bims-drudre Biomed News
on Targeted drug delivery and programmed release mechanisms
Issue of 2021‒03‒28
fifteen papers selected by
Ceren Kimna
Technical University of Munich

  1. Nature. 2021 Mar 24.
      Mutated isocitrate dehydrogenase 1 (IDH1) defines a molecularly distinct subtype of diffuse glioma1-3. The most common IDH1 mutation in gliomas affects codon 132 and encodes IDH1(R132H), which harbours a shared clonal neoepitope that is presented on major histocompatibility complex (MHC) class II4,5. An IDH1(R132H)-specific peptide vaccine (IDH1-vac) induces specific therapeutic T helper cell responses that are effective against IDH1(R132H)+ tumours in syngeneic MHC-humanized mice4,6-8. Here we describe a multicentre, single-arm, open-label, first-in-humans phase I trial that we carried out in 33 patients with newly diagnosed World Health Organization grade 3 and 4 IDH1(R132H)+ astrocytomas (Neurooncology Working Group of the German Cancer Society trial 16 (NOA16), identifier NCT02454634). The trial met its primary safety endpoint, with vaccine-related adverse events restricted to grade 1. Vaccine-induced immune responses were observed in 93.3% of patients across multiple MHC alleles. Three-year progression-free and death-free rates were 0.63 and 0.84, respectively. Patients with immune responses showed a two-year progression-free rate of 0.82. Two patients without an immune response showed tumour progression within two years of first diagnosis. A mutation-specificity score that incorporates the duration and level of vaccine-induced IDH1(R132H)-specific T cell responses was associated with intratumoral presentation of the IDH1(R132H) neoantigen in pre-treatment tumour tissue. There was a high frequency of pseudoprogression, which indicates intratumoral inflammatory reactions. Pseudoprogression was associated with increased vaccine-induced peripheral T cell responses. Combined single-cell RNA and T cell receptor sequencing showed that tumour-infiltrating CD40LG+ and CXCL13+ T helper cell clusters in a patient with pseudoprogression were dominated by a single IDH1(R132H)-reactive T cell receptor.
  2. Nat Commun. 2021 03 09. 12(1): 1541
      Pancreatic ductal adenocarcinoma (PDAC) is characterized by marked desmoplasia and drug resistance due, in part, to poor drug delivery to extravascular tumor tissue. Here, we report that carcinoma-associated fibroblasts (CAFs) induce β5 integrin expression in tumor cells in a TGF-β dependent manner, making them an efficient drug delivery target for the tumor-penetrating peptide iRGD. The capacity of iRGD to deliver conjugated and co-injected payloads is markedly suppressed when β5 integrins are knocked out in the tumor cells. Of note, β5 integrin knock-out in tumor cells leads to reduced disease burden and prolonged survival of the mice, demonstrating its contribution to PDAC progression. iRGD significantly potentiates co-injected chemotherapy in KPC mice with high β5 integrin expression and may be a powerful strategy to target an aggressive PDAC subpopulation.
  3. Nat Chem. 2021 Mar 25.
      Efforts to use RNA-cleaving DNA enzymes (DNAzymes) as gene-silencing agents in therapeutic applications have stalled due to their low efficacy in clinical trials. Here we report a xeno-nucleic-acid-modified version of the classic DNAzyme 10-23 that achieves multiple-turnover activity under cellular conditions and resists nuclease digestion. The new reagent, X10-23, overcomes the problem of product inhibition, which limited previous 10-23 designs, using molecular chemotypes with DNA, 2'-fluoroarabino nucleic acid and α-L-threofuranosyl nucleic acid backbone architectures that balance the effects of enhanced biological stability with RNA hybridization and divalent metal ion coordination. In cultured mammalian cells, X10-23 facilitates persistent gene silencing by efficiently degrading exogenous and endogenous messenger RNA transcripts. Together, these results demonstrate that new molecular chemotypes can improve the activity and stability of DNAzymes, and may provide a new route for nucleic acid enzymes to reach the clinic.
