Antitumor Drugs and Their Targets

Self-Immolative Domino Dendrimers as Anticancer-Drug Delivery Systems: A Review

Worldwide cancer statistics have indicated about 20 million new cancer cases and over 10 million deaths in 2022 (according to data from the International Agency for Research on Cancer). One of the leading cancer treatment strategies is chemotherapy, using innovative drug delivery systems (DDSs). Self-immolative domino dendrimers (SIDendr) for triggered anti-cancer drugs appear to be a promising type of DDSs. The present review provides an up-to-date survey on the contemporary advancements in the field of SIDendr-based anti-cancer drug delivery systems (SIDendr-ac-DDSs) through an exhaustive analysis of the discovery and application of these materials in improving the pharmacological effectiveness of both novel and old drugs. In addition, this article discusses the designing, chemical structure, and targeting techniques, as well as the properties, of several SIDendr-based DDSs. Approaches for this type of targeted DDSs for anti-cancer drug release under a range of stimuli are also explored.

Antioxidants activities of phytochemicals perspective modulation of autophagy and apoptosis to treating cancer

The study of chemicals extracted from natural sources should be encouraged due to the significant number of cancer deaths each year and the financial burden imposed by this disease on society. The causes of almost all cancers involve a combination of lifestyle, environmental factors, and genetic and inherited factors. Modern medicine researchers are increasingly interested in traditional phytochemicals as they hold potential for new bioactive compounds with medical applications. Recent publications have provided evidence of the antitumor properties of phytochemicals, a key component of traditional Chinese medicine, thereby opening new avenues for their use in modern medicine. Various studies have demonstrated a strong correlation between apoptosis and autophagy, two critical mechanisms involved in cancer formation and regulation, indicating diverse forms of crosstalk between them. Phytochemicals have the ability to activate both pro-apoptotic and pro-autophagic pathways. Therefore, understanding how phytochemicals influence the relationship between apoptosis and autophagy is crucial for developing a new cancer treatment strategy that targets these molecular mechanisms. This review aims to explore natural phytochemicals that have demonstrated anticancer effects, focusing on their role in regulating the crosstalk between apoptosis and autophagy, which contributes to uncontrolled tumor cell growth. Additionally, the review highlights the limitations and challenges of current research methodologies while suggesting potential avenues for future research in this field.

Antitumor activity of genetically engineered NK-cells in non-hematological solid tumor: a comprehensive review

Recent advancements in genetic engineering have made it possible to modify Natural Killer (NK) cells to enhance their ability to fight against various cancers, including solid tumors. This comprehensive overview discusses the current status of genetically engineered chimeric antigen receptor NK-cell therapies and their potential for treating solid tumors. We explore the inherent characteristics of NK cells and their role in immune regulation and tumor surveillance. Moreover, we examine the strategies used to genetically engineer NK cells in terms of efficacy, safety profile, and potential clinical applications. Our investigation suggests CAR-NK cells can effectively target and regress non-hematological malignancies, demonstrating enhanced antitumor efficacy. This implies excellent promise for treating tumors using genetically modified NK cells. Notably, NK cells exhibit low graft versus host disease (GvHD) potential and rarely induce significant toxicities, making them an ideal platform for CAR engineering. The adoptive transfer of allogeneic NK cells into patients further emphasizes the versatility of NK cells for various applications. We also address challenges and limitations associated with the clinical translation of genetically engineered NK-cell therapies, such as off-target effects, immune escape mechanisms, and manufacturing scalability. We provide strategies to overcome these obstacles through combination therapies and delivery optimization. Overall, we believe this review contributes to advancing NK-cell-based immunotherapy as a promising approach for cancer treatment by elucidating the underlying mechanisms, evaluating preclinical and clinical evidence, and addressing remaining challenges.

Review of Personalized Medicine and Pharmacogenomics of Anti-Cancer Compounds and Natural Products

In recent years, the FDA has approved numerous anti-cancer drugs that are mutation-based for clinical use. These drugs have improved the precision of treatment and reduced adverse effects and side effects. Personalized therapy is a prominent and hot topic of current medicine and also represents the future direction of development. With the continuous advancements in gene sequencing and high-throughput screening, research and development strategies for personalized clinical drugs have developed rapidly. This review elaborates the recent personalized treatment strategies, which include artificial intelligence, multi-omics analysis, chemical proteomics, and computation-aided drug design. These technologies rely on the molecular classification of diseases, the global signaling network within organisms, and new models for all targets, which significantly support the development of personalized medicine. Meanwhile, we summarize chemical drugs, such as lorlatinib, osimertinib, and other natural products, that deliver personalized therapeutic effects based on genetic mutations. This review also highlights potential challenges in interpreting genetic mutations and combining drugs, while providing new ideas for the development of personalized medicine and pharmacogenomics in cancer study.

