The role of ABCC10/MRP7 in anti-cancer drug resistance and beyond.

Multidrug resistance protein 7 (MRP7), also known as ATP-binding cassette (ABC) transporter subfamily C10 (ABCC10), is an ABC transporter that was first identified in 2001. ABCC10/MRP7 is a 171 kDa protein located on the basolateral membrane of cells. ABCC10/MRP7 consists of three transmembrane domains and two nucleotide binding domains. It mediates multidrug resistance of tumor cells to a variety of anticancer drugs by increasing drug efflux and results in reducing intracellular drug accumulation. The transport substrates of ABCC10/MRP7 include antineoplastic drugs such as taxanes, vinca alkaloids, and epothilone B, as well as endobiotics such as leukotriene C4 (LTC4) and estradiol 17 ß-D-glucuronide. A variety of ABCC10/MRP7 inhibitors, including cepharanthine, imatinib, erlotinib, tariquidar, and sildenafil, can reverse ABCC10/MRP7-mediated MDR. Additionally, the presence or absence of ABCC10/MRP7 is also closely related to renal tubular dysfunction, obesity, and other diseases. In this review, we discuss: 1) Structure and functions of ABCC10/MRP7; 2) Known substrates and inhibitors of ABCC10/MRP7 and their potential therapeutic applications in cancer; and 3) Role of ABCC10/MRP7 in non-cancerous diseases.

Detection of vinblastine and related bioactive compounds from culture extracts of endophytic fungi of Catharanthus roseus.

This study investigates the synthesis of vinblastine by endophytic fungi isolated from leaf of C. roseus. A total of 10 endophytic fungi were selected for secretion of vinca alkaloids based on the initial screening by biochemical tests and thin-layer chromatography (TLC). Out of these ten, only four fungal extracts showed positive results for presence of vinblastine at same retention time (10 min.) compared to reference compound on HPLC analysis. The detected concentration of vinblastine was maximum (17 µg/ml) in isolate no. CRL 22 followed by CRL 52, CRL 17 and CRL 28. To validate the presence of vinblastine, ultra-high-performance liquid chromatography coupled with high-resolution accurate mass spectrometry (HRMS) was employed. This analysis confirmed the presence of anhydrovinblastine, a precursor of vinblastine through the detection of molecular ions at m/z 793.4185 in extract of CRL 17. In addition to anhydrovinblastine, the intermediate compounds essential to the biosynthetic pathway of vinblastine were also detected in the extract of CRL 17. These host-origin compounds strongly suggest the presence of a biosynthetic pathway within the endophytic fungus. Based on morphological observation and sequence analysis of the ITS region of rDNA, endophytic fungi were identified as Alternaria alternata (CRL 17), Curvularia lunata (CRL 28), Aspergillus terrus (CRL 52), and Aspergillus clavatonanicus (CRL 22).

Visualizing vinca alkaloids in the petal of Catharanthus roseus using functionalized titanium oxide nanowire substrate for surface-assisted laser desorption/ionization imaging mass spectrometry.

Imaging mass spectrometry (IMS) is a powerful technique that enables analysis of various molecular species at a high spatial resolution with low detection limits. In contrast to the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) approach, surface-assisted laser desorption/ionization (SALDI) can be more effective in the detection of small molecules due to the absence of interfering background signals in low m/z ranges. We developed a functionalized TiO2 nanowire as a solid substrate for IMS of low-molecular-weight species in plant tissues. We prepared TiO2 nanowires using an inexpensive modified hydrothermal process and subsequently functionalized them chemically with various silane analogs to overcome the problem of superhydrophilicity of the substrate. Chemical modification changed the selectivity of imprinting of samples deposited on the substrate surface and thus improved the detection limits. The substrate was applied to image distribution of the metabolites in very fragile specimens such as the petal of Catharanthus roseus. We observed that the metabolites are distributed heterogeneously in the petal, which is consistent with previous results reported for the C. roseus plant leaf and stem. The intermediates corresponding to the biosynthesis pathway of some vinca alkaloids were clearly shown in the petal. We also performed profiling of petals from five different cultivars of C. roseus plant. We verified the semi-quantitative capabilities of the imprinting/imaging approach by comparing results using the LC-MS analysis of the plant extracts. This suggested that the functionalized TiO2 nanowire substrate-based SALDI is a powerful technique complementary to MALDI-MS.

