Vinflunine, the latest Vinca alkaloid in clinical development. A review of its preclinical anticancer properties

From Crypts to Cancer: A Holistic Perspective on Colorectal Carcinogenesis and Therapeutic Strategies

Colorectal cancer (CRC) represents a significant global health burden, with high incidence and mortality rates worldwide. Recent progress in research highlights the distinct clinical and molecular characteristics of colon versus rectal cancers, underscoring tumor location's importance in treatment approaches. This article provides a comprehensive review of our current understanding of CRC epidemiology, risk factors, molecular pathogenesis, and management strategies. We also present the intricate cellular architecture of colonic crypts and their roles in intestinal homeostasis. Colorectal carcinogenesis multistep processes are also described, covering the conventional adenoma-carcinoma sequence, alternative serrated pathways, and the influential Vogelstein model, which proposes sequential APC, KRAS, and TP53 alterations as drivers. The consensus molecular CRC subtypes (CMS1-CMS4) are examined, shedding light on disease heterogeneity and personalized therapy implications.

Catalysts of Healing: A Symphony of Synthesis and Clinical Artistry in Small-Molecule Agents for Breast Cancer Alleviation

Breast cancer, characterized by its molecular intricacy, has witnessed a surge in targeted therapeutics owing to the rise of small-molecule drugs. These entities, derived from cutting-edge synthetic routes, often encompassing multistage reactions and chiral synthesis, target a spectrum of oncogenic pathways. Their mechanisms of action range from modulating hormone receptor signaling and inhibiting kinase activity, to impeding DNA damage repair mechanisms. Clinical applications of these drugs have resulted in enhanced patient survival rates, reduction in disease recurrence, and improved overall therapeutic indices. Notably, certain molecules have showcased efficacy in drug-resistant breast cancer phenotypes, highlighting their potential in addressing treatment challenges. The evolution and approval of small-molecule drugs have ushered in a new era for breast cancer therapeutics. Their tailored synthetic pathways and defined mechanisms of action have augmented the precision and efficacy of treatment regimens, paving the way for improved patient outcomes in the face of this pervasive malignancy. The present review embarks on a detailed exploration of small-molecule drugs that have secured regulatory approval for breast cancer treatment, emphasizing their clinical applications, synthetic pathways, and distinct mechanisms of action.

Phyto-therapeutics as anti-cancer agents in breast cancer: Pathway targeting and mechanistic elucidation

Cancer of the breast is the mainly prevalent class of cancer in females diagnosed over the globe. It also happens to be the 2nd most prevalent reason of cancer-related deaths among females worldwide. Some of the most common type's therapies for carcinoma of the breast involve radiation therapy, chemotherapy, and resection. Many studies are being conducted to develop new therapeutic strategies for better diagnosis of breast cancer. An enormous number of anticancer medications have been developed as a result of growing understanding of the molecular pathways behind the advancement of cancer. Over the past few decades, the general survival rate has not greatly increased due to the usage of chemically manufactured medications. Therefore, in order to increase the effectiveness of current cancer treatments, new tactics and cutting-edge chemoprevention drugs are required. Phytochemicals, which are naturally occurring molecules derived from plants, are important sources for both cancer therapy and innovative medication development. These phytochemicals frequently work by controlling molecular pathways linked to the development and spread of cancer. Increasing antioxidant status, inactivating carcinogens, preventing proliferation, causing cell cycle arrest and apoptosis, and immune system control are some of the specific ways. This primary objective of this review is to provide an overview of the active ingredients found in natural goods, including information on their pharmacologic action, molecular targets, and current state of knowledge. We have given a thorough description of a number of natural substances that specifically target the pathways linked to breast carcinoma in this study. We've conducted a great deal of study on a few natural compounds that may help us identify novel targets for the detection of breast carcinoma.

Switch Maintenance Therapy for Metastatic Urothelial Carcinoma

INTRODUCTION

While switch maintenance therapy is being increasingly investigated in solid tumors, it is a standard in only a few. We conducted a systematic review on switch maintenance therapy for metastatic urothelial carcinoma.

EVIDENCE ACQUISITION

In this systematic review, we conducted a literature search in PubMed and Cochrane databases up to 2021, based on PRISMA statement guidelines. One hundred and fifty eight articles were identified and after a three-step selection process and six articles, using different agents were included in evidence synthesis. The primary end points were effect on overall survival, progression free survival, safety and tolerability.

EVIDENCE SYNTHESIS

In the pre-immunotherapy era, targeted therapies like sunitinib, lapatinib and vinflunine were studied as switch maintenance therapy in metastatic urothelial carcinoma but did not show any overall survival benefit. Use of anti-PD-1/PD-L1 agents have shown promise as switch maintenance therapy; pembrolizumab showed improvement in progression free survival in a phase 2 trial and avelumab showed improvement in overall survival and progression free survival in the phase 3 JAVELIN Bladder 100 trial.

CONCLUSION

Immunotherapy with anti-PD-1/PD-L1 agents has emerged as an effective switch maintenance strategy in patients with metastatic urothelial carcinoma. Intensification of the immunotherapy backbone in this setting can potentially further enhance outcomes. Emerging evidence shows a potential role of Poly (ADP-ribose) polymerase (PARP) inhibitors in this setting as well. Results from ongoing and planned studies will help us understand which switch maintenance approaches would be most effective for improving outcomes in metastatic urothelial carcinoma.

