著者
Zhaorigetu Siqin Sasaki Masahiro Watanabe Hiromitsu KATO Norihisa
出版者
社団法人日本農芸化学会
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.65, no.10, pp.2181-2186, 2001-10-23
参考文献数
31
被引用文献数
10 97

This study was done to discover the underlying mechanism of the inhibitory effect of sericin against colon tumorigenesis. Mice were fed a diet with 30 g/kg sericin for 115 d, and given a weekly injection of 1,2-dimethylhydrazine (10 mg/kg body weight) for the initial 10 wk. Dietary supplemental sericin caused a 62% reduction in the incidence of colonic adenoma (P<0.05), but did not affect the incidence of colonic adenocarcinoma. Sericin intake significantly reduced the number of colon adenomas. Consumption of sericin significantly reduced the BrdU labeling index of colonic proliferating cells and the expression of colonic c-myc and c-fos. The levels of colonic 8-hydroxydeoxyguanosine, 4-hydroxynonenal, and inducible nitric oxide synthase protein were significantly suppressed by sericin. The results suggest that dietary sericin suppresses the development of colon tumors by reducing oxidative stress, cell proliferation, and nitric oxide production.
著者
Nan-Yin CHEN Hsi-Huai LAI Tai-Hao HSU Fang-Yi LIN Jian-Zhi CHEN Hui-Chen LO
出版者
Japan Society for Bioscience, Biotechnology, and Agrochemistry
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.72, no.5, pp.1283-1289, 2008-05-23 (Released:2008-05-23)
参考文献数
18
被引用文献数
16

Tremella mesenterica (TM) is a common food and folk medicine widely used in several Asian countries as a tonic for the lungs. In the present study, we compared the effects of extracellular polysaccharides (EPS), intracellular polysaccharides (IPS), and ethanol extract (EE) of Tremella mesenterica on the induction of apoptosis into human lung carcinoma A549 epithelial cells. The EE, but not the EPS or the IPS, almost completely inhibited the growth of A549 cells. The results of Annexin V-FITC/PI staining and flow cytometric analysis indicated that the percentage of Annexin V+/PI− cells in EE-treated cells increased to 32.8%. The results of further investigation showed a disruption of mitochondrial transmembrane potential (ΔΨm), the production of reactive oxygen species (ROS), and the activation of caspase-3 protein in EE-treated cells. These findings suggest that EE can decrease cell viability and induce apoptosis in A549 cell lines by activating a mitochondrial pathway.
著者
Hattori Noriaki Kajiyama Naoki Maeda Masako MURAKAMI Seiji
出版者
社団法人日本農芸化学会
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.66, no.12, pp.2587-2593, 2002-12-23
参考文献数
31
被引用文献数
5 17

Benzalkonium chloride (BAC), used to extract intracellular ATP, interferes with subsequent firefly luciferase-luciferin assays. There was a significant difference among wild-type luciferases with respect to BAC resistance. Luciola later alis luciferase (LlL) was the most tolerant, followed by Luciola cruciata luciferase (LcL) and Photinus pyralis luciferase. Random mutagenesis of thermostable mutants of LcL showed that the Glu490Lys mutation contributes to improved resistance to BAC. The corresponding Glu490Lys mutation was introduced into thermostable mutants of LlL by sitedirected mutagenesis. Kinetic analysis demonstrated that the resultant LlL-217L490K mutant, having both an Ala217Leu and a Glu490Lys mutation, showed the highest resistance to BAC, with an initial remaining bioluminescence intensity of 87.4% and a decay rate per minute of 29.6% in the presence of 0.1% BAC. The Glu490Lys mutation was responsible for increased resistance to inactivation but not inhibition by BAC. The LlL-217L490K had identical thermostability and pH stability to the parental thermostable mutant. From these results, it was concluded that the LlL-217L490K enzyme is advantageous for hygiene monitoring and biomass assays based on the ATP-bioluminescence methodology. This is the first report demonstrating improved resistance to BAC of the firefly luciferase enzyme.
著者
Park Keun-Hong Kim Mi-Hyun Park Sang-Hyug LEE Hyun Jung KIM In Kyu CHUNG Hyung-Min
出版者
Japan Society for Bioscience, Biotechnology, and Agrochemistry
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.68, no.11, pp.2224-2229, 2004-11-23
参考文献数
25
被引用文献数
1 19

