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  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 82, No. 12_Supplement ( 2022-06-15), p. LB564-LB564
    Abstract: While epoxyeicosatrienoic acids (EETs) have been implicated in breast cancer growth and progression, less is known about their effects on oncogene transcription. We have previously found that the oncogenic regioisomer (±)14,15-EET drives mitochondrial respiration, ATP synthesis, and proliferation of ER+/HER2- breast cancer cells [Cell Chem Biol. 2017 Oct 19;24(10):1259-1275]. RNAseq analysis was performed (5 replicates per condition) on serum starved (16 hours) MCF-7 cells which were then treated with (±)14,15-EET or vehicle (2 hours; serum and phenol red free medium without estradiol). Using gene set enrichment analysis (GSEA), we found that (±)14,15-EET activated an estrogen receptor alpha (ER) hallmark early response gene set and synchronously activated a MYC hallmark gene set. With activation of the MYC hallmark gene set, c-Myc gene expression was also induced at 2 hours (3.99-fold; P=2.3 x 10-17; FDR=2.8 x 10-14). These data suggest an alternative path way for activation of estrogen and MYC regulated genes in the absence of estradiol. The 15 genes most transcriptionally activated by (±)14,15-EET at 2 hours were: VMP1, ZFP36, JUNB, FOS, IER3, EGR1, IER5L, ELF3, JUN, NR4A1, HES1, DUSP1, MYC, TOB1, and CITED2 [fold change range: 3.25 (CITED2) to 90.5 (FOS); all P & lt; 2.86 x 10-17; all FDR & lt; 3.03 x 10-14]. The ER regulated genes most transcriptionally activated ( & gt;1.5 fold) were: IER3, TOB1, AREG, CISH, KCNMB3, and PDK4 (fold change range: 1.77 to 4.35; P= 1.74 x 10-18 to 1.35 x 10-5; FDR=5.54 x 10-15 to 6.4 x 10-4). The MYC regulated genes most transcriptionally activated ( & gt; 1.5-fold change) were EIF4A1 (fold change= 2.37; P=1.0 x 10-7; FDR=1.33 x 10-5), IRF9 (fold change=1.58; P=0.0044; FDR= 0.026), and FOSL1 (fold change=1.51; P=0.008; FDR=0.04). Supporting the hypothesis of (±)14,15-EET activation of ER-regulated transcription, (±)14,15-EET promoted nuclear translocation of ER at 1 hour measured by DAPI normalized immunofluorescence [MCF-7 nuclear ER increase of 1.66-fold (P=0.031); ZR75-1 nuclear ER increase of 1.77-fold (P=0.015)]. Supporting the hypothesis of (±)14,15-EET activation of MYC-regulated transcription, (±)14,15-EET treatment promoted nuclear translocation of c-Myc with MCF-7 cells exhibiting a 1.22-fold increase at 2 hours (P=0.002). (±)14,15-EET also promoted nuclear translocation of FITC-70 kDa dextran with MCF-7 cells exhibiting an increase of 1.35-fold at 1 hour (P=0.029). These data suggest that (±)14,15-EET can induce an estradiol-like immediate early gene response in ER+/HER2- breast cancer cells correlating with c-Myc activation. In summary, while the effect of (±)14,15-EET on nuclear translocation may be partially cargo agnostic, (±)14,15-EET promotes ER and c-Myc nuclear translocation and associated transcription, mimicking a tandem hormonal and growth factor response. Citation Format: Jianxun Lei, Zhijun Guo, Julissa Molina-Vega, Paloma Cervantes, Swaathi Jayaraman, John R. Hawse, Carlos Perez, Juan Abrahante, Xiaojia Tang, Krishna Kalari, Jinhua Wang, John R. Falck, Carol Lange, Matthew P. Goetz, David Potter. (±) 14,15-epoxyeicosatrienoic acid induces hallmark ER and MYC gene expression and associated ER and c-Myc nuclear translocation in ER+/HER2- breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB564.
