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Peng Xia

Publications and source records attributed to Peng Xia.

18 recordsLinked to original sources
PubMed2026

Pathomics-based machine learning models for predicting METTL5 expression and prognosis in lung adenocarcinoma.

BACKGROUND: METTL5, an N6-methyladenosine (m6A) RNA methyltransferase, has been implicated in tumor progression, but its prognostic value and non-invasive prediction in lung adenocarcinoma (LUAD) remain unclear. This study aimed to develop a pathomics-based machine learning model to predict METTL5 expression from histopathological images and evaluate its prognostic significance in LUAD. METHODS: A total of 327 LUAD patients from The Cancer Genome Atlas (TCGA) with matched hematoxylin and eosin (H&E) slides, transcriptomic, and clinical data were included and randomly divided into training and validation sets (7:3). Quantitative histopathological features were extracted using PyRadiomics. Feature selection was performed via maximum relevance minimum redundancy (mRMR) and recursive feature elimination (RFE), followed by construction of a Gradient Boosting Machine (GBM) model. A pathomics score (PS) was generated to assess prognostic relevance. Survival analyses, gene set variation analysis (GSVA), tumor mutational burden (TMB), immune infiltration analysis, and in vitro functional assays were conducted. RESULTS: METTL5 overexpression was independently associated with poor overall survival [hazard ratio (HR) =1.637, P=0.007]. The model achieved good predictive performance [area under the curve (AUC) =0.847 in the training set and 0.752 in the validation set]. High PS was significantly associated with worse survival and remained an independent prognostic factor (HR =1.563, P=0.03). Elevated PS correlated with altered metabolic pathways, increased TMB, and immune microenvironment changes. METTL5 knockdown reduced proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) in A549 cells. CONCLUSIONS: The pathomics-based model accurately predicts METTL5 expression and provides prognostic stratification in LUAD, supporting its potential as a practical imaging-derived biomarker.

Methyltransferase-like 5↗
PubMed2026

Development and preliminary validation of plasma cell-free DNA methylation-based diagnostic prediction model for colorectal cancer detection.

BACKGROUND: Colorectal cancer (CRC) is a common malignancy associated with genetic and epigenetic alterations. Several methylation biomarkers have been investigated for non-invasive CRC detection; however, their reported performance varies across clinical settings, and the detection of early-stage or precancerous disease and discrimination from non-malignant colorectal conditions remain challenging. This exploratory study aimed to identify reproducible CRC-associated plasma cell-free DNA (cfDNA) methylation regions and to develop and preliminarily evaluate diagnostic prediction model for distinguishing CRC from healthy controls and benign samples. METHODS: Public CRC tissue methylation datasets from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) were analyzed to identify reproducible CRC-associated methylation alterations. Plasma cfDNA methylation was profiled using methyl-CpG-binding-domain enrichment followed by paired-end sequencing in patients with CRC, patients with colorectal polyps, and healthy controls. After quality-control filtering, 30 CRC and healthy-control samples were randomly allocated at the participant level in a 7:3 ratio to a development set comprising 10 patients with CRC and 11 healthy controls and a held-out test set comprising 4 patients with CRC and 5 healthy controls. Hypermethylated regions were selected using least absolute shrinkage and selection operator (LASSO) logistic regression. The 12-region model was evaluated in the held-out test set and subsequently applied to 10 colorectal polyp samples without refitting or recalibration. RESULTS: Tissue methylation analysis identified reproducible CRC-associated alterations across independent datasets. In the plasma development set, 707 differentially methylated regions (DMRs) were identified between CRC and healthy-control samples, including 324 hypermethylated and 383 hypomethylated regions. LASSO regression selected a 12-region hypermethylation signature. In the held-out test set, the model achieved an area under the curve (AUC) of 0.85 [95% confidence interval (CI): 0.579-1.000]. At the development-set-derived threshold, sensitivity was 75.0% (3/4), specificity was 60.0% (3/5), and accuracy was 66.7% (6/9). When the original model was applied to colorectal polyp samples, model scores were significantly higher in both CRC and polyp samples than in healthy controls, while CRC samples showed a tendency toward higher scores than polyp samples. CONCLUSIONS: This exploratory study identified a 12-region plasma cfDNA hypermethylation signature associated with CRC and developed a LASSO-based diagnostic prediction model that showed preliminary discrimination between CRC and healthy controls in a small held-out test set. By integrating tissue methylation evidence with plasma cfDNA profiling, this study expands the repertoire of candidate region-level methylation markers for blood-based CRC detection.

Colorectal cancer (CRC)↗
PubMed2026

Prognostic Role of Global DNA Methylation in Renal Cancer Reveals Decitabine Treatment Benefit.

