Leonurine Promotes Cisplatin Sensitivity in Human Cervical Cancer Cells Through Increasing Apoptosis and Inhibiting Drug-Resistant Proteins

A facile fluorescence-coupling approach to visualizing leonurine uptake and distribution in living cells and Caenorhabditis elegans

BACKGROUND

Caenorhabditis elegans (C. elegans) has been recognized for being a useful model organism in small-molecule drug screens and drug efficacy investigation. However, there remain bottlenecks in evaluating such processes as drug uptake and distribution due to a lack of appropriate chemical tools.

PURPOSE

This study aims to prepare fluorescence-labeled leonurine as an example to monitor drug uptake and distribution of small molecule in C. elegans and living cells.

METHODS

FITC-conjugated leonurine (leonurine-P) was synthesized and characterized by LC/MS, NMR, UV absorption and fluorescence intensity. Leonurine-P was used to stain C. elegans and various mammalian cell lines. Different concentrations of leonurine were tested in conjunction with a competing parent molecule to determine whether leonurine-P and leonurine shared the same biological targets. Drug distribution was analyzed by imaging. Fluorometry in microplates and flow cytometry were performed for quantitative measurements of drug uptake.

RESULTS

The UV absorption peak of leonurine-P was 490∼495 nm and emission peak was 520 nm. Leonurine-P specifically bound to endogenous protein targets in C. elegans and mammalian cells, which was competitively blocked by leonurine. The highest enrichment levels of leonurine-P were observed around 72 h following exposure in C. elegans. Leonurine-P can be used in a variety of cells to observe drug distribution dynamics. Flow cytometry of stained cells can be facilely carried out to quantitatively detect probe signals.

CONCLUSIONS

The strategy of fluorescein-labeled drugs reported herein allows quantification of drug enrichment and visualization of drug distribution, thus illustrates a convenient approach to study phytodrugs in pharmacological contexts.

Leonurine ameliorates the STAT3 pathway through the upregulation of SHP-1 to retard the growth of hepatocellular carcinoma cells

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that directs the transcription of genes involved in the promotion of cell survival and proliferation, inflammation, angiogenesis, invasion, and migration. Overactivation of STAT3 is often witnessed in human cancers, thereby making it a good target in oncology. Herein the efficacy of Leonurine (Leo), a bioactive alkaloid present in Herba leonuri, was investigated for its STAT3-inhibitory potential in hepatocellular carcinoma (HCC) cells. Leo downregulated the persistent as well as IL-6-driven activation of STAT3. Leo abrogated the nuclear localization and DNA interacting ability of STAT3. Leo was also found to impart STAT3 inhibition by mitigating the activation of upstream kinases such as JAK1, JAK2, and Src both in constitutive and IL-6 inducible systems. Leo curbed the STAT3-driven luciferase gene expression and the depletion of STAT3 resulted in the reduced responsiveness of HCC cells to Leo. Pervanadate exposure counteracted Leo-induced STAT3 inhibition suggesting the involvement of a protein tyrosine phosphatase. SHP-1 was significantly elevated upon Leo exposure whereas the depletion of SHP-1 was found to revert the effect of Leo on STAT3. Leo induced apoptosis and also significantly potentiated the cytotoxic effect of paclitaxel, doxorubicin, and sorafenib. Leo was found to be non-toxic up to the dose of 10 mg/kg in NCr nude mice. In conclusion, Leo was demonstrated to induce cytotoxicity in HCC cells by mitigating the persistent of activation of STAT3 pathway.

Synergistic anticancer activity of cisplatin combined with tannic acid enhances apoptosis in lung cancer through the PERK-ATF4 pathway

BACKGROUND

Cisplatin (CDDP) is a common anticancer drug whose side effects limit its clinical applications. Tannins (TA) are plant-derived polyphenols that inhibit tumor growth in different types of cancer. Here, we evaluated the anticancer effect of TA combined with CDDP on lung cancer cell lines (GLC-82 and H1299) and investigated the underlying molecular mechanism of endoplasmic reticulum (ER) stress-induced apoptosis.

