Lineage reprogramming of fibroblasts into induced cardiac progenitor cells by CRISPR/Cas9-based transcriptional activators

Overexpression of exogenous lineage-determining factors succeeds in directly reprogramming fibroblasts to various cell types. Several studies have reported reprogramming of fibroblasts into induced cardiac progenitor cells (iCPCs). CRISPR/Cas9-mediated gene activation is a potential approach for cellular reprogramming due to its high precision and multiplexing capacity. Here we show lineage reprogramming to iCPCs through a dead Cas9 (dCas9)-based transcription activation system. Targeted and robust activation of endogenous cardiac factors, including GATA4, HAND2, MEF2C and TBX5 (G, H, M and T; GHMT), can reprogram human fibroblasts toward iCPCs. The iCPCs show potentials to differentiate into cardiomyocytes, smooth muscle cells and endothelial cells . Addition of MEIS1 to GHMT induces cell cycle arrest in G2/M and facilitates cardiac reprogramming. Lineage reprogramming of human fibroblasts into iCPCs provides a promising cellular resource for disease modeling, drug discovery and individualized cardiac cell therapy.

CT and MRI diagnose of primary extragonadal seminoma / 实用放射学杂志

Objective To explore the CT and MRI performances of primary extragonadal seminoma .Methods The imaging find‐ings of primary extragonadal seminoma in 16 patients proved by histopathology were analyzed retrospectively .The tumor location , size ,contour ,periphery ,density or signal and contrast enhancement patterns were evaluated ,and these were compared with the pathological results .Results The lesions in 16 patients were solitary including the ovoid lesions in 6 and lobulated ones in 10 .They were located in intracranial area in 10 patients ,anterior middle mediastinum in 4 and abdomen in 2 .Mean size of the tumors was(7 .0 ± 5 .6) cm (ranging from 1 .3 cm to 18 .6 cm) .Unenhanced CT in 13 patients showed the soft tissue masses with necrosis in 8 ,stip‐pled calcification in 2 and hemorrhage in 2 .Enhanced CT in 6 patients showed homogeneity in 2 and heterogeneity in 4 ,and the de‐grees of enhancement increased gradually .The plain and enhanced MRI in 10 patients showed iso‐or slight hypointensity on T1WI and slight hyperintensity on T2 WI in 8 lesions ,heterogeneous enhancement in 7 and slight enhancement in one ,peripheral enhance‐ment in 2 due to central hemorrhage .Pathology showed most of the lesions were well‐vascularized with inner cystic change .Tumor stroma was divided by the fibrovascular tissue .Conclusion The imaging findings of primary extragonadal seminoma are not specific , CT ,MRI can demonstrate the invasive extent accurately .

Chitosan/PIK3CA siRNA nanoparticle-mediated PIK3CA gene interference decreases the invasive capacity of gastric cancer cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of PIK3CA/siRNA chitosan nanoparticle on the invasiveness of gastric carcinoma and the potential value of PIK3CA/siRNA chitosan nanoparticle in suppressing the metastasis of gastric carcinoma.</p><p><b>METHODS</b>Gastric cancer cells were treated with PIK3CA/siRNA nanoparticle (with a diameter of 350 nm), and the efficiency of PIK3CA gene interference was evaluated using Western blotting and real-time PCR. The changes of the invasive capacity of the treated cells was assessed with Transwell assay.</p><p><b>RESULTS</b>PIK3CA/siRNA chitosan nanoparticle efficiently lowered the expression level of PIK3CA and significantly decreased the invasion of BGC823 cells.</p><p><b>CONCLUSION</b>PIK3CA gene interference mediated by PIK3CA/siRNA chitosan nanoparticle can decrease the invasive capacity of gastric cancer cells in vitro.</p>

Analysis of transfection characteristic of two different fluorescently labeled siRNA targeting PIK3CA gene in vitro / 中国基层医药

Objective To compare transfection properties of two different fluorescently labeled PIK3CA siR-NA and to screen out PIK3CA siRNA with high transfection efficiency and strong anti-quenching ability.Methods Two different fluorescently labeled PIK3CA siRNA was transfected into gastric cancer cell BGC-823 by Lipofectamine 2000.The distribution and quenching of fluorescence were observed by inverted fluorescence microscope.Image J software was used to analyze their transfection efficiency.Real-time quantitative PCR was performed to detect the effect of different fluorescently labeled PIK3CA siRNA on PIK3CA mRNA expression.Results The transfection efficiency and anti-quenching ability of two different fluorescently labeled PIK3CA siRNA were different under the same transfection conditions.The transfection efficiency showed no significant differences between Cy3 or FAM labeled PIK3CA siRNA and negative control siRNA(P ＞ 0.05),but the transfection efficiency of Cy3 labeled PIK3CA siRNA and negative control siRNA was significantly higher than the FAM labeled (P ＜ 0.05).Inhibitory efficacy of target mRNA expression induced by Cy3 labeled PIK3CA siRNA was significantly higher than that of FAM labeled PIK3CA siRNA.Conclusion Cy3 labeled PIK3CA siRNA could act as a good tracer and provide an important evidence for further construction of Cy3 labeled PIK3CA siRNA nanoparticle.