The mechanics of the microenvironment continuously modulates cell functions like growth, survival, apoptosis, differentiation, and morphogenesis via cytoskeletal remodeling and actomyosin contractility 1 – 3 . Although all these processes consume energy 4 , 5 , it is unknown if and how cells adapt their metabolic activity to variable mechanical cues. Here, we report that transfer of human bronchial epithelial cells (HBECs) from stiff to soft substrates causes downregulation of glycolysis via proteasomal degradation of the rate-limiting metabolic enzyme phosphofructokinase (PFK). PFK degradation is triggered by stress fiber disassembly, which releases the PFK-targeting E3 ubiquitin ligase tripartite motif (TRIM)-containing protein 21 (TRIM21). Transformed non-small cell lung cancer cells (NSCLCs), which maintain high glycolytic rates regardless of changing environmental mechanics, retain PFK expression by downregulating TRIM21, and by sequestering residual TRIM21 on a stress fiber population that is insensitive to substrate stiffness. In sum, our data unveil a mechanism by which glycolysis responds to architectural features of the actomyosin cytoskeleton, thus coupling cell metabolism to the mechanical properties of the surrounding tissue. These processes enable normal cells to attune energy production in variable microenvironments, while the resistance of the cytoskeleton to respond to mechanical cues allows high glycolytic rates to persist in cancer cells despite constant alterations of the tumor tissue.

Despite the increased interest in epigenetic research, its progress has been hampered by a lack of satisfactory tools to control epigenetic factors in specific genomic regions. Until now, many attempts to manipulate DNA methylation have been made using drugs but these drugs are not target-specific and have global effects on the whole genome. However, due to new genome editing technologies, potential epigenetic factors can now possibly be regulated in a site-specific manner. Here, we demonstrate the utility of CRISPR/Cas9 to modulate methylation at specific CpG sites and to elicit gene expression. We targeted the murine Oct4 gene which is transcriptionally locked due to hypermethylation at the promoter region in NIH3T3 cells. To induce site-specific demethylation at the Oct4 promoter region and its gene expression, we used the CRISPR/Cas9 knock-in and CRISPR/dCas9-Tet1 systems. Using these two approaches, we induced site-specific demethylation at the Oct4 promoter and confirmed the up-regulation of Oct4 expression. Furthermore, we confirmed that the synergistic effect of DNA demethylation and other epigenetic regulations increased the expression of Oct4 significantly. Based on our research, we suggest that our proven epigenetic editing methods can selectively modulate epigenetic factors such as DNA methylation and have promise for various applications in epigenetics.

Endoscopic ultrasound (EUS)-guided tissue acquisition of pancreatic solid tumor requires a strict recommendation for its proper use in clinical practice because of its technical difficulty and invasiveness. The Korean Society of Gastrointestinal Endoscopy (KSGE) appointed a task force to draft clinical practice guidelines for EUS-guided tissue acquisition of pancreatic solid tumor. The strength of recommendation and the level of evidence for each statement were graded according to the Minds Handbook for Clinical Practice Guideline Development 2014. The committee, comprising a development panel of 16 endosonographers and an expert on guideline development methodology, developed 12 evidence-based recommendations in eight categories intended to help physicians make evidence-based clinical judgments with regard to the diagnosis of pancreatic solid tumor. This clinical practice guideline discusses EUS-guided sampling in pancreatic solid tumor and makes recommendations on circumstances that warrant its use, technical issues related to maximizing the diagnostic yield (e.g., needle type, needle diameter, adequate number of needle passes, sample obtaining techniques, and methods of specimen processing), adverse events of EUS-guided tissue acquisition, and learning-related issues. This guideline was reviewed by external experts and suggests best practices recommended based on the evidence available at the time of preparation. This guideline may not be applicable for all clinical situations and should be interpreted in light of specific situations and the availability of resources. It will be revised as necessary to cover progress and changes in technology and evidence from clinical practice.

A normal incident infrared detector has been fabricated using electron intersubband transition in a InGaAs/GaAs quantum well structure. With the light polarized in the plane of the layers (normal incident) a nominally forbidden absorption peak was observed. Such an absorption is most likely a result of spin-flip intersubband transitions induced by the spin-orbit coupling. In addition, for the light polarized in the plane of incidence, the usual intersubband absorption due to envelope function transition is observed. The responsivity of 0.2 A/W was obtained for the normal incident infrared on the detector. This work demonstrates the fabrication of high sensitivity quantum well infrared detectors operating in the normal incident mode without fabricating grating structures on the device for focal plane applications.