Infection associated with CDK4/6 inhibitors: a pharmacovigilance analysis of the FDA adverse event reporting system database.

Introduction: Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors are first-line treatments for hormone receptor-positive/human epidermal growth factor receptor 2-negative breast cancer. With their increasing clinical use, infection-related adverse events (AEs) associated with CDK4/6 inhibitors have been widely reported in recent years. This study aimed to analyze the occurrence of infections associated with the CDK4/6 inhibitors (palbociclib, ribociclib and abemaciclib) based on the real-world data from the US Food and Drug Administration Adverse Event Reporting System (FAERS) database. Methods: Data were extracted from the FAERS database between 2015Q1 and 2022Q3. The clinical characteristics of patients with primary suspected infection-related AEs were analyzed. A disproportionality analysis was performed to investigate the potential association between AEs and CDK4/6 inhibitors. The influencing factors were evaluated using Pearson's chi-square test. Results: Reports of infection-related AEs associated with ribociclib accounted for 8.58% of the total reports of AEs associated with ribociclib, followed by palbociclib (2.72%) and abemaciclib (1.24%). Ribociclib (67.65%) was associated with more serious outcome events than palbociclib (30%) or abemaciclib (48.08%). The sex and age were not associated with outcome severity. Disproportionality analysis showed that fourteen, sixteen and two infection-related preferred terms were detected for palbociclib, ribociclib and abemaciclib, respectively. Conclusion: Infection-related AEs were highly associated with three CDK4/6 inhibitors, especially palbociclib and ribociclib, based on the real-world data from the FAERS database. However, further causality assessment is required.

A pharmacovigilance study on antibody-drug conjugate (ADC)-related neurotoxicity based on the FDA adverse event reporting system (FAERS).

Background: Antibody-drug conjugates (ADCs) are a relatively new class of anticancer agents that use monoclonal antibodies to specifically recognize tumour cell surface antigens. However, off-target effects may lead to severe adverse events. This study evaluated the neurotoxicity of ADCs using the FDA Adverse Event Reporting System (FAERS) database. Research design and methods: Data were extracted from the FAERS database for 2004 Q1 to 2022 Q4. We analysed the clinical characteristics of ADC-related neurological adverse events (AEs). We used the reporting odds ratio (ROR) and proportional reporting ratio (PRR) for the disproportionality analysis to evaluate the potential association between AEs and ADCs. Results: A total of 562 cases of neurological AEs were attributed to ADCs. The median age was 65 years old [(Min; Max) = 3; 92]. Neurotoxic signals were detected in patients receiving brentuximab vedotin, enfortumab vedotin, polatuzumab vedotin, trastuzumab emtansine, gemtuzumab ozogamicin, inotuzumab ozogamicin, and trastuzumab deruxtecan. The payloads of brentuximab vedotin, enfortumab vedotin, polatuzumab vedotin, and trastuzumab emtansine were microtubule polymerization inhibitors, which are more likely to develop neurotoxicity. We also found that brentuximab vedotin- and gemtuzumab ozogamicin-related neurological AEs were more likely to result in serious outcomes. The eight most common ADC-related nervous system AE signals were peripheral neuropathy [ROR (95% CI) = 16.98 (14.94-19.30), PRR (95% CI) = 16.0 (14.21-18.09)], cerebral haemorrhage [ROR (95% CI) = 9.45 (7.01-12.73), PRR (95% CI) = 9.32 (6.95-12.50)], peripheral sensory neuropathy [ROR (95% CI) = 47.87 (33.13-69.19), PRR (95% CI) = 47.43 (32.93-68.30)], polyneuropathy [ROR (95% CI) = 26.01 (18.61-36.33), PRR (95% CI) = 25.75 (18.50-35.86)], encephalopathy [ROR (95% CI) = 5.16 (3.32-8.01), PRR (95% CI) = 5.14 (3.32-7.96)], progressive multifocal leukoencephalopathy [ROR (95% CI) = 22.67 (14.05-36.58), PRR (95% CI) = 22.52 (14.01-36.21)], taste disorder [ROR (95% CI) = 26.09 (15.92-42.76), PRR (95% CI) = 25.78 (15.83-42.00)], and guillain barrier syndrome [ROR (95% CI) = 17.844 (10.11-31.51), PRR (95% CI) = 17.79 (10.09-31.35)]. The mortality rate appeared to be relatively high concomitantly with AEs in the central nervous system. Conclusion: ADCs may increase the risk of neurotoxicity in cancer patients, leading to serious mortality. With the widespread application of newly launched ADC drugs, combining the FAERS data with other data sources is crucial for monitoring the neurotoxicity of ADCs. Further studies on the potential mechanisms and preventive measures for ADC-related neurotoxicity are necessary.

