Evolution of targeted therapies in cancer: opportunities and challenges in the clinic

Strategies for the Nuclear Delivery of Metal Complexes to Cancer Cells

The nucleus is an essential organelle for the function of cells. It holds most of the genetic material and plays a crucial role in the regulation of cell growth and proliferation. Since many antitumoral therapies target nucleic acids to induce cell death, tumor-specific nuclear drug delivery could potentiate therapeutic effects and prevent potential off-target side effects on healthy tissue. Due to their great structural variety, good biocompatibility, and unique physico-chemical properties, organometallic complexes and other metal-based compounds have sparked great interest as promising anticancer agents. In this review, strategies for specific nuclear delivery of metal complexes are summarized and discussed to highlight crucial parameters to consider for the design of new metal complexes as anticancer drug candidates. Moreover, the existing opportunities and challenges of tumor-specific, nucleus-targeting metal complexes are emphasized to outline some new perspectives and help in the design of new cancer treatments.

Edaravone: A Novel Possible Drug for Cancer Treatment?

Despite significant advancements in understanding the causes and progression of tumors, cancer remains one of the leading causes of death worldwide. In light of advances in cancer therapy, there has been a growing interest in drug repurposing, which involves exploring new uses for medications that are already approved for clinical use. One such medication is edaravone, which is currently used to manage patients with cerebral infarction and amyotrophic lateral sclerosis. Due to its antioxidant and anti-inflammatory properties, edaravone has also been investigated for its potential activities in treating cancer, notably as an anti-proliferative and cytoprotective drug against side effects induced by traditional cancer therapies. This comprehensive review aims to provide updates on the various applications of edaravone in cancer therapy. It explores its potential as a standalone antitumor drug, either used alone or in combination with other medications, as well as its role as an adjuvant to mitigate the side effects of conventional anticancer treatments.

Targeting carcinoma-associated mesothelial cells with antibody-drug conjugates in ovarian carcinomatosis

Ovarian carcinomatosis is characterized by the accumulation of carcinoma-associated mesothelial cells (CAMs) in the peritoneal stroma and mainly originates through a mesothelial-to-mesenchymal transition (MMT) process. MMT has been proposed as a therapeutic target for peritoneal metastasis. Most ovarian cancer (OC) patients present at diagnosis with peritoneal seeding, which makes tumor progression control difficult by MMT modulation. An alternative approach is to use antibody-drug conjugates (ADCs) targeted directly to attack CAMs. This strategy could represent the cornerstone of precision-based medicine for peritoneal carcinomatosis. Here, we performed complete transcriptome analyses of ascitic fluid-isolated CAMs in advanced OC patients with primary-, high-, and low-grade, serous subtypes and following neoadjuvant chemotherapy. Our findings suggest that both cancer biological aggressiveness and chemotherapy-induced tumor mass reduction reflect the MMT-associated changes that take place in the tumor surrounding microenvironment. Accordingly, MMT-related genes, including fibroblast activation protein (FAP), mannose receptor C type 2 (MRC2), interleukin-11 receptor alpha (IL11RA), myristoylated alanine-rich C-kinase substrate (MARCKS), and sulfatase-1 (SULF1), were identified as specific actionable targets in CAMs of OC patients, which is a crucial step in the de novo design of ADCs. These cell surface target receptors were also validated in peritoneal CAMs of colorectal cancer peritoneal implants, indicating that ADC-based treatment could extend to other abdominal tumors that show peritoneal colonization. As proof of concept, a FAP-targeted ADC reduced tumor growth in an OC xenograft mouse model with peritoneal metastasis-associated fibroblasts. In summary, we propose MMT as a potential source of ADC-based therapeutic targets for peritoneal carcinomatosis. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Dietary Antioxidant-Constructed Nanodrugs Can High-Efficiently Kill Cancer Cells while Protecting Noncancer Cells

