Fangchinoline suppresses conjunctival melanoma by directly binding FUBP2 and inhibiting the homologous recombination pathway

The mechanism of high mobility group box-1 in the proliferation and macrophage polarization in esophageal squamous cell carcinoma cells

BACKGROUND

Previous studies showed that high mobility group box-1 (HMGB1) facilitates the initiation and progression of esophageal squamous cell carcinoma (ESCC), and the current research investigated the detailed mechanisms implicated.

METHODS

The impact of HMGB1 and IGFBP3 levels on the survival of ESCC was examined by plotting Kaplan-Meier (KM) curves based on the data collected from The Cancer Genome Atlas (TCGA). Quantitative real-time PCR (qRT-PCR) was performed to detect the expressions of HMGB1 in both human esophageal epithelial cells (HEEC) and ESCC cells. After cell transfection, the proliferation of ESCC cells was measured, and the cell metastasis was determined based on the levels of cadherins (CDHs) and Vimentin (VIM). Macrophage polarization was determined by calculating the mean fluorescence intensity (MFI) of CD206 and CD86. In addition, co-immunoprecipitation and immunoblotting were applied to evaluate the interaction between insulin-like growth factor binding protein 3 (IGFBP3)/DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and HMGB1.

RESULTS

A high level of HMGB1 was predictive of an unfavorable prognosis of ESCC (p < 0.05). HMGB1 showed a higher expression in ESCC cells (p < 0.05), while knockdown of HMGB1 inhibited ESCC cell proliferation, downregulated the levels of CDH2 and VIM and upregulated the level of CDH1 (p < 0.05). In contrast, overexpressed HMGB1 showed the opposite effects (p < 0.05), suggesting the role of HMGB1 in the epithelial-mesenchymal transition (EMT) of ESCC. After the knockout of HMGB1, the MFI of CD86 was increased but that of CD206 was reduced, indicating the polarization towards M1 macrophages (p < 0.05). However, the results were reversed when HMGB1 was overexpressed (p < 0.05). Meanwhile, HMGB1 could interact with the IGFBP3/DNA-PKcs complex (p < 0.05). Low-expressed IGFBP3 was predictive of an unfavorable prognosis of ESCC, and IGFBP3 silencing promoted the proliferation of ESCC cells (p < 0.05). Besides, HMGB1 and IGFBP3 could act antagonistically in influencing the proliferation of ESCC cells and macrophage polarization.

CONCLUSIONS

Through in vitro experiments, this study found that HMGB1 was linked to the proliferation and polarization of macrophages in ESCC, providing novel evidence for the role of HMGB1 in ESCC development.

A Comprehensive Appraisal of Bisbenzylisoquinoline Alkaloids Isolated From Genus Cyclea for Anticancer Potential

The pharmaceutical industry and academia are continuously searching for novel and effective anticancer lead compounds to ensure patient safety, provide a cure, and surpass all other obstacles. Given the indeterminate nature of cancer etiology, the importance of drugs capable of targeting multiple pathways cannot be overstated. Among naturally occurring compounds, bisbenzylisoquinoline (BBIQ) alkaloids, such as berberine, tetrandrine, chelidonine, and berbamine, have demonstrated significant anticancer potential by modulating diverse signaling pathways. Several of these compounds are currently in clinical trials, highlighting their relevance in cancer treatment. This review emphasizes the need for further investigation into the anticancer properties of BBIQ alkaloids, particularly those isolated from eight Cyclea species in India. With around 27 BBIQ alkaloids identified, these compounds hold promise, especially in combating multidrug resistance-a critical challenge in cancer therapy. Given the rising cancer incidence, these alkaloids warrant a deeper exploration of their therapeutic potential.

