Self-assembly of amphiphilic helical-coiled peptide nanofibers and inhibition of fibril formation with curcumin.

Amphiphilic peptide sequences are conducive to secondary structures that self-assemble into higher-ordered peptide nanostructures. A select set of amphiphilic polycationic peptides displayed stable helical-coiled structures that self-assembled into peptide nanofibers. The progression of peptide fibril formation revealed short protofibrils that extended into thin filaments and into an entangled network of nanofibers over an extended (5 days) incubation period. Ligand binding with 8-anilinonaphthalene-1-sulfonic acid (ANS) and Congo Red (CR) confirmed the amphiphilic helical-coiled peptide structure assembly into nanofibers, whereas curcumin treatment led to inhibition of fibril formation. Considering the vast repertoire of fibrous biomaterials and peptide or protein (mis)folding contingent on fibril formation, this work relates the molecular interplay in between sequence composition, structural folding and the ligand binding events impacting peptide self-assembly into nanofibers.

Assessment of adherence to routine vaccination schedules in oncology patients.

INTRODUCTION: Patients diagnosed with cancer are at an increased risk of infection. Vaccines remain one of the most critical public health strategies in limiting infectious diseases, with a heightened importance in cancer patients. Data across the general US population indicates that vaccine adherence rates are suboptimal across all adult vaccine schedules. This study aims to define vaccine adherence rates within the oncology population. METHODS: This retrospective cohort study includes adult patients with a new cancer diagnosis. Vaccine administrations for COVID-19 (SARS-CoV-2), influenza, pneumococcal, tetanus/diphtheria/pertussis (TDaP), herpes zoster (RZV), human papillomavirus (HPV), and hepatitis B (hepB) were assessed. The primary outcome was complete vaccine adherence. RESULTS: Two hundred and eighty-three oncology patients were included. The median age at diagnosis was 63 years old, and most subjects were females (60%). The two most common malignancies were gastrointestinal and breast cancer at 26.5% and 15.2%, respectively. Suboptimal vaccine adherence rates were observed across the entire oncology population. Complete adherence was observed in only 1.4% of patients. Vaccine specific adherence rates were as follows, SARS-CoV-2: 38.9%; influenza: 11.4%; pneumococcal: 12.7%; TDaP: 13.1%; RZV: 3.5%; HPV: 0%; and hepB: 34%. Among the vaccine schedules assessed, SARS-CoV-2 vaccination rates were the highest with 38.9% of patients being fully adherent and 73% receiving at least one dose. CONCLUSION: Lower vaccine adherence rates were observed in oncology patients compared to currently published rates. Providers and pharmacists can play a role in assessing and counseling patients on the importance of vaccine adherence before chemotherapy is initiated and after a remission is obtained.

Evaluation of the efficacy of ursodiol for prevention of hepatotoxicity in patients receiving gemtuzumab ozogamicin and inotuzumab ozogamicin.

Gemtuzumab ozogamicin (GO) and inotuzumab ozogamicin (InO) are indicated for newly diagnosed or relapsed/refractory CD33-positive acute myeloid leukemia and relapsed/refractory B-cell precursor acute lymphoblastic leukemia respectively. Patients undergoing therapy with these agents are at increased risk for hepatotoxicity. Forty-nine patients received either GO or InO with concomitant ursodiol (n=14) or no ursodiol (n=35) for hepatotoxicity prophylaxis. Hepatotoxicity occurred in 2 (14%) patients in the ursodiol group compared to 15 (43%) patients in the no ursodiol group (p=0.10). Median days (17 versus 11; p=0.66) and doses (4 versus 2; p=0.28) to development of hepatotoxicity were higher in the ursodiol versus no ursodiol group. After adjusting for concomitant hepatotoxic medications and prior chemotherapy, ursodiol did not significantly reduce the incidence of hepatotoxicity. Ursodiol prophylaxis was associated with a similar incidence of hepatotoxicity compared to no ursodiol, but may delay the time to occurrence.

Elevated posaconazole trough concentrations are not associated with increased risk for posaconazole toxicity in lung transplant recipients.

