Nanoparticle BAF312@CaP-NP Overcomes Sphingosine-1-Phosphate Receptor-1-Mediated Chemoresistance Through Inhibiting S1PR1/P-STAT3 Axis in Ovarian Carcinoma

Enhancing cancer therapy: The role of drug delivery systems in STAT3 inhibitor efficacy and safety

The signal transducer and activator of transcription 3 (STAT3), a member of the STAT family, resides in the nucleus to regulate genes essential for vital cellular functions, including survival, proliferation, self-renewal, angiogenesis, and immune response. However, continuous STAT3 activation in tumor cells promotes their initiation, progression, and metastasis, rendering STAT3 pathway inhibitors a promising avenue for cancer therapy. Nonetheless, these inhibitors frequently encounter challenges such as cytotoxicity and suboptimal biocompatibility in clinical trials. A viable strategy to mitigate these issues involves delivering STAT3 inhibitors via drug delivery systems (DDSs). This review delineates the regulatory mechanisms of the STAT3 signaling pathway and its association with cancer. It offers a comprehensive overview of the current application of DDSs for anti-STAT3 inhibitors and investigates the role of DDSs in cancer treatment. The conclusion posits that DDSs for anti-STAT3 inhibitors exhibit enhanced efficacy and reduced adverse effects in tumor therapy compared to anti-STAT3 inhibitors alone. This paper aims to provide an outline of the ongoing research and future prospects of DDSs for STAT3 inhibitors. Additionally, it presents our insights on the merits and future outlook of DDSs in cancer treatment.

Lysophosphatidic acid responsive photosensitive supramolecular organic frameworks for tumor imaging, drug loading, and photodynamic therapy

Supramolecular organic frameworks have been widely applied for biological detection and drug delivery. In this study, a supramolecular organic framework (SOF) is constructed through the self-assembly of a highly photosensitive triarylphosphine oxide guest molecule, OTPP-6-Methyl, with cucurbit [8] uril (CB [8]). The formation of the SOF gradually enhances the weak fluorescence of OTPP-6-Methyl owing to the restriction of the molecular folding motion. Although the high positive charge of OTPP-6-Methyl facilitates binding to various negatively charged substances, the SOF system only demonstrated an obvious fluorescence response to LPA, a biomarker of ovarian cancer, via the disassembly of SOF and subsequent binding of OTPP-6-Methyl with LPA. The fluorescence changes during the entire process are insufficient to allow the sensitive detection of LPA; thus, we further designed a FRET system by introducing Cy5, which can act as an energy receptor to achieve a ratiometric readout for LPA. The tumor-targeting cRGD group was introduced into the SOF system as part of another guest molecule, OTPP-5-M-1-cRGD, to improve the tumor-targeting ability of the SOF system. The SOF system further improves the photosensitivity of guest molecules, and is therefore used in the in vivo imaging of ovarian cancer subcutaneous tumors and as a DDS for loading DOX for the combined in vivo chemotherapy and photodynamic treatment of tumors.

CB[8]- and triarylboron-based supramolecular organic framework for microRNA detection, tumor-targeted drug delivery, and photodynamic therapy

Supramolecular organic frameworks (SOFs) are widely used for biological detection and drug delivery. In this study, a SOF system was fabricated through the self-assembly of photosensitive triarylboron (TAB), TAB-6-methyl, and CB[8]. The maximum fluorescence emission of TAB-6-methyl was greatly enhanced and red-shifted from 560 nm to 610 nm after SOF formation. The SOF can specifically respond to a microRNA by dissembling and then combining with microRNA, which is accompanied by a fluorescence shift from 610 nm to 560 nm, thus providing a ratiometric readout for microRNA detection. The photosensitivity of TAB-6-methyl can be further improved by forming a SOF, which can be used in photodynamic therapy. By constructing another guest molecule, TAB-5-1-cRGD, we successfully embedded cRGD in the SOF system to improve its tumor-targeting ability. Moreover, we used this SOF system as a fluorescence imaging probe for targeted tumor imaging and as a drug carrier system for loading DOX to achieve combined photodynamic and chemotherapy treatment of tumors.

S1PR1 regulates ovarian cancer cell senescence through the PDK1-LATS1/2-YAP pathway

