Effect of Reactive Oxygen Scavenger N,N'-Dimethylthiourea (DMTU) on Seed Germination and Radicle Elongation of Maize.

Reactive oxygen species (ROS) are an important part of adaptation to biotic and abiotic stresses and regulate seed germination through positive or negative signaling. Seed adaptation to abiotic stress may be mediated by hydrogen peroxide (H2O2). The effects of the ROS scavenger N,N'-dimethylthiourea (DMTU) on maize seed germination through endogenous H2O2 regulation is unclear. In this study, we investigated the effects of different doses of DMTU on seed endogenous H2O2 and radicle development parameters using two maize varieties (ZD958 and DMY1). The inhibitory effect of DMTU on the germination rate and radicle growth was dose-dependent. The inhibitory effect of DMTU on radicle growth ceased after transferring maize seeds from DMTU to a water medium. Histochemical analyses showed that DMTU eliminated stable H2O2 accumulation in the radicle sheaths and radicles. The activity of antioxidant enzyme and the expression of antioxidant enzyme-related genes (ZmAPX2 and ZmCAT2) were reduced in maize seeds cultured with DMTU compared with normal culture conditions (0 mmol·dm-3 DMTU). We suggest the use of 200 mmol·dm-3 DMTU as an H2O2 scavenger to study the ROS equilibrium mechanisms during the germination of maize seeds, assisting in the future with the efficient development of plant growth regulators to enhance the seed germination performance of test maize varieties under abiotic stress.

Clinicopathological significance of ribosomal protein S6 kinase A6 in lung squamous cell carcinoma: an immunohistochemical and RNA-seq study.

Ribosomal protein S6 kinase A6 (RPS6KA6) is a downstream factor of the ERK-MAPK pathway and has been extensively studied in various types of cancer. However, the role of RPS6KA6 in lung squamous cell carcinoma (LUSC) remains unclear. This study investigated expression of the RPS6KA6 and its clinicopathological correlation with LUSC and explored genetic alterations in the ribosomal protein S6 kinase (RSK) family in LUSC and their impact on the survival of patients. Expression of the RPS6KA6 protein in 175 LUSC samples and 30 normal lung tissues samples was determined by immunohistochemistry (IHC). RPS6KA6 protein expression in the LUSC tissues was significantly higher compared with that in the normal lung tissues (P=0.017). Overexpression of RPS6KA6 protein correlated with tumor size (r=0.260, P=0.001), lymph node metastasis (r=0.683, P<0.001), and TNM stage (r=0.378, P<0.001). RPS6KA6 RNA-seq data were obtained from the Cancer Genome Atlas (TCGA) and ONCOMINE database. RPS6KA6 mRNA expression in the LUSC tissues was significantly higher than that in paired noncancerous samples (TCGA: P=0.005; ONCOMINE: P=0.018). According to the cBioPortal online software, three detecting methods, including Seqv2, Array and U133, identified that the frequency of the genetic alterations in the RSKs in LUSC were 77%, 44%, and 42%, respectively. However, survival analysis of LUSC patients with or without RSKs genetic alterations reached no statistical significance. This study suggests that RPS6KA6 may be an oncogene in LUSC, and that expression of the RPS6KA6 protein is associated with the progression of LUSC. The RSK genes are frequently altered in LUSC, but the alterations have no significant effect on the survival of patients.

A case of immunoglobulin G4-related constrictive pericarditis.

A 47-year-old man was admitted with a complaint of upper abdominal distension and shortness of breath. The constrictive pericarditis was diagnosed based on the transthoracic echocardiogram (TTE) and chest CT scan. Pathology revealed it is immunoglobulin (Ig) G4-related constrictive pericarditis. Likely, this is the first case of IgG4-related constrictive pericarditis reported in China.