OBJECTIVE: Posaconazole is used for prophylaxis and treatment of invasive fungal infections in lung transplant recipients (LTR). Previous studies have not described the relationship between elevated posaconazole trough concentrations and adverse drug reactions in this population. METHODS: This IRB-approved, retrospective cohort study at NewYork-Presbyterian Hospital included LTR who had posaconazole trough concentrations measured. The primary aim of this study was to evaluate elevated posaconazole trough concentrations and changes in liver function tests as well as QTc interval. A secondary aim of this study was to identify patient factors associated with elevated posaconazole trough levels. RESULTS: A total of 109 LTR were included. The average age was 58.1 years (IQR, 48-65), the majority were male (56%). A total of 932 trough levels were assessed with a median number of 8 (IQR, 5-15) levels per patient. The median posaconazole trough concentration was 1.7 mg/L (IQR, 1.1-2.5). Hepatotoxicity, as defined by common terminology criteria for adverse events (CTCAE), was observed in 73.4% of subjects, with the majority classified as grade 1 (67.5%). However, there was no correlation between elevated posaconazole levels and aspartate aminotransferase (r = .03), alanine aminotransferase (r = .04), alkaline phosphatase (r = .04), and total bilirubin (r = .02). There was also no correlation between posaconazole trough concentrations and QTc interval (r = .03). CONCLUSION: This analysis demonstrates that no correlation exists between whole blood posaconazole levels and hepatotoxicity or QTc prolongation. Based on these results, posaconazole dose reductions may not be warranted for posaconazole levels that are significantly above the therapeutic target to avert risk for hepatotoxicity or QTc prolongation.

Synthetic Antibody Mimics Based on Cancer-Targeting Immunostimulatory Peptides.

De novo cancer-targeting immunostimulatory peptides have been designed and developed as synthetic antibody mimics. A series of bifunctional peptides incorporating NKp30-binding and NK-cell-activating domains were synthesized as linear dimers and then extended into branching trimeric peptides by the incorporation of GRP78-targeting and tumor-cell-binding sequences. A selected trimeric peptide from this small set of peptides displayed binding capabilities on GRP78+ HepG2 and A549 target cells. Cell binding diminished in the presence of an anti-GRP78 peptide blocker, thus suggesting GRP78-binding dependence. Similarly, the selected trimeric peptide was also found to exhibit NK cell binding in an NKp30-dependent manner, which translated into NK cell activation as indicated by cytokine secretion. In co-culture, fluorescence microscopy revealed that the target GFP-expressing A549 cells were visibly associated with the effector NK cells when pre-activated with lead trimeric peptide. Accordingly, A549 cells were found to be compromised, as evidenced by the loss of GFP signal and notable detection of early-/late-stage apoptosis. Investigation of the immunological markers related to toxicity revealed detectable secretion of pro-inflammatory cytokines and chemokines, including IFN-γ, TNF-α, and IL-8. Furthermore, administration of peptide-activated NK cells into A549-tumor-bearing mice resulted in a consistent decrease in tumor growth when compared to the untreated control group. Taken together, the identification of a lead trimeric peptide capable of targeting and activating NK cells' immunotoxicity directly towards GRP78+ /B7H6- tumors provides a novel proof-of-concept for the development of cancer-targeting immunostimulatory peptide ligands that mimic antibody-targeting and -activating functions related to cancer immunotherapy applications.

Medicinal Chemistry and Methodological Advances in the Development of Peptide-Based Vaccines.

The evolution of rapidly proliferating infectious and tumorigenic diseases has resulted in an urgent need to develop new and improved intervention strategies. Among the many therapeutic strategies at our disposal, our immune system remains the gold-standard in disease prevention, diagnosis, and treatment. Vaccines have played an important role in eradicating or mitigating the spread of infectious diseases by bolstering our immunity. Despite their utility, the design and development of new, more effective vaccines remains a public health necessity. Peptide-based vaccines have been developed for a wide range of established and emerging infectious and tumorigenic diseases. New innovations in epitope design and selection, synthesis, and formulation as well as screening techniques against immunological targets have led to more effective peptide vaccines. Current and future work is geared toward the translation of peptide vaccines from preclinical to clinical utility.

Synthesis and Biomedical Potential of Azapeptide Modulators of the Cluster of Differentiation 36 Receptor (CD36).