Total synthesis of (-)-4-desacetoxy-1-oxovindoline: Single atom exchange of an embedded core heteroatom in vindoline.

A concise total synthesis of (-)-4-desacetoxy-1-oxovindoline is disclosed, bearing a single heteroatom exchange in the core structure of the natural product 4-desacetoxyvindoline. Central to the synthesis is powerful oxadiazole intramolecular [4+2]/[3+2] cycloaddition cascade that formed four C-C bonds, created three new rings, and established five contiguous stereocenters about the new formed central 6-membered ring.

Effect of lubiprostone on vinca alkaloid-induced constipation in patients with hematological malignancies: a propensity score-matched analysis.

Patients receiving vinca alkaloids for hematological malignancies frequently experience constipation that is unresponsive to laxatives. Research on treatment of vinca alkaloid-induced constipation is limited. This study aimed to determine whether the chloride channel activator lubiprostone ameliorates vinca alkaloid-induced constipation in patients with hematological malignancies. In this retrospective cohort study, vinca alkaloid-induced constipation (grade ≥ 3 using the Common Terminology Criteria for Adverse Events) was investigated in patients treated for hematological malignancies between July 2014 and June 2019 who had already been prescribed osmotic laxatives and additionally received either a stimulant laxative or lubiprostone. Univariate and multivariate analyses were performed to identify the risk factors for persistent constipation after introduction of the second laxative. A propensity score model was used to match 67 patients taking a stimulant laxative and 67 treated with lubiprostone, and the occurrence of intractable constipation was compared between groups. Overall, 203 patients were included, among whom 50 (25%) had constipation. On multivariate analysis, body mass index, opioid use, and addition of lubiprostone were independently associated with constipation. Patients treated with lubiprostone were significantly less likely to experience intractable constipation than did those treated with stimulant laxatives (10% vs. 34%, P = 0.002). Moreover, post-constipation diarrhea was significantly less frequent among patients treated with lubiprostone (42% vs. 63%, P = 0.024). Lubiprostone was more effective than stimulant laxatives at treating vinca alkaloid-induced intractable constipation in patients with hematological malignancies, and its use could enable safe vinca alkaloid chemotherapy.

Synthesis and Cytotoxic Activity of New Vindoline Derivatives Coupled to Natural and Synthetic Pharmacophores.

New Vinca alkaloid derivatives were synthesized to improve the biological activity of the natural alkaloid vindoline. To this end, experiments were performed to link vindoline with various structural units, such as amino acids, a 1,2,3-triazole derivative, morpholine, piperazine and N-methylpiperazine. The structure of the new compounds was characterized by NMR spectroscopy and mass spectrometry (MS). Several compounds exhibited in vitro antiproliferative activity against human gynecological cancer cell lines with IC50 values in the low micromolar concentration range.

Ultra-potent vinblastine analogues improve on-target activity of the parent microtubulin-targeting compound.

In recent efforts, several C20' urea vinblastine analogues were discovered that displayed remarkable potency against vinblastine-sensitive tumor cell lines (IC50 50-75 pM), being roughly 100-fold more potent than vinblastine, and that exhibited decreased susceptibility to Pgp efflux-derived resistance in a vinblastine-resistant cell line. Their extraordinary activity indicate that it is not likely or even possible that their cellular functional activity is derived from stoichiometric occupancy of the intracellular tubulin binding sites. Rather, their potency indicates sub-stoichiometric or even catalytic occupancy of candidate binding sites may be sufficient to disrupt tubulin dynamics or microtubule assembly during mitosis. We detail efforts to delineate the underlying behavior responsible for the increased potency and show that the ultra-potent extended C20' ureas retain the mechanistic behavior of vinblastine, display enhanced affinity for tubulin and on-target activity approximately 100-fold both in vitro and in HeLa cells, but do not show evidence of catalytic disassembly of microtubulin. We also use the analogues to show that, in live interphase cells, the effects of the vinblastine class of drugs do not display a catastrophic effect on the microtubule skeleton, but rather a subtler insult to its dynamicity, acting as sub-stoichiometric drugs that inhibit normal microtubulin maturation and dynamics.

