow­derived mesenchymal stem cells into neuron­like cells.

While the neurotrophic factor neuritin is known to be involved in neurodevelopment, the effects of this compound on cell differentiation remain unclear. The present study demonstrated that neuritin treatment induced the differentiation of rat bone marrow­derived mesenchymal stem cells (rBM­MSCs) into neuron­like (NL) cells. For these analyses, rBM­MSCs were incubated with 0.5 µg/ml neuritin for 24 h. Following induction, 27% of the rBM­MSCs exhibited typical NL cell morphologies. Subsequently, NL cells were characterized by examining the expression of neuronal markers and by analysis of cell functions. The findings demonstrated that the NL cells produced by neuritin treatment expressed the neuronal markers neuron­specific enolase and microtubule associate protein 2, and secreted the neurotransmitter 5­hydroxytryptamine. Furthermore, the NL cells exhibited certain partial neural­electrophysiological functions. In conclusion, neuritin treatment may be an effective method for inducing the differentiation of BM­MSCs towards NL cells. This may provide an alternative, potentially complementary tool for disease modeling and the development of cell­based therapies.