Simultaneous online SPE-HPLC-MS/MS quantification of gefitinib, osimertinib and icotinib in dried plasma spots: Application to therapeutic drug monitoring in patients with non-small cell lung cancer.

Gefitinib, osimertinib and icotinib are the most commonly used tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) with EGFR mutation. Therapeutic drug monitoring (TDM) for these TKIs has become a standard and essential procedure. Dried plasma spots (DPS) was choosen for microsampling strategies for TDM, allowing easy and cost-effective logistics in many settings. This study developd and validated an assay for the simultaneous quantitative determination of gefitinib, osimertinib and icotinib in DPS by online solid-phase extraction-liquid chromatography-tandem mass spectrometry (online SPE-LC-MS) system. The TKIs were extracted from DPS with methanol and enriched on a Welch Polar-RP SPE column (30 × 4.6 mm, 5 µm), followed by separation on Waters X Bridge C18 analytical column(4.6 × 100 mm, 3.5 µm). The method achieved LLOQ of 2 ng mL-1 for gefitinib and osimertinib (4 ng mL-1 for icotinib), respectively (r2 > 0.99). Precision (within-run 1.54-7.41 % RSD; between-run 3.03-12.84 % RSD), accuracy (range from 81.47 % to 105.08 %; between-run bias 87.87-104.13 %). Osimertinib and icotinib were stable in DPS stored at - 40 °C for 30 days, 4 °C, 42 °C and 60 °C for 5 days and well-sealed 37 °C,75 % humidity (except gefitinib). Lastly, the assay was applied to TDM of TKIs in 46 patients and the results were compared to SALLE assisted LC-MS analysis, it could be confirmed that the developed method achieves similarly good results as the already established one and no bias could be detected. It implies that this method capable of supporting clinical follow-up TDM of TKIs in DPS from poor medical environment.

A systematic comparison of anti-angiogenesis efficacy and cardiotoxicity of receptor tyrosine kinase inhibitors in zebrafish model.

Pathological angiogenesis is fundamental to progression of cancerous tumors and blinding eye diseases. Anti-angiogenic receptor tyrosine kinase inhibitors (TKIs) are in broad use for the treatment of these diseases. With more and more TKIs available, it is a challenge to make an optimal choice. It remains unclear whether TKIs demonstrate similar anti-angiogenesis activities in different tissues. Many TKIs have shown varying degrees of toxic effects that should also be considered in clinical use. This study investigates the anti-angiogenic effects of 13 FDA-approved TKIs on the intersegmental vessels (ISVs), subintestinal vessels (SIVs) and retinal vasculature in zebrafish embryos. The results show that vascular endothelial growth factor receptor TKIs (VEGFR-TKIs) exhibit anti-angiogenic abilities similarly on ISVs and SIVs, and their efficacy is consistent with their IC50 values against VEGFR2. In addition, VEGFR-TKIs selectively induces the apoptosis of endothelial cells in immature vessels. Among all TKIs tested, axitinib demonstrates a strong inhibition on retinal neovascularization at a low dose that do not strongly affect ISVs and SIVs, supporting its potential application for retinal diseases. Zebrafish embryos demonstrate cardiotoxicity after VEGFR-TKIs treatment, and ponatinib and sorafenib show a narrow therapeutic window, suggesting that these two drugs may need to be dosed more carefully in patients. We propose that zebrafish is an ideal model for studying in vivo antiangiogenic efficacy and cardiotoxicity of TKIs.

Simultaneous and rapid determination of 12 tyrosine kinase inhibitors by LC-MS/MS in human plasma: Application to therapeutic drug monitoring in patients with non-small cell lung cancer.

In recent years, more than 50 tyrosine kinase inhibitors (TKIs) was indicated against numerous cancers, especially outstanding advantages in the treatment of non-small cell lung cancer (NSCLC), and several studies have shown that therapeutic drug monitoring (TDM) of TKIs can improve treatment efficacy and safety. The present study aimed to develop and validate a LC-MS/MS method for the TDM of 12 TKIs (gefitinib, erlotinib, afatinib, dacomitinib, icotinib, osimertinib, crizotinib, ceritinib, alectinib, dabrafenib, trametinib, anlotinib) in patients with NSCLC. The analytes of interest and internal standard were extracted from human plasma. Salting-out assisted liquid-liquid extraction (SALLE) with 5 M ammonium acetate solution was optimized for method validation and compared to simple protein precipitation (PPT). Chromatographic separation was conducted on Waters X bridge C18 column (100 × 4.6 mm, 3.5 µm) using a gradient elution of acetonitrile/5mM ammonium acetate in pure water with 0.1% (v/v) formic acid at 40 °C within 6 min. The total flow was maintained at 1 mL/min, 30% of the post column flow was split into the mass spectrometer and the rest to waste via a 3-way tee. The mass analysis was performed by positive ion electrospray ionization (ESI) in multiple-reaction monitoring (MRM) mode. The assay was validated based on the guidelines on bioanalytical methods by FDA. This quantification method was proved to be satisfactory in selectivity, accuracy, precision, linearity (r2 > 0.995), recovery, matrix effect and stability and the accuracy was further assessed in plasma with a degree of hemolysis of 4%. The described method to simultaneously quantify the 12 selected anticancer drugs in human plasma was successfully validated and applied to routine TDM of gefitinib, erlotinib, icotinib, osimertinib, crizotinib and anlotinib in cancer patients. TKIs plasma monitoring helps to individualize dose adjustment and manage adverse effects in NSCLC patients.