Naturally occurring, natural product inspired and synthetic heterocyclic anti-cancer drugs

This chapter describes the importance and activity of a huge number of commercially available naturally occurring, natural product derived or synthetic heterocyclic anti-cancer drugs.

Epithelial-to-Mesenchymal Transition Mediates Resistance to Maintenance Therapy with Vinflunine in Advanced Urothelial Cell Carcinoma

Simple Summary

Platinum-based chemotherapy is the first-line treatment for advanced urothelial cell carcinoma (aUCC). After first-line treatment, we previously showed that maintenance therapy with vinflunine improves progression-free survival. However, some patients are resistant to vinflunine and the specific mechanisms of resistance in aUCC are unclear. We analyzed the genomic landscape and the biological processes potentially related to vinflunine activity and found that epithelial-to-mesenchymal transition (EMT) plays a pivotal role as a resistance mechanism. In experiments with cell lines, curcumin reversed EMT and sensitized cells to vinflunine. We suggest that EMT mediates resistance to vinflunine and that the reversion of this process could enhance the effect of vinflunine in aUCC patients.

Abstract

In the phase II MAJA trial, maintenance therapy with vinflunine resulted in longer progression-free survival compared to best supportive care in advanced urothelial cell carcinoma (aUCC) patients who did not progress after first-line platinum-based chemotherapy. However, despite an initial benefit observed in some patients, unequivocal resistance appears which underlying mechanisms are presently unknown. We have performed gene expression and functional enrichment analyses to shed light on the discovery of these underlying resistance mechanisms. Differential gene expression profile of eight patients with poor outcome and nine with good outcome to vinflunine administered in the MAJA trial were analyzed. RNA was isolated from tumor tissue and gene expression was assessed by microarray. Differential expression was determined with linear models for microarray data. Gene Set Enrichment Analysis (GSEA) was used for the functional classification of the genes. In vitro functional studies were performed using UCC cell lines. Hierarchical clustering showed a differential gene expression pattern between patients with good and poor outcome to vinflunine treatment. GSEA identified epithelial-to-mesenchymal transition (EMT) as the top negatively enriched hallmark in patients with good outcome. In vitro analyses showed that the polyphenol curcumin downregulated EMT markers and sensitized UCC cells to vinflunine. We conclude that EMT mediates resistance to vinflunine and suggest that the reversion of this process could enhance the effect of vinflunine in aUCC patients.

A review of research progress of antitumor drugs based on tubulin targets

Microtubules exist in all eukaryotic cells and are one of the critical components that make up the cytoskeleton. Microtubules play a crucial role in supporting cell morphology, cell division, and material transport. Tubulin modulators can promote microtubule polymerization or cause microtubule depolymerization. The modulators interfere with the mitosis of cells and inhibit cell proliferation. Tubulin mainly has three binding domains, namely, paclitaxel, vinca and colchicine binding domains, which are the best targets for the development of anticancer drugs. Currently, drugs for tumor therapy have been developed for these three domains. However, due to its narrow therapeutic window, poor selectivity, and susceptibility to drug resistance, it has severely limited clinical applications. The method of combined medication, the change of administration method, the modification of compound structure, and the research and development of new targets have all changed the side effects of tubulin drugs to a certain extent. In this review, we briefly introduce a basic overview of tubulin and the main mechanism of anti-tumor. Secondly, we focus on the application of drugs which developed based on the three domains of tubulin to various cancers in various fields. Finally, we further provide the development progress of tubulin inhibitors currently in clinical trials.

An overview on anti-tubulin agents for the treatment of lymphoma patients

Anti-tubulin agents constitute a large class of compounds with broad activity both in solid tumors and hematologic malignancies, due to the interference with microtubule dynamics. Since microtubules play crucial roles in the regulation of the mitotic spindles, the interference with their function usually leads to a block in cell division with arrest at the metaphase/anaphase junction of mitosis, followed to apoptosis. This explains the reason why tubulin-binding agents (TBAs) proved to be extremely active in patients with cancer. Several anti-tubulin agents are indicated in the treatment of patients with lymphomas both alone and in combination chemotherapy regimens. The article reviews the literature on classic and more recent anti-tubulin agents, providing an insight into their mechanisms of action and their use in the treatment of lymphoma.

Utilizing Synergistic Potential of Mitochondria-Targeting Drugs for Leukemia Therapy

Acute myeloid leukemia (AML) is an aggressive group of cancers with high mortality rates and significant relapse risks. Current treatments are insufficient, and new therapies are needed. Recent discoveries suggest that AML may be particularly sensitive to chemotherapeutics that target mitochondria. To further investigate this sensitivity, six compounds that target mitochondria [IACS-010759, rotenone, cytarabine, etoposide, ABT-199 (venetoclax), and carbonyl cyanide m-chlorophenylhydrazone] were each paired with six compounds with other activities, including tyrosine kinase inhibitors (midostaurin and dasatinib), glycolytic inhibitors (2-deoxy-D-glucose, 3-bromopyruvate, and lonidamine), and the microtubule destabilizer vinorelbine. The 36 resulting drug combinations were tested for synergistic cytotoxicity against MOLM-13 and OCI-AML2 AML cell lines. Four combinations (IACS-010759 with vinorelbine, rotenone with 2-deoxy-D-glucose, carbonyl cyanide m-chlorophenylhydrazone with dasatinib, and venetoclax with lonidamine) showed synergistic cytotoxicity in both AML cell lines and were selective for tumor cells, as survival of healthy PBMCs was dramatically higher. Among these drug pairs, IACS-010759/vinorelbine decreased ATP level and impaired mitochondrial respiration and coupling efficiency most profoundly. Some of these four treatments were also effective in K-562, KU812 (chronic myelogenous leukemia) and CCRF-CEM, MOLT-4 (acute lymphoblastic leukemia) cells, suggesting that these treatments may have value in treating other forms of leukemia. Finally, two of the four combinations retained high synergy and strong selectivity in primary AML cells from patient samples, supporting the potential of these treatments for patients.

