Restoring SRSF3 in Kupffer cells attenuates obesity-related insulin resistance.

BACKGROUND AND AIMS: In obesity, depletion of KCs expressing CRIg (complement receptor of the Ig superfamily) leads to microbial DNA accumulation, which subsequently triggers tissue inflammation and insulin resistance. However, the mechanism underlying obesity-mediated changes in KC complement immune functions is largely unknown. APPROACH AND RESULTS: Using KC-specific deactivated Cas9 transgenic mice treated with guide RNA, we assessed the effects of restoring CRIg or the serine/arginine-rich splicing factor 3 (SRSF3) abundance on KC functions and metabolic phenotypes in obese mice. The impacts of weight loss on KC responses were evaluated in a diet switch mouse model. The role of SRSF3 in regulating KC functions was also evaluated using KC-specific SRSF3 knockout mice. Here, we report that overexpression of CRIg in KCs of obese mice protects against bacterial DNA accumulation in metabolic tissues. Mechanistically, SRSF3 regulates CRIg expression, which is essential for maintaining the CRIg+ KC population. During obesity, SRSF3 expression decreases, but it is restored with weight loss through a diet switch, normalizing CRIg+ KCs. KC SRSF3 is also repressed in obese human livers. Lack of SRSF3 in KCs in lean and obese mice decreases their CRIg+ population, impairing metabolic parameters. During the diet switch, the benefits of weight loss are compromised due to SRSF3 deficiency. Conversely, SRSF3 overexpression in obese mice preserves CRIg+ KCs and improves metabolic responses. CONCLUSIONS: Restoring SRSF3 abundance in KCs offers a strategy against obesity-associated tissue inflammation and insulin resistance by preventing bacterial DNA accumulation.

Obesity, cancer risk, and time-restricted eating.

Obesity and the associated metabolic syndrome is considered a pandemic whose prevalence is steadily increasing in many countries worldwide. It is a complex, dynamic, and multifactorial disorder that presages the development of several metabolic, cardiovascular, and neurodegenerative diseases, and increases the risk of cancer. In patients with newly diagnosed cancer, obesity worsens prognosis, increasing the risk of recurrence and decreasing survival. The multiple negative effects of obesity on cancer outcomes are substantial, and of great clinical importance. Strategies for weight control have potential utility for both prevention efforts and enhancing cancer outcomes. Presently, time-restricted eating (TRE) is a popular dietary intervention that involves limiting the consumption of calories to a specific window of time without any proscribed caloric restriction or alteration in dietary composition. As such, TRE is a sustainable long-term behavioral modification, when compared to other dietary interventions, and has shown many health benefits in animals and humans. The preliminary data regarding the effects of time-restricted feeding on cancer development and growth in animal models are promising but studies in humans are lacking. Interestingly, several short-term randomized clinical trials of TRE have shown favorable effects to reduce cancer risk factors; however, long-term trials of TRE have yet to investigate reductions in cancer incidence or outcomes in the general population. Few studies have been conducted in cancer populations, but a number are underway to examine the effect of TRE on cancer biology and recurrence. Given the simplicity, feasibility, and favorable metabolic improvements elicited by TRE in obese men and women, TRE may be useful in obese cancer patients and cancer survivors; however, the clinical implementation of TRE in the cancer setting will require greater in-depth investigation.

Stimulating Antitumoral Immunity by Percutaneous Cryoablation and Combination Immunoadjuvant Therapy in a Murine Model of Hepatocellular Carcinoma.