Design, synthesis, and biological evaluation of naphthoylamide derivatives as inhibitors of STAT3 phosphorylation

The phosphorylation of STAT3 plays a critical physiological role in the proliferation of rectal cancer. Hence, inhibiting STAT3 phosphorylation is an effective anticancer approach. In this work, we designed a novel 5-R'-1-naphthylmethylamide scaffold as a small molecule inhibitor of STAT3 phosphorylation. The results showed that 3D and 4D have exceptional inhibitory ability against three different colorectal cancer (CRC) cell lines, and can induce apoptosis of CRC cells by inhibiting STAT3 phosphorylation, while having no killing effect on normal human cells. 3D and 4D can inhibit STAT3 phosphorylation in a time- and concentration-dependent manner, and also inhibit the nuclear translocation of interleukin (IL)-6-induced STAT3. In the in vivo tumor model research, 4D significantly reduced the tumor volume of mice and had no drug toxicity on other organ tissues. Furthermore, molecular docking studies revealed that 3D and 4D had greater binding free energy when interacting with the STAT3 SH2 structural domain, and could establish H-π interaction modes. Dynamic simulation studies indicated that both compounds were able to bind tightly to STAT3.

Design, synthesis, and antiproliferative evaluation of novel dehydroabietic acid-1,2,3-triazole-oxazolidinone hybrids

A series of novel dehydroabietic acid derivatives containing both 1,2,3-triazole and oxazolidinone 4a-4t have been synthesized and their antiproliferative activity in vitro against HeLa, HepG2, MGC-803 and T-24 cell lines evaluated. Most of them displayed cell proliferation inhibition on four tested human malignant tumour cell lines to some degree. Among them, compound 4p exhibited promising cytotoxicity with IC50 values ranging from 3.18 to 25.31 μM and weak cytotoxicity toward normal cells. The mechanism of action of 4p was then studied using flow cytometry, Hoechst 33258 staining, ROS generation assay, and JC-1 mitochondrial membrane potential staining, which illustrated that compound 4p induced apoptosis, arrested mitotic process at the G1 phase of the cell cycle, reduced the mitochondrial membrane potential, and increased intracellular ROS levels. In summary, the introduction of an oxazolidinone group via a "1,2,3-triazole" linker significantly improved the antitumor activity of dehydroabietic acid, and deserves to be further investigated.

Nanoplatform-Mediated Autophagy Regulation and Combined Anti-Tumor Therapy for Resistant Tumors

The overall cancer incidence and death toll have been increasing worldwide. However, the conventional therapies have some obvious limitations, such as non-specific targeting, systemic toxic effects, especially the multidrug resistance (MDR) of tumors, in which, autophagy plays a vital role. Therefore, there is an urgent need for new treatments to reduce adverse reactions, improve the treatment efficacy and expand their therapeutic indications more effectively and accurately. Combination therapy based on autophagy regulators is a very feasible and important method to overcome tumor resistance and sensitize anti-tumor drugs. However, the less improved efficacy, more systemic toxicity and other problems limit its clinical application. Nanotechnology provides a good way to overcome this limitation. Co-delivery of autophagy regulators combined with anti-tumor drugs through nanoplatforms provides a good therapeutic strategy for the treatment of tumors, especially drug-resistant tumors. Notably, the nanomaterials with autophagy regulatory properties have broad therapeutic prospects as carrier platforms, especially in adjuvant therapy. However, further research is still necessary to overcome the difficulties such as the safety, biocompatibility, and side effects of nanomedicine. In addition, clinical research is also indispensable to confirm its application in tumor treatment.

