Mercury pollution risks of agricultural soils and crops in mercury mining areas in Guizhou Province, China: effects of large mercury slag piles.

The historical large mercury slag piles still contain high concentrations of mercury and their impact on the surrounding environment has rarely been reported. In this study, three different agricultural areas [the area with untreated piles (PUT), the area with treated piles (PT), and the background area with no piles (NP)] were selected to investigate mercury slag piles pollution in the Tongren mercury mining area. The mercury concentrations of agricultural soils ranged from 0.42 to 155.00 mg/kg, determined by atomic fluorescence spectrometry of 146 soil samples; and mercury concentrations in local crops (rice, maize, pepper, eggplant, tomato and bean) all exceeded the Chinese food safety limits. Soil and crop pollution trends in the three areas were consistent as PUT > PT > NP, indicating that mercury slag piles have exacerbated pollution. Mercury in the slag piles was adsorbed by multiple pathways of transport into soils with high organic matter, which made the ecological risk of agricultural soils appear extremely high. The total hazard quotients for residents from ingesting mercury in these crops were unacceptable in all areas, and children were more likely to be harmed than adults. Compared to the PT area, treatment of slag piles in the PUT area may decrease mercury concentrations in paddy fields and dry fields by 46.02% and 70.36%; further decreasing health risks for adults and children by 47.06% and 79.90%. This study provided a scientific basis for the necessity of treating large slag piles in mercury mining areas.

Identification of a glycolysis-related gene signature for predicting prognosis in patients with hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common primary liver cancer in the world. Although great advances in HCC diagnosis and treatment have been achieved, due to the complicated mechanisms in tumor development and progression, the prognosis of HCC is still dismal. Recent studies have revealed that the Warburg effect is related to the development, progression and treatment of various cancers; however, there have been a few explorations of the relationship between glycolysis and HCC prognosis. METHODS: mRNA expression profiling was downloaded from public databases. Gene set enrichment analysis (GSEA) was used to explore glycolysis-related genes (GRGs), and the LASSO method and Cox regression analysis were used to identify GRGs related to HCC prognosis and to construct predictive models associated with overall survival (OS) and disease-free survival (DFS). The relationship between the predictive model and the tumor mutation burden (TMB) and tumor immune microenvironment (TIME) was explored. Finally, real-time PCR was used to validate the expression levels of the GRGs in clinical samples and different cell lines. RESULTS: Five GRGs (ABCB6, ANKZF1, B3GAT3, KIF20A and STC2) were identified and used to construct gene signatures to predict HCC OS and DFS. Using the median value, HCC patients were divided into low- and high-risk groups. Patients in the high-risk group had worse OS/DFS than those in the low-risk group, were related to higher TMB and were associated with a higher rate of CD4+ memory T cells resting and CD4+ memory T cells activated. Finally, real-time PCR suggested that the five GRGs were all dysregulated in HCC samples compared to adjacent normal samples. CONCLUSIONS: We identified five GRGs associated with HCC prognosis and constructed two GRGs-related gene signatures to predict HCC OS and DFS. The findings in this study may contribute to the prediction of prognosis and promote HCC treatment.

Impact of Postoperative Complications on Long-Term Survival After Resection of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

BACKGROUND: Controversy exists over the relationship between postoperative complications (POCs) and long-term survival for hepatocellular carcinoma (HCC) after hepatectomy. This study aimed to evaluate the impact of POCs on overall survival (OS) and disease-free survival (DFS) for HCC after liver resection. PATIENTS AND METHODS: The PubMed, EMBASE, and Cochrane Library databases were used to search for eligible studies published through 18 April 2020, and studies comparing the long-term outcomes between HCC patients with and without POCs after hepatectomy were included. A random-effects model was used to calculate the pooled hazard ratio (HR) with a 95% confidence interval (CI). Subgroup analysis and meta-regression were performed to assess the potential influence of study-, patient-, and tumor-related factors on the relationship between POCs and oncologic outcomes and to adjust their effect. This study was registered at the International Prospective Register of Systematic Reviews (CRD42019136109). RESULTS: Thirty-seven studies, including 14,096 patients, were deemed eligible and included in this study. Compared with those without POCs, patients who developed POCs had a significant reduction in OS (HR 1.39, 95% CI 1.28-1.50, P < 0.001; prediction interval 1.04-1.85) and tended to have worse DFS (HR 1.25, 95% CI 1.16-1.35, P < 0.001; prediction interval 0.98-1.60). Contour-enhanced funnel plots suggested a risk of publication bias. Subgroup analysis and meta-regression showed that POCs remained a threat to OS and DFS regardless of the influence of clinicopathological factors. CONCLUSION: This study demonstrated that POCs had an adverse impact on OS and DFS in HCC patients after liver resection.

