Irinotecan-Still an Important Player in Cancer Chemotherapy: A Comprehensive Overview

Efficacy and safety of Shengjiang Xiexin decoction on irinotecan-induced diarrhea in small cell lung cancer patients: a multicenter, randomized, double-blind, placebo-controlled trial

BACKGROUND

Irinotecan is a standard chemotherapeutic agent in small cell lung cancer (SCLC), however, as a common adverse reaction, diarrhea limits the use of irinotecan. Shengjiang Xiexin decoction (SXD) has been used in various gastrointestinal diseases in China two thousand years ago. We designed this clinical trial to supply more evidences on the use of SXD as prophylaxis for irinotecan-induced diarrhea, especially for high-risk population predicted by gene testing of uridine diphosphate glucuronosyl transferase 1A1 (UGT1A1).

METHODS

In this clinical trial, 120 patients with SCLC were recruited from six hospitals in China. They received two cycles of chemotherapy, meanwhile they were randomized to receive SXD or placebo for 14 days of oral administration in each cycle of chemotherapy. The primary outcome is the incidence of diarrhea. And secondary outcomes include the the degree of diarrhea and neutropenia, the number of chemotherapy cycles with diarrhea, first occurrence time and duration of diarrhea. To evaluate the effect of SXD on the intestine, a rat model with delayed-onset diarrhea induced by irinotecan was established, and the expression of inflammatory factors including IL-1β, IL-6 and TNF-α, anti-inflammatory factors including IL-10, TGF- β in jejunal tissue was detected by ELISA.

RESULTS

101 patients (53 in SXD group, 48 in placebo group) completed the trial. The incidence of diarrhea in SXD group and placebo group were 26.42% (14/53) and 52.08% (25/48), respectively (P < 0.05), and the degree of diarrhea also had significant differences (P < 0.05). In UGT1A1 high-risk population, the incidence of diarrhea in two groups were 9.09% and 66.67% (P < 0.05), but there was no significant differences in UGT1A1 low-risk population. The incidence of neutropenia with degree 1-3 between two groups was 20.75% vs 20.83%, 13.21% vs 18.57%, 9.43% vs 20.83% (P < 0.05). No severe adverse events were reported in any group. And animal studies had shown SXD reduced content of IL-1β, IL-6, TNF-α, increased content of IL-10, TGF-β in jejunum tissue.

CONCLUSIONS

SXD had a prophylactic effect in the diarrhea induced by irinotecan, especially for UGT1A1 high-risk population, and this effect from SXD appeared to be maintained the completion of chemotherapy schedule. The mechanism of action of SXD was related to the regulation of inflammatory factors. Trial registration Chinese Clinical Trial Register: ChiCTR1800018490. Registered on 20 September 2018. https://www.chictr.org.cn/showproj.html?proj=25250 . The preliminary protocol of this clinical study has been published in the journal "Trials" in the form of protocol before this paper (Deng et al. in Trials 21:370, 2020).

Investigating the therapeutic promise of drug-repurposed-loaded nanocarriers: A pioneering strategy in advancing colorectal cancer treatment

Globally, colorectal cancer is a major health problem that ranks in third place in terms of occurrence and second in terms of mortality worldwide. New cases increase annually, with the absence of effective therapies, especially for metastatic colorectal cancer, emphasizing the need for novel therapeutic approaches. Although conventional treatments are commonly used in oncotherapy, their success rate is low, which leads to the exploration of novel technologies. Recent efforts have focused on developing safe and efficient cancer nanocarriers. With their nanoscale properties, nanocarriers have the potential to utilize internal metabolic modifications amid cancer and healthy cells. Drug repurposing is an emerging strategy in cancer management as it is a faster, cheaper, and safer method than conventional drug development. However, most repurposed drugs are characterized by low-key pharmacokinetic characteristics, such as poor aqueous solubility, permeability, retention, and bioavailability. Nanoparticles formulations and delivery have expanded over the past few decades, creating opportunities for drug repurposing and promises as an advanced cancer modality. This review provides a concise and updated overview of colorectal cancer treatment regimens and their therapeutic limitations. Furthermore, the chemotherapeutic effect of various FDA-approved medications, including statins, non-steroidal anti-inflammatory drugs, antidiabetic and anthelmintic agents, and their significance in colorectal cancer management. Along with the role of various nanocarrier systems in achieving the desired therapeutic outcomes of employing these redefined drugs.

Magnetic lipid-poly(lactic-co-glycolic acid) nanoparticles conjugated with epidermal growth factor receptor antibody for dual-targeted delivery of CPT-11

To entrap sparingly water-soluble drugs like CPT-11 (irinotecan), the poly(lactic-co-glycolic acid) (PLGA) nanoparticle (NP) is highly favored due to its low cytotoxicity and approval for clinical use. On the other hand, entrapping hydrophobic oleic acid-coated iron oxide magnetic nanoparticles (OMNP) in PLGA NP can provide a nanovehicle for magnetically targeted drug delivery. Our goal in this study is to develop a new dual-targeted magnetic lipid-polymer NP for the delivery of CPT-11. We first co-entrap OMNP and CPT-11 in self-assembled lipid-PLGA NP to prepare OLNP@CPT-11. The OLNP@CPT-11 surface was modified with an epidermal growth factor receptor (EGFR) antibody Cetuximab (CET), which can actively target the overexpressed EGFR on the U87 glioblastoma cell surface. The OLNP-CET@CPT-11 enables dual targeting through both external magnetic guidance and CET-mediated active targeting. The NP was characterized for physicochemical properties using various analytical techniques. In vitro study confirms ligand-receptor interaction results in enhanced endocytosis of OLNP-CET@CPT-11 by U87 cells, which offers increased cytotoxicity and elevated cell apoptosis rates. Furthermore, magnetic guidance of OLNP-CET@CPT-11 to U87 cells can induce cell death exclusively in the magnetically targeted zone. The dual-targeted strategy also provides the best therapeutic efficacy against subcutaneously implanted U87 tumors in nude mice with intravenously delivered OLNP-CET@CPT-11.

Evaluating the impact of loperamide on irinotecan-induced adverse events: a disproportionality analysis of data from the World Health Organization pharmacovigilance database (VigiBase)

PURPOSE

SN-38, the active metabolite of irinotecan, may cause adverse events necessitating treatment discontinuation and management. Diarrhea, which is treated with loperamide, is one such event. However, loperamide may delay SN-38 elimination, causing more adverse events. Therefore, understanding the adverse events caused by symptomatic drugs is crucial for safe drug therapy. This study aimed to assess the association between loperamide and irinotecan-induced adverse events.

METHODS

We analyzed data up to December 2022 from VigiBase, the World Health Organization's adverse event database. The study used reporting odds ratios (RORs) to evaluate the associations between concomitant medications and irinotecan-induced adverse events. Fisher's exact probability test was used to analyze the adverse events. Logistic regression analysis was performed to identify associated adverse event signals.

RESULTS

Of the 32,520,983 cases analyzed, 57,454 involved the use of irinotecan. Among these, 1589 (2.8%) patients were co-treated with loperamide. Signals for neutropenia (ROR 1.37, 95% confidence interval (CI) 1.20-1.57, p < 0.001), anemia (ROR 1.81, 95% CI 1.43-2.30, p < 0.001), and alopecia (ROR 1.89, 95% CI 1.30-2.74, p < 0.01) were detected with concomitant loperamide. Multivariate logistic regression analysis confirmed that concomitant loperamide use was associated with signals for neutropenia, anemia, and alopecia.

CONCLUSION

Our results suggest that loperamide increases the risk of irinotecan-induced adverse events and enhances irinotecan toxicity. The study methodology may be useful for predicting adverse event risk when choosing symptomatic therapy drugs during irinotecan use.

Semisynthetic phytochemicals in cancer treatment: a medicinal chemistry perspective

Cancer is the uncontrolled proliferation of abnormal cells that invade other areas, spread to other organs, and cause metastases, which is the most common cause of death. A review of all FDA-approved new molecular entities (NMEs) shows that natural products and derivatives account for over one-third of all NMEs. Before 1940, unmodified products and derivatives accounted for 43% and 14% of NME registrations, respectively. Since then, the share of unmodified products has decreased to 9.5% of all approved NMEs, while the share of derivatives has increased to 28%. Since the 1940s, semi-synthetic and synthetic derivatives of natural substances have gained importance, and this trend continues to date. In this study, we have discussed in detail isolated phytoconstituents with chemical modifications that are either FDA-approved or under clinical trials, such as podophyllotoxin, Taxol (paclitaxel, docetaxel), vinca alkaloids (vincristine, vinblastine), camptothecin, genistein, cephalotaxine, rohitukine, and many more, which may act as essential leads to the development of novel anticancer agents. Furthermore, we have also discussed recent developments in the most potent semisynthetic phytoconstituents, their unique properties, and their importance in cancer treatment.

Unraveling the pathogenesis of myelosuppression and therapeutic potential of natural products

BACKGROUND

Myelosuppression is a serious and common complication of radiotherapy and chemotherapy in cancer patients and is characterized by a reduction of peripheral blood cells. This condition not only compromises the efficacy of treatment but also increases the risk of patient death. Natural products are emerging as promising adjuvant therapies due to their antioxidant properties, ability to modulate immune responses, and capacity to stimulate haematopoietic stem cell proliferation. These therapies demonstrate significant potential in ameliorating myelosuppression.