Randomised phase III trial of vinflunine plus capecitabine versus capecitabine alone in patients with advanced breast cancer previously treated with an anthracycline and resistant to taxane

Background

Capecitabine is an approved standard therapy for anthracycline- and taxane-pretreated locally advanced or metastatic breast cancer (BC). Vinflunine has demonstrated single-agent activity in phase II studies in this setting and activity and tolerability when combined with capecitabine. We compared the combination of vinflunine plus capecitabine (VC) with single-agent capecitabine.

Patients and methods

Patients with locally recurrent/metastatic BC previously treated or resistant to an anthracycline and resistant to taxane therapy were randomly assigned to either vinflunine (280 mg/m2, day 1) plus oral capecitabine [825 mg/m2 twice daily (b.i.d.), days 1-14] every 3 weeks (q3w) or single-agent oral capecitabine (1250 mg/m2 b.i.d., days 1-14) q3w. The primary end point was progression-free survival (PFS) assessed by an independent review committee. The study had 90% power to detect a 30% improvement in PFS.

Results

Overall, 770 patients were randomised. PFS was significantly longer with VC than with capecitabine alone [hazard ratio, 0.84, 95% confidence interval (CI), 0.71-0.99; log-rank P = 0.043; median 5.6 versus 4.3 months, respectively]. Median overall survival was 13.9 versus 11.7 months with VC versus capecitabine alone, respectively (hazard ratio, 0.98; 95% CI, 0.83-1.15; log-rank P = 0.77). No difference in quality of life was observed between the two treatment arms. The most common adverse events (NCI CTCAE version 3.0) in the combination arm were haematological and gastrointestinal. Grade 4 neutropenia was more frequent with VC (12% versus 1% with capecitabine alone); febrile neutropenia occurred in 2% versus 0.5%, respectively. Hand-foot syndrome was less frequent with VC (grade 3: 4% versus 19% for capecitabine alone). Peripheral neuropathy was uncommon in both arms (grade 3: 1% versus 0.3%).

Conclusions

Vinflunine combined with capecitabine demonstrated a modest improvement in PFS and an acceptable safety profile compared with capecitabine alone in patients with anthracycline- and taxane-pretreated locally recurrent/metastatic BC.

ClinicalTrials.gov

NCT01095003.

Vinflunine in the treatment of relapsed metastatic urothelial cancer: A systematic review and meta-analysis of real-world series

BACKGROUND

Vinflunine (VFL) is approved in Europe as second-line treatment of metastatic urothelial cancer after failure of platinum-containing therapy. We performed a systematic review and meta-analysis of real-world data (RWD) to assess utilization, efficacy and safety of VFL.

METHODS

We performed a MEDLINE search for the period of 1/1/2000-31/8/2017. Full-length articles providing post-marketing RWD on VFL in patients failing previous chemotherapy were eligible. Interventional clinical trials were excluded.

RESULTS

Ten studies with 797 patients were identified. According to pooled REs analysis, overall response rate was 19%, most frequent, all-grade toxicities were fatigue (41%), constipation (39%), nausea/vomiting (25%), and most prevalent Grade 3-4 toxicities were neutropenia (13%), anaemia (9%), fatigue (8%). Median OS was comparable to results reported in recent randomized studies.

CONCLUSION

Our findings confirm the efficacy and safety of VFL in an unselected population and support the use of VFL in the changing treatment paradigm of relapsed mUC.

Towards modern anticancer agents that interact with tubulin

Tubulin is the primary target of an ever growing number of natural, semisynthetic and synthetic products as potential anticancer agents. The mechanisms of interaction of these molecules with tubulin are varied. These drug classes have shown to inhibit effectively several cancer types with IC₅₀ from midmicromolar to low nanomolar concentrations. However, some limiting obstacles still remain, such as the development of multidrug resistance and cytotoxicity. We have reviewed recent advances in different classes of tubulin binding agents, including colchicine site agents, Vinca alkaloids, tryprostatins, moroidin, hemiasterlin, diazonamide, taxanes, epothilones and laulimalide.

Safety of Vinflunine in Patients with Advanced Urothelial Carcinoma Refractory to Platinum-based Chemotherapy: A Prospective Pilot Study

BACKGROUND

Several single chemotherapeutic agents have been evaluated as the second-line treatment of advanced urothelial carcinoma. Despite encouraging efficacy outcomes, toxicity has often led to dose modifications or discontinuation. We aimed to assess the safety of vinflunine in a particular population of advanced transitional cell carcinoma of urothelium (TCCU), that were exposed to the previous toxicity of chemotherapy.