Adhesion molecules composed of Gly–Arg–Gly–Asp–Ser (GRGDS) peptides and cell recognition ligands were inculcated into thermo-reversible hydrogel composed of <I>N</I>-isopropylacrylamide, with a small amount of succinyl poly(ethylene glycol) (PEG) acrylate (MW 3400) used as a biomimetic extracellular matrix (ECM). The GRGDS-containing p(NiPAAm-<I>co</I>-PEG) copolymer gel was studied <I>in vitro</I> for its ability to promote cell spreading and to increase the viability of cells by introducing PEG spacers. Hydrogel lacking the adhesion molecules proved to be a poor ECM for adhesion, permitting only a 20% spread of the seeded cells after 10 days. When PEG spacer arms, immobilized by a peptide linkage, had been integrated into the hydrogel, conjugation of RGD promoted cell spread by 600% in a 10-day trial. In addition, in a serum-free medium, only GRGDS peptides conjugated with the spacer arm were able to promote cell spread. In terms of the cell viability, GRGDS peptides conjugated with the PEG-carrying copolymer gel specifically mediated cell spread. This result supports the theory that specific recognition is the result of interaction between the integrin families on the fibroblast, and the RGD sequence on the p(NiPAAm-<I>co</I>-PEG) copolymer gel.
著者
Ayumi ABE Kozo ASANO Teruo SONE
出版者
Japan Society for Bioscience, Biotechnology, and Agrochemistry
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.74, no.7, pp.1325-1331, 2010-07-23 (Released:2010-07-23)
参考文献数
21
被引用文献数
46

In order to establish the molecular taxonomy of the genus Rhizopus, all described species of the genus were collected and the nucleotide sequences of the internal transcribed spacer of the rRNA gene (rDNA ITS), actin, and translation elongation factor 1α (EF-1α) were determined. Quantitative real-time PCR revealed that R. americanus had a R. stolonifer-type ITS sequence as the dominant sequence type, although it had three different types of ITS sequences in a single genome. Phylogenetic analysis and gene genealogy concordance phylogenetic species recognition (GCPSR) identified eight species in the genus, whereas recent morphological taxonomy includes 10 species. R. niveus is proposed to be re-classified as R. delemar, and R. sexualis and R. americanus are re-classified as R. stolonifer.
著者
Naomi OSAKABE Chiaki SANBONGI Megumi YAMAGISHI Toshio TAKIZAWA Toshihiko OSAWA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.62, no.8, pp.1535-1538, 1998 (Released:2005-03-25)
参考文献数
26
被引用文献数
35

The antiulcer activity of cacao liquor water-soluble crude polyphenols (CWSP) was examined.   CWSP, α-tocopherol, sucralfate (500 mg/kg), and cimetidine (250 mg/kg) were orally administerted to male SD rats 30 minutes before ethanol treatment. 5 ml/kg of ethanol given intragastrically caused lesions in mucosa of the glandular stomach. CWSP caused a reduction of such hemorrhagic lesions as well as cimetidine and sucralfate which are typical antiulcer drugs, but α-tocopherol was less effective. Thiobarbituric acid reactive substances in gastric mucosa significantly increased with ethanol administration. CWSP treatment significantly reduced this change. The administration of ethanol extensively increased myeloperoxidase (MPO) but not xanthine oxidase (XOD) activity. CWSP reduced the activities of both enzymes; they were considered the main sources of oxygen radicals. According to an in vitro study, CWSP directly reducted XOD but not MPO. These results suggest that the antiulcer mechanism of CWSP was not only radical scavenging but also modulation of leukocyte function.
著者
Yong LI Man-Li ZHANG Bin CONG Si-Ming WANG Mei DONG Françoise SAURIOL Chang-Hong HUO Qing-Wen SHI Yu-Cheng GU Hiromasa KIYOTA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.75, no.8, pp.1554-1556, 2011-08-23 (Released:2011-08-23)
参考文献数
27
被引用文献数
27 13

