Diterpenoid alkaloids are major pharmaceutically active constituents of Aconitum plants. In phytochemical investigations on Aconitum japonicum subsp. subcuneatum, Aconitum yesoense var. macroyesoens, and Delphinium elatum cv. Pacific Giant (Ranunclaceae), the structures of isolated C19- and C20-diterpenoid alkaloids were elucidated. Three aconitine-type C19-diterpenoid alkaloids, jesaconitine, aconitine, and mesaconitine, which are main components of A. japonicum subsp. subcuneatum, are significantly toxic to the central nervous system. However, lycoctonine-type C19-diterpenoid alkaloids and C20-diterpenoid alkaloids are less toxic. Several diterpenoid alkaloids from the genera Aconitum and Delphinium and their derivatives exhibited slight cytotoxic activity against several human tumor cell lines [A549 (lung carcinoma), DU145 (prostate carcinoma), MDA-MB-231 (triple-negative breast cancer), MCF-7 (estrogen receptor-positive, HER2-negative breast cancer), KB (identical to cervical carcinoma HeLa derived AV-3 cell line), and multidrug-resistant (MDR) subline KB-VIN]. In our course of studies on synthetic derivatives of the C19-diterpenoid alkaloids delcosine and delpheline and the C20-diterpenoid alkaloids lucidusculine, pseudokobusine, and kobusine, we found several derivatives showing significant cytotoxic activity and, thus, providing promising new leads for further development as antitumor agents. Notably, several diterpenoid alkaloids were more potent against MDR subline KB-VIN cells than the parental drug-sensitive KB cells. Among non-cytotoxic synthetic analogues, several lycoctonine-type C19-diterpenoid alkaloid derivatives effectively and significantly sensitized MDR cells to three anticancer drugs, paclitaxel, vincristine, and doxorubicin.

A 76-year-old man with advanced colorectal cancer was started on oral S-1 monotherapy as postoperative chemotherapy. He had dyspnea on exertion, and imaging studies revealed frosted shadows in the bilateral lower lung fields. Transbronchial lung biopsy showed thickening of the alveolar wall, infiltration of inflammatory cells. Based on clinical history and examination results, he was diagnosed interstitial pneumonia with caused by S-1. His respiratory distress on exertion was markedly improved by oral administration of prednisolone(PSL). Thereafter, S-1 medication was not resumed and the patient was followed up on an outpatient basis while the PSL was gradually reduced. According to the S-1 package insert, the frequency of interstitial pneumonia is 0.3%, regardless of the presence or absence of concomitant chemotherapy, so the incidence of S-1 monotherapy is considered to be even lower. In this study, we report a case of colorectal cancer with interstitial pneumonia during monotherapy with S-1, with a review of the literature.

Tumor-specific active drug release from macromolecular antitumor drugs after tumor delivery is critical to achieve efficient cellular uptake of the active drug, thereby ensuring therapeutic efficacy. Upon reaching the tumor tissue, protease-facilitated depegylation of pegylated zinc protoporphyrin with ester bonds between PEG and ZnPP (esPEG-ZnPP) occurs, leading to a faster cellular uptake and superior antitumor efficacy compared to PEG-ZnPP with ether bonds (etPEG-ZnPP). This finding provides a viable strategy for achieving efficient tumor-specific drug release by utilizing an ester linkage between PEG and antitumor drugs. Another strategy involves using styrene-maleic acid copolymer (SMA), an amphiphilic polymer. Drug-encapsulating SMA aggregates disintegrate upon interaction with cell membrane components, releasing the encapsulated active drug. The author has demonstrated an improvement in the tumor accumulation of SMA-based macromolecular drugs by conjugating pirarubicin (THP), an anthracycline antitumor drug, with SMA. Furthermore, by conjugating various molecular weights of N-(2-hydroxypropyl)methacrylamide (HPMA) to THP via a hydrazone bond (P-THP, DP-THP, and SP-THP), the author has established a positive correlation between HPMA molecular weight and therapeutic efficacy as well as toxicity. Notably, P-THPs release THP under acidic conditions within tumor tissue; however, this release occurs solely outside tumor cells due to HPMA-mediated inhibition of cellular uptake. The author is currently developing macromolecular anticancer drugs using albumin for the tumor-targeted release of anticancer agents both intra- and extracellularly. The strategic development of tumor-targeting macromolecular antitumor drugs based on a comprehensive understanding of polymer characteristics and the tumor-specific environment is imperative for effective cancer therapy.

