Citations

Abstract Background: Dysregulated Notch signalling contributes to breast cancer development and progression, but validated tools to measure the level of Notch signalling in breast cancer subtypes and in response to systemic therapy are largely lacking. A transcriptomic signature of Notch signalling would thus be warranted, and in this report, we have established such a classifier. Methods: To generate the signature, we first identified Notch-regulated genes from six basal-like breast cancer cell lines subjected to elevated and reduced Notch signalling by culturing on immobilized Notch ligand Jagged1 or blockade of Notch by g-secretase inhibitors, respectively. From this cadre of Notch-regulated genes, we developed candidate transcriptomic signatures that were trained on a breast cancer patient dataset (the TCGA-BRCA cohort) and a broader breast cancer cell line cohort and sought to validate in independent data sets. Results: An optimal 20-gene transcriptomic signature was selected. We validated the signature on two independent patient datasets (METABRIC and Oslo2) and it showed an improved coherence score and tumour specificity compared with previously published signatures. Furthermore, the signature score was particularly high for basal-like breast cancer, indicating an enhanced level of Notch signalling in this subtype. The signature score was increased after neoadjuvant treatment in the PROMIX and BEAUTY patient cohorts, and a lower signature score generally correlated with better clinical outcome. Conclusions: The 20-gene transcriptional signature has the potential to better stratify patients and to evaluate the response of future Notch-based therapies for breast cancer. Citation Format: Eike-Benjamin Braune, Felix Geist, Xiaojia Tang, Krishna Kalari, Judy Boughey, Liewei Wang, Roberto A. Leon-Ferre, Antonino B. D’Assoro, James N. Ingle, Matthew P. Goetz, Kang Wang, Theodoros Foukakis, Anita Seshire, Dirk Wienke, Urban Lendahl. Identification of a Notch transcriptomic signature for breast cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B013.

ImportanceAurora A kinase (AURKA) activation, related in part to AURKA amplification and variants, is associated with downregulation of estrogen receptor (ER) α expression, endocrine resistance, and implicated in cyclin-dependent kinase 4/6 inhibitor (CDK 4/6i) resistance. Alisertib, a selective AURKA inhibitor, upregulates ERα and restores endocrine sensitivity in preclinical metastatic breast cancer (MBC) models. The safety and preliminary efficacy of alisertib was demonstrated in early-phase trials; however, its activity in CDK 4/6i–resistant MBC is unknown.ObjectiveTo assess the effect of adding fulvestrant to alisertib on objective tumor response rates (ORRs) in endocrine-resistant MBC.Design, Setting, and ParticipantsThis phase 2 randomized clinical trial was conducted through the Translational Breast Cancer Research Consortium, which enrolled participants from July 2017 to November 2019. Postmenopausal women with endocrine-resistant, ERBB2 (formerly HER2)–negative MBC who were previously treated with fulvestrant were eligible. Stratification factors included prior treatment with CDK 4/6i, baseline metastatic tumor ERα level measurement (<10%, ≥10%), and primary or secondary endocrine resistance. Among 114 preregistered patients, 96 (84.2%) registered and 91 (79.8%) were evaluable for the primary end point. Data analysis began after January 10, 2022.InterventionsAlisertib, 50 mg, oral, daily on days 1 to 3, 8 to 10, and 15 to 17 of a 28-day cycle (arm 1) or alisertib same dose/schedule with standard-dose fulvestrant (arm 2).Main Outcomes and MeasuresImprovement in ORR in arm 2 of at least 20% greater than arm 1 when the expected ORR for arm 1 was 20%.ResultsAll 91 evaluable patients (mean [SD] age, 58.5 [11.3] years; 1 American Indian/Alaskan Native [1.1%], 2 Asian [2.2%], 6 Black/African American [6.6%], 5 Hispanic [5.5%], and 79 [86.8%] White individuals; arm 1, 46 [50.5%]; arm 2, 45 [49.5%]) had received prior treatment with CDK 4/6i. The ORR was 19.6%; (90% CI, 10.6%-31.7%) for arm 1 and 20.0% (90% CI, 10.9%-32.3%) for arm 2. In arm 1, the 24-week clinical benefit rate and median progression-free survival time were 41.3% (90% CI, 29.0%-54.5%) and 5.6 months (95% CI, 3.9-10.0), respectively, and in arm 2 they were 28.9% (90% CI, 18.0%-42.0%) and 5.4 months (95% CI, 3.9-7.8), respectively. The most common grade 3 or higher adverse events attributed to alisertib were neutropenia (41.8%) and anemia (13.2%). Reasons for discontinuing treatment were disease progression (arm 1, 38 [82.6%]; arm 2, 31 [68.9%]) and toxic effects or refusal (arm 1, 5 [10.9%]; arm 2, 12 [26.7%]).Conclusions and RelevanceThis randomized clinical trial found that adding fulvestrant to treatment with alisertib did not increase ORR or PFS; however, promising clinical activity was observed with alisertib monotherapy among patients with endocrine-resistant and CDK 4/6i–resistant MBC. The overall safety profile was tolerable.Trial RegistrationClinicalTrials.gov Identifier: NCT02860000