Vinca alkaloids, thalidomide and eribulin-induced peripheral neurotoxicity: From pathogenesis to treatment.

Vinca alkaloids, thalidomide, and eribulin are widely used to treat patients with childhood acute lymphoblastic leukemia (ALL), adults affected by multiple myeloma and locally invasive or metastatic breast cancer, respectively. However, soon after their introduction into clinical practice, chemotherapy-induced peripheral neurotoxicity (CIPN) emerged as their main non-hematological and among dose-limiting adverse events. It is generally perceived that vinca alkaloids and the antiangiogenic agent thalidomide are more neurotoxic, compared to eribulin. The exposure to these chemotherapeutic agents is associated with an axonal, length-dependent, sensory polyneuropathy of mild to moderate severity, whereas it is considered that the peripheral nerve damage, unless severe, usually resolves soon after treatment discontinuation. Advanced age, high initial and prolonged dosing, coadministration of other neurotoxic chemotherapeutic agents and pre-existing neuropathy are the common risk factors. Pharmacogenetic biomarkers might be used to define patients at increased susceptibility of CIPN. Currently, there is no established therapy for CIPN prevention or treatment; symptomatic treatment for neuropathic pain and dose reduction or withdrawal in severe cases is considered, at the cost of reduced cancer therapeutic efficacy. This review critically examines the pathogenesis, epidemiology, risk factors (both clinical and pharmacogenetic), clinical phenotype and management of CIPN as a result of exposure to vinca alkaloids, thalidomide and its analogue lenalidomide as also eribulin.

High expression of class III ß-tubulin has no impact on functional cancer cell growth inhibition of a series of key vinblastine analogs.

Clinical association studies have implicated high expression of class III ß-tubulin as a predictive factor for lower response rates and reduced overall survival in patients receiving tubulin binding drugs, most notably the taxanes. Because of the implications, we examined a series of key vinblastine analogs that emerged from our studies in functional cell growth inhibition assays for their sensitivity to high expression of class III ß-tubulin (human non-small cell lung cancer cell line A549 vs taxol-resistant A549-T24). Unlike taxol, vinblastine and a set of key analogs 3-10 did not exhibit any loss in sensitivity toward A549-T24. The results suggest that vinblastine and related analogs are not likely prone to resistance derived from high expression of class III ß-tubulin unlike the taxanes. Most significant are the results with 4-6, a subset of 20' amide vinblastine analogs. They match or exceed the potency of vinblastine and they display more potent activity against taxol-resistant A549-T24 than even wild type A549 cells (1.2-2-fold), complementing our prior observations that they also display no sensitivity to overexpression of Pgp (HCT116/VM46 vs HCT116) and are not subject to resistance derived from Pgp efflux.

Vinca alkaloids and analogues as anti-cancer agents: Looking back, peering ahead.

Cancer still represents a "nightmare" worldwide, causing annually millions of victims. Several antiproliferative molecules are currently used as drugs market and offer a pharmaceutical opportunity for attenuating and treating tumor manifestations. In this context, natural sources have a relevant role, since they provide the 60% of currently-used anticancer agents. Among the numerous natural products, acting via different mechanisms of action, microtubule-targeting agents (MTAs) have a high therapeutic potential, since they disrupt the abnormal cancer cell growth, interfering with the continuous mitotic division. Vinca alkaloids (VAs) are the earliest developed MTAs and approved for clinical use (Vincristine, Vinblastine, Vinorelbine, Vindesine, and Vinflunine) as agents in the treatment of hematological and lymphatic neoplasms. Here, we review the state-of-art of VAs, discussing their mechanism of action and pharmacokinetic properties and highlighting their therapeutic relevance and toxicological profile. Additionally, we briefly disclosed the technological approaches faced so far to ameliorate the pharmacological properties, as well as to avoid the drug resistance. Lastly, we introduced the recent advances in the discovery of new derivatives.