A Modified Suture Technique in Hepaticojejunostomy.

BACKGROUND Hepaticojejunostomy is a common biliary reconstruction procedure in hepatobiliary surgery. The suture technique plays a key role in the procedure. The conventional suture technique is complex and time-consuming. To facilitate the procedure, we performed it with a modified suture technique. In the present study, we evaluated the efficacy and safety of the technique in hepaticojejunostomy. MATERIAL AND METHODS We enrolled 120 adult patients who underwent hepaticojejunostomy. The patients were divided into a conventional group and a modified suture group according to the suture technique used. Clinical data were collected for analysis. RESULTS No significant differences were found between the 2 groups in terms of demographic data. No significant differences were found between the 2 groups in terms of serum bilirubin, albumin, AST, ALT, or hemoglobin (p>0.05). There were no significant differences between the 2 groups in terms of bile hemorrhage, fever, or cholangitis (p>0.05). The incidences of stenosis and cholelithiasis were similar in the 2 groups (p>0.05). The incidence of bile leakage was lower in the modified suture group than in the conventional group (p=0.04). The average bile duct diameter was 25±6 mm in the modified continuous suture group and 29±7mm in the conventional group, but the difference was not statistically significant (p=0.5). The duration of the anastomosis procedure was 15.4±4.4 min in the modified continuous suture group, which was shorter than in the conventional group (p<0.05). CONCLUSIONS The modified continuous suture technique is efficient and safe for use in hepaticojejunostomy. It can facilitate the procedure and reduce the incidence of bile leakage after hepaticojejunostomy.

Inhibition of wild-type p53-induced phosphatase 1 promotes liver regeneration in mice by direct activation of mammalian target of rapamycin.

UNLABELLED: The liver possesses extraordinary regenerative capacity in response to injury. However, liver regeneration (LR) is often impaired in disease conditions. Wild-type p53-induced phosphatase 1 (Wip1) is known as a tumor promoter and enhances cell proliferation, mainly by deactivating antioncogenes. However, in this work, we identified an unexpected role of Wip1 in LR. In contrast to its known role in promoting cell proliferation in extrahepatic tissue, we found that Wip1 suppressed hepatocyte proliferation after partial hepatectomy (PHx). Deletion of Wip1 increased the rate of LR after PHx. Enhanced LR in Wip1-deficient mice was a result of the activation of the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) pathway. Furthermore, we showed that Wip1 physically interacted with and dephosphorylated mTOR. Interestingly, inhibition of Wip1 also activated the p53 pathway during LR. Disruption of the p53 pathway further enhanced LR in Wip1-deficient mice. Therefore, inhibition of Wip1 has a dual role in LR, i.e., promoting hepatocyte proliferation through activation of the mTORC1 pathway, meanwhile suppressing LR through activation of the p53 pathway. However, the proregenerative role of mTORC1 overwhelms the antiproliferative role of p53. Furthermore, CCT007093, a Wip1 inhibitor, enhanced LR and increased the survival rate of mice after major hepatectomy. CONCLUSION: mTOR is a new direct target of Wip1. Wip1 inhibition can activate the mTORC1 pathway and enhance hepatocyte proliferation after hepatectomy. These findings have clinical applications in cases where LR is critical, including acute liver failure, cirrhosis, or small-for-size liver transplantations.

Identification of prognostic biomarkers in hepatitis B virus-related hepatocellular carcinoma and stratification by integrative multi-omics analysis.

