Resistance Pathways Research Articles

Exploring the Clinical Impact of RANK Pathway Inhibition in Advanced Breast Cancer: Insights From a Retrospective Study on CDK4/6 Inhibitors and Antiresorptive Therapy.

Breast cancer (BC) remains a significant health concern, particularly in advanced stages where the prognosis is poor. The combination of endocrine therapy (ET) with cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) has improved outcomes for advanced BC (aBC) patients. However, resistance to CDK4/6i remains a challenge, with no validated biomarkers to predict response. The receptor activator of the nuclear factor-kB (RANK) pathway has emerged as a key player in aBC, particularly in luminal BC. RANK overexpression has been associated with aggressive phenotypes and resistance to therapy. In view of these findings, we proceeded to investigate the potential involvement of the RANK pathway in luminal BC resistance to CDK4/6i. The objective was to evaluate the effectiveness of denosumab in increasing overall survival (OS) and progression-free survival (PFS). In this retrospective analysis, 158 BC patients with bone metastases were included. Patients with human epidermal growth factor receptor-2 (HER2)-negative and hormone receptor-positive BC who received palbociclib or ribociclib in addition to antiresorptive medication were included. Patients received either denosumab or zoledronic acid (ZA) therapy. The primary endpoint was OS, with PFS as a secondary endpoint. Although the PFS and OS of denosumab were better than ZA in this study, it did not show a significant difference between the two drugs. Meanwhile, mOS was not achievable in patients in the denosumab group, while it was 34.1 months in patients in the ZA group. The hazard ratio (HR) showed a significant improvement for the denosumab group in patients under 60 of age (HR: 0.33, p<0.01), patients with a score of 1 HER2 overexpression (HR: 0.09, p=0.01), and patients with resistant endocrine (HR: 0.42, p=0.02) compared to ZA. This study highlights the potential clinical relevance of the RANK pathway in BC treatment, and our findings suggest that denosumab may offer significant benefits in terms of PFS and OS for certain subgroups, particularly those with HER2 scores of 1, patients under 60, and those with endocrine-resistant BC. In conclusion, considering that RANK pathway status may be a predictive biomarker for CDK4/6i treatment and may cause treatment resistance, our results demonstrate the clinical relevance of the combination of CDK4/6i + ET with RANKL inhibition.

Preliminary safety, efficacy and molecular characterization of emavusertib (CA-4948) in patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) with FLT3 mutation (FLT3m).

6539 Background: AML is a heterogenous disease and exhibits a dynamic mutational landscape as the disease progresses. Internal tandem duplication (ITD) of FLT3 is considered an acquired late-event mutation and is associated with a poor prognosis in AML. Emavusertib is a potent oral inhibitor of both IRAK4 and FLT3, conferring potential dual efficacy advantages compared to other IRAK4 or FLT3 inhibitors as single agents. IRAK4 is upregulated during anti-FLT3- or other cytotoxic therapies, which drives a resistance pathway of early relapse and progression. Methods: The safety, clinical activity, and potential biomarkers of emavusertib in R/R AML and higher-risk myelodysplastic syndrome are being investigated in the ongoing open-label, Phase 1/2a TakeAim Leukemia trial (NCT04278768). Next generation sequencing (NGS) of 68 genes was performed on genomic DNA from bone marrow or peripheral blood mononuclear cells at baseline and on treatment. Here, we present preliminary safety, efficacy data and molecular characterization in a subset of enrolled AML patients who carried FLT3m at baseline and were treated with emavusertib monotherapy. Results: In this study, we treated 11 R/R AML patients with FLT3m at dose levels of 200-400 mg BID. The median number of prior anti-cancer therapies was 2 (range 1-6). 8 of 11 patients had prior exposure to FLT3 inhibitors. Treatment-related adverse events (TRAEs) Grade ≥ 3 were reported in 2 of 11 (18%) patients. All responders were dosed at the Recommended Phase 2 Dose (RP2D) of 300 mg BID and with &lt; 3 lines of prior therapy. In addition, responders demonstrated more than 90% bone marrow blast reduction compared to baseline. The most common co-mutations in this subset of patients included RUNX1, NRAS, and TET2. Emavusertib treatment significantly decreased the variant allele frequency of these mutations. FLT3-ITD levels were decreased or became undetectable in responders. Additional corelative analysis between bone marrow blast counts and mutation status indicates that AML patients with FLT3m demonstrated increased bone marrow blast reductions (P≤0.05) on emavusertib treatment, when compared to FLT3 WT AML patients. Conclusions: Emavusertib has a favorable safety and tolerability profile in pretreated AML patients with FLT3m and demonstrated monotherapy anti-cancer activity in patients with FLT3m, including patients who have progressed on prior FLT3 inhibitors. Mutational profiles are suggestive of disease-modifying activity of emavusertib. We will present updated safety and efficacy data, including data for patients who proceeded to stem cell transplant. Enrollment in this ongoing trial is continuing at RP2D in patients with &lt; 3 lines of prior anti-cancer therapies. Clinical trial information: NCT04278768 .

