Vincristine Disposition and Neurotoxicity Are Unchanged in Humanized CYP3A5 Mice.

Previous studies have suggested that the incidence of vincristine-induced peripheral neuropathy (VIPN) is potentially linked with cytochrome P450 (CYP)3A5, a polymorphic enzyme that metabolizes vincristine in vitro, and with concurrent use of azole antifungals such as ketoconazole. The assumed mechanism for these interactions is through modulation of CYP3A-mediated metabolism, leading to decreased vincristine clearance and increased susceptibility to VIPN. Given the controversy surrounding the contribution of these mechanisms, we directly tested these hypotheses in genetically engineered mouse models with a deficiency of the entire murine Cyp3a locus [Cyp3a(-/-) mice] and in humanized transgenic animals with hepatic expression of functional and nonfunctional human CYP3A5 variants. Compared with wild-type mice, the systemic exposure to vincristine was increased by only 1.15-fold (95% confidence interval, 0.84-1.58) in Cyp3a(-/-) mice, suggesting that the clearance of vincristine in mice is largely independent of hepatic Cyp3a function. In line with these observations, we found that Cyp3a deficiency or pretreatment with the CYP3A inhibitors ketoconazole or nilotinib did not influence the severity and time course of VIPN and that exposure to vincristine was not substantially altered in humanized CYP3A5*3 mice or humanized CYP3A5*1 mice compared with Cyp3a(-/-) mice. Our study suggests that the contribution of CYP3A5-mediated metabolism to vincristine elimination and the associated drug-drug interaction potential is limited and that plasma levels of vincristine are unlikely to be strongly predictive of VIPN. SIGNIFICANCE STATEMENT: The current study suggests that CYP3A5 genotype status does not substantially influence vincristine disposition and neurotoxicity in translationally relevant murine models. These findings raise concerns about the causality of previously reported relationships between variant CYP3A5 genotypes or concomitant azole use with the incidence of vincristine neurotoxicity.

Impact of low- or moderate-risk gonadotoxic chemotherapy prior to testicular tissue freezing on spermatogonia quantity in human (pre)pubertal testicular tissue.