The effect of conjugation on antitumor activity of vindoline derivatives with octaarginine, a cell-penetrating peptide.

Some Vinca alkaloids (eg, vinblastine, vincristine) have been widely used as antitumor drugs for a long time. Unfortunately, vindoline, a main alkaloid component of Catharanthus roseus (L.) G. Don, itself, has no antitumor activity. In our novel research program, we have prepared and identified new vindoline derivatives with moderate cytostatic activity. Here, we describe the effect of conjugation of vindoline derivative with oligoarginine (tetra-, hexa-, or octapeptides) cell-penetrating peptides on the cytostatic activity in vitro and in vivo. Br-Vindoline-(l)-Trp-OH attached to the N-terminus of octaarginine was the most effective compound in vitro on HL-60 cell line. Analysis of the in vitro activity of two isomer conjugates (Br-vindoline-(l)-Trp-Arg8 and Br-vindoline-(d)-Trp-Arg8 suggests the covalent attachment of the vindoline derivatives to octaarginine increased the antitumor activity significantly against P388 and C26 tumour cells in vitro. The cytostatic effect was dependent on the presence and configuration of Trp in the conjugate as well as on the cell line studied. The configuration of Trp notably influenced the activity on C26 and P388 cells: conjugate with (l)-Trp was more active than conjugate with the (d)-isomer. In contrast, conjugates had very similar effect on both the HL-60 and MDA-MB-231 cells. In preliminary experiments, conjugate Br-vindoline-(l)-Trp-Arg8 exhibited some inhibitory effect on the tumor growth in P388 mouse leukemia tumor-bearing mice. Our results indicate that the conjugation of modified vindoline could result in an effective compound even with in vivo antitumor activity.

Microtubule destabilising agents: far more than just antimitotic anticancer drugs.

Vinca alkaloids have been approved as anticancer drugs for more than 50 years. They have been classified as cytotoxic chemotherapy drugs that act during cellular mitosis, enabling them to target fast growing cancer cells. With the evolution of cancer drug development there has been a shift towards new "targeted" therapies to avoid the side effects and general toxicities of "cytotoxic chemotherapies" such as the vinca alkaloids. Due to their original classification, many have overlooked the fact that vinca alkaloids, taxanes and related drugs do have a specific molecular target: tubulin. They continue to be some of the most effective anticancer drugs, perhaps because their actions upon the microtubule network extend far beyond the ability to halt cells in mitosis, and include the induction of apoptosis at all phases of the cell cycle. In this review, we highlight the numerous cellular consequences of disrupting microtubule dynamics, expanding the textbook knowledge of microtubule destabilising agents and providing novel opportunities for their use in cancer therapy.

[Chemotherapy-induced peripheral neuropathy and neuropathic pain]. / Chemotherapie-induzierte periphere Neuropathie und neuropathischer Schmerz.

The perception of the media is that chemotherapy is mainly associated with nausea, vomiting and hair loss. In the longer term the development of peripheral neuropathy, i.e. chemotherapy-induced peripheral neuropathy (CIPN) is often more important for patients. The CIPN represents a side effect of many antineoplastic substances with severe functional impairment and its prevention and treatment is an important task. In addition to many interventions, which have been shown to be ineffective, physiotherapeutic measures and possibly the prophylactic application of cold are helpful for prevention. Randomized studies on the treatment of painful CIPN provided positive data for duloxetine and to a lesser extent for venlafaxine.

Synthesis and antiproliferativeactivity of new vinca alkaloids containing an α,ß-unsaturated aromatic side chain.

A new series of vinca-alkaloids derivatives containing various α,ß-unsaturated aromatic side chains was synthesized. Four new vinca-alkaloids derivatives showed selective cytotoxicities against KB tumor cell lines with IC50 value below 0.1 µM, thus comparable with vinblastine.

Synthesis and biological evaluation of C-13' substituted 7'-homo-anhydrovinblastine derivatives.

