Cardiovascular outcomes associated with SGLT2 inhibitor therapy in patients with type 2 diabetes mellitus and cancer: a systematic review and meta-analysis.

BACKGROUND: Cancer patients with diabetes are at increased risk for cardiovascular diseases due to common risk factors and well-documented drug-associated cardiotoxicity. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have shown cardiovascular benefits in patients with diabetes, but their effects on cancer patients remain unclear. This study aimed to evaluate the cardiovascular outcomes associated with SGLT2 inhibitor therapy in patients with concomitant diabetes and cancer. METHODS: We conducted a systematic review and meta-analysis of cohort studies comparing cardiovascular outcomes between cancer patients with diabetes receiving SGLT2 inhibitors and those not receiving SGLT2 inhibitors. PubMed, Embase, and the Cochrane Library were searched from inception to February 29, 2024. The primary outcome was all-cause mortality, and the secondary outcomes were heart failure hospitalization, and adverse events. Random-effect models were used to calculate pooled risk ratios (RR) with 95% confidence intervals (CI). Subgroup and sensitivity analyses were conducted to identify potential sources of heterogeneity and explore the effect of SGLT2 inhibitors on mitigating cardiotoxicity. RESULTS: Nine cohort studies involving 82,654 patients were included. SGLT2 inhibitor use was associated with a significantly lower risk of all-cause mortality (RR 0.46, 95% CI 0.31-0.68, P < 0.0001; I2 = 98%) and heart failure hospitalization (RR 0.49, 95% CI 0.30-0.81, P = 0.006; I2 = 21%) compared to non-use. The mortality benefit remained significant in patients receiving anthracycline chemotherapy (RR 0.50, 95% CI 0.28-0.89, P = 0.02; I2 = 71%). SGLT2 inhibitor use was also associated with a lower risk of sepsis (RR 0.32, 95% CI 0.23-0.44, P < 0.00001; I2 = 0%) and no increased risk of diabetic ketoacidosis (RR 0.66, 95% CI 0.20-2.16, P = 0.49; I2 = 0%). CONCLUSIONS: SGLT2 inhibitor therapy is associated with lower risks of all-cause mortality and heart failure hospitalization in patients with concomitant diabetes and cancer. These findings suggest that SGLT2 inhibitors may offer cardiovascular benefits in this high-risk population. Randomized controlled trials are needed to validate these findings and evaluate the safety and efficacy of SGLT2 inhibitors in specific cancer types and treatment regimens.

Therapeutic Efficacy and Radiobiological Effects of Boric-Acid-Mediated BNCT in an Osteosarcoma-Bearing SD Rat Model.

BACKGROUND: Osteosarcoma (OS) is the most common primary malignancy of the bone and is notoriously resistant to radiation therapy. High-dose cytotoxic chemotherapy and surgical resection have improved the survival rate and prognosis of patients with OS. Nonetheless, treatment challenges remain when the tumor cannot be removed by surgery. Boron neutron capture therapy (BNCT) provides high linear energy transfer (LET) radiation, and its internal targeted characteristics make BNCT a novel therapy for removing OS and reducing radiation damage to adjacent healthy tissues. METHODS: In this study, a UMR-106-grafted OS rat model was developed, and boric acid (BA) was used as the boron drug for BNCT. The pharmacokinetics of BA, following intravenous injection, were evaluated to determine the optimal time window for neutron irradiation. OS-bearing rats were irradiated by an epithermal neutron beam at Tsing Hua Open-Pool Reactor (THOR). The therapeutic efficacy of and tissue response after BNCT were evaluated by radiographic and histopathological observations. RESULTS: OS-bearing rats were irradiated by neutrons in the first hour following the intravenous injection of BA. The prescription-absorbed doses in the tumor regions were 5.8 and 11.0 Gy. BNCT reduced the body weight of the tumor-bearing rats, but they recovered after a few days. The BA-mediated BNCT effectively controlled the orthotopic OS tumor, reduced osteolysis, and induced bone healing. Autoradiography and histological analysis confirmed that the BA retention region is consistent with the calcification region in OS tissue. CONCLUSION: BA is specifically retained in OS, and the BA-mediated BNCT can significantly reduce the tumor burden and osteolysis in OS-bearing rats.