BACKGROUND: Renal cancer presents a significant global health challenge due to its rising incidence and mortality rates. Often undetected in early stages, it complicates diagnosis and treatment. Current therapies face resistance and limited effectiveness, especially in advanced stages. The diverse subtypes of renal cancer highlight the need for new biomarkers and risk assessment tools for targeted treatments. OBJECTIVE: This study aims to assess the prognostic significance of global DNA methylation (GM) levels in renal cancer, identify new biomarkers, and evaluate the therapeutic potential of the DNA methyltransferase inhibitor decitabine. METHODS: Data on RNA sequencing, gene mutations, DNA methylation, and clinical outcomes were collected from TCGA and GEO databases. We calculated global DNA methylation scores (GMS) and categorized patients into high, intermediate, and low GMS groups. Survival analysis and genomic analyses were conducted to explore the relationships between GMS, clinical outcomes, and tumor characteristics. RESULTS: Higher GMS was identified as an independent prognostic factor associated with worse outcomes in renal cancer. Patients with elevated GMS showed increased mutations, copy number variations, and a more aggressive tumor phenotype. Treatment with decitabine was observed to reduce tumor hypermethylation and downregulate cell cycle pathway activity, indicating potential therapeutic benefits. CONCLUSION: Global DNA methylation plays a significant role in renal cancer prognosis. GMS may serve as valuable biomarkers for prognosis and personalized treatment strategies. Decitabine shows potential efficacy for high GMS patients, particularly through its impact on cell cycle regulation, underscoring the importance of personalized approaches in cancer treatment.

Humans↗
PubMed2006

A concise effective deprotection of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-one.

An effective deprotective method of spiro 3-cyclic thiaza ketal of steroidal 1,4-dien-3-ones using alkyl vinyl ether in the presence of protic acid followed by the treatment of aqueous alkali was described. This novel protocol could be fulfilled under mild condition with high yield. The mechanism mediated by a carbonium ion formed in situ was clarified by the capture of the cleaved fragment.

Catalysis↗
PubMed2006

Syntaxin 1A promotes the endocytic sorting of EAAC1 leading to inhibition of glutamate transport.

The neuronal glutamate transporter, excitatory amino-acid carrier 1 (EAAC1), plays an important role in the modulation of neurotransmission and contributes to synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) and to epileptogenesis. However, the mechanisms that regulate EAAC1 endocytic sorting and function remain largely unknown. Here, we first demonstrate that EAAC1 undergoes internalization through the clathrin-mediated pathway and further show that syntaxin 1A, a key molecule in synaptic exocytosis, potentiates EAAC1 internalization, thus leading to the functional inhibition of EAAC1. In the presence of the transmembrane domain of syntaxin 1A, its H3 coiled-coil domain of syntaxin 1A is necessary and sufficient for the inhibition of EAAC1. Furthermore, specific suppression of endogenous syntaxin 1A significantly blocked EAAC1 endocytic sorting and lysosomal degradation promoted by kainic acid, a drug for kindling the animal model of human temporal lobe epilepsy in rat, indicating a potential role of syntaxin 1A in epileptogenesis. These findings provide new evidence that syntaxin 1A serves as an intrinsic enhancer to EAAC1 endocytic sorting and further suggest that syntaxin 1A is conversant with both ;ins' and ;outs' of synaptic neurotransmission.

Amino Acid Transport Systems↗
PubMed2006

[Detection of 16S ribosomal RNA gene of bacteria in prostate tissues of adults].

OBJECTIVE: To investigate the role of bacteria in chronic prostatitis. METHODS: Complete specimens of prostate were obtained from 140 organ donors, aged 20 - 35, at autopsy. A piece of tissue was collected from the peripheral zone of prostate from each specimen and was divided into 2 parts to undergo pathological examination and PCR so as to detect the 16S ribosomal RNA (16S rRNA) gene of bacteria. RESULTS: Focal mild inflammation was shown in 46 of the 104 specimens (32.9%), including interstitial inflammation in 42 specimens, inflammation in both interstitial and body of gland in 3 specimens, and perigladulitis in 1 specimen. Twenty-seven of the 140 specimens (19.3%) were positive in 16S rRNA gene. The positive rate of 16S rRNA gene of the specimens with prostatitis was 48.9%, significantly higher than that of the specimens without prostatitis (5.3%, P < 0.001). CONCLUSION: Bacteria may play an important role in the pathogenesis of chronic prostatitis.

Adult↗
PubMed2006

Regulation of the glutamate transporter EAAC1 by expression and activation of delta-opioid receptor.