METHODS

This is an open-label, prospective, single-center pilot study to evaluate the response rate and safety profile of vinflunine in patients with advanced TCCU. It was planned to enroll 25 evaluable patients. Eligible patients are those with progressive disease after first-line platinum-based regimen for advanced or metastatic disease.

RESULTS

The study was prematurely closed due to two sudden deaths that were judged by the review board as treatment-related. Only ten patients were evaluated and received at least one cycle of vinflunine. All but one were male and seven underwent radical surgery. Eight had a distant metastasis (mainly lung and/or liver). Disease control rate was 40%, four patients had a partial response with median duration of response of 3.5 months. The median overall survival was 3.2 months (95% CI:1.67- 4.73). There were three serious adverse events namely two sudden deaths and one grade 4 thrombocytopenia. Nine grade 3/4 adverse events occurred. The most common all-grade adverse events were fatigue (50%), constipation (40%) and vomiting (40%). Moreover, grade 3 fatigue occurred in 30% of patients. Only one patient, who achieved PR for 5 months, was fit to receive further cytotoxic chemotherapy.

CONCLUSION

The activity of vinflunine in advanced urothelial carcinoma came at the expense of its safety. The use of vinflunine has to be limited to the selected group of patients. However, this is a single institute experience in a limited number of patients.

Vinflunine for the treatment of advanced or metastatic transitional cell carcinoma of the urothelial tract: an evidence-based review of safety, efficacy, and place in therapy

Background

A systematic review and meta-analysis of the use of systemic vinflunine (VIN) in the treatment of urothelial carcinoma (UC) was performed to evaluate its efficacy based on current available clinical data.

Methods

This review was prospectively registered at the International Prospective Register of Systematic Reviews, PROSPERO (registration CRD42016049294). Electronic databases including MEDLINE^®, Embase^®, Cochrane Central Register of Controlled Trials, and Web of Science were searched through December 2016. We performed a meta-analysis of the published data. Primary end points were progression-free survival (PFS) and overall survival (OS). Numerous secondary clinical outcomes were analyzed including response and toxicity data.

Results

We identified 382 publications, of which 35 met inclusion criteria for this review representing 29 unique studies. A total of 2,255 patients received VIN for the treatment of UC in the included studies. OS and PFS were analyzed in a pooled Kaplan–Meier analysis. Response data were available for 1,416 VIN-treated patients with random effects proportion of complete response in 1%, partial response in 18%, and overall response rate of 21%. Toxicity analysis revealed fatigue (40.1%), nausea (33.9%), constipation (34.1%), and alopecia (26.0%) as the most prevalent overall non-hematologic adverse events (AEs). Most prevalent grade 3–4 AEs were fatigue (10.2%), abdominal pain (8.2%), myalgias (2.5%), and nausea (2.3%). Most common hematologic AEs of all grades were anemia (56.6%), neutropenia (46.0%), thrombocytopenia (25.5%), and febrile neutropenia (6.6%). Grade 3–4 hematologic AEs had the following pooled rates: neutropenia, 24.6%; anemia, 10.2%; febrile neutropenia, 5.4%; and thrombocytopenia, 3.0%.

Conclusion

VIN has been explored as a combination first-line treatment as well as a single-agent second-line, third-line, and maintenance therapy for advanced and metastatic UC. In first-line treatment of UC, either as a maintenance agent after cisplatin or as a primary combination therapy, VIN may be a promising alternative to current treatments. Further studies are needed to compare first-line combination VIN regimens to the current standard of care in order to assess long-term survival outcomes. Second- and third-line VIN monotherapy does provide a proven, although limited, survival benefit in platinum-refractory patients.

Anti-mitotic agents: Are they emerging molecules for cancer treatment?

Mutations in cancer cells frequently result in cell cycle alterations that lead to unrestricted growth compared to normal cells. Considering this phenomenon, many drugs have been developed to inhibit different cell-cycle phases. Mitotic phase targeting disturbs mitosis in tumor cells, triggers the spindle assembly checkpoint and frequently results in cell death. The first anti-mitotics to enter clinical trials aimed to target tubulin. Although these drugs improved the treatment of certain cancers, and many anti-microtubule compounds are already approved for clinical use, severe adverse events such as neuropathies were observed. Since then, efforts have been focused on the development of drugs that also target kinases, motor proteins and multi-protein complexes involved in mitosis. In this review, we summarize the major proteins involved in the mitotic phase that can also be targeted for cancer treatment. Finally, we address the activity of anti-mitotic drugs tested in clinical trials in recent years.

Vinflunine in the treatment of advanced urothelial cancer: clinical evidence and experience

Vinflunine (VFL) has been approved in Europe for second-line treatment of metastatic and advanced urothelial cancer after failure of platin-containing therapy. Since approval, the drug has been investigated in few clinical trials. Most of the currently available reports describe experiences with VFL in a daily clinical setting. This review gives a short overview on clinical experiences and clinical trials involving VFL since the approval of this drug in 2009.