The innovative development of azapeptide analogues of growth hormone releasing peptide-6 (GHRP-6) has produced selective modulators of the cluster of differentiation 36 receptor (CD36). The azapeptide CD36 modulators curb macrophage-driven inflammation and mitigate atherosclerotic and angiogenic pathology. In macrophages activated with Toll-like receptor-2 heterodimer agonist, they reduced nitric oxide production and proinflammatory cytokine release. In a mouse choroidal explant microvascular sprouting model, they inhibited neovascularization. In murine models of cardiovascular injury, CD36-selective azapeptide modulators exhibited cardioprotective and anti-atherosclerotic effects. In subretinal inflammation models, they altered activated mononuclear phagocyte metabolism and decreased immune responses to alleviate subsequent inflammation-dependent neuronal injury associated with retinitis pigmentosa, diabetic retinopathy and age-related macular degeneration. The translation of GHRP-6 to potent and selective linear and cyclic azapeptide modulators of CD36 is outlined in this review which highlights the relevance of turn geometry for activity and the biomedical potential of prototypes for the beneficial treatment of a wide range of cardiovascular, metabolic and immunological disorders.

Polyamide Backbone Modified Cell Targeting and Penetrating Peptides in Cancer Detection and Treatment.

Cell penetrating and targeting peptides (CPPs and CTPs) encompass an important class of biochemically active peptides owning the capabilities of targeting and translocating within selected cell types. As such, they have been widely used in the delivery of imaging and therapeutic agents for the diagnosis and treatment of various diseases, especially in cancer. Despite their potential utility, first generation CTPs and CPPs based on the native peptide sequences are limited by poor biological and pharmacological properties, thereby restricting their efficacy. Therefore, medicinal chemistry approaches have been designed and developed to construct related peptidomimetics. Of specific interest herein, are the design applications which modify the polyamide backbone of lead CTPs and CPPs. These modifications aim to improve the biochemical characteristics of the native peptide sequence in order to enhance its diagnostic and therapeutic capabilities. This review will focus on a selected set of cell penetrating and targeting peptides and their related peptidomimetics whose polyamide backbone has been modified in order to improve their applications in cancer detection and treatment.

Bifunctional Au-templated RNA nanoparticles enable direct cell uptake detection and GRP75 knockdown in prostate cancer.

Nucleic acids templated on gold (Au) surfaces have led to a wide range of functional materials ranging from microarrays, sensors and probes in addition to drug delivery and treatment. In this application, we describe a simple and novel method for templating amino-functionalized RNA onto Au surfaces and their self-assembly into small, discrete nanoparticles. In our method, sample hybridization with a complementary RNA strand with and without a fatty acid (palmitamide) appendage produced functionalized double-stranded RNA on the Au surface. The resulting Au-functionalized RNA particles were found to be stable under reducing conditions according to UV-Vis spectroscopy. Sample characterization by DLS and TEM confirmed self-assembly into primarily small (∼10-40 nm) spherical shaped nanoparticles expected to be amenable to cell biology. However, fluorescence emission (λexc: 350 nm, λem: 650 nm) revealed radiative properties which limited cell uptake detection. Introduction of FITC within the Au-functionalized RNA particles produced a bifunctional probe, in which FITC fluorescence emission (λexc: 494 nm, λem: 522 nm) facilitated cell uptake detection, in a time-dependent manner. The dual encapsulation-release profiles of the FITC-labeled Au-functionalized RNA particles were validated by time-dependent UV-Vis spectroscopy and spectrofluorimetry. These experiments respectively indicated an increase in FITC absorption (λabs: 494 nm) and fluorescence emission (λem: 522 nm) with increased sample incubation times, under physiological conditions. The release of Au-functionalized siRNA particles in prostate cancer (PC-3) cells resulted in concomitant knockdown of GRP75, which led to detectable levels of cell death in the absence of a transfection vector. Thus, the formulation of stable, small and discrete Au-functionalized RNA nanoparticles may prove to be valuable bifunctional probes in the theranostic study of cancer cells.

Size Matters: Arginine-Derived Peptides Targeting the PSMA Receptor Can Efficiently Complex but Not Transfect siRNA.

Oligoarginine sequences conjugated to a short cancer-targeting peptide (CTP) selective for the prostate-specific membrane antigen (PSMA) receptor was developed for selective small interfering RNA (siRNA) delivery to a human metastatic/castration-resistant prostate cancer (PCa) cell line, which expresses PSMA on the surface. The PSMA-Rn (n = 6 and 9) peptides were synthesized by solid-phase peptide synthesis, characterized by liquid chromatography-mass spectrometry (LC-MS) and condensed with glucose-regulated protein (GRP)-silencing siRNAs. Native gels showed formation of stable CTP:siRNA ionic complexes. Furthermore, siRNA release was effected by heparin competition, supporting the peptides' capabilities to act as condensing and releasing agents. However, dynamic light scattering (DLS) and transmission electron microscopy (TEM) studies revealed large anionic complexes that were prone to aggregation and limited cell uptake for RNAi activity. Taken together, these data support the notion that the development of efficient peptide-based siRNA delivery systems is in part contingent on the formulation of discrete nanoparticles that can effectively condense and release siRNA in cells.

