Transcriptional regulators with broad expression in the zebrafish spinal cord.

BACKGROUND: The spinal cord is a crucial part of the vertebrate CNS, controlling movements and receiving and processing sensory information from the trunk and limbs. However, there is much we do not know about how this essential organ develops. Here, we describe expression of 21 transcription factors and one transcriptional regulator in zebrafish spinal cord. RESULTS: We analyzed the expression of aurkb, foxb1a, foxb1b, her8a, homeza, ivns1abpb, mybl2b, myt1a, nr2f1b, onecut1, sall1a, sall3a, sall3b, sall4, sox2, sox19b, sp8b, tsc22d1, wdhd1, zfhx3b, znf804a, and znf1032 in wild-type and MIB E3 ubiquitin protein ligase 1 zebrafish embryos. While all of these genes are broadly expressed in spinal cord, they have distinct expression patterns from one another. Some are predominantly expressed in progenitor domains, and others in subsets of post-mitotic cells. Given the conservation of spinal cord development, and the transcription factors and transcriptional regulators that orchestrate it, we expect that these genes will have similar spinal cord expression patterns in other vertebrates, including mammals and humans. CONCLUSIONS: Our data identify 22 different transcriptional regulators that are strong candidates for playing different roles in spinal cord development. For several of these genes, this is the first published description of their spinal cord expression.

Sounding out maerl sediment thickness: an integrated data approach.

Maerl beds are listed as a priority marine feature in Scotland. They are noted for creating suitable benthic habitat for diverse communities of fauna and flora and in supporting a wide array of ecosystem services. Within the context of climate change, they are also recognised as a potential blue carbon habitat through sequestration of carbon in living biomass and underlying sediment. There are, however, significant data gaps on the potential of maerl carbon sequestration which impede inclusion in blue carbon policy frameworks. Key data gaps include sediment thickness, from which carbon content is extrapolated. There are additional logistical and financial barriers associated with quantification methods that aim to address these data gaps. This study investigates the use of sub-bottom profiling (SBP) to lessen financial and logistical constraints of maerl bed sediment thickness estimation and regional blue carbon quantification. SBP data were cross validated with cores, other SBP data on blue carbon sediments, and analysed with expert input. Combining SBP data with estimates of habitat health (as % cover) from drop-down video (DDV) data, and regional abiotic data, this study also elucidates links between abiotic and biotic factors in determining maerl habitat health and maerl sediment thickness through pathway analysis in structural equation modelling (SEM). SBP data were proved to be sufficiently robust for identification of maerl sediments when corroborated with core data. SBP and DDV data of maerl bed habitats in Orkney exhibited some positive correlations of sediment thickness with maerl % cover. The average maerl bed sediment thickness was 1.08 m across all ranges of habitat health. SEM analysis revealed maerl bed habitat health was strongly determined by abiotic factors. Maerl habitat health had a separate positive effect on maerl bed sediment thickness.

Transcriptional Regulators with Broad Expression in the Zebrafish Spinal Cord.

Background: The spinal cord is a crucial part of the vertebrate CNS, controlling movements and receiving and processing sensory information from the trunk and limbs. However, there is much we do not know about how this essential organ develops. Here, we describe expression of 21 transcription factors and one transcriptional regulator in zebrafish spinal cord. Results: We analyzed the expression of aurkb, foxb1a, foxb1b, her8a, homeza, ivns1abpb, mybl2b, myt1a, nr2f1b, onecut1, sall1a, sall3a, sall3b, sall4, sox2, sox19b, sp8b, tsc22d1, wdhd1, zfhx3b, znf804a, and znf1032 in wild-type and MIB E3 ubiquitin protein ligase 1 zebrafish embryos. While all of these genes are broadly expressed in spinal cord, they have distinct expression patterns from one another. Some are predominantly expressed in progenitor domains, and others in subsets of post-mitotic cells. Given the conservation of spinal cord development, and the transcription factors and transcriptional regulators that orchestrate it, we expect that these genes will have similar spinal cord expression patterns in other vertebrates, including mammals and humans. Conclusions: Our data identify 22 different transcriptional regulators that are strong candidates for playing different roles in spinal cord development. For several of these genes, this is the first published description of their spinal cord expression.

