Cellular and molecular effects of metronomic vinorelbine and 4-O-deacetylvinorelbine on human umbilical vein endothelial cells

Biomodulatory therapy induces durable remissions in multi-system Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is rare hematological neoplasia originating from the aberrant proliferation of CD207-positive dendritic cells. Refractory multi-system LCH is difficult to treat necessitating the continuous development of different salvage therapies. At our medical center, eleven patients (age 11 months to 77 years) with multi-system LCH were treated on a compassionate use basis with metronomic biomodulation therapy (MBT) involving the daily oral application of low-dose trofosfamide, etoricoxib, pioglitazone and low-dose dexamethasone. Overall, four patients including two heavily pretreated pediatric patients achieved ongoing complete remission. Moreover, partial disease remission was observed in three patients, and four patients attained stable disease. MBT demonstrated high activity against multi-system LCH even in patients, refractory to multiple systemic chemotherapies. Further confirmation of efficacy should be systematically evaluated in prospective trials.

Co-targeting triple-negative breast cancer cells and endothelial cells by metronomic chemotherapy inhibits cell regrowth and migration via downregulation of the FAK/VEGFR2/VEGF axis and autophagy/apoptosis activation

High-dose standard-of-care chemotherapy is the only option for triple-negative breast cancer (TNBC) patients, which eventually die due to metastatic tumors. Recently, metronomic chemotherapy (mCHT) showed advantages in treating TNBCs leading us to investigate the anti-metastatic and anti-angiogenic potential of metronomic 5-Fluorouracil plus Vinorelbine (5-FU+VNR) on endothelial cells (ECs) and TNBCs in comparison to standard treatment (STD). We found that 10-fold lower doses of 5-FU+VNR given mCHT vs. STD inhibits cell proliferation and survival of ECs and TNBC cells. Both schedules strongly affect ECs migration and invasion, but in TNBC cells mCHT is significantly more effective than STD in impairing cell migration and invasion. The two treatments disrupt FAK/VEGFR/VEGF signaling in both ECs and TNBC cells. mCHT, and to a much lesser extent STD treatment, induces apoptosis in ECs, whereas it switches the route of cell death from apoptosis (as induced by STD) to autophagy in TNBC cells. mCHT-treated TNBCs-derived conditioned medium also strongly affects ECs' migration, modulates different angiogenesis-associated proteins, and hampers angiogenesis in matrix sponge in vivo. In conclusion, mCHT administration of 5-FU+VNR is more effective than STD schedule in controlling cell proliferation/survival and migration/invasion of both ECs and TNBC cells and has a strong anti-angiogenic effect. Our data suggest that the stabilization of tumor growth observed in TNBC patients treated with mCHT therapy schedule is likely due not only to direct cytotoxic effects but also to anti-metastatic and anti-angiogenic effects.

Metronomic chemotherapy regimens and targeted therapies in non-Hodgkin lymphoma: The best of two worlds

Novel drugs are rapidly moving forward the treatment-paradigm of non-Hodgkin-lymphomas (NHLs). Notwithstanding, especially in aggressive subtypes, chemotherapy remains the pillar of treatment. Indeed, the combination of highly effective Maximum-Tolerated-Dose Chemotherapy (MTD-CHEMO) + "novel drugs", has so far, fallen short from expectations, often because it caused excessive toxicity. Metronomic chemotherapy (mCHEMO), which is the frequent, long-term administration of low dose cytotoxic drugs, may allow more effective and tolerable combinations. mCHEMO pharmacodynamics, has been described as pleiotropic. In fact, it may have different cellular and molecular targets, when drugs or their schedules are modified. Although mCHEMO has been little explored in NHLs, pre-clinical studies - in lymphoma models - which addressed the activity of mCHEMO in combination with novel drugs, have shown very promising results. These included inhibitors of histone deacetylase, mTOR and PI3K/mTOR, as well as the immune checkpoint inhibitor anti-PD-L1. Moreover, a few impressive reports have recently shown all-oral mCHEMO schedules, with or without rituximab, can effectively shrink both B and T-cell aggressive NHLs. Indeed, these regimens allowed elderly-frail patients to achieve sustained remission, while toxicity proved manageable. In our opinion, all-oral mCHEMO, is an active, easy-to start, well-tolerated, and inexpensive therapeutic approach, which deserves further investigation. Most importantly, mCHEMO, holds promise to empower the activity of novel targeted therapies, without causing excessive toxicity.

