Current Molecular Medicine - Volume 18, Issue 6, 2018

Hypoxia is a condition always present in tumor environment owing to the fast growth of tumor cells not supported by adequate blood supply. There is increasing evidence that hypoxia plays an important role in cancer dormancy and cancer metabolism, increasing stemness activity and bringing about cancer initiation and progression. This condition may influence the production of hypoxia inducible factor (HIF) a helix transcription factor which is involved in carcinogenesis and tumor growth through the regulation of genes involved in angiogenesis, glycolytic metabolism and other biological mechanisms. In normoxia condition HIF is inactivated by prolyl hydroxylase enzymes (EGLN 1–3, also known as PHD 1–3) using oxygen as a substrate. Once hydroxilated it binds to a protein called Von Hippel Lindau protein (VHL) for its degradation, whereas in hypoxia condition stabilization and nuclear translocation occur, leading to oncogenes activation. It has got three isoforms HIF-1 HIF-2 and HIF-3. The most studied factor is HIF-1 which is a heterodimer consisting of two forms, the form α is expressed in manner oxygen dependent, the form β is expressed constitutively. Its presence in tumor microenvironment could foster among other the expression of VEGF, HGF, Met protoncogene which induces degradation of the extracellular matrix and TWIST gene, which is in turn involved in a mechanism of cancer cell metastasis called epithelial-mesenchimal transition(EMT). In this review, we summarize the most important findings in HIF action in different types of cancer focusing on its properties to induce tumor cell growth and highlighting its poor prognostic value in different cancers sites.

Background: Animal models play critical roles in studies of the etiology and therapy of retinal degeneration (RD). Objective: To establish an RD model without severe systemic side effects in monkeys. Methods: Cynomolgus monkeys and Sprague-Dawley rats were treated with intravenous and intravitreal sodium iodate (SI). Electroretinographic (ERG) recording, fluorescein fundus angiography (FFA), optical coherence tomography (OCT) and a retinal morphology examination were conducted to evaluate retinal function and structure. ARPE-19 cells were treated with SI to assess cell viability and morphology. Glutathione (GSH) was administered to SI-treated cultured cells and rats for mechanistic studies. Results: Intravenous SI failed to induce RD in monkeys due to its lethal toxicity and the spontaneous recovery of visual function. However, intravitreal SI injection induced very rapid and severe retinal damage in both monkeys and rats. Different doses of SI were tested in both rats and monkeys, and the SI dose appropriate for the model was calculated. GSH partially rescued oxidative damage to SI-treated retinas. A combination of the appropriate dose of intravitreal SI and intravenous GSH generated moderate subacute RD. Conclusions: An RD model was established in cynomolgus monkeys by intravitreal SI injection. The key advantages of this model are that lethal SI side effects can be avoided and that the structural and functional changes are similar to those in patients with RD, although the development of RD in the model is too rapid and more severe. An appropriate dose of SI plus systemic GSH generates delayed and moderate RD; this prolonged therapeutic window allows the development of new therapies, such as gene or stem cell-based therapy, for RD.

Background: In our previous study, both allogeneic and xenogeneic smallincision femtosecond laser-assisted intrastromal keratoplasty were demonstrated to be safe and effective surgeries. Glycerol-dehydrated corneal lamellae could serve as alternative xenogeneic inlay grafts. However, these xenogeneic lamellae have not been explored in lamellar keratoplasty (LK). The immunoreactivity differences between corneal intrastromal xenotransplantation and xenogeneic LK have not been assessed. Methods: Rabbit lamellae were formed by femtosecond laser-assisted surgeries and dehydrated in glycerol for 1 week at 4°C. The lamellae were used in two surgical approaches in the small incision lenticule extraction (SMILE) group and the LK group. Postoperatively, slit-lamp examinations, corneal topography, anterior segment optical coherence tomography (AS-OCT), in vivo confocal microscopy and tear inflammatory mediator assays were performed. Results: Throughout the 12-month observation period, all rejection index ratings were higher in the LK group than in the SMILE group. No signs of graft rejection were observed in the SMILE group, but obvious neovascularization and corneal rejection occurred in the LK group. Corneal topography showed that the anterior curvatures at the central cornea and the mid-peripheral cornea were significantly increased in the SMILE group but decreased in the LK group. All the grafts from both groups were clearly visible on AS-OCT. In vivo confocal microscopy showed few dendritic cells in the subepithelial region in the SMILE group. Numerous dendritic cells and inflammatory cells were observed in the basal epithelium and stroma in the LK group. In the LK group, the levels of TGF-β1, CD40, ICAM-1, CD14 and IL-10 changed more than those in the SMILE group. The levels of VEGF were significantly elevated 1 month after surgery in the LK group. Conclusion: Small-incision femtosecond laser-assisted intrastromal keratoplasty minimized invasiveness and improved surgical efficiency. This small-incision intrastromal keratoplasty technique is superior to LK in terms of xenogeneic lamellae biocompatibility. Moreover, glycerol-dehydrated corneal lamellae might be a viable xenogenic corneal inlay graft.