Association and mechanism of montelukast on depression: A combination of clinical and network pharmacology study

BackgroundPost-marketing surveillance found montelukast use was associated with an increased risk of depression. However, results of observational studies are inconsistent. ObjectiveThis study aimed to assess whether montelukast exposure is associated with depression and elucidate the possible molecular mechanism. MethodWe conducted a cross-sectional study of 9508 adults from the National Health and Nutrition Examination Survey (NHANES) 2007–2016. Multivariable regression was used to evaluate the association between montelukast exposure and depression. Network pharmacology was conducted to identify the mechanisms of montelukast on depression. ResultsMontelukast exposure had a higher prevalence of depression (37.4 %). In a multivariable logistic regression model adjusted for sociodemographic, behavioural, and health characteristics, montelukast exposure was associated with depression (odds ratio [OR]: 1.61; confidence interval [CI]: 1.18–2.19). Network pharmacology was identified 69 key targets of montelukast on depression. The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested montelukast mainly works through multiple pathways in endocrine resistance, chemical carcinogenesis-receptor activation, estrogen signaling pathway, etc. LimitationsCross-sectional data. ConclusionsThe study implies a potential positive association between long-term montelukast exposure and depression through multi-faceted mechanisms. It is suggested that attention be given to the possibility of depression in patients undergoing prolonged montelukast therapy.

Exploring the mechanism of diabetic cardiomyopathy treated with Qigui Qiangxin mixture based on UPLC-Q/TOF-MS, network pharmacology and experimental validation.

Despite its effectiveness in treating diabetic cardiomyopathy (DCM), Qigui Qiangxin Mixture (QGQXM) remains unclear in terms of its active ingredients and specific mechanism of action. The purpose of this study was to explore the active ingredients and mechanism of action of QGQXM in the treatment of DCM through the comprehensive strategy of serum pharmacology, network pharmacology and combined with experimental validation. The active ingredients of QGQXM were analyzed using Ultra-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-Q/TOF-MS). Network pharmacology was utilized to elucidate the mechanism of action of QGQXM for the treatment of DCM. Finally, in vivo validation was performed by intraperitoneal injection of STZ combined with high-fat feeding-induced DCM rat model. A total of 25 active compounds were identified in the drug-containing serum of rats, corresponding to 121 DCM-associated targets. GAPDH, TNF, AKT1, PPARG, EGFR, CASP3, and HIF1 were considered as the core therapeutic targets. Enrichment analysis showed that QGQXM mainly treats DCM by regulating PI3K-AKT, MAPK, mTOR, Insulin, Insulin resistance, and Apoptosis signaling pathways. Animal experiments showed that QGQXM improved cardiac function, attenuated the degree of cardiomyocyte injury and fibrosis, and inhibited apoptosis in DCM rats. Meanwhile, QGQXM also activated the PI3K/AKT signaling pathway, up-regulated Bcl-2, and down-regulated Caspase9, which may be an intrinsic mechanism for its anti-apoptotic effect. This study preliminarily elucidated the mechanism of QGQXM in the treatment of DCM and provided candidate compounds for the development of new drugs for DCM.

Walnut protein isolate-epigallocatechin gallate nanoparticles: A functional carrier enhanced stability and antioxidant activity of lycopene

Walnut isolate protein (WPI)-epigallocatechin gallate (EGCG) conjugates can be employed to creat food-grade delivery systems for preserving bioactive compounds. In this study, WPI-EGCG nanoparticles (WENPs) were developed for encapsulating lycopene (LYC) using the ultrasound-assisted method. The results indicated successful loading of LYC into these WENPs, forming the WENPs/LYC (cylinder with 200–300 nm in length and 14.81–30.05 nm in diameter). Encapsulating LYC in WENPs led to a notable decrease in release rate and improved stability in terms of thermal, ultraviolet (UV), and storage conditions compared to free LYC. Simultaneously, WENPs/LYC exhibited a synergistic and significantly higher antioxidant activity with an EC50 value of 23.98 μg/mL in HepG2 cells compared to free LYC’s 31.54 μg/mL. Treatment with WENPs/LYC led to a dose-dependent restoration of intracellular antioxidant enzyme activities (SOD, CAT, and GSH-Px) and inhibition of intracellular malondialdehyde (MDA) formation. Furthermore, transcriptome analysis indicated that enrichment in glutathione metabolism and peroxisome processes following WENPs/LYC addition. Quantitative real-time reverse transcription PCR (qRT-PCR) verified the expression levels of related genes involved in the antioxidant resistance pathway of WENPs/LYC on AAPH-induced oxidative stress. This study offers novel perspectives into the antioxidant resistance pathway of WENPs/LYC, holding significant potential in food industry.

The Effect of the PhoP/PhoQ System on the Regulation of Multi-Stress Adaptation Induced by Acid Stress in Salmonella Typhimurium.

Acidic stress in beef cattle slaughtering abattoirs can induce the acid adaptation response of in-plant contaminated Salmonella. This may further lead to multiple resistance responses threatening public health. Therefore, the acid, heat, osmotic and antibiotic resistances of Salmonella typhimurium (ATCC14028) were evaluated after a 90 min adaption in a pH = 5.4 "mild acid" Luria-Bertani medium. Differences in such resistances were also determined between the ∆phoP mutant and wild-type Salmonella strains to confirm the contribution of the PhoP/PhoQ system. The transcriptomic differences between the acid-adapted and ∆phoP strain were compared to explore the role of the PhoP/Q two-component system in regulating multi-stress resistance. Acid adaptation was found to increase the viability of Salmonella to lethal acid, heat and hyperosmotic treatments. In particular, acid adaptation significantly increased the resistance of Salmonella typhimurium to Polymyxin B, and such resistance can last for 21 days when the adapted strain was stored in meat extract medium at 4 °C. Transcriptomics analysis revealed 178 up-regulated and 274 down-regulated genes in the ∆phoP strain. The Salmonella infection, cationic antimicrobial peptide (CAMP) resistance, quorum sensing and two-component system pathways were down-regulated, while the bacterial tricarboxylic acid cycle pathways were up-regulated. Transcriptomics and RT-qPCR analyses revealed that the deletion of the phoP gene resulted in the down-regulation of the expression of genes related to lipid A modification and efflux pumps. These changes in the gene expression result in the change in net negative charge and the mobility of the cell membrane, resulting in enhanced CAMP resistance. The confirmation of multiple stress resistance under acid adaptation and the transcriptomic study in the current study may provide valuable information for the control of multiple stress resistance and meat safety.

