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Glioblastoma is the most aggressive type of brain cancer with an average overall survival of 15-21 months after first diagnosis. The relapse is mainly caused by migrating glioblastoma cells that diffuse away from the tumor mass into the brain parenchyma and retain cancer stem cell (GSC) properties. Current therapeutic options are ineffective and inevitably result in relapse, indicating a high unmet medical need for innovative therapies in the treatment of invasive glioblastoma. To address this challenge, we propose a new therapeutic modality: GliaTrap, a biodegradable non-swelling, injectable hydrogel with sustained release of a chemoattractant for GSCs that lures and traps the migrating cells back to the tumor resection cavity. We developed a biodegradable and injectable hyaluronan/collagen II-based (HA/Col) hydrogel that does not swell in vivo. The hydrogel is embedded with CXCL12 loaded liposomes and is tuned for sustained release of CXCL12. The safety profile of liposome-embedded HA/Col hydrogel was determined in-vivo after stereotactic implantation in the mouse brain. The efficacy of GliaTrap to attract GSCs was determined ex vivo using a 3D tumor spheroid model and in-vivo using 3D light-sheet microscopy in orthotopic human glioblastoma xenografts. Our findings suggest that GliaTrap could represent a safe and efficacious new therapeutic approach for glioblastoma and potentially serve as a drug delivery platform to locally deliver tumor-killing agents.One Sentence SummaryGliaTrap is a biodegradable non-swelling hydrogel with tuned release of a chemoattractant to attract invading glioma cells and serve as delivery platform for local therapeutics.

There is an impressive number of data and code reproducibility initiatives, both within Europe and across the world. To motivate researchers to use this amazing infrastructure, we must show the translational research community that the aforementioned initiatives are able to drive change in translational science. Here we demonstrate that using public datasets, it is reasonable to build a pipeline for proposal and validation of driver mutation and subtype-specific colorectal cancer medications. While all three molecular, clinical and chemical name harmonization were necessary, open data and code initiatives, while varied in their approaches, made this project possible.

Glioblastoma stem cells (GSCs) are a subset of cells in the Glioblastoma (GBM) tumor microenvironment that play an important role in tumor heterogeneity, aggressiveness, recurrence, and therapy resistance. Dynamic environmental, transcriptional, and epigenetic oscillations envelope GSCs in a variety of cellular states, contributing to GSC heterogeneity and carcinogenesis. The creation of effective therapies may therefore benefit from a better understanding of the factors associated with the GSC's distinct traits as well as the mechanisms affecting GSC cellular states and transformation. Galectin-3 is a molecule that is highly expressed in GBM, and higher levels are linked to poor survival and mesenchymal subtype. Although Galectin-3 has previously been found primarily in microglia and tumor-infiltrating macrophages, our studies using patient-derived GSCs show that it is abundantly produced by GSCs and that its expression significantly decreases when they differentiate into non-stem differentiated cancer cells, which are more responsive to therapies. Our findings also show that Galectin-3 is not expressed in normal neural stem cells, leading us to believe that it could serve as a unique identifier for GSCs. Additionally, when Galectin-3 is silenced in GSCs, we see a decreased self-renewal frequency and enrichment of genes associated with pro-neural state, which has a less aggressive phenotype. Confocal imaging and single-cell RNA-seq analysis further revealed heterogeneous expression of Galectin-3 in GSCs, and the functional pathway analysis shows that Galectin-3high cell clusters have a significant overlap with cells enriched in EMT pathways. Therefore, our findings suggest that Galectin-3 may be a unique distinguishing characteristic of GSCs and may play a particular role in regulating GSC stemness and determining GSCs states, making it a potential molecular target for the treatment of glioblastoma. Citation Format: Bedia Akosman, Shaan Lalvani, Yusuke Suita, David Karambizi, Nikos Tapinos. Galectin-3 regulates stemness and cellular states in glioblastoma stem cells [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 2448.