USP2 promotes tumor immune evasion via deubiquitination and stabilization of PD-L1.

The abnormal upregulation of programmed death ligand-1 (PD-L1) on tumor cells impedes T-cell mediated cytotoxicity through PD-1 engagement, and further exploring the mechanisms regulation of PD-L1 in cancers may enhance the clinical efficacy of PD-L1 blockade. Here, using single-guide RNAs (sgRNAs) screening system, we identify ubiquitin-specific processing protease 2 (USP2) as a novel regulator of PD-L1 stabilization for tumor immune evasion. USP2 directly interacts with and increases PD-L1 abundance in colorectal and prostate cancer cells. Our results show that Thr288, Arg292 and Asp293 at USP2 control its binding to PD-L1 through deconjugating the K48-linked polyubiquitination at lysine 270 of PD-L1. Depletion of USP2 causes endoplasmic reticulum (ER)-associated degradation of PD-L1, thus attenuates PD-L1/PD-1 interaction and sensitizes cancer cells to T cell-mediated killing. Meanwhile, USP2 ablation-induced PD-L1 clearance enhances antitumor immunity in mice via increasing CD8+ T cells infiltration and reducing immunosuppressive infiltration of myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs), whereas PD-L1 overexpression reverses the tumor growth suppression by USP2 silencing. USP2-depletion combination with anti-PD-1 also exhibits a synergistic anti-tumor effect. Furthermore, analysis of clinical tissue samples indicates that USP2 is positively associated with PD-L1 expression in cancer. Collectively, our data reveal a crucial role of USP2 for controlling PD-L1 stabilization in tumor cells, and highlight USP2 as a potential therapeutic target for cancer immunotherapy.

Efficacy of Jinshuibao as an adjuvant treatment for chronic renal failure in China: A meta-analysis.

BACKGROUND: Research on Jinshuibao (JSB) for chronic renal failure (CRF) is limited, its clinical efficacy on CRF has not been evaluated. Our aim is to systematically evaluate the efficacy of JSB for the treatment of CRF in Chinese patients, and to provide evidence-based medical advice for clinical practice. METHODS: Randomized controlled trials (RCTs) which compared JSB combined with conventional treatment (CT) with CT alone in CRF were searched in 8 databases including PubMed, EMBASE, Cochrane Library, Web of science, China Biology Medicine disc, Wanfang, Chinese Scientific Journal Database (VIP) and China National Knowledge Infrastructure form inception to March 31, 2023. RevMan5.4 statistical software was used for meta-analysis. RESULTS: 17 trials involving 1431 cases were identified for meta-analysis. The results showed that total effective rate (relative risk [RR] = 1.25, 95% confidence internal [CI]: 1.17-1.34, P < .00001), creatinine clearance rate (Ccr) (MD = -8.63, 95% CI: -12.42 to -4.84, P < .00001), albumin (Alb) (MD = -2.88, 95% CI: -4.85 to -0.92, P = .004) and hemoglobin (Hb) (MD = -5.88, 95% CI: -7.42 to -4.34, P < .00001) in JSB plus CT were significantly higher than those in CT; while blood urea nitrogen (BUN) (MD = 2.03, 95% CI: 1.27-2.80, P < .00001), serum creatinine (Scr) (MD = 48.23, 95% CI: 31.96-64.49, P < .00001), 24-hour urine protein (24hpro) (MD = 0.19, 95% CI: 0.06-0.31, P = .003), uric acid (UA) (MD = 76.36, 95% CI: 12.40-140.31, P = .02), tumor necrosis factor-α (TNF-α) (MD = 10.74, 95% CI: 5.04-16.45, P = .0002), interleukin-6 (IL-6) (MD = 5.07,95% CI: 1.21-8.92, P = .01), high-sensitivity C-reactive protein (hs-CRP) (MD = 3.74, 95% CI: 0.96-6.52, P = .008) in JSB plus CT were significantly lower than those in CT. CONCLUSION: Combining JSB with CT has a good effect on the treatment of CRF in Chinese people. High-quality RCTs are needed to further confirm the results.