Physiological responses and transcriptome analysis of Hemerocallis citrina Baroni exposed to Thrips palmi feeding stress.

Thrips are serious pests of Hemerocallis citrina Baroni (daylily), affecting crop yield and quality. To defend against pests, daylily has evolved a set of sophisticated defense mechanisms. In the present study, induction of systemic resistance in Hemerocallis citrina 'Datong Huanghua' by Thrips palmi feeding was investigated at both biochemical and molecular levels. The soluble sugar content of daylily leaves was significantly lower than that in control check (CK) at all time points of feeding by T. palmi, whereas the amino acid and free fatty acid contents started to be significantly lower than those in CK after 7 days. Secondary metabolites such as tannins, flavonoids, and total phenols, which are harmful to the growth and reproduction of T. palmi, were increased significantly. The activities of defense enzymes such as peroxidase (POD), phenylalanine ammonia lyase (PAL), and polyphenol oxidase (PPO) were significantly increased, and the degree of damage to plants was reduced. The significant increase in protease inhibitor (PI) activity may lead to disrupted digestion and slower growth in T. palmi. Using RNA sequencing, 1,894 differentially expressed genes (DEGs) were identified between control and treatment groups at five timepoints. DEGs were mainly enriched in secondary metabolite synthesis, jasmonic acid (JA), salicylic acid (SA), and other defense hormone signal transduction pathways, defense enzyme synthesis, MAPK signaling, cell wall thickening, carbohydrate metabolism, photosynthesis, and other insect resistance pathways. Subsequently, 698 DEGs were predicted to be transcription factors, including bHLH and WRKY members related to biotic stress. WGCNA identified 18 hub genes in four key modules (Purple, Midnight blue, Blue, and Red) including MYB-like DNA-binding domain (TRINITY_DN2391_c0_g1, TRINITY_DN3285_c0_g1), zinc-finger of the FCS-type, C2-C2 (TRINITY_DN21050_c0_g2), and NPR1 (TRINITY_DN13045_c0_g1, TRINITY_DN855_c0_g2). The results indicate that biosynthesis of secondary metabolites, phenylalanine metabolism, PIs, and defense hormones pathways are involved in the induced resistance to T. palmi in daylily.

Selenium Nanomaterials Enhance Sheath Blight Resistance and Nutritional Quality of Rice: Mechanisms of Action and Human Health Benefit.

In the current work, the foliar application of selenium nanomaterials (Se0 NMs) suppressed sheath blight in rice (Oryza sativa). The beneficial effects were nanoscale specific and concentration dependent. Specifically, foliar amendment of 5 mg/L Se0 NMs decreased the disease severity by 68.8% in Rhizoctonia solani-infected rice; this level of control was 1.57- and 2.20-fold greater than that of the Se ions with equivalent Se mass and a commercially available pesticide (Thifluzamide). Mechanistically, (1) the controlled release ability of Se0 NMs enabled a wider safe concentration range and greater bioavailability to Se0 NMs, and (2) transcriptomic and metabolomic analyses demonstrated that Se0 NMs simultaneously promoted the salicylic acid- and jasmonic-acid-dependent acquired disease resistance pathways, antioxidative system, and flavonoid biosynthesis. Additionally, Se0 NMs improved rice yield by 31.1%, increased the nutritional quality by 6.4-7.2%, enhanced organic Se content by 44.8%, and decreased arsenic and cadmium contents by 38.7 and 42.1%, respectively, in grains as compared with infected controls. Human simulated gastrointestinal tract model results showed that the application of Se0 NMs enhanced the bioaccessibility of Se in grains by 22.0% and decreased the bioaccessibility of As and Cd in grains by 20.3 and 13.4%, respectively. These findings demonstrate that Se0 NMs can serve as an effective and sustainable strategy to increase food quality and security.

Metabolites of traditional Chinese medicine targeting PI3K/AKT signaling pathway for hypoglycemic effect in type 2 diabetes.

Type 2 diabetes mellitus is a chronic metabolic disease characterized by insulin resistance, with high morbidity and mortality worldwide. Due to the tightly intertwined connection between the insulin resistance pathway and the PI3K/AKT signaling pathway, regulating the PI3K/AKT pathway and its associated targets is essential for hypoglycemia and the prevention of type 2 diabetes mellitus. In recent years, metabolites isolated from traditional Chinese medicine has received more attention and acceptance for its superior bioactivity, high safety, and fewer side effects. Meanwhile, numerous in vivo and in vitro studies have revealed that the metabolites present in traditional Chinese medicine possess better bioactivities in regulating the balance of glucose metabolism, ameliorating insulin resistance, and preventing type 2 diabetes mellitus via the PI3K/AKT signaling pathway. In this article, we reviewed the literature related to the metabolites of traditional Chinese medicine improving IR and possessing therapeutic potential for type 2 diabetes mellitus by targeting the PI3K/AKT signaling pathway, focusing on the hypoglycemic mechanism of the metabolites of traditional Chinese medicine in type 2 diabetes mellitus and elaborating on the significant role of the PI3K/AKT signaling pathway in type 2 diabetes mellitus. In order to provide reference for clinical prevention and treatment of type 2 diabetes mellitus.