Vinflunine for the treatment of non-small cell lung cancer

INTRODUCTION

Vinflunine belongs to the class of vinca alkaloids and acts by disrupting the microtubule dynamics during cell cycle; this agent is currently available for previously treated advanced transitional cell carcinoma in Europe. The aim of this invited review is to evaluate the potential role of vinflunine for the treatment of non-small cell lung cancer (NSCLC). Areas covered: The potential role of vinflunine in NSCLC is discussed on the basis of the available data, including full papers and meeting abstracts. Relevant preclinical studies describing the pharmacological properties of vinflunine are also included. The review also summarizes clinical studies, including phase I trials involving NSCLC among other tumors as well as phase II/III trials specifically addressing this malignancy. Additionally, the safety profile and the current regulatory status of vinflunine is discussed. Expert opinion: Vinflunine is active as single agent and as part of platinum-based combinations in NSCLC. It results non-inferior to docetaxel in a randomized phase III trial including previously treated NSCLC patients; additionally, its safety profile is generally considered manageable. Ultimately, further studies are needed to confirm the role of vinflunine in NSCLC, in consideration of the evolving evidence regarding targeted therapies and immune check-point inhibitors.

A Novel Resveratrol Based Tubulin Inhibitor Induces Mitotic Arrest and Activates Apoptosis in Cancer Cells

Resveratrol is one of the most widely studied bioactive plant polyphenols which possesses anticancer properties. Previously we have reported synthesis, characterization and identification of a novel resveratrol analog, SS28. In the present study, we show that SS28 induced cytotoxicity in several cancer cell lines ex vivo with an IC₅₀ value of 3–5 μM. Mechanistic evaluation of effect of SS28 in non-small cell lung cancer cell line (A549) and T-cell leukemic cell line (CEM) showed that it inhibited Tubulin polymerization during cell division to cause cell cycle arrest at G2/M phase of the cell cycle at 12–18 h time period. Immunofluorescence studies confirmed the mitotic arrest upon treatment with SS28. Besides, we show that SS28 binds to Tubulin with a dissociation constant of 0.414 ± 0.11 μM. Further, SS28 treatment resulted in loss of mitochondrial membrane potential, activation of Caspase 9 and Caspase 3, leading to PARP-1 cleavage and finally cell death via intrinsic pathway of apoptosis. Importantly, treatment with SS28 resulted in regression of tumor in mice. Hence, our study reveals the antiproliferative activity of SS28 by disrupting microtubule dynamics by binding to its cellular target Tubulin and its potential to be developed as an anticancer molecule.

Vinflunine for the treatment of breast cancer

INTRODUCTION

Breast cancer is the most frequently diagnosed cancer and the highest cause of cancer mortality in females worldwide. The development of drugs improving overall survival in late-stage metastatic breast cancer remains a challenge. Vinflunine is the most recently developed drug in the vinca alkaloid class. Its arrival has been eagerly awaited for treatment of solid tumors, and in particular, for metastatic breast cancer.

AREAS COVERED

The pharmacological features of vinflunine are described. Its clinical development as monotherapy or in combination in metastatic breast cancer is detailed. A literature search on the topic was conducted through PubMed, clinical trials and the proceedings of the main cancer congresses.

EXPERT OPINION

The overall results from phase III studies, and in particular those that combined vinflunine with capecitabine, have been less favorable. The combination's effectiveness was at best moderate compared with other drugs which also target metastatic breast cancer, and complicated by significant hematological and gastrointestinal adverse effects. Its use in advanced metastatic breast cancer cannot currently be recommended.

From Clinical Trials to the Front Line: Vinflunine for Treatment of Urothelial Cell Carcinoma at the National Cancer Institute of Naples

BACKGROUND

The efficacy of Vinflunine, after failure of platinum-based chemotherapy in patients with metastatic or recurrent Transitional Cell Cancer of the Urothelial Tract, TCCU, has been demonstrated in an international, randomized, phase III trial comparing Vinflunine plus Best Supportive Care, BSC, with BSC alone. On the basis of that study vinflunine has been approved by the European Medicine Association, EMA, for treatment of TCCU patients after failure of a platinum treatment. However, since data in clinical trials often differ from routine clinical practice due to unselected population and less strict monitoring, "real life" experiences are very helpful to verify the efficacy of a new therapy.

METHODS

This was a spontaneous, observational, retrospective study involving 43 patients with metastatic TCCU treated with vinflunine at our cancer center, data about demographics, disease characteristics, and previous treatments were collected and outcome and toxicities of vinflunine were analyzed.

RESULTS

41 of 43 patients were eligible for RR analysis, the Overall RR was 12%, the Disease Control Rate was 29%; when including only patients treated in II line the DCR rose to 33%; the median PFS and the median OS were 2.2 and 6.9 months, respectively.

CONCLUSION

Our findings were consistent with the outcome data emerged in the phase III randomized trial and in the other observational studies conducted all around Europe in the last 2-3 years. This experience supports the use of vinflunine in patients with advanced TTCU as effective and manageable antineoplastic drug.

Drug delivery systems and combination therapy by using vinca alkaloids

Developing new methods for chemotherapy drug delivery has become a topic of great concern. Vinca alkaloids are among the most widely used chemotherapy reagents for tumor therapy; however, their side effects are particularly problematic for many medical doctors. To reduce the toxicity and enhance the therapeutic efficiency of vinca alkaloids, many researchers have developed strategies such as using liposome-entrapped drugs, chemical- or peptide-modified drugs, polymeric packaging drugs, and chemotherapy drug combinations. This review mainly focuses on the development of a vinca alkaloid drug delivery system and the combination therapy. Five vinca alkaloids (eg, vincristine, vinblastine, vinorelbine, vindesine, and vinflunine) are reviewed.