Design, synthesis, and biological evaluation of novel molecules as potent inhibitors of PLK1.

Polo-like kinase 1 (PLK1) is an attractive therapeutic target for the treatment of tumors, as it is an essential cell-cycle regulator frequently overexpressed in tumor tissues. PLK1 can promote tumor invasion and metastasis, and is often associated with poor prognosis in cancer patients. However, no PLK1 inhibitor has been granted marketing approval until now. Therefore, more potentially promising PLK1 inhibitors need to be investigated. In this study, a series of novel inhibitors targeting PLK1 was designed and optimized derived from a new scaffold. After synthesis and characterization, we obtained the structure-activity relationship and led to the discovery of the most promising compound 30e for PLK1. The antiproliferative activity against HCT116 cells (IC50 = 5 nM versus 45 nM for onvansertib) and the cellular permeability and efflux ratio were significantly improved (PappA→B = 2.03 versus 0.345 and efflux ratio = 1.65 versus 94.7 for 30e and onvansertib, respectively). Further in vivo studies indicated that 30e had favorable antitumor activity with 116.2% tumor growth inhibition (TGI) in comparison with TGI of 43.0% for onvansertib. Furthermore, 30e improved volume of tumor tissue distribution in mice as compared to onvansertib. This initial study on 30e holds promise for further development of an antitumor agent.

Raddeanin A Enhances Mitochondrial DNA-cGAS/STING Axis-Mediated Antitumor Immunity by Targeting Transactive Responsive DNA-Binding Protein 43.

Immune checkpoint therapies (ICT) have achieved unprecedented efficacy in multiple cancer treatments, but are still limited by low clinical response rates. Identification of immunogenic cell death (ICD)-inducing drugs that can induce tumor cell immunogenicity and reprogram the tumor microenvironment is an attractive approach to enhance antitumor immunity. In the present study, Raddeanin A (RA), an oleanane class triterpenoid saponin isolated from Anemone raddeana Regel, is uncovered as a potent ICD inducer through an ICD reporter assay combined with a T cell activation assay. RA significantly increases high-mobility group box 1 release in tumor cells and promotes dendritic cell (DC) maturation and CD8+ T cell activation for tumor control. Mechanistically, RA directly binds to transactive responsive DNA-binding protein 43 (TDP-43) and induces TDP-43 localization to mitochondria and mtDNA leakage, leading to cyclic GMP-AMP synthase/stimulator of interferon gene-dependent upregulation of nuclear factor κB and type I interferon signaling, thereby potentiating the DC-mediated antigen cross-presentation and T cell activation. Moreover, combining RA with anti-programmed death 1 antibody effectively enhances the efficacy of ICT in animals. These findings highlight the importance of TDP-43 in ICD drug-induced antitumor immunity and reveal a potential chemo-immunotherapeutic role of RA in enhancing the efficacy of cancer immunotherapy.

Modification of Iron-Rich Phase in Al-7Si-3Fe Alloy by Mechanical Vibration during Solidification.