Glutamate transporters play an essential role in regulating temporal and spatial glutamate concentration in the synaptic cleft. The excitatory amino acid carrier 1 (EAAC1) is a neuronal-specific transporter. Opioid receptors are found to modulate the glutamatergic system in brain, but the regulatory mechanism remains to be investigated. Here we report that the delta-opioid receptor (DOR) co-expressed with EAAC1 in Xenopus oocytes, but not the micro-opioid receptor, down-regulates EAAC1 function, and that [d-Pen(2,5)]-enkephalin stimulation of DOR can counteract the down-regulation of the EAAC1-mediated uptake. Results from co-immunoprecipitation and immunofluorescence microscopy in both oocytes and rat hippocampal neurons indicate co-localization and suggest direct interaction between DOR and EAAC1. The results suggest that DOR can reduce EAAC1 function by direct protein-protein interaction and that activation of DOR releases the inhibitory interaction. We suggest that this mechanism may be important for modulation of the glutamatergic system following opioid stimulation.

Animals↗
PubMed2005

[Analysis of the EEG information of rats epileptic model using unstable periodic orbits].

In order to further research into the EEG information of rats epileptic model, we applied different nonlinear dynamic methods. After having analyzed the EEG signal of rat falling sickness by means of approximate entropy and correlation dimension, we adopted a the new method, unstable periodic orbits, which was used to analyze complex activity of neurons system to look for the change regularity of change in the EEG signal in the whole course of rat's falling sickness. We found period 1 orbits and period 2 orbits to be statistically significant in the data of ictal time of epilepsy. At the same time, we found period 1 orbits to be statistically significant in the data of preictal time of epilepsy.

Animals↗
PubMed2004

Anti-AIDS agents. Part 56: Synthesis and anti-HIV activity of 7-thia-di-O-(-)-camphanoyl-(+)-cis-khellactone (7-thia-DCK) analogs.

Two thia-DCK analogs (3a,b) were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. Compound 3a showed potent anti-HIV activity with an EC50 value of 0.14 microM and a therapeutic index of 1110. However, the corresponding 6-tert-butyl-substituted compound (3b) showed no suppression. The bioassay results indicated that thia-DCK analogs merit attention as potential HIV-1 inhibitors.

Anti-HIV Agents↗
PubMed2004

Some unreported by-products from the reaction of 1,4-dien-3-one steroids with 2-(methylammo)benzethiol/BF3.

In a previous report, it was demonstrated that the 3-carbonyl of androsta-1,4-dien-3,17-dione (ADD) can be selectively protected with 2-(methylamino)benzethiol in the presence of BF3 in good yield. We explored the applicability of this method for other 1,4-dien-3-one steroids and got the desired protective products in different yield. Other than the usual protected products, we also got some unexpected by-products, including benzathiazol[4,3-b]-estra steroids. Their structures were determined by spectral analysis.

Boranes↗
PubMed2004

Anti-AIDS agents. Part 62: anti-HIV activity of 2'-substituted 4-methyl-3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (4-methyl DCK) analogs.

Four 4-methyl-3',4'-di-O-(-)-camphanoyl-(+)-cis-khellactone (4-methyl DCK) analogs (7a-d) with different alkyl substituents at the 2'-position were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. 2'-Methyl-2'-ethyl-4-methyl DCK (7b) was more potent (EC(50)=0.22 microM, TI>175) than the other three compounds (7a, 7c, and 7d), but significantly less potent than 4-methyl DCK (2, EC(50)=0.0059 microM, TI>6600). The bioassay results indicated that the 2'-substituents had a strong effect on the anti-HIV activity, and gem-dimethyl substitution at the 2'-position was greatly preferable to larger alkyl substituents or hydrogen atoms.

Anti-HIV Agents↗
PubMed2004

Anti-AIDS agents. Part 58: synthesis and anti-HIV activity of 1-thia-di-O-(-)-camphanoyl-(+)-cis-khellactone (1-thia-DCK) analogues.

Two 1-thia-DCK analogues (9a and 9b) were synthesized and evaluated for inhibition of HIV-1 replication in H9 lymphocytes. Compound 9a showed excellent anti-HIV activity with an EC(50) value of 0.00012 microM and therapeutic index of 1408000. Compound 9b was less active with EC(50) and TI values of 3.11 microM and 62.3, respectively. The bioassay results indicated that thia-DCK analogues merit attention as potential HIV-1 inhibitors.

Anti-HIV Agents↗
PubMed2003

Antitumor agents. Part 226: synthesis and cytotoxicity of 2-phenyl-4-quinolone acetic acids and their esters.

