A murine lung cancer co-clinical trial identifies genetic modifiers of therapeutic response.

Targeted therapies have demonstrated efficacy against specific subsets of molecularly defined cancers. Although most patients with lung cancer are stratified according to a single oncogenic driver, cancers harbouring identical activating genetic mutations show large variations in their responses to the same targeted therapy. The biology underlying this heterogeneity is not well understood, and the impact of co-existing genetic mutations, especially the loss of tumour suppressors, has not been fully explored. Here we use genetically engineered mouse models to conduct a 'co-clinical' trial that mirrors an ongoing human clinical trial in patients with KRAS-mutant lung cancers. This trial aims to determine if the MEK inhibitor selumetinib (AZD6244) increases the efficacy of docetaxel, a standard of care chemotherapy. Our studies demonstrate that concomitant loss of either p53 (also known as Tp53) or Lkb1 (also known as Stk11), two clinically relevant tumour suppressors, markedly impaired the response of Kras-mutant cancers to docetaxel monotherapy. We observed that the addition of selumetinib provided substantial benefit for mice with lung cancer caused by Kras and Kras and p53 mutations, but mice with Kras and Lkb1 mutations had primary resistance to this combination therapy. Pharmacodynamic studies, including positron-emission tomography (PET) and computed tomography (CT), identified biological markers in mice and patients that provide a rationale for the differential efficacy of these therapies in the different genotypes. These co-clinical results identify predictive genetic biomarkers that should be validated by interrogating samples from patients enrolled on the concurrent clinical trial. These studies also highlight the rationale for synchronous co-clinical trials, not only to anticipate the results of ongoing human clinical trials, but also to generate clinically relevant hypotheses that can inform the analysis and design of human studies.

Helical antimicrobial polypeptides with radial amphiphilicity.

α-Helical antimicrobial peptides (AMPs) generally have facially amphiphilic structures that may lead to undesired peptide interactions with blood proteins and self-aggregation due to exposed hydrophobic surfaces. Here we report the design of a class of cationic, helical homo-polypeptide antimicrobials with a hydrophobic internal helical core and a charged exterior shell, possessing unprecedented radial amphiphilicity. The radially amphiphilic structure enables the polypeptide to bind effectively to the negatively charged bacterial surface and exhibit high antimicrobial activity against both gram-positive and gram-negative bacteria. Moreover, the shielding of the hydrophobic core by the charged exterior shell decreases nonspecific interactions with eukaryotic cells, as evidenced by low hemolytic activity, and protects the polypeptide backbone from proteolytic degradation. The radially amphiphilic polypeptides can also be used as effective adjuvants, allowing improved permeation of commercial antibiotics in bacteria and enhanced antimicrobial activity by one to two orders of magnitude. Designing AMPs bearing this unprecedented, unique radially amphiphilic structure represents an alternative direction of AMP development; radially amphiphilic polypeptides may become a general platform for developing AMPs to treat drug-resistant bacteria.

Investigating the optimal size of anticancer nanomedicine.

Nanomedicines (NMs) offer new solutions for cancer diagnosis and therapy. However, extension of progression-free interval and overall survival time achieved by Food and Drug Administration-approved NMs remain modest. To develop next generation NMs to achieve superior anticancer activities, it is crucial to investigate and understand the correlation between the physicochemical properties of NMs (particle size in particular) and their interactions with biological systems to establish criteria for NM optimization. Here, we systematically evaluated the size-dependent biological profiles of three monodisperse drug-silica nanoconjugates (NCs; 20, 50, and 200 nm) through both experiments and mathematical modeling and aimed to identify the optimal size for the most effective anticancer drug delivery. Among the three NCs investigated, the 50-nm NC shows the highest tumor tissue retention integrated over time, which is the collective outcome of deep tumor tissue penetration and efficient cancer cell internalization as well as slow tumor clearance, and thus, the highest efficacy against both primary and metastatic tumors in vivo.