Valproic Acid Enhances Radiosensitization via DNA Double-strand Breaks for Boronophenylalanine-mediated Neutron Capture Therapy in Melanoma Cells.

BACKGROUND: Boron neutron capture therapy (BNCT) is a radiotherapeutic approach that can destroy cancer cells while sparing the surrounding normal cells. Currently, boronophenylalanine (BPA) is the most common boron delivery agent used in BNCT for treating recurrent cancers of the head and neck, gliomas, and melanomas. On the other hand, valproic acid (VPA) is one of the representative class I histone deacetylase inhibitors (HDACi), which is a promising sensitizer for cancer therapies. In this study, we aimed to verify whether VPA could induce an enhanced effect in destroying melanoma cells in concurrence with BNCT and to explore the underlying mechanism of VPA-BNCT action in killing these cells. MATERIALS AND METHODS: Murine melanoma B16-F10 cells were pre-treated with VPA and irradiated with neutron during BPA-BNCT. We explored the clonogenic assay and the expression of phosphorylated H2AX (γH2AX) for cell survival and DNA double-strand breaks (DSBs), respectively. We also examined the expression levels of DNA damage responses-associated proteins and performed a cell cycle analysis. RESULTS: Our data indicated that the combination treatment of VPA and BNCT could significantly inhibit the growth of melanoma cells. Furthermore, VPA-BNCT treatment could exacerbate and perturb DNA DSBs in B16-F10 cells. In addition, pre-treatment of VPA abolished the G2/M arrest checkpoint caused by BNCT. CONCLUSION: Our results demonstrate that VPA has the potential to serve as a radiosensitizer of BPA-mediated BNCT for melanoma. These findings could improve BNCT treatments for melanoma.

Boron Neutron Capture Therapy Eliminates Radioresistant Liver Cancer Cells by Targeting DNA Damage and Repair Responses.

Introduction: For advanced hepatocellular carcinoma (HCC), resistance to conservative treatments remains a challenge. In previous studies, the therapeutic effectiveness and DNA damage responses of boric acid-mediated boron neutron capture therapy (BA-BNCT) in HCC have been demonstrated in animal models and HCC cell line. On the other hand, numerous studies have shown that high linear energy transfer (LET) radiation can overcome tumor resistance. Since BNCT yields a mixture of high and low LET radiation, we aimed to explore whether and how BA-BNCT could eliminate radioresistant HCC cells. Methods: Radioresistant human HCC (HepG2-R) cells were established from HepG2 cells via intermittent irradiation. HepG2 and HepG2-R cells were then irradiated with either γ-ray or neutron radiation of BA-BNCT. Colony formation assays were used to assess cell survival and the relative biological effectiveness (RBE). The expression of phosphorylated H2AX (γH2AX) was also examined by immunocytochemistry and Western blot assays to evaluate the extent of DNA double-strand breaks (DSBs). Finally, the expression levels of DNA damage response-associated proteins were determined, followed by cell cycle analysis and caspase-3 activity analysis. Results: Our data demonstrated that under the same dose by γ-ray, BNCT effectively eliminated radioresistant HCC by increasing the number of DNA DSBs (p < 0.05) and impeding their repair (p < 0.05), which verified the high RBE of BNCT. We also found that BNCT resulted in delayed homologous recombination (HR) and inhibited the nonhomologous end-joining (NHEJ) pathway during DNA repair. Markedly, BNCT increased cell arrest (p < 0.05) in the G2/M phase by altering G2 checkpoint signaling and increased PUMA-mediated apoptosis (p < 0.05). Conclusion: Our data suggest that DNA damage and repair responses could affect the anticancer efficiency of BNCT in radioresistant HepG2-R cells, which highlights the potential of BNCT as a viable treatment option for recurrent HCC.

