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1.  CD123 targeting oncolytic adenoviruses suppress acute myeloid leukemia cell proliferation in vitro and in vivo 
Li, G | Li, X | Wu, H | Yang, X | Zhang, Y | Chen, L | Wu, X | Cui, L | Wu, L | Luo, J | Liu, X Y
Blood Cancer Journal  2014;4(3):e194-.
We report here a novel strategy to redirect oncolytic adenoviruses to CD123 by carry a soluble coxsackie-adenovirus receptor (sCAR)-IL3 expression cassette in the viral genome to form Ad.IL3, which sustainably infected acute myeloid leukemia (AML) cells through CD123. Ad.IL3 was further engineered to harbor gene encoding manganese superoxide dismutase (MnSOD) or mannose-binding plant lectin Pinellia pedatisecta agglutinin (PPA), forming Ad.IL3-MnSOD and Ad.IL3-PPA. As compared with Ad.IL3 or Ad.sp-E1A control, Ad.IL3-MnSOD and Ad.IL3-PPA significantly suppressed in vitro proliferation of HL60 and KG-1 cells. Elevated apoptosis was detected in HL60 and KG-1 cells treated with either Ad.IL3-MnSOD or Ad.IL3-PPA. The caspase-9–caspase-7 pathway was determined to be activated by Ad.IL3-MnSOD as well as by Ad.IL3-PPA in HL60 cells. In an HL60/Luc xenograft nonobese diabetic/severe-combined immunodeficiency mice model, Ad.IL3-MnSOD and Ad.IL3-PPA suppressed cancer cell growth as compared with Ad.IL3. A significant difference of cancer cell burden was detected between Ad.IL3 and Ad.IL3-PPA groups at day 9 after treatment. Furthermore, Ad.IL3-MnSOD significantly prolonged mouse survival as compared with Ad.sp-E1A. These findings demonstrated that Ad.IL3-gene could serve as a novel agent for AML therapy. Harboring sCAR-ligand expression cassette in the viral genome may provide a universal method to redirect oncolytic adenoviruses to various membrane receptors on cancer cells resisting serotype 5 adenovirus infection.
PMCID: PMC3972701  PMID: 24658372
2.  Feedback loops blockade potentiates apoptosis induction and antitumor activity of a novel AKT inhibitor DC120 in human liver cancer 
Cell Death & Disease  2014;5(3):e1114-.
The serine/threonine kinase AKT is generally accepted as a promising anticancer therapeutic target. However, the relief of feedback inhibition and enhancement of other survival pathways often attenuate the anticancer effects of AKT inhibitors. These compensatory mechanisms are very complicated and remain poorly understood. In the present study, we found a novel 2-pyrimidyl-5-amidothiazole compound, DC120, as an ATP competitive AKT kinase inhibitor that suppressed proliferation and induced apoptosis in liver cancer cells both in vitro and in vivo. DC120 blocked the phosphorylation of downstream molecules in the AKT signal pathway in dose- and time-dependent manners both in vitro and in vivo. However, unexpectedly, DC120 activated mammalian target of rapamycin complex 1 (mTORC1) pathway that was suggested by increased phosphorylation of 70KD ribosomal protein S6 kinase (P70S6K) and eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1). The activated mTORC1 signal was because of increase of intracellular Ca2+ via Ca2+/calmodulin (CaM)/ signaling to human vacuolar protein sorting 34 (hVps34) upon AKT inhibition. Meanwhile, DC120 attenuated the inhibitory effect of AKT on CRAF by decreasing phosphorylation of CRAF at Ser259 and thus activated the mitogen-activated protein kinase (MAPK) pathway. The activation of the mTORC1 and MAPK pathways by DC120 was not mutually dependent, and the combination of DC120 with mTORC1 inhibitor and/or MEK inhibitor induced significant apoptosis and growth inhibition both in vitro and in vivo. Taken together, the combination of AKT, mTORC1 and/or MEK inhibitors would be a promising therapeutic strategy for liver cancer treatment.
