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Breast cancer is the major leading cause of cancer-related fatalities nationally and globally. There will be 287,850 new breast cancer cases and 43,250 breast cancer related deaths in the United States in 2022. The relapsed, treatment-resistant, undruggable, and incurable breast cancers are often associated with EGFR/HER2/K-RAS/SIAH pathway activation. The EGFR/HER2/K-RAS/SIAH pathway is a major tumor-driver whose hyperactivation is associated malignant tumor growth, multidrug-resistant phenotypes, early tumor relapse, and systematic metastasis. Seven-In-Absentia (SINA) homologues (SIAH) are extraordinarily evolutionarily-conserved E3 ubiquitin ligases that play a critical gatekeeper role downstream of the EGFR/HER2/K-RAS pathway. SIAH is a major tumor vulnerability that is ideally positioned to become an attractive target for innovative targeted therapy development against metastatic breast cancer (MBC). Prior studies have shown that tumor growth was abolished in malignant tumor cell lines such as MDA-MB-231, MDA-MB-468, MiaPaCa, A459, and HeLa following SIAH inhibition in xenograft models; however, the underpinning molecular mechanisms that give rise to this striking anti-EGFR/K-RAS and anticancer phenotype remain unclear. Specific objectives: to delineate the molecular mechanism(s) of why anti-SIAH2PD targeted therapy is so effective in impeding and eradicating the stage IV and aggressive tumors, we conducted reverse phase protein array (RPPA)-based kinomic analysis to delineate how major cancer signaling pathways and EGFR/HER2/K-RAS/SIAH-dependent signaling networks are rewired and remodeled in response to anti-SIAH2 targeted therapy. Brief statement of methods: About 300 proteins/phosphoproteins were quantititatively measured by the RPPA platform to identify new tumor vulnerabilities and actionable targets, compensatory signaling network activation/inhibition in response to anti-SIAH targeted therapies in five highly malignant cancer cell lines. Doxycycline (DOX)-inducible Tet-ON MDA-MB-231, MDA-MB-468, MiaPaCa, HeLa and A459 cell lines were amplified from single cell and DOX-induced SIAH2PD expression was confirmed. Each of the cell lines was then subjected to one of four experimental conditions: Tet-ON control cells without DOX induction (group A), Tet-ON control cells with DOX induction (group B), Tet-ON-SIAH2PD cancer cells without DOX-induction (no SIAH2PD inhibitor) (group C), Tet-ON-SIAH2PD cancer cells with DOX-induction (SIAH2PD inhibitor) (group D). Reverse Phase Protein Array (RPPA) in conjunction with Principal Component Analysis (PCA) was conducted to quantify fold-changes of proteins/phosphoproteins in response to SIAH inhibition. The ratios of D/C/B/A, D/C, D/B, C/A, and B/A were calculated using GAPDH normalized data. Summary of results: Supported by statistical analyses, we identified 6 unique phospho-proteins that were either up- or down-regulated in response to SIAHLoss-of-function. Many have known roles in controlling and regulating cell growth, cell death, NFκB signaling, stress response, DNA damage, and cell attachment pathways, supporting a tumor eradication phenotype in the absence of SIAH function in these cancer cell lines. Conclusion: Cancer landscape (CScape) functional protein pathway mapping has categorized the synergistic feedforward, feedback, and compensatory signaling pathway activation/inactivation in response to SIAH blockade in these EGFR/HER2/K-RAS-driven malignant human cell lines. Further validation analysis will be conducted to gain better insight into the global cancer pathway alterations to reveal the molecular mechanism(s) of why SIAH inhibition works so effectively to shut down malignant tumor growth in the preclinical models. Citation Format: Andrew P. Howell, Julia Wulfkuhle, Rosa I. Gallagher, Emanuel F. Petricoin, Amy H. Tang. The Use of Reverse Phase Protein Arrays (RPPA), Principal Component Analysis (PCA), and CScape Pathway Mapping to Identify New Tumor Vulnerability and Actionable Targets in Human Malignant Triple-Negative Breast cancer cell lines [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-08-13.

FBP1-associated proteins identified by tandem affinity purification and mass spectrometry

Assessment of the effectiveness of IQGAP1 depletion and the effect of gemcitabine on the pERK1/2 levels in the PDAC patient samples.

Assessment of the effect of gemcitabine treatment on the cell cycle and interaction of IQGAP1 and ERK1/2 in PANC-1 cells.

Supplementary Materials and Methods

Supplementary Materials and Methods from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Supplementary Figure 1 from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Supplementary Figure 3 from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Supplementary Table 1 from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Supplementary Figure 4 from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Supplementary Figure 5 from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Supplementary Figure 2 from Inhibition of RAS-Mediated Transformation and Tumorigenesis by Targeting the Downstream E3 Ubiquitin Ligase Seven in Absentia Homologue

Constitutively active RAS small GTPases promote the genesis of human cancers. An important goal in cancer biology is to identify means of countervailing activated RAS signaling to reverse malignant transformation. Oncogenic K-RAS mutations are found in virtually all pancreatic adenocarcinomas, making the RAS pathway an ideal target for therapeutic intervention. How to best contravene hyperactivated RAS signaling has remained elusive in human pancreatic cancers. Guided by the Drosophila studies, we reasoned that a downstream mediator of RAS signals might be a suitable anti-RAS target. The E3 ubiquitin ligase seven in absentia (SINA) is an essential downstream component of the Drosophila RAS signal transduction pathway. Thus, we determined the roles of the conserved human homologues of SINA, SIAHs, in mammalian RAS signaling and RAS-mediated tumorigenesis. We report that similar to its Drosophila counterpart, human SIAH is also required for oncogenic RAS signaling in pancreatic cancer. Inhibiting SIAH-dependent proteolysis blocked RAS-mediated focus formation in fibroblasts and abolished the tumor growth of human pancreatic cancer cells in soft agar as well as in athymic nude mice. Given the high level of conservation of RAS and SIAH function, our study provides useful insights into altered proteolysis in the RAS pathway in tumor initiation, progression, and oncogenesis. By targeting SIAH, we have found a novel means to contravene oncogenic RAS signaling and block RAS-mediated transformation/tumorigenesis. Thus, SIAH may offer a novel therapeutic target to halt tumor growth and ameliorate RAS-mediated pancreatic cancer. [Cancer Res 2007;67(24):11798–810]