A benzimidazolium salt induces apoptosis and arrests cells at sub-G1 phase in epithelial ovarian cancer cells

BACKGROUND

Ovarian cancer, also known as a silent killer, is the deadliest gynecological cancer in women worldwide. Epithelial ovarian cancers constitute the majority of ovarian cancers, and diagnosis can be made in advanced stages, which greatly reduces the likelihood of treatment and lowers the survival rate. For the treatment of epithelial ovarian cancers, the search for synthetic agents as well as agents of natural origin continues. The effects of 1-(2-cyanobenzyl)-3-(4-vinylbenzyl)-1H-benzo[d]imidazole-3-ium chloride (BD), a benzimidazole derivative, were investigated on epithelial ovarian cancer cells.

METHODS AND RESULTS

In our study, the effects of BD on proliferation, colony formation, cell death by apoptosis and the cell cycle in A2780 and A2780 Adriamycin (ADR) ovarian cancer cell lines were investigated. Proliferation was examined with cell viability analysis, colony formation and apoptosis with Annexin V staining and cell cycle analyses with PI staining, respectively. As a result of the analyses, BD inhibited cell proliferation and colony formation, induced apoptosis and cell death at 48 h in A2780 and A2780 ADR cells at 10.10 and 10.36 µM concentrations, respectively. In addition, A2780 and A2780ADR cells were arrested in the Sub-G1 phase of the cell cycle.

CONCLUSIONS

BD suppresses cancer cell progression by showing antiproliferative effects on ovarian cancer cells. Further analyses are required to determine the mechanism of action of this agent and to demonstrate its potential as a suitable candidate for the treatment of epithelial ovarian cancer.

Anticancer effect of covalent purine-containing EGFR TKI, ZZC4 and its mechanism of action through network pharmacology

AIMS

Epidermal growth factor receptor (EGFR) has been documented in many malignancies as participating in the progression of cancer cells. Here, we present a novel EGFR tyrosine kinase inhibitor, ZZC4, and examine its effect on cancer cell proliferation, migration, and tumor-bearing xenograft models.

MAIN METHODS

The antiproliferative effect of ZZC4 was assessed in vitro by MTT assay, colony formation, and wound healing assay and in vivo with tumor-bearing xenograft nude mice. Further, Western blotting analysis and computational network pharmacology were used to explore and understand the mechanism of ZZC4.

KEY FINDINGS

The results showed that ZZC4 potently inhibited the proliferation of lung, breast, and melanoma cells, and was more sensitive to lung cancer cells HCC827, H1975, and breast cancer cell T47D. In vitro findings were corroborated in vivo as results showed the suppressive effect of ZZC4 on HCC827 and H1975 tumor growth. Western blotting analysis confirmed that ZZC4 is an effective inhibitor of the EGFR pathways as it down-regulated p-EGFR, p-Akt, and p-MAPK. Computational molecular docking confirmed the strong binding affinity between ZZC4 and EGFR. Moreover, network pharmacology suggested that ZZC4 might play a suppressive role in the progression of malignancies with EGFR/PI-3K/Akt axis dysregulation or in cancer-related drug resistance.

SIGNIFICANCE

Our study showed that ZZC4 is an anticancer drug candidate.

Oncofetal reprogramming in tumor development and progression: novel insights into cancer therapy

Emerging evidence indicates that cancer cells can mimic characteristics of embryonic development, promoting their development and progression. Cancer cells share features with embryonic development, characterized by robust proliferation and differentiation regulated by signaling pathways such as Wnt, Notch, hedgehog, and Hippo signaling. In certain phase, these cells also mimic embryonic diapause and fertilized egg implantation to evade treatments or immune elimination and promote metastasis. Additionally, the upregulation of ATP-binding cassette (ABC) transporters, including multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 1 (MRP1), and breast cancer-resistant protein (BCRP), in drug-resistant cancer cells, analogous to their role in placental development, may facilitate chemotherapy efflux, further resulting in treatment resistance. In this review, we concentrate on the underlying mechanisms that contribute to tumor development and progression from the perspective of embryonic development, encompassing the dysregulation of developmental signaling pathways, the emergence of dormant cancer cells, immune microenvironment remodeling, and the hyperactivation of ABC transporters. Furthermore, we synthesize and emphasize the connections between cancer hallmarks and embryonic development, offering novel insights for the development of innovative cancer treatment strategies.