METHODS

Cell lines were treated with CDDP, TA, and CDDP + TA, and the effect of the combination was assessed using MTT assay and observed under light and fluorescence microscopes. Cell apoptosis was detected by flow cytometry, and the levels of ERS apoptosis pathway related genes were valuated by qRT-PCR and western blotting. The effects of the drug combination on the tumors of nude mice injected with H1299 cells were investigated, and the expression of key factors in the ER stress apoptotic pathway was investigated.

RESULTS

The combination of CDDP and TA significantly inhibited lung cancer cell viability indicating a synergistic antitumoral effect. The mRNA and protein expression levels of key ER stress factors in the CDDP + TA group were considerably higher than those in the CDDP and TA groups, the tumor volume in tumor-bearing mice was the smallest, and the number of apoptotic cells and the protein expression levels of the key ER stress in the combination group were considerably higher.

CONCLUSIONS

The combination of TA and CDDP may produce synergistic antitumoral effects mediated by the PERK-ATF4-CHOP apoptotic axis, suggesting a novel adjuvant treatment for lung cancer.

A literature review: mechanisms of antitumor pharmacological action of leonurine alkaloid

Leonurine refers to the desiccated aerial portion of a plant in the Labiatae family. The primary bioactive constituent of Leonurine is an alkaloid, Leonurine alkaloid (Leo), renowned for its substantial therapeutic efficacy in the treatment of gynecological disorders, in addition to its broad-spectrum antineoplastic capabilities. Over recent years, the pharmacodynamic mechanisms of Leo have garnered escalating scholarly interest. Leo exhibits its anticancer potential by means of an array of mechanisms, encompassing the inhibition of neoplastic cell proliferation, induction of both apoptosis and autophagy, and the containment of oncogenic cell invasion and migration. The key signal transduction pathways implicated in these processes include the Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL), the Phosphoinositide3-Kinase/Serine/Threonine Protein Kinase (PI3K/AKT), the Signal Transducer and Activator of Transcription 3 (STAT3), and the Mitogen-Activated Protein/Extracellular Signal-Regulated Kinase (MAP/ERK). This paper commences with an exploration of the principal oncogenic cellular behaviors influenced by Leo and the associated signal transduction pathways, thereby scrutinizing the mechanisms of Leo in the antineoplastic sequence of events. The intention is to offer theoretical reinforcement for the elucidation of more profound mechanisms underpinning Leo's anticancer potential and correlating pharmaceutical development.

Investigating the potential mechanism of quercetin against cervical cancer

BACKGROUND

Cervical cancer is emerging as a potential target of increased susceptibility to coronavirus disease-2019 (COVID-19), leading to compromised survival rates. Despite this critical link, efficacious anti-cervical cancer/COVID-19 interventions remain limited. Quercetin, known for its efficacy against both cancer and viral infections, holds promise as a therapeutic agent. This study aims to elucidate quercetin's anti-cervical cancer/COVID-19 mechanisms and potential targets.

METHODS

We initiated our investigation with differential gene expression analysis using cervical cancer transcriptome data from The Cancer Genome Atlas (TCGA) and The Genotype-Tissue Expression (GTEx), focusing on intersections with COVID-19-related genes. Network pharmacology was employed to identify the shared targets between cervical cancer/COVID-19 DEGs and quercetin's targets. Subsequently, Cox proportional hazards analyses were employed to establish a risk score based on these genes. Molecular docking techniques were applied to predict quercetin's therapeutic targets and mechanisms for mitigating cervical cancer and COVID-19.

RESULTS

Our findings unveiled 45 potential quercetin targets with anti-cervical cancer/COVID-19 actions. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses highlighted significant enrichment in immune pathways and COVID-19-related pathways. A refined risk score model, comprising PLA2G7, TNF, TYK2, F2, and NRP1, effectively stratified cervical cancer patients into distinct risk groups. Importantly, molecular docking analyses illuminated quercetin's remarkable binding affinity to the primary protease of the coronavirus.