Fangchinoline Inhibits Zika Virus by Disrupting Virus Internalization

The Zika virus (ZIKV) has garnered significant public attention, particularly following the outbreak in Brazil, due to its potential to cause severe damage to the central nervous system and its ability to cross the placental barrier, resulting in microcephaly in infants. Despite the urgency, there remains a lack of targeted therapies or vaccines for the prevention or treatment of ZIKV infection and its related diseases. Fangchinoline (FAN), an alkaloid derived from traditional Chinese medicinal herbs, has a range of biological activities. In this study, we employed both in vitro and in vivo infection models to demonstrate the efficacy of FAN in inhibiting ZIKV. Our findings indicate that FAN effectively suppresses the replication of ZIKV viral RNA and protein, thereby validating its anti-ZIKV capabilities in living organisms. Further analysis through dosing time assays and infectious inhibition assays revealed that FAN exerts its antiviral effects by impeding the early stages of infection, specifically by inhibiting the internalization of ZIKV. These results underscore the potential of FAN as a candidate for anti-ZIKV drug development and offer novel insights into drug design strategies that target the virus's internalization process.

Study of the multitarget mechanism of Astragalus (HUANGQI) in the treatment of Alzheimer's disease based on network pharmacology and molecular docking technology

CONTEXT

In China, HUANGQI is widely used for the treatment of Alzheimer's disease (AD). However, a comprehensive understanding of its mechanism of anti-AD effects is lacking.

OBJECTIVE

To explore the active ingredients of HUANGQI and its potential targets and mechanisms of action in AD.

MATERIALS AND METHODS

The active ingredients and targets of HUANGQI were screened from databases (TCSMP, ETCM, and BATMan), and AD-related genes were obtained from DrugBank and GeneCards. The same target genes were screened, and a drug-target disease network was constructed. The PPI network was constructed and GO and KEGG pathway enrichment analyses of the targets. The Cell Counting Kit-8 (CCK-8) assay was used to determine suitable HUANGQI treatment concentrations for HT-22 cells between 0-480 μg/mL. CCK-8, FITC-phalloidin and propidium iodide (PI) assays were used to examine the protective effect of (0, 60, 120, 240 μg/mL) of HUANGQI on 20 μM Aβ1-42-induced HT-22 cell cytotoxicity.

RESULTS

Twelve active ingredients of HUANGQI were selected, with 679 common targets associated with AD. GO and KEGG analysis revealed that the therapeutic mechanisms of HUANGQI involve TNF, AGE, the NF-κB pathway, and nuclear receptor activity-related processes. The CCK-8 assay indicated that HUANGQI was not cytotoxic to HT-22 cells at concentrations less than 240 μg/mL and was able to attenuate Aβ1-42-induced cellular damage (EC50 = 83.46 μg/mL). FITC-phalloidin and PI assays suggested that HUANGQI could alleviate 20 μM Aβ1-42-induced neuronal cell cytotoxicity in a dose-dependent manner.

CONCLUSION

HUANGQI has a protective effect on Aβ1-42-induced nerve cell injury; further mechanism research was needed.

Fangchinoline inhibits mouse oocyte meiosis by disturbing MPF activity

Fangchinoline (FA) is an alkaloid derived from the traditional Chinese medicine Fangji. Numerous studies have shown that FA has a toxic effect on various cancer cells, but little is known about its toxic effects on germ cells, especially oocytes. In this study, we investigated the effects of FA on mouse oocyte maturation and its potential mechanisms. Our results showed that FA did not affect meiosis resumption but inhibited the first polar body extrusion. This inhibition is not due to abnormalities at the organelle level, such as chromosomes and mitochondrial, which was proved by detection of DNA damage and reactive oxygen species. Further studies revealed that FA arrested the oocyte at the metaphase I stage, and this arrest was not caused by abnormal kinetochore-microtubule attachment or spindle assembly checkpoint activation. Instead, FA inhibits the activity of anaphase-promoting complexes (APC/C), as evidenced by the inhibition of CCNB1 degeneration. The decreased activity of APC/C may be due to a reduction in CDC25B activity as indicated by the high phosphorylation level of CDC25B (Ser323). This may further enhance Maturation-Promoting Factor (MPF) activity, which plays a critical role in meiosis. In conclusion, our study suggests that the metaphase I arrest caused by FA may be due to abnormalities in MPF and APC/C activity.

