Citations

Abstract The range of Babesia microti (Franca, 1910)-infected ticks is expanding, resulting in locally acquired human babesiosis cases occurring in new areas: Maryland (2009), the District of Columbia (2013), Virginia (2016), and West Virginia (2017). We collected host-seeking ticks from old fields, ecotones, forested habitats and animal hosts in Delaware, Maryland, and Virginia, 2010 to 2024. Ixodes scapularis Say, the tick vector of babesiosis, was captured in all 3 states. PCR revealed B. microti in 2.7% (36/1310) of I. scapularis, with site prevalence ranging from <1% to 12.5% infected. The first B. microti-positive I. scapularis was collected in Northampton County, Virginia, 2012. Of the B. microti-infected ticks, 50% (18/36) were coinfected with Borrelia burgdorferi and one was triple-infected with B. microti, B. burgdorferi, and Anaplasma phagocytophilum. We collected Ixodes keiransi Beati, Nava, Venzal, and Guglielmone ticks from Delaware and Virginia. We found B. microti and B. burgdorferi in those from Virginia, and B. burgdorferi in ticks from a shrew in Delaware. To our knowledge, this is the first report of B. microti and B. burgdorferi-positive I. keiransi from Virginia, and the first report of B. burgdorferi-positive I. keiransi from Delaware. Ixodes keiransi ticks rarely bite humans but are involved in the maintenance and spread of pathogens when sympatric with I. scapularis. We tested a subset of both tick species for Babesia duncani; none were positive. Jurisdictions in the southern mid-Atlantic region should expect babesiosis cases, and Lyme disease and anaplasmosis coinfections, and healthcare providers should consider these tick-borne infections as part of the differential diagnosis.

Background. MicroRNAs are small, single-stranded non-coding RNA molecules that play major role in gene regulation. miRNAs have been reported as both tumor suppressive and oncogenic and are promising candidates for cancer prognosis and treatment. miR-494 is known to promote cell migration and invasion in CRC. Our study aimed to further explore the role of miR-494 modulation (inhibition and overexpression) in CRC. Methods. We evaluated the impact of tumor gene expression of MIR494 on outcomes (overall survival: OS; progression-free survival: PFS) in data for 433 metastatic CRC (mCRC) patients (pts) (bevacizumab [bev] (N = 226) vs cetuximab [cet] (N = 207)) enrolled in randomized phase III CALGB/SWOG 80405 trial obtained from Alliance for Clinical Trials in Oncology. RNA extracted from FFPE tumor samples was sequenced using the HiSeq 2500 (Illumina). Gene expression was divided into high, medium and low. Associations were assessed by log-rank test and multivariable Cox proportional hazards regression model. Treatment-gene interactions were analyzed using the likelihood ratio test. CRC cell lines HCT116 and HT29 were transfected with miR-494 inhibitors and mimics for 48 hours and total RNA was collected, followed by RT-qPCR (miR-494 and target genes BMAL1, PAK1, CDH1, CDH2, SNAI1, TWIST) and clonogenic assays. Results. High miR-494 was significantly associated with worse PFS in overall (median survival: high vs low: 9.3 vs 11.3 months, P<0.025) and cet-treated (median survival high vs low: 9.2 vs 9.6 months, P<0.025) mCRC cohorts, while no significance was observed in bev-treated mCRC. Multivariable Cox model showed significant association between high miR-494 and worse PFS and OS in the cet-treated cohort; however, treatment-gene interaction was not statistically significant. Expression analysis revealed miR-494 was significantly reduced and increased following inhibitor and mimic transfection, respectively. Differential gene expression of the target genes analyzed was observed between the miR-494 inhibitor and mimic-treated HCT116 and HT29 samples. In HCT116 cells, inhibition of miR-494 significantly (P < 0.01) reduced expression of PAK1, while increased the expression of CDH1. The number of colonies formed relatively increased after transfection with miR-494 inhibitor compared to miR-494 mimic. Conclusion. Our findings showed that high miR-494 expression correlated with worse PFS overall and in cet-treated mCRC pts. It would be interesting to check for potential associations with EGFR signaling (direct or indirect). Further studies are warranted for efficient targeting and to gain better understanding of the associated signaling involved in miR-494 modulation in CRC. Support: U10CA180821, U10CA180882; U10CA180888 (SWOG): Genentech. https://acknowledgments.alliancefound.org; P30CA014089, UG1CA180830 [HJL]. Clinicaltrials.gov Identifier: NCT00265850 Citation Format: Pooja Mittal, Joshua Millstein, Shivani Soni, Francesca Battaglin, Karam Ashouri, Sandra Algaze, Priya Jayachandran, Yan Yang, Lesly T. Gonzalez, Unnati H. Shah, Wu Zhang, Fang-Shu Ou, Alan P. Venook, Indrakant K. Singh, Heinz J. Lenz. Effect of miR-494 modulation in colorectal cancer (CRC): Clinical outcome, target expression and cell characteristics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 2787.