    Type of Medium: Online Resource
    ISSN: 1538-7445
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2022
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  • 2
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 35, No. 30 ( 2017-10-20), p. 3391-3400
    Abstract: Endoxifen is a tamoxifen metabolite with potent antiestrogenic activity. Patients and Methods We performed a phase I study of oral Z-endoxifen to determine its toxicities, maximum tolerated dose (MTD), pharmacokinetics, and clinical activity. Eligibility included endocrine-refractory, estrogen receptor–positive metastatic breast cancer. An accelerated titration schedule was applied until moderate or dose-limiting toxicity occurred, followed by a 3+3 design and expansion at 40, 80, and 100 mg per day. Tumor DNA from serum (circulating cell free [cf); all patients] and biopsies [160 mg/day and expansion] ) was sequenced. Results Of 41 enrolled patients, 38 were evaluable for MTD determination. Prior endocrine regimens during which progression occurred included aromatase inhibitor (n = 36), fulvestrant (n = 21), and tamoxifen (n = 15). Patients received endoxifen once daily at seven dose levels (20 to 160 mg). Dose escalation ceased at 160 mg per day given lack of MTD and endoxifen concentrations 〉 1,900 ng/mL. Endoxifen clearance was unaffected by CYP2D6 genotype. One patient (60 mg) had cycle 1 dose-limiting toxicity (pulmonary embolus). Overall clinical benefit rate (stable 〉 6 months [n = 7] or partial response by RECIST criteria [n = 3] ) was 26.3% (95% CI, 13.4% to 43.1%) including prior tamoxifen progression (n = 3). cfDNA mutations were observed in 13 patients ( PIK3CA [n = 8], ESR1 [n = 5] , TP53 [n = 4], and AKT [n = 1] ) with shorter progression-free survival ( v those without cfDNA mutations; median, 61 v 132 days; log-rank P = .046). Clinical benefit was observed in those with ESR1 amplification (tumor; 80 mg/day) and ESR1 mutation (cfDNA; 160 mg/day). Comparing tumor biopsies and cfDNA, some mutations ( PIK3CA, TP53, and AKT) were undetected by cfDNA, whereas cfDNA mutations ( ESR1, TP53, and AKT) were undetected by biopsy. Conclusion In endocrine-refractory metastatic breast cancer, Z-endoxifen provides substantial drug exposure unaffected by CYP2D6 metabolism, acceptable toxicity, and promising antitumor activity.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2017
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  • 3
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 4_Supplement ( 2020-02-15), p. PD7-06-PD7-06
    Abstract: Background: Endx is a Tam metabolite with promising antitumor activity in Tam and aromatase inhibitor (AI) resistant estrogen receptor (ER) positive (+) metastatic breast cancer (MBC). Methods: This randomized phase II study compared progression-free survival (PFS) and toxicity of Endx 80 mg/day to Tam 20 mg/day in patients (pts) with ER+ MBC. Eligibility included postmenopausal women, ECOG PS 0-2, prior progression on AI but not Tam (unlimited endocrine therapy [ET] lines allowed), and a preregistration biopsy confirming ER+ ( & gt;10% nuclear staining) and HER2-negative MBC. Stratified randomization was used balancing prior CDK 4/6 inhibitor (CDK 4/6i) use and/or everolimus (yes/no), measurable disease (yes/no) and endocrine resistance (primary/secondary) between arms. Pts randomized to Tam were allowed to cross over to Endx at progression. Due to short expected median PFS, differences in PFS were assessed using approaches for interval-censored data (ICD). 40 eligible pts were to be randomized to each arm so a one-sided alpha=0.10 generalized log-rank test (GLRT) would have a 90% chance of detecting a 50% decrease in hazard of disease progression with Endx (median: 6 months) relative to Tam (median: 3 months). Secondary endpoints include clinical benefit rate (stable or partial response & gt; 6 cycles) (CBR) for measurable and non-measurable disease. Pharmacokinetic (PK) data were obtained Day (d) 1 (4 hour), end of cycle 2, and at time of progression. Results: From March 2015 to March 2017, 108 women with endocrine refractory recurrent or MBC were preregistered. 