Abstract Purpose: Emergence of de novo or acquired resistance to standard of care endocrine therapies represents a major challenge in the clinical management of estrogen receptor alpha positive (ER+) breast tumors. This process is characterized by high tumor plasticity that confers to cancer cells the ability to shift from a differentiated state, with limited tumorigenic potential, to an undifferentiated state which is responsible for drug resistance and tumor relapse. In ER+ breast tumors, this plasticity is manifest by the enrichment of breast tumor initiating cells (BTICs) with stemness features, such as self-renewal capacity, CD44 expression and high ALDH activity, and ER down-regulation. Development of clinically relevant ER+ breast tumor models to test novel therapeutic strategies that inhibit the enhanced tumor cell plasticity and restore or extend endocrine sensitivity are urgently needed. Experimental Design: Unique endocrine resistant and metastatic breast cancer models were utilized to define in vitro and in vivo the pivotal role of Aurora-A mitotic kinase (AURKA) in the induction of stemness plasticity, endocrine therapy resistance and tumor progression. Unbiased phospho-proteomic analysis was performed in the absence or presence of alisertib, a clinically relevant AURKA inhibitor, that was used to identify novel down-stream targets of AURKA signaling pathway. Results: Phospho-proteomic analysis showed that AURKA targeting reduced the phosphorylation of STAT3 transcription factor at the serine-727 site. Significantly, herein we define a novel mechanism by which AURKA-induced self-renewal capacity is mediated through the activation of a phosphorylated serine727-STAT3/serine294-progesterone receptor (PR) transcriptional complex that regulates the expression of KLF4 stemness reprogramming gene. Remarkable, pharmacologic and genetic targeting of AURKA/STAT3/PR oncogenic axis impairs self-renewal capacity of endocrine therapy resistant breast cancer cells. Conclusions: In this study we demonstrate the pivotal role of a novel AURKA/STAT3/PR oncogenic axis in promoting stemness plasticity and endocrine therapy resistance. These findings provide the strong preclinical rationale for the development of novel combinatorial therapeutic strategies targeting cooperative AURKA/serine727-STAT3 and serine294-PR pathways predicted to result in the selective eradication of CD44High/ALDHHigh BTICs from the bulk tumor with consequent benefits to the clinical outcomes of patients with advanced ER+ breast cancer refractory to standard of care endocrine therapy. Citation Format: Antonino B. D'Assoro. PR/STAT3 nuclear transcriptional complexes mediate aurora-A kinase-induced stemness plasticity in ER+ breast cancer [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 3163.

The Notch signaling pathway is an architecturally simple signaling mechanism, well known for its role in cell fate regulation during organ development and in tissue homeostasis. In keeping with its importance for normal development, dysregulation of Notch signaling is increasingly associated with different types of tumors, and proteins in the Notch signaling pathway can act as oncogenes or tumor suppressors, depending on the cellular context and tumor type. In addition to a role as a driver of tumor initiation and progression in the tumor cells carrying oncogenic mutations, it is an emerging realization that Notch signaling also plays a role in non-mutated cells in the tumor microenvironment. In this review, we discuss how aberrant Notch signaling can affect three types of cells in the tumor stroma—cancer-associated fibroblasts, immune cells and vascular cells—and how this influences their interactions with the tumor cells. Insights into the roles of Notch in cells of the tumor environment and the impact on tumor-stroma interactions will lead to a deeper understanding of Notch signaling in cancer and inspire new strategies for Notch-based tumor therapy.

