Silencing of Rac3 Inhibits Proliferation and Induces Apoptosis of Human Lung Cancer Cells

Liu, Tie-Qin,Wang, Ge-Bang,Li, Zheng-Jun,Tong, Xiang-Dong,Liu, Hong-Xu Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.7

Background: Rac3, a member of the Rac family of small guanosine triphosphatases (GTPases), regulates a variety of cell functions, including the organization of the cytoskeleton, cell migration, and invasion. Overexpression of Rac3 has been reported in several human cancers. However, the role of Rac3 in lung cancer (LC) has not been determined in detail. The purpose of this study was to investigate the effect of silencing of Rac3 expression in human LC cells and the consequences for cell survival. Materials and Methods: Lentivirus small hairpin RNA (shRNA) interference techniques were utilized to knock down the Rac3 gene. Gene and protein expression was quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. LC cell apoptosis was examined by annexin V-APC /propidium iodide staining. Results: Efficient silencing of Rac3 strongly inhibited A549 cell proliferation and colony formation ability, and significantly decreased tumor growth. Moreover, flow cytometry analysis showed that knockdown of Rac3 led to G2/M phase cell cycle arrest as well as an excess accumulation of cells in the G1 and S phase. Conclusions: Thus, functional analysis using shRNAs revealed a critical role for Rac3 in the tumor growth of LC cells. shRNA silencing of Rac3 could provide an effective strategy to treat LC.

SMA OBSERVATIONS OF THE W3(OH) COMPLEX: PHYSICAL AND CHEMICAL DIFFERENTIATION BETWEEN W3(H₂O) AND W3(OH)

Qin, Sheng-Li,Schilke, Peter,Wu, Jingwen,Wu, Yuefang,Liu, Tie,Liu, Ying,Sá,nchez-Monge, Á,lvaro IOP Publishing 2015 The Astrophysical journal Vol.803 No.1

<P>We report on the Submillimeter Array (SMA) observations of molecular lines at 270 GHz toward the W3(OH) and W3(H2O) complex. Although previous observations already resolved the W3(H2O) into two or three subcomponents, the physical and chemical properties of the two sources are not well constrained. Our SMA observations clearly resolved the W3(OH) and W3(H2O) continuum cores. Taking advantage of the line fitting tool XCLASS, we identified and modeled a rich molecular spectrum in this complex, including multiple CH3CN and CH3OH transitions in both cores. HDO, C2H5CN, (OCS)-C-13, and vibrationally excited lines of HCN, CH3CN, and CH3OCHO were only detected in W3(H2O). We calculate gas temperatures and column densities for both cores. The results show that W3(H2O) has higher gas temperatures and larger column densities than W3(OH) as previously observed, suggesting physical and chemical differences between the two cores. We compare the molecular abundances in W3(H2O) to those in the Sgr B2(N) hot core, the Orion KL hot core, and the Orion Compact Ridge, and discuss the chemical origin of specific species. An east-west velocity gradient is seen in W3 (H2O), and the extension is consistent with the bipolar outflow orientation traced by water masers and radio jets. A north-south velocity gradient across W3(OH) is also observed. However, with current observations we cannot be assured whether the velocity gradients are caused by rotation, outflow, or radial velocity differences of the subcomponents of W3(OH).</P>

Compressed Magnetic Field in the Magnetically Regulated Global Collapsing Clump of G9.62+0.19

Liu, Tie,Kim, Kee-Tae,Liu, Sheng-Yuan,Juvela, Mika,Zhang, Qizhou,Wu, Yuefang,Li, Pak Shing,Parsons, Harriet,Soam, Archana,Goldsmith, Paul F.,Su, Yu-Nung,Tatematsu, Ken’ichi,Qin, Sheng-Li,Garay, Guido American Astronomical Society 2018 ASTROPHYSICAL JOURNAL LETTERS - Vol.869 No.1

ALMA Reveals Sequential High-mass Star Formation in the G9.62+0.19 Complex

Liu, Tie,Lacy, John,Li, Pak Shing,Wang, Ke,Qin, Sheng-Li,Zhang, Qizhou,Kim, Kee-Tae,Garay, Guido,Wu, Yuefang,Mardones, Diego,Zhu, Qingfeng,Tatematsu, Ken’ichi,Hirota, Tomoya,Ren, Zhiyuan,Liu, Sheng-Yu American Astronomical Society 2017 The Astrophysical journal Vol.849 No.1