Abstract Purpose: Black women are disproportionately affected by aggressive breast cancers compared to white women, suggesting underlying biological differences in normal breast tissue. This study aims to identify molecular disparities in normal breast tissue between premenopausal Black and white women that may contribute to increased breast cancer risk. Experimental Procedures: Visium spatial transcriptomic analysis was performed on a pilot cohort of normal breast tissue samples from premenopausal Black and white women. Tissue sections were spatially profiled, and capture spots were classified based on predominant cell types: epithelial, stromal, or endothelial. Differential gene expression analysis between racial groups was conducted for each cell type classification. Multiplex immunofluorescence (mIF) was used to validate selected markers in the pilot cohort. Meta-analysis compared differentially expressed genes with published gene sets associated with breast cancer subtypes. Results: Significant racial differences in gene expression profiles were identified in both epithelial and stromal spots. In epithelial spots, genes upregulated in Black women significantly overlapped with over 20 published gene sets associated with estrogen receptor-negative (ER−) breast cancer, including key genes involved in Wnt signaling inhibition (e.g., WIF1) and basal epithelial markers (e.g., KRT14, KRT15). This suggests alterations in pathways linked to more aggressive breast cancer phenotypes. In stromal spots, differentially expressed genes related to extracellular matrix remodeling and fibroblast activation (e.g., PI16, DPT, EFEMP1) were observed, indicating potential differences in stromal-epithelial interactions. Ongoing deconvolution and spatial analyses are being performed to further elucidate these findings. Preliminary mIF validation confirmed increased expression of PI16 in samples from Black women. Validation of additional markers is underway in a larger cohort of premenopausal Black and white women. Conclusions: Spatial transcriptomic profiling of normal breast tissue reveals distinct molecular differences between Black and white women, particularly in pathways associated with aggressive breast cancer subtypes and stromal interactions. These findings suggest that inherent variations in the normal breast microenvironment may contribute to the increased risk and aggressiveness of breast cancer in Black women. Further validation and analysis may identify potential biomarkers for risk assessment and inform targeted prevention strategies. Citation Format: Camila Pacheco Erak, Nicole Cruz-Reyes, Pria Westerman, Joshua Ogony, Jean R. Clemenceau, Tae Hyun Hwang, Sarah McLaughlin, Derek Radisky. Spatial transcriptomic profiling of normal breast tissue reveals potential mechanisms underlying increased breast cancer risk in Black women [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 765.