Microtubule Targeting Agents in Disease: Classic Drugs, Novel Roles

Microtubule-targeting agents (MTAs) represent one of the most successful first-line therapies prescribed for cancer treatment. They interfere with microtubule (MT) dynamics by either stabilizing or destabilizing MTs, and in culture, they are believed to kill cells via apoptosis after eliciting mitotic arrest, among other mechanisms. This classical view of MTA therapies persisted for many years. However, the limited success of drugs specifically targeting mitotic proteins, and the slow growing rate of most human tumors forces a reevaluation of the mechanism of action of MTAs. Studies from the last decade suggest that the killing efficiency of MTAs arises from a combination of interphase and mitotic effects. Moreover, MTs have also been implicated in other therapeutically relevant activities, such as decreasing angiogenesis, blocking cell migration, reducing metastasis, and activating innate immunity to promote proinflammatory responses. Two key problems associated with MTA therapy are acquired drug resistance and systemic toxicity. Accordingly, novel and effective MTAs are being designed with an eye toward reducing toxicity without compromising efficacy or promoting resistance. Here, we will review the mechanism of action of MTAs, the signaling pathways they affect, their impact on cancer and other illnesses, and the promising new therapeutic applications of these classic drugs.

Pharmacokinetics of oral vinorelbine in French children with recurrent or progressive primary low-grade glioma

AIM

There is a crucial need for pharmacokinetic (PK) data of oral vinorelbine (VNR) in pediatric population. The aim of this work was to assess the PK profile of orally administered VNR in children with recurrent/progressive primary low-grade glioma (LGG).

METHODS

A multicentric, open-label, single-arm intervention phase II study was conducted. Patients, aged between 6 and 18 years, with histologically confirmed recurrent or progressive primary LGG or non-documented typical optic pathway tumors, were included. PK parameters were estimated by non-compartmental analysis using Phoenix WinNonlin® software (version 8.0, Certara, Inc.). The Influence of demographic and biological covariates on VNR PK parameters was investigated using a multivariate linear regression analysis.

RESULTS

PK analysis included 36 patients with a median age (range) of 11 (6-17) years. Estimates of apparent oral clearance (CL/F), apparent volume of distribution (V/F), half-life (t_1/2 ) and their between-subject variability (CV%) at 60 mg.m^-2 dose level, were 472 L.h^-1 (51.8%), 7002 L (57.9%) and 10 h (21.0%), respectively. Negligible accumulation of VNR between C1 and C2 was observed. CL/F and V/F were found to increase with body surface area (BSA) (p = 0.004). Lower area under the concentration-time curve (AUC) levels were observed among children in comparison to adults.

CONCLUSION

Higher doses may be necessary for children with LGG. BSA showed a significant impact on VNR systemic exposure. We believe that our findings will serve as a basis for further studies to better characterize the concentration-response relationships of VNR among pediatric patients.

Metronomic therapy in advanced breast cancer and NSCLC: vinorelbine as a paradigm of recent progress

INTRODUCTION

Metronomic chemotherapy (MCT) is based on frequent dosing of the drug. . This leads to pharmacologically active but low plasma concentrations that reduce toxicity. MCT seems to work primarily via indirect effects on tumor cells and their microenvironment, rather than direct antitumor effects. Oral vinorelbine is one of the most widely studied MCT approaches in both advanced breast cancer and non-small cell lung cancer.

EXPERT OPINION

MCT with vinorelbine has proven efficacy, tolerability and quality of life benefits both as monotherapy and in combination with other MCTs or targeted agents, in first-line therapy and in previously treated patients. Key populations are emerging who may be particularly well suited to metronomic vinorelbine, including those with indolent disease, older individuals, and those with multiple comorbidities and/or bone metastases. Ongoing trials should help to further delineate these target groups. Additional work is needed to better understand the optimal vinorelbine regimen, particularly when used in combination or in non-Caucasian patients. Markers are also required to help identify individuals who are most likely to respond. Nonetheless, the efficacy and tolerability of MCT, allied to improved patient convenience, reduced need for medical engagement and lower cost, make it an appealing option - particular in resource-constrained healthcare environments.

Feasibility study of in vitro drug sensitivity assay of advanced non-small cell lung adenocarcinomas

Background Despite improved screening techniques, diagnosis of lung cancer is often late and its prognosis is poor. In the present study, in vitro chemosensitivity of solid tumours and pleural effusions of lung adenocarcinomas were analysed and compared with clinical drug response.Methods Tumour cells were isolated from resected solid tumours or pleural effusions, and cryopreserved. Three-dimensional (3D) tissue aggregate cultures were set up when the oncoteam reached therapy decision for individual patients. The aggregates were then treated with the selected drug or drug combination and in vitro chemosensitivity was tested individually measuring ATP levels. The clinical response to therapy was assessed by standard clinical evaluation over an 18 months period.Results Based on the data, the in vitro chemosensitivity test results correlate well with clinical treatment response.Conclusions Such tests if implemented into the clinical decision making process might allow the selection of an even more individualised chemotherapy protocol which could lead to better therapy response.