Many anticancer drugs, including anthracycline drugs, pose a risk of cardiovascular damage as an adverse reaction. This can detrimentally impact the prognosis and quality of life of patients, potentially leading to the interruption of cancer chemotherapy and compromising cancer treatment. Recently, onco-cardiology (or cardio-oncology) has developed as a new interdisciplinary field that focuses on the prevention and treatment of cardiovascular toxicity of anticancer drugs. In this review, we explore the mechanism underlying the cardiotoxicity of anthracyclines and examine pharmacological agents that safeguard the heart from anthracycline-induced damage. Anthracycline-induced cardiotoxicity primarily involves oxidative stress, characterized by radical production in mitochondria and subsequent apoptosis in cardiomyocytes. While various antioxidant agents, such as resveratrol, vitamin E, and melatonin have demonstrated efficacy in reducing anthracycline-induced cardiotoxicity in animal models, their clinical effectiveness remains inconclusive. Alternatively, dexrazoxane, an intracellular iron chelator, along with standard heart failure medications, such as β-blockers, angiotensin-converting enzyme inhibitors, and angiotensin II receptor blockers, reduce anthracycline cardiotoxicity and prevent subsequent heart failure in both animal and human studies. Additionally, statins [hydroxymethylglutaryl (HMG)-CoA reductase inhibitors] and ranolazine have emerged as potential candidates for attenuating anthracycline-induced cardiotoxicity in clinical settings. Notably, recent in vitro findings suggest that everolimus, an autophagy/mitophagy-inducing antitumor drug, may protect cardiomyocytes from anthracycline-induced toxicity without reducing the antitumor effects of anthracycline. Although promising, further clinical research is warranted to validate the potential of everolimus as a safer and more effective anthracycline chemotherapeutic strategy.

Currently, a variety of anticancer agents are used in the treatment of cancer. Since anticancer agents are used continuously over a long time, they carry the risk of side effects. One of the major side effects is cardiac dysfunction. For example, doxorubicin, an anthracycline-type anticancer agent, is clinically restricted because of its dose-dependent cardiotoxicity. Cardiotoxicity includes decreased ejection fraction, arrhythmias, and congestive heart failure, all of which are associated with high mortality rates. Therefore, it is important to assess the risk of cardiotoxicity of anticancer agents in advance. Cardiomyocytes require energy to beat and retain an abundance of mitochondria. We established quantitative measurements of mitochondrial length and respiratory activities using cardiomyocytes. We found that exposure of human iPS cell-derived cardiomyocytes (hiPSC-CMs) to anticancer agents with reported cardiotoxicity enhanced mitochondrial hyperfission and the oxygen consumption rate was significantly reduced. Knockdown of dynamin-related protein 1 (Drp1), mitochondrial fission-accelerating GTP-binding protein, suppressed mitochondrial hyperfission in hiPSC-CMs. This indicates that visualizing mitochondrial functions in hiPSC-CMs will be helpful in assessing the risk of cardiotoxicity caused by anticancer agents and that maintaining mitochondrial quality will become a new strategy to reduce anticancer agents-induced cardiotoxicity. In this review, we present the evaluation of cardiotoxicity targeting mitochondrial quality in anticancer agents, using osimertinib, a non-small cell lung cancer drug, as an example.