Achillinin A (2β,3β-epoxy-1α,4β,10α-trihydroxyguai-11(13)-en-12,6α-olide, 1), a new guaianolide isolated from the flower of Achillea millefolium, exhibited potential antiproliferative activity to A549, RERF-LC-kj and QG-90 cells with 50% inhibitory concentration (IC50) values of 5.8, 10 and 0.31 μM, respectively.
著者
Yoshinori TSUKAMOTO Makoto KASAI Hiroyuki KAKUDA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.65, no.9, pp.2007-2015, 2001 (Released:2002-08-30)
参考文献数
31
被引用文献数
58

To invent a functional natto promoting bone formation, the construction of a strain with high productivity of vitamin K2 (menaquinone-7: MK-7), which is important in the carboxylation of a kind of bone protein participating in bone formation, osteocalcin, was investigated. To screen for a strain appropriate to making natto (a Japanese traditional fermented soybean food) with high productivity of MK-7, a combination of analog resistance to the compounds on the biosynthetic pathway of menaquinones with mutation was done. Consequently, strain OUV23481, with 2-fold higher productivity (1,719 μg/100 g natto) of MK-7 than that of a commercial strain, was constructed as a mutant with analog resistance to 1-hydroxy-2-naphthoic acid (HNA), p-fluoro-D,L-phenylalanine (pFP), m-fluoro-D,L-phenylalanine (mFP), and β-2-thienytalanine (βTA). This strain was classified as Bacillus subtilis (natto). The natto made using this strain was evaluated to have a good quality as natto in all the viewpoints of appearance, flavor, taste, texture, and stringiness.
著者
IZUMIKAWA Miho KAWAHARA Teppei HWANG Ji-Hwan TAKAGI Motoki SHIN-YA Kazuo
出版者
Japan Society for Bioscience, Biotechnology, and Agrochemistry
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.77, no.3, pp.663-665, 2013-03-23
被引用文献数
8

As part of our chemical screening program for new microbial secondary metabolites, we discovered a new compound, JBIR-107 (<b>1</b>), from the culture of <i>Streptomyces tateyamensis</i> NBRC 105047 isolated from a marine sponge sample. Extensive NMR and MS spectroscopic data enabled the structure of <b>1</b> to be determined as 5-acetamido-6-(4-(methyl(2-oxo-3-phenylpropyl)amino)phenyl)-4-oxohexanoic acid.
著者
Tsutomu SATO
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.77, no.6, pp.1155-1159, 2013-06-23 (Released:2013-06-23)
参考文献数
38
被引用文献数
25

To the best of my knowledge, only 19 cyclic and 8 linear C35 terpenes have been identified to date, and no family name was assigned to this terpene class until recently. In 2011, it was proposed that these C35 terpenes should be called sesquarterpenes. This review highlights the biosynthesis of two kinds of sesquarterpenes (C35 terpenes) that are produced via cyclization of a linear C35 isoprenoid in Bacillus and Mycobacterium species. In Bacillus species, a new type of terpene cyclase that has no sequence homology with any known terpene synthases, as well as a bifunctional terpene cyclase that biosynthesizes two classes of cyclic terpenes with different numbers of carbons as natural products, have been identified. On the other hand, in Mycobacterium species, the first bifunctional Z-prenyltransferase has been found, but a novel terpene cyclase and a unique polyprenyl reductase remain unidentified. The identification of novel enzyme types should lead to the discovery of many homologous enzymes and their products including novel natural compounds. On the other hand, many enzymes responsible for the biosynthesis of natural products have low substrate specificities in vitro. Therefore, to find novel natural products present in organisms, the multifunctionality of enzymes in the biosynthetic pathway of natural products should be analyzed.
著者
KAWABATA Yasuyuki KUNO Atsushi GAMA Yasuo KUSAKABE Isao
出版者
社団法人日本農芸化学会
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.60, no.3, pp.524-525, 1996-03-23
被引用文献数
1 5

