Identification of a rhodium(iii) complex as a Wee1 inhibitor against TP53-mutated triple-negative breast cancer cells

Marine Staurosporine Analogues: Activity and Target Identification in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with high mortality and drug resistance and no targeted drug available at present. Compound 4, a staurosporine alkaloid derived from Streptomyces sp. NBU3142 in a marine sponge, exhibits potent anti-TNBC activity. This research investigated its impact on MDA-MB-231 cells and their drug-resistant variants. The findings highlighted that compound 4 inhibits breast cancer cell migration, induces apoptosis, arrests the cell cycle, and promotes cellular senescence in both regular and paclitaxel-resistant MDA-MB-231 cells. Additionally, this study identified mitogen-activated protein kinase kinase kinase 11 (MAP3K11) as a target of compound 4, implicating its role in breast tumorigenesis by affecting cell proliferation, migration, and cell cycle progression.

Emerging role of Jumonji domain-containing protein D3 in inflammatory diseases

Jumonji domain-containing protein D3 (JMJD3) is a 2-oxoglutarate-dependent dioxygenase that specifically removes transcriptional repression marks di- and tri-methylated groups from lysine 27 on histone 3 (H3K27me2/3). The erasure of these marks leads to the activation of some associated genes, thereby influencing various biological processes, such as development, differentiation, and immune response. However, comprehensive descriptions regarding the relationship between JMJD3 and inflammation are lacking. Here, we provide a comprehensive overview of JMJD3, including its structure, functions, and involvement in inflammatory pathways. In addition, we summarize the evidence supporting JMJD3's role in several inflammatory diseases, as well as the potential therapeutic applications of JMJD3 inhibitors. Additionally, we also discuss the challenges and opportunities associated with investigating the functions of JMJD3 and developing targeted inhibitors and propose feasible solutions to provide valuable insights into the functional exploration and discovery of potential drugs targeting JMJD3 for inflammatory diseases.

Advanced Design, Synthesis, and Evaluation of Highly Selective Wee1 Inhibitors: Enhancing Pharmacokinetics and Antitumor Efficacy

Wee1 is a kinase that regulates cell cycle arrest in response to DNA damage. Wee1 inhibition is a potential strategy to suppress the growth of tumors with defective p53 or DNA repair pathways. However, the development of Wee1 inhibitors faces some challenges. AZD1775, the first-in-class Wee1 inhibitor, has poor kinase selectivity and dose-limiting toxicity. Here, we report the discovery of 12h, a highly selective and potent Wee1 inhibitor with a favorable pharmacokinetic profile. 12h showed strong antiproliferative effects against Lovo cells, a colorectal cancer cell line, both in vitro and in vivo. Moreover, 12h showed a clean kinase profile and effectively induced cell apoptosis. Our results suggest that 12h is a promising drug candidate for further development as a novel anticancer agent.

Exploiting Co(III)-Cyclopentadienyl Complexes To Develop Anticancer Agents

In recent years, organometallic complexes have attracted much attention as anticancer therapeutics aiming at overcoming the limitations of platinum drugs that are currently marketed. Still, the development of half-sandwich organometallic cobalt complexes remains scarcely explored. Four new cobalt(III)-cyclopentadienyl complexes containing N,N-heteroaromatic bidentate, and phosphane ligands were synthesized and fully characterized by elemental analysis, spectroscopic techniques, and DFT methods. The cytotoxicity of all complexes was determined in vitro by the MTS assay in colorectal (HCT116), ovarian (A2780), and breast (MDA-MB-231 and MCF-7) human cancer cell lines and in a healthy human cell line (fibroblasts). The complexes showed high cytotoxicity in cancer cell lines, mostly due to ROS production, apoptosis, autophagy induction, and disruption of the mitochondrial membrane. Also, these complexes were shown to be nontoxic in vivo in an ex ovo chick embryo yolk sac membrane (YSM) assay.