A concise review on miRNAs as regulators of colon cancer stem cells and associated signalling pathways

Despite recent therapy advances and a better understanding of colon cancer biology, it remains one of the major causes of death. The cancer stem cells, associated with the progression, metastasis, and recurrence of colon cancer, play a major role in promoting the development of tumour and are found to be chemo resistant. The stroma of the tumour, which makes up the bulk of the tumour mass, is composed of the tumour microenvironment. With the advent of theranostic and the development of personalised medicine, miRNAs are becoming increasingly important in the context of colon malignancies. A holistic understanding of the regulatory roles of miRNAs in cancer cells and cancer stem cells will allow us to design effective strategies to regulate miRNAs, which could lead to improved clinical translation and creating a potent colon cancer treatment strategy. In this review paper, we briefly discuss the history of miRNA as well as the mechanisms of miRNA and cancer stem cells that contribute to the tumour growth, apoptosis, and advancement of colon cancer. The usefulness of miRNA in colorectal cancer theranostic is further concisely reviewed. We conclude by holding a stance in addressing the prospects and possibilities for miRNA by the disclosure of recent theranostic approaches aimed at eradicating cancer stem cells and enhancing overall cancer treatment outcomes.

Pan-cancer analysis revealing that PTPN2 is an indicator of risk stratification for acute myeloid leukemia

The non-receptor protein tyrosine phosphatases gene family (PTPNs) is involved in the tumorigenesis and development of many cancers, but the role of PTPNs in acute myeloid leukemia (AML) remains unclear. After a comprehensive evaluation on the expression patterns and immunological effects of PTPNs using a pan-cancer analysis based on RNA sequencing data obtained from The Cancer Genome Atlas, the most valuable gene PTPN2 was discovered. Further investigation of the expression patterns of PTPN2 in different tissues and cells showed a robust correlation with AML. PTPN2 was then systematically correlated with immunological signatures in the AML tumor microenvironment and its differential expression was verified using clinical samples. In addition, a prediction model, being validated and compared with other models, was developed in our research. The systematic analysis of PTPN family reveals that the effect of PTPNs on cancer may be correlated to mediating cell cycle-related pathways. It was then found that PTPN2 was highly expressed in hematologic diseases and bone marrow tissues, and its differential expression in AML patients and normal humans was verified by clinical samples. Based on its correlation with immune infiltrates, immunomodulators, and immune checkpoint, PTPN2 was found to be a reliable biomarker in the immunotherapy cohort and a prognostic predictor of AML. And PTPN2'riskscore can accurately predict the prognosis and response of cancer immunotherapy. These findings revealed the correlation between PTPNs and immunophenotype, which may be related to cell cycle. PTPN2 was differentially expressed between clinical AML patients and normal people. It is a diagnostic biomarker and potentially therapeutic target, providing targeted guidance for clinical treatment.

Synthetic lipo-polylysine with anti-cancer activity

Development of novel therapeutic agents that possess different anticancer mechanisms from the traditional antitumor drugs is highly attractive as no medication can cure all types of cancers. Herein, we report a rational design of antitumor lipo-polylysine polymers as synthetic mimics of biosynthetic lipopeptide surfactants featuring antimicrobial or cytotoxic activities for cancer therapy. The optimal polymer shows a wide range of anticancer activities against multiple cancer cells, including highly metastatic and drug-resistant ones, but low toxicity to normal cells. Mechanism studies show that the optimal polymer can interact with the membrane of cancer cells and induce cell necrosis by triggering cell membrane perforation, which is different from the therapeutic mechanisms of traditional anticancer drugs. In vivo studies imply that the optimal polymer efficiently inhibits tumor growth without causing obvious side effects on a C26 graft tumor model. Overall, the lipopeptide-mimicking lipo-polylysine with the advantages of easy synthesis and low cost provides a new anticancer strategy with high efficacy and biocompatibility.

Targeting Triple-Negative Breast Cancer by the Phytopolyphenol Carnosol: ROS-Dependent Mechanisms

Triple-negative breast cancer (TNBC), which lacks the expression of the three hormone receptors (i.e., estrogen receptor, progesterone receptor, and human epidermal growth factor receptor), is characterized by a high proliferative index, high invasiveness, poor prognosis, early relapse, and a tendency to be present in advanced stages. These characteristics rank TNBC among the most aggressive and lethal forms of breast cancer. The lack of the three receptors renders conventional hormonal therapy ineffective against TNBC. Moreover, there are no clinically approved therapies that specifically target TNBC, and the currently used chemotherapeutic agents, such as cisplatin, taxanes, and other platinum compounds, have a limited clinical effect and develop chemoresistance over time. Phytochemicals have shown efficacy against several types of cancer, including TNBC, by targeting several pathways involved in cancer development and progression. In this review, we focus on one phytochemical carnosol, a natural polyphenolic terpenoid with strong anti-TNBC effects and its ROS-dependent molecular mechanisms of action. We discuss how carnosol targets key pathways and proteins regulating the cell cycle, growth, epigenetic regulators, invasion, and metastasis of TNBC. This review identifies carnosol as a potential novel targeting protein degradation molecule.

