Rammohan Devulapally

Polymer Nanoparticles Mediated Codelivery of AntimiR-10b and AntimiR-21 for Achieving Triple Negative Breast Cancer Therapy

The current study shows the therapeutic outcome achieved in triple negative breast cancer (TNBC) by simultaneously antagonizing miR-21-induced antiapoptosis and miR-10b-induced metastasis, using antisense-miR-21-PS and antisense-miR-10b-PS delivered by polymer nanoparticles (NPs). We synthesized the antisense-miR-21 and antisense-miR-10b loaded PLGA-b-PEG polymer NPs and evaluated their cellular uptake, serum stability, release profile, and the subsequent synchronous blocking of endogenous miR-21 and miR-10b function in TNBC cells in culture, and tumor xenografts in living animals using molecular imaging. Results show that multitarget antagonization of endogenous miRNAs could be an efficient strategy for targeting metastasis and antiapoptosis in the treatment of metastatic cancer. Targeted delivery of antisense-miR-21 and antisense-miR-10b coloaded urokinase plasminogen activator receptor (uPAR) targeted polymer NPs treated mice showed substantial reduction in tumor growth at very low dose of 0.15 mg/kg, compared to the control NPs treated mice and 40% reduction in tumor growth compared to scramble peptide conjugated NPs treated mice, thus demonstrating a potential new therapeutic option for TNBC.

Ultrasound-guided delivery of microRNA loaded nanoparticles into cancer

Ultrasound induced microbubble cavitation can cause enhanced permeability across natural barriers of tumors such as vessel walls or cellular membranes, allowing for enhanced therapeutic delivery into the target tissues. While enhanced delivery of small (<1nm) molecules has been shown at acoustic pressures below 1MPa both in vitro and in vivo, the delivery efficiency of larger (>100nm) therapeutic carriers into cancer remains unclear and may require a higher pressure for sufficient delivery. Enhanced delivery of larger therapeutic carriers such as FDA approved pegylated poly(lactic-co-glycolic acid) nanoparticles (PLGA-PEG-NP) has significant clinical value because these nanoparticles have been shown to protect encapsulated drugs from degradation in the blood circulation and allow for slow and prolonged release of encapsulated drugs at the target location. In this study, various acoustic parameters were investigated to facilitate the successful delivery of two nanocarriers, a fluorescent semiconducting polymer model drug nanoparticle as well as PLGA-PEG-NP into human colon cancer xenografts in mice. We first measured the cavitation dose produced by various acoustic parameters (pressure, pulse length, and pulse repetition frequency) and microbubble concentration in a tissue mimicking phantom. Next, in vivo studies were performed to evaluate the penetration depth of nanocarriers using various acoustic pressures, ranging between 1.7 and 6.9MPa. Finally, a therapeutic microRNA, miR-122, was loaded into PLGA-PEG-NP and the amount of delivered miR-122 was assessed using quantitative RT-PCR. Our results show that acoustic pressures had the strongest effect on cavitation. An increase of the pressure from 0.8 to 6.9MPa resulted in a nearly 50-fold increase in cavitation in phantom experiments. In vivo, as the pressures increased from 1.7 to 6.9MPa, the amount of nanoparticles deposited in cancer xenografts was increased from 4- to 14-fold, and the median penetration depth of extravasated nanoparticles was increased from 1.3-fold to 3-fold, compared to control conditions without ultrasound, as examined on 3D confocal microscopy. When delivering miR-122 loaded PLGA-PEG-NP using optimal acoustic settings with minimum tissue damage, miR-122 delivery into tumors with ultrasound and microbubbles was 7.9-fold higher compared to treatment without ultrasound. This study demonstrates that ultrasound induced microbubble cavitation can be a useful tool for delivery of therapeutic miR loaded nanocarriers into cancer in vivo.

Polymer nanoparticles for drug and small silencing RNA delivery to treat cancers of different phenotypes

Advances in nanotechnology have provided powerful and efficient tools in the development of cancer diagnosis and therapy. There are numerous nanocarriers that are currently approved for clinical use in cancer therapy. In recent years, biodegradable polymer nanoparticles have attracted a considerable attention for their ability to function as a possible carrier for target-specific delivery of various drugs, genes, proteins, peptides, vaccines, and other biomolecules in humans without much toxicity. This review will specifically focus on the recent advances in polymer-based nanocarriers for various drugs and small silencing RNAs loading and delivery to treat different types of cancer.