The emerging roles of lysine-specific demethylase 4A in cancer: Implications in tumorigenesis and therapeutic opportunities

Lysine-specific demethylase 4 A (KDM4A, also named JMJD2A, KIA0677, or JHDM3A) is a demethylase that can remove methyl groups from histones H3K9me2/3, H3K36me2/3, and H1.4K26me2/me3. Accumulating evidence suggests that KDM4A is not only involved in body homeostasis (such as cell proliferation, migration and differentiation, and tissue development) but also associated with multiple human diseases, especially cancers. Recently, an increasing number of studies have shown that pharmacological inhibition of KDM4A significantly attenuates tumor progression in vitro and in vivo in a range of solid tumors and acute myeloid leukemia. Although there are several reviews on the roles of the KDM4 subfamily in cancer development and therapy, all of them only briefly introduce the roles of KDM4A in cancer without systematically summarizing the specific mechanisms of KDM4A in various physiological and pathological processes, especially in tumorigenesis, which greatly limits advances in the understanding of the roles of KDM4A in a variety of cancers, discovering targeted selective KDM4A inhibitors, and exploring the adaptive profiles of KDM4A antagonists. Herein, we present the structure and functions of KDM4A, simply outline the functions of KDM4A in homeostasis and non-cancer diseases, summarize the role of KDM4A and its distinct target genes in the development of a variety of cancers, systematically classify KDM4A inhibitors, summarize the difficulties encountered in the research of KDM4A and the discovery of related drugs, and provide the corresponding solutions, which would contribute to understanding the recent research trends on KDM4A and advancing the progression of KDM4A as a drug target in cancer therapy.

Lysine-specific demethylase 7A (KDM7A): A potential target for disease therapy

Histone demethylation is a kind of epigenetic modification mediated by a variety of enzymes and participates in regulating multiple physiological and pathological events. Lysine-specific demethylase 7A is a kind of α-ketoglutarate- and Fe(II)-dependent demethylase belonging to the PHF2/8 subfamily of the JmjC demethylases. KDM7A is mainly localized in the nucleus and contributes to transcriptional activation via removing mono- and di-methyl groups from the lysine residues 9 and 27 of Histone H3. Mounting studies support that KDM7A is not only necessary for normal embryonic, neural, and skeletal development, but also associated with cancer, inflammation, osteoporosis, and other diseases. Herein, the structure of KDM7A is described by comparing the similarities and differences of its amino acid sequences of KDM7A and other Histone demethylases; the functions of KDM7A in homeostasis and dyshomeostasis are summarized via documenting its content and related signaling; the currently known KDM7A-specific inhibitors and their structural relationship are listed based on their structure optimization and pharmacological activities; and the challenges and opportunities in exploring functions and developing targeted agents of KDM7A are also prospected via presenting encountered problems and potential solutions, which will provide an insight in functional exploration and drug discovery for KDM7A-related diseases.

Synthetic and Medicinal Chemistry Approaches Toward WEE1 Kinase Inhibitors and Its Degraders

WEE1 is a checkpoint kinase critical for mitotic events, especially in cell maturation and DNA repair. Most cancer cells' progression and survival are linked with elevated levels of WEE1 kinase. Thus, WEE1 kinase has become a new promising druggable target. A few classes of WEE1 inhibitors are designed by rationale or structure-based techniques and optimization approaches to identify selective acting anticancer agents. The discovery of the WEE1 inhibitor AZD1775 further emphasized WEE1 as a promising anticancer target. Therefore, the current review provides a comprehensive data on medicinal chemistry, synthetic approaches, optimization methods, and the interaction profile of WEE1 kinase inhibitors. In addition, WEE1 PROTAC degraders and their synthetic procedures, including a list of noncoding RNAs necessary for regulation of WEE1, are also highlighted. From the standpoint of medicinal chemistry, the contents of this compilation serve as an exemplar for the further design, synthesis, and optimization of promising WEE1-targeted anticancer agents.

HDAC inhibitors enhance the anti-tumor effect of immunotherapies in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the most common liver malignancy with a poor prognosis and increasing incidence, remains a serious health problem worldwide. Immunotherapy has been described as one of the ideal ways to treat HCC and is transforming patient management. However, the occurrence of immunotherapy resistance still prevents some patients from benefiting from current immunotherapies. Recent studies have shown that histone deacetylase inhibitors (HDACis) can enhance the efficacy of immunotherapy in a variety of tumors, including HCC. In this review, we present current knowledge and recent advances in immunotherapy-based and HDACi-based therapies for HCC. We highlight the fundamental dynamics of synergies between immunotherapies and HDACis, further detailing current efforts to translate this knowledge into clinical benefits. In addition, we explored the possibility of nano-based drug delivery system (NDDS) as a novel strategy to enhance HCC treatment.