PMCID: PMC3973233  PMID: 24625973
AKT inhibitor; apoptosis; MAPK pathway; mTOR complexes; PI3K/AKT pathway
3.  TXNL1-XRCC1 pathway regulates cisplatin-induced cell death and contributes to resistance in human gastric cancer 
Xu, W | Wang, S | Chen, Q | Zhang, Y | Ni, P | Wu, X | Zhang, J | Qiang, F | Li, A | Røe, O D | Xu, S | Wang, M | Zhang, R | Zhou, J
Cell Death & Disease  2014;5(2):e1055-.
Cisplatin is a cytotoxic platinum compound that triggers DNA crosslinking induced cell death, and is one of the reference drugs used in the treatment of several types of human cancers including gastric cancer. However, intrinsic or acquired drug resistance to cisplatin is very common, and leading to treatment failure. We have recently shown that reduced expression of base excision repair protein XRCC1 (X-ray repair cross complementing group1) in gastric cancerous tissues correlates with a significant survival benefit from adjuvant first-line platinum-based chemotherapy. In this study, we demonstrated the role of XRCC1 in repair of cisplatin-induced DNA lesions and acquired cisplatin resistance in gastric cancer by using cisplatin-sensitive gastric cancer cell lines BGC823 and the cisplatin-resistant gastric cancer cell lines BGC823/cis-diamminedichloridoplatinum(II) (DDP). Our results indicated that the protein expression of XRCC1 was significantly increased in cisplatin-resistant cells and independently contributed to cisplatin resistance. Irinotecan, another chemotherapeutic agent to induce DNA damaging used to treat patients with advanced gastric cancer that progressed on cisplatin, was found to inhibit the expression of XRCC1 effectively, and leading to an increase in the sensitivity of resistant cells to cisplatin. Our proteomic studies further identified a cofactor of 26S proteasome, the thioredoxin-like protein 1 (TXNL1) that downregulated XRCC1 in BGC823/DDP cells via the ubiquitin-proteasome pathway. In conclusion, the TXNL1-XRCC1 is a novel regulatory pathway that has an independent role in cisplatin resistance, indicating a putative drug target for reversing cisplatin resistance in gastric cancer.
PMCID: PMC3944244  PMID: 24525731
cisplatin; gastric cancer; drug resistance; XRCC1; TXNL1
4.  Single-photon property characterization of 1.3 μm emissions from InAs/GaAs quantum dots using silicon avalanche photodiodes 
Scientific Reports  2014;4:3633.
We developed a new approach to test the single-photon emissions of semiconductor quantum dots (QDs) in the optical communication band. A diamond-anvil cell pressure device was used for blue-shifting the 1.3 μm emissions of InAs/GaAs QDs to 0.9 μm for detection by silicon avalanche photodiodes. The obtained g(2)(0) values from the second-order autocorrelation function measurements of several QD emissions at 6.58 GPa were less than 0.3, indicating that this approach provides a convenient and efficient method of characterizing 1.3 μm single-photon source based on semiconductor materials.
PMCID: PMC3887382  PMID: 24407193
5.  A NANOS3 mutation linked to protein degradation causes premature ovarian insufficiency 
Wu, X | Wang, B | Dong, Z | Zhou, S | Liu, Z | Shi, G | Cao, Y | Xu, Y
Cell Death & Disease  2013;4(10):e825-.
Primary ovarian insufficiency (POI), or premature ovarian failure, is defined as the cessation of ovarian function before the age of 40. An insufficient ovarian follicle pool derived from primordial germ cells (PGCs) is an important cause of POI. Although the Nanos gene family is known to be required for PGC development and maintenance in diverse model organisms, the relevance of this information to human biology is not yet clear. In this study, we screened the coding regions of the NANOS1, NANOS2 and NANOS3 genes in 100 Chinese POI patients and identified four variants in the coding regions of these three genes, including one synonymous variant in NANOS3, one missense variant in each of NANOS1 and NANOS2 and one potentially relevant mutation (c.457C>T; p.Arg153Trp, heterozygous) in NANOS3. We demonstrated that the p.Arg153Trp substitution decreases the stability of NANOS3, potentially resulting in a hypomorph. Furthermore, an investigation of the relationship between the number of PGCs and the dosage of NANOS3 in mouse models showed that the population of PGCs is controlled by the level of NANOS3 protein. Taken together, our results provide new insight into the properties of the NANOS3 protein and establish that NANOS3 mutation is one possible cause of POI.
