Trastuzumab: More than a Guide in HER2-Positive Cancer Nanomedicine

HER2-targeted therapies for HER2-positive early-stage breast cancer: present and future

Breast cancer (BC) has the second highest incidence among cancers and is the leading cause of death among women worldwide. The human epidermal growth factor receptor 2 (HER2) is overexpressed in approximately 20%-30% of BC patients. The development of HER2-targeted drugs, including monoclonal antibodies (mAbs), tyrosine kinase inhibitors (TKIs) and antibody-drug conjugates (ADCs), has improved the operation rate and pathological remission rate and reduced the risk of postoperative recurrence for HER2-positive early-stage BC (HER2+ EBC) patients. This review systematically summarizes the mechanisms, resistance, therapeutic modalities and safety of HER2-targeted drugs and helps us further understand these drugs and their use in clinical practice for patients with HER2+ EBC.

Albumin incorporation into recognising layer of HER2-specific magnetic nanoparticles as a tool for optimal targeting of the acidic tumor microenvironment

Cancer is unquestionably a global healthcare challenge, spurring the exporation of novel treatment approaches. In recent years, nanomaterials have garnered significant interest with the greatest hopes for targeted nanoformulations due to their cell-specific delivery, improved therapeutic efficacy, and reduced systemic toxicity for the organism. The problem of successful clinical translation of nanoparticles may be related to the fact that most in vitro tests are performed at pH values of normal cells and tissues, ranging from 7.2 to 7.4. The extracellular pH values of tumors are characterized by a shift to a more acidic region in the range of 5.6-7.0 and represent a crucial target for enhancing nanoparticle delivery to cancer cells. Here we show the method of non-active protein incorporation into the surface of HER2-targeted nanoparticles to achieve optimal cellular uptake within the pH range of the tumor microenvironment. The method efficacy was confirmed in vitro and in vivo showing the maximum binding of nanoparticles to cells at a pH value 6.4. Namely, fluorescent magnetic nanoparticles, modified with HER2-recognising affibody ZHER2:342, with proven specificity in terms of HER2 recognition (with 62-fold higher cellular uptake compared to control nanoparticles) were designed for targeting cancer cells at slightly acidic pH values. The stabilizing protein, namely, bovine serum albumin, one of the major blood components with widespread availability and biocompatibility, was used for the decoration of the nanoparticle surface to alter the pH response of the targeting magnetic conjugates. The optimally designed nanoparticles showed a bell-shaped dependency of interaction with cancer cells in the pH range of 5.6-8.0 with maximum cellular uptake at pH value 6.4 close to that of the tumor microenvironment. In vivo experiments revealed that after i.v. administration, BSA-decorated nanoparticles exhibited 2 times higher accumulation in tumors compared to magnetic nanoparticles modified with affibody only. Thus, we demonstrated a valid method for enhancing the specificity of targeted nanoparticle delivery to cancer cells without changing the functional components of nanoparticles.

Efficacy and delivery strategies of the dual Rac/Cdc42 inhibitor MBQ-167 in HER2 overexpressing breast cancer

Trastuzumab and trastuzumab-based treatments are the standard of care for breast cancer patients who overexpress the human epidermal growth factor receptor 2 (HER2). However, patients often develop resistance to trastuzumab via signaling from alternative growth factor receptors that converge to activate guanine nucleotide exchange factors (GEFs) that in turn activate the Rho GTPases Rac and Cdc42. Since Rac and Cdc42 have been implicated in high tumor grade and therapy resistance, inhibiting the activity of Rac and Cdc42 is a rational strategy to overcome HER2-targeted therapy resistance. Therefore, our group developed MBQ-167, a dual Rac/Cdc42 inhibitor with IC50s of 103 nM and 78 nM for Rac and Cdc42, respectively, which is highly effective in reducing cell and tumor growth and metastasis in breast cancer cell and mouse models. Herein, we created a trastuzumab resistant variant of the SKBR3 HER2 positive breast cancer cell line and show that Rac activation is a central mechanism in trastuzumab resistance. Next, we tested the potential of targeting MBQ-167 to HER2 overexpressing trastuzumab-resistant cell lines in vitro, and show that MBQ-167, but not trastuzumab, reduces cell viability and induces apoptosis. When MBQ-167 was targeted to mammary fatpad tumors established from HER2 overexpressing cells via immunoliposomes functionalized with trastuzumab, MBQ-167 and MBQ-167-loaded liposomes show equal efficacy in reducing the viability of trastuzumab-resistant cells, inhibiting tumor growth in mouse xenografts, and reducing metastasis to lungs and liver. This study demonstrates the efficacy of MBQ-167 as an alternative therapeutic in HER2 overexpressing cancers, delivered either in free form or in liposomes.

