Multifunctional Nanoparticles Loading with Docetaxel and GDC0941 for Reversing Multidrug Resistance Mediated by PI3K/Akt Signal Pathway

The Effect of Quercetin in the Yishen Tongluo Jiedu Recipe on the Development of Prostate Cancer through the Akt1-related CXCL12/ CXCR4 Pathway

BACKGROUND

It remains a challenge to effectively treat prostate cancer (PCa) that affects global men's health. It is essential to find a natural alternative drug and explore its antitumor mechanism due to the serious toxic side effects of chemotherapy.

METHODS

The targets and signaling pathways were analyzed by network pharmacology and verified by molecular docking and LC-MS. The proliferation, apoptosis, invasion, and migration of DU145 cells were detected by the CCK-8 method, flow cytometry, and Transwell, respectively. The Bcl-2, caspase-3, CXCL12, and CXCR4 expressions and Akt1 phosphorylation were determined by Western blot. Akt1 overexpression was applied to identify the involvement of the Akt1- related CXCL12/CXCR4 pathway in regulating PCa. Nude mouse tumorigenesis was performed to analyze the effect of quercetin on PCa in vivo.

RESULTS

Network pharmacology analysis displayed that quercetin was the main active component of the Yishen Tongluo Jiedu recipe and Akt1 was the therapy target of PCa. LC-MS analysis showed that quercetin existed in the Yishen Tongluo Jiedu recipe, and molecular docking proved that quercetin bound to Akt1. Quercetin inhibited the proliferation of DU145 cells by upregulating caspase-3 and downregulating Bcl-2 expression, promoting apoptosis and reducing invasion and migration abilities. In vivo, quercetin downregulated CXCL12 and CXCR4 expressions and inhibited PCa development by the Akt1-related CXCL12/CXCR4 pathway.

CONCLUSION

As the active component of the Yishen Tongluo Jiedu recipe, quercetin inhibited PCa development through the Akt1-related CXCL12/CXCR4 pathway. This study provided a new idea for PCa treatment and a theoretical basis for further research.

Combined Docetaxel/Pictilisib-Loaded mPEGylated Nanocarriers with Dual HER2 Targeting Antibodies for Synergistic Chemotherapy of Breast Cancer

Introduction

Approximately 15%~30% of breast cancers have gene amplification or overexpression of the human epidermal growth factor receptor 2 (HER2), resulting in the chemotherapy resistance, a more-aggressive phenotype and poor prognosis.

Methods

We propose a strategy of nanocarriers co-loaded with docetaxel (DTX) and pictilisib (PIC) at a synergistic ratio and non-covalently bound with dual anti-HER2 epitopes bispecific antibodies (BsAbs: anti-HER2-IV/methoxy-polyethylene glycol (mPEG) and anti-HER2-II/methoxy-PEG) for synergistic targeting to overcome the therapeutic dilemmas of the resistance for HER2-targetable chemodrugs. DTX/PIC-loaded nanocarriers (D/P_NCs) were prepared with single emulsion methods and characterized using dynamic light scattering analysis, and the drug content was assayed by high-performance liquid chromatographic method. The integrity and function of BsABs were evaluated using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and enzyme-linked immunosorbent assay (ELISA). The in vitro cell studies and in vivo breast tumor-bearing mice model were used to evaluate the anti-cancer effect and biosafety of formulations.

Results

D/P_NCs optimally prepared exhibited a spherical morphology with small particle sizes (~140 nm), high drug loading (~5.5%), and good colloidal stability. The synergistic tumor cytotoxicity of loading DTX and PIC at 2:1 ratio in D/P_NCs was discovered. The BsAbs are successfully decorated on mPEGylated DTX/PIC-loaded nanocarriers via anti-mPEG moiety. In vitro studies revealed that non-covalent decoration with dual BsAbs on D_P-NCs significantly and synergistically increased cellular uptake, while with loading DTX and PIC at a synergistic ratio of 2:1 in D/P_NCs further resulted in synergistic cytotoxicity. In vivo tumor inhibition studies showed the comparable results for synergistic antitumor efficacy while minimizing systemic toxicity of chemodrugs.