2-Phenyl-4-quinolone acetic acids and their esters were synthesized and evaluated for interaction with tubulin and for cytotoxicity against a panel of human tumor cell lines. 2-Phenyl- and 2-(2'-fluorophenyl)-4-quinolone-8-acetic acids (11 and 12) displayed potent cytotoxicity with ED(50) values at nanomolar concentrations, but had minimal activity against tubulin polymerization. 2-(2'-Fluorophenyl)-4-quinolone-6-acetic acid (3) and 2-(2'-fluorophenyl)-4-quinolone-8-acetic acid methyl ester (10) moderately inhibited tubulin polymerization.

Acetates↗
PubMed2003

Synthesis and bioactivity of 4,10-dimethyl-pyridino[2,3-h]quinolin-2(1H)-one-9-carboxylic acid and its esters.

4,10-Dimethyl-pyridino[2,3-h]quinolin-2(1H)-one-9-carboxylic acid (1) was synthesized by a new approach via the key intermediate 7-[1-aza-2-(dimethylamino)vinyl]-4-methylquinolin-2(1H)-one (4). Compound 1 and its esters were evaluated in cytotoxicity and anti-HIV assays. The 9-carboxyl (1s)-endo-(-)-borneol ester (9) showed marginal cytotoxic activity in CAK1-1, HOS, KB, and HCT-8 cells.

Anti-HIV Agents↗
PubMed2003

Modification of hippocampal neurogenesis and neuroplasticity by social environments.

Synaptic plasticity and neurogenesis in the brain are affected by environmental stimuli. The present study was designed to investigate the effects of social environments on learning and memory, neurogenesis, and neuroplasticity. Twenty-two-day-old rats were housed in isolation or in groups for 4 or 8 weeks and injected intraperitoneally with bromodeoxyuridine to detect proliferation among progenitor cells. The animals were also tested for learning in a water maze and for hippocampal CA1 long-term potentiation in vivo and in vitro. The results show that the number of newborn neurons in the dentate gyrus and the learning in a water maze decreased significantly in rats reared in isolation for 4 or 8 weeks, as compared with grouped controls. Induction of long-term potentiation in the CA1 area of rat hippocampus in vivo and in vitro was also significantly reduced by isolation. Furthermore, the effects of isolation rearing on spatial learning, hippocampal neurogenesis, and long-term potentiation could be reversed by subsequent group rearing. These findings demonstrated that social environments can modify neurogenesis and synaptic plasticity in adult hippocampal regions, which is associated with alterations in spatial learning and memory.

Animals↗
PubMed2002

[Reversal of nomegestrol acetate on multidrug resistance in drug-resistant human breast cancer cell line MCF7/ADR].

OBJECTIVE: To study the reversal effect of nomegestrol acetate (NOM) on mutidrug resistance (MDR) in MCF7/ADR and its mechanism. METHODS: Using tetrazolium dye assay, effects of various concentrations of NOM on sensitivity to ADR in MCF7/ADR was studied. Expression of MDR related genes MDR1, glutathoine S-transferase Pi (GSTpi), Topoisomerase II alpha (Topo II alpha) and MDR related protein (MRP) were assayed by reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry assay. Using flow cytometry (FCM), intracellular ADR concentration effects on cell cycle were observed. RESULTS: NOM significantly reversed MDR in MCF7/ADR. After NOM 20, 10 and 5 micromol/L treatment, the chemosensitivity to ADR increased to 21, 12 and 8 times. The reversal activity of NOM was stronger than that of the precursor compound megestrol acetate, and was comparable to that of verapamail. After treatment with NOM 5 micromol/L both MDR1 and GSTpi mRNA genes expression began to decline on D2 (P < 0.05, & P < 0.01) and reached the lowest level on D3 (both P < 0.01), but the expression levels began to rise on D6 again (both P < 0.05). The expression of MRP and Topo II alpha gave no significant change. Changes of P-gp and GSTpi protein expressions were similar to those of their mRNA expressions, showing early decline and late rise. Two hours after NOM 20, 10, and 5 micromol/L treatment, intracellular ADR concentration increased 2.7, 2.3 and 1.5 times, respectively. FCM data showed that after forty-eight hours, combined administration of NOM (20 micromol/L) and ADR (from low concentration to high concentration), MCF7/ADR cells showed gradual arrest in the G(2)M phase with the increase of ADR dose. CONCLUSION: NOM has strong reversal effects on MDR in MCF7/ADR. The reversal takes place via different routes, i.e. down regulating mRNA and protein expression levels of MDR1 and GSTpi, increasing intracellular drug concentration, and enhancing the arrest of ADR in cells at G(2)M phase.

ATP Binding Cassette Transporter, Subfamily B, Mem↗