Synergistic Effect of Simultaneous versus Sequential Combined Treatment of Histone Deacetylase Inhibitor Valproic Acid with Etoposide on Melanoma Cells.

Melanoma is the most lethal form of skin cancer, which is intrinsically resistant to conventional chemotherapy. Combination therapy has been developed to overcome this challenge and show synergistic anticancer effects on melanoma. Notably, the histone deacetylase inhibitor, valproic acid (VPA), has been indicated as a potential sensitizer of chemotherapy drugs on various metastatic cancers, including advanced melanoma. In this study, we explored whether VPA could serve as an effective sensitizer of chemotherapy drug etoposide (ETO) on B16-F10 and SK-MEL-2-Luc melanoma cell lines in response to drug-induced DNA damages. Our results demonstrated that the VPA-ETO simultaneous combined treatment and ETO pretreated sequential combined treatment generated higher inhibitory effectivities than the individual treatment of each drug. We found the VPA-ETO simultaneous combined treatment contributed to the synergistic inhibitory effect by the augmented DNA double-strand breaks, accompanied by a compromised homologous recombination activity. In comparison, the ETO pretreated sequential combined treatment led to synergistic inhibitory effect via enhanced apoptosis. Surprisingly, the enhanced homologous recombination activity and G2/M phase arrest resulted in the antagonistic effect in both cells under VPA pretreated sequential combined treatment. In summary, our findings suggested that sequential order and effective dose of drug administration in VPA-ETO combination therapy could induce different cellular responses in melanoma cells. Such understanding might help potentiate the effectiveness of melanoma treatment and highlight the importance of sequential order and effective dose in combination therapy.

Cell-Penetrating Delivery of Nitric Oxide by Biocompatible Dinitrosyl Iron Complex and Its Dermato-Physiological Implications.

After the discovery of endogenous dinitrosyl iron complexes (DNICs) as a potential biological equivalent of nitric oxide (NO), bioinorganic engineering of [Fe(NO)2] unit has emerged to develop biomimetic DNICs [(NO)2Fe(L)2] as a chemical biology tool for controlled delivery of NO. For example, water-soluble DNIC [Fe2(µ-SCH2CH2OH)2(NO)4] (DNIC-1) was explored for oral delivery of NO to the brain and for the activation of hippocampal neurogenesis. However, the kinetics and mechanism for cellular uptake and intracellular release of NO, as well as the biocompatibility of synthetic DNICs, remain elusive. Prompted by the potential application of NO to dermato-physiological regulations, in this study, cellular uptake and intracellular delivery of DNIC [Fe2(µ-SCH2CH2COOH)2(NO)4] (DNIC-2) and its regulatory effect/biocompatibility toward epidermal cells were investigated. Upon the treatment of DNIC-2 to human fibroblast cells, cellular uptake of DNIC-2 followed by transformation into protein-bound DNICs occur to trigger the intracellular release of NO with a half-life of 1.8 ± 0.2 h. As opposed to the burst release of extracellular NO from diethylamine NONOate (DEANO), the cell-penetrating nature of DNIC-2 rationalizes its overwhelming efficacy for intracellular delivery of NO. Moreover, NO-delivery DNIC-2 can regulate cell proliferation, accelerate wound healing, and enhance the deposition of collagen in human fibroblast cells. Based on the in vitro and in vivo biocompatibility evaluation, biocompatible DNIC-2 holds the potential to be a novel active ingredient for skincare products.

Gain-of-Function Mutant TP53 R248Q Overexpressed in Epithelial Ovarian Carcinoma Alters AKT-Dependent Regulation of Intercellular Trafficking in Responses to EGFR/MDM2 Inhibitor.