Mediating Trauma and Anxiety: Letters to Françoise Dolto, 1976-1978.

Françoise Dolto (1908-88) was a prominent French cultural figure thanks to her practice of dispensing psychoanalytically-informed child-rearing advice via the radio. From 1976 to 1978, on her show Lorsque l'enfant paraît, she responded to thousands of letters sent in by listeners requesting help with parenting problems and personal questions of a psychological nature. The article explores Dolto's cultural position as a child psychoanalyst - understood in the 1960s and 1970s as a radical profession - but from a conservative, Catholic background. It then examines a sample of the letters sent in to her show, analysing the demographics of the correspondents and highlighting their most common concerns. Finally the article studies the relationship between psychoanalysis and trauma. It indicates the anxiety that a psychoanalytic understanding can cause, by reinforcing parents' fears that childhood traumas are common, can be created unwittingly by parents, and lead to major psychological consequences in later life.

Antibody-Drug Conjugate-Based Therapeutics: State of the Science.

Antibody-drug conjugates (ADCs) are complex engineered therapeutics consisting of monoclonal antibodies, directed toward tumor-associated antigens, to which highly potent cytotoxic agents are attached using chemical linkers. This targeted drug delivery strategy couples the precision of the antibody targeting moiety with the cytocidal activity of the payload, which is generally too toxic on its own to be systemically administered. In this manner, ADCs confer a means to reduce off-target toxicities in patients by limiting the exposure of normal tissues to the payload, thus broadening the potential therapeutic window compared with traditional chemotherapy. The pace of ADC development is accelerating, with the number of investigational agents in human trials having more than tripled over the past 5 years, underscoring the enthusiasm for this transformative approach to cancer treatment. Here, we review the key structural elements of ADC design (antibody, linker, and payload), highlighting critical aspects and technological advances that have affected the clinical effectiveness of this class of biopharmaceuticals. The ADC field continues to evolve, including ongoing efforts aimed at improving target selection, developing payloads with varied mechanisms of action and increased potency, designing innovative bioconjugation strategies, as well as maximizing efficacy and tolerability in patients. An overview of the current clinical trial landscape is provided, with emphasis on the clinical experience of the four ADCs to have received regulatory approval to date, as well as additional promising candidates currently in late-stage clinical development in both solid tumor and hematological malignancies.

Planning simulation space needs in uncertain contexts.

Introduction: King's College London delivers simulation-based education to approximately 5500 different students who use a Simulation and Interactive Learning (SaIL) centre which was designed for significantly different needs. The management team needs to plan for current and future demand in the context of changing regulatory and curricular requirements, and changing technologies. The authors developed a model to address this challenge. Methods: We used a structured approach involving university data and interviews with module leaders. Assumptions were needed on target student numbers, group sizes and time spent in a simulation centre. The algorithm at the core of the model applies the targets and assumptions to a profile of room use by type of room, as experienced by a typical student over the course of one year. Individual course results are summed and rounded up, to provide an overall demand for space which can be compared to capacity. Results: The number of SaIL rooms required is expected to almost double by 2022/2023. The mix of spaces must also change to enable more simultaneous immersive simulation of diverse types, with associated debrief spaces also increasing. Conclusions: This model helps maximise impact by creating connectivity between a vision, business targets and the physical space. Financial resources are used more effectively by avoiding potential over or underprovision. Flexibility of build will remain important, as no-one can predict the future; however, a detailed, quantified model can help raise the quality of discussion about future aspirations and how closely we might meet them.

Climatic variability, plasticity, and dispersal: A case study from Lake Tana, Ethiopia.