PMCID: PMC3824677  PMID: 24091668
POI; PGCs; NANOS3; human genetics; mouse model
6.  OCT4 promotes tumorigenesis and inhibits apoptosis of cervical cancer cells by miR-125b/BAK1 pathway 
Cell Death & Disease  2013;4(8):e760-.
Octamer-binding transcription factor 4 (OCT4) is a key regulatory gene that maintains the pluripotency and self-renewal properties of embryonic stem cells. Although there is emerging evidence that it can function as oncogene in several cancers, the role in mediating cervical cancer remains unexplored. Here we found that OCT4 protein expression showed a pattern of gradual increase from normal cervix to cervical carcinoma in situ and then to invasive cervical cancer. Overexpression of OCT4 in two types of cervical cancer cells promotes the carcinogenesis, and inhibits cancer cell apoptosis. OCT4 induces upregulation of miR-125b through directly binding to the promoter of miR-125b-1 confirmed by chromatin immunoprecipitation analysis. MiRNA-125b overexpression suppressed apoptosis and expression of BAK1 protein. In contrast, miR-125b sponge impaired the anti-apoptotic effect of OCT4, along with the upregulated expression of BAK1. Significantly, Luciferase assay showed that the activity of the wild-type BAK1 3′-untranslated region reporter was suppressed and this suppression was diminished when the miR-125b response element was mutated or deleted. In addition, we observed negative correlation between levels of BAK1 and OCT4, and positive between OCT4 and miR-125b in primary cervical cancers. These findings suggest an undescribed regulatory pathway in cervical cancer, by which OCT4 directly induces expression of miR-125b, which inhibits its direct target BAK1, leading to suppression of cervical cancer cell apoptosis.
PMCID: PMC3763434  PMID: 23928699
OCT4; cervical cancer; apoptosis; miR-125b-1; BAK1
7.  A robust general phase retrieval method for medical applications 
From medical imaging perspective the robustness of a phase retrieval method is of critical importance. In this presentation we compare the robustness of two general phase retrieval methods, namely the transport of intensity equation inversion (TIE-inversion) method and the attenuation partition based (AP-based) method. We showed that the TIE-inversion method, regardless if being assisted with the Tikhonov regularization, failed to retrieve the phase maps in two experimental studies. The failure exposes this method’s weakness as being unstable against the noise. In contrast, the sample phase maps are retrieved successfully by using the AP-based method. The stark performance differences of the two methods are rooted in their different techniques dealing with the singularity problem. This comparison shows that the robust AP-based phase retrieval method will be superior to the TIE-inversion method for medical imaging applications where radiation doses are stringently limited.
PMCID: PMC3721370  PMID: 23894250
Medical-image reconstruction methods and algorithms; computer-aided so; X-ray radiography and digital radiography (DR)
8.  Genome wide linkage disequilibrium in Chinese asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm: implications for domestication history and genome wide association studies 
Heredity  2012;109(1):34-40.
