A Vulnerability of a Subset of Colon Cancers with Potential Clinical Utility.

BRAF(V600E) mutant colon cancers (CCs) have a characteristic gene expression signature that is also found in some tumors lacking this mutation. Collectively, they are referred to as "BRAF-like" tumors and represent some 20% of CCs. We used a shRNA-based genetic screen focused on genes upregulated in BRAF(V600E) CCs to identify vulnerabilities of this tumor subtype that might be exploited therapeutically. Here, we identify RANBP2 (also known as NUP358) as essential for survival of BRAF-like, but not for non-BRAF-like, CC cells. Suppression of RANBP2 results in mitotic defects only in BRAF-like CC cells, leading to cell death. Mechanistically, RANBP2 silencing reduces microtubule outgrowth from the kinetochores, thereby inducing spindle perturbations, providing an explanation for the observed mitotic defects. We find that BRAF-like CCs display far greater sensitivity to the microtubule poison vinorelbine both in vitro and in vivo, suggesting that vinorelbine is a potential tailored treatment for BRAF-like CCs.

Characterization of a CrPME indicates its possible role in determining vindoline accumulation in Catharanthus roseus leaves.

The leaf-specific Catharanthus roseus alkaloid, vindoline, is the major bottleneck precursor in the production of scarce and costly anticancer bisindoles (vincristine and vinblastine). The final steps of its biosynthesis and storage occur in the laticifers. Earlier, we have shown that vindoline content is directly related to laticifer number. Pectin remodeling enzymes, like pectin methylesterase (PME), are known to be involved in laticifer development. A search in the croFGD yielded a leaf-abundant CrPME isoform that co-expressed with a few vindoline biosynthetic genes. Full-length cloning, tissue-specific expression profiling, and in silico analysis of CrPME were carried out. It was found to possess all the specific characteristics of a typical plant PME. Transient silencing (through VIGS) and overexpression of CrPME in C. roseus indicated a direct relationship between its expression and vindoline content. Comparative analysis of transcript abundance and enzyme activity in three familial C. roseus genotypes differing significantly in their vindoline content and laticifer count (CIM-Sushil > Dhawal > Nirmal) also corroborated the positive relationship of CrPME expression with vindoline content. This study highlights the possible role of CrPME, a cell wall remodeling enzyme, in modulating laticifer-associated secondary metabolism.

Nimotuzumab-vinorelbine combination therapy versus other regimens in the treatment of pediatric diffuse intrinsic pontine glioma.

PURPOSE: Pediatric diffuse intrinsic pontine glioma (DIPG) is a fatal disease associated with a median survival of < 1 year despite aggressive treatments. This retrospective study analyzed the treatment outcomes of patients aged < 18 years who were diagnosed with DIPG between 2012 and 2022 and who received different chemotherapy regimens. METHODS: After radiotherapy, patients with DIPG received nimotuzumab-vinorelbine combination or temozolomide-containing therapy. When nimotuzumab was unavailable, it was replaced by vincristine, etoposide, and carboplatin/cyclophosphamide (VECC). Temozolomide was administered as a single agent or a part of the combination chemotherapy comprising temozolomide, irinotecan, and bevacizumab. Furthermore, 1- and 3-year overall survival (OS), progression-free survival (PFS), and median OS and PFS were analyzed. RESULTS: The median age of 40 patients with DIPG was 97 ± 46.93 (23-213) months; the median follow-up time was 12 months. One and 3-year OS were 35.0% and 7.5%, respectively. Median OS was 12 months in all patients (n = 40), and it was 16, 10, and 11 months in those who received first-line nimotuzumab-vinorelbine combination (n = 13), temozolomide-based (n = 14), and VECC (n = 6) chemotherapy regimens, respectively (p = 0.360). One patient who received gefitinib survived for 16 months. Conversely, patients who never received radiotherapy and any antineoplastic medicamentous therapy (n = 6) had a median OS of 4 months. CONCLUSION: Nimotuzumab-vinorelbine combination therapy prolonged OS by 6 months compared with temozolomide-containing chemotherapy, although the difference was not statistically significant.

Synthesis and Antiproliferative Effect of New Alkyne-Tethered Vindoline Hybrids Containing Pharmacophoric Fragments.