Tamarix aphylla derived metabolites ameliorate indomethacin-induced gastric ulcers in rats by modulating the MAPK signaling pathway, alleviating oxidative stress and inflammation: In vivo study supported by pharmacological network analysis.

Nature has proven to be a treasure resource of bioactive metabolites. In this regard, Tamarix aphylla (F. Tamaricaceae) leaves crude extract was investigated for its gastroprotective effect against indomethacin-induced damage to the gastric mucosa. Additionally, phytochemical investigation of the methanolic extract afforded eight flavonoids' derivatives (1-8). On pharmacology networking study, the isolated compounds identified 123 unique targets where only 45 targets were related to peptic ulcer conditions, these 45 targets include 11 targets specifically correlate to gastric ulcer. The protein-protein interaction defined the PTGS2 gene as one of the highly interacted genes and the complete pharmacology network defined the PTGS2 gene as the most represented gene. The top KEGG signaling pathways according to fold enrichment analysis was the EGFR tyrosine kinase inhibitor resistance pathway. As a result, these findings highlighted the significance of using T. aphylla leaves crude extract as an anti-gastric ulcer candidate, which provides a safer option to chemical antisecretory medicines, which are infamous for their negative side effects. Our findings have illuminated the potent anti-inflammatory and antioxidant effects of T. aphylla, which are likely mediated by suppressing IL-1β, IL-6, TNF-α, and MAPK signaling pathways, without compromising gastric acidity.

Pericyte Control of Gene Expression in the Blood-Brain Barrier Endothelium: Implications for Alzheimer's Disease.

A strong body of evidence suggests that cerebrovascular pathologies augment the onset and progression of Alzheimer's disease (AD). One distinctive aspect of this cerebrovascular dysfunction is the degeneration of brain pericytes-often overlooked supporting cells of blood-brain barrier endothelium. The current study investigates the influence of pericytes on gene and protein expressions in the blood-brain barrier endothelium, which is expected to facilitate the identification of pathophysiological pathways that are triggered by pericyte loss and lead to blood-brain barrier dysfunction in AD. Bioinformatics analysis was conducted on the RNA-Seq expression counts matrix (GSE144474), which compared solo-cultured human blood-brain barrier endothelial cells against endothelial cells co-cultured with human brain pericytes in a non-contact model. We constructed a similar cell culture model to verify protein expression using western blots. The insulin resistance and ferroptosis pathways were found to be enriched. Western blots of the insulin receptor and heme oxygenase expressions were consistent with those observed in RNA-Seq data. Additionally, we observed more than 5-fold upregulation of several genes associated with neuroprotection, including insulin-like growth factor 2 and brain-derived neurotrophic factor. Results suggest that pericyte influence on blood-brain barrier endothelial gene expression confers protection from insulin resistance, iron accumulation, oxidative stress, and amyloid deposition. Since these are conditions associated with AD pathophysiology, they imply mechanisms by which pericyte degeneration could contribute to disease progression.

Unravelling the Triad of Lung Cancer, Drug Resistance, and Metabolic Pathways.

Lung cancer, characterized by its heterogeneity, presents a significant challenge in therapeutic management, primarily due to the development of resistance to conventional drugs. This resistance is often compounded by the tumor's ability to reprogram its metabolic pathways, a survival strategy that enables cancer cells to thrive in adverse conditions. This review article explores the complex link between drug resistance and metabolic reprogramming in lung cancer, offering a detailed analysis of the molecular mechanisms and treatment strategies. It emphasizes the interplay between drug resistance and changes in metabolic pathways, crucial for developing effective lung cancer therapies. This review examines the impact of current treatments on metabolic pathways and the significance of considering metabolic factors to combat drug resistance. It highlights the different challenges and metabolic alterations in non-small-cell lung cancer and small-cell lung cancer, underlining the need for subtype-specific treatments. Key signaling pathways, including PI3K/AKT/mTOR, MAPK, and AMPK, have been discussed for their roles in promoting drug resistance and metabolic changes, alongside the complex regulatory networks involved. This review article evaluates emerging treatments targeting metabolism, such as metabolic inhibitors, dietary management, and combination therapies, assessing their potential and challenges. It concludes with insights into the role of precision medicine and metabolic biomarkers in crafting personalized lung cancer treatments, advocating for metabolic targeting as a promising approach to enhance treatment efficacy and overcome drug resistance. This review underscores ongoing advancements and hurdles in integrating metabolic considerations into lung cancer therapy strategies.

Abstract PO2-16-03: ESR1 genomic alterations (GAs) and coexistent putative resistance alterations in comprehensive genomic profiling (CGP) of metastatic breast cancer (MBC)