The role of lysine-specific demethylase 6A (KDM6A) in tumorigenesis and its therapeutic potentials in cancer therapy

Histone demethylation is a key post-translational modification of chromatin, and its dysregulation affects a wide array of nuclear activities including the maintenance of genome integrity, transcriptional regulation, and epigenetic inheritance. Lysine specific demethylase 6A (KDM6A, also known as UTX) is an Fe²⁺- and α-ketoglutarate- dependent oxidase which belongs to KDM6 Jumonji histone demethylase subfamily, and it can remove mono-, di- and tri-methyl groups from methylated lysine 27 of histone H3 (H3K27me1/2/3). Mounting studies indicate that KDM6A is responsible for driving multiple human diseases, particularly cancers and pharmacological inhibition of KDM6A is an effective strategy to treat varieties of KDM6A-amplified cancers in cellulo and in vivo. Although there are several reviews on the roles of KDM6 subfamily in cancer development and therapy, all of them only simply introduce the roles of KDM6A in cancer without systematically summarizing the specific mechanisms of KDM6A in tumorigenesis, which greatly limits the advances on the understanding of roles KDM6A in varieties of cancers, discovering targeting selective KDM6A inhibitors, and exploring the adaptive profiles of KDM6A antagonists. Herein, we present the structure and functions of KDM6A, simply outline the functions of KDM6A in homeostasis and non-cancer diseases, summarize the role of KDM6A and its distinct target genes/ligand proteins in development of varieties of cancers, systematically classify KDM6A inhibitors, sum up the difficulties encountered in the research of KDM6A and the discovery of related drugs, and provide the corresponding solutions, which will contribute to understanding the roles of KDM6A in carcinogenesis and advancing the progression of KDM6A as a drug target in cancer therapy.

A state-of-the-art review on LSD1 and its inhibitors in breast cancer: Molecular mechanisms and therapeutic significance

Breast cancer (BC) is a kind of malignant cancer in women, and it has become the most diagnosed cancer worldwide since 2020. Histone methylation is a common biological epigenetic modification mediating varieties of physiological and pathological processes. Lysine-specific demethylase 1 (LSD1), a first identified histone demethylase, mediates the removal of methyl groups from histones H3K4me1/2 and H3K9me1/2 and plays a crucial role in varieties of cancer progression. It is also specifically amplified in breast cancer and contributes to BC tumorigenesis and drug resistance via both demethylase and non-demethylase manners. This review will provide insight into the overview structure of LSD1, summarize its action mechanisms in BC, describe the therapeutic potential of LSD1 inhibitors in BC, and prospect the current opportunities and challenges of targeting LSD1 for BC therapy.

Berberine as a potential agent for breast cancer therapy

Breast cancer (BC) is a common malignancy that mainly occurred in women and it has become the most diagnosed cancer annually since 2020. Berberine (BBR), an alkaloid extracted from the Berberidacea family, has been found with broad pharmacological bioactivities including anti-inflammatory, anti-diabetic, anti-hypertensive, anti-obesity, antidepressant, and anticancer effects. Mounting evidence shows that BBR is a safe and effective agent with good anticancer activity against BC. However, its detailed underlying mechanism in BC treatment remains unclear. Here, we will provide the evidence for BBR in BC therapy and summarize its potential mechanisms. This review briefly introduces the source, metabolism, and biological function of BBR and emphasizes the therapeutic effects of BBR against BC via directly interacting with effector proteins, transcriptional regulatory elements, miRNA, and several BBR-mediated signaling pathways. Moreover, the novel BBR-based therapeutic strategies against BC improve biocompatibility and water solubility, and the efficacies of BBR are also briefly discussed. Finally, the status of BBR in BC treatment and future research directions is also prospected.

Bioactivity and Development of Small Non-Platinum Metal-Based Chemotherapeutics

Countless expectations converge in the multidisciplinary endeavour for the search and development of effective and safe drugs in fighting cancer. Although they still embody a minority of the pharmacological agents currently in clinical use, metal-based complexes have great yet unexplored potential, which probably hides forthcoming anticancer drugs. Following the historical success of cisplatin and congeners, but also taking advantage of conventional chemotherapy limitations that emerged with applications in the clinic, the design and development of non-platinum metal-based chemotherapeutics, either as drugs or prodrugs, represents a rapidly evolving field wherein candidate compounds can be fine-tuned to access interactions with druggable biological targets. Moving in this direction, over the last few decades platinum family metals, e.g., ruthenium and palladium, have been largely proposed. Indeed, transition metals and molecular platforms where they originate are endowed with unique chemical and biological features based on, but not limited to, redox activity and coordination geometries, as well as ligand selection (including their inherent reactivity and bioactivity). Herein, current applications and progress in metal-based chemoth are reviewed. Converging on the recent literature, new attractive chemotherapeutics based on transition metals other than platinum—and their bioactivity and mechanisms of action—are examined and discussed. A special focus is committed to anticancer agents based on ruthenium, palladium, rhodium, and iridium, but also to gold derivatives, for which more experimental data are nowadays available. Next to platinum-based agents, ruthenium-based candidate drugs were the first to reach the stage of clinical evaluation in humans, opening new scenarios for the development of alternative chemotherapeutic options to treat cancer.