This is a personal review of my chemistry research on retirement from Teikyo University. Under the guidance of Prof. Masaji Ohno of the Faculty of Pharmaceutical Sciences, The University of Tokyo, my research career started with the synthesis of water-soluble basic natural compounds, including the first artificial bleomycin showing potent molecular-oxygen activation effects and DNA binding abilities. While studying abroad at Eidgenössische Technische Hochschule (ETH) under the guidance of Prof. Albert Eschenmoser, I studied the formation of ribose under prebiotic conditions. The condensation reaction between formaldehyde and glycolaldehyde phosphate produced ribose in far greater yield than the formose reaction. In the School of Pharmacy, Showa University, I conducted research in nucleic acid chemistry to synthesize, for example, anomeric spiro-nucleosides using radical chemistry and oligonucleotides that interacted with the κB motif. After moving to Teikyo University in 1999, I engaged in studies on the synthesis of vitamin D derivatives, included in fat-soluble vitamins, with selective biological activities without calcemic side-effects, and discovered, for example, 2α-(3-hydroxypropyl)-19-nor-1α,25-dihydroxyvitamin D3 (MART-10), which exhibits potent anticancer activity in vivo, 2α-[2-(tetrazol-2-yl)ethyl]-1α,25-dihydroxyvitamin D3 (AH-1), which shows greater bone-forming effects than natural active vitamin D3 in vivo, and the A-ring-converted vitamin D derivative KK-052, which is an in vivo selective inhibitor of sterol regulatory-element binding protein (SREBP), a master transcription factor of lipogenesis, independent of the vitamin D canonical activity through a vitamin D receptor.

L-asparaginase is a key drug in the treatment of acute lymphocytic leukemia/lymphoblastic lymphoma and is currently used in treatment regimens for a wide range of age groups, including children, adolescents, young adults, and older adults. Discontinuation of L-asparaginase leads to worse survival outcomes. Strategies such as appropriate prevention and management of asparaginase-specific adverse events such as hypersensitivity reactions and optimizing administration by therapeutic drug monitoring are important to ensure completion of all asparaginase doses planned in each regimen. Two new L-asparaginase preparations with different properties are now available in Japan, and attempts to leverage these properties for more effective and safe administration are attracting attention. This article reviews previous advances in therapy with L-asparaginase and outlines current and future challenges for maximizing the therapeutic efficacy of L-asparaginase.

The efficacy of antibody-drug conjugates(ADCs)has been well-established in clinical use, prompting ongoing research and development efforts to advance the field of ADCs further. This chapter provides overview of the structure and mechanism of action of ADCs, detailing the roles of its components: the antibody, the payload, and the linker. ADCs leak from cancer vessels to bind to specific antigens on the surface of tumor cells. Upon binding and internalization, the drug is released by metabolic enzymes, such as peptidases in the lysosome. The therapeutic window of the conjugated drug is therefore expanded. To enhance the efficacy of ADCs, the chapter will also explore the development of methodologies for generating homogeneous ADCs and the concept of bystander effects, which are particularly relevant in the tumor microenvironment. Additionally, innovative approaches such as radioimmunotherapy, utilizing alpha-ray emitting radionuclides, and photoimmunotherapy, are discussed as promising next-generation ADC strategies. The integration of ADCs with immunotherapy may offer amplified effectiveness through synergistic actions. The chapter underscores that the prolonged therapeutic impact of ADCs cannot be solely attributed to the targeted delivery and controlled release of the payload. A comprehensive understanding from the perspective of cancer immunology is imperative for elucidating the underlying mechanisms contributing to their sustained efficacy.

Neurological immune-related adverse events (irAEs) associated with cancer treatment with immune checkpoint inhibitors (ICI) present diverse clinical characteristics. Neurological irAEs affect the peripheral nervous system and muscles more than they affect the central nervous system. Among the various subsets of peripheral neuropathies, polyradiculoneuropathy, which includes Guillain-Barre syndrome and chronic inflammatory demyelinating polyneuropathy, stands out as the most severe form, leading to significant muscle weakness. ICIs can induce dysautonomia, including autoimmune autonomic ganglionopathy. Autonomic neuropathy represents a neurological irAE. Neurological irAEs of neuromuscular junctions include myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS). Diagnosing MG or myositis independently can be challenging when they occur as irAEs. Myocarditis is sometimes observed as an irAE in patients with MG and can cause both severe heart failure and lethal arrhythmias, resulting in fatal outcomes. Anti-Kv1.4 antibodies are biomarkers of the severe form of MG and myocarditis. The administration of ICI in patients with small cell lung cancer increases the risk of LEMS. The distinction between LEMS is an irAE or a manifestation of paraneoplastic neurological syndrome is unclear as both conditions share common immunological mechanisms.

