Efficient Identification of the MYC Regulator with the Use of the CRISPR Library and Context-Matched Database Screenings

MYC is a major oncogene that plays an important role in cell proliferation in human cancers. Therefore, the mechanism behind MYC regulation is a viable therapeutic target for the treatment of cancer. Comprehensive and efficient screening of MYC regulators is needed, and we had previously established a promoter screening system using fluorescent proteins and the CRISPR library. For the efficient identification of candidate genes, a database was used, for which mRNA expression was correlated with MYC using datasets featuring “Similar” and “Not exactly similar” contexts. INTS14 and ERI2 were identified using datasets featuring the “Similar” context group, and INTS14 and ERI2 were capable of enhancing MYC promoter activity. In further database analysis of human cancers, a higher expression of MYC mRNA was observed in the INTS14 mRNA high-expressing prostate and liver cancers. The knockdown of INTS14 in prostate cell lines resulted in decreased MYC mRNA and protein expression and also induced G0/1 arrest. This study confirmed that CRISPR screening combined with context-matched database screening is effective in identifying genes that regulate the MYC promoter. This method can be applied to other genes and is expected to be useful in identifying the regulators of other proto-oncogenes.     

Evaluation of quasi-isotropic plate and cylindrical shell fabricated with green composite sheets

Conventional fiber reinforced plastics (FRPs) have some problems in the case of disposal. Their combustion disposal discharges the carbon dioxide in the air because resins of FRPs are made of fossil fuel. In the case of disposal into the ground, these FRPs remain semi-permanently without decomposing. Therefore, green composites are now developed and are studied as one of less the environmental burden materials. In this study, two kinds of continuous green composite sheets, which were composed of Kenaf fibers or Linen fibers as reinforcement and biodegradable poly butylene succinate (PBS) resin as a matrix, were fabricated with a pultrusion molding. Since the PBS resin is a thermoplastic resin, the PBS/KENAF or PBS/LINEN composite sheets can be treated as intermediate materials such as Carbon Fiber Reinforced Plastic prepregs. In order to apply the PBS/KENAF or PBS/LINEN composite sheets to structural components, quasi-isotropic plates and cylindrical shells were fabricated and evaluated.     

Concentration measurement of refrigerant/refrigeration oil mixture by refractive index

Refrigeration oil having good miscibility with refrigerant is generally used in refrigeration units. Precise measurement of the mixing ratio of refrigerant to refrigeration oil is required for a sufficient understanding of the refrigeration cycle. In this paper, refractive index is chosen as a property which indicates the mixing concentration of the refrigerant/oil mixture. A laser displacement sensor is used to detect a change of optical path which changes according to the refractive index of test medium. The refractive indices of pure refrigerant, pure refrigeration oil and refrigerant/refrigeration oil mixture are measured with several combination of refrigerant/oil. It is found that the difference of refractive index between the refrigerant and the oil is sufficient for the measurement of the mixing concentration of refrigerant/oil mixture, and that the refractive index of the refrigerant/oil mixture changes almost linearly according to the mixing concentration. These data will be utilized for development of an in situ sensor in refrigerant compressors.     

Screening of α-Amylase Suitable for Evaluating the Degree of Starch Retrogradation

To estimate the degrees of starch retrogradation in the complex foods, an enzymatic method using α-amylase from Bacillus subtilis was proposed in the previous report (Tsuge, H. et al.: Starch/Stärke 42 (1990), 213–216). However, actual digestibility of the enzyme for the native starch granules was not checked at that time. A comparative study to see the digestibility of native starch granules was carried out using four different α-amylase preparations and digestion of retrograded wheat starch was tested by two α-amylase preparations. Pancreas α-amylase preparation digested some native starch granules to a great extent, while Aspergillus oryzae enzyme did not digest native starch granules virtually. In conclusion, α-amylase preparation from A. oryzae was an ideal enzyme as the tool to distinguish between raw and gelatinized starches. It was justified for the use of A. oryzae enzyme as well as B. subtilis α-amylase to evaluate the retrograded starch contents in the complex foods.