SummaryHuman cancers often re-express germline factors, yet their mechanistic role in oncogenesis and cancer progression remains unknown. Here we demonstrate that DDX4, a germline factor and RNA helicase conserved in all multicellular organisms, contributes to epithelial mesenchyme transition (EMT)-like features and cisplatin resistance in small cell lung cancer (SCLC) cells. DDX4 depletion in H69AR and SHP77 cell lines decreased motility and resistance to cisplatin, whereas its overexpression increased these features. Proteomic analysis suggests that DDX4 upregulates metabolic protein expression related to DNA repair and immune/inflammatory response, suggesting its fundamental function may be in regulating cellular metabolism. Consistent with these trends in cell lines, DDX4 depletion compromised in vivo tumor development while its overexpression enhanced tumor growth even after cisplatin treatment in nude mice. Although the DDX4 expression level in somatic tumors is generally low compared to that in the germline, the relatively higher DDX4 expression in SCLC patients correlates with decreased survival and shows increased expression of EMT and cisplatin resistance markers. Taken together, we conclude that DDX4 influences the survival of SCLC patients by altering cellular metabolism in response to environmental cues such as drug treatments. This fundamental function of DDX4 as a germline factor might be applicable in other cancer types that express DDX4 and may serve as a key to combat specific tumors that are highly resistant to treatments.HighlightsDDX4 contributes to cellular motility and drug resistance in SCLC cells.DDX4-overexpression globally alters the proteome and suppresses cytokine production.DDX4 promotes tumorigenesis and drug resistance in vitro and in vivo.DDX4 expression correlates with survival in SCLC patients and with immune/inflammatory response both in cell lines and patient samples.

Nanomedicines have shown great potential in cancer therapy; in particular, the combination of chemotherapy and immunotherapy (namely chemoimmunotherapy) that is revolutionizing cancer treatment. Currently, most nanomedicines for chemoimmunotherapy are still in preclinical and clinical trials. Lipid-based nanoparticles, the most widely used nanomedicine platform in cancer therapy, is a promising delivery platform for chemoimmunotherapy. In this review, we introduce the commonly used immunotherapy agents and discuss the opportunities for chemoimmunotherapy mediated by lipid-based nanoparticles. We summarize the clinical trials involving lipid-based nanoparticles for chemoimmunotherapy. We also highlight different chemoimmunotherapy strategies based on lipid-based nanoparticles such as liposomes, nanodiscs, and lipid-based hybrid nanoparticles in preclinical research. Finally, we discuss the challenges that have hindered the clinical translation of lipid-based nanoparticles for chemoimmunotherapy, and their future perspectives.

Ultraviolet (UV) light and incompletely understood genetic and epigenetic variations determine skin color. Here we describe an UV- and microphthalmia-associated transcription factor (MITF)-independent mechanism of skin pigmentation. Targeting the mitochondrial redox-regulating enzyme nicotinamide nucleotide transhydrogenase (NNT) resulted in cellular redox changes that affect tyrosinase degradation. These changes regulate melanosome maturation and, consequently, eumelanin levels and pigmentation. Topical application of small-molecule inhibitors yielded skin darkening in human skin, and mice with decreased NNT function displayed increased pigmentation. Additionally, genetic modification of NNT in zebrafish alters melanocytic pigmentation. Analysis of four diverse human cohorts revealed significant associations of skin color, tanning, and sun protection use with various single-nucleotide polymorphisms within NNT. NNT levels were independent of UVB irradiation and redox modulation. Individuals with postinflammatory hyperpigmentation or lentigines displayed decreased skin NNT levels, suggesting an NNT-driven, redox-dependent pigmentation mechanism that can be targeted with NNT-modifying topical drugs for medical and cosmetic purposes.

SUMMARY The presence of dark melanin (eumelanin) within human epidermis represents one of the strongest predictors of low skin cancer risk. Topical rescue of eumelanin synthesis, previously achieved in “redhaired” Mc1r-deficient mice, demonstrated significant protection against UV damage. However, application of a topical strategy for human skin pigmentation has not been achieved, largely due to the greater barrier function of human epidermis. Salt-inducible kinase (SIK) has been demonstrated to regulate MITF, the master regulator of pigment gene expression, through its effects on CRTC and CREB activity. Here, we describe the development of small-molecule SIK inhibitors that were optimized for human skin penetration, resulting in MITF upregulation and induction of melanogenesis. When topically applied, pigment production was induced in Mc1r-deficient mice and normal human skin. These findings demonstrate a realistic pathway toward UV-independent topical modulation of human skin pigmentation, potentially impacting UV protection and skin cancer risk., Graphical abstract Mujahid et al. describe the successful generation of topical small molecules capable of inducing dark pigmentation in human skin, thus potentially generating a variety of new applications.