The plate-like iron-rich intermetallic phases in recycled aluminum alloys significantly deteriorate the mechanical properties. In this paper, the effects of mechanical vibration on the microstructure and properties of the Al-7Si-3Fe alloy were systematically investigated. Simultaneously, the modification mechanism of the iron-rich phase was also discussed. The results indicated that the mechanical vibration was effective in refining the α-Al phase and modifying the iron-rich phase during solidification. The forcing convection and a high heat transfer inside the melt to the mold interface caused by mechanical vibration inhibited the quasi-peritectic reaction: L + α-Al8Fe2Si → (Al) + ß-Al5FeSi and eutectic reaction: L → (Al) + ß-Al5FeSi + Si. Thus, the plate-like ß-Al5FeSi phases in traditional gravity-casting were replaced by the polygonal bulk-like α-Al8Fe2Si. As a result, the ultimate tensile strength and elongation were increased to 220 MPa and 2.6%, respectively.

Combination of mTOR inhibitor PP242 and AMPK activator metformin exerts enhanced inhibitory effects on colorectal carcinoma cells in vitro by blocking multiple kinase pathways.

The second-generation mammalian target of rapamycin (mTOR) inhibitor PP242 has demonstrated limited success in some rapamycin-insensitive tumours. We examined the therapeutic potential of combining PP242 with adenosine 50- monophosphate-activated protein kinase (AMPK) activator metformin, using a panel of colorectal carcinoma (CRC) cell lines. We found that the PP242 and metformin combination enhanced the suppression of CRC cell proliferation, colony formation, and cancer cell apoptosis induction. The effect of this combination was observed on AMPK phosphorylation. Western blotting showed that PP242 inhibited mTORC1 activation, as indicated by the reduced expression of its major substrate p-S6K1 and the partially reduced phosphorylation of eIF4E-binding protein 1 (4E-BP1). The inhibition of mTORC2-mediated AKT phosphorylation at Ser 473 (AKT Ser473) was transient and occurred in the first few hours of PP242 treatment; metformin exposure decreased the PP242 activity, counteracting AKT activation. We further demonstrated that this was related to direct AMPK-mediated phosphorylation of IRS-1 at Ser789. Thus, the combination of PP242 and metformin completely blocked the activity of both mTORC1 and mTORC2 kinase. This study suggests that this combination could be a more effective strategy for the treatment of CRC.

A pan-cancer analysis of the expression of gasdermin genes in tumors and their relationship with the immune microenvironment.

BACKGROUND: Gasdermins (GSDMs) are a class of proteins related to pyrolysis and in humans, consist of GSDMA, GSDMB, GSDMC, GSDMD, DFNA5, and DFNB59. The inflammatory factors and cell contents released during pyrolysis can recruit immune cells and change the microenvironment. However, to date, there is a paucity of studies examining the relationship between GSDMs and the immune microenvironment in tumors. Therefore, this current report analyzed the expression of GSDM genes in tumors and their relationship with the immune microenvironment. METHODS: Apply GSCALite and GEPIA2 online analysis tools to analyze the gene expression levels and the Single nucleotide variant (SNV), copy number variation (CNV), and methylation characteristics of GSDM genes respectively. Use R software or TISIDB online analysis tool to carry out the correlation analysis required in the article. Furthermore, Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were conducted to examine the role of these GSDM genes in various cancers. RESULTS: The results demonstrated that CNV can cause an increase in GSDM gene expression, and methylation can inhibit GSDM gene expression. The elevated expression of GSDMA, GSDMB, GSDMC, GSDMD, and DFNA5 in some or most tumors was often accompanied by elevated immune scores, increased immune cell infiltration, and high expression of major histocompatibility complex (MHC) molecules, chemokines and their receptors, and immune checkpoint-related genes. However, DFNB59 was often negatively correlated with these indicators in tumors. GSDMD was the most highly expressed GSDM protein in various normal tissues and tumors, and showed the strongest correlation with immune microenvironment-related genes. Moreover, the methylation of GSDMD was accompanied by low immune cell infiltration, low expression of MHC molecule-related genes, low expression of chemokines and receptor-related genes, and low expression of immune checkpoint-related genes. CONCLUSIONS: Therefore, the expression of GSDM-related genes is associated with the tumor immune microenvironment. The GSDM genes, especially GSDMD, may be used as therapeutic targets to predict or change the tumor microenvironment and as biomarkers to predict the therapeutic efficacy of immune checkpoint inhibitors.