Analytical Techniques for Characterizing Tumor-Targeted Antibody-Functionalized Nanoparticles

The specific interaction between cell surface receptors and corresponding antibodies has driven opportunities for developing targeted cancer therapies using nanoparticle systems. It is challenging to design and develop such targeted nanomedicines using antibody ligands, as the final nanoconjugate's specificity hinges on the cohesive functioning of its components. The multicomponent nature of antibody-conjugated nanoparticles also complicates the characterization process. Regardless of the type of nanoparticle, it is essential to perform physicochemical characterization to establish a solid foundation of knowledge and develop suitable preclinical studies. A meaningful physicochemical evaluation of antibody-conjugated nanoparticles should include determining the quantity and orientation of the antibodies, confirming the antibodies' integrity following attachment, and assessing the immunoreactivity of the obtained nanoconjugates. In this review, the authors describe the various techniques (electrophoresis, spectroscopy, colorimetric assays, immunoassays, etc.) used to analyze the physicochemical properties of nanoparticles functionalized with antibodies and discuss the main results.

Novel Strategies Using Sagacious Targeting for Site-Specific Drug Delivery in Breast Cancer Treatment: Clinical Potential and Applications

For more than a decade, researchers have been working to achieve new strategies and smart targeting drug delivery techniques and technologies to treat breast cancer (BC). Nanotechnology presents a hopeful strategy for targeted drug delivery into the building of new therapeutics using the properties of nanomaterials. Nanoparticles are of high regard in the field of diagnosis and the treatment of cancer. The use of these nanoparticles as an encouraging approach in the treatment of various cancers has drawn the interest of researchers in recent years. In order to achieve the maximum therapeutic effectiveness in the treatment of BC, combination therapy has also been adopted, leading to minimal side effects and thus an enhancement in the quality of life for patients. This review article compares, discusses and criticizes the approaches to treat BC using novel design strategies and smart targeting of site-specific drug delivery systems.

Nanomaterials in Targeting Cancer Cells with Nanotherapeutics: Transitioning Towards Responsive Systems

On a global scale, cancer is a difficult and devastating illness. Several problems with current chemotherapies include cytotoxicity, lack of selectivity, stem-like cell growth, and multi-drug resistance. The most appropriate nanomaterials for cancer treatment are those with characteristics, such as cytotoxicity, restricted specificity, and drug capacity and bioavailability; these materials are nanosized (1-100 nm). Nanodrugs are rarely licenced for therapeutic use despite growing research. These compounds need nanocarrier-targeted drug delivery experiments to improve their translation. This review describes new nanomaterials reported in the literature, impediments to their clinical studies, and their beneficial cancer therapeutic use. It also suggests ways to use nanomaterials in cancer therapy more efficiently and describes the intrinsic challenges of cancer treatment and the different nanocarriers and chemicals that can be utilised for specified tumour targeting. Furthermore, it provides a concise overview of cancer theranostics methods, with a focus on those that make use of nanomaterials. Although nanotechnology offers a great source for future advancements in cancer detection and therapy, there is an emerging need for more studies to address the present barriers to clinical translation.