Theoretical insight into the structural mechanism for the binding of vinblastine with tubulin

Vinblastine (VLB) is one of vinca alkaloids with high cytotoxicity toward cancer cells approved for clinical use. However, because of drug resistance, toxicity, and other side effects caused from the use of VLB, new vinca alkaloids with higher cytotoxicity toward cancer cells and other good qualities need to develop. One strategy is to further study and better understand the essence why VLB possesses the high cytotoxicity toward cancer cells. In present work, by using molecular simulation, molecular docking, density functional calculation, and the crystal structure of α,β-tubulin complex, we find two modes labeled in catharanthine moiety (CM) and vindoline moiety (VM) modes of VLB bound with the interface of α,β-tubulin to probe the essence why VLB has the high cytotoxicity toward cancer cells. In the CM mode, nine key residues B-Ser178, B-Asp179, B-Glu183, B-Tyr210, B-Asp226, C-Lys326, C-Asp327, C-Lys336, and C-Lys352 from the α,β-tubulin complex are determined as the active sites for the interaction of VLB with α,β-tubulin. Some of them such as B-Ser178, B-Glu183, B-Tyr210, B-Asp226, C-Lys326, C-Asp327, and C-Lys336 are newly identified as the active sites in present work. The affinity between VLB and the active pocket within the interface of α,β-tubulin is -60.8 kJ mol(-1) in the CM mode. In the VM mode, that is a new mode established in present paper, nine similar key residues B-Lys176, B-Ser178, B-Asp179, B-Glu183, B-Tyr210, B-Asp226, C-Lys326, C-Asp327, and C-Lys336 from the α,β-tubulin complex are found as the active sites for the interaction with VLB. The difference is from one key residue C-Lys352 in the CM mode changed to the key residue B-Lys176 in the VM mode. The affinity between VLB and the active pocket within the interface of α,β-tubulin is -96.3 kJ mol(-1) in the VM mode. Based on the results obtained in present work, and because VLB looks like two faces, composed of CM and VM both to have similar polar active groups, to interact with the active sites, we suggest double-faces sticking mechanism for the binding of VLB to the interface of α,β-tubulin. The double-faces sticking mechanism can be used to qualitatively explain high cytotoxicity toward cancer cells of vinca alkaloids including vinblastine, vincristine, vindestine, and vinorelbine approved for clinical use and vinflunine still in a phase III clinical trial. Furthermore, this mechanism will be applied to develop novel vinca alkaloids with much higher cytotoxicity toward cancer cells.

Safety and effectiveness of vinflunine in patients with metastatic transitional cell carcinoma of the urothelial tract after failure of one platinum-based systemic therapy in clinical practice

BACKGROUND

Patients with transitional cell carcinoma of the urothelial tract (TCCU) who fail initial platinum-based chemotherapy for advanced disease represent a challenge in daily clinical practice. Vinflunine is approved by the European Medicine Agency (EMA) but, up to now, limited experience has been reported outside clinical trials.

METHODS

We assessed the efficacy and safety of vinflunine in an unselected group of 102 consecutive patients with metastatic TCCU.

RESULTS

The median age was 67 years (range 45-83). Among the most common comorbidities that patients presented at baseline were hypertension (50.5%) and diabetes (20.7%).Distant metastases were present in retroperitoneal nodes (58%), lung (29.3%), and bone (20.2%). The ECOG 0, 1 and 2 performance status at the start of vinflunine were 31.3%, 60.6% and 8.1%, respectively. The most commonly reported adverse events of any grade were constipation 70.6% (5.9% grade 3-4), vomiting 49.1% (2% grade 3-4), neutropenia 48.1% (12.8% grade 3-4) and abdominal pain 34.3% (4.9% grade 3-4). A median of 4 cycles of vinflunine was administered per patient (range 1-18). Median progression free and overall survival for all patients (N = 102) were 3.9 months (2.3-5.5) and 10 months (7.3-12.8), respectively. Time to tumor progression was 4.3 months (2.6-5.9). Two patients (2%) achieved CR, 23 (22.5%) patients had PR, and 42 (41.2%) presented SD as best response. The clinical benefit rate with vinflunine was 65.7%.

CONCLUSIONS

Our results show that the behavior of vinflunine in routine clinical practice resembles that of the pivotal phase III randomized study.

Monotherapy with intravenous vinflunine in patients with advanced or metastatic urothelial cancer after failure of a platinum-containing regimen: a retrospective analysis of German routine data

OBJECTIVE

The objective of this retrospective study was to investigate the efficacy and safety of vinflunine monotherapy and the utility of second-line prognostic factors in patients with advanced or metastatic urothelial cancer relapsing/progressing during or after a prior platinum-containing regimen under daily routine clinical conditions in Germany.

METHODS

The selection was based on the marketing authorization indication and recommendations as well as on the evaluation of second-line prognostic factors issued from prior pivotal trials.

