Allograft Mice Research Articles

Multifunctional elastin-like polypeptide nanocarriers for efficient miRNA delivery in cancer therapy.

The exogenous delivery of miRNA to mimic and restore miRNA-34a activity in various cancer models holds significant promise in cancer treatment. Nevertheless, its effectiveness is often impeded by challenges, including a short half-life, propensity for off-target accumulation, susceptibility to inactivation by blood-based enzymes, concerns regarding patient safety, and the substantial cost associated with scaling up. As a means of overcoming these barriers, we propose the development of miRNA-loaded Tat-A86 nanoparticles by virtue of Tat-A86's ability to shield the loaded agent from external environmental factors, reducing degradation and inactivation, while enhancing circulation time and targeted accumulation. Genetically engineered Tat-A86, featuring 16 copies of the interleukin-4 receptor (IL-4R)-binding peptide (AP1), Tat for tumor penetration, and an elastin-like polypeptide (ELP) for presenting target ligands and ensuring stability, served as the basis for this delivery system. Comparative groups, including Tat-E60 and A86, were employed to discern differences in binding and penetration. The designed ELP-based nanoparticle Tat-A86 effectively condensed miRNA, forming stable nanocomplexes under physiological conditions. The miRNA/Tat-A86 formulation bound specifically to tumor cells and facilitated stable miRNA delivery into them, effectively inhibiting tumor growth. The efficacy of miRNA/Tat-A86 was further evaluated using three-dimensional spheroids of lewis lung carcinoma (LLC) as in vitro model and LLC tumor-bearing mice as an in vivo model. It was found that miRNA/Tat-A86 facilitates effective cell killing by markedly improving miRNA penetration, leading to a substantial reduction in the size of LLC spheroids. Compared to other controls, Tat-A86 demonstrated superior efficacy in suppressing the growth of 3D cellular aggregates. Moreover, at equivalent doses, miRNA-34a delivered by Tat-A86 inhibited the growth of LLC cells in allograft mice. Overall, these studies demonstrate that Tat-A86 nanoparticles can deliver miRNA systemically, overcoming the basic hurdles impeding miRNA delivery by facilitating both miRNA uptake and stability, ultimately leading to improved therapeutic effects.

Para-toluenesulfonamide, a novel potent carbonic anhydrase inhibitor, improves hypoxia-induced metastatic breast cancer cell viability and prevents resistance to αPD-1 therapy in triple-negative breast cancer

Overexpression of the hypoxia-induced transmembrane enzyme carbonic anhydrase IX (CA9) has been associated with poor prognosis and chemoresistance in aggressive breast cancer. This study aimed to investigate the involvement of CA9 in the anti-tumor activity of para-toluenesulfonamide (PTS) and elucidate its mechanism of action against breast cancer both in vitro and in vivo. MCF-7 and MDA-MB-231 breast cancer cells were treated with PTS or subjected to hypoxic conditions using cobalt chloride (CoCl2), with acetazolamide serving as a positive control. Additionally, 4T1 breast cancer cell allograft mice were co-treated with PTS and α-programmed cell death 1 (αPD-1) monoclonal antibody for one month. The results demonstrated that PTS effectively reduced cell viability and reversed migration ability in MCF-7 and MDA-MB-231 cells under CoCl2-induced hypoxia. Furthermore, PTS upregulated the expression of apoptosis-related proteins and downregulated CA9, hypoxia-inducible factor-1α (HIF-1α), and vascular endothelial growth factor (VEGF) proteins, possibly through modulation of p38 MAPK and ERK1/2 phosphorylated proteins. In the animal model, PTS100 inhibited tumor growth and lung metastasis in mammary tumor allograft mice, exhibiting synergistic effects when combined with αPD-1 therapy. Collectively, our findings suggest that PTS inhibits breast cancer growth and metastasis through the p38 MAPK/ERK1/2 pathway. Moreover, PTS may have the potential to prevent the development of resistance to αPD-1 therapy in breast cancer.