Enhanced therapeutic action of Trastuzumab loaded ZnxMn1-xFe2O4 nanoparticles using a pre-treatment step for hyperthermia treatment of HER2+ breast cancer

In this study, Ferrites (Fe3O4, MnFe2O4, ZnFe2O4) and different stoichiometric ratios of ZnxMn1-xFe2O4 (x = 0.2, 0.4, 0.6, and 0.8) nanoparticles (<15 nm) were synthesized by microwave-assisted method and optimised for hyperthermia studies. The selection of the optimised variant of ferrite i.e. Zn0.4Mn0.6Fe2O4 was found to be the best variant based on VSM (38.14 emu g-1) hyperthermia-based temperature rise (maximum ΔT of 38 °C), SAR and ILP values. Trastuzumab, which is known to bind with HER2 receptors of breast cancer was chemically tethered onto Zn0.4Mn0.6Fe2O4 nanoparticles through EDC/NHS coupling with a loading efficiency of 80%. The attached Trastuzumab aided during the pre-treatment step by aiding in the internalisation of Zn0.4Mn0.6Fe2O4 nanoparticles, with cellular uptake of 11% in SK-BR-3 (cancerous HER2+) cells compared to ∼5% for MDA-MB-231 (cancerous HER2-) and RPE-1 (non-cancerous) cells. In the presence of a hyperthermia trigger for 15 mins, ZnxMn1-xFe2O4 -Trastuzumab formulation had a maximum therapeutic effect by reducing the SK-BR-3 cell viability to 14% without adversely affecting the RPE-1 cells. The mechanism of ZnxMn1-xFe2O4-Trastuzumab combination was examined using an internalisation study, MTT-based viability, proliferation study, and ROS generation assay. By utilizing both Trastuzumab and hyperthermia, we achieve their synergistic anticancer properties while minimizing the drug requirement and reducing any effect on non-cancerous cells.

An immuno-magnetophoresis-based microfluidic chip to isolate and detect HER2-Positive cancer-derived exosomes via multiple separation

Exosomes are useful for cancer diagnosis and monitoring. However, clinical samples contain impurities that complicate direct analyses of cancer-derived exosomes. Therefore, a microfluidic chip-based magnetically labeled exosome isolation system (MEIS-chip) was developed as a lab-on-a-chip platform for human epidermal growth factor receptor 2 (HER2)-positive cancer diagnosis and monitoring. Various magnetic nanoclusters (MNCs) were synthesized with different degrees of magnetization, and antibodies were introduced to capture HER2-overexpressing and common exosomes using immunoaffinity. MNC-bonded exosomes were separated into different exits according to their magnetization degrees. The MEIS-chip efficiently separated HER2-overexpressing exosomes from common exosomes that did not contain disease-related information. The simultaneous separation of HER2-and non-HER2-overexpressing exosomes provided a means of analyzing high-purity HER2-overexpressing exosomes while minimizing the contribution of non-target exosomes, reducing misdiagnosis risk. Notably, common exosomes served as a negative control for monitoring real-time changes in HER2 expression. These findings support the application of MEIS-chip for cancer diagnosis and treatment monitoring via effective exosome isolation.

Crosstalk between endoplasmic reticulum stress and multidrug-resistant cancers: hope or frustration

Endoplasmic reticulum stress (ERS) is a kind of cell response for coping with hypoxia and other stresses. Pieces of evidence show that continuous stress can promote the occurrence, development, and drug resistance of tumors through the unfolded protein response. Therefore, the abnormal ac-tivation of ERS and its downstream signaling pathways not only can regulate tumor growth and metastasis but also profoundly affect the efficacy of antitumor therapy. Therefore, revealing the molecular mechanism of ERS may be expected to solve the problem of tumor multidrug resistance (MDR) and become a novel strategy for the treatment of refractory and recurrent tumors. This re-view summarized the mechanism of ERS and tumor MDR, reviewed the relationship between ERS and tumor MDR, introduced the research status of tumor tissue and ERS, and previewed the prospect of targeting ERS to improve the therapeutic effect of tumor MDR. This article aims to provide researchers and clinicians with new ideas and inspiration for basic antitumor treatment.

