Proactive therapeutic drug monitoring of vincristine in pediatric and adult cancer patients: current supporting evidence and future efforts.

Vincristine (VCR), an effective antitumor drug, has been utilized in several polytherapy regimens for acute lymphoblastic leukemia, neuroblastoma and rhabdomyosarcoma. However, clinical evidence shows that the metabolism of VCR varies greatly among patients. The traditional based body surface area (BSA) administration method is prone to insufficient exposure to VCR or severe VCR-induced peripheral neurotoxicity (VIPN). Therefore, reliable strategies are urgently needed to improve efficacy and reduce VIPN. Due to the unpredictable pharmacokinetic changes of VCR, therapeutic drug monitoring (TDM) may help to ensure its efficacy and to manage VIPN. At present, there is a lot of supporting evidence for the suitability of applying TDM to VCR therapy. Based on the consensus guidelines drafted by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT), this review aimed to summarize various available data to evaluate the potential utility of VCR TDM for cancer patients. Of note, valuable evidence has accumulated on pharmacokinetics variability, pharmacodynamics, drug exposure-clinical response relationship, biomarkers for VIPN prediction, and assays for VCR monitoring. However, there are still many relevant clinical pharmacological questions that cannot yet be answered merely based on insufficient evidence. Currently, we cannot recommend a therapeutic exposure range and cannot yet provide a dose-adaptation strategy for clinicians and patients. In areas where the evidence is not yet sufficient, more research is needed in the future. The precision medicine of VCR cannot rely on TDM alone and needs to consider the clinical, environmental, genetic background and patient-specific factors as a whole.

Severe Vincristine-Induced Neuropathic Pain: A Case Report with Pharmacogenetic Analysis and Literature Review.

Vincristine-induced peripheral neuropathy (VIPN) is a common adverse effect of vincristine (VCR) for which there is no preventative or curative treatment. Here, we report a case of a patient suffering from severe VCR-related neurotoxicity. To explore the possible causes of severe VIPN in this patient, a set of genes involved in VCR metabolism, transport or are related to the cytoskeleton, microtubules, and inherited neurological diseases gene polymorphisms were examined via pharmacogenetic analyses. The genotyping results revealed the presence of a complex pattern of polymorphisms in CYP3A5, ABCC2, SYNE2, BAHD1, NPSR1, MTNR1B, CEP72, miR-4481 and miR-3117. A comprehensive understanding of all the pharmacogenetic risk factors for VIPN may explain the occurrence of severe neurotoxicity in our patient. This case brings to light the potential importance of pharmacogenetic testing in clinical practice. It also exemplifies the importance of developing early-detection strategies to optimize treatment regimens through prior risk stratification while reducing adverse drug reactions and personalizing therapy.

The Value of Susceptibility-Weighted Imaging (SWI) in Evaluating the Ischemic Penumbra of Patients with Acute Cerebral Ischemic Stroke.

BACKGROUND: The aim of this study was to discuss the value of susceptibility-weighted imaging (SWI) in evaluating the ischemic penumbra of patients with acute cerebral ischemic stroke. METHODS: Data were collected from 52 patients with acute cerebral ischemic stroke upon clinical diagnosis and routine examinations of magnetic resonance imaging (MRI), including SWI, diffusion-weighted imaging (DWI), and perfusion-weighted imaging (PWI) within 72 hours after onset in this retrospective study. The methods also included fusing the DWI and SWI images and calculating the volume of anomaly extension of DWI and PWI-MTT (mean transit time) using semi-automatic analysis software. The SWI-DWI and PWI-DWI mismatches were interpreted, and the statistical analysis was completed. RESULTS: The two physicians found that the ischemic penumbra consistency is high throughout the SWI-DWI and PWI-DWI mismatches, without a significant difference (P > 0.05). CONCLUSION: SWI-DWI mismatch can prevent the injection of contrast agents and make an accurate diagnosis of acute stroke ischemic penumbra, which helps guide the selection of the clinical therapeutic plan.

Vincristine-Induced Peripheral Neuropathy in Childhood Acute Lymphoblastic Leukemia: Genetic Variation as a Potential Risk Factor.

Vincristine (VCR) is the first-line chemotherapeutic medication often co-administered with other drugs to treat childhood acute lymphoblastic leukemia. Dose-dependent neurotoxicity is the main factor restricting VCR's clinical application. VCR-induced peripheral neuropathy (VIPN) sometimes results in dose reduction or omission, leading to clinical complications or affecting the patient's quality of life. With regard to the genetic basis of drug responses, preemptive pharmacogenomic testing and simultaneous blood level monitoring could be helpful for the transformation of various findings into individualized therapies. In this review, we discussed the potential associations between genetic variants in genes contributing to the pharmacokinetics/pharmacodynamics of VCR and VIPN incidence and severity in patients with acute lymphoblastic leukemia. Of note, genetic variants in the CEP72 gene have great potential to be translated into clinical practice. Such a genetic biomarker may help clinicians diagnose VIPN earlier. Besides, genetic variants in other genes, such as CYP3A5, ABCB1, ABCC1, ABCC2, TTPA, ACTG1, CAPG, SYNE2, SLC5A7, COCH, and MRPL47, have been reported to be associated with the VIPN, but more evidence is needed to validate the findings in the future. In fact, a variety of complex factors jointly determine the VIPN. In implementing precision medicine, the combination of genetic, environmental, and personal variables, along with therapeutic drug monitoring, will allow for a better understanding of the mechanisms of VIPN, improving the effectiveness of VCR treatment, reducing adverse reactions, and improving patients' quality of life.