27 pts did not register due to: biopsy demonstrating ER-/HER2- (3 pts), ER+/HER2+ (5 pts), cancer other than breast (3 pts), no cancer in specimen (6 pts), brain metastases (2 pts), acute infection (1 pt), progression on or recent use of Tam (2 pts), or pt refusal (5 pts). 4/81 pts who registered were excluded due to ineligibility (3 pts) or refusal to start protocol treatment (1 pt). The study cohort consisted of 40 pts randomized to Endx and 37 pts to Tam. The median (m) number of ETs in the metastatic setting was 2 (range 1-4) for each arm including prior CDK 4/6i (Endx: 42.5%, Tam: 29.7%) and everolimus (Endx: 35.0%, Tam: 40.5%). The m cycle number was 6 for Endx (range: 1-35) and 3 for Tam (range: 1-42). PFS for Endx was not significantly different compared to Tam (HR= 0.77; 95% CI: 0.49-1.22, GLRT p=0.309; mPFS: Endx 130 days [95% CI: 76-138 days] and Tam 42 days [95%CI: 24-129 days] ). However, PFS was significantly longer in pts with no prior CDK 4/6i in the Endx arm (GLRT p=0.002; HR(no/yes)=0.31; 95%CI: 0.15-0.65) but not in the Tam arm (GLRT p=0.708) (unplanned analysis). Severe (grade (G) 3+) toxicities included: Endx G3 hypertriglyceridemia (3 pts); Tam: G3 hypertension with G2 stroke (1 pt), G3 thromboembolic event (1 pt), and G3 abdominal, bone and liver pain (1 pt). In Endx arm, d1 m Endx plasma concentration (conc) was 216 ng/ml (n=17; range: 144-400). For Tam arm, d1 m Tam conc was 17 ng/ml (n=17; range:11-23) (Endx not detectable). For the 25 pts that crossed over to Endx, CBR was 28.0% (90% CI: 14.0-46.2%) and 14 pts had pk data at progression. A lower median Endx conc (6 ng/ml range: 3.3-16.3) was observed in Tam patients at progression who then had Endx clinical benefit compared to Tam pts without clinical benefit after Endx crossover (median Endx 12 ng/ml; range 4.4-36.6).Conclusions: In endocrine-resistant breast cancer, Z-Endx was not significantly superior to Tam, but clinical benefit was observed in 28% that crossed over to Endx after Tam progression. In pts with no prior CDK 4/6i, the observation of significantly longer PFS in the Endx arm is hypothesis generating. Support: U10CA180821, U10CA180882, U24CA196171, U10CA180820 (ECOG-ACRIN), https://acknowledgments.alliancefound.org; Clinical Trials.gov Identifier:NCT02311933 Citation Format: Matthew P. Goetz, Vera J Suman, Joel M Reid, Mary Kuffel, Sarah A Buhrow, Renee M McGovern, John Black, Travis Dockter, William F Symmans, Minetta C Liu, John R Hawse, James Doroshow, Anna M Storniolo, Jerry M Collins, Howard Streicher, Matthew M Ames, James N Ingle, Ann Partridge, Lisa Carey. A randomized phase II trial of tamoxifen versus Z-endoxifen HCL in postmenopausal women with metastatic estrogen receptor positive, HER2 negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr PD7-06.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
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  • 4
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 81, No. 13 ( 2021-07-01), p. 3727-3737
    Abstract: Chemotherapy-induced cognitive impairment (CICI) is often reported as a neurotoxic side effect of chemotherapy. Although CICI has emerged as a significant medical problem, meaningful treatments are not currently available due to a lack of mechanistic understanding underlying CICI pathophysiology. Using the platinum-based chemotherapy cisplatin as a model for CICI, we show here that cisplatin suppresses nicotinamide adenine dinucleotide (NAD+) levels in the adult female mouse brain in vivo and in human cortical neurons derived from induced pluripotent stem cells in vitro. Increasing NAD+ levels through nicotinamide mononucleotide (NMN) administration prevented cisplatin-induced abnormalities in neural progenitor proliferation, neuronal morphogenesis, and cognitive function without affecting tumor growth and antitumor efficacy of cisplatin. Mechanistically, cisplatin inhibited expression of the NAD+ biosynthesis rate-limiting enzyme nicotinamide phosphoribosyl transferase (Nampt). Selective restoration of Nampt expression in adult-born neurons was sufficient to prevent cisplatin-induced defects in dendrite morphogenesis and memory function. Taken together, our findings suggest that aberrant Nampt-mediated NAD+ metabolic pathways may be a key contributor in cisplatin-induced neurogenic impairments, thus causally leading to memory dysfunction. Therefore, increasing NAD+ levels could represent a promising and safe therapeutic strategy for cisplatin-related neurotoxicity. Significance: Increasing NAD+ through NMN supplementation offers a potential therapeutic strategy to safely prevent cisplatin-induced cognitive impairments, thus providing hope for improved quality of life in cancer survivors.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2021