RESULTS

Eight centers across Germany provided a total of 21 patient records. Demographic and clinical characteristics were similar to the data previously reported in pivotal trials. Complete and partial response to vinflunine treatment was observed in 1 (4.8%) and 3 (14.3%) patients, respectively, resulting in an overall response rate of 19.1%. The disease control rate reached 47.7%. The median progression-free survival amounted to 4.4 months (95% CI 2.6-6.6), with a median overall survival of 6.2 months (95% CI 3.9-10.7). The observed toxicity profile was manageable and consistent with prior clinical trials: leukopenia (33.3%), neutropenia (9.5%), anemia (9.5%) and hyperglycemia (4.8%). The reported satisfaction rate with the treatment was 90.5 and 61.9% among patients and physicians, respectively.

CONCLUSIONS

This retrospective study confirms that the clinical outcomes obtained from routine medical practice in Germany with vinflunine in the treatment of advanced/metastatic urothelial cancer are in line with the data observed in prior clinical trials.

Vascular disrupting activity and the mechanism of action of EHT 6706, a novel anticancer tubulin polymerization inhibitor

Tumor blood vessels are an important emerging target for anticancer therapy. Here, we characterize the in vitro antiproliferative and antiangiogenic properties of the synthetic small molecule, 7-ethoxy-4-(3,4,5-trimethoxybenzyl)isoquinolin-8-amine dihydrochloride, EHT 6706, a novel microtubule-disrupting agent that targets the colchicine-binding site to inhibit tubulin polymerization. At low nM concentrations, EHT 6706 exhibits highly potent antiproliferative activity on more than 60 human tumor cell lines, even those described as being drug resistant. EHT 6706 also shows strong efficacy as a vascular-disrupting agent, since it prevents endothelial cell tube formation and disrupts pre-established vessels, changes the permeability of endothelial cell monolayers and inhibits endothelial cell migration. Genome-wide transcriptomic analysis of EHT 6706 effects on human endothelial cells shows that the antiangiogenic activity elicits gene deregulations of antiangiogenic pathways. These findings indicate that EHT 6706 is a promising tubulin-binding compound with potentially broad clinical antitumor efficacy.

Traditional West African pharmacopeia, plants and derived compounds for cancer therapy

Traditional pharmacopeia is strongly involved in the continuous search for the well being of African populations. The World Health Organization (WHO) estimates that 80% of the population of developing countries relies on traditional medicine for their primary care needs. Medicinal plants are the major resource of this folk medicine where several species are used for the treatment of diseases with an inflammatory and/or infectious component as it is the case of old wounds, skin diseases and malfunctions affecting internal organs such as liver, lung, prostate and kidney. Many of these pathologies described by practitioners of traditional medicine have similarities with certain cancers, but the lack of training of many of these healers does not allow them to establish a link with cancer. However, ethnobotanical and ethnopharmacological surveys conducted by several researchers allowed to identify plants of interest for cancer treatment. Most scientific investigations on these plants demonstrated an anti-inflammatory or antioxidant effect, and sometimes, antiproliferative and cytotoxic activities against cancer cells were reported as well. The emergence of resistance to cancer chemotherapy has forced researchers to turn to natural products of plant and marine origin. In the West African sub-region, research on natural anti-cancer molecules is still in its infancy stage because of very limited financial resources and the scarcity of adequate technical facilities. However, several plants were investigated for their anticancer properties through north-south or south-south partnerships. In this review, we will review the role of West African traditional pharmacopeia in cancer treatment as well as medicinal plants with anti-cancer properties.

Synthesis and biological evaluation of 1-benzylidene-3,4-dihydronaphthalen-2-one as a new class of microtubule-targeting agents

A series of 1-benzylidene-3,4-dihydronaphthalen-2-one derivatives were designed and synthesized, and their biological activities in vitro and in vivo were evaluated. The results showed a number of the title compounds exhibiting potent nanomolar activity in several human cancer cell lines. Of these, compound 22b showed the strongest inhibitory activity against human CEM, MDA-MBA-435, and K562 cells (IC(50) = 1 nM), displayed in vitro inhibition of tubulin polymerization (IC(50) = 3.93 μM), and significantly induced cell cycle arrest in G2/M phase. In addition, compound 22b could inhibit the tumor growth in colon nude mouse xenograft tumor model significantly and seemed safer than CA-4 when achieving a similar tumor suppression. This study provided a new molecular scaffold for the further development of antitumor agents that target tubulin.

Antimitotic inhibitors

Of the agents available in the treatment of both solid and hematologic cancers, microtubule-targeted agents are among the most widely used and exploiting other mechanisms involving the microtubule and its role in mitosis is an area of continued interest. This review will focus on novel microtubule-targeted agents, both recently approved (eg, ixabepilone and eribulin) and in later-stage clinical trials, and kinase inhibitors that aim to directly inhibit the mitotic spindle, such as the aurora kinase, pololike kinase, and kinsein-spindle protein inhibitors.

Ceric ammonium nitrate-promoted oxidative coupling reaction for the synthesis and evaluation of a series of anti-tumor amide anhydrovinblastine analogs

A new, practical and efficient method for the synthesis of anhydrovinblastine AVBL (1f) by oxidative coupling of vindoline and catharanthine in the presence of ceric ammonium nitrate (CAN) was developed. Under the optimized reaction conditions, we synthesized a new series of amide anhydrovinblastine analogs substituted at the vindoline moiety of C-23 site and, evaluated for their proliferation inhibition against HeLa cell. The aryl-substituted derivatives showed loss of potency, while alkyl-substituted derivatives retained some of its cytotoxic potency. The iso-butylamide compound 10b and 2-furancorboxamide compound 18b displayed a similar cytotoxic potency compared to the positive control AVBL.