As the most common gene mutation found in cancers, p53 mutations are detected in up to 96% of high-grade serous ovarian carcinoma (HGSOC). Meanwhile, mutant p53 overexpression is known to drive oncogenic phenotypes in cancer patients and to sustain the activation of EGFR signaling. Previously, we have demonstrated that the combined inhibition of EGFR and MDM2-p53 pathways, by gefitinib and JNJ-26854165, exerts a strong synergistic lethal effect on HGSOC cells. In this study, we investigated whether the gain-of-function p53 mutation (p53R248Q) overexpression could affect EGFR-related signaling and the corresponding drug inhibition outcome in HGSOC. The targeted inhibition responses of gefitinib and JNJ-26854165, in p53R248Q-overexpressing cells, were extensively evaluated. We found that the phosphorylation of AKT increased when p53R248Q was transiently overexpressed. Immunocytochemistry analysis further showed that upon p53R248Q overexpression, several AKT-related regulatory proteins translocated in unique intracellular patterns. Subsequent analysis revealed that, under the combined inhibition of gefitinib and JNJ-26854165, the cytonuclear trafficking of EGFR and MDM2 was disrupted. Next, we analyzed the gefitinib and JNJ-26854165 responses and found differential sensitivity to the single- or combined-drug inhibitions in p53R248Q-overexpressing cells. Our findings suggested that the R248Q mutation of p53 in HGSOC caused significant changes in signaling protein function and trafficking, under EGFR/MDM2-targeted inhibition. Such knowledge could help to advance our understanding of the role of mutant p53 in ovarian carcinoma and to improve the prognosis of patients receiving EGFR/MDM2-targeted therapies.

c-MYC-directed NRF2 drives malignant progression of head and neck cancer via glucose-6-phosphate dehydrogenase and transketolase activation.

Rationale: NRF2, a redox sensitive transcription factor, is up-regulated in head and neck squamous cell carcinoma (HNSCC), however, the associated impact and regulatory mechanisms remain unclear. Methods: The protein expression of NRF2 in HNSCC specimens was examined by IHC. The regulatory effect of c-MYC on NRF2 was validated by ChIP-qPCR, RT-qPCR and western blot. The impacts of NRF2 on malignant progression of HNSCC were determined through genetic manipulation and pharmacological inhibition in vitro and in vivo. The gene-set enrichment analysis (GSEA) on expression data of cDNA microarray combined with ChIP-qPCR, RT-qPCR, western blot, transwell migration/ invasion, cell proliferation and soft agar colony formation assays were used to investigate the regulatory mechanisms of NRF2. Results: NRF2 expression is positively correlated with malignant features of HNSCC. In addition, carcinogens, such as nicotine and arecoline, trigger c-MYC-directed NRF2 activation in HNSCC cells. NRF2 reprograms a wide range of cancer metabolic pathways and the most notable is the pentose phosphate pathway (PPP). Furthermore, glucose-6-phosphate dehydrogenase (G6PD) and transketolase (TKT) are critical downstream effectors of NRF2 that drive malignant progression of HNSCC; the coherently expressed signature NRF2/G6PD/TKT gene set is a potential prognostic biomarker for prediction of patient overall survival. Notably, G6PD- and TKT-regulated nucleotide biosynthesis is more important than redox regulation in determining malignant progression of HNSCC. Conclusions: Carcinogens trigger c-MYC-directed NRF2 activation. Over-activation of NRF2 promotes malignant progression of HNSCC through reprogramming G6PD- and TKT-mediated nucleotide biosynthesis. Targeting NRF2-directed cellular metabolism is an effective strategy for development of novel treatments for head and neck cancer.

A novel NRF2/ARE inhibitor gossypol induces cytotoxicity and sensitizes chemotherapy responses in chemo-refractory cancer cells.