<P>Stellar feedback from high-mass stars (e.g., H II regions) can strongly influence the surrounding interstellar medium and regulate star formation. Our new ALMA observations reveal sequential high-mass star formation taking place within one subvirial filamentary clump (the G9.62 clump) in the G9.62+0.19 complex. The 12 dense cores (MM1-MM12) detected by ALMA are at very different evolutionary stages, from the starless core phase to the UC H II region phase. Three dense cores (MM6, MM7/G, MM8/F) are associated with outflows. The mass-velocity diagrams of the outflows associated with MM7/G and MM8/F can be well-fit by broken power laws. The mass-velocity diagram of the SiO outflow associated with MM8/F breaks much earlier than other outflow tracers (e.g., CO, SO, CS, HCN), suggesting that SiO traces newly shocked gas, while the other molecular lines (e.g., CO, SO, CS, HCN) mainly trace the ambient gas continuously entrained by outflow jets. Five cores (MM1, MM3, MM5, MM9, MM10) are massive starless core candidates whose masses are estimated to be larger than 25 M-circle dot, assuming a dust temperature of <= 20 K. The shocks from the expanding H II regions ('B' and 'C') to the west may have a great impact on the G9.62 clump by compressing it into a filament and inducing core collapse successively, leading to sequential star formation. Our findings suggest that stellar feedback from H II regions may enhance the star formation efficiency and suppress low-mass star formation in adjacent pre-existing massive clumps.</P>

STAR FORMATION LAWS IN BOTH GALACTIC MASSIVE CLUMPS AND EXTERNAL GALAXIES: EXTENSIVE STUDY WITH DUST CONINUUM, HCN (4-3), AND CS (7-6)

Liu, Tie,Kim, Kee-Tae,Yoo, Hyunju,Liu, Sheng-yuan,Tatematsu, Ken’ichi,Qin, Sheng-Li,Zhang, Qizhou,Wu, Yuefang,Wang, Ke,Goldsmith, Paul F.,Juvela, Mika,Lee, Jeong-Eun,Tó,th, L. Viktor,Mardones, D American Astronomical Society 2016 The Astrophysical journal Vol.829 No.2

<P>We observed 146 Galactic clumps in HCN (4-3) and CS (7-6) with the Atacama Submillimeter Telescope Experiment 10 m telescope. A tight linear relationship between star formation rate and gas mass traced by dust continuum emission was found for both Galactic clumps and the high redshift (z > 1) star forming galaxies (SFGs), indicating a constant gas depletion time of similar to 100 Myr for molecular gas in both Galactic clumps and high z SFGs. However, low z galaxies do not follow this relation and seem to have a longer global gas depletion time. The correlations between total infrared luminosities (L-TIR) and molecular line luminosities (L-mol') of HCN (4-3) and CS (7-6) are tight and sublinear extending down to clumps with L-TIR similar to 10(3) L-circle dot. These correlations become linear when extended to external galaxies. A bimodal behavior in the L-TIR-L-mol' correlations was found for clumps with different dust temperature, luminosity-to-mass ratio, and sigma(line)/sigma(vir). Such bimodal behavior may be due to evolutionary effects. The slopes of L-TIR-L-mol' correlations become more shallow as clumps evolve. We compared our results with lower J transition lines in Wu et al. (2010). The correlations between clump masses and line luminosities are close to linear for low effective excitation density tracers but become sublinear for high effective excitation density tracers for clumps with L-TIR larger than L-TIR similar to 10(4.5) L-circle dot. High effective excitation density tracers cannot linearly trace the total clump masses, leading to a sublinear correlations for both M-clump-L-mol' and L-TIR-L-mol' relations.</P>

Electronic structure and optical properties of V-doped Bi₄Ti₃O₁₂ nanoparticles

Gu, Daguo,Qin, Yingying,Wen, Yongchun,Li, Tie,Qin, Lin,Seo, Hyo Jin Elsevier 2017 Journal of Alloys and Compounds Vol.695 No.-

<P><B>Abstract</B></P> <P>Pure and V<SUP>5+</SUP>-doped Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> (BTO) photocatalysts were prepared by sol–gel routine and subsequent hydrothermal synthesis. The samples were developed into the platelike microparticles with the exposed (001) facets. The crystalline phases were verified via the XRD measurement. The surface characteristics of the photocatalysts were studied by TEM, SEM, BET, EDX and XPS measurements. The UV–vis optical absorption spectra showed that the V-doped photocatalysts exhibit an obvious red shift in the visible light absorption band compared with the pure BTO. Rhodamine B (RhB) dye solution was used as the model organic pollutants to verify the influence of V-doping on the photocatalytic activity. The 10 mol % V-doped BTO showed efficient photocatalytic ability. The photocatalytic activities and mechanisms were discussed on the crystal structure characteristics and the measurements such as EES and XPS results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> V-doped Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> has been synthesized by sol-gel hydrothermal process. </LI> <LI> Single-crystal micro-plates with exposed {001} facets are reached. </LI> <LI> Visible light absorption in Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> can be greatly improved by V-doping. </LI> <LI> V-doped Bi<SUB>4</SUB>Ti<SUB>3</SUB>O<SUB>12</SUB> gives better visible light photoactivity. </LI> </UL> </P>

