Advancements and recent explorations of anti-cancer activity of chrysin: from molecular targets to therapeutic perspective.

In recent times, there have been notable advancements in comprehending the potential anti-cancer effects of chrysin (CH), a naturally occurring flavonoid compound found abundantly in various plant sources like honey, propolis, and certain fruits and vegetables. This active compound has garnered significant attention due to its promising therapeutic qualities and minimal toxicity. CH's ability to combat cancer arises from its multifaceted mechanisms of action, including the initiation of apoptosis and the inhibition of proliferation, angiogenesis, metastasis, and cell cycle progression. CH also displays potent antioxidant and anti-inflammatory properties, effectively counteracting the harmful molecules that contribute to DNA damage and the development of cancer. Furthermore, CH has exhibited the potential to sensitize cancer cells to traditional chemotherapy and radiotherapy, amplifying the effectiveness of these treatments while reducing their negative impact on healthy cells. Hence, in this current review, the composition, chemistry, mechanisms of action, safety concerns of CH, along with the feasibility of its nanoformulations. To conclude, the recent investigations into CH's anti-cancer effects present a compelling glimpse into the potential of this natural compound as a complementary therapeutic element in the array of anti-cancer approaches, providing a safer and more comprehensive method of combating this devastating ailment.

Network pharmacology- and cell-based assessments identify the FAK/Src pathway as a molecular target for the antimetastatic effect of momordin Ic against cholangiocarcinoma.

Previous studies have indicated the efficacy of momordin Ic (MIc), a plant-derived triterpenoid, against several types of cancers, implying its potential for further development. However, comprehensive insights into the molecular mechanisms and targets of MIc in cholangiocarcinoma (CCA) are lacking. This study aimed to investigate the actions of MIc against CCA at the molecular level. Network pharmacology analysis was first employed to predict the mechanisms and targets of MIc. The results unveiled the potential involvement of MIc in apoptosis and cell migration, pinpointing Src and FAK as key targets. Subsequently, cell-based assays, in accordance with FAK/Src-associated metastasis, were conducted, demonstrating the ability of MIc to attenuate the metastatic behaviours of KKU-452 cells. The in vitro results further indicated the capability of MIc to suppress the epithelial-mesenchymal transition (EMT) process, notably by downregulating EMT regulators, including N-cadherin, vimentin, ZEB2 and FOXC1/2 expression. Furthermore, MIc suppressed the activation of the FAK/Src signalling pathway, influencing critical downstream factors such as MMP-9, VEGF, ICAM-1, and c-Myc. Molecular docking simulations also suggested that MIc could interact with FAK and Src domains and restrain kinases from being activated by hindering ATP binding. In conclusion, this study employs a comprehensive approach encompassing network pharmacology analysis, in vitro assays, and molecular docking to unveil the mechanisms and targets of MIc in CCA. MIc mitigates metastatic behaviours and suppresses key pathways, offering a promising avenue for future therapeutic strategies against this aggressive cancer.

[Corrigendum] Next­generation sequencing analysis reveals that MTH­3, a novel curcuminoid derivative, suppresses the invasion of MDA­MB­231 triple­negative breast adenocarcinoma cells.

Subsequently to the publication of the article, an interested reader drew to the authors' attention that, in Fig. 2A on p. 5, the 'Control  (24 h)' and 'MTH­3 (1 µM; 24 h)' data panels contained partially overlapping data, such that they appeared to have been derived from the same original source. The authors have examined their original data, and realized that this error arose inadvertently as a consequence of having compiled this figure incorrectly. The revised version of Fig. 2, featuring the data from one of the repeated experiments in Fig. 2A, is shown below. The revised data shown for this figure do not affect the overall conclusions reported in the paper. The authors apologize to the Editor of Oncology Reports and to the readership for any inconvenience caused. [Oncology Reports 46: 133, 2021; DOI: 10.3892/or.2021.8084].

Interface-driven structural evolution on diltiazem as novel uPAR inhibitors: from in silico design to in vitro evaluation.