Community health centers (CHC) play a key role in latent tuberculosis infection (LTBI) testing and treatment. We performed a retrospective analysis of LTBI testing and treatment among pediatric and adult patients at a CHC with a large non-U.S.-born (USB) population during a series of quality improvement (QI) interventions from 2010 to 2019. Among 124,695 patients with primary care visits, 40% of patients were tested for tuberculosis (TB) infection and among those tested, 20% tested positive, including 39% of adults aged 50–79 years. Compared to adults aged 18–49 years, children aged 6–17 had increased odds of LTBI testing and treatment initiation [odds ratio and 95% confidence interval 3.23 (3.10, 3.36) and 1.41 (1.12, 1.79), respectively], while age ≥ 65 was associated with lower odds of both testing and treatment initiation. Over the analysis period, coinciding with unfunded QI interventions intended to reduce barriers to LTBI care, there was a significant increase in the proportion of patients receiving LTBI testing for both adults (6% to 47%, p

There have been significant changes in clinical guidelines for sickle cell disease (SCD) over the past two decades, including updated indications for hydroxyurea, transfusions, and iron overload management. In practice however, there are few studies that examine SCD care utilization over time.We conducted a serial cross-sectional cohort study of pediatric SCD patients from 2004 to 2019 using Georgia Medicaid claims data. For each year, we reported receipt of any transfusion, chronic transfusion, or three or more filled hydroxyurea prescriptions. For children receiving chronic transfusion (six or more annual transfusions), we evaluated iron overload diagnosis, monitoring, and chelation use. Among children with sickle cell anemia (SCA), we examined rates of transfusions and hydroxyurea use. The Cochran-Armitage test was used to assess trend.There were 5316 unique children 2-18 years old with SCD enrolled in Georgia Medicaid from 2004 to 2019. Children receiving any transfusion increased from 2004 to 2010, then stabilized. In SCA patients, chronic transfusions initially increased from 2004 to 2010, then stabilized from 2010 to 2019. For chronically transfused children, monitoring of iron burden and filled chelator prescriptions both increased significantly. Hydroxyurea use in SCA patients increased from 12% to 37%, with increases noted within each age group, most notably from 21% to 60% in the 13-18-year-old cohort.We demonstrated changes in SCD care utilization over time, including increased hydroxyurea use, changes in transfusion rates, and increased attention to iron overload management. While trends in clinical management do follow updates in treatment guidelines, there is still delayed and suboptimal uptake of guideline recommendations in pediatric SCD patients.

Introduction: The EGFR/K-RAS pathway is a major tumor driver whose hyperactivation is associated with malignant tumor growth, multidrug resistance, early tumor relapse, chemo-resistance, and metastasis. Despite more than 40 years of research, oncogenic K-RAS activation remains an undruggable target in clinical oncology. Seven-In-Absentia (SINA) homologues (SIAH) are conserved E3 ubiquitin ligases that play a critical gatekeeper role downstream of the EGFR/K-RAS pathway. Our prior studies have shown that tumor growth was abolished in human tumor cell lines following SIAH inhibition; however, the underpinning molecular mechanisms that give rise to this anti-EGFR/K-RAS and anticancer phenotype remain unclear. Specific Objectives: to delineate the molecular mechanism(s) of why anti-SIAH2PD targeted therapy is so effective in impeding growth, we conducted reverse-phase protein array (RPPA)-based kinomic analysis to discover how major cancer signaling pathways and K-RAS-dependent signaling networks are remodeled in response to SIAH2 inhibition. Ongoing studies aim to identify and validate dysregulated phospho-proteins identified by RPPA-based kinomic analysis. Methods: 300 proteins/phosphoproteins were quantitatively measured by the RPPA platform to identify new tumor vulnerabilities, actionable targets, and compensatory signaling network alterations in response to anti-SIAH targeted therapies in five cancer cell lines in triplicate. Doxycycline (DOX)-inducible Tet-ON MiaPaCa, MDA-MB-231, MDA-MB-468, HeLa, and A459 cell lines were generated from a single cell, and DOX-induced SIAH2PD expression was confirmed. Reverse Phase Protein Array (RPPA) was conducted to quantify fold-changes of proteins whose expression was significantly (p Results: Supported by statistical analyses, we identified 6 unique proteins that were significantly up-or down-regulated in response to SIAH inhibition. These proteins play a role in controlling and regulating cell growth, cell death, NFκB signaling, stress response, DNA damage, immune function, and cell attachment pathways. Thus, our data provide additional evidence supporting our tumor eradication phenotype observed in these human cancer cell lines lacking functional SIAH. Western Blot and IF validation studies have yielded further supporting evidence to confirm our RPPA results. Conclusion: Validation studies are being conducted to gain insight into pathway alterations and dynamic rewiring in order to uncover SIAH as a major tumor vulnerability in multiple malignant cancers. Our data supports the explanation as to why anti-SIAH targeted therapy works so effectively to shut down malignant tumor growth, as reported in the literature. Citation Format: Andrew Howell, Julia Wulfkhule, Rosa Gallagher, Jonathan Baker, Ashleigh Hannah, Emanuel F. Petricoin, Amy H. Tang. The use of reverse phase protein array (RPPA) to identify new tumor vulnerability and actionable drug targets against human cancer cell lines. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5248.

