p53 Represses the Mevalonate Pathway to Mediate Tumor Suppression.

There are still gaps in our understanding of the complex processes by which p53 suppresses tumorigenesis. Here we describe a novel role for p53 in suppressing the mevalonate pathway, which is responsible for biosynthesis of cholesterol and nonsterol isoprenoids. p53 blocks activation of SREBP-2, the master transcriptional regulator of this pathway, by transcriptionally inducing the ABCA1 cholesterol transporter gene. A mouse model of liver cancer reveals that downregulation of mevalonate pathway gene expression by p53 occurs in premalignant hepatocytes, when p53 is needed to actively suppress tumorigenesis. Furthermore, pharmacological or RNAi inhibition of the mevalonate pathway restricts the development of murine hepatocellular carcinomas driven by p53 loss. Like p53 loss, ablation of ABCA1 promotes murine liver tumorigenesis and is associated with increased SREBP-2 maturation. Our findings demonstrate that repression of the mevalonate pathway is a crucial component of p53-mediated liver tumor suppression and outline the mechanism by which this occurs.

A Non-catalytic Function of SETD1A Regulates Cyclin K and the DNA Damage Response.

MLL/SET methyltransferases catalyze methylation of histone 3 lysine 4 and play critical roles in development and cancer. We assessed MLL/SET proteins and found that SETD1A is required for survival of acute myeloid leukemia (AML) cells. Mutagenesis studies and CRISPR-Cas9 domain screening show the enzymatic SET domain is not necessary for AML cell survival but that a newly identified region termed the "FLOS" (functional location on SETD1A) domain is indispensable. FLOS disruption suppresses DNA damage response genes and induces p53-dependent apoptosis. The FLOS domain acts as a cyclin-K-binding site that is required for chromosomal recruitment of cyclin K and for DNA-repair-associated gene expression in S phase. These data identify a connection between the chromatin regulator SETD1A and the DNA damage response that is independent of histone methylation and suggests that targeting SETD1A and cyclin K complexes may represent a therapeutic opportunity for AML and, potentially, for other cancers.

p53-dependent Nestin regulation links tumor suppression to cellular plasticity in liver cancer.

The p53 tumor suppressor coordinates a series of antiproliferative responses that restrict the expansion of malignant cells, and as a consequence, p53 is lost or mutated in the majority of human cancers. Here, we show that p53 restricts expression of the stem and progenitor-cell-associated protein nestin in an Sp1/3 transcription-factor-dependent manner and that Nestin is required for tumor initiation in vivo. Moreover, loss of p53 facilitates dedifferentiation of mature hepatocytes into nestin-positive progenitor-like cells, which are poised to differentiate into hepatocellular carcinomas (HCCs) or cholangiocarcinomas (CCs) in response to lineage-specific mutations that target Wnt and Notch signaling, respectively. Many human HCCs and CCs show elevated nestin expression, which correlates with p53 loss of function and is associated with decreased patient survival. Therefore, transcriptional repression of Nestin by p53 restricts cellular plasticity and tumorigenesis in liver cancer.

A preclinical platform for assessing antitumor effects and systemic toxicities of cancer drug targets.

Anticancer drug development campaigns often fail due to an incomplete understanding of the therapeutic index differentiating the efficacy of the agent against the cancer and its on-target toxicities to the host. To address this issue, we established a versatile preclinical platform in which genetically defined cancers are produced using somatic tissue engineering in transgenic mice harboring a doxycycline-inducible short hairpin RNA against the target of interest. In this system, target inhibition is achieved by the addition of doxycycline, enabling simultaneous assessment of efficacy and toxicity in the same animal. As proof of concept, we focused on CDK9­a cancer target whose clinical development has been hampered by compounds with poorly understood target specificity and unacceptable toxicities. We systematically compared phenotypes produced by genetic Cdk9 inhibition to those achieved using a recently developed highly specific small molecule CDK9 inhibitor and found that both perturbations led to robust antitumor responses. Remarkably, nontoxic levels of CDK9 inhibition could achieve significant treatment efficacy, and dose-dependent toxicities produced by prolonged CDK9 suppression were largely reversible upon Cdk9 restoration or drug withdrawal. Overall, these results establish a versatile in vivo target validation platform that can be employed for rapid triaging of therapeutic targets and lend support to efforts aimed at advancing CDK9 inhibitors for cancer therapy.