Association mapping of important traits of crop plants relies on first understanding the extent and patterns of linkage disequilibrium (LD) in the particular germplasm being investigated. We characterize here the genetic diversity, population structure and genome wide LD patterns in a set of asparagus bean (Vigna. unguiculata ssp. sesquipedialis) germplasm from China. A diverse collection of 99 asparagus bean and normal cowpea accessions were genotyped with 1127 expressed sequence tag-derived single nucleotide polymorphism markers (SNPs). The proportion of polymorphic SNPs across the collection was relatively low (39%), with an average number of SNPs per locus of 1.33. Bayesian population structure analysis indicated two subdivisions within the collection sampled that generally represented the ‘standard vegetable' type (subgroup SV) and the ‘non-standard vegetable' type (subgroup NSV), respectively. Level of LD (r2) was higher and extent of LD persisted longer in subgroup SV than in subgroup NSV, whereas LD decayed rapidly (0–2 cM) in both subgroups. LD decay distance varied among chromosomes, with the longest (≈5 cM) five times longer than the shortest (≈1 cM). Partitioning of LD variance into within- and between-subgroup components coupled with comparative LD decay analysis suggested that linkage group 5, 7 and 10 may have undergone the most intensive epistatic selection toward traits favorable for vegetable use. This work provides a first population genetic insight into domestication history of asparagus bean and demonstrates the feasibility of mapping complex traits by genome wide association study in asparagus bean using a currently available cowpea SNPs marker platform.
PMCID: PMC3375410  PMID: 22378357
asparagus bean; association mapping; cowpea; domestication history; linkage disequilibrium; population structure
9.  Quantitative analysis of rectal cancer by spectral domain optical coherence tomography 
Physics in medicine and biology  2012;57(16):5235-5244.
To quantify OCT images of rectal tissue for clinic diagnosis, the scattering coefficient of the tissue is extracted by curve fitting the OCT signals to a confocal single model. A total of 1000 measurements (half and half of normal and malignant tissues) were obtained from 16 recta. The normal rectal tissue has a larger scattering coefficient ranging from 1.09 to 5.41 mm–1 with a mean value of 2.29 mm–1 (std: ± 0.32), while the malignant group shows lower scattering property and the values ranging from 0.25 to 2.69 mm–1 with a mean value of 1.41 mm–1 (std: ± 0.18). The peri-cancer of recta has also been investigated to distinguish the difference between normal and malignant rectal tissue. The results demonstrate that the quantitative analysis of the rectal tissue can be used as a promising diagnostic criterion of early rectal cancer, which has great value for clinical medical applications.
PMCID: PMC3691818  PMID: 22850124
11.  Safety and efficacy of intravitreal injection of recombinant erythropoietin for protection of photoreceptor cells in a rat model of retinal detachment 
Xie, Z | Chen, F | Wu, X | Zhuang, C | Zhu, J | Wang, J | Ji, H | Wang, Y | Hua, X
Eye  2011;26(1):144-152.
To elucidate the safety and efficacy of exogenous erythropoietin (EPO) for the protection of photoreceptor cells in a rat model of retinal detachment (RD).
Recombinant rat EPO (400 ng) was injected into the vitreous cavity of normal rats to observe the eye manifestations. Retinal function was assessed by flash electroretinograms. Histopathological examination of retinal tissue was performed at 14 days and 2 months after injection, respectively. To investigate the inhibitory effect of EPO on photoreceptor cell apoptosis in RD rats, 100, 200, or 400 ng EPO was injected into the vitreous cavity immediately after RD model establishment. Apoptosis of photoreceptor cells was determined at 3 days after injection. Caspase-3 activation was measured by western blot analysis and immunofluorescence, respectively, and the level of Bcl-XL expression was analyzed by western blot.
Intravitreal injection of EPO 400 ng into normal rats had no significant impact on retinal function, morphology, or structure. Apoptosis of retinal photoreceptor cells apparently increased after RD and was significantly reduced following EPO treatment. The thickness of the outer nuclear layer in the RD+400 ng group was significantly thicker than that in other experimental RD groups both at 14 days and at 2 months after RD (P<0.05). Western blot and immunofluorescence analyses showed decreased caspase-3 activation and increased Bcl-XL expression following EPO treatment.
Intravitreal injection of EPO 400 ng is safe, and EPO may suppress caspase-3 activation and enhance Bcl-XL expression, resulting in inhibition of apoptosis and protection of photoreceptor cells.
PMCID: PMC3259587  PMID: 22020175
erythropoietin; retinal detachment/experimental; flash electroretinogram; apoptosis
American journal of obstetrics and gynecology  2011;205(5):485.e17-485.e23.