Despite great advances, the development of cancer drugs that can efficiently kill cancer cells while protecting noncancer cells has not been achieved. By using only dietary antioxidants vitamin C (VC) and (R)-(+)-lipoic acid (LA), we herein develop a nanodrug VC@cLAV featuring the above function. After entering cells, cLAV dissociates into LA and DHLA (dihydrolipoic acid, reduced form of LA) and releases VC and DHA (dehydroascorbate, oxidized form of VC). In cancer cells, the two redox pairs recycle each other and dramatically promote the intracellular reactive oxygen species production to kill cancer cells at low doses comparable to cytotoxic drugs. Oppositely in noncancer cells, the LA/DHLA and VC/DHA pairs exert anti-oxidant action to actively protect the organism by preventing the normal cells from oxidative stress and repairing cells suffering from oxidative stress. When compared with the first-line cytotoxic drug, VC@cLAV displayed superior therapeutic outcomes yet without side effects in diverse tumor models including patient-derived xenograft (PDX). This drug with efficient cancer cell killing and noncancer cell protection represents a new cancer therapy.

Nitroreductase-induced bioorthogonal ligation for prodrug activation: A traceless strategy for cancer-specific imaging and therapy

Prodrug development is of great interest in cancer therapy. From bio-friendly standpoints, traceless prodrug activation would be an ideal approach for cancer treatment owning to the avoidance of byproduct which might induce side effects in living system. Here, we report a fully traceless strategy for cancer imaging and therapy via a metal-free bioorthogonal ligation triggered by nitroreductase (NTR) overexpressed in solid tumors. The reduction of nitro substrates to amines by NTR and further condensation of amines with aldehydes can be seamlessly combined to yield imine-based resveratrol (RSV) with water as the only byproduct. In comparison with RSV, this precursor exhibited not only the same level of anticancer efficiency both in vitro and in vivo under hypoxia, but also a high sensitivity to hypoxia and much lower perturbation towards normal cells, which holds a great potential of theranostic prodrug for cancer therapy.

Small molecules and their impact in drug discovery: A perspective on the occasion of the 125th anniversary of the Bayer Chemical Research Laboratory

The year 2021 marks the 125th anniversary of the Bayer Chemical Research Laboratory in Wuppertal, Germany. A significant number of prominent small-molecule drugs, from aspirin to Xarelto, have emerged from this research site. In this review, we shed light on historic cornerstones of small-molecule drug research, discussing current and future trends in drug discovery as well as providing a personal outlook on the future of drug research with a focus on small molecules.

Oral and Subcutaneous Anticancer Therapy Training Course for Non-physician Healthcare Professionals: a Survey Evaluating the Relevance of its Content and its Implications in the Practice of Cancer Care

The creation of antitumor agents with an oral or subcutaneous route of administration has had important positive implications in the development of drugs to treat cancers, but issues such as false drug intake, uncontrolled side effects, and limited supervision may jeopardize the ability of these agents to improve treatment. A potential solution is the recruitment of non-physician healthcare professionals (i.e., nurses and physician assistants) and a special training course for them that focuses on the improvement of patient compliance. We developed and implemented three special professional training modules for non-physician healthcare professionals, which focus on the pharmacological aspects and side effects of oral and subcutaneous antitumor medications in regard to management strategies and communication issues that these non-physician healthcare professionals should address. Subsequently, we administered a questionnaire survey evaluating the course content and the implementation of the course in practice to the training participants to collect data for its implementation. Of 165 questionnaires that were administered, 44 (27%) were answered. The participants rated the course as being highly useful for their daily work. The participants reported a significant improvement in their professional expertise from the course. They emphasized the importance of medical topics and practical content to be included in the course delivery. The course encouraged 75% of the responders to start independent consultations with cancer patients that focused on questions of medication adherence for oral and subcutaneous antitumor medications, as well as the management of their side effects. Based on our results, at least a portion of the non-physician healthcare workforce is highly interested in engaging in active and autonomous co-supervision of patients who are treated with oral and subcutaneous antitumor medications. In addition to the theoretical basics of the treatment modalities, educational courses on oral and subcutaneous antitumor medications for non-physician healthcare professionals should focus on practical training and topics relevant to patient care.