Organotypic Models for Functional Drug Testing of Human Cancers

In the era of personalized oncology, there have been accelerated efforts to develop clinically relevant platforms to test drug sensitivities of individual cancers. An ideal assay will serve as a diagnostic companion to inform the oncologist of the various treatments that are sensitive and insensitive, thus improving outcome while minimizing unnecessary toxicities and costs. To date, no such platform exists for clinical use, but promising approaches are on the horizon that take advantage of improved techniques in creating human cancer models that encompass the entire tumor microenvironment, alongside technologies for assessing and analyzing tumor response. This review summarizes a number of current strategies that make use of intact human cancer tissues as organotypic cultures in drug sensitivity testing.

Analogues of Anticancer Natural Products: Chiral Aspects

Life is chiral, as its constituents consist, to a large degree, of optically active molecules, be they macromolecules (proteins, nucleic acids) or small biomolecules. Hence, these molecules interact disparately with different enantiomers of chiral compounds, creating a preference for a particular enantiomer. This chiral discrimination is of special importance in medicinal chemistry, since many pharmacologically active compounds are used as racemates—equimolar mixtures of two enantiomers. Each of these enantiomers may express different behaviour in terms of pharmacodynamics, pharmacokinetics, and toxicity. The application of only one enantiomer may improve the bioactivity of a drug, as well as reduce the incidence and intensity of adverse effects. This is of special significance regarding the structure of natural products since the great majority of these compounds contain one or several chiral centres. In the present survey, we discuss the impact of chirality on anticancer chemotherapy and highlight the recent developments in this area. Particular attention has been given to synthetic derivatives of drugs of natural origin, as naturally occurring compounds constitute a major pool of new pharmacological leads. Studies have been selected which report the differential activity of the enantiomers or the activities of a single enantiomer and the racemate.

Taurine and Creatine Transporters as Potential Drug Targets in Cancer Therapy

Cancer cells are characterized by uncontrolled growth, proliferation, and impaired apoptosis. Tumour progression could be related to poor prognosis and due to this fact, researchers have been working on novel therapeutic strategies and antineoplastic agents. It is known that altered expression and function of solute carrier proteins from the SLC6 family could be associated with severe diseases, including cancers. These proteins were noticed to play important physiological roles through transferring nutrient amino acids, osmolytes, neurotransmitters, and ions, and many of them are necessary for survival of the cells. Herein, we present the potential role of taurine (SLC6A6) and creatine (SLC6A8) transporters in cancer development as well as therapeutic potential of their inhibitors. Experimental data indicate that overexpression of analyzed proteins could be connected with colon or breast cancers, which are the most common types of cancers. The pool of known inhibitors of these transporters is limited; however, one ligand of SLC6A8 protein is currently tested in the first phase of clinical trials. Therefore, we also highlight structural aspects useful for ligand development. In this review, we discuss SLC6A6 and SLC6A8 transporters as potential biological targets for anticancer agents.

Ruthenium-based antitumor drugs and delivery systems from monotherapy to combination therapy

Ruthenium complex is an important compound group for antitumor drug research and development. NAMI-A, KP1019, TLD1433 and other ruthenium complexes have entered clinical research. In recent years, the research on ruthenium antitumor drugs has not been limited to single chemotherapy drugs; other applications of ruthenium complexes have emerged such as in combination therapy. During the development of ruthenium complexes, drug delivery forms of ruthenium antitumor drugs have also evolved from single-molecule drugs to nanodrug delivery systems. The review summarizes the following aspects: (1) ruthenium complexes from monotherapy to combination therapy, including the development of single-molecule compounds, carrier nanomedicine, and self-assembly of carrier-free nanomedicine; (2) ruthenium complexes in the process of ADME in terms of absorption, distribution, metabolism and excretion; (3) the applications of ruthenium complexes in combination therapy, including photodynamic therapy (PDT), photothermal therapy (PTT), photoactivated chemotherapy (PACT), immunotherapy, and their combined application; (4) the future prospects of ruthenium-based antitumor drugs.