Differential expression patterns of capping protein, protein phosphatase 1, and casein kinase 1 may serve as diagnostic markers for malignant melanoma

Early and accurate diagnosis of malignant melanoma is critical for patient survival. However, currently used diagnostic markers are insufficiently specific, which limits their utility. We aimed to identify molecular markers that are more specific to malignant melanoma, thereby aiding in melanoma diagnosis and treatment. A PCR-based suppression subtractive hybridization was used to identify capping protein Z-line α1, protein phosphatase 1 catalytic subunit β isoform (PP1CB), and casein kinase 1 α1 (CSNK1A1) as being differentially expressed between melanoma cells and normal melanocytes. Quantitative reverse transcription-PCR and western blot analysis confirmed that these genes were overexpressed in melanoma cells. In addition, immunohistochemical assays revealed that the expression of PP1CB and CSNK1A1 was significantly greater in human melanoma specimens than nevi (P<0.0001). Combined application of PP1CB and CSNK1A showed high sensitivity and specificity for melanoma. Thus, our data suggest that PP1CB and CSNK1A1 are potential biomarkers for distinguishing malignant melanoma from other melanocytic lesions. In addition, because capping protein Z-line α1, PP1CB, and CSNK1A1 are involved in cell motility, which underlies invasion and metastasis of human cancer; they may be novel targets for antimetastatic therapies as well.

Current therapeutic strategies for invasive and metastatic bladder cancer

BACKGROUND

Bladder cancer is one of the most common cancers in Europe, the United States, and Northern African countries. Muscle-invasive bladder cancer is an aggressive epithelial tumor, with a high rate of early systemic dissemination. Superficial, noninvasive bladder cancer can most often be cured; a good proportion of invasive cases can also be cured by a combined modality approach of surgery, chemotherapy, and radiation. Recurrences are common and mostly manifest as metastatic disease. Those with distant metastatic disease can sometime achieve partial or complete remission with combination chemotherapy.

RECENT DEVELOPMENTS

Better understanding of the biology of the disease has led to the incorporation of molecular and genetic features along with factors such as tumor grade, lympho-vascular invasion, and aberrant histology, thereby allowing identification of 'favorable' and 'unfavorable' cancers which helps a more accurate informed and objective selection of patients who would benefit from neoadjuvant and adjuvant chemotherapy. Gene expression profiling has been used to find molecular signature patterns that can potentially be predictive of drug sensitivity and metastasis. Understanding the molecular pathways of invasive bladder cancer has led to clinical investigation of several targeted therapeutics such as anti-angiogenics, mTOR inhibitors, and anti-EGFR agents.

CONCLUSION

With improvements in the understanding of the biology of bladder cancer, clinical trials studying novel and targeted agents alone or in combination with chemotherapy have increased the armamentarium for the treatment of bladder cancer. Although the novel biomarkers and gene expression profiles have been shown to provide important predictive and prognostic information and are anticipated to be incorporated in clinical decision-making, their exact utility and relevance calls for a larger prospective validation.

On the elucidation of the mechanism of Vinca alkaloid fluorination in superacidic medium

Detailed investigations on one of the key steps of the superacidic fluorination of Vinca alkaloids that is the origin of C20' activation are reported. While two different pathways can be envisioned for the emergence of the transient secondary carbocationic intermediate, isotopic labeling experiments unambiguously revealed the involvement of a 1,2-hydride shift mechanism.

Serine 59 phosphorylation of {alpha}B-crystallin down-regulates its anti-apoptotic function by binding and sequestering Bcl-2 in breast cancer cells

The small heat shock protein (sHSP) αB-crystallin is a new oncoprotein in breast carcinoma that predicts poor clinical outcome in breast cancer. However, although several reports have demonstrated that phosphorylation of sHSPs modify their structural and functional properties, the significance of αB-crystallin phosphorylation in cancer cells has not yet been investigated. In this study, we have characterized the phosphorylation status of αB-crystallin in breast epithelial carcinoma cells line MCF7 submitted to anti-cancer agents like vinblastine. We have showed that the main phosphorylation site of αB-crystallin in response to vinblastine is serine 59 and determined a correlation between this post-translational modification and higher apoptosis level. The overexpression of the serine 59 "pseudophosphorylated" mutant (S59E) induces a significant increase in the apoptosis level of vinblastine-treated MCF7 cells. In contrast, overexpression of wild-type αB-crystallin or "nonphosphorylatable" mutant (S59A) result in a resistance to this microtubule-depolymerizing agent, while inhibition of endogenous levels of αB-crystallin by expression of shRNA lowers it. Analyzing further the molecular mechanism of this phenomenon, we report for the first time that phosphorylated αB-crystallin preferentially interacts with Bcl-2, an anti-apoptotic protein, and this interaction prevents the translocation of Bcl-2 to mitochondria. Hence, this study identifies serine 59 phosphorylation as an important key in the down-regulation of αB-crystallin anti-apoptotic function in breast cancer and suggests new strategies to improve anti-cancer treatments.