Formulation of Anti-miR-21 and 4-Hydroxytamoxifen Co-loaded Biodegradable Polymer Nanoparticles and Their Antiproliferative Effect on Breast Cancer Cells.

Breast cancer is the second leading cause of cancer-related death in women. The majority of breast tumors are estrogen receptor-positive (ER+) and hormone-dependent. Neoadjuvant anti-estrogen therapy has been widely employed to reduce tumor mass prior to surgery. Tamoxifen is a broadly used anti-estrogen for early and advanced ER+ breast cancers in women and the most common hormone treatment for male breast cancer. 4-Hydroxytamoxifen (4-OHT) is an active metabolite of tamoxifen that functions as an estrogen receptor antagonist and displays higher affinity for estrogen receptors than that of tamoxifen and its other metabolites. MicroRNA-21 (miR-21) is a small noncoding RNA of 23 nucleotides that regulates several apoptotic and tumor suppressor genes and contributes to chemoresistance in numerous cancers, including breast cancer. The present study investigated the therapeutic potential of 4-OHT and anti-miR-21 coadministration in an attempt to combat tamoxifen resistance, a common problem often encountered in anti-estrogen therapy. A biodegradable poly(d,l-lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-b-PEG-COOH) copolymer was utilized as a carrier to codeliver 4-OHT and anti-miR-21 to ER+ breast cancer cells. 4-OHT and anti-miR-21 co-loaded PLGA-b-PEG nanoparticles (NPs) were developed using emulsion-diffusion evaporation (EDE) and water-in-oil-in-water (w/o/w) double emulsion methods. The EDE method was found to be best method for 4-OHT loading, and the w/o/w method proved to be more effective for coloading NPs with anti-miR-21 and 4-OHT. The optimal NPs, which were prepared using the double emulsion method, were evaluated for their antiproliferative and apoptotic effects against MCF7, ZR-75-1, and BT-474 human breast cancer cells as well as against 4T1 mouse mammary carcinoma cells. We demonstrated that PLGA-b-PEG NP encapsulation significantly extended 4-OHT’s stability and biological activity compared to that of free 4-OHT. MTT assays indicated that treatment of MCF7 cells with 4-OHT–anti-miR-21 co-loaded NPs resulted in dose-dependent antiproliferative effects at 24 h, which was significantly higher than what was achieved with free 4-OHT at 48 and 72 h post-treatment. Cell proliferation analysis showed that 4-OHT and anti-miR-21 co-loaded NPs significantly inhibited MCF-7 cell growth compared to that of free 4-OHT (1.9-fold) and untreated cells (5.4-fold) at 1 μM concentration. The growth rate of MCF7 cells treated with control NPs or NPs loaded with anti-miR-21 showed no significant difference from that of untreated cells. These findings demonstrate the utility of the PLGA-b-PEG polymer NPs as an effective nanocarrier for co-delivery of anti-miR-21 and 4-OHT as well as the potential of this drug combination for use in the treatment of ER+ breast cancer.

Folate Receptor–Targeted Polymeric Micellar Nanocarriers for Delivery of Orlistat as a Repurposed Drug against Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a recalcitrant malignancy with no available targeted therapy. Off-target effects and poor bioavailability of the FDA-approved antiobesity drug orlistat hinder its clinical translation as a repurposed new drug against TNBC. Here, we demonstrate a newly engineered drug formulation for packaging orlistat tailored to TNBC treatment. We synthesized TNBC-specific folate receptor–targeted micellar nanoparticles (NP) carrying orlistat, which improved the solubility (70–80 μg/mL) of this water-insoluble drug. The targeted NPs also improved the delivery and bioavailability of orlistat to MDA-MB-231 cells in culture and to tumor xenografts in a nude mouse model. We prepared HEA–EHA copolymer micellar NPs by copolymerization of 2-hydroxyethylacrylate (HEA) and 2-ethylhexylacrylate (EHA), and functionalized them with folic acid and an imaging dye. Fluorescence-activated cell sorting (FACS) analysis of TNBC cells indicated a dose-dependent increase in apoptotic populations in cells treated with free orlistat, orlistat NPs, and folate-receptor–targeted Fol-HEA-EHA-orlistat NPs in which Fol-HEA-EHA-orlistat NPs showed significantly higher cytotoxicity than free orlistat. In vitro analysis data demonstrated significant apoptosis at nanomolar concentrations in cells activated through caspase-3 and PARP inhibition. In vivo analysis demonstrated significant antitumor effects in living mice after targeted treatment of tumors, and confirmed by fluorescence imaging. Moreover, folate receptor–targeted Fol-DyLight747-orlistat NP–treated mice exhibited significantly higher reduction in tumor volume compared to control group. Taken together, these results indicate that orlistat packaged in HEA-b-EHA micellar NPs is a highly promising new drug formulation for TNBC therapy. Mol Cancer Ther; 15(2); 221–31. ©2015 AACR.