Microtubule-targeting agents and their impact on cancer treatment

Microtubule-targeting agents (MTAs) constitute a diverse group of chemical compounds that bind to microtubules and affect their properties and function. Disruption of microtubules induces various cellular responses often leading to cell cycle arrest or cell death, the most common effect of MTAs. MTAs have found a plethora of practical applications in weed control, as fungicides and antiparasitics, and particularly in cancer treatment. Here we summarize the current knowledge of MTAs, the mechanisms of action and their role in cancer treatment. We further outline the potential use of MTAs in anti-metastatic therapy based on inhibition of cancer cell migration and invasiveness. The two main problems associated with cancer therapy by MTAs are high systemic toxicity and development of resistance. Toxic side effects of MTAs can be, at least partly, eliminated by conjugation of the drugs with various carriers. Moreover, some of the novel MTAs overcome the resistance mediated by both multidrug resistance transporters as well as overexpression of specific β-tubulin types. In anti-metastatic therapy, MTAs should be combined with other drugs to target all modes of cancer cell invasion.

Gemcitabine, vinorelbine and cyclooxygenase inhibitors in the treatment of glioblastoma. Ultrastructural analyses in C6 glioma in vitro

OBJECTIVES

To define ultrastructural features accompanying to antitumor effects of gemcitabine, vinorelbine and cyclooxygenase inhibitors in C6 glioma cells in vitro. Vinorelbine is a semisynthetic vinca alkaloid and recent studies showed its antitumor activity in pediatric optic and pontine gliomas. Vinorelbine infusion induces a severe tumor site-pain in systemic cancers, but it is unknown whether algesia and inflammation contribute to its antitumor effects. Gemcitabine is a nucleoside-chemotherapeutic which was recently shown to act as a radiosensitizer in high-grade glioma. Some studies showed synergism of anti-inflammatory cyclooxygenase-inhibitors with microtubule inhibitors and gemcitabine. DMSO is a solvent and blocks both cylooxygenase and ribonucleotide reductase, another target of gemcitabine. Rofecoxib is withdrawn from the market, yet we used it for investigational purposes, since it blocks cylooxygenase-2 1000-times more potently than cylooxygenase -1 and is also a selective inhibitor of crinophagy.

METHODS

Plating efficacy, 3D-spheroid S-phase analysis with BrdU labelling and transmission electron microscopical analyses were performed.

RESULTS

Vinorelbine induced frequent mitotic slippage/apoptosis and autophagy. Despite both DMSO and rofecoxib induced autophagy alone and in synergy, they reduced mitotic catastrophe and autophagy triggered by vinorelbine, which was also reflected by reduced inhibition of spheroid S-phase. Gemcitabine induced karyolysis and margination of coarse chromatin towards the nuclear membrane, abundant autophagy, gutta adipis formation and decrease in mitochondria, which were enhanced by DMSO and rofecoxib.

CONCLUSIONS

Detailed ultrastructural analysis of the effects of chemotherapeutic drugs may provide a broader insight about their actions and pave to develop better strategies in treatment of glioblastoma.

Cell cycle arrest in mitosis promotes interferon-induced necroptosis

Resistance to apoptosis is a hallmark of cancer and deregulation of apoptosis often leads to chemoresistance. Therefore, new approaches to target apoptosis-resistant cancer cells are crucial for the development of directed cancer therapies. In the present study, we investigated the effect of cell cycle regulators on interferon (IFN)-induced necroptosis as an alternative cell death mechanism to overcome apoptosis resistance. Here, we report a novel combination treatment of IFNs with cell cycle arrest-inducing compounds that induce necroptosis in apoptosis-resistant cancer cells and elucidate the underlying molecular mechanisms. Combination treatment of IFNs (i.e. IFNβ) with inhibitors of the cell cycle (e.g. vinorelbine (VNR), nocodazole (Noc), polo-like kinase-1 (Plk-1) inhibitor BI 6727) co-operate to induce necroptotic cell death upon caspase inactivation. The mode of cell death was confirmed by pharmacological inhibition and siRNA-mediated downregulation of the key necroptotic factors receptor-interacting protein (RIP) kinase 3 (RIP3) and mixed-lineage kinase-like (MLKL) in various cell lines. Mechanistically, we show that necroptosis upon VNR/IFNβ/zVAD.fmk treatment is RIP1-independent but relies on IFNβ-induced gene expression of Z-DNA-binding protein 1 (ZBP1) as shown by quantitative RT-PCR and genetic knockdown experiments. Interestingly, we find that RIP3 is phosphorylated in response to compounds that trigger mitotic arrest, even in the absence of IFNβ signaling and necroptosis induction. Together, the identification of a novel combination treatment that triggers necroptosis has implications for the development of molecular-targeted therapies to circumvent apoptosis resistance and point to an underestimated role of cell cycle regulation in cell death signaling.