Abstract Background: Postpartum breast cancer (PPBC) is associated with increased morbidity and mortality among women within 5 to 10 years following childbirth. The postpartum breast undergoes involution, involving tissue remodeling and immune cell infiltration, potentially creating a pro-tumorigenic microenvironment. The molecular mechanisms underlying this elevated risk remain poorly understood. In this study, we compared normal breast tissue samples and human mammary epithelial cells (HMECs) from postpartum women to those from age- and BMI-matched nulliparous women to elucidate potential molecular contributors to PPBC risk. Methods: Transcriptomic profiling was performed on RNA extracted from FFPE normal breast tissues using the NanoString IO 360 and BC 360 platforms to examine gene expression in nulliparous and postpartum women under 45 years of age. HMECs were isolated from organoids derived from breast tissue samples and used for next-generation sequencing and knockdown experiments targeting STAT1 and GBP1. Gene set enrichment analysis (GSEA) was applied to NanoString and RNA-seq datasets to identify differentially enriched genes between postpartum and nulliparous women. Results: Transcriptomic analysis revealed significant upregulation of interferon-stimulated genes, including STAT1 and GBP1, in postpartum breast tissues, consistent with increased immune responses during involution. NanoString data showed that markers of cell proliferation, such as Ki67, STAT1, and GBP1, were significantly higher in samples from parous compared to nulliparous women (p < 0.05). GSEA revealed that cell cycle-promoting genes (GBP1, cyclins, CDKs) were upregulated, while cyclin-dependent kinase inhibitors (CDKNs) were downregulated in postpartum breast tissues. Immunohistochemistry confirmed significantly higher expression of Ki67, STAT1, and GBP1 in postpartum versus nulliparous breast tissues (p < 0.0001). Silencing STAT1 and GBP1 in HMECs resulted in decreased cell proliferation, G1 cell cycle arrest, and increased expression of CDKN1A and CDKN1C. Conclusion: These findings suggest that STAT1 and GBP1 promote proliferation in postpartum breast epithelial cells by downregulating cyclin-dependent kinase inhibitors, potentially contributing to the increased risk of PPBC. Targeting these pathways may offer novel strategies for mitigating postpartum breast cancer risk. Citation Format: Joshua Ogony, Melody Stallings-Mann, Sarah McLaughlin, Mark Sherman, Derek C. Radisky. STAT1 and GBP1 promote proliferation in postpartum breast epithelium by downregulating cyclin-dependent kinase inhibitors: implications for increased postpartum breast cancer risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 187.

Abstract Introduction: Cholangiocarcinoma (CCA) is an aggressive biliary malignancy with poor survival outcomes and multiple mechanisms of resistance to targeted therapies. We previously validated NXP800, a novel GCN2 small-molecule activator, as an effective anti-cancer drug in six CCA cell lines. In vitro testing identified upregulation of phosphorylated eIF2a, as well as upregulation of ATF4, in CCA cells treated with of NXP800 compared to vehicle, suggesting that treated cells led to stimulation of stress-induced genes and subsequently, apoptosis. Furthermore, patient derived xenografts (PDX) models treated with NXP800 were found to have decreased tumor size, particularly in models containing ARID1A, FGFR1, and ATM mutations. Here, we aimed to predict response to NXP800 using sensitivity and resistance signatures from our profiled PDX models. Methods: GCN2 activation in multiple previously profiled PDX models was evaluated. Whole Exome Sequencing (WES) was done on multiple PDX models to characterize the mutational signature and activity in CCA. Two additional CCA xenografts were expanded into the flank of NOD/SCID mice. Tumor bearing mice were treated with NXP800 (35 mg/kg) or vehicle via oral gavage for 28 days once tumors averaged 120 mm3. Tumor volume and animal weight were collected twice weekly. Median Efficacy Index (MEI) scores were generated as drug response rates based on tumor growth. Predicted sensitivity and resistance kinase signatures to predict drug response were produced using multi-omics. Results: Treatment with NXP800 was associated with a statistically significant decrease in tumor size in two additional PDX models, which included ARID1A and BRAF mutants. Preliminary multi-omics on the PDX models revealed that sensitivity mechanisms were upregulated most in EGFR signaling, while resistance signatures were focused around CSNK2A1 signaling. Conclusion: Multi-omics analysis revealed a sensitivity mechanism structured around EGFR signaling, providing insights into which patients should be selected for treatment with NXP800. A Phase 1b clinical trial investigating the effects of NXP800 use in patients with advanced CCA is open and currently accepting patients. Citation Format: Danielle Marie Carlson, Hendrien Kuipers, Amro Abdelrahman, Erik Jessen, Joshua Roldan Kalill, Jennifer Tomlinson, Jack Sample, Akhilesh Pandey, Mark Truty, Rory Smoot. Modeling response prediction to a novel GCN2 kinase activator (NXP800) in patient-derived xenograft cholangiocarcinoma models using a multi-omics approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5592.