STUDY QUESTION: What is the impact of low- or moderate-risk gonadotoxic chemotherapy received prior to testicular tissue freezing (TTF), and of the cancer itself, on spermatogonia quantity in testicular tissue from (pre)pubertal boys? SUMMARY ANSWER: Vincristine, when associated with alkylating agents, has an additional adverse effect on spermatogonia quantity, while carboplatin has no individual contribution to spermatogonia quantity, in testicular tissue of (pre)pubertal boys, when compared to patients who have received non-alkylating chemotherapy. WHAT IS KNOWN ALREADY: The improved survival rates after cancer treatment necessitate the inclusion of fertility preservation procedures as part of the comprehensive care for patients, taking into consideration their age. Sperm cryopreservation is an established procedure in post-pubertal males while the TTF proposed for (pre)pubertal boys remains experimental. Several studies exploring testicular tissue of (pre)pubertal boys after TTF have examined the tubular fertility index (TFI, percentage of seminiferous tubule cross-sections containing spermatogonia) and the number of spermatogonia per seminiferous tubule cross-section (S/T). All studies have demonstrated that TFI and S/T always decrease after the introduction of chemotherapeutic agents, especially those which carry high gonadotoxic risks such as alkylating agents. STUDY DESIGN, SIZE, DURATION: Testicular tissue samples from 79 (pre)pubertal boys diagnosed with cancer (from 6 months to 16 years of age) were cryopreserved between May 2009 and June 2014. Their medical diagnoses and previous chemotherapy exposures were recorded. We examined histological sections of (pre)pubertal testicular tissue to elucidate whether the chemotherapy or the primary diagnosis affects mainly TFI and S/T. PARTICIPANTS/MATERIALS, SETTING, METHODS: (Pre)pubertal boys with cancer diagnosis who had been offered TTF prior to conditioning treatment for hematopoietic stem cell transplantation were included in the study. All the patients had previously received chemotherapy with low- or moderate-risk for future fertility. We have selected patients for whom the information on the chemotherapy received was complete. The quantity of spermatogonia and quality of testicular tissue were assessed by both morphological and immunohistochemical analyses. MAIN RESULTS AND THE ROLE OF CHANCE: A significant reduction in the number of spermatogonia was observed in boys treated with alkylating agents. The mean S/T values in boys exposed to alkylating agents were significantly lower compared to boys exposed to non-alkylating agents (P = 0.018). In contrast, no difference was observed for patients treated with carboplatin as the sole administered alkylating agent compared to the group of patients exposed to non-alkylating agents. We observed an increase of S/T with age in the group of patients who did not receive any alkylating agent and a decrease of S/T with age when patients received alkylating agents included in the cyclophosphamide equivalent dose (CED) formula (r = 0.6166, P = 0.0434; r = -0.3759, P = 0.0036, respectively). The TFI and S/T decreased further in the group of patients who received vincristine in combination with alkylating agents (decrease of 22.4%, P = 0.0049 and P < 0.0001, respectively), but in this group the CED was also increased significantly (P < 0.0001). Multivariate analysis, after CED adjustment, showed the persistence of a decrease in TFI correlated with vincristine administration (P = 0.02). LIMITATIONS, REASONS FOR CAUTION: This is a descriptive study of testicular tissues obtained from (pre)pubertal boys who were at risk of infertility. The study population is quite heterogeneous, with a small number of patients in each sub-group. Our results are based on comparisons between patients receiving alkylating agents compared to patients receiving non-alkylating agents rather than chemotherapy-naive patients. The French national guidelines for fertility preservation in cancer patients recommend TTF before highly gonadotoxic treatment. Therefore, all the patients had received low- or moderate-risk gonadotoxic chemotherapy before TTF. Access to testicular tissue samples from chemotherapy-naive patients with comparable histological types of cancer was not possible. The functionality of spermatogonia and somatic cells could not be tested by transplantation or in vitro maturation due to limited sample sizes. WIDER IMPLICATIONS OF THE FINDINGS: This study summarizes the spermatogonial quantity of (pre)pubertal boys prior to TTF. We confirmed a negative correlation between the cumulative exposure to alkylating agents and spermatogonial quantity. In addition, the synergistic use of vincristine in combination with alkylating agents showed a cumulative deleterious effect on the TFI. For patients for whom fertility preservation is indicated, TTF should be proposed for chemotherapy with a predicted CED above 4000 mg/m2. However, the data obtained from vincristine and carboplatin use should be confirmed in a subsequent study including more patients. STUDY FUNDING/COMPETING INTEREST(S): This study had financial support from a French national research grant PHRC No. 2008/071/HP obtained by the French Institute of Cancer and the French Healthcare Organization. The sponsors played no role in the study. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Simultaneous quantification and pharmacokinetics of vincristine and its major metabolite M1 in Chinese pediatric ALL patients by LC-MS/MS.

Vincristine (VCR) is a vital component in numerous treatment regimens for pediatric blood cancer. VCR-induced peripheral neuropathy (VIPN) represents a type of VCR toxicity influenced by multiple factors, including age, race, genetic traits, dosage, interactions, and administration regimen. However, the dose-response relationship of VIPN remains elusive. VCR is primarily metabolized by cytochrome P450 (CYP) 3 A to generate the major metabolite M1. To date, there is a lack of literature documenting the pharmacokinetics (PK) characteristics of VCR and M1 in Chinese children within a 96 h timeframe. To address the gap, a developed LC-MS/MS method was successfully employed in the PK study of VCR and M1 in Chinese pediatric acute lymphoblastic leukemia (ALL) patients. M1 was obtained through in vitro metabolism experiments, and mixed plasma samples of M1 and VCR were prepared. Plasma samples were pre-processed using the solid-phase extraction (SPE) technique. Samples were loaded into ProElut C18 Cartridges, washed with 5% methanol aqueous solution, and eluted with methanol. The eluent was concentrated and reconstituted for liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The standard calibration curves for VCR and M1 were 0.1-50 ng/mL and 0.05-5 ng/mL, respectively, with linear coefficients exceeding 0.99. Accuracy and precision of quality control (QC) samples fell within 115%. The analytical approach satisfied the quantitative demands for VCR and M1 in plasma samples within 96 h. VCR was metabolized to M1 at a relatively constant proportion (5.37%-18.06%) of VCR in vivo. No significant differences were observed in PK parameters of VCR in Chinese children compared to other countries and races. Further investigation is required to identify the key factors influencing VIPN in Chinese children.

STAT1/3 signaling suppresses axon degeneration and neuronal cell death through regulation of NAD+-biosynthetic and consuming enzymes.

