Convallatoxin promotes apoptosis and inhibits proliferation and angiogenesis through crosstalk between JAK2/STAT3 (T705) and mTOR/STAT3 (S727) signaling pathways in colorectal cancer

PI3K/AKT/mTORC1 signalling pathway regulates MMP9 gene activation via transcription factor NF-κB in mammary epithelial cells of dairy cows

Matrix metalloproteinase 9 (MMP9) plays a pivotal role in mammary ductal morphogenesis, angiogenesis and glandular tissue architecture remodeling. However, the molecular mechanism of MMP9 expression in mammary epithelial cells of dairy cows remains unclear. This study aimed to explore the underlying mechanism of MMP9 expression. In this study, to determine whether the PI3K/AKT/mTORC1/NF-κB signalling pathway participates in the regulation of MMP9 expression, we treated mammary epithelial cells with specific pharmacological inhibitors of PI3K (LY294002), mTORC1 (Rapamycin) or NF-κB (Celastrol), respectively. Western blotting results indicated that LY294002, Rapamycin and Celastrol markedly decreased MMP9 expression and P65 nuclear translocation. Furthermore, we found that NF-κB (P65) overexpression resulted in elevated expression of MMP9 protein and activation of MMP9 promoter. In addition, we observed that Celastrol markedly decreases P65-overexpression-induced MMP9 promoter activity. Moreover, the results of the promoter assay indicated that the core regulation sequence for MMP9 promoter activation may be located at -420 ∼ -80 bp downstream from the transcription start site. These observations indicated that the PI3K/AKT/mTORC1 signalling pathway is involved in MMP9 expression by regulating MMP9 promoter activity via NF-κB in the mammary epithelial cells of dairy cows.

Relationship between Indel Variants within the JAK2 Gene and Growth Traits in Goats

Janus kinase 2 (JAK2) plays a critical role in myoblast proliferation and fat deposition in animals. Our previous RNA-Seq analyses identified a close association between the JAK2 gene and muscle development. To date, research delving into the relationship between the JAK2 gene and growth traits has been sparse. In this study, we sought to investigate the relationship between novel mutations within the JAK2 gene and goat growth traits. Herein, two novel InDel (Insertion/Deletion) polymorphisms within the JAK2 gene were detected in 548 goats, and only two genotypes were designated as ID (Insertion/Deletion) and DD (Deletion/Deletion). The results indicate that the two InDels, the del19008 locus in intron 2 and del72416 InDel in intron 6, showed significant associations with growth traits (p < 0.05). Compared to Nubian and Jianzhou Daer goats, the del72416 locus displayed a more pronounced effect in the Fuqing breed group. In the Nubian breed (NB) group, both InDels showed a marked influence on body height (BH). There were strong linkages observed for these two InDels between the Fuqing (FQ) and Jianzhou (JZ) populations. The DD-ID diplotype was associated with inferior growth traits in chest width (ChW) and cannon circumference (CaC) in the FQ goats compared to the other diplotypes. In the NB population, the DD-DD diplotype exhibited a marked negative impact on BH and HuWI (hucklebone width index), in contrast to the other diplotypes. In summary, our findings suggest that the two InDel polymorphisms within the JAK2 gene could serve as valuable molecular markers for enhancing goat growth traits in breeding programs.

Application of 18β-glycyrrhetinic acid in the structural modification of natural products: a review

18β-Glycyrrhetinic acid (GA) is an oleane-type pentacyclic triterpene saponin obtained from glycyrrhizic acid by removing 2 glucuronic acid groups. GA and its analogues are active substances of glycyrrhiza aicd, with similar structure and important pharmacological effects such as anti-inflammatory, anti-diabetes, anti-tumor and anti-fibrosis. Although GA combined compounds are in the clinical trial stages, its application potential is severely restricted by its low bioavailability, water solubility and membrane permeability. In this article, synthetic methods and structure-activity relationships (SARs) of GA derivatives from 2018 to present are reviewed based on pharmacological activity. It is hoped that this review can provide reference for the future development of potential GA preclinical candidate compounds, and furnish ideas for the development of pentacyclic triterpenoid lead compounds.

Deciphering JAK/STAT signaling pathway: A multifaceted approach to tumorigenesis, progression and therapeutic interventions

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway, essential for cellular communication, orchestrates a myriad of physiological and pathological processes. Recently, the intricate association between the pathway's dysregulation and the progression of malignant tumors has garnered increasing attention. Nevertheless, there is no systematic summary detailing the anticancer effects of molecules targeting the JAK/STAT pathway in the context of tumor progression. This review offers a comprehensive overview of pharmaceutical agents targeting the JAK/STAT pathway, encompassing phytochemicals, synthetic drugs, and biomolecules. These agents can manifest their anticancer effects through various mechanisms, including inhibiting proliferation, inducing apoptosis, suppressing tumor metastasis, and angiogenesis. Notably, we emphasize the clinical challenges of drug resistance while spotlighting the potential of integrating JAK/STAT inhibitors with other therapies as a transformative approach in cancer treatment. Moreover, this review delves into the avant-garde strategy of employing nanocarriers to enhance the solubility and bioavailability of anticancer drugs, significantly amplifying their therapeutic prowess. Through this academic exploration of the multifaceted roles of the JAK/STAT pathway in the cancer milieu, we aim to sketch a visionary trajectory for future oncological interventions.

Synthesis and anti-liver fibrosis activity of imidazole and thiazole compounds containing amino acids

Four series of imidazoles (15a-g, 20c, and 20d) and thiazoles (18a-g, 22a, and 22b) possessing various amino acids were synthesized and evaluated for activin receptor-like kinase 5 (ALK5) inhibitory activities in an enzymatic assay. Among them, compounds 15g and 18c showed the highest inhibitory activity against ALK5, with IC50 values of 0.017 and 0.025 μM, respectively. Compounds 15g and 18c efficiently inhibited extracellular matrix (ECM) deposition in TGF-β-induced hepatic stellate cells (HSCs), and eventually suppressed HSC activation. Moreover, compound 15g showed a good pharmacokinetic (PK) profile with a favorable half-life (t1/2 = 9.14 h). The results indicated that these compounds exhibited activity targeting ALK5 and may have potential in the treatment of liver fibrosis; thus they are worthy of further study.

Synthesis and Antimicrobial Activity Evaluation of Pyridine Derivatives Containing Imidazo[2,1-b][1,3,4]Thiadiazole Moiety

Four series of novel pyridine derivatives (17 a-i, 18 a-i, 19 a-e, and 20 a-e) were synthesized and their antimicrobial activities were evaluated. Of all the target compounds, almost half target compounds showed moderate or high antibacterial activity. The 4-F substituted compound 17 d (MIC=0.5 μg/mL) showed the highest antibacterial activity, its activity was twice the positive control compound gatifloxacin (MIC=1.0 μg/mL). For fungus ATCC 9763, the activities of compounds 17 a and 17 d are equivalent to the positive control compound fluconazole (MIC=8 μg/mL). Furthermore, compounds 17 a and 17 d showed little cytotoxicity to human LO2 cells, and did not show hemolysis even at ultra-high concentration (200 μM). The results indicate that these compounds are valuable for further development as antibacterial and antifungal agents.

Erianin inhibits tumor growth by promoting ferroptosis and inhibiting invasion in hepatocellular carcinoma through the JAK2/STAT3/SLC7A11 pathway

Iron has been found to be involved in the tumor cell proliferation process, which can lead to the increased sensitivity of cancer cells to ferroptosis. Since erianin is associated with oxidative stress in hepatocellular carcinoma (HCC), we hypothesized that the therapeutic effect and mechanism of erianin on HCC is related to ferroptosis. HCC cells were stimulated with increase of erianin concentrations for 24 h, and the survival rates of Huh-7 and HepG2 cells gradually decreased. After intervention with different doses of erianin, cell proliferation, clone number, and invasion were prominently decreased, apoptosis ratio was increased. Moreover, Nec-1, CQ, and Z-VAD had no effect on the cell viability induced by erianin, while the combination of ferroptosis inhibitors (deferoxamine mesylate, ferrostatin-1, and liproxstatin-1) and erianin prominently increased cell survival rate. Erianin pretreatment induced ferroptosis by enhancing reactive oxygen species, MDA, and Fe2+ levels, and reducing GSH levels. Erianin activated JAK2/STAT3 pathway and inhibited SLC7A11 and GPX4 expression, thereby inducing ferroptosis. Besides, tumor growth was significantly inhibited in the erianin-treated mice, and there was no obvious toxicity in the mice. Erianin reduced proliferation and invasion of HCC cells by inducing ferroptosis by blocking the JAK2/STAT3/SLC7A11 pathway, thereby impeding tumor growth.