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  • 5
    In: Frontiers in Endocrinology, Frontiers Media SA, Vol. 9 ( 2018-8-23)
    Type of Medium: Online Resource
    ISSN: 1664-2392
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2018
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  • 6
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 81, No. 4_Supplement ( 2021-02-15), p. PD2-09-PD2-09
    Abstract: Tamoxifen (T) is a pro-drug that undergoes CYP2D6-mediated metabolic activation to metabolites that more potently inhibit estrogen stimulated growth compared to the parent drug. While many studies have examined the role of CYP2D6 genotype in T-treated postmenopausal women, the role of CYP2D6 metabolism in premenopausal women (pre-MW) receiving T, with or without ovarian function suppression (OFS) or exemestane (E) and OFS is unknown. Methods: SOFT randomized 3066 (pre-MW) from 2003-2011 in 27 countries, stratified according to prior receipt or nonreceipt of chemotherapy and nodal status, to receive 5 years of T, T+OFS, or E+OFS. We designed a pharmacogenetics substudy (activated October 2010) to collect blood DNA from North American (NA) patients (pts) or to extract non-tumor DNA from available formalin fixed paraffin embedded (FFPE) tissue blocks. For pts with a blood sample, CYP2D6 was genotyped beginning with the Luminex Tag-It Mutation Detection Kit and when needed, with a copy number variation assay and/or sequencing assays. For pts with FFPE-derived DNA, CYP2D6 genotyping for *3, *4, *6, *9, *10, *17 and *41 was performed using a Taqman Allelic Discrimination Assay. CYP2D6 phenotypes were called by classifying pts on the basis of a combination of poor (PM: *3, *4, *5, *6, *7, *8), slow (SM: *10), intermediate (IM: *9, *17, *29, *41) and extensive metabolizer alleles (EM; all others). Activity scores (AS) from phenotypes assigned for each allele: 0 if PM, 0.25 if SM, 0.5 if IM and 1 if EM allele, and multiplied x2 or x3 if duplicate or triplicate. With concomitant use of potent CYP2D6 inhibitor, AS=0; use of weak inhibitor subtracted 0.5. Metabolizer status was defined by CYP2D6 genotype alone or in combination with CYP2D6 inhibitor use at randomization from the AS: extensive (AS 1.25 to 3), intermediate (AS & gt;0.5 to & lt;1.25), slow/poor (AS 0 to 0.5) metabolizer status. The laboratory was blinded to all clinical data. The substudy primary objective was to assess the association between disease-free survival (DFS) and CYP2D6 metabolizer status in the T arm, and secondarily in the T + OFS, and E + OFS arms. A Cox model estimated hazard ratios comparing status according to treatment assignment, with prespecified prognostic factors. Results: 1200/3047 (39%) randomized pts in the intention-to-treat (ITT) population had successful CYP2D6 genotyping and 50% received prior chemotherapy. Following randomization, 435/1023 (42%) NA pts provided a blood sample and CYP2D6 genotypes were derived in 435/435. Non-tumor tissue was macrodissected from 1277 available FFPE blocks, resulting in DNA concentrations of & gt; 0.3 ng/ml in 1053, and successfully derived CYP2D6 genotypes for 765/3047 pts (25%). 182 (15%) pts had DFS events after 8 yrs median follow-up. Metabolizer status from genotype was 57% extensive, 29% intermediate, 15% slow/poor. Metabolizer status was not associated with DFS in pts assigned T alone (P=0.60; Table), nor in pts assigned T+OFS (P=0.41) or E+OFS (P=0.30). 