The numerous dispersal events that have occurred during the prehistory of hominin lineages are the subject of longstanding and increasingly active debate in evolutionary anthropology. As well as research into the dating and geographic extent of such dispersals, there is an increasing focus on the factors that may have been responsible for dispersal. The growing body of detailed regional palaeoclimatic data is invaluable in demonstrating the often close relationship between changes in prehistoric environments and the movements of hominin populations. The scenarios constructed from such data are often overly simplistic, however, concentrating on the dynamics of cyclical contraction and expansion during severe and ameliorated conditions respectively. This contribution proposes a two-stage hypothesis of hominin dispersal in which populations (1) accumulate high levels of climatic tolerance during highly variable climatic phases, and (2) express such heightened tolerance via dispersal in subsequent low-variability phases. Likely dispersal phases are thus proposed to occur during stable climatic phases that immediately follow phases of high climatic variability. Employing high resolution palaeoclimatic data from Lake Tana, Ethiopia, the hypothesis is examined in relation to the early dispersal of Homo sapiens out of East Africa and into the Levant. A dispersal phase is identified in the Lake Tana record between c. 112,550 and c. 96,975 years ago, a date bracket that accords well with the dating evidence for H. sapiens occupation at the sites of Qafzeh and Skhul. Results are discussed in relation to the complex pattern of H. sapiens dispersal out of East Africa, with particular attention paid to the implications of recent genetic chronologies for the origin of non-African modern humans.

HSP90 Inhibitor-SN-38 Conjugate Strategy for Targeted Delivery of Topoisomerase I Inhibitor to Tumors.

The clinical benefits of chemotherapy are commonly offset by insufficient drug exposures, narrow safety margins, and/or systemic toxicities. Over recent decades, a number of conjugate-based targeting approaches designed to overcome these limitations have been explored. Here, we report on an innovative strategy that utilizes HSP90 inhibitor-drug conjugates (HDC) for directed tumor targeting of chemotherapeutic agents. STA-12-8666 is an HDC that comprises an HSP90 inhibitor fused to SN-38, the active metabolite of irinotecan. Mechanistic analyses in vitro established that high-affinity HSP90 binding conferred by the inhibitor backbone could be exploited for conjugate accumulation within tumor cells. In vivo modeling showed that the HSP90 inhibitor moiety was required for selective retention of STA-12-8666, and this enrichment promoted extended release of active SN-38 within the tumor compartment. Indeed, controlled intratumoral payload release by STA-12-8666 contributed to a broad therapeutic window, sustained biomarker activity, and remarkable degree of efficacy and durability of response in multiple cell line and patient-derived xenograft models. Overall, STA-12-8666 has been developed as a unique HDC agent that employs a distinct mechanism of targeted drug delivery to achieve potent and sustained antitumor effects. These findings identify STA-12-8666 as a promising new candidate for evaluation as novel anticancer therapeutic.

The HSP90 Inhibitor Ganetespib Alleviates Disease Progression and Augments Intermittent Cyclophosphamide Therapy in the MRL/lpr Mouse Model of Systemic Lupus Erythematosus.

Systemic lupus erythematosus (SLE) is a complex, systemic autoimmune disease with a diverse range of immunological and clinical manifestations. The introduction of broad spectrum immunosuppressive therapies and better management of acute disease exacerbations have improved outcomes for lupus patients over recent years. However, these regimens are burdened by substantial toxicities and confer significantly higher risks of infection, thus there remains a significant and unmet medical need for alternative treatment options, particularly those with improved safety profiles. Heat shock protein 90 (HSP90) is a ubiquitously expressed molecular chaperone that acts as an important modulator of multiple innate and adaptive inflammatory processes. Of note, accumulating clinical and experimental evidence has implicated a role for HSP90 in the pathogenesis of SLE. Here we evaluated the potential of HSP90 as a therapeutic target for this disease using the selective small molecule inhibitor ganetespib in the well-characterized MRL/lpr autoimmune mouse model. In both the prophylactic and therapeutic dosing settings, ganetespib treatment promoted dramatic symptomatic improvements in multiple disease parameters, including suppression of autoantibody production and the preservation of renal tissue integrity and function. In addition, ganetespib exerted profound inhibitory effects on disease-related lymphadenopathy and splenomegaly, and reduced pathogenic T and B cell lineage populations in the spleen. Ganetespib monotherapy was found to be equally efficacious and tolerable when compared to an effective weekly dosing regimen of the standard-of-care immunosuppressive agent cyclophosphamide. Importantly, co-treatment of ganetespib with a sub-optimal, intermittent dosing schedule of cyclophosphamide resulted in superior therapeutic indices and maximal disease control. These findings highlight the potential of HSP90 inhibition as an alternative, and potentially complementary, strategy for therapeutic intervention in SLE. Such approaches may have important implications for disease management, particularly for limiting or preventing treatment-related toxicities, a major confounding factor in current SLE therapy.