BACKGROUND & AIMS: The differentiation of distinct multifocal hepatocellular carcinoma (HCC): multicentric disease vs. intrahepatic metastases, in which the management and prognosis varies substantively, remains problematic. We aim to stratify multifocal HCC and identify novel diagnostic and prognostic biomarkers by performing whole genome and transcriptome sequencing, as part of a multi-omics strategy. METHODS: A complete collection of tumour and somatic specimens (intrahepatic HCC lesions, matched non-cancerous liver tissue and blood) were obtained from representative patients with multifocal HCC exhibiting two distinct postsurgical courses. Whole-genome and transcriptome sequencing with genotyping were performed for each tissue specimen to contrast genomic alterations, including hepatitis B virus integrations, somatic mutations, copy number variations, and structural variations. We then constructed a phylogenetic tree to visualise individual tumour evolution and performed functional enrichment analyses on select differentially expressed genes to elucidate biological processes involved in multifocal HCC development. Multi-omics data were integrated with detailed clinicopathological information to identify HCC biomarkers, which were further validated using a large cohort of HCC patients (n = 174). RESULTS: The multi-omics profiling and tumour biomarkers could successfully distinguish the two multifocal HCC types, while accurately predicting clonality and aggressiveness. The dual-specificity protein kinase TTK, which is a key mitotic checkpoint regulator with links to p53 signaling, was further shown to be a promising overall prognostic marker for HCC in the large patient cohort. CONCLUSIONS: Comprehensive multi-omics characterisation of multifocal tumour evolution may improve clinical decision-making, facilitate personalised medicine, and expedite identification of novel biomarkers and therapeutic targets in HCC.

Possible benefit of splenectomy in liver transplantation for autoimmune hepatitis.

Liver transplantation for autoimmune hepatitis (AIH) is usually successful with excellent long-term outcomes, but primary disease may recur. The recurrence of AIH is a significant cause of graft loss. This study was to analyze the effect of splenectomy in preventing AIH relapse. The clinical courses of 12 patients who had transplantation for AIH were analyzed retrospectively. All patients were subjected to transplantation for end-stage liver disease caused by chronic AIH. Based on the duration of immunosuppressive treatment before liver transplantation, simultaneous splenectomy was performed in ten patients. Two patients underwent liver transplantation without splenectomy, one of them developed recurrent AIH and died from graft failure caused by AIH relapse. However, no episode of AIH recurrence was observed in patients who had undergone simultaneous splenectomy. Splenectomy might be an option to prevent AIH relapse in some patients with high risk factors.

Methyl Cinnamate (MC) Alleviates Free Fatty Acids (FFAs) Induced Lipid Accumulation Through the AMPK Pathway in HepG2 Cells.

Background: AMP-activated protein kinase (AMPK) plays a critical role in energy metabolism. Its activation leads to the phosphorylation of downstream proteins such as acetyl-CoA carboxylase (ACC) and sterol regulatory element-binding protein-1 (SREBP1), subsequently inhibiting de novo fatty acid synthesis, thereby reducing intracellular triglyceride accumulation. MC is a compound found in extracts from Zanthoxylum armatum DC plants. Research has shown that MC can inhibit the differentiation of 3T3-L1 adipocytes through the CAMKK2-AMPK pathway. However, the biological effect of MC in HepG2 cells remains unknown. Methods: In this study, we utilized HepG2 cells to establish a model of MAFLD through FFAs stimulation. We investigated the biological effects of MC on HepG2 cells and studied its impact on lipid metabolism. Small interfering RNA was employed to explore the mechanism by which MC activates AMPK. Finally, molecular docking was conducted, establishing a model of the interaction between AMPK and MC. Results: We observed that MC can alleviate triglyceride accumulation in HepG2 cells. We observed the elevated p-AMPK/AMPK, P-ACC/ ACC, and elevated CPT1a after treatment of MC in HepG2 cells. The interference of CAMKK2 mRNA did not impact the ability of MC to phosphorylate AMPK. Compound C attenuates the ability of MC to increase p-AMPK. Molecular docking results led us to hypothesize that MC directly interacts with AMPK, resulting in AMPK phosphorylation and improved lipid accumulation in HepG2 cells.

Elevating PLK1 overcomes BETi resistance in prostate cancer via triggering BRD4 phosphorylation-dependent degradation in mitosis.

Bromodomain-containing protein 4 (BRD4) has emerged as a promising therapeutic target in prostate cancer (PCa). Understanding the mechanisms of BRD4 stability could enhance the clinical response to BRD4-targeted therapy. In this study, we report that BRD4 protein levels are significantly decreased during mitosis in a PLK1-dependent manner. Mechanistically, we show that BRD4 is primarily phosphorylated at T1186 by the CDK1/cyclin B complex, recruiting PLK1 to phosphorylate BRD4 at S24/S1100, which are recognized by the APC/CCdh1 complex for proteasome pathway degradation. We find that PLK1 overexpression lowers SPOP mutation-stabilized BRD4, consequently rendering PCa cells re-sensitized to BRD4 inhibitors. Intriguingly, we report that sequential treatment of docetaxel and JQ1 resulted in significant inhibition of PCa. Collectively, the results support that PLK1-phosphorylated BRD4 triggers its degradation at M phase. Sequential treatment of docetaxel and JQ1 overcomes BRD4 accumulation-associated bromodomain and extra-terminal inhibitor (BETi) resistance, which may shed light on the development of strategies to treat PCa.