The urokinase-type plasminogen activator receptor (uPAR) emerges as a key target for anti-metastasis owing to its pivotal role in facilitating the invasive and migratory processes of cancer cells. Recently, we identified the uPAR-targeting anti-metastatic ability of diltiazem (22), a commonly used antihypertensive agent. Fine-tuning the chemical structures of known hits represents a vital branch of drug development. To develop novel anti-metastatic drugs, we performed an interface-driven structural evolution strategy on 22. The uPAR-targeting and anti-cancer abilities of this antihypertensive drug wereidentified by us recently. Based on in silico strategy, including extensive molecular dynamics (MD) simulations, hierarchical binding free energy predictions, and ADMET profilings, we designed, synthesized, and identified three new diltiazem derivatives (221-8, 221-57, and 221-68) as uPAR inhibitors. Indeed, all of these three derivatives exhibited uPAR-depending inhibitory activity against PC-3 cell line invasion at micromolar level. Particularly, derivatives 221-68 and 221-8 showed enhanced uPAR-dependent inhibitory activity against the tumor cell invasion compared to the original compound. Microsecond timesclae MD simulations demonstrated the optimized moiety of 221-68 and 221-8 forming more comprehensive interactions with the uPAR, highlighting the reasonability of our strategy. This work introduces three novel uPAR inhibitors, which not only pave the way for the development of effective anti-metastatic therapeutics, but also emphasize the efficacy and robustness of an in silico-based lead compound optimization strategy in drug design.

A "Ferroptosis-Amplifier" Hydrogel for Eliminating Refractory Cancer Stem Cells Post-lumpectomy.

The unique "Iron Addiction" feature of cancer stem cells (CSCs) with tumorigenicity and plasticity generally contributes to the tumor recurrence and metastasis after a lumpectomy. Herein, a novel "Ferroptosis Amplification" strategy is developed based on integrating gallic acid-modified FeOOH (GFP) and gallocyanine into Pluronic F-127 (F127) and carboxylated chitosan (CC)-based hydrogel for CSCs eradication. This "Ferroptosis Amplifier" hydrogel is thermally sensitive and achieves rapid gelation at the postsurgical wound in a breast tumor model. Specifically, gallocyanine, as the Dickkopf-1 (DKK1) inhibitor, can decrease the expression of SLC7A11 and GPX4 and synergistically induce ferroptosis of CSCs with GFP. Encouragingly, it is found that this combination suppresses the migratory and invasive capability of cancer cells via the downregulation of matrix metalloproteinase 7 (MMP7). The in vivo results further confirm that this "Ferroptosis Amplification" strategy is efficient in preventing tumor relapse and lung metastasis, manifesting an effective and promising postsurgical treatment for breast cancer.

First total synthesis, antitumor evaluation and target identification of mornaphthoate E: A new tubulin inhibitor template acting on PI3K/Akt signaling pathway.

Mornaphthoate E (MPE) is a prenylated naphthoic acid methyl ester isolated from the roots of a famous Chinese medicinal plant Morinda officinalis and shows remarkable cytotoxicity against several human tumor cell lines. In the current project, the first total synthesis of (±)-MPE was achieved in seven steps and 5.6% overall yield. Then the in vitro anti-tumor activity of MPE was first assessed for both enantiomers in two breast cancer cells, with the levoisomer exerting slightly better potency. The in vivo anti-tumor effect was further verified by applying the racemate in an orthotopic autograft mouse model. Notably, MPE exerted promising anti-metastasis activity both in vitro and in vivo and showed no obvious toxicity on mice at the therapeutic dosage. Mechanistic investigations demonstrated that MPE acted as a tubulin polymerization stabilizer and disturbed the dynamic equilibrium of microtubules via regulating PI3K/Akt signaling. In conclusion, our work has provided a new chemical template for the future design and development of next-generation tubulin-targeting chemotherapies.

ROS-responsive core-shell nano-inhibitor impedes pyruvate metabolism for reinforced photodynamic therapy and interrupted pre-metastatic niche formation.