PURPOSE: To test the hypothesis that antitumoral immunity can be induced after cryoablation (cryo) of hepatocellular carcinoma (HCC) through coadministration of the immunostimulant CpG and an immune checkpoint (programmed cell death 1 [PD-1]) inhibitor. MATERIALS AND METHODS: Sixty-three immunocompetent C57BL/6J mice were generated with 2 orthotopic HCC tumor foci: 1 for treatment and 1 to observe for antitumoral immunity. Tumors were treated with incomplete cryo alone or intratumoral CpG and/or a PD-1 inhibitor. The primary endpoint was death or when the following criteria for sacrifice were met: tumor > 1 cm (determined using ultrasound) or moribund state. Antitumoral immunity was assessed using flow cytometry and histology (tumor and liver) as well as enzyme-linked immunosorbent assay (serum). Analysis of variance was used for statistical comparisons. RESULTS: At 1 week, the nonablated satellite tumor growth was reduced by 1.9-fold (P = .047) in the cryo + CpG group and by 2.8-fold (P = .007) in the cryo + CpG + PD-1 group compared with that in the cryo group. Compared with cryo alone, the time to tumor progression to endpoints was also prolonged for cryo + CpG + PD-1 and cryo + CpG mice, with log-rank hazard ratios of 0.42 (P = .031) and 0.27 (P < .001), respectively. Flow cytometry and histology showed increased cytotoxic T-cell infiltration (P = .002) and serum levels of the proinflammatory cytokine interferon-γ (P = .015) in tumors and serum of cryo + CpG mice compared with those in tumors and serum of mice treated with cryo alone. High serum levels of the anti-inflammatory cytokine tumor growth factor-ß and the proangiogenesis chemokine C-X-C motif chemokine ligand 1 were correlated with a shorter time to endpoints and faster tumor growth. CONCLUSIONS: Cryo combined with the immunostimulant CpG promoted cytotoxic T-cell infiltration into tumors, slowed tumor growth, and prolonged the time to progression to endpoints in an aggressive murine HCC model.

Multifunctional nanoparticle-EpCAM aptamer bioconjugates: a paradigm for targeted drug delivery and imaging in cancer therapy.

The promising proposition of multifunctional nanoparticles for cancer diagnostics and therapeutics has inspired the development of theranostic approach for improved cancer therapy. Moreover, active targeting of drug carrier to specific target site is crucial for providing efficient delivery of therapeutics and imaging agents. In this regard, the present study investigates the theranostic capabilities of nutlin-3a loaded poly (lactide-co-glycolide) nanoparticles, functionalized with a targeting ligand (EpCAM aptamer) and an imaging agent (quantum dots) for cancer therapy and bioimaging. A wide spectrum of in vitro analysis (cellular uptake study, cytotoxicity assay, cell cycle and apoptosis analysis, apoptosis associated proteins study) revealed superior therapeutic potentiality of targeted NPs over other formulations in EpCAM expressing cells. Moreover, our nanotheranostic system served as a superlative bio-imaging modality both in 2D monolayer culture and tumor spheroid model. Our result suggests that, these aptamer-guided multifunctional NPs may act as indispensable nanotheranostic approach toward cancer therapy. FROM THE CLINICAL EDITOR: This study investigated the theranostic capabilities of nutlin-3a loaded poly (lactide-co-glycolide) nanoparticles functionalized with a targeting ligand (EpCAM aptamer) and an imaging agent (quantum dots) for cancer therapy and bioimaging. It was concluded that the studied multifunctional targeted nanoparticle may become a viable and efficient approach in cancer therapy.

Time-Restricted Feeding Attenuates Metabolic Dysfunction-Associated Steatohepatitis and Hepatocellular Carcinoma in Obese Male Mice.

Metabolic dysfunction-associated steatotic liver disease (MASLD) has surpassed the hepatitis B virus and hepatitis C virus as the leading cause of chronic liver disease in most parts of the Western world. MASLD (formerly known as NAFLD) encompasses both simple steatosis and more aggressive metabolic dysfunction-associated steatohepatitis (MASH), which is accompanied by inflammation, fibrosis, and cirrhosis, and ultimately can lead to hepatocellular carcinoma (HCC). There are currently very few approved therapies for MASH. Weight loss strategies such as caloric restriction can ameliorate the harmful metabolic effect of MASH and inhibit HCC; however, it is difficult to implement and maintain in daily life, especially in individuals diagnosed with HCC. In this study, we tested a time-restricted feeding (TRF) nutritional intervention in mouse models of MASH and HCC. We show that TRF abrogated metabolic dysregulation induced by a Western diet without any calorie restriction or weight loss. TRF improved insulin sensitivity and reduced hyperinsulinemia, liver steatosis, inflammation, and fibrosis. Importantly, TRF inhibited liver tumors in two mouse models of obesity-driven HCC. Our data suggest that TRF is likely to be effective in abrogating MASH and HCC and warrant further studies of time-restricted eating in humans with MASH who are at higher risk of developing HCC.

