The PRMT5 inhibitor C9 mitigates hypoxia-induced carboplatin resistance in lung cancer by inducing autophagy.

Hypoxia, a common feature of solid tumors, can promote chemoresistance in cancer cells. PRMT5 mediates various cellular processes involved in cancer development and progression. However, the role of PRMT5 in hypoxia-induced chemoresistance is unclear. In this study, hypoxia upregulated PRMT5 expression in lung cancer cells. Additionally, PRMT5 overexpression promoted cancer cell resistance to carboplatin. In carboplatin-resistant cancer cells, PRMT5 overexpression promoted the methylation of ULK1, a critical regulator of autophagy. ULK1 hypermethylation leads to the upregulation of autophagy, which can improve the survival of cancer cells under hypoxic conditions. Furthermore, this study demonstrated that the PRMT5 inhibitor C9 significantly enhanced the sensitivity of lung cancer cells to carboplatin. These findings suggest that targeting PRMT5-mediated autophagy with C9 can overcome hypoxia-induced carboplatin resistance and improve the efficacy of chemotherapy in patients with cancer.

Application of the patient-reported outcome-based postoperative symptom management model in lung cancer: a multicenter randomized controlled trial protocol.

INTRODUCTION: Lung cancer is the most common cancer in China, with the highest mortality rate. Surgery is the primary treatment for early lung cancer. However, patients with lung cancer have a heavy burden of symptoms within 3 months after surgery, which seriously affects their quality of life (QOL). The symptom management model based on the patient-reported outcome (PRO) is considered the best caregiving model. The clinical evidence about the symptom management of lung cancer within 3 months after the operation is very limited. Herein, we propose a randomized controlled trial to evaluate the PRO score-based monitoring and alert system for follow-up on psychological and physiological symptoms of lung cancer patients within 3 months after surgery and further investigate the effect of intervention measures based on this PRO score-based system. METHODS AND ANALYSIS: This multicenter, open-label, randomized, parallel superiority trial will be conducted at four hospitals in China. A total of 440 lung cancer patients will be recruited in this study, who will be randomly assigned to the intervention group or the control group in a ratio of 1:1. Any of the target symptoms reaches the preset threshold (score ≥ 4), the patients will accept the symptom management advices based on the PRO. The patients in the control group will follow the current standard procedure of symptom management. The symptom management system is an electronic management system based on WeChat mini programs. All patients will be evaluated for symptoms through the lung cancer module of the MDASI lung cancer-specific scale on the day before surgery, days 1, 3, 5, and 7 after surgery, and once a week during the 12-week post-discharge period. Simultaneously, the EORTC QLQ-C30 scale will be used to evaluate patients' quality of life at baseline and the fourth and twelfth week after the surgery. The mean number of symptom threshold events of the intervention and the control groups were compared by t-test, and the changes of PRO were compared by a mixed effect model. The primary endpoint has been set as the 12-week post-discharge period. DISCUSSION: This study will test the feasibility of the symptom management system based on the mobile social media applet in postoperative caregiving and the efficacy of psychiatrist-assisted treatment and provide evidence in managing the symptoms of patients in the medium and long term. TRIALS REGISTRATION: Trials registration number: ChiCTR 2200058876, Registered 18 April 2022.

Evaluation of an ex vivo fibrogenesis model using human lung slices prepared from small tissues.

BACKGROUND: In recent years, there have been breakthroughs in the preclinical research of respiratory diseases, such as organoids and organ tissue chip models, but they still cannot provide insight into human respiratory diseases well. Human lung slices model provides a promising in vitro model for the study of respiratory diseases because of its preservation of lung structure and major cell types. METHODS: Human lung slices were manually prepared from small pieces of lung tissues obtained from lung cancer patients subjected to lung surgery. To evaluate the suitability of this model for lung fibrosis research, lung slices were treated with CdCl2 (30 µM), TGF-ß1 (1 ng/ml) or CdCl2 plus TGF-ß1 for 3 days followed by toxicity assessment, gene expression analysis and histopathological observations. RESULTS: CdCl2 treatment resulted in a concentration-dependent toxicity profile evidenced by MTT assay as well as histopathological observations. In comparison with the untreated group, CdCl2 and TGF-ß1 significantly induces MMP2 and MMP9 gene expression but not MMP1. Interestingly, CdCl2 plus TGF-ß1 significantly induces the expression of MMP1 but not MMP2, MMP7 or MMP9. Microscopic observations reveal the pathogenesis of interstitial lung fibrosis in the lung slices of all groups; however, CdCl2 plus TGF-ß1 treatment leads to a greater alveolar septa thickness and the formation of fibroblast foci-like pathological features. The lung slice model is in short of blood supply and the inflammatory/immune-responses are considered minimal. CONCLUSIONS: The results are in favor of the hypothesis that idiopathic pulmonary fibrosis (IPF) is mediated by tissue damage and abnormal repair. Induction of MMP1 gene expression and fibroblast foci-like pathogenesis suggest that this model might represent an early stage of IPF.

miR-24-3p/KLF8 Signaling Axis Contributes to LUAD Metastasis by Regulating EMT.