Abstract Background: ESR1 mutations (ESR1mut) are an established biomarker of endocrine therapy (ET) resistance in patients (pts) with hormone receptor positive (HR+) MBC. Moreover, ESR1mut acquired in response to standard-of-care ET now confer access to novel ET recently approved by health authorities. However, the nuanced genomic landscape beyond the simple presence or absence of ESR1mut may be critically important. We report on detailed ESR1 GAs detected by tissue and liquid biopsies (TBx, LBx) and examine the prevalence of co-occurring GAs in other genes reported to confer intrinsic or acquired resistance to ET. Methods: CGP results from MBC biopsies were retrospectively analyzed (TBx 33,653 pts; LBx 7,134 pts) using FoundationOne® CDx and FoundationOne® Liquid CDx, hybrid-capture based sequencing platforms profiling 324 cancer-related genes. Foundation Medicine’s ctDNA tumor fraction (TF) is a composite algorithm prioritizing aneuploidy at higher levels to avoid germline signal and prioritizing variant allele frequency (VAF) of canonical alterations at lower levels to maximize dynamic range. Results: ESR1mut were detected in 3,755 (11.2%) TBx and 1,513 (21.2%) LBx. Among samples with ESR1mut, multiple ESR1mut were more common in LBx (19% 2, 12% 3+) than in TBx (6% 2, 0.5% 3+), with up to 10 different ESR1mut seen in one LBx. The most common mutations were D538G (39% and 52% of TBx and LBx with ESR1mut), Y537S (27%, 38%), Y537N (10%, 15%), and E380Q (10%, 14%). Activating ESR1 insertion-deletion mutations (indels) were detected in 81 TBx and 62 LBx (2% and 4%), representing 23 distinct variants at the protein level, including V422del (107), indels affecting codons 532-538 (29), G344_L345insC (7), and Y328_S329del (6). 28 fusions of the ESR1 DNA binding domain to 13 unique gene partners were detected; 10/28 (36%) were ESR1-CCDC170 fusions. ESR1 amplifications (ESR1amp) were detected in 704 (2.1%) TBx; 62 (8.8%) also harbored ESR1mut. ESR1amp were detected among 34 (0.5%) LBx; 8 (24%) also had ESR1mut. In TBx with ESR1mut and LBx collected from the same pt within 8 months (43 pairs), LBx sensitivity of detection of ESR1mut was 96% (26/27, 95% confidence interval CI [95%CI]: 79%-99%) when TF was ≥1%, but only 6% (1/16, 95%CI: 0.3%-32%) when LBx had TF &amp;lt; 1%. In 988/1,513 (65%) of LBx with ESR1mut, ≥1 mutations or fusions in genes associated with alternative ET resistance pathways were detected, including PIK3CA (46% of ESR1mut LBx), RB1 (12%), PTEN (10%), NF1 (7%), ARID1A (7%), AKT1 (5%), FGFR2 (4%), and KRAS (4%) and ERBB2 (3%). Prevalence of co-occurring GA associated with ET resistance was higher in LBx than in TBx (RB1, NF1, FGFR2, PTEN, EGFR, KRAS, PIK3CA, FDR &amp;lt; 0.001). Moreover, prevalence was higher in 240 LBx where ESR1 was a minor allele (VAF/TF &amp;lt; 10%) compared to 1,273 LBx were ESR1 was a major allele (FGFR2, PIK3CA, FGFR3, BRAF, ERBB2, RB1, FDR &amp;lt; 0.05). In pts with ESR1mut LBx and a historical TBx collected &amp;lt; 5 years earlier (182 pairs), GAs in RB1, FGFR2, KRAS, EGFR, and BRAF were detected primarily on the LBx but not the preceding TBx. Conclusions: CGP detects a wide spectrum of mutations in ESR1, including missense and indel mutations and fusions. When LBx TF is &amp;lt; 1%, sensitivity for ESR1mut is reduced and repeat testing should be considered. ESR1mut can coexist with complementary or competing resistance mechanisms, particularly when ESR1 is a minor allele, which could impact benefit from novel ET approved for patients with ESR1 mutations. Currently, CGP of LBx informs therapeutic recommendations for pts with HR+ MBC based on the binary presence or absence of ESR1mut; however, the clinical implications of the ESR1 mutation spectrum described herein and the potential impact of co-expression of other key pathway signals warrant further investigation. Citation Format: Heather McArthur, Hanna Tukachinsky, Alexa Schrock, Russell Madison, Oliver Holmes, Smruthy Sivakumar, Ethan Sokol, Ryon Graf, Julia Quintanilha, Kali Dougherty, Lincoln Pasquina, Geoffrey Oxnard, Mia Levy, Eric Winer. ESR1 genomic alterations (GAs) and coexistent putative resistance alterations in comprehensive genomic profiling (CGP) of metastatic breast cancer (MBC) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-16-03.

Abstract PS09-08: Genomic characterization of endocrine resistance in ER+HER2+ breast cancers in the POETIC Trial