Targeted regulated cell death with small molecule compounds in colorectal cancer: Current perspectives of targeted therapy and molecular mechanisms

Colorectal cancer (CRC), a tumor of the digestive system, is characterized by high malignancy and poor prognosis. Currently, targeted therapy of CRC is far away from satisfying. The molecular mechanisms of regulated cell death (RCD) have been clearly elucidated, which can be intervened by drug or genetic modification. Numerous studies have provided substantial evidence linking these mechanisms to the progression and treatment of CRC. The RCD includes apoptosis, autophagy-dependent cell death (ADCD), ferroptosis, necroptosis, and pyroptosis, and immunogenic cell death, etc, which provide potential targets for anti-cancer treatment. For the last several years, small-molecule compounds targeting RCD have been a well concerned therapeutic strategy for CRC. This present review aims to describe the function of small-molecule compounds in the targeted therapy of CRC via targeting apoptosis, ADCD, ferroptosis, necroptosis, immunogenic dell death and pyroptosis, and their mechanisms. In addition, we prospect the application of newly discovered cuproptosis and disulfidptosis in CRC. Our review may provide references for the targeted therapy of CRC using small-molecule compounds targeting RCD, including the potential targets and candidate compounds.

ZNF70 regulates IL-1β secretion of macrophages to promote the proliferation of HCT116 cells via activation of NLRP3 inflammasome and STAT3 pathway in colitis-associated colorectal cancer

Chronic inflammation is a key driver for colitis-associated colorectal cancer (CAC). It has been reported that inflammatory cytokines, such as IL-1β, could promote CAC. Zinc finger protein 70 (ZNF70) is involved in multiple biological processes. Here, we identified a previously unknown role for ZNF70 regulates macrophages IL-1β secretion to promote HCT116 proliferation in CAC, and investigated its underlying mechanism. We showed ZNF70 is much higher expressed in CAC tumor tissues compared with adjacent normal tissues in clinical CAC samples. Further experiments showed ZNF70 promoted macrophages IL-1β secretion and HCT116 proliferation. In LPS/ATP-stimulated THP-1 cells, we found ZNF70 activated NLRP3 inflammasome, resulting in robust IL-1β secretion. Interestingly, we discovered the ZnF domain of ZNF70 could interact with NLRP3 and decrease the K48-linked ubiquitination of NLRP3. Moreover, ZNF70 could activate STAT3, thereby promoting IL-1β synthesis. Noteworthy, ZNF70 enhanced proliferation by upregulating STAT3 activation in HCT116 cells cultured in the conditioned medium of THP-1 macrophages treated with LPS/ATP. Finally, the vivo observations were confirmed using AAV-mediated ZNF70 knockdown, which improved colitis-associated colorectal cancer in the AOM/DSS model. The correlation between ZNF70 expression and overall survival/IL-1β expression in colorectal cancer was verified by TCGA database. Taken together, ZNF70 regulates macrophages IL-1β secretion to promote the HCT116 cells proliferation via activation of NLRP3 inflammasome and STAT3 pathway, suggesting that ZNF70 may be a promising preventive target for treating in CAC.

Uncovering the Anti-Angiogenic Mechanisms of Centella asiatica via Network Pharmacology and Experimental Validation

BACKGROUND

Centella asiatica (CA) has been used to address cancer for centuries in traditional Chinese medicine (TCM). Previous studies demonstrated its anti-angiogenesis efficacy, but the underlying mechanism of its action remains to be further clarified. This study aims to investigate the underlying mechanisms of CA and its triterpenes in anti-angiogenesis for cancer therapeutics through network pharmacology and experimental validation.

METHODS

Cytoscape was used to construct a network of compound-disease targets and protein-protein interactions (PPIs) from which core targets were identified. GO and KEGG analyses were performed using Metascape, and the AutoDock-Vina program was used to realize molecular docking for further verification. Then, VEGF165 was employed to establish an induced angiogenesis model. The anti-angiogenic effects of CA were evaluated through assays measuring cell proliferation, migration, and tubular structure formation.

RESULTS

Twenty-five active ingredients in CA had potential targets for anti-angiogenesis including madecassoside, asiaticoside, madecassic acid, asiatic acid, and asiaticoside B. In total, 138 potential targets for CA were identified, with 19 core targets, including STAT3, SRC, MAPK1, and AKT1. A KEGG analysis showed that CA is implicated in cancer-related pathways, specifically PD-1 and AGE-RAGE. Molecular docking verified that the active components of CA have good binding energy with the first four important targets of angiogenesis. In experimental validation, the extracts and triterpenes of CA improved VEGF165-induced angiogenesis by reducing the proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs).

CONCLUSIONS

Our results initially demonstrate the effective components and great anti-angiogenic activity of CA. Evidence of the satisfactory anti-angiogenic action of the extracts and triterpenes from CA was verified, suggesting CA's significant potential as a prospective agent for the therapy of cancer.

Synthesis and Evaluation of Imidazole Derivatives Bearing Imidazo[2,1-b] [1,3,4]thiadiazole Moiety as Antibacterial Agents

BACKGROUND

Drug-resistant infections kill hundreds of thousands of people globally every year. In previous work, we found that tri-methoxy- and pyridine-substituted imidazoles show strong antibacterial activities.

OBJECTIVE

The aim of this work was to investigate the antibacterial activities and bacterial resistances of imidazoles bearing an aromatic heterocyclic, alkoxy, or polycyclic moiety on the central ring.

METHODS

Three series of 2-cyclopropyl-5-(5-(6-methylpyridin-2-yl)-2-substituted-1H-imidazol-4- yl)-6-phenylimidazo[2,1-b][1,3,4]thiadiazoles (13a-e, 14a-d, and 15a-f) were synthesized and their antibacterial activity was evaluated. The structures were confirmed by their 1H NMR, 13C NMR, and HRMS spectra. All the synthesized compounds were screened against Gram-positive, Gramnegative, and multidrug-resistant bacterial strains.

RESULTS

More than half of the compounds showed moderate or strong antibacterial activity. Among them, compound 13e (MICs = 1-4 μg/mL) showed the strongest activity against Gram-positive and drug-resistant bacteria as well as high selectivity against Gram-negative bacteria. Furthermore, it showed no cytotoxicity against HepG2 cells, even at 100 μM, and no hemolysis at 20 μM.

CONCLUSION

These results indicate that compound 13e is excellent candicate for further study as a potential antibacterial agent.

Recent Advances in Research on Active Compounds Against Hepatic Fibrosis

BACKGROUND

Almost all chronic liver diseases cause fibrosis, which can lead to cirrhosis and eventually liver cancer. Liver fibrosis is now considered to be a reversible pathophysiological process and suppression of fibrosis is necessary to prevent liver cancer. At present, no specific drugs have been found that have hepatic anti-fibrotic activity.

OBJECTIVE

The research progress of anti-hepatic fibrosis compounds in recent ten years was reviewed to provide a reference for the design and development of anti-hepatic fibrosis drugs.

METHODS

According to the structure of the compounds, they are divided into monocyclic compounds, fused-heterocyclic compounds, and acyclic compounds.

RESULTS

In this article, the natural products and synthetic compounds with anti-fibrotic activity in recent ten years were reviewed, with emphasis on their pharmacological activity and structure-activity relationship (SAR).