Archaeology. Sedimentary DNA from a submerged site reveals wheat in the British Isles 8000 years ago.

The Mesolithic-to-Neolithic transition marked the time when a hunter-gatherer economy gave way to agriculture, coinciding with rising sea levels. Bouldnor Cliff, is a submarine archaeological site off the Isle of Wight in the United Kingdom that has a well-preserved Mesolithic paleosol dated to 8000 years before the present. We analyzed a core obtained from sealed sediments, combining evidence from microgeomorphology and microfossils with sedimentary ancient DNA (sedaDNA) analyses to reconstruct floral and faunal changes during the occupation of this site, before it was submerged. In agreement with palynological analyses, the sedaDNA sequences suggest a mixed habitat of oak forest and herbaceous plants. However, they also provide evidence of wheat 2000 years earlier than mainland Britain and 400 years earlier than proximate European sites. These results suggest that sophisticated social networks linked the Neolithic front in southern Europe to the Mesolithic peoples of northern Europe.

The HSP90 inhibitor ganetespib potentiates the antitumor activity of EGFR tyrosine kinase inhibition in mutant and wild-type non-small cell lung cancer.

Small molecule inhibitors of epidermal growth factor receptor (EGFR) tyrosine kinase activity, such as erlotinib and gefitinib, revolutionized therapy for non-small cell lung cancer (NSCLC) patients whose tumors harbor activating EGFR mutations. However, mechanisms to overcome the invariable development of acquired resistance to such agents, as well as realizing their full clinical potential within the context of wild-type EGFR (WT-EGFR) disease, remain to be established. Here, the antitumor efficacy of targeted EGFR tyrosine kinase inhibitors (TKIs) and the HSP90 inhibitor ganetespib, alone and in combination, were evaluated in NSCLC. Ganetespib potentiated the efficacy of erlotinib in TKI-sensitive, mutant EGFR-driven NCI-HCC827 xenograft tumors, with combination treatment causing significant tumor regressions. In erlotinib-resistant NCI-H1975 xenografts, concurrent administration of ganetespib overcame erlotinib resistance to significantly improve tumor growth inhibition. Ganetespib co-treatment also significantly enhanced antitumor responses to afatinib in the same model. In WT-EGFR cell lines, ganetespib potently reduced cell viability. In NCI-H1666 cells, ganetespib-induced loss of client protein expression, perturbation of oncogenic signaling pathways, and induction of apoptosis translated to robust single-agent activity in vivo. Dual ganetespib/erlotinib therapy induced regressions in NCI-H322 xenograft tumors, indicating that the sensitizing properties of ganetespib for erlotinib were conserved within the WT-EGFR setting. Mechanistically, combined ganetespib/erlotinib exposure stabilized EGFR protein levels in an inactive state and completely abrogated extracellular-signal-regulated kinase (ERK) and AKT signaling activity. Thus, selective HSP90 blockade by ganetespib represents a potentially important complementary strategy to targeted TKI inhibition alone for inducing substantial antitumor responses and overcoming resistance, in both the mutant and WT-EGFR settings.

Implementation of ultrasonic sensing for high resolution measurement of binary gas mixture fractions.

We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a single gas. Sensitivity < 5 × 10(-5) is demonstrated to leaks of octaflouropropane (C3F8) coolant into nitrogen during a long duration (18 month) continuous study. The sensitivity of the described measurement system is shown to depend on the difference in molecular masses of the two gases in the mixture. The impact of temperature and pressure variances on the accuracy of the measurement is analysed. Practical considerations for the implementation and deployment of long term, in situ ultrasonic leak detection systems are also described. Although development of the described systems was motivated by the requirements of an evaporative fluorocarbon cooling system, the instrument is applicable to the detection of leaks of many other gases and to processes requiring continuous knowledge of particular binary gas mixture fractions.