In the frame of our diversity-oriented research on multitarget small molecule anticancer agents, utilizing convergent synthetic sequences terminated by Sonogashira coupling reactions, a preliminary selection of representative alkyne-tethered vindoline hybrids was synthesized. The novel hybrids with additional pharmacophoric fragments of well-documented anticancer agents, including FDA-approved tyrosine-kinase inhibitors (imatinib and erlotinib) or ferrocene or chalcone units, were evaluated for their antiproliferative activity on malignant cell lines MDA-MB-231 (triple negative breast cancer), A2780 (ovarian cancer), HeLa (human cervical cancer), and SH-SY5Y (neuroblastoma) as well as on human embryonal lung fibroblast cell line MRC-5, which served as a reference non-malignant cell line for the assessment of the therapeutic window of the tested hybrids. The biological assays identified a trimethoxyphenyl-containing chalcone-vindoline hybrid (36) as a promising lead compound exhibiting submicromolar activity on A2780 cells with a marked therapeutic window.

Novel Piperazine Derivatives of Vindoline as Anticancer Agents.

A series of novel vindoline-piperazine conjugates were synthesized by coupling 6 N-substituted piperazine pharmacophores at positions 10 and 17 of Vinca alkaloid monomer vindoline through different types of linkers. The in vitro antiproliferative activity of the 17 new conjugates was investigated on 60 human tumor cell lines (NCI60). Nine compounds presented significant antiproliferative effects. The most potent derivatives showed low micromolar growth inhibition (GI50) values against most of the cell lines. Among them, conjugates containing [4-(trifluoromethyl)benzyl]piperazine (23) and 1-bis(4-fluorophenyl)methyl piperazine (25) in position 17 of vindoline were outstanding. The first one was the most effective on the breast cancer MDA-MB-468 cell line (GI50 = 1.00 µM), while the second one was the most effective on the non-small cell lung cancer cell line HOP-92 (GI50 = 1.35 µM). The CellTiter-Glo Luminescent Cell Viability Assay was performed with conjugates 20, 23, and 25 on non-tumor Chinese hamster ovary (CHO) cells to determine the selectivity of the conjugates for cancer cells. These compounds exhibited promising selectivity with estimated half-maximal inhibitory concentration (IC50) values of 2.54 µM, 10.8 µM, and 6.64 µM, respectively. The obtained results may have an impact on the design of novel vindoline-based anticancer compounds.

Vindoline ameliorates intestinal barrier damage in Crohn's disease mice through MAPK signaling pathway.

Intestinal inflammation and intestinal barrier damage are important pathological changes in Crohn's disease (CD). Vindoline is a natural monomer with anti-inflammatory effects. We employed CD model mice to explore the effect of Vindoline on CD-like colitis and the possible mechanism. Il-10-deficient (Il-10-/- ) mice and wild-type (WT) mice (both aged 15 weeks, male) were used to explore the effect of Vindoline on colitis and intestinal barrier damage, as well as macrophage-mediated inflammation. Bone-marrow-derived macrophages (BMDMs) and colonic organoids from mice were used to explore the inhibitory effect of Vindoline on macrophage-mediated inflammation and the protective effect on inflammation-induced intestinal barrier damage as well as the possible mechanism. We found that Vindoline significantly ameliorated colitis in CD mice, as evidenced by increased weight change and colon length and decreased the colon macroscopic injury score, histological inflammatory score, and the expression of pro-inflammatory mediators. Vindoline also protected against intestinal barrier damage in CD mice. Furthermore, Vindoline inhibited macrophage-mediated inflammation and protected against inflammation-induced intestinal barrier damage in the coculture system. In addition, Vindoline ameliorated colitis in CD mice by protecting against inflammation-induced intestinal barrier damage, which may be caused by inhibition of MAPK signaling pathway. This protective effect suggests that Vindoline has potential value for clinical application in the treatment of CD.

Tris(4-bromophenyl)aminium Hexachloroantimonate-Mediated Intermolecular C(sp2)-C(sp3) Free Radical Coupling of Vindoline with ß-Ketoesters and Related Compounds.