  4. Mol Med. 2021 Mar 25. 27(1): 28
      BACKGROUND: Glioblastoma is the most common primary brain tumor and remains uniformly fatal, highlighting the dire need for developing effective therapeutics. Significant intra- and inter-tumor heterogeneity and inadequate delivery of therapeutics across blood-brain barrier continue to be significant impediments towards developing therapies which can significantly enhance survival. We hypothesize that microRNAs have the potential to serve as effective therapeutics for glioblastoma as they modulate the activity of multiple signaling pathways, and hence can counteract heterogeneity if successfully delivered.METHODS: Using a computational approach, we identified microRNA-34a as a microRNA that maximally reduces the activation status of the three core signaling networks (the receptor tyrosine kinase, p53 and Rb networks) that have been found to be deregulated in most glioblastoma tumors. Glioblastoma cultures were transfected with microRNA-34a or control microRNA to assess biological function and therapeutic potential in vitro. Nanocells were derived from genetically modified bacteria and loaded with microRNA-34a for intravenous administration to orthotopic patient-derived glioblastoma xenografts in mice.
    RESULTS: Overexpression of microRNA-34a strongly reduced the activation status of the three core signaling networks. microRNA-34a transfection also inhibited the survival of multiple established glioblastoma cell lines, as well as primary patient-derived xenograft cultures representing the proneural, mesenchymal and classical subtypes. Transfection of microRNA-34a enhanced temozolomide (TMZ) response in in vitro cultures of glioblastoma cells with primary TMZ sensitivity, primary TMZ resistance and acquired TMZ resistance. Mechanistically, microRNA-34a downregulated multiple therapeutic resistance genes which are associated with worse survival in glioblastoma patients and are enriched in specific tumor spatial compartments. Importantly, intravenous administration of nanocells carrying miR-34a and targeted to epidermal growth factor receptor (EGFR) strongly enhanced TMZ sensitivity in an orthotopic patient-derived xenograft mouse model of glioblastoma.
    CONCLUSIONS: Targeted bacterially-derived nanocells are an effective vehicle for the delivery of microRNA-34a to glioblastoma tumors. microRNA-34a inhibits survival and strongly sensitizes a wide range of glioblastoma cell cultures to TMZ, suggesting that combination therapy of TMZ with microRNA-34a loaded nanocells may serve as a novel therapeutic approach for the treatment of glioblastoma tumors.
    Keywords:  Glioblastoma; Heterogeneity; MicroRNA delivery; Nanoparticle; Temozolomide resistance
  5. Sci Adv. 2021 Mar;pii: eabd7614. [Epub ahead of print]7(13):
      To address long-standing issues with tumor penetration and targeting among cancer therapeutics, we developed an anticancer platelet-based biomimetic formulation (N+R@PLTs), integrating photothermal nanoparticles (N) and immunostimulator (R) into platelets (PLTs). Exploiting the aggregative properties of platelets and high photothermal capacity, N+R@PLTs functioned as an arsenal by targeting defective tumor vascular endothelial cells, accumulating in a positive feedback aggregation cascade at sites of acute vascular damage induced by N-generated local hyperthermia, and subsequently secreting nanosized proplatelets (nPLTs) to transport active components to deep tumor tissue. The immunostimulator augmented the immunogenicity of antigens released from ablated tumors, inducing a stronger immunological response to attack residual, metastatic, and recurrent tumors. Following activation by low-power near-infrared light irradiation, the photothermal and immunological components synergistically provide exceptionally high therapeutic efficacy across nine murine models that mimicked a range of clinical requirements, and, most notably, a sophisticated model based on humanized mouse and patient-derived tumor xenograft.
  6. Nano Lett. 2021 Mar 23.
      The poor drug delivery to cerebral ischemic regions is a key challenge of ischemic stroke treatment. Inspired by the intriguing blood-brain barrier (BBB)-penetrating ability of 4T1 cancer cells upon their brain metastasis, we herein designed a promising biomimetic nanoplatform by camouflaging a succinobucol-loaded pH-sensitive polymeric nanovehicle with a 4T1 cell membrane (MPP/SCB), aiming to promote the preferential targeting of cerebral ischemic lesions to attenuate the ischemia/reperfusion injury. In transient middle cerebral artery occlusion (tMCAO) rat models, MPP/SCB could be preferentially delivered to the ischemic hemisphere with a 4.79-fold higher than that in the normal hemisphere. Moreover, MPP/SCB produced notable enhancement of microvascular reperfusion in the ischemic hemisphere, resulting in a 69.9% reduction of infarct volume and showing remarkable neuroprotective effects of tMCAO rats, which was superior to the counterpart uncamouflaged nanovehicles (PP/SCB). Therefore, this design provides a promising nanoplatform to target the cerebral ischemic lesions for ischemic stroke therapy.