Natural products exert anti-tumor effects by regulating exosomal ncRNA

Currently, more than 60% of the approved anti-cancer drugs come from or are related to natural products. Natural products and exosomal non-coding RNAs (ncRNAs) exert anti-cancer effects through various regulatory mechanisms, which are of great research significance. Exosomes are a form of intercellular communication and contain ncRNAs that can act as intercellular signaling molecules involved in the metabolism of tumor cells. This review exemplifies some examples of natural products whose active ingredients can play a role in cancer prevention and treatment by regulating exosomal ncRNAs, with the aim of illustrating the mechanism of action of exosomal ncRNAs in cancer prevention and treatment. Meanwhile, the application of exosomes as natural drug delivery systems and predictive disease biomarkers in cancer prevention and treatment is introduced, providing research ideas for the development of novel anti-tumor drugs.

Hydroxysafflor yellow B induces apoptosis via mitochondrial pathway in human gastric cancer cells

OBJECTIVES

Hydroxysafflor yellow B (HSYB) is extracted from the petals of the safflower, a Chinese medicine. Relevant research results have demonstrated that HSYA can suppress the abnormal tumour cell proliferation and induce cell apoptosis. However, the properties of HSYB have rarely been reported, especially its antitumour effects on gastric cancer (GC).

METHODS

SGC-7901 and BGC-823 cells were treated with different concentrations of HSYB. Cell proliferation inhibition rate was detected by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and colony formation detection. The changes in morphology of cells was observed by Hoechst 33258 staining. Cell apoptosis was evaluated by Annexin V-FITC/PI (fluoresceinisothiocyanate/propidium iodide) double staining. JC-1 was used to detect the level of mitochondrial membrane potential (MMP). The protein levels of cleaved-caspase-3, cleaved-caspase-9, APAF-1, cytoplasmic cytochrome C, BAX and BCL-2 were examined by western blot.

KEY FINDINGS

HSYB significantly suppressed the proliferation of SGC-7901 and BGC-823 cells. Hoechst 33258 staining assay showed that HSYB treatment triggered apoptotic morphology and the apoptotic rates were significantly increased after being treated with HSYB and the mitochondrial membrane potential was gradually decreased in human GC cells. In addition, Western blot analysis revealed that the levels of cleaved-caspase-3 and cleaved-caspase-9 were remarkably increased in HSYB-treated BGC-823 and SGC-7901 cells. And, the levels of apoptotic protease activating factor-1 (APAF-1) and cytoplasmic cytochrome C were remarkably up-regulated in HSYB-treated cells. At the same time, HSYB could up-regulate the level of BAX and down-regulate the level of BCL-2.

CONCLUSIONS

Our data suggest that HSYB could induce GC cell apoptosis via the mitochondrial pathway.

Anticancer Potential of Xanthohumol and Isoxanthohumol Loaded into SBA-15 Mesoporous Silica Particles against B16F10 Melanoma Cells

Xanthohumol (XN) and isoxanthohumol (IXN), prenylated flavonoids from Humulus lupulus, have been shown to possess antitumor/cancerprotective, antioxidant, antiinflammatory, and antiangiogenic properties. In this study, mesoporous silica (SBA-15) was loaded with different amounts of xanthohumol and isoxanthohumol and characterized by standard analytical methods. The anticancer potential of XN and IXN loaded into SBA-15 has been evaluated against malignant mouse melanoma B16F10 cells. When these cells were treated with SBA-15 containing xanthohumol, an increase of the activity correlated with a higher immobilization rate of XN was observed. Considering the amount of XN loaded into SBA-15 (calculated from TGA), an improved antitumor potential of XN was observed (IC₅₀ = 10.8 ± 0.4 and 11.8 ± 0.5 µM for SBA-15|XN2 and SBA-15|XN3, respectively; vs. IC₅₀ = 18.5 ± 1.5 µM for free XN). The main mechanism against tumor cells of immobilized XN includes inhibition of proliferation and autophagic cell death. The MC₅₀ values for SBA-15 loaded with isoxanthohumol were over 300 µg/mL in all cases investigated.