Recent advances in cancer therapy have significantly improved the survival rate of patients with cancer. In contrast, anti-cancer drug-induced adverse effects, especially cardiotoxicity, have come to affect patients' prognosis and quality of life. Therefore, there is a growing need to understand the anti-cancer drug-induced cardiotoxicity. Human induced pluripotent stem (iPS) cell-derived cardiomyocytes (hiPSC-CMs) have been used to assess drug-induced cardiotoxicity by improving the predictability of clinical cardiotoxicity and the principles of the 3Rs (replacement, reduction and refinement). To predict the anti-cancer drug-induced cardiotoxicity, we developed a novel method to assess drug-induced proarrhythmia risk using hiPSC-CMs by participating in the international validation. In addition, we established the chronic contractility toxicity assessment by image-based motion analysis. The compound BMS-986094, which was withdrawn from clinical trials, inhibited contractility velocity and relaxation velocity in hiPSC-CMs. Currently, we are trying to investigate the predictability of the contractility assay by comparing the hiPSC-CM data with adverse events reports from real-world database. In this review, we would like to introduce the novel imaging-based contractility method using hiPSC-CMs and future perspectives in anti-cancer drug-induced cardiotoxicity.

Nephrotoxicity is one of the most important complications in cancer patients. In particular, acute kidney injury(AKI)is known to be associated with discontinuing effective oncological treatments, longer hospitalizations and increased costs, a higher risk of death. In addition to AKI, clinical signs associated with nephrotoxicity during anti-cancer agents include chronic kidney disease, proteinuria, hypertension, electrolyte abnormalities, and other characteristic manifestations. It is noted that many of these signs are not only caused by cancer treatment, but also by the cancer itself. Therefore, it is important to carefully recognize whether underlying causes of renal impairment in cancer patients are cancer-related, treatment- related, or both. This review describes the epidemiology and pathophysiology of anti-cancer agents-induced AKI, proteinuria, hypertension, and other characteristic manifestations.

Immune checkpoint inhibitors (ICIs) provide excellent benefits to the treatment of various cancer types, including urothelial carcinoma. Conversely, they can cause immune-related adverse events (irAEs), and some of them are severe or fatal. Furthermore, evidence on the safety and effectiveness of the readministration of ICIs after the occurrence of irAEs is limited. In this case report, a 78-year-old man who suffered from metastatic right renal pelvic cancer was treated with pembrolizumab. He had a partial response to pembrolizumab, but he developed grade 3 myasthenia gravis. The myasthenia gravis symptoms were immediately relieved by corticosteroids and intravenous immunoglobulin therapy. When the disease rapidly progressed, he was treated again with pembrolizumab. After 5 days, a chest radiograph showed shrinkage of pulmonary metastases. Unfortunately, he died of multiple brain infarctions 7 days after the readministration. We report this case with a literature review on the efficacy and safety of the readministration of ICIs after the occurrence irAEs including myasthenia gravis.