A powerful tris(4-bromophenyl)aminium hexachloroantimonate (BAHA) mediated regioselective intermolecular coupling reaction of vindoline with a wide range of substrates that include ß-ketoesters, ß-diketones, ß-ketoaldehydes, ß-ketonitriles, ß-ketolactones, ß-ketolactams, ß-cyanoesters, and malononitriles is detailed. The BAHA-promoted intermolecular sp3/sp2 coupling, representing a special class of selective C-H functionalization reactions with direct carbon-carbon bond formation, proceeds with generation of a quaternary center bound to the aryl C15 center of vindoline capable of accommodating of the vinblastine C16' methyl ester and functionalized for subsequent divergent heterocycle introduction. A comprehensive examination of the reaction scope, optimization of subtle reaction parameters, and key insights into the reaction mechanism are described. Contrary to what might be prevailing expectations, studies suggest the plausible mechanism entails initial single-electron oxidation of the substrate enolate, not vindoline, and subsequent regiospecific addition of the resulting electrophilic radical to vindoline. As such and beyond the new arylation reaction with vindoline, the studies define a host of new, previously unrecognized, applications of BAHA and related triarylaminium radical cations that arises from their ability to generate stabilized electrophilic radicals from ß-ketoesters and related substrates under nonreducing and metal-free conditions. Those exemplified herein include mediating stabilized enolate free radical arylation, dimerization, allylation, alkene addition, and α-oxidation reactions.

VinCaP: a phase II trial of vinflunine in locally advanced and metastatic squamous carcinoma of the penis.

BACKGROUND: We investigated the first-line activity of vinflunine in patients with penis cancer. Cisplatin-based combinations are commonly used, but survival is not prolonged; many patients are unfit for such treatment or experience toxicity that outweighs clinical benefit. METHODS: Twenty-five patients with inoperable squamous carcinoma of the penis were recruited to a single-arm, Fleming-A'Hern exact phase II trial. Treatment comprised 4 cycles of vinflunine 320 mg/m2, given every 21 days. Primary endpoint was clinical benefit rate (CBR: objective responses plus stable disease) assessed after 4 cycles. Seven or more objective responses or disease stabilisations observed in 22 evaluable participants would exclude a CBR of <15%, with a true CBR of >40% being probable. RESULTS: Twenty-two participants were evaluable. Ten objective responses or disease stabilisations were confirmed. CBR was 45.5%, meeting the primary endpoint; partial response rate was 27.3%. Seven patients received >4 cycles of vinflunine. Dose reduction or treatment delay was required for 20% of cycles. In all, 68% of patients experienced at least one grade 3 adverse event. Two deaths on treatment were not caused by disease progression. CONCLUSIONS: Pre-specified clinical activity threshold was exceeded. Toxicity was in keeping with experience in other tumours. Vinflunine merits further study in this disease. TRIAL REGISTRATION: NCT02057913.

Enhancement of Vindoline and Catharanthine Accumulation, Antioxidant Enzymes Activities, and Gene Expression Levels in Catharanthus roseus Leaves by Chitooligosaccharides Elicitation.

Catharanthus roseus (L.) G. Don is a plant belonging to the genus Catharanthus of the Apocynaceae family. It contains more than one hundred alkaloids, of which some exhibit significant pharmacological activities. Chitooligosaccharides are the only basic aminooligosaccharides with positively charged cations in nature, which can regulate plant growth and antioxidant properties. In this study, the leaves of Catharanthus roseus were sprayed with chitooligosaccharides of different molecular weights (1 kDa, 2 kDa, 3 kDa) and different concentrations (0.01 µg/mL, 0.1 µg/mL, 1 µg/mL and 10 µg/mL). The fresh weights of its root, stem and leaf were all improved after chitooligosaccharides treatments. More importantly, the chitooligosaccharides elicitor strongly stimulated the accumulation of vindoline and catharanthine in the leaves, especially with the treatment of 0.1 µg/mL 3 kDa chitooligosaccharides, the contents of them were increased by 60.68% and 141.54%, respectively. Furthermore, as the defensive responses, antioxidant enzymes activities (catalase, glutathione reductase, ascorbate peroxidase, peroxidase and superoxide dismutase) were enhanced under chitooligosaccharides treatments. To further elucidate the underlying mechanism, qRT-PCR was used to investigate the genes expression levels of secologanin synthase (SLS), strictosidine synthase (STR), strictosidine glucosidase (SGD), tabersonine 16-hydroxylase (T16H), desacetoxyvindoline-4-hydroxylase (D4H), deacetylvindoline-4-O-acetyltransferase (DAT), peroxidase 1 (PRX1) and octadecanoid-responsive Catharanthus AP2-domain protein 3 (ORCA3). All the genes were significantly up-regulated after chitooligosaccharides treatments, and the transcription abundance of ORCA3, SLS, STR, DAT and PRX1 reached a maximal level with 0.1 µg/mL 3 kDa chitooligosaccharides treatment. All these results suggest that spraying Catharanthus roseus leaves with chitooligosaccharides, especially 0.1 µg/mL of 3 kDa chitooligosaccharides, may effectively improve the pharmaceutical value of Catharanthus roseus.