Conclusion

Non-covalent modification with dual distinct epitopes BsAbs on the nanocarriers loaded with dual chemodrugs at a synergistic ratio was expected to be a promising therapeutic platform to overcome the chemoresistance of various cancers and warrants further development for future therapy in the clinical.

PI3K/AKT/mTOR-Targeted Therapy for Breast Cancer

Phosphatidylinositol 3-kinase (PI3K), protein kinase B (PKB/AKT) and mechanistic target of rapamycin (mTOR) (PAM) pathways play important roles in breast tumorigenesis and confer worse prognosis in breast cancer patients. The inhibitors targeting three key nodes of these pathways, PI3K, AKT and mTOR, are continuously developed. For breast cancer patients to truly benefit from PAM pathway inhibitors, it is necessary to clarify the frequency and mechanism of abnormal alterations in the PAM pathway in different breast cancer subtypes, and further explore reliable biomarkers to identify the appropriate population for precision therapy. Some PI3K and mTOR inhibitors have been approved by regulatory authorities for the treatment of specific breast cancer patient populations, and many new-generation PI3K/mTOR inhibitors and AKT isoform inhibitors have also been shown to have good prospects for cancer therapy. This review summarizes the changes in the PAM signaling pathway in different subtypes of breast cancer, and the latest research progress about the biomarkers and clinical application of PAM-targeted inhibitors.

Current Trends and Challenges in Pharmacoeconomic Aspects of Nanocarriers as Drug Delivery Systems for Cancer Treatment

Nanotherapy is a part of nanomedicine that involves nanoparticles as carriers to deliver drugs to target locations. This novel targeting approach has been found to resolve various problems, especially those associated with cancer treatment. In nanotherapy, the carrier plays a crucial role in handling many of the existing challenges, including drug protection before early-stage degradations of active substances, allowing them to reach targeted cells and overcome cell resistance mechanisms. The present review comprises the following sections: the first part presents the introduction of pharmacoeconomics as a branch of healthcare economics, the second part covers various beneficial aspects of the use of nanocarriers for in vitro, in vivo, and pre- and clinical studies, as well as discussion on drug resistance problem and present solutions to overcome it. In the third part, progress in drug manufacturing and optimization of the process of nanoparticle synthesis were discussed. Finally, pharmacokinetic and toxicological properties of nanoformulations due to up-to-date studies were summarized. In this review, the most recent developments in the field of nanotechnology's economic impact, particularly beneficial applications in medicine were presented. Primarily focus on cancer treatment, but also discussion on other fields of application, which are strongly associated with cancer epidemiology and treatment, was made. In addition, the current limitations of nanomedicine and its huge potential to improve and develop the health care system were presented.

Progress in tumour-targeted drug delivery based on cell-penetrating peptides

Since the discovery of cell-penetrating peptides (CPP) in the 1980s, they have played a unique role in various fields owing to their excellent and unique cell membrane penetration function. In particular, in the treatment of tumours, CPPS have been used to deliver several types of 'cargos' to cancer cells. To address the insufficient targeting ability, non-selectivity, and blood instability, activatable cell-penetrating peptides, which can achieve targeted drug delivery in tumour treatment, enhance curative effects, and reduce toxicity have been developed. This study reviews the application of different cell-penetrating peptides in tumour-targeted delivery, overcoming multidrug resistance, organelle targeting, tumour imaging, and diagnosis, and summarises the different mechanisms of activatable cell-penetrating peptides in detail.

Smart Nanocarriers for Targeted Cancer Therapy

Cancer is considered one of the most threatening diseases worldwide. Although many therapeutic approaches have been developed and optimized for ameliorating patient's conditions and life expectancy, however, it frequently remains an incurable pathology. Notably, conventional treatments may reveal inefficient in the presence of metastasis development, multidrug resistance and inability to achieve targeted drug delivery. In the last decades, nanomedicine has gained a prominent role, due to many properties ascribable to nanomaterials. It is worth mentioning their small size, their ability to be loaded with small drugs and bioactive molecules and the possibility to be functionalized for tumor targeting. Natural vehicles have been exploited, such as exosomes, and designed, such as liposomes. Biomimetic nanomaterials have been engineered, by modification with biological membrane coating. Several nanoparticles have already entered clinical trials and some liposomal formulations have been approved for therapeutic applications. In this review, natural and synthetic nanocarriers functionalized for actively targeting cancer cells will be described, focusing on their advantages with respect to conventional treatments. Recent innovations related to biomimetic nanoparticles camouflaged with membranes isolated from different types of cells will be reported, together with their promising applications. Finally, a short overview on the latest advances in carrier-free nanomaterials will be provided.