Biocontrol efficiency of Meyerozyma guilliermondii Y-1 against apple postharvest decay caused by Botryosphaeria dothidea and the possible mechanisms of action.

Apple ring rot, caused by Botryosphaeria dothidea, is one of the important diseases in China. This pathogen infects branches and fruit and also results in fruit decay during storage. Biocontrol agents have been proposed to reduce apple decays during storage and are considered as a promising alternative strategy to traditional chemical treatment. In this study, Meyerozyma guilliermondii Y-1, isolated from healthy grape fruit, was firstly evaluated for its biocontrol efficiency against B. dothidea in postharvest apple fruit, and the possible mechanisms were investigated. The results revealed that M. guilliermondii Y-1 treatment effectively reduced apple ring rot caused by B. dothidea in vivo. The disease incidence and lesion diameter were reduced by 32.22% and 57.51% compared with those of control fruit. Furthermore, the use of filtrate and autoclaved culture of M. guilliermondii Y-1 also showed a certain degree of control efficiency against fruit ring rot. M. guilliermondii Y-1 significantly inhibited the mycelial growth and spore generation of B. dothidea in vitro and exhibited an obvious ability to colonize in apple fruit wounds and surface at 25 °C or 4 °C. In addition, M. guilliermondii Y-1 treatment significantly enhanced the activities of catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonialyase (PAL), and polyphenoloxidase (PPO), promoted the total phenolics content, and alleviated lipid peroxidation in apple fruit. As expected, we found that the expression of four pathogenesis-related proteins genes (MdPR1, MdPR5, MdGLU, and MdCHI) was remarkably increased by M. guilliermondii Y-1 treatment. Our data together suggest that M. guilliermondii Y-1 is a potential biocontrol agent against B. dothidea postharvest infection in apple fruit, partially through inhibiting mycelial growth and spore germination of B. dothidea, competing for space and nutrient with pathogen, and inducing resistance in apple fruit by stimulating a series of defense responses.

Are Posttraumatic Stress Symptoms and Avoidant Coping Inhibitory Factors? The Association Between Posttraumatic Growth and Quality of Life Among Low-Grade Gliomas Patients in China.

Background: Diagnosing with low-grade gliomas (LGGs) can be a very shocking and stressful experience, a traumatic event potentially leading to the development of posttraumatic stress symptoms (PTSS), and posttraumatic growth (PTG). Understanding how patients cognitively and behaviorally response to their diagnosing is also important to postoperative treatment. Thus, the current study explored the association between PTG and quality of life (QoL) of Chinese patients with LGGs. The moderation effects of coping strategies and PTSS on the relationship between PTG and QoL have been examined as well. Methods: Posttraumatic stress symptoms, Posttraumatic growth, coping strategies, and QoL were measured by using self-report surveys. Three hundred and thirty patients completed surveys approximately 1 month after surgery. We used three multiple regression models and added interaction terms in these models to test the moderation effects of PTSS and coping strategies on the relationship between PTG and QoL. Results: The results of hierarchical multiple regression suggested that PTG significantly predicted QoL, both PTSS and coping strategies moderated the association between PTG and QoL. Specifically, the association between PTG and QoL for patients who have non-significant PTSS is stronger than those who have significant PTSS. Furthermore, as the score of Avoidant Coping increases, the association between PTG and QoL becomes weaker. Conclusion: Posttraumatic growth may help to improve the QoL of LGGs patients, but PTSS and Avoidant Coping impeded the positive effect of PTG on QoL.

Facile synthesis of fluorescent carbon dots from Prunus cerasifera fruits for fluorescent ink, Fe3+ ion detection and cell imaging.

