Efficiently targeted therapy of glioblastoma xenograft via multifunctional biomimetic nanodrugs

SECTM1 promotes the development of glioblastoma and mesenchymal transition by regulating the TGFβ1/Smad signaling pathway

Objective: Secreted and transmembrane protein 1 (SECTM1) is a gene encoding a transmembrane protein. The role of SECTM1 in glioblastoma (GBM) is unclear. Here, we reported the abnormal expression of SECTM1 in GBM for the first time and studied the role and mechanism of SECTM1 in GBM. Methods: qRT-PCR, Western blotting and immunofluorescence were used to detect the expression of SECTM1 in gliomas of different grades and GBM cell lines. After the knockdown of SECTM1 expression in cell lines by shRNA, the effect of SECTM1 in GBM cell lines was verified by CCK-8, Transwell, EdU and wound healing experiments. We further investigated the effect and mechanism of SECTM1 on GBM in vitro and in vivo. The effect of SECTM1 on glioma growth was detected by subcutaneous tumor xenografts in nude mice in vivo. Results: The results showed that the knockdown of SECTM1 expression in cell lines significantly inhibited the proliferation, migration and invasion of GBM cells while inhibiting the progression of subcutaneous xenograft tumors in nude mice. However, the role and molecular mechanism of SECTM1 in GBM remain unclear. SECTM1 was found to promote GBM epithelial-mesenchymal transition (EMT) like processes. Bioinformatics analysis and Western blotting showed that SECTM1 regulates glioblastoma invasion and EMT-like processes mainly through the TGFβ1/Smad signaling pathway. Conclusion: The low expression of SECTM1 has an inhibitory effect on GBM and is a potential target for GBM treatment. SECTM1 may also be a promising biomarker for the diagnosis and prognosis of GBM.

Hollow Cu2MoS4 nanoparticles loaded with immune checkpoint inhibitors reshape the tumor microenvironment to enhance immunotherapy for pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease that responds poorly to single-drug immunotherapy with PD-L1 (CD274) inhibitors. Here, we prepared mesoporous nanomaterials Cu2MoS4 (CMS)/PEG loaded with PD-L1 inhibitor BMS-1 and CXCR4 inhibitor Plerixafor to form the nanodrug CMS/PEG-B-P. In vitro experiments, CMS/PEG-B-P have a more substantial inhibitory effect on the expression of PD-L1 and CXCR4 as well as to promote the apoptosis of pancreatic cancer cells KPC and suppressed KPC cell proliferation were detected by flow cytometry, qPCR and Western blotting (WB). Promotes the release of the cytotoxic substance reactive oxygen species (ROS) and the production of the immunogenic cell death (ICD) marker calreticulin (CRT) in KPC cells. CMS/PEG-B-P was also detected to have a certain activating effect on mouse immune cells, dendritic cells (mDC) and macrophage RAW264.7. Subcutaneous tumorigenicity experiments in C57BL/6 mice verified that CMS/PEG-B-P had an inhibitory effect on the growth of tumors and remodeling of the tumor immune microenvironment, including infiltration of CD4+ and CD8+ T cells and polarization of macrophages, as well as reduction of immunosuppressive cells. Meanwhile, CMS/PEG-B-P was found to have different effects on the release of cytokines in the tumor immune microenvironment, including The levels of immunostimulatory cytokines INF-γ and IL-12 are increased and the levels of immunosuppressive cytokines IL-6, IL-10 and IFN-α are decreased. In conclusion, nanomaterial-loaded immune checkpoint inhibitor therapies can enhance the immune response and reduce side effects, a combination that shows great potential as a new immunotherapeutic approach. STATEMENT OF SIGNIFICANCE: Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease that has a low response to single-drug immunotherapy with PD-L1 (CD274) inhibitors. We preared PEG-modified mesoporous nanomaterials Cu2MoS4 (CMS) loaded with PD-L1 inhibitor BMS-1 and CXCR4 inhibitor Plerixafor to form the nanodrug CMS/PEG-B-P. Our study demonstrated that Nanomaterial-loaded immune checkpoint inhibitor therapies can enhance the immune response and reduce side effects, a combination that shows great potential as a new immunotherapeutic approach.

Design of chimeric GLP-1A using oligomeric bile acids to utilize transporter-mediated endocytosis for oral delivery

BACKGROUND

Despite the effectiveness of glucagon-like peptide-1 agonist (GLP-1A) in the treatment of diabetes, its large molecular weight and high hydrophilicity result in poor cellular permeability, thus limiting its oral bioavailability. To address this, we developed a chimeric GLP-1A that targets transporter-mediated endocytosis to enhance cellular permeability to GLP-1A by utilizing the transporters available in the intestine, particularly the apical sodium-dependent bile acid transporter (ASBT).

METHODS

In silico molecular docking and molecular dynamics simulations were used to investigate the binding interactions of mono-, bis-, and tetra-deoxycholic acid (DOCA) (monoDOCA, bisDOCA, and tetraDOCA) with ASBT. After synthesizing the chimeric GLP-1A-conjugated oligomeric DOCAs (mD-G1A, bD-G1A, and tD-G1A) using a maleimide reaction, in vitro cellular permeability and insulinotropic effects were assessed. Furthermore, in vivo oral absorption in rats and hypoglycemic effect on diabetic db/db mice model were evaluated.

RESULTS

In silico results showed that tetraDOCA had the lowest interaction energy, indicating high binding affinity to ASBT. Insulinotropic effects of GLP-1A-conjugated oligomeric DOCAs were not different from those of GLP-1A-Cys or exenatide. Moreover, bD-G1A and tD-G1A exhibited improved in vitro Caco-2 cellular permeability and showed higher in vivo bioavailability (7.58% and 8.63%) after oral administration. Regarding hypoglycemic effects on db/db mice, tD-G1A (50 μg/kg) lowered the glucose level more than bD-G1A (50 μg/kg) compared with the control (35.5% vs. 26.4%).

CONCLUSION

GLP-1A was conjugated with oligomeric DOCAs, and the resulting chimeric compound showed the potential not only for glucagon-like peptide-1 receptor agonist activity but also for oral delivery. These findings suggest that oligomeric DOCAs can be used as effective carriers for oral delivery of GLP-1A, offering a promising solution for enhancing its oral bioavailability and improving diabetes treatment.

Albumin-binding photosensitizer capable of targeting glioma via the SPARC pathway

BACKGROUND

Malignant glioma is among the most lethal and frequently occurring brain tumors, and the average survival period is 15 months. Existing chemotherapy has low tolerance and low blood-brain barrier (BBB) permeability; therefore, the required drug dose cannot be accurately delivered to the tumor site, resulting in an insufficient drug effect.

METHODS

Herein, we demonstrate a precision photodynamic tumor therapy using a photosensitizer (ZnPcS) capable of binding to albumin in situ, which can increase the permeability of the BBB and accurately target glioma. Albumin-binding ZnPcS was designed to pass through the BBB and bind to secreted protein acidic and rich in cysteine (SPARC), which is abundant in the glioma plasma membrane.

RESULTS

When the upper part of a mouse brain was irradiated using a laser (0.2 W cm^- 2) after transplantation of glioma and injection of ZnPcS, tumor growth was inhibited by approximately 83.6%, and the 50% survival rate of the treatment group increased by 14 days compared to the control group. In glioma with knockout SPARC, the amount of ZnPcS entering the glioma was reduced by 63.1%, indicating that it can target glioma through the SPARC pathway.

CONCLUSION

This study showed that the use of albumin-binding photosensitizers is promising for the treatment of malignant gliomas.