Fangchinoline derivatives inhibits PI3K signaling in vitro and in vivo in non-small cell lung cancer

Fangchinoline (Fan) are extracted from the traditional Chinese medicine Stephania tetrandra S., which is a bis-benzyl isoquinoline alkaloids with anti-tumor activity. Therefore, 25 novel Fan derivatives have been synthesized and evaluated for their anti-cancer activity. In CCK-8 assay, these fangchinoline derivatives displayed higher proliferation inhibitory activity on six tumor cell lines than the parental compound. Compared to the parent Fan, compound 2h presented the anticancer activity against most cancer cells, especially A549 cells, with an IC50 value of 0.26 μM, which was 36.38-fold, and 10.61-fold more active than Fan and HCPT, respectively. Encouragingly, compound 2h showed low biotoxicity to the human normal epithelial cell BEAS-2b with an IC50 value of 27.05 μM. The results indicated compound 2h remarkably inhibited the cell migration by decreasing MMP-2 and MMP-9 expression and inhibited the proliferation of A549 cells by arresting the G2/M cell cycle. Meanwhile, compound 2h could also induce A549 cell apoptosis by promoting endogenous pathways of mitochondrial regulation. In nude mice presented that the growth of tumor tissues was markedly inhibited by the consumption of compound 2h in a dose-dependent manner, and it was found that compound 2h could inhibit the mTOR/PI3K/AKT pathway in vivo. In docking analysis, high affinity interaction between 2h and PI3K was responsible for drastic kinase inhibition by the compound. To conclude, this derivative compound may be useful as a potent anti-cancer agent for treatment of NSCLC.

Far upstream element-binding protein 1 confers lobaplatin resistance by transcriptionally activating PTGES and facilitating the arachidonic acid metabolic pathway in osteosarcoma

Drug resistance is a major obstacle in cancer treatment and recurrence prevention and leads to poor outcomes in patients suffering from osteosarcoma. Clarification of the mechanism of drug resistance and exploration of effective strategies to overcome this obstacle could lead to clinical benefits for these patients. The expression of far upstream element-binding protein 1 (FUBP1) was found to be markedly elevated in osteosarcoma cell lines and clinical specimens compared with osteoblast cells and normal bone specimens. High expression of FUBP1 was correlated with a more aggressive phenotype and a poor prognosis in osteosarcoma patients. We found that overexpression of FUBP1 confers lobaplatin resistance, whereas the inhibition of FUBP1 sensitizes osteosarcoma cells to lobaplatin-induced cytotoxicity both in vivo and in vitro. Chromatin immunoprecipitation-seq and RNA-seq were performed to explore the potential mechanism. It was revealed that FUBP1 could regulate the transcription of prostaglandin E synthase (PTGES) and subsequently activate the arachidonic acid (AA) metabolic pathway, which leads to resistance to lobaplatin. Our investigation provides evidence that FUBP1 is a potential therapeutic target for osteosarcoma patients. Targeting FUBP1, its downstream target PTGES and the AA metabolic pathway may be promising strategies for sensitizing chemoresistant osteosarcoma cells to lobaplatin.

Fangchinoline Exerts Anticancer Effects on Colorectal Cancer Cells by Evoking Cell Apoptosis via Endoplasmic Reticulum Stress

We studied the anti-tumor effect of fangchinoline (FAN) against human colorectal cancer cell lines CCL-244 and SW480 and analyzed the mechanism of FAN action. The cell viability and apoptosis were assessed by MTT test and Annexin V-PI staining; caspase-3 activity was measured by Western blotting. The expression of endoplasmic reticulum stress-related proteins was assessed by real-time PCR, Western blotting, and gene transfection. It was found that FAN inhibited cell growth and induced apoptosis in human colorectal cancer cell lines CCL-244 and SW480 in a dose-dependent manner. The caspase-3 inhibitor Ac-DEVD-CHO could reverse the inhibitory effect of FAN. Moreover, FAN significantly increased the expression of endoplasmic reticulum stress-related proteins p-PERK, p-eIF2α, ATF4, and CHOP in CCL-244 and SW480 cells. In addition, endoplasmic reticulum stress inhibitor 4-phenylbutyric acid or CHOP knockdown could prevent FAN-induced apoptosis. Thus, FAN induced apoptosis of human colorectal cancer through activation of endoplasmic reticulum stress.