11% of pts used CYP2D6 inhibitors concomitantly at randomization; for 8% it changed the metabolizer status. The results using this definition were consistent. Conclusion: This retrospective-prospective SOFT pharmacogenetics substudy found no relation of CYP2D6 metabolizer status with DFS in premenopausal pts receiving T, T + OFS, or E + OFS. Given that 50% were pretreated with chemotherapy, further study is needed regarding the role of CYP2D6 metabolism in patients treated with T monotherapy. TableTreatment GroupN pts (N events)Comparison (N pts)Hazard Ratio95% CITamoxifen324 (56)Intermediate (114) vs Extensive (210)0.780.43-1.39Tamoxifen265 (52)Slow/Poor (55) vs Extensive (210)1.110.58-2.13Tamoxifen + OFS357 (46)Intermediate (122) vs Extensive (235)0.730.38-1.40Tamoxifen + OFS299 (45)Slow/Poor (64) vs Extensive (235)1.250.64-2.43Exemestane + OFS344 (46)Intermediate (107) vs Extensive (237)0.590.28-1.22Exemestane + OFS293 (47)Slow/Poor (56) vs Extensive (237)1.130.56-2.27 Citation Format: Matthew P. Goetz, Gini F. Fleming, Mary Kuffel, John R. Hawse, John L. Black, Richard Weinshilboum, James N. Ingle, Patrizia dell’Orto, Olivia Biasi, Roswitha Kammler, Sherene Loi, Marco Colleoni, Giuseppe Viale, Prudence A Francis, Meredith M Regan. The role of CYP2D6 mediated tamoxifen metabolism in the suppression of ovarian function trial (SOFT) [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD2-09.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2021
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  • 7
    Online Resource
    Online Resource
    American Society of Clinical Oncology (ASCO) ; 2010
    In:  Journal of Clinical Oncology Vol. 28, No. 16 ( 2010-06-01), p. 2768-2776
    In: Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 28, No. 16 ( 2010-06-01), p. 2768-2776
    Abstract: Evidence has emerged that the clinical benefit of tamoxifen is related to the functional status of the hepatic metabolizing enzyme cytochrome P450 2D6 (CYP2D6). CYP2D6 is the key enzyme responsible for the generation of the potent tamoxifen metabolite, endoxifen. Multiple studies have examined the relationship of CYP2D6 status to breast cancer outcomes in tamoxifen-treated women; the majority of studies demonstrated that women with impaired CYP2D6 metabolism have lower endoxifen concentrations and a greater risk of breast cancer recurrence. As a result, practitioners must be aware that some of the most commonly prescribed medications coadministered with tamoxifen interfere with CYP2D6 function, thereby reducing endoxifen concentrations and potentially increasing the risk of breast cancer recurrence. After reviewing the published data regarding tamoxifen metabolism and the evidence relating CYP2D6 status to breast cancer outcomes in tamoxifen-treated patients, we are providing a guide for the use of medications that inhibit CYP2D6 in patients administered tamoxifen.
    Type of Medium: Online Resource
    ISSN: 0732-183X , 1527-7755
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    Language: English
    Publisher: American Society of Clinical Oncology (ASCO)
    Publication Date: 2010
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  • 8
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 4_Supplement ( 2020-02-15), p. P6-04-06-P6-04-06
    Abstract: Background: The first in-human phase-I clinical trial of the tamoxifen metabolite, Z-endoxifen, demonstrated promising antitumor activity in both aromatase inhibitor (AI) and tamoxifen resistant ER+ breast cancer patients (Goetz M.P., et al; JCO, 2017). By utilizing a letrozole-sensitive MCF7 aromatase expressing (MCF7AC1) cell line, and its corresponding letrozole-resistant (MCF7LR) cell line, we have shown superior antitumor and antiestrogenic activity of Z-endoxifen over tamoxifen in the AI-sensitive and resistant settings in vivo. This study also revealed that Z-endoxifen may target protein kinases in addition to estrogen receptor alpha. Follow-up studies demonstrated that Z-endoxifen, but not tamoxifen, binds to protein kinase C beta 1 (PKCβ1), a member of the serine/threonine-specific protein kinase family that regulates signaling pathways involved in cell proliferation and tumorigenic transformation (Guo C., et al; SABCS, 2017). We have further shown that PKCβ1 silencing, similar to Z-endoxifen, potently inhibits ER+ cell proliferation and additionally causes ERα turnover. Here, we report a potential