Effects of vindoline on rat cytochrome P450 isoform activities in vitro.

A specific ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS) method has been described for the simultaneous determination of the metabolites of tacrine, bupropion, diclofenac, dextromethorphan and midazolam, which are the five probe drugs of the five cytochrome P450 (CYP450) isoforms CYP1A2, CYP2B, CYP2C11, CYP2D1 and CYP3A4. The inhibition degree was determined by calculating the IC50 . The chromatographic separation was performed on a C18 column with a mobile phase consisting of 0.1% formic acid and acetonitrile. The mass spectrometric analysis was conducted in positive electrospray ionization mode. The IC50 values of CYP1A2, CYP2B, CYP2C11, CYP2D1 and CYP3A were 113.4, 83.78, 22.50, 9.081 and 52.76 µmol L-1 , respectively. The in vitro results demonstrated that vindoline could inhibit CYP2D1 activity in rats, and weak inhibitory effect on CYP2C11 and CYP3A, but had no obvious effects on CYP1A2 and CYP2B.

Synthesis of Novel Vindoline-Chrysin Hybrids.

Vinca alkaloids are well-known microtubule targeting agents, which are used against some types of cancer. Vindoline is one of the monomeric Vinca alkaloids which does not have anti-tumor effect, although its derivatives have serious impact on the field of these indole alkaloids. Chrysin is a secondary plant metabolite, which has broad-spectrum biological activity, among others anticancer activity. Chrysin had shown synergic effect with several antiproliferative compounds (e. g., doxorubicin, cisplatin and ciglitazone), therefore, we attempted the synthesis of a novel vindoline-chrysin hybrid molecule. However, in the first case a diphenylamine structure was isolated. The mechanism of the unexpected reaction was studied, and then the originally targeted hybrid was synthesized by a reverse route coupling. A further hybrid was produced using a different site of the molecule. The antitumor activities were determined against 60 human tumor cell lines (NCI60), where the aimed hybrid showed low micromolar GI50 values on most of the cell lines.

Optimization of Tabersonine Methoxylation to Increase Vindoline Precursor Synthesis in Yeast Cell Factories.

Plant specialized metabolites are widely used in the pharmaceutical industry, including the monoterpene indole alkaloids (MIAs) vinblastine and vincristine, which both display anticancer activity. Both compounds can be obtained through the chemical condensation of their precursors vindoline and catharanthine extracted from leaves of the Madagascar periwinkle. However, the extensive use of these molecules in chemotherapy increases precursor demand and results in recurrent shortages, explaining why the development of alternative production approaches, such microbial cell factories, is mandatory. In this context, the precursor-directed biosynthesis of vindoline from tabersonine in yeast-expressing heterologous biosynthetic genes is of particular interest but has not reached high production scales to date. To circumvent production bottlenecks, the metabolic flux was channeled towards the MIA of interest by modulating the copy number of the first two genes of the vindoline biosynthetic pathway, namely tabersonine 16-hydroxylase and tabersonine-16-O-methyltransferase. Increasing gene copies resulted in an optimized methoxylation of tabersonine and overcame the competition for tabersonine access with the third enzyme of the pathway, tabersonine 3-oxygenase, which exhibits a high substrate promiscuity. Through this approach, we successfully created a yeast strain that produces the fourth biosynthetic intermediate of vindoline without accumulation of other intermediates or undesired side-products. This optimization will probably pave the way towards the future development of yeast cell factories to produce vindoline at an industrial scale.

Completion of the canonical pathway for assembly of anticancer drugs vincristine/vinblastine in Catharanthus roseus.