Orlistat and antisense-miRNA-loaded PLGA-PEG nanoparticles for enhanced triple negative breast cancer therapy

BACKGROUND This study explores the use of hydrophilic poly(ethylene glycol)-conjugated poly(lactic-co-glycolic acid) nanoparticles (PLGA-PEG-NPs) as delivery system to improve the antitumor effect of antiobesity drug orlistat for triple-negative breast cancer (TNBC) therapy by improving its bioavailability. MATERIALS & METHODS PLGA-PEG-NPs were synthesized by emulsion-diffusion-evaporation method, and the experiments were conducted in vitro in MDA-MB-231 and SKBr3 TNBC and normal breast fibroblast cells. RESULTS Delivery of orlistat via PLGA-PEG-NPs reduced its IC50 compared with free orlistat. Combined treatment of orlistat-loaded NPs and doxorubicin or antisense-miR-21-loaded NPs significantly enhanced apoptotic effect compared with independent doxorubicin, anti-miR-21-loaded NPs, orlistat-loaded NPs or free orlistat treatments. CONCLUSION We demonstrate that orlistat in combination with antisense-miR-21 or current chemotherapy holds great promise as a novel and versatile treatment agent for TNBC.

Ultrasound-guided therapeutic modulation of hepatocellular carcinoma using complementary microRNAs.

Treatment options for patients with hepatocellular carcinoma (HCC) are limited, in particular in advanced and drug resistant HCC. MicroRNAs (miRNA) are non-coding small RNAs that are emerging as novel drugs for the treatment of cancer. The aim of this study was to assess treatment effects of two complementary miRNAs (sense miRNA-122, and antisense antimiR-21) encapsulated in biodegradable poly (lactic-co-glycolic acid) nanoparticles (PLGA-NP), administered by an ultrasound-guided and microbubble-enhanced delivery approach in doxorubicin-resistant and non-resistant human HCC xenografts. Proliferation and invasiveness of human HCC cells after miRNA-122/antimiR-21 and doxorubicin treatment were assessed in vitro. Confocal microscopy and qRT-PCR were used to visualize and quantitate successful intracellular miRNA-loaded PLGA-NP delivery. Up and down-regulation of miRNA downstream targets and multidrug resistance proteins and extent of apoptosis were assessed in vivo in treated human HCC xenografts in mice. Compared to single miRNA therapy, combination therapy with the two complementary miRNAs resulted in significantly (P<0.05) stronger decrease in cell proliferation, invasion, and migration of HCC cells as well as higher resensitization to doxorubicin. Ultrasound-guided delivery significantly increased in vivo miRNA-loaded PLGA-NP delivery in human HCC xenografts compared to control conditions by 5-9 fold (P<0.001). miRNA-loaded PLGA-NP were internalized in HCC cells and anti-apoptotic proteins were down regulated with apoptosis in ~27% of the tumor volume of doxorubicin-resistant human HCC after a single treatment with complementary miRNAs and doxorubicin. Thus, ultrasound-guided delivery of complementary miRNAs is highly efficient in the treatment of doxorubicin- resistant and non-resistant HCC. Further development of this new treatment approach could aid in better treatment of patients with HCC.

