Denosumab-induced hypocalcemia in patients with solid tumors and renal dysfunction: a multicenter, retrospective, observational study.

BACKGROUND: Bone metastases are frequently observed in advanced cancer, and bone modifying agents are used to prevent or treat skeletal-related events. Zoledronic acid is contraindicated in patients with severe renal impairment (Ccr < 30 mL/min), but it is not completely known whether denosumab can be used in them. We aimed to determine the association between renal function and hypocalcemia development during denosumab treatment. METHODS: We included patients with solid cancer and bone metastases who started denosumab treatment between April 2017 and March 2019. They were classified into four groups based on creatinine clearance (Ccr; mL/min): normal (Ccr ≥ 80), mild (50 ≤ Ccr ˂80), moderate (30 ≤ Ccr ˂50), and severe (Ccr ˂30). Hypocalcemia was evaluated using the Common Terminology Criteria for Adverse Events (v5.0) based on the albumin-adjusted serum calcium levels; its incidence (stratified by renal function) and risk factors were investigated using a Chi-square test and logistic regression analysis. RESULTS: Of 524 patients (age: 69 ± 11 years; 303 men), 153 had a normal renal function and 222, 117, and 32 had mild, moderate, and severe renal dysfunction. The albumin-adjusted serum calcium level was higher than the measured (total) calcium level in most patients. The incidence of grade ≥ 1 hypocalcemia was 32.0% in the normal group and 37.4%, 29.9%, and 62.5% in the mild, moderate, and severe renal dysfunction groups, respectively. It was, therefore, higher in the severe renal dysfunction groups than in the normal group (P = 0.002). The incidence of grade ≥ 3 hypocalcemia did not differ significantly among the groups. Pre-treatment low serum calcium levels and severe renal dysfunction were risk factors for hypocalcemia. CONCLUSIONS: Evaluating denosumab-induced hypocalcemia required albumin adjustment, and its incidence was high among patients with severe renal dysfunction. Reduced serum calcium levels and severely impaired renal function were associated with an elevated hypocalcemia risk.

Anti-UV activity of lignin-carbohydrate complex and related compounds.

BACKGROUND: We recently reported that an alkaline extract of the leaves of Sasa senanensis Rehder (SE) and Lentinus edodes mycelia extract (LEM), exhibiting lignin-carbohydrate complex (LCC)-like activity, protected cells from UV-induced injury (referred to as anti-UV activity). We investigated whether LCC is the major active components responsible for anti-UV activity. MATERIALS AND METHODS: Human oral squamous cell carcinoma HSC-2 cells were exposed to short UV irradiation in phosphate-buffered saline, containing different concentrations of LCC. After culturing for 48 h in fresh culture medium, the viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. From the dose-response curve, the 50% cytotoxic concentration (CC(50)) and the concentration that increased the viability of the UV-irradiated cells to 50% of the control value (EC(50)) were determined. The selectivity index (SI) was determined by the following equation: SI=CC(50)/EC(50). RESULTS: LCCs (Fr. VI) of pine cones and seed shell, and sulfated LCC exhibited relatively high anti-UV activity (SI=7.1-38), compared with that of SE and LEM. LCCs with lower lignin content (Fr. VII) exhibited anti-UV activity, approximately one half that of Fr. VI. However, polysaccharides (laminarin, pullulan, dextran) introduced with dimethylaminoethyl- or sulfate groups with different substitution ratios were totally inactive (SI<1). The introduction of a sulfate group to LCC did not enhance the anti-UV activity of LCC. Sodium ascorbate and vanillin were the most active (SI=65), whereas gallic acid (SI=5), epigallocatechin gallate (SI=2.6), ar-trumeron (SI<1), and turmeric extract (SI<1) were much less active. CONCLUSION: The prominent anti-UV activity of SE and LEM seems to be generated by LCCs present in the extract.

Analysis of type of cell death induced by topoisomerase inhibitor SN-38 in human oral squamous cell carcinoma cell lines.