Identification of recurrence related microRNAs in hepatocellular carcinoma after surgical resection.

Hepatocellular carcinoma (HCC) is one of the most aggressive human cancers with a high frequency of post-surgical recurrence. It is very critical to diagnose HCC recurrence at an early stage for a better therapeutic treatment. In this study, we examined the microRNA (miRNA) expression profiling in tumor tissues obtained from early and late recurrent HCC patients post-resection, using a microarray assay. A total of 32 miRNAs were identified to be differentially expressed during the progression of recurrence. Among these, 16 miRNAs were upregulated and 16 were downregulated. In addition, this miRNA expression signature was further validated by quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Moreover, functional annotation of predicted target genes of these recurrent HCC-related miRNAs indicates that multiple biological pathways (i.e., focal adhesion pathway, cancer-related pathways and mitogen-activated protein kinase (MAPK) signaling) that are all critical for cancer development and progression, may participate in the recurrence of HCC. Our data suggest potential molecular mechanisms underpinning miRNA-controlled HCC recurrence, and support the notion that miRNA expression signature and miRNA-based therapy can be useful tools for a better diagnosis and treatment stratification of this disease.

A novel PTEN gene promoter mutation and untypical Cowden syndrome.

Cowden syndrome (CS), an autosomal dominant disorder, is one of a spectrum of clinical disorders that have been linked to germline mutations in the phosphatase and tensin homolog (PTEN) gene. Although 70-80% of patients with CS have an identifiable germline PTEN mutation, the clinical diagnosis presents many challenges because of the phenotypic and genotypic variations. In the present study, we sequenced the exons and the promoter of PTEN gene, mutations and variations in the promoter and exons were identified, and a PTEN protein expression negative region was determined by immunohistochemistry (IHC). In conclusion, a novel promoter mutation we found in PTEN gene may turn off PTEN protein expression occasionally, leading to the disorder of PTEN and untypical CS manifestations.

Protein Induced by Vitamin K Absence II: A Potential Biomarker to Differentiate Pancreatic Ductal Adenocarcinoma from Pancreatic Benign Lesions and Predict Vascular Invasion.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant gastrointestinal tumor with a poor prognosis. Serum biomarker carbohydrate antigen 19-9 (CA19-9) was the only well-established biomarker for PDAC with inadequate efficacy. This present study aimed to determine the ability of PIVKA-II to discriminate PDAC from pancreatic benign lesions and predict vascular invasion preoperatively. METHODS: Patients who underwent pancreatic surgery from 2017 to 2020 were enrolled. We examined the differential diagnostic ability of protein induced by vitamin K absence II (PIVKA-II), CA19-9, and their combination and 138 with PDAC evaluated the predictive value of PIVKA-II for vascular invasion in PDAC. METHODS: A total of 138 patients with PDAC and 90 patients with pancreatic benign lesions who underwent pancreatic surgery from 2017 to 2020 were enrolled. The clinicopathological characteristics were recorded. RESULTS: There was a significant difference in levels of serum PIVKA-II between PDAC patients and patients with pancreatic benign lesions (p < 0.001). When the cut-off value was set to 28.9 mAU/mL according to the ROCs, the AUC, sensitivity, and specificity of PIVKA-II were 0.787, 68.1%, and 83.3%, respectively. The combined PIVKA-II and carbohydrate antigen 19-9 (CA19-9) enhanced the diagnostic accuracy, and the AUC, sensitivity, and specificity were 0.945, 87.7%, and 94.4%, respectively. PIVKA-II > 36.4 mAU/mL were independent predictive factors of vascular invasion in PDAC (p < 0.001). CONCLUSION: PIVKA-II was a potential diagnostic biomarker to differentiate PDAC from pancreatic benign lesions. PIVKA-II was complementary to CA19-9, and the combination enhanced the differential diagnostic performance. PIVKA-II > 36.4 mAU/mL was an independent predictive factor of vascular invasion in PDAC.