Personalized Neoantigen-Pulsed DC Vaccines: Advances in Clinical Applications

In the past few decades, great progress has been made in the clinical application of dendritic cell (DC) vaccines loaded with personalized neoantigens. Personalized neoantigens are antigens arising from somatic mutations in cancers, with specificity to each patient. DC vaccines work based on the fundamental characteristics of DCs, which are professional antigen-presenting cells (APCs), responsible for the uptake, processing, and presentation of antigens to T cells to activate immune responses. Neoantigens can exert their antitumor effects only after they are taken up by APCs and presented to T cells. In recent years, neoantigen-based personalized tumor therapeutic vaccines have proven to be safe, immunogenic and feasible treatment strategies in patients with melanoma and glioblastoma that provide new hope in the treatment of cancer patients and a new approach to cure cancer. In addition, according to ClinicalTrials.gov, hundreds of registered DC vaccine trials are either completed or ongoing worldwide, of which 9 are in early phase I, 191 in phase I, 166 in phase II and 8 in phase III. Hundreds of clinical studies on therapeutic tumor vaccines globally have proven that DC vaccines are stable, reliable and very safe. However, in this process, many other factors still limit the effectiveness of the vaccine. This review will focus on the current research progress on personalized neoantigen-pulsed DC vaccines, their limitations and future research directions of DC vaccines loaded with neoantigens. This review aims to provide a better understanding of DCs biology and manipulation of activated DCs for DCs researchers to produce the next generation of highly efficient cancer vaccines for patients.

Parathyroid hormone related protein (PTHrP)-mediated hypercalcemia in malignancy associated with anti-PD-1 immune checkpoint inhibitor treatment and related inflammatory reactions

Over the last decade, the breakthrough of immune checkpoint inhibitors has revolutionized cancer therapeutics, an enterprise not devoid of a novel constellation of unique immune-related adverse events. In this article, we present the first two patients, one with metastatic urothelial bladder cancer and another one with inoperable non-small squamous cell lung carcinoma, with immune-related parathyroid hormone related protein (PTHrP)-mediated hypercalcemia concurrent with immune-related pneumonitis following administration of anti-PD-1 monoclonal antibody nivolumab. The second patient present immune-related colitis as well. In both patients the hypercalcemia developed when cancer was in remission, rendering unlikely the diagnosis of humoral hypercalcemia of malignancy. The time of onset of PTHrP-mediated hypercalcemia-11 weeks and 15 weeks after initiation of nivolumab for the first and second patient respectively- insinuated the immune-related origin of PTHrP. The concurrent immune-related pneumonitis raised the question of whether the immune-related inflammatory milieu in the context of pneumonitis could be the source of the immune-related PTHrP. In conclusion, increased awareness of nivolumab-related hypercalcemia -an extremely rare immune-related adverse event- could enable the identification of immune-related elevation of PTHrP. Moreover, our cases provide the rationale for further research in pursuit of not only the source of immune-related PTHrP expression, but also of a causative link connecting the inflammatory milieu of immune-related pneumonitis and/or immune-related colitis with PTHrP-mediated hypercalcemia. Finally, the correlation of immune-related adverse events observed herein with response to nivolumab is in line with previous reports, necessitating further consolidation.

Personalization of prostate cancer therapy through phosphoproteomics

Castration-resistant prostate cancer (CRPC) remains incurable despite the approval of several new treatments. Identification of new biomarkers and therapeutic targets to enable personalization of CRPC therapy, with the aim of maximizing therapeutic responses and minimizing toxicity in patients, is urgently needed. Prostate cancer progression and therapeutic resistance are frequently driven by aberrantly activated kinase signalling pathways that are amenable to pharmacological inhibition. Personalized phosphoproteomics, which enables the analysis of signalling networks in individual tumours, is a promising approach to advance personalized therapy by discovering biomarkers of pathway activity and clinically actionable targets. Several technologies for global and targeted phosphoproteomic analysis exist, each with its own strengths and shortcomings. Global discovery phosphoproteomics is predominantly conducted using liquid chromatography-tandem mass spectrometry coupled with data-dependent or data-independent acquisition technologies. Multiplexed targeted phosphoproteomics can be divided into platforms based on mass spectrometry or antibodies, including selected or parallel reaction monitoring and triggered by offset, multiplexed, accurate mass, high-resolution, absolute quantification (known as TOMAHAQ) or forward-phase or reverse-phase protein arrays, respectively. Several obstacles still need to be overcome before the full potential of phosphoproteomics can be realized in routine clinical practice, but a future phosphoproteomics-centric trans-omic profiling approach should enable optimized personalized CRPC management through improved biomarkers and targeted treatments.