Inhibition of the CDK9-cyclin T1 protein-protein interaction as a new approach against triple-negative breast cancer

Cyclin-dependent kinase 9 (CDK9) activity is correlated with worse outcomes of triple-negative breast cancer (TNBC) patients. The heterodimer between CDK9 with cyclin T1 is essential for maintaining the active state of the kinase and targeting this protein-protein interaction (PPI) may offer promising avenues for selective CDK9 inhibition. Herein, we designed and generated a library of metal complexes bearing the 7-chloro-2-phenylquinoline CˆN ligand and tested their activity against the CDK9-cyclin T1 PPI. Complex 1 bound to CDK9 via an enthalpically-driven binding mode, leading to disruption of the CDK9-cyclin T1 interaction in vitro and in cellulo. Importantly, complex 1 showed promising anti-metastatic activity against TNBC allografts in mice and was comparably active compared to cisplatin. To our knowledge, 1 is the first CDK9-cyclin T1 PPI inhibitor with anti-metastatic activity against TNBC. Complex 1 could serve as a new platform for the future design of more efficacious kinase inhibitors against cancer, including TNBC.

Cell cycle involvement in cancer therapy; WEE1 kinase, a potential target as therapeutic strategy

Mitosis is the process of cell division and is regulated by checkpoints in the cell cycle. G1-S, S, and G2-M are the three main checkpoints that prevent initiation of the next phase of the cell cycle phase until previous phase has completed. DNA damage leads to activation of the G2-M checkpoint, which can trigger a downstream DNA damage response (DDR) pathway to induce cell cycle arrest while the damage is repaired. If the DNA damage cannot be repaired, the replication stress response (RSR) pathway finally leads to cell death by apoptosis, in this case called mitotic catastrophe. Many cancer treatments (chemotherapy and radiotherapy) cause DNA damages based on SSBs (single strand breaks) or DSBs (double strand breaks), which cause cell death through mitotic catastrophe. However, damaged cells can activate WEE1 kinase (as a part of the DDR and RSR pathways), which prevents apoptosis and cell death by inducing cell cycle arrest at G2 phase. Therefore, inhibition of WEE1 kinase could sensitize cancer cells to chemotherapeutic drugs. This review focuses on the role of WEE1 kinase (as a biological macromolecule which has a molecular mass of 96 kDa) in the cell cycle, and its interactions with other regulatory pathways. In addition, we discuss the potential of WEE1 inhibition as a new therapeutic approach in the treatment of various cancers, such as melanoma, breast cancer, pancreatic cancer, cervical cancer, etc.

Pharmacological inhibition of KDM5A for cancer treatment

Lysine-specific demethylase 5A (KDM5A, also named RBP2 or JARID1A) is a demethylase that can remove methyl groups from histones H3K4me1/2/3. It is aberrantly expressed in many cancers, where it impedes differentiation and contributes to cancer cell proliferation, cell metastasis and invasiveness, drug resistance, and is associated with poor prognosis. Pharmacological inhibition of KDM5A has been reported to significantly attenuate tumor progression in vitro and in vivo in a range of solid tumors and acute myeloid leukemia. This review will present the structural aspects of KDM5A, its role in carcinogenesis, a comparison of currently available approaches for screening KDM5A inhibitors, a classification of KDM5A inhibitors, and its potential as a drug target in cancer therapy.

A review on the emerging roles of pyruvate kinase M2 in anti-leukemia therapy

Glycolysis is an important step in respiration and provides energy for cellular processes. Pyruvate kinase M2 (PKM2), a key rate-limiting enzyme of glycolysis, plays an important role in tumor cell metabolism and proliferation. It is also specifically overexpressed in leukemia cells and contributes to leukemic proliferation, differentiation, and drug resistance through both aerobic glycolysis and non-metabolic pathways. In this review, the functions and regulatory roles of PKM2 are firstly introduced. Then, the molecular mechanisms of PKM2 in leukemogenesis are summarized. Next, reported PKM2 modulators and their anti-leukemia mechanisms are described. Finally, the current challenges and the potential opportunities of PKM2 inhibitors or agonists in leukemia therapy are discussed.

