The long non-coding RNA H19 induces hypoxia/reoxygenation injury by up-regulating autophagy in the hepatoma carcinoma cells

BACKGROUND: Long non-coding RNA H19 (H19) plays an important role by regulating protein expression in different tissues and organs of the body. However, whether H19 induces hypoxia/reoxygenation (h/R) injury via increase of autophagy in the hepatoma carcinoma cells is unknown. RESULTS: H19 was expressed in the hepatoma carcinoma cells (Hep G2 and HCCLM3 cells) and its expression was most in 8 h/24R. The knockdown of H19 and 3-MA (an autophagy inhibitor) protected against h/R-induced apoptosis, cell damage, the expression of cleaved caspase-3 and cleaved caspase-9, the release of cytochrome c (Cyt c). The knockdown of H19 and 3-MA also decreased the autophagic vesicles (AVs) and the expression of Beclin-1 and the ration of LC3-II/LC3-I, and increased cell viability, the expression of Bcl-2 and P62 and the phosphorylation of PI3K, Akt and mTOR. In addition, chloroquine (CQ, an inhibitor of autophagy flux) markedly decreased formation of autophagy flux (the ration of LC3-II/LC3-I). The results of the knockdown of H19 group were similar to those of the 3-MA (or CQ) group. Rapamycin (a mTOR inhibitor, an autophagy activator) further down-regulated h/R-induced decrease of the phosphorylated PI3K, Akt and mTOR. The knockdown of H19 cancelled the effect of rapamycin. The overexpression of H19 further expanded h/R-induced increase of the ration of LC3-II/LC3-I and decrease of the phosphorylated PI3K, Akt and mTOR. CONCLUSIONS: Our results suggest that the long non-coding RNA H19 induces h/R injury by up-regulation of autophagy via activation of PI3K-Akt-mTOR pathway in the hepatoma carcinoma cells.

A new mitochondria-targeted platinum complex Mor-platin inhibits HepG2 cell prolif-eration and cell invasion / 中国肿瘤临床

Objective:To investigate the effects of Mor-platin, a novel mitochondrial platinum complex, on proliferation and migration of human hepatoma carcinoma HepG2 cells. Methods:Cell counting kit-8 (CCK-8) assay was used to analyze cell proliferation of Mor-platin and classic anticancer drugs, particularly cisplatin, in HepG2 cells. A laser confocal microscope was used to observe whether Mor-platin can target mitochondria. The morphological changes in cellular mitochondria after treatment with Mor-platin were ob-served on a transmission electron microscope. Cell apoptosis was measured by flow cytometry, and cell invasion was evaluated by three-dimensional tumor spheroid model. Results:Mor-platin can inhibit cell proliferation and is dose dependent. The half inhibitory concentration (IC50) of Mor-platin is lower than that of cisplatin. Laser confocal images showed that Mor-platin can target cell mito-chondria and enrich cell mitochondria. Transmission electron microscopy images showed that cell mitochondrial morphology changed after Mor-platin treatment. Furthermore, cell mitochondrial membrane is incomplete and mitochondrial cristae are reduced. Cell apoptosis caused by Mor-platin is dose dependent. The three-dimensional tumor spheroid model showed that the cell areas of the group subjected to Mor-platin treatment are smaller than those of the control group. Conclusion:Mor-platin can target cell mitochon-dria, change the cell mitochondrial morphology, inhibit cell proliferation, and thus promote cell apoptosis. It also showed better anti-cancer effects than cisplatin. Furthermore, Mor-platin can inhibit three-dimensional tumor spheroid invasion. These results suggest that Mor-platin is a potential antitumor drug.

Effects of substrate stiffness on confluent growth of hepatic and hepatoma carcinoma cells / 医用生物力学

Objective To investigate the cause of differences in confluent growth between hepatic(L02) and hepatoma carcinoma(HCCLM3) cells by comparing responses of the two cells to different substrate stiffness (0.5, 4 kPa and glass). MethodsThe real-time photomicrography, immunofluorescence staining, flow cytometry, and Western Blotting techniques were respectively employed to observe the morphological characteristics, the cytoskeleton conformation and the distribution of E-cad of confluent L02 and HCCLM3 cells on different substrates, and test the changes in expression of E-cad, Integrinβ1 and p-Src. Results (1) Confluent L02 cells displayed a round or cubic shape, while HCCLM3 cells showed a polygon shape. The morphology of HCCLM3 cells were spread and polarized more obviously than that of L02 cells. With the increase of substrate stiffness, the variation of L02 cells with time was smaller than that of HCCLM3 cells. (2) The cytoskeleton of confluent L02 cells showed a ring-like conformation under the cortex, and E-cad was located at the cell-cell contact sites. However, the ring-like cytoskeleton of HCCLM3 cells was incomplete and distributed radially along the basement, while E-cad was dispersed in cytoplasm. (3) As the substrate stiffness increased, expression of E-cadherin in both L02 and HCCLM3 cells was significantly decreased (P<0.01), while the level of p-Src and integrinβ1 was increased significantly, with greater changes in HCCLM3 cells than in L02 cells. Conclusions The assembling of cortical ring-like cytoskeleton was positively correlated with the location of E-cad at the cell-cell contact sites. The substrate stiffness showed a more obvious impact on the balanced regulation between cadherin and integrin mediated adhesion system of hepatocarcinoma cells than that of hepatic cells.

Effects of substrate stiffness on the migration of hepatic and hepatoma carcinoma cells / 医用生物力学

Objective To investigate the cause of tumor cell migration by comparing the effect of substrate stiffness on hepatic and hepatoma carcinoma cell migration so as to understand the invasive characteristics of tumor cells. Methods Immunofluorescence staining, morphological analysis and transwell were employed to observe the morphological characteristics of HCCLM3 and L02 cells on different substrates and test their migration characteristics with the quantitative analysis. Results (1) The migration rate and net translocation of HCCLM3 and L02 cells on 4 kPa substrate was higher than those both on 0.5 kPa(most soft one) and on glass (the hardest one) substrates, and L02 cells also displayed higher migration efficiency than HCCLM3 cells on such substrates. (2) The mean squared displacement of HCCLM3 and L02 cells on different substrates showed consistent tendency, and the directional persistence of L02 cells on the softer substrate was significantly higher than that of HCCLM3 cells. (3) In 0.5 and 1 mg/mL three dimensional collagen environment, the number of invasive cells of HCCLM3 was remarkably more than that of L02 cells. After adding MMPs inhibitor GM6001 (40 μg/mL), the number of invasive cells was notably increased in HCCLM3 cells, but notably decreased in L02 cells. Conclusions (1) In two dimensional comparatively soft environment, L02 cells displayed an efficient migration due to its higher directional persistence. (2) In three-dimensional collagen environment, the invasion efficiency of HCCLM3 cells was significantly higher due to the various modes of migration adaptation to the microenvironment.