Abstract Text While the importance of estrogen in driving ER+ breast cancer progression is clear, data from pre-clinical studies exploring the role of tumoral progesterone (PR) and androgen (AR) receptors are conflicting, likely due in part to the promiscuity of steroid receptor ligands, as well as relative levels of steroid hormone receptor expression and of steroid hormones within the tumor milieu. While bone is usually the first site of metastases in ER+ metastatic breast cancer, the roles of tumoral PR and AR (present in 58 percent and 86 percent of clinical ER+ bone metastases [BMET], respectively) in ER+ breast cancer progression at this site have not been well studied. Studies were undertaken to examine the effects of ovariectomy (OVX), a model of surgical menopause that significantly reduces endogenous progesterone and androgen levels, in a pre-clinical model of human ER+ bone metastases that is dependent on exogenous 17ß-estradiol (E2) supplementation. Effects of OVX (at 9-weeks of age) were ascertained using skeletally mature female nude mice supplemented with a modest dose of E2 (0.36 mg 60 day pellets) prior to intracardiac inoculation (at 10 weeks of age) with bone metastasis-derived MCF7 cells (43.4M cells) that form robust E2- and TGFß-dependent osteolytic metastasis in vivo, and express PR and AR in vitro. Osteolytic bone metastatic lesions in E2-supplemented mice were reduced in both incidence and size in OVX (vs ovary intact) mice. Anti-tumoral effects of OVX were not limited to bone; E2-driven orthotopic tumor progression was similarly reduced. Histologic assessment of cytokeratin-positive breast cancer tumor cells within bone revealed a small but statistically significant reduction in Ki67-positivity in OVX (vs ovary -intact) mice that correlated with osteolytic lesion size. In addition, PR and AR expression in BMET lesions, which was readily detected by IHC in ovary-intact mice, was markedly reduced in OVX mice. While additional experiments are underway to query possible roles of specific reproductive hormones altered in OVX mice, these results are consistent with the postulate that tumoral AR and PR signaling may promote ER+ bone metastases progression in this model. In addition, while ovariectomy is a common pre-clinical means of reducing estrogen to model natural menopause in women, resultant changes in steroid receptor signaling are clearly much more complex. Funding: NIH 5R25CA275753, 5P30CA023074 Date of Presentation October 17, 2024

Abstract Text While the importance of estrogen in driving ER+ breast cancer progression is clear, data from pre-clinical studies exploring the role of tumoral progesterone (PR) and androgen (AR) receptors are conflicting, likely due in part to the promiscuity of steroid receptor ligands, as well as relative levels of steroid hormone receptor expression and of steroid hormones within the tumor milieu. While bone is usually the first site of metastases in ER+ metastatic breast cancer, the roles of tumoral PR and AR (present in 58 percent and 86 percent of clinical ER+ bone metastases [BMET], respectively) in ER+ breast cancer progression at this site have not been well studied. Studies were undertaken to examine the effects of ovariectomy (OVX), a model of surgical menopause that significantly reduces endogenous progesterone and androgen levels, in a pre-clinical model of human ER+ bone metastases that is dependent on exogenous 17ß-estradiol (E2) supplementation. Effects of OVX (at 9-weeks of age) were ascertained using skeletally mature female nude mice supplemented with a modest dose of E2 (0.36 mg 60 day pellets) prior to intracardiac inoculation (at 10 weeks of age) with bone metastasis-derived MCF7 cells (43.4M cells) that form robust E2- and TGFß-dependent osteolytic metastasis in vivo, and express PR and AR in vitro. Osteolytic bone metastatic lesions in E2-supplemented mice were reduced in both incidence and size in OVX (vs ovary intact) mice. Anti-tumoral effects of OVX were not limited to bone; E2-driven orthotopic tumor progression was similarly reduced. Histologic assessment of cytokeratin-positive breast cancer tumor cells within bone revealed a small but statistically significant reduction in Ki67-positivity in OVX (vs ovary -intact) mice that correlated with osteolytic lesion size. In addition, PR and AR expression in BMET lesions, which was readily detected by IHC in ovary-intact mice, was markedly reduced in OVX mice. While additional experiments are underway to query possible roles of specific reproductive hormones altered in OVX mice, these results are consistent with the postulate that tumoral AR and PR signaling may promote ER+ bone metastases progression in this model. In addition, while ovariectomy is a common pre-clinical means of reducing estrogen to model natural menopause in women, resultant changes in steroid receptor signaling are clearly much more complex. Funding: NIH 5R25CA275753, 5P30CA023074 Date of Presentation October 17, 2024