NRF2/ARE signaling pathway is a principal regulator of cellular redox homoeostasis. The stress-induced transcription factor, NRF2, can shield cells from the oxidative damages via binding to the consensus antioxidant-responsive element (ARE) and driving several cyto-protective genes expression. Increasing evidence indicated that aberrant activation of NRF2 in malignant cells may support their survival through various pathways to detoxify chemotherapy drugs, attenuate drug-induced oxidative stress, or induce drug efflux, all of which are crucial in developing drug resistance. Accordingly, NRF2 is a potential drug target for improving the effectiveness of chemotherapy and to reverse drug resistance in cancer cells. A stable ARE-driven reporter human head and neck squamous cell carcinoma (HNSCC) cell line, HSC3-ARE9, was established and utilized to screen novel NRF2 inhibitors from a compound library. The cotton plant derived phenolic aldehyde-gossypol was selected for further analyses. The effects of gossypol in cancer cells were determined by western blotting, RT-qPCR, clonogenic assay, and cell viability assays. The gossypol-responsive gene expression levels were assessed in the Oncomine database. The effects of gossypol on conferring chemo-sensitization were evaluated in etoposide-resistant and cisplatin-resistant cancer cells. Our study is the first to identify that gossypol is effective to reduce both basal and NRF2 activator tert-butylhydroquinone (t-BHQ)-induced ARE-luciferase activity. Gossypol diminishes NRF2 protein stability and thereby leads to the suppression of NRF2/ARE pathway, which resulted in decreasing the expression levels of NRF2 downstream genes in both time- and dose-dependent manners. Inhibition of NRF2 by gossypol significantly decreases cell viabilities in human cancer cells. In addition, we find that gossypol re-sensitizes topoisomerase II poison treatment in etoposide-resistant cancer cells via suppression of NRF2/ABCC1 axis. Moreover, gossypol suppresses NRF2-mediated G6PD expression thereby leads to induce synthetic lethality with cisplatin not only in parental cancer cells but also in cisplatin-resistant cancer cells. These findings suggest that gossypol is a novel NRF2/ARE inhibitor, and can be a potential adjuvant chemotherapeutic agent for treatment of chemo-refractory tumor.

Suitability of boric acid as a boron drug for boron neutron capture therapy for hepatoma.

Hepatoma is the second leading cause of cancer death worldwide. Due to the poor outcomes of patients with late diagnosis, newer treatments for hepatoma are still needed. As an emerging therapy, boron neutron capture therapy (BNCT) may be an effective solution in hepatoma management. In this study, boric acid (BA) was used as the boron drug for in vivo analysis of action mechanism. The N1S1 single liver tumor-bearing rat and the VX2 multifocal liver tumor-bearing rabbit models were used to investigate the retention status of BA in the tumor regions during BNCT. The autoradiographic examination showed BA can localize specifically not only in the hepatoma cells but also in tumor blood vessels. Our findings indicate that superior hepatoma targeting could be achieved in BA-mediated BNCT, which supports BA to be a suitable boron drug for BNCT for hepatoma.

Exposure to the AhR agonist cyprodinil impacts the cardiac development and function of zebrafish larvae.

Cyprodinil is a broad-spectrum pyrimidine amine fungicide that has been reportedly used worldwide. However, toxicity studies of cyprodinil on aquatic organisms, specifically zebrafish (Danio rerio), are lacking. In our present study, we predicted cyprodinil binding to the aryl hydrocarbon receptor (AhR) by using molecular docking simulation. Then, we used recombinant HepG2 cells and Tg(cyp1a1-12DRE:egfp) transgenic zebrafish to further assess the AhR agonistic activity of cyprodinil. Besides, the significant upregulation of cyp1a1 further verified that statement. Moreover, we found that zebrafish exposure to cyprodinil induced developmental toxicity in the larvae, particularly during cardiac development. The expression levels of cardiac development-related genes, namely tbx5, nkx2.5, gata4, and tnnt2, were markedly altered, which might cause the adverse effects of cyprodinil on cardiac function and development. In summary, we found that cyprodinil, as an AhR agonist, induced development toxicity in zebrafish larvae, especially on cardiac. Data here can assess the potential effects on organisms in the aquatic environment and promote the regulation and safe use of cyprodinil.

The Phenoxyphenol Compound 4-HPPP Selectively Induces Antiproliferation Effects and Apoptosis in Human Lung Cancer Cells through Aneupolyploidization and ATR DNA Repair Signaling.