Loss of cAMP Signaling in CD11c Immune Cells Protects Against Diet-Induced Obesity.

In obesity, CD11c+ innate immune cells are recruited to adipose tissue and create an inflammatory state that causes both insulin and catecholamine resistance. We found that ablation of Gnas, the gene that encodes Gαs, in CD11c expressing cells protects mice from obesity, glucose intolerance, and insulin resistance. Transplantation studies showed that the lean phenotype was conferred by bone marrow-derived cells and did not require adaptive immunity. Loss of cAMP signaling was associated with increased adipose tissue norepinephrine and cAMP signaling, and prevention of catecholamine resistance. The adipose tissue had reduced expression of catecholamine transport and degradation enzymes, suggesting that the elevated norepinephrine resulted from decreased catabolism. Collectively, our results identified an important role for cAMP signaling in CD11c+ innate immune cells in whole-body metabolism by controlling norepinephrine levels in white adipose tissue, modulating catecholamine-induced lipolysis and increasing thermogenesis, which, together, created a lean phenotype. ARTICLE HIGHLIGHTS: We undertook this study to understand how immune cells communicate with adipocytes, specifically, whether cAMP signaling in the immune cell and the adipocyte are connected. We identified a reciprocal interaction between CD11c+ innate immune cells and adipocytes in which high cAMP signaling in the immune cell compartment induces low cAMP signaling in adipocytes and vice versa. This interaction regulates lipolysis in adipocytes and inflammation in immune cells, resulting in either a lean, obesity-resistant, and insulin-sensitive phenotype, or an obese, insulin-resistant phenotype.

Sustained wound healing activity of curcumin loaded oleic acid based polymeric bandage in a rat model.

Wound healing is an intricate multistage process that includes inflammation, cell proliferation, matrix deposition and remodeling phases. It is often associated with oxidative stress and consequent prolonged inflammation, resulting in impaired wound healing. Curcumin has been reported to improve wound healing in different animal models. In order to increase the efficacy of curcumin in the healing arena a curcumin loaded oleic acid based polymeric (COP) bandage was formulated. The in vivo wound healing potency was compared with void bandage and control (cotton gauze treatment) in a rat model. Biochemical parameters and histological analysis revealed increased wound reduction and enhanced cell proliferation in COP bandage treated groups due to its efficient free radical scavenging properties. Comparative acceleration in wound healing was due to early implementation of fibroblasts and its differentiation (increased level of α-smooth muscle actin). Western blotting and semiquantitative PCR analysis clearly indicate that COP bandage can efficiently quench free radicals leading to reduced antioxidative enzyme activity. Further evidence at mRNA and protein level indicates that our system is potent enough to reduce the inflammatory response mediated by the NFκB pathway during wound healing. With this background, we anticipate that such a versatile approach may seed new arena for topical wound healing in the near future.

Hepatocyte Deletion of IGF2 Prevents DNA Damage and Tumor Formation in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Serine-arginine rich splicing factor 3 (SRSF3) plays a critical role in hepatocyte function and its loss in mice promotes chronic liver damage and leads to HCC. Hepatocyte-specific SRSF3 knockout mice (SKO mice) also overexpress insulin-like growth factor 2 (IGF2). In the present study, double deletion of Igf2 and Srsf3 (DKO mice) prevents hepatic fibrosis and inflammation, and completely prevents tumor formation, and is associated with decreased proliferation, apoptosis and DNA damage, and restored DNA repair enzyme expression. This is confirmed in vitro, where IGF2 treatment of HepG2 hepatoma cells decreases DNA repair enzyme expression and causes DNA damage. Tumors from the SKO mice also show mutational signatures consistent with homologous recombination and mismatch repair defects. Analysis of frozen human samples shows that SRSF3 protein is decreased sixfold in HCC compared to normal liver tissue but SRSF3 mRNA is increased. Looking at public TCGA data, HCC patients having high SRSF3 mRNA expression show poor survival, as do patients with alterations in known SRSF3-dependent splicing events. The results indicate that IGF2 overexpression in conjunction with reduced SRSF3 splicing activity could be a major cause of DNA damage and driver of liver cancer.