FGFR3 translocations in bladder cancer: differential sensitivity to HSP90 inhibition based on drug metabolism.

UNLABELLED: Activating mutations and/or overexpression of FGFR3 are common in bladder cancer, making FGFR3 an attractive therapeutic target in this disease. In addition, FGFR3 gene rearrangements have recently been described that define a unique subset of bladder tumors. Here, a selective HSP90 inhibitor, ganetespib, induced loss of FGFR3-TACC3 fusion protein expression and depletion of multiple oncogenic signaling proteins in RT112 bladder cells, resulting in potent cytotoxicity comparable with the pan-FGFR tyrosine kinase inhibitor BGJ398. However, in contrast to BGJ398, ganetespib exerted pleiotropic effects on additional mitogenic and survival pathways and could overcome the FGFR inhibitor-resistant phenotype of FGFR3 mutant-expressing 97-7 and MHG-U3 cells. Combinatorial benefit was observed when ganetespib was used with BGJ398 both in vitro and in vivo. Interestingly, two additional FGFR3 fusion-positive lines (RT4 and SW480) retained sensitivity to HSP90 inhibitor treatment by the ansamycins 17-AAG and 17-DMAG yet displayed intrinsic resistance to ganetespib or AUY922, both second-generation resorcinol-based compounds. Both cell lines, compared with RT112, expressed considerably higher levels of endogenous UGT1A enzyme; this phenotype resulted in a rapid glucuronidation-dependent metabolism and subsequent efflux of ganetespib from SW780 cells, thus providing a mechanism to account for the lack of bioactivity. IMPLICATIONS: Pharmacologic blockade of the molecular chaperone HSP90 represents a promising approach for treating bladder tumors driven by oncogenic gene rearrangements of FGFR3. Furthermore, UDP-glucuronosyltransferase enzyme expression may serve as a predictive factor for clinical response to resorcinol-based HSP90 inhibitors.

The HSP90 inhibitor ganetespib has chemosensitizer and radiosensitizer activity in colorectal cancer.

The integration of targeted agents to standard cytotoxic regimens has improved outcomes for patients with colorectal cancer (CRC) over recent years; however this malignancy remains the second leading cause of cancer mortality in industrialized countries. Small molecule inhibitors of heat shock protein 90 (HSP90) are one of the most actively pursued classes of compounds for the development of new cancer therapies. Here we evaluated the activity of ganetespib, a second-generation HSP90 inhibitor, in models of CRC. Ganetespib reduced cell viability in a panel of CRC cell lines in vitro with low nanomolar potency. Mechanistically, drug treatment exerted concomitant effects on multiple oncogenic signaling pathways, cell cycle regulation, and DNA damage repair capacity to promote apoptosis. Combinations of ganetespib and low-dose ionizing radiation enhanced the radiosensitivity of HCT 116 cells and resulted in superior cytotoxic activity over either treatment alone. In vivo, the single-agent activity of ganetespib was relatively modest, suppressing HCT 116 xenograft tumor growth by approximately half. However, ganetespib significantly potentiated the antitumor efficacy of the 5-Fluorouracil (5-FU) prodrug capecitabine in HCT 116 xenografts, causing tumor regressions in a model that is intrinsically resistant to fluoropyrimidine therapy. This demonstration of combinatorial benefit afforded by an HSP90 inhibitor to a standard CRC adjuvant regimen provides an attractive new framework for the potential application of ganetespib as an investigational agent in this disease.

Hominin footprints from early Pleistocene deposits at Happisburgh, UK.