Phytogalactolipids activate humoral immunity against colorectal cancer

BackgroundColorectal cancer (CRC) is the third most lethal cancer in the world, and its incidence is steadily rising. In this study, we investigated the induction of humoral immunity by a phytogalactolipid enriched fraction (CRA) derived from the medicinal plant Crassocephalum rabens (Benth.) S. Moore to combat CRC.MethodsImmunocompetent BALB/c mice were used to evaluate CRA's therapeutic effects in CRC. The phenotypes of B cell subsets in splenocytes and tumors from the CRA-treated mice were isolated and analyzed by flow cytometry. The titers, isotypes, specificity, antigen recognition, and cytotoxic activity of CRA-induced anti-tumor antibodies were determined. The mechanisms of CRA on B cell differentiation were determined by cell-based analyses, including co-cultural with T cells, cytokine analysis, gene expression by qPCR, and protein expression by western blotting.ResultsCRA efficiently inhibited tumor growth in colorectal tumor-bearing allograft mice. CRA treatment attracted an abundance of B cells into the tumor consequently enhancing the anti-tumor antibodies in sera and inducing a class-switch. CRA-induced antisera (designated CRA antisera) specifically recognized surface antigens on the plasma membrane of cancer cells. CRA antisera induced cytotoxicity including antibody-dependent cell cytotoxicity, phagocytosis, and complement-dependent cytotoxicity. CRA interacted with IL-6 receptor to activate STAT3 and cMaf, resulting in T cell secretion of IL-21, which, in turn induced B cell differentiation through the IL-21R/STAT3/Blimp-1 pathway.ConclusionsCRA regulated T cell activity resulting in B cell activation and triggering of anti-tumor antibodies to impede CRC progression.

Abstract 4037: Doxazosin exerts anti-metastatic potential in triple-negative breast cancer via impairment of cancer stem-like features

Abstract Background and Purpose: Triple-negative breast cancer (TNBC) tumors typically harbor a high cancer stem-like population leading to chemo-resistance, recurrence, and metastasis. Tumor metastasis is associated with 90% of cancer-related deaths, highlighting the urgent clinical unmet need. Doxazosin is known to inhibit cell migration and invasion in several cancer cell types; however, the precise mechanisms underlying doxazosin’s anticancer effects in TNBC have not been fully elucidated. In the present study, we sought to investigate the mechanism of action of doxazosin responsible for its effects on apoptosis, cancer stem cell (CSC)-like properties, cell migration, and metastasis in TNBC. Experimental designs: Doxazosin on TNBC cell lines [MDA-MB-231, BT549, and 4T1] in vitro was evaluated in cell viability, apoptosis, cell migration, CD44/CD24 staining, ALDH1 activity, and mammosphere formation. The effect of doxazosin on tumor growth, angiogenesis, and metastasis was evaluated in an orthotopic allograft mice model with CSC-enriched population. Results: Doxazosin significantly reduced cell viability and induced apoptosis in MDA-MB-231 and BT549 cells via activation of caspase-3/-7 and cleavage of PARP. Doxazosin significantly suppressed cell migratory capability, concomitant with disrupting cytoskeletal proteins, including vimentin and F-actin expression in TNBC cells. An impairment of BCSC-like properties was associated with reduction of ALDH1 activity and the CD44+/CD24- population, concomitant with suppression of mammosphere-forming ability. Doxazosin administration reduced tumor growth and lung metastasis, as evidenced by a sharp decline in bioluminescence signal intensity. Inhibitory effect of tumor growth was accompanied by a significant decrease of Ki-67 and enhancement of apoptosis with DNA fragmentation and increased cleaved-caspase-3 expression. The latter phenomenon was associated with the impediment of JAK2/STAT3 signaling pathway and CSC-like properties. Furthermore, no toxic effects of doxazosin were found in liver and kidney function in animals. Conclusion: Taken together, our findings highlight doxazosin as a promising candidate for drug repurposing in suppressing metastatic TNBC. Citation Format: Seongjae Kim, Dongmi Ko, Juyeon Seo, Soeun Park, Minsu Park, Kee Dal Nam, Yong koo Kang, So Ra Seock, Jaeyoun Park, Eunhye Oh, Eunsun Jung, Yoon-Jae Kim, Ji Young Kim, Jae Hong Seo. Doxazosin exerts anti-metastatic potential in triple-negative breast cancer via impairment of cancer stem-like features. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4037.