Abstract Background: Mechanisms of resistance to endocrine therapy are not well understood within ER+HER2+ breast cancer (BC). Our prior work suggested that intrinsic HER2-Enriched (HER2E) molecular subtype predicts early resistance to aromatase inhibitors (AI) (Bergamino eBioMedicine 2022) and high on-treatment (on-Txt) Ki67 levels predict poor survival (Smith Lancet Oncol 2020). Improved early detection of persistent proliferating tumor cells with endocrine resistance pathways could be targeted by pre-emptive personalized therapy and reduction in recurrence. In this study, we proposed to further identify additional alterations/features from genomic and spatial data to provide unprecedented new insight into intrinsic and adaptive resistant pathways in tumor cells that may assist to identify molecular targets for treatment. Materials: POETIC was a phase III trial of post-menopausal patients with ER/PR+ invasive BC (n = 4480) randomized 2:1 to 2 weeks of peri-operative AI (POAI) vs control, followed by standard-of-care treatment. Ki67 was assessed by IHC and intra-tumor heterogeneity was evaluated (5-15 regions) for all the POETIC POAI samples (N = 2487). ER+HER2+ samples were classified as good responders (GR) or poor responders (PR) based on a reduction in Ki67 between pre-treatment (pre-Txt) and 2-week on-Txt samples. Tumor-infiltrating lymphocytes were assessed; multiplex Immunofluorescence (mIF) was performed to measure immune cell densities in tumor and stroma compartments (CD3, CD20, CD68, FOXP3, and CD3 FOXP3 co-expression). Gene expression profiles by BC360™ (Nanostring) on all 210 pairs of POAI treated ER+/HER2+; whole exome sequencing (WES, 100X) were performed on pre-Txt tumor and blood samples from 13 GR, 17 PR, and 9 HER2E GR. We performed GeoMx Whole Transcriptome on 4 pairs (pre-Txt and on-Txt) of GR and GeoMx Proteins (77 including IO proteins) on 6 pairs of GRs and 6 pairs of PRs. Results: The most frequently mutated genes were TP53, PIK3CA, GATA3, and CHD4. Only TP53 was associated with PR (Fisher’s exact p=0.01). TP53 mutated cases had higher expression of TP53 mutant-like gene expression signature compared to wild-type cases (Wilcoxon test p=0.001), mIF FOXP3 (Wilcoxon test p = 0.0005), and CD68 (Wilcoxon test p = 0.019) density score. However, within the HER2-E subset, we found that TP53 mutations were associated with GR (Fisher’s exact p=0.02). We found spatial heterogeneity of Ki67 IHC levels across POAI samples. Examining IHC, while there was higher heterogeneity of Ki67 in the ER+HER2- samples (n = 2264) with 3% of pre-Txt and 9% on-Txt, 6% of ER+HER2+ samples (13/223, 6 LumA, 5 LumB, and 2 HER2E) showed heterogeneity of Ki67 exclusively on-Txt. Even in GR tumors with Ki67 &amp;lt; 10% on-Txt, we identified hotspots with retained proliferating Ki67+ cells after 2 weeks of POAI. The lobular tumors were GR and had characteristic CDH1 mutations. Importantly, cases with persistent areas of Ki67+ cells, regardless of Her2 status, were associated with late relapse. To further explore intratumoral heterogeneity, we performed spatial whole transcriptomics profiling on 95 regions from 4 pairs of GR samples (Ki67 &amp;gt; 10% at baseline and Ki67 &amp;lt; 10% on-Txt) and found low intratumoral heterogeneity in the pre-Txt samples that increased at 2 weeks on-Txt. In a larger set of samples including both GR and PR with the GeoMx protein method, we found increased intratumoral heterogeneity in the PR vs GR. Conclusion: While TP53 mutation was generally a predictor of poor response; in HER2-E it paradoxically was associated with a good early response to aromatase inhibitor which warrants further investigation. Ki67 levels in ER+HER2+ showed higher intratumoral heterogeneity in a subset of patients on treatment suggesting the potential of persistent, proliferating cells leading to later recurrence. Our spatial RNA and protein data further observe the intratumoral heterogeneity that identifies pathways for use as potential spatial biomarkers. Citation Format: Maggie Chon U Cheang, Xixuan Zhu, Orsolya Sipos, Anastasia Alataki, Mikayla Feldbauer, Elena López-Knowles, Holly Tovey, Lucy Kilburn, Milana Bergamino Sirvén, Dhrusti Patel, Hui Xiao, Perry Maxwell, Anthony Skene, Chris Holcombe, Manuel Salto-Tellez, Nicholas Turner, Andrew Dodson, Ian Smith, John Robertson, Judith Bliss, Gene Schuster, Roberto Salgado, Mitch Dowsett, Katherine A Hoadley. Genomic characterization of endocrine resistance in ER+HER2+ breast cancers in the POETIC Trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PS09-08.

Abstract PO2-23-12: Innovative Metastatic Breast Cancer Therapy, CBT300, Reverses Drug and Immune Resistance

Abstract For many patients with metastatic breast cancer (MBC), their disease is treatable but incurable. Although the rate of death from MBC has significantly decreased over the last 10 years due to early detection and new treatment options, MBC still accounts for over 40,000 deaths each year in the US that has been consistent for the past 30 years. Recently, it is estimated that 90% of those deaths were due to drug resistant recurrent disease. Nearly 45% of MBC deaths can be attributed to a subpopulation of patients with metastatic triple negative breast cancer (mTNBC). Despite MBC’s initial sensitivity to chemotherapy, it often recurs at greater than 40% in stage I-III patients and greater than 80% in stage IV patients which have a dismal 5-year survival of 12%. African American women have a 40% greater incidence of death from MBC despite a 4% lower risk of diagnosis. Unfortunately, current therapies do little to reduce drug resistance and death for recurrent drug resistant MBC. Currently, the only therapies approved by the FDA for recurrent TNBC patients are Keytruda plus chemotherapy and an Antibody Drug Conjugate (ADC) called Sacituzumab Govitecan. Keytruda (anti-PD-L1) is an immune checkpoint inhibitor(ICI) given with chemotherapy (nab-paclitaxel, paclitaxel, or gemcitabine plus carboplatin). The second recently approved therapy, Sacituzumab Govitecan (SG), is composed of an antibody to human trophoblast cell-surface antigen 2 (Trpo-2) coupled to SN-38 (topoisomerase I inhibitor). Although these results are very encouraging, the 80% of TNBC patients that either do not have high positive PD-L1 tumors, or don’t respond to these therapies and become drug resistant suggests that most patients with TNBC will have recurrent disease with little or no hope for survival. For contrast, our novel MBC therapy, CBT300, targets cell surface GRP78 that has been found in over 95% of MBC and in 93% of TNBC tumors. We can now show that inhibition of cell surface GRP78 can a) induce apoptosis of drug resistant TNBC cells in vitro and in vivo, b) eliminate drug resistance showing synergistic effects with chemotherapy in vitro and in vivo, c) decrease amount of chemotherapy in combination with CBT300 and d) reduce immune suppression. Recent publications show that GRP78 is found on many types of tumor cell surfaces but not on normal cell surfaces. In fact, tumor cell surface GRP78 (csGRP78) is important for many aspects of MBC development, including cell survival, proliferation, chemoresistance, angiogenesis, metastasis formation, immune suppression, and stem cell formation. Recently, it has been shown that increased cell surface GRP78 expression in TNBC patients was significantly associated with later stage, increased distant metastasis, increased aggressiveness, shorter disease-free survival, and decreased overall survival. In studies to help understand how cell surface GRP78 causes MBC progression and drug resistance, we discovered a novel GRP78 binding transmembrane protein on TNBC cells called Receptor Tyrosine Kinase Orphan Receptor-1 (ROR1). Using the GRP78 binding domain from ROR1 and a human Fc IgG1 domain, we created a biologic fusion protein that is a potent and cell surface specific GRP78 inhibitor, CBT300. We now show that CBT300’s elimination of cell surface GRP78 destabilizes and removes oncofetal proteins ROR1, Cripto-1, and checkpoint protein PD-L1 from tumor cell surfaces resulting in reversal of chemoresistance, reduction in immune suppression, inhibition of stem cell phenotype and increased tumor cell apoptosis. Since ROR1, Cripto-1 and PD-L1 are three of the major redundant pathways for tumor drug resistance, immune suppression and stem cell formation, the ability to inhibit all these pathways with CBT300, a single safe and very efficacious therapy, is very innovative and could be a significant advance for the treatment of MBC. Citation Format: Elizabeth Stolarik, Jorryn Zelek, Mariah Thigpen, Anita Davidson, Donald Davidson. Innovative Metastatic Breast Cancer Therapy, CBT300, Reverses Drug and Immune Resistance [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-23-12.