Ru(ii), Ir(iii), Re(i) and Rh(iii) based complexes as next generation anticancer metallopharmaceuticals

Several anticancer drugs such as cisplatin, and its analogues, epirubicin, and doxorubicin are well known for their anticancer activity but the therapeutic value of these drugs comes with certain side effects and they cannot distinguish between normal and cancer cells. Thus, a major challenge for researchers around the world is to develop an anticancer drug with the least toxicity and more target specificity. With the successful reporting of NAMI-A and KP1019, a new path has emerged in the anticancer field. Recently, several Ru(ii) complexes have been reported for their anticancer activity due to their enhanced cellular uptake and selectivity towards cancer cells. Apart from the Ru(ii) complexes, a large amount of research has been carried out with Ir(iii), Re(i), and Rh(iii) based complexes, which exhibited promising anticancer activity. The present review reports various Ru(ii), Ir(iii), Re(i), and Rh(iii) based complexes for their anticancer activity based on their cytotoxicity profiles, biological targets and mechanism of action.

Mitochondria-targeted cyclometalated rhodium(III) complexes: synthesis, characterization and anticancer research

Over the past few decades, the landscape of inorganic medicinal chemistry has been dominated by investigations on platinum or ruthenium, while the research based on other metal centers such as rhodium has been relatively insufficient. In this work, a series of cyclometalated rhodium(iii) complexes with imidazo[4,5-f][1,10]phenanthroline containing different aromatic rings were synthesized and characterized. Notably, all the complexes displayed stronger anticancer activity against various cancer cells compared with cisplatin. A mechanism study revealed that the rhodium complexes accumulated in the mitochondria, elevated the levels of mitochondrial reactive oxygen species (ROS) and released cytochrome c, indicating severe mitochondrial damage during the anticancer activity. Further studies illustrated that the rhodium complexes caused cell cycle arrest at the G2/M phase, upregulated the expression of p53 and reduced the ratio of B-cell lymphoma-2 (Bcl-2)/Bcl-2-associated x (Bax), which ultimately resulted in cellular apoptosis. Overall, through mitochondrial pathways, these Rh(iii) complexes could induce cellular apoptosis to a larger extent than cisplatin and should be paid close attention as promising chemotherapeutic drugs in anticancer research.

Exploring the Potential of Metallodrugs as Chemotherapeutics for Triple Negative Breast Cancer

This review focuses on studies of coordination and organometallic compounds as potential chemotherapeutics against triple negative breast cancer (TNBC) which has one of the poorest prognoses and worst survival rates from all breast cancer types. At present, chemotherapy is still the standard of care for TNBC since only one type of targeted therapy has been recently developed. References for metal-based compounds studied in TNBC cell lines will be listed, and those of metal-specific reviews, but a detailed overview will also be provided on compounds studied in vivo (mostly in mice models) and those compounds for which some preliminary mechanistic data was obtained (in TNBC cell lines and tumors) and/or for which bioactive ligands have been used. The main goal of this review is to highlight the most promising metal-based compounds with potential as chemotherapeutic agents in TNBC.

Recent advances in biological activities of rhodium complexes: Their applications in drug discovery research

Unique structure, characteristic reactivity, and facile synthesis of metal complexes have made them efficient ligands in drug development research. Among them, rhodium complexes have a limited history and there are a few discussions about their biological activities documented in the literature. However, investigation of kinetically inert rhodium complexes has recently attracted lots of attention and especially there are various evidences on their anti-cancer activity. It seems that they can be investigated as a versatile surrogates or candidates for the existing drugs which do not affect selectively or suffer from various side effects. In recent years, there has been an increasing interest in the use of mononuclear rhodium (III) organometallo drugs due to its versatile structurally important aspects to inhibit various enzymes. It has been demonstrated that organometallic Rh complexes profiting from both organic and inorganic aspects have shown more potent biological activities than classical inorganic compartments. In this respect, smart design, use of the appropriate organic ligands, and efficient and user-friendly synthesis of organometallic Rh complexes have played crucial roles in the inducing desirable biological activities. In this review, we focused on the recent advances published on the bioactivity of Rh (III/II/I) complexes especially inhibitory activity, from 2013 till now. Accordingly, considering the structure-activity relationship (SAR), the effect of oxidation state (+1, +2, and +3) and geometry (dimer or monomer complexes with coordination number of 4 and 6) of Rh complexes as well as various ligands on in vitro and in vivo studies was comprehensively discussed.