Reprogramming of the tumor immune microenvironment is a salient feature during metastasis in LUAD. miR-24-3p and KLF8, which are key regulators of the tumor immune microenvironment, had been proved to show metastasis-promoting property in LUAD. However, whether miR-24-3p could regulate LUAD metastasis by targeting KLF8 remains unclear. This study explored the functions and mechanisms of miR-24-3p/KLF8 signaling in advanced LUAD. The expression level of miR-24-3p and KLF8 were tested in LUAD patients, and the corelation of miR-24-3p and KLF8 was evaluated. The interaction of miR-24-3p and KLF8 was demonstrated by luciferase reporter activity assay, in vitro migration and invasion studies, and in vivo metastatic studies. miR-24-3p level was downregulated in LUAD and negatively associated with KLF8 mRNA expression. miR-24-3p controls LUAD metastasis by directly targeting KLF8 and inducing Snail and E-cadherin expressions. Targeting the miR-24-3p/KLF8/EMT axis might be of great therapeutic value to advanced LUAD patients.

The methylation induced by protein arginine methyltransferase 5 promotes tumorigenesis and progression of lung cancer.

Arginine methylation as a common pattern of post-translational modification is involved in many cellular biological processes. Protein arginine methyltransferase 5 (PRMT5) is a primary enzyme in charge of symmetric dimethylation (me2s) of arginine residues. Increasing literatures lead to the belief that PRMT5, as a potential oncogene, plays crucial roles in the tumorigenesis and progression of cancers. First of all, PRMT5 is overexpressed in several cancer cells, with various sub-cellular localization in different type of cells and different phases. Besides, PRMT5 participates in controlling cellular proliferation, differentiation, invasion, migration as well apoptosis through histone and other protein methylation. Moreover, PRMT5 is essential for growth and metastasis of lung cancer cells, and its overexpression indicates a poor clinical outcome of lung cancer. Therefore, in this review, we reviewed the substantial new literatures on PRMT5 and its functions, in order to highlight the significance of understanding this essential enzyme in lung cancer tumorigenesis and progression.

Note: Possibilities of detecting the trace-level erosion products from an electric propulsion hollow cathode plasma source by the method of time-of-flight mass spectrometry.

A hollow cathode produces electrons which neutralize ions from electric propulsion thrusters. After hundreds to thousands of hours of operation in space, the cathode materials can be significantly eroded due to ion bombardment. As a result, the electric propulsion system performance will be obviously changed or even fail. In this work, the erosion products from a LaB6 hollow cathode (widely used presently in electric propulsion systems) are studied by using a specific detection system, which consists of a molecular beam sampler and a time-of-flight mass spectrometer. This system measures trace-level-concentration (10-6-10-3) products. Boron (B), tantalum (Ta), and tungsten (W)-originating from the emitter, keeper, and orifice of the hollow cathode-are measured. It is found that the erosion rate is significantly influenced by the gas flow rate to the cathode.

A cryptic polyene biosynthetic gene cluster in Streptomyces calvus is expressed upon complementation with a functional bldA gene.

Streptomyces calvus is best known as the producer of the fluorinated natural product nucleocidin. This strain of Streptomycetes is also unusual for displaying a "bald" phenotype that is deficient in the formation of aerial mycelium and spores. Genome sequencing of this organism revealed a point mutation in the bldA gene that is predicted to encode a misfolded Leu-tRNA(UUA) molecule. Complementation of S. calvus with a correct copy of bldA restored sporulation and additionally promoted production of a polyeneoic acid amide, 4-Z-annimycin, and a minor amount of the isomer, 4-E-annimycin. Bioassays reveal that these compounds inhibit morphological differentiation in other Actinobacteria. The annimycin gene cluster encoding a type 1 polyketide synthase was identified and verified through disruption studies. This study underscores the importance of the bldA gene in regulating the expression of cryptic biosynthetic genes.

Chromatic-free spatially resolved optical emission spectroscopy diagnostics for microplasma.

A chromatic-free spatially resolved diagnostic system for microplasma measurement is proposed and demonstrated, which consists of an optical chromatic-free microscope mirror system, an electron multiplying charge coupled device (EMCCD), and bandpass filters. The diagnostic system free of chromatic aberrations with a spatial resolution of about 6 microm is achieved. The factors that limit the resolution of this diagnostic system have been analyzed, which are optical diffraction, the pixel size of the EMCCD, and the thickness of the microplasma. In this paper, the optimal condition for achieving a maximum resolution power has been analyzed. With this diagnostic system, we revealed the spatial nonuniformity of a microwave atmospheric-pressure argon microplasma. Furthermore, the spatial distribution of the time-averaged effective electron temperature has been estimated from the intensity distributions of 750.4 and 415.8 nm emissions.