Abstract PO1-23-10: Multi-omics analysis identifies the mechanism in cross-resistance to endocrine therapy and CDK4/6 inhibitor in breast cancer

Abstract Background In advanced/metastatic breast cancer (MBC) or recurrent breast cancer on prior endocrine therapy (ET), selective estrogen receptor downregulator (SERD) of fulvestrant and CDK4/6i are the mainstream therapy regimen. In the clinical, fulvestrant combined with CDK4/6i is the second-line therapy for breast cancer (BC) that had progressed during previous endocrine therapy. The alternation of backbone from aromatase inhibitor or tamoxifen (endocrine sensitive) to fulvestrant (endocrine resistance) partially comes from the mechanism of ET resistance. Moreover, in the PALOMA-2 trial, approximately 30% of patients developed into recurrence after two years of CDK4/6i treatment, indicating that the ET backbone may affect CDK4/6i efficacy, bringing an emerging clinical issue of cross-resistance. However, whether the cross-resistance of ET would be more sensitive to CDK4/6i or impair the efficacy of CDK4/6i is still an ambiguous and heterogeneous issue. Also, in CDK4/6i resistance, whether the mechanism of ET resistance is associated with the dysregulation of the cell cycle or activation of other “bypass” signaling pathways is not fully understood. Methods We use a 3D and 2D culture of ET-sensitive cell S0.5, tamoxifen-resistant cell TAM, and fulvestrant-resistant cell 182R6 as our model. The 3D culture was performed by using the Tools 3d culture plus kit. Drug responses to fulvestrant and ribociclib were conducted by using CCK-8 assay. The potential target and pathway involved in the mechanisms of cross-resistance were analyzed by using multi-omics analysis of sequential window acquisition of all theoretical mass spectra (SWATH-MS), RNA-seq, micro-western array (MWA), traditional western blots, and open access database. Results In comparison with S0.5, the sensitivity to fulvestrant was indeed reduced in 182R6 cell; however, we found the sensitivity to ribociclib was also reduced in 182R6 cell, which was in contrast to the ribociclib-sensitive TAM cell. The different response to ribociclib between 182R6 and TAM, indicating that cross-resistance between fulvestrant and ribociclib existed in the model of 182R6 and TAM would be another control for 182R6 to find the target with or without cross-resistance. With multi-omics analysis of SWATH-MS, RNA-seq, MWA, western blots, and open access database, we found some unique or high expression of targets and pathways including EGFR, HER2, CDK6, CDK2, MAPK, and TNF-α pathways in cross-resistance R6 cell than in parental and TAM cell. We reconfirmed the above targets by 3D culture and found MAPK signaling pathway of p-ERK was not affected under ribociclib treatment, indicating the important role of the MAPK signaling pathway in ribociclib resistance. Conclusion To our knowledge, these results provide the first preliminary mechanism of cross-resistance between fulvestrant and ribociclib. We found fulvestrant resistant cell R6 exhibited the phenomenon of cross-resistance to ribociclib, which was in contrast to ribociclib-sensitive TAM cell. We also found some unique or high expression of target and pathway in cross-resistance R6 cells than in parental and TAM cells. In the future, with compound library screening and in vivo animal models, we expect to discover an FDA-approved drug or potential compound to overcome the cross-resistance between fulvestrant and ribociclib. Citation Format: Ming-Feng Hou, Chung-Liang Li, Chih-Po Chiang. Multi-omics analysis identifies the mechanism in cross-resistance to endocrine therapy and CDK4/6 inhibitor in breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-23-10.

