Nerves are integral to the adenoid cystic carcinoma (ACC) microenvironment. The strong association of ACC with perineural invasion (PNI) is considered a hallmark of this disease. In human salivary ACC, we identify intratumoral, small-caliber, disorganized sympathetic nerves not observed in other salivary neoplasms. Norepinephrine or sympathetic ganglia explants enhance ACC proliferation in vitro. Two novel orthotopic ACC patient-derived xenograft (PDX) models recapitulate ACC morphology and demonstrate sympathetic innervation. Pharmacologic or surgical blockade of sympathetic nerves decreases ACC PDX growth. Bulk RNA sequencing of salivary ACC reveals correlations between noradrenergic nerve development signatures and worse patient survival. Metastatic ACC foci exhibit lower nerve signature gene expression levels than primary ACC. Sympathetic innervation in ACC is distinct from PNI and reflects tumor axonogenesis driven by noradrenergic neural development programs. These programs support ACC progression, are associated with poor prognosis, and may be inhibited as a therapeutic strategy.

Omacetaxine, a semisynthetic form of Homoharringtonine (HHT), was approved for the treatment of Chronic Myeloid Leukemia (CML). Previously, we have published the synthesis of this natural alkaloid and three of its derivatives: Deoxyharringtonine (DHT), Deoxyhomoharringtonine (DHHT), and Bis(demethyl)-deoxyharringtonine (BDHT), and reported its refractory activity against the HL-60/RV+ cells over-expressing P-glycoprotein 1 (MDR1). In this study, we have explored the extent of this resistance by first expanding the panel of established cell lines and using a panel of 21 leukemia patient-derived primary cells. Herein, we have reported consistent resistance to HTT of K562-derived cells and to mitoxantrone of MES-SA/MX2-derived cells; all of them have been found to overexpress MDR1, while we have found U87MG-ABCG2 and H69AR cells to be very sensitive to HTT. In contrast, DHT, DHHT, and BDHT seemingly overcame this resistance due to the changes made to the acyl chain of HTT, rendering the derivatives less susceptible to efflux. Surprisingly, the leukemia primary cells were very sensitive to HHT and its derivatives with low nanomolar potencies, followed by a new class of CDC7 kinase inhibitors, the anthracycline class of topoisomerase inhibitors, the DNA intercalator actinomycin-D, and the vinca alkaloid class of microtubule inhibitors. The mechanism of cell death induced by HTT and DHHT was found to be mediated via caspase 3 cleavage, leading to apoptosis. Taken together, our results confirm that HHT is a substrate for MDR1. It opens the door to a new opportunity to clinically evaluate HHT and its derivatives for the treatment of AML and other cancers.

Dramatic strides have been made in real-time adaptive radiation therapy, where treating single tumors as dynamic but rigid bodies has demonstrated a halving of toxicities for prostate cancer. However, the human body is much more complex than a rigid body. This review explores the ongoing development and future potential of dose-guided radiation therapy, where the three core process steps of volumetric imaging of the patient, dose accumulation, and dose-guided treatment adaptation occur quasi-continuously during treatment, fully accounting for the complexity of the dynamic human body. The clinical evidence supporting real-time adaptive radiation therapy was reviewed. The foundational studies, status, and potential of real-time volumetric imaging using both x-ray and magnetic resonance imaging technology were described. The development of real-time dose accumulation to the dynamic patient was evaluated, and a method to measure real-time dose delivery was assessed. The growth of real-time treatment adaptation was examined. Literature demonstrates continued improvements in patient outcomes because the treatment becomes more conformal to the dynamic patient. Real-time volumetric imaging using both x-ray and magnetic resonance imaging technology is poised for broader implementation. Real-time dose accumulation has demonstrated clinical feasibility, with approximations made to achieve real-time operation. Real-time treatment adaptation to deforming targets and multiple targets has been experimentally demonstrated. Tying together the inputs of the real-time volumetric anatomy and dose accumulation is real-time treatment adaptation that uses the available degrees of freedom to optimize the dose delivered to the patient, maximizing the treatment intent. Opportunities exist for artificial intelligence to accelerate the application of dose-guided radiation therapy to broader patient use. In summary, the emerging field of real-time dose-guided radiation therapy has the potential to significantly improve patient outcomes. The advances are primarily software-driven and therefore could be widely available and cost-effective upgrades to improve imaging and targeting cancer.

Type III CRISPR-Cas systems defend against viral infection in prokaryotes using an RNA-guided complex that recognizes foreign transcripts and synthesizes cyclic oligo-adenylate (cOA) messengers to activate CARF immune effectors. Here we investigated a protein containing a CARF domain fused Toll/interleukin-1 receptor (TIR) domain, Cat1. We found that Cat1 provides immunity by cleaving and depleting NAD+ molecules from the infected host, inducing a growth arrest that prevents viral propagation. Cat1 forms dimers that stack upon each other to generate long filaments that are maintained by bound cOA ligands, with stacked TIR domains forming the NAD+ cleavage catalytic sites. Further, Cat1 filaments assemble into unique trigonal and pentagonal networks that enhance NAD+ degradation. Cat1 presents an unprecedented chemistry and higher-order protein assembly for the CRISPR-Cas response.