CONCLUSION

Most of these compounds are natural active products and their derivatives, and there are few researches on synthetic compounds and SAR studies on natural product.

Solamargine induces apoptosis of human renal carcinoma cells via downregulating phosphorylated STAT3 expression

Solamargine (SM), an active compound derived from Solanum nigrum, triggers apoptosis and inhibits the metastatic and oxidative activities of various types of tumor cells. However, the effect of SM on human renal carcinoma cells remains unknown. In the present study, the molecular mechanisms underlying the antitumor effects of SM on ACHN and 786-O cells were elucidated. Specifically, MTT and colony formation assays were conducted to evaluate the impact of SM treatment on the proliferation of ACHN and 786-O cells, and flow cytometry was conducted to determine the influence of SM on the apoptosis rates of these cells. In addition, the expression of target proteins was determined by western blotting. The results revealed that SM not only inhibited cell viability but also promoted the apoptosis of ACHN and 786-O cells in a time- and dose-dependent manner. Moreover, treatment of ACHN and 786-O cells with SM significantly enhanced the caspase-3, caspase-8 and caspase-9 activities. Furthermore, SM downregulated the expression of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) and Bcl-2 but increased the expression of cleaved caspase-3, -8, -9 and Bax. BAY2353, a p-STAT3 inhibitor, inhibited the viability of ACHN and 786-O cells, increased the expression of cleaved caspase-9 and Bax and decreased the expression of p-STAT3 and Bcl-2. Further experiments demonstrated that SM inhibited tumor growth in xenograft nude mice without causing specific toxicity to the major organs. Collectively, these findings indicated that SM not only inhibited the viability but also promoted the apoptosis of ACHN and 786-O cells, through a mechanism involving downregulation of p-STAT3 expression.

STAT3 as a newly emerging target in colorectal cancer therapy: Tumorigenesis, therapy response, and pharmacological/nanoplatform strategies

Colorectal cancer (CRC) ranks as the third most aggressive tumor globally, and it can be categorized into two forms: colitis-mediated CRC and sporadic CRC. The therapeutic approaches for CRC encompass surgical intervention, chemotherapy, and radiotherapy. However, even with the implementation of these techniques, the 5-year survival rate for metastatic CRC remains at a mere 12-14%. In the realm of CRC treatment, gene therapy has emerged as a novel therapeutic approach. Among the crucial molecular pathways that govern tumorigenesis, STAT3 plays a significant role. This pathway is subject to regulation by cytokines and growth factors. Once translocated into the nucleus, STAT3 influences the expression levels of factors associated with cell proliferation and metastasis. Literature suggests that the upregulation of STAT3 expression is observed as CRC cells progress towards metastatic stages. Consequently, elevated STAT3 levels serve as a significant determinant of poor prognosis and can be utilized as a diagnostic factor for cancer patients. The biological and malignant characteristics of CRC cells contribute to low survival rates in patients, as the upregulation of STAT3 prevents apoptosis and promotes pro-survival autophagy, thereby accelerating tumorigenesis. Furthermore, STAT3 plays a role in facilitating the proliferation of CRC cells through the stimulation of glycolysis and promoting metastasis via the induction of epithelial-mesenchymal transition (EMT). Notably, an intriguing observation is that the upregulation of STAT3 can mediate resistance to 5-fluorouracil, oxaliplatin, and other anti-cancer drugs. Moreover, the radio-sensitivity of CRC diminishes with increased STAT3 expression. Compounds such as curcumin, epigallocatechin gallate, and other anti-tumor agents exhibit the ability to suppress STAT3 and its associated pathways, thereby impeding tumorigenesis in CRC. Furthermore, it is worth noting that nanostructures have demonstrated anti-proliferative and anti-metastatic properties in CRC.

Glycosides as Potential Medicinal Components for Ulcerative Colitis: A Review

Ulcerative colitis (UC) is a chronic, non-specific disease of unknown etiology. The disease develops mainly in the rectum or colon, and the main clinical symptoms include abdominal pain, diarrhea, and purulent bloody stools, with a wide variation in severity. The specific causative factors and pathogenesis of the disease are not yet clear, but most scholars believe that the disease is caused by the interaction of genetic, environmental, infectious, immune, and intestinal flora factors. As for the treatment of UC, medications are commonly used in clinical practice, mainly including aminosalicylates, glucocorticoids, and immunosuppressive drugs. However, due to the many complications associated with conventional drug therapy and the tendency for UC to recur, there is an urgent need to discover new, safer, and more effective drugs. Natural compounds with biodiversity and chemical structure diversity from medicinal plants are the most reliable source for the development of new drug precursors. Evidence suggests that glycosides may reduce the development and progression of UC by modulating anti-inflammatory responses, inhibiting oxidative stress, suppressing abnormal immune responses, and regulating signal transduction. In this manuscript, we provide a review of the epidemiology of UC and the available drugs for disease prevention and treatment. In addition, we demonstrate the protective or therapeutic role of glycosides in UC and describe the possible mechanisms of action to provide a theoretical basis for preclinical studies in drug development.

Advances in Osteosarcoma

PURPOSE OF REVIEW

This article gives a brief overview of the most recent developments in osteosarcoma treatment, including targeting of signaling pathways, immune checkpoint inhibitors, drug delivery strategies as single or combined approaches, and the identification of new therapeutic targets to face this highly heterogeneous disease.

RECENT FINDINGS

Osteosarcoma is one of the most common primary malignant bone tumors in children and young adults, with a high risk of bone and lung metastases and a 5-year survival rate around 70% in the absence of metastases and 30% if metastases are detected at the time of diagnosis. Despite the novel advances in neoadjuvant chemotherapy, the effective treatment for osteosarcoma has not improved in the last 4 decades. The emergence of immunotherapy has transformed the paradigm of treatment, focusing therapeutic strategies on the potential of immune checkpoint inhibitors. However, the most recent clinical trials show a slight improvement over the conventional polychemotherapy scheme. The tumor microenvironment plays a crucial role in the pathogenesis of osteosarcoma by controlling the tumor growth, the metastatic process and the drug resistance and paved the way of new therapeutic options that must be validated by accurate pre-clinical studies and clinical trials.

Synthesis and antimicrobial activity evaluation of pyrazole derivatives containing the imidazo[2,1-b][1,3,4]thiadiazole moiety

Four series of novel pyrazole derivatives (compounds 17a-m, 18a-m, 19a-g, and 20a-g) were synthesized, and their antibacterial and antifungal activities were evaluated. Most of the target compounds (17a-m, 18k-m, and 19b-g) showed strong antifungal activity and high selectivity relative to both Gram-positive and Gram-negative bacteria. Among them, compounds 17l (minimum inhibitory concentration [MIC] = 0.25 µg/mL) and 17m (MIC = 0.25 µg/mL) showed the strongest antifungal activity, being 2- and 4-fold more active than the positive controls gatifloxacin and fluconazole, respectively. In particular, compound 17l showed little cytotoxicity against human LO2 cells and did not exhibit hemolysis at ultrahigh concentrations, as did the positive control compounds gatifloxacin and fluconazole. These results indicate that these compounds are valuable for further development as antifungal agents.

A homogeneous Lonicera japonica polysaccharide alleviates atopic dermatitis by promoting Nrf2 activation and NLRP3 inflammasome degradation via p62

ETHNOPHARMACOLOGICAL RELEVANCE

Lonicera japonica Thunb. is a traditional medicinal herb with a long history owing to its widespread use in Asia for the treatment of several inflammatory diseases including allergic dermatitis; however, its active components and mechanism of action have not been fully elucidated.

AIM OF THE STUDY

In this study, a homogeneous polysaccharide with strong anti-inflammatory effects was extracted from the traditional Chinese medicine Lonicera japonica. The mechanism by which the polysaccharide WLJP-025p regulates p62 to activate Nrf2, promote NLRP3 inflammasome degradation, and improve AD was investigated.

