Human BRCA1 mutation carriers and BRCA1-deficient mouse mammary glands contain an abnormal population of mammary luminal progenitors that can form 3D colonies in a hormone-independent manner. The ...intrinsic cellular regulatory defect in these presumptive breast cancer precursors is not known. We have discovered that nuclear factor kappaB (NF-κB) (p52/RelB) is persistently activated in a subset of BRCA1-deficient mammary luminal progenitors. Hormone-independent luminal progenitor colony formation required NF-κB, ataxia telangiectasia-mutated (ATM), and the inhibitor of kappaB kinase, IKKα. Progesterone (P4)-stimulated proliferation resulted in a marked enhancement of DNA damage foci in Brca1−/− mouse mammary. In vivo, NF-κB inhibition prevented recovery of Brca1−/− hormone-independent colony-forming cells. The majority of human BRCA1mut/+ mammary glands showed marked lobular expression of nuclear NF-κB. We conclude that the aberrant proliferative capacity of Brca1−/− luminal progenitor cells is linked to the replication-associated DNA damage response, where proliferation of mammary progenitors is perpetuated by damage-induced, autologous NF-κB signaling.
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•NF-κB is autonomously activated in BRCA1-deficient mammary progenitors•NF-κB and ATM are required for aberrant proliferation of BRCA1-deficient progenitors•BRCA1 prevents a replication-induced DNA damage response and resulting NF-κB activation
BRCA1 mutations increase the risk for breast cancer and have been linked with hormone-independent abnormal proliferation of mammary luminal progenitors. In this study, Sau et al. find that DNA-damage-induced NF-κB activation in BRCA1-deficient luminal progenitors is a cellular mechanism required for hormone-uncoupled proliferation, increasing the risk of genomic instability and transformation.
The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often ...termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34+) leukemic versus normal specimens. Our data indicate that CD34+ AML cells have elevated expression of multiple glutathione pathway regulatory proteins, presumably as a mechanism to compensate for increased oxidative stress in leukemic cells. Consistent with this observation, CD34+ AML cells have lower levels of reduced glutathione and increased levels of oxidized glutathione compared with normal CD34+ cells. These findings led us to hypothesize that AML cells will be hypersensitive to inhibition of glutathione metabolism. To test this premise, we identified compounds such as parthenolide (PTL) or piperlongumine that induce almost complete glutathione depletion and severe cell death in CD34+ AML cells. Importantly, these compounds only induce limited and transient glutathione depletion as well as significantly less toxicity in normal CD34+ cells. We further determined that PTL perturbs glutathione homeostasis by a multifactorial mechanism, which includes inhibiting key glutathione metabolic enzymes (GCLC and GPX1), as well as direct depletion of glutathione. These findings demonstrate that primitive leukemia cells are uniquely sensitive to agents that target aberrant glutathione metabolism, an intrinsic property of primary human AML cells.
Background: Eradication of primary human leukemia cells represents a major challenge. Therapies have not substantially changed in over 30 years.
Results: Using normal versus leukemia specimens enriched for primitive cells, we document aberrant regulation of glutathione metabolism.
Conclusion: Aberrant glutathione metabolism is an intrinsic property of human leukemia cells.
Significance: Interventions based on modulation of glutathione metabolism represent a powerful means to improve therapy.
Based on previous SAR studies on N-benzylindole and barbituric acid hybrid molecules, we have synthesized a series of aromatic substituted ...5-((1-benzyl-1H-indol-3-yl)methylene)-1,3-dimethylpyrimidine-2,4,6(1H,3H,5H)-trione analogs (3a–i) and evaluated them for their in vitro growth inhibition and cytotoxicity against a panel of 60 human tumor cell lines. Compounds 3c, 3d, 3f and 3g were identified as highly potent anti-proliferative compounds against ovarian, renal and breast cancer cell lines with GI50 values in low the nanomolar range. The 4-methoxy-N-benzyl analog (3d) was the most active compound with GI50 values of 20nM and 40nM against OVCAR-5 ovarian cancer cells and MDA-MB-468 breast cancer cells, respectively. Two other analogs, 3c (the 4-methyl-N-benzyl analog) and 3g (the 4-fluoro-N-benzyl analog) exhibited equimolar potency against MDA-MB-468 cells GI50=30nM). Analog 3f (the 4-chloro-N-benzyl analog) exhibited a GI50 value of 40nM against renal cancer cell line A498. These results suggest that aromatic substituted N-benzylindole dimethylbarbituric acid hybrids may have potential for development as clinical candidates to treat a variety of solid tumors.