Description of Photodegradation Mechanisms and Structural Characteristics in Carbon@Titania Yolk-Shell Nanostructures by XAS.

Carbon@titania yolk-shell nanostructures are successfully synthesized at different calcination conditions. These unique structure nanomaterials can be used as a photocatalyst to degrade the emerging water pollutant, acetaminophen (paracetamol). The photodegradation analysis studies have shown that the samples with residual carbon nanospheres have improved the photocatalytic efficiency. The local electronic and atomic structure of the nanostructures are analyzed by X-ray absorption spectroscopy (XAS) measurements. The spectra confirm that the hollow shell has an anatase phase structure, slight lattice distortion, and variation in Ti 3d orbital orientation. In situ XAS measurements reveal that the existence of amorphous carbon nanospheres inside the nano spherical shell inhibit the recombination of electron-hole pairs; more mobile holes are formed in the p-d hybridized bands near the Fermi surface and enables the acceleration of the carries that significantly enhance the photodegradation of paracetamol under UV-visible irradiation. The observed charge transfer process from TiO2  hybridized orbital to the carbon nanospheres reduces the recombination rate of electrons and holes, thus increasing the photocatalytic efficiency.

Quest for singlet fission of organic sulfur-containing systems in the higher lying singlet excited state: application prospects of anti-Kasha's rule.

In this study, we explore the possibilities of the deactivating pathways of organic thione containing systems through first-principles calculations. We particularly pay attention to the second lying singlet excited state, S2, due to its large energy difference from the lowest lying S1 state in the sulfur-containing systems. Several theoretical models including the previously synthesized thiones and the strategically designed molecules are investigated to search for the basic conjugation unit that exhibits the prospect of S2 fission. Various molecular motifs and different substituents are combined to maneuver the relative alignment of the relevant low excited energy states. The results lead us to conclude that the thione derivatives, under rational and delicate molecular designs, may be engineered to possess a sufficiently high S2-S1 energy gap as high as 2 eV and that these systems may exhibit S2 fission to triplet excitons in the red to near infrared region.

CDK9-mediated transcription elongation is required for MYC addiction in hepatocellular carcinoma.

One-year survival rates for newly diagnosed hepatocellular carcinoma (HCC) are <50%, and unresectable HCC carries a dismal prognosis owing to its aggressiveness and the undruggable nature of its main genetic drivers. By screening a custom library of shRNAs directed toward known drug targets in a genetically defined Myc-driven HCC model, we identified cyclin-dependent kinase 9 (Cdk9) as required for disease maintenance. Pharmacological or shRNA-mediated CDK9 inhibition led to robust anti-tumor effects that correlated with MYC expression levels and depended on the role that both CDK9 and MYC exert in transcription elongation. Our results establish CDK9 inhibition as a therapeutic strategy for MYC-overexpressing liver tumors and highlight the relevance of transcription elongation in the addiction of cancer cells to MYC.

Successful Resection of Retrobulbar Carcinosarcoma without Recurrence: A Case Report.

Carcinosarcomas are biphasic tumors comprising carcinoma and sarcoma components that occur in many tissues but are rarely found in the orbit. A 70-year-old male presented to the ophthalmic clinic with progressive proptosis, having decreased vision in the left eye for 8 months. On examination, severe exophthalmos and lagophthalmos with limited extraocular movement were noted. Orbital computed tomography scans revealed a large, well-defined, heterogeneously enhanced mass in the left retrobulbar orbital cavity. The tumor was completely resected, and the pathological examination revealed a carcinosarcoma. The prognosis was excellent without local recurrence at 48 months postoperatively. Thus, when considering treatment for effective management of such tumors, tumor resection followed by radiotherapy or chemotherapy is highly recommended.

Chapter Open for the Excited-State Intramolecular Thiol Proton Transfer in the Room-Temperature Solution.