MATERIALS AND METHODS

An AD model was established using DNCB, and saline was used as a control. The WLJP-L and WLJP-H groups were administered 30 and 60 mg/kg WLJP-025p during the model challenge period, respectively. The therapeutic effect of WLJP-025p was evaluated by determining the skin thickness, performing HE and toluidine blue staining, detecting TSLP via IHC, and determining serum IgE and IL-17 levels. Th17 differentiation was detected using flow cytometry. IF and WB were performed to evaluate the expression levels of c-Fos, p-p65, NLRP3 inflammatory bodies, autophagy pathway, ubiquitination, and Nrf2 proteins.

RESULTS

WLJP-025p significantly inhibited DNCB-induced skin hyperplasia and pathological abnormalities and increased TSLP levels in mice. The differentiation of Th17 in the spleen, IL-17 release, p-c-Fos, p-p65 protein expression, and NLRP3 inflammasome activation in the skin tissues were reduced. Furthermore, p62 expression, p62 Ser403 phosphorylation, and ubiquitinated proteins were increased.

CONCLUSIONS

WLJP-025p improved AD in mice by upregulating p62 to activate Nrf2 and promote the ubiquitination and degradation of NLRP3.

Galangin inhibits programmed cell death-ligand 1 expression by suppressing STAT3 and MYC and enhances T cell tumor-killing activity

BACKGROUND

The flavonoid galangin (3,5,7-trihydroxyflavone) is derived from the root of Alpinia officinarum Hance, an edible and medicinal herb. Galangin has many biological activities, such as anti-inflammatory, anti-microbial, anti-viral, anti-obesogenic, and anti-oxidant effects. However, the anti-tumor mechanism of galangin remains unclear.

PURPOSE

To elucidate the anti-tumor mechanisms of galangin in vitro and in vivo.

METHODS

MTT, western blotting, immunoprecipitation, RT-PCR, and immunofluorescence assays were used to assess the mechanism of galangin inhibiting PD-L1 expression. The effect of galangin on T cell activity was analyzed in Hep3B/T cell co-cultures. Colony formation, EdU, migration, and invasion assays were performed to explore the effect of galangin on cancer progression and metastasis. Anti-tumor effects of galangin were investigated in a xenograft model.

RESULTS

Galangin inhibited PD-L1 expression dose-dependently, which plays a major role in tumor progression. Moreover, galangin blocked STAT3 activation through the JAK1/JAK2/Src signaling pathway and Myc activation through the Ras/RAF/MEK/ERK signaling pathway. Galangin reduced PD-L1 expression by suppressing STAT3 and Myc cooperatively. Galangin increased the killing effect of T cells on tumor cells in Hep3B/T cell co-cultures. Moreover, galangin inhibited tumor cell proliferation, migration, and invasion through PD-L1. In vivo experiments showed that galangin suppressed tumor growth.

CONCLUSION

Galangin enhances T-cell activity and inhibits tumor cell proliferation, migration, and invasion through PD-L1. The current study emphasizes the anti-tumor properties of galangin, offering new insights into the development of tumor therapeutics targeting PD-L1.

Regulatory mechanisms of natural compounds from traditional Chinese herbal medicines on the microglial response in ischemic stroke

BACKGROUND

Development of clinically effective neuroprotective agents for stroke therapy is still a challenging task. Microglia play a critical role in brain injury and recovery after ischemic stroke. Traditional Chinese herbal medicines (TCHMs) are based on a unique therapeutic principle, have various formulas, and have long been widely used to treat stroke. Therefore, the active compounds in TCHMs and their underlying mechanisms of action are attracting increasing attention in the field of stroke drug development.

PURPOSE

To summarize the regulatory mechanisms of TCHM-derived natural compounds on the microglial response in animal models of ischemic stroke.

METHODS

We searched studies published until 10 April 2023 in the Web of Science, PubMed, and ScienceDirect using the following keywords: natural compounds, natural products or phytochemicals, traditional Chinese Medicine or Chinese herbal medicine, microglia, and ischemic stroke. This review was prepared according to PRISMA (Preferred Reporting Item for Systematic Reviews and Meta-Analysis) guidelines.

RESULTS

Natural compounds derived from TCHMs can attenuate the M1 phenotype of microglia, which is involved in the detrimental inflammatory response, via inhibition of NF-κB, MAPKs, JAK/STAT, Notch, TLR4, P2X7R, CX3CR1, IL-17RA, the NLRP3 inflammasome, and pro-oxidant enzymes. Additionally, the neuroprotective response of microglia with the M2 phenotype can be enhanced by activating Nrf2/HO-1, PI3K/AKT, AMPK, PPARγ, SIRT1, CB2R, TREM2, nAChR, and IL-33/ST2. Several clinical trials showed that TCHM-derived natural compounds that regulate microglial responses have significant and safe therapeutic effects, but further well-designed clinical studies are needed.

CONCLUSIONS

Further research regarding the direct targets and potential pleiotropic or synergistic effects of natural compounds would provide a more reasonable approach for regulation of the microglial response with the possibility of successful stroke drug development.

Telocinobufagin inhibits osteosarcoma growth and metastasis by inhibiting the JAK2/STAT3 signaling pathway

Osteosarcoma is the most common primary bone malignancy in children and adolescents; it exhibits rapid growth and a high metastatic potential and may thus lead to relatively high mortality. The JAK2/STAT3 signaling pathway, which plays a critical role in the occurrence and development of osteosarcoma, is a potential target for the treatment of osteosarcoma. Here, we identified the natural product telocinobufagin (TCB), which is a component isolated from toad cake, as a potent candidate with anti-osteosarcoma effects. TCB inhibited osteosarcoma cell growth, migration, invasion and induced cancer cell apoptosis. Mechanistically, TCB specifically inhibited the JAK2/STAT3 signaling pathway. More importantly, TCB significantly suppressed tumor growth and metastasis in an osteosarcoma xenograft animal model. Moreover, TCB also showed strong inhibitory effects in other cancer types, such as lung cancer, liver cancer, colon cancer, breast cancer and gastric cancer. Hence, our study reveals TCB as a potent anti-osteosarcoma therapeutic agent that inhibits the JAK2/STAT3 signaling pathway.

Antiovarian cancer mechanism of esculetin: inducing G0/G1 arrest and apoptosis via JAK2/STAT3 signalling pathway

OBJECTIVES

Esculetin is a coumarin derivative, which is extracted from the dried barks of fraxinus chinensis Roxb. Although it is reported esculetin possesses multiple pharmacological activities, its associated regulatory mechanism on ovarian cancer isn't well investigated.

METHODS

Cytotoxicity is evaluated by MTT, clonogenic and living/dead cells staining assays. Migration and invasion effects are investigated by wound healing, and transwell assays. The effect of cell cycle and apoptosis are analyzed by flow cytometry and western blotting. Mitochondrial membrane potential and intracellular reactive oxygen species (ROS) is assessed by fluorescence microscope. Analysis of animal experiments are carried out by various pathological section assays.

KEY FINDINGS

Esculetin exerts an anti- ovarian cancer effect. It is found that apoptosis induction is promoted by the accumulation of excessive ROS and inhibition of JAK2/STAT3 signalling pathway. In addition, exposure to esculetin leads to the cell viability reduction, migration and invasion capability decrease and G0/G1 phase cell cycle arrest induced by down-regulating downstream targets of STAT3. In vivo experimental results also indicate esculetin can inhibit tumour growth of mice.

CONCLUSIONS

Our study provides some strong evidences to support esculetin as a potential anti-cancer agent in ovarian cancer.