New insights into the anticancer therapeutic potential of maytansine and its derivatives

Maytansine is a pharmacologically active 19-membered ansamacrolide derived from various medicinal plants and microorganisms. Among the most studied pharmacological activities of maytansine over the past few decades are anticancer and anti-bacterial effects. The anticancer mechanism of action is primarily mediated through interaction with the tubulin thereby inhibiting the assembly of microtubules. This ultimately leads to decreased stability of microtubule dynamics and cause cell cycle arrest, resulting in apoptosis. Despite its potent pharmacological effects, the therapeutic applications of maytansine in clinical medicine are quite limited due to its non-selective cytotoxicity. To overcome these limitations, several derivatives have been designed and developed mostly by modifying the parent structural skeleton of maytansine. These structural derivatives exhibit improved pharmacological activities as compared to maytansine. The present review provides a valuable insight into maytansine and its synthetic derivatives as anticancer agents.

Antibody-Loaded Nanoplatforms for Colorectal Cancer Diagnosis and Treatment: An Update

At present, colorectal cancer (CRC) is the second deadliest type of cancer, partly because a high percentage of cases are diagnosed at advanced stages when tumors have already metastasized. Thus, there is an urgent need to develop novel diagnostic systems that allow early detection as well as new therapeutic systems that are more specific than those currently available. In this context, nanotechnology plays a very important role in the development of targeted platforms. In recent decades, many types of nanomaterials with advantageous properties have been used for nano-oncology applications and have been loaded with different types of targeted agents, capable of recognizing tumor cells or biomarkers. Indeed, among the different types of targeted agents, the most widely used are monoclonal antibodies, as the administration of many of them is already approved by the main drug regulatory agencies for the treatment of several types of cancer, including CRC. In this way, this review comprehensively discusses the main drawbacks of the conventional screening technologies and treatment for CRC, and it presents recent advances in the application of antibody-loaded nanoplatforms for CRC detection, therapy or theranostics applications.

Stability of trastuzumab during nanomedicine formulation using SEC-HPLC coupled with polyacrylamide gel electrophoresis

The anti-HER2 antibody trastuzumab has been proven to be an effective targeting ligand for drug delivery. This study investigates the structural integrity of trastuzumab under different stress factors in formulation development and its long-term stability. A validated size exclusion high performance liquid chromatographic (SEC-HPLC) method was first developed. The stability of trastuzumab (0.21-21 mg/ml) under stress conditions (mechanical, freeze-and-thaw, pH and temperature) and long-term storage in the presence of formulation excipients were monitored for up to 12 months, using both the SEC-HPLC method and sodium-dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The anti-proliferation activity of the reconstituted antibody stored at 4 °C against HER2⁺ BT-474 breast cells was also monitored over 12 months. The developed SEC-HPLC method was sensitive and accurate. Solutions of trastuzumab were resistant to mechanical stress and repeated freeze-and-thaw; but were unstable under acidic (pH 2.0 and 4.0) and alkaline (pH 10.0 and 12.0) environments. The samples degraded over 5 days at 60 °C, and within 24 h at 75 °C. Low temperature (-80 °C or 4 °C) and low concentration (0.21 mg/ml) favoured the long-term stability. The anti-proliferation activity was conserved at 4 °C for at least 12 months. This study provided valuable stability information in developing trastuzumab involved nano-formulation as well as in clinical settings.

Click Chemistry for Liposome Surface Modification

Click chemistry, and particularly azide-alkyne cycloaddition, represents one of the principal bioconjugation strategies that can be used to conveniently attach various ligands to the surface of preformed liposomes. This efficient and chemoselective reaction involves a Cu(I)-catalyzed azide-alkyne cycloaddition which can be performed under mild experimental conditions in aqueous media. Here we describe the application of a model click reaction to the conjugation, in a single step, of unprotected α-1-thiomannosyl ligands, functionalized with an azide group, to liposomes containing a terminal alkyne-functionalized lipid anchor. Excellent coupling yields were obtained in the presence of bathophenanthrolinedisulphonate, a water-soluble copper-ion chelator, acting as catalyst. No vesicle leakage was triggered by this conjugation reaction, and the coupled mannose ligands were exposed at the surface of the liposomes. The major limitation of Cu(I)-catalyzed click reactions is that this type of conjugation is restricted to liposomes made of saturated (phospho)lipids. To circumvent this constraint, an example of alternate copper-free azide-alkyne click reaction has been developed, and it was applied to the anchoring of a biotin moiety that was fully functional and could be therefore quantified. Molecular tools and results are presented here.