mechanism by which PKCβ1 may mediate its anti-proliferative effects in ER+ breast cancer cells. Methods: The effects of siRNA-mediated PKCβ1-silencing on gene transcription were evaluated by RNAseq in MCF7AC1 cells. RNAseq results were further validated by quantitative real-time polymerase chain reaction (qRT-PCR) in PKCβ1-silenced MCF7AC1 cells as well as in ER+ T47D cells. The effects of Z-endoxifen on the mRNA expression of genes altered by PKCβ1-silencing in MCF7AC1 cells were evaluated by qRT-PCR analysis. PKCβ1 silencing effects on protein expression in MCF7AC1 cells were evaluated by immunoblot analysis. Results: RNAseq analysis of PKCβ1-silenced MCF7AC1 cells compared to non-silenced cells revealed NF-κB signaling pathway as the top biological pathway significantly altered by PKCβ1 silencing (p=5.93e-08). Enhanced mRNA expression of multiple NF-κB downstream target genes including CXCL10, RELB, MMP1 and IL6 were observed following PKCβ1 silencing. qRT-PCR analyses validated increased mRNA expression of these genes in PKCβ1-silenced MCF7AC1 and T47D cells. Notably, Z-endoxifen treatment in MCF7AC1 cells mirrored PKCβ1 silencing effects, resulting in enhanced mRNA expression of the aforementioned genes. Evaluation of the protein expression of RelA and RelB, the canonical and noncanonical NF-κB transcription factors respectively, in PKCβ1-silenced MCF7AC1 cells revealed significant upregulation of RelA (p=0.0203) but not RelB (p=0.1360) expression. ERα silencing in MCF7AC1 cells did not affect RelA protein expression. Consistent with prior reports, treatment of MCF7 cells with TNFα inhibited cell proliferation. Finally, targeted siRNA-mediated silencing of RelA in PKCβ1-silenced MCF7AC1 cells significantly attenuated PKCβ1-mediated growth inhibition (p=0.0002). Conclusion: Our findings demonstrate that both Z-endoxifen treatment and PKCβ1-silencing commonly activates a NF-κB-mediated gene signature in ER+ breast cancer cells. Notably, PKCβ1-silencing induces the protein expression of the NF-κB transcription factor RelA in an ERα-independent manner, which appears to contribute to PKCβ1-mediated growth inhibition. Current studies are ongoing to evaluate the impact of RelA silencing on Z-endoxifen mediated growth inhibition. This information will foster our understanding of the estrogenic and non-estrogenic mechanisms by which Z-endoxifen mediates its antitumor activity in ER+ breast cancer. Citation Format: Swaathi Jayaraman, Mary J Kuffel, Krishna R Kalari, Kevin J Thompson, Xiaojia Tang, Elizabeth S Bruinsma, John R Hawse, Matthew P Goetz. Protein kinase C beta 1 (PKCβ1), a novel drug target of Z-endoxifen, inhibits growth of estrogen receptor positive (ER+) breast cancer via activation of the NF-kB transcription factor RelA [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-04-06.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
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  • 9
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    Online Resource
    American Association for Cancer Research (AACR) ; 2022
    In:  Cancer Research Vol. 82, No. 4_Supplement ( 2022-02-15), p. P4-02-09-P4-02-09
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 82, No. 4_Supplement ( 2022-02-15), p. P4-02-09-P4-02-09
    Abstract: Background:. Poor patient outcomes in triple negative breast cancer (TNBC) largely stem from a lack of understanding of therapeutic vulnerabilities and an insufficient armamentarium of effective drugs. The standard of care for most early stage TNBC patients continues to be (neo)adjuvant chemotherapy and radiation. Identifying additional therapeutic options for this subset of patients represents a major unmet need. We and others demonstrated that estrogen receptor beta (ERβ) is expressed in about 20% of TN tumors. Prior research has shown that ligand-mediated activation of ERβ decreases proliferation, invasion, and migration in TNBC cell lines. In vivo, ERβ suppresses the growth of cell line xenograft models and prevents the development of metastatic lesions in a ligand dependent manner. Mechanistically, we found that ERβ repurposes EZH2 to suppress oncogenic NFκB signaling and that pharmacologic inhibition