We report here, for the first time, the experimental observation on the excited-state intramolecular proton transfer (ESIPT) reaction of the thiol proton in room-temperature solution. This phenomenon is demonstrated by a derivative of 3-thiolflavone (3TF), namely, 2-(4-(diethylamino)phenyl)-3-mercapto-4H-chromen-4-one (3NTF), which possesses an -S-H···O═ intramolecular H-bond (denoted by the dashed line) and has an S1 absorption at 383 nm. Upon photoexcitation, 3NTF exhibits a distinctly red emission maximized at 710 nm in cyclohexane with an anomalously large Stokes shift of 12 230 cm-1. Upon methylation on the thiol group, 3MeNTF, lacking the thiol proton, exhibits a normal Stokes-shifted emission at 472 nm. These, in combination with the computational approaches, lead to the conclusion of thiol-type ESIPT unambiguously. Further time-resolved study renders an unresolvable (<180 fs) ESIPT rate for 3NTF, followed by a tautomer emission lifetime of 120 ps. In sharp contrast to 3NTF, both 3TF and 3-mercapto-2-(4-(trifluoromethyl)phenyl)-4H-chromen-4-one (3FTF) are non-emissive. Detailed computational approaches indicate that all studied thiols undergo thermally favorable ESIPT. However, once forming the proton-transferred tautomer, the lone-pair electrons on the sulfur atom brings non-negligible nπ* contribution to the S1' state (prime indicates the proton-transferred tautomer), for which the relaxation is dominated by the non-radiative deactivation. For 3NTF, the extension of π-electron delocalization by the diethylamino electron-donating group endows the S1' state primarily in the ππ* configuration, exhibiting the prominent tautomer emission. The results open a new chapter in the field of ESIPT, covering the non-canonical sulfur intramolecular H-bond and its associated ESIPT at ambient temperature.

Risk of Breast Cancer in Females With Hypothyroidism: A Nationwide, Population-Based, Cohort Study.

OBJECTIVES: The results of studies investigating the relationship between breast cancer and hypothyroidism vary greatly from study to study. In this study, we analyzed a large and reliable, population-based database to gain a better understanding of the correlation. METHODS: This retrospective cohort study analyzed patients with hypothyroidism between January 1, 2000 and December 31, 2012 (hypothyroidism cohort) from the Longitudinal Health Insurance Database 2000 in Taiwan. For each woman with hypothyroidism, 1 woman without a history of breast cancer was randomly selected from the Longitudinal Health Insurance Database 2000 and frequency matched (1:4) with women without hypothyroidism by age and index year of hypothyroidism. The study outcome was the diagnosis of breast cancer during a 12-year follow-up period. RESULTS: In this study, 6665 women with hypothyroidism and 26 660 women without hypothyroidism were identified. The hypothyroidism cohort had a significantly higher risk of breast cancer than the nonhypothyroidism cohort (adjusted hazard ratio [aHR] 1.69 [95% CI, 1.15-2.49]; P = .01), especially in the group aged 40 to 64 years (aHR 2.07 [95% CI, 1.32-3.23]; P = .01). Women in the hypothyroidism cohort taking levothyroxine for a duration ˃588 days showed a significantly decreased risk of breast cancer (aHR 0.37 [95% CI, 0.19-0.71]; P = .003). CONCLUSION: Women with hypothyroidism are at a higher risk of breast cancer than those without hypothyroidism. Levothyroxine may reduce the risk of breast cancer in a woman with hypothyroidism.

A computational exploration of the 1D TiS2(en) nanostructure for lithium ion batteries.

First-principles investigations on 1D TiS2(en) are performed to evaluate its potential as an electrode for lithium ion batteries. The intercalation of lithium ions into LixTiS2(en) follows the Rüdorff model and the lithium ions are predicted to diffuse along the one-dimensional axis of the TiS2(en) nanostructure with a small diffusion barrier of 0.27 eV.

Sulfur-Based Intramolecular Hydrogen-Bond: Excited-State Hydrogen-Bond On/Off Switch with Dual Room-Temperature Phosphorescence.

We report O-H----S hydrogen-bond (H-bond) formation and its excited-state intramolecular H-bond on/off reaction unveiled by room-temperature phosphorescence (RTP). In this seminal work, this phenomenon is demonstrated with 7-hydroxy-2,2-dimethyl-2,3-dihydro-1 H-indene-1-thione (DM-7HIT), which possesses a strong polar (hydroxy)-dispersive (thione) type H-bond. Upon excitation, DM-7HIT exhibits anomalous dual RTP with maxima at 550 and 685 nm. This study found that the lowest lying excited state (S1) of DM-7HIT is a sulfur nonbonding (n) to π* transition, which undergoes O-H bond flipping from S1(nπ*) to the non-H-bonded S'1(nπ*) state, followed by intersystem crossing and internal conversion to populate the T'1(nπ*) state. Fast H-bond on/off switching then takes place between T'1(nπ*) and T1(nπ*), forming a pre-equilibrium that affords both the T'1(nπ*, 685 nm) and T1(nπ*, 550 nm) RTP. The generality of the sulfur H-bond on/off switching mechanism, dubbed a molecule wiper, was rigorously evaluated with a variety of other H-bonded thiones, and these results open a new chapter in the chemistry of hydrogen bonds.