METHODS

A systematic review of the literature was performed utilizing the search terms "natural products," "traditional Chinese medicine," and "myelosuppression" across prominent databases, including Google Scholar, PubMed, and Web of Science. All pertinent literature was meticulously analysed and summarized. The objective of this study was to perform a pertinent analysis to elucidate the mechanisms underlying myelosuppression and to categorize and synthesize information on natural products and traditional Chinese medicines employed for the therapeutic management of myelosuppression.

RESULTS

Myelosuppression resulting from drug and radiation exposure, viral infections, and exosomes is characterized by multiple underlying mechanisms involving immune factors, target genes, and the activation of diverse signalling pathways, including the (TGF-β)/Smad pathway. Recently, traditional Chinese medicine monomers and compounds, including more than twenty natural products, such as Astragalus and Angelica, have shown promising potential as therapeutics for ameliorating myelosuppression. These natural products exert their effects by modulating haematopoietic stem cells, immune factors, and critical signalling pathways.

CONCLUSIONS

Understanding the various mechanisms of myelosuppression facilitates the exploration of natural product therapies and biological target identification for evaluating herbal medicine efficacy. This study aimed to establish a foundation for the clinical application of natural products and provide methodologies and technical support for exploring additional treatments for myelosuppression.

Phase 2 dose-ranging study to evaluate the efficacy and safety of liposomal irinotecan (LY01610) as a second-line treatment for patients with relapsed small cell lung cancer

Background

This was a multicenter, single-arm dose-ranging phase 2 study aimed to assess the efficacy and safety of LY01610, a liposomal irinotecan, at various doses for patients with relapsed small cell lung cancer (SCLC).

Methods

This study (NCT04381910) enrolled patients with relapsed SCLC at 10 hospitals across China, who have failed with previous platinum-based treatments. LY01610 was administered at doses of 60 mg/m2, 80 mg/m2, and 100 mg/m2. Primary endpoints were investigator-assessed objective response rate (ORR) and investigator-assessed duration of response (DoR). Secondary endpoints included investigator-assessed disease control rate (DCR), investigator-assessed progression-free survival (PFS), overall survival (OS), and safety.

Findings

From September 3, 2020 to March 3, 2022, a total of 66 patients were enrolled, with 6, 30, and 30 allocated to the 60 mg/m2, 80 mg/m2, and 100 mg/m2 dose groups, respectively, with 68% (45/66) having a chemotherapy-free interval <90 days. In all 66 patients, the ORR was 32% (21/66, 95% confidence interval [CI], 21-44), with a median DoR of 5.2 months (95% CI, 3.0-8.3). Median PFS and OS were 4.0 (95% CI, 2.9-5.5) and 9.7 (95% CI, 7.2-12.3) months, respectively. The ORR of 60 mg/m2, 80 mg/m2, and 100 mg/m2 dose group were 33% (2/6), 33% (10/30), and 30% (9/30), respectively. The median DoR of 60 mg/m2, 80 mg/m2, and 100 mg/m2 dose group were 4.2 (95% CI, 2.8-not reached), 6.9 (95% CI, 2.5-9.9), and 4.0 (95% CI, 2.7-6.8) months, respectively. The incidence of ≥ grade 3 treatment-related adverse events (TRAEs) in the 60 mg/m2, 80 mg/m2, and 100 mg/m2 dose group were 33% (2/6), 47% (14/30), and 50% (15/30), respectively. The most common ≥ grade 3 TRAEs of all 66 patients were neutropenia (27%), leukopenia (24%) and anemia (15%).

Interpretation

LY01610 exhibited promising clinical efficacy and manageable safety profiles in patients with relapsed SCLC, the 80 mg/m2 dose group had the best benefit-risk ratio.

Funding

This study was supported by Luye Pharma Group Ltd.

Vitamins and fatty acids against chemotherapy-induced intestinal mucositis

Chemotherapy has allowed an increase in cancer survivorship, but it causes important adverse effects. Mucositis affecting the gastrointestinal tract is one of the main problems acutely caused by many antineoplastic drugs, such as 5-fluorouracil or methotrexate. Mucositis may cause pain, diarrhea, anorexia, weight loss, systemic infections and even death. This narrative review focuses on intestinal mucositis and the role that some nutraceuticals, namely vitamins (both lipid- and water-soluble) as well as fatty acids (FAs) and lipid-based products, can have in it. In preclinical (cell cultures, animal models) and/or human studies, vitamins A, D, E, B2, B9 and C, omega-3 long-chain FAs (eicosapentaenoic, docosahexaenoic, conjugated linoleic acid), short-chain FAs (mainly butyrate), medium-chain FAs (capric acid), and different lipid-based products (emu oil, extra-virgin olive oil, lipid replacement therapy), enriched in beneficial FAs and natural antioxidants, were shown to exert beneficial effects (both preventative and palliative) against chemotherapy-induced intestinal mucositis. Although the exact mechanisms of action involved in these effects are not yet well known, our review highlights the interest of investigating on diet and nutrition to implement scientifically robust strategies to improve protection of cancer patients against chemotherapy-induced adverse effects.

Harnessing the therapeutic potential of phytochemicals in neuroblastoma

Neuroblastomas are the most common solid tumors outside of the brain that originate from immature neural crest cells, accounting for about 10% of all pediatric malignancies. The treatment for neuroblastomas involves a multimodal schedule, including surgery, radiation, chemotherapy, and immunotherapy. All these modalities are limited by side effects that might be severe, poor prognosis, and a high risk of recurrence. In the quest for additional therapeutic approaches, phytochemicals have attracted attention owing to their reported antitumor properties, safety, and multimechanistic mode of action. Several studies have used plant-derived bioactive compounds such as phenolics and flavonoids, suggesting modulation of biomolecules and signal transduction pathways involved in neuroblastoma. We reviewed the findings of recent preclinical and clinical studies demonstrating the effects of phytochemicals on neuroblastoma, shedding light on their molecular mechanism of action and potential therapeutic applications.

Discovery of Indolo[3,2-c]isoquinoline Derivatives as Novel Top1/2 Dual Inhibitors with Orally Efficacious Antitumor Activity and Low Toxicity

Topoisomerase (Top) inhibitors used in clinical cancer treatments are limited because of their toxicity and severe side effects. Noteworthily, Top1/2 dual inhibitors overcome the compensatory effect between Top1 and 2 inhibitors to exhibit stronger antitumor efficacies. In this study, a series of indolo[3,2-c]isoquinoline derivatives were designed as Top1/2 dual inhibitors possessing apparent antiproliferative activities. Mechanistic studies indicated that the optimal compounds 23 and 31 with increasing reactive oxygen species levels damage DNA, inducing both cancer cell apoptosis and cycle arrest. Importantly, the results of the toxicity studies showed that compounds 23 and 31 possessed good oral safety profiles. In xenograft models, compound 23 exhibited remarkable antitumor potency, which was superior to the clinical Top inhibitors irinotecan and etoposide. Overall, this work highlights the therapeutic potential and safety profile of compound 23 as a Top1/2 dual inhibitor in tumor therapy and provides valuable lead compounds for further development of Top inhibitors.

Chemical Isotope Labeling and Dual-Filtering Strategy for Comprehensive Profiling of Urinary Glucuronide Conjugates

Glucuronidation, a crucial process in phase II metabolism, plays a vital role in the detoxification and elimination of endogenous substances and xenobiotics. A comprehensive and confident profiling of glucuronate-conjugated metabolites is imperative to understanding their roles in physiological and pathological processes. In this study, a chemical isotope labeling and dual-filtering strategy was developed for global profiling of glucuronide metabolites in biological samples. N,N-Dimethyl ethylenediamine (DMED-d0) and its deuterated counterpart DMED-d6 were used to label carboxylic acids through an amidation reaction. First, carboxyl-containing compounds were extracted based on a characteristic mass difference (Δm/z, 6.037 Da) observed in MS between light- and heavy-labeled metabolites (filter I). Subsequently, within the pool of carboxyl-containing compounds, glucuronides were identified using two pairs of diagnostic ions (m/z 247.1294/253.1665 and 229.1188/235.1559 for DMED-d0/DMED-d6-labeled glucuronides) originating from the fragmentation of the derivatized glucuronic acid group in MS/MS (filter II). Compared with non-derivatization, DEMD labeling significantly enhanced the detection sensitivity of glucuronides, as evidenced by a 3- to 55-fold decrease in limits of detection for representative standards. The strategy was applied to profiling glucuronide metabolites in urine samples from colorectal cancer (CRC) patients. A total of 685 features were screened as potential glucuronides, among which 181 were annotated, mainly including glucuronides derived from lipids, organic oxygen, and phenylpropanoids. Enzymatic biosynthesis was employed to accurately identify unknown glucuronides without standards, demonstrating the reliability of the dual-filtering strategy. Our strategy exhibits great potential for profiling the glucuronide metabolome with high coverage and confidence to reveal changes in CRC and other diseases.

Obesity-Associated Colorectal Cancer

Colorectal cancer (CRC) affects approximately 2 million people worldwide. Obesity is the major risk factor for CRC. In addition, obesity contributes to a chronic inflammatory stage that enhances tumor progression through the secretion of proinflammatory cytokines. In addition to an increased inflammatory response, obesity-associated cancer presents accrued molecular factors related to cancer characteristics, such as genome instability, sustained cell proliferation, telomere dysfunctions, angiogenesis, and microbial alteration, among others. Despite the evidence accumulated over the last few years, the treatments for obesity-associated CRC do not differ from the CRC treatments in normal-weight individuals. In this review, we summarize the current knowledge on obesity-associated cancer, including its epidemiology, risk factors, molecular factors, and current treatments. Finally, we enumerate possible new therapeutic targets that may improve the conditions of obese CRC patients. Obesity is key for the development of CRC, and treatments resulting in the reversal of obesity should be considered as a strategy for improving antineoplastic CRC therapies.