Anticancer Activity of the Bioactive Extract of the Morel Mushroom (Morchella elata, Ascomycetes) from Kashmir Himalaya (India) and Identification of Major Bioactive Compounds

Morel mushrooms, Morchella species are highly nutritional, excellently edible and medicinal. Anticancer activity of M. elata, growing in forests of Kashmir Himalaya was studied. Ethyl acetate extract of fruiting bodies of M. elata (MEAE) was evaluated for cytotoxicity by MTT assay using Daltons lymphoma ascites (DLA), human colon cancer (HCT-116) and normal cell lines. Anti-carcinogenic and antiangiogenic activities of MEAE were tested using mouse models. Proapoptotic activity was detected by double staining of acridine orange-ethidium bromide assay. MEAE was partially purified by column chromatography and the bioactive compounds were identified by LC-MS analysis. The bioactive extract of M. elata showed significant cytotoxicic activity against DLA (P < 0.05), HCT-116 cell lines (P < 0.05) and did not possess appreciable adverse effect on the viability of normal cells. At a concentration of 100 µg/mL, 60% cell death was observed in HCT-116 cell line while 80% cell death was found in DLA cell line. The extract also possessed profound anticarcinogenic, antiangiogenic and proapoptotic activities. LC-MS analysis showed celastrol (RT 9.504, C29H38O4, MW 450.27), convallatoxin (RT 9.60, C29H42O10, MW 550.27), cucurbitacin A (RT 11.97, C32H46O9, MW 574.71) and madecassic acid (RT 14.35, C30H48O6, MW 504.70) as the major bioactive components. Current experimental studies indicated that bioactive extract of M. elata possessed significant anticancer activity. Being an excellently edible mushroom, the potential therapeutic use of M. elata and its bioactive extract in complementary therapy of cancer is envisaged.

Anti-Cancer Effects of a New Herbal Medicine PSY by Inhibiting the STAT3 Signaling Pathway in Colorectal Cancer Cells and Its Phytochemical Analysis

Colorectal cancer (CRC) is an inflammation-associated common cancer worldwide. Paejang-san and Mori Cortex Radicis have been traditionally used for treating intestinal inflammatory diseases in Korea and China. In the present study, we developed a new herbal formula as an alternative to CRC treatments, which is composed of two main components of Paejangsan (Patriniae Radix (Paejang in Korean) and Coix Seed (Yiyiin in Korean)), and Mori Cortex Radicis (Sangbekpi in Korean) based on the addition and subtraction theory in traditional medicine, hence the name PSY, and explored the potential therapeutic effects of the new formula PSY in human CRC cells by analyzing viability, cell cycle and apoptosis. We found that PSY ethanol extract (EtOH-Ex), but not water extract, significantly suppressed the viability of human CRC cells, and synergistically decreased the cell proliferation compared to each treatment of Patriniae Radix and Coix Seed extract (PY) or Mori Cortex Radicis extract (S), suggesting the combination of PY and S in a 10-to-3 ratio for the formula PSY. PSY EtOH-Ex in the combination ratio reduced cell viability but induced cell cycle arrest at the G₂/M and sub-G₁ phases as well as apoptosis in CRC cells. In addition, the experimental results of Western blotting, immunofluorescence staining and reporter assays showed that PSY also inhibited STAT3 by reducing its phosphorylation and nuclear localization, which resulted in lowering STAT3-mediated transcriptional activation. In addition, PSY regulated upstream signaling molecules of STAT3 by inactivating JAK2 and Src and increasing SHP1. Moreover, the chemical profiles of PSY from UPLC-ESI-QTOF MS/MS analysis revealed 38 phytochemicals, including seven organic acids, eight iridoids, two lignans, twelve prenylflavonoids, eight fatty acids, and one carbohydrate. Furthermore, 21 potentially bioactive compounds were highly enriched in the PSY EtOH-Ex compared to the water extract. Together, these results indicate that PSY suppresses the proliferation of CRC cells by inhibiting the STAT3 signaling pathway, suggesting PSY as a potential therapeutic agent for treating CRC and 21 EtOH-Ex-enriched phytochemicals as anti-cancer drug candidates which may act by inhibiting STAT3.

Overexpression of ELL-associated factor 2 suppresses invasion, migration, and angiogenesis in colorectal cancer

BACKGROUND

The androgen responsive gene, ELL-associated factor 2 (EAF2), expressed in benign prostate tissues, has been shown to play an important role in tumor suppression in a variety of malignant tumors. In addition, some scholars found that EAF2 frameshift mutations are associated with intratumor heterogeneity in colorectal cancer (CRC) and inactivation of EAF2 in microsatellite instability-high CRC. However, the molecular mechanism by which EAF2 is involved in CRC invasion and metastasis remains unclear.

AIM

To determine the clinical value of expression of EAF2 protein in CRC, and to study the effects of EAF2 on the invasion, migration, and angiogenesis of CRC cells in vitro.

METHODS

In this study, we collected colorectal adenocarcinoma and corresponding adjacent tissues to investigate the clinical expression of EAF2 protein in patients with advanced CRC. Subsequently, we investigated the effect of EAF2 on the invasion, migration, and angiogenesis of CRC cells in vitro using plasmid transfection.

RESULTS

EAF2 protein was lowly expressed in cancer tissues of patients with advanced CRC. Kaplan-Meier survival analysis showed that the survival rate of the high EAF2 level group was higher than that of the low EAF2 level group.

CONCLUSION

Our results demonstrated that EAF2, as a tumor suppressor, may inhibit the invasion, metastasis, and angiogenesis of CRC cells by regulating the signal transducer and activator of transcription 3/transforming growth factor-β1 crosstalk pathway, and play a cancer suppressive and protective role in the occurrence and development of CRC. Our findings are of great significance to provide a new idea and theoretical basis for the targeted diagnosis and treatment of CRC.

Classical Angiogenic Signaling Pathways and Novel Anti-Angiogenic Strategies for Colorectal Cancer

Although productive progress has been made in colorectal cancer (CRC) researchs, CRC is the second most frequent type of malignancy and the major cause of cancer-related death among gastrointestinal cancers. As angiogenesis constitutes an important point in the control of CRC progression and metastasis, understanding the key signaling pathways that regulate CRC angiogenesis is critical in elucidating ways to inhibit CRC. Herein, we comprehensively summarized the angiogenesis-related pathways of CRC, including vascular endothelial growth factor (VEGF), nuclear factor-kappa B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), Wingless and int-1 (Wnt), and Notch signaling pathways. We divided the factors influencing the specific pathway into promoters and inhibitors. Among these, some drugs or natural compounds that have antiangiogenic effects were emphasized. Furthermore, the interactions of these pathways in angiogenesis were discussed. The current review provides a comprehensive overview of the key signaling pathways that are involved in the angiogenesis of CRC and contributes to the new anti-angiogenic strategies for CRC.

Selective suppression of melanoma lacking IFN-γ pathway by JAK inhibition depends on T cells and host TNF signaling

Therapeutic resistance to immune checkpoint blockers (ICBs) in melanoma patients is a pressing issue, of which tumor loss of IFN-γ signaling genes is a major underlying mechanism. However, strategies of overcoming this resistance mechanism have been largely elusive. Moreover, given the indispensable role of tumor-infiltrating T cells (TILs) in ICBs, little is known about how tumor-intrinsic loss of IFN-γ signaling (IFNγR1^KO) impacts TILs. Here, we report that IFNγR1^KO melanomas have reduced infiltration and function of TILs. IFNγR1^KO melanomas harbor a network of constitutively active protein tyrosine kinases centered on activated JAK1/2. Mechanistically, JAK1/2 activation is mediated by augmented mTOR. Importantly, JAK1/2 inhibition with Ruxolitinib selectively suppresses the growth of IFNγR1^KO but not scrambled control melanomas, depending on T cells and host TNF. Together, our results reveal an important role of tumor-intrinsic IFN-γ signaling in shaping TILs and manifest a targeted therapy to bypass ICB resistance of melanomas defective of IFN-γ signaling.