Carbon dots (CDs) synthesized from natural products have drawn numerous attentions due to some unique properties. Here, Prunus cerasifera fruits were used as carbon source to synthesize high luminescent CDs by hydrothermal method. The obtained CDs were characterized by TEM, FTIR and XPS methods, founding the CDs were near-spherical and contained abundant nitrogen element. The CDs aqueous solution exhibited bright blue fluorescence under ultraviolet illumination, with the maximum emission at 450 nm. They could be potentially used as invisible fluorescent ink by written on the paper and irradiated by UV light, due to their fluorescent properties. Moreover, the CDs were found being selectively quenched by Fe3+ ion. The quench of CDs was linearly related to the concentration of Fe3+ ion in the range of 0-0.5 mM, meaning they could be developed as fluorescent probe of Fe3+ ion. At last, the CDs were used for cell imaging, founding they were low toxicity to HepG2 cells and exhibited blue and green fluorescence under a fluorescence microscope. In summary, the CDs prepared from Prunus cerasifera fruits exhibited excellent fluorescence properties, and could be potentially applied in the field of fluorescent ink, Fe3+ ion detection and cell imaging.

Quantifying Aflatoxin B1 in peanut oil using fabricating fluorescence probes based on upconversion nanoparticles.

Rare earth doped upconversion nanoparticles convert near-infrared excitation light into visible emission light. Compared to organic fluorophores and semiconducting nanoparticles, upconversion nanoparticles (UCNPs) offer high photochemical stability, sharp emission bandwidths, and large anti-Stokes shifts. Along with the significant light penetration depth and the absence of autofluorescence in biological samples under infrared excitation, these UCNPs have attracted more and more attention on toxin detection and biological labelling. Herein, the fluorescence probe based on UCNPs was developed for quantifying Aflatoxin B1 (AFB1) in peanut oil. Based on a specific immunity format, the detection limit for AFB1 under optimal conditions was obtained as low as 0.2ng·ml(-1), and in the effective detection range 0.2 to 100ng·ml(-1), good relationship between fluorescence intensity and AFB1 concentration was achieved under the linear ratios up to 0.90. Moreover, to check the feasibility of these probes on AFB1 measurements in peanut oil, recovery tests have been carried out. A good accuracy rating (93.8%) was obtained in this study. Results showed that the nanoparticles can be successfully applied for sensing AFB1 in peanut oil.

Arginine-Glycine-Aspartate-Binding Integrins as Therapeutic and Diagnostic Targets.

Arginine-glycine-aspartate (RGD)-binding integrins, including αvß1, αvß3, αvß5, αvß6, αvß8, α5ß1, αIIbß3, and α8ß1, recognize the tripeptide motif RGD in their ligands. RGD-binding integrins are involved in various cell functions, including cell proliferation, survival, differentiation, and motility that are critically important to both health and disease. The diagnostic and therapeutic value of some RGD-binding integrin inhibitors are either clinically proven or at different stages of development. In this review, we first summarized the structure and signaling characteristics of RGD-binding integrins. We then discussed the functions of RGD-binding integrins and their association with human disease. Finally, we recapitulated the research efforts and clinical trials of targeting RGD-binding integrins for the diagnosis and treatment of human disease. This comprehensive review of the current advances in RGD-binding integrins could assist scientists and clinicians in gaining a complete understanding of this group of molecules. It can also contribute to the design of new projects to further advance this field of research and to better apply the research results to benefit patients in clinical practice.

Integrins: players in cancer progression and targets in cancer therapy.

Integrins are a large family of cell surface receptors that bind extracellular matrix proteins. The interaction of integrins with extracellular matrix activates a number of intracellular signaling pathways involved in cell proliferation, differentiation, motility, and other essential cell functions. Integrins are critically important to both health and disease. In this review, we first describe the structure, functions, and signaling characteristics of integrins. We then discuss the roles of integrins in cancer progression. Finally, we recapitulate the laboratory and clinical efforts of targeting integrins as effective means of cancer therapy and diagnosis. This comprehensive review could help scientists and clinicians gain a complete understanding of integrins. It could also contribute toward the development of new drugs, new methods of diagnostics, and new treatment of cancers to benefit the patients in clinical practice.