In the development of drug delivery system (DDS)-based anticancer drugs, the techniques for the intratumor mapping and quantification of active pharmaceutical ingredients (API) in pharmaceuticals must be pivotal for predicting pharmacological effects and adverse events. X-ray fluorescence spectrometry (XRF) is a potent analytical tool for mapping/quantifying platinum pharmaceutics such as oxaliplatin (l-OHP) and its liposomal formulation. In recent studies, we employed XRF to visualize the intratumor micro-distribution of l-OHP in a tumor-bearing model mouse intravenously injected with either free l-OHP or l-OHP liposomes. The intratumor distribution of l-OHP within tumor sections could be determined by XRF to detect platinum atoms. After treatment with the liposomal formulation, the l-OHP was localized near the tumor vessels and, via repeated injections, increasingly accumulated in tumors by a much greater degree than treatment with free l-OHP. The repeated injections of l-OHP liposomes improved the vascular permeability via inducing the apoptosis of tumor cells near the tumor vessels, which should improve the tumor microenvironment and enhance the intratumor accumulation of repeated doses of l-OHP liposomes. The proposed process was also used to visualize the intratumor distribution of l-OHP in rectal cancer specimens resected from a patient who had received l-OHP-based preoperative chemotherapy. We further revealed that neutralization of an acidic tumor microenvironment via oral administration with NaHCO3 could improve the therapeutic efficacy of weakly basic anticancer agent-encapsulating liposomes. Collectively, mapping/quantifying the intratumor API in DDS drugs and/or improving the tumor microenvironment would be an effective means to accelerate the clinical development of DDS-based anticancer drugs.

This article reviews the clinical features of toxicity in the peripheral and central nervous systems from anticancer drugs, including conventional cytotoxic chemotherapy, biologics, and targeted therapies, and excluding newer immunotherapies (immune checkpoint inhibitors and chimeric antigen receptor T cells). Neurologic complications from chemotherapy can be substantially disabling to patients and are being seen with increasing frequency because patients with cancer therapy are living longer and receiving multiple courses of anticancer regimens with combinations and longer duration. Clinicians, including neurologists, must know treatment-related neurotoxicity since discontinuation of the offending agent or dose adjustment may prevent further or permanent neurologic injury.

Management of chemotherapy-induced adverse effects and the associated pharmaceutical interventions as well as supportive care evidence creation are the most important responsibilities of oncology pharmacists. We have evaluated the (1) efficacy of long-term and successive pharmaceutical care in outpatient chemotherapy and (2) nephroprotective effects of magnesium (Mg) against cisplatin-induced nephrotoxicity (CIN). The results revealed that the adoption rate of pharmaceutical proposals was 98%, and that approximately 70% of the proposals attenuated painful symptoms. Moreover, approximately 60% of pharmaceutical interventions were established after the third visit; in particular, approximately 20% were suggested after the tenth visit. These results have shown that long-term and successive pharmaceutical care by oncology pharmacists in outpatient chemotherapy contributes to a safe and less onerous chemotherapy implementation. CIN frequency and serum creatinine elevation were significantly attenuated by Mg premedication during the cisplatin, docetaxel, and fluorouracil regimen, without changes in adverse effects and response rate. Mg premedication has been suggested to exert a protective effect against CIN without influencing on adverse effects and anti-tumor efficacy. The nephroprotective effect of Mg against CIN was evaluated using Wistar rats. Cisplatin (2.5 mg/kg) was administered once or three times weekly with or without 40 mg/kg MgSO4. The results revealed that Mg regulates the expression of organic cation transporter 2, multidrug and toxin extrusion protein 1, and copper transporter 1, leading to reduced renal platinum accumulation, which results in CIN attenuation. In conclusion, evaluation of pharmaceutical care and supportive care by oncology pharmacists is necessary for advanced care of cancer patients.

Metabolome analysis is an approach to investigate cell characteristics from the metabolites that are constantly produced and changed by those cells. We conducted a metabolome analysis of the response of 786-O renal cell carcinoma (RCC) cells to histone deacetylase (HDAC) inhibitors, which are expected to increase anticancer drug sensitivity, and compared the response with that of drug-resistant cells. Trichostatin A (TSA), an HDAC inhibitor, increased the sensitivity of 786-O cells to sunitinib. Moreover, TCA cycle and nucleotide metabolism of the cells were promoted. The findings that acetylated p53 (active form) and early apoptotic cells were increased suggests that the mechanism involved enhancement of mitochondrial metabolism and function. In addition, established sunitinib-resistant RCC cells were exposed to a combination of sunitinib and TSA, resulting in significant growth inhibition. Principal component analysis revealed that the parent and resistant cells were obviously different, but approximately half their fluctuations were illustrated by the same pathways. In summary, it was suggested that TSA reduced sunitinib resistance by triggering intracellular metabolome shifts in energy metabolism. This was the first recognized mechanism of action of TSA as an HDAC inhibitor.