Role of Nrf2, STAT3, and Src as Molecular Targets for Cancer Chemoprevention

Cancer is a complex and multistage disease that affects various intracellular pathways, leading to rapid cell proliferation, angiogenesis, cell motility, and migration, supported by antiapoptotic mechanisms. Chemoprevention is a new strategy to counteract cancer; to either prevent its incidence or suppress its progression. In this strategy, chemopreventive agents target molecules involved in multiple pathways of cancer initiation and progression. Nrf2, STAT3, and Src are promising molecular candidates that could be targeted for chemoprevention. Nrf2 is involved in the expression of antioxidant and phase II metabolizing enzymes, which have direct antiproliferative action as well as indirect activities of reducing oxidative stress and eliminating carcinogens. Similarly, its cross-talk with NF-κB has great anti-inflammatory potential, which can be utilized in inflammation-induced/associated cancers. STAT3, on the other hand, is involved in multiple pathways of cancer initiation and progression. Activation, phosphorylation, dimerization, and nuclear translocation are associated with tumor cell proliferation and angiogenesis. Src, being the first oncogene to be discovered, is important due to its convergence with many upstream stimuli, its cross-talk with other potential molecular targets, such as STAT3, and its ability to modify the cell cytoskeleton, making it important in cancer invasion and metastasis. Therefore, the development of natural/synthetic molecules and/or design of a regimen that can reduce oxidative stress and inflammation in the tumor microenvironment and stop multiple cellular targets in cancer to stop its initiation or retard its progression can form newer chemopreventive agents.

Acacetin Inhibits Cell Proliferation and Induces Apoptosis in Human Hepatocellular Carcinoma Cell Lines

Human hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of death across the world. Recent evidence suggests that STAT3 regulates proliferative, survival, metastasis, and angiogenesis genes in HCC. Novel agents that suppress STAT3 activation can be used to prevent or treat HCC. We used a functional proteomics tumor pathway technology platform and multiple HCC cell lines to investigate the effects of acacetin (ACN) on STAT3 activation, protein kinases, phosphatases, products of STAT3-regulated genes, and apoptosis. ACN was found to inhibit STAT3 activation in a dose- and time-dependent manner in HCC cells. Upstream kinases c-Src, Janus-activated kinase 1, and Janus-activated kinase 2 were also inhibited. The ACN inhibition of STAT3 was abolished by vanadate treatment, suggesting the involvement of tyrosine phosphatase activity. ACN was found to suppress the protein expression of genes involved in proliferation, survival, and angiogenesis via STAT3 inhibition. ACN appears to be a novel STAT3 inhibitor and may be a promising therapeutic compound for application in the treatment of HCC and other cancers.

Mucin 16 Promotes Colorectal Cancer Development and Progression Through Activation of Janus Kinase 2

BACKGROUND

Mucin 16 (MUC16), a cell surface-associated mucin, has been implicated to be upregulated in a large repertoire of malignances. However, its function in the pathogenesis of colorectal cancer (CRC) is unknown.

AIMS

Here, we explored the regulatory role of MUC16 in CRC.

METHODS

First, tumor and paracancerous tissues, and serum samples from 162 CRC patients, peripheral blood samples from 48 healthy volunteers and 72 benign colorectal patients were collected. The correlation between the MUC16 expression and the clinical phenotypes of the patients was analyzed. Subsequently, HCT116 and SW480 cells with deletion of MUC16 were established to detect changes in the growth and metastatic capacities of CRC cells. The genes with the highest correlation with MUC16 were predicted by bioinformatics, and their binding relationships were detected by Co-IP and double-labeled immunofluorescence, followed by functional rescue experiments.

RESULTS

Overexpression of MUC16 in CRC patients was positively correlated with serum biomarkers and poor prognosis of patients. It was demonstrated by in vitro and in vivo experiments that knocking-down the expression of MUC16 could significantly inhibit the growth and metastasis of CRC cells. MUC16 activated janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) by interacting with JAK2. Further overexpression of JAK2 in cells with poor expression of MUC16 revealed a significant increase in the proliferative and metastatic capacities of CRC cells.

CONCLUSIONS

MUC16 contributes to the development and progression of CRC by binding to JAK2, thereby promoting phosphorylation of JAK2 and further activating STAT3 phosphorylation.

Convallatoxin suppresses osteosarcoma cell proliferation, migration, invasion, and enhances osteogenic differentiation by downregulating parathyroid hormone receptor 1 (PTHR1) expression and inactivating Wnt/β-catenin pathway

Osteosarcoma (OS) is the most common primary malignant bone tumor in children and adolescents. Convallatoxin, a natural cardiac glycoside, exhibits potent anti-tumor activities. Literature has confirmed that PTHR1 is highly expressed in OS tissues and cells and downregulation of PTHR1 could decrease the invasion and growth of OS cells and increase tumor differentiation. In addition, PTHR1 could activate Wnt signaling pathway to promote the malignant functions of OS. In the present study, MG63 and U2OS cells were treated with 0, 12.5, 25, and 50 nM convallatoxin in order to elucidate the precise function of convallatox on the malignant behaviors of OS cells. Moreover, MG63 and U2OS cells treated with convallatoxin were transfected with Ov-PTHR1 or sh-DKK1, aiming to explore whether convallatoxin impeded the malignant progression of OS by modulating PTHR1 and Wnt/β-catenin pathway. CCK-8, wound healing and transwell assays were employed to assess the proliferation, migration, and invasion of OS cells. Differentiation markers (collagen 1, osteopontin, RANKL, Runx2, osteocalcin) were measured to evaluate OS cell differentiation. Results illuminated that convallatoxin suppressed proliferation, migration, and invasion as well as promoted osteogenic differentiation of OS cells. Besides, convallatoxin inhibited PTHR1 expression and inactivated Wnt/β-catenin pathway and PTHR1 overexpression activated Wnt/β-catenin pathway. Furthermore, PTHR1 overexpression or DKK1 knockdown reversed the suppressing effects of convallatoxin on OS cell proliferation, migration, and invasion, as well as the enhancing effect of convallatoxin on OS cell osteogenic differentiation. Collectively, convallatoxin may repress the malignant progression of OS by blocking PTHR1 and Wnt/β-catenin pathway.

Relationship between VEGF Family Members, Their Receptors and Cell Death in the Neoplastic Transformation of Colorectal Cancer

Colorectal cancer (CRC) is the second most common cause of cancer death in the world. Both modifiable and nonmodifiable risk factors play a significant role in the pathogenesis of this tumor. The diagnosis is usually made late due to limitations of screening tests; therefore, the scientists are looking for new diagnostic tools such as gene or miRNA expression or different proteins’ concentrations, e.g., vascular endothelial growth factor (VEGF) family members. The VEGF family (VEGF-A, VEGF-B, VEGF-C, VEGF-D and PlGF) plays a key role in the processes of blood vessel formation in embryonic development as well as in pathological angiogenesis and lymphangiogenesis, which allow the tumor to grow exponentially. Blockage of VEGF-related pathways seems to be a valid therapeutic target. It was suggested in recent studies, that besides already used drugs, e.g., bevacizumab, there are other agents with potential usefulness in anticancer activity such as miRNAs, TMEA, granzyme K, baicalein and arginine. Moreover, VEGF proteins were assessed to induce the expression of anti-apoptotic proteins such as BCL-2 and BAX. Therefore, investigations concerning the usefulness of VEGF family members, not only in the development but also in the therapy of CRC, in order to fully elucidate their role in carcinogenesis, are extremely important.

ND-16: A Novel Compound for Inhibiting the Growth of Cutaneous T Cell Lymphoma by Targeting JAK2

Objective:

Cutaneous T cell lymphoma (CTCL) is a kind of extranodal non-Hodgkin Tcell lymphoma without healable treatment in the clinic. JAK2 amplification in CTCL patients makes it a potential target for CTCL treatment. In the present study, we aimed to evaluate the anticancer effect of ND-16, a novel nilotinib derivate, on CTCL cells and the underlying mechanism targeting JAK2.

Methods and Results:

We found that ND-16 was capable of regulating JAK2 and had a selective inhibitory effect on CTCL H9 cells. The surface plasmon resonance and molecular docking study indicated ND-16 bound to JAK2 with a high binding affinity. Further investigation revealed that ND-16 inhibited the downstream cascades of JAK2, including STATs, PI3K/AKT/mTOR, and MAPK pathways, followed by regulation of Bcl-2 family members and cell cycle proteins CDK/- Cyclins. Flow cytometry analysis confirmed these results that ND-16-treated H9 cells showed cell apoptosis and cell cycle arrest at S-phase.