Nicotinamide adenine dinucleotide (NAD)+-biosynthetic and consuming enzymes are involved in various intracellular events through the regulation of NAD+ metabolism. Recently, it has become clear that alterations in the expression of NAD+-biosynthetic and consuming enzymes contribute to the axonal stability of neurons. We explored soluble bioactive factor(s) that alter the expression of NAD+-metabolizing enzymes and found that cytokine interferon (IFN)-γ increased the expression of nicotinamide nucleotide adenylyltransferase 2 (NMNAT2), an NAD+-biosynthetic enzyme. IFN-γ activated signal transducers and activators of transcription 1 and 3 (STAT1/3) followed by c-Jun N-terminal kinase (JNK) suppression. As a result, STAT1/3 increased the expression of NMNAT2 at both mRNA and protein levels in a dose- and time-dependent manner and, at the same time, suppressed activation of sterile alpha and Toll/interleukin receptor motif-containing 1 (SARM1), an NAD+-consuming enzyme, and increased intracellular NAD+ levels. We examined the protective effect of STAT1/3 signaling against vincristine-mediated cell injury as a model of chemotherapy-induced peripheral neuropathy (CIPN), in which axonal degeneration is involved in disease progression. We found that IFN-γ-mediated STAT1/3 activation inhibited vincristine-induced downregulation of NMNAT2 and upregulation of SARM1 phosphorylation, resulting in modest suppression of subsequent neurite degradation and cell death. These results indicate that STAT1/3 signaling induces NMNAT2 expression while simultaneously suppressing SARM1 phosphorylation, and that both these actions contribute to suppression of axonal degeneration and cell death.

Do Fungicides Affect Alkaloid Production in Catharanthus roseus (L.) G. Don. Seedlings?

The presence of endophytes in plants is undeniable, but how significant their involvement is in the host plant biosynthetic pathways is still unclear. The results reported from fungicide treatments in plants varied. Fungicide treatment in Taxus was found to decrease the taxol content. In Ipomoea asarifolia, Pronto Plus and Folicur treatments coincided with the disappearance of ergot alkaloids from the plant. In Narcissus pseudonarcissus cv. Carlton, a mixture of fungicide applications decreased the alkaloids concentration and altered the carbohydrate metabolism. Jacobaea plants treated with Folicur reduced the pyrrolizidine alkaloids content. There have not been any studies into the involvement of endophytic fungi on alkaloids production of Catharanthus roseus until now. Though there is a report on the isolation of the endophytic fungi, Fusarium oxysporum from C. roseus, which was reported to produce vinblastine and vincristine in vitro. To detect possible collaborations between these two different organisms, fungicides were applied to suppress the endophytic fungi in seedlings and then measure the metabolomes by 1HNMR and HPLC analysis. The results indicate that endophytic fungi were not directly involved in alkaloids biosynthesis. Treatment with fungicides influenced both the primary and secondary metabolism of C. roseus. The systemic fungicides Pronto Plus and Folicur caused an increase in loganin and secologanin levels. In contrast, control samples had higher level of catharanthine and vindoline. This means that fungicide treatments cause changes in plant secondary metabolism.

Establishment of recombinant Catharanthus roseus stem cells stably overexpressing ORCA4 for terpenoid indole alkaloids biosynthesis.

Catharanthus roseus is a perennial herb of the Apocynaceae family, from which about 200 kinds of alkaloids have been characterized. Most alkaloids from C. roseus are terpenoid indole alkaloids (TIAs), such as vinblastine and vincristine, which are widely used in the clinic for their good antitumor activity. However, they were only biosynthesized in C. roseus, and their content in C. roseus is extremely low. The access to these valuable compounds is by plant extraction or chemical semisynthesis from their precursors catharanthine and vindoline. Since catharanthine and vindoline are also obtained from C. roseus, the supply of vinblastine and vincristine makes it difficult to meet market demands. Therefore, how to improve the yield of TIAs is an attractive issue. In this study, we compared the regulatory effect of two critical transcription factors, octadecanoid-derivative responsive Catharanthus AP2-domain protein 3 (ORCA3) and octadecanoid-derivative responsive Catharanthus AP2-domain protein 4 (ORCA4), on the biosynthesis of TIAs in C. roseus. The results showed that overexpressing both two transcription factors could increase the accumulation of TIAs. The effect was more significant when ORCA4 was overexpressed. To acquire C. roseus TIAs on a continuous and consistent basis, we then created and acquired C. roseus stem cells stably overexpressing ORCA4. This is the first time a recombinant C. roseus stem cell system with stable ORCA4 overexpression has been developed, which not only provides new ideas for future research in this area but also breaches new life into the industrial application of using plant cell culture to obtain natural products.