Introduction: Metastatic breast cancer (MBC) is the 2nd leading cause of cancer-related deaths in American women. While improvements in local and systemic therapies have significantly improved survival, 43,250 MBC patients are expected to succumb to their disease in the United States in 2022 alone. Triple-negative breast cancer (TNBC) represents 15% of all breast cancer and is defined by the lack of expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). TNBC is the most aggressive subtype of breast cancer, known for its early relapse rate, chemo-resistance, and reduced survival. TNBC is also nearly twice as common in African American (AA) than in White women. In this study, we aim to ascertain the cancer disparity in a large cohort of Black/AA TNBC patients compared to their White counterparts in Hampton Roads, Virginia, as well as to the national SEER database. Methods: A retrospective chart review and survival study of 554 TNBC patients who received standard of care (SOC) treatment at Sentara-EVMS-VOA was performed. Kaplan-Meier survival curves were generated. Statistical analyses were conducted to determine if any clinicopathologic parameters, chemotherapy regimens, insurance, or socioeconomic status could be used to predict patient survival and risk stratify Black/AA and White TNBC patients in this Sentara cohort. Results: According to the national SEER TNBC database, 5-year survival rates for Black/AA and Whites are reported as 71.65% and 78.98%, respectively, compared to 70.33% and 75.53% within our local TNBC cohort. The Kaplan-Meier curve, which stratified our TNBC patients by race, predicted significant reduction in breast cancer-specific survival among Black/AA patients as compared to their White counterparts at all TNBC stages, especially in advanced and metastatic settings. This disparity is notably pronounced at stages II and III, as the Black/AA survival curves trend below that of the White TNBC patients for years following surgical intervention. A higher percentage of Black/AA patients were uninsured or under Medicaid coverage and did not receive standard AC-T regimens, particularly for TNBC patients with stage II disease, likely contributing to a reduced 5-year survival in the Black/AA TNBC cohort. We detected racial disparity in prescription of monotherapy or combination chemotherapy that might have also linked to reduced survival in the Black/AA patients from the Sentara catchment areas. Conclusion: Low socioeconomic status is a major impediment for access to health care. Multipronged combination chemotherapy regimens are critical in treating high-risk and high-grade TNBC patients. Therefore, it is imperative that Medicaid coverage includes AC-T regimens to improve TNBC survival, especially in our Black/AA patients in Hampton Roads, Virginia. Citation Format: Taylor N. Drake, Brandon Euker, Angela M. Tang-Tan, Caroline Dasom Lee, Emily L. Breeding, Janet S. Winston, Billur Samli, Rick J. Jansen, Michael Danso, Mary L. Guye, Richard A. Hoefer, Amy H. Tang. Stratifying high-risk patients, quantifying therapy efficacy, and detecting treatment/racial disparity in triple-negative breast cancer (TNBC) at Sentara-EVMS-VOA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1961.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype and disproportionately affects BRCA1 mutation carriers and young black women. Black/African American (AA) patients with TNBC have the highest mortality rate and the shortest survival of any racial/ethnic group in the United States. TNBC challenges our ability to personalize effective therapy. Neoadjuvant chemotherapy (NACT) is the standard-of-care (SOC) to treat T2 or LN+ TNBC. The addition of immune checkpoint blockade (ICB) has revolutionized treatment for these high-risk patients. Pembrolizumab plus chemotherapy is the new SOC for neoadjuvant systemic therapy (NST) in TNBC. Pathologic complete response (pCR) is a reliable indicator that correlates with improved long-term survival. However, clinical uncertainties remain in those who have an incomplete pathologic response (pIR) since many similarly treated TNBC patients with identical stage and comparable residual cancer burden (RCB) demonstrate disparate clinical outcomes. Current methods fall short in predicting tumor recurrence and treatment resistance in the clinic. Supported by ample evidence in developmental, evolutionary, and cancer biology, we proposed that EGFR-K-RAS-SIAH pathway activation is a major driving force in TNBC and that its most downstream gatekeeper, SIAH, is a tumor-specific, therapy-responsive, and prognostic biomarker for patient risk stratification in TNBC. The persistent high expression of SIAH in residual tumors after neoadjuvant therapy reflects EGFR/K-RAS pathway activation (ON) and resistance to treatment. The loss of expression of SIAH in residual tumors reflects EGFR/K-RAS pathway inactivation (OFF) and response to treatment (i.e. treatment efficacy). Here we propose to establish the power of SIAH as a prognostic biomarker to differentiate high-risk from low-risk tumors and predict “real-time” therapy response, in both pre- and post-neoadjuvant (NACT/NST) setting. Breast cancer mortality rates in Hampton Roads Virginia and Richmond Virginia are among the worst in the U.S. and demonstrate a major cancer health disparity. Black patients in our region have a 60-70% higher mortality rate than white patients according to CDC/SEER databases. Using a large cohort of 525 racially diverse TNBC patients (246 black and 279 white patients) at Sentara Cancer Network, we conducted Kaplan-Meier survival analyses and detected a major racial disparity, with significantly lower survival among the Black/AA TNBC cohort, compared to national databases. We will expand this TNBC disparity study by using 2 large racially-diverse cohorts of 981 TNBC patients (459 Black and 493 white patients) from the Sentara Cancer Network and VCU Massey Cancer Center to analyze the prognosis of SIAH expression. By focusing on this tumor-driving EGFR-K-RAS-SIAH pathway, we aim to delineate the underlying molecular basis of treatment resistance and racial disparity in high-risk TNBC. Citation Format: Amy H. Tang, Richard A. Hoefer, Dasom Lee, Emily L. Breeding, Mary L. Guye, Janet S. Winston, Billur Samli, Jennifer Koblinski, Valentina Robila, Michael O. Idowu, Rick J. Jansen, Harry D. Bear. Early detection of cancer disparity and treatment resistance in TNBC. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5531.

Purpose of Review The World Health Organization has set a target for the elimination of hepatitis B virus (HBV) infection as a public health threat by 2030, but the U.S. is not currently on track. In this review, we describe specific barriers to HBV elimination, provide examples of potential solutions, and offer recommendations for how the U.S. can reach HBV elimination goals. Recent Findings In the U.S., there are many barriers to eliminating hepatitis B, worsened by the siloing of healthcare and public health services. In recent years, we have not seen progress toward improving HBV screening or adult vaccination, and acute cases are on the rise. Current policies, guidelines, and recommendations can hinder elimination progress. Summary Simple policy and guideline changes will allow us to decentralize and scale-up hepatitis B screening, vaccination, and care. Dismantling current barriers will be critical to eliminating hepatitis B in the U.S.

SUMMARY Receptor-interacting protein kinase 1 (RIPK1) and 3 (RIPK3) are well known for their capacity to drive necroptosis via mixed-lineage kinase-like domain (MLKL). Recently, RIPK1/3 kinase activity has been shown to drive inflammation via activation of MAPK signaling. However, the regulatory mechanisms underlying this kinase-dependent cytokine production remain poorly understood. In the present study, we establish that the kinase activity of RIPK1/3 regulates cytokine translation in mouse and human macrophages. Furthermore, we show that this inflammatory response is downregulated by type I interferon (IFN) signaling, independent of type I IFN-promoted cell death. Specifically, low-level constitutive IFN signaling attenuates RIPK-driven activation of cap-dependent translation initiation pathway components AKT, mTORC1, 4E-BP and eIF4E, while promoting RIPK-dependent cell death. Altogether, these data characterize constitutive IFN signaling as a regulator of RIPK-dependent inflammation and establish cap-dependent translation as a crucial checkpoint in the regulation of cytokine production., In Brief Balancing inflammatory responses is critical for host survival. Muendlein et al. show that constitutive type I IFN signaling inhibits translation machinery activated downstream of the kinase activity of RIPK1/3, preventing the production of a subset of inflammatory cytokines. This work identifies cap-dependent translation as a checkpoint in regulation of RIPK1/3-kinase-dependent inflammation., Graphical Abstract