The formation of pre-metastatic niche (PMN) in a hospitable organ derived from the primary tumor requires the communication between the tumor cells and the host environment. Pyruvate is a fundamental nutrient by which the tumor cells metabolically reshape the extracellular matrix in the lung to facilitate their own metastatic development. Here we report a combination regimen by integrating the photo-sensitizer and the mitochondrial pyruvate carrier (MPC) inhibitor in a dendritic polycarbonate core-hyaluronic acid shell nano-platform with multivalent reversible crosslinker embedded in it (DOH-NI+L) to reinforce photodynamic therapy (PDT) toward the primary tumor and interrupt PMN formation in the lung via impeding pyruvate uptake. We show that DOH-NI+L mediates tumor-specific MPC inhibitor liberation, inhibiting the aerobic respiration for facilitated PDT and restraining ATP generation for paralyzing cell invasion. Remarkably, DOH-NI+L is demonstrated to block the metabolic crosstalk of tumor cell-host environment by dampening pyruvate metabolism, provoking a series of metabolic responses and resulting in the pulmonary PMN interruption. Consequently, DOH-NI+L realizes a significant primary tumor inhibition and an efficient pulmonary metastasis prevention. Our research extends nano-based anti-metastatic strategies aiming at PMN intervention and such a dendritic core-shell nano-inhibitor provides an innovative paradigm to inhibit tumor growth and prevent metastasis efficiently. STATEMENT OF SIGNIFICANCE: In the progression of cancer metastasis, the formation of a pre-metastatic niche (PMN) in a hospitable organ derived from the primary tumor is one of the rate-limiting stages. The current nano-based anti-metastatic modalities mainly focus on targeted killing of tumor cells and specific inhibition of tumor cell invasion, while nanomedicine-mediated interruption of PMN formation has been rarely reported. Here we report a combination regimen by integrating a photo-sensitizer and an inhibitor of mitochondrial pyruvate carrier in a dendritic core-shell nano-platform with a reversible crosslinker embedded in it to reinforce PDT toward the primary tumor and interrupt PMN formation via impeding the uptake of pyruvate that is a fundamental nutrient facilitating aerobic respiration and PMN formation. Our research proposed a nano-based anti-metastatic strategy aiming at PMN intervention.

LINC02535 + miR-30a-5p combination enhances proliferation and inhibits apoptosis in metastatic breast Cancer cells.

Current clinical therapies for metastatic breast cancer (MBC) have limited therapeutic efficacy and induce significant systemic side effects, leading to poor patient compliance. To address this challenge, this investigation focuses on the design of LINC02535 + miR-30a-5p for treating breast cancer. In vitro cytotoxicity studies confirmed that LINC02535 + miR-30a-5p was more effective in 4 T1 cells, with reduced toxicity in NIH3T3 cells. Further verification of cellular morphology was achieved through various biochemical staining methods. Additionally, the antimetastatic attributes of LINC02535 + miR-30a-5p have been evaluated using both migration scratch and Transwell migration assays, which have collectively revealed excellent antimetastatic potential. The DNA fragmentation of the 4 T1 cells was assessed using a comet assay. LINC02535 + miR-30a-5p improved ROS levels and caused mitochondrial membrane potential alterations and DNA damage, which resulted in apoptosis. Therefore, we propose that LINC02535 + miR-30a-5p could be an alternative therapeutic strategy for breast cancer therapy.

The Remarkable Anti-Breast Cancer Efficacy and Anti-Metastasis by Multifunctional Nanoparticles Co-Loading Squamocin, R848 and IR 780.