Development and validation of a gene expression-based nomogram to predict the prognosis of patients with cholangiocarcinoma.

AIM: To establish and validate a prognostic nomogram of cholangiocarcinoma (CCA) using independent clinicopathological and genetic mutation factors. METHODS: 213 patients with CCA (training cohort n = 151, validation cohort n = 62) diagnosed from 2012 to 2018 were included from multi-centers. Deep sequencing targeting 450 cancer genes was performed. Independent prognostic factors were selected by univariate and multivariate Cox analyses. The clinicopathological factors combined with (A)/without (B) the gene risk were used to establish nomograms for predicting overall survival (OS). The discriminative ability and calibration of the nomograms were assessed using C-index values, integrated discrimination improvement (IDI), decision curve analysis (DCA), and calibration plots. RESULTS: The clinical baseline information and gene mutations in the training and validation cohorts were similar. SMAD4, BRCA2, KRAS, NF1, and TERT were found to be related with CCA prognosis. Patients were divided into low-, median-, and high-risk groups according to the gene mutation, the OS of which was 42.7 ± 2.7 ms (95% CI 37.5-48.0), 27.5 ± 2.1 ms (95% CI 23.3-31.7), and 19.8 ± 4.0 ms (95% CI 11.8-27.8) (p < 0.001), respectively. The systemic chemotherapy improved the OS in high and median risk groups, but not in the low-risk group. The C-indexes of the nomogram A and B were 0.779 (95% CI 0.693-0.865) and 0.725 (95% CI 0.619-0.831), p < 0.01, respectively. The IDI was 0.079. The DCA showed a good performance and the prognostic accuracy was validated in the external cohort. CONCLUSION: Gene risk has the potential to guide treatment decision for patients at different risks. The nomogram combined with gene risk showed a better accuracy in predicting OS of CCA than not.

Primary liver cancer presenting as pyogenic liver abscess: characteristics, diagnosis, and management.

BACKGROUND AND OBJECTIVES: Primary liver cancer (PLC) presenting as pyogenic liver abscess (PLA) is potentially life-threatening, but has been occasionally reported, especially for cholangiocarcinoma. METHODS: Medical records of nine patients who presented as PLA, but were eventually confirmed as hepatocellular carcinoma (HCC; n = 5) or intrahepatic cholangiocarcinoma (IHCC; n = 4), from September 1997 through April 2011, were retrospectively reviewed. RESULTS: Presenting symptoms included fever, chills, right-upper-quadrant abdominal pain, nausea, vomiting, weight loss, and diarrhea. Physical signs included tenderness in the right-upper-quadrant abdomen, jaundice, and ascites. With the exception of elevated alpha-fetoprotein (AFP) in HCC patients and elevated carbohydrate antigen 19-9 (CA19-9) in IHCC patients, lab results were not significantly different between these nine patients and PLA patients. All the nine patients underwent invasive treatment in addition to antibiotics. CONCLUSIONS: Elevated AFP and CA19-9 could suggest HCC and IHCC in patients with symptoms/signs typical of PLA. Contrast-enhanced computed tomography could be helpful in patients with normal AFP and CA19-9. Making an accurate and early diagnosis and seizing the opportunity of surgery are essential to improve the management strategies of patients with PLC mimicking PLA.

(E)-1-(5-Bromo-2-hy-droxy-phen-yl)-3-[4-(dimethyl-amino)-phen-yl]prop-2-en-1-one.

In the title compound, C(17)H(16)BrNO(2), the two benzene rings make a dihedral angle of 7.4 (3)°; the hy-droxy group links to the carbonyl group via an intra-molecular O-H⋯O hydrogen bond. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into a supra-molecular chain running along the c axis.

Long-term immobilization of soil metalloids under simulated aging: Experimental and modeling approach.

Aging is an inevitable natural process, leading to faded performances of soil amendments. Understanding long-term aging features is crucial for the risk management of contaminated soil. In this study, a novel quantitative aging method, namely, the "soil coin" method, was developed, which can simulate the effects of natural aging on metal(loid) immobilization performances. To better depict the aging features, two models on the basis of conditional probability-induced failure were developed. To effectively immobilize soil arsenic (As) and antimony (Sb), magnesium (Mg) and iron (Fe) oxides were simultaneously introduced to either fresh or pre-oxidized biochar via a facile method. Although post-application aging is harmful, pre-aging (i.e., pre-oxidation using H2O2) in turn served as an effective means to introduce more metal oxides, thereby rendering better short-term and long-term effectiveness for metalloid immobilization. Experimental and modeling approaches suggested that precipitation accounted for long-term immobilization, while a constant aging rate is the key feature for a promising soil amendment. It is suggested that to further calibrate this method and better understand the immobilization performances in the long run, more evidence from the field is needed.