The substrate speciticity of a p-nitrophenyl α-D-glucopyranosyl-uronic acid-hydrolyzinig enzyme (PNP-GAase) isolated from snail acetone powder has been investigated with various substrates, such as P-nitrophenyl α-D-glucopyranosyluronic acid (PNP-GA), 2-O-α-D-glucopyraniosyluronic acid-D-xylose (GA-2X), 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid)-D-xylose (MeGA-2X), and O-α-D-glucopyranosyluronic acid-α-D-glucopyranosiduronic acid (GA-GA). The K_m (mM) and V_<max> (μmol of glucuronic acid formed/mg of en-zyme protein/min) toward these substrates were as follows; 0.13 and 3.21 for PNP-GA, 0.33 and 0.089 for GA-2X, 17.6 and 0.094 for MeGA-2X, and 0.36 and 0.015 for GA-GA, respectively. The results indicate that the PNP-GAase specifically hydrolyzed PNP-GA, however, the enzyme had broad substrate specificity.
著者
Sayuri TSURUDA Kouichi AKAKI Hiroshi HIWAKI Akira SUZUKI Hiroshi AKIYAMA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.76, no.7, pp.1343-1349, 2012-07-23 (Released:2012-07-23)
参考文献数
33
被引用文献数
8

A rapid multiplex real-time PCR assay was developed to achieve highly specific, simultaneous detection of two kinds of mushrooms, Omphalotus guepiniformis and Lentinula edodes. Primers and TaqMan minor groove binder probes were designed according to the internal transcribed spacers 1-5.8S region of rDNA and evaluated by the specificity for fruiting bodies of 17 O. guepiniformis, 16 L. edodes and samples from 57 other species. DNA extracts of all the target species had positive signals with no cross-reaction, the limit of detection being 0.00025 ng of DNA. Threshold cycle (Ct) values for raw and processed fruiting bodies and for fruiting bodies (1% (w/w)) mixed with foodstuffs or artificial gastric juice contents ranged from 17.16 to 26.60 for both examined species. This new assay proved specific to the target species, highly sensitive, and applicable to processed food samples and gastric juice contents, making it useful for rapidly identifying O. guepiniformis and L. edodes.
著者
Yu ISHIDA Futoshi NAKAMURA Hiroki KANZATO Daisuke SAWADA Naoyuki YAMAMOTO Hiroko KAGATA Masato OH-IDA Haruo TAKEUCHI Shigeru FUJIWARA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.69, no.9, pp.1652-1660, 2005 (Released:2005-09-23)
参考文献数
31
被引用文献数
88

A placebo-controlled, single-blind study was conducted to evaluate the effects of Lactobacillus acidophilus strain L-92 (L-92) on the symptoms of Japanese cedar-pollen allergy. This study was carried out during the 2002 and 2003 seasons of Japanese cedar pollination. Twenty-three in-house volunteers were asked to drink 100 ml of heat-treated milk fermented with L-92 containing 5×1010 of the bacteria, twice a day, for 6 consecutive weeks. A similar study was carried out during the 2003 season for 10 weeks, but the daily dose of bacteria was 2×1010. A significant improvement of the ocular symptom-medication score (SMS) was observed in 2002 and of the score of distress of life in 2003. These data show that a daily oral intake of not less than 2×1010 heat-treated L-92 cells improved the symptoms of Japanese cedar pollinosis, thereby contributing to reduce the dose of concomitant medications. However, no blood parameter was significantly affected in these trials.
著者
Ji Yeon KIM Mochammad Amin ALAMSJAH Aoi HAMADA Yuji FUJITA Fumito ISHIBASHI
出版者
Japan Society for Bioscience, Biotechnology, and Agrochemistry
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.70, no.10, pp.2571-2574, 2006-10-23 (Released:2006-10-23)
参考文献数
11
被引用文献数
34