    Keywords:  bioinspired nanovehicle; blood−brain barrier; cell membrane; drug delivery; ischemic stroke
  7. Nano Today. 2021 Mar 19. 101139
      Effective vaccines are vital to the fight against the COVID-19 global pandemic. As a critical component of a subunit vaccine, the adjuvant is responsible for strengthening the antigen-induced immune responses. Here, we present a new nanovaccine that comprising the Receptor-Binding Domain (RBD) of spike protein and the manganese nanoadjuvant (MnARK), which induces humoral and cellular responses. Notably, even at a 5-fold lower antigen dose and with fewer injections, mice immunized with the MnARK vaccine immunized mice showed stronger neutralizing abilities against the infection of the pseudovirus (~270-fold) and live coronavirus (>8-fold) in vitro than that of Alum-adsorbed RBD vaccine (Alu-RBD). Furthermore, we found that the effective co-delivery of RBD antigen and MnARK to lymph nodes (LNs) elicited an increased cellular internalization and the activation of immune cells, including DC cells, CD4+ and CD8+ T lymphocytes. Our findings highlight the importance of MnARK adjuvant in the design of novel coronavirus vaccines and provide a rationale strategy to design protective vaccines through promoting cellular internalization and the activation of immune-related pathways.
  8. ACS Nano. 2021 Mar 24.
      The exine capsules of pollen particles exhibit a variety of characteristic surface morphologies that promote their cell interactions; their use as antigen carriers for vaccination has been proposed. However, the allergy-causing substances in pollen particles may not all be removed, even by vigorous chemical treatments. To resolve this issue, this work develops systemic approaches for synthesizing pollen-mimetic metal-organic frameworks (MOFs), which comprise aluminum (Al) ions and an organic linker (2-aminoterephthalic acid), with tunable spike-like nanostructures on their surfaces. The as-synthesized MOFs act not only as a delivery vehicle that carries a model antigen (ovalbumin, OVA) but also as an adjuvant (Al). Scanning and transmission electron microscopies images reveal that the aspect ratio of the nanospikes that are grown on the MOFs can be controlled. A higher aspect ratio of the nanospikes on the MOFs is associated with greater cell attachment and faster and more efficient phagocytosis in cells, which results in greater expressions of pro-inflammatory cytokines. Consequently, a more robust immune response against the antigen of interest is elicited. These findings have broad implications for the rational design of the future antigen/adjuvant-presenting particles for vaccination.
    Keywords:  adjuvant; antigen; biomimetics; nanospikes; vaccination
  9. Nat Nanotechnol. 2021 Mar 25.
      Nanoformulations of therapeutic drugs are transforming our ability to effectively deliver and treat a myriad of conditions. Often, however, they are complex to produce and exhibit low drug loading, except for nanoparticles formed via co-assembly of drugs and small molecular dyes, which display drug-loading capacities of up to 95%. There is currently no understanding of which of the millions of small-molecule combinations can result in the formation of these nanoparticles. Here we report the integration of machine learning with high-throughput experimentation to enable the rapid and large-scale identification of such nanoformulations. We identified 100 self-assembling drug nanoparticles from 2.1 million pairings, each including one of 788 candidate drugs and one of 2,686 approved excipients. We further characterized two nanoparticles, sorafenib-glycyrrhizin and terbinafine-taurocholic acid both ex vivo and in vivo. We anticipate that our platform can accelerate the development of safer and more efficacious nanoformulations with high drug-loading capacities for a wide range of therapeutics.