Introduction:Deep Vein Thrombosis (DVT) of both lower and upper limbs is increasingly being recognized as a clinical entity in patients with chronic diseases hospitalized for several comorbidities. The occurrence of DVT in sites other than lower limbs is an emerging clinical presentation in a setting of a Department of Medicine. The relationship between score models, based on risk factors, symptoms and clinical signs of lower limbs DVT, and circulating biomarkers is not well studied. Hypothesis:We hypothesized to give an additional value to score models using circulating biomarkers in the prediction of DVT in patients hospitalized in Internal Medicine Department. Methods:We prospectively recruited 178 consecutive patients who presented a D-dimer value >500 ng/ml. In each patient Wells modified score for DVT, Hamilton score, Kahn score and St. André Hospital score were applied. We measured serum levels of albumin (%) and protein S (%). Diagnosis of DVT was made by Extended Compression Ultra-Sonography (ECUS) standardized procedure. All patients underwent also an angiographic-CT-scan Results:In 85 (48%) patients the diagnosis of DVT was confirmed. Sites of DVT were as follows: Lower limbs venous thrombosis n=71 (84%); Upper limb venous thrombosis n=8 (9%); portal vein thrombosis n=6 (7%). Patients with DVT had significantly lower albumin levels as compared with controls (mean ± SD 47.6 ± 7.9 vs 55.4 ± 4.6 %, respectively, P<0.001) and lower Protein S (60.7 ± 26.3 vs. 87.6 ± 11.9 %, P<0.001). In this setting, the use of clinical risk scores based on symptoms and clinical signs showed low accuracy (AUC 0.690). We gave an additional value to these scores by testing in combination biomarkers and two of the best items of all clinical score models used to predict DVT: we evaluated a ROC curve analysis including value of Albumin (%), Protein S (%), previous DVT and cancer obtaining a higher accuracy (AUC 0.901, Positive Likelihood Ratio (LR+) 12.97 and Negative Likelihood Ratio (LR-) 0.17). Conclusions:This study demonstrates that biomarkers improve the prediction of clinical scores in the diagnosis of DVT of all sites in hospitalized patients.

Formation of transplantable reproducible hiPSC organoids can be aided with real-time label-free intracellular spectroscopy.

