Bauhinia purprea agglutinin-modified liposomes for human prostate cancer treatment

Lectins as the prominent potential to deliver bioactive metal nanoparticles by recognizing cell surface glycans

Lectins are renowned for recognizing specific carbohydrates, but there is evidence that they can bind to other endogenous ligands. Therefore, lectin can be used as a carrier to recognize glycoconjugates on the cell surface. The anticancer, antibacterial, and immunomodulatory properties of some lectins are established. Metal nanoparticles (MNPs) have been used in various fields recently, but their documented toxicity has raised questions about their suitability for biomedical uses. The advantages of MNPs can be realized if we deliver the NPs to the site of action; as a result, NPs may achieve greater therapeutic efficiency at lower doses with less toxicity. The use of carbohydrate specificity by lectin MNPs conjugates for diagnostics and therapeutics was addressed. The review summarised the multidimensional application of lectins and described their potential for delivery of MNPs in future drug development.

Novel Selectively Targeted Multifunctional Nanostructured Lipid Carriers for Prostate Cancer Treatment

Prostate cancer (PC) is the most common cancer in men over 50 and the 4th most prevalent human malignancy. PC treatment may include surgery, androgen deprivation therapy, chemotherapy, and radiation therapy. However, the therapeutic efficacy of systemic chemotherapy is limited due to low drug solubility and insufficient tumor specificity, inflicting toxic side effects and frequently provoking the emergence of drug resistance. Towards the efficacious treatment of PC, we herein developed novel selectively PC-targeted nanoparticles (NPs) harboring a cytotoxic drug cargo. This delivery system is based upon PEGylated nanostructured lipid carriers (NLCs), decorated with a selective ligand, targeted to prostate-specific membrane antigen (PSMA). NPs loaded with cabazitaxel (CTX) displayed a remarkable loading capacity of 168 ± 3 mg drug/g SA-PEG, encapsulation efficiency of 67 ± 1%, and an average diameter of 159 ± 3 nm. The time-course of in vitro drug release from NPs revealed a substantial drug retention profile compared to the unencapsulated drug. These NPs were selectively internalized into target PC cells overexpressing PSMA, and displayed a dose-dependent growth inhibition compared to cells devoid of the PSMA receptor. Remarkably, these targeted NPs exhibited growth-inhibitory activity at pM CTX concentrations, being markedly more potent than the free drug. This selectively targeted nano-delivery platform bears the promise of enhanced efficacy and minimal untoward toxicity.

Research advances and prospects of legume lectins

Lectins are widely distributed proteins having ability of binding selectively and reversibly with carbohydrates moieties and glycoconjugates. Although lectins have been reported from different biological sources, the legume lectins are the best-characterized family of plant lectins. Legume lectins are a large family of homologous proteins with considerable similarity in amino acid sequence and their tertiary structures. Despite having strong sequence conservation, these lectins show remarkable variability in carbohydrate specificity and quaternary structures. The ability of legume lectins in recognizing glycans and glycoconjugates on cells and other intracellular structures make them a valuable research tool in glycomic research. Due to variability in binding with glycans, glycoconjugates and multiple biological functions, legume lectins are the subject of intense research for their diverse application in different fields such as glycobiology, biomedical research and crop improvement. The present review specially focuses on structural and functional characteristics of legume lectins along with their potential areas of application.

Lectins applied to diagnosis and treatment of prostate cancer and benign hyperplasia: A review

Environmental factors, as well as genetic factors, contribute to the increase in prostate cancer cases (PCa), the second leading cause of cancer death in men. This fact calls for the development of more reliable, quick and low-cost early detection tests to distinguish between malignant and benign cases. Abnormal cell glycosylation pattern is a promising PCa marker for this purpose. Proteins, such as lectins can decode the information contained in the glycosylation patterns. Several studies have reported on applications of plant lectins as diagnostic tools for PCa considering the ability to differentiate it from benign cases. In addition, they can be used to detect, separate and differentiate the glycosylation patterns of cells or proteins present in serum, urine and semen. Herein, we present an overview of these studies, showing the lectins that map glycans differentially expressed in PCa, as well as benign hyperplasia (BPH). We further review their applications in biosensors, histochemical tests, immunoassays, chromatography, arrays and, finally, their therapeutic potential. This is the first study to review vegetable lectins applied specifically to PCa.

