About

Gary Firestone is a Professor of the Graduate School in the Division of Cell Biology, Development and Physiology at the University of California, Berkeley. His research description can be found at http://mcb.berkeley.edu/faculty/CDB/firestoneg.html. He is associated with the Department of Molecular and Cell Biology and is involved in research related to cell biology, development, and physiology. His office is located at 565 Weill Hall, and he can be contacted via email at glfire@berkeley.edu or by phone at (510) 642-8319.

Research topics

• Biology
• Biochemistry
• Cell biology
• Cancer research
• Internal medicine
• Medicine
• Chemistry
• Genetics

Selected publications

• Supplementary Methods, Figures 1-3 from Direct Inhibition of Elastase Activity by Indole-3-Carbinol Triggers a CD40-TRAF Regulatory Cascade That Disrupts NF-κB Transcriptional Activity in Human Breast Cancer Cells

  2023

  Senior authorCorresponding
  • Chemistry
  • Cancer research
  • Cell biology

  Supplementary Methods, Figures 1-3 from Direct Inhibition of Elastase Activity by Indole-3-Carbinol Triggers a CD40-TRAF Regulatory Cascade That Disrupts NF-κB Transcriptional Activity in Human Breast Cancer Cells

  PublisherOA PDFDOI

• Supplementary Methods, Figures 1-3 from Direct Inhibition of Elastase Activity by Indole-3-Carbinol Triggers a CD40-TRAF Regulatory Cascade That Disrupts NF-κB Transcriptional Activity in Human Breast Cancer Cells

  2023

  Senior authorCorresponding
  • Chemistry
  • Cancer research
  • Cell biology

  Supplementary Methods, Figures 1-3 from Direct Inhibition of Elastase Activity by Indole-3-Carbinol Triggers a CD40-TRAF Regulatory Cascade That Disrupts NF-κB Transcriptional Activity in Human Breast Cancer Cells

  PublisherDOI

• Data from Direct Inhibition of Elastase Activity by Indole-3-Carbinol Triggers a CD40-TRAF Regulatory Cascade That Disrupts NF-κB Transcriptional Activity in Human Breast Cancer Cells

  2023-03-30

  preprintOpen accessSenior author

  <div>Abstract<p>Treatment of highly tumorigenic MDA-MB-231 human breast cancer cells with indole-3-carbinol (I3C) directly inhibited the extracellular elastase-dependent cleavage of membrane-associated CD40, a member of the tumor necrosis factor (TNF) receptor superfamily. CD40 signaling has been implicated in regulating cell survival, apoptosis, and proliferation, as well as in sensitizing breast cancer cells to chemotherapy, and is therefore an important potential target of novel breast cancer treatments. The I3C-dependent accumulation of full-length unprocessed CD40 protein caused a shift in CD40 signaling through TNF receptor–associated factors (TRAF), including the TRAF1/TRAF2 positive regulators and TRAF3 negative regulator of NF-κB transcription factor activity. Because TRAF1 is a transcriptional target gene of NF-κB, I3C disrupted a positive feedback loop involving these critical cell survival components. siRNA ablation of elastase expression mimicked the I3C inhibition of CD40 protein processing and G<sub>1</sub> cell cycle arrest, whereas siRNA knockdown of TRAF3 and the NF-κB inhibitor IκB prevented the I3C-induced cell cycle arrest. In contrast, siRNA knockdown of PTEN had no effect on the I3C control of NF-κB activity, showing the importance of CD40 signaling in regulating this transcription factor. Our study provides the first direct <i>in vitro</i> evidence that I3C directly inhibits the elastase-mediated proteolytic processing of CD40, which alters downstream signaling to disrupt NF-κB–induced cell survival and proliferative responses. Furthermore, we have established a new I3C-mediated antiproliferative cascade that has significant therapeutic potential for treatment of human cancers associated with high levels of elastase and its CD40 membrane substrate. Cancer Res; 70(12); 4961–71. ©2010 AACR.</p></div>

  PublisherDOI

• Data from Direct Inhibition of Elastase Activity by Indole-3-Carbinol Triggers a CD40-TRAF Regulatory Cascade That Disrupts NF-κB Transcriptional Activity in Human Breast Cancer Cells

