Cellular Responses to Widespread DNA Replication Stress.

Replicative DNA polymerases are blocked by nearly all types of DNA damage. The resulting DNA replication stress threatens genome stability. DNA replication stress is also caused by depletion of nucleotide pools, DNA polymerase inhibitors, and DNA sequences or structures that are difficult to replicate. Replication stress triggers complex cellular responses that include cell cycle arrest, replication fork collapse to one-ended DNA double-strand breaks, induction of DNA repair, and programmed cell death after excessive damage. Replication stress caused by specific structures (e.g., G-rich sequences that form G-quadruplexes) is localized but occurs during the S phase of every cell division. This review focuses on cellular responses to widespread stress such as that caused by random DNA damage, DNA polymerase inhibition/nucleotide pool depletion, and R-loops. Another form of global replication stress is seen in cancer cells and is termed oncogenic stress, reflecting dysregulated replication origin firing and/or replication fork progression. Replication stress responses are often dysregulated in cancer cells, and this too contributes to ongoing genome instability that can drive cancer progression. Nucleases play critical roles in replication stress responses, including MUS81, EEPD1, Metnase, CtIP, MRE11, EXO1, DNA2-BLM, SLX1-SLX4, XPF-ERCC1-SLX4, Artemis, XPG, FEN1, and TATDN2. Several of these nucleases cleave branched DNA structures at stressed replication forks to promote repair and restart of these forks. We recently defined roles for EEPD1 in restarting stressed replication forks after oxidative DNA damage, and for TATDN2 in mitigating replication stress caused by R-loop accumulation in BRCA1-defective cells. We also discuss how insights into biological responses to genome-wide replication stress can inform novel cancer treatment strategies that exploit synthetic lethal relationships among replication stress response factors.

Graphene woven fabric-polydimethylsiloxane piezoresistive films for smart multi-stimuli responses.

The outstanding properties of graphene, including its electromechanical property, could be engineered for wearable electronic sensor platforms. The tubular graphene weaved into a mesh or graphene woven fabrics (GWF) has been reported as one of the most sensitive materials for deformation detection, as well as a promising temperature sensor. Herein, we present the performance of our developed flexible, stretchable, and multiple sensitive sensors fabricated from GWF embedded in polydimethylsiloxane (PDMS) film substrate. The GWF/PDMS sensor shows a pressure sensitivity of 0.0142 kPa-1 in a wide linearity range of 0-20 kPa, an outstanding Gauge factor (GF) of 582 at a strain of 6.2 %, and a very high positive sensitivity of 0.0238 °C-1 in the temperature range of 25-80 °C. A practical application as a high sensitivity air pressure sensor able to measure low pressures (in the range of Pa to kPa) was also demonstrated. This sensor platform having desirable performance characteristics is an excellent candidate for wearable devices in the healthcare sector.

Totally Endoscopic Resection of Right Atrial Diverticulum: A Case Report.

Right atrial diverticulum is a rare congenital heart defect with only about 30 cases reported. Surgery is the main method of treatment and is indicated when the patients have signs of right heart compression. In this study, we report the case of a 43-year-old male patient who was diagnosed with massive right atrial diverticulum. This patient was the first case who underwent successful repair by totally endoscopic surgery on the beating heart.

Discordant Atrioventricular Connections in Situs Inversus, Dextrocardia with Double Outlet Right Ventricle, Pulmonary Stenosis, and Anomalous Coronary Artery: A Rare Case Report.

We report a case of a 2-year-old female presenting with cyanosis since birth and having rare cardiac anatomy of visceral situs inversus, dextrocardia, discordant atrioventricular connections with double outlet right ventricle, atrial communication, subaortic interventricular communication, anteriorly leftward aorta with right aortic arch, single coronary artery with a branch crossing right ventricle outflow tract, pulmonary stenosis, and bilateral superior vena cava. Corrective repair with atrial switch (Senning technique), intracardiac baffle, and right ventricle outflow reconstruction was successfully performed with challenges from altered anatomical location and orientation of the heart and abnormal coronary artery.

Totally endoscopic atrial septal defect repair in a patient with interrupted inferior vena cava with azygos-hemiazygos continuation.

Atrial septal defect combined with interrupted inferior vena cava (IVC), which is a rare condition, makes it impossible to apply totally endoscopic surgery (TES). The most difficulty is how to drain blood from the posthepatic segment of the IVC. In this study, we report a case of a 44-year-old female patient who was diagnosed with secundum atrial septal defect combined with interrupted IVC with azygos-hemiazygos continuation. This patient underwent successful repair by TES with transthoracic cannulation for the posthepatic segment of the IVC.

Congenital coronary vein aneurysm: A case report.

A 61-year-old female patient with chest pain was diagnosed with localized pericardial effusion, resistance to medical therapy. Cardiac magnetic resonance imaging revealed a massive aneurysm originating from coronary veins, which was successfully removed.

Extracellular Vesicles Enriched with Moonlighting Metalloproteinase Are Highly Transmissive, Pro-Tumorigenic, and Trans-Activates Cellular Communication Network Factor (CCN2/CTGF): CRISPR against Cancer.

Matrix metalloproteinase 3 (MMP3) plays multiple roles in extracellular proteolysis as well as intracellular transcription, prompting a new definition of moonlighting metalloproteinase (MMP), according to a definition of protein moonlighting (or gene sharing), a phenomenon by which a protein can perform more than one function. Indeed, connective tissue growth factor (CTGF, aka cellular communication network factor 2 (CCN2)) is transcriptionally induced as well as cleaved by MMP3. Moreover, several members of the MMP family have been found within tumor-derived extracellular vesicles (EVs). We here investigated the roles of MMP3-rich EVs in tumor progression, molecular transmission, and gene regulation. EVs derived from a rapidly metastatic cancer cell line (LuM1) were enriched in MMP3 and a C-terminal half fragment of CCN2/CTGF. MMP3-rich, LuM1-derived EVs were disseminated to multiple organs through body fluid and were pro-tumorigenic in an allograft mouse model, which prompted us to define LuM1-EVs as oncosomes in the present study. Oncosome-derived MMP3 was transferred into recipient cell nuclei and thereby trans-activated the CCN2/CTGF promoter, and induced CCN2/CTGF production in vitro. TRENDIC and other cis-elements in the CCN2/CTGF promoter were essential for the oncosomal responsivity. The CRISPR/Cas9-mediated knockout of MMP3 showed significant anti-tumor effects such as the inhibition of migration and invasion of tumor cells, and a reduction in CCN2/CTGF promoter activity and fragmentations in vitro. A high expression level of MMP3 or CCN2/CTGF mRNA was prognostic and unfavorable in particular types of cancers including head and neck, lung, pancreatic, cervical, stomach, and urothelial cancers. These data newly demonstrate that oncogenic EVs-derived MMP is a transmissive trans-activator for the cellular communication network gene and promotes tumorigenesis at distant sites.