Abstract PO5-27-10: Next generation antibody drug conjugates: Multi-payload conjugates targeting multiple mechanisms of cell killing

Abstract Background: ADCs have had tremendous impact on patient outcomes in breast cancer and are rapidly moving towards second line use. However, many patients fail to respond or relapse after treatment with ADC therapies due to tumor heterogeneity and resistance to ADC payloads. Method: CatenaBio has developed a novel Multi-Payload-Conjugate (MPC) system capable of attaching distinct payloads at different sites to the same antibody, enabling the production of single-molecule targeted combination therapies with defined DAR. Results: We screened combinations of different payloads targeting several different mechanisms attached to trastuzumab at different drug-antibody ratios to optimize tumor cell killing. These targeted combination ADCs demonstrated robust killing in both HER2 high and low tumor cell lines. Conclusion: Antibody Drug Conjugates have revolutionized the treatment of high HER2 positive breast cancer. More recently advances have been made in the design of ADCs to expand indications to include HER2 low as well as HER2 negative patients. These constructs offer the next step in ADC design and allow for the combination of multiple mechanisms of action in a single MPC that are highly effective across multiple breast cancer cell lines. These molecules offer the potential to circumvent tumor resistance pathways and deliver deeper and more durable responses. Disclosures: Marco Lobba, Devin Trinter, Maxwell Nguyen, Daniel Gutierrez, Samantha Brady, Chanez Symister, Andrew Lau, Richard Kendall, and Saurabh Johri are employed by Catena Biosciences. Matthew Francis is a co-founder and advisor to Catena Biosciences. Citation Format: Marco Lobba, Devin Trinter, Maxwell Nguyen, Daniel Gutierrez, Samantha Brady, Chanez Symister, Andrew Lau, Richard Kendall, Saurabh Johri, Matthew Francis. Next generation antibody drug conjugates: Multi-payload conjugates targeting multiple mechanisms of cell killing [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-27-10.

Analysis of ginseng rusty root symptoms transcriptome and its pathogenesis directed by reactive oxygen species theory.

Ginseng rusty root symptoms (GRS) is a primary disease of ginseng, which seriously decreases the yield and quality of ginseng and causes enormous losses to ginseng production. GRS prevention and control is still challenging due to its unclear etiology. In this study, the phloem tissue of healthy Panax ginseng (AG), the nonred tissue of the phloem epidermis around the lesion (BG), and the red lesion site tissue of GRS (CG) were extracted for mRNA transcriptomic analysis; 35,958 differentially expressed genes (DEGs) were identified and were associated with multiple stress resistance pathways, reactive oxygen species (ROS), and iron ion binding. Further study showed that the contents of O2 •-, H2O2, and malondialdehyde (MDA) were significantly increased in BG and CG tissues. Under anaerobic conditions caused by excessive soil moisture, the overproduction of ROS destroys cell membranes, simultaneously converting Fe2+ to Fe3+ and depositing it in the cell wall, which results in GRS, as evidenced by the success of the GRS induction test.

Fine mapping and characterization of stripe rust resistance gene YrAYH in near-isogenic lines derived from a cross involving wheat landrace Anyuehong

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is a devastating disease in wheat worldwide. Discovering and characterizing new resistance genes/QTL is crucial for wheat breeding programs. In this study, we fine-mapped and characterized a stripe rust resistance gene, YRAYH, on chromosome arm 5BL in the Chinese wheat landrace Anyuehong (AYH). Evaluations of stripe rust response to prevalent Chinese Pst races in near-isogenic lines derived from a cross of Anyuehong and Taichung 29 showed that YrAYH conferred a high level of resistance at all growth stages. Fine mapping using a large segregating population of 9748 plants, narrowed the YRAYH locus to a 3.7 Mb interval on chromosome arm 5BL that included 61 annotated genes. Transcriptome analysis of two NIL pairs identified 64 upregulated differentially expressed genes (DEGs) in the resistant NILs (NILs-R). Annotations indicated that many of these genes have roles in plant disease resistance pathways. Through a combined approach of fine-mapping and transcriptome sequencing, we identified a serine/threonine-protein kinase SRPK as a candidate gene underlying YrAYH. A unique 25 bp insertion was identified in the NILs-R compared to the NILs-S and previously published wheat genomes. An InDel marker was developed and co-segregated with YrAYH. Agronomic trait evaluation of the NILs suggested that YrAYH not only reduces the impact of stripe rust but was also associated with a gene that increases plant height and spike length.

Prostate-Specific Membrane Antigen-Targeted Therapy in Prostate Cancer: History, Combination Therapies, Trials, and Future Perspective.

In the last decades, the development of PET/CT radiopharmaceuticals, targeting the Prostate-Specific Membrane Antigen (PSMA), changed the management of prostate cancer (PCa) patients thanks to its higher diagnostic accuracy in comparison with conventional imaging both in staging and in recurrence. Alongside molecular imaging, PSMA was studied as a therapeutic agent targeted with various isotopes. In 2021, results from the VISION trial led to the Food and Drug Administration (FDA) approval of [177Lu]Lu-PSMA-617 as a novel therapy for metastatic castration-resistant prostate cancer (mCRPC) and set the basis for a radical change in the future perspectives of PCa treatment and the history of Nuclear Medicine. Despite these promising results, primary resistance in patients treated with single-agent [177Lu]Lu-PSMA-617 remains a real issue. Emerging trials are investigating the use of [177Lu]Lu-PSMA-617 in combination with other PCa therapies in order to cover the multiple oncologic resistance pathways and to overcome tumor heterogeneity. In this review, our aim is to retrace the history of PSMA-targeted therapy from the first preclinical studies to its future applications in PCa.