Genetic Interaction-Based Biomarkers Identification for Drug Resistance and Sensitivity in Cancer Cells

Cancer cells generally harbor hundreds of alterations in the cancer genomes and act as crucial factors in the development and progression of cancer. Gene alterations in the cancer genome form genetic interactions, which affect the response of patients to drugs. We developed an algorithm that mines copy number alteration and whole-exome mutation profiles from The Cancer Genome Atlas (TCGA), as well as functional screen data generated to identify potential genetic interactions for specific cancer types. As a result, 4,529 synthetic viability (SV) interactions and 10,637 synthetic lethality (SL) interactions were detected. The pharmacogenomic datasets revealed that SV interactions induced drug resistance in cancer cells and that SL interactions mediated drug sensitivity in cancer cells. Deletions of HDAC1 and DVL1, both of which participate in the Notch signaling pathway, had an SV effect in cancer cells, and deletion of DVL1 induced resistance to HDAC1 inhibitors in cancer cells. In addition, patients with low expression of both HDAC1 and DVL1 had poor prognosis. Finally, by integrating current reported genetic interactions from other studies, the Cancer Genetic Interaction database (CGIdb) (http://www.medsysbio.org/CGIdb) was constructed, providing a convenient retrieval for genetic interactions in cancer.

Development and validation of a bioanalytical method for the quantification of the CDK4/6 inhibitors abemaciclib, palbociclib, and ribociclib in human and mouse matrices using liquid chromatography-tandem mass spectrometry

A novel method was developed and validated for the quantification of the three approved CDK4/6 inhibitors (abemaciclib, palbociclib, and ribociclib) in both human and mouse plasma and mouse tissue homogenates (liver, kidney, spleen, brain, and small intestine) using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). For all matrices, pretreatment was performed using 50 μL of sample by protein precipitation with acetonitrile, followed by dilution of the supernatant. Chromatographic separation of the analytes was done on a C18 column using gradient elution. A full validation was performed for human plasma, while a partial validation was executed for mouse plasma and mouse tissue homogenates. The method was linear in the calibration range from 2 to 200 ng/mL, with a correlation coefficient (r) ≥0.996 for each analyte. For both human and mouse plasma, the accuracy and precision were within ±15% and ≤15%, respectively, for all concentrations, except for the lower limit of quantification, where they were within ±20% and ≤20%, respectively. A fit-for-purpose strategy was followed for tissue homogenates, and the accuracy and precision were within ±20% and ≤20%, respectively, for all concentrations. Stability of all analytes in all matrices at different processing and storage conditions was tested; ribociclib and palbociclib were unstable in most tissue homogenates and conditions were modified to increase the stability. The method was successfully applied for the analysis of mouse samples from preclinical studies. A new ribociclib metabolite was detected in mouse plasma samples with the same m/z transition as the parent drug.

Prodrugs for targeted cancer therapy

Introduction: Prodrugs have been used to improve the selectivity and efficacy of cancer therapy by targeting unique abnormal markers that are overexpressed by cancer cells and are absent in normal tissues. In this context, different strategies have been exploited and new ones are being developed each year. Areas covered: In this review, an integrated view of the potential use of prodrugs in targeted cancer therapy is provided. Passive and active strategies are discussed in light of the advantages of each one and some successful examples are provided, as well as the clinical status of several prodrugs. Among them, antibody-drug conjugates (ADCs) are the most commonly used. However, several drawbacks, including limited prodrug uptake, poor pharmacokinetics, immunogenicity problems, difficulties in selective targeting and gene expression, and optimized bystander effects limit their clinical applications. Expert opinion: Despite the efforts of different companies and research groups, several drawbacks, such as the lack of relevant in vivo models, complexity of the human metabolism, and economic limitations, have hampered the development of new prodrugs for targeted cancer therapy. As a result, we believe that the combination of prodrugs with cancer nanotechnology and other newly developed approaches, such as aptamer-conjugated nanomaterials, are efficient strategies.

A Microwell-Assisted Multiaptamer Immunomagnetic Platform for Capture and Genetic Analysis of Circulating Tumor Cells

Detection of circulating tumor cells (CTCs) in peripheral blood is of paramount significance for cancer diagnosis, progress evaluation, and individualized therapy. However, the rareness and heterogeneity of CTCs introduces significant challenges in the capture of cancer cells as well as downstream genetic analysis. In this work, a microwell-assisted multiaptamer immunomagnetic platform (MMAIP) is proposed for highly efficient capture of CTCs with minimum influence of heterogeneity. Assisted by a microwell chip, the purity of CTCs is greatly improved, thus meeting the requirement of downstream gene analysis. This is, as far as is known, the first aptamer based platform enabling mutation analysis of the captured CTCs from cancer patients, which will contribute to the practical application of aptamers in clinics.