Association of CD98, integrin ß1, integrin ß3 and Fak with the progression and liver metastases of colorectal cancer.

CD98-mediated ß1 and ß3 integrins activation can induce Fak phosphorylation which eventually promotes cell survival, proliferation, and migration. We evaluated the expression of CD98, integrin ß1, integrin ß3 and Fak in 45 cases of matched colorectal cancer (CRC) and liver metastases as well as 35 cases of CRC without liver metastases. There was a gradual increase of the expression of CD98, integrin ß1, integrin ß3 and Fak as tumor progressed from normal colon to carcinoma to budding tumor cells at the invasive front and to liver metastases. The expression of CD98 and integrin ß1 in CRC with liver metastases was significantly higher than that in CRC without liver metastases. Furthermore, for those liver metastases with desmoplastic growth pattern, expression of CD98, integrin ß1, integrin ß3 and Fak at the metastases center was as strong as that at the metastases periphery. For those liver metastases with pushing or replacement growth patterns, more intense expression of these markers was found at the metastases center than the periphery. Overexpression of CD98, integrin ß1, integrin ß3 and Fak is associated with the progression and liver metastases of CRC. Overexpression of these markers in liver metastases requires direct contact between tumor cells and the stroma.

Riccardin D, a macrocyclic bisbibenzy, inhibits human breast cancer growth through the suppression of telomerase activity.

Riccardin D, a liverwort-derived naturally occurring macrocyclic bisbibenzyl, has been found to exert anticancer effects in multiple cancer cell types. In this study, we investigated the effect and mechanism of Riccardin D on human breast cancer. Experiments were performed on human breast cancer MCF-7 and MDA-MB-231 cells. The antitumour effects of Riccardin D were assessed by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and human breast cancer xenografts mice model. TRAPeze(®) XL Telomerase Detection assay was used for the detection of telomerase activity. γ-H2 AX foci formation was tested for the induction of DNA damage response. Cell cycle distribution was analysed by flow cytometry, and cell apoptosis was determined by annexin V-FITC/PI staining, terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay and Western blotting. Riccardin D effectively inhibited the growth of MCF-7 and MDA-MB-231 cells in vitro. And Riccardin D also effectively delayed the growth of MCF-7 and MDA-MB-231-luc-D3H2LN xenografts without significant loss of body-weight. Further analysis suggested that Riccardin D's effects may arise from its suppression of telomerase activity, which led to telomere dysfunction. Telomerase inhibition and telomere dysfunction could activate the canonical ataxia telangiectasia-mutated (ATM) kinase-mediated DNA damage response, as shown by elevated expression of γ-H2 AX, p-ATM and p-Chk2. This is finally followed by the induction of cell cycle arrest and apoptosis, as shown by the increase of TUNEL-stained cells, caspase activation, PARP cleavage and the increase of bax/bcl-2 ratio. Moreover, Riccardin D induced p53-proficient MCF-7 cells to arrest in G1 phase and p53-deficient MDA-MB-231 cells to arrest in G2/M phase. Overall, these results demonstrate that Riccardin D may inhibit human breast cancer growth through suppression of telomerase activity.

SL-01, an oral gemcitabine derivative, inhibited human cancer growth more potently than gemcitabine.

SL-01, an oral gemcitabine derivative, was synthesized by introducing the moiety of 3-(dodecyloxycarbonyl)pyrazine-2-carbonyl at the N4-position on the cytidine ring of gemcitabine. Our goal in this study was to evaluate the efficacy of SL-01 on the growth of human cancers with gemcitabine as control. Experiments were performed on human non-small cell lung cancer NCI-H460 and colon cancer HCT-116 both in vitro and in vivo. In vitro assays, SL-01 significantly inhibited the growth of cancer cells as determined by the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide (MTT) assay. Further studies indicated that SL-01 induced the cancer cells to apoptosis showing chromatin condensation and externalization of phosphatidylserine. In in vivo studies, we evaluated the efficacy of SL-01 in nude mice bearing human cancer xenografts. SL-01 effectively delayed the growth of NCI-H460 and HCT-116 without significant loss of body weight. Molecular analysis indicated that the high efficacy of SL-01 was associated with its ability to induce apoptosis as evidenced by increase of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining cells, activation of caspase-9, caspase-3 and cleaved poly ADP-ribose polymerase (PARP) in tumor tissues. SL-01 also increased Bax/Bcl-2 ratio in cancer cells. These biological activities of SL-01 were more potential than that of gemcitabine. Based on these in vitro and in vivo results, SL-01 is proposed as a potent oral anticancer agent that may supplant the use of gemcitabine in the clinic.