A Pilot Study of Vinorelbine Safety and Pharmacokinetics in Patients with Varying Degrees of Liver Dysfunction

Vinorelbine tartrate is a semi‐synthetic vinca alkaloid and an inhibitor of microtubule polymerization with demonstrated antitumor properties across a spectrum of cancers. The pharmacokinetics of vinorelbine may be altered in individuals with liver dysfunction, considering that hepatic metabolism serves as the predominant route of drug elimination. This article reports the pharmacokinetics and safety of vinorelbine in patients with varying degrees of hepatic impairment, including dosing recommendations in this population.

Background.

Vinorelbine has demonstrated anticancer activity and is primarily metabolized in the liver. This single‐institution, phase I pilot study describes the safety and pharmacokinetics of vinorelbine in patients with varying degrees of hepatic impairment.

Materials and Methods.

Patients with treatment‐refractory solid tumors were enrolled into treatment arms based on vinorelbine dose (weekly infusions of 7.5–30 mg/m²) and liver function (normal liver function, mild, moderate, or severe liver dysfunction). Vinorelbine pharmacokinetics were evaluated to describe its relationship with liver function. Indocyanine green (ICG) clearance was assessed for correlation with pharmacokinetics.

Results.

Forty‐seven patients were enrolled, and a total of 108 grade 3–4 treatment‐related adverse events (AEs) occurred. Of these, grade 3–4 myelosuppression was the most common (34.3%). Thirty‐three (30.6%), 22 (20.4%), and 9 (8.3%) grade 3–4 AEs were observed in the vinorelbine 20 mg/m²/severe, 15 mg/m²/moderate, and 7.5 mg/m²/severe liver dysfunction groups, respectively, with the majority being nonhematologic toxicities. ICG clearance decreased as liver function worsened. Vinorelbine pharmacokinetics were not correlated with ICG elimination or the degree of liver dysfunction.

Conclusion.

For patients with severe liver dysfunction (bilirubin >3.0 mg/dL), vinorelbine doses ≥7.5 mg/m² are poorly tolerated. The high incidence of grade 3–4 AEs with 15 mg/m² vinorelbine in moderate liver dysfunction (bilirubin 1.5–3.0 mg/dL) raises concerns for its safety in this population. Vinorelbine pharmacokinetics are not affected by liver dysfunction; however, levels of the active metabolite 4‐O‐deacetylvinorelbine were not measured and may be higher in patients with liver dysfunction if its elimination is impacted by liver impairment to a greater degree than the parent drug.

Implications for Practice.

Vinorelbine remains widely prescribed in advanced malignancies and is under development in immunotherapy combinations. Given vinorelbine is primarily hepatically metabolized, understanding its safety and pharmacokinetics in liver dysfunction remains paramount. In this phase I pilot study, weekly vinorelbine at doses ≥7.5 mg/m² is poorly tolerated in those with severe liver dysfunction. Furthermore, a high incidence of grade 3–4 toxicities was observed with vinorelbine at 15 mg/m² in those with moderate liver dysfunction. Vinorelbine pharmacokinetics do not appear affected by degree of liver dysfunction. Further evaluation of levels of the free drug and active metabolites in relationship to liver function are warranted.

Pan-European Expert Meeting on the Use of Metronomic Chemotherapy in Advanced Breast Cancer Patients: The PENELOPE Project

INTRODUCTION

Metronomic chemotherapy (mCHT) is a treatment regimen in which drugs are administered frequently or continuously and that maintains low, prolonged, and pharmacologically active plasma concentrations of drugs to avoid toxicity associated with traditional chemotherapy regimens, while achieving tumor response. Despite the increasing use of mCHT in patients with metastatic breast cancer (MBC) and the endorsement of mCHT in guidelines, no consensus exists about which patients may substantially benefit from mCHT, which agents can be recommended, and in which treatment setting mCHT is most appropriate.