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•Tetrazolylresveratrols exhibit anti-cancer activity against human cancer cells.•Tetrazolylresveratrols are cytotoxic against MV4-11 cells but not normal cells.•Tetrazolylresveratrols ...inhibit tubulin polymerization.•Tetrazolylresveratrols interact with the colchicine binding site on tubulin.•Lead analogue 8h had GI50 values of <10 nM in 94% of a 60-human cancer cell panel.
A series of novel tetrazole analogues of resveratrol were synthesized and evaluated for their anti-leukemic activity against an extensive panel of human cancer cell lines and against the MV4-11 AML cell line. These molecules were designed as drug-like derivatives of the resveratrol analogue DMU-212 and its cyano derivatives. Four compounds 8g, 8h, 10a and 10b exhibited LD50 values of 4.60 µM, 0.02 µM, 1.46 µM, and 1.08 µM, respectively, against MV4-11 leukemia cells. The most potent compounds, 8h and 10b, were also found to be active against an extensive panel of human hematological and solid tumor cell lines; compound 8h was the most potent compound with GI50 values <10 nM against more than 90% of the human cancer cell lines in the 60-cell panel. Analogues 8g, 8h, 10a and 10b were also tested for their ability to inhibit the polymerization of tubulin, and compound 8h was found to be the most potent analogue. Molecular modeling studies demonstrated that 8h binds to the colchicine binding site on tubulin. Thus, compound 8h is considered to be a lead druglike molecule from this tetrazole series of compounds.
A series of novel hybrid 8-hydroxyquinoline-indole derivatives (
,
and
) were synthesized and screened for inhibitory activity against self-induced and metal-ion induced Aβ
aggregation as potential ...treatments for Alzheimer's disease (AD). In vitro studies identified the most inhibitory compounds against self-induced Aβ
aggregation as
,
and
(EC
= 1.72, 1.48 and 1.08 µM, respectively) compared to the known anti-amyloid drug, clioquinol (
, EC
= 9.95 µM). The fluorescence of thioflavin T-stained amyloid formed by Aβ
aggregation in the presence of Cu
or Zn
ions was also dramatically decreased by treatment with
,
and
. The most potent hybrid compound
afforded 82.3% and 88.3% inhibition, respectively, against Cu
- induced and Zn
- induced Aβ
aggregation. Compounds
,
and
were shown to be effective in reducing protein aggregation in HEK-tau and SY5Y-APP
cells. Molecular docking studies with the most active compounds performed against Aβ
peptide indicated that the potent inhibitory activity of
and
were predicted to be due to hydrogen bonding interactions, π-π stacking interactions and π-cation interactions with Aβ
which may inhibit both self-aggregation as well as metal ion binding to Aβ
to favor the inhibition of Aβ
aggregation.
Glioblastoma (GBM) is highly resistant to treatment and invasion into the surrounding brain is a cancer hallmark that leads to recurrence despite surgical resection. With the emergence of precision ...medicine, patient-derived 3D systems are considered potentially robust GBM preclinical models. In this study, we screened a library of 22 anti-invasive compounds (i.e., NF-kB, GSK-3-B, COX-2, and tubulin inhibitors) using glioblastoma U-251 MG cell spheroids. We evaluated toxicity and invasion inhibition using a 3D Matrigel invasion assay. We next selected three compounds that inhibited invasion and screened them in patient-derived glioblastoma organoids (GBOs). We developed a platform using available macros for FIJI/ImageJ to quantify invasion from the outer margin of organoids. Our data demonstrated that a high-throughput invasion screening can be done using both an established cell line and patient-derived 3D model systems. Tubulin inhibitor compounds had the best efficacy with U-251 MG cells, however, in ex vivo patient organoids the results were highly variable. Our results indicate that the efficacy of compounds is highly related to patient intra and inter-tumor heterogeneity. These results indicate that such models can be used to evaluate personal oncology therapeutic strategies.
Antibacterial activity: ZOI50 μg/ml: E. coli—15mm and B. subtilis—18mm.