Mitochondrial Dysfunction in Obesity and Reproduction.

Mounting evidence suggests a role for mitochondrial dysfunction in the pathogenesis of many diseases, including type 2 diabetes, aging, and ovarian failure. Because of the central role of mitochondria in energy production, heme biosynthesis, calcium buffering, steroidogenesis, and apoptosis signaling within cells, understanding the molecular mechanisms behind mitochondrial dysregulation and its potential implications in disease is critical. This review will take a journey through the past and summarize what is known about mitochondrial dysfunction in various disorders, focusing on metabolic alterations and reproductive abnormalities. Evidence is presented from studies in different human populations, and rodents with genetic manipulations of pathways known to affect mitochondrial function.

Time-restricted feeding normalizes hyperinsulinemia to inhibit breast cancer in obese postmenopausal mouse models.

Accumulating evidence indicates that obesity with its associated metabolic dysregulation, including hyperinsulinemia and aberrant circadian rhythms, increases the risk for a variety of cancers including postmenopausal breast cancer. Caloric restriction can ameliorate the harmful metabolic effects of obesity and inhibit cancer progression but is difficult to implement and maintain outside of the clinic. In this study, we aim to test a time-restricted feeding (TRF) approach on mouse models of obesity-driven postmenopausal breast cancer. We show that TRF abrogates the obesity-enhanced mammary tumor growth in two orthotopic models in the absence of calorie restriction or weight loss. TRF also reduces breast cancer metastasis to the lung. Furthermore, TRF delays tumor initiation in a transgenic model of mammary tumorigenesis prior to the onset of obesity. Notably, TRF increases whole-body insulin sensitivity, reduces hyperinsulinemia, restores diurnal gene expression rhythms in the tumor, and attenuates tumor growth and insulin signaling. Importantly, inhibition of insulin secretion with diazoxide mimics TRF whereas artificial elevation of insulin through insulin pumps implantation reverses the effect of TRF, suggesting that TRF acts through modulating hyperinsulinemia. Our data suggest that TRF is likely to be effective in breast cancer prevention and therapy.

Degradation of splicing factor SRSF3 contributes to progressive liver disease.

Serine rich splicing factor 3 (SRSF3) plays a critical role in liver function and its loss promotes chronic liver damage and regeneration. As a consequence, genetic deletion of SRSF3 in hepatocytes caused progressive liver disease and ultimately led to hepatocellular carcinoma. Here we show that SRSF3 is decreased in human liver samples with non-alcoholic fatty liver disease (NAFLD), non-alcoholic steatohepatitis (NASH), or cirrhosis that was associated with alterations in RNA splicing of known SRSF3 target genes. Hepatic SRSF3 expression was similarly decreased and RNA splicing dysregulated in mouse models of NAFLD and NASH. We showed that palmitic acid-induced oxidative stress caused conjugation of the ubiquitin like NEDD8 protein to SRSF3 and proteasome mediated degradation. SRSF3 was selectively neddylated at lysine11 and mutation of this residue (SRSF3-K11R) was sufficient to prevent both SRSF3 degradation and alterations in RNA splicing. Finally prevention of SRSF3 degradation in vivo partially protected mice from hepatic steatosis, fibrosis and inflammation. These results highlight a neddylation-dependent mechanism regulating gene expression in the liver that is disrupted in early metabolic liver disease and may contribute to the progression to NASH, cirrhosis and ultimately hepatocellular carcinoma.

Evaluation of curcumin loaded chitosan/PEG blended PLGA nanoparticles for effective treatment of pancreatic cancer.