Abstract Allogeneic hematopoietic cell transplantation (allo-HCT) can provide curative treatment for hematologic malignancies but is associated with prolonged lymphopenia that may contribute to an increased risk of infection and relapse, resulting in decreased survival. We hypothesized that patients with rapid and robust CD4 T- and B-cell recovery have improved survival and decreased treatment-related mortality (TRM). A total of 2089 patients were included who underwent first allo-HCT for acute myeloid leukemia/acute lymphoblastic leukemia/myelodysplastic syndrome from 2008 to 2019 reported to the Center for International Blood and Marrow Transplant Research with available CD4 counts at days 100 and 180. Patients (median age, 51 years [range, 2-75]) were categorized into 4 groups based on graft-versus-host disease (GVHD) prophylaxis: ex vivo T-cell depletion (TCD/CD34), posttransplant cyclophosphamide, calcineurin inhibitor alone (CNI), or CNI with antithymocyte globulin. Based upon survival, we could identify optimal cutoff points for CD4+ T cells in pediatric (age of <20 years) patients: 248 × 106/L and 420 × 106/L at days 100 and 180, respectively; and in adult (age of >20 years) patients: 104 × 106/L and 115 × 106/L at days 100 and 180, respectively. In adults, day-100 CD4 count was associated with overall survival (OS), progression-free survival (PFS), and TRM but not relapse, incidence of infections, or chronic GVHD. Similarly, CD4 counts above the cutoff point at day 180 in adults were associated with improved OS, PFS, and TRM but no other outcomes. No clinical associations for CD4 counts were identifiable in pediatric patients. These findings underscore the importance of tailoring transplant strategies for adults to optimize immune recovery and improve patient outcomes.

Gastric point-of-care ultrasound (POCUS) may offer clinical value in assessing aspiration risk among medically complex patients undergoing regional anesthesia and pain procedures. While the American Society of Anesthesiologists (ASA) preoperative fasting guidelines primarily apply to healthy individuals, medically complex populations often present with differing gastric emptying and aspiration risk. This narrative review, conducted by the American Society of Regional Anesthesia and Pain Medicine (ASRA-PM), adhered to PRISMA guidelines and was registered with PROSPERO. It focused on seven medically complex patient groups: those who are pregnant, obese, diabetic, have gastroesophageal reflux disease (GERD), are receiving emergency care, are enterally fed, or are taking GLP-1 receptor agonists (GLP-1RA). Study quality was assessed using the Mixed Methods Appraisal Tool (MMAT). Practice recommendations were developed using an iterative expert consensus process, with final recommendations based on evidence strength, clinical relevance, and expert agreement. Findings support the use of gastric POCUS in patients in active labor, those undergoing urgent cesarean sections, and those with diabetes. Conditional support is given for obesity, emergency care, enteral feeding, and GLP-1RA use. Routine use is not recommended in non-laboring pregnancies, elective cesarean delivery, or GERD. While gastric POCUS may aid with aspiration risk evaluation, its use should complement clinical judgment. Implementation may be limited by practical and training constraints, requiring individualized decision-making. These recommendations serve as a foundation for future research and potential clinical guideline development. PROSPERO registration number: CRD42023445927.