Spermidine attenuates monocrotaline-induced pulmonary arterial hypertension in rats by inhibiting purine metabolism and polyamine synthesis-associated vascular remodeling.

Ensuring the homeostatic integrity of pulmonary artery endothelial cells (PAECs) is essential for combatting pulmonary arterial hypertension (PAH), as it equips the cells to withstand microenvironmental challenges. Spermidine (SPD), a potent facilitator of autophagy, has been identified as a significant contributor to PAECs function and survival. Despite SPD's observed benefits, a comprehensive understanding of its protective mechanisms has remained elusive. Through an integrated approach combining metabolomics and molecular biology, this study uncovers the molecular pathways employed by SPD in mitigating PAH induced by monocrotaline (MCT) in a Sprague-Dawley rat model. The study demonstrates that SPD administration (5 mg/kg/day) significantly corrects right ventricular impairment and pathological changes in pulmonary tissues following MCT exposure (60 mg/kg). Metabolomic profiling identified a purine metabolism disorder in MCT-treated rats, which SPD effectively normalized, conferring a protective effect against PAH progression. Subsequent in vitro analysis showed that SPD (0.8 mM) reduces oxidative stress and apoptosis in PAECs challenged with Dehydromonocrotaline (MCTP, 50 µM), likely by downregulating purine nucleoside phosphorylase (PNP) and modulating polyamine biosynthesis through alterations in S-adenosylmethionine decarboxylase (AMD1) expression and the subsequent production of decarboxylated S-adenosylmethionine (dcSAM). These findings advocate SPD's dual inhibitory effect on PNP and AMD1 as a novel strategy to conserve cellular ATP and alleviate oxidative injuries, thus providing a foundation for SPD's potential therapeutic application in PAH treatment.

The potential clinical applications and prospects of microRNAs in lung cancer.

Lung cancer is the major cause of cancer deaths worldwide due to its late diagnosis and poor outcome. Understanding genomic medicine may widen our vision into the oncogenesis of lung cancer and may open the door to improvements in the clinical management of lung cancer. It is well known that almost half of all genes are regulated by microRNAs (miRNAs). This review focuses on the role of miRNAs in lung cancer and also touches on the value of miRNA-based novel therapies for lung cancers.

[Concurrent chemoradiotherapy followed by consolidation chemotherapy and sequential chemoradiotherapy for stage III non-small cell lung cancer: comparison in 93 patients].

OBJECTIVE: To compare the efficacy and toxicity of concurrent chemoradiotherapy followed by consolidation chemotherapy (CCRT-CT) and sequential chemoradiotherapy (SCRT) in the treatment of stage III non-small cell lung cancer. METHODS: From February, 2007 to June, 2010, 93 patients with unresectable stage III non-small cell lung cancer were treated with SCRT or CCRT-CT. SCRT group (50 cases) received radiotherapy after 2-6 cycles of chemotherapy (median 2 cycles) followed by 0-4 cycles (median 2 cycles) of chemotherapy. CCRT-CT group (43 cases) received 2 cycles of chemotherapy every 3 weeks with concurrent radiotherapy followed by 2-4 cycles (median 2 cycles) of chemotherapy with the same drugs. The chemotherapy consisted of cisplatin plus gemcitabine, docetaxel or vinorelbine. Radiotherapy was administered using two-dimensional conformal irradiation (36-40 Gy/18-20f) followed by three-dimensional conformal boost to 56-70 Gy/28-35f (median DT64Gy) or using three-dimensional conformal irradiation 50-74 Gy/25-37f (median DT62Gy). RESULTS: The response rates were 76.7% and 54.0% in CCRT-CT and SCRT group, respectively (P<0.05). The median progression-free time in the two groups was 16.0 and 10.0 months, with the overall survival time of 18.0 and 12.5 months, respectively. The 1-, 2- and 3-year overall survival rates were 83.7%, 48.8% and 20.9% in CCRT-CT group and 52.0%, 20.0%, and 2.0% in SCRT group, respectively (P<0.05). CCRT-CT group showed a significantly lower rate of distant metastasis than SCRT group (P<0.05), but the local recurrence rate was similar between the two groups. The main side effects included radiation pneumonitis, radiation esophagitis, nausea/vomiting and anemia/leucopenia/thrombocytopenia. CCRT-CT group had a significantly higher rate of III-IV grade nausea/vomiting and anemia/leucopenia/thrombocytopenia than SCRT group. CONCLUSION: Compared to SCRT, CCRT-CT can improve the response rate, progression free survival and overall survival and decrease the rate of distant metastasis, but is associated with a higher toxicity.