METHODS

In October 2017, ten international experts in the management of breast cancer convened to develop a report describing the current status of the use of mCHT for the treatment of advanced breast cancer, based not only on current literature but also on their opinion. The Delphi method was used to reach consensus.

RESULTS

A full consensus was reached concerning the acknowledgement that mCHT is not simply a different way of administering chemotherapy but a truly new treatment option. The best-known effect of mCHT is on angiogenesis inhibition, but exciting new data are on the way regarding potential activity on immune system activation. The experts strongly suggest that the ideal patients for mCHT are those with hormone receptor (HR)-positive tumors or those with triple-negative disease. Independently of HR status, mCHT could be an advantageous option for elderly patients, who are often under-treated simply because of their age.

CONCLUSION

Current data support the use of mCHT in selected patients with MBC.

FUNDING

Pierre Fabre.

Peroxisome Proliferator-Activated Receptors (PPAR)γ Agonists as Master Modulators of Tumor Tissue

In most clinical trials, thiazolidinediones do not show any relevant anti-cancer activity when used as mono-therapy. Clinical inefficacy contrasts ambiguous pre-clinical data either favoring anti-tumor activity or tumor promotion. However, if thiazolidinediones are combined with additional regulatory active drugs, so-called ‘master modulators’ of tumors, i.e., transcriptional modulators, metronomic low-dose chemotherapy, epigenetically modifying agents, protein binding pro-anakoinotic drugs, such as COX-2 inhibitors, IMiDs, etc., the results indicate clinically relevant communicative reprogramming of tumor tissues, i.e., anakoinosis, meaning ‘communication’ in ancient Greek. The concerted activity of master modulators may multifaceted diversify palliative care or even induce continuous complete remission in refractory metastatic tumor disease and hematologic neoplasia by establishing novel communicative behavior of tumor tissue, the hosting organ, and organism. Re-modulation of gene expression, for example, the up-regulation of tumor suppressor genes, may recover differentiation, apoptosis competence, and leads to cancer control—in contrast to an immediate, ‘poisoning’ with maximal tolerable doses of targeted/cytotoxic therapies. The key for uncovering the therapeutic potential of Peroxisome proliferator-activated receptor γ (PPARγ) agonists is selecting the appropriate combination of master modulators for inducing anakoinosis: Now, anakoinosis is trend setting by establishing a novel therapeutic pillar while overcoming classic obstacles of targeted therapies, such as therapy resistance and (molecular-)genetic tumor heterogeneity.

Vinorelbine's anti-tumor actions may depend on the mitotic apoptosis, autophagy and inflammation: hypotheses with implications for chemo-immunotherapy of advanced cancers and pediatric gliomas

Vinorelbine is a very potent chemotherapeutic agent which is used to treat a number of cancers including breast and non-small cell lung tumors. Vinorelbine mainly acts via blocking microtubules and induces a specific type of cell death called 'mitotic catastrophe/apoptosis' subsequent to mitotic slippage, which is the failure of cells to stay in a mitotic arrested state and replicating their DNA without cytokinesis. Glial tumor cells are especially sensitive to mitotic slippage. In recent years, vinorelbine demonstrated potency in pediatric optic and pontine gliomas. In this manuscript, we propose that vinorelbine's anti-tumor actions involve mitotic apoptosis, autophagy and inflammation. Intravenous infusion of vinorelbine induces a peculiar severe pain in the tumor site and patients with highly vascularized, oedematous and necrotic tumors are particularly vulnerable to this pain. Severe pain is a sign of robust inflammation and anti-inflammatory agents are used in treatment of this side effect. However, no one has questioned whether inflammation contributes to anti-tumor effects of vinorelbine, despite the existing data that vinorelbine induces Toll-Like Receptor-4 (TLR4), cytokines and cell death in endothelial cells especially under hypoxia. Robust inflammation may contribute to tumor necrosis such as seen during immunotherapy with lipopolysaccharides (LPS). Evidence also emerges that enhanced cyclooxygenase activity may increase cancer cell death in certain contexts. There are data indicating that non-steroidal anti-inflammatory drugs (NSAIDs) could block anti-tumor efficacy of taxanes, which also work mainly via anti-microtubule actions. Further, combining vinorelbine with immunostimulant cytokines provided encouraging results in far advanced melanoma and renal cell carcinoma, which are highly antigenic tumors. Vinorelbine also showed potential in treatment of inflammatory breast cancer. Finally, pontine gliomas - where partial activity of vinorelbine is shown by some studies - are also tumors which partially respond to immune stimulation. Animal experiments shall be conducted whether TLR4-activating molecules or immune-checkpoint inhibitors could augment anti-tumor actions of vinorelbine. Noteworthy, TLR4-activation seems as the most promising way of cancer immunotherapy, as a high percentage of molecules which demonstrated clinical benefits in cancer treatment are activators of TLR4, including BCG vaccine, monophosphoryl lipid A and picibanil (OKT-432). The provided data would be meaningful for the oncological practice.