Membrane-Disrupting Nanofibrous Peptide Hydrogels.

Self-assembled peptide nanofibers can form biomimetic hydrogels at physiological pH and ionic strength through noncovalent and reversible interactions. Inspired by natural antimicrobial peptides, we designed a class of cationic amphiphilic self-assembled peptides (CASPs) that self-assemble into thixotropic nanofibrous hydrogels. These constructs employ amphiphilicity and high terminal charge density to disrupt bacterial membranes. Here, we focus on three aspects of the self-assembly of these hydrogels: (a) the material properties of the individual self-assembled nanofibers, (b) emergence of bulk-scale elasticity in the nanofibrous hydrogel, and (c) trade-off between the desirable material properties and antimicrobial efficacy. The design of the supramolecular nanofibers allows for higher-order noncovalent ionic cross-linking of the nanofibers into a viscoelastic network. We determine the stiffness of the self-assembled nanofibers via the peak force quantitative nanomechanical atomic force microscopy and the bulk-scale rheometry. The storage moduli depend on peptide concentration, ionic strength, and concentration of multivalent ionic cross-linker. CASP nanofibers are demonstrated to be effective against Pseudomonas aeruginosa colonies. We use nanomechanical analysis and microsecond-time scale coarse-grained simulation to elucidate the interaction between the peptides and bacterial membranes. We demonstrate that the membranes stiffen, contract, and buckle after binding to peptide nanofibers, allowing disruption of osmotic equilibrium between the intracellular and extracellular matrix. This is further associated with dramatic changes in cell morphology. Our studies suggest that self-assembled peptide nanofibrils can potentially acts as membrane-disrupting antimicrobial agents, which can be formulated as injectable hydrogels with tunable material properties.

Solid phase synthesis and self-assembly of higher-order siRNAs and their bioconjugates.

New methods for the synthesis of higher-order siRNA motifs and their bioconjugates have recently gained widespread attention in the development of new and improved gene therapeutics. Our efforts aim to produce new chemical tools and protocols for the generation of modified siRNAs that screen for important oncogene targets as well as silence their activity for effective gene therapy in cancer models. More specifically, we have developed an efficient solution-phase synthesis for the production of a ribouridine branchpoint synthon that can be effectively incorporated by solid phase synthesis within higher-order RNA structures, including those adopting V-, and Y- and >-< shape RNA templates. Self-assembly of complementary RNA to the template strands produced higher-order siRNA nanostructures that were characterized by a combination of PAGE, DLS, and TEM techniques. In an effort to extend the repertoire of functionally diverse siRNAs, we have also developed solid phase bioconjugation strategies for incorporating bio-active probes such as fatty acid appendages and fluorescent reporters. Taken together, these methods highlight the ability to generate higher-order siRNAs and their bioconjugates for exploring the influence of modified siRNA structure on anti-cancer activity.

GRP78 modulates cell adhesion markers in prostate Cancer and multiple myeloma cell lines.

BACKGROUND: Glucose regulated protein 78 (GRP78) is a resident chaperone of the endoplasmic reticulum and a master regulator of the unfolded protein response under physiological and pathological cell stress conditions. GRP78 is overexpressed in many cancers, regulating a variety of signaling pathways associated with tumor initiation, proliferation, adhesion and invasion which contributes to metastatic spread. GRP78 can also regulate cell survival and apoptotic pathways to alter responsiveness to anticancer drugs. Tumors that reside in or metastasize to the bone and bone marrow (BM) space can develop pro-survival signals through their direct adhesive interactions with stromal elements of this niche thereby resisting the cytotoxic effects of drug treatment. In this study, we report a direct correlation between GRP78 and the adhesion molecule N-cadherin (N-cad), known to play a critical role in the adhesive interactions of multiple myeloma and metastatic prostate cancer with the bone microenvironment. METHODS: N-cad expression levels (transcription and protein) were evaluated upon siRNA mediated silencing of GRP78 in the MM.1S multiple myeloma and the PC3 metastatic prostate cancer cell lines. Furthermore, we evaluated the effects of GRP78 knockdown (KD) on epithelial-mesenchymal (EMT) transition markers, morphological changes and adhesion of PC3 cells. RESULTS: GRP78 KD led to concomitant downregulation of N-cad in both tumors types. In PC3 cells, GRP78 KD significantly decreased E-cadherin (E-cad) expression likely associated with the induction in TGF-ß1 expression. Furthermore, GRP78 KD also triggered drastic changes in PC3 cells morphology and decreased their adhesion to osteoblasts (OSB) dependent, in part, to the reduced N-cad expression. CONCLUSION: This work implicates GRP78 as a modulator of cell adhesion markers in MM and PCa. Our results may have clinical implications underscoring GRP78 as a potential therapeutic target to reduce the adhesive nature of metastatic tumors to the bone niche.

