Trastuzumab-modified DM1-loaded nanoparticles for HER2+ breast cancer treatment: an in vitro and in vivo study

Receptor-Mediated Targeted Delivery of Surface-ModifiedNanomedicine in Breast Cancer: Recent Update and Challenges

Breast cancer therapeutic intervention continues to be ambiguous owing to the lack of strategies for targeted transport and receptor-mediated uptake of drugs by cancer cells. In addition to this, sporadic tumor microenvironment, prominent restrictions with conventional chemotherapy, and multidrug-resistant mechanisms of breast cancer cells possess a big challenge to even otherwise optimal and efficacious breast cancer treatment strategies. Surface-modified nanomedicines can expedite the cellular uptake and delivery of drug-loaded nanoparticulate constructs through binding with specific receptors overexpressed aberrantly on the tumor cell. The present review elucidates the interesting yet challenging concept of targeted delivery approaches by exploiting different types of nanoparticulate systems with multiple targeting ligands to target overexpressed receptors of breast cancer cells. The therapeutic efficacy of these novel approaches in preclinical models is also comprehensively discussed in this review. It is concluded from critical analysis of related literature that insight into the translational gap between laboratories and clinical settings would provide the possible future directions to plug the loopholes in the process of development of these receptor-targeted nanomedicines for the treatment of breast cancer.

Expression of a recombinant FLT3 ligand and its emtansine conjugate as a therapeutic candidate against acute myeloid leukemia cells with FLT3 expression

Background

Most patients with acute myeloid leukemia (AML) remain uncurable and require novel therapeutic methods. Gain-of-function FMS-like tyrosine kinase 3 (FLT3) mutations are present in 30–40% of AML patients and serve as an attractive therapeutic target. In addition, FLT3 is aberrantly expressed on blasts in > 90% of patients with AML, making the FLT3 ligand-based drug conjugate a promising therapeutic strategy for the treatment of patients with AML. Here, E. coli was used as a host to express recombinant human FLT3 ligand (rhFL), which was used as a specific vehicle to deliver cytotoxic drugs to FLT3 + AML cells.

Methods

Recombinant hFL was expressed and purified from induced recombinant BL21 (DE3) E. coli. Purified rhFL and emtansine (DM1) were conjugated by an N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP) linker. We evaluated the potency of the conjugation product FL-DM1 against FLT3-expressing AML cells by examining viability, apoptosis and the cell cycle. The activation of proteins related to the activation of FLT3 signaling and apoptosis pathways was detected by immunoblotting. The selectivity of FL-DM1 was assessed in our unique HCD-57 cell line, which was transformed with the FLT3 internal tandem duplication mutant (FLT3-ITD).

Results

Soluble rhFL was successfully expressed in the periplasm of recombinant E. coli. The purified rhFL was bioactive in stimulating FLT3 signaling in AML cells, and the drug conjugate FL-DM1 showed activity in cell signaling and internalization. FL-DM1 was effective in inhibiting the survival of FLT3-expressing THP-1 and MV-4-11 AML cells, with half maximal inhibitory concentration (IC₅₀) of 12.9 nM and 1.1 nM. Additionally, FL-DM1 induced caspase-3-dependent apoptosis and arrested the cell cycle at the G2/M phase. Moreover, FL-DM1 selectively targeted HCD-57 cells transformed by FLT3-ITD but not parental HCD-57 cells without FLT3 expression. FL-DM1 can also induce obvious apoptosis in primary FLT3-positive AML cells ex vivo.

Conclusions

Our data demonstrated that soluble rhFL can be produced in a bioactive form in the periplasm of recombinant E. coli. FL can be used as a specific vehicle to deliver DM1 into FLT3-expressing AML cells. FL-DM1 exhibited cytotoxicity in FLT3-expressing AML cell lines and primary AML cells. FL-DM1 may have potential clinical applications in treating patients with FLT3-positive AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-021-01559-6.