  2023-03-30

  preprintOpen accessSenior author

  <div>Abstract<p>Treatment of highly tumorigenic MDA-MB-231 human breast cancer cells with indole-3-carbinol (I3C) directly inhibited the extracellular elastase-dependent cleavage of membrane-associated CD40, a member of the tumor necrosis factor (TNF) receptor superfamily. CD40 signaling has been implicated in regulating cell survival, apoptosis, and proliferation, as well as in sensitizing breast cancer cells to chemotherapy, and is therefore an important potential target of novel breast cancer treatments. The I3C-dependent accumulation of full-length unprocessed CD40 protein caused a shift in CD40 signaling through TNF receptor–associated factors (TRAF), including the TRAF1/TRAF2 positive regulators and TRAF3 negative regulator of NF-κB transcription factor activity. Because TRAF1 is a transcriptional target gene of NF-κB, I3C disrupted a positive feedback loop involving these critical cell survival components. siRNA ablation of elastase expression mimicked the I3C inhibition of CD40 protein processing and G<sub>1</sub> cell cycle arrest, whereas siRNA knockdown of TRAF3 and the NF-κB inhibitor IκB prevented the I3C-induced cell cycle arrest. In contrast, siRNA knockdown of PTEN had no effect on the I3C control of NF-κB activity, showing the importance of CD40 signaling in regulating this transcription factor. Our study provides the first direct <i>in vitro</i> evidence that I3C directly inhibits the elastase-mediated proteolytic processing of CD40, which alters downstream signaling to disrupt NF-κB–induced cell survival and proliferative responses. Furthermore, we have established a new I3C-mediated antiproliferative cascade that has significant therapeutic potential for treatment of human cancers associated with high levels of elastase and its CD40 membrane substrate. Cancer Res; 70(12); 4961–71. ©2010 AACR.</p></div>

  PublisherDOI

• Anti-cancer Dynamics of Natural Phytochemical Inhibitors of Cyclin-Dependent Kinases

  Springer eBooks · 2020 · 3 citations

  Senior authorCorresponding
  • Biology
  • Cancer research
  • Cell biology
  PublisherDOI

• 2’, 3’, 4’-trihydroxychalcone is an Estrogen Receptor Ligand Which Modulates the Activity of 17β-estradiol

  bioRxiv (Cold Spring Harbor Laboratory) · 2019-04-13 · 1 citations

  preprintOpen access

  ABSTRACT Menopausal hormone therapy (MHT) reduces the risk of osteoporosis, fractures, obesity and diabetes, but long-term MHT increases risk of other diseases. Safe long-term MHT that exploits its benefits and abrogates its adverse effects requires a new approach. Here we demonstrate that 2’, 3’, 4’-trihydroxychalcone (CC7) acts as an estrogen receptor alpha (ERα) ligand that may improve the safety profile of MHT. CC7 reprograms the actions of estradiol (E2) to regulate unique genes in bone-derived U2OS cells, with 824/1358 genes not regulated by E2. The proliferative action of E2 on human MCF-7 breast cancer cells and mouse uterus is blocked when combined with CC7. Thermostability and molecular dynamics simulation studies suggest that CC7 binds concurrently with E2 in the ERα ligand binding pocket to produce a unique coliganded conformation to modulate ERα. Compounds such as CC7 that act as coligands represent a new class of ERα reprograming drugs that potentially can be combined with existing estrogens to produce a safer MHT regimen for long-term therapy.

  PublisherOA PDFDOI

• 1-Benzyl-indole-3-carbinol is a highly potent new small molecule inhibitor of Wnt/β-catenin signaling in melanoma cells that coordinately inhibits cell proliferation and disrupts expression of microphthalmia-associated transcription factor isoform-M

  Carcinogenesis · 2017-09-19 · 14 citations

  articleOpen accessSenior authorCorresponding

  1-Benzyl-indole-3-carbinol (1-benzyl-I3C), a synthetic analogue of the crucifer-derived natural phytochemical I3C, displayed significantly wider sensitivity and anti-proliferative potency in melanoma cells than the natural compound. Unlike I3C, which targets mainly oncogenic BRAF-expressing cells, 1-benzyl-I3C effectively inhibited proliferation of melanoma cells with a more extensive range of mutational profiles, including those expressing wild-type BRAF. In both cultured melanoma cell lines and in vivo in melanoma cell-derived tumor xenografts, 1-benzyl-I3C disrupted canonical Wnt/β-catenin signaling that resulted in the downregulation of β-catenin protein levels with a concomitant increase in levels of the β-catenin destruction complex components such as glycogen synthase kinase-3β (GSK-3β) and Axin. Concurrent with the inhibition of Wnt/β-catenin signaling, 1-benzyl-I3C strongly downregulated expression of the melanoma master regulator, microphthalmia-associated transcription factor isoform-M (MITF-M) by inhibiting promoter activity through the consensus lymphoid enhancer factor-1 (LEF-1)/T-cell transcription factor (TCF) DNA-binding site. Chromatin immunoprecipitation revealed that 1-benzyl-I3C downregulated interactions of endogenous LEF-1 with the MITF-M promoter. 1-Benzyl-I3C ablated Wnt-activated LEF-1-dependent reporter gene activity in a TOP FLASH assay that was rescued by expression of a constitutively active form of the Wnt co-receptor low-density lipoprotein receptor-related protein (LRP6), indicating that 1-benzyl-I3C disrupts Wnt/β-catenin signaling at or upstream of LRP6. In oncogenic BRAF-expressing melanoma cells, combinations of 1-benzyl-I3C and Vemurafenib, a clinically employed BRAF inhibitor, showed strong anti-proliferative effects. Taken together, our observations demonstrate that 1-benzyl-I3C represents a new and highly potent indolecarbinol-based small molecule inhibitor of Wnt/β-catenin signaling that has intriguing translational potential, alone or in combination with other anti-cancer agents, to treat human melanoma.