Conclusion:

ND-16 may be of value in a potential therapy for the management of CTCL

Detection of aflatoxin B1 with a new label-free fluorescence aptasensor based on PVP-coated single-walled carbon nanohorns and SYBR Gold

This paper describes a novel fluorescence label-free aptasensor to detect aflatoxin B₁ (AFB₁) by utilizing SYBR Gold, aptamer, and single-walled carbon nanohorns (SWCNHs). In the presence of AFB₁, the conformation of AFB₁-specific aptamer went through and the spatial structure of this specific aptamer was transformed accordingly. Due to the resistance of the transformed aptamer when adsorbed on the surface of SWCNHs, the protection of the fluorescence of SYBR Gold was accomplished. Consequently, concentrations of AFB₁ showed a strong association with fluorescence intensity. The detection limit (LOD) of AFB₁ was 1.89 ng/mL, while the linear range was 5-200 ng/mL and fluorescence intensity satisfactorily correlated (R² = 0.9919) with the logarithm of AFB₁ concentration.

Panaxadiol inhibits IL-1β secretion by suppressing zinc finger protein 91-regulated activation of non-canonical caspase-8 inflammasome and MAPKs in macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

The use of Panax ginseng C.A.Mey. in traditional Chinese medicine dates back to about 5000 years ago thanks to its several beneficial and healing properties. Panaxadiol is a triterpenoid sapogenin monomer found in the roots of Panax ginseng C.A.Mey. and has been proven to have various bio-activities such as anti-inflammatory, anti-tumour and neuroprotective effects.

AIM OF THE STUDY

The present study focuses on investigating the inflammation inhibitory effect and mechanism of panaxadiol by regulating zinc finger protein 91-regulated activation of non-canonical caspase-8 inflammasome and MAPKs in macrophages.

MATERIALS AND METHODS

In vitro, the underlying mechanisms by which panaxadiol inhibits ZFP91-regulated IL-1β expression were investigated using molecular docking, western blotting, RT-PCR, ELISA, immunofluorescence, and immunoprecipitation assays. In vivo, colitis was induced by oral administration of DSS in drinking water, and peritonitis was induced by an intraperitoneal injection of alum. Recombinant adeno-associated virus (AAV serotype 9) vector was used to establish ZFP91 knockdown mouse.

RESULTS

We confirmed that panaxadiol inhibited IL-1β secretion by suppressing ZFP91 in macrophages. Further analysis revealed that panaxadiol inhibited IL-1β secretion by suppressing ZFP91-regulated activation of non-canonical caspase-8 inflammasome. Meanwhile, panaxadiol inhibited IL-1β secretion by suppressing ZFP91-regulated activation of MAPKs. In vivo, prominent anti-inflammatory effects of panaxadiol were demonstrated in a DSS induced acute colitis mouse model and in an alum-induced peritonitis model by suppressing ZFP91-regulated secretion of inflammatory mediators, consistent with the results of the AAV-ZFP91 knockdown in mice.

CONCLUSIONS

We report for the first time that panaxadiol inhibited IL-1β secretion by suppressing ZFP91-regulated activation of non-canonical caspase-8 inflammasome and MAPKs, providing evidence for anti-inflammation mechanism of panaxadiol treatment for inflammatory diseases.

The potential roles of JAK/STAT signaling in the progression of osteoarthritis

Osteoarthritis (OA) is an age-related chronic progressive degenerative disease that induces persistent pain and disabilities. The development of OA is a complex process, and the risk factors are various, including aging, genetics, trauma and altered biomechanics. Inflammation and immunity play an important role in the pathogenesis of OA. JAK/STAT pathway is one of the most prominent intracellular signaling pathways, regulating cell proliferation, differentiation, and apoptosis. Inflammatory factors can act as the initiators of JAK/STAT pathway, which is implicated in the pathophysiological activity of chondrocyte. In this article, we provide a review on the importance of JAK/STAT pathway in the pathological development of OA. Potentially, JAK/STAT pathway becomes a therapeutic target for managing OA.

Dihydrotanshinone I inhibits the growth of hepatoma cells by direct inhibition of Src

BACKGROUND

Liver cancer is one of the leading causes of cancer-related death worldwide. Dihydrotanshinone I (DHI) was shown to inhibit the growth of several types of cancer. However, research related to hepatoma treatment using DHI is limited.

PURPOSE

Here, we explored the inhibitory effect of DHI on the growth of hepatoma cells, and investigated the underlying molecular mechanisms.

METHODS

The proliferation of Hep3B, SMCC-7721 and SK-Hep1 hepatoma cells was evaluated using the MTS and Edu staining assay. Hepatoma cell death was analyzed with a LIVE/DEAD Cell Imaging Kit. The relative expression and phosphorylation of proto-oncogene tyrosine-protein kinase Src (Src) and signal transducer and activator of transcription-3 (STAT3) proteins in hepatoma cells, as well as the expression of other protein components, were measured by western blotting. The structural interaction of DHI with Src proteins was evaluated by molecular docking, molecular dynamics simulation, surface plasmon resonance imaging and Src kinase inhibition assay. Src overexpression was achieved by infection with an adenovirus vector encoding human Src. Subsequently, the effects of DHI on tumor growth inhibition were further validated using mouse xenograft models of hepatoma.

RESULTS

In vitro studies showed that treatment with DHI inhibited the proliferation and promoted cell death of Hep3B, SMCC-7721 and SK-Hep1 hepatoma cells. We further identified and verified Src as a direct target of DHI by using molecular stimulation, surface plasmon resonance image and Src kinase inhibition assay. Treatment with DHI reduced the in vitro phosphorylation levels of Src and STAT3, a transcription factor regulated by Src. In the xenograft mouse models, DHI dose-dependently suppressed tumor growth and Src and STAT3 phosphorylation. Moreover, Src overexpression partly abrogated the inhibitory effects of DHI on the proliferation and cell death in hepatoma cells.

CONCLUSION

Our results suggest that DHI inhibits the growth of hepatoma cells by direct inhibition of Src.

The therapeutic effect and mechanism of Rapamycin combined with HO-3867 on monocrotaline-induced pulmonary hypertension in rats

This study test was designed to investigate the possible modulatory effect of rapamycin combined with HO-3867 in monocrotaline(MCT)-induced pulmonary arterial hypertension in rats. We hypothesized that combined treatment with rapamycin and HO-3867 is superior to either alone in attenuating MCT-induced rat pulmonary arterial hypertension (PAH). Pulmonary arterial hypertension was induced by a single intraperitoneal injection of monocrotaline (60 mg/kg). 2 weeks later, rapamycin (2 mg/kg i.p.) and HO3867 (10 mg/kg i.h.) were administered daily, alone and in combination, for 2 weeks. Right ventricular systolic pressure, echocardiography were recorded and then rats were sacrificed. Histological analysis of pulmonary arteries medial wall thickness, right ventricular hypertrophy index (RVHI), the ratio of right ventricular to body weight, and collagen volume fraction (CVF) of right ventricular were performed. Moreover, the expression of t-STAT3, p-STAT3, t-Akt, p-Akt in lung and t-STAT3, p-STAT3, t-S6, p-S6 in right ventricular were examined. The result showed that combined treatment provided a considerable improvement toward maintaining hemodynamic changes, lung vascular remodeling as well as amending RV remodeling and function. Furthermore, Combined treatment can normalize the protein levels of two signal pathways in lung and heart tissue, where p-S6 or p-Akt significantly decreased compared to HO-3867 alone, or p-STAT3 significantly reduced compared to rapamycin alone. In conclusion, combined treatment with rapamycin and HO-3867 is superior to either alone in attenuating MCT-induced PAH in rats.

Development of natural products for anti-PD-1/PD-L1 immunotherapy against cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) immune checkpoint is one of the most promising therapeutic targets for cancer immunotherapy, but several challenges remain in current anti-PD-1/PD-L1 therapy. Natural products, mainly derived from traditional medicine, could improve and expand anti-PD-1/PD-L1 therapy because of their advantages such as large diversity and multi-target effects.