Development of Photoremovable Linkers as a Novel Strategy to Improve the Pharmacokinetics of Drug Conjugates and Their Potential Application in Antibody–Drug Conjugates for Cancer Therapy

Although there have been extensive research and progress on the discovery of anticancer drug over the years, the application of these drugs as stand-alone therapy has been limited by their off-target toxicities, poor pharmacokinetic properties, and low therapeutic index. Targeted drug delivery, especially drug conjugate, has been recognized as a technology that can bring forth a new generation of therapeutics with improved efficacy and reduced side effects for cancer treatment. The linker in a drug conjugate is of essential importance because it impacts the circulation time of the conjugate and the release of the drug for full activity at the target site. Recently, the light-triggered linker has attracted a lot of attention due to its spatiotemporal controllability and attractive prospects of improving the overall pharmacokinetics of the conjugate. In this paper, the latest developments of UV- and IR-triggered linkers and their application and potential in drug conjugate development are reviewed. Some of the most-well-researched photoresponsive structural moieties, such as UV-triggered coumarin, ortho-nitrobenzyl group (ONB), thioacetal ortho-nitrobenzaldehyde (TNB), photocaged C40-oxidized abasic site (PC4AP), and IR-triggered cyanine and BODIPY, are included for discussion. These photoremovable linkers show better physical and chemical stabilities and can undergo rapid cleavage upon irradiation. Very importantly, the drug conjugates containing these linkers exhibit reduced off-target toxicity and overall better pharmacokinetic properties. The progress on photoactive antibody–drug conjugates, such as antibody–drug conjugates (ADC) and antibody–photoabsorber conjugate (APC), as precision medicine in clinical cancer treatment is highlighted.

Defending and Integrating an Organism by the Immune System

The Integrity model proposes that the adaptive immune response defends, protects and keeps vigilance over the unity of an organism. These functions conceptually rely on three signals that can explain them. All signals have a dual character. The signal‐1 is the recognition of antigen or peptide/MHC ligand. The signal‐2 comprises either help and costimulation or suppression and coinhibition. Lastly, the signal‐3 signals tissues' condition, state or integrity. A part overlaps with the Danger‐associated molecular patterns, and the other part should be detected by putative cell‐surface molecules, intracellular factors or epigenetic events. They are called the Integrity‐associated molecular patterns (IAMPs). The IAMPs originate from damaged (positive signal‐3) or undamaged (negative signal‐3) tissues. The positive signal‐3 would induce costimulatory signal‐2, whereas the negative signal‐3 would induce coinhibitory signal‐2 in APCs. However, in analogue reality, we might more likely encounter a range of signals supposedly sensed by a group of responder cells and integrated overtime (quorum sensing). The predominant option would sway the decision of the immune system to perform either defence or protection (active tolerance). Thus, the quorum sensing supposedly delivers two qualitative thresholds for T (and B) cells' decisions to defend or suppress. If these were not attained, the vigilance (anergy) of adaptive immunocytes for T‐dependent antigens would ensue. These functions provide defence against pathogens and preservation of unity/integrity of an organism, which in turn permits protection of commensals.

In Vitro Pharmacological Screening of Essential Oils from Baccharis parvidentata and Lippia origanoides Growing in Brazil

In this study, the in vitro antimicrobial, antiparasitic, antiproliferative and cytotoxic activities of essential oil from Baccharis parvidentata Malag. (EO-Bp) and Lippia origanoides Kunth (EO-Lo) were explored. The relevant effects were observed against the parasitic protozoans Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei and Leishmania amazonensis (ranging 0.6 to 39.7 µg/mL) and malignant MCF-7, MCF-7/HT, 22Rv1, and A431 cell lines (ranging 6.1 to 31.5 µg/mL). In parallel, EO-Bp showed better selective indexes in comparison with EO-Lo against peritoneal macrophages from BALB/c mice and MRC-5 cell line. In conclusion, EO-Lo is known to show a wide range of health benefits that could be added as another potential use of this oil with the current study. In the case of EO-Bp, the wide spectrum of its activities against protozoal parasites and malignant cells, as well as its selectivity in comparison with non-malignant cells, could suggest an interesting candidate for further tests as a new therapeutic alternative.

Are smart delivery systems the solution to overcome the lack of selectivity of current metallodrugs in cancer therapy?