Acetyltransferase from Akkermansia muciniphila blunts colorectal tumourigenesis by reprogramming tumour microenvironment

ObjectiveThe protein post-translational modification (PTM) in host cells can be rewritten by bacterial enzymes and represents an unprecedented mechanism in the communication between intestinal flora and the host. Although Akkermansia...

Improved Pilot-Plant-Scale Synthesis of Chlorin e6 and Its Efficacy as a Photosensitizer for Photodynamic Therapy and Photoacoustic Contrast Agent

Photodynamic therapy and photoacoustic (PA) imaging are emerging therapeutic modalities for the diagnosis and treatment of various types of cancer or other diseases. In this study, the second-generation photosensitizer Chlorin e6 was prepared on a pilot scale by using the rapid, simple, and green synthetic method as compared to a conventional protocol. In the modified method, the extraction/reaction time and volume of solvents were significantly reduced. The dark and photodynamic cytotoxicity of Ce6 was measured against B16F10 melanoma cell line. Ce6 did not affect cancer cells in the dark up to 192 µM, ensuring their safety in the absence of light. After PDT, it displayed significant cytotoxicity at lower concentrations (IC50: 18.9 µM). For in vivo study, B16F10 allograft mice were treated with Ce6 at 2.5 mg/kg and then exposed to red light (660 nm) after 3 h. The Ce6-PDT caused the inhibition of tumor growth. Furthermore, Ce6 was also used as a photoacoustic imaging agent in ICR mice to visualize the internal organs. Therefore, this study provides valuable information about Ce6-PDT as a promising strategy for anti-cancer therapy as well as visualization of internal organs without surgery or x-rays.

Synergistic effects of sodium butyrate and cisplatin against cervical carcinoma in vitro and in vivo.

Cisplatin-based chemotherapy has been considered as the pivotal option for treating cervical cancer. However, some patients may present a poor prognosis due to resistance to chemotherapy. As a metabolite of natural products, sodium butyrate (NaB) could inhibit the proliferation of several malignant cells, but little is known about its combination with cisplatin in the treatment of cervical cancer. Flow cytometry, CCK-8 assay, and Transwell assay were utilized to analyze the cellular apoptosis, viability, cellular migration and invasion upon treating with NaB and/or cisplatin. The allograft mice model was established, followed by evaluating the tumor volume and necrotic area in mice treated with NaB and/or cisplatin. Western blot was performed for detecting protein expression involved in epithelial-mesenchymal transition (EMT) and the expression of MMPs. Immunohistochemical staining was conducted with the tumor sections. The transcription, expression, and cellular translocation of β-catenin were determined using luciferase reporter gene assay, Real-Time PCR, Western blot, and confocal laser scanning microscope, respectively. NaB combined with cisplatin inhibited cell viability by promoting apoptosis of cervical cancer cells. In vivo experiments indicated that NaB combined with cisplatin could inhibit tumor growth and induce cancer cell necrosis. Single application of NaB activated the Wnt signaling pathway and induced partial EMT. NaB alone up-regulated MMP2, MMP7 and MMP9 expression, and promoted the migration and invasion of cervical cancer cells. The combination of cisplatin and NaB inhibited cellular migration and invasion by abrogating the nuclear transition of β-catenin, reverse EMT and down-regulate MMP2, MMP7 and MMP9. Immunohistochemical staining indicated that NaB combined with cisplatin up-regulated the expression of E-cadherin and reverse the EMT phenotype in the mice model. NaB serves as a sensitizer for cisplatin, which may be a promising treatment regimen for cervical cancer when combined both. NaB alone should be utilized with caution for treating cervical cancer as it may promote the invasion and migration of cervical cancer cells.

Liposomes Loaded with Amaranth Unsaponifiable Matter and Soybean Lunasin Prevented Melanoma Tumor Development Overexpressing Caspase-3 in an In Vivo Model.