To investigate whether resistance to annexin A5 anticoagulant activity (AnxA5) occurs in women with histories for obstetric complications of antiphospholipid syndrome (Obs-APS) and whether this correlates with antibody recognition of domain 1 of β2- glycoprotein.
Study Design
136 women with antiphospholipid antibodies, including 70 with histories for Obs-APS, and 30 controls, were investigated.
Women with Obs-APS showed resistance to AnxA5 activity (median (range) 216% (130-282%) vs. controls 247% (217-283%), p<0.0001) and elevated levels of anti-domain I IgG (OD: median (range) 0.056 (0.021-0.489) vs. 0.042 (0.020-0.323); p=0.002). Those in the lowest tertile of AnxA5 anticoagulant ratios had an OR for Obs-APS APS of 58.0 (95% CI 3.3-1021.5). There was an inverse correlation between levels of annexin A5 anticoagulant activity and anti-domain I IgG.
Resistance to AnxA5 anticoagulant activity is associated with antibody recognition of domain I of β2GPI and identifies a subset of women with histories for Obs-APS.
PMCID: PMC3205287  PMID: 21784397
annexin V; obstetric; Antiphospholipid antibodies; Antiphospholipid syndrome; Annexin A5; β2-glycoprotein I; Pregnancy loss
13.  Cysteine 149 in the extracellular finger domain of ASIC1b subunit is critical for zinc-mediated inhibition 
Neuroscience  2011;193:89-99.
Acid-sensing ion channel 1b (ASIC1b) is a proton-gated Na+ channel mostly expressed in peripheral sensory neurons. To date, the functional significance of ASIC1b in these cells is unclear due to the lack of a specific inhibitor/blocker. A better understanding of the regulation of ASIC1b may provide a clue for future investigation of its functional importance. One important regulator of acid-sensing ion channels (ASICs) is zinc. In this study, we examined the detailed zinc inhibition of ASIC1b currents and specific amino acid(s) involved in the inhibition. In CHO cells expressing rat ASIC1b subunit, pretreatment with zinc concentration-dependently inhibited the ASIC1b currents triggered by pH dropping from 7.4 to 6.0 with a half-maximum inhibitory concentration of 26 μM. The inhibition of ASIC1b currents by pre-applied zinc was independent of pH, voltage, or extracellular Ca2+. Further, we showed that the effect of zinc is dependent on the extracellular cysteine, but not histidine residue. Mutating cysteine 149, but not cysteine 58 or cysteine 162, located in the extracellular domain of the ASIC1b subunit abolished the zinc inhibition. These findings suggest that cysteine 149 in the extracellular finger domain of ASIC1b subunit is critical for zinc-mediated inhibition and provide the basis for future mechanistic studies addressing the functional significance of zinc inhibition of ASIC1b.
PMCID: PMC3387560  PMID: 21767613
acid-sensing ion channels; zinc; ASIC1b; patch-clamp
14.  Gene Expression in Accumbens GABA Neurons from Inbred Rats with Different Drug-Taking Behavior 
Genes, brain, and behavior  2011;10(7):778-788.
Inbred Lewis and Fisher 344 rat strains differ greatly in drug self-administration; Lewis rats operantly self-administer drugs of abuse including nicotine, whereas Fisher self-administer poorly. As shown herein, operant food self-administration is similar. Based on their pivotal role in drug reward, we hypothesized that differences in basal gene expression in GABAergic neurons projecting from nucleus accumbens (NAcc) to ventral pallidum (VP) play a role in vulnerability to drug taking behavior. The transcriptomes of NAcc shell-VP GABAergic neurons from these two strains were analyzed in adolescents, using a multidisciplinary approach that combined stereotaxic ionotophoretic brain microinjections, laser-capture microdissection (LCM) and microarray measurement of transcripts. LCM enriched the gene transcripts detected in GABA neurons compared to the residual NAcc tissue: a ratio of neuron/residual > 1 and false discovery rate (FDR) <5% yielded 6,623 transcripts, whereas a ratio of >3 yielded 3,514. Strain-dependent differences in gene expression within GABA neurons were identified; 322 vs. 60 transcripts showed 1.5-fold vs. 2-fold differences in expression (FDR<5%). Classification by gene ontology showed these 322 transcripts were widely distributed, without categorical enrichment. This is most consistent with a global change in GABA neuron function. Literature-mining by Chilibot found 38 genes related to synaptic plasticity, signaling and gene transcription, all of which determine drug-abuse; 33 genes have no known association with addiction or nicotine. In Lewis rats, upregulation of Mint-1, Cask, CamkIIδ, Ncam1, Vsnl1, Hpcal1 and Car8 indicates these transcripts likely contribute to altered signaling and synaptic function in NAcc GABA projection neurons to VP.