  10. Small. 2021 Mar 24. e2005222
      Among programmable nuclease-based genome editing tools, the clustered regularly interspaced short palindromic repeats (CRISPR) system with accuracy and the convenient operation is most promising to be applied in gene therapy. The development of effective delivery carriers for the CRISPR system is the major premise to achieve practical applications. Although many nanocarrier-mediated deliveries have been reported to be safer and cheaper over the physical and viral delivery, the accumulation at disease sites or controllability with the spatial or temporal resolution are still desired on nanocarriers to reduce side effects and off-target from the CRISPR system. Therefore, the targetable and controllable nanocarriers to actively deliver the CRISPR system are summarized. The cell or even organ selective nanocarriers are introduced first, followed by the discussion of nanocarriers controlled by biochemical or physical signals. At last, the potential challenges faced by existing nanocarriers are discussed.
    Keywords:  clustered regularly interspaced short palindromic repeats system; controllable delivery; gene editing; nanomedicine; targetable delivery
  11. Cancer Lett. 2021 Mar 17. pii: S0304-3835(21)00120-8. [Epub ahead of print]507 97-111
      KRAS mutation is associated with the progression and growth of pancreatic cancer and contributes to chemo-resistance, which poses a significant clinical challenge in pancreatic cancer. Here, we developed a RT22-ep59 antibody (Ab) that directly targets the intracellularly activated GTP-bound form of oncogenic KRAS mutants after it is internalized into cytosol by endocytosis through tumor-associated receptor of extracellular epithelial cell adhesion molecule (EpCAM) and investigated its synergistic anticancer effects in the presence of gemcitabine in pancreatic cancer. We first observed that RT22-ep59 specifically recognized tumor-associated EpCAM and reached the cytosol by endosomal escape. In addition, the anticancer effect of RT22-ep59 was observed in the high-EpCAM-expressing pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells, but it had little effect on the low-EpCAM-expressing pancreatic cancer cells. Additionally, co-treatment with RT22-ep59 and gemcitabine synergistically inhibited cell viability, migration, and invasion in 3D-cultures and exhibited synergistic anticancer activity by inhibiting the RAF/ERK or PI3K/AKT pathways in cells with high-EpCAM expression. In an orthotopic mouse model, combined administration of RT22-ep59 and gemcitabine significantly inhibited tumor growth. Furthermore, the co-treatment suppressed cancer metastasis by blocking EMT signaling in vitro and in vivo. Our results demonstrated that RT22-ep59 synergistically increased the antitumor activity of gemcitabine by inhibiting RAS signaling by specifically targeting KRAS. This indicates that co-treatment with RT22-ep59 and gemcitabine might be considered a potential therapeutic strategy for pancreatic cancer patients harboring KRAS mutation.
    Keywords:  Endosomal escape; Gemcitabine; KRAS target antibody; Pancreatic cancer
  12. Endokrynol Pol. 2021 ;72(1): 73-80
      MicroRNAs (miRNAs) are part of the epigenetic mechanisms that regulate gene expression at a post-transcriptional level. This review describes some miRNAs whose expression is modified in obesity and that may be involved in the development of insulin resistance. The metabolic alterations associated with obesity are due to an adipose tissue dysfunction. miRNAs are a mechanism that regulates gene expression, one miRNA can regulate the expression up to a thousand genes, and at the same time one gene can be regulated by several miRNAs; moreover, miRNA expression is tissue specific. Obesity leads to a dysregulation of miRNA expression in adipose tissue, and changes in miRNA expression relate to changes in gene expression related to the development of insulin resistance. However, because miRNA can be exported to the extracellular medium through exosomes, proteins, and lipoproteins, miRNA can be found in extracellular fluids like blood, urine, saliva, and cerebrospinal fluid. Considering the above, miRNA have been proposed as biological markers of different diseases, and also as potential therapeutic targets.