The objective of this study was to assess the effectiveness of liposomes loaded with soybean lunasin and amaranth unsaponifiable matter (UM + LunLip) as a source of squalene in the prevention of melanoma skin cancer in an allograft mice model. Tumors were induced by transplanting melanoma B16-F10 cells into the mice. The most effective treatments were those including UM + LunLip, with no difference between the lunasin concentrations (15 or 30 mg/kg body weight); however, these treatments were statistically different from the tumor-bearing untreated control (G3) (p < 0.05). The groups treated with topical application showed significant inhibition (68%, p < 0.05) compared to G3. The groups treated with subcutaneous injections showed significant inhibition (up to 99%, p < 0.05) in G3. During tumor development, UM + LunLip treatments under-expressed Ki-67 (0.2-fold compared to G3), glycogen synthase kinase-3β (0.1-fold compared to G3), and overexpressed caspase-3 (30-fold compared to G3). In addition, larger tumors showed larger necrotic areas (38% with respect to the total tumor) (p < 0.0001). In conclusion, the UM + LunLip treatment was effective when applied either subcutaneously or topically in the melanoma tumor-developing groups, as it slowed down cell proliferation and activated apoptosis.

Abstract 5462: BPI-361175, a 4th generation EGFR-TKI for the treatment of non-small cell lung cancer (NSCLC)

Abstract EGFR-activating mutations (Del19 or L858R) are major drivers in NSCLC (~40% in Asian and 10-20% in non-Asian). EGFR-TKIs have brought benefit to NSCLC patients with EGFR mutations, prolonging PFS and increasing quantity of life. Nevertheless, resistance inevitably emerges and leads to disease progression. Acquired EGFR C797S mutation is the most common event underlying resistance to the 3rd generation EGFR-TKIs, and there are no therapies. Herein, we report the discovery of BPI-361175, a 4th generation EGFR-TKI that overcomes EGFR resistant mutations. In vitro, BPI-361175 potently inhibited the activity of a variety of EGFR kinases, including triple (EGFRdel19 or L858R/T790M/C797S), double (EGFRdel19 or L858R/T790M, EGFRdel19 or L858R/C797S) and single (EGFRdel19 or L858R) mutations. Accordingly, BPI-361175 dose-dependently inhibited the phosphorylation of EGFR and the proliferation of cell lines harboring the above-mentioned mutations. Meanwhile, BPI-361175 were not active towards EGFRWT and IGF1R, therefore displayed good selectivity, both in kinase assays and in cell-based assays. In vivo, oral administration of BPI-361175 led to tumor suppression and regression in multiple EGFR mutant models, such as BaF3 EGFRDel19 or L858R/T790M/C797S, BaF3 EGFRDel19/C797S allograft models, and PC9 EGFRDel19/T790M/C797S, NCI-H1975 EGFRDel19/T790M/C797S, NCI-H1975 (EGFRL858R/T790M), HCC827 (EGFRDel19) CDX models, as well as a LDI-0025-200717 (EGFRDel19/T790M/C797S) PDX model. Remarkably, BPI-361175 significantly prolonged the life span of brain orthotropic BaF3 EGFRDel19/T790M/C797S allograft mice, demonstrating activity towards brain metastasis. In conclusion, BPI-361175 is a potent, selective, and orally bioavailable 4th generation EGFR-TKI which can potentially be used to treat NSCLC resistant mutations as well as at front line. Phase I clinical trial of BPI-361175 is enrolling patients in China, and US Phase I trial is expected to initiate in Q1 2022. Citation Format: Lijia Liu, Changyong Qiu, Xiangyong Liu, Yuanyan Lian, Haibo Chen, Xiaodong Song, Qichao Shen, Guolong Du, Jing Guo, Dan Yan, Hong Lan, Lieming Ding, Jiabing Wang. BPI-361175, a 4th generation EGFR-TKI for the treatment of non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5462.

Saikosaponin B1 and Saikosaponin D inhibit tumor growth in medulloblastoma allograft mice via inhibiting the Hedgehog signaling pathway.