Treatment of advanced breast cancer with a metronomic schedule of oral vinorelbine: what is the opinion of Italian oncologists?

BACKGROUND

The aim of this study was to record the opinions of Italian oncologists about the use of oral vinorelbine administered metronomically in patients with advanced breast cancer.

METHODS

A series of meetings were held throughout Italy, and participants were asked how much they agreed with each of the several statements.

RESULTS

The majority of oncologists agreed that the concept of the minimum biologically effective dose should be used for drugs administered metronomically. Over 50% agreed that metronomic vinorelbine is an option in first-line chemotherapy for patients with advanced breast cancer, including those with a terminal illness and the elderly, as well as in young and fit patients. Just over one-third of experts agreed that a combination of two chemotherapy agents instead of one is not desirable in metastatic breast cancer because of increased toxicity. Most experts agreed that the main aim of a first-line therapy is to control the disease over time and to preserve quality of life.

CONCLUSION

Metronomically administered oral vinorelbine, either as monotherapy or in combination with other drugs, is effective in the long-term treatment of patients with advanced breast cancer. The clinical profiles of patients should be carefully considered to determine the appropriate treatment strategy.

Metronomic combination of Vinorelbine and 5Fluorouracil is able to inhibit triple-negative breast cancer cells. Results from the proof-of-concept VICTOR-0 study

Triple Negative Breast Cancer (TNBC) is an aggressive neoplasia with median Overall Survival (OS) less than two years. Despite the availability of new drugs, the chance of survival of these patients did not increase. The combination of low doses of drugs in a metronomic schedule showed efficacy in clinical trials, exhibiting an anti-proliferative and anti-tumour activity. In Victor-2 study we recently evaluated a new metronomic combination (mCHT) of Capecitabine (CAPE) and Vinorelbine (VNR) in breast cancer patients showing a disease control rate with a median Progression-Free Survival (PFS) of 4.7 months in 28 TNBC patients.

Here in Victor-0 study, we examined the effect of mCHT vs standard (STD) schedule of administration of different combinations of 5-Fluorouracil (5FU), the active metabolite of CAPE, and VNR in TNBC cell lines MDA-MB-231 and BT-549. A significant anti-proliferative activity was observed in cells treated with metronomic vs STD administration of 5FU or VNR alone. Combination of the two drugs showed an additive inhibitor effect on cell growth in both cell lines. Moreover, after exposure of cells to 5FU and VNR under mCHT or conventional schedule of administration we also observed a downregulation of chemoresistance factor Bcl-2, changes in pro-apoptotic protein Bax and in cleaved effector caspase-3 and increased expression of LC3A/B autophagy protein.

Our results therefore suggest that molecular mechanisms implicated in apoptosis and autophagy as well as the cross-talk between these two forms of cell death in MDA-MB-231 and BT-549 cells treated with 5FU and VNR is dose- and schedule-dependent and provide some insights about the roles of autophagy and senescence in 5FU/VNR-induced cell death.

Does metronomic chemotherapy induce tumor angiogenic dormancy? A review of available preclinical and clinical data

Tumor dormancy is the ability of cancer cells to survive in a non-proliferating state. This condition can depend on three main mechanisms: cell cycle arrest (quiescence or cell dormancy), immunosurveillance (immunologic dormancy), or lack of functional blood vessels (angiogenic dormancy). In particular, under angiogenic dormancy, cancer cell proliferation is counterbalanced by apoptosis owing to poor vascularization, impeding tumor mass expansion beyond a microscopic size, with an asymptomatic and non-metastatic state. Tumor vasculogenic or non-angiogenic switch is essential to promote escape from tumor dormancy, leading to tumor mass proliferation and metastasis. In avascular lesions angiogenesis process results blocked from the equilibrium between pro- and anti-angiogenic factors, such as vascular endothelial growth factor (VEGF) and thrombospondin-1 (TSP-1), respectively. The angiogenic switch mainly depends on the disruption of this balance, in favor of pro-angiogenic factors, and on the recruitment of circulating endothelial progenitors (CEPs) that promote the formation of new blood vessels. Metronomic chemotherapy, the regular intake of doses able to sustain low but active concentrations of chemotherapeutic drugs during protracted time periods, is an encouraging therapeutic approach that has shown to upregulate anti-angiogenic factors such as TSP-1 and decline pro-angiogenic factors such as VEGF, suppressing the proangiogenic cells such as CEPs. In this perspective, metronomic chemotherapy may be one of the available therapeutic approaches capable to modulate favorably the angiogenic tumor dormancy, but further research is essential to better define this particular characteristic.