Enhanced Cancer Theranostics with Self-Assembled, Multilabeled siRNAs.

The integration of therapy and diagnostics, termed "theranostics", has recently gained widespread utility in the development of new and improved therapeutics that effectively diagnose and treat diseases, such as cancer. In this study, the covalent attachment of multiple fluorescent labels (i.e., fluorescein isothiocyanate (FITC)) to a wide range of siRNAs, including those adopting linear, V- and Y-shape nanostructures, was successfully accomplished by solid-phase bioconjugation for monitoring cell uptake, co-localization, and biological activity in cell culture. The FITC-labeled higher-order V- and Y-shape siRNAs maintained the requisite hybrid stabilities and A-type helical structures for invoking RNAi activity. The FITC-siRNA hybrids with sense-strand modifiers enabled efficient mRNA knockdown (∼50-90%), which also translated to increased cell death (∼20-95%) in a bone metastatic prostate cancer cell line, over a 72 h incubation period. Significantly, the Y-shaped siRNA containing three FITC probes enhanced fluorescent signaling relative to the siRNA constructs containing single and double fluorophores while retaining potent knockdown and cell death effects post-transfection. Taken together, this data highlights the theranostic utility of the multilabeled FITC-siRNA constructs for potential cancer gene therapy applications.

Direct Transfection of Fatty Acid Conjugated siRNAs and Knockdown of the Glucose-Regulated Chaperones in Prostate Cancer Cells.

The emerging field of RNAi nanotechnology has led to rapid advances in the applications of siRNAs in chemical biology, medicinal chemistry, and biotechnology. In our RNAi approach, bioconjugation of linear, V-, and Y-shaped RNA templates were designed using a series of saturated and unsaturated fatty acids to improve cell uptake and knockdown efficacy of the oncogenic glucose regulated proteins (GRPs) in prostate (PC-3) cancer cells. An optimized HCTU-coupling procedure was developed for tagging variable saturated and unsaturated fatty acids onto the 5'-ends of linear and V-shaped RNA templates that were constructed by semiautomated solid phase RNA synthesis. Hybridization and self-assembly of complementary strands yielded linear, V-, and Y-shaped fatty acid-conjugated siRNAs which were characterized by native PAGE. CD spectroscopy confirmed their A-type helix conformations. RP IP HPLC provided trends in amphiphilic properties, whereas DLS and TEM confirmed multicomponent self-assembled structures that were prone to aggregation. Subsequently, the fatty acid conjugated siRNA bioconjugates were tested for their RNAi activity by direct transfection within PC-3 cells known to overexpress oncogenic GRP activity. The siRNA bioconjugates with sense strand modifiers provided more potent GRP knockdown relative to the antisense modified siRNAs, but to a lesser extent when compared to the unconjugated siRNA controls that were transfected with the commercial Trans-IT X2 dynamic delivery system. Flow cytometry revealed that the latter may be at least in part attributed to limited cell uptake of the fatty acid conjugated siRNAs. Nonetheless, these new constructs represent an entry point in modifying higher-order siRNA constructs that may lead to the generation of more efficient siRNA bioconjugates for screening important oncogene targets and for cancer gene therapy applications.

Functionalization of peptide nucleolipid bioconjugates and their structure anti-cancer activity relationship studies.