Drug repurposing of propafenone to discover novel anti-tumor agents by impairing homologous recombination to delay DNA damage recovery of rare disease conjunctival melanoma

Conjunctival melanoma (CM), a rare and fatal malignant ocular tumor, lacks proper diagnostic biomarkers and therapy. Herein, we revealed the novel application of propafenone, an FDA-approved antiarrhythmic medication, which was identified effective in inhibiting CM cells viability and homologous recombination pathway. Detailed structure-activity relationships generated D34 as one of the most promising derivatives, which strongly suppressed the proliferation, viability, and migration of CM cells at submicromolar concentrations. Mechanically, D34 had the potential to increase γ-H2AX nuclear foci and aggravated DNA damage by suppressing homologous recombination pathway and its factors, particularly the complex of MRE11-RAD50-NBS1. D34 bound to human recombinant MRE11 protein and inhibited its endonuclease activity. Moreover, D34 dihydrochloride significantly suppressed tumor growth in the CRMM1 NCG xenograft model without obvious toxicity. Our finding shows that propafenone derivatives modulating the MRE11-RAD50-NBS1 complex will most likely provide an approach for CM targeted therapy, especially for improving chemo- and radio-sensitivity for CM patients.

Upregulation of TRPC6 inhibits astrocyte activation and proliferation after spinal cord injury in rats by suppressing AQP4 expression

AIMS

This work investigates the effects and mechanisms of inhibiting TRPC6 (a non-selective cation channel) downregulation on rat astrocyte activation and proliferation following spinal cord injury (SCI) by suppressing AQP4 expression. We used HYP9 (TRPC6-specific agonist) and TGN-020 (AQP4-specific inhibitor) to explore the relationship between TRPC6 and AQP4 and their probable protective effects on SCI.

METHODS

In a rat SCI model, we randomly assigned female Sprague-Dawley rats into the following four groups: Sham, SCI, SCI+HYP9, and SCI+TGN-020. Western blotting and immunofluorescence staining were used to determine protein expression among groups following SCI. TUNEL and immunofluorescence staining were used to identify changes in the rate of apoptosis and the fraction of surviving neurons after SCI. The Basso-Beattie-Bresnahan open-field locomotor scale was used to identify changes in motor function after SCI. In vitro astrocyte scratch model, we first used the CCK8 assay to test the effects of varying doses of HYP9 or TGN-020 on astrocytes and then split the astrocytes into four groups: Con, Scratch, Scratch+HYP9, and Scratch+TGN-020. Western blotting and immunofluorescence were used to identify changes in the expression of target proteins.

RESULTS

In vivo and in vitro models, SCI dramatically decreased TRPC6 while considerably upregulating AQP4, glial fibrillary acidic protein (GFAP), and proliferating cell nuclear antigen (PCNA) expression. However, HYP9 or TGN-020 significantly suppressed activation of astrocytes, promoted neurons survival in the anterior horn of the spinal cords, and benefited the recovery of motor function in the hind limbs of rats following SCI. Interestingly, TRPC6 agonists dramatically suppressed AQP4 overexpression, indicating that the probable mechanism of HYP9 benefiting alleviation of SCI may be connected to AQP4 inhibition and astrocyte activation and proliferation reduction.

CONCLUSION

we discovered for the first time that HYP9 inhibits astrocyte activation and proliferation by inhibiting AQP4 in SCI rats in vivo and in vitro models and that it preserves neuronal survival and functional recovery after SCI.