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype. It disproportionately affects BRCA mutation carriers and young women, especially African American (AA) women. Chemoresistant TNBC is a heterogeneous and molecularly unstable disease that challenges our ability to apply personalized therapies. With the approval of immune checkpoint blockade (ICB) for TNBC, the addition of pembrolizumab to systemic chemotherapy has become standard of care (SOC) in neoadjuvant systemic therapy (NST) for high-risk early-stage TNBC. Pembrolizumab plus chemotherapy significantly increased the pathologic complete response (pCR) and improved event-free survival in TNBC. However, clinical uncertainties remain because similarly treated TNBC partial responders with comparable tumor responses to neoadjuvant therapy often experience disparate clinical outcomes. Current methods fall short in accurately predicting which high-risk patients will develop chemo-resistance and tumor relapse. Therefore, novel treatment strategies and innovative new research initiatives are needed. We propose that the EGFR-K-RAS-SIAH pathway activation is a major tumor driver in chemoresistant TNBC. Persistent high expression of SIAH in residual tumors following NACT/NST reflects that the EGFR/K-RAS pathway remains activated (ON), indicating an ineffective response to treatment. These chemoresistant tumor clones persist in expressing SIAH (SIAHHigh/ON) and are linked to early tumor relapse and poorer prognosis. Conversely, the loss of SIAH expression (SIAHLow/OFF) in residual tumors post-NACT/NST reflects EGFR/K-RAS pathway inactivation (OFF), indicating effective therapy and chemo-sensitive tumor cells. SIAHLow/OFF signal is linked to tumor remission and better prognosis post-NACT/NST. Therefore, SIAH is well-positioned to become a novel tumor-specific, therapy-responsive, and prognostic biomarker. Potentially, this new biomarker (SIAHHigh/ON) could be used to quantify therapy response, predict chemo-resistance, and identify those patients at the highest risk for tumor relapse and poor survival in TNBC.

Regional gene therapy using a lentiviral vector containing the BMP-2 complementary DNA (cDNA) has been shown to heal critical-sized bone defects in rodent models. An appropriate “cellular dose” needs to be defined for eventual translation into human trials. The purpose of this study was to evaluate bone defect healing potential and quality using three different doses of transduced human bone marrow cells (HBMCs). HBMCs were transduced with a lentiviral vector containing either BMP-2 or green fluorescent protein (GFP). All cells were loaded onto compression-resistant matrices and implanted in the bone defect of athymic rats. Treatment groups included femoral defects that were treated with a low-dose (1 × 10(6) cells), standard-dose (5 × 10(6) cells), and high-dose (1.5 × 10(7) cells) HBMCs transduced with lentiviral vector containing BMP-2 cDNA. The three control groups were bone defects treated with HBMCs that were either nontransduced or transduced with vector containing GFP. All animals were sacrificed at 12 weeks. The bone formed in each defect was evaluated with plain radiographs, microcomputed tomography (microCT), histomorphometric analysis, and biomechanical testing. Bone defects treated with higher doses of BMP-2-producing cells were more likely to have healed (6/14 of the low-dose group; 12/14 of the standard-dose group; 14/14 of the high-dose group; χ(2)(2) = 15.501, p

The hospital-acquired pathogen Acinetobacter baumannii possesses a complex cell envelope that is key to its multidrug resistance and virulence. The bacterium, however, lacks many canonical enzymes that build the envelope in model organisms. Instead, A. baumannii contains a number of poorly annotated proteins that may allow alternative mechanisms of envelope biogenesis. We demonstrated previously that one of these unusual proteins, ElsL, is required for cell elongation and for withstanding antibiotics that attack the septal cell wall. Curiously, ElsL is composed of a leaderless YkuD-family domain usually found in secreted, cell-wall-modifying L,D-transpeptidases (LDTs). Here, we show that, rather than being an LDT, ElsL is actually a new class of cytoplasmic L,D-carboxypeptidase (LDC) that provides a critical step in cell-wall recycling previously thought to be missing from A. baumannii. Absence of ElsL impairs cell wall integrity, elongation, and intrinsic resistance due to buildup of murein tetrapeptide precursors, toxicity of which is bypassed by preventing muropeptide recycling. Multiple pathways in the cell become sites of vulnerability when ElsL is inactivated, including L,D-crosslink formation, cell division, and outer membrane lipid homoeostasis, reflecting its pleiotropic influence on cell envelope physiology. We thus reveal a novel class of cell-wall-recycling LDC critical to growth and homeostasis of A. baumannii and likely many other bacteria.ImportanceTo grow efficiently, resist antibiotics, and control the immune response, bacteria recycle parts of their cell wall. A key step in the typical recycling pathway is the reuse of cell wall peptides by an enzyme known as an LDC. Acinetobacter baumannii, an “urgent-threat” pathogen causing drug-resistant sepsis in hospitals, was previously thought to lack this enzymatic activity due to absence of a known LDC homolog. Here, we show that A. baumannii possesses this activity in the form of an enzyme class not previously associated with cell wall recycling. Absence of this protein intoxicates and weakens the A. baumannii cell envelope in multiple ways due to the accumulation of dead-end intermediates. Several other organisms of importance to health and disease encode homologs of the A. baumannii enzyme. This work thus reveals an unappreciated mechanism of cell wall recycling, manipulation of which may contribute to enhanced treatments targeting the bacterial envelope.

The objective of the present study was to assess the ability of transduced rat bone marrow cells (RBMCs) that overexpress BMP-2 loaded on a three-dimensionally (3D) printed scaffold to heal a critical sized rat femoral defect. Tricalcium phosphate (TCP) scaffolds were 3D printed to fit a critical sized rat femoral defect. The RBMCs were transduced with a lentiviral (LV) vector expressing BMP-2 or GFP. The rats were randomized into the following treatment groups: (1) RBMC/LV-BMP-2 + TCP, (2) RBMC/LV-GFP + TCP, (3) nontransduced RBMCs + TCP, (4) TCP scaffold alone. The animals were euthanized at 12 weeks and evaluated with plain radiographs, microcomputed tomography (micro-CT), histology, histomorphometry, and biomechanically. Each LV-BMP-2 + TCP treated specimen demonstrated complete healing of the femoral defect on plain radiographs and micro-CT. No femurs healed in the control groups. Micro-CT demonstrated that LV-BMP-2 + TCP treated femoral defects formed 197% more bone volume compared to control groups (p < 0.05). Histologic analysis demonstrated bone formation across the TCP scaffold, uniting the femoral defect on both ends in the LV-BMP-2 + TCP treated specimens. Biomechanical assessment demonstrated similar stiffness (p = 0.863), but lower total energy to failure, peak torque, and peak displacement (p < 0.001) of the femurs treated with LV-BMP-2 + TCP when compared to the contralateral control femur. Regional gene therapy induced over-expression of BMP-2 via transduced RBMCs combined with an osteoconductive 3D printed TCP scaffold can heal a critically sized femoral defect in an animal model. The combination of regional gene therapy and 3D printed osteoconductive scaffolds has significant clinical potential to enhance bone regeneration.