Cannabinoids and triple-negative breast cancer treatment

Triple-negative breast cancer (TNBC) accounts for about 10-20% of all breast cancer cases and is associated with an unfavorable prognosis. Until recently, treatment options for TNBC were limited to chemotherapy. A new successful systemic treatment is immunotherapy with immune checkpoint inhibitors, but new tumor-specific biomarkers are needed to improve patient outcomes. Cannabinoids show antitumor activity in most preclinical studies in TNBC models and do not appear to have adverse effects on chemotherapy. Clinical data are needed to evaluate efficacy and safety in humans. Importantly, the endocannabinoid system is linked to the immune system and immunosuppression. Therefore, cannabinoid receptors could be a potential biomarker for immune checkpoint inhibitor therapy or a novel mechanism to reverse resistance to immunotherapy. In this article, we provide an overview of the currently available information on how cannabinoids may influence standard therapy in TNBC.

Selected phytocannabinoids inhibit SN-38- and cytokine-evoked increases in epithelial permeability and improve intestinal barrier function in vitro

Irinotecan use is linked to the development of gastrointestinal toxicity and inflammation, or gastrointestinal mucositis. Selected phytocannabinoids have been ascribed anti-inflammatory effects in models of gastrointestinal inflammation, associated with maintaining epithelial barrier function. We characterised the mucoprotective capacity of the phytocannabinoids: cannabidiol, cannabigerol, cannabichromene and cannabidivarin in a cell-based model of intestinal epithelial stress occurring in mucositis. Transepithelial electrical resistance (TEER) was measured to determine changes in epithelial permeability in the presence of SN-38 (5 μM) or the pro-inflammatory cytokines TNFα and IL-1β (each at 100 ng/mL), alone or with concomitant treatment with each of the phytocannabinoids (1 μM). The DCFDA assay was used to determine the ROS-scavenging ability of each phytocannabinoid following treatment with the lipid peroxidant tbhp (200 μM). Each phytocannabinoid provided significant protection against cytokine-evoked increases in epithelial permeability. Cannabidiol, cannabidivarin and cannabigerol were also able to significantly inhibit SN-38-evoked increases in permeability. None of the tested phytocannabinoids inhibited tbhp-induced ROS generation. These results highlight a novel role for cannabidiol, cannabidivarin and cannabigerol as inhibitors of SN-38-evoked increases in epithelial permeability and support the rationale for the further development of novel phytocannabinoids as supportive therapeutics in the management of irinotecan-associated mucositis.

In vitro evaluation of novel SN-38 prodrug activated by α-rhamnosidase of exogenous enzyme

This study introduces the α-rhamnose (Rham)-conjugated prodrug of SN-38 (Rham-SN-38) as a promising alternative to irinotecan. α-rhamnosidase, responsible for SN-38 release from Rham-SN-38, does not express in human cells, minimizing individual variability and side effects. The injection of the α-rhamnosidase into the tumor tissues makes it possible, for the first time, to activate the Rham-SN-38. Furthermore, α-rhamnosidase demonstrates significantly higher activity than carboxylesterase, the specific enzyme activating irinotecan. SN-38 release mediated by α-rhamnosidase completes within 2 h, with a kcat/Km value approximately 5.0 × 104-fold higher than that of irinotecan. The 50% inhibition concentration (IC50) of Rham-SN-38 against three types of cancer cells and one normal cell exceeds 4.5 × 103 nM. The addition of α-rhamnosidase significantly increases cytotoxicity, with IC50 comparable to free SN-38. The QIC50, an index reflecting the difference in cytotoxicity with and without α-rhamnosidase, exceeds approximately 1.0 × 102-fold. Rham-SN-38, synthesized in this study, demonstrates significant potential as a prodrug for cancer therapy.

An Organ-on-Chip Platform for Simulating Drug Metabolism Along the Gut-Liver Axis

The human microbiome significantly influences drug metabolism through the gut-liver axis, leading to modified drug responses and potential toxicity. Due to the complex nature of the human gut environment, the understanding of microbiome-driven impacts on these processes is limited. To address this, a multiorgan-on-a-chip (MOoC) platform that combines the human microbial-crosstalk (HuMiX) gut-on-chip (GoC) and the Dynamic42 liver-on-chip (LoC), mimicking the bidirectional interconnection between the gut and liver known as the gut-liver axis, is introduced. This platform supports the viability and functionality of intestinal and liver cells. In a proof-of-concept study, the metabolism of irinotecan, a widely used colorectal cancer drug, is imitated within the MOoC. Utilizing liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), irinotecan metabolites are tracked, confirming the platform's ability to represent drug metabolism along the gut-liver axis. Further, using the authors' gut-liver platform, it is shown that the colorectal cancer-associated gut bacterium, Escherichia coli, modifies irinotecan metabolism through the transformation of its inactive metabolite SN-38G into its toxic metabolite SN-38. This platform serves as a robust tool for investigating the intricate interplay between gut microbes and pharmaceuticals, offering a representative alternative to animal models and providing novel drug development strategies.

Dual-targeted nanoparticulate drug delivery systems for enhancing triple-negative breast cancer treatment

The efficacy of DNA-damaging agents, such as the topoisomerase I inhibitor SN38, is often compromised by the robust DNA repair mechanisms in tumor cells, notably homologous recombination (HR) repair. Addressing this challenge, we introduce a novel nano-strategy utilizing binary tumor-killing mechanisms to enhance the therapeutic impact of DNA damage and mitochondrial dysfunction in cancer treatment. Our approach employs a synergistic drug pair comprising SN38 and the BET inhibitor JQ-1. We synthesized two prodrugs by conjugating linoleic acid (LA) to SN38 and JQ-1 via a cinnamaldehyde thioacetal (CT) bond, facilitating co-delivery. These prodrugs co-assemble into a nanostructure, referred to as SJNP, in an optimal synergistic ratio. SJNP was validated for its efficacy at both the cellular and tissue levels, where it primarily disrupts the transcription factor protein BRD4. This disruption leads to downregulation of BRCA1 and RAD51, impairing the HR process and exacerbating DNA damage. Additionally, SJNP releases cinnamaldehyde (CA) upon CT linkage cleavage, elevating intracellular ROS levels in a self-amplifying manner and inducing ROS-mediated mitochondrial dysfunction. Our results indicate that SJNP effectively targets murine triple-negative breast cancer (TNBC) with minimal adverse toxicity, showcasing its potential as a formidable opponent in the fight against cancer.

Ferroptosis and cuproptosis: Metal-dependent cell death pathways activated in response to classical chemotherapy - Significance for cancer treatment?

Apoptosis has traditionally been regarded as the desired cell death pathway activated by chemotherapeutic drugs due to its controlled and non-inflammatory nature. However, recent discoveries of alternative cell death pathways have paved the way for immune-stimulatory treatment approaches in cancer. Ferroptosis (dependent on iron) and cuproptosis (dependent on copper) hold promise for selective cancer cell targeting and overcoming drug resistance. Copper ionophores and iron-bearing nano-drugs show potential for clinical therapy as single agents and as adjuvant treatments. Here we review up-to-date evidence for the involvement of metal ion-dependent cell death pathways in the cytotoxicity of classical chemotherapeutic agents (alkylating agents, topoisomerase inhibitors, antimetabolites, and mitotic spindle inhibitors) and their combinations with cuproptosis and ferroptosis inducers, indicating the prospects, advantages, and obstacles of their use.

Homotherapy-for-heteropathy of Bupleurum Chinense DC.-Scutellaria baicalensis Georgi in treating depression and colorectal cancer: A network pharmacology and animal model approach

ETHNOPHARMACOLOGICAL RELEVANCE

Bupleurum chinense DC.-Scutellaria baicalensis Georgi (BS) is a classic drug pair that has good clinical effects on depression and many tumors. However, the concurrent targeting mechanism of how the aforementioned drug pair is valid in the two distinct diseases, has not been clarified yet.

AIM OF THE STUDY

The components of BS were detected by LC-MS, combined with network pharmacology to explore the active ingredients and common targeting mechanism of its multi-pathway regulation of BS in treating depression and CRC, and to validate the dual effects of BS using the CUMS mice model and orthotopic transplantation tumor mice model of CRC.

RESULTS

Twenty-nine components were screened, 84 common gene targets were obteined, and the top 5 key targets including STAT3, PIK3R1, PIK3CA, AKT1, IL-6 were identified by PPI network. GO and KEGG analyses revealed that PI3K/AKT and JAK/STAT signaling pathways might play a crucial role of BS in regulating depression and CRC. BS significantly modulated CUMS-induced depressive-like behavior, attenuated neuronal damage, and reduced serum EPI and NE levels in CUMS model mice. BS improved the pathological histological changes of solid tumors and liver tissues and inhibited solid tumors and liver metastases in tumor-bearing mice. BS significantly decreased the proteins' expression of IL-6, p-JAK2, p-STAT3, p-PI3K, p-AKT1 in hippocampal tissues and solid tumors, and regulated the levels of IL-2, IL-6 and IL-10 in serum of two models of mice.