Medulloblastoma (MB), accounting for nearly 10% of all childhood brain tumors, are implicated with aberrant activation of the Hedgehog (Hh) signaling pathway. Saikosaponin B1 (SSB1) and Saikosaponin D (SSD), two bioactive constituents of Radix Bupleuri, are reported to have many biological activities including anticancer activities. In our work, we evaluated the inhibition of SSB1 and SSD on MB tumor growth in allograft mice and explored the underlying mechanisms. The associated biological activity was investigated in Shh Light II cells, an Hh-responsive fibroblast cell line, using the Dual-Glo® Luciferase Assay System. First, SSB1 (IC50, 241.8nM) and SSD (IC50, 168.7nM) inhibited GLI-luciferase activity in Shh Light II cells stimulated with ShhN CM, as well as Gli1 and Ptch1 mRNA expression. In addition, both compounds suppressed the Hh signaling activity provoked by smoothened agonist (SAG) or excessive Smoothened (SMO) expression. Meanwhile, SSB1 and SSD did not inhibit glioma-associated oncogene homolog (GLI) luciferase activity activated by abnormal expression of downstream molecules, suppressor of fuse (SUFU) knockdown or GLI2 overexpression. Consequently, SSB1 (30mg/kg, ip) and SSD (10mg/kg, ip) displayed excellent in vivo inhibitory activity in MB allografts, and the tumor growth inhibition ratios were approximately 50% and 70%, respectively. Our findings, thus, identify SSB1 and SSD significantly inhibit tumor growth in MB models by inhibiting the Hedgehog pathway through targeting SMO.

Identification of new potent anticancer derivatives through simplifying the core structure and modification on their 14- hydroxyl group from oridonin

The natural product oridonin has the potential to be a broad-spectrum antineoplastic agent. To develop oridonin analogues with high potency, a series of novel oridonin analogues were designed and synthesized by removing the multiple hydroxyl groups of parent compound. The representative analogues 14, 19, and 26 exhibited potent anticancer effects against K562, MDA-MB-231, SMMC-7721, and MCF-7 cells. Further structural modification on their 14-OH generated more potent derivatives 16n, 21d, and 28d respectively, in which the IC50 value of compound 16n was 50-fold more potent than parent oridonin in K562 cells. Furthermore, compound 16n significantly induced the cell cycle arrest of K562 cells at the G2 phase and increased the fraction of apoptotic cells. Importantly, compounds 16n, 21d, and 28d exhibited good antitumor activities in H22 allograft mice in vivo. These results suggest that compounds 16n, 21d, and 28d deserve further development as promising candidates for the treatment of cancers.

Mithramycin suppresses tumor growth by regulating CD47 and PD-L1 expression

Mithramycin A (MIT) has reacquired extensive research attention due to its anti-solid tumor activity and improved pharmacological production. Mechanismly, MIT was broadly used as a c-Myc inhibitor, and c-Myc regulated CD47 and PD-L1 expression which has been demonstrated. However, how MIT affects immune check-point molecules remains unknown. In this study, we found CD47 expression was higher in melanoma of pan-tissue array. MIT inhibited CD47 expression both in mRNA and protein level in melanoma cells (SK-MEL-28 and B16). MIT inhibited c-Myc, Sp-1 and CD47 expression in a concentration-dependent way. MIT inhibited the surface CD47 expression and promoted the phagocytosis of SK-MEL-28 cells by THP-1 cells. We found MIT inhibited tumor growth in melanoma allograft mice and CD47 expression in tumor mass. We also found MIT upregulated PD-L1 expression in cancer cells possibly via inhibiting PD-L1 ubiquitination, increasing ROS and IFN-γ. Combination of MIT and anti-PD-1 antibody showed enhanced antitumor activity compared to MIT and anti-PD-1 antibody alone in MC38 allograft mice. Using immune checkpoint array we found MIT inhibited expression of FasL and Galectin3. These results suggest that MIT inhibits CD47 expression, while improves PD-L1 expression. Furthermore, the combination of MIT and anti-PD-1 antibody exerts potent antitumor effect.