Lung cancer is a leading cause of cancer death worldwide, and non-small-cell lung cancer (NSCLC) accounts for 85% of lung cancer, which is highly metastatic, leading to the poor survival rate of patients. We recently reported that 4-[4-(4-hydroxyphenoxy)phenoxy]phenol (4-HPPP), a phenoxyphenol, exerts antihepatoma effects by inducing apoptosis and autophagy. In this study, we further examined the effect of 4-HPPP and its analogs on NSCLC cells. Colony formation assays showed that 4-HPPP exerts selective cytotoxicity against NSCLC H1299 cells; furthermore, the inhibitory effect of 4-HPPP on the proliferation and migration of NSCLC cells was validated using an in vivo zebrafish-based tumor xenograft assay. The flow cytometry-based dichlorofluorescein diacetate (DCF-DA) assays indicated that 4-HPPP caused an increase in reactive oxygen species (ROS) in NSCLC cells, and Western blot assays showed that the major ROS scavenging enzymes superoxide dismutases- (SODs-) 1/2 were upregulated, whereas peroxidase (PRX) was downregulated. Furthermore, 4-HPPP caused both aneuploidization and the accumulation of γH2AX, a sensor of DNA damage, as well as the activation of double-strand break (DSB) markers, especially Ataxia-telangiectasia-mutated and Rad3-related (ATR) in NSCLC cells. Our present work suggests that the antiproliferative effects of 4-HPPP on lung cancer cells could be due to its phenoxyphenol structure, and 4-HPPP could be a candidate molecule for treating NSCLC by modulating ROS levels and lowering the threshold of polyploidy-specific cell death in the future.

Analysis of DNA Damage Responses After Boric Acid-mediated Boron Neutron Capture Therapy in Hepatocellular Carcinoma.

BACKGROUND: Boron neutron capture therapy (BNCT) selectively kills tumor cells while sparing adjacent normal cells. Boric acid (BA)-mediated BNCT showed therapeutic efficacy in treating hepatocellular carcinoma (HCC) in vivo. However, DNA damage and corresponding responses induced by BA-mediated BNCT remained unclear. This study aimed to investigate whether BA-mediated BNCT induced DNA double-strand breaks (DSBs) and to explore DNA damage responses in vitro. MATERIALS AND METHODS: Huh7 Human HCC cells were treated with BA and irradiated with neutrons during BA-BNCT. Cell survival and DNA DSBs were examined by clonogenic assay and expression of phosphorylated H2A histone family member X (γH2AX), respectively. The DNA damage response was explored by determining the expression levels of DNA repair- and apoptosis-associated proteins and conducting a cell-cycle analysis. RESULTS: DNA DSBs induced by BA-mediated BNCT were primarily repaired through the homologous recombination pathway. BA-mediated BNCT induced G2/M arrest and apoptosis in HCC. CONCLUSION: Our findings may enable the identification of radiosensitizers or adjuvant drugs for potentiating the therapeutic effectiveness of BA-mediated BNCT for HCC.

Therapeutic Efficacy and Radiobiological Effects of Boric Acid-mediated BNCT in a VX2 Multifocal Liver Tumor-bearing Rabbit Model.

BACKGROUND/AIM: Most patients with hepatocellular carcinoma (HCC) cannot be treated using traditional therapies. Boron neutron capture therapy (BNCT) may provide a new treatment for HCC. In this study, the therapeutic efficacy and radiobiological effects of boric acid (BA)-mediated BNCT in a VX2 multifocal liver tumor-bearing rabbit model are investigated. MATERIALS AND METHODS: Rabbits were irradiated with neutrons at the Tsing Hua Open Pool Reactor 35 min following an intravenous injection of BA (50 mg 10B/kg BW). The tumor size following BNCT treatment was determined by ultrasonography. The radiobiological effects were identified by histopathological examination. RESULTS: A total of 92.85% of the tumors became undetectable in the rabbits after two fractions of BNCT treatment. The tumor cells were selectively eliminated and the tumor vasculature was collapsed and destroyed after two fractions of BA-mediated BNCT, and no injury to the hepatocytes or blood vessels was observed in the adjacent normal liver regions. CONCLUSION: Liver tumors can be cured by BA-mediated BNCT in the rabbit model of a VX2 multifocal liver tumor. BA-mediated BNCT may be a breakthrough therapy for hepatocellular carcinoma.