Treg-selective IL-2 starvation synergizes with CD40 activation to sustain durable responses in lymphoma models.

BACKGROUND: Roughly half of all diffuse large B-cell lymphomas (DLBCLs) are infiltrated by large numbers of regulatory T-cells (Tregs). Although the presence of 'effector' Tregs in particular is associated with an inferior prognosis in patients on standard rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) immunochemotherapy, the role of this cell type during lymphoma initiation and progression is poorly understood. METHODS: Here, we use tissue microarrays containing prospectively collected DLBCL patient specimens, as well as data from publicly available cohorts to explore the mutational landscape of Treg-infiltrated DLBCL. We further take advantage of a model of MYC-driven lymphoma to mechanistically dissect the contribution of Tregs to lymphoma pathogenesis and to develop a strategy of Treg-selective interleukin-2 (IL-2) starvation to improve immune control of MYC-driven lymphoma. RESULTS: We find that all genetic DLBCL subtypes, except for one characterized by co-occurring MYD88/CD79 mutations, are heavily infiltrated by Tregs. Spectral flow cytometry and scRNA-sequencing reveal the robust expression of functional and immunosuppressive markers on Tregs infiltrating MYC-driven lymphomas; notably, we find that intratumoral Tregs arise due to local conversion from naïve CD4+ precursors on tumor contact. Treg ablation in Foxp3iDTR mice, or by antibody-mediated Treg-selective blockade of IL-2 signaling, strongly reduces the lymphoma burden. We identify lymphoma B-cells as a major source of IL-2, and show that the effects of Treg depletion are reversed by the simultaneous depletion of Foxp3-negative CD4+ T-cells, but not CD8+ T-cells or natural killer (NK) cells. The inhibition of ATP hydrolyzation and adenosine production by Tregs at least partly phenocopies the effects of Treg depletion. Treg depletion further synergizes with pro-apoptotic CD40 activation to sustain durable responses. CONCLUSION: The combined data implicate Tregs as a potential therapeutic target in DLBCL, especially in combination with other immunotherapies.

Cell type matters: competence for alkaloid metabolism differs in two seed-derived cell strains of Catharanthus roseus.

Since the discovery of the anticancer drugs vinblastine and vincristine, Catharanthus roseus has been intensively studied for biosynthesis of several terpene indole alkaloids (TIAs). Due to their low abundance in plant tissues at a simultaneously high demand, modes of production alternative to conventional extraction are mandatory. Plant cell fermentation might become one of these alternatives, yet decades of research have shown limited success to certain product classes, leading to the question: how to preserve the intrinsic ability to produce TIAs (metabolic competence) in cell culture? We used the strategy to use the developmental potency of mature embryos to generate such strains. Two cell strains (C1and C4) from seed embryos of Catharanthus roseus were found to differ not only morphologically, but also in their metabolic competence. This differential competence became manifest not only under phytohormone elicitation, but also upon feeding with alkaloid pathway precursors. The more active strain C4 formed larger cell aggregates and was endowed with longer mitochondria. These cellular features were accompanied by higher alkaloid accumulation in response to methyl jasmonate (MeJA) elicitation. The levels of catharanthine could be increased significantly, while the concurrent vindoline branch of the pathway was blocked, such that no bisindole alkaloids were detectable. By feeding vindoline to MeJA-elicited C4 cells, vincristine became detectable; however, only to marginal amounts. In conclusion, these results show that cultured cells are not "de-differentiated", but can differ in metabolic competence. In addition to elicitation and precursor feeding, the cellular properties of the "biomatter" are highly relevant for the success of plant cell fermentation.

CaMKII and CaV3.2 T-type calcium channel mediate Connexin-43-dependent inflammation by activating astrocytes in vincristine-induced neuropathic pain.