Acinetobacter baumannii is a poorly understood bacterium capable of life-threatening infections in hospitals. Few antibiotics remain effective against this highly resistant pathogen. Development of rationally designed antimicrobials that can target A. baumannii requires improved knowledge of the proteins that carry out essential processes allowing growth of the organism. Unfortunately, studying essential genes has been challenging using traditional techniques, which usually require time-consuming recombination-based genetic manipulations. Here, we performed saturating mutagenesis with dual transposon systems to identify essential genes in A. baumannii, and we developed a CRISPR interference (CRISPRi) system for facile analysis of these genes. We show that the CRISPRi system enables efficient transcriptional silencing in A. baumannii. Using these tools, we confirmed the essentiality of the novel cell division protein AdvA and discovered a previously uncharacterized AraC family transcription factor (ACX60_RS03245) that is necessary for growth. In addition, we show that capsule biosynthesis is a conditionally essential process, with mutations in late-acting steps causing toxicity in strain ATCC 17978 that can be bypassed by blocking early-acting steps or activating the BfmRS stress response. These results open new avenues for analysis of essential pathways in A. baumannii. IMPORTANCE New approaches are urgently needed to control A. baumannii, one of the most drug-resistant pathogens known. To facilitate the development of novel targets that allow inhibition of the pathogen, we performed a large-scale identification of genes whose products the bacterium needs for growth. We also developed a CRISPR-based gene knockdown tool that operates efficiently in A. baumannii, allowing rapid analysis of these essential genes. We used these methods to define multiple processes vital to the bacterium, including a previously uncharacterized gene regulatory factor and export of a protective polymeric capsule. These tools will enhance our ability to investigate processes critical for the essential biology of this challenging hospital-acquired pathogen.

BACKGROUND: Previous reports suggest that intact SMAD4 expression is associated with a locally aggressive pancreas cancer phenotype. The objectives of this work were to determine the frequency of intact SMAD4 and its association with patterns of recurrence in patients with upfront resected pancreas cancer receiving adjuvant therapy. METHODS: A tissue microarray was constructed using resected specimens from patients who underwent upfront surgery and adjuvant gemcitabine with no neoadjuvant treatment for pancreas cancer. SMAD4 expression was determined by immunohistochemical staining. Associations of SMAD4 expression and clinicopathologic parameters with clinical outcomes were evaluated using Cox proportional hazard models. RESULTS: One hundred twenty-seven patients were included with a median follow up of 5.7 years. Most patients had stage ≥ pT3 tumors (75%) and pN1 (68%). All patients received adjuvant gemcitabine, and 79% of patients received adjuvant chemoradiotherapy. Ten (8%) patients had intact SMAD4 expression. Grade was the only clinicopathologic parameter statistically associated with SMAD4 expression (P=0.05). Median overall survival was 2.1 years. On univariate analysis, SMAD4 expression was associated with increased locoregional recurrence (hazard ratio 7.0, P

Acinetobacter baumanniiis a poorly understood bacterium capable of life-threatening infections in hospitals. Few antibiotics remain effective against this highly resistant pathogen. Developing rationally-designed antimicrobials that can targetA. baumanniirequires improved knowledge of the proteins that carry out essential processes allowing growth of the organism. Unfortunately, studying essential genes has been challenging using traditional techniques, which usually require time-consuming recombination-based genetic manipulations. Here, we performed saturating mutagenesis with dual transposon systems to identify essential genes inA. baumanniiand we developed a CRISPR-interference (CRISPRi) system for facile analysis of these genes. We show that the CRISPRi system enables efficient transcriptional silencing inA. baumannii. Using these tools, we confirmed the essentiality of the novel cell division protein AdvA and discovered a previously uncharacterized AraC-family transcription factor (ACX60_RS03245) that is necessary for growth. In addition, we show that capsule biosynthesis is a conditionally essential process, with mutations in late-acting steps causing toxicity in strain ATCC 17978 that can be bypassed by blocking early-acting steps or activating the BfmRS stress response. These results open new avenues for analysis of essential pathways inA. baumannii.ImportanceNew approaches are urgently needed to controlA. baumannii,one of the most drug resistant pathogens known. To facilitate the development of novel targets that allow inhibition of the pathogen, we performed a large-scale identification of genes whose products the bacterium needs for growth. We also developed a CRISPR-based gene knockdown tool that operates efficiently inA. baumannii, allowing rapid analysis of these essential genes. We used these methods to define multiple processes vital to the bacterium, including a previously uncharacterized gene-regulatory factor and export of a protective polymeric capsule. These tools will enhance our ability to investigate processes critical for the essential biology of this challenging hospital-acquired pathogen.

A unique, protective cell envelope contributes to the broad drug resistance of the nosocomial pathogen Acinetobacter baumannii. Here we use transposon insertion sequencing to identify A. baumannii mutants displaying altered susceptibility to a panel of diverse antibiotics. By examining mutants with antibiotic susceptibility profiles that parallel mutations in characterized genes, we infer the function of multiple uncharacterized envelope proteins, some of which have roles in cell division or cell elongation. Remarkably, mutations affecting a predicted cell wall hydrolase lead to alterations in lipooligosaccharide synthesis. In addition, the analysis of altered susceptibility signatures and antibiotic-induced morphology patterns allows us to predict drug synergies; for example, certain beta-lactams appear to work cooperatively due to their preferential targeting of specific cell wall assembly machineries. Our results indicate that the pathogen may be effectively inhibited by the combined targeting of multiple pathways critical for envelope growth., A unique cell envelope contributes to the antibiotic resistance of the pathogen Acinetobacter baumannii. Here, Geisinger et al. identify A. baumannii mutants with altered antibiotic susceptibility, infer the function of uncharacterized proteins involved in envelope synthesis, and predict antibiotic synergies.

