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1.
Masayo Suzuki Hiroyuki Ishida Yukimasa Shiotsu Taisuke Nakata Shiro Akinaga Shigemitsu Takashima Toshiaki Utsumi Toshiaki Saeki Nobuhiro Harada 《The Journal of steroid biochemistry and molecular biology》2009,113(3-5):195-201
In order to evaluate the importance of estrogen production in tumor and surrounding tissues, we measured mRNA expression levels of 5 enzymes participating to estrogen synthesis in situ and 4 breast cancer-related proteins in 27 pairs of tumor and non-malignant tissues. Steroid sulfatase (STS) mRNA was more frequently detected in tumor tissues rather than in their non-malignant counterparts. Estrogen sulfotransferase (EST) was constantly expressed with high level not only in tumor tissues but also in their surrounding non-malignant counterparts. In contrast, mRNA expression levels of aromatase, and 17β-hydroxysteroid dehydrogenase type I and II were relatively low and detected only in small proportion of the patients. We also measured the mRNA expression levels of the same nine genes in tumor tissues of 197 breast cancer patients, and analyzed relationship between the mRNA expression level and the clinicopathological parameters. The mRNA expression levels of STS, aromatase and erbB2 in tumor tissues increased as breast cancer progressed. The tumoral mRNA expression levels of STS, estrogen receptor β, and erbB2 in patients with recurrence were higher than those in patients without recurrence. Upregulation of STS expression plays an important role in tumor progression of human breast cancer and is considered to be responsible for estrogen production in tumor and surrounding tissues. 相似文献
2.
M Ohtsubo M Yoshida S Ohta Y Kagawa M Yohda T Date 《Biochemical and biophysical research communications》1987,146(2):705-710
Using site-directed mutagenesis, Glu-190 or Glu-201 of the beta subunit of the F1-ATPase from the thermophilic bacterium PS3 were replaced with glutamine. It was possible to reconstitute complexes of the mutated beta subunits with alpha and gamma subunits, but the complexes did not have ATPase activity. It is concluded that carboxylic acid side chains of Glu-190 and Glu-201 of the beta subunit are essential for catalytic activity of F1-ATPase. 相似文献
3.
Homogeneous populations of hybrid alpha 3 beta 3 gamma complexes of the thermostable F1-ATPase containing one, two, or three copies of the mutationally impaired beta subunits were produced using the solid phase reconstitution method. Two kinds of mutated beta subunits were used for the reconstitution, one of which lacked the ability to bind any adenine nucleotides. The complexes containing one impaired beta and two wild-type beta subunits retained a significant amount of ATPase activity with cooperative kinetics, whereas those containing two or three impaired beta subunits showed very little ATPase activity. These results imply that the catalysis of steady-state ATP hydrolysis can proceed even if one of the three beta subunits in F1-ATPase is not functional. 相似文献
4.
Itoh Shigeru; Iwaki Masayo; Tomo Tatsuya; Satoh Kimiyuki 《Plant & cell physiology》1996,37(6):833-839
Transient absorbance changes of the primary electron donor chlorophylla (P680) and acceptor pheophytin a (H) were measured at 77 Kby nanosecond laser spectroscopy in the D1-D2-cytochrome b559photosystem II reaction center complex containing dibromomethylisopropylbenzoquinone (DBMIB). After the laser excitation of the reactioncenter in the presence of DBMIB, only the P680+-(DBMIB-) statewas detected. P680+ mainly decayed with a t1/e of 11 ms. Inthe absence of DBMIB, the excitation produced the P680+H- radicalpair. The radical pair produced the triplet state (P680T) witha t1/e of 50 ns, and P680T then decayed with a t1/e of 2.1 ms.It was concluded that H- was oxidized by DBMIB in a time rangefaster than the detecting time resolution (3.5 ns) even at 77K. The rapid oxidation of H- by DBMIB was also confirmed bythe suppression of delayed fluorescence with a decay t1/e of50 ns. The P680+(DBMIB-)/P680(DBMIB) difference spectrum exhibiteda Qy, band with a peak at 682 nm with a shoulder at 673 nm.The spectral shape was almost temperature insensitive between77 and 265 K. The feature of this spectrum in the wavelengthrange between 330 and 720 nm was compared with that of P680T/P680or H-/H at 77 K. (Received May 8, 1996; Accepted June 24, 1996) 相似文献
5.