Abstract Background: In ER+ breast cancer (BC) models, Aurora A kinase (AURKA) activation is associated with expansion of CD44+/CD24low/- tumor initiating cells, down-regulation of ERα, and endocrine therapy resistance. Alisertib, a selective AURKA inhibitor, can restore ERα expression and endocrine sensitivity. Early phase studies evaluating alisertib alone or with fulvestrant for ER+ metastatic BC (MBC) demonstrated a favorable safety profile and promising antitumor activity [Haddad, Breast Cancer Res Treat. 2018]. A phase II trial was conducted to determine if the addition of fulvestrant to alisertib improved objective response rate (ORR) and to assess clinical activity of alisertib alone or with fulvestrant in patients (pts) with prior fulvestrant and CDK 4/6 inhibitor (CDK 4/6i). Methods: Pts were randomized 1:1 to Arm A, alisertib (50 mg PO BID Days 1-3, 8-10, 15-17 q 28 days) or Arm B, alisertib with fulvestrant (500 mg IM Day 1, 15 for Cycle 1 and q 28 days thereafter). Eligibility included postmenopausal women, history of ER+ BC, prior fulvestrant, ≤ 2 prior chemotherapy lines, and measurable disease. Stratification factors included prior CDK4/6i, ER level (&lt;10%, ≥10%), and primary/secondary endocrine resistance. Pts on Arm A could cross over to Arm B at progression. With 45 pts per arm, a one sided alpha=0.15 sequential binomial test would have an 85% chance of detecting an increase of ≥ 20% in the ORR of ArmB when the true ORR for Arm A is ≤ 20%. ORR was defined as a partial response (PR) + complete response (CR) by RECIST v.1.1 criteria. Secondary endpoints include progression free survival (PFS), 24-week clinical benefit rate (CBR = CR + PR + absence of progression for&gt; 6 cycles), overall survival, duration of response (DoR), and safety. Blood and tumor specimens were collected at baseline, end of Cycle 1, and progression. Results: Pts enrolled July 2017 - November 2019 with 118 pre-registered, 96 registered, and 90 evaluable for the primary endpoint (Arm A: 45, Arm B: 45). Median age was 60 (range 33, 85). Nearly all received prior fulvestrant (n=89, 98.9%), aromatase inhibitor (n=83, 92.2%), and CDK4/6i (n=88, 97.8%). Most had secondary endocrine resistance (n=71, 78.9%). Pre-registration biopsy for ER was positive in 84 pts (86.7%) and negative in 6 pts (13.3%). More pts on Arm B had prior everolimus (A: 35.6%, B: 57.8%) and prior chemotherapy (A: 44.4%, B: 55.6%) for MBC. The ORR for alisertib and fulvestrant was 20.0% (90% CI: 10.9-32.3%), not significantly greater than alisertib alone 17.8% (90% CI: 9.2-29.8%). The 24-week CBR for Arm A was 42.2% (90% CI: 29.7-55.6%; n=19, including 7 PR) and Arm B was 31.1% (90% CI: 19.9-44.3%; n=14, including 8 PR). As of July 1, 2020, the median DoR was not reached in either arm. The median PFS time was 5.6 months (95% CI: 3.9 - 9.3) for Arm A and 5.1 months (95%CI: 3.8 - 7.6) for Arm B. Seventeen pts (18.9%) remain on treatment (A: 12, B: 5) having received at least 11 cycles (range up to 32+ cycles). At least one dose reduction was required for pts (A: 19, B: 18), most commonly due to neutropenia. The most common severe (grade ≥3) adverse events included neutropenia (n=19, 42.2% in each arm), anemia (A: 15.6%, B: 8.8%), and fatigue (n=5, 11.1% Arm B only). Pts discontinued therapy due to disease progression equally in each arm (n=28, 62.2%), however more pts on Arm B (n=12) than Arm A (n=5) discontinued therapy due to toxicity, refusal or other reasons. Conclusion: While the addition of fulvestrant to alisertib did not improve ORR, promising clinical activity with alisertib monotherapy was observed overall and notably for pts with endocrine and CDK 4/6i-resistant MBC. More severe toxicities and treatment discontinuation were observed in pts receiving combination therapy. Correlative blood (CTC/cfDNA) and tissue (AURKA, ERα, and stemness biomarkers) studies are underway. Citation Format: Tufia Haddad, Antonino D'Assoro, Vera Suman, Jodi Carter, Brendan McMenomy, Erica Mayer, Meghan Karuturi, Aki Morikawa, Paul Marcom, Claudine Isaacs, Sun Young Oh, Amy Clark, Ingrid Mayer, Khandan Keyomarsi, Roberto Leon-Ferre, Karthik Giridhar, Ciara O'Sullivan, Prema Peethambaram, Timothy Hobday, Minetta Liu, James Ingle, Matthew Goetz. Randomized phaseII trial to evaluate alisertib alone or combined with fulvestrant for advanced, endocrine-resistant breast cancer (TBCRC 041) [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 PD2-05.