Triple-negative breast cancer (TNBC), characterized by the absence or low expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2), is the most aggressive subtype of breast cancer. TNBC accounts for about 15% of breast cancer cases in the U.S., and is known for high relapse rates and poor overall survival (OS). Chemo-resistant TNBC is a genetically diverse, highly heterogeneous, and rapidly evolving disease that challenges our ability to individualize treatment for incomplete responders and relapsed patients. Currently, the frontline standard chemotherapy, composed of anthracyclines, alkylating agents, and taxanes, is commonly used to treat high-risk and locally advanced TNBC. Several FDA-approved drugs that target programmed cell death protein-1 (Keytruda) and programmed death ligand-1 (Tecentriq), poly ADP-ribose polymerase (PARP), and/or antibody drug conjugates (Trodelvy) have shown promise in improving clinical outcomes for a subset of TNBC. These inhibitors that target key genetic mutations and specific molecular signaling pathways that drive malignant tumor growth have been used as single agents and/or in combination with standard chemotherapy regimens. Here, we review the current TNBC treatment options, unmet clinical needs, and actionable drug targets, including epidermal growth factor (EGFR), vascular endothelial growth factor (VEGF), androgen receptor (AR), estrogen receptor beta (ERβ), phosphoinositide-3 kinase (PI3K), mammalian target of rapamycin (mTOR), and protein kinase B (PKB or AKT) activation in TNBC. Supported by strong evidence in developmental, evolutionary, and cancer biology, we propose that the K-RAS/SIAH pathway activation is a major tumor driver, and SIAH is a new drug target, a therapy-responsive prognostic biomarker, and a major tumor vulnerability in TNBC. Since persistent K-RAS/SIAH/EGFR pathway activation endows TNBC tumor cells with chemo-resistance, aggressive dissemination, and early relapse, we hope to design an anti-SIAH-centered anti-K-RAS/EGFR targeted therapy as a novel therapeutic strategy to control and eradicate incurable TNBC in the future.

Chemo-resistant breast cancer is a major barrier to curative treatment for a significant number of women with breast cancer. Neoadjuvant chemotherapy (NACT) is standard first- line treatment for most women diagnosed with high-risk TNBC, HER2+, and locally advanced ER+ breast cancer. Current clinical prognostic tools evaluate four clinicopathological factors: Tumor size, LN status, pathological stage, and tumor molecular subtype. However, many similarly treated patients with identical residual cancer burden (RCB) following NACT experience distinctly different tumor relapse rates, clinical outcomes and survival. This problem is particularly apparent for incomplete responders with a high-risk RCB classification following NACT. Therefore, there is a pressing need to identify new prognostic and predictive biomarkers, and develop novel curative therapies to augment current standard of care (SOC) treatment regimens to save more lives. Here, we will discuss these unmet needs and clinical challenges that stand in the way of precision medicine and personalized cancer therapy.

Seven-IN-Absentia (SINA) is the most downstream signaling gatekeeper identified thus far in the RAS/EGFR pathway that controls photoreceptor cell fate determination inDrosophila. Underscoring the central importance of SINA is its phylogenetic conservation in metazoans, with over 83% amino acid identities shared betweenDrosophilaSINA and human SINA homologs (SIAHs). SIAH is a major tumor vulnerability in multidrug-resistant and incurable cancer. SIAH inhibition is an effective strategy to shut down the tumor-driving K-RAS/EGFR/HER2 pathway activation that promotes malignant tumor growth and metastatic dissemination. To further delineate the SINA function in the RAS/EGFR pathway, a genetic modifier screen was conducted, and 28 newsinamutant alleles were isolated via ethyl methanesulfonate (EMS) and X-ray mutagenesis. Among them, 26 of the newsinamutants are embryonic, larval, or pupal lethal, and stronger than the five publishedsinamutants (sina1,sina2,sina3,sina4, andsina5) which are early adult lethal. By sequencing the SINA-coding region ofsinaES10,sinaES26,sinaES79, andsinaES473homozygous mutant animals, we identified three invariable amino acid residues in SINA’s RING-domain whose single point mutation ablates SINA function. To demonstrate the functional conservation of this medically important family of RING domain E3 ligases inDrosophila, we established a collection of transgenic lines, expressing either wild type (WT) or proteolysis-deficient (PD) SINA/SIAH inhibitors ofDrosophilaSINAWT/PDand human SIAH1WT/PD/2WT/PDunder tissue-specific GAL4-drivers inDrosophilaeye, wing, and salary gland. Our results showed thatDrosophilaSINA and human SIAH1/2 are functionally conserved. Our bioengineered SINAPD/SIAHPDinhibitors are effective in blocking the RAS-dependent neuronal cell fate determination inDrosophila.

Acinetobacter baumannii is an opportunistic pathogen that is a critical, high-priority target for new antibiotic development. Clearing of A. baumannii requires relatively high doses of antibiotics across the spectrum, primarily due to its protective cell envelope. Many of the proteins that support envelope integrity and modulate drug action are uncharacterized, largely because there is an absence of orthologs for several proteins that perform essential envelope-associated processes, impeding progress on this front. To identify targets that can synergize with current antibiotics, we performed an exhaustive analysis of A. baumannii mutants causing hypersensitivity to a multitude of antibiotic treatments. By examining mutants with antibiotic hypersensitivity profiles that parallel mutations in proteins of known function, we show that the function of poorly annotated proteins can be predicted and used to identify candidate missing link proteins in essential A. baumannii processes. Using this strategy, we uncovered multiple uncharacterized proteins with critical roles in cell division or cell elongation, and revealed that a predicted cell wall D,D-endopeptidase has an unappreciated function in lipooligosaccharide synthesis. Moreover, we provide a genetic strategy that uses hypersensitivity signatures to predict drug synergies, allowing the identification of β-lactams that work cooperatively based on the cell wall assembly machineries that they preferentially target. These data reveal multiple pathways critical for envelope growth in A. baumannii that can be targeted in combination strategies for attacking the pathogen.

The development of an ex vivo regional gene therapy clinical pathway using adipose-derived stem cells (ASCs) may require cryopreservation for cell culture, storage, and transport prior to clinical use. ASCs isolated from five donors were transduced with a lentiviral vector containing BMP-2. Three groups were assessed: transduction without cell freezing (group 1), freezing of cells for 3 weeks followed by transduction (group 2), and cell transduction prior to freezing (group 3). Nontransduced cells were used as a control. The cluster of differentiation (CD) marker profiles, cell number, BMP-2 production, and osteogenic potential were measured. The CD marker profile (CD44, CD73, CD90, and CD105) was unchanged after cryopreservation. Cell number was equivalent among cryopreservation protocols in transduced and nontransduced cells. There was a trend toward decreased BMP-2 production in group 3 compared to groups 1 and 2. Osteogenic potential based on Alizarin red concentration was higher in group 2 compared to group 3, with no difference compared to group 1. Freezing ASCs prior to transduction with a lentiviral vector containing BMP-2 has no detrimental effect on cell number, BMP-2 production, osteogenic potential, or immunophenotype. Transduction prior to freezing, however, may limit the BMP-2 production and potential osteogenic differentiation of the ASCs.