A STUDY OF DYNAMICAL PROCESSES IN THE ORION KL REGION USING ALMA-PROBING MOLECULAR OUTFLOW AND INFLOW

Wu, Yuefang,Liu, Tie,Qin, Sheng-Li IOP Publishing 2014 The Astrophysical journal Vol.791 No.2

<P>This work reports high spatial resolution observations toward the Orion KL region with high critical density lines of CH3CN (124-114) and CH3OH (8-1,8-70,7), as well as a continuum at similar to 1.3 mm band. The observations were made using the Atacama Large Millimeter/Submillimeter Array with a spatial resolution of similar to 1.'' 5 and sensitivity of about 0.07 K and similar to 0.18 K for continuum and line, respectively. The observational results showed that the gas in the Orion KL region consists of jet-propelled cores at the ridge and dense cores east and south of the region that are shaped like a wedge ring. The outflow has multiple lobes, which may originate from an explosive ejection, and is not driven by young stellar objects. Four infrared bubbles were found in the Spitzer/IRAC emissions. These bubbles, the distributions of the previously found H-2 jets, the young stellar objects, and molecular gas suggest that BN is the explosive center. The burst time was estimated to be similar to 1300 yr. At the same time, signatures of gravitational collapse toward Source I and the hot core were detected with material infall velocities of 1.5 km s(-1) and similar to 0.6 km s(-1), corresponding to mass accretion rates of 1.2 x 10-3M(circle dot)/yr and 8.0 x 10-5M(circle dot)/yr, respectively. These observations may support the belief that high-mass stars form via the accretion model, similar to their low-mass counterparts.</P>

The Properties of Planck Galactic Cold Clumps in the L1495 Dark Cloud

Tang, Mengyao,Liu, Tie,Qin, Sheng-Li,Kim, Kee-Tae,Wu, Yuefang,Tatematsu, Ken’ichi,Yuan, Jinghua,Wang, Ke,Parsons, Harriet,Koch, Patrick M.,Sanhueza, Patricio,Ward-Thompson, D.,Tó,th, L. Viktor,S American Astronomical Society 2018 The Astrophysical journal Vol.856 No.2

INFLOWS IN MASSIVE STAR FORMATION REGIONS

WU, YUEFANG,LIU, TIE,QIN, SHENGLI The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

How high-mass stars form is currently unclear. Calculations suggest that the radiation pressure of a forming star can halt spherical infall, preventing further growth when it reaches $10M_{\odot}$. Two major theoretical models on the further growth of stellar mass have been proposed. One model suggests the merging of less massive stellar objects, and the other is through accretion, but with the help of a disk. Inflow motions are key evidence for how forming stars gain further mass to build up massive stars. Recent developments in technology have boosted the search for inflow motion. A number of high-mass collapse candidates were obtained with single dish observations, and mostly showed blue profiles. Infalling signatures seem to be more common in regions which have developed radiation pressure than in younger cores, which is the opposite of the theoretical prediction and is also very different from observations of low mass star formation. Interferometer studies so far confirm this tendency with more obvious blue profiles or inverse P Cygni profiles. Results seem to favor the accretion model. However, the evolution of the infall motion in massive star forming cores needs to be further explored. Direct evidence for monolithic or competitive collapse processes is still lacking. ALMA will enable us to probe more detail of the gravitional processes.

Subcellular Characterization of Porcine Oocytes with Different Glucose-6-phosphate Dehydrogenase Activities

Fu, Bo,Ren, Liang,Liu, Di,Ma, Jian-Zhang,An, Tie-Zhu,Yang, Xiu-Qin,Ma, Hong,Zhang, Dong-Jie,Guo, Zhen-Hua,Guo, Yun-Yun,Zhu, Meng,Bai, Jing Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.12

The in vitro maturation (IVM) efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+) oocytes with low glucose-6-phosphate dehydrogenase (G6PDH) activity have shown superior quality than BCB negative (-) oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG) migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9) and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB- oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.