Cervical cancer control: deaf and hearing women's response to an educational video.

Deaf people encounter barriers to accessing cancer information. In this study, a graphically enriched educational video about cervical cancer was created in American Sign Language, with English open captioning and voice overlay. Deaf (n = 127) and hearing (n = 106) women completed cancer knowledge surveys before and after viewing the video. Hearing women yielded higher scores before the intervention. Both groups demonstrated a significant increase in general and cervical cancer knowledge after viewing the video, rendering posttest knowledge scores nearly equal between the groups. These findings indicate that this video is an effective strategy for increasing cervical cancer knowledge among deaf women.

Exploring clinician perspectives on patients with atrial fibrillation who are not prescribed anticoagulation therapy.

Objective: To explore themes underlying why anticoagulants are under-prescribed for stroke prevention in atrial fibrillation (AF) patients from the clinician's perspective and characteristics of those patients. Methods: Clinicians at the University of Utah Health system were recruited for semi-structured 15-minute interviews. An interview guide focused on anticoagulant prescribing practices for patients with AF. Interviews were transcribed verbatim. Two reviewers independently coded passages corresponding with key themes. Results: Eleven practitioners were interviewed from cardiology, internal medicine, and family practice. Five themes were found: the role of compliance in anticoagulation decision making, the role of pharmacists in supporting clinicians, the use of shared decision making and risk communication, risk of bleeding as the main barrier to taking anticoagulants, and the variety of reasons patients have for not starting or discontinuing anticoagulants. Conclusion: Fear of bleeding was the foremost reason underlying anticoagulant underutilization in patients with AF followed by compliance, and patient worries. Communication between patients and clinicians as well as interdisciplinary teamwork are key to understanding and improving anticoagulant prescribing in AF. Innovation: Our study was the first to assess the role pharmacists play in prescribing clinician's decisions surrounding anticoagulant use in AF. Pharmacists could play an important collaborative role in SDM.

AP-1 and TGFß cooperativity drives non-canonical Hedgehog signaling in resistant basal cell carcinoma.

Tumor heterogeneity and lack of knowledge about resistant cell states remain a barrier to targeted cancer therapies. Basal cell carcinomas (BCCs) depend on Hedgehog (Hh)/Gli signaling, but can develop mechanisms of Smoothened (SMO) inhibitor resistance. We previously identified a nuclear myocardin-related transcription factor (nMRTF) resistance pathway that amplifies noncanonical Gli1 activity, but characteristics and drivers of the nMRTF cell state remain unknown. Here, we use single cell RNA-sequencing of patient tumors to identify three prognostic surface markers (LYPD3, TACSTD2, and LY6D) which correlate with nMRTF and resistance to SMO inhibitors. The nMRTF cell state resembles transit-amplifying cells of the hair follicle matrix, with AP-1 and TGFß cooperativity driving nMRTF activation. JNK/AP-1 signaling commissions chromatin accessibility and Smad3 DNA binding leading to a transcriptional program of RhoGEFs that facilitate nMRTF activity. Importantly, small molecule AP-1 inhibitors selectively target LYPD3+/TACSTD2+/LY6D+ nMRTF human BCCs ex vivo, opening an avenue for improving combinatorial therapies.

Noncanonical hedgehog pathway activation through SRF-MKL1 promotes drug resistance in basal cell carcinomas.