A Tumor-Targeting Metal-Organic Nanoparticle Constructed by Dynamic Combinatorial Chemistry toward Accurately Redressing Carcinogenic Wnt Cascade.

Targeted and immunological therapy have revolutionized the malignancy treatment, but is suffering from the dose-limiting side effects and inadequate responsiveness. The emerging nanoscale infinite coordination polymers provide a feasible strategy for tumor targeting and immune sensitization. Herein, a "one-pot" self-assembled strategy based on dynamic combinatorial chemistry (DCC) principle is designed to construct a tumor-targeting metal-organic nanoparticle (MOICP) through a spontaneous co-assembling among three metal-organic coordination polymers tuned by a Wnt-inhibitor carnosic acid (CA). Responding to the tumor microenvironment, MOICP presents an optimized tumor-preferential accumulation and the satisfactory biosafety. MOICP is more active in vitro and in vivo than CA in suppressing of Wnt signaling pathway, and potently inhibits tumor growth in a patient-derived xenograft model of Wnt-activated pancreatic carcinoma. Moreover, MOICP reverses the lack of intratumoral infiltration of T lymphocytes, and hence augments the action of Anti-PD1 (programmed cell death protein 1) immunotherapy in B16F10 melanoma allograft mice model. This clinically viable MOICP can not only be applied to Wnt inhibition for cancer targeted therapy and immunotherapeutic sensitization, but also provides a de novo pattern for nanomedicine architecture with cargo-initiated co-self-assembly guided by DCC, thereby bringing new inspiration in general for disease intervention.

Anticancer Effect of Benzimidazole Derivatives, Especially Mebendazole, on Triple-Negative Breast Cancer (TNBC) and Radiotherapy-Resistant TNBC In Vivo and In Vitro.

In this study, we aimed to evaluate the anticancer effect of benzimidazole derivatives on triple-negative breast cancer (TNBC) and investigate its underlying mechanism of action. Several types of cancer and normal breast cells including MDA-MB-231, radiotherapy-resistant (RT-R) MDA-MB-231, and allograft mice were treated with six benzimidazole derivatives including mebendazole (MBZ). Cells were analyzed for viability, colony formation, scratch wound healing, Matrigel invasion, cell cycle, tubulin polymerization, and protein expression by using Western blotting. In mice, liver and kidney toxicity, changes in body weight and tumor volume, and incidence of lung metastasis were analyzed. Our study showed that MBZ significantly induced DNA damage, cell cycle arrest, and downregulation of cancer stem cell markers CD44 and OCT3/4, and cancer progression-related ESM-1 protein expression in TNBC and RT-R-TNBC cells. In conclusion, MBZ has the potential to be an effective anticancer agent that can overcome treatment resistance in TNBC.

Development of hedgehog pathway inhibitors by epigenetically targeting GLI through BET bromodomain for the treatment of medulloblastoma

Medulloblastoma (MB) is a common yet highly heterogeneous childhood malignant brain tumor, however, clinically effective molecular targeted therapy is lacking. Modulation of hedgehog (HH) signaling by epigenetically targeting the transcriptional factors GLI through bromodomain-containing protein 4 (BRD4) has recently spurred new interest as potential treatment of HH-driven MB. Through screening of current clinical BRD4 inhibitors for their inhibitory potency against glioma-associated oncogene homolog (GLI) protein, the BRD4 inhibitor 2 was selected as the lead for further structural optimization, which led to the identification of compounds 25 and 35 as the high potency HH inhibitors. Mechanism profiling showed that both compounds suppressed HH signaling by interacting with the transcriptional factor GLI, and were equally potent against the clinical resistant mutants and the wild type of smoothened (SMO) receptor with IC50 values around 1 nmol/L. In the resistant MB allograft mice, compound 25 was well tolerated and markedly suppressed tumor growth at both 5 mg/kg (TGI = 83.3%) and 10 mg/kg (TGI = 87.6%) doses. Although further modification is needed to improve the pharmacokinetic (PK) parameters, compound 25 represents an efficacious lead compound of GLI inhibitors, possessing optimal safety and tolerance to fight against HH-driven MB.