Association of endothelin-1 gene single-nucleotide polymorphisms and haplotypes with risk of hormone refractory prostate cancer.

Androgen deprivation is often the treatment of choice for patients with a new diagnosis of metastatic or locally advanced prostate cancer (CaP). However, most CaP patients showing a first response to androgen deprivation will progress to a hormone refractory phase of the disease (HRPC) with a much poorer prognosis. Accumulating evidence suggests that endothelin-1 (ET-1) plays an important role in CaP progression. Singlenucleotide polymorphisms (SNPs) of the ET-1 gene reportedly have been associated with cancer progression and chemoresistance. In the present study, we explored the association of SNPs and haplotypes of the ET-1 gene with the risk of HRPC. We genotyped three SNPs (rs1800541, rs2070699 and rs5370) in the ET-1 gene in a case-control study; 234 CaP patients who developed HRPC within six years after androgen deprivation therapy was used as HRPC cases, and 234 age- and primary therapy-matched CaP patients who had not developed HRPC within six years after androgen deprivation therapy were used as non-HRPC controls. Our results revealed that the G allele at rs1800541 and the G allele at rs2070699 were respectively associated with reduced and increased risk of HRPC at borderline statistical significance (p=0.047 and p=0.058, respectively). With adjustment for potential confounders including body mass index, initial Gleason score at diagnosis of CaP, and post-treatment nadir serum PSA level, we found that rs1800541-rs2070699 TG haplotype was significantly associated with increased risk of HRPC (p=0.033; adjusted OR, 2.10; 95% CI, 1.37-5.04). In conclusion, this study provides the first evidence that a 2-SNP haplotype of the ET-1 gene is associated with increased risk of HRPC, which adds new insights into early identification of CaP patients who are likely to develop HRPC in a later stage of the disease.

Nucleotidyl transferase TUT1 inhibits lipogenesis in osteosarcoma cells through regulation of microRNA-24 and microRNA-29a.

Osteosarcoma is the most common type of bone cancer. In the present study, by way of PCR-based microarrays, we found that TUT1, a nucleotidyl transferase, was significantly downregulated in osteosarcoma, compared with adjacent normal tissues. In the current study, we performed PCR-based microarrays using the cDNA prepared from osteosarcoma and adjacent normal tissues. The enforced expression of TUT1 was able to inhibit cell proliferation in U2OS and MG63 cells, while its knockdown using small interfering RNA (siRNA) oligos promoted cell proliferation. At the molecular level, we found that TUT1 could inhibit the expression levels of PPARgamma and SREBP-1c, two key regulators in lipogenesis, through upregulation of microRNA-24 and microRNA-29a. Therefore, our results suggest that TUT1 may act as a tumor suppressor for osteosarcoma, which might provide a novel mechanism for the tumor development.

FOXO1 Up-Regulates Human L-selectin Expression Through Binding to a Consensus FOXO1 Motif.

L-selectin plays important roles in lymphocyte homing and leukocyte rolling. Mounting evidence shows that it is involved in many disease entities including diabetes, ischemia/reperfusion injuries, inflammatory diseases, and tumor metastasis. Regulation of L-selectin at protein level has been well characterized. However, the regulation of human L-selectin transcription remains largely unknown. To address transcriptional regulation of L-selectin, we cloned 1088 bp 5' of the start codon ATG. Luciferase analysis of the serial 5' deletion mutants located the core promoter region at -288/-1. A major transcription initiation site was mapped at -115 by 5'RACE. Transcription factors Sp1, Ets1, Mzf1, Klf2, and Irf1 bind to and transactivate the L-selectin promoter. Significantly, FOXO1 binds to a FOXO1 motif, CCCTTTGG, at -87/-80, and transactivates the L-selectin promoter in a dose-dependent manner. Over-expression of a constitutive-active FOXO1 increased the endogenous L-selectin expression in Jurkat cells. We conclude that FOXO1 regulates L-selectin expression through targeting its promoter.

FASLG polymorphism is associated with cancer risk.

Many studies have reported the association between the FASLG -844T/C polymorphism and cancer risk, but the data are remaining controversial. A pooled analysis was performed to assess this relationship comprehensively. Medline, PubMed, Embase and Web of Science were searched, and data were extracted and cross-checked independently by three authors. A total of 18 published studies including 22389 subjects were involved in this analysis. Overall, the -844C allele was associated with a significantly increased cancer risk (for CC versus TT: OR=1.23, 95% confidence interval (CI)=1.04-1.45; for CC+TC versus TT: OR=1.15, 95% CI=1.01-1.30; for CC versus TT+TC: OR=1.20, 95% CI=1.05-1.38). In the subgroup analysis by ethnicity, significantly elevated risks were found among Asians (for CC versus TT: OR=1.61, 95% CI=1.37-1.89; for CC+TC versus TT: OR=1.36, 95% CI=1.16-1.60; for CC versus TT+TC: OR=1.44, 95% CI=1.22-1.70). In the subgroup analysis by study design, significantly increased risks were found among population-based case-control studies (for CC versus TT: OR=1.40, 95% CI=1.06-1.84; for CC+TC versus TT: OR=1.25, 95% CI=1.01-1.55; for CC versus TT+TC: OR=1.31, 95% CI=1.06-1.61). These findings indicate that the FASLG -844C allele is emerging as a low-penetrant cancer susceptibility allele for cancer development. However, more comprehensive understanding of the association would certainly have an immense prospect in the promising field of individualised preventive care.