In the search for more potent peptide-based anti-cancer conjugates the generation of new, functionally diverse nucleolipid derived D-(KLAKLAK)2-AK sequences has enabled a structure and anti-cancer activity relationship study. A reductive amination approach was key for the synthesis of alkylamine, diamine and polyamine derived nucleolipids as well as those incorporating heterocyclic functionality. The carboxy-derived nucleolipids were then coupled to the C-terminus of the D-(KLAKLAK)2-AK killer peptide sequence and produced with and without the FITC fluorophore for investigating biological activity in cancer cells. The amphiphilic, α-helical peptide-nucleolipid bioconjugates were found to exhibit variable effects on the viability of MM.1S cells, with the histamine derived nucleolipid peptide bioconjugate displaying the most significant anti-cancer effects. Thus, functionally diverse nucleolipids have been developed to fine-tune the structure and anti-cancer properties of killer peptide sequences, such as D-(KLAKLAK)2-AK.

Synthesis and Photophysical and Photocatalytic Properties of a Highly Fluorinated and Durable Phthalocyanine-Peptide Bioconjugate for Potential Theranostic Applications.

The functionalized, asymmetric fluoro-fluoroalkyl scaffold F48H7COOHPcZn (3) was used to prepare F48H7COOPcZn-6-amino-hexanoate-CTVALPGGYVRVC (5), a Pep42 peptide bioconjugate envisioned for photodynamic therapy, which can specifically target the GRP78 chaperone protein overexpressed and exclusively localized on some cancer cell surfaces. The analogous F48H7COOHPcCu (4) has also been prepared, and its single-crystal X-ray structure was elucidated. Despite reduced steric hindrance relative to the nonfunctionalized, single-site complexes of the F64Pc scaffold, no aggregation was detected in solution via UV-vis spectroscopy, for either 3, 4, or 5, consistent with the lack of π stacking observed for the crystalline 4. The 6-aminohexanoic acid-Pep42 moiety diminishes the fluorescence efficiency of 5, relative to 3, but for singlet oxygen (1O2) generation, photochemical hydroperoxidation of ß-(-)-citronellol using 5 and 3 occurs with comparable substrate turnover efficiency, albeit at a slower initial triplet oxygen uptake for 5. The bioconjugate 5 is durable; it does not decompose under 1O2 photoreaction conditions. These results suggest a synthetic coupling pathway for obtaining diverse biotargeting polypeptide-fluorinated phthalocyanine bioconjugates of potential utility as both fluorescence reporters and photocatalysts and highlight the importance of fluorinated scaffolds for generating chemically resilient, catalytic, theranostic materials.

RNAi Screening of the Glucose-Regulated Chaperones in Cancer with Self-Assembled siRNA Nanostructures.

The emerging field of RNA nanotechnology has been used to design well-programmed, self-assembled nanostructures for applications in chemistry, biology, and medicine. At the forefront of its utility in cancer is the unrestricted ability to self-assemble multiple siRNAs within a single nanostructure formulation for the RNAi screening of a wide range of oncogenes while potentiating the gene therapy of malignant tumors. In our RNAi nanotechnology approach, V- and Y-shape RNA templates were designed and constructed for the self-assembly of discrete, higher-ordered siRNA nanostructures targeting the oncogenic glucose regulated chaperones. The GRP78-targeting siRNAs self-assembled into genetically encoded spheres, triangles, squares, pentagons and hexagons of discrete sizes and shapes according to TEM imaging. Furthermore, gel electrophoresis, thermal denaturation, and CD spectroscopy validated the prerequisite siRNA hybrids for their RNAi application. In a 24 sample siRNA screen conducted within the AN3CA endometrial cancer cells known to overexpress oncogenic GRP78 activity, the self-assembled siRNAs targeting multiple sites of GRP78 expression demonstrated more potent and long-lasting anticancer activity relative to their linear controls. Extending the scope of our RNAi screening approach, the self-assembled siRNA hybrids (5 nM) targeting of GRP-75, 78, and 94 resulted in significant (50-95%) knockdown of the glucose regulated chaperones, which led to synergistic effects in tumor cell cycle arrest (50-80%) and death (50-60%) within endometrial (AN3CA), cervical (HeLa), and breast (MDA-MB-231) cancer cell lines. Interestingly, a nontumorigenic lung (MRC5) cell line displaying normal glucose regulated chaperone levels was found to tolerate siRNA treatment and demonstrated less toxicity (5-20%) relative to the cancer cells that were found to be addicted to glucose regulated chaperones. These remarkable self-assembled siRNA nanostructures may thus encompass a new class of potent siRNAs that may be useful in screening important oncogene targets while improving siRNA therapeutic efficacy and specificity in cancer.