of EZH2 diminishes ERβ function and its anti-cancer effects. This research has led to an ongoing clinical trial (NCT03941730) assessing the efficacy of estradiol in ERβ+ TNBC patients with chemorefractory disease. As with all therapies, patients will exhibit de novo and acquired resistance and therefore we sought to understand the mechanisms of resistance to ERβ targeted therapies. Methods:. Using multiple models of ERβ positive TNBC, we developed ERβ resistant cell lines through chronic exposure to estradiol and the ERβ specific agonist LY500307 over a period of 8 months. We employed RNA sequencing to characterize the transcriptomic changes which occurred following ERβ resistance. We profiled XIST expression across multiple publicly available datasets, including TCGA, Metabric, BEAUTY, and GTEx. XIST expression was also modulated using CRISPR/Cas9 to assess subsequent effects on TNBC cell biology, ERβ function, and response to ERβ targeted therapies. Results:. Our resistant cell line models of ERβ positive TNBC maintained ERβ expression, but were no longer growth inhibited by ERβ agonists. RNAseq revealed substantial differences comparing the transcriptome of resistant versus sensitive cell lines, of which the most increased transcript in the resistant setting was the lncRNA XIST. XIST is best known for its role in X-chromosome inactivation through recruitment and association with the PRC2 complex, and thus EZH2. However, little is known about its functions in breast cancer. We therefore assessed the expression levels of XIST in breast tumors and cell lines. XIST expression was highly variable in breast cancer, was found in a proportion of all breast cancer sub-types and did not correlate with ERβ status. However, XIST expression was up-regulated in ERβ expressing cell lines following long term estrogen treatment. No effects on XIST expression were identified in multiple ERα positive models following estrogen, SERM/SERD treatment, or estrogen deprivation. Furthermore, upregulation of XIST was not associated with resistance to Paclitaxel or Doxorubicin, suggesting XIST is not a part of a broad resistance phenotype. Strikingly, CRISPR mediated knockout of XIST in ERβ resistant cells completely re-sensitized cells to ERβ targeted therapies suggesting that XIST expression is a critical component of ERβ resistance. Conclusions:. ERβ represents a relevant therapeutic target that is being tested in clinical trials. Using multiple in vitro models, we provide evidence that XIST expression is sufficient to induce resistance to. ERβ targeted therapies in TNBC and may therefore represent a relevant biomarker for patient stratification. Further strategies to suppress XIST expression may elicit anti-cancer effects on their own and may resensitize a sub-set of ERβ resistant tumors to ERβ agonists. Citation Format: Michael J Emch, Kirsten GM Aspros, Elizabeth S Bruinsma, Krishna R Kalari, Calley J Jones, Brandon W Simone, Matthew P Goetz, John R Hawse. The lncRNA XIST mediates sensitivity to ERβ targeted therapies in triple negative breast cancer [abstract]. In: Proceedings of the 20 21 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-02-09.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2022
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  • 10
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 4_Supplement ( 2020-02-15), p. P4-17-08-P4-17-08
    Abstract: Background: The clinical utility of routine annual mammogram after curative-intent treatment for male breast cancer is uncertain. There is potentially greater value after lumpectomy (as surveillance for ipsilateral recurrence) than mastectomy (as screening for a new contralateral cancer). The goal of this study was to assess real world use of mammography in men during the first year after lumpectomy or mastectomy to treat breast cancer. Methods: Administrative claims data from OptumLabs Data Warehouse (a large US database that includes privately insured patients and Medicare Advantage-insured enrollees from all 50 states and of all ages and ethnic and racial groups) were used to identify men treated with breast surgery for a new diagnosis of breast cancer between 2007 and 2017. We