Investigations at Happisburgh, UK, have revealed the oldest known hominin footprint surface outside Africa at between ca. 1 million and 0.78 million years ago. The site has long been recognised for the preservation of sediments containing Early Pleistocene fauna and flora, but since 2005 has also yielded humanly made flint artefacts, extending the record of human occupation of northern Europe by at least 350,000 years. The sediments consist of sands, gravels and laminated silts laid down by a large river within the upper reaches of its estuary. In May 2013 extensive areas of the laminated sediments were exposed on the foreshore. On the surface of one of the laminated silt horizons a series of hollows was revealed in an area of ca. 12 m(2). The surface was recorded using multi-image photogrammetry which showed that the hollows are distinctly elongated and the majority fall within the range of juvenile to adult hominin foot sizes. In many cases the arch and front/back of the foot can be identified and in one case the impression of toes can be seen. Using foot length to stature ratios, the hominins are estimated to have been between ca. 0.93 and 1.73 m in height, suggestive of a group of mixed ages. The orientation of the prints indicates movement in a southerly direction on mud-flats along the river edge. Early Pleistocene human fossils are extremely rare in Europe, with no evidence from the UK. The only known species in western Europe of a similar age is Homo antecessor, whose fossil remains have been found at Atapuerca, Spain. The foot sizes and estimated stature of the hominins from Happisburgh fall within the range derived from the fossil evidence of Homo antecessor.

mTOR inhibition potentiates HSP90 inhibitor activity via cessation of HSP synthesis.

UNLABELLED: Because of their pleiotropic effects on critical oncoproteins, inhibitors of HSP90 represent a promising new class of therapeutic agents for the treatment of human cancer. However, pharmacologic inactivation of HSP90 subsequently triggers a heat shock response that may mitigate the full therapeutic benefit of these compounds. To overcome this limitation, a clinically feasible method was sought to block HSP synthesis induced by the potent HSP90 inhibitor ganetespib. An immunoassay screen of 322 late-stage or clinically approved drugs was performed to uncover compounds that could block upregulation of the stress-inducible HSP70 that results as a consequence of HSP90 blockade. Interestingly, inhibitors of the phosphoinositide 3-kinase (PI3K)/mTOR class counteracted ganetespib-induced HSP70 upregulation at both the gene and protein level by suppressing nuclear translocation of heat shock factor 1 (HSF1), the dominant transcription factor controlling cellular stress responses. This effect was conserved across multiple tumor types and was found to be regulated, in part, by mTOR-dependent translational activity. Pretreatment with cycloheximide, PI3K/mTOR inhibitor, or an inhibitor of eIF4E (a translation initiation factor and downstream effector of mTOR) all reduced ganetespib-mediated nuclear HSF1 accumulation, indicating that mTOR blockade confers a negative regulatory effect on HSF1 activity. Moreover, combined therapy regimens with mTOR or dual PI3K/mTOR inhibitors potentiated the antitumor efficacy of ganetespib in multiple in vivo models. IMPLICATIONS: Collectively these data identify a novel strategy to optimize the therapeutic potential of HSP90 inhibitors.

Ganetespib and HSP90: translating preclinical hypotheses into clinical promise.

As with many physiologic processes that become subverted during tumorigenesis, the chaperoning activity of heat shock protein 90 (HSP90) is often exploited by cancer cells to confer aberrant proliferative, survival, and/or metastatic potential. Functional inhibition of HSP90 results in the degradation of its client proteins, in turn providing a means to concomitantly disrupt multiple oncogenic signaling cascades through one molecular target. Pharmacologic blockade of HSP90 has, therefore, emerged as an innovative and multifaceted approach for the development of new antineoplastic agents. However, no HSP90 inhibitors are currently approved for cancer therapy and the full promise of this class of agents is yet to be realized. This review focuses on the preclinical activity profile of ganetespib, a potent small-molecule inhibitor of HSP90, the characterization of which has provided important frameworks for the optimal design and application of HSP90 inhibitor-based strategies in a variety of cancer types. Beyond client protein-driven tumors, ganetespib can also potentiate the effects of other molecularly targeted and standard-of-care therapeutics while simultaneously overcoming drug resistance in multiple tumor types, thereby positioning this compound as the leading HSP90 inhibitor currently under clinical development.

Overcoming acquired BRAF inhibitor resistance in melanoma via targeted inhibition of Hsp90 with ganetespib.

