Intermedin promotes hepatocellular carcinoma cell proliferation through the classical Wnt signaling pathway

Intermedin (adrenomedullin 2) promotes breast cancer metastasis via Src/c-Myc-mediated ribosome production and protein translation

PURPOSE

Breast cancer is the most frequently diagnosed cancer and is the leading cause of cancer-associated mortality in women worldwide. Intermedin (IMD, also known as Adrenomedullin 2, ADM2) is an endogenous peptide that belongs to the calcitonin gene-related peptide family and has been reported to play important roles in several types of cancers, including breast cancer. In this study, we sought to investigate how IMD affects the behavior of breast cancer cells, the underlying mechanism of these effects, and whether blockade of IMD has a therapeutic effect against breast cancer.

METHODS

Transcriptome sequencing (RNA-Seq), cell biological experiments, Western blotting, immunoprecipitation, and animal tumor models were used.

RESULTS

IMD expression was significantly increased in breast cancer samples, and the IMD level was positively correlated with lymph node metastasis and Ki67 expression. Cell biological experiments showed that IMD promoted the anchorage-independent growth, migration, and invasive ability of breast cancer cells. Inhibiting IMD activity with an anti-IMD monoclonal antibody blocked these tumor-promoting effects. In addition, blockade of IMD reduced in situ tumor growth and significantly decreased lung metastasis of 4T1 breast cancer in vivo. IMD induced Src kinase phosphorylation, which triggered the transcription of c-Myc, a major oncoprotein controlling the expression of genes that encode ribosomal components. Our data suggest that IMD is involved in breast cancer cell invasion and metastasis, potentially through increasing ribosome biogenesis and protein translation via the Src/c-Myc signaling pathway.

CONCLUSION

These results suggest that IMD may be a novel target for the treatment of breast cancer.

Study on Protection of Human Umbilical Vein Endothelial Cells from Amiodarone-Induced Damage by Intermedin through Activation of Wnt/β-Catenin Signaling Pathway

Amiodarone (AM) is one of the most effective antiarrhythmic drugs and normally administrated by intravenous infusion which is liable to cause serious phlebitis. The therapeutic drugs for preventing this complication are limited. Intermedin (IMD), a member of calcitonin family, has a broad spectrum of biological effects including anti-inflammatory effects, antioxidant activities, and antiapoptosis. But now, the protective effects of IMD against amiodarone-induced phlebitis and the underlying molecular mechanism are not well understood. In this study, the aim was to investigate the protective efficiency and potential mechanisms of IMD in amiodarone-induced phlebitis. The results of this study revealed that treatment with IMD obviously attenuated apoptosis and exfoliation of vascular endothelial cells and infiltration of inflammatory cells in the rabbit model of phlebitis induced by intravenous infusion of amiodarone compared with control. Further tests in vitro demonstrated that IMD lessened amiodarone-induced endothelial cell apoptosis, improved amiodarone-induced oxidative stress injury, reduced inflammatory reaction, and activated the Wnt/β-catenin signal pathway which was inhibited by amiodarone. And these effects could be reversed by Wnt/β-catenin inhibitor IWR-1-endo, and si-RNA knocked down the gene of Wnt pathway. These results suggested that IMD exerted the protective effects against amiodarone-induced endothelial injury via activating the Wnt/β-catenin pathway. Thus, IMD could be used as a potential agent for the treatment of phlebitis.

Screening and analysis of differentially expressed genes of human melanocytes in skin cells mixed culture

BACKGROUND

This study aims to screen the key genes and possible signaling pathways involved in the differentiation and proliferation of human melanocytes (MCs) by in vitro culture of mixed skin cells. This will be helpful to further study the mechanisms and treatment strategies of pigment-related diseases such as vitiligo.

METHODS

Mixed skin cells were obtained by digesting and separating normal human foreskin tissues. Ribonucleic acid (RNA) was extracted from sorting cells and high-throughput transcriptome sequencing was performed at different culture time points. Differentially expressed genes (DEGs) were obtained by comparing the expression abundance of genes at different culture time points. Then the key genes and signaling pathways involved in the differentiation and proliferation of MCs were screened and verified by real-time quantitative polymerase chain reaction (qPCR) test.

RESULTS

Twenty one DEGs were finally screened for further qPCR validation, mainly involved in 4 signaling pathways. The expressions of Wnt5A, Wnt5B, FZD2 and FZD3 in Wnt pathway were continuously up-regulated, and that of Wnt4 gene was continuously down-regulated, however, all the above hadn't been verified by qPCR. The expressions of COL5A2, COL6A3, ITGB1, ITGA4, ITGAV, AKT3, PIK3CD, PIK3R1 and PIK3R2 in phosphoinositide 3-kinase (PI3K) pathway were continuously up-regulated, of which PIK3CD, PIK3R2, COL5A2, ITGA4, ITGAV and AKT3 were verified by qPCR. PDGFB and GRB2 gene expressions were down-regulated in platelet-derived growth factor (PDGF) pathway, while PDGFRB was continuously up-regulated, of which PDGFB and PDGFRB were verified. The DHRS3, DHRS9, RDH10 and SDR16C5 genes in retinol metabolic pathway were continuously down-regulated and verified by qPCR.

CONCLUSION

We suggested that Wnt5A gene in Wnt/β-catenin classical pathway, integrin combining with extracellular matrix through PI3K signaling pathway, retinoic acid catabolism-related genes could promote the differentiation and proliferation of MCs; however, PDGFB gene might have a negative regulatory effect on the growth of MCs.