Two-photon fluorescence lifetime imaging microscopy (FLIM) is a technique that not only probes the intensity of fluorophores, but also provides the temporal decay trace of said fluorophores on a pixel-by-pixel basis. These traces can then be transformed into the frequency domain for subsequent analysis, resulting in a scatterplot of phasor coordinates where each phasor corresponds to a single image pixel. With this in mind, it follows that individual fluorophores result in distinct clusters in the phasor plot, and a mixture of two fluorophores results in phasors that fall somewhere along a line linking the two clusters depending on the relative fluorophore concentrations. Until now, distinction of fluorescent species has relied mainly on computing the Euclidean distance between a given phasor and the mean coordinates of reference phasor clusters. However, this approach becomes inadequate in cases where one fluorophore has a much wider lifetime distribution than the other. As such, we propose the use of the Mahalanobis distance as an alternative to the Euclidean distance, as this metric additionally factors in the relative spread of each reference phasor cluster. This method has been applied to studying the oxidative response of ex vivo human skin via endogenous NADH fluorescence as it is exposed to chemical sun filters, the active ingredients in sunscreens. Given that both NADH and sun filters are fluorescent under the same excitation and emission conditions, the proposed Mahalanobis distance approach was used to distinguish the source of fluorescence in images of human skin. This allowed for the assessment of oxidative response as well as the tracking and monitoring of the sun filter formulation as it permeated throughout the skin.

Chemical sun filters are commonly used as active ingredients in sunscreens due to their efficient absorption of ultraviolet (UV) radiation. Yet, it is known that these compounds can photochemically react with UV light and generate reactive oxygen species and oxidative stress in vitro, though this has yet to be validated in vivo. One label-free approach to probe oxidative stress is to measure and compare the relative endogenous fluorescence generated by cellular coenzymes nicotinamide adenine dinucleotides and flavin adenine dinucleotides. However, chemical sun filters are fluorescent, with emissive properties that contaminate endogenous fluorescent signals. To accurately distinguish the source of fluorescence in ex vivo skin samples treated with chemical sun filters, fluorescence lifetime imaging microscopy data were processed on a pixel-by-pixel basis using a non-Euclidean separation algorithm based on Mahalanobis distance and validated on simulated data. Applying this method, ex vivo samples exhibited a small oxidative shift when exposed to sun filters alone, though this shift was much smaller than that imparted by UV irradiation. Given the need for investigative tools to further study the clinical impact of chemical sun filters in patients, the reported methodology may be applied to visualize chemical sun filters and measure oxidative stress in patients' skin.

Ectopic expression of lineage master regulators induces transdifferentiation. Whether cell fate transitions can be induced during various developmental stages has never been systemically examined. Here we discovered that amongst different developmental stages, embryonic stem cells (ESCs) were resistant to cell fate conversion induced by the melanocyte lineage master regulator MITF. We generated a transgenic system and found that in ESCs, the pluripotency master regulator, OCT4, counteracts pro-differentiation induced by MITF by physical interference with MITF transcriptional activity. We further found that ESCs must be released from OCT4-maintained pluripotency prior to ectopically induced differentiation. Moreover, OCT4 induction in various differentiated cells repressed their lineage identity in vivo. Alongside, chromatin architecture combined with ChIP-seq analysis suggested that OCT4 competes with various lineage master regulators for binding promoters and enhancers. Our analysis reveals pluripotency and transdifferentiation regulatory principles and could open new opportunities in the field of regenerative medicine.