Anticancer activity: Leukemia: CCRF-CEM (GI50: 0.33μM); Non-Small Cell Lung Cancer: NCI-H522 (GI50: 1.03μM); Colon Cancer: ...HCT-116 (GI50: 1.60μM), CNS Cancer: SF-539 (GI50: 1.58μM), Melanoma MALME-3M (GI50: 1.59μM), Ovarian Cancer: OVCAR-3 (GI50: 1.16μM), Renal Cancer: UO-31 (GI50: 0.76μM), Prostate Cancer: PC-3 (GI50: 0.82μM); Breast Cancer: BT-549 (GI50: 1.13μM).
DNA cleavage activity: Completely cleaved the DNA even at 50μg/mL. Display omitted
A series of indole incorporated thiazolylcoumarins (7a–q) have been synthesized and evaluated for their antibacterial, anticancer and DNA cleavage studies. Analysis of antibacterial studies indicated that all the synthesized compounds possess promising activity towards the screened bacterial strains. In vitro anticancerous action was studied for compound 7a (NSC: 768621/1) against the full panel of 60 human tumor cell lines. The five dose level activity results revealed that, the compound 7a was active against all the cell lines among them it has shown potent activity against Leukemia: CCRF-CEM (GI50: 0.33μM), Non-Small Cell Lung Cancer: NCI-H522 (GI50: 1.03μM), Colon Cancer: HCT-116 (GI50: 1.60μM), CNS Cancer: SF-539 (GI50: 1.58μM), Melanoma MALME-3M (GI50: 1.59μM), Ovarian Cancer: OVCAR-3 (GI50: 1.16μM), Renal Cancer: UO-31 (GI50: 0.76μM), Prostate Cancer: PC-3 (GI50: 0.82μM) and Breast Cancer: BT-549 (GI50: 1.13μM). DNA cleavage studies revealed that even at 50μg/mL concentration complete DNA digestion was observed for all the compounds, except for compound (7o) where partial DNA digestion was observed even at 100μg/mL.
Leukemia stem cells (LSCs) are thought to play a central role in the pathogenesis of acute leukemia and likely contribute to both disease initiation and relapse. Therefore, identification of agents ...that target LSCs is an important consideration for the development of new therapies. To this end, we have previously demonstrated that the naturally occurring compound parthenolide (PTL) can induce death of human LSCs in vitro while sparing normal hematopoietic cells. However, PTL has relatively poor pharmacologic properties that limit its potential clinical use. Consequently, we generated a family of PTL analogs designed to improve solubility and bioavailability. These studies identified an analog, dimethylamino-parthenolide (DMAPT), which induces rapid death of primary human LSCs from both myeloid and lymphoid leukemias, and is also highly cytotoxic to bulk leukemic cell populations. Molecular studies indicate the prevalent activities of DMAPT include induction of oxidative stress responses, inhibition of NF-κB, and activation of p53. The compound has approximately 70% oral bioavailability, and pharmacologic studies using both mouse xenograft models and spontaneous acute canine leukemias demonstrate in vivo bioactivity as determined by functional assays and multiple biomarkers. Therefore, based on the collective preclinical data, we propose that the novel compound DMAPT has the potential to target human LSCs in vivo.
The ability of chemo-radiation therapy to control locally advanced stage III non-small cell lung cancer (NSCLC) is poor. While addition of consolidation immunotherapy has improved outcomes in subsets ...of patients there is still an urgent need for new therapeutic targets. Emerging research indicates that nucleophosmin1 (NPM1) is over-expressed in NSCLC, promotes tumor growth and that over-expression correlates with a lower survival probability. NPM1 is critical for APE1 base excision activity and for RAD51-mediated repair of DNA double strand breaks (DSBs). YTR107 is a small molecule radiation sensitizer that has been shown to bind to NPM1, suppressing pentamer formation. Here we show that in irradiated cells YTR107 inhibits SUMOylated NPM1 from associating with RAD51, RAD51 foci formation and repair of DSBs. YTR107 acts synergistically with the PARP1/2 inhibitor ABT 888 to increase replication stress and radiation-induced cell lethality. YTR107 was found to radiosensitize tumor initiating cells. Congruent with this knowledge, adding YTR107 to a fractionated irradiation regimen diminished NSCLC xenograft growth and increased overall survival. These data support the hypothesis that YTR107 represents a therapeutic target for control of NSCLC.
•The small molecule YTR107 inhibits NPM1 from binding to RAD51.•YTR107 inhibits RAD51 recruitment to DNA DSBs.•YTR107 inhibits repair of DNA DSBs.•YTR107 radiosensitizes tumor initiating cells and tumor xenografts.
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