Investigation of uniform sized multicellular spheroids raised by microwell arrays after the combined treatment of electric field and anti-cancer drug.

Nowadays, cancer disease is continuously identified as the leading cause of mortality worldwide. Cancer chemotherapeutic agents have been continuously developing to achieve high curative effectiveness and low side effects. However, solid tumors present the properties of low drug penetration and resistance of quiescent cells. Radiation therapy is concurrently given in some cases; but it induces different levels of adverse effects. In the current work, uniform sized multicellular spheroids were raised by microwell arrays to mimic the architecture of solid tumors. Investigation of the response of the spheroids was conducted after the treatment of alternating electric field. The result showed that the electric field could induce early apoptosis by disturbing cell membrane. Moreover, combined treatment of electric field and anti-cancer drug was applied to the spheroids. The electric field synergistically enhanced the treatment efficacy because the anti-cancer drug could permeate through the disrupted cell membrane. Significant improvement of late apoptosis was shown by the combined treatment. Because the electric field treatment induces limited side effect to the patient, lower dosage of anti-cancer drug may be applied to the patients for achieving curative effectiveness.

Dissociated effect and Chemosensitive enhancement of tumor spheroids influenced by an electric field in a microdevice.

The use of electric field for cancer therapy has been proposed for a novel non-invasive cancer therapeutic approach that provides better quality of life for patients. However, argument of the efficacy hampers the therapeutic development for various cancer diseases. More scientific evidences are necessary to be addressed by basic research. The current in vitro cell culture study reports the responses of tumor spheroids after the application of an alternating electric field. Human hepatocarchinoma cells suspended in soft hydrogel were cultured in a cell culture device embedded with stimulating electrodes. Tumor spheroids gradually formed and alternating electric field was then applied during the culture course. Investigation of cell viability and cell cycle were conducted to optimize the treatment conditions. The results showed that the electric potential of 1.0 Vpp and frequency of 130 kHz was the minimal effective conditions for inhibiting tumor spheroids. Importantly, dissociation of tumor spheroids was observed after the treatment. The effectiveness of chemotherapeutic agents was shown to be enhanced while the electric filed was simultaneously applied to the tumor spheroids. These results provided solid foundation for developing the effective therapeutic strategies.

Effects of Taping on Achilles Tendon Protection and Kendo Performance.

CONTEXT: It has been reported that there is a high rate of Achilles tendon injury among kendo athletes. For protection and to support the area, kendo athletes habitually use taping during practice or games. OBJECTIVE: To investigate the effect of various taping techniques on injury prevention and functional performance in kendo athletes. DESIGN: Case-control study. SETTING: Laboratory. PARTICIPANTS: 15 University Kendo Team athletes with at least 2 y kendo experience. MAIN OUTCOME MEASURES: Athletes completed 5 stepping backwards and striking cycles under 4 taping conditions: no taping, athletic taping of ankle joint (AT-Ankle), athletic taping of Achilles tendon (AT-Achilles), and Kinesio-Tex taping of Achilles tendon (KT-Achilles). Jump distance, lower limb angular motion, left foot-ground contact time, Achilles tendon force (ATF), and soleus and medial gastrocnemius muscle activities were measured. RESULTS: Lowest peak ATF was found in AT-Achilles during heel-down phase, with statistically significant difference from KT-Achilles peak force. Significant decline of soleus muscle electromyography amplitude was also found when compared to no taping during heel-down phase and other conditions during pushing phase. Conversely, KT-Achilles showed significant decrease in foot-ground contact time compared with no taping and greater ankle range of motion than in AT-Ankle. CONCLUSION: To protect the Achilles tendon, AT-Achilles taping is recommended since it tends to decrease ATF. Conversely, to enhance athlete performance, we recommend KT-Achilles taping to speed up kendo striking motion. However, the Achilles tendon must withstand greatest forces concurrently. This finding implies that AT-Achilles taping can protect the injured Achilles tendon and KT-Achilles taping can enhance performance on the kendo striking motion.

Room-temperature phosphorescence from small organic systems containing a thiocarbonyl moiety.