CONCLUSION

BS can exert dual antidepressant and anti-CRC effects by inhibiting the expression of IL-6/JAK2/STAT3 and PI3K/AKT pathway proteins and regulating the release of inflammatory cytokines.

Gynotoxic Effects of Chemotherapy and Potential Protective Mechanisms

Chemotherapy is one of the leading cancer treatments. Unfortunately, its use can contribute to several side effects, including gynotoxic effects in women. Ovarian reserve suppression and estrogen deficiency result in reduced quality of life for cancer patients and are frequently the cause of infertility and early menopause. Classic alkylating cytostatics are among the most toxic chemotherapeutics in this regard. They cause DNA damage in ovarian follicles and the cells they contain, and they can also induce oxidative stress or affect numerous signaling pathways. In vitro tests, animal models, and a few studies among women have investigated the effects of various agents on the protection of the ovarian reserve during classic chemotherapy. In this review article, we focused on the possible beneficial effects of selected hormones (anti-Müllerian hormone, ghrelin, luteinizing hormone, melatonin), agents affecting the activity of apoptotic pathways and modulating gene expression (C1P, S1P, microRNA), and several natural (quercetin, rapamycin, resveratrol) and synthetic compounds (bortezomib, dexrazoxane, goserelin, gonadoliberin analogs, imatinib, metformin, tamoxifen) in preventing gynotoxic effects induced by commonly used cytostatics. The presented line of research appears to provide a promising strategy for protecting and/or improving the ovarian reserve in the studied group of cancer patients. However, well-designed clinical trials are needed to unequivocally assess the effects of these agents on improving hormonal function and fertility in women treated with ovotoxic anticancer drugs.

Chitosan-grafted folic acid decorated one-dimensional GONS: A biocompatible drug cargo for targeted co-delivery of anticancer agents

In conventional chemotherapy, the cancer cells can become highly resilient due to a phenomenon known as multi-drug resistance (MDR). The co-delivery of chemotherapeutic agents assisted with novel nanocarrier-based targeted DDS may counter the MDR issues and subsequently improve their therapeutic efficacy. In line with this, the present work deals with the development of 1D graphene oxide nanoscrolls (GONS)-based nano delivery system for co-delivery of chemosensitizer along with the chemotherapeutic agent. Herein, the 1D GONS nanocarrier was initially functionalized with chitosan (CS) biopolymer and folic acid (FA) further to enhance their biocompatibility and target-specific co-delivery. The resultant GONS-CS-FA (GCF) nanocarriers were co-loaded with doxorubicin (DOX) and caffeic acid (CA) at different weight proportions with respect to nanocarrier and drug composition. The optimum loading efficiency of 51.14 ± 1.47 % (DOX) and 49.70 ± 1.19 % (CA) was observed for GCF: drug ratio of 2.5 with drug composition of 1:1. In vitro release at pH 5 yielded ~83 % DOX and 75 % CA, compared to ~71 % DOX and 61 % CA at pH 7.4 over 7 days, suggesting a higher and targeted drug release in the cancer microenvironment. Cytotoxicity tests revealed selective apoptosis in cancer cells (A549) while maintaining cytocompatibility with normal cells (HEK293).

Banxia Xiexin decoction combined with 5-ASA protects against CPT-11-induced intestinal dysfunction in rats via inhibiting TLR4/NF-κB signaling pathway

BACKGROUND

Banxia Xiexin decoction (BXD) can control irinotecan (CPT-11)-caused delayed diarrhea, but the corresponding mechanism remains undefined.

AIMS

This paper aimed to uncover the mechanism of BXD in regulating CPT-11-caused delayed diarrhea.

MATERIALS & METHODS

Sprague-Dawley (SD) rats were assigned into the control, model, BXD low-dose (BXD-L, 5 g/kg), BXD medium-dose (BXD-M, 10 g/kg), BXD high-dose (BXD-H, 15 g/kg), 5-aminosalicylic acid (5-ASA, 10 mL/kg), and BXD-M + 5-ASA groups. Rats were injected intraperitoneally with 150 mg/kg CPT-11 at Day 4 and Day 5 to induce delayed diarrhea, and later treated with various doses (low, medium, and high) of BXD and 5-ASA for 9 days, except for rats in control group. The body weight of rats was measured. The rat colon tissue injury, inflammatory cytokine levels, and the activation of toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) signaling pathway were detected.

RESULTS

BXD (5, 10, or 15 g/kg) or 5-ASA (10 mL/kg) alleviated body weight loss and colon tissue injury, decreased levels of inflammatory cytokines, and inactivated TLR4/NF-κB signaling pathway in CPT-11-induced model rats. BXD at 10 g/kg (the optimal concentration) could better treat CPT-11-induced intestinal dysfunction, as evidenced by the resulting approximately 50% reduction on injury score of model rats. Moreover, BXD-M (10 g/kg) synergistic with 5-ASA (10 mL/kg) further strengthened the inhibition on rat body weight loss, colon tissue injury, inflammatory cytokine levels, and TLR4/NF-κB signaling pathway.

CONCLUSION

To sum up, BXD has a protective effect against CPT-11-induced intestinal dysfunction by inhibiting inflammation through inactivation TLR4/NF-κB signaling pathway. In particular, the combined use of BXD and 5-ASA holds great promise for treating CPT-11-induced delayed diarrhea.

Combination of FOLFOXIRI Drugs with Oncolytic Coxsackie B3 Virus PD-H Synergistically Induces Oncolysis in the Refractory Colorectal Cancer Cell Line Colo320

FOLFOXIRI chemotherapy is a first-line therapy for advanced or metastatic colorectal cancer (CRC), yet its therapeutic efficacy remains limited. Immunostimulatory therapies like oncolytic viruses can complement chemotherapies by fostering the infiltration of the tumor by immune cells and enhancing drug cytotoxicity. In this study, we explored the effect of combining the FOLFOXIRI chemotherapeutic agents with the oncolytic coxsackievirus B3 (CVB3) PD-H in the CRC cell line Colo320. Additionally, we examined the impact of the drugs on the expression of microRNAs (miRs), which could be used to increase the safety of oncolytic CVB3 containing corresponding miR target sites (miR-TS). The measurement of cytotoxic activity using the Chou-Talalay combination index approach revealed that PD-H synergistically enhanced the cytotoxic activity of oxaliplatin (OX), 5-fluorouracil (5-FU) and SN-38. PD-H replication was not affected by OX and SN-38 but inhibited by high concentrations of 5-FU. MiR expression levels were not or only slightly elevated by the drugs or with drug/PD-H combinations on Colo320 cells. Moreover, the drug treatment did not increase the mutation rate of the miR-TS inserted into the PD-H genome. The results demonstrate that the combination of FOLFOXIRI drugs and PD-H may be a promising approach to enhance the therapeutic effect of FOLFOXIRI therapy in CRC.

Biological impact and therapeutic potential of a novel camptothecin derivative (FLQY2) in pancreatic cancer through inactivation of the PDK1/AKT/mTOR pathway

BACKGROUND

Camptothecin (CPT), a pentacyclic alkaloid with antitumor properties, is derived from the Camptotheca acuminata. Topotecan and irinotecan (CPT derivatives) were first approved by the Food and Drug Administration for cancer treatment over 25 years ago and remain key anticancer drugs today. However, their use is often limited by clinical toxicity. Despite extensive development efforts, many of these derivatives have not succeeded clinically, particularly in their effectiveness against pancreatic cancer which remains modest.

AIM OF THE STUDY

This study aimed to evaluate the therapeutic activity of FLQY2, a CPT derivative synthesized in our laboratory, against pancreatic cancer, comparing its efficacy and mechanism of action with those of established clinical drugs.

METHODS

The cytotoxic effects of FLQY2 on cancer cells were assessed using an MTT assay. Patient-derived organoid (PDO) models were employed to compare the sensitivity of FLQY2 to existing clinical drugs across various cancers. The impact of FLQY2 on apoptosis and cell cycle arrest in Mia Paca-2 pancreatic cancer cells was examined through flow cytometry. Transcriptomic and proteomic analyses were conducted to explore the underlying mechanisms of FLQY2's antitumor activity. Western blotting was used to determine the levels of proteins regulated by FLQY2. Additionally, the antitumor efficacy of FLQY2 in vivo was evaluated in a pancreatic cancer xenograft model.

RESULTS

FLQY2 demonstrated (1) potent cytotoxicity; (2) superior tumor-suppressive activity in PDO models compared to current clinical drugs such as gemcitabine, 5-fluorouracil, cisplatin, paclitaxel, ivosidenib, infinitinib, and lenvatinib; (3) significantly greater tumor inhibition than paclitaxel liposomes in a pancreatic cancer xenograft model; (4) robust antitumor effects, closely associated with the inhibition of the TOP I and PDK1/AKT/mTOR signaling pathways. In vitro studies revealed that FLQY2 inhibited cell proliferation, colony formation, induced apoptosis, and caused cell cycle arrest at nanomolar concentrations. Furthermore, the combination of FLQY2 and gemcitabine exhibited significant inhibitory and synergistic effects.

CONCLUSION

The study confirmed the involvement of topoisomerase I and the PDK1/AKT/mTOR pathways in mediating the antitumor activity of FLQY2 in treating Mia Paca-2 pancreatic cancer. Therefore, FLQY2 has potential as a novel therapeutic option for patients with pancreatic cancer.