Despite frequent use of topoisomerase inhibitors (TIs) as antitumor agents, their application to oral squamous cell carcinoma (OSCC) has not been reported. We investigated three inhibitors of topoisomerase I [camptothecin, irinotecan, SN-38 (active metabolite of irinotecan)] and two inhibitors of topoisomerase II (etoposide, teniposide) for their cytotoxicity towards a total of 15 human tumor cell lines and normal cultured cells. All TIs exhibited higher cytotoxicity towards tumor cell lines (OSCC, glioblastoma, myelogenous leukemia) as compared with normal mesenchymal (gingival fibroblast, pulp cell, periodontal ligament fibroblast) and epithelial cells (skin keratinocytes). Among TIs, SN-38 had the highest cytotoxicity towards OSCC cell lines, with a tumor specificity index of 1321 compared to mesenchymal cells and 22 compared with epithelial cells. SN-38 induced different types of cell death in two OSCC cell lines: apoptosis (caspase-3 activation and internucleosomal DNA fragmentation) in HSC-2 cells and autophagy (formation of autophagosome and secondary lysosome) in HSC-4 cells. The cell death of HSC-2 and HSC-4 cells was significantly inhibited by pre-treatment with caspase inhibitor (Z-VAD-FMK) and autophagy inhibitors (3-methyladenine, bafilomycin A1), respectively. The present study demonstrated that SN-38 is highly cytotoxic to OSCC cell lines, regardless of the type of induced cell death, suggesting its future application for chemotherapy of OSCC.

Protection against copper-induced cytotoxicity by inclusion of gold.

BACKGROUND: We previously reported that contact with copper (Cu) induced immediate cell death via an oxidation-involved mechanism, and the Cu-induced oxidation and cell death were effectively alleviated under hypoxic conditions. In order to explore alternative strategies for the protection from the Cu-induced cytotoxicity, we investigated whether the inclusion of gold (Au) in the Cu plate, as alloy,has a protective effect. MATERIALS AND METHODS: Human gingival fibroblast (HGF) cells, established from periodontal tissues, were inoculated on Au/Cu alloy of different Au ratios. After incubation at 37°C for different times under normoxic conditions, cellular viability and amino acid consumption were determined. Changes in the elemental composition of the alloy and in the culture medium were chemically analyzed by X-ray photoelectron spectroscopy and by inductively coupled plasma-optical emission spectrometry. RESULTS: Contact with the Cu plate induced cytotoxicity and cystine oxidation in time-dependent manners. Inclusion of Au at more than 10% in the alloy, completely abrogated the cytotoxicity and reduced the oxidation of Cu and the elution of Cu from the alloy. CONCLUSION: Inclusion of Au as a component of alloy reduces the cytotoxicity of the Cu plate, possibly by reducing its oxidation.

Suitability of chemiluminescent enzyme immunoassay for the measurement of blood tacrolimus concentrations in rheumatoid arthritis.

OBJECTIVES: The aim of this study was to evaluate the suitability of chemiluminescent enzyme immunoassay (CLIA) for the monitoring of whole-blood tacrolimus concentrations in rheumatoid arthritis (RA) patients. DESIGN AND METHODS: Sixty-three RA patients and 47 renal transplant (RT) patients treated with tacrolimus were enrolled. Tacrolimus concentrations in spiked blood and patient blood were measured by CLIA and HPLC-MS/MS. The cross-reactivity in CLIA was evaluated using 13-O-demethylated or 31-O-demethylated tacrolimus. RESULTS: Tacrolimus concentrations measured by CLIA correlated with those measured by HPLC-MS/MS. Bland-Altman analysis revealed the 95% confidence intervals between CLIA and HPLC-MS/MS in RA and RT patients were -20.7 to 109.9% and -5.0 to 74.1%, respectively. While 31-O-demethylated tacrolimus cross-reaction amounted to an equivalent of 120% tacrolimus in CLIA, 13-O-demethylated tacrolimus did not cross-react. CONCLUSION: CLIA values should be carefully interpreted in RA patients, especially those receiving a low dose of tacrolimus.

