The phosphorylation-deubiquitination positive feedback loop of the CHK2-USP7 axis stabilizes p53 under oxidative stress.

p53 regulates multiple signaling pathways and maintains cell homeostasis under conditions of DNA damage and oxidative stress. Although USP7 has been shown to promote p53 stability via deubiquitination, the USP7-p53 activation mechanism has remained unclear. Here, we propose that DNA damage induces reactive oxygen species (ROS) production and activates ATM-CHK2, and CHK2 then phosphorylates USP7 at S168 and T231. USP7 phosphorylation is essential for its deubiquitination activity toward p53. USP7 also deubiquitinates CHK2 at K119 and K131, increasing CHK2 stability and creating a positive feedback loop between CHK2 and USP7. Compared to peri-tumor tissues, thyroid cancer and colon cancer tissues show higher CHK2 and phosphorylated USP7 (S168, T231) levels, and these levels are positively correlated. Collectively, our results uncover a phosphorylation-deubiquitination positive feedback loop involving the CHK2-USP7 axis that supports the stabilization of p53 and the maintenance of cell homeostasis.

Mechanism and clinical progression of solid tumors bone marrow metastasis.

The rich blood supply of the bone marrow provides favorable conditions for tumor cell proliferation and growth. In the disease's early stages, circulating tumor cells can escape to the bone marrow and form imperceptible micro metastases. These tumor cells may be reactivated to regain the ability to grow aggressively and eventually develop into visible metastases. Symptomatic bone marrow metastases with abnormal hematopoiesis solid tumor metastases are rare and have poor prognoses. Treatment options are carefully chosen because of the suppression of bone marrow function. In this review, we summarized the mechanisms involved in developing bone marrow metastases from tumor cells and the clinical features, treatment options, and prognosis of patients with symptomatic bone marrow metastases from different solid tumors reported in the literature.

Insights on E1-like enzyme ATG7: functional regulation and relationships with aging-related diseases.

Autophagy is a dynamic self-renovation biological process that maintains cell homeostasis and is responsible for the quality control of proteins, organelles, and energy metabolism. The E1-like ubiquitin-activating enzyme autophagy-related gene 7 (ATG7) is a critical factor that initiates classic autophagy reactions by promoting the formation and extension of autophagosome membranes. Recent studies have identified the key functions of ATG7 in regulating the cell cycle, apoptosis, and metabolism associated with the occurrence and development of multiple diseases. This review summarizes how ATG7 is precisely programmed by genetic, transcriptional, and epigenetic modifications in cells and the relationship between ATG7 and aging-related diseases.

Covalent organic framework with donor-acceptor structure for rapid and sensitive photothermal sensing detection.

Given the serious harm caused by dietary intake of diethylstilbestrol (DES), it is urgent to explore rapid and sensitive DES sensing methods. In this work, a photothermal DES immunochromatography sensor based on covalent organic framework (COF) was constructed. The performance of COF in the field of photothermal sensing was systematically investigated for the first time. A donor-acceptor type of COF with a photothermal conversion rate of 51.17 % was synthesized. The logarithm of the DES concentrations-temperature change value standard curve was plotted. The intensity of the photothermal sensing signal was inversely proportional to the sample concentration. The detection limit of the proposed photothermal method (0.24 µg·L-1) was 10 times higher than that of visual detection (3 µg·L-1). This work not only constructed a novel detection method for DES sensing, but also provided a feasible demonstration for the application of COF in photothermal sensing and expanded the application of their photothermal properties.

Primary site surgery of de novo stage IV HER2-positive breast cancer in the era of new drug treatments.

Objective: The surgical treatment of the primary site has been a subject of controversy in patients with de novo metastatic breast cancer. In recent years, studies using large databases and retrospective analyses have provided evidence of the survival benefits of localized surgery for these patients. However, due to the improved prognosis associated with novel antitumor agents and the widespread use of anti-HER2 therapy, it is important to investigate the role of primary site surgery in the context of new drug treatments for stage IV HER2-positive breast cancer. Methods: This retrospective analysis included patients with metastatic breast cancer at diagnosis who were consulted at the First Hospital of Jilin University between 2016 and 2022. We compared the patients' clinical and pathological characteristics, treatment regimens, and prognosis between the surgery and non-surgery groups. Results: A total of 96 patients with stage IV HER2-positive breast cancer were included in the study, with 24 patients (25%) undergoing surgery for the primary lesion. Patients with lower Eastern Cooperative Oncology Group (ECOG) scores, earlier T-stage, metastases confined to one organ/site, and fewer metastases were more likely to undergo surgery. Patients in the surgical group had longer progression-free survival (median 25.7 vs. 15.9 months, p=0.073) and overall survival (median 79.1 vs. 48 months, p=0.073) compared to patients in the non-surgical group, however, there was no statistical difference. Univariate and multivariate Cox regression analysis suggested that the choice of first-line targeted therapy regimens rather than surgical treatment influenced the patients' prognoses. In the subgroup of patients receiving first-line targeted therapy with trastuzumab plus pertuzumab, the decision to undergo surgery on the primary site did not have a statistically significant effect on prognosis. Conclusion: Primary site surgery does not improve the prognosis of de novo stage IV HER2-positive breast cancer. In the era of anti-HER2 therapy, primary surgery is not recommended, except in exceptional circumstances.