The important anticancer drugs, vinblastine, vincristine and analogs, are composed of the monoterpenoid indole alkaloids (MIAs), catharanthine and vindoline, found uniquely in the medicinal plant, Catharanthus roseus. While 26 genes involved in the assembly of these two MIAs are known, two key reactions have eluded characterization to complete the documentation of the vinblastine pathway in this plant species. The assembly of these dimeric MIAs requires O-acetylstemmadenine oxidase (ASO) and a dual function geissoschizine synthase (GS) that reduces cathenamine to form geissoschizine, and that also reduces the ASO product to form a common intermediate for subsequent conversion by four separate hydrolases to catharanthine, tabersonine or vincadifformine, respectively. The in planta role of ASO is supported by identifying a single amino acid-substituted ASO mutant with very low enzyme activity and by virus-induced gene silencing of ASO to produce plants that accumulate O-acetylstemmadenine rather than catharanthine and vindoline found in wild-type (WT) plants. The in planta role of GS is supported by showing that a low GS-expressing mutant accumulating lower levels of catharanthine and vindoline also displays significantly lower tabersonine-forming activity in coupled enzyme assays than in the WT background. Gene expression analyses demonstrate that both ASO and GS are highly enriched in the leaf epidermis where the pathways for catharanthine and tabersonine biosynthesis are expressed. The full elucidation of this canonical pathway enables synthetic biology approaches for manufacturing a broad range of MIAs, including these dimers used in cancer treatment.

Pembrolizumab as Second-Line Therapy for Advanced Urothelial Carcinoma.

BACKGROUND: Patients with advanced urothelial carcinoma that progresses after platinum-based chemotherapy have a poor prognosis and limited treatment options. METHODS: In this open-label, international, phase 3 trial, we randomly assigned 542 patients with advanced urothelial cancer that recurred or progressed after platinum-based chemotherapy to receive pembrolizumab (a highly selective, humanized monoclonal IgG4κ isotype antibody against programmed death 1 [PD-1]) at a dose of 200 mg every 3 weeks or the investigator's choice of chemotherapy with paclitaxel, docetaxel, or vinflunine. The coprimary end points were overall survival and progression-free survival, which were assessed among all patients and among patients who had a tumor PD-1 ligand (PD-L1) combined positive score (the percentage of PD-L1-expressing tumor and infiltrating immune cells relative to the total number of tumor cells) of 10% or more. RESULTS: The median overall survival in the total population was 10.3 months (95% confidence interval [CI], 8.0 to 11.8) in the pembrolizumab group, as compared with 7.4 months (95% CI, 6.1 to 8.3) in the chemotherapy group (hazard ratio for death, 0.73; 95% CI, 0.59 to 0.91; P=0.002). The median overall survival among patients who had a tumor PD-L1 combined positive score of 10% or more was 8.0 months (95% CI, 5.0 to 12.3) in the pembrolizumab group, as compared with 5.2 months (95% CI, 4.0 to 7.4) in the chemotherapy group (hazard ratio, 0.57; 95% CI, 0.37 to 0.88; P=0.005). There was no significant between-group difference in the duration of progression-free survival in the total population (hazard ratio for death or disease progression, 0.98; 95% CI, 0.81 to 1.19; P=0.42) or among patients who had a tumor PD-L1 combined positive score of 10% or more (hazard ratio, 0.89; 95% CI, 0.61 to 1.28; P=0.24). Fewer treatment-related adverse events of any grade were reported in the pembrolizumab group than in the chemotherapy group (60.9% vs. 90.2%); there were also fewer events of grade 3, 4, or 5 severity reported in the pembrolizumab group than in the chemotherapy group (15.0% vs. 49.4%). CONCLUSIONS: Pembrolizumab was associated with significantly longer overall survival (by approximately 3 months) and with a lower rate of treatment-related adverse events than chemotherapy as second-line therapy for platinum-refractory advanced urothelial carcinoma. (Funded by Merck; KEYNOTE-045 ClinicalTrials.gov number, NCT02256436 .).

GATA and Phytochrome Interacting Factor Transcription Factors Regulate Light-Induced Vindoline Biosynthesis in Catharanthus roseus.