Degron Protease Blockade Sensor to Image Epigenetic Histone Protein Methylation in Cells and Living Animals

Lysine methylation of histone H3 and H4 has been identified as a promising therapeutic target in treating various cellular diseases. The availability of an in vivo assay that enables rapid screening and preclinical evaluation of drugs that potentially target this cellular process will significantly expedite the pace of drug development. This study is the first to report the development of a real-time molecular imaging biosensor (a fusion protein, [FLuc2]-[Suv39h1]-[(G4S)3]-[H3-K9]-[cODC]) that can detect and monitor the methylation status of a specific histone lysine methylation mark (H3-K9) in live animals. The sensitivity of this sensor was assessed in various cell lines, in response to down-regulation of methyltransferase EHMT2 by specific siRNA, and in nude mice with lysine replacement mutants. In vivo imaging in response to a combination of methyltransferase inhibitors BIX01294 and Chaetocin in mice reveals the potential of this sensor for preclinical drug evaluation. This biosensor thus has demonstrated its utility in the detection of H3-K9 methylations in vivo and potential value in preclinical drug development.

Targeted nanoparticle delivery of therapeutic antisense microRNAs presensitizes glioblastoma cells to lower effective doses of temozolomide in vitro and in a mouse model

Temozolomide (TMZ) chemotherapy for glioblastoma (GBM) is generally well tolerated at standard doses but it can cause side effects. GBMs overexpress microRNA-21 and microRNA-10b, two known oncomiRs that promote cancer development, progression and resistance to drug treatment. We hypothesized that systemic injection of antisense microRNAs (antagomiR-21 and antagomiR-10b) encapsulated in cRGD-tagged PEG-PLGA nanoparticles would result in high cellular delivery of intact functional antagomiRs, with consequent efficient therapeutic response and increased sensitivity of GBM cells to lower doses of TMZ. We synthesized both targeted and non-targeted nanoparticles, and characterized them for size, surface charge and encapsulation efficiency of antagomiRs. When using targeted nanoparticles in U87MG and Ln229 GBM cells, we showed higher uptake-associated improvement in sensitivity of these cells to lower concentrations of TMZ in medium. Co-inhibition of microRNA-21 and microRNA-10b reduced the number of viable cells and increased cell cycle arrest at G2/M phase upon TMZ treatment. We found a significant increase in expression of key target genes for microRNA-21 and microRNA-10b upon using targeted versus non-targeted nanoparticles. There was also significant reduction in tumor volume when using TMZ after pre-treatment with loaded nanoparticles in human GBM cell xenografts in mice. In vivo targeted nanoparticles plus different doses of TMZ showed a significant therapeutic response even at the lowest dose of TMZ, indicating that preloading cells with antagomiR-21 and antagomiR-10b increases cellular chemosensitivity towards lower TMZ doses. Future clinical applications of this combination therapy may result in improved GBM response by using lower doses of TMZ and reducing nonspecific treatment side effects.

Longitudinal assessment of ultrasound-guided complementary microRNA therapy of hepatocellular carcinoma

ABSTRACT Hepatocellular carcinoma (HCC) is the second‐leading cause of cancer related deaths worldwide and new strategies to efficiently treat HCC are critically needed. The aim of this study was to assess the longitudinal treatment effects of two complementary miRNAs (miRNA‐122 and antimiR‐21) encapsulated in biodegradable poly lactic‐co‐glycolic acid (PLGA) ‐ poly ethylene glycol (PEG) nanoparticles (PLGA‐PEG‐NPs), administered by an ultrasound‐guided and microbubble‐mediated delivery approach in doxorubicin‐resistant and non‐resistant human HCC xenografts. Using in vitro assays, we show that repeated miRNA treatments resulted in gradual reduction of HCC cell proliferation and reversal of doxorubicin resistance. Optimized US parameters resulted in a 9–16 fold increase (p=0.03) in miRNA delivery in vivo in HCC tumors after two US treatments compared to tumors without US treatment. Furthermore, when combined with doxorubicin (10mg/kg), longitudinal miRNA delivery showed a significant inhibition of tumor growth in both resistant and non‐resistant tumors compared to non‐treated, and doxorubicin treated controls. We also found that ultrasound‐guided miRNA therapy was not only effective in inhibiting HCC tumor growth but also allowed lowering the dose of doxorubicin needed to induce apoptosis. In conclusion, the results of this study suggest that ultrasound‐guided and MB‐mediated delivery of miRNA‐122 and antimiR‐21, when combined with doxorubicin, is a highly effective approach to treat resistant HCC while reducing doxorubicin doses needed for treating non‐resistant HCC in longitudinal treatment experiments. Further refinement of this strategy could potentially lead to better treatment outcomes for patients with HCC.