Irinotecan dosing and pharmacogenomics: a comprehensive exploration based on UGT1A1 variants and emerging insights

Irinotecan is a critical anticancer drug used to treat metastatic colorectal cancer and advanced pancreatic ductal adenocarcinoma by obstructing topoisomerase 1; however, it can cause minor-to-severe and life-threatening adverse effects. UDP glucuronosyltransferase family 1 member A1 (UGT1A1) polymorphisms increase the risk of irinotecan-induced neutropenia and diarrhea. Hence, screening for UGT1A1 polymorphisms before irinotecan-based chemotherapy is recommended to minimize toxicity, whereas liposomes offer the potential to deliver irinotecan with fewer side effects in patients with pancreatic ductal adenocarcinoma. This review presents a comprehensive overview of the effects of genotype-guided dosing of irinotecan on UGT1A1*28 and UGT1A1*6 variants, incorporating pharmacogenomic research, optimal regimens for metastatic colorectal and pancreatic cancer treatment using irinotecan, guidelines for toxicity reduction, and an evaluation of the cost-effectiveness of UGT1A1 genotype testing.

Novel FOXM1 inhibitor STL001 sensitizes human cancers to a broad-spectrum of cancer therapies

Forkhead box protein M1 (FOXM1) is often overexpressed in human cancers and strongly associated with therapy resistance and less good patient survival. The chemotherapy options for patients with the most aggressive types of solid cancers remain very limited because of the acquired drug resistance, making the therapy less effective. NPM1 mutation through the inactivation of FOXM1 via FOXM1 relocalization to the cytoplasm confers more favorable treatment outcomes for AML patients, confirming FOXM1 as a crucial target to overcome drug resistance. Pharmacological inhibition of FOXM1 could be a promising approach to sensitize therapy-resistant cancers. Here, we explore a novel FOXM1 inhibitor STL001, a first-generation modification drug of our previously reported FOXM1 inhibitor STL427944. STL001 preserves the mode of action of the STL427944; however, STL001 is up to 50 times more efficient in reducing FOXM1 activity in a variety of solid cancers. The most conventional cancer therapies studied here induce FOXM1 overexpression in solid cancers. The therapy-induced FOXM1 overexpression may explain the failure or reduced efficacy of these drugs in cancer patients. Interestingly, STL001 increased the sensitivity of cancer cells to conventional cancer therapies by suppressing both the high-endogenous and drug-induced FOXM1. Notably, STL001 does not provide further sensitization to FOXM1-KD cancer cells, suggesting that the sensitization effect is conveyed specifically through FOXM1 suppression. RNA-seq and gene set enrichment studies revealed prominent suppression of FOXM1-dependent pathways and gene ontologies. Also, gene regulation by STL001 showed extensive overlap with FOXM1-KD, suggesting a high selectivity of STL001 toward the FOXM1 regulatory network. A completely new activity of FOXM1, mediated through steroid/cholesterol biosynthetic process and protein secretion in cancer cells was also detected. Collectively, STL001 offers intriguing translational opportunities as combination therapies targeting FOXM1 activity in a variety of human cancers driven by FOXM1.

Targeting of neuroblastoma cells through Kynurenine-AHR pathway inhibition

Neuroblastoma poses significant challenges in clinical management. Despite its relatively low incidence, this malignancy contributes disproportionately to cancer-related childhood mortality. Tailoring treatments based on risk stratification, including MYCN oncogene amplification, remains crucial, yet high-risk cases often confront therapeutic resistance and relapse. Here, we explore the aryl hydrocarbon receptor (AHR), a versatile transcription factor implicated in diverse physiological functions such as xenobiotic response, immune modulation, and cell growth. Despite its varying roles in malignancies, AHR's involvement in neuroblastoma remains elusive. Our study investigates the interplay between AHR and its ligand kynurenine (Kyn) in neuroblastoma cells. Kyn is generated from tryptophan (Trp) by the activity of the enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO2). We found that neuroblastoma cells displayed sensitivity to the TDO2 inhibitor 680C91, exposing potential vulnerabilities. Furthermore, combining TDO2 inhibition with retinoic acid or irinotecan (two chemotherapeutic agents used to treat neuroblastoma patients) revealed synergistic effects in select cell lines. Importantly, clinical correlation analysis using patient data established a link between elevated expression of Kyn-AHR pathway genes and adverse prognosis, particularly in older children. These findings underscore the significance of the Kyn-AHR pathway in neuroblastoma progression, emphasizing its potential role as a therapeutic target.

Targeting Methionine Addiction Combined With Low-dose Irinotecan Arrested Colon Cancer in Contrast to High-dose Irinotecan Alone, Which Was Ineffective, in a Nude-mouse Model

BACKGROUND/AIM

Colorectal cancer (CRC) is the third-leading cause of death in the world. Although the prognosis has improved due to improvement of chemotherapy, metastatic CRC is still a recalcitrant disease, with a 5-year survival of only 13%. Irinotecan (IRN) is used as first-line chemotherapy for patients with unresectable CRC. However, there are severe side effects, such as neutropenia and diarrhea, which are dose-limiting. We have previously shown that methionine restriction (MR), effected by recombinant methioninase (rMETase), lowered the effective dose of IRN of colon-cancer cells in vitro. The aim of the present study was to evaluate the efficacy of the combination of low-dose IRN and MR on colon-cancer in nude mice.

MATERIALS AND METHODS

HCT-116 colon-cancer cells were cultured and subcutaneously injected into the flank of nude mice. After the tumor size reached approximately 100 mm3, 18 mice were randomized into three groups; Group 1: untreated control on a normal diet; Group 2: high-dose IRN on a normal diet (2 mg/kg, i.p.); Group 3: low-dose IRN (1 mg/kg i.p.) on MR effected by a methionine-depleted diet.

RESULTS

There was no significant difference between the control mice and the mice treated with high-dose IRN, without MR. However, low-dose IRN combined with MR was significantly more effective than the control and arrested colon-cancer growth (p=0.03). Body weight loss was reversible in the mice treated by low-dose IRN combined with MR.

CONCLUSION

The combination of low-dose IRN and MR acted synergistically in arresting HCT-116 colon-cancer grown in nude mice. The present study indicates the MR has the potential to reduce the effective dose of IRN in the clinic.

The Safety and Efficacy of the Combination of Sacituzumab Govitecan and Palliative Radiotherapy-A Retrospective Multi-Center Cohort Study

Sacituzumab govitecan (SG) is a new treatment option for patients with metastatic triple-negative and hormone receptor-positive, HER2-negative breast cancer. This antibody-drug conjugate is currently approved as monotherapy. Palliative radiotherapy is frequently used to treat symptomatic metastases locally. Concurrent use of SG and irradiation was excluded in clinical trials of SG, and there are currently limited published data. We report here a systematic review, as well as a retrospective multi-center study of 17 patients with triple-negative breast cancer who received concurrent SG and radiotherapy. In these patients, concurrent use was found to be efficient, safe and well tolerated. There were no apparent differences in moderate or severe acute toxicity according to the timing of SG administration.

A new TROP2-targeting antibody-drug conjugate shows potent antitumor efficacy in breast and lung cancers

Trophoblast cell surface antigen 2 (Trop2) is considered to be an attractive therapeutic target in cancer treatments. We previously generated a new humanized anti-Trop2 antibody named hIMB1636, and designated it as an ideal targeting carrier for cancer therapy. Lidamycin (LDM) is a new antitumor antibiotic, containing an active enediyne chromophore (AE) and a noncovalently bound apoprotein (LDP). AE and LDP can be separated and reassembled, and the reassembled LDM possesses cytotoxicity similar to that of native LDM; this has made LDM attractive in the preparation of gene-engineering drugs. We herein firstly prepared a new fusion protein hIMB1636-LDP composed of hIMB1636 and LDP by genetic engineering. This construct showed potent binding activities to recombinant antigen with a KD value of 4.57 nM, exhibited binding to Trop2-positive cancer cells and internalization and transport to lysosomes, and demonstrated powerful tumor-targeting ability in vivo. We then obtained the antibody-drug conjugate (ADC) hIMB1636-LDP-AE by molecular reconstitution. In vitro, hIMB1636-LDP-AE inhibited the proliferation, migration, and tumorsphere formation of tumor cells with half-maximal inhibitory concentration (IC50) values at the sub-nanomolar level. Mechanistically, hIMB1636-LDP-AE induced apoptosis and cell-cycle arrest. In vivo, hIMB1636-LDP-AE also inhibited the growth of breast and lung cancers in xenograft models. Moreover, compared to sacituzumab govitecan, hIMB1636-LDP-AE showed more potent antitumor activity and significantly lower myelotoxicity in tumors with moderate Trop2 expression. This study fully revealed the potent antitumor efficacy of hIMB1636-LDP-AE, and also provided a new preparation method for LDM-based ADC, as well as a promising candidate for breast cancer and lung cancer therapeutics.

Roles of breast cancer resistance protein and organic anion transporting polypeptide 2B1 in gastrointestinal toxicity induced by SN-38 under inflammatory conditions

Drug transporters are among the factors that determine the pharmacokinetic profiles after drug administration. In this study, we investigated the roles of drug transporters involved in transport of SN-38, which is an active metabolite of irinotecan, in the intestine under inflammatory conditions in vitro and determined their functional consequences. The expression alterations of breast cancer resistance protein (BCRP) and organic anion transporting polypeptide (OATP) 2B1 were determined at the mRNA and protein levels, and the subsequent functional alterations were evaluated via an accumulation study with the representative transporter substrates [prazosin and dibromofluorescein (DBF)] and SN-38. We also determined the cytotoxicity of SN-38 under inflammatory conditions. Decreased BCRP expression and increased OATP2B1 expression were observed under inflammatory conditions in vitro, which led to altered accumulation profiles of prazosin, DBF, and SN-38, and the subsequent cytotoxic profiles of SN-38. Treatment with rifampin or novobiocin supported the significant roles of BCRP and OATP2B1 in the transport and cytotoxic profile of SN-38. Collectively, these results suggest that BCRP and OATP2B1 are involved in the increased cytotoxicity of SN-38 under inflammatory conditions in vitro. Further comprehensive research is warranted to completely understand SN-38-induced gastrointestinal cytotoxicity and aid in the successful treatment of cancer with irinotecan.