Cell senescence deters the activation of various oncogenes. Induction of senescence is, therefore, a potentially effective strategy to interfere with vital processes in tumor cells. Sphingosine-1-phosphate receptor 1 (S1PR1) has been implicated in various cancer types, including ovarian cancer. The mechanism by which S1PR1 regulates ovarian cancer cell senescence is currently elusive. In this study, we demonstrate that S1PR1 was highly expressed in human ovarian cancer tissues and cell lines. S1PR1 deletion inhibited the proliferation and migration of ovarian cancer cells. S1PR1 deletion promoted ovarian cancer cell senescence and sensitized ovarian cancer cells to cisplatin chemotherapy. Exposure of ovarian cancer cells to sphingosine-1-phosphate (S1P) increased the expression of 3-phosphatidylinositol-dependent protein kinase 1 (PDK1), decreased the expression of large tumor suppressor 1/2 (LATS1/2), and induced phosphorylation of Yes-associated protein (p-YAP). Opposite results were obtained in S1PR1 knockout cells following pharmacological inhibition. After silencing LATS1/2 in S1PR1-deficient ovarian cancer cells, senescence was suppressed and S1PR1 expression was increased concomitantly with YAP expression. Transcriptional regulation of S1PR1 by YAP was confirmed by chromatin immunoprecipitation. Accordingly, the S1PR1-PDK1-LATS1/2-YAP pathway regulates ovarian cancer cell senescence and does so through a YAP-mediated feedback loop. S1PR1 constitutes a druggable target for the induction of senescence in ovarian cancer cells. Pharmacological intervention in the S1PR1-PDK1-LATS1/2-YAP signaling axis may augment the efficacy of standard chemotherapy.

Interplay between G protein-coupled receptors and nanotechnology

G protein-coupled receptors (GPCRs), as the largest family of membrane receptors, actively modulate plasma membrane and endosomal signalling. Importantly, GPCRs are naturally nanosized, and spontaneously formed nanoaggregates of GPCRs (natural nano-GPCRs) may enhance GPCR-related signalling and functions. Although GPCRs are the molecular targets of the majority of marketed drugs, the poor pharmacokinetics and physicochemical properties of GPCR ligands greatly limit their clinical applicability. Nanotechnology, as versatile techniques, can encapsulate GPCR ligands to assemble synthetic nano-GPCRs to overcome their obstacles, robustly elevating drug efficacy and safety. Moreover, endosomal delivery of GPCR ligands by nanoparticles can precisely initiate sustained endosomal signal transduction, while nanotechnology has been widely utilized for isolation, diagnosis, and detection of GPCRs. In turn, due to overexpression of GPCRs on the surface of various types of cells, GPCR ligands can endow nanoparticles with active targeting capacity for specific cells via ligand-receptor binding and mediate receptor-dependent endocytosis of nanoparticles. This significantly enhances the potency of nanoparticle delivery systems. Therefore, emerging evidence has revealed the interplay between GPCRs and nanoparticles, although investigations into their relationship have been inadequate. This review aims to summarize the interaction between GPCRs and nanotechnology for understanding their mutual influences and utilizing their interplay for biomedical applications. It will provide a fundamental platform for developing powerful and safe GPCR-targeted drugs and nanoparticle systems. STATEMENT OF SIGNIFICANCE: GPCRs as molecular targets for the majority of marketed drugs are naturally nanosized, and even spontaneously form nano aggregations (nano-GPCRs). Nanotechnology has also been applied to construct synthetic nano-GPCRs or detect GPCRs, while endosomal delivery of GPCR ligands by nanoparticles can magnify endosomal signalling. Meanwhile, molecular engineering of nanoparticles with GPCRs or their ligands can modulate membrane binding and endocytosis, powerfully improving the efficacy of nanoparticle system. However, there are rare summaries on the interaction between GPCRs and nanoparticles. This review will not only provide a versatile platform for utilizing nanoparticles to modulate or detect GPCRs, but also facilitate better understanding of the designated value of GPCRs for molecular engineering of biomaterials with GPCRs in therapeutical application.

MiR-4284 inhibits sensitivity to paclitaxel in human ovarian carcinoma SKOV3ip1 and HeyA8 cells by targeting DMC1

An increasing number of studies have confirmed that microRNAs (miRNAs) are involved in various biological processes, including tumor growth and drug resistance. MiR-4284 has been proved to be abnormally regulated in several cancers, but the function of miR-4284 in ovarian carcinoma (OC) is unclear. Paclitaxel resistance is a key obstacle in OC treatment. Here, the role of miR-4284 in cell sensitivity to paclitaxel in OC was investigated. Two OC cell lines (SKOV3ip1 and HeyA8) were utilized for the establishment of paclitaxel-resistant cell lines. Reverse transcription-quantitative PCR (RT-qPCR) was applied to analyze the levels of miR-4284 and potential mRNAs in OC cell lines. Western blotting was performed to evaluate the levels of DNA meiotic recombinase 1 (DMC1) protein and cell cycle-associated proteins. Identification of the relationship between miR-4284 and DMC1 was achieved by luciferase reporter assay. CCK-8 and flow cytometry assays were utilized for evaluating the impact of miR-4284 on the malignant characteristics of paclitaxel-resistant OC cells. MiR-4284 was upregulated in paclitaxel-resistant OC cell lines and correlated with an adverse prognosis in OC patients. Depletion of miR-4284 suppressed cell proliferation and cell cycle progression of paclitaxel-resistant OC. MiR-4284 targeted DMC1 which was downregulated in paclitaxel-resistant cells and reversed the inhibitory influence of miR-4284 silencing on the malignant characters of paclitaxel-resistant OC cells. MiR-4284 targets DMC1 to suppress sensitivity to paclitaxel in human OC cells.