PMCID: PMC3193935  PMID: 21745336
GABA; nicotine; nucleus accumbens; addiction; ventral pallidum; synapse; transcriptome; Lewis rats; Fisher 344 rats; laser capture microdissection
15.  Pinellia pedatisecta agglutinin interacts with the methylosome and induces cancer cell death 
Lu, Q | Li, N | Luo, J | Yu, M | Huang, Y | Wu, X | Wu, H | Liu, X Y | Li, G
Oncogenesis  2012;1(10):e29-.
Pinellia pedatisecta agglutinin (PPA) is a specific mannose-binding plant lectin accumulated in the tuber of P. pedatisecta. In the work presented, the cytotoxicity of PPA to cancer cells was investigated through exogenous expression. A PPA gene was transduced into normal and cancer cell lines through plasmid vectors, and the effect of PPA expression was examined. Results showed that PPA translocated into the nucleus, colocalized with DNA and induced cell death. A mannose-binding motif and a V103-W130 region directed the nuclear translocation of PPA. Coprecipitation, mass spectrometry and western blotting analysis further indentified that PPA was associated with the methylosome, which contains methylosome protein 50 and protein arginine methyltransferase 5 (PRMT5). Knockdown of PRMT5 significantly inhibited the PPA-induced cell death, suggesting that PPA used the methylosome as a target. Furthermore, Ad.surp-PPA, an adenovirus vector in which the PPA gene was controlled by a survivin promoter (surp), selectively inhibited the proliferation of cancer cell lines. Taken together, the expression of PPA gene elicited significant cytotoxicity to cancer cells through targeting the methylosome and might be developed into a novel agent in cancer gene therapy.
PMCID: PMC3503292  PMID: 23552401
methylosome; Pinellia pedatisecta agglutinin; MEP50; PRMT5; nuclear translocation
18.  Partial germline reversions can increase VRC07 potency and breadth 
Retrovirology  2012;9(Suppl 2):P101.
PMCID: PMC3441513
23.  Timing of Antiretroviral Therapy for HIV-1 Infection and Tuberculosis 
The New England Journal of Medicine  2011;365(16):1482-1491.
Antiretroviral therapy (ART) is indicated during tuberculosis (TB) treatment of patients infected with HIV-1, but the urgency to start ART at TB diagnosis for patients of varying levels of immune compromise is not known.
We conducted an open label, randomized study comparing immediate (within 2 weeks of TB treatment initiation) to early (8–12 weeks) ART among HIV-1 infected patients with CD4+ lymphocytes < 250/mm3 and suspected TB. The primary study endpoint was proportion of patients who survived without an AIDS-defining illness at 48 weeks.
809 patients with median baseline CD4+ lymphocytes of 77 cells/mm3 and HIV-1 RNA of 5.43 log10 copies/mL were enrolled. In the immediate arm, 12.9% of patients experienced an AIDS-defining illness or death by 48 weeks compared to 16.1% in the early arm (p=0.45; 95% confidence interval (CI) for difference: −1.8%, 8.1%). In patients with screening CD4+ lymphocytes <50 cells/mm3, 15.5% of patients on the immediate arm vs. 26.6% on early ART experienced an AIDS defining illness or death (p=0.02; difference CI: 1.5%, 20.5%). TB immune reconstitution inflammatory syndrome (IRIS) was more common with immediate ART (11% vs. 5%: p=0.002). Viral suppression at 48 weeks was 74% and did not differ between arms (p=0.38).