Vincristine (VCR), an alkaloid isolated from vinca, is a commonly used chemotherapeutic drug. However, VCR therapy can lead to dose-dependent peripheral neurotoxicity, mainly manifesting as neuropathic pain, which is one of the dominant reasons for limiting its utility. Experimentally, we discovered that VCR-induced neuropathic pain (VINP) was accompanied by astrocyte activation; the upregulation of phospho-CaMKII (p-CaMKII), CaV3.2, and Connexin-43 (Cx43) expression; and the production and release of inflammatory cytokines and chemokines in the spinal cord. Similar situations were also observed in astrocyte cultures. Interestingly, these alterations were all reversed by intrathecal injection of KN-93 (a CaMKII inhibitor) or L-Ascorbic acid (a CaV3.2 inhibitor). In addition, KN-93 and L-Ascorbic acid inhibited the increase in [Ca2+]i associated with astrocyte activation. We also verified that knocking down or inhibiting Cx43 level via intrathecal injection of Cx43 siRNA or Gap27 (a Cx43 mimetic peptide) relieved pain hypersensitivity and reduced the release of inflammatory factors; however, they did not affect astrocyte activation or p-CaMKII and CaV3.2 expression. Besides, the overexpression of Cx43 through the transfection of the Cx43 plasmid did not affect p-CaMKII and CaV3.2 expressions in vitro. Therefore, CaMKII and CaV3.2 may activate astrocytes by increasing [Ca2+]i, thereby mediating Cx43-dependent inflammation in VINP. Moreover, we demonstrated that the CaMKII signalling pathway was involved in VCR-induced inflammation, apoptosis, and mitochondrial damage. Collectively, our findings show a novel mechanism by which CaMKII and CaV3.2 mediate Cx43-dependent inflammation by activating astrocytes in neuropathic pain induced by VCR.

Effect of the plant probiotic bacteria on terpenoid indole alkaloid biosynthesis pathway gene expression profiling, vinblastine and vincristine content in the root of Catharanthus roseus.

BACKGROUND: Catharanthus roseus is the sole resource of vinblastine and vincristine, two TIAs of great interest for their powerful anticancer activities. Increasing the concentration of these alkaloids in various organs of the plant is one of the important goals in C. roseus breeding programs. Plant probiotic bacteria (PBB) act as biotic elicitors and can induce the synthesis of secondary products in plants. The purpose of this research is to study the effects of PBB on expression of the TIA biosynthetic pathway genes and the content of alkaloids in C. roseus. METHODS AND RESULTS: The individual and combined effects of P. fluorescens strains 169 and A. brasilense strains Ab-101 was studied for expression of the TIA biosynthetic pathway genes (G10H, DAT, T16H and CrPRX) using qRT-PCR and the content of vinblastine and vincristine using HPLC method in roots of C. roseus. P. fluorescens. This drastically increased the content of vinblastine and vincristine alkaloids, compared to the control in the roots, to 174 and 589 (µg/g), respectively. Molecular analysis showed bacterium significantly increased the expression of more genes in the TIA biosynthetic pathway compared to the control. P. fluorescens increased the expression of the final gene of the biosynthetic pathway (CrPRX) 47.9 times compared to the control. Our findings indicate the correlation between transcriptional and metabolic outcomes. The same was true for A. brasilense. CONCLUSIONS: It can be concluded that seed treatments and seedling root treatments composed of naturally occurring probiotic bacteria are likely to be widely applicable for inducing enhanced alkaloid contents in medicinal plants.

DAT and PRX1 gene expression modulates vincristine production in Catharanthus roseus L. propagates using Cu, Fe and Zn nano structures.

Underlying mechanism of nanostructures upon monoterpene induction in Catharanthus roseus has not been explored yet. In the current study, Copper, Iron and Zinc nanoparticles were biosynthesized by Eriobotrya japonica seed extract and capped with reduced glutathione. Biosynthesized nanoparticles and their capped analogues were characterized by UV-visible spectrophotometer, FTIR, XRD and SEM. Selected concentration of nanostructures were used in plant tissue culture media which instigated the production of alkaloids, tannins and flavonoids without significantly affecting the growth index of propagated calli and shoots cultures of C. roseus. Accelerated vincristine production was noticed in propagated calli and shoots under copper and zinc nanostress (1645-1865 µg/ml respectively) with the least effect by iron nanostructure. Highest concentration of calcium was recorded in in vitro shoots under capped (3.42 mg/ml ± 7.16) and uncapped (4.41 mg/ml ± 20.44) Zn nanoparticles compared to control (2.82 mg/ml ± 13.41). Real time PCR depicts nano-zinc mediated increased expression of DAT and PRX1 genes of TIA pathway. Significant correlation among PRX1/DAT gene expression with vincristine production and calcium accumulation in the presence of nanostress validate by PCA. This study paved way the opportunities of metal biogenic nanomaterials as an ideal drug modulator in plant tissue culture studies.

Primary acute lymphoblastic leukemia cells are susceptible to microtubule depolymerization in G1 and M phases through distinct cell death pathways.