It is now well established that protein sumoylation is an important mechanism to regulate multiple cellular processes including gene transcription, chromatin structure, cell proliferation and differentiation, as well as pathogenesis. In the vertebrate eye, we and others have previously shown that sumoylation can regulate differentiation of major ocular tissues including retina and lens. However, the expression patterns of the three types of sumoylation enzymes, the activating enzymes SAE1 and UBA2, the conjugating enzyme UBC9, and the ligating enzymes such as RanBP2 and PIAS1 have not been well studied in the ocular tissues. In the present study, using QRT-PCR and western blot analysis, we have determined the differentiatial expression patterns of the above three types of enzymes, and the obtained results lay down a foundation for further exploration of sumoylation functions in vertebrate eye.

Objective: To study transfection efficiency of folate-modified chitosan (FACS) nanoparticles as a non-viral vector delivering pEGFP-C3plasmid (FA-CS/P) to 293T cells with or without the combination of ultrasound and microbubble. Method: pEGFP-C3 was used as a reporter gene and FA-CS nanoparticles, which were prepared by complex coagulation method, were used as biological carriers. Transfection efficiency to 293T cells mediated by FA-CS/P nanoparticles, ultrasound (US) and microbubble (MB) was assessed by fluorescence microscopy and flow cytometry. Result: FA-CS/P nanoparticles have a particle size of 355.1 nm and zeta potential of 10.4 mV. Significant green fluorescence could be observed in CS/P group, FA-CS/P group, US+MB/P group, US+FA-CS/P group, Liposome 2000 (L) group under an inverted fluorescence microscope, while for US+MB+FA-CS/P group, only scattered fluorescence was observed. Result of flow cytometry showed that the transfection rate of US+MB+FA-CS/P group was (2.0±0.2)%, which was significantly lower than other groups (P<0.05). CCK-8 experiments showed that cell vitality of US+MB+FA-CS/P was groups (P<0.05). CCK-8 experiments showed that cell vitality of US+MB+FA-CS/P was (64.1±4.6)%, which was also lower than other groups (P<0.05). Conclusion: In this study, FA-CS was successfully synthesized. FA-CS could combine with pEGFP-C3 effectively forming nanoparticles with nanoparticle size, well dispersion, high encapsulation efficiency and no significant toxicity to cells. The application of ultrasound increased the transfection rate of FA-CS/P. However, while being exposed to ultrasound and microbubble, the transfection rate of FA-CS/P decreased obviously, may indicate that there was no synergistic effect for gene transfection by the combination of ultrasound, folate modified chitosan and microbubbles.

Background: Store-operated calcium entry (SOCE), primarily mediated by Orai1 and stromal interaction molecule 1 (STIM1), is a major Ca2+ influx pathway that has been linked to human diseases including myopathy, epilepsy, immunodeficiency, and cancer. Despite of the recent rapid progress of dissecting molecular mechanisms underlying SOCE activation, the development of therapies against dysfunctional SOCE significantly lags behind, partly due to the lack of more specific pharmacological tools and poor understanding of currently available SOCE modifiers, including the a newly identified SOCE inhibitor, digitoxin. Objective and methods: Capitalizing on Ca2+ imaging and pharmacological tools, we aimed to systemically delineate the mechanism of action of digitoxin by defining how it impinges on Orai1 to exert its suppressive effect on SOCE. Results: The SOCE-suppressive function of digitoxin is dependent on S27-S30 residues of wild-type Orai1. With 8h-incubation of digitoxin with STIM1-prebound Orai1 or a constitutively active mutant Orai1-ANSGA, its inhibition was no longer dependent on S27-S30 residues. Instead, the inhibition may involve the pore region of Orai1 channels, as V102C mutant at the pore region would greatly diminish or abolish the inhibition on pre-activated Orai1. Conclusions: Our study identified two regions that are critical for the inhibition on Orai1 channels, providing valuable hotspots for future design of SOCE inhibitors.

Background: Cadmium is a major heavy metal pollutant. Even at low concentrations in waste water Cadmium can accumulate in algae and sediments, and it is absorbed by both plants and aquatic animals, like shellfish and fish. Triploid crucian carp is an important economic fish, and have been farmed on a large scale in China. Objective: to explore the molecular mechanisms underlying Cadmium stress of triploid crucian carp. Method: we applied following experimental method to conduct research: transcriptomes analysis, histological observation, Quantitative real-time PCR and enzyme activity analysis et al. Results: in the present study, we obtained following important results: 1) Under Cd stress, the mortality and abnormality rates in triploid crucian carp were lower than those of diploid strains and the effects of Cadmium treatment on the liver were revealed by histological observation; 2) the liver transcriptomes of triploid crucian carp were obtained and the data was analyzed; 3) 14 genes related to algae and sediments stress were screened from transcriptome data, and the expression of these genes was verified by Quantitative real-time PCR. The results were consistent with the gene results in transcriptome data; 4) Quantitative real-time PCR and enzyme activity analysis all confirmed triploid crucian carp resistance to Cadmium stress was regulated by both oxidative stress and ER stress responses; 5) We found that IRE-1 and PERK, not ATF- 6, were involved in the enhance Cadmium resistance of triploid crucian carp. Conclusion: these studies demonstrate that triploid crucian carp have strong resistance to Cadmium.