Astraoleanosides E-P, oleanane-type triterpenoid saponins from the aerial parts of Astragalus membranaceus Bunge and their β-glucuronidase inhibitory activity

Historically, Astragalus membranaceus Bunge has been used as a beneficial medicinal plant, particularly in the Asian traditional medical systems, for the treatment of various human diseases such as stomach ulcers, diarrhea, and respiratory issues associated with phlegm. In this study, a phytochemical characterization of the aerial parts of A. membranaceusled to the isolation of 29 oleanane-type triterpenoid saponins, including 11 new compounds named astraoleanosides E-P (6-9, 13, 14, 18-22), as well as 18 known ones. The structures of these compounds were elucidated using nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry. Among them, astraoleanoside H (9) and cloversaponin III (15) demonstrated the most potent β-glucuronidase inhibitory activities, with IC50 values of 21.20 ± 0.75 and 9.05 ± 0.47 µM, respectively, compared to the positive control d-saccharic acid 1,4-lactone (IC50 = 20.62 ± 1.61 µM). Enzyme kinetics studies were then conducted to investigate the type of inhibition exhibited by these active compounds. In addition, the binding mechanism, key interactions, binding stability, and dynamic behavior of protein-ligand complexes were investigated through in silico approaches, such as molecular docking and molecular dynamics simulations. These findings highlight the promising potential of triterpenoid saponins from A. membranaceus as lead compounds for β-glucuronidase inhibitors, offering new possibilities for the development of therapeutic agents targeting various diseases where β-glucuronidase plays a crucial role.

Three-dimensional morphology scoring of hepatocellular carcinoma stratifies prognosis and immune infiltration

BACKGROUND

The morphological attributes could serve as pivotal indicators precipitating early recurrence and dismal overall survival in hepatocellular carcinoma (HCC), and quantifying morphological features may better stratify the prognosis of HCC.

OBJECTIVE

To develop a radiomics approach based on 3D tumor morphology features for predicting the prognosis of HCC and identifying differentially expressed genes related to morphology to guide HCC treatment.

MATERIALS AND METHODS

Retrospective study of 357 HCC patients. Radiomic features were extracted from MRI tumor regions; 14 morphology-related features predicted early HCC recurrence and patient stratification via LASSO-Cox modeling. Overall survival (OS) and recurrence-free survival (RFS) were analyzed. RNA sequencing from the Cancer Imaging Archive (TCIA) examined drug sensitivity and stratified HCC using morphological immunity genes, validating recurrence and prognosis.

RESULTS

Patients were split into training (n = 225), test (n = 132), and 50 TCIA dataset cohorts. Two features (Maximum2DdiameterColumn, Sphericity) in Cox regression stratified patients into high/low-risk Morphological Radiological Score (Morph-RS) groups. Significant OS and RFS were seen across all sets. Differentially expressed genes focused on T cell receptor signaling; low-risk group had higher T cells (P = 0.039), B cells (P = 0.041), NK cells (P = 0.018). SN-38, GSK2126458 might treat high-risk morphology. Morphology-immune genes stratified HCC, showing significant RFS/OS differences.

CONCLUSION

Tumor Morph-RS effectively stratifies HCC patients' recurrence and prognosis. Limited immune infiltration seen in Morph-RS high-risk groups signifies the potential of employing tumor morphology as a potent visual biomarker for diagnosing and managing HCC.

Construction and Analysis of a Mitochondrial Metabolism-Related Prognostic Model for Breast Cancer to Evaluate Survival and Immunotherapy

As one of the most prevalent malignancies among women, breast cancer (BC) is tightly linked to metabolic dysfunction. However, the correlation between mitochondrial metabolism-related genes (MMRGs) and BC remains unclear. The training and validation datasets for BC were obtained from The Cancer Genome Atlas and Gene Expression Omnibus databases, respectively. MMRG-related data were obtained from the Molecular Signatures Database. A risk score prognostic model incorporating MMRGs was established based on univariate, LASSO, and multivariate Cox regression analyses. Independent factors affecting BC prognosis were identified through regression analysis and presented in a nomogram. Single-sample gene set enrichment analysis was employed to assess the immune levels of high-risk (HR) and low-risk (LR) groups. The sensitivity of BC patients in the two groups to common anti-tumor drugs was evaluated by utilizing the Genomics of Drug Sensitivity in Cancer database. 12 MMRGs significantly associated with survival were selected from 1234 MMRGs. A 12-gene risk score prognostic model was built. In the multivariate regression analysis incorporating classical clinical factors, the MMRG-related risk score remained an independent prognostic factor. As revealed by tumor immune microenvironment analysis, the LR group with higher survival rates had elevated immune levels. The drug sensitivity results unmasked that the LR group demonstrated higher sensitivity to Irinotecan, Nilotinib, and Oxaliplatin, while the HR group demonstrated higher sensitivity to Lapatinib. The development of MMRG characteristics provides a comprehensive understanding of mitochondrial metabolism in BC, aiding in the prediction of prognosis and tumor microenvironment, and offering promising therapeutic choices for BC patients with different MMRG risk scores.

Innovative Nanoparticulate Strategies in Colon Cancer Treatment: A Paradigm Shift

As a major public health issue, colorectal cancer causes 9.4% of total cancer-related deaths and comprises 10% of new cancer diagnoses worldwide. In the year 2023, an estimated 153,020 people are expected to receive an identification of colorectal cancer (CRC), resulting in roughly 52,550 fatalities anticipated as a result of this illness. Among those impacted, approximately 19,550 cases and 3750 deaths are projected to occur in individuals under the age of 50. Irinotecan (IRN) is a compound derived from the chemical structure of camptothecin, a compound known for its action in inhibiting DNA topoisomerase I. It is employed in the treatment strategy for CRC therapies. Comprehensive in vivo and in vitro studies have robustly substantiated the anticancer efficacy of these compounds against colon cancer cell lines. Blending irinotecan in conjunction with other therapeutic cancer agents such as oxaliplatin, imiquimod, and 5 fluorouracil enhanced cytotoxicity and improved chemotherapeutic efficacy. Nevertheless, it is linked to certain serious complications and side effects. Utilizing nano-formulated prodrugs within "all-in-one" carrier-free self-assemblies presents an effective method to modify the pharmacokinetics and safety portfolio of cytotoxic chemotherapeutics. This review focuses on elucidating the mechanism of action, exploring synergistic effects, and innovating novel delivery approaches to enhance the therapeutic efficacy of irinotecan.

Chemical Proteomics and Morphological Profiling Revealing MYDGF as a Target for Synthetic Anticancer Macromolecules

Biodegradable guanidinium-functionalized polycarbonates kill cancer cells via membrane translocation without causing resistance after repeated use, but the exact molecular targets of the polycarbonates are unknown. Here, we investigate the protein targets of the polycarbonates through affinity-based protein profiling and report myeloid-derived growth factor (MYDGF) as the main protein target. Direct binding of the polycarbonates to MYDGF protein is validated through biolayer interferometry. MYDGF is overexpressed in a range of cancer cells, and knockdown of MYDGF is shown to reduce cell proliferation in cancer cells. Through morphological profiling, we also identify similarities in phenotypic effects of the functionalized polycarbonates with topoisomerase I inhibitors, MDM2 inhibitors, and phosphatidylinositol 3kinase inhibitors against cancer cells, suggesting a common mechanism through the PIK3/AKT pathway leading to apoptosis. These findings present the first macromolecular compound targeting MYDGF and may serve as an example for MYDGF modulation as a potential new target for macromolecular chemotherapeutic development.

The effective combination therapies with irinotecan for colorectal cancer

Colorectal cancer is the third most common type of cancer worldwide and has become one of the major human disease burdens. In clinical practice, the treatment of colorectal cancer has been closely related to the use of irinotecan. Irinotecan combines with many other anticancer drugs and has a broader range of drug combinations. Combination therapy is one of the most important means of improving anti-tumor efficacy and overcoming drug resistance. Reasonable combination therapy can lead to better patient treatment options, and inappropriate combination therapy will increase patient risk. For the colorectal therapeutic field, the significance of combination therapy is to improve the efficacy, reduce the adverse effects, and improve the ease of treatment. Therefore, we explored the clinical advantages of its combination therapy based on mechanism or metabolism and reviewed the rationale basis and its limitations in conducting exploratory clinical trials on irinotecan combination therapy, including the results of clinical trials on the combination potentiation of cytotoxic drugs, targeted agents, and herbal medicine. We hope that these can evoke more efforts to conduct irinotecan in the laboratory for further studies and evaluations, as well as the possibility of more in-depth development in future clinical trials.