Cordycepin Suppresses Endothelial Cell Proliferation, Migration, Angiogenesis, and Tumor Growth by Regulating Focal Adhesion Kinase and p53.

Focal adhesion kinase (FAK) plays an important role in vascular development, including the regulation of endothelial cell (EC) adhesion, migration, proliferation, and survival. 3'-deoxyadenosine (cordycepin) is known to suppress FAK expression, cell migration, and the epithelial⁻mesenchymal transition in hepatocellular carcinoma (HCC). However, whether cordycepin affects FAK expression and cellular functions in ECs and the specific molecular mechanism remain unclear. In this study, we found that cordycepin suppressed FAK expression and the phosphorylation of FAK (p-FAK) at Tyr397 in ECs. Cordycepin inhibited the proliferation, wound healing, transwell migration, and tube formation of ECs. Confocal microscopy revealed that cordycepin significantly reduced FAK expression and decreased focal adhesion number of ECs. The suppressed expression of FAK was accompanied by induced p53 and p21 expression in ECs. Finally, we demonstrated that cordycepin suppressed angiogenesis in an in vivo angiogenesis assay and reduced HCC tumor growth in a xenograft nude mice model. Our study indicated that cordycepin could attenuate cell proliferation and migration and may result in the impairment of the angiogenesis process and tumor growth via downregulation of FAK and induction of p53 and p21 in ECs. Therefore, cordycepin may be used as a potential adjuvant for cancer therapy.

Extension of C. elegans lifespan using the ·NO-delivery dinitrosyl iron complexes.

The ubiquitous and emerging physiology function of endogenous nitric oxide in vascular, myocardial, immune, and neuronal systems prompts chemists to develop a prodrug for the controlled delivery of ·NO in vivo and for the translational biomedical application. Inspired by the discovery of natural [Fe(NO)2] motif, herein, we develop the synthetic dinitrosyl iron complexes (DNICs) [Fe2(µ-SR)2(NO)4] (1) as a universal platform for the O2-triggered release of ·NO, for the regulation of ·NO-release kinetics (half-life = 0.6-27.4 h), and for the activation of physiological function of ·NO. Using C. elegans as a model organism, the ·NO-delivery DNIC 1 regulates IIS signaling pathway, AMPK signaling pathway, and mitochondrial function pathway to extend the lifespan and to delay the aging process based on the lifespan analysis, SA-ßgal activity assay, and next-generation RNA sequencing analysis. This study unveils the anti-aging effect of ·NO and develops DNICs as a chemical biology probe for the continued discovery of unprecedented NO physiology.

Proteomic investigating the cooperative lethal effect of EGFR and MDM2 inhibitors on ovarian carcinoma.

With the concept of precision medicine, combining multiple molecular-targeting therapies has brought new approaches to current cancer treatments. Malfunction of the tumor suppressor protein, p53 is a universal hallmark in human cancers. Under normal conditions, p53 is degraded through an ubiquitin-proteosome pathway regulated by its negative regulator, MDM2. In contrast, cellular stress such as DNA damage will activate p53 to carry out DNA repair, cell cycle arrest, and apoptosis. In this study, we focused on ovarian carcinoma with high EGFR and MDM2 overexpression rate. We assessed the effects of combined inhibition by MDM2 (JNJ-26854165) and EGFR (gefitinib) inhibitors on various ovarian cell lines to determine the importance of these two molecular targets on cell proliferation. We then used a proteomic strategy to investigate the relationship between MDM2 and EGFR inhibition to explore the underlying mechanisms of how their combined signaling blockades work together to exert cooperative inhibition. Our results demonstrated that all four cell lines were sensitive to both individual and combined, MDM2 and EGFR inhibition. The proteomic analysis also showed that gefitinib/JNJ-treated CAOV3 cells exhibited downregulation of proteins involved in nucleotide biosynthesis such as nucleoside diphosphate kinase B (NME2). In conclusion, our study showed that the combined treatment with JNJ and gefitinib exerted synergistic inhibition on cell proliferation, thereby suggesting the potential application of combining MDM2 inhibitors with EGFR inhibitors for enhancing efficacy in ovarian cancer treatment.