Nanomaterial-Based Drug Delivery Systems: A New Weapon for Cancer Immunotherapy

Cancer immunotherapy, a major breakthrough in cancer treatment, has been successfully applied to treat a number of tumors. However, given the presence of factors in the tumor microenvironment (TME) that impede immunotherapy, only a small proportion of patients achieve a good clinical response. With the ability to increase permeability and cross biological barriers, nanomaterials have been successfully applied to deliver immunotherapeutic agents, thus realizing the anti-cancer therapeutic potential of therapeutic agents. This has driven a wave of research into systems for the delivery of immunotherapeutic agents, which has resulted in widespread interest in nanomaterial-based drug delivery systems. Nanomaterial-based drug delivery systems are able to overcome the challenges from TME and thus achieve good results in cancer immunotherapy. If it can make a breakthrough in improving biocompatibility and reducing cytotoxicity, it will be more widely used in clinical practice. Different types of nanomaterials may also have some subtle differences in enhancing cancer immunotherapy. Moreover, delivery systems made of nanomaterials loaded with drugs, such as cytotoxic drugs, cytokines, and adjuvants, could be used for cancer immunotherapy because they avoid the toxicity and side effects associated with these drugs, thereby enabling their reuse. Therefore, further insights into nanomaterial-based drug delivery systems will provide more effective treatment options for cancer patients.

Current Progress in Cancer Treatment Using Nanomaterials

The pathological processes of cancer are complex. Current methods used for chemotherapy have various limitations, such as cytotoxicity, multi-drug resistance, stem-like cells growth, and lack of specificity. Several types of nanomaterials are used for cancer treatment. Nanomaterials 1–100 nm in size have special optical, magnetic, and electrical characteristics. Nanomaterials have been fabricated for cancer treatments to overcome cytotoxicity and low specificity, and improve drug capacity and bioavailability. Despite the increasing number of related studies, few nanodrugs have been approved for clinical use. To improve translation of these materials, studies of targeted drug delivery using nanocarriers are needed. Cytotoxicity, enhanced permeability and retention effects, and the protective role of the protein corona remain to be addressed. This mini-review summarizes new nanomaterials manufactured in studies and in clinical use, analyses current barriers preventing their translation to clinical use, and describes the effective application of nanomaterials in cancer treatment.

HER-2-Targeted Nanoparticles for Breast Cancer Diagnosis and Treatment

Human epidermal growth factor receptor-2 (HER-2) overexpressing breast cancer is a breast cancer subtype characterized by high aggressiveness, high frequency of brain metastases and poor prognosis. HER-2, a glycoprotein belonging to the ErbB receptor family, is overexpressed on the outer membrane of cancer cells and has been an important therapeutic target for the development of targeted drugs, such as the monoclonal antibodies trastuzumab and pertuzumab. These therapies have been available in clinics for more than twenty years. However, despite the initial enthusiasm, a major issue emerged limiting HER-2 targeted therapy efficacy, i.e., the evolution of drug resistance, which could be tackled by nanotechnology. The aim of this review is to provide a first critical update on the different types of HER-2-targeted nanoparticles that have been proposed in the literature in the last decade for therapeutic purposes. We focus on the different targeting strategies that have been explored, their relative outcomes and current limitations that still need to be improved. Then, we review the nanotools developed as diagnostic kits, focusing on the most recent techniques, which allow accurate quantification of HER-2 levels in tissues, with the aim of promoting more personalized medicinal approaches in patients.

Trastuzumab in breast cancer treatment: the Era of biosimilars

BACKGROUND

The discovery of trastuzumab as anti-HER2 therapy markedly improved disease control and the survival rates of patients with HER2+ breast cancer. However, as trastuzumab is considered a complex molecule, the cost of production is usually elevated, which significantly affects health budgets and limits the treatment access for patients who live in underdeveloped countries. Recently, trastuzumab production became more accessible and sustainable due to the patents' expiration, allowing biosimilar versions of trastuzumab to be developed.