Tuning the Luminescent Properties of Ruthenium(II) Amino-1,10-Phenanthroline Complexes by Varying the Position of the Amino Group on the Heterocycle

Eight 1,10-phenanthrolines bearing one or two 2-(1-adamantyloxy)ethylamino substituents attached to different positions of the heterocyclic core were prepared according to S_N Ar or palladium-catalyzed amination reactions. Their reaction with cis-Ru(bpy)₂ Cl₂ (bpy=2,2'-bipyridine) was investigated and Ru(bpy)₂ (L)(PF₆ )₂ (phen=1,10-phenanthroline) (L=amino-substituted 1,10-phenanthroline) complexes were obtained in good yields. The electronic structure and emissive properties of these complexes are strongly dependent on the position of the amino substituent in the heterocycle. Emission bands of the complexes bearing 2- and 4-substituted 1,10-phenanthroline ligands are red-shifted (up to 56 nm) and less intense compared to that of the parent [Ru(phen)(bpy)₂ ](PF₆ )₂ . In contrast, the introduction of the substituent in 3- or 5-position of 1,10-phenanthroline ring induces only small decrease of luminescence and the brightness of the complex with the 3-substituted ligand is comparable to that of the parent complex.

Cobalt(II) Diphenylazodioxide Complexes Induce Apoptosis in SK-HEP-1 Cells

The cobalt(II) complex salts [Co(bpy)(az)₂](PF₆)₂ and [Co(az)₄](PF₆), each bearing the unusual cis-N,N'-diphenylazodioxide ligand, were both screened as possible anticancer agents against SK-HEP-1 liver cancer cells. Both compounds were found to induce substantial apoptosis as an increasing function of concentration and time. Measurement of apoptosis-related proteins indicated that both the extrinsic and intrinsic pathways of apoptosis were activated. The apoptotic activity induced by these salts is not displayed either by simple cobalt(II) salts or complexes or by the free nitrosobenzene ligand. Additionally, these compounds did not induce apoptosis, as assessed by poly(adenosine diphosphate-ribose) polymerase cleavage, in several other cell lines.

Recent therapeutic trends and promising targets in triple negative breast cancer

Breast cancer accounts for 25% of all types of cancer in women, and triple negative breast cancer (TNBC) comprises around 15~20% of breast cancers. Conventional chemotherapy and radiation are the primary systemic therapeutic strategies; no other FDA-approved targeted therapies are yet available as for TNBC. TNBC is generally characterized by a poor prognosis and high rates of proliferation and metastases. Due to these aggressive features and lack of targeted therapies, numerous attempts have been made to discover viable molecular targets for TNBC. Massive cohort studies, clinical trials, and in-depth analyses have revealed diverse molecular alterations in TNBC; however, controversy exists as to whether many of these changes are beneficial or detrimental in caner progression. Here we review the complicated tumorigenic processes and discuss critical findings and therapeutic trends in TNBC with a focus on promising therapeutic approaches, the clinical trials currently underway, and potent experimental compounds under preclinical and evaluation.

Expression and biological function of rhotekin in gastric cancer through regulating p53 pathway

Background/aim

Gastric cancer (GC) is one of a most threatening cancer globally. Rhotekin (RTKN), a Rho effector, has been reported to be upregulated in GC tissues. This study aimed to investigate the underlying regulatory roles of RTKN in the biological behavior of GC.

Methods

Real-time PCR and Western blotting were carried out to detect the mRNA and protein expression, respectively. Cell Counting Kit-8 and xenograft nude mice model were used to evaluate cell proliferation. Flow cytometry analysis was performed to assess cell cycle distribution and cell apoptosis.

Results

RTKN had high expression level in GC compared with normal tissues. RTKN expression strongly associated with tumor size, TNM stage, lymphnode metastasis and the poor prognosis of patients with GC. Downregulation of RTKN significantly repressed GC cell proliferation, but increased cell population in G1/S phase and induced cell apoptosis. Moreover, the RTKN expression level was related to the p53 signaling pathway and histone deacetylase (HDAC) Class I pathway. RTKN knockdown caused a notable increment in the acetylation level of p53 (Lys382), and the expression of p53-target genes (p21, Bax, and PUMA), as well as a reduction in the expression of a potential deacetylase for p53, HDAC1. Notably, downregulation of HDAC1 had similar effects as RTKN knockdown, and RTKN overexpression could hardly abrogate the effects of HDAC1 knockdown on GC cells.

Conclusion

RTKN could work as an oncogene via regulating HDAC1/p53 and may become a promising treatment strategy for GC.

