DNMT3a-mediated methylation of PPARγ promote intervertebral disc degeneration by regulating the NF-κB pathway.

Intervertebral disc degeneration (IVDD) is a common chronic musculoskeletal disease that causes chronic low back pain and imposes an immense financial strain on patients. The pathological mechanisms underlying IVDD have not been fully elucidated. The development of IVDD is closely associated with abnormal epigenetic changes, suggesting that IVDD progression may be controlled by epigenetic mechanisms. Consequently, this study aimed to investigate the role of epigenetic regulation, including DNA methyltransferase 3a (DNMT3a)-mediated methylation and peroxisome proliferator-activated receptor γ (PPARγ) inhibition, in IVDD development. The expression of DNMT3a and PPARγ in early and late IVDD of nucleus pulposus (NP) tissues was detected using immunohistochemistry and western blotting analyses. Cellularly, DNMT3a inhibition significantly inhibited IL-1ß-induced apoptosis and extracellular matrix (ECM) degradation in rat NP cells. Pretreatment with T0070907, a specific inhibitor of PPARγ, significantly reversed the anti-apoptotic and ECM degradation effects of DNMT3a inhibition. Mechanistically, DNMT3a modified PPARγ promoter hypermethylation to activate the nuclear factor-κB (NF-κB) pathway. DNMT3a inhibition alleviated IVDD progression. Conclusively, the results of this study show that DNMT3a activates the NF-κB pathway by modifying PPARγ promoter hypermethylation to promote apoptosis and ECM degradation. Therefore, we believe that the ability of DNMT3a to mediate the PPARγ/NF-κB axis may provide new ideas for the potential pathogenesis of IVDD and may become an attractive target for the treatment of IVDD.

PARP in colorectal cancer: Molecular mechanisms, immunity, clinical trials, and drug combinations.

The changes in cell homeostasis in the tumor microenvironment may affect the development of colorectal cancer (CRC). Genomic instability is an important factor. Persistent genomic instability leads to epigenetic changes, and mutations are a major factor in the progression of CRC. Based on these mechanisms, it is reasonable to link poly (ADP-ribose) polymerase (PARP) with the treatment of CRC. PARP is mainly involved in DNA repair, which has an essential role in the DNA damage response and prevention of DNA damage, and maintains oxidation and superoxide redox homeostasis in the intracellular environment of the tumor. This article reviews the latest research progress on PARP and PARP inhibitors (PARPi) in CRC. It mainly includes molecular mechanisms, immunity, clinical trials, and combination strategies of CRC. The research of PARPi in CRC has broad prospects, and the combinations with other drugs are the main research direction in the future.

Periostin: a predictable molecule to prognosis and chemotherapy responses of gastrointestinal and hepato-biliary-pancreatic malignant tumors?

With the continuous development of medical science and technology, the medical community's understanding of the disease is constantly updated, just as strategies for treating malignant tumors are constantly updated. New diagnoses, follow-up indicators, and treatment plan formulations need more evidence to be supported. To date, radical surgical resection is still the preferred treatment for advanced digestive system malignancies, and combination therapy including chemotherapy and targeted therapy before or after surgery is aimed at improving the prognosis and quality of life of patients. However, if tumor recurrence, metastasis, chemotherapy, and drug resistance to targeted agents after surgery prevent the achievement of the desired therapeutic effect, and if neoadjuvant chemotherapy and targeted therapy cannot reduce the staging of the tumor, surgery cannot be performed. These are huge problems that we face now and will continue to face for some time. Relevant scientific data and evidence have been produced to explain unsatisfactory efficacy, such as epithelial-mesenchymal transformation, the tumor microenvironment, extracellular matrix proteins, cancer-related fibroblasts, and other factors that may be related to tumor progression and poor therapeutic effects. An extracellular matrix protein, periostin (POSTN), influences the above factors and has received multidisciplinary attention. In this paper, periostin and digestive system-related tumors are reviewed, and the production, mechanism of action, drug resistance correlation analysis, and coping strategies of periostin are summarized to further understand its characteristics. This work provides evidence for potential therapeutic targets for digestive system tumors in the future.