Targeted nanomedicine modalities for prostate cancer treatment

Prostate cancer (PC) is the second most common cause of death amongst men in the USA. Therapy of PC has been transformed in the past decade by introducing novel therapeutics, advanced functional imaging and diagnostic approaches, next generation sequencing, as well as improved application of existing therapies in localized PC. Treatment of PC at the different stages of the disease may include surgery, androgen deprivation therapy (ADT), chemotherapy and radiation therapy. However, although ADT has proven efficacious in PC treatment, its effectiveness may be temporary, as these tumors frequently develop molecular mechanisms of therapy resistance, which allow them to survive and proliferate even under conditions of testosterone deprivation, inhibition of androgen receptor signaling, or cytotoxic drug treatment. Importantly, ADT was found to induce key alterations which frequently result in the formation of metastatic tumors displaying a therapy refractory phenotype. Hence, to overcome these serious therapeutic impediments, novel PC cell-targeted therapeutic strategies are being developed. These include diverse platforms enabling specific enhanced antitumor drug uptake and increased intracellular accumulation. Studies have shown that these novel treatment modalities lead to enhanced antitumor activity and diminished systemic toxicity due to the use of selective targeting and decreased drug doses. The underlying mechanism of targeting and internalization is based upon the interaction between a selective ligand, conjugated to a drug-loaded nanoparticle or directly to an anti-cancer drug, and a specific plasma membrane biomarker, uniquely overexpressed on the surface of PC cells. Another targeted therapeutic approach is the delivery of unique anti-oncogenic signaling pathway-based therapeutic drugs, which are selectively cytotoxic to PC cells. The current paper reviews PC targeted modalities reported in the past 6 years, and discusses both the advantages and limitations of the various targeted treatment strategies.

Nanosystem functionalization strategies for prostate cancer treatment: a review

Prostate cancer (PC) has a high morbidity and mortality rate worldwide, and the current clinical guidelines can vary depending on the stage of the disease. Drug delivery nanosystems (DDNs) can improve biopharmaceutical properties of encapsulated anti-cancer drugs by modulating their release kinetics, improving physicochemical stability and reducing toxicity. DDN can also enhance the ability of specific targeting through surface modification by coupling ligands (antibodies, nucleic acids, peptides, aptamer, proteins), thus favouring the cell internalisation process by endocytosis. The purposes of this review are to describe the limitations in the treatment of PC, explore different functionalization such as polymeric, lipid and inorganic nanosystems aimed at the treatment of PC, and demonstrate the improvement of this modification for an active target, as alternative and promising candidates for new therapies.

Novel Pancreatic Cancer Therapy Targeting Cell Surface Glycans by Liposomes Modified with rBC2LCN Lectin

INTRODUCTION

Since the outermost layer of cancer cells is covered with various glycans, targeting these groups may serve as an effective strategy in cancer therapy. We previously reported that fucosylated glycans are specifically expressed on pancreatic cancer cells, and that a protein specifically binding to these glycans, namely rBC2LCN lectin, is a potential guiding drug carrier. In the present study, a novel type of glycan-targeting nanoparticle was developed by modifying the surface of doxorubicin-containing liposomes with rBC2LCN lectin. The efficiency and specificity of this formulation, termed Lec-Doxosome, were examined in vitro and in vivo in human pancreatic cancer models.

METHODS

Lec-Doxosome was prepared by a post-insertion method based on the insertion of rBC2LCN lectin into the liposomal surface via a lipid linker. The in vitro cellular binding, uptake, and cytotoxicity of Lec-Doxosome were compared with the corresponding parameters in the unmodified liposomes by applying to human pancreatic cancer cell line (Capan-1) with affinity for rBC2LCN lectin. For the in vivo assay, Lec-Doxosome was intravenously injected once per week for a total of 3 weeks into mice bearing subcutaneous tumors.

RESULTS

The in vitro application of Lec-Doxosome resulted in a 1.2- to 1.6-fold higher intracellular doxorubicin accumulation and a 1.5-fold stronger cytotoxicity compared with the respective rates of accumulation and cytotoxicity in the unmodified liposomes. In vivo, Lec-Doxosome reduced the mean tumor weight (368 mg) compared with that in mice treated with unmodified liposomes (456 mg), without causing any additional adverse events.

CONCLUSION

It was demonstrated from the results obtained herein that rBC2LCN lectin is a potent modifier, as a means for boosting the efficiency of nanoparticles in the targeting of cancer cell surface glycans.

Research advances and prospects of legume lectins

Lectins are widely distributed proteins having ability of binding selectively and reversibly with carbohydrates moieties and glycoconjugates. Although lectins have been reported from different biological sources, the legume lectins are the best-characterized family of plant lectins. Legume lectins are a large family of homologous proteins with considerable similarity in amino acid sequence and their tertiary structures. Despite having strong sequence conservation, these lectins show remarkable variability in carbohydrate specificity and quaternary structures. The ability of legume lectins in recognizing glycans and glycoconjugates on cells and other intracellular structures make them a valuable research tool in glycomic research. Due to variability in binding with glycans, glycoconjugates and multiple biological functions, legume lectins are the subject of intense research for their diverse application in different fields such as glycobiology, biomedical research and crop improvement. The present review specially focuses on structural and functional characteristics of legume lectins along with their potential areas of application.