Recent publications highlighted that vinca derivatives either functionalized on C-12' or enlarged on cycle C' could be more cytotoxic than vinblastine or vinorelbine, both used in anti-cancer therapy. By combining these two results, nine new 7'-homo-anhydrovinblastine derivatives functionalized on C-13' were elaborated. The synthesis of key intermediates, their one-step transformation into final products in mild conditions and their biological activities are presented.

Mechanisms of mitotic inhibition in human aorta endothelial cells: Molecular and morphological in vitro spectroscopic studies.

Mitotic inhibitors are drugs commonly used in chemotherapy, but their nonspecific and indiscriminate distribution throughout the body after intravenous administration can lead to serious side effects, particularly on the cardiovascular system. In this context, our investigation into the mechanism of the cytotoxic effects on endothelial cells of mitotic inhibitors widely used in cancer treatment, such as paclitaxel (also known as Taxol) and Vinca alkaloids, holds significant practical implications. Understanding these mechanisms can lead to more targeted and less harmful cancer treatments. Human aorta endothelial cells (HAECs) were incubated with selected mitotic inhibitors in a wide range of concentrations close to those in human plasma during anticancer therapy. The analysis of single cells imaged by Raman spectroscopy allowed for visualization of the nuclear, cytoplasmic, and perinuclear areas to assess biochemical changes induced by the drug's action. The results showed significant changes in the morphology and molecular composition of the nucleus. Moreover, an effect of a given drug on the cytoplasm was observed, which can be related to its mechanism of action (MoA). Raman data supported by fluorescence microscopy measurements identified unique changes in DNA form and proteins and revealed drug-induced inflammation of endothelial cells. The primary goal of mitotic inhibitors is based on the impairment of tubulin formation and the inhibition of the mitosis process. While all three drugs affect microtubules and disrupt cell division, they do so through different MoA, i.e., Vinca alkaloids inhibit microtubule formation, whereas paclitaxel stabilizes microtubules. To sum up, the work shows how a specific drug can interact with endothelial cells.

Catharanthus roseus intoxication mimicking acute cholangitis.

BACKGROUND: Catharanthus roseus, a Madagascar native flowering plant, is known for its glossy leaves and vibrant flowers, and its medicinal significance due to its alkaloid compounds. As a source of vinblastine and vincristine used in chemotherapy, Catharanthus roseus is also employed in traditional medicine with its flower and stalks in dried form. Its toxicity can lead to various adverse effects. We report a case of Catharanthus roseus juice toxicity presenting as acute cholangitis, emphasizing the importance of healthcare providers obtaining detailed herbal supplement histories. CASE PRESENTATION: A 65-year-old woman presented with abdominal pain, fever, anorexia, and lower limb numbness. Initial diagnosis of acute cholangitis was considered, but imaging excluded common bile duct stones. Further investigation revealed a history of ingesting Catharanthus roseus juice for neck pain. Laboratory findings showed leukocytosis, elevated liver enzymes, and hyperbilirubinemia. The patient developed gastric ulcers, possibly due to alkaloids in Catharanthus roseus. No bacterial growth was noted in blood cultures. The patient recovered after discontinuing the herbal extract. CONCLUSIONS: Catharanthus roseus toxicity can manifest as fever, hepatotoxicity with cholestatic jaundice, and gastric ulcers, mimicking acute cholangitis. Awareness of herbal supplement use and potential toxicities is crucial for healthcare providers to ensure prompt diagnosis and appropriate management. This case emphasizes the need for public awareness regarding the possible toxicity of therapeutic herbs and the importance of comprehensive patient histories in healthcare settings.

Evaluation of the Effect of Loratadine versus Diosmin/Hesperidin Combination on Vinca Alkaloids-Induced Neuropathy: A Randomized Controlled Clinical Trial.