Small organic molecules based on the unnatural DNA base pair dTPT3 are designed and synthesized, among which compounds bearing the thiocarbonyl group, compared with their carbonyl counterparts, show a much larger SOC integral between S1(1nπ*) and T1(3ππ*) states due to the appropriate energy level alignment and the heavy sulfur atom effect, resulting in the appearance of both fluorescence and phosphorescence in solution and solid state at room temperature.

Advances in Neuroprotection in Glaucoma: Pharmacological Strategies and Emerging Technologies.

Glaucoma is a major global health concern and the leading cause of irreversible blindness worldwide, characterized by the progressive degeneration of retinal ganglion cells (RGCs) and their axons. This review focuses on the need for neuroprotective strategies in glaucoma management, addressing the limitations of current treatments that primarily target intraocular pressure (IOP) reduction. Despite effective IOP management, many patients continue to experience RGC degeneration, leading to irreversible blindness. This review provides an overview of both pharmacological interventions and emerging technologies aimed at directly protecting RGCs and the optic nerve, independent of IOP reduction. Pharmacological agents such as brimonidine, neurotrophic factors, memantine, Ginkgo biloba extract, citicoline, nicotinamide, insulin, and resveratrol show promise in preclinical and early clinical studies for their neuroprotective properties. Emerging technologies, including stem cell therapy, gene therapy, mitochondrial-targeted therapies, and nanotechnologies, offer innovative approaches for neuroprotection and regeneration of damaged RGCs. While these interventions hold significant potential, further research and clinical trials are necessary to confirm their efficacy and establish their role in clinical practice. This review highlights the multifaceted nature of neuroprotection in glaucoma, aiming to guide future research and clinical practice toward more effective management of glaucoma-induced neurodegeneration.

Individual joint contributions to forward propulsion during treadmill walking in women with hip osteoarthritis.

As we age, reliance on the ankle musculature for push-off during walking reduces and increased reliance on the hip musculature is observed. It is unclear how joint pathology like osteoarthritis may affect this distal-to-proximal redistribution of propulsion. Here, we revisited a proof-of-concept study to study the effect of split-belt treadmill training, designed to reduce step length asymmetry, on forward propulsion during walking. Eleven women with hip osteoarthritis and five age-matched control participants walked on an instrumented split-belt treadmill at their preferred speed (hip osteoarthritis: 0.73 ± 0.11 m/s; controls: 0.59 ± 0.26 m/s). Women with hip osteoarthritis had less ankle power and propulsive force than controls, and greater hip contributions to forward propulsion on their involved limb. Following split-belt treadmill training, propulsive force increased on the involved limb. Five of 11 participants experienced a change in redistribution ratio that was greater than the minimal clinically meaningful difference. These "responders" had greater variability in pre-training redistribution ratio compared to non-responders. Women with hip osteoarthritis had poorer propulsive gait mechanics than controls yet split-belt treadmill training improved propulsive force. Redistribution ratio also changed in participants with high baseline variability. Our results suggest that split-belt treadmill training may be beneficial to people with hip osteoarthritis who have high variability in walking parameters. Further, the age-related shift to increased hip contributions to propulsion across populations of older adults may be due to increased variability during walking.

Substrate Charge Transfer Induced Ferromagnetism in MnSe/SrTiO3 Ultrathin Films.

The observation of superconductivity in MnSe at 12 GPa motivated us to investigate whether superconductivity could be induced in MnSe at ambient conditions. A strain-induced structural change in the ultrathin film could be one route to the emergence of superconductivity. In this report, we present the physical property of MnSe ultrathin films, which become tetragonal (stretched ab-plane and shortened c-axis) on a (001) SrTiO3 (STO) substrate, prepared by the pulsed laser deposition (PLD) method. The physical properties of the tetragonal MnSe ultrathin films exhibit very different characteristics from those of the thick films and polycrystalline samples. The tetragonal MnSe films show substantial conductivity enhancement, which could be associated with the presence of superparamagnetism. The optical absorption data indicate that the electron transition through the indirect bandgap to the conduction band is significantly enhanced in tetragonal MnSe. Furthermore, the X-ray Mn L-edge absorption results also reveal an increase in unoccupied state valance bands. This theoretical study suggests that charge transfer from the substrate plays an important role in conductivity enhancement and the emergence of a ferromagnetic order that leads to superparamagnetism.