Bioassay-guided fractionation of an ethanol extract of the brown alga, Dictyota dichotoma, led to the isolation of a novel chlorine-containing perhydroazulene diterpene together with two known diterpenes, dictyolactone and sanadaol. The structure of the novel compound, named dictyol J, was elucidated on the basis of spectroscopic information. Dictyolactone showed the highest algicidal activity against red-tide phytoplanktons among the three isolated compounds.
著者
Takehito MIURA Lan YUAN Buxiang SUN Hajime FUJII Mayumi YOSHIDA Koji WAKAME Ken-ichi KOSUNA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.66, no.12, pp.2626-2631, 2002 (Released:2003-06-25)
参考文献数
21
被引用文献数
80

Soybean extracts (SBE) containing isoflavone glycosides were cultured with Ganoderma lucidum mycelia producing β-glucosidase. The anti-angiogenic effects of the cultivated product, containing rich in genistein, named GCP (genistein combined polysaccharide), were assessed with chick chorioallantoic membranes (CAM) and a mouse dorsal air-sac model. β-Glucosidase produced by the mycelia converted the isoflavone glycosides into aglycons. A test of volunteers showed that serum concentrations of genistein in the subjects treated with GCP (n=4) at 3 h after administration were significantly higher than those in the subjects treated with SBE (n=4). GCP inhibited angiogenesis in CAM, and the activity of GCP was greater than that of SBE. GCP inhibited the formation of new vessels induced by colon carcinoma cells in vivo.
著者
Onaka Hiroyasu Taniguchi Shin-ichi Igarashi Yasuhiro FURUMAI Tamotsu
出版者
社団法人日本農芸化学会
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.67, no.1, pp.127-138, 2003-01-23
被引用文献数
10 101

The biosynthetic gene cluster for rebeccamycin, an indolocarbazole antibiotic, from Lechevalieria aerocolonigenes ATCC 39243 has 11 ORFs. To clarify their functions, mutants with rebG, rebD, rebC, rebP, rebM, rebR, rebH, rebT, or orfD2 disrupted were constructed, and the gene products were examined. rebP disruptants produced 11,11'-dichlorochromopyrrolic acid, found to be a biosynthetic intermediate by a bioconversion experiment. Other genes encoded N-glycosyltransferase (rebG), monooxygenase (rebC), methyltransferase (rebM), a transcriptional activator (rebR), and halogenase (rebH). rebT disruptants produced rebeccamycin as much as the wild strain, so rebT was probably not involved in rebeccamycin production. Biosynthetic genes of staurosporine, an another indolocarbazole antibiotic, were cloned from Streptomyces sp. TP-A0274. staO, staD, and staP were similar to rebO, rebD, and rebP, respectively, all of which are responsible for indolocarbazole biosynthesis, But a rebC homolog, encoding a putative enzyme oxidizing the C-7 site of pyrrole rings, was not found in the staurosporine biosynthetic gene cluster. These results suggest that indolocarbazole is constructed by oxidative decarboxylation of chromopyrrolic acid (11,11'-dichlorochromopyrrolic acid in rebeccamycin) generated from two molecules of tryptophan by coupling and that the oxidation state at the C-7 position depends on the additional enzyme(s) encoded by the biosynthetic genes.
著者
Yoshihisa Tomoda Kenji Umemura Takashi Adachi
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.58, no.1, pp.202-203, 1994-01-23 (Released:2008-02-08)
参考文献数
16
被引用文献数
37 88 80