OBJECTIVE

Our main goal was to shed more light on the uses of biosimilars in breast cancer treatment, emphasizing trastuzumab.

METHOD

An integrative review was carried out in the PubMed, Scielo, Web of Science, and SCOPUS databases using the terms "biosimilar," "breast cancer," "monoclonal antibody," and "trastuzumab." The time range included scientific articles published from 2015 to 2021.

RESULTS AND DISCUSSION

The bibliographic survey showed the complexities in biological medicine manufacturing and how the monoclonal antibody's therapy with trastuzumab improved the patients' life expectancy, revolutionizing HER2+ breast cancer treatment. Nonetheless, despite its benefits, trastuzumab generates certain restrictions, especially from the economic perspective. Trastuzumab biosimilars have high selectivity and rarely cause adverse effects compared to conventional chemotherapy.

CONCLUSION

This study shows that trastuzumab biosimilars improve patients' accessibility to breast cancer treatment through a safe and effective therapy compared to the drug reference.

A recent development of new therapeutic agents and novel drug targets for cancer treatment

Despite recent advances in cancer diagnosis, prevention, detection, as well as management, the disease is expected to be the top cause of death globally. The chemotherapy approach for cancer has become more advanced in its design, yet no medication can cure enough against all types of cancer and its stage. Thus, this review aimed to summarize a recent development of new therapeutic agents and novel drug targets for the treatment of cancer. Several obstacles stand in the way of effective cancer treatment and drug development, including inaccessibility of tumor site by appropriate drug concentration, debilitating untoward effects caused by non-selective tissue distribution of chemotherapeutic agents, and occurrence of drug resistance, which leads to cross-resistance to a variety of drugs. Resistance to treatment with anticancer drugs results from multiple factors and the most common reason for acquiring drug resistance is marking and expelling drugs that prevent cancer cells to be targeted by chemotherapeutic agents. Moreover, insensitivity to drug-induced apoptosis, alteration, and mutation of drug target and interference/change of DNA replication are other main causes of treatment failure.

Nanobiotechnology and Immunotherapy: Two Powerful and Cooperative Allies against Cancer

A number of novel cancer therapies have recently emerged that have rapidly moved from the bench to the clinic. Onco-immunotherapies, such as immune checkpoint blockade inhibitors and adoptive cell therapies, have revolutionized the field, since they provide a way to induce strong anti-tumor immune responses, which are able to fight cancer effectively. However, despite showing great efficacy in hematological and some solid tumors, unresponsiveness, development of therapy resistance and the development of serious adverse effects, limit their capacity to impact the vast majority of tumors. Nanoparticle-based delivery systems are versatile vehicles for a wide variety of molecular cargoes and provide an innovative strategy to improve conventional onco-immunotherapies. They can be finely tuned to release their contents in the tumor microenvironment, or to deliver combinations of adjuvants and antigens in the case of nanovaccines. In this review, we summarize the recent advancements in the field of nanobiotechnology, to remodel the tumor microenvironment and to enhance immunotherapies.

Nanomaterials for cancer therapy: current progress and perspectives

Cancer is a disease with complex pathological process. Current chemotherapy faces problems such as lack of specificity, cytotoxicity, induction of multi-drug resistance and stem-like cells growth. Nanomaterials are materials in the nanorange 1–100 nm which possess unique optical, magnetic, and electrical properties. Nanomaterials used in cancer therapy can be classified into several main categories. Targeting cancer cells, tumor microenvironment, and immune system, these nanomaterials have been modified for a wide range of cancer therapies to overcome toxicity and lack of specificity, enhance drug capacity as well as bioavailability. Although the number of studies has been increasing, the number of approved nano-drugs has not increased much over the years. To better improve clinical translation, further research is needed for targeted drug delivery by nano-carriers to reduce toxicity, enhance permeability and retention effects, and minimize the shielding effect of protein corona. This review summarizes novel nanomaterials fabricated in research and clinical use, discusses current limitations and obstacles that hinder the translation from research to clinical use, and provides suggestions for more efficient adoption of nanomaterials in cancer therapy.