C-type natriuretic peptide-modified lipid vesicles: fabrication and use for the treatment of brain glioma

Chemotherapy of brain glioma faces a major obstacle owing to the inability of drug transport across the blood-brain barrier (BBB). Besides, neovasculatures in brain glioma site result in a rapid infiltration, making complete surgical removal virtually impossible. Herein, we reported a novel kind of C-type natriuretic peptide (CNP) modified vinorelbine lipid vesicles for transferring drug across the BBB, and for treating brain glioma along with disrupting neovasculatures. The studies were performed on brain glioma U87-MG cells in vitro and on glioma-bearing nude mice in vivo. The results showed that the CNP-modified vinorelbine lipid vesicles could transport vinorelbine across the BBB, kill the brain glioma, and destroy neovasculatures effectively. The above mechanisms could be associated with the following aspects, namely, long circulation in the blood; drug transport across the BBB via natriuretic peptide receptor B (NPRB)-mediated transcytosis; elimination of brain glioma cells and disruption of neovasculatures by targeting uptake and cytotoxic injury. Besides, CNP-modified vinorelbine lipid vesicles could induce apoptosis of the glioma cells. The mechanisms could be related to the activations of caspase 8, caspase 3, p53, and reactive oxygen species (ROS), and inhibition of survivin. Hence, CNP-modified lipid vesicles could be used as a carrier material for treating brain glioma and disabling glioma neovasculatures.

Metronomic vinorelbine is directly active on Non Small Cell Lung Cancer cells and sensitizes the EGFRL858R/T790M cells to reversible EGFR tyrosine kinase inhibitors

Metronomic vinorelbine (mVNR) has been described primarily as an antiangiogenic therapy, and no direct effects of mVNR on Non Small Cell Lung Cancer (NSCLC) cells has yet been demonstrated. The aims of this study were i) to establish the direct activity of mVNR on NSCLC cells either EGFR wt or EGFR^L858R/T790M, and ii) to quantify the synergism of the combination with reversible EGFR tyrosine kinase inhibitors (TKIs), investigating the underlying mechanism of action. Proliferation assays were performed on A-549 (wt EGFR^high), H-292 (EGFR-wt), H-358 (EGFR-wt), H-1975 (EGFR^L858R/T790M) NSCLC cell lines exposed to mVNR, its active metabolite deacetyl-VNR (D-VNR), gefitinib and erlotinib for 144 h treatments. The synergism between mVNR and EGFR TKIs was determined by the combination index (CI) in EGFR-wt and H-1975 NSCLC cells. Cyclin-D1 and ABCG2 genes expression and protein levels were measured by RT-PCR and ELISA assays, as well as the phosphorylation of ERK1/2 and Akt. Intracellular concentrations of EGFR TKIs and VNR were investigated with a mass spectrometry system. mVNR, and its active metabolite D-VNR, were extremely active on NSCLC cells, in particular on H-1975 (IC₅₀ = 13.56 ± 2.77 pM), resistant to TKIs. mVNR inhibited the phosphorylation of ERK1/2 and Akt and significantly decreased the expression of both cyclin-D1 and ABCG2 m-RNA and protein. The simultaneous combination of VNR and reversible EGFR TKIs showed a strong synergism on EGFR-wt NSCLC cells and on H-1975 cells (e.g. CI = 0.501 for 50% of affected cells), increasing the intracellular concentrations of EGFR TKIs (e.g. +50.5% vs. gefitinib alone). In conclusions, mVNR has direct effects on NSCLC cells and sensitizes resistant cells to EGFR TKIs, increasing their intracellular concentrations.

Communicative reprogramming non-curative hepatocellular carcinoma with low-dose metronomic chemotherapy, COX-2 inhibitor and PPAR-gamma agonist: a phase II trial