CONCLUSIONS

In summation, our study suggests that quercetin holds promise as a potential therapeutic agent for mitigating coronavirus function, specifically through its interaction with the primary protease. This research offers novel insights into exploring COVID-19 susceptibility and enhancing survival in cervical cancer patients.

Leonurine suppresses prostate cancer growth in vitro and in vivo by regulating miR-18a-5p/SLC40A1 axis

Prostate cancer is a leading cause of cancer-associated death in males. Leonurine (Leo) is a pleiotropic anti-tumor agent isolated from traditional Chinese herb that was used in gynecologic treatments. However, its pharmacological effect against prostate cancer progression remains unclear. Here, we showed that Leo dose dependently inhibited prostate cancer cell proliferation, promoted cell apoptosis, and induced cell cycle arrest. Moreover, we noticed that miR-18a-5p was downregulated and the solute carrier family 40 member 1 (SLC40A1) is upregulated by Leo treatment. SLC40A1 knockdown by siRNA abrogated the inhibitory effect of Leo on prostate cancer progression. Notably, Leo also significantly inhibited prostate cancer progression in a subcutaneous xenograft tumor mouse model in vivo. This study further unveiled the mechanism by which Leo inhibited prostate cancer progression, which provides a promising potential for its future clinical application.

Fbxo22 promotes cervical cancer progression via targeting p57Kip2 for ubiquitination and degradation

F-box only protein 22 (FBXO22) is a key subunit of the Skp1-Cullin 1-F-box protein (SCF) E3 ubiquitin ligase complex. Little is known regarding its biological function and underlying molecular mechanisms in regulating cervical cancer (CC) progression. In this study, we aim to explore the role and mechanism of FBXO22 in CC progression. The correlation between FBXO22 and clinicopathological characteristics of CC was analyzed by tissue microarray. MTT, colony formation, flow cytometry, Western blotting, qRT-PCR, protein half-life, co-immunoprecipitation, ubiquitination, and xenograft experiments were performed to assess the functions of FBXO22 and potential molecular mechanisms of FBXO22-mediated malignant progression in CC. The expression of FBXO22 protein in CC tissues was higher than that in adjacent non-tumor cervical tissues. Notably, high expression of FBXO22 was significantly associated with high histology grades, positive lymph node metastasis, and poor outcomes in CC patients. Functionally, ectopic expression of FBXO22 promoted cell viability in vitro and induced tumor growth in vivo, while knockdown of FBXO22 exhibited opposite effects. In addition, overexpression of FBXO22 promoted G1/S phase progression and inhibited apoptosis in CC cells. Mechanistically, FBXO22 physically interacted with the cyclin-dependent kinase inhibitor p57Kip2 and subsequently mediated its ubiquitination and proteasomal degradation leading to tumor progression. FBXO22 protein level was found negatively associated with p57Kip2 protein levels in patient CC samples. FBXO22 promotes CC progression partly through regulating the ubiquitination and proteasomal degradation of p57Kip2. Our study indicates that FBXO22 might be a novel prognostic biomarker and therapeutic target for CC.

Prediction of the Mechanisms by Which Quercetin Enhances Cisplatin Action in Cervical Cancer: A Network Pharmacology Study and Experimental Validation