Catharanthus roseus is the exclusive source of an array of terpenoid indole alkaloids including the anticancer drugs vincristine and vinblastine, derived from the coupling of catharanthine and vindoline. Leaf-synthesized vindoline is regulated by light. A seven-step enzymatic process is involved in the sequential conversion of tabersonine to vindoline; however, the regulatory mechanism controlling the expression of genes encoding these enzymes has not been elucidated. Here, we identified CrGATA1, an Leu-Leu-Met domain GATA transcription factor that regulates light-induced vindoline biosynthesis in C. roseus seedlings. Expression of CrGATA1 and the vindoline pathway genes T16H2, T3O, T3R, D4H, and DAT was significantly induced by light. In addition, CrGATA1 activated the promoters of five light-responsive vindoline pathway genes in plant cells. Two GATC motifs in the D4H promoter were critical for CrGATA1-mediated transactivation. Transient overexpression of CrGATA1 in C. roseus seedlings resulted in up-regulation of vindoline pathway genes and increased vindoline accumulation. Conversely, virus-induced gene silencing of CrGATA1 in young C. roseus leaves significantly repressed key vindoline pathway genes and reduced vindoline accumulation. Furthermore, we showed that a C. roseus Phytochrome Interacting Factor, CrPIF1, is a repressor of CrGATA1 and vindoline biosynthesis. Transient overexpression or virus-induced gene silencing of CrPIF1 in C. roseus seedlings altered CrGATA1 and vindoline pathway gene expression in the dark. CrPIF1 repressed CrGATA1 and DAT promoter activity by binding to G/E-box/PBE elements. Our findings reveal a regulatory module involving Phytochrome Interacting Factor -GATA that governs light-mediated biosynthesis of specialized metabolites.

Pembrolizumab versus chemotherapy in recurrent, advanced urothelial cancer in Japanese patients: a subgroup analysis of the phase 3 KEYNOTE-045 trial.

BACKGROUND: The open-label, randomized, active-controlled KEYNOTE-045 study (NCT02256436) showed that second-line pembrolizumab significantly improved overall survival (OS) of patients with advanced/metastatic urothelial cancer (UC) that progressed after first-line platinum-containing chemotherapy, compared with standard chemotherapy (paclitaxel, docetaxel, or vinflunine). Pembrolizumab is approved for patients with bladder cancer in Japan. PATIENTS AND METHODS: Analysis was performed in the subgroup of Japanese patients enrolled in the KEYNOTE-045 study. Coprimary end points were OS and progression-free survival (PFS). Objective response rate (ORR) and safety were secondary end points. RESULTS: Fifty-two Japanese patients (pembrolizumab, n = 30; chemotherapy, n = 22) were followed up for a median of 26.1 months. Patients who received pembrolizumab compared with chemotherapy had a 19% lower risk for death (hazard ratio [HR] 0.81, 95% CI 0.44-1.50); after adjusting for baseline covariates, the HR for OS was 0.61 (95% CI 0.32-1.15). The 24-month OS rate was higher with pembrolizumab (26.9% vs 14.3%). PFS was 2.0 and 4.9 months for pembrolizumab and chemotherapy, respectively (HR 1.71, 95% CI 0.95-3.08). ORR was similar for pembrolizumab and chemotherapy (20.0% vs 18.2%); durability of response was higher with pembrolizumab: 67% and 33% of patients, respectively, maintained a response for > 12 months. Treatment-related adverse events, including grade 3-5 events, occurred less frequently with pembrolizumab. CONCLUSIONS: Pembrolizumab provided durable antitumor activity in patients with locally advanced/metastatic UC that progressed after platinum-containing chemotherapy in the overall population and in the Japanese subgroup; safety profile was consistent with that previously observed for pembrolizumab.

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.

In Vitro Antidiabetic and Antioxidant Effects of Different Extracts of Catharanthus roseus and Its Indole Alkaloid, Vindoline.

The Catharanthus roseus plant has been used traditionally to treat diabetes mellitus. Scientific evidence supporting the antidiabetic effects of this plant's active ingredient-vindoline has not been fully evaluated. In this study, extracts of C. roseus and vindoline were tested for antioxidant activities, alpha amylase and alpha glucosidase inhibitory activities and insulin secretory effects in pancreatic RIN-5F cell line cultured in the absence of glucose, at low and high glucose concentrations. The methanolic extract of the plant showed the highest antioxidant activities in addition to the high total polyphenolic content (p < 0.05). The HPLC results exhibited increased concentration of vindoline in the dichloromethane and the ethylacetate extracts. Vindoline showed noticeable antioxidant activity when compared to ascorbic acid at p < 0.05 and significantly improved the in vitro insulin secretion. The intracellular reactive oxygen species formation in glucotoxicity-induced cells was significantly reduced following treatment with vindoline, methanolic and the dichloromethane extracts when compared to the high glucose untreated control (p < 0.05). Plant extracts and vindoline showed weaker inhibitory effects on the activities of carbohydrate metabolizing enzymes when compared to acarbose, which inhibited the activities of the enzymes by 80%. The plant extracts also exhibited weak alpha amylase and alpha glucosidase inhibitory effects.