Camptothecin structure simplification elaborated new imidazo[2,1-b]quinazoline derivative as a human topoisomerase I inhibitor with efficacy against bone cancer cells and colon adenocarcinoma

Camptothecin is a pentacyclic natural alkaloid that inhibits the hTop1 enzyme involved in DNA transcription and cancer cell growth. Camptothecin structure pitfalls prompted us to design new congeners using a structure simplification strategy to reduce the ring extension number from pentacyclic to tetracyclic while maintaining potential stacking of the new compounds with the DNA base pairs at the Top1-mediated cleavage complex and aqueous solubility, as well as minimizing compound-liver toxicity. The principal axis of this study was the verification of hTop1 inhibiting activity as a possible mechanism of action and the elaboration of new simplified inhibitors with improved pharmacodynamic and pharmacokinetic profiling using three structure panels (A-C) of (isoquinolinoimidazoquinazoline), (imidazoquinazoline), and (imidazoisoquinoline), respectively. DNA relaxation assay identified five compounds as hTop1 inhibitors belonging to the imidazoisoquinolines 3a,b, the imidazoquinazolines 12, and the isoquinolinoimidazoquinazolines 7a,b. In an MTT cytotoxicity assay against different cancer cell lines, compound 12 was the most potent against HOS bone cancer cells (IC50 = 1.47 μM). At the same time, the other inhibitors had no detectable activity against any cancer cell type. Compound (12) demonstrated great penetrating power in the HOS cancer cells' 3D-multicellular tumor spheroid model. Bioinformatics research of the hTop1 gene revealed that the TP53 cell proliferative gene is in the network of hTop1. The finding is confirmed empirically using the gene expression assay that proved the increase in p53 expression. The impact of structure simplification on compound 12 profile, characterized by the absence of acute oral liver toxicity when compared to Doxorubicin as a standard inhibitor, the lethal dose measured on Swiss Albino female mice and reported at LD50 = 250 mg/kg, and therapeutic significance in reducing colon adenocarcinoma tumor volume by 75.36 % after five weeks of treatment with compound 12. The molecular docking solutions of the active CPT-based derivative 12 and the inactive congener 14 into the active site of hTop1 and the activity cliffing of such MMP directed us to recommend the addition of HBD and HBA variables to compound 12 imidazoquinazoline core scaffold to enhance the potency via hydrogen bond formation with the major groove amino acids (Asp533, Lys532) as well as maintaining the hydrogen bond with the minor groove amino acid Arg364.

A dual catalytic functionalized hollow mesoporous silica-based nanocarrier coated with bacteria-derived exopolysaccharides for targeted delivery of irinotecan to colorectal cancer cells

In this study, we introduced a multifunctional hollow mesoporous silica-based nanocarrier (HMSN) for the targeted delivery of irinotecan (IRT) to colorectal cancer cells. Due to their large reservoirs, hollow mesoporous silica nanoparticles are suitable platforms for loading significant amounts of drugs for sustained drug release. To respond to pH and redox, HMSNs were functionalized with cerium and iron oxides. Additionally, they were coated with bacterial-derived exopolysaccharide (EPS) as a biocompatible polymer. In vitro analyses revealed that cytotoxicity induced in cancer cells through oxidative stress, mediated by mature nanocarriers (EPS.IRT.Ce/Fe.HMSN), was surprisingly greater than that caused by free drugs. Cerium and iron ions, in synergy with the drug, were found to generate reactive oxygen species when targeting the acidic pH within lysosomes and the tumor microenvironment. This, in turn, triggered cascade reactions, leading to cell death. In vivo experiments revealed that the proposed nanocarriers had no noticeable effect on healthy tissues. These findings indicate the selective delivery of the drug to cancerous tissue and the induction of antioxidant effects due to the dual catalytic properties of cerium in normal cells. Accordingly, this hybrid drug delivery system provides a more effective treatment for colorectal cancer with the potential for cost-effective scaling up.

High-accuracy prediction of colorectal cancer chemotherapy efficacy using machine learning applied to gene expression data

Introduction: FOLFOX and FOLFIRI chemotherapy are considered standard first-line treatment options for colorectal cancer (CRC). However, the criteria for selecting the appropriate treatments have not been thoroughly analyzed. Methods: A newly developed machine learning model was applied on several gene expression data from the public repository GEO database to identify molecular signatures predictive of efficacy of 5-FU based combination chemotherapy (FOLFOX and FOLFIRI) in patients with CRC. The model was trained using 5-fold cross validation and multiple feature selection methods including LASSO and VarSelRF methods. Random Forest and support vector machine classifiers were applied to evaluate the performance of the models. Results and Discussion: For the CRC GEO dataset samples from patients who received either FOLFOX or FOLFIRI, validation and test sets were >90% correctly classified (accuracy), with specificity and sensitivity ranging between 85%-95%. In the datasets used from the GEO database, 28.6% of patients who failed the treatment therapy they received are predicted to benefit from the alternative treatment. Analysis of the gene signature suggests the mechanistic difference between colorectal cancers that respond and those that do not respond to FOLFOX and FOLFIRI. Application of this machine learning approach could lead to improvements in treatment outcomes for patients with CRC and other cancers after additional appropriate clinical validation.

Identification of the first selective bioluminescent probe for real-time monitoring of carboxylesterase 2 in vitro and in vivo

Carboxylesterase (CES), a main hydrolysis enzyme family in the human body, plays a crucial role in drug metabolism. Among them, CES1 and CES2 are the primary subtypes, and each exhibits distinct distribution and functions. However, convenient and non-invasive methods for distinguishing them and the real-time monitoring of CES2 are relatively rare, hindering the further understanding of physiological functions and underlying mechanisms. In this study, we have designed, synthesized, and evaluated the first selective bioluminescent probe (CBP 1) for CES2 with high sensitivity, high specificity and rapid reactivity. This probe offers a promising approach for the real-time detection of CES2 and its dynamic fluctuations both in vitro and in vivo.

[WITHDRAWN] Novel FOXM1 inhibitor STL001 sensitizes human cancers to a broad-spectrum of cancer therapies

The full text of this preprint has been withdrawn by the authors while they make corrections to the work. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

[WITHDRAWN] Novel FOXM1 inhibitor STL001 sensitizes human cancers to a broad-spectrum of cancer therapies

The full text of this preprint has been withdrawn by the authors while they make corrections to the work. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.

Deciphering treatment resistance in metastatic colorectal cancer: roles of drug transports, EGFR mutations, and HGF/c-MET signaling

In 2023, colorectal cancer (CRC) is the third most diagnosed malignancy and the third leading cause of cancer death worldwide. At the time of the initial visit, 20% of patients diagnosed with CRC have metastatic CRC (mCRC), and another 25% who present with localized disease will later develop metastases. Despite the improvement in response rates with various modulation strategies such as chemotherapy combined with targeted therapy, radiotherapy, and immunotherapy, the prognosis of mCRC is poor, with a 5-year survival rate of 14%, and the primary reason for treatment failure is believed to be the development of resistance to therapies. Herein, we provide an overview of the main mechanisms of resistance in mCRC and specifically highlight the role of drug transports, EGFR, and HGF/c-MET signaling pathway in mediating mCRC resistance, as well as discuss recent therapeutic approaches to reverse resistance caused by drug transports and resistance to anti-EGFR blockade caused by mutations in EGFR and alteration in HGF/c-MET signaling pathway.

Bifidobacterium longum SX-1326 ameliorates gastrointestinal toxicity after irinotecan chemotherapy via modulating the P53 signaling pathway and brain-gut axis

BACKGROUND

Colorectal cancer (CRC) is a prevalent malignant malignancy affecting the gastrointestinal tract that is usually treated clinically with chemotherapeutic agents, whereas chemotherapeutic agents can cause severe gastrointestinal toxicity, which brings great pain to patients. Therefore, finding effective adjuvant agents for chemotherapy is crucial.

METHODS

In this study, a CRC mouse model was successfully constructed using AOM/DSS, and the treatment was carried out by probiotic Bifidobacterium longum SX-1326 (B. longum SX-1326) in combination with irinotecan. Combining with various techniques of modern biomedical research, such as Hematoxylin and Eosin (H&E), Immunohistochemistry (IHC), Western blotting and 16S rDNA sequencing, we intend to elucidate the effect and mechanism of B. longum SX-1326 in improving the anticancer efficacy and reducing the side effects on the different levels of molecules, animals, and bacteria.

RESULTS

Our results showed that B. longum SX-1326 enhanced the expression of Cleaved Caspase-3 (M vs. U = p < 0.01) and down-regulated the expression level of B-cell lymphoma-2 (Bcl-2) through up-regulation of the p53 signaling pathway in CRC mice, which resulted in an adjuvant effect on the treatment of CRC with irinotecan. Moreover, B. longum SX-1326 was also able to regulate the gut-brain-axis (GBA) by restoring damaged enterochromaffin cells, reducing the release of 5-hydroxytryptamine (5-HT) in brain tissue (I vs. U = 89.26 vs. 75.03, p < 0.05), and further alleviating the adverse effects of nausea and vomiting. In addition, B. longum SX-1326 reversed dysbiosis in CRC model mice by increasing the levels of Dehalobacterium, Ruminnococcus, and Mucispirillum. And further alleviated colorectal inflammation by downregulating the TLR4/MyD88/NF-κB signaling pathway.

CONCLUSIONS

In conclusion, our work reveals that B. longum SX-1326 has a favorable effect in adjuvant irinotecan for CRC and amelioration of post-chemotherapy side effects, and also provides the theoretical basis and data for finding a safe and efficient chemotherapeutic adjuvant.