Microtubule targeting agents (MTAs) are widely used cancer chemotherapeutics which conventionally exert their effects during mitosis, leading to mitotic or postmitotic death. However, accumulating evidence suggests that MTAs can also generate death signals during interphase, which may represent a key mechanism in the clinical setting. We reported previously that vincristine and other microtubule destabilizers induce death not only in M phase but also in G1 phase in primary acute lymphoblastic leukemia cells. Here, we sought to investigate and compare the pathways responsible for phase-specific cell death. Primary acute lymphoblastic leukemia cells were subjected to centrifugal elutriation, and cell populations enriched in G1 phase (97%) or G2/M phases (80%) were obtained and treated with vincristine. We found death of M phase cells was associated with established features of mitochondrial-mediated apoptosis, including Bax activation, loss of mitochondrial transmembrane potential, caspase-3 activation, and nucleosomal DNA fragmentation. In contrast, death of G1 phase cells was not associated with pronounced Bax or caspase-3 activation but was associated with loss of mitochondrial transmembrane potential, parylation, nuclear translocation of apoptosis-inducing factor and endonuclease G, and supra-nucleosomal DNA fragmentation, which was enhanced by inhibition of autophagy. The results indicate that microtubule depolymerization induces distinct cell death pathways depending on during which phase of the cell cycle microtubule perturbation occurs. The observation that a specific type of drug can enter a single cell type and induce two different modes of death is novel and intriguing. These findings provide a basis for advancing knowledge of clinical mechanisms of MTAs.

CRISPR/Cas9-mediated SARM1 knockout and epitope-tagged mice reveal that SARM1 does not regulate nuclear transcription, but is expressed in macrophages.

SARM1 is a toll/interleukin-1 receptor -domain containing protein, with roles proposed in both innate immunity and neuronal degeneration. Murine SARM1 has been reported to regulate the transcription of chemokines in both neurons and macrophages; however, the extent to which SARM1 contributes to transcription regulation remains to be fully understood. Here, we identify differential gene expression in bone-marrow-derived macrophages (BMDMs) from C57BL/6 congenic 129 ES cell-derived Sarm1-/- mice compared with wild type (WT). However, we found that passenger genes, which are derived from the 129 donor strain of mice that flank the Sarm1 locus, confound interpretation of the results, since many of the identified differentially regulated genes come from this region. To re-examine the transcriptional role of SARM1 in the absence of passenger genes, here we generated three Sarm1-/- mice using CRISPR/Cas9. Treatment of neurons from these mice with vincristine, a chemotherapeutic drug causing axonal degeneration, confirmed SARM1's function in that process; however, these mice also showed that lack of SARM1 has no impact on transcription of genes previously shown to be affected such as chemokines. To gain further insight into SARM1 function, we generated an epitope-tagged SARM1 mouse. In these mice, we observed high SARM1 protein expression in the brain and brainstem and lower but detectable levels in macrophages. Overall, the generation of these SARM1 knockout and epitope-tagged mice has clarified that SARM1 is expressed in mouse macrophages yet has no general role in macrophage transcriptional regulation and has provided important new models to further explore SARM1 function.

Chemotherapy for non-Hodgkin lymphoma in the hemodialysis patient: A comprehensive review.

Chemotherapy for non-Hodgkin lymphoma (NHL) in the hemodialysis (HD) patient is a challenging situation. Because many drugs are predominantly eliminated by the kidneys, chemotherapy in the HD patient requires special considerations concerning dose adjustments to avoid overdose and toxicities. Conversely, some drugs are removed by HD and may expose the patient to undertreatment, therefore the timing of drug administration in relation to HD sessions must be carefully planned. Also, the metabolites of some drugs show different toxicities and dialysability as compared with the parent drug, therefore this must also be catered for. However, the pharmacokinetics of many chemotherapeutics and their metabolites in HD patients are unknown, and the fact that NHL patients are often treated with distinct multiagent chemotherapy regimens makes the situation more complicated. In a realm where uncertainty prevails, case reports and case series reporting on actual treatment and outcomes are extremely valuable and can aid physicians in decision making from drug selection to dosing. We carried out an exhaustive review of the literature and adopted 48 manuscripts consisting of 66 HD patients undergoing 71 chemotherapy regimens for NHL, summarized the data, and provide recommendations concerning dose adjustments and timing of administration for individual chemotherapeutics where possible. The chemotherapy regimens studied in this review include, but are not limited to, rituximab, cyclophosphamide + vincristine + prednisolone (CVP) and cyclophosphamide + doxorubicin + vincristine + prednisolone (CHOP)-like regimens, chlorambucil, ibrutinib, bendamustine, methotrexate, platinum compounds, cytarabine, gemcitabine, etoposide, ifosfamide, melphalan, busulfan, fludarabine, mogamulizumab, brentuximab vedotin, and 90 Y-ibritumomab tiuxetan.