Lyophilized photosystem I particles from spinach were treatedwith diethyl ether that contained various organic solvents withdifferent dielectric constants. More pigments were extractedas the dielectric constant of the solvent added to ether increased.The reaction-center chlorophylldimer, P700, was more resistantto extraction than the rest of the chlorophyll. Particles thatcontained only 6 chlorophylls in addition to P700 and the primaryelectron acceptor (A0), in a single reaction-center unit, wereprepared by extraction with a mixture of ether and acetaldehyde.A distinct shoulder at 695 nm due to P700 or at 686 nm due toP700+ was observed in the absorption spectra of the reducedor oxidized particles, respectively, even at room temperature.No secondary acceptor phylloquinone remained in the particles.Stable charge separation was restored upon the addition of 2-amino-anthraquinone,even though the particles had the lowest molar ratio of chlorophyllto P700 of any reported particles. (Received February 20, 1995; Accepted May 8, 1995) 相似文献
6.
7.
There are two major types of hepatitis C virus in Japan 总被引:29,自引:0,他引:29
N Enomoto A Takada T Nakao T Date 《Biochemical and biophysical research communications》1990,170(3):1021-1025
The polymerase chain reaction (PCR) was used to detect hepatitis C virus (HCV) in plasma from chronic non-A, non-B hepatitis patients. By choice of adequate primers, 19 of 24 samples (79%) were found positive. Sequence analysis of amplified 400 bp cDNA fragments encoding a portion of NS5 gene suggested that HCV can be classified into two types (named K1 and K2) in Japan. Slot blot hybridization of the fragments indicated that 13 were HCV-K1 and 6 were HCV-K2, which show 80% and 67% nucleotide sequence homology, respectively, with that of the prototype. 相似文献
8.
9.
Seasonal and areal features of the lagoonal environment in Lake Nakanoumi,a shallow coastal lagoon in Japan 总被引:1,自引:1,他引:0
Lake Nakanoumi is a shallow coastal lagoon connected with the Japan Sea by a narrow channel. Over the past decade, land reclamation resulted in a 33% reduction of the lagoon's surface area. The remaining water basin of Lake Nakanoumi is scheduled to be artificially freshened to supply irrigation water for the newly reclaimed lands. This paper deals with the seasonal and areal features of the lagoonal environment prior to the beginning of the artificial desalinization. 相似文献
10.
Shuso Takeda Masayo Hirao-Suzuki Mitsuru Shindo Hironori Aramaki 《Current issues in molecular biology》2022,44(9):3849
Experimental evidence accumulated by our research group and others strongly suggests that (–)-xanthatin, a xanthanolide sesquiterpene lactone, exhibits anti-proliferative effects on human breast cancer cells (in vitro) as well as anti-tumor effects in experimental animals (in vivo). In cancer biology, it is now critically important for anti-cancer agents to selectively target cancer stem cells (CSCs) in order to overcome cancer therapeutic resistance and recurrence. However, it has not yet been established whether (–)-xanthatin abrogates the formation of breast CSCs. In the present study, we utilized chemically synthesized pure (–)-xanthatin and a culture system to obtain mammospheres from human breast cancer MCF-7 cells, which are a CSC-enriched population. We herein demonstrated for the first time that (–)-xanthatin exhibited the ability to kill mammospheres, similar to salinomycin, an established selective killer of CSCs. A possible anti-proliferative mechanism toward mammospheres by (–)-xanthatin is discussed. 相似文献