Background: Breast cancer is a heterogeneous disease globally accounting for approximately 1 million new cases annually. Chemotherapy remains the main therapeutic option, but the antitumor efficacy needs to be improved. Methods: Two multifunctional nanoparticles were developed in this paper using oleic acid and mPEG2k-PCL2k as the drug carriers. Squamocin (Squ) was employed as a chemotherapeutic agent. Resiquimod (R848) or ginsenoside Rh2 was co-encapsulated in the nanoparticles to remold the immunosuppressive tumor microenvironment, and IR780 was coloaded as a photosensitizer to realize photothermal therapy. Results: The obtained Squ-R848-IR780 nanoparticles and Squ-Rh2-IR780 nanoparticles were uniformly spherical and approximately (162.200 ± 2.800) nm and (157.300 ± 1.1590) nm, respectively, in average diameter, with good encapsulation efficiency (above 85% for each drug), excellent stability in various physiological media and high photothermal conversion efficiency (24.10% and 22.58%, respectively). After intravenous administration, both nanoparticles quickly accumulated in the tumor and effectively enhanced the local temperature of the tumor to over 45 °C when irradiated by an 808 nm laser. At a low dose of 0.1 mg/kg, Squ nanoparticles treatment alone displayed a tumor inhibition rate of 55.28%, pulmonary metastasis inhibition rate of 59.47% and a mean survival time of 38 days, which were all higher than those of PTX injection (8 mg/kg) (43.64%, 25 days and 37.25%), indicating that Squ was a potent and effective antitumor agent. Both multifunctional nanoparticles, Squ-Rh2-IR780 nanoparticles and Squ-R848-IR780 nanoparticles, demonstrated even better therapeutic efficacy, with tumor inhibition rates of 90.02% and 97.28%, pulmonary metastasis inhibition rates of 95.42% and 98.09, and mean survival times of 46 days and 52 days, respectively. Conclusion: The multifunctional nanoparticles coloaded with squamocin, R848 and IR 780 achieved extraordinary therapeutic efficacy and excellent antimetastasis activity and are thus promising in the future treatment of breast tumors and probably other tumors.

Gamma radiation assisted green synthesis of hesperidin-reduced graphene oxide nanocomposite targeted JNK/SMAD4/MMP2 signaling pathway.

In this study, a novel method for the fabrication of hesperidin/reduced graphene oxide nanocomposite (RGOH) with the assistance of gamma rays is reported. The different RGOHs were obtained by varying hesperidin concentrations (25, 50, 100, and 200 wt.%) in graphene oxide (GO) solution. Hesperidin concentrations (25, 50, 100, and 200 wt.%) in graphene oxide (GO) were varied to produce the various RGOHs. Upon irradiation with 80 kGy from γ-Ray, the successful reduction of GO occurred in the presence of hesperidin. The reduction process was confirmed by different characterization techniques such as FTIR, XRD, HRTEM, and Raman Spectroscopy. A cytotoxicity study using the MTT method was performed to evaluate the cytotoxic-anticancer effects of arbitrary RGOH on Wi38, CaCo2, and HepG2 cell lines. The assessment of RGOH's anti-inflammatory activity, including the monitoring of IL-1B and IL-6 activities as well as NF-kB gene expression was done. In addition, the anti-invasive and antimetastatic properties of RGOH, ICAM, and VCAM were assessed. Additionally, the expression of the MMP2-9 gene was quantified. The assessment of apoptotic activity was conducted by the detection of gene expressions related to BCl2 and P53. The documentation of the JNK/SMAD4/MMP2 signaling pathway was ultimately accomplished. The findings of our study indicate that RGOH therapy has significant inhibitory effects on the JNK/SMAD4/MMP2 pathway. This suggests that it could be a potential therapeutic option for cancer.

Phytochemical composition of the diethyl ether extract of Artemisia lactiflora Wall. ex DC and its antimetastatic activity in human lung cancer cells.

Artemisia lactiflora Wall. ex DC. is a traditional Chinese medicinal plant used in the treatment of menstrual and hepatic disorders due to its antioxidant and anti-inflammatory properties. However, its anti-metastatic activity, which is the clinical challenge of lung cancer treatment, has not yet been reported. From the diethyl ether extract of Artemisia lactiflora, the four terpenoids, including dihydroactinidiolide, megastigmatrienone, alpha-curcumene, and dehydrovomifoliol, were the most intense peaks observed using LC-MS/MS, whereas bis (2-ethylhexyl) phthalate was a contaminant. In a transwell assay, the A. lactiflora diethyl ether extract (32 µg/ml) and dihydroactinidiolide (250 µg/ml) markedly inhibited the migration and invasion of non-small cell lung cancer (NSCLC) cells, similar to the standard anti-metastatic drug (capmatinib). Western blot analysis revealed that mesenchymal N-cadherin is downregulated in NSCLC cells under the treatment conditions. The potential anti-metastatic property of dihydroactinidiolide is promising as a new candidate anti-metastatic agent for lung cancer treatment.