Activating BRAF kinase mutations serve as oncogenic drivers in over half of all melanomas, a feature that has been exploited in the development of new molecularly targeted approaches to treat this disease. Selective BRAF(V600E) inhibitors, such as vemurafenib, typically induce initial, profound tumor regressions within this group of patients; however, durable responses have been hampered by the emergence of drug resistance. Here, we examined the activity of ganetespib, a small-molecule inhibitor of Hsp90, in melanoma lines harboring the BRAF(V600E) mutation. Ganetespib exposure resulted in the loss of mutant BRAF expression and depletion of mitogen-activated protein kinase and AKT signaling, resulting in greater in vitro potency and antitumor efficacy compared with targeted BRAF and MAP-ERK kinase (MEK) inhibitors. Dual targeting of Hsp90 and BRAF(V600E) provided combinatorial benefit in vemurafenib-sensitive melanoma cells in vitro and in vivo. Importantly, ganetespib overcame mechanisms of intrinsic and acquired resistance to vemurafenib, the latter of which was characterized by reactivation of extracellular signal-regulated kinase (ERK) signaling. Continued suppression of BRAF(V600E) by vemurafenib potentiated sensitivity to MEK inhibitors after acquired resistance had been established. Ganetespib treatment reduced, but not abolished, elevations in steady-state ERK activity. Profiling studies revealed that the addition of a MEK inhibitor could completely abrogate ERK reactivation in the resistant phenotype, with ganetespib displaying superior combinatorial activity over vemurafenib. Moreover, ganetespib plus the MEK inhibitor TAK-733 induced tumor regressions in vemurafenib-resistant xenografts. Overall these data highlight the potential of ganetespib as a single-agent or combination treatment in BRAF(V600E)-driven melanoma, particularly as a strategy to overcome acquired resistance to selective BRAF inhibitors.

Preclinical activity profile and therapeutic efficacy of the HSP90 inhibitor ganetespib in triple-negative breast cancer.

PURPOSE: Treatment options for patients with triple-negative breast cancer (TNBC) are largely limited to systemic chemotherapies, which have shown disappointing efficacy in the metastatic setting. Here, we undertook a comprehensive evaluation of the activity of ganetespib, a potent inhibitor of HSP90, in this malignancy. EXPERIMENTAL DESIGN: The antitumor and antimetastatic activity of ganetespib was investigated using TNBC cell lines and xenograft models. Combinatorial drug analyses were performed with chemotherapeutic agents and concomitant effects on DNA damage and cell-cycle disruption were assessed in vitro; antitumor efficacy was assessed in vivo. Metabolic and objective tumor responses were evaluated in patients with metastatic TNBC undergoing ganetespib treatment. RESULTS: Ganetespib simultaneously deactivated multiple oncogenic pathways to potently reduce cell viability in TNBC cell lines, and suppressed lung metastases in experimental models. Ganetespib potentiated the cytotoxic activity of doxorubicin via enhanced DNA damage and mitotic arrest, conferring superior efficacy to the doxorubicin-cyclophosphamide regimen in TNBC xenografts. Ganetespib also promoted mitotic catastrophe and apoptosis in combination with taxanes in vitro, and these effects translated to significantly improved combinatorial activity in vivo. Marked tumor shrinkage of metastatic lung and lymphatic lesions were seen in patients on ganetespib monotherapy. CONCLUSION: The preclinical activity profile and clinical evidence of tumor regression suggest that ganetespib offers considerable promise as a new therapeutic candidate to target TNBC.

Cryptic uveitis in a patient with morning glory syndrome.

BACKGROUND: A 71-year-old female presented on 3 occasions with escalating pain in a congenitally blind eye. Examination revealed hypertensive uveitis with morning glory optic disc dysplasia and absence of a crystalline lens. There was no previous intraocular surgery or trauma. Intensive anti-hypertensive agents and topical steroids did not control intraocular pressure (IOP) or inflammation. RESULTS: Dilated fundus examination on the third clinical review revealed a luxated cataractous lens on the retina. Pars plana vitrectomy and fragmatome lensectomy controlled inflammation and IOP, with resolution of ocular pain. DISCUSSION: This is an exceptional case of phacogenic uveitis with secondary glaucoma occurring years after spontaneous crystalline lens luxation in a patient with morning glory syndrome. The embryological pathogenesis of morning glory syndrome and the significance of accelerated cataractogenesis and zonular weakness are discussed. Hypertensive uveitis with unexplained absence of a crystalline lens in a blind eye must prompt suspicion of delayed phacogenic uveitis following asymptomatic lens luxation.