Objectives. To measure disparities in hepatitis B virus (HBV) infection and immunity among a high-risk patient population at a community health center in New York City. Methods. We performed a retrospective chart review of 25 565 adults with HBV surface antigen, surface antibody, and total core antibody tests from 1997 to 2017. We categorized HBV test results by infection and immunity status and analyzed by demographic characteristics with χ2 and logistic regression analysis. Results. Of 25 565 adults, 13.4% were currently infected, 52.1% were ever infected, 33.4% were immune from vaccination, and 14.5% were susceptible. Significant factors associated with ever infection were age, male sex, being China-born, limited English proficiency, having Medicaid or no insurance, and family history of HBV (P Conclusions. Our study demonstrated a high burden of HBV infection among foreign-born Asian Americans seeking care at a community health center. Public Health Implications. It is important to test patients at high risk for HBV infection with all 3 tests to identify those with current infection, risk for reactivation, or need for vaccination, and to assess the effectiveness of public health interventions.

The purpose of this study was to evaluate the viability of human adipose-derived stem cells (ADSCs) transduced with a lentiviral (LV) vector to overexpress bone morphogenetic protein-2 (BMP-2) loaded onto a novel 3D printed scaffold. Human ADSCs were transduced with a LV vector carrying the cDNA for BMP-2. The transduced cells were loaded onto a 3D printed Hyperelastic "Bone" (HB) scaffold. In vitro BMP-2 production was assessed using enzyme-linked immunosorbent assay analysis. The ability of ADSCs loaded on the HB scaffold to induce in vivo bone formation in a hind limb muscle pouch model was assessed in the following groups: ADSCs transduced with LV-BMP-2, LV-green fluorescent protein, ADSCs alone, and empty HB scaffolds. Bone formation was assessed using radiographs, histology and histomorphometry. Transduced ADSCs BMP-2 production on the HB scaffold at 24 hours was similar on 3D printed HB scaffolds versus control wells with transduced cells alone, and continued to increase after 1 and 2 weeks of culture. Bone formation was noted in LV-BMP-2 animals on plain radiographs at 2 and 4 weeks after implantation; no bone formation was noted in the other groups. Histology demonstrated that the LV-BMP-2 group was the only group that formed woven bone and the mean bone area/tissue area was significantly greater when compared with the other groups. 3D printed HB scaffolds are effective carriers for transduced ADSCs to promote bone repair. The combination of gene therapy and tissue engineered scaffolds is a promising multidisciplinary approach to bone repair with significant clinical potential. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1104-1110, 2018.

Dysregulation of the MAPK pathway correlates with progression of pancreatic ductal adenocarcinoma (PDAC) progression. IQ motif containing GTPase-activating protein 1 (IQGAP1) is a MAPK scaffold that directly regulates the activation of RAF, MEK, and ERK. Fructose-1,6-bisphosphatase (FBP1), a key enzyme in gluconeogenesis, is transcriptionally downregulated in various cancers, including PDAC. Here, we demonstrate that FBP1 acts as a negative modulator of the IQGAP1–MAPK signaling axis in PDAC cells. FBP1 binding to the WW domain of IQGAP1 impeded IQGAP1-dependent ERK1/2 phosphorylation (pERK1/2) in a manner independent of FBP1 enzymatic activity. Conversely, decreased FBP1 expression induced pERK1/2 levels in PDAC cell lines and correlated with increased pERK1/2 levels in patient specimens. Treatment with gemcitabine caused undesirable activation of ERK1/2 in PDAC cells, but cotreatment with the FBP1-derived small peptide inhibitor FBP1 E4 overcame gemcitabine-induced ERK activation, thereby increasing the anticancer efficacy of gemcitabine in PDAC. These findings identify a primary mechanism of resistance of PDAC to standard therapy and suggest that the FBP1–IQGAP1–ERK1/2 signaling axis can be targeted for effective treatment of PDAC. Cancer Res; 77(16); 4328–41. ©2017 AACR.

BACKGROUND: The treatment of complex bone loss scenarios remains challenging. This study evaluates the efficacy of ex vivo regional gene therapy using transduced human adipose-derived stem cells (ASCs) overexpressing bone morphogenetic protein-2 (BMP-2) to treat critical-sized bone defects. METHODS: Critical-sized femoral defects created surgically in immunocompromised rats were treated with ASCs transduced with a lentivirus encoding BMP-2 (Group 1, n=14), or green fluorescent protein (Group 2, n=5), nontransduced ASCs (Group 3, n=5), or rhBMP-2 (Group 4, n=14). At 12 weeks, femurs were evaluated for quantity and quality of bone formation with plain radiographs, micro-computed tomography, histology/histomorphometry, and biomechanical strength testing. RESULTS: Thirteen of 14 samples in Group 1 and all 14 samples in Group 4 showed radiographic healing, while no samples in either Groups 2 or 3 healed. Groups 1 and 4 had significantly higher radiographic scores (p

Traditionally, ex vivo gene therapy involves a two-step approach, with culture expansion of cells prior to transduction and implantation. We have tried to simplify this strategy and eliminate the time and cost associated with culture expansion, by introducing “next-day” regional gene therapy using human bone marrow cells. The purpose of this study was to determine whether a lentiviral vector (LV) carrying the cDNA for BMP-2 can transduce freshly isolated human BM cells, leading to abundant BMP production and bone formation in vivo, and evaluate the in vivo osteoinductive potential of “next-day” gene therapy and the standard “two-step” tissue culture expansion approach. To this end, human bone marrow cells (HBMC) from patients undergoing total hip arthroplasty were harvested, transduced with a BMP-2-expressing LV either overnight (“next day” gene therapy; ND) or after culture expansion (cultured “two-step” approach; C) and then implanted into a rat critical-sized femoral defect. The animals were randomly assigned to one of the following groups: I; ND-HBMC transduced with LV-TSTA BMP-2, II; ND-HBMC transduced with LV-TSTA GFP, III; non-transduced ND-HBMC; IV; C-HBMC transduced with LV-TSTA BMP-2, V; C-HBMC transduced with LV-TSTA-GFP, VI; non-transduced C-HBMC. Treatment with either “next-day” or cultured HBMC demonstrated a significant increase in new bone formation compared with all negative control groups as seen in plain radiographs, microCT and histologic/histomorphometric analysis. At 12 weeks post-op, complete defect union on plain X-rays occurred in 7/14 animals in the ND-HBMC/BMP-2 group and 12/14 in the C-HBMC/BMP-2 treated rats. The two-step approach was associated with more consistent results, a higher union rate, and superiority with regards to all of the studied bone healing parameters. In this study we demonstrate proof of concept that BMP-2-transduced human bone marrow cells can be used to enhance bone healing in segmental bone defects, and that regional gene therapy using lentiviral transduction has the osteoinductive potential to heal large bone defects in clinical settings.