Hedgehog pathway-dependent cancers can escape Smoothened (SMO) inhibition through mutations in genes encoding canonical hedgehog pathway components; however, around 50% of drug-resistant basal cell carcinomas (BCCs) lack additional variants of these genes. Here we use multidimensional genomics analysis of human and mouse drug-resistant BCCs to identify a noncanonical hedgehog activation pathway driven by the transcription factor serum response factor (SRF). Active SRF along with its coactivator megakaryoblastic leukemia 1 (MKL1) binds DNA near hedgehog target genes and forms a previously unknown protein complex with the hedgehog transcription factor glioma-associated oncogene family zinc finger-1 (GLI1), causing amplification of GLI1 transcriptional activity. We show that cytoskeletal activation through Rho and the formin family member Diaphanous (mDia) is required for SRF-MKL-driven GLI1 activation and for tumor cell viability. Remarkably, nuclear MKL1 staining served as a biomarker in tumors from mice and human subjects to predict tumor responsiveness to MKL inhibitors, highlighting the therapeutic potential of targeting this pathway. Thus, our study illuminates, for the first time, cytoskeletal-activation-driven transcription as a personalized therapeutic target for combatting drug-resistant malignancies.

Gsα Deficiency in the Ventromedial Hypothalamus Enhances Leptin Sensitivity and Improves Glucose Homeostasis in Mice on a High-Fat Diet.

In both mice and patients with Albright hereditary osteodystrophy, heterozygous inactivating mutations of Gsα, a ubiquitously expressed G protein that mediates receptor-stimulated intracellular cAMP production, lead to obesity and insulin resistance but only when the mutation is present on the maternal allele. This parent-of-origin effect in mice was shown to be due to Gsα imprinting in one or more brain regions. The ventromedial hypothalamus (VMH) is involved in the regulation of energy and glucose homeostasis, but the role of Gsα in VMH on metabolic regulation is unknown. To examine this, we created VMH-specific Gsα-deficient mice by mating Gsα-floxed mice with SF1-cre mice. Heterozygotes with Gsα mutation on either the maternal or paternal allele had a normal metabolic phenotype, and there was no molecular evidence of Gsα imprinting, indicating that the parent-of-origin metabolic effects associated with Gsα mutations is not due to Gsα deficiency in VMH SF1 neurons. Homozygous VMH Gsα knockout mice (VMHGsKO) showed no changes in body weight on either a regular or high-fat diet. However, glucose metabolism (fasting glucose, glucose tolerance, insulin sensitivity) was significantly improved in male VMHGsKO mice, with the difference more dramatic on the high-fat diet. In addition, male VMHGsKO mice on the high-fat diet showed a greater anorexigenic effect and increased VMH signal transducer and activator of transcription-3 phosphorylation in response to leptin. These results indicate that VMH Gsα/cyclic AMP signaling regulates glucose homeostasis and alters leptin sensitivity in mice, particularly in the setting of excess caloric intake.

Suppression of Hepatic Inflammation via Systemic siRNA Delivery by Membrane-Disruptive and Endosomolytic Helical Polypeptide Hybrid Nanoparticles.

Treatment of inflammatory diseases represents one of the biggest clinical challenges. RNA interference (RNAi) against TNF-α provides a promising modality toward anti-inflammation therapy, but its therapeutic potential is greatly hampered by the by the lack of efficient siRNA delivery vehicles in vivo. Herein, we report a hybrid nanoparticulate (HNP) system based on a cationic helical polypeptide PPABLG for the efficient delivery of TNF-α siRNA. The helical structure of PPABLG features pore formation on cellular and endosomal membranes to facilitate the direct translocation as well as endosomal escape of TNF-α siRNA in macrophages, representing a unique superiority to a majority of the existing polycation-based gene vectors that experience severe endosomal entrapment and lysosomal degradation. As such, HNPs containing TNF-α siRNA afforded effective systemic TNF-α knockdown following systemic administration at a low dose of 50 µg of siRNA/kg and thus demonstrated a potent anti-inflammatory effect to rescue animals from LPS/d-GalN-induced hepatic sepsis. This study therefore verifies that the bioactive secondary structure of polypeptides significantly dominates the in vivo siRNA delivery efficiency, and the unique properties of PPABLG HNPs render remarkable potentials for anti-inflammation therapies.

The Growing Public Health Challenges of Exposure to Ultraviolet Radiation From Use of Indoor Tanning Devices in the United States.