Ginsenoside Rb1 Deters Cell Proliferation, Induces Apoptosis, Alleviates Oxidative Stress, and Antimetastasis in Oral Squamous Carcinoma Cells.

There are numerous therapeutic applications for ginsenoside Rb1 (GRb1), the primary saponin derived from ginseng root. According to earlier research, ginsenoside Rb1 causes apoptosis and reduces the cell cycle. Its adverse effects, especially those on the development of the embryo, still need to be thoroughly studied. A host's lifestyle choices, including smoking, drinking too much alcohol, using tobacco products, and having an HPV infection, can increase the risk of oral squamous cell carcinoma (OSCC), one of the most prevalent malignancies of the oral cavity. To address this challenge, this investigation focuses on the design of GRb1 for treating OSCC. In vitro cytotoxicity studies confirmed that GRb1 was more effective in PCI-9A and PCI-13 cells, with reduced toxicity in non-cancerous cells. Further verification of cellular morphology was achieved through various biochemical staining methods. The mechanism of cell death was investigated by Annexin V-FITC and PI methods. Additionally, the antimetastatic attributes of GRb1 have been evaluated using both migration scratch and Transwell migration assays, which have collectively revealed excellent antimetastatic potential. The DNA fragmentation of the PCI-9A and PCI-13 cells was assessed using a comet assay. Ginsenoside Rb1 improved ROS levels and caused mitochondrial membrane potential alterations and DNA damage, which resulted in apoptosis. OSCC administration significantly reduced the levels of SOD, GSH, GPx, and CAT, increasing the levels of PCI-9A and PCI-13 cells, while GRb1 improved this situation. Therefore, we propose that Ginsenoside Rb1 could be an alternative therapeutic strategy for OSCC therapy.

Spatiotemporally controlled Pseudomonas exotoxin transgene system combined with multifunctional nanoparticles for breast cancer antimetastatic therapy.

The tumor microenvironment is a barrier to breast cancer therapy. Cancer-associated fibroblast cells (CAFs) can support tumor proliferation, metastasis, and drug resistance by secreting various cytokines and growth factors. Abnormal angiogenesis provides sufficient nutrients for tumor proliferation. Considering that CAFs express the sigma receptor (which recognizes anisamide, AA), we developed a CAFs and breast cancer cells dual-targeting nano drug delivery system to transport the LightOn gene express system, a spatiotemporal controlled gene expression consisting of a light-sensitive transcription factor and a specific minimal promoter. We adopted RGD (Arg-Gly-Asp) to selectively bind to the αvß3 integrin on activated vascular endothelial cells and tumor cells. After the LightOn system has reached the tumor site, LightOn gene express system can spatiotemporal controllably express toxic Pseudomonas exotoxin An under blue light irradiation. The LightOn gene express system, combined with multifunctional nanoparticles, achieved high targeting delivery efficiency both in vitro and in vivo. It also displayed strong tumor and CAFs inhibition, anti-angiogenesis ability and anti-metastasis ability, with good safety. Moreover, it improved survival rate, survival time, and lung metastasis rate in a mouse breast cancer model. This study proves the efficacy of combining the LightOn system with targeted multifunctional nanoparticles in tumor and anti-metastatic therapy and provides new insights into tumor microenvironment regulation.

Multi-Enzyme Co-Expressed Nanomedicine for Anti-Metastasis Tumor Therapy by Up-Regulating Cellular Oxidative Stress and Depleting Cholesterol.

Tumor cells movement and migration are inseparable from the integrity of lipid rafts and the formation of lamellipodia, and lipid rafts are also a prerequisite for the formation of lamellipodia. Therefore, destroying the lipid rafts is an effective strategy to inhibit tumor metastasis. Herein, a multi-enzyme co-expressed nanomedicine: cholesterol oxidase (CHO) loaded Co─PN3 single-atom nanozyme (Co─PN3 SA/CHO) that can up-regulate cellular oxidative stress, disrupt the integrity of lipid rafts, and inhibit lamellipodia formation to induce anti-metastasis tumor therapy, is developed. In this process, Co─PN3 SA can catalyze oxygen (O2 ) and hydrogen peroxide (H2 O2 ) to generate reactive oxygen species (ROS) via oxidase-like and Fenton-like properties. The doping of P atoms optimizes the adsorption process of the intermediate at the active site and enhances the ROS generation properties of nanomedicine. Meantime, O2 produced by catalase-like catalysis can combine with excess cholesterol to generate more H2 O2 under CHO catalysis, achieving enhanced oxidative damage to tumor cells. Most importantly, cholesterol depletion in tumor cells also disrupts the integrity of lipid rafts and inhibits the formation of lamellipodia, greatly inhibiting the proliferation and metastasis of tumor cells. This strategy by up-regulating cellular oxidative stress and depleting cellular cholesterol constructs a new idea for anti-metastasis-oriented cancer therapy strategies.