Development of Natural Product-Conjugated Metal Complexes as Cancer Therapies

Platinum-based drugs have revolutionized cancer care, but are unfortunately associated with various adverse effects. Meanwhile, natural product scaffolds exhibit multifarious bioactivities and serve as an attractive resource for cancer therapy development. Thus, the conjugation of natural product scaffolds to metal complexes becomes an attractive strategy to reduce the severe side effects arising from the use of metal bearing drugs. This review aims to highlight the recent examples of natural product-conjugated metal complexes as cancer therapies with enhanced selectivity and efficacy. We discuss the mechanisms and features of different conjugate complexes and present an outlook and perspective for the future of this field.

Metal-based antitumor compounds: beyond cisplatin

Despite improvements in the 5-year survival rate to over 80% in cancers, such as Hodgkin lymphoma and testicular cancer, more aggressive tumors including pancreatic and brain cancer still have extremely low survival rates. The establishment of chemoresistance, responsible for the reduction in treatment efficiency and cancer relapse, is one possible explanation for this setback. Metal-based compounds, a class of anticancer drugs, are largely used in the treatment of cancer. Herein, we will review the use of metal-based small molecules in chemotherapy, focusing on recent studies, and we will discuss how new nonplatinum-based agents are prompting scientists to increase drug specificity to overcome chemoresistance in cancer cells.

Structure-Based Discovery of a Selective KDM5A Inhibitor that Exhibits Anti-Cancer Activity via Inducing Cell Cycle Arrest and Senescence in Breast Cancer Cell Lines

Breast cancer is the one of the most frequent causes of female cancer mortality. KDM5A, a histone demethylase, can increase the proliferation, metastasis, and drug resistance of cancers, including breast cancer, and is thus an important therapeutic target. In the present work, we performed hierarchical virtual screening towards the KDM5A catalytic pocket from a chemical library containing 90,000 compounds. Using multiple biochemical methods, the cyclopenta[c]chromen derivative 1 was identified as the top candidate for KDM5A demethylase inhibitory activity. Compared with the well-known KDM5 inhibitor CPI-455 (18), 1 exhibited higher potency against KDM5A and much higher selectivity for KDM5A over both KDM4A and other KDM5 family members (KDM5B and KDM5C). Additionally, compound 1 repressed the proliferation of various KDM5A-overexpressing breast cancer cell lines. Mechanistically, 1 promoted accumulation of p16 and p27 by blocking KDM5A-mediated H3K4me3 demethylation, leading to cell cycle arrest and senescence. To date, compound 1 is the first cyclopenta[c]chromen-based KDM5A inhibitor reported, and may serve as a novel motif for developing more selective and efficacious pharmacological molecules targeting KDM5A. In addition, our research provides a possible anti-cancer mechanism of KDM5A inhibitors and highlights the feasibility and significance of KDM5A as a therapeutic target for KDM5A-overexpressing breast cancer.

A study of 99mTc/Re-tricarbonyl complexes of 4-amino-1,8-naphthalimides

4-Amino-1,8-naphthalimide ligands were coordinated to fac-Re/^99mTc(CO)₃ giving complexes of varying charge for applications in fluorescence microscopy and as components of SPECT imaging agents.

Nuclear localization of dirhodium(ii) complexes in breast cancer cells by X-ray fluorescence microscopy

X-ray fluorescence microscopy confirms the necessity of vacant axial sites in dirhodium(ii) carboxylates for their cellular uptake and cytotoxicity.

Synthesis of Camphor-Derived Bis(pyrazolylpyridine) Rhodium(III) Complexes: Structure-Reactivity Relationships and Biological Activity