required continuous coverage starting at least 6 months prior to the non-metastatic breast cancer diagnosis and continuing until at least 13 months after the breast surgery. Our primary endpoint was the proportion of patients who had at least one mammogram during the year (13-month period, to allow for scheduling and other logistical delays) after lumpectomy or mastectomy. Univariate and multivariate testing were performed to identify predictors of mammography (with p & lt;0.05 used as the threshold for statistical significance for both). Our secondary endpoint was the proportion with at least one mammogram within 24 months of surgery, performed in a subset who maintained their insurance coverage for at least that duration. Results: The 13-month analysis included 730 men with a median age at diagnosis of 62 years (Range: 25 to 87 years) and a median follow-up duration of 35 months (Range: 13 to 134 months). 209 (29%) of these men underwent mammography within 13 months after surgery. The characteristics of patients who underwent mammography and those who did not are shown in Table 1. Mammography was more likely after lumpectomy than mastectomy (41% vs. 27%) and after radiation therapy (41% vs. 32% in those who did not receive radiation). In a multivariate logistic regression model, more recent diagnosis (2015+) was associated with lower odds of undergoing mammography, while receipt of radiation was associated with higher odds of undergoing mammography. In the subset of patients with two or more years of post-surgery coverage (n=527), the proportion who had at least one mammogram during that 24-month period was 49% after lumpectomy and 40% after mastectomy. Conclusions: In this insured cohort, 73% of men did not undergo mammography within a year after mastectomy, and 59% did not within a year after lumpectomy. Mammography was less likely in patients diagnosed more recently (perhaps due to acknowledgment of the unique aspects of male breast cancer including a relatively low risk of contralateral second primary tumors), and more likely in those who received radiation. These variations in practice likely result from the paucity of evidence-based guidelines for male breast cancer survivorship care. More research is needed pertaining to whether or not mammograms improve clinical outcomes after curative intent treatment for male breast cancer. Table 1: Patient characteristics associated with receipt of mammogram within first 13 months after male breast cancer surgeryUnivariate AnalysisMultivariate AnalysisNo Mammogram (N=521)Mammogram (N=209)P-value, chi-square testOdds Ratio (OR) and 95% CIP-value for ORAge Group:0.1225-4966 (12.7%)32 (15.3%)Reference50-64216 (41.5%)98 (46.9%)0.99 (0.60, 1.63)0.9665-74112 (21.5%)44 (21.1%)0.87 (0.48, 1.57)0.6575+127 (24.4%)35 (16.7%)0.57 (0.30, 1.07)0.08Census Region:0.52Midwest138 (26.5%)59 (28.2%)ReferenceNortheast97 (18.6%)47 (22.5%)1.10 (0.68, 1.78)0.69South223 (42.8%)79 (37.8%)0.74 (0.49, 1.11)0.15West63 (12.1%)24 (11.5%)0.83 (0.47, 1.47)0.51Year of diagnosis:0.072007-2010126 (24.2%)65 (31.1%)Reference2011-2014199 (38.2%)82 (39.2%)0.80 (0.54, 1.20)0.292015+196 (37.6%)62 (29.7%)0.63 (0.41, 0.96)0.03Elixhauser Category:0.250148 (28.4%)69 (33.0%)Reference1-2218 (41.8%)74 (35.4%)0.85 (0.56, 1.28)0.433+155 (29.8%)66 (31.6%)1.18 (0.75, 1.87)0.47Surgery Type:0.005Lumpectomy55 (10.6%)38 (18.2%)ReferenceMastectomy466 (89.4%)171 (81.8%)1.57 (0.97, 2.55)0.07Chemotherapy:0.79No301 (57.8%)123 (58.9%)ReferenceYes220 (42.2%)86 (41.1%)0.79 (0.54, 1.16)0.23Radiation:0.02No355 (68.1%)124 (59.3%)ReferenceYes166 (31.9%)85 (40.7%)1.51 (1.03, 2.20)0.03 Citation Format: Siddhartha Yadav, Lindsey Sangaralingham, Stephanie R. Payne, Karthik V. Giridhar, Tina J. Hieken, Judy C. Boughey, Robert W. Mutter, John R. Hawse, Rafael E. Jimenez, Rachel A. Freedman, Sadia Choudhery, Fergus J. Couch, Celine M. Vachon, Nilay Shah, Roberto A. Leon-Ferre, Kathryn J. Ruddy. Surveillance mammography after treatment for male breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-17-08.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2020
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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