Nature-Inspired Nanoparticles as Paclitaxel Targeted Carrier for the Treatment of HER2-Positive Breast Cancer

Despite the advances made in the fight against HER2-positive breast cancer, the need for less toxic therapies and strategies that avoid the apparition of resistances is indisputable. For this reason, a targeted nanovehicle for paclitaxel and trastuzumab, used in the first-line treatment of this subtype of breast cancer, had already been developed in a previous study. It yielded good results in vitro but, with the aim of further reducing paclitaxel effective dose and its side effects, a novel drug delivery system was prepared in this work. Thus, polydopamine nanoparticles, which are gaining popularity in cancer nanomedicine, were novelty loaded with paclitaxel and trastuzumab. The effectiveness and selectivity of the nanoparticles obtained were validated in vitro with different HER2-overexpressing tumor and stromal cell lines. These nanoparticles showed more remarkable antitumor activity than the nanosystem previously designed and, in addition, to affect stromal cell viability rate less than the parent drug. Moreover, loaded polydopamine nanoparticles, which notably increased the number of apoptotic HER2-positive breast cancer cells after treatment, also maintained an efficient antineoplastic effect when validated in tumor spheroids. Thereby, these bioinspired nanoparticles charged with both trastuzumab and paclitaxel may represent an excellent approach to improve current HER2-positive breast cancer therapies.

Identification of Prognostic Biomarkers and Molecular Targets Among JAK Family in Breast Cancer

Background

Janus kinases (JAKs) are a family of non-receptor tyrosine kinases involved in multiple malignancies. However, clinical values of JAKs as prognostic markers and potential mechanism as molecular targets in breast invasive carcinoma (BC) are not completely clarified.

Methodology

TIMER, UALCAN and GEPIA were used to assess the expression and methylation levels of JAKs in BC. Kaplan–Meier Plotter, bc-GenExMiner, SurvExpress, TRGAted, MethSurv, and SurvivalMeth were used to assess the multilevel prognostic significance of JAKs in breast cancer patients. And cBioPortal, TIMER, STRING, GeneMANIA, NetworkAnalysis, LinkedOmics, DAVID 6.8, and Metascape were applied for multilayer networks and functional enrichment analyses. Correlations between immune cell infiltrates/their gene markers and JAKs were evaluated by TIMER.

Results

We first explored the expression and methylation level of JAKs in breast cancer and found significantly reduced JAK1 and JAK2 expression at mRNA and protein levels, significantly higher JAK3 protein expression, and significantly increased TYK2 expression at mRNA level but decreased at protein level. In addition, hypermethylation of JAK3 and TYK2 and hypomethylation of JAK1 were found in tumor samples. In terms of prognostic values of JAKs in BC patients, low transcriptional levels of JAK1, JAK2, JAK3, and TYK2 indicated worse OS/DMFS/PPS/RFS/DFS, inferior DFS, worse RFS, and shorter OS/DMFS/RFS, respectively. The mRNA signature analysis showed that high-risk group had unfavorable OS/RFS/MFS. Low JAK2 protein level indicated unfavorable DSS/PFS in BC patients. Five CpGs of JAK1, four CpGs of JAK2, 20 CpGs of JAK3, and 13 CpGs of TYK2 were significantly associated with prognosis in BC patients. The DNA methylation signature analysis also suggested worse prognosis in the high-risk group. For potential biological roles of JAKs, interaction analyses, functional enrichment analyses for biological process, cellular component, molecular function, and KEGG pathway analyses of JAKs and their neighbor genes in BC were conducted. Kinase targets, gene–miRNA interactions, and transcription factor–gene interactions of JAKs were also identified. Furthermore, JAKs were found to be significantly related to immune infiltrates as well as the expression levels of multiple immune markers in BC.

Conclusion

JAKs showed multilevel prognostic value and important biological roles in BC. They might serve as promising prognostic markers and possible targets in breast cancer.