Targosomes: Anti-HER2 PLGA nanocarriers for bioimaging, chemotherapy and local photothermal treatment of tumors and remote metastases

Developing combined cancer therapy strategies is of utmost importance as it can enhance treatment efficacy, overcome drug resistance, and ultimately improve patient outcomes by targeting multiple pathways and mechanisms involved in cancer growth and progression. Specifically, the potential of developing a combination chemo&photothermal therapy using targeted polymer nanoparticles as nanocarriers offers a promising approach for synergistic cancer treatment by combining the benefits of both therapies, such as targeted drug delivery and localized hyperthermia. Here, we report the first targeted anti-HER2 PLGA nanocarriers, called targosomes, that simultaneously possess photothermal, chemotherapeutic and diagnostic properties using only molecular payloads. Biocompatible poly(lactic-co-glycolic acid), PLGA, nanoparticles were loaded with photosensitizer phthalocyanine, diagnostic dye Nile Blue, and chemotherapeutic drug irinotecan, which was chosen as a result of screening a panel of theragnostic nanoparticles. The targeted delivery to cell surface oncomarker HER2 was ensured by nanoparticle modification with the anti-HER2 monoclonal antibody, trastuzumab, using the one-pot synthesis method without chemical conjugation. The irradiation tests revealed prominent photothermal properties of nanoparticles, namely heating by 35 °C in 10 min. Nanoparticles exhibited a 7-fold increase in binding and nearly an 18-fold increase in cytotoxicity for HER2-overexpressing cells compared to cells lacking HER2 expression. This enhancement of cytotoxicity was further amplified by >20-fold under NIR light irradiation. In vivo studies proved the efficacy of nanoparticles for bioimaging of primary tumor and metastasis sites and demonstrated 93% tumor growth inhibition, making these nanoparticles excellent candidates for translation into theragnostic applications.

Potential of Nanomedicines as an Alternative for the Treatment of Colorectal Cancer - A Review

Colorectal cancer is the third most common cancer and the second in cases of cancer-related death. Polytherapy generates many adverse effects, leading the patient to give up. Nanotechnology has been studied in recent years to circumvent limitations. Groups composed of polymeric, lipid, and inorganic nanoparticles are the most purpose. Thus, the objective of this work is to bring information on how nanosystems can improve the chemotherapeutic treatment for colorectal cancer. Therefore, a search in journals such as "LILACS", "SciELO" and "PubMed/Medline" was performed, resulting in 25,000 articles found when applied the search engines "nanoparticle," "colorectal cancer," "malignant neoplasms," and "chemotherapy." After inclusion and exclusion factors, 24 articles remained, which were used as the basis for this integrative review. The results reveal that, regardless of the choice of matrix, nanoparticles showed an increase in bioavailability of the active, increasing the half-life by up to 13 times, modified release, as well as a significant reduction in tumor size, with cell viability up to 20% lower than the free drug tested, in different colorectal cancer cell lines, such as HCT-116, HT-29, and CaCo-2. However, more in vivo and clinical studies need to be performed, regardless of the formulation of its matrix, aiming at a higher rate of safety for patients and stability of the formulations, as well as knowledge of detailed indices of its pharmacokinetics and pharmacodynamics, seeking to avoid further damage to the recipient organism.

PEGylated therapeutics in the clinic

The covalent attachment of polyethylene glycol (PEG) to therapeutic agents, termed PEGylation, is a well-established and clinically proven drug delivery approach to improve the pharmacokinetics and pharmacodynamics of drugs. Specifically, PEGylation can improve the parent drug's solubility, extend its circulation time, and reduce its immunogenicity, with minimal undesirable properties. PEGylation technology has been applied to various therapeutic modalities including small molecules, aptamers, peptides, and proteins, leading to over 30 PEGylated drugs currently used in the clinic and many investigational PEGylated agents under clinical trials. Here, we summarize the diverse types of PEGylation strategies, the key advantages of PEGylated therapeutics over their parent drugs, and the broad applications and impacts of PEGylation in clinical settings. A particular focus has been given to the size, topology, and functionalities of PEG molecules utilized in clinically used PEGylated drugs, as well as those under clinical trials. An additional section has been dedicated to analyzing some representative PEGylated drugs that were discontinued at different stages of clinical studies. Finally, we critically discuss the current challenges faced in the development and clinical translation of PEGylated agents.

Single protein encapsulated SN38 for tumor-targeting treatment

BACKGROUND

The alkaloid camptothecin analog SN38 is a potent antineoplastic agent, but cannot be used directly for clinical application due to its poor water solubility. Currently, the prodrug approach on SN38 has resulted in 3 FDA-approved cancer therapeutics, irinotecan, ONIVYDE, and Trodelvy. However, only 2-8% of irinotecan can be transformed enzymatically in vivo into the active metabolite SN38, which severely limits the drug's efficacy. While numerous drug delivery systems have been attempted to achieve effective SN38 delivery, none have produced drug products with antitumor efficacy better than irinotecan in clinical trials. Therefore, novel approaches are urgently needed for effectively delivering SN38 to cancer cells with better efficacy and lower toxicity.

METHODS

Based on the unique properties of human serum albumin (HSA), we have developed a novel single protein encapsulation (SPE) technology to formulate cancer therapeutics for improving their pharmacokinetics (PK) and antitumor efficacy and reducing their side effects. Previous application of SPE technology to doxorubicin (DOX) formulation has led to a promising drug candidate SPEDOX-6 (FDA IND #, 152154), which will undergo a human phase I clinical trial. Using the same SPE platform on SN38, we have now produced two SPESN38 complexes, SPESN38-5 and SPESN38-8. We conducted their pharmacological evaluations with respect to maximum tolerated dose, PK, and in vivo efficacy against colorectal cancer (CRC) and soft tissue sarcoma (STS) in mouse models.

RESULTS

The lyophilized SPESN38 complexes can dissolve in aqueous media to form clear and stable solutions. Maximum tolerated dose (MTD) of SPESN38-5 is 250 mg/kg by oral route (PO) and 55 mg/kg by intravenous route (IV) in CD-1 mice. SPESN38-8 has the MTD of 45 mg/kg by IV in the same mouse model. PK of SPESN38-5 by PO at 250 mg/kg gave mouse plasma AUC0-∞ of 0.05 and 4.5 nmol × h/mL for SN38 and SN38 glucuronidate (SN38G), respectively, with a surprisingly high molar ratio of SN38G:SN38 = 90:1. However, PK of SPESN38-5 by IV at 55 mg/kg yielded much higher mouse plasma AUC0-∞ of 19 and 28 nmol × h/mL for SN38 and SN38G, producing a much lower molar ratio of SN38G:SN38 = 1.5:1. Antitumor efficacy of SPESN38-5 and irinotecan (control) was evaluated against HCT-116 CRC xenograft tumors. The data indicates that SPESN38-5 by IV at 55 mg/kg is more effective in suppressing HCT-116 tumor growth with lower systemic toxicity compared to irinotecan at 50 mg/kg. Additionally, SPESN38-8 and DOX (control) by IV were evaluated in the SK-LMS-1 STS mouse model. The results show that SPESN38-8 at 33 mg/kg is highly effective for inhibiting SK-LMS-1 tumor growth with low toxicity, in contrast to DOX's insensitivity to SK-LMS-1 with high toxicity.

CONCLUSION

SPESN38 complexes provide a water soluble SN38 formulation. SPESN38-5 and SPESN38-8 demonstrate better PK values, lower toxicity, and superior antitumor efficacy in mouse models, compared with irinotecan and DOX.

Drug-Induced Conformational Dynamics of P-Glycoprotein Underlies the Transport of Camptothecin Analogs

P-glycoprotein (Pgp) plays a pivotal role in drug bioavailability and multi-drug resistance development. Understanding the protein's activity and designing effective drugs require insight into the mechanisms underlying Pgp-mediated transport of xenobiotics. In this study, we investigated the drug-induced conformational changes in Pgp and adopted a conformationally-gated model to elucidate the Pgp-mediated transport of camptothecin analogs (CPTs). While Pgp displays a wide range of conformations, we simplified it into three model states: 'open-inward', 'open-outward', and 'intermediate'. Utilizing acrylamide quenching of Pgp fluorescence as a tool to examine the protein's tertiary structure, we observed that topotecan (TPT), SN-38, and irinotecan (IRT) induced distinct conformational shifts in the protein. TPT caused a substantial shift akin to AMPPNP, suggesting ATP-independent 'open-outward' conformation. IRT and SN-38 had relatively moderate effects on the conformation of Pgp. Experimental atomic force microscopy (AFM) imaging supports these findings. Further, the rate of ATPase hydrolysis was correlated with ligand-induced Pgp conformational changes. We hypothesize that the separation between the nucleotide-binding domains (NBDs) creates a conformational barrier for substrate transport. Substrates that reduce the conformational barrier, like TPT, are better transported. The affinity for ATP extracted from Pgp-mediated ATP hydrolysis kinetics curves for TPT was about 2-fold and 3-fold higher than SN-38 and IRT, respectively. On the contrary, the dissociation constants (KD) determined by fluorescence quenching for these drugs were not significantly different. Saturation transfer double difference (STDD) NMR of TPT and IRT with Pgp revealed that similar functional groups of the CPTs are accountable for Pgp-CPTs interactions. Efforts aimed at modifying these functional groups, guided by available structure-activity relationship data for CPTs and DNA-Topoisomerase-I complexes, could pave the way for the development of more potent next-generation CPTs.