Two novel rhodium(III) complexes, namely, [Rh^III(X)Cl₃] (X = 2 2,6-bis((4 S,7 R)-7,8,8-trimethyl-4,5,6,7-tetrahydro-1 H-4,7-methanoindazol-3-yl)pyridine or 2,6-bis((4 S,7 R)-1,7,8,8-tetramethyl-4,5,6,7-tetrahydro-1 H-4,7-methanoindazol-3-yl)pyridine), were synthesized from camphor derivatives of a bis(pyrazolylpyridine), tridentate nitrogen-donor chelate system, giving [Rh^III(H₂L*)Cl₃] (1a) and [Rh^III(Me₂L*)Cl₃] (1b). A rhodium(III) terpyridine (terpy) ligand complex, [Rh^III(terpy)Cl₃] (1c), was also synthesized. By single-crystal X-ray analysis, 1b crystallizes in an orthorhombic P2₁2₁2₁ system, with two molecules in the asymmetric unit. Tridentate coordination by the N,N,N-donor localizes the central nitrogen atom close to the rhodium(III) center. Compounds 1a and 1b were reactive toward l-methionine (l-Met), guanosine-5'-monophosphate (5'-GMP), and glutathione (GSH), with an order of reactivity of 5'-GMP > GSH > l-Met. The order of reactivity of the Rh^III complexes was: 1b> 1a > 1c. The Rh^III complexes showed affinity for calf thymus DNA and bovine serum albumin by UV-vis and emission spectral studies. Furthermore, 1b showed significant in vitro cytotoxicity against human epithelial colorectal carcinoma cells. Since the Rh^III complexes have similar coordination modes, stability differences were evaluated by density functional theory (DFT) calculations (B3LYP(CPCM)/LANL2DZp). With (H₂L*) and (terpy) as model ligands, DFT calculations suggest that both tridentate ligand systems have similar stability. In addition, molecular docking suggests that all test compounds have affinity for the minor groove of DNA, while 1b and 1c have potential for DNA intercalation.

MIIP is downregulated in gastric cancer and its forced expression inhibits proliferation and invasion of gastric cancer cells in vitro and in vivo

Background

MIIP is associated with cancer progression in various cancers. However, its expression pattern, and associated molecular mechanisms in gastric cancer (GC) progression are still mysterious. We aimed to explore the role of MIIP in proliferation and invasion of GC.

Materials and methods

MIIP expression was evaluated in human GC tissues and cell lines. Public clinical database of GC patients was used to probe the correlation between MIIP expression and prognosis of patients. The effects of forced MIIP expression on GC cells were determined by MTT, cell cycle distribution, colony formation, wound-healing and Transwell assays in vitro, as well as in vivo growth of subcutaneous tumor xenografts and metastasis of xenografted tumors to the lungs in mice. The expressions of GC progression-associated genes, including HOTAIR, MALAT1, HDAC6, AC-tubulin, and cyclin D1, were assessed by Western blotting or qRT-PCR.

Results

Both GC tissues and GC cell lines had lower MIIP expression. Higher level of MIIP in GC tissues predicts better survival in patients. Ectopic expression of MIIP in GC cell lines BGC823 and HGC27 induced G₀/G₁ cell cycle arrest and inhibited cell proliferation, colony formation, migration and invasion in vitro, as well as the growth of GC xenografts and metastasis of tumors in vivo. Furthermore, overexpression of MIIP suppressed mRNA expressions of HOTAIR and MALAT1, decreased protein expression of HDAC6 and cyclin D1, and elevated AC-tubulin protein expression.

Conclusion

MIIP is a suppressor for GC progression and is a potential therapeutic target for treating GC.

Pharmacological Inhibition of LSD1 for Cancer Treatment

Lysine-specific demethylase 1A (LSD1, also named KDM1A) is a demethylase that can remove methyl groups from histones H3K4me1/2 and H3K9me1/2. It is aberrantly expressed in many cancers, where it impedes differentiation and contributes to cancer cell proliferation, cell metastasis and invasiveness, and is associated with inferior prognosis. Pharmacological inhibition of LSD1 has been reported to significantly attenuate tumor progression in vitro and in vivo in a range of solid tumors and acute myeloid leukemia. This review will present the structural aspects of LSD1, its role in carcinogenesis, a comparison of currently available approaches for screening LSD1 inhibitors, a classification of LSD1 inhibitors, and its potential as a drug target in cancer therapy.

Non-Platinum Metal Complexes as Potential Anti-Triple Negative Breast Cancer Agents

Breast cancer (BC) is the most common cancer in women worldwide, with a mortality rate that has been forecasted to rise in the next decade. This is especially worrying for people with triple-negative BC (TNBC), because of its unresponsiveness to current therapies. Different drugs to treat TNBC have been assessed, and, although platinum chemotherapy drugs seem to offer some hope, their drawbacks have motivated extensive investigations into alternative metal-based BC therapies. This paper aims to: (i) describe the preliminary in vitro and in vivo anticancer properties of non-platinum metal-based complexes (NPMBC) against TNBC; and (ii) analyze the likely molecular targets involved in their anticancer activity.

Future potential of osmium complexes as anticancer drug candidates, photosensitizers and organelle-targeted probes

Here we summarize recent progress in the design and application of innovative osmium compounds as anticancer agents with diverse modes of action, as organelle-targeted imaging probes and photosensitizers for photodynamic therapy.