Ectopic expression of lineage master regulators induces transdifferentiation. Whether cell fate transitions can be induced during various developmental stages has not been systemically examined. Here we discover that amongst different developmental stages, mouse embryonic stem cells (mESCs) are resistant to cell fate conversion induced by the melanocyte lineage master regulator MITF. By generating a transgenic system we exhibit that in mESCs, the pluripotency master regulator Oct4, counteracts pro-differentiation induced by Mitf by physical interference with MITF transcriptional activity. We further demonstrate that mESCs must be released from Oct4-maintained pluripotency prior to ectopically induced differentiation. Moreover, Oct4 induction in various differentiated cells represses their lineage identity in vivo. Alongside, chromatin architecture combined with ChIP-seq analysis suggest that Oct4 competes with various lineage master regulators for binding promoters and enhancers. Our analysis reveals pluripotency and transdifferentiation regulatory principles and could open new opportunities in the field of regenerative medicine., Lineage master regulators induce differentiation and how the melanocyte master regulator Microphthalmia-associated transcription factor (MITF) is regulated is unclear. Here, the authors show that the pluripotency master regulator, OCT4, counteracts differentiation induced by MITF in mouse embryonic stem cells.

Skin cancer, including basal cell carcinoma, squamous cell carcinoma, and melanoma, is the most common form of cancer in North America. Paradoxically, skin cancer incidence is steadily on the rise even despite the growing use of sunscreens over the past decades. One potential explanation for this discrepancy involves the sun filters in sunscreen, which are responsible for blocking harmful ultraviolet radiation. It is proposed that these agents may produce reactive oxygen species (ROS) at the site of application, thereby generating oxidative stress in skin that gives rise to genetic mutations, which may explain the rising incidence of skin cancer. To test this hypothesis, ex vivo human skin was treated with five common chemical sun filters (avobenzone, octocrylene, homosalate, octisalate, and oxybenzone) as well as two physical sun filters (zinc oxide compounds), both with and without UV irradiation. To non-invasively evaluate oxidative stress, two-photon excitation fluorescence (2PEF) and fluorescence lifetime imaging microscopy (FLIM) of the skin samples were used to monitor levels of NADH and FAD, two key cofactors in cellular redox metabolism. The relative redox state of the skin was assessed based on the fluorescence intensities and lifetimes of these endogenous cofactors. While the sun filters were indeed shown to have a protective effect from UV radiation, it was observed that they also generate oxidative stress in skin, even in the absence of UV light. These results suggest that sun filter induced ROS production requires more careful study, especially in how these reactive species impact the rise of skin cancer.

Skin cancer is the most common cancer in the United States of America, including melanoma and non-melanoma skin cancer. Malignant melanoma, being ranked as the fifth most common cancer within the US shows a yearly incidence of 73,870 cases and remains the most aggressive form of all skin cancers with a mortality rate of 2.7 per 100,000 [1,2]. Fortunately, over the last decade melanoma treatment options have tremendously improved. Progress in areas such as immunotherapy and targeted therapies has lead to increased melanoma survival rates, rising from 82% (1975-1977) to 93% (2004-2010) [3]. In consequence, the cost of skin cancer treatments, specifically for melanoma treatments increased from an average annual total cost of $864 million in 2002 to $3349 million in 2011 [4].

The purpose of this work was to study the role of feeding on the energetics of cornsnakes. We measured oxygen consumption in cornsnakes prior to a meal and 6, 15, 20, 30, 40, 48, 72, and 96 h after eating a meal that was equivalent to 10% of the snake's body mass. We monitored temperature selection of individual cornsnakes in a thermal gradient in the spring and again in the fall when snakes were starved, digesting a meal equivalent to 10% of its body mass, and digesting a meal equivalent to 25% of its body mass. We measured the gastric digestion rate by monitoring the passage of magnetic stir bars, placed inside a mouse meal, through the digestive tracts of cornsnakes maintained at 22°C, 25°C, 28°C, and 32°C. Oxygen consumption peaked at 2.3 times higher than baseline levels 24 h after feeding and had returned to pre-feeding levels by 72 h. Meal size affected temperature selection in both seasons; in fall, starved snakes selected lower body temperatures than fed snakes, but meal size had no effect on temperature selection by fed snakes. Passage rates from the stomach to the intestine did not significantly differ among the temperatures studied.