Zinc finger protein 36 (ZFP36) was found to be downregulated in osteosarcoma (OS) tumor tissues. We aimed to investigate the roles and mechanisms of ZFP36 in ferroptosis regulation during OS development. Two Gene Expression Omnibus (GEO) datasets showed that ZFP36 was a differentially expressed gene (DEG) in OS. Western blot and immunohistochemistry results showed that ZFP36 was downregulated in OS tumors and cell lines. ZFP36 overexpression plasmids and small interfering RNAs (siRNAs) were respectively transfected into OS cells. ZFP36 overexpression restrained proliferation, migration, and invasion in MG63 and U2OS cells, while ZFP36 knockdown displayed the opposite results. Moreover, ZFP36 overexpression increased the levels of intracellular Fe²⁺, reactive oxygen species (ROS), and malondialdehyde (MDA), and decreased the levels of glutathione (GSH), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11). ZFP36 overexpression disturbed mitochondrial membrane potential (MMP) and mitochondrial morphology in OS cells. However, ZFP36 knockdown had the opposite results. Mechanistic studies indicated that ZFP36 promoted E2F transcription factor 1 (E2F1) messenger RNA (mRNA) degradation by binding to the AU-rich elements (AREs) within E2F1 3' untranslated region (3'UTR) in OS cells. E2F1 overexpression abrogated the effects of ZFP36 overexpression on malignant progression, ferroptosis, and mitochondrial dysfunction in OS cells. Furthermore, E2F1 promoted the transcription activation of activating transcription factor 4 (ATF4) by binding to ATF4 promoter. E2F1 knockdown inhibited malignant progression, and promoted ferroptosis and mitochondrial dysfunction in OS cells, which was abrogated by ATF4 overexpression. Additionally, MG63 cells transfected with lentivirus ZFP36 overexpression vector (Lv-ZFP36) were injected into nude mice and tumor growth was monitored. ZFP36 overexpression significantly suppressed OS tumor growth under in vivo settings. In conclusion, ZFP36 overexpression promoted ferroptosis and mitochondrial dysfunction and inhibited malignant progression in OS by regulating the E2F1/ATF4 axis. We may provide the promising ZFP36 target for OS treatment.

Objective:To investigate the protective mechanism of TRPV4 channel inhibitor on blood-brain barrier(BBB)damage after traumatic brain injury(TBI).Methods:The TBI rat model was established.TRPV4 channel inhibitor HC067047 or PKC-δ inhibitor Rottlerin was used to detect changes in BBB permeability,neurological function score,and the expression of microvascular endothelial tight junction proteins ZO-1 and ZO-2 in brain injury areas after TBI.Results:Compared with the Sham group,BBB permeability significantly increased,brain neurological function score significantly decreased,and the expression of ZO-1 and ZO-2 significantly decreased in TBI group(P＜0.05).Compared with the TBI group,after administration of HC067047 or Rottlerin,changes in BBB permeability,brain neurological function score,the expression of ZO-1 and ZO-2 were partially reversed(P＜0.05).Conclusions:TBI-induced BBB injury may be mediated by TRPV4 channel regulating PKC-δ signaling pathway to affect the expression of tight junction proteins ZO-1 and ZO-2.Inhibition of TRPV4 channel function or PKC-δ signal molecule can partially alleviate BBB damage induced by TBI.This study may provide new ideas for the treatment of clinical TBI.

Objective In view of the controversy over radiotherapy target volume for patients with limited-stage small cell lung cancer ( SCLC), a prospective randomized controlled trial was conducted to compare the impact of different radiotherapy target volumes on prognosis. Methods After 2 cycles of EP chemotherapy,patients without progressive disease were randomly assigned to receive thoracic radiotherapy (TRT) to either the post-or pre-chemotherapy primary tumour extent as study arm or control. Involved field radiotherapy (IFRT) to the entire metastatic lymph node regions was applied for both arms. TRT consisted of 45 Gy/30Fx/19 d administered concurrently with cycle 3 chemotherapy. Prophylactic cranial irradiation was administered to patients achieved complete or partial remission. Kaplan-Meier method was used for survival analysis. Results Between June 2002 and December 2017,159 and 150 patients were randomly assigned to study arm and control respectively. The 1-,2-,and 5-year local/regional control rates were 79. 4%,61. 5% and 60. 1% respectively in the study arm versus 79. 8%,66. 5%,and 57. 3% in the control arm (P=0. 73). The median OS time was 22. 1 months in the study arm (95%CI,18. 2-26. 0 months) and 26. 9 months (95%CI,23. 5-30. 3 months) in the control arm,the 1-,3-,5-,and 7-year OS rates were 81. 1%,31. 6%, 23. 9% and 22. 2% respectively in the study arm versus 85. 3%,36. 6%,26. 1% and 20. 0% in the control arm (P=0. 51).Grade 2-3 acute esophagitis was developed in 32. 9% and 43. 2% of patients respectively in study arm and control arm (P=0. 01),while grade 2-3 pulmonary fibrosis was observed in 2. 0% and 10. 9% of patients ( P= 0. 01 ) respectively. Conclusions For patients with limited-stage SCLC who received induction chemotherapy,thoracic radiotherapy can be limited to post-chemotherapy tumour extent and IFRT can be routinely applied.