ABSTRACT
Platinum-based chemotherapy drugs play a very important role in the treatment of patients with advanced colorectal cancer, but the drug resistance of platinum-based chemotherapy drugs is an important topic that puzzles us. If we can find mechanisms of resistance, it will be revolutionary for us. We analysed the differential genes, core genes and their enrichment pathways in platinum-resistant and non-resistant patients through a public database. Platinum-resistant cell lines were cultured in vitro for in vitro colony and Transwell analysis. Tumorigenesis analysis of nude mice in vivo. Verify the function of core genes. Through differential gene and enrichment analysis, we found that CUL4B was the main factor affecting platinum drug resistance and EMT. Our hypothesis was further verified by in vitro drug-resistant and wild-type cell lines and in vivo tumorigenesis analysis of nude mice. CUL4B leads to platinum drug resistance in colorectal cancer by affecting tumour EMT.
Subject(s)
Colorectal Neoplasms , Drug Resistance, Neoplasm , Platinum Compounds , Animals , Mice , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Carcinogenesis , Cell Transformation, Neoplastic , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Drug Resistance/genetics , Drug Resistance, Neoplasm/genetics , Epithelial-Mesenchymal Transition/drug effects , Epithelial-Mesenchymal Transition/genetics , Mice, Nude , Platinum Compounds/pharmacology , Platinum Compounds/therapeutic useABSTRACT
Autophagy has been shown to maintain neural system homeostasis during stroke. However, the molecular mechanisms underlying neuronal autophagy in ischemic stroke remain poorly understood. This study aims to investigate the regulatory mechanisms of the pathway consisting of MEG3 (maternally expressed gene 3), microRNA-378 (miR-378), and GRB2 (growth factor receptor-bound protein 2) in neuronal autophagy and neurological functional impairment in ischemic stroke. A mouse model of the middle cerebral artery occluded-induced ischemic stroke and an in vitro model of oxygen-glucose deprivation-induced neuronal injury were developed. To understand the role of the MEG3/miR-378/GRB2 axis in the neuronal regulation, the expression of proteins associated with autophagy in neurons was measured by Western blotting analysis, and neuron death was evaluated using a lactate dehydrogenase leakage rate test. First, it was found that the GRB2 gene, up-regulated in middle cerebral artery occluded-operated mice and oxygen-glucose deprivation-exposed neurons, was a target gene of miR-378. Next, miR-378 inhibited neuronal loss and neurological functional impairment in mice, as well as neuronal autophagy and neuronal death by silencing of GRB2. Confirmatory in vitro experiments showed that MEG3 could specifically bind to miR-378 and subsequently up-regulate the expression of GRB2, which in turn suppressed the activation of Akt/mTOR pathway. Taken together, these findings suggested that miR-378 might protect against neuronal autophagy and neurological functional impairment and proposed that a MEG3/miR-378/GRB2 regulatory axis contributed to better understanding of the pathophysiology of ischemic stroke.
Subject(s)
Autophagy , Brain Ischemia/metabolism , GRB2 Adaptor Protein/metabolism , MicroRNAs/metabolism , Neurons/metabolism , RNA, Long Noncoding/metabolism , Signal Transduction , Stroke/metabolism , Animals , Brain Ischemia/genetics , Brain Ischemia/pathology , Disease Models, Animal , GRB2 Adaptor Protein/genetics , Humans , Mice , Mice, Mutant Strains , MicroRNAs/genetics , Neurons/pathology , RNA, Long Noncoding/genetics , Stroke/genetics , Stroke/pathologyABSTRACT
The insulin-like growth factor-1 receptor (IGF-1R) overexpression contributes to the development of a variety of cancers. The present study explored the role of IGF-1R in the development and progression of hepatocellular carcinoma (HCC) and the possibility of IGF-1R silencing by lentivirus-mediated RNA interference (RNAi) as a therapeutic target for HCC. We showed that IGF-1R mRNA was up-regulated in Huh7 and Hep3B cells and human HCC tissues, and that IGF-1R knockdown by RNAi led to decreased proliferation, apoptosis induction, and decreased migration and invasion of Huh7 and Hep3B cells. Further, the in vivo study indicated that IGF-1R knockdown markedly diminished the tumorigenesis and metastasis of Huh7 xenograft. Moreover, the intratumoral administration of lentivirus-IGF-1R siRNA led to significant tumor growth inhibition in an established Huh7 xenograft model. Mechanistic investigations showed that midkine was found to be the most significantly down-regulated protein in Huh7 cells with IGF-1R knockdown, and ectopic overexpression of midkine significantly rescued inhibition of Huh7 cell proliferation, migration, and invasion caused by IGF-1R suppression. Collectively, these data suggest that IGF-1R inhibition by RNAi can significantly suppress HCC growth and invasion at least partially through down-regulating midkine expression, and IGF-1R is a potential target for HCC gene therapy.