Vincristine attenuates cardiac fibrosis through the inhibition of NLRP3 inflammasome activation.

Vincristine (VCR) is widely used in cancer therapies, although its benefits on cardiac fibrosis remain unknown. Here, we investigated VCR's efficacy on cardiac fibrosis and elucidated the underlying mechanism of action. Network pharmacology was employed to predict the mechanism of VCR action on cardiac fibrosis. We induced cardiac fibrosis in adult male Sprague-Dawley (SD) rats via isoproterenol (ISO) injection, followed by treatment with VCR or vehicle. After 10 days of treatment, VCR-treated rats exhibited a significantly lower heart/body weight ratio relative to those treated with the vehicle. Moreover, cardiac fibrosis was alleviated in VCR-treated rats relative to vehicle-treated rats. The results revealed the down-regulation of mature caspase-1, interleukin (IL)-1ß, and IL-18 in VCR-treated rats relative to vehicle-treated rats. We also observed less colocalization between the nucleotide-binding domain, leucine-rich repeat, and pyrin domain-containing protein 3 (NLRP3) and apoptosis-associated speck-like protein containing a CARD (ASC) in VCR-treated rats compared with vehicle-treated rats. We then cultured neonatal rat cardiac fibroblasts (NRCFs) and exposed them to lipopolysaccharide (LPS) and adenosine triphosphate (ATP) in the presence or absence of VCR. The results indicated that VCR mediated the down-regulation of caspase-1, IL-1ß, and IL-18 and the colocalization of NLRP3 and ASC in LPS+ATP-stimulated cardiac fibroblasts (CFs). We found evidence that VCR attenuates cardiac fibrosis by directly suppressing the activation of the NLRP3 inflammasome. These findings provide novel insights into VCR's mechanism of action in alleviating cardiac fibrosis.

5-Hydroxymethylcytosine profiles of cfDNA are highly predictive of R-CHOP treatment response in diffuse large B cell lymphoma patients.

BACKGROUND: Although R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) remains the standard chemotherapy regimen for diffuse large B cell lymphoma (DLBCL) patients, not all patients are responsive to the scheme, and there is no effective method to predict treatment response. METHODS: We utilized 5hmC-Seal to generate genome-wide 5hmC profiles in plasma cell-free DNA (cfDNA) from 86 DLBCL patients before they received R-CHOP chemotherapy. To investigate the correlation between 5hmC modifications and curative effectiveness, we separated patients into training (n = 56) and validation (n = 30) cohorts and developed a 5hmC-based logistic regression model from the training cohort to predict the treatment response in the validation cohort. RESULTS: In this study, we identified thirteen 5hmC markers associated with treatment response. The prediction performance of the logistic regression model, achieving 0.82 sensitivity and 0.75 specificity (AUC = 0.78), was superior to existing clinical indicators, such as LDH and stage. CONCLUSIONS: Our findings suggest that the 5hmC modifications in cfDNA at the time before R-CHOP treatment are associated with treatment response and that 5hmC-Seal may potentially serve as a clinical-applicable, minimally invasive approach to predict R-CHOP treatment response for DLBCL patients.

Cryo-EM structures reveal distinct mechanisms of inhibition of the human multidrug transporter ABCB1.

ABCB1 detoxifies cells by exporting diverse xenobiotic compounds, thereby limiting drug disposition and contributing to multidrug resistance in cancer cells. Multiple small-molecule inhibitors and inhibitory antibodies have been developed for therapeutic applications, but the structural basis of their activity is insufficiently understood. We determined cryo-EM structures of nanodisc-reconstituted, human ABCB1 in complex with the Fab fragment of the inhibitory, monoclonal antibody MRK16 and bound to a substrate (the antitumor drug vincristine) or to the potent inhibitors elacridar, tariquidar, or zosuquidar. We found that inhibitors bound in pairs, with one molecule lodged in the central drug-binding pocket and a second extending into a phenylalanine-rich cavity that we termed the "access tunnel." This finding explains how inhibitors can act as substrates at low concentration, but interfere with the early steps of the peristaltic extrusion mechanism at higher concentration. Our structural data will also help the development of more potent and selective ABCB1 inhibitors.