Protein Disulfide Isomerase 4 Drives Docetaxel Resistance in Prostate Cancer

BACKGROUND

Protein disulfide isomerase 4 (PDIA4) has been reported to be closely associated with chemoresistance in several types of malignancies. But the pathogenic mechanisms of PDIA4 involved in docetaxel (DTX) resistance in prostate cancer (PCa) are still unknown. Hence, this study was conducted to evaluate the potential effect of PDIA4 on chemoresistance to DTX in PCa cells and to investigate the underlying mechanisms.

METHODS

Two types of DTX-resistant PCa cells, that is, DTX-resistant PC-3 cells (PC-3/DTXR) and C4-2B cells (C4-2B/DTXR) were developed, as well as the parental PC-3 and C4-2B cells were obtained to investigate these issues. Short hairpin RNAs targeting human PDIA4 to knockdown the expression of PDIA4 or PDIA4-expressing adenoviral vectors to overexpress the PDIA4 were transfected into PCa cells to study the underlying mechanisms of PDIA4 involving in PCa DTX resistance.

RESULTS

Results showed that PDIA4 exhibited a dramatic overexpression in PC-3/DTXR and C4-2B/DTXR cells. Down-regulation of PDIA4 by infecting PC-3/DTXR and C4-2B/DTXR cells with shPDIA4 lentivirus stimulated cell death by prompting apoptosis. Up-regulation of PDIA4 by infecting PC-3 and C4-2B cells with PDIA4-expressing adenovirus showed severer resistance to DTX. In addition, PDIA4 up-regulation induced phosphorylated protein kinase B (Akt) expression, while PDIA4 knockdown significantly inhibited the expression in PCa cells.

CONCLUSIONS

Our study indicates that PDIA4 is a negative regulator of PCa cell apoptosis and plays a critical role in PCa DTX resistance by activating the Akt-signaling pathway. Thereby, it implies that targeting PDIA4 could be a potential adjuvant therapeutic approach against DTX resistance in PCa.

Quercetin reverses docetaxel resistance in prostate cancer via androgen receptor and PI3K/Akt signaling pathways

Docetaxel is the first-line chemotherapy agent for metastatic prostate cancer. However, the emergence of resistance diminishes its efficacy and limits the survival benefit. Quercetin is a dietary flavonoid which has been shown to have multiple anti-cancer effects. Also, quercetin has been reported to reverse chemo-resistance in many other cancers. This study was to determine whether quercetin could reverse docetaxel resistance in prostate cancer cells and xenograft models, thereby exploring the underlying mechanism. Depending on the docetaxel-resistant cells (LNCaP/R, PC-3/R) which were established from docetaxel-sensitive cells (LNCaP, PC-3), it was demonstrated that quercetin could reverse docetaxel resistance in prostate cancer on proliferation, colony formation, migration, invasion and apoptosis. Although single docetaxel application had little effect on docetaxel-resistant cells, combining docetaxel with quercetin was significantly effective. Combination therapy could maximally inhibited PI3K/Akt pathway and promoted apoptosis. As shown by in-vivo study, xenograft tumors treated by docetaxel with quercetin had poorest growth. Then, to investigate the underlying mechanisms, the differences among parental cells, docetaxel-resistant subclones and quercetin treated resistant subclones were evaluated. It was found that docetaxel-resistant subclones had stronger activation of androgen receptor and PI3K/Akt pathway, more remarkable mesenchymal and stem-like cell phenotypes, and more P-gp expression than that of parental cells. Interestingly, quercetin could reverse these transformations. Our data revealed that quercetin had docetaxel-resistance reversal effect both in vitro and in vivo and provided in-depth support for clinical use of quercetin in docetaxel-resistant prostate cancer.