    Keywords:  adipose tissue; epigenetics; insulin resistance; microRNA; obesity
  13. ACS Nano. 2021 Mar 23.
      Emerging therapeutic treatments based on the production of proteins by delivering mRNA have become increasingly important in recent times. While lipid nanoparticles (LNPs) are approved vehicles for small interfering RNA delivery, there are still challenges to use this formulation for mRNA delivery. LNPs are typically a mixture of a cationic lipid, distearoylphosphatidylcholine (DSPC), cholesterol, and a PEG-lipid. The structural characterization of mRNA-containing LNPs (mRNA-LNPs) is crucial for a full understanding of the way in which they function, but this information alone is not enough to predict their fate upon entering the bloodstream. The biodistribution and cellular uptake of LNPs are affected by their surface composition as well as by the extracellular proteins present at the site of LNP administration, e.g., apolipoproteinE (ApoE). ApoE, being responsible for fat transport in the body, plays a key role in the LNP's plasma circulation time. In this work, we use small-angle neutron scattering, together with selective lipid, cholesterol, and solvent deuteration, to elucidate the structure of the LNP and the distribution of the lipid components in the absence and the presence of ApoE. While DSPC and cholesterol are found to be enriched at the surface of the LNPs in buffer, binding of ApoE induces a redistribution of the lipids at the shell and the core, which also impacts the LNP internal structure, causing release of mRNA. The rearrangement of LNP components upon ApoE incubation is discussed in terms of potential relevance to LNP endosomal escape.
    Keywords:  ApoE; lipid nanoparticles; mRNA delivery; protein corona; small-angle scattering
  14. Mol Med Rep. 2021 May;pii: 385. [Epub ahead of print]23(5):
      It has been reported that microRNAs (miRs) contribute to several biological functions and are associated with drug resistance in various types of cancer. However, to the best of our knowledge, whether miR‑613 can affect cisplatin (CDDP) sensitivity in non‑small cell lung cancer (NSCLC) remains unknown. Reverse transcription‑quantitative PCR was performed to detect the expression levels of miR‑613 and gap junction α‑1 protein (GJA1) in patients with NSCLC. Cell Counting Kit‑8, colony formation and Transwell assays were employed to exam the effects of miR‑613 and GJA1 on cell functions. Cell apoptosis was analyzed using flow cytometry. An in vivo experiment was conducted to determine the influence of miR‑613 on tumor formation. In the present study, miR‑613 was revealed to be significantly downregulated in lung cancer tissues compared with in adjacent normal tissues, and low miR‑613 expression indicated a poor prognosis. Furthermore, cell proliferation, colony formation and migration of lung cancer cells were inhibited by overexpression of miR‑613. In vivo experiments also demonstrated that miR‑613 could inhibit tumor growth. Moreover, miR‑613 could enhance the negative effects of CDDP on cell proliferation, apoptosis and migration. GJA1 was revealed to be a target gene of miR‑613 and was upregulated in human lung cancer tissues. Rescue experiments demonstrated that miR‑613 increased the chemosensitivity of lung cancer cells by targeting GJA1. Collectively, the results suggested a tumor suppressor role of miR‑613 in NSCLC and indicated that miR‑613 could strengthen CDDP sensitivity in NSCLC cells by targeting GJA1, which may provide a novel therapeutic target for NSCLC.
  15. Nano Lett. 2021 Mar 23.
      Microtubules are highly strategic targets of cancer therapies. Small molecule antimitotic agents are so far the best chemotherapeutic medication in cancer treatment. However, the high rate of neuropathy and drug resistance limit their clinical usage. Inspired by the multicomponent-targeting feature of molecular self-assembly (MSA) overcoming drug resistance, we synthesized peptide-based rotor molecules that self-assemble in response to the surrounding environment to target the microtubule array. The MSAs self-adjust morphologically in response to the pH change and viscosity variations during Golgi-endosome trafficking, escape trafficking cargos, and eventually bind to the microtubule array physically in a nonspecific manner. Such unrefined nano-bio interactions suppress regional tubulin polymerization triggering atypical prometaphase--metaphase oscillations to inhibit various cancer cells proliferating without inducing obvious neurotoxicity. The MSA also exerts potent antiproliferative effects in the subcutaneous cervix cancer xenograft tumor model equivalent to Cisplatin, better than the classic antimitotic drug Taxol.
    Keywords:  antimicrotubule; antiproliferation; cancer; molecular self-assembly; prometaphase−metaphase oscillation