In this study, we aimed at investigating the role of isoleucyl-tRNA synthetase in the growth, migration, and angiogenesis of human umbilical vein endothelial cells and the underlying molecular mechanism.To assess the role of isoleucyl-tRNA synthetase, we silenced isoleucyl-tRNA synthetase in human umbilical vein endothelial cells using lentiviral 2 specific short hairpin RNAs (short hairpin RNAs 1 and 2) and examined silencing efficiency using real time quantitative polymerase chain reaction and western blot analyses. Short hairpin RNAs 1-isoleucyl-tRNA synthetase had greater knockdown efficiency, it was used in the entire downstream analysis. Short hairpin RNAs 1- isoleucyl-tRNA synthetase silencing effects on cell proliferation, cell colony generation, cell migration, as well as angiogenesis were assessed using cell counting kit-8, colony development, cell migration, and angiogenesis tube formation assays, respectively.Compared to the control group, anti-isoleucyl-tRNA synthetase short hairpin RNAs significantly silenced isoleucyl-tRNA synthetase expression in human umbilical vein endothelial cells, and suppressed their proliferation, migration, and angiogenic capacity. To characterize the underlying mechanism, western blot analyses showed that isoleucyl-tRNA synthetase knockdown suppressed phosphorylation of extracellular-regulated kinase ½ and protein-serine- threonine kinase, as well as expression of vascular endothelial growth factor, GSK-3β, and β-catenin.We have shown, for the first time, the critical role of isoleucyl-tRNA synthetase in human umbilical vein endothelial cells. Our data show that isoleucyl-tRNA synthetase knockdown suppresses human umbilical vein endothelial cell proliferation, migration, and angiogenesis. We have also shown that isoleucyl-tRNA synthetase knockdown suppresses phosphorylation of extracellular-regulated kinase ½ and protein-serine- threonine kinase, as well as expression of vascular endothelial growth factor, GSK-3β, and β-catenin. Together, these data highlight isoleucyl-tRNA synthetase as a potential antitumor anti-angiogenic target.
In order to improve the anti-cancer therapy efficiency of hydrophobic drugs such as curcumin (Cur), a novel dual pH/redox sensitive marine laminarin-based nanomedicine carrier biomaterial with photo-dynamic therapy (PDT) was synthesized in this study. The new synthetic chemical structure, named as Hematin-Laminarin-Dithiodipropionic Acid-MGK (HLDM), was characterized by 1H-NMR and IR. The Cur-loaded micelles were then prepared via dialysis method. The HLDM could self-assemble into micelles in water with hydrodynamic diameter of 135±15 nm. The particle size, zeta potential and morphology of micelles were detected by transmission electron microscope (TEM). Interestingly, the in vitro release experiment showed that the release amount of Cur-loaded HLDM micelles could reach 80% in the pH and redox sensitive environment. Furthermore, cell study showed that the Cur-loaded HLDM micelles had stronger cellular uptake and cytotoxicity to MCF-7 cells than that of HLDM. The multifunctional marine laminarin based nanomedicine carrier biomaterial can be used for new drug delivery systems with dual pH/redox sensitivity for cancer therapy.
The many circadian clock genes buildup a network structure that controls physiological processes such as sleep cycle, metabolism and hormone secretion. A close relationship exists between circadian rhythm and cancers because cell cycle is affected by clock controlled genes (CCGs), including Cyclin D1, Cyclin A, Cyclin E and P21. The abnormal expression of the core circadian clock gene Cryptochrome 1 (Cry1) was found in many types of cancers. However, it is still unclear the exact mechanism of Cry1 dysregulation influences carcinogenesis and progression of cancers. In this study, we investigated the role of Cry1 in regulating proliferation and migration of Hos and U2os human osteosarcoma cells by silencing Cry1 using short hairpin RNA interference. Our data from in vitro and in vivo experiments confirmed that Cry1 knockdown enhanced proliferation and migration of osteosarcoma cells. Then, Cry2, Per1, Per2, Per3, Bmal1 and Clock were found up regulated, while Dec1, Dec2, CK1ε and Npas2 were downregulated at mRNA level. Besides, Akt/P53/P21 signaling was activated after Cry1 silencing and Akt was negatively phosphorylated along with Cry1 expression, while enhanced progression of osteosarcoma cells by Cry1 knockdown was reversed when Akt inhibitor treated. Furthermore, the rescue experiment verified the Akt/P53/P21 was downstream genes of Cry1 to control osteosarcoma progression. Taken together, these findings provide a new insight into how Cry1 regulates clock gene network and promotes proliferation and migration in a Akt dependent manner in human osteosarcoma cells.
In bone tissue engineering, the use of osteoblastic seed cells has been widely adopted to mediate the osteogenic differentiation so as to prompt bone regeneration and repair. It is hypothesized that Dok5 can regulate the proliferation and differentiation of osteoblasts. In this study, the role of Dok5 in osteoblast proliferation and differentiation was investigated.A lentiviral vector to silence Dok5 was transferred to C3H10, 293T and C2C12 cells. CCK-8 assay was used to detect the cell proliferation. Cells were stained by ALP and AR-S staining. Western blot and RT-PCR were used to detect the expression levels of related factors.Dok5 expression level was gradually up-regulated during the osteoblast differentiation. Dok5 silencing down-regulated the expression levels of osteogenic biosignatures OPN, OCN, and Runx2 and suppressed the osteogenesis. Additionally, the osteoblast proliferation and canonical Wnt/β-catenin signaling were suppressed upon Dok5 knockdown, β-catenin expression level was significantly down-regulated in the knockdown group, while the expression levels of GSK3-β and Axin, negative regulators in the Wnt signaling pathway, were up-regulated. Furthermore, overexpression of Dok5 promoted the proliferation and osteogenesis and activated the canonical Wnt/β-catenin signaling pathway.Dok5 may regulate the osteogenic proliferation and differentiation via the canonical Wnt/β-catenin signaling pathway.