Ultraviolet radiation is recognized as a human carcinogen by the International Agency for Research on Cancer, the world's authority on cancer research. In particular, exposure to ultraviolet radiation can lead to melanoma of the skin, which is the deadliest form of skin cancer in the United States. Yet despite the significant public health burden that is associated with skin cancer in the United States, each year over a million Americans engage in indoor tanning where exposure to artificial ultraviolet radiation occurs. In this article, we argue for an immediate ban on the use of commercial indoor tanning by minors and, based on international precedents, the phasing out of all commercial tanning operations in the United States. We consider the use of indoor tanning devices in the United States, epidemiological data on indoor tanning devices and cancer, regulation of tanning devices, and scientific evidence for increased government intervention.

GPI-80 defines self-renewal ability in hematopoietic stem cells during human development.

Advances in pluripotent stem cell and reprogramming technologies have given us the hope of generating hematopoietic stem cells (HSCs) in culture. To succeed, greater understanding of the self-renewing HSC during human development is required. We discovered that the glycophosphatidylinositol-anchored surface protein GPI-80 defines a subpopulation of human fetal liver hematopoietic stem/progenitor cells (HSPCs) with self-renewal ability. CD34(+)CD38(lo/-)CD90(+)GPI-80(+) HSPCs were the sole population that maintained proliferative potential and an undifferentiated state in stroma coculture and engrafted in immunodeficient mice. GPI-80 expression also enabled tracking of HSPCs once they emerged from endothelium and migrated between human fetal hematopoietic niches. GPI-80 colocalized on the surface of HSPCs with Integrin alpha-M (ITGAM), which in leukocytes cooperates with GPI-80 to support migration. Knockdown of GPI-80 or ITGAM was sufficient to compromise HSPC expansion in culture and engraftment in vivo. These findings indicate that human fetal HSCs employ mechanisms used in leukocyte adhesion and migration to mediate HSC self-renewal.

Redox-responsive, reversibly-crosslinked thiolated cationic helical polypeptides for efficient siRNA encapsulation and delivery.

Cationic helical polypeptides, although highly efficient for inducing membrane penetration, cannot stably condense siRNA molecules via electrostatic interactions, which greatly limit the gene knockdown efficiency. By developing and crosslinking the thiolated polypeptide via formation of disulfide bonds post formation of the polypeptide/siRNA complexes, we were able to obtain stable complexes without compromising the helical secondary structure as well as the membrane activity of the polypeptide. As such, the stable polypeptide/siRNA complex was able to notably protect the siRNA cargo from nuclease digestion in the extracellular environment, while the functions of the polypeptide/siRNA complex for effective cellular internalization and endosomal escape are still largely preserved. Because the disulfide is susceptible to cleavage in response to intracellular redox triggers, siRNA release from the complex is expected upon redox triggering by glutathione (GSH) intracellularly and was actually observed upon redox triggers mediated by glutathione (GSH). With the collective contribution of the potent membrane activity and redox-responsive cargo release profiles, the crosslinked complexes enable efficient gene silencing without appreciable cytotoxicity, thus providing a potential strategy for polypeptide-based intracellular siRNA delivery.

Smoothened variants explain the majority of drug resistance in basal cell carcinoma.

Advanced basal cell carcinomas (BCCs) frequently acquire resistance to Smoothened (SMO) inhibitors through unknown mechanisms. Here we identify SMO mutations in 50% (22 of 44) of resistant BCCs and show that these mutations maintain Hedgehog signaling in the presence of SMO inhibitors. Alterations include four ligand binding pocket mutations defining sites of inhibitor binding and four variants conferring constitutive activity and inhibitor resistance, illuminating pivotal residues that ensure receptor autoinhibition. In the presence of a SMO inhibitor, tumor cells containing either class of SMO mutants effectively outcompete cells containing the wild-type SMO. Finally, we show that both classes of SMO variants respond to aPKC-ι/λ or GLI2 inhibitors that operate downstream of SMO, setting the stage for the clinical use of GLI antagonists.