Chemotherapeutic metallodrugs such as cisplatin and its derivatives are among the most widely applied anticancer treatments worldwide. Nonetheless their clinical success, patients suffer from severe adverse effects while subjected to...

Mannich Bases: Centrality in Cytotoxic Drug Design

Mannich bases identified by Professor Carl Mannich have been the most extensively explored scaffolds for more than 100 years now. The versatile biological roles that they play have promoted their applications in many clinical conditions. The present review highlights the application of Mannich bases as cytotoxic agents, categorizing them into synthetic, semisynthetic and prodrugs classes and gives an exhaustive account of the work reported in the last two decades. The methods of synthesis of these cytotoxic agents, their anti-cancer potential in various cell lines and promising leads for future drug development have also been discussed. Structure-activity relationships along with the targets on which these cytotoxic Mannich bases act have been included as well.

Cell-Free Supernatant of Odoribacter splanchnicus Isolated From Human Feces Exhibits Anti-colorectal Cancer Activity

The gut microbiota (GM) has been shown to be closely associated with the development of colorectal cancer (CRC). However, the involvement of GM is CRC has mainly been demonstrated by metagenomic profiling studies showing the compositional difference between the GM of healthy individuals and that of CRC patients and not by directly studying isolated gut microbes. Thus, to discover novel gut microbes involved in CRC, we isolated the GM from the feces of healthy individuals and evaluated its anti-CRC activity in vitro and in vivo. After GM isolation, cell-free supernatants (CFSs) were prepared from the isolated gut microorganisms to efficiently screen a large amount of the GM for anti-proliferative ability in vitro. Our results showed that the CFSs of 21 GM isolates had anti-proliferative activity against human colon cancer HCT 116 cells. Of these 21 GM isolates, GM07 was chosen for additional study because it had the highest anti-cancer activity against mouse colon cancer CT 26 cells in vitro and was further evaluated in a CT 26 allograft mouse model in vivo. GM07 was identified as Odoribacter splanchnicus through phylogenetic analysis based on 16S rRNA gene sequencing. Further investigation determined that the CFS of O. splanchnicus (OsCFS) induced anti-proliferative activity via apoptosis, but not cell cycle arrest. Moreover, GC/MS analysis suggested that the putative active molecule in OsCFS is malic acid. Finally, in the CRC mouse model, peri-tumoral injection of OsCFS significantly decreased CRC formation, compared to the control group. Altogether, these findings will provide valuable information for the discovery of potential probiotic candidates that inhibit CRC.

Ocular Toxicity of Targeted Anticancer Agents

The proliferation of targeted anticancer agents over the last two decades has revolutionized cancer treatment and improved survival in many previously refractory malignancies. However, many agents are associated with characteristic ophthalmic adverse effects. It is important that ophthalmologists recognize and maintain a high index of suspicion for these side effects in patients on targeted therapy. Most ophthalmic adverse effects can be treated with specific ocular therapy without discontinuation of cancer treatment, although it is important to be aware of the life-threatening and vision-threatening circumstances that would require therapy cessation in conjunction with the patient's oncologist. This review aims to summarize the ophthalmic adverse effects of targeted and hormonal anticancer agents and briefly describe their management.

In Silico Inference of Synthetic Cytotoxic Interactions from Paclitaxel Responses

To exploit negatively interacting pairs of cancer somatic mutations in chemotherapy responses or synthetic cytotoxicity (SC), we systematically determined mutational pairs that had significantly lower paclitaxel half maximal inhibitory concentration (IC₅₀) values. We evaluated 407 cell lines with somatic mutation profiles and estimated their copy number and drug-inhibitory concentrations in Genomics of Drug Sensitivity in Cancer (GDSC) database. The SC effect of 142 mutated gene pairs on response to paclitaxel was successfully cross-validated using human cancer datasets for urogenital cancers available in The Cancer Genome Atlas (TCGA) database. We further analyzed the cumulative effect of increasing SC pair numbers on the TP53 tumor suppressor gene. Patients with TCGA bladder and urogenital cancer exhibited improved cancer survival rates as the number of disrupted SC partners (i.e., SYNE2, SON, and/or PRY) of TP53 increased. The prognostic effect of SC burden on response to paclitaxel treatment could be differentiated from response to other cytotoxic drugs. Thus, the concept of pairwise SC may aid the identification of novel therapeutic and prognostic targets.