Development of 5D3-DM1: A Novel Anti-Prostate-Specific Membrane Antigen Antibody-Drug Conjugate for PSMA-Positive Prostate Cancer Therapy

Prostate cancer (PC) is a potentially high-risk disease and the most common cancer in American men. It is a leading cause of cancer-related deaths in men in the US, second only to lung and bronchus cancer. Advanced and metastatic PC is initially treated with androgen deprivation therapy (ADT), but nearly all cases eventually progress to castrate-resistant prostate cancer (CRPC). CRPC is incurable in the metastatic stage but can be slowed by some conventional chemotherapeutics and second-generation ADT, such as enzalutamide and abiraterone. Therefore, novel therapeutic strategies are urgently needed. Prostate-specific membrane antigen (PSMA) is overexpressed in almost all aggressive PCs. PSMA is widely used as a target for PC imaging and drug delivery. Anti-PSMA monoclonal antibodies (mAbs) have been developed as bioligands for diagnostic imaging and targeted PC therapy. However, these mAbs are successfully used in PC imaging and only a few have gone beyond phase-I for targeted therapy. The 5D3 mAb is a novel, high-affinity, and fast-internalizing anti-PSMA antibody. Importantly, 5D3 mAb demonstrates a unique pattern of cellular localization to the centrosome after internalization in PSMA(+) PC3-PIP cells. These characteristics make 5D3 mAb an ideal bioligand to deliver tubulin inhibitors, such as mertansine, to the cell centrosome, leading to mitotic arrest and elimination of dividing PC cells. We have successfully developed a 5D3 mAb- and mertansine (DM1)-based antibody-drug conjugate (ADC) and evaluated it in vitro for binding affinity, internalization, and cytotoxicity. The in vivo therapeutic efficacy of 5D3-DM1 ADC was evaluated in PSMA(+) PC3-PIP and PSMA(-) PC3-Flu mouse models of human PC. This therapeutic study has revealed that this new anti-PSMA ADC can successfully control the growth of PSMA(+) tumors without inducing systemic toxicity.

Combination Therapy and Nanoparticulate Systems: Smart Approaches for the Effective Treatment of Breast Cancer

Breast cancer has become one of the biggest concerns for oncologists in the past few decades because of its unpredictable etiopathology and nonavailability of personalized translational medicine. The number of women getting affected by breast cancer has increased dramatically, owing to lifestyle and environmental changes. Besides, the development of multidrug resistance has become a challenge in the therapeutic management of breast cancer. Studies reveal that the use of monotherapy is not effective in the management of breast cancer due to high toxicity and the development of resistance. Combination therapies, such as radiation therapy with adjuvant therapy, endocrine therapy with chemotherapy, and targeted therapy with immunotherapy, are found to be effective. Thus, multimodal and combination treatments, along with nanomedicine, have emerged as a promising strategy with minimum side effects and drug resistance. In this review, we emphasize the multimodal approaches and recent advancements in breast cancer treatment modalities, giving importance to the current data on clinical trials. The novel treatment approach by targeted therapy, according to type, such as luminal, HER2 positive, and triple-negative breast cancer, are discussed. Further, passive and active targeting technologies, including nanoparticles, bioconjugate systems, stimuli-responsive, and nucleic acid delivery systems, including siRNA and aptamer, are explained. The recent research exploring the role of nanomedicine in combination therapy and the possible use of artificial intelligence in breast cancer therapy is also discussed herein. The complexity and dynamism of disease changes require the constant upgrading of knowledge, and innovation is essential for future drug development for treating breast cancer.

Zein nanoparticles as nontoxic delivery system for maytansine in the treatment of non-small cell lung cancer

Purpose: Maytansine (DM1) is a potent anticancer drug and limited in clinical application due to its poor water solubility and toxic side effects. Zein is widely used in nano drug delivery systems due to its good biocompatibility. In this study, we prepared DM1-loaded zein nanoparticles (ZNPs) to achieve tumor targeting and reduce toxic side effects of DM1. Methods: ZNPs were prepared by phase separation and Box-Behnken design was used to optimize the formulation. Then, confocal fluorescence microscope and flow cytometry were used to determine cellular uptake of ZNPs. A549 cells were cultured in vitro to study cytotoxicity and used to establish tumor xenografts in nude mice. Biodistribution and antitumor activity of ZNPs were performed in vivo experiments. In addition, we also performed histological and immunohistochemical examinations on tumors and viscera. Results: The optimal prescription was obtained by using 120 μL zein added to 2 mL water under stirring in 300 rpm. The encapsulation efficiency and drug loading were 82.97 ± 0.80% and 3.32 ± 0.03%, respectively. We found that DM1-loaded ZNPs have a strong inhibitory effect on A549 cells, which stemmed from the ability of ZNPs to enhance cellular uptake. Furthermore, we demonstrated that DM1-loaded ZNPs exhibits a better antitumor efficacy than DM1, which tumor inhibition rate were 97.3% and 92.7%, respectively. The biodistribution revealed that ZNPs could targeted to tumor. Finally, we confirmed by histological that DM1-loaded ZNPs are nontoxic. Conclusion: DM1-loaded ZNPs have considerable antitumor activity. Thus, DM1-loaded ZNPs are a promising treatment of non-small cell lung cancer.