Valvular heart disease as a possible predictor of trastuzumab-induced cardiotoxicity in patients with breast cancer

Although the use of trastuzumab has been reported to improve overall survival in patients with HER2-positive breast cancer, there is increasing concern about the adverse effects of trastuzumab-induced cardiotoxicity (TIC). The aim of the present study was to investigate the predictor of TIC and to consider appropriate management for such patients. The present study breast cancer 119 patients with breast cancer who had been treated with trastuzumab. Patients were referred to our department for cardiac function screening. The patients' baseline characteristics, echocardiographic data, presence of trastuzumab-induced cardiotoxicity (TIC) and all-cause mortality were investigated. TIC was defined as a manifestation of overt heart failure or ≥10% reduction of left ventricular ejection fraction (LVEF) from baseline to an LVEF <55% in asymptomatic patients. During the follow-up period (mean, 1,410 days), symptomatic heart failure occurred in 2 out of 119 patients (1.6%), 11 patients (9.2%) had asymptomatic impairment of cardiac function that was ameliorated by discontinuing trastuzumab and 20 patients (16.8%) succumbed to cancer-associated fatality. In the logistic regression analysis, only the presence of valvular heart disease at the baseline was indicated to be a predictor of TIC. There was no other predictor for TIC, including baseline characteristics, other therapies and echocardiographic parameters. In addition, impairment of cardiac function was ameliorated by discontinuing trastuzumab. TIC occurred in ~10% of the patients treated with trastuzumab. Only the presence of valvular heart disease seems to be associated with occurrence of TIC, with no other specific predictor of TIC demonstrated in the present study. The present data suggests the importance of regular monitoring of cardiac function, and that presence of valvular heart disease may be a possible predictor of TIC.

Synthesis and Evaluation of 131I-Skyrin as a Necrosis Avid Agent for Potential Targeted Radionuclide Therapy of Solid Tumors

An innovative anticancer approach targeted to necrotic tissues, which serves as a noncancerous and generic anchor, may present a breakthrough. Necrosis avid agents with a flat conjugate aromatic structure selectively accumulate in necrotic tissues, but they easily form aggregates that undesirably distribute to normal tissues. In this study, skyrin, a dianthraquinone compound with smaller and distorted π-cores and thus decreased aggregates as compared with hypericin (Hyp), was designed to target necrosis for tumor therapy. Aggregation studies of skyrin by UV/vis spectroscopy showed a smaller self-association constant with skyrin than with Hyp. Skyrin was labeled by iodine-131 with a radiochemical purity of 98% and exhibited good stability in rat serum for 72 h. In vitro cell uptake studies showed significant difference in the uptake of ¹³¹I-skyrin by necrotic cells compared to normal cells (P < 0.05). Compared in rats with liver and muscle necrosis, radiobiodistribution, whole-body autoradiography, and SPECT/CT studies revealed higher accumulation of ¹³¹I-skyrin in necrotic liver and muscle (p < 0.05), but lower uptake in normal organs, relative to that of ¹³¹I-Hyp. In mice bearing H22 tumor xenografts treated with combretastatin A4 disodium phosphate, the highest uptake of ¹³¹I-skyrin was found in necrotic tumor. In conclusion, ¹³¹I-skyrin appears a promising agent with reduced accumulation in nontarget organs for targeted radionuclide therapy of solid tumors.

Natural products as probes in pharmaceutical research

From the start of the pharmaceutical research natural products played a key role in drug discovery and development. Over time many discoveries of fundamental new biology were triggered by the unique biological activity of natural products. Unprecedented chemical structures, novel chemotypes, often pave the way to investigate new biology and to explore new pathways and targets. This review summarizes the recent results in the area with a focus on research done in the laboratories of Novartis Institutes for BioMedical Research. We aim to put the technological advances in target identification techniques in the context to the current revival of phenotypic screening and the increasingly complex biological questions related to drug discovery.