The dysfunction of osteogenesis is a key character in the pathogenesis of osteoporosis, but the network of signaling mechanisms in controlling the differentiation of osteoblast remain unclear. Thrap3 has been proved participating in various biological process, especially in the differentiation of stem cells. Here, we demonstrate that Thrap3 could promote osteogenesis through the inhibition of the degradation of Runx2, which is a key molecular structure in early osteoblast differentiation. Furthermore, we found that the osteogenesis enhancing capacity of Thrap3 was caused by physically binding with Sox9, inhibiting the transcriptional activity of Sox9, and then decreasing the decomposition-promoted effect of Sox9 on Runx2. Our data shows that Thrap3 promotes osteoblast differentiation through the Thrap3-Sox9-Runx2 axis. What we found may help for further clarifying the molecular mechanism of osteogenic differentiation and give a new potential therapeutic target for osteoporosis.
Normal ratio of type I collagen α1 to α2 (2:1) maintains normal bone microarchitecture. Altered ratios lead to formation of collagen homotrimers and deteriorated bone microarchitecture. In this study, we aimed to investigate the role of lncRNA AWPPH in osteoporosis. We observed that the expression of lncRNA AWPPH was downregulated in osteoporosis patients than that in healthy controls. Downregulated expression of lncRNA AWPPH distinguished osteoporosis patients from healthy controls. In vitro cell experiments showed that knockdown of lncRNA AWPPH led to upregulated α1 but downregulated expression of α2 in osteoblasts, which made the α1 to α2 ratio higher than 2:1. In contrast, overexpression of lncRNA AWPPH led to downregulated α1 but upregulated α2 in osteoblasts, which made the α1 to α2 ratio lower than 2:1. Therefore, lncRNA AWPPH is downregulated in osteoporosis and altered the expression of lncRNA AWPPH regulates type I collagen α1 and α2 ratio in osteoblasts.
Objective
Aim at investigating the function and mechanism of cryptochrome gene 1 in human osteosarcoma.
Methods
The lentivirus vector with short hairpin RNA (shRNA) targeting CRY1 was transfected into human osteosarcoma cells (HOS). The knockdown of CRY1 in HOS was confirmed by Western blotting; the proliferation of HOS cells was detected by cell counting kit-8 (CCK-8) assay; the downstream molecules was confirmed by Western blotting; the mRNA expression level of clock gene cryptochrome gene (CRY1, CRY2), period gene (PER1, PER2), BMAL1, CLOCK was tested by quantitative real-time polymerase chain reaction (RT-qPCR).
Results
After the knockdown of CRY1, the proliferation of HOS was enhanced (0.839±0.020 vs. 0.553±0.019, P<0.01) and the canonical Wnt signaling was found activated (0.729±0.067 vs. 1.119±0.018, P<0.01), as well as the mRNA levels of all clock network key genes but CRY1 were increased. What’s more, proliferation of HOS cell was inhibited in rescue experiment (1.012±0.151 vs. 1.483±0.095 vs. 0.541±0.129, P<0.01).
Conclusion
CRY1 controls proliferation of human osteosarcoma cells via Wnt signaling pathway and regulates the expression levels of other clock network key genes, including CRY2, PER1, PER2, BMAL1 and CLOCK, which indicates that CRY1 plays an important role in human osteosarcoma progression.
Key words:
Cryptochrome gene 1; Wnt signaling pathway; Clock gene networks; Osteosarcoma
To remedy the problems resulting from the usage of anti-cancer drugs in cancer chemotherapy, such as deficient drug concentration in tumour cells, low water-solubility and non-specific distribution of antitumour drugs, a kind of reduction-sensitive polymer prodrug of curcumin (Cur) containing in the nano-echinus was synthesized and designed. The nano-echinus-like nanomedicine presented synergistic effect with glycyrrhetic acid (GA) and oligomeric hyaluronic (HA) for targeting and combating HepG2 human liver cancer cell. Firstly, a kind of small molecular prodrug of Cur, dithiodipropionic acid-Cur (-SS-Cur), was chemically conjugated onto the side chain of the conjugated glycyrrhetic acid- oligomeric hyaluronic (GA-HA) to generate an amphiphilic polymeric prodrug of Cur, GA-HA-SS-Cur. The obtained GA-HA-SS-Cur prodrug and subsidiary material mPEG-DSPE could self-assemble into a sea urchin-like micelles in aqueous media and release Cur rapidly in response to glutathion (GSH). Then, Cur was loaded into the nano-echinus with a particle size of (118.1 ± 0.2 nm) and drug-loading efficiency of (8.03 ± 2.1%). The structure of GA-HA-SS-Cur was characterized by 1H-NMR in this report. The morphology of micelles was observed with a transmission electron microscope (TEM). Subsequently, the reduction-sensitivity of the nano-echinus was confirmed by the changes in in-vitro drug release after different concentrations of GSH treatment. Besides, the cellular uptake behaviour and MTT assays of the nano-echinus were investigated, suggesting that the nano-echinus was of desirable safety and could be taken into HepG2 cells in a time-dependent manner. Later, anti-tumour efficacy in vivo revealed the effective inhibition of tumour growth.
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