Synthesis and biological evaluation of oral prodrugs based on the structure of gemcitabine.

A series of oral prodrugs based on the structure of gemcitabine (2',2'-difluorodeoxycytidine) were synthesised by introducing an amide group at the N4-position of the cytidine ring. A total of 16 compounds were obtained, and their chemical and biological characteristics were evaluated. The half-maximal inhibitory concentrations (IC(50)s) for most of these compounds were higher than that of gemcitabine in vitro. Compounds 5d and 5m, the representative compounds, were examined in terms of their physiological stabilities and pharmacokinetics. Compound 5d showed good stability in PBS and simulated intestinal fluid, and an analysis of its pharmacokinetics in mice suggested that the introduction of an amide group to gemcitabine could greatly improve its bioavailability. Further evaluation of compound 5d in vivo showed that this compound possesses higher activity than gemcitabine against the growth of HepG2 human hepatocellular carcinoma cells and HCT-116 colon adenocarcinoma cells with less toxicity to animals. These results suggest that compound 5d could be further developed as a potential oral anticancer agent for clinical applications in which gemcitabine is currently used.

Inhibitory effect of riccardin D on growth of human non-small cell lung cancer: in vitro and in vivo studies.

Riccardin D is a macrocyclic bisbibenzyl compound extracted from liverwort plant Dumortiera hirsuta. Our previous study showed that riccardin D induced apoptosis of human leukemia cells by targeting DNA topoisomerase II (topo II). Riccardin D has been considered as a novel DNA topo II inhibitor and potential chemotherapeutic agent for treatment of cancers. In this study, we evaluated the inhibitory effects of riccardin D on growth of human non-small cell lung cancer (NSCLC) both in vitro and in vivo. Riccardin D effectively inhibited the proliferation of NSCLC cells as estimated by the MTT assay. Further examination showed that the ability of invasion and migration of NSCLC cells was suppressed on exposure to riccardin D as estimated by the assays of scratch and transwell chamber. The anticancer activity of riccardin D was verified in mice bearing human NSCLC H460 xenografts. Riccardin D injection produced a 44.5% inhibition of cancer growth without apparent signs of toxicity to animals. Further, riccardin D induced apoptosis of NSCLC cells as evidenced by the increases of cells with externalization of phosphatidylserine and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive in H460 xenografts. The analysis of apoptotic proteins showed that riccardin D activated the caspases cascade signaling pathway as demonstrated by the increases of cleaved caspase-3 and cleaved PARP in NSCLC cells in vitro and in H460 xenografts in mice. The pBR322 DNA relaxation assay indicated that riccardin D inhibited the activity of DNA topo II in H460 and A549 cells, suggesting the mechanism of riccardin D in induction of NSCLC apoptosis. In addition, we studied the activity and expression of matrix metalloproteinases (MMPs) in NSCLC cells. The activities of MMP-2 and MMP-9 in supernatants of NSCLC cells were suppressed on exposure to riccardin D as estimated by gelatin zymography assay. The inhibitory effects of riccardin D on expressions of MMP-2 and MMP-9 were verified in H460 xenografts in mice and the decreases of vascular endothelial growth factor (VEGF) and Erk1/2 might associate with the inhibition of MMPs and NSCLC growth. Together, our results suggest that riccardin D has a high inhibitory effect on human NSCLC growth through induction of apoptosis.