Cyclometalated iridium(III) complexes as anti-breast cancer and anti-metastasis agents via STAT3 inhibition.

Breast cancer is the most commonly diagnosed cancer and second­leading cause of cancer deaths in women. Signal transducer and activator of transcription 3 (STAT3) plays a critical role in promoting breast cancer cell proliferation, invasion, angiogenesis, and metastasis, and the high expression of STAT3 is related to the occurrence and poor chemotherapy sensitivity of breast cancer. Iridium(III) complexes Ir-PTS-1- 4 containing a pterostilbene-derived ligand were synthesized to inhibit the STAT3 pathway in breast cancer. Ir-PTS-4 inhibited the proliferation of breast cancer cells by suppressing the expression of phosphorylated STAT3 and STAT3-related cyclin D1, arresting cell cycle in the S-phase, inducing DNA damage and reactive oxygen species (ROS) generation, eventually leading to autophagic cell death. The cell metastasis and invasion were also inhibited after Ir-PTS-4 treatment. Besides, Ir-PTS-4 exhibited excellent anti-proliferation activity in 3D multicellular tumor spheroids, showing potential for the treatment of solid tumors. This work presents the rational design of metal-based anticancer agents to block the STAT3 pathway for simultaneously inhibiting breast cancer proliferation and metastasis.

Localization of Cancer Cells for Subsequent Robust Photodynamic Therapy by ROS Responsive Polymeric Nanoparticles With Anti-Metastasis Complexes NAMI-A.

Photodynamic therapy (PDT), as a new type of light-mediated reactive oxygen species (ROS) cancer therapy, has the advantages of high therapeutic efficiency, non-resistance, and less trauma than traditional cancer therapy such as surgery, radiotherapy, and chemotherapy. However, oxygen-dependent PDT further exacerbates tumor metastasis. To this end, a strategy that circumvents tumor metastasis to improve the therapeutic efficacy of PDT is proposed. Herein, a near-infrared light-activated photosensitive polymer is synthesized and branched the anti-metastatic ruthenium complex NAMI-A on the side, which is further assembled to form nanoparticles (NP2) for breast cancer therapy. NP2 can kill tumor cells by generating ROS under 808 nm radiation (NP2 + L), reduce the expression of matrix metalloproteinases (MMP2/9) in cancer cells, decrease the invasive and migration capacity of cancer cells, and eliminate cancer cells. Further animal experiments show that NP2 + L can inhibit tumor growth and reduce liver and lung metastases. In addition, NP2 + L can activate the immune system in mice to avoid tumor recurrence. In conclusion, a PDT capable of both preventing tumor metastasis and precisely hitting the primary tumor to achieve effective treatment of highly metastatic cancers is developed.

Pharmacological mechanisms of norcantharidin against hepatocellular carcinoma.

Norcantharidin (NCTD) is a water-soluble synthetic small molecule drug that has been approved by the Chinese FDA for the treatment of cancer in China. Among these NCTD-treated cancers, hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide and one of the most extensively studied. Research over the past few decades has made great strides in understanding how NCTD induces mitotic arrest, anti-proliferation, anti-metastasis, apoptosis and cytotoxic autophagy or autophagic cell death in HCC. In this article, we review recent progress in the application of NCTD for the treatment of HCC, with emphasis on the pharmacological mechanism of NCTD against hepatocellular carcinoma. The accumulated results show that NCTD has the ability to induce mitotic arrest, anti-proliferation, anti-metastasis, apoptosis and cytotoxic autophagy or autophagic cell death in HCC by down-regulating the expression of ISG15, MMP-9, u-PA, Mcl-1 and the accumulation of regulatory T cells, up-regulating the expression of FAM46C, miR-214 and the expression and phosphorylation of p21Cip1/Waf1 and CDC25C, and by inhibiting the c-Met-mTOR and JAK/STAT3 signaling pathways, reversing the methylation of RASSF1A gene, and activating TRAIL-R2/DR5 signal transduction.