Hydrogel implants for transscleral drug delivery for retinoblastoma treatment.

Retinoblastoma (Rb) is the most common primary malignant intraocular tumor in children which develops from the retinal stem cells. Systemic chemotherapy is the typical therapeutic treatment and though most children survive Rb, they often lose their vision, or the eye needs to be enucleated. Regarding to the pure availability of the target tumor by systemic chemotherapy, the local anticancer drug administration would be advantageous to increase the local drug concentration and minimize adverse side effects of chemotherapy. The present paper describes a new hydrogel implant enabled to deliver therapeutically active doses of low molecular weight hydrophilic antitumor drugs topotecan and vincristine. The hydrogel implant is proposed as bi-layered with an inner hydrophilic layer from 2-hydroxyethyl methacrylate (HEMA) serving as a reservoir of the chemotherapeutic agent and an outer hydrophobic layer from 2-ethoxyethyl methacrylate (EOEMA) acting as a barrier to protect the surrounding vascularized tissue against cytotoxicity of the delivered chemotherapeutics. The experiments with enucleated pig eyes demonstrated the ability of tested drugs to diffuse through sclera and reach the vitreous humor. HEMA-based hydrogels were examined in terms of sorption, release and transport properties, showing the possibility of adjusting the loading capacity and diffusion of the drugs by the degree of crosslinking. The EOEMA-based gels proved to be an inert for drug sorption and diffusion. A chorioallantoic membrane assay demonstrated excellent biocompatibility of unloaded hydrogels, and in vitro experiments confirmed significant cytotoxicity of drug-loaded hydrogels against a Rb cell line; 2 days for those topotecan-loaded and a minimum of 6 days for vincristine-loaded hydrogels. The bi-layered hydrogel implant can be considered promising for local administration of active agents to eye-globe for the treatment of Rb and also other ocular disorders.

Vincristine combination with Ca+2 channel blocker increase antitumor effects.

In this study, it was aimed to determine the effects of Amlodipine, a calcium channel blocker and vincristine (VCR) an antineoplastic, on human neuroblastomas using different doses. The cytotoxicity assays of the study were performed using the MTT method depending on time and concentration. After obtaining the mixture (up to 85% for SH-SY5Y) and sufficient branches (cortex neurons), the cells were treated with amlodipine (10 µM) and vincristine (0.5, 1 and 2 µg) at different concentrations for 24 h. MTT assay was performed by the commercially available kit (Sigma Aldrich, USA). Cells were harvested, washed and stained with PI and Annexin V, respectively, according to the manufacturer's protocol (Biovision, USA). Than analyzes were carried out. The results were quite impressive. When amlodipine (10 µM) was administered alone there was little change compared to the control. However, all doses of amlodipine (10 µM) and vincristine (0.5, 1 and 2 µg) were greater than the deaths in the doses alone (0.5, 1 and 2 µg) of vincristine alone. (P < 0.05). As a result, the combination of vincristine and amlodipine is more effective than vincristine alone in reducing the viability of cancer cells.

Striatal spreading depolarization: Possible implication in levodopa-induced dyskinetic-like behavior.

OBJECTIVE: Spreading depolarization (SD) is a transient self-propagating wave of neuronal and glial depolarization coupled with large membrane ionic changes and a subsequent depression of neuronal activity. Spreading depolarization in the cortex is implicated in migraine, stroke, and epilepsy. Conversely, spreading depolarization in the striatum, a brain structure deeply involved in motor control and in Parkinson's disease (PD) pathophysiology, has been poorly investigated. METHODS: We characterized the participation of glutamatergic and dopaminergic transmission in the induction of striatal spreading depolarization by using a novel approach combining optical imaging, measurements of endogenous DA levels, and pharmacological and molecular analyses. RESULTS: We found that striatal spreading depolarization requires the concomitant activation of D1-like DA and N-methyl-d-aspartate receptors, and it is reduced in experimental PD. Chronic l-dopa treatment, inducing dyskinesia in the parkinsonian condition, increases the occurrence and speed of propagation of striatal spreading depolarization, which has a direct impact on one of the signaling pathways downstream from the activation of D1 receptors. CONCLUSION: Striatal spreading depolarization might contribute to abnormal basal ganglia activity in the dyskinetic condition and represents a possible therapeutic target. © 2019 International Parkinson and Movement Disorder Society.