Novel Strategies for Targeting Prostate Cancer

Prostate cancer (PCa) is a worldwide issue, with a rapid increase in its occurrence and mortality. Over the years, various strategies have been implemented to overcome the hurdles that exist in the treatment of PCa. Consistently, there is a change in opinion about the methodologies in clinical trial that have engrossed towards the treatment of PCa. Currently, there is a need to resolve these newly recognized challenges by developing newer rational targeting systems. The ongoing clinical protocol for the therapy using different targeting systems is undertaken followed by local targeting to cancer site. A number of new drug targeting systems like liposomes, nanoemulsions, magnetic nanoparticles (MNPs), solid lipid nanoparticles, drug-peptide conjugate systems, drug-antibody conjugate systems, epigenetic and gene therapy approaches, and therapeutic aptamers are being developed to suit this protocol. Recent advancements in the treatment of PCa with various nanocarriers have been reported with respect to newly identified biological barriers and intended to solve the contexts. This review encompasses the input of nanotechnology in particular targeting of PCa which might escape the lifethreatening side effects and potentially contribute to bring fruitful clinical outcomes.

Lectins as possible tools for improved urinary bladder cancer management

Urinary bladder cancer is the ninth most common cancer in developed countries with poor prognosis and outcome for the patient due to the challenging diagnosis and limited treatment possibilities. Bladder cancer arises mainly from urothelial cells lining the lumen. Urothelial cells form a three- to five-layered urothelium, which maintains the blood-urine barrier. The carbohydrates that cover the apical surface of superficial urothelial cells, i.e. umbrella cells, are crucial for this function. The composition of the carbohydrate covering is altered during urothelial cancer transformation. These bladder cancer-associated carbohydrate changes are a promising field for diagnosis, therapy and management. Lectins, which are carbohydrate-binding proteins, can be used to detect subtle alterations in carbohydrate composition during urothelial cancer transformation. Extensive research into various lectin applications has already been conducted, but the results are often contradictory and confusing. None of these applications have reached clinical trials. We review the literature and discuss (i) current bladder cancer management, (ii) lectin-based assays for detection of various cancer subtypes, (iii) lectin-based strategies for innovative bladder cancer treatment and finally (iv) lectins in nanotheranostics for personalized bladder cancer management.

Structure-function and application of plant lectins in disease biology and immunity

Lectins are proteins with a high degree of stereospecificity to recognize various sugar structures and form reversible linkages upon interaction with glyco-conjugate complexes. These are abundantly found in plants, animals and many other species and are known to agglutinate various blood groups of erythrocytes. Further, due to the unique carbohydrate recognition property, lectins have been extensively used in many biological functions that make use of protein-carbohydrate recognition like detection, isolation and characterization of glycoconjugates, histochemistry of cells and tissues, tumor cell recognition and many more. In this review, we have summarized the immunomodulatory effects of plant lectins and their effects against diseases, including antimicrobial action. We found that many plant lectins mediate its microbicidal activity by triggering host immune responses that result in the release of several cytokines followed by activation of effector mechanism. Moreover, certain lectins also enhance the phagocytic activity of macrophages during microbial infections. Lectins along with heat killed microbes can act as vaccine to provide long term protection from deadly microbes. Hence, lectin based therapy can be used as a better substitute to fight microbial diseases efficiently in future.

Phytochemicals in Prostate Cancer: From Bioactive Molecules to Upcoming Therapeutic Agents

Prostate cancer is a heterogeneous disease, the second deadliest malignancy in men and the most commonly diagnosed cancer among men. Traditional plants have been applied to handle various diseases and to develop new drugs. Medicinal plants are potential sources of natural bioactive compounds that include alkaloids, phenolic compounds, terpenes, and steroids. Many of these naturally-occurring bioactive constituents possess promising chemopreventive properties. In this sense, the aim of the present review is to provide a detailed overview of the role of plant-derived phytochemicals in prostate cancers, including the contribution of plant extracts and its corresponding isolated compounds.