Gut Microbial Metabolites Induce Donor-Specific Tolerance of Kidney Allografts through Induction of T Regulatory Cells by Short-Chain Fatty Acids.

Short-chain fatty acids derived from gut microbial fermentation of dietary fiber have been shown to suppress autoimmunity through mechanisms that include enhanced regulation by T regulatory cells (Tregs). Using a murine kidney transplantation model, we examined the effects on alloimmunity of a high-fiber diet or supplementation with the short-chain fatty acid acetate. Kidney transplants were performed from BALB/c(H2d) to B6(H2b) mice as allografts in wild-type and recipient mice lacking the G protein-coupled receptor GPR43 (the metabolite-sensing receptor of acetate). Allograft mice received normal chow, a high-fiber diet, or normal chow supplemented with sodium acetate. We assessed rejection at days 14 (acute) and 100 (chronic), and used 16S rRNA sequencing to determine gut microbiota composition pretransplantation and post-transplantation. Wild-type mice fed normal chow exhibited dysbiosis after receiving a kidney allograft but not an isograft, despite the avoidance of antibiotics and immunosuppression for the latter. A high-fiber diet prevented dysbiosis in allograft recipients, who demonstrated prolonged survival and reduced evidence of rejection compared with mice fed normal chow. Allograft mice receiving supplemental sodium acetate exhibited similar protection from rejection, and subsequently demonstrated donor-specific tolerance. Depletion of CD25+ Tregs or absence of the short-chain fatty acid receptor GPR43 abolished this survival advantage. Manipulation of the microbiome by a high-fiber diet or supplementation with sodium acetate modified alloimmunity in a kidney transplant model, generating tolerance dependent on Tregs and GPR43. Diet-based therapy to induce changes in the gut microbiome can alter systemic alloimmunity in mice, in part through the production of short-chain fatty acids leading to Treg cell development, and merits study as a potential clinical strategy to facilitate transplant acceptance.

Chitinase 3 like 1 suppresses the stability and activity of p53 to promote lung tumorigenesis

BackgroundChitinase 3 like 1 protein (Chi3L1) is expressed in several cancers, and a few evidences suggest that the secreted Chi3L1 contributes to tumor development. However, the molecular mechanisms of intracellular Chi3L1 are unknown in the lung tumor development. Methods: In the present study, we generated Chi3L1 knockout mice (Chi3L1KO(−/−)) using CRISPR/Cas9 system to investigate the role of Chi3L1 on lung tumorigenesis.ResultsWe established lung metastasis induced by i.v. injections of B16F10 in Chi3L1KO(−/−). The lung tumor nodules were significantly reduced in Chi3L1KO(−/−) and protein levels of p53, p21, BAX, and cleaved-caspase 3 were significantly increased in Chi3L1KO(−/−), while protein levels of cyclin E1, CDK2, and phsphorylation of STAT3 were decreased in Chi3L1KO(−/−). Allograft mice inoculated with B16F10 also suppressed tumor growth and increased p53 and its target proteins including p21 and BAX. In addition, knockdown of Chi3L1 in lung cancer cells inhibited lung cancer cell growth and upregulated p53 expression with p21 and BAX, and a decrease in phosphorylation of STAT3. Furthermore, we found that intracellular Chi3L1 physically interacted and colocalized with p53 to inhibit its protein stability and transcriptional activity for target genes related with cell cycle arrest and apoptosis. In lung tumor patient, we clinically found that Chi3L1 expression was upregulated with a decrease in p53 expression, as well as we validated that intracellular Chi3L1 was colocalized, reversely expressed, and physically interacted with p53, which results in suppression of the expression and function of p53 in lung tumor patient.ConclusionsOur studies suggest that intracellular Chi3L1 plays a critical role in the lung tumorigenesis by regulating its novel target protein, p53 in both an in vitro and in vivo system.