Interferon-alpha-induced mTOR activation is an anti-hepatitis C virus signal via the phosphatidylinositol 3-kinase-Akt-independent pathway.

OBJECT: The interferon-induced Jak-STAT signal alone is not sufficient to explain all the biological effects of IFN. The PI3-K pathways have emerged as a critical additional component of IFN-induced signaling. This study attempted to clarify that relationship between IFN-induced PI3-K-Akt-mTOR activity and anti-viral action. RESULT: When the human normal hepatocyte derived cell line was treated with rapamycin (rapa) before accretion of IFN-alpha, tyrosine phosphorylation of STAT-1 was diminished. Pretreatment of rapa had an inhibitory effect on the IFN-alpha-induced expression of PKR and p48 in a dose dependent manner. Rapa inhibited the IFN-alpha inducible IFN-stimulated regulatory element luciferase activity in a dose-dependent manner. However, wortmannin, LY294002 and Akt inhibitor did not influence IFN-alpha inducible luciferase activity. To examine the effect of PI3-K-Akt-mTOR on the anti-HCV action of IFN-alpha, the full-length HCV replication system, OR6 cells were used. The pretreatment of rapa attenuated its anti-HCV replication effect in comparison to IFN-alpha alone, whereas the pretreatment with PI3-K inhibitors, wortmannin and LY294002 and Akt inhibitor did not influence IFN-induced anti-HCV replication. CONCLUSION: IFN-induced mTOR activity, independent of PI3K and Akt, is the critical factor for its anti-HCV activity. Jak independent mTOR activity involved STAT-1 phosphorylation and nuclear location, and then PKR is expressed in hepatocytes.

Differential effects of calcineurin inhibitors, tacrolimus and cyclosporin a, on interferon-induced antiviral protein in human hepatocyte cells.

The premise of our study is that selective inhibition of interferon (IFN) by calcineurin inhibitors contribute to the increased severity of hepatitis C virus (HCV) posttransplantation. Therefore, we examined the influence of calcineurin inhibitors in the human hepatocyte cell line on IFN-alpha-induced phosphorylation of Janus kinase (Jak) and signal transducers and activators of transcription (STAT), nuclear translocation of IFN-stimulated gene factor 3 (ISGF-3), IFN-stimulated regulatory element (ISRE)-contained promoter activity, and the expressions of antiviral proteins. Tacrolimus (Tac), but not cyclosporin A (CyA), had an inhibitory effect on IFN-alpha-induced double-stranded ribonucleic acid (RNA)-dependent protein kinase (PKR) in a dose-dependent manner. STAT-1 also acted in a similar fashion to PKR. IFN-alpha combined with Tac attenuated the ISRE-containing promoter gene activity as compared with IFN-alpha alone. In contrast, its expression in pretreated CyA was slightly attenuated. In pretreated Tac, but not CyA, the levels of IFN-alpha-induced tyrosine phosphorylated STAT-1 and -2 were clearly lower than those induced by IFN-alpha alone. Tac and CyA did not decrease the IFN-alpha-induced JAK-1 phosphorylation. The nuclear translocation rate of tyrosine phosphorylated STAT-1 was inhibited by pretreatment of both Tac and CyA by western blotting and immunohistochemistry. In an HCV replicon system, pretreated Tac diminished the replication inhibitory effect of IFN-alpha. In this study, we show that calcineurin inhibitors, especially Tac, are the negative regulators of IFN signaling in the hepatocyte; the greatest cause of such inhibition is the phosphorylation disturbance of STAT-1, next to inhibition of the nuclear translocation of STAT-1. In conclusion, disturbance of tyrosine phosphorylation of STAT-1 resulted in diminished ISRE-containing promoter activity and a decline in antiviral protein expression. Moreover, the replication of HCV was activated. This phenomenon is detrimental to IFN therapy after liver transplantation, and the selection of calcineurin inhibitors may warrant further discussion depending on the transplant situation.