Ascertaining the absorption, distribution, metabolism, and excretion (ADME) profile of drugs is one of the most crucial factors in the process of drug discovery. Since it is important to combine water solubility and cell permeability within the compound to achieve the desired ADME properties, an appropriate balance between lipophilicity and hydrophilicity is required. It is often necessary to facilitate hydrophilicity of very hydrophobic candidates, because quite lipophobic molecules are rarely hit as positive in molecular-targeted or cell-based screenings. For that purpose, it has been popular to conjugate hydrophobic molecules with polyethylene glycol (PEG). However, PEG is a polymer, and PEG-conjugated molecules are not uniform. Besides, the dosage should be much increased compared with the original molecule due to the increase in molecular weight. Therefore we have been developing alternative ways to endow hydrophobic compounds with extra hydrophilicity by conjugating with symmetrically branched glycerol oligomers. This technology is versatile and easily applicable to various hydrophobic compounds. Water-solubility of fenofibrate, one of the most hydrophobic medicines in clinical use, was facilitated by a factor of more than 2000, and its lipid-lowering effect in vivo improved more than ten-fold, by simply conjugating with branched glycerol trimer, for instance. Here we will briefly introduce the basic concepts and our successful experiences of applying branched glycerol oligomers including antitumor agents in terms of water-solubility, pharmacological effects, and pharmacokinetics, and merits and current issues will be discussed in this review.

Traditionally, anticancer drug discovery research has been conducted based on immortalized cancer cell lines, either cultured in vitro or grown in vivo. In the USA and Europe, patient derived xenograft (PDX) model is rapidly expelling traditional in vitro and in vivo models due to the good predictability of clinical outcome and its nature of retaining characteristics and heterogeneity in the original tumor. Furthermore, a significant association was also reported between drug responses in patient and corresponding PDX as high as 87%. We are preparing a PDX model for Japanese cancer patients including drug resistance examples and rare cancers. Using the established PDX model, we confirmed the possibility that the tumor microenvironment might affect the efficacy and distribution of drugs even if the target receptor is expressed in tumor sites as compared to the cell line (CDX) model, which has been widely used in drug discovery. Interestingly, although expressing a target receptor in viable tumor cells, we also have found a PDX model with a lower distribution of molecular target drug. Therefore we will evaluate the usefulness of the PDX model in drug development by exploring new biomarkers and elucidating the mechanisms of drug resistance in target tumors. Moreover, pharmaco-imaging system will allow us to visualize the exposure and distribution of drugs in tumors at macro and micro levels. Finally, we evaluate relations between distribution of drugs in the tumor microenvironment including target tumor cells, neovessels, stromal cells, immune cells, and fibroblasts.

Pancreatic cancer is the fourth-leading cause of death from cancer in Japan, after lung, colorectal, and stomach cancers and has the lowest survival among these tumors, because of not only no symptoms, no screening tool and no biomarkers but also high rates of recurrence and metastasis. In addition, pancreatic cancer has excessive stroma which serves as a severe biological barrier for anticancer drug delivery and successful treatment. Therefore, there are many challenges for drug delivery systems for the treatment of pancreatic cancer. Recently, we developed self-assembly PEGylation retaining activity (SPRA) technology, which comprises a reversible pegylated protein complex without loss of bioactivity. SPRA technology is based on a host-guest interaction between PEGylated β-cyclodextrin and adamantane-appended protein. In this review, first pancreatic cancer is introduced, second, principle drug delivery systems for the treatment of pancreatic cancer are described, and third the concept of SPRA technology as well as examples of SPRA proteins, especially focusing on the potential of SPRA-bromelain for treatment of pancreatic cancer, are introduced.