Triarylaminium Radical Cation Promoted Coupling of Catharanthine with Vindoline: Diastereospecific Synthesis of Anhydrovinblastine and Reaction Scope.

A new triarylaminium radical cation promoted coupling of catharanthine with vindoline is disclosed, enlisting tris(4-bromophenyl)aminium hexachlororantimonate (BAHA, 1.1 equiv) in aqueous 0.05 N HCl/trifluoroethanol (1-10:1) at room temperature (25 °C), that provides anhydrovinblastine in superb yield (85%) with complete control of the newly formed quaternary C16' stereochemistry. A definition of the scope of aromatic substrates that participate with catharanthine in the BAHA-mediated diastereoselective coupling reaction and simplified indole substrates other than catharanthine that participate in the reaction are disclosed that identify the key structural features required for participation in the reaction, providing a generalized indole functionalization reaction that bears little structural relationship to catharanthine or vindoline.

Atezolizumab versus chemotherapy in patients with platinum-treated locally advanced or metastatic urothelial carcinoma (IMvigor211): a multicentre, open-label, phase 3 randomised controlled trial.

BACKGROUND: Few options exist for patients with locally advanced or metastatic urothelial carcinoma after progression with platinum-based chemotherapy. We aimed to assess the safety and efficacy of atezolizumab (anti-programmed death-ligand 1 [PD-L1]) versus chemotherapy in this patient population. METHODS: We conducted this multicentre, open-label, phase 3 randomised controlled trial (IMvigor211) at 217 academic medical centres and community oncology practices mainly in Europe, North America, and the Asia-Pacific region. Patients (aged ≥18 years) with metastatic urothelial carcinoma who had progressed after platinum-based chemotherapy were randomly assigned (1:1), via an interactive voice and web response system with a permuted block design (block size of four), to receive atezolizumab 1200 mg or chemotherapy (physician's choice: vinflunine 320 mg/m2, paclitaxel 175 mg/m2, or 75 mg/m2 docetaxel) intravenously every 3 weeks. Randomisation was stratified by PD-L1 expression (expression on <1% [IC0] or 1% to <5% [IC1] of tumour-infiltrating immune cells vs ≥5% of tumour-infiltrating immune cells [IC2/3]), chemotherapy type (vinflunine vs taxanes), liver metastases (yes vs no), and number of prognostic factors (none vs one, two, or three). Patients and investigators were aware of group allocation. Patients, investigators, and the sponsor were masked to PD-L1 expression status. The primary endpoint of overall survival was tested hierarchically in prespecified populations: IC2/3, followed by IC1/2/3, followed by the intention-to-treat population. This study, which is ongoing but not recruiting participants, is registered with ClinicalTrials.gov, number NCT02302807. FINDINGS: Between Jan 13, 2015, and Feb 15, 2016, we randomly assigned 931 patients from 198 sites to receive atezolizumab (n=467) or chemotherapy (n=464). In the IC2/3 population (n=234), overall survival did not differ significantly between patients in the atezolizumab group and those in the chemotherapy group (median 11·1 months [95% CI 8·6-15·5; n=116] vs 10·6 months [8·4-12·2; n=118]; stratified hazard ratio [HR] 0·87, 95% CI 0·63-1·21; p=0·41), thus precluding further formal statistical analysis. Confirmed objective response rates were similar between treatment groups in the IC2/3 population: 26 (23%) of 113 evaluable patients had an objective response in the atezolizumab group compared with 25 (22%) of 116 patients in the chemotherapy group. Duration of response was numerically longer in the atezolizumab group than in the chemotherapy group (median 15·9 months [95% CI 10·4 to not estimable] vs 8·3 months [5·6-13·2]; HR 0·57, 95% CI 0·26-1·26). In the intention-to-treat population, patients receiving atezolizumab had fewer grade 3-4 treatment-related adverse events than did those receiving chemotherapy (91 [20%] of 459 vs 189 [43%] of 443 patients), and fewer adverse events leading to treatment discontinuation (34 [7%] vs 78 [18%] patients). INTERPRETATION: Atezolizumab was not associated with significantly longer overall survival than chemotherapy in patients with platinum-refractory metastatic urothelial carcinoma overexpressing PD-L1 (IC2/3). However, the safety profile for atezolizumab was favourable compared with chemotherapy, Exploratory analysis of the intention-to-treat population showed well-tolerated, durable responses in line with previous phase 2 data for atezolizumab in this setting. FUNDING: F Hoffmann-La Roche, Genentech.