e13106 Background: Chemotherapy resistance remains a significant barrier in the effective treatment of patients with triple negative breast cancer (TNBC). TGF-β signaling is a well characterized oncogenic pathway in TNBC that promotes chemoresistance by inducing epithelial to mesenchymal transition (EMT) and tumor stemness. Aurora-A kinase (AURKA) is a serine/threonine kinase responsible for chromosomal stability during mitosis. Significantly, aberrant expression of AURKA induces breast cancer progression. We hypothesized that aberrant activation of TGF-β and AURKA signaling pathways contributes to chemoresistance in TNBC by promoting EMT and tumor stemness and that dual-targeting of these oncoproteins will enhance chemosensitivity. Methods: RNA-Seq data were analyzed from patient derived xenografts (PDx) established from patients with Stage I-III TNBC who received pre-operative taxane and anthracycline based chemotherapy. Chemoresistance was defined as an RCB score of 1-3, and chemosensitivity was defined as an RCB score of 0. Unique TNBC cell lines developed from brain metastasis PDxs (TNBC M14, TNBC M25) were treated in vitro with 10nM docetaxel (DTX), 50nM LY2157299 (TGF-β inhibitor) and 50nM MLN8237 (AURKA inhibitor). EMT reprogramming was determined by measuring the expression of vimentin, ALDH activity and mammosphere growth. Apoptotic cells following drug treatment were labeled with Red Annexin-V marker and monitored in real time using the IncuCyte instrument. Results: RNA-Seq revealed that there was no baseline difference in expression of AURKA between chemoresistant and chemosensitive TNBC PDxs. However, there was a 2.7-fold increase in AURKA expression in the post-treatment PDx models compared to pre-treatment PDx models. In vitro treatment of the M14 and M25 cell lines with DTX demonstrated no significant increase in apoptotic cells compared to control, whereas treatment with the combination of DTX, LY2157299 and MLN8237 resulted in a two-fold increase in apoptosis compared to treatment with DTX alone (p = 0.0068 M14, p = 0.003 M25). Dual-targeting with LY2157299 and MLN8237 reduced the expression of vimentin and ALDH activity. Conclusions: TGF-β and AURKA play a central role inducing EMT and a stem-cell-like phenotype in TNBC that confers chemoresistance. AURKA is up-regulated after exposure to chemotherapy in chemoresistant TNBC PDx models. LY2157299 and MLN8237 reduce TNBC stemness in M14 and M25 cell lines and enhance DTX chemosensitivity. Dual-targeting of TGF-β and AURKA is a potentially promising approach in chemoresistant TNBC.

Abstract Background: Onset of metastases involves a complex multistep biological process termed the invasion-metastasis cascade, which include dissemination of cancer cells from the primary tumor to secondary organs. NOTCH signaling plays a critical role in promoting Triple Negative Breast Cancer (TNBC) metastasis. Although all four NOTCH receptors show oncogenic properties, the unique role of each of these receptors in the sequential stepwise events that typify the invasion-metastasis cascade remains elusive. Methods: We established unique TNBC cells (TNBC-M14, -M25 and -M40), isolated from patient-derived brain metastasis xenografts (PD-BMXs). NOTCH3 genetic targeting was achieved using Lenti-vector shRNAs. Immunoblot analysis was used to assess NOTCH3 expression. ALDH1 activity was established using the ALDEOFLUOR Kit. To assess self-renewal capacity and resistance to docetaxel-based chemotherapy, TNBC cells were cultured under non-adherent conditions to form mammospheres (MPS). A publicly clinical database (http://kmplot.com) was employed to analyze NOTCH3 expression in a selected cohort of 107 lymph- node+ TNBC patients. Results: TNBC-M14, -M25 and -M40 MPS showed NOTCH3 overexpression and higher ALDH1 activity compared to MDA-MB 231 MPS used as control. To investigate the causative role of NOTCH3 in inducing ALDH1 activity, self-renewal capacity and chemoresistance, we infected TNBC MPS with Lenti-vector shRNAs targeting NOTCH3. NOTCH3 geneting targeting induced a significant reduction of ALDH1 activity compared to TNBC MPS infected with scrambled Lenti-shRNAs. Significantly, NOTCH3 geneting targeting significantly impaired MPS formation and restored sensitivity to docetaxel. The correlation between aberrant NOTCH3 expression and poor outcome in patients with advanced TNBC was also investigated in a publicly clinical database. Conclusions: These findings provide a compelling preclinical rationale for the design of novel clinical trials that will selectively target NOTCH3 to delay metastatic growth and to improve the clinical outcome of patients with advanced TNBC. Citation Format: Antonino Bonaventura D'Assoro. NOTCH3 targeting inhibits ALDH1 activity and restores chemosensitivity in metastatic TNBC [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 P6-03-07.