Biomedical subjects

Rongrong Chen

Publications and source records attributed to Rongrong Chen.

3 recordsLinked to original sources

PubMed2026

Directed evolution of Lactiplantibacillus plantarum for utilizing ethanol to produce postbiotics.

Alcohol is a recognized carcinogen worldwide. In this study, we aimed to utilize probiotics to metabolize ethanol and produce postbiotics. Initially, we identified a lactic acid bacteria community in kimchi with excellent probiotic activity. By employing our previously developed directed evolution techniques, a Lactiplantibacillus plantarum mutant with safe characteristics and an ethanol utilization capacity of 40 g/L and 0.15 g/L/OD was obtained. Genome sequencing and RT-qPCR analysis revealed the up-regulated expression of alcohol dehydrogenase and aldehyde dehydrogenase genes greatly contributed to ethanol utilization. Furthermore, the mutant strain demonstrated marked superiority in producing postbiotics, including antimicrobial peptides and beneficial organic acids such as lactic acid, phenyllactic acid, succinic acid, and indole-3-lactic acid. In the ethanol-fed fermentation process, the mutant strain achieved a lactic acid yield of 8.47 g/L and a carbon conversion rate of 21.8%. In vivo testing further validated its safety and ability to assist alcohol metabolism.

Adaptive laboratory evolution↗

PubMed2026

Genetic Mutation and Epigenetic Silencing Drive Antigen-Negative Relapse in CD7 CAR T-Treated T-cell Lymphoid Malignancies.

UNLABELLED: CD7 is a promising target for chimeric antigen receptor (CAR) T-cell therapy in T-cell lymphoid malignancies; however, antigen loss-mediated relapse has emerged as a major challenge. In this study, we systematically analyzed the genetic and epigenetic alterations of paired specimens (pretreatment and relapsed) from 10 patients with T-cell lymphoma/leukemia receiving CD7 CAR T cells. Overall, we identified three distinct mechanisms underlying CD7 loss: first, frameshift insertion (patient 4; c.164dupG:p.R55fs) or deletion (patient 7; c.122delG:p.G41Efs*19) resulting in truncation of the CD7 transmembrane domain in two of 10 patients; second, hypermethylation of the CD7 promoter in seven of 10 patients without CD7 mutation; third, simultaneous occurrence of promoter region hypermethylation and multiple in-frame mutations with predicted functional interference in one of 10 patients (patient 2). Collectively, these findings demonstrate that both clonal heterogeneity and epigenetic plasticity drive antigen-negative relapse in T-cell lymphoid malignancies under the selective pressure of CD7 CAR T-cell therapy. SIGNIFICANCE: Understanding mechanisms of antigen-negative relapse is critical for developing effective CD7-targeting CAR-T therapies against T-cell lymphoid malignancies. Our study identifies both genetic truncation mutations and epigenetic silencing as contributors to CD7-negative relapse. Monitoring and preventing these events is warranted to improve treatment outcomes.

Humans↗

PubMed2025

Comprehensive assessment of homologous recombination deficiency via simultaneous methylation and mutation analysis in epithelial ovarian cancer: implications for PARP inhibitors efficacy.

BACKGROUND: The advent of poly (ADP-ribose) polymerase inhibitors (PARPi) over the past decade has significantly altered the management of epithelial ovarian cancer (EOC). We proposed that the etiology of homologous recombination deficiency (HRD) might underlie the variable responses to PARPi observed across patient populations. METHODS: As part of the phase 2 study of the Chinese HRD Harmonization Project, we developed a genomic methylation sequencing (GM-seq) pipeline facilitated by the TET enzyme for the simultaneous identification of methylated modifications and genetic variations in EOC tumor samples, and compared with established DNA sequencing-based HRD assays. RESULTS: Somatic mutation and HRD scores were confounded by low tumor purity in our cohort of 98 locally advanced/advanced EOC patients. In samples with tumor purity ≥ 30% (n = 45), the GM-seq pipeline showed high consistency with DNA sequencing-based HRD assay, identifying genetic variations in homologous recombination repair (HRR) genes and HRD score with 92.6% (25/27) and 97.1% (33/34) consistency respectively, in addition to conducting methylation profiling. Moreover, different underlying mechanisms of HRD were associated with varying degrees of PARPi efficacy, with BRCA1/2 LOH group having the best efficacy (median PFS, undefined), followed by BRCA1 methylation group (median PFS, 23.4 months), and those with unknown etiology of HRD having the worst efficacy (median PFS, 8.8 months, p < 0.001). CONCLUSION: Our findings underscore the importance of considering HRD etiology when evaluating PARPi efficacy in EOC patients. The GM-seq pipeline, represents a significant advancement in HRD detection, enabling more accurate predictions of PARPi response.

Epithelial ovarian cancer (EOC)↗