In silico screening of natural products as uPAR inhibitors via multiple structure-based docking and molecular dynamics simulations.

Cancer remains one of the most pressing challenges to global healthcare, exerting a significant impact on patient life expectancy. Cancer metastasis is a critical determinant of the lethality and treatment resistance of cancer. The urokinase-type plasminogen activator receptor (uPAR) shows great potential as a target for anticancer and antimetastatic therapies. In this work, we aimed to identify potential uPAR inhibitors by structural dynamics-based virtual screenings against a natural product library on four representative apo-uPAR structural models recently derived from long-timescale molecular dynamics (MD) simulations. Fifteen potential inhibitors (NP1-NP15) were initially identified through molecular docking, consensus scoring, and visual inspection. Subsequently, we employed MD-based molecular mechanics-generalized Born surface area (MM-GBSA) calculations to evaluate their binding affinities to uPAR. Structural dynamics analyses further indicated that all of the top 6 compounds exhibited stable binding to uPAR and interacted with the critical residues in the binding interface between uPAR and its endogenous ligand uPA, suggesting their potential as uPAR inhibitors by interrupting the uPAR-uPA interaction. We finally predicted the ADMET properties of these compounds. The natural products NP5, NP12, and NP14 with better binding affinities to uPAR than the uPAR inhibitors previously discovered by us were proven to be potentially orally active in humans. This work offers potential uPAR inhibitors that may contribute to the development of novel effective anticancer and antimetastatic therapeutics.Communicated by Ramaswamy H. Sarma.

The Pharmacological Implications of Flavopiridol: An Updated Overview.

Flavopiridol is a flavone synthesized from the natural product rohitukine, which is derived from an Indian medicinal plant, namely Dysoxylum binectariferum Hiern. A deeper understanding of the biological mechanisms by which such molecules act may allow scientists to develop effective therapeutic strategies against a variety of life-threatening diseases, such as cancer, viruses, fungal infections, parasites, and neurodegenerative diseases. Mechanistic insight of flavopiridol reveals its potential for kinase inhibitory activity of CDKs (cyclin-dependent kinases) and other kinases, leading to the inhibition of various processes, including cell cycle progression, apoptosis, tumor proliferation, angiogenesis, tumor metastasis, and the inflammation process. The synthetic derivatives of flavopiridol have overcome a few demerits of its parent compound. Moreover, these derivatives have much improved CDK-inhibitory activity and therapeutic abilities for treating severe human diseases. It appears that flavopiridol has potential as a candidate for the formulation of an integrated strategy to combat and alleviate human diseases. This review article aims to unravel the potential therapeutic effectiveness of flavopiridol and its possible mechanism of action.

Bacterial Expression of Promelittin for Safe and Effective Tumor Therapy.

Bacteria-based tumor therapy has attracted much attention due to its unique mechanism and abundant application. With the rapid development of synthetic biology, utilizing gene technology to make bacteria express therapeutic agents has greatly innovated bacterial therapy paradigms. Herein, we constructed an Escherichia coli expressing promelittin protein system based on the Trojan horse strategy, which limited the toxicity of melittin through the fusion protein during melittin expression. After targeted colonization of bacteria in tumor tissues, promelittin was activated by matrix metalloproteinase, followed by causing tumor cell death through a membrane-lytic mechanism. Additionally, the released cytolytic melittin in turn killed the maternal bacteria, eliminating safety hazards and triggering host immunity. Detailed experiments revealed that the bacteria expressing the promelittin system could significantly inhibit the proliferation and metastasis of primitive tumors in a CT26-bearing mice model. This study sheds insights into the development of bacteria-based synergistic tumor therapy.