Yimucao has been used as an herbal medicine to treat gynecological diseases. Common genes of Yimucao active compounds were investigated using network pharmacology. The components and targets of Yimucao were retrieved from the TCMSP database. Cervical cancer targets were collected from GeneCards, TTD, DisGeNET, and KEGG. Cisplatin-related genes were downloaded from GeneWeaver. The protein-protein interaction (PPI) network was created using the STRING database. A drug-bioactive compound-disease-target network was constructed using Cytoscape. GO and KEGG analyses were performed to investigate common targets of quercetin and cisplatin in cervical cancer. We found that quercetin was the highly bioactive compound in Yimucao. The drug-bioactive compound-disease-target network contained 93 nodes and 261 edges. Drug-related key targets were identified, including EGFR, IL6, CASP3, VEGFA, MYC, CCND1, ERBB2, FOS, PPARG, and CASP8. Core targets were primarily related to the response to metal ions, cellular response to xenobiotic stimulus, and transcription factor complex. The KEGG pathway analysis revealed that quercetin and cisplatin may affect cervical cancer through platinum drug resistance and the p53 and HIF-1 pathways. Furthermore, quercetin combined with cisplatin downregulated the expression of EGFR, MYC, CCND1, and ERBB2 proteins and upregulated CASP8 expression in HeLa and SiHa cells. Functionally, quercetin enhanced cisplatin-induced anticancer activity in cervical cancer cells. Our results indicate that quercetin can be used to overcome cisplatin resistance in cervical cancer cells.

Leonurine-Repressed miR-18a-5p/SOCS5/JAK2/STAT3 Axis Activity Disrupts CML malignancy

Leonurine, an active natural alkaloid compound isolated from Herba leonuri, has been reported to exhibit promising anticancer activity in solid tumors. The aim of this study was to explore whether leonurine is able to inhibit chronic myeloid leukemia (CML) malignancy. Here, we found that leonurine dose dependently inhibited the proliferation, migration, colony formation and promoted apoptosis of CML cells. Furthermore, leonurine markedly reduced CML xenograft growth in vivo. Mechanically, leonurine upregulated SOCS5 expression, thus leading JAK2/STAT3 signaling suppression. Silencing of SOCS5 by its siRNA abrogated the effect of leonurine on CML cells, demonstrating that SOCS5 mediates the anti-leukemia effect of leonurine. Notably, we observed that miR-18a-5p was remarkably increased in CML cells. Treating CML cells with leonurine significantly decreased miR-18a-5p expression. Moreover, we found miR-18a-5p repressed SOCS5 by directly targeting its 3′-UTR. miR-18a-5p downregulation induced by leonurine reduced the biological activity of CML cells by relieving miR-18a-5p repression of SOCS5 expression. Taken together, leonurine exerts significant anti-leukemia efficacy in CML by regulating miR-18a-5p/SOCS5/JAK2/STAT3 axis.

Employing siRNA tool and its delivery platforms in suppressing cisplatin resistance: Approaching to a new era of cancer chemotherapy

Although chemotherapy is a first option in treatment of cancer patients, drug resistance has led to its failure, requiring strategies to overcome it. Cancer cells are capable of switching among molecular pathways to ensure their proliferation and metastasis, leading to their resistance to chemotherapy. The molecular pathways and mechanisms that are responsible for cancer progression and growth, can be negatively affected for providing chemosensitivity. Small interfering RNA (siRNA) is a powerful tool extensively applied in cancer therapy in both pre-clinical (in vitro and in vivo) and clinical studies because of its potential in suppressing tumor-promoting factors. As such oncogene pathways account for cisplatin (CP) resistance, their targeting by siRNA plays an important role in reversing chemoresistance. In the present review, application of siRNA for suppressing CP resistance is discussed. The first priority of using siRNA is sensitizing cancer cells to CP-mediated apoptosis via down-regulating survivin, ATG7, Bcl-2, Bcl-xl, and XIAP. The cancer stem cell properties and related molecular pathways including ID1, Oct-4 and nanog are inhibited by siRNA in CP sensitivity. Cell cycle arrest and enhanced accumulation of CP in cancer cells can be obtained using siRNA. In overcoming siRNA challenges such as off-targeting feature and degradation, carriers including nanoparticles and biological carriers have been applied. These carriers are important in enhancing cellular accumulation of siRNA, elevating gene silencing efficacy and reversing CP resistance.