Biologicals to direct nanotherapeutics towards HER2-positive breast cancers

HER2-positive breast cancer, an aggressive cancer, is treated with combinations of conventional anticancer drugs viz., cytotoxic drugs, nibs, and mAbs. Major limitations associated with this therapy are patient non-compliance due to the adverse drug reactions and rapid development of resistance by the HER2-positive malignant cells. While the former is addressed by the nano-formulations of the anticancer-drugs to some extent, the latter is still at large. This is because the nanocarriers of the anticancer drugs, by and large, lack the target specificity and selectivity. Thus, nowadays, to overcome these problems, various safe and efficacious biological agents are being used to direct the nanotherapeutics towards the HER2-positive breast cancers. The present review describes the potentials of such biological agents.

Lanthanide-Doped SPIONs Bioconjugation with Trastuzumab for Potential Multimodal Anticancer Activity and Magnetic Hyperthermia

Iron oxide-based nanoparticles have been modified in their core with holmium(III) in an amount affecting only slightly their magnetic properties. Nanoparticles were conjugated covalently with biomolecule of trastuzumab (Herceptin®), the monoclonal antibody that recognizes cancer cells overexpressing HER2 receptors targeting such nanoparticles to the specified tumor tissues. Systematic studies of Ho3+-doped bioconjugates were carried out as a preliminary step for future replacement of 'cold' Ho with 166Ho radionuclide, emitting 'soft' beta(-) radiation for possible targeted radionuclide therapy. Physicochemical properties of the obtained bioconjugates were subsequently tested for use in magnetic hyperthermia, considered as an effective, low-invasiveness anticancer therapy. With such a system we expect to achieve both: active targeting and multimodal action by simultaneous internal and localized irradiation and magnetic hyperthermia of specific cancers.

Drug Combinations in Breast Cancer Therapy

Breast cancer therapy involves a multidisciplinary approach comprising surgery, radiotherapy, neoadjuvant and adjuvant therapy. Effective therapy of breast cancer requires maximum therapeutic efficacy, with minimal undesirable effects to ensure a good quality of life for patients. The carefully selected combination of therapeutic interventions provides patients with the opportunity to derive maximum benefit from therapy while minimizing or eliminating recurrence, resistance and toxic effects, as well as ensuring that patients have a good quality of life. This review discusses therapeutic options for breast cancer treatments and various combinations that had been previously exploited. The review will also give an insight into the potential application of the nanotechnology platform for codelivery of therapeutics in breast cancer therapy.

Carvacrol nanoemulsion evokes cell cycle arrest, apoptosis induction and autophagy inhibition in doxorubicin resistant-A549 cell line

Carvacrol is a monoterpenoid flavonoid found abundantly in thyme plants. Its physiochemical instability and partial solubility in water is the principal limitation for its industrial use. Hence, we made a carvacrol nanoemulsion (CANE) using ultrasonication method and characterized it by dynamic light scattering (DLS) technique which revealed a negative surface charge (-29.89 mV) with 99.1 nm average droplet size. CANE effectively induced apoptosis in doxorubicin-resistant A549 lung carcinoma cells (A549^DR) evident by the elevated expression of apoptotic proteins such as Bax, Cytochrome C, and Cleaved caspase 3 and 9. Also, CANE displayed cell senescence leading to cell cycle arrest by reducing CDK2, CDK4, CDK6, Cyclin E, Cyclin D1 and enhancing p21 protein expression. In addition, a potential role of CANE in the inhibition of autophagy was noted by evaluating the reduced conversion of LC-3 I to II. Beside this, a down-regulation of important autophagy markers ATG5 and ATG7 and upregulation of p62 were detected in response to CANE. We conclude that the synthesized CANE has potential to cause cell senescence, cell cycle arrest, autophagy inhibition and apoptosis in A549^DR cells and could be used as a potential candidate for lung cancer therapy.