DNA Methylation Biomarkers as Prediction Tools for Therapeutic Response and Prognosis in Intermediate-Stage Hepatocellular Carcinoma.

INTRODUCTION: Alfa-fetoprotein (AFP), as the main serum tumor marker of hepatocellular carcinoma (HCC), is limited in terms of specificity and ability to predict outcomes. This study investigated the clinical utility of DNA methylation biomarkers to predict therapeutic responses and prognosis in intermediate-stage HCC. METHODS: This study enrolled 72 patients with intermediate-stage HCC who underwent locoregional therapy (LRT) between 2020 and 2021. The immediate therapeutic response and disease status during a two-year follow-up were recorded. Analysis was performed on 10 selected DNA methylation biomarkers via pyrosequencing analysis of plasma collected before and after LRT. RESULTS: Analysis was performed on 53 patients with complete responses and 19 patients with disease progression after LRT. The mean follow-up duration was 2.4 ± 0.6 years. A methylation prediction model for tumor response (MMTR) and a methylation prediction model for early progression (MMEP) were constructed. The area under the curve (AUC) for sensitivity and specificity of MMTR was 0.79 for complete response and 0.759 for overall survival. The corresponding AUCs for sensitivity and specificity of AFP and protein induced by vitamin K absence-II (PIVKA-II) were 0.717 and 0.708, respectively. Note that the MMTR index was the only significant predictor in multivariate analysis. The AUC for sensitivity and specificity of the MMEP in predicting early progression was 0.79. The corresponding AUCs for sensitivity and specificity of AFP and PIVKA-II were 0.758 and 0.714, respectively. Multivariate analysis revealed that platelet count, beyond up-to-7 criteria, and the MMEP index were strongly correlated with early tumor progression. Combining the indexes and serum markers further improved the predictive accuracy (AUC = 0.922). Multivariate analysis revealed the MMEP index was the only independent risk factor for overall survival. DISCUSSION/CONCLUSIONS: This study indicates that these methylation markers could potentially outperform current serum markers in terms of accuracy and reliability in assessing treatment response and predicting outcomes. Combining methylation markers and serum markers further improved predictive accuracy, indicating that a multi-marker approach may be more effective in clinical practice. These findings suggest that DNA methylation biomarkers may be a useful tool for managing intermediate-stage HCC patients and guiding personalized treatment, particularly for those who are at high risk for close surveillance or adjuvant treatment after LRT.

Identification of essential ß-oxidation genes and corresponding metabolites for oestrogen degradation by actinobacteria.

Steroidal oestrogens (C18 ) are contaminants receiving increasing attention due to their endocrine-disrupting activities at sub-nanomolar concentrations. Although oestrogens can be eliminated through photodegradation, microbial function is critical for removing oestrogens from ecosystems devoid of sunlight exposure including activated sludge, soils and aquatic sediments. Actinobacteria were found to be key oestrogen degraders in manure-contaminated soils and estuarine sediments. Previously, we used the actinobacterium Rhodococcus sp. strain B50 as a model microorganism to identify two oxygenase genes, aedA and aedB, involved in the activation and subsequent cleavage of the estrogenic A-ring respectively. However, genes responsible for the downstream degradation of oestrogen A/B-rings remained completely unknown. In this study, we employed tiered comparative transcriptomics, gene disruption experiments and mass spectrometry-based metabolite profile analysis to identify oestrogen catabolic genes. We observed the up-regulation of thiolase-encoding aedF and aedK in the transcriptome of strain B50 grown with oestrone. Consistently, two downstream oestrogenic metabolites, 5-oxo-4-norestrogenic acid (C17 ) and 2,3,4-trinorestrogenic acid (C15 ), were accumulated in aedF- and aedK-disrupted strain B50 cultures. Disruption of fadD3 [3aα-H-4α(3'-propanoate)-7aß-methylhexahydro-1,5-indanedione (HIP)-coenzyme A-ligase gene] in strain B50 resulted in apparent HIP accumulation in oestrone-fed cultures, indicating the essential role of fadD3 in actinobacterial oestrogen degradation. In addition, we detected a unique meta-cleavage product, 4,5-seco-estrogenic acid (C18 ), during actinobacterial oestrogen degradation. Differentiating the oestrogenic metabolite profile and degradation genes of actinobacteria and proteobacteria enables the cost-effective and time-saving identification of potential oestrogen degraders in various ecosystems through liquid chromatography-mass spectrometry analysis and polymerase chain reaction-based functional assays.

Chloroplast import of an intermembrane space protein is facilitated by translocon components Toc75 and Tic236.

Chloroplasts are divided into six subcompartments: the outer membrane, intermembrane space, and inner membrane of the envelope, the stroma, the thylakoid membrane, and the thylakoid lumen. Compared with our knowledge of protein import into other subcompartments, extremely little is known about how proteins are imported into the intermembrane space of the envelope. Tic22 was one of the first proteins identified as localizing to the intermembrane space and the only one for which import has been analyzed in some detail. However, conflicting results have been obtained concerning whether the general translocon is used to import Tic22 into the intermembrane space. Taking advantage of available translocon component mutants, we reanalyzed import of Tic22. We reveal reduced in vitro import of Tic22 preprotein (prTic22) into chloroplasts isolated from the Arabidopsis mar1 and tic236 mutants, which are functional knockdown mutants of the outer-membrane channel Toc75 and the intermembrane space linker Tic236, respectively. Import competition experiments also showed that prTic22 import was reduced by excess amounts of a stroma-targeted preprotein. Our results indicate that prTic22 uses at least part of the general translocon for import into the intermembrane space.

Mechanistic and phylogenetic insights into actinobacteria-mediated oestrogen biodegradation in urban estuarine sediments.

Steroidal oestrogens are often accumulated in urban estuarine sediments worldwide at microgram per gram levels. These aromatic steroids have been classified as endocrine disruptors and group 1 carcinogens. Microbial degradation is a naturally occurring mechanism that mineralizes oestrogens in the biosphere; however, the corresponding genes in oestrogen-degrading actinobacteria remain unidentified. In this study, we identified a gene cluster encoding several putative oestrogen-degrading genes (aed; actinobacterial oestrogen degradation) in actinobacterium Rhodococcus sp. strain B50. Among them, the aedA and aedB genes involved in oestrogenic A-ring cleavage were identified through gene-disruption experiments. We demonstrated that actinobacterial oestrone 4-hydroxylase (AedA) is a cytochrome P450-type monooxygenase. We also detected the accumulation of two extracellular oestrogenic metabolites, including pyridinestrone acid (PEA) and 3aα-H-4α(3'-propanoate)-7aß-methylhexahydro-1,5-indanedione (HIP), in the oestrone-fed strain B50 cultures. Since actinobacterial aedB and proteobacterial edcB shared < 40% sequence identity, 4-hydroxyestrone 4,5-dioxygenase genes (namely aedB and edcB) could serve as a specific biomarker to differentiate the contribution of actinobacteria and proteobacteria in environmental oestrogen degradation. Therefore, 4-hydroxyestrone 4,5-dioxygenase genes and the extracellular metabolites PEA and HIP were used as biomarkers to investigate oestrogen biodegradation in an urban estuarine sediment. Interestingly, our data suggested that actinobacteria are active oestrogen degraders in the urban estuarine sediment.