Increased Golgi protein 73 expression in hepatocellular carcinoma tissue correlates with tumor aggression but not survival.

BACKGROUND AND AIM: Serum Golgi protein 73 (sGP73) is a novel and promising biomarker for hepatocellular carcinoma (HCC). However, there are few reports on the pattern of GP73 expression in HCC and the relationship of this expression to clinicopathologic features of patients. This study aimed to investigate the expression of GP73 and it correlation with clinical parameters. METHODS: We examined GP73 expression in HCC and adjacent paracarcinomatous liver (PCL) tissue in 36 HCC patients, and took 14 normal liver (NL) samples from hepatic hemangioma patients. Western blot analysis and quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR) were used for analyses. RESULTS: GP73 expression in HCC was significantly higher than in the corresponding PCL and NL samples at both protein and mRNA levels (P < 0.001). The elevated level of GP73 protein was strongly associated with tumor size, vein invasion, and tumor differentiation, suggesting augmented tumor invasion and metastasis. However, there was no association between GP73 expression and patient survival. CONCLUSION: Significant overexpression of GP73 at both protein and mRNA levels along with overexpression of GP73 protein is associated with aggressive behavior of HCC, but not overall patient survival. Further research is needed to determine the potential of GP73 as a therapeutic target.

Progression of Prothrombin Induced by Vitamin K Absence-II in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer-related death worldwide. Due to the lack of efficient tools for early detection, asymptomatic HCC patients are diagnosed at an advanced stage, leading to a poor prognosis. To improve survival, serum biomarker prothrombin induced by vitamin K absence-II (PIVKA-II) was under investigation. PIVKA-II is an abnormal protein produced in HCC. The coagulation function was insufficient due to the lack of Gla residues. Elevated PIVKA-II was associated with bad tumor behavior in terms of proliferation, metastasis, and invasion. Three major signaling pathways were proposed to clarify the mechanism. With the advantages including affordability, minimal invasiveness, convenience, and efficiency, PIVKA-II could improve HCC management consisting of four aspects. First, PIVKA-II was an effective and dynamic tool for improving HCC surveillance in high-risk population. Changes in the serum levels of PIVKA-II provided valuable molecular alteration information before imaging discovery. Second, PIVKA-II offered a complementary approach for HCC early detection. Compared to traditional diagnostic approaches, the combination of PIVKA-II and other biomarkers had better performance. Third, PIVKA-II was an indicator for the assessment of response to treatment in HCC. Preoperative assessment was for selecting personalized therapy, and postoperative measurement was for assessing treatment efficacy. Fourth, PIVKA-II was considered as a prognostic predictor for HCC. Patients with elevated PIVKA-II were more likely to develop microvascular invasion, metastasis, and recurrence.

Analysis of N6-Methyladenosine Modification Patterns and Tumor Immune Microenvironment in Pancreatic Adenocarcinoma.

Background: Pancreatic adenocarcinoma (PAAD) is a rare cancer with a poor prognosis. N6-methyladenosine (m6A) is the most common mRNA modification. However, little is known about the relationship between m6A modification and the tumor immune microenvironment (TIME) in PAAD. Methods: Based on 22 m6A regulators, m6A modification patterns of PAAD samples extracted from public databases were systematically evaluated and correlated with the tumor immune and prognosis characteristics. An integrated model called the "m6Ascore" was constructed, and its prognostic role was evaluated. Results: Three different m6Aclusters and gene clusters were successively identified; these clusters were characterized by differences in prognosis, immune cell infiltration, and pathway signatures. The m6Ascore was constructed to quantify the m6A modifications of individual patients. Subsequent analysis revealed that m6Ascore was an independent prognostic factor of PAAD and could be a potential indicator to predict the response to immunotherapy. Conclusion: This study comprehensively evaluated the features of m6A modification patterns in PAAD. m6A modification patterns play a non-negligible role in the TIME of PAAD. m6Ascore provides a more holistic understanding of m6A modification in PAAD, and will help clinicians predict the prognosis and response to immunotherapy.