Alginate lyase-lysate (A.L.L., Algin-Oligo(R)), which had been prepared by degrading sodium alginate by alginate lyase, was found to have a growth-promoting effect on the elongation of barley roots, and especially that of the radicle, the effective concentration of A.L.L. for elongation of the roots being 100-3000μg/ml, with no inhibition at the highest concentration. When a radicle was brought into contact with A.L.L., it responded by initiating elongation within 2 to 4h. The elongation rate increased from 2.9mm/h to 5.3mm/h. Treatment with A.L.L. resulted in about a 2-fold increase in the alcohol dehydrogenase activity of the control under hypoxic conditions.
著者
Ohkuma Moriya Noda Satoko Hongoh Yuichi KUDO Toshiaki
出版者
社団法人日本農芸化学会
雑誌
Bioscience, biotechnology, and biochemistry (ISSN:09168451)
巻号頁・発行日
vol.66, no.1, pp.78-84, 2002-01-23
被引用文献数
13 59 66

Phylogenetically diverse clones of the partial 16S rDNA (ca. 850 bp) of bacteria belonging to the bacteroides subgroup of the cytophaga-flavobacter-bacteroides phylum were collected from the symbiotic microbial communities in the guts of six termite species without cultivation. Combined with the sequences reported previously, a total of thirty phylotypes of the subgroup were identified and classified into five phylogenetic clusters. One that was comprised of the phylotypes from a single termite species was related to the genus Rikenella. Two were clustered each with some cultured strains, genera of which have not been clearly defined yet. The remaining two clusters had no culturable representatives, suggesting the presence of yetuncultivated genera within the termite guts. From these sequence data, we designed a specific primer for the bacteroides subgroup, which was successful in the terminalrestriction fragment length polymorphism analysis to detect the phylotypes of the subgroup in the termite gut.
著者
Hiromichi Itoh Hiroaki Okaya Anisur Rahman Khan Shigeyuki Tajima Shigeru Hayakawa Ken Izumori
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.58, no.12, pp.2168-2171, 1994-12-23 (Released:2008-02-08)
参考文献数
11
被引用文献数
41 137

A new enzyme, D-tagatose 3-epimerase, was found in Pseudomonas sp. ST-24 during the course of studies on D-sorbose fermentation. This new enzyme catalyzes epimerization of keto-sugars, for example between D-tagatose and D-sorbose, and between D-fructose and D-psicose. It was shown that this enzyme epimerizes the configuration at the C-3 position of these substrates. This epimerase didn't act on D-fructose 6-phosphate and D-ribulose 5-phosphate. The enzyme has been purified from cells grown on a medium containing 1% D-glucose and 0.05% D-tagatose, and it appeared homogeneous on electrophoresis. The enzyme has a molecular weight of about 68, 000 by gel filtration and consists of two subunits identical in molecular weight (about 33, 000 by SDS-PAGE). The maximum activity at 30°C was obtained at pH 7-9, and the enzyme was stable from pH 7-11. The optimum temperature was around 60°C, and it was stable up to 60°C for 10 min.
著者
Yoshinori KATAKURA Eriko NAKATA Yukiko TABIRA Takumi MIURA Kiichiro TERUYA Toshie TSUCHIYA Sanetaka SHIRAHATA
出版者
(社)日本農芸化学会
雑誌
Bioscience, Biotechnology, and Biochemistry (ISSN:09168451)
巻号頁・発行日
vol.67, no.4, pp.815-821, 2003 (Released:2003-06-28)
参考文献数
23
被引用文献数
12

We have previously reported that transforming growth factor β (TGF-β) triggers two independent senescence programs, 1) replicative senescence dependent upon telomere shortening and 2) premature senescence independent of telomere shortening, in the cell line of A549 human lung adenocarcinoma. In this study, we examined the possibility that cancer cell tumor phenotypes could be suppressed by forced senescence. We used A549 cells treated with TGF-β for a long time (over 50 days), where senescence was induced in a telomere-shortening-dependent or an independent way. Fully senescent A549 cells were elongated, acquired contact inhibition capabilities when reaching confluence, and secreted the senescence-associated cytokine IL-6. Furthermore, senescent A549 cells had no tumorigenicity in nude mice. These results indicate that the forced induction of senescence in cancer cells may be a novel and potentially powerful method for advancing anti-cancer therapy.