Umbilical cord blood (UCB) has been increasingly explored as an alternative source of stem cells for use in regenerative medicine due to several advantages over other stem-cell sources, including the need for less stringent human leukocyte antigen matching. Combined with an osteoinductive signal, UCB-derived mesenchymal stem cells (MSCs) could revolutionize the treatment of challenging bone defects. This study aimed to develop an ex vivo regional gene-therapy strategy using BMP-2-transduced allogeneic UCB-MSCs to promote bone repair. To this end, human UCB-MSCs were transduced with a lentiviral vector carrying the cDNA for BMP-2 (LV-BMP-2). In vitro assays to determine the UCB-MSC osteogenic potential and BMP-2 production were followed by in vivo implantation of LV-BMP-2-transduced UCB-MSCs in a mouse hind-limb muscle pouch. Non-transduced and LV-GFP-transduced UCB-MSCs were used as controls. Transduction with LV-BMP-2 was associated with abundant BMP-2 production and induction of osteogenic differentiation in vitro. Implantation of BMP-2-transduced UCB-MSCs led to robust heterotopic bone formation 4 weeks postoperatively, as seen on radiographs and histology. These results, along with the fact that UCB-MSCs can be easily collected with no donor-site morbidity and low immunogenicity, suggest that UCB might be a preferable allogeneic source of MSCs to develop an ex vivo gene-therapy approach to treat difficult bone-repair scenarios.

Background Metastatic breast cancer exhibits diverse and rapidly evolving intra- and inter-tumor heterogeneity. Patients with similar clinical presentations often display distinct tumor responses to standard of care (SOC) therapies. Genome landscape studies indicate that EGFR/HER2/RAS “pathway” activation is highly prevalent in malignant breast cancers. The identification of therapy-responsive and prognostic biomarkers is paramount important to stratify patients and guide therapies in clinical oncology and personalized medicine. Methods In this study, we analyzed matched pairs of tumor specimens collected from 182 patients who received neoadjuvant systemic therapies (NST). Statistical analyses were conducted to determine whether EGFR/HER2/RAS pathway biomarkers and clinicopathological predictors, alone and in combination, are prognostic in breast cancer. Findings SIAH and EGFR outperform ER, PR, HER2 and Ki67 as two logical, sensitive and prognostic biomarkers in metastatic breast cancer. We found that increased SIAH and EGFR expression correlated with advanced pathological stage and aggressive molecular subtypes. Both SIAH expression post-NST and NST-induced changes in EGFR expression in invasive mammary tumors are associated with tumor regression and increased survival, whereas ER, PR, and HER2 were not. These results suggest that SIAH and EGFR are two prognostic biomarkers in breast cancer with lymph node metastases. Interpretation The discovery of incorporating tumor heterogeneity-independent and growth-sensitive RAS pathway biomarkers, SIAH and EGFR, whose altered expression can be used to estimate therapeutic efficacy, detect emergence of resistant clones, forecast tumor regression, differentiate among partial responders, and predict patient survival in the neoadjuvant setting, has a clear clinical implication in personalizing breast cancer therapy. Funding This work was supported by the Dorothy G. Hoefer Foundation for Breast Cancer Research (A.H. Tang); Center for Innovative Technology (CIT)-Commonwealth Research Commercialization Fund (CRCF) (MF14S-009-LS to A.H. Tang), and National Cancer Institute (CA140550 to A.H. Tang)., Graphical abstract Image 1, Highlights • EGFR/RAS pathway activation is prevalent in breast cancer with poor prognosis. • The two RAS pathway biomarkers, SIAH and EGFR, are prognostic in breast cancer. • The RAS pathway biomarkers can be used to stratify patients and guide therapies. • The RAS pathway biomarkers can be used to identify resistant tumor clones post NST. • SIAH and EGFR outperform ER, PR, HER2 and Ki67 in predicting patient survival. The prognostic power of SIAH/EGFR is comparable to that of clinical predictors Early stage breast cancer is amenable to standard of care therapies with excellent long-tern survival. Locally advanced and metastatic breast cancer has a much worse prognosis despite intense systemic and locoregional therapies. This disparity in prognosis underlines the acute need to identify resistant breast cancer cells, and administer and select effective therapies to eradicate resistant mammary tumors. We report that the activation of the EGFR/RAS/SIAH pathway can be used to identify resistant tumor clones and differentiate effective from ineffective therapies, and therefore predict tumor relapse and patient survival in human breast cancer during first-line neoadjuvant systemic therapy in clinic.

A unique, protective cell envelope contributes to the broad drug resistance of the nosocomial pathogen Acinetobacter baumannii. Here we use transposon insertion sequencing to identify A. baumannii mutants displaying altered susceptibility to a panel of diverse antibiotics. By examining mutants with antibiotic susceptibility profiles that parallel mutations in characterized genes, we infer the function of multiple uncharacterized envelope proteins, some of which have roles in cell division or cell elongation. Remarkably, mutations affecting a predicted cell wall hydrolase lead to alterations in lipooligosaccharide synthesis. In addition, the analysis of altered susceptibility signatures and antibiotic-induced morphology patterns allows us to predict drug synergies; for example, certain beta-lactams appear to work cooperatively due to their preferential targeting of specific cell wall assembly machineries. Our results indicate that the pathogen may be effectively inhibited by the combined targeting of multiple pathways critical for envelope growth.

Cell death and inflammation are intimately linked during Yersinia infection. Pathogenic Yersinia inhibits the MAP kinase TGFβ-activated kinase 1 (TAK1) via the effector YopJ, thereby silencing cytokine expression while activating caspase-8–mediated cell death. Here, using Yersinia pseudotuberculosis in corroboration with costimulation of lipopolysaccharide and (5Z)-7-Oxozeaenol, a small-molecule inhibitor of TAK1, we show that caspase-8 activation during TAK1 inhibition results in cleavage of both gasdermin D (GSDMD) and gasdermin E (GSDME) in murine macrophages, resulting in pyroptosis. Loss of GsdmD delays membrane rupture, reverting the cell-death morphology to apoptosis. We found that the Yersinia-driven IL-1 response arises from asynchrony of macrophage death during bulk infections in which two cellular populations are required to provide signal 1 and signal 2 for IL-1α/β release. Furthermore, we found that human macrophages are resistant to YopJ-mediated pyroptosis, with dampened IL-1β production. Our results uncover a form of caspase-8–mediated pyroptosis and suggest a hypothesis for the increased sensitivity of humans to Yersinia infection compared with the rodent reservoir.