[Changes of Peripheral Blood Marrow-Derived Suppressor Cell Level after Chemotherapy Induction Remission by VDLP Regimen and Their Relationship with Immune System in B-ALL Children].

OBJECTIVE: To investigate the changes of peripheral blood marrow-derived suppressor cell level after chemotherapy induction remission by regimen consisting of vincristine, daunorubicin, L-asparaginase and prednisone (VDLP) and to analyze their relationship with immume system in B-ALL children. METHODS: Thirty B-ALL children after induction remission by VDLP regimen from August 2015 to August 2016 were selected as B-ALL group and 30 normal healthy children were selected as control group. The peripheral blood in 2 groups was collected and detected by flow cytometry, then the ratios of CD30+ cells and CD33+ HLA-DR- marrow-derived suppressor cells, CD14+CD33+HLA-DR- marrow-derived suppressor cells and CD15+CD33+HLA-DR- marrow-derived suppressor cells were calculated, and their changes after induction remission by VDLP regimen and the relationship with immune system were analyzed. RESULTS: After treatment the ratio of CD33+ cells in peripheral blood of B-ALL group and control group was not significantly different (P> 0.05), moreover, the ratio of CD33+ cells in B-ALL group was significantly higher than that before treatment (P<0.05), while the ratios of CD33+ HLA-DR- marrow-derived suppressor cells, CD14+CD33+HLA-DR- marrow-derived suppressor cells and CD15+CD33+HLA-DR- marrow-derived suppressor cells in B-ALL group were significantly lower than those in control group (all P<0.05), but the ratios of these cells in B-ALL group were higher than those before treatment, and yet there was no statistical significance (P>0.05). CONCLUSION: The ratios of marrow-derived suppressor cells in peripheral blood of B-ALL children in complete remission after treatment with VDLP regimen are higher than those before treatment, but are significantly lower than normal value, which may be related with non-complese recovery of immune system in B-ALL children after treatment.

Evaluation of different small bowel contrast agents by multi - detector row CT.

OBJECTIVE: This study aims to evaluate the effects of different oral small bowel contrast agents towards the intestinal dilatation and intestinal wall structure exhibition by the abdominal multi - detector row CT (MDCT) examination. METHODS: 80 patients were performed the whole abdominal CT examination, then randomly divided into four groups, with 20 patients in each group. 45 minutes before the CT examination, the patients were served with a total of 1800 ml pure water, pure milk, dilute lactulose solution and isotonic mannitol solution, respectively. RESULTS: The images were blinded read by two experienced abdominal radiologists in the workstation, the cross-sectional diameters of duodenum, jejunum, proximal and terminal ends of ileum of each patient were measured, then the analysis of variance was performed to analyze the differences in the intestinal dilatation among the experimental groups. The scoring method was used to score the intestinal dilatation and intestinal structure exhibition. The diluted lactulose solution and 2.5% mannitol exhibited the best intestinal dilation degrees. Similarly, the diluted lactulose solution and 2.5% mannitol exhibited the highest scores in the entire small bowel dilatation degree and intestinal structure exhibition. CONCLUSIONS: 2.5% osmotic mannitol and the diluted lactulose solution enabled the full dilatation of small bowel, and could clearly exhibit the wall structure.

[Effects of proteasome inhibitor bortezomib on NF-kappaB activity and ICAM-1 mRNA expression of K562 cells].

This study was aimed to investigate the effects of proteasome inhibitor bortezomib (Velcade, PS-341) on the activation of NF-kappaB and the expression of intercellular adhesion molecule-1 (ICAM-1) in K562 cells. The K562 cells were incubated in the culture of RPMI 1640 with 10% calf serum in 12-well plates and exposed to 0, 10, 20, 30, 50 and 100 nmol/L of bortezomib for 6 hours. The activation of NF-kappaB was analyzed by SP immunohistochemistry, meanwhile RT-PCR was performed to detect expression of ICAM-1. The results showed that the activation of NF-kappaB and the expression of ICAM-1 in K562 cells decreased significantly after bortezomib treatment. The inhibitory effect on ICAM-1 was probably related with the activity suppression of NF-kappaB. It is concluded that proteasome inhibitor bortezomib downregulates the expression of K562 cell ICAM-1 by inhibiting the activity of NF-kappaB, which provides a new way for the target therapy in acute leukemia.

[Effects of As2O3, dexamethasone and thalidomide on apoptosis and cytoplasmic [Ca2+] of myeloma cell line U266].

To investigate the influence of As2O3, dexamethasone (Dex) and thalidomide (Thal) on apoptosis-induced myeloma cell line U266 cytoplasmic calcium concentrations ([Ca2+]i), U266 cells were incubated in the culture of RPMI 1640 with 15% FBS in 24-well plate and exposed to different concentrations of As2O3, Dex and Thal for 8 hours, respectively, then cell apoptosis was analyzed by fluorescence microscopy and flow cytometry (FCM) with Annexin V-FITC/PI double staining, and cytoplasmic free calcium were detected on FCM through Fluo-3/AM loading. The results indicated that (1) apoptotic cells were gradually increased with enhancement of As2O3, Dex and Thal concentrations; (2) apoptotic cell rates increased from 0.56% in control to 31.54%, 28.35% and 21.97% respectively after treatment with As2O3, Dex and Thal; (3) As2O3, Dex induced U266 cell apoptosis accompanied with raise of [Ca2+]i; (4) [Ca2+]i had no statistically significant changes in Thal-induced apoptotic U266 cells. It is concluded that the raise of [Ca2+]i is one of the mechanisms for As2O3 and Dex-induced U266 cells apoptosis, whereas Thal-induced U266 apoptosis has no significant relation to [Ca2+]i changes.