Pancreatic cancer is considered as one of the most lethal type of cancer with a poor 5-year survival rate. Cancer metastasis represents one of the primary cause which limits therapy against this disease. Current chemotherapeutic approaches are largely ineffective, thus calling for the development of alternative strategies to combat this disease. In this regard, numerous studies have reported the anticancer effect of curcumin in different types of cancer including pancreatic cancer. However, low aqueous solubility, poor stability and decreased bioavailability associated with native curcumin holds back its use in clinical settings. In order to enhance its therapeutic value, polymeric nanoparticles (NPs) represent an ideal delivery system. Further, surface modification of NPs with various macromolecules, such as chitosan and polyethylene glycol (PEG) holds tremendous potential for improving the bioavailability and circulation time of native drug in the blood. In the present study, we have explored the above approach to formulate curcumin-loaded Poly d,l-lactide-co-glycolide (PLGA) NPs and further surface coated it with chitosan and PEG (CNPs) with anticipation to reduce the limitations associated with native curcumin delivery for achieving an optimum therapeutic effect. Results revealed that NPs are of nanometre range having smooth and spherical surface morphology and with an efficient loading of curcumin. In vitro, cellular studies revealed superior cytotoxicity, enhanced anti-migratory, anti-invasive and apoptosis-inducing ability of CNPs in metastatic pancreatic cancer in comparison to a native counterpart. Thus, we anticipate that the results from these studies can open up novel options for the treatment of pancreatic cancer.

Delivery of Dual Drug Loaded Lipid Based Nanoparticles across the Blood-Brain Barrier Impart Enhanced Neuroprotection in a Rotenone Induced Mouse Model of Parkinson's Disease.

Parkinson's disease (PD) is the most widespread form of dementia where there is an age related degeneration of dopaminergic neurons in the substantia nigra region of the brain. Accumulation of α-synuclein (αS) protein aggregate, mitochondrial dysfunction, oxidative stress, and neuronal cell death are the pathological hallmarks of PD. In this context, amalgamation of curcumin and piperine having profound cognitive properties, and antioxidant activity seems beneficial. However, the blood-brain barrier (BBB) is the major impediment for delivery of neurotherapeutics to the brain. The present study involves formulation of curcumin and piperine coloaded glyceryl monooleate (GMO) nanoparticles coated with various surfactants with a view to enhance the bioavailability of curcumin and penetration of both drugs to the brain tissue crossing the BBB and to enhance the anti-parkinsonism effect of both drugs in a single platform. In vitro results demonstrated augmented inhibition of αS protein into oligomers and fibrils, reduced rotenone induced toxicity, oxidative stress, and apoptosis, and activation of autophagic pathway by dual drug loaded NPs compared to native counterpart. Further, in vivo studies revealed that our formulated dual drug loaded NPs were able to cross BBB, rescued the rotenone induced motor coordination impairment, and restrained dopaminergic neuronal degeneration in a PD mouse model.

CCND1 mutations increase protein stability and promote ibrutinib resistance in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is characterized by the t(11;14) translocation, which leads to deregulated expression of the cell cycle regulatory protein cyclin D1 (CCND1). Genomic studies of MCL have also identified recurrent mutations in the coding region of CCND1. However, the functional consequence of these mutations is not known. Here, we showed that, compared to wild type (WT), single E36K, Y44D or C47S CCND1 mutations increased CCND1 protein levels in MCL cell lines. Mechanistically, these mutations stabilized CCND1 protein through attenuation of threonine-286 phosphorylation, which is important for proteolysis through the ubiquitin-proteasome pathway. In addition, the mutant proteins preferentially localized to the nucleus. Interestingly, forced expression of WT or mutant CCND1 increased resistance of MCL cell lines to ibrutinib, an FDA-approved Bruton tyrosine kinase inhibitor for MCL treatment. The Y44D mutant sustained the resistance to ibrutinib even at supraphysiologic concentrations (5-10 µM). Furthermore, primary MCL tumors with CCND1 mutations also expressed stable CCND1 protein and were resistant to ibrutinib. These findings uncover a new mechanism that is critical for the regulation of CCND1 protein levels, and is directly relevant to primary ibrutinib resistance in MCL.

Reversal of multidrug resistance in vitro by co-delivery of MDR1 targeting siRNA and doxorubicin using a novel cationic poly(lactide-co-glycolide) nanoformulation.