Effect of Tumor Microenvironment on Selective Uptake of Boric Acid in HepG2 Human Hepatoma Cells.

BACKGROUND: Feasibility and efficacy of boric acid (BA)-mediated boron neutron capture therapy (BNCT) was first demonstrated by eliminating hepatocellular carcinoma (HCC) in a rat model. Furthermore, selective uptake of BA by liver tumor cells was shown in a rabbit model. To gain further insight, this study aimed to investigate the mechanisms of transportation and selective uptake of BA in HepG2 liver tumor cells. MATERIALS AND METHODS: Transportation of BA in HepG2 cells was analyzed by time-course assays and by analyzing the rate of diffusion versus the concentration of BA. The effect of different tumor conditions on BA uptake was studied by treating HepG2 cells with 25 µg 10B/ml BA under different concentrations of glucose, at different pH and in the presence of water-soluble cholesterol. RESULTS: HepG2 cells mainly uptake BA by simple diffusion. Cell membrane permeability may also contribute to tumor-specific uptake of BA. CONCLUSION: The selective uptake of BA was achieved primarily by diffusion, while other factors, such as low pH and increased membrane fluidity, which are hallmarks of HCC, might further enhance BA uptake.

Effects of an injectable functionalized self-assembling nanopeptide hydrogel on angiogenesis and neurogenesis for regeneration of the central nervous system.

Brain injury is a devastating medical condition and represents a major health problem. Tissue and organ reconstruction have been regarded as promising therapeutic strategies. Here, we propose a regenerative methodology focusing on the provision of functionalized nanopeptide scaffolds to facilitate angiogenesis and neurogenesis at the brain injury site. The peptide RADA16-SVVYGLR undergoes self-assembly to construct an interconnected network with intertwining nanofibers, and can be controlled to display various physicochemical properties by the adjustment of microenvironmental factors such as pH and ion concentration. Such scaffolds can support endothelial cells to form tube-like structures and neural stem cells to survive and proliferate. In an in vivo zebrafish brain injury model, sprouting angiogenesis and developmental neurogenesis were achieved, and functional recovery of the severed optic tectum was enhanced in RADA16-SVVYGLR hydrogel-implanted zebrafish. This nanopeptide hydrogel was non-toxic to zebrafish embryos during early developmental stages. This angiogenic self-assembling peptide hydrogel had programmable physical properties, good biocompatibility, and regenerative ability for functional recovery in the injured brain. We suggest that functionalized self-assembling peptides encapsulated with neural stem cells or used alone could be an attractive and effective therapeutic modality for brain injury and diseases (e.g., trauma, stroke, tumor, degenerative neurological disorders, etc.).

NEAP/DUSP26 suppresses receptor tyrosine kinases and regulates neuronal development in zebrafish.

Expression of neuroendocrine-associated phosphatase (NEAP, also named as dual specificity phosphatase 26, [DUSP26]) is restricted to neuroendocrine tissues. We found that NEAP, but not its phosphatase-defective mutant, suppressed nerve growth factor (NGF) receptor TrkA and fibroblast growth factor receptor 1 (FGFR1) activation in PC12 cells upon NGF stimulation. Conversely, suppressing NEAP expression by RNA interference enhanced TrkA and FGFR1 phosphorylation. NEAP was capable of de-phosphorylating TrkA and FGFR1 directly in vitro. NEAP-orthologous gene existed in zebrafish. Morpholino (MO) suppression of NEAP in zebrafish resulted in hyper-phosphorylation of TrkA and FGFR1 as well as abnormal body postures and small eyes. Differentiation of retina in zebrafishes with NEAP MO treatment was severely defective, so were cranial motor neurons. Taken together, our data indicated that NEAP/DUSP26 have a critical role in regulating TrkA and FGFR1 signaling as well as proper development of retina and neuronal system in zebrafish.