Overall, immediate ART did not reduce AIDS-defining illnesses and death compared to early ART. For persons with CD4+ lymphocytes < 50 cells/mm3, immediate ART had 42% less AIDS defining illnesses and death compared to early ART. ( number NCT00108862.)
PMCID: PMC3327101  PMID: 22010914
24.  The circadian mutation PER2S662G is linked to cell cycle progression and tumorigenesis 
Gu, X | Xing, L | Shi, G | Liu, Z | Wang, X | Qu, Z | Wu, X | Dong, Z | Gao, X | Liu, G | Yang, L | Xu, Y
Cell Death and Differentiation  2011;19(3):397-405.
Circadian oscillation and cell cycle progression are the two most essential rhythmic events present in almost all organisms. Circadian rhythms keep track of time and provide temporal regulation with a period of about 24 h. The cell cycle is optimized for growth and division, but not for time keeping. Circadian gated cell divisions are observed in nearly all organisms. However, the implications of this coupling to the physiology of mammals are unknown. A mutation (S662G) in the clock protein PERIOD2 (PER2) is responsible for familial advanced sleep phase syndrome in which sleep onset occurs in the early evening and wakefulness occurs in the early morning. Here, we provide evidence that the PER2S662 mutation leads to enhanced resistance to X-ray-induced apoptosis and increased E1A- and RAS-mediated oncogenic transformation. Accordingly, the PER2S662 mutation affects tumorigenesis in cancer-sensitized p53R172H/+ mice. Finally, analyzing the clock-controlled cell cycle genes p21, c-Myc, Cyclin D1 and p27, we found that the relative phases between p21 and Cyclin D expression profiles have been changed significantly in these Per2 allele mutant mouse embryonic fibroblasts. This key role of the Per2-mediated phase alteration of p21 provides what we believe to be a novel mechanism in understanding cell cycle progression, its plasticity and its resistance to interference.
PMCID: PMC3278723  PMID: 21818120
PER2; circadian rhythms; cell cycle; tumorigenesis; FASPS
25.  A natural BH3 mimetic induces autophagy in apoptosis-resistant prostate cancer via modulating Bcl-2–Beclin1 interaction at endoplasmic reticulum 
Cell Death and Differentiation  2010;18(1):60-71.
A natural BH3-mimetic, small-molecule inhibitor of Bcl-2, (−)-gossypol, shows promise in ongoing phase II and III clinical trials for human prostate cancer. In this study we show that (−)-gossypol preferentially induces autophagy in androgen-independent (AI) prostate cancer cells that have high levels of Bcl-2 and are resistant to apoptosis, both in vitro and in vivo, but not in androgen-dependent (AD) cells with low Bcl-2 and sensitive to apoptosis. The Bcl-2 inhibitor induces autophagy through blocking Bcl-2–Beclin1 interaction, together with downregulating Bcl-2, upregulating Beclin1, and activating the autophagic pathway. The (−)-gossypol-induced autophagy is dependent on Beclin1 and Atg5. Our results show for the first time that (−)-gossypol can also interrupt the interactions between Beclin1 and Bcl-2/Bcl-xL at endoplasmic reticulum, thus releasing the BH3-only pro-autophagic protein Beclin1, which in turn triggers the autophagic cascade. Oral administration of (−)-gossypol significantly inhibited the growth of AI prostate cancer xenografts, representing a promising new regimen for the treatment of human hormone-refractory prostate cancer with Bcl-2 overexpression. Our data provide new insights into the mode of cell death induced by Bcl-2 inhibitors, which will facilitate the rational design of clinical trials by selecting patients who are most likely to benefit from the Bcl-2-targeted molecular therapy.
PMCID: PMC2950895  PMID: 20577262
(−)-gossypol; Bcl-2; Beclin1; autophagy; apoptosis

Results 1-25 (104)