Development of elastin-like polypeptide for targeted specific gene delivery in vivo

BackgroundThe successful deliveries of siRNA depend on their stabilities under physiological conditions because greater in vivo stability enhances cellular uptake and enables endosomal escape. Viral-based systems appears as most efficient approaches for gene delivery but often compromised in terms of biocompatibility, patient safety and high cost scale up process. Here we describe a novel platform of gene delivery by elastin-like polypeptide (ELP) based targeting biopolymers.ResultsFor better tumor targeting and membrane penetrating characteristics, we designed various chimeric ELP-based carriers containing a cell penetrating peptide (Tat), single or multiple copies of AP1 an IL-4 receptor targeting peptide along with coding sequence of ELP and referred as Tat-A1E28 or Tat-A4V48. These targeted polypeptides were further analyzed for its ability to deliver siRNA (Luciferase gene) in tumor cells in comparison with non-targeted controls (Tat-E28 or E28). The positively charged amino acids of these polypeptides enabled them to readily complex with negatively charged nucleic acids. The complexation of nucleic acid with respective polypeptides facilitated its transfection efficiency as well as stability. The targeted polypeptides (Tat-A1E28 or Tat-A4V48) selectively delivered siRNA into tumor cells in a receptor-specific fashion, achieved endosomal and lysosomal escape, and released gene into cytosol. The target specific delivery of siRNA by Tat-A1E28 or Tat-A4V48 was further validated in murine breast carcinoma 4T1 allograft mice model.ConclusionThe designed delivery systems efficiently delivered siRNA to the target site of action thereby inducing significant gene silencing activity. The study shows Tat and AP1 functionalized ELPs constitute a novel gene delivery system with potential therapeutic applications.

Immature dendritic cells derived exosomes promotes immune tolerance by regulating T cell differentiation in renal transplantation.

Objective: To investigate the mechanism of immature dendritic cells-derived exosomes (imDECs) in the regulation of T cell differentiation and immune tolerance in renal allograft model mice.Results: imDECs significantly improved the percent of survival, relieved inflammatory response, and reduced CD4+T cell infiltration. In addition, imDECs reduced the rejection associated cytokines in allograft mice, and increased the percentage of Foxp3+CD4+T cells in spleen and kidney tissues. imDECs suppressed the IL17+CD4+T cells and promoted the Foxp3+CD4+T cells under Th17 polarization condition. Moreover, miR-682 was found to be highly expressed in imDECs which suppressed the IL17+CD4+T cells and promoted the Foxp3+CD4+T cells. Luciferase reporter assay showed ROCK2 was a target of miR-682, and ROCK mRNA level was negative correlated with miR-682 mRNA level.Conclusion: miR-682 was highly expressed in imDECs, and imDECs-secreted miR-682 promoted Treg cell differentiation by negatively regulating ROCK2 to promote immune tolerance in renal allograft model mice.Methods: Renal allograft model mice were established, and imDECs or mature dendritic cells-derived exosomes (mDECs) were injected into model mice. Rejection associated cytokines IFN-γ, IL-2, IL-17 levels in plasma were detected by ELISA. IL-17A, Foxp3, miR-682, ROCK2, p-STAT3, p-STAT5 expressions were measured by qRT-PCR or western blot.

The Adjuvant Effect of Squalene, an Active Ingredient of Functional Foods, on Doxorubicin-Treated Allograft Mice

Many functional foods or physiologically active ingredients derived from plants and animals are actively being investigated for their role in chronic disease prevention. Squalene (SQ) is found as active ingredient in the functional foods predominantly present in olive oil and shark liver oil. It is known that during chemotherapy anticancer drugs induce inflammation. SQ has been thought to prevent and suppress inflammation; however, there is little direct evidence available. We examined the adjuvant effect of SQ on tumor-transplanted mice along with anticancer drug doxorubicin (DOX). SQ significantly suppressed the DOX-induced increase in prostaglandin E2 (PGE2) concentration (P < 0.05) in plasma of tumor-bearing mice. SQ inhibited the numbers of writhing response (P < 0.05), formalin-induced pain and decreased COX-2 and substance P expression in the tumor tissue compared to control mice and also enhanced the antitumor efficacy of DOX in allograft mice. Thus, SQ reduces inflammation through modulation of PGE2 production indicating its potential as an adjuvant during chemotherapy in tumor-bearing mice.