Targeted Delivery to Tumors: Multidirectional Strategies to Improve Treatment Efficiency

Malignant tumors are characterized by structural and molecular peculiarities providing a possibility to directionally deliver antitumor drugs with minimal impact on healthy tissues and reduced side effects. Newly formed blood vessels in malignant lesions exhibit chaotic growth, disordered structure, irregular shape and diameter, protrusions, and blind ends, resulting in immature vasculature; the newly formed lymphatic vessels also have aberrant structure. Structural features of the tumor vasculature determine relatively easy penetration of large molecules as well as nanometer-sized particles through a blood⁻tissue barrier and their accumulation in a tumor tissue. Also, malignant cells have altered molecular profile due to significant changes in tumor cell metabolism at every level from the genome to metabolome. Recently, the tumor interaction with cells of immune system becomes the focus of particular attention, that among others findings resulted in extensive study of cells with preferential tropism to tumor. In this review we summarize the information on the diversity of currently existing approaches to targeted drug delivery to tumor, including (i) passive targeting based on the specific features of tumor vasculature, (ii) active targeting which implies a specific binding of the antitumor agent with its molecular target, and (iii) cell-mediated tumor targeting.

Lectins, Interconnecting Proteins with Biotechnological/Pharmacological and Therapeutic Applications

Lectins are proteins extensively used in biomedical applications with property to recognize carbohydrates through carbohydrate-binding sites, which identify glycans attached to cell surfaces, glycoconjugates, or free sugars, detecting abnormal cells and biomarkers related to diseases. These lectin abilities promoted interesting results in experimental treatments of immunological diseases, wounds, and cancer. Lectins obtained from virus, microorganisms, algae, animals, and plants were reported as modulators and tool markers in vivo and in vitro; these molecules also play a role in the induction of mitosis and immune responses, contributing for resolution of infections and inflammations. Lectins revealed healing effect through induction of reepithelialization and cicatrization of wounds. Some lectins have been efficient agents against virus, fungi, bacteria, and helminths at low concentrations. Lectin-mediated bioadhesion has been an interesting characteristic for development of drug delivery systems. Lectin histochemistry and lectin-based biosensors are useful to detect transformed tissues and biomarkers related to disease occurrence; antitumor lectins reported are promising for cancer therapy. Here, we address lectins from distinct sources with some biological effect and biotechnological potential in the diagnosis and therapeutic of diseases, highlighting many advances in this growing field.

Development of New Liposome Targeting Strategies for Application of Disease Therapies

Drug delivery systems (DDS) are based on the concept of providing the optimal amount of a drug to a specific area requiring treatment. Liposomes are lipid-based nanoparticles capable of encapsulating any drug into both their membrane and aqueous phases. They have the potential to be targeted when their surfaces are modified with functional molecules such as antibodies and peptides. Thus, liposomes have strong potential as drug carriers if designed for active targeting. Our research group has recently developed a new concept for liposome targeting called "reverse targeting DDS (RT-DDS)". RT-DDS differs from conventional active targeting in that the surface of the liposomes is modified with an antigenic molecule that is specifically recognized by antigen-specific immune cells. This review describes in detail the differences between these two DDS targeting concepts and proposes the application of RT-DDS to the treatment of allergies based on research using ovalbumin as a model allergy antigen.

Self-assembled nanoparticles covalently consisting of doxorubicin and EDB fibronectin specific peptide for solid tumour treatment

We developed a facile modality to prepare nanoparticles consisting of doxorubicin and ZD2 motif for treating solid tumours. The nanoparticles showed great preferential cellular uptake in PC3 cells, high cell suppression, and strong anti-tumour ability.

Bauhinia purprea agglutinin-modified liposomes for human prostate cancer treatment

Bauhinia purprea agglutinin (BPA) is a well‐known lectin that recognizes galactosyl glycoproteins and glycolipids. In the present study, we firstly found that BPA bound to human prostate cancer specimens but not to normal prostate ones. Therefore, we sought to develop BPA‐PEG‐modified liposomes (BPA‐PEG‐LP) encapsulating anticancer drugs for the treatment of prostate cancer. We examined the tumor targetability of BPA‐PEG‐LP with human prostate cancer DU145 cells, and observed that fluorescently labeled BPA‐PEG‐LP dominantly associated with the cells via the interaction between liposome‐surface BPA and cell‐surface galactosyl molecules. We also observed that BPA‐PEG‐LP accumulated in the prostate cancer tissue after the i.v. injection to DU145 solid cancer‐bearing mice, and strongly bound to the cancer cells. In a therapeutic study, DU145 solid cancer‐bearing mice were i.v. injected thrice with BPA‐PEG‐LP encapsulating doxorubicin (BPA‐PEG‐LPDOX, 2 mg/kg/day as the DOX dosage) or PEG‐modified liposomes encapsulating DOX (PEG‐LPDOX). As a result, BPA‐PEG‐LPDOX significantly suppressed the growth of the DU145 cancer cells, whereas PEG‐LPDOX at the same dosage as DOX showed little anti‐cancer effect. The present study suggested that BPA‐PEG‐LP could be a useful drug carrier for the treatment of human prostate cancers.