  PublisherOA PDFDOI

• Artemisinin disrupts androgen responsiveness of human prostate cancer cells by stimulating the 26S proteasome-mediated degradation of the androgen receptor protein

  Anti-Cancer Drugs · 2017-07-14 · 24 citations

  articleSenior authorCorresponding

  Androgen receptor (AR) expression and activity is highly linked to the development and progression of prostate cancer and is a target of therapeutic strategies for this disease. We investigated whether the antimalarial drug artemisinin, which is a sesquiterpene lactone isolated from the sweet wormwood plant Artemisia annua, could alter AR expression and responsiveness in cultured human prostate cancer cell lines. Artemisinin treatment induced the 26S proteasome-mediated degradation of the receptor protein, without altering AR transcript levels, in androgen-responsive LNCaP prostate cancer cells or PC-3 prostate cancer cells expressing exogenous wild-type AR. Furthermore, artemisinin stimulated AR ubiquitination and AR receptor interactions with the E3 ubiquitin ligase MDM2 in LNCaP cells. The artemisinin-induced loss of AR protein prevented androgen-responsive cell proliferation and ablated total AR transcriptional activity. The serine/threonine protein kinase AKT-1 was shown to be highly associated with artemisinin-induced proteasome-mediated degradation of AR protein. Artemisinin treatment activated AKT-1 enzymatic activity, enhanced receptor association with AKT-1, and induced AR serine phosphorylation. Treatment of LNCaP cells with the PI3-kinase inhibitor LY294002, which inhibits the PI3-kinase-dependent activation of AKT-1, prevented the artemisinin-induced AR degradation. Furthermore, in transfected receptor-negative PC-3 cells, artemisinin failed to stimulate the degradation of an altered receptor protein (S215A/S792A) with mutations in its two consensus AKT-1 serine phosphorylation sites. Taken together, our results indicate that artemisinin induces the degradation of AR protein and disrupts androgen responsiveness of human prostate cancer cells, suggesting that this natural compound represents a new potential therapeutic molecule that selectively targets AR levels.

  PublisherDOI

• Cooperative antiproliferative signaling by aspirin and indole-3-carbinol targets microphthalmia-associated transcription factor gene expression and promoter activity in human melanoma cells

  Cell Biology and Toxicology · 2016-04-01 · 14 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Indole-3-carbinol (I3C) analogues are potent small molecule inhibitors of NEDD4-1 ubiquitin ligase activity that disrupt proliferation of human melanoma cells

  Biochemical Pharmacology · 2016-12-12 · 72 citations

  articleSenior authorCorresponding
  PublisherDOI

Recent grants

• NIH Grant R01CA102360

  NIH · $1.3M · 2011

• NIH Grant R01CA035547

  NIH · $77k · 1986

• NIH Grant T32CA009041

  NIH · $7.1M · 2013

• NIH Grant R01CA164095

  NIH · $862k · 2017

• NIH Grant P01CA005388

  NIH · $9.2M · 1998

Frequent coauthors

• Leonard F. Bjeldanes

  University of California, Berkeley

  48 shared

• Patricia Buse

  University of California, Berkeley

  16 shared

• Ida Aronchik

  Revolution Medicines (United States)

  14 shared

• Anita C. Maiyar

  University of California, Berkeley

  12 shared

• David Pearce

  University of California, San Francisco

  11 shared

• Shyam N. Sundar

  University of California, Berkeley

  11 shared

• François Verrey

  University of Zurich

  10 shared

• Keith R. Yamamoto

  HudsonAlpha Institute for Biotechnology

  10 shared

Labs

• Molecular and Cell BiologyPI