Neurological injury is a crucial problem that interferes with the therapeutic use of vinca alkaloids as well as the quality of patient life. This study was conducted to assess the impact of using loratadine or diosmin/hesperidin on neuropathy induced by vinca alkaloids. Patients were randomized into one of three groups as follows: group 1 was the control group, group 2 received 450 mg diosmin and 50 mg hesperidin combination orally twice daily, and group 3 received loratadine 10 mg orally once daily. Subjective scores (numeric pain rating scale, douleur neuropathique 4, and functional assessment of cancer therapy/gynecologic oncology group-neurotoxicity (FACT/GOG-Ntx) scores), neuroinflammation biomarkers, adverse drug effects, quality of life, and response to chemotherapy were compared among the three groups. Both diosmin/hesperidin and loratadine improved the results of the neurotoxicity subscale in the FACT/GOG-Ntx score (p < 0.001, p < 0.01 respectively) and ameliorated the upsurge in neuroinflammation serum biomarkers. They also reduced the incidence and timing of paresthesia (p = 0.001 and p < 0.001, respectively) and dysuria occurrence (p = 0.042). Both loratadine and diosmin/hesperidin attenuated the intensity of acute neuropathy triggered by vinca alkaloids. Furthermore, they did not increase the frequency of adverse effects or interfere with the treatment response.

Probing the Mechanisms Underlying the Transport of the Vinca Alkaloids by P-glycoprotein.

The efficacy of many cancer drugs is hindered by P-glycoprotein (Pgp), a cellular pump that removes drugs from cells. To improve chemotherapy, drugs capable of evading Pgp must be developed. Despite similarities in structure, vinca alkaloids (VAs) show disparate Pgp-mediated efflux ratios. ATPase activity and binding affinity studies show at least two binding sites for the VAs: high- and low-affinity sites that stimulate and inhibit the ATPase activity rate, respectively. The affinity for ATP from the ATPase kinetics curve for vinblastine (VBL) at the high-affinity site was 2- and 9-fold higher than vinorelbine (VRL) and vincristine (VCR), respectively. Conversely, VBL had the highest Km (ATP) for the low-affinity site. The dissociation constants (KDs) determined by protein fluorescence quenching were in the order VBL < VRL< VCR. The order of the KDs was reversed at higher substrate concentrations. Acrylamide quenching of protein fluorescence indicate that the VAs, either at 10 µM or 150 µM, predominantly maintain Pgp in an open-outward conformation. When 3.2 mM AMPPNP was present, 10 µM of either VBL, VRL, or VCR cause Pgp to shift to an open-outward conformation, while 150 µM of the VAs shifted the conformation of Pgp to an intermediate orientation, between opened inward and open-outward. However, the conformational shift induced by saturating AMPPNP and VCR condition was less than either VBL or VRL in the presence of AMPPNP. At 150 µM, atomic force microscopy (AFM) revealed that the VAs shift Pgp population to a predominantly open-inward conformation. Additionally, STDD NMR studies revealed comparable groups in VBL, VRL, and VCR are in contact with the protein during binding. Our results, when coupled with VAs-microtubule structure-activity relationship studies, could lay the foundation for developing next-generation VAs that are effective as anti-tumor agents. A model that illustrates the intricate process of Pgp-mediated transport of the VAs is presented.

Effects of the semisynthetic bis-indole derivative KAR-2 on store-operated calcium entry in human neutrophils.

We studied the effect of KAR-2 on cytosolic Ca(2+) level in human neutrophils by using a fluorescent dye (Fura-2) trapped in the cells. KAR-2 is a semisynthetic bis-indole derivative that shares vinblastine anti-microtubular properties, but does not share the vinblastine antagonistic effect on calmodulin. Therefore KAR-2 offers a convenient mean of studying the effect of microtubule destabilization, without concomitant calmodulin alterations. We found that KAR-2 induces Ca(2+) release from intracellular stores, whereby the stores are depleted. In addition KAR-2 reduces store-operated entry of extracellular Ca(2+) induced by agonists such as thapsigargin or ATP. On the other hand, in Ca(2+) refilled cells, KAR-2 promotes limited entry of extracellular Ca(2+) in the absence of agonist, but still interferes prominently with Ca(2+) entry triggered by ATP and with Ca(2+) uptake by intracellular stores. We suggest that Ca(2+) traffic through the plasma membrane is operated by two diverse pathways: the prominent pathway is interfered with by microtubule destabilization, while an alternate and minor pathway is actually favored (or uncovered) following microtubule destabilization.