Systemic therapy for advanced hepatocellular carcinoma (HCC) is still challenging. A biomodulatory therapy approach targeting the communicative infrastructure of HCC, including metronomic low-dose chemotherapy with capecitabine, pioglitazone and rofecoxib, has been evaluated in patients with non-curative HCC. Altogether 38 patients were evaluable in this one-arm, multicenter phase II trial. The primary endpoint, median progression-free survival was 2.7 months (95% CI: 1.6-3.79) for all evaluable patients and 8.4 months (95% CI: 0-18.13) for patients ≥ 6 weeks on protocol. Median overall survival (OS) was 6.7 months (95% CI: 4.08-9.31) and 9.4 months (95% CI: 4.82-13.97), respectively. Most common adverse events were edemas grade 3, which were commonly related to the advanced stage, with 66% of the patients suffering from liver cirrhosis. Exploratory data analyses showed significant impact of ECOG performance status grade 0 versus 1 and CLIP score 0/1 versus > 1 on OS, 9.8 months (95% CI: 4.24-15.35) versus 2.7 months (95% CI: 1.03-4.36; P = 0.002), and 9.8 months (95% CI: 3.23-16.37) versus 4.4 months (95% CI: 3.14-5.66; P = 0.009), respectively. Preceding tumor surgery had significant beneficial impact on survival, as well as maximal tumor diameter of < 5 cm. The correlation of C-reactive protein decrease with significantly improved OS underlines the close link between inflammation and tumor control. Biomodulatory therapy in advanced HCC may be a low toxic, efficacious treatment and principally demonstrates that such approaches should be followed further for treatment of advanced HCC.

Clinical Development of Anti-mitotic Drugs in Cancer

Mitosis is one of the most fundamental processes of life by which a mammalian cell divides into two daughter cells. Mitosis has been an attractive target for anticancer therapies since fast proliferation was identified as one of the hallmarks of cancer cells. Despite efforts into developing specific inhibitors for mitotic kinases and kinesins, very few drugs have shown the efficiency of microtubule targeting-agents in cancer cells with paclitaxel being the most successful. A deeper translational research accompanying clinical trials of anti-mitotic drugs will help in identifying potent biomarkers predictive for response. Here, we review the current knowledge of mitosis targeting agents that have been tested so far in the clinics.

Metronomic chemotherapy: A potent macerator of cancer by inducing angiogenesis suppression and antitumor immune activation

Metronomic chemotherapy is a low dosing treatment strategy that attracts growing scientific and clinical interest. It refers to dense and uninterrupted administration of low doses of chemotherapeutic agents (without prolonged drug free intervals) over extended periods of time. Cancer chemotherapy is conventionally given in cycles of maximum tolerated doses (MTD) with the aim of inducing maximum cancer cell apoptosis. In contrast, the primary target of metronomic chemotherapy is the tumor's neovasculature. This is relevant to the emerging concept that tumors exist in a complex microenvironment of cancer cells, stromal cells and supporting vessels. In addition to its anti-angiogenetic properties, metronomic chemotherapy halts tumor growth by activating anti-tumor immunity, thus decreasing the acquired resistance to conventional chemotherapy. Herein, we present a review of the literature that provides a scientific basis for the merits of chemotherapy when administered on a metronomic schedule.

Vinorelbine Delivery and Efficacy in the MDA-MB-231BR Preclinical Model of Brain Metastases of Breast Cancer

PURPOSE

To evaluate vinorelbine drug exposure and activity in brain metastases of the human MDA-MB-231BR breast cancer model using integrated imaging and analysis.

METHODS

Brain and systemic metastases were created by administration of cancer cells in female NuNu mice. After metastases developed, animals were administered vinorelbine at the maximal tolerated dose (12 mg/kg), and were evaluated thereafter for total and unbound drug pharmacokinetics, biomarker TUNEL staining, and barrier permeability to Texas red.

RESULTS

Median brain metastasis drug exposure was 4-fold greater than normal brain, yet only ~8% of non-barrier systemic metastases, which suggests restricted brain exposure. Unbound vinorelbine tissue/plasma partition coefficient, K_p,uu, equaled ~1.0 in systemic metastases, but 0.03-0.22 in brain metastases, documenting restricted equilibration. In select sub-regions of highest drug-uptake brain metastases, K_p,uu approached 1.0, indicating complete focal barrier breakdown. Most vinorelbine-treated brain metastases exhibited little or no positive early apoptosis TUNEL staining in vivo. The in vivo unbound vinorelbine IC₅₀ for TUNEL-positive staining (56 nM) was 4-fold higher than that measured in vitro (14 nM). Consistent with this finding, P-glycoprotein expression was observed to be substantially upregulated in brain metastasis cells in vivo.

CONCLUSIONS

Vinorelbine exposure at maximum tolerated dose was less than one-tenth that in systemic metastases in >70% of brain metastases, and was associated with negligible biomarker effect. In small subregions of the highest uptake brain metastases, compromise of blood-tumor barrier appeared complete. The results suggest that restricted delivery accounts for 80% of the compromise in drug efficacy for vinorelbine against this model.