Over expression of drug efflux transporters such as P-glycoprotein (P-gp) cumulatively leading to multidrug resistance (MDR) embodies a major hindrance for successful cancer therapy. A paradigm nanomedicinal approach involving an anticancer drug and modulators of drug resistance within one multifunctional nanocarrier-based delivery system represent an ideal modality for the treatment of MDR. In this regards, we have developed a cationic polymeric nanoparticulate system loaded with MDR1-siRNA and doxorubicin. Results indicated augmented synergistic effect of combinational nanoformulation in overcoming MDR in MCF-7/ADR cells. Therefore, the above regime could be a promising co-delivery system for effective therapy of drug resistant breast cancer.

Coexistence of cutaneous tuberculosis (scrofuloderma) and hanseniasis-a rare presentation.

Cutaneous tuberculosis, pulmonary tuberculosis and hanseniasis are all caused by different spp. of Mycobacterium, an intracellular pathogen whose development depends on impaired cell mediated immunity. Scrofuloderma is the most common variant of cutaneous tuberculosis, which is characterized by a direct extension of the skin which overlies the infected lymph gland, bone or joint, that breaks down to form an undermined ulcer. We are reporting a rare association of Scrofuloderma (cutaneous tuberculosis) with Hanseniasis (leprosy) in an adult male whose immune status was controversial.

Folate decorated dual drug loaded nanoparticle: role of curcumin in enhancing therapeutic potential of nutlin-3a by reversing multidrug resistance.

Retinoblastoma is the most common intraocular tumor in children. Malfunctioning of many signaling pathways regulating cell survival or apoptosis, make the disease more vulnerable. Notably, resistance to chemotherapy mediated by MRP-1, lung-resistance protein (LRP) is the most challenging aspect to treat this disease. Presently, much attention has been given to the recently developed anticancer drug nutlin-3a because of its non-genotoxic nature and potency to activate tumor suppressor protein p53. However, being a substrate of multidrug resistance protein MRP1 and Pgp its application has become limited. Currently, research has step towards reversing Multi drug resistance (MDR) by using curcumin, however its clinical relevance is restricted by plasma instability and poor bioavailability. In the present investigation we tried to encapsulate nutlin-3a and curcumin in PLGA nanoparticle (NPs) surface functionalized with folate to enhance therapeutic potential of nutlin-3a by modulating MDR. We document that curcumin can inhibit the expression of MRP-1 and LRP gene/protein in a concentration dependent manner in Y79 cells. In vitro cellular cytotoxicity, cell cycle analysis and apoptosis studies were done to compare the effectiveness of native drugs (single or combined) and single or dual drug loaded nanoparticles (unconjugated/folate conjugated). The result demonstrated an augmented therapeutic efficacy of targeted dual drug loaded NPs (Fol-Nut-Cur-NPs) over other formulation. Enhanced expression or down regulation of proapoptotic/antiapoptotic proteins respectively and down-regulation of bcl2 and NFκB gene/protein by Fol-Nut-Cur-NPs substantiate the above findings. This is the first investigation exploring the role of curcumin as MDR modulator to enhance the therapeutic potentiality of nutlin-3a, which may opens new direction for targeting cancer with multidrug resistance phenotype.

Emerging role of nanocarriers to increase the solubility and bioavailability of curcumin.

INTRODUCTION: Curcumin is a safe, affordable and natural bioactive molecule of turmeric (Curcuma longa). It has gained considerable attention in recent years for its multiple pharmacological activities. However, its optimum pharmaceutical potential has been limited by its lack of aqueous solubility and poor bioavailability. To mitigate the above limitations, recently various nanostructured water-soluble delivery systems were developed to increase the solubility and bioavailability of curcumin. AREAS COVERED: Major reasons contributing to the low bioavailability of curcumin appear to be owing to its poor solubility, low absorption, rapid metabolism and rapid systemic elimination. The present review summarizes the strategies using curcumin in various nanocarrier delivery systems to overcome poor solubility and inconsistent bioavailability of curcumin and describes the current status and challenges for the future. EXPERT OPINION: The development of various drug delivery systems to deliver curcumin will certainly provide a step up towards augmenting the therapeutic activity of curcumin thereby increasing the solubility and bioavailability of curcumin. However, the future of such delivery technology will be highly dependent on the development of safe, non-toxic and non-immunogenic nanocarriers.