Crotamiton derivative JM03 extends lifespan and improves oxidative and hypertonic stress resistance in Caenorhabditis elegans via inhibiting OSM-9

While screening our in-house 1072 marketed drugs for their ability to extend the lifespan using Caenorhabditis elegans (C. elegans) as an animal model, crotamiton (N-ethyl-o-crotonotoluidide) showed anti-aging activity and was selected for further structural optimization. After replacing the ortho-methyl of crotamiton with ortho-fluoro, crotamiton derivative JM03 was obtained and showed better activity in terms of lifespan-extension and stress resistance than crotamiton. It was further explored that JM03 extended the lifespan of C. elegans through osmotic avoidance abnormal-9 (OSM-9). Besides, JM03 improves the ability of nematode to resist oxidative stress and hypertonic stress through OSM-9, but not osm-9/capsaicin receptor related-2 (OCR-2). Then the inhibition of OSM-9 by JM03 reduces the aggregation of Q35 in C. elegans via upregulating the genes associated with proteostasis. SKN-1 signaling was also found to be activated after JM03 treatment, which might contribute to proteostasis, stress resistance and lifespan extension. In summary, this study explored a new small molecule derived from crotamiton, which has efficient anti-oxidative, anti-hypertonic, and anti-aging effects, and could further lead to promising application prospects.

Cucurbitacin B-induced G2/M cell cycle arrest of conjunctival melanoma cells mediated by GRP78–FOXM1–KIF20A pathway

Conjunctival melanoma (CM) is a rare and fatal malignant eye tumor. In this study, we deciphered a novel anti-CM mechanism of a natural tetracyclic compound named as cucurbitacin B (CuB). We found that CuB remarkably inhibited the proliferation of CM cells including CM-AS16, CRMM1, CRMM2 and CM2005.1, without toxicity to normal cells. CuB can also induce CM cells G2/M cell cycle arrest. RNA-seq screening identified KIF20A, a key downstream effector of FOXM1 pathway, was abolished by CuB treatment. Further target identification by activity-based protein profiling chemoproteomic approach revealed that GRP78 is a potential target of CuB. Several lines of evidence demonstrated that CuB interacted with GRP78 and bound with a K_d value of 0.11 μmol/L. Furthermore, ATPase activity evaluation showed that CuB suppressed GRP78 both in human recombinant GRP78 protein and cellular lysates. Knockdown of the GRP78 gene significantly induced the downregulation of FOXM1 and related pathway proteins including KIF20A, underlying an interesting therapeutic perspective. Finally, CuB significantly inhibited tumor progression in NCG mice without causing obvious side effects in vivo. Taken together, our current work proved that GRP78–FOXM1–KIF20A as a promising pathway for CM therapy, and the traditional medicine CuB as a candidate drug to hinder this pathway.

Novel Aurora A Kinase Inhibitor Fangchinoline Enhances Cisplatin-DNA Adducts and Cisplatin Therapeutic Efficacy in OVCAR-3 Ovarian Cancer Cells-Derived Xenograft Model

Aurora A kinase (Aurora A) is a serine/threonine kinase regulating control of multiple events during cell-cycle progression. Playing roles in promoting proliferation and inhibiting cell death in cancer cells leads Aurora A to become a target for cancer therapy. It is overexpressed and associated with a poor prognosis in ovarian cancer. Improving cisplatin therapy outcomes remains an important issue for advanced-stage ovarian cancer treatment, and Aurora A inhibitors may improve it. In the present study, we identified natural compounds with higher docking scores than the known Aurora A ligand through structure-based virtual screening, including the natural compound fangchinoline, which has been associated with anticancer activities but not yet investigated in ovarian cancer. The binding and inhibition of Aurora A by fangchinoline were verified using cellular thermal shift and enzyme activity assays. Fangchinoline reduced viability and proliferation in ovarian cancer cell lines. Combination fangchinoline and cisplatin treatment enhanced cisplatin-DNA adduct levels, and the combination index revealed synergistic effects on cell viability. An in vivo study showed that fangchinoline significantly enhanced cisplatin therapeutic effects in OVCAR-3 ovarian cancer-bearing mice. Fangchinoline may inhibit tumor growth and enhance cisplatin therapy in ovarian cancer. This study reveals a novel Aurora A inhibitor, fangchinoline, as a potentially viable adjuvant for ovarian cancer therapy.