Epithelial cell adhesion molecule targeted nutlin-3a loaded immunonanoparticles for cancer therapy.

Recently much attention has been given to the anti-cancer drug nutlin-3a, an antagonist of murine double minute 2 (MDM2) that actively inhibits p53-MDM2 interaction. Reactivating p53 function by nutlin-3a thus provides a promising therapeutic strategy for the treatment of cancer. Although nutlin-3a seems a potential candidate in restoring p53 activity, it has many lacunae, toxicity, poor bioavailability, nonspecific delivery, and most importantly it is a substrate of multidrug resistance protein. The objective of the present study is to prepare and characterize nutlin-3a loaded poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs), surface functionalized with epithelial cell adhesion molecule (EpCAM) antibody, with an aim to deliver encapsulated drug in a targeted manner to its site of action and to enhance its therapeutic efficacy many times over. The enhanced cellular uptake of EpCAM antibody conjugated nutlin-3a loaded NPs (EpCAM-nutlin-3a-NPs) over native nulin-3a, nutlin-3a loaded NPs (nutlin-3a-NPs) in HCT116 and A549 cells substantiate the targeting potentiality of conjugated system. IC50 values depicted superior antiproliferative activity of EpCAM-nutlin-3a-NPs over nutlin-3a-NPs and native nutlin-3a in the above studied cell lines. Cell cycle arrest, loss of mitochondrial membrane potential and apoptosis induced by above formulation were confirmed by flow cytometry. Expression of p53, p21, EpCAM, and C-myc proteins involved in cell cycle regulation and apoptosis were investigated by western blotting. The above investigation indicates the enhanced therapeutic ability of EpCAM-nutlin-3a-NPs compared to nutlin-3a or nutlin-3a-NPs. Thus, our results suggest that EpCAM-nutlin-3a-NPs could be a potentially useful drug carrier system for targeted delivery of potent anti-cancer drug nutlin-3a for cancer therapy.

Targeted nutlin-3a loaded nanoparticles inhibiting p53-MDM2 interaction: novel strategy for breast cancer therapy.

AIM: The objective of the present study is to prepare and characterize nutlin-3a loaded polymeric poly(lactide-co-glycolide) nanoparticles (NPs) surface functionalized with transferrin ligand, to deliver the encapsulated drug in a targeted manner to its site of action and to evaluate the efficacy of the nanoformulation in terms of its cellular uptake, cell cytotoxicity, cell cycle arrest, apoptosis and activation of p53 pathway at molecular level in MCF-7 breast cancer cell line. METHOD: Nutlin-3a loaded poly(lactide-co-glycolide) NPs were prepared following the single oil-in-water emulsion method. Physicochemical characterization of the formulation included size and surface charge measurement, transmission electron microscopy characterization, study of surface morphology using scanning electron microscopy, Fourier-transform infrared spectral analysis and in vitro release kinetics studies. Furthermore, targeting ability of the conjugated system was assessed by cellular uptake and cell cytotoxicity studies in an in vitro cell model. Molecular basis of nutlin-3a-mediated p53 activation pathway was investigated by western blot analysis. Inhibition of cell cycle progression and apoptosis was evaluated by flow cytometry. RESULTS: Physiochemical characterization of the formulations revealed that nutlin-3a was efficiently encapsulated in the nanoparticulate system, reaching an encapsulation efficiency of approximately 80% with size of approximately 220 nm and negative zeta potential of approximately -10.4 mV. Higher cellular uptake efficiency of the conjugated system proved the effectiveness of targeted therapy. IC(50) values, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay, showed superior antiproliferative activity of transferrin-conjugated NPs over unconjugated NPs and native nutlin-3a, owing to enhanced cellular uptake by cancer cells. At the molecular level the conjugated system showed enhanced activation of p53 pathway in comparison to native drug as evident from western blot analysis. Augmented cell cycle arrest and apoptosis was exhibited by the conjugated system. Thus, our results suggest that transferrin-conjugated nutlin-3a loaded NPs could be a potential drug carrier system for targeted delivery of potent anticancer drug nutlin-3a for breast cancer therapy.