AIM OF THE STUDY

This review summarize natural products, raw extracts, and traditional medicines with pharmacological effects associated with the PD-1/PD-L1 axis, particularly PD-L1.

MATERIALS AND METHODS

Electronic literature databases, including Web of Science, PubMed, and ScienceDirect, and online drugs and chemicals databases, including DrugBank, ZINC, PubChem, STITCH, and CTD, were searched without date limitation by February 2021. 'Natural product or herb or herbal plant or traditional medicine' and 'PD-L1' and 'Cancer immunotherapy' were used as the search keywords. Among 112 articles identified in database searching, 54 articles are full text articles, reporting in silico, in vitro, in vivo and clinical trials. 68 articles included are review articles and grey literature such as thesis and congress abstracts.

RESULTS

Several natural products and traditional medicines have exhibited diverse and multi-functional effects including direct blockade of PD-1/PD-L1 interactions, modulation of PD-L1 expression, and cooperation with PD-1/PD-L1 inhibitors.

CONCLUSION

Natural products and traditional medicines can facilitate the development of more effective and acceptable diverse strategies for anti-PD-1/PD-L1 therapy, but further exploration of natural products and pharmaceutical techniques is required.

Convallatoxin inhibits IL-1β production by suppressing zinc finger protein 91-mediated pro-IL-1β ubiquitination and caspase-8 inflammasome activity

BACKGROUND AND PURPOSE

ZFP91 positively regulates IL-1β production in macrophages and may be a potential therapeutic target to treat inflammatory-related diseases. Therefore, we investigated whether this process is modulated by convallatoxin, which is a cardiac glycoside isolated from the traditional Chinese medicinal plant Adonis amurensis Regel et Radde.

EXPERIMENTAL APPROACH

In vitro, the underlying mechanisms by which convallatoxin inhibits ZFP91-regulated IL-1β expression were investigated using molecular docking, western blotting, RT-PCR, ELISA, immunofluorescence, and immunoprecipitation assays. In vivo, liver injury was induced by an intraperitoneal injection of D-GalN and LPS, colitis was induced by oral administration of DSS in drinking water, and peritonitis was induced by an intraperitoneal injection of alum.

KEY RESULTS

We confirmed that convallatoxin inhibited the release of IL-1β by downregulating ZFP91. Importantly, we found that convallatoxin significantly reduced K63-linked polyubiquitination of pro-IL-1β regulated by ZFP91 and decreased the efficacy of pro-IL-1β cleavage. Moreover, convallatoxin suppressed ZFP91-mediated activation of the non-canonical caspase-8 inflammasome and MAPK signaling pathways in macrophages. Furthermore, we showed that ZFP91 promoted the assembly of the caspase-8 inflammasome complex, whereas convallatoxin treatment reversed this result. In vivo studies further demonstrated that convallatoxin ameliorated D-GalN/LPS-induced liver injury, DSS-induced colitis, and alum-induced peritonitis by downregulating ZFP91.

CONCLUSION AND IMPLICATIONS

We report for the first time that convallatoxin-mediated inhibition of ZFP91 is an important regulatory event that prevents inappropriate inflammatory responses to maintain of immune homeostasis. This mechanism provides new perspectives for the development of convallatoxin as a novel anti-inflammatory drug targeting ZFP91.

Nifuroxazide Mitigates Angiogenesis in Ehlrich's Solid Carcinoma: Molecular Docking, Bioinformatic and Experimental Studies on Inhibition of Il-6/Jak2/Stat3 Signaling

Nifuroxazide is an antidiarrheal medication that has promising anticancer activity against diverse types of tumors. The present study tested the anticancer activity of nifuroxazide against Ehrlich’s mammary carcinoma grown in vivo. Furthermore, we investigated the effect of nifuroxazide on IL-6/jak2/STAT3 signaling and the possible impact on tumor angiogenesis. The biological study was supported by molecular docking and bioinformatic predictions for the possible effect of nifuroxazide on this signaling pathway. Female albino mice were injected with Ehrlich carcinoma cells to produce Ehrlich’s solid tumors (ESTs). The experimental groups were as follows: EST control, EST + nifuroxazide (5 mg/kg), and EST + nifuroxazide (10 mg/kg). Nifuroxazide was found to reduce tumor masses (730.83 ± 73.19 and 381.42 ± 109.69 mg vs. 1099.5 ± 310.83) and lessen tumor pathologies. Furthermore, nifuroxazide downregulated IL-6, TNF-α, NFk-β, angiostatin, and Jak2 proteins, and it also reduced tumoral VEGF, as indicated by ELISA and immunohistochemical analysis. Furthermore, nifuroxazide dose-dependently downregulated STAT3 phosphorylation (60% and 30% reductions, respectively). Collectively, the current experiment shed light on the antitumor activity of nifuroxazide against mammary solid carcinoma grown in vivo. The antitumor activity was at least partly mediated by inhibition of IL-6/Jak2/STAT3 signaling that affected angiogenesis (low VEGF and high angiostatin) in the EST. Therefore, nifuroxazide might be a promising antitumor medication if appropriate human studies will be conducted.

Formononetin represses cervical tumorigenesis by interfering with the activation of PD-L1 through MYC and STAT3 downregulation

Astragalus membranaceus is a traditional Chinese medicine that regulates blood sugar levels, suppresses inflammation, protects the liver, and enhances immunity. In addition, A. membranaceus is also widely used in diet therapy and is a well-known health tonic. Formononetin is a natural product isolated from A. membranaceus that has multiple biological functions, including anti-cancer activity. However, the mechanism by which formononetin inhibits tumor growth is not fully understood. In this present study, we demonstrated that formononetin suppresses PD-L1 protein synthesis via reduction of MYC and STAT3 protein expression. Furthermore, formononetin markedly reduced the expression of MYC protein via the RAS/ERK signaling pathway and inhibited STAT3 activation through JAK1/STAT3 pathway. Co-immunoprecipitation experiments illustrated that formononetin suppresses protein expression of PD-L1 by interfering with the interaction between MYC and STAT3. Meanwhile, formononetin promoted PD-L1 protein degradation via TFEB and TFE3-mediated lysosome biogenesis. T cell killing assay revealed that formononetin could enhance the activity of cytotoxic T lymphocytes (CTLs) and restore ability to kill tumor cells in a co-culture system of T cells and tumor cells. In addition, formononetin inhibited cell proliferation, tube formation, cell migration, and promoted tumor cell apoptosis by suppressing PD-L1. Finally, the inhibitory effect of formononetin on tumor growth was confirmed in a murine xenograft model. The present study revealed the anti-tumor potential of formononetin, and the findings should support further research and development of anti-cancer drugs for cervical cancer.

Discovery and Validation of Nitroxoline as a Novel STAT3 Inhibitor in Drug-resistant Urothelial Bladder Cancer

Repeated cycles of first-line chemotherapy drugs such as doxorubicin (DOX) and cisplatin (CIS) trigger frequent chemoresistance in recurrent urothelial bladder cancer (UBC). Nitroxoline (NTX), an antibiotic to treat urinary tract infections, has been recently repurposed for cancer treatment. Here we aimed to investigate whether NTX suppresses drug-resistant UBC and its molecular mechanism. The drug-resistant cell lines T24/DOX and T24/CIS were established by continual exposure of parental cell line T24 to DOX and CIS, respectively. T24/DOX and T24/CIS cells were resistant to DOX and CIS, respectively, but they were sensitive to NTX time- and dose-dependently. Overexpressions of STAT3 and P-glycoprotein (P-gp) were identified in T24/DOX and T24/CIS, which could be reversed by NTX. Western blot revealed that NTX downregulated p-STAT3, c-Myc, Cyclin D1, CDK4, CDK6, Bcl-xL, Mcl-1, and Survivin, which were further confirmed by Stattic, a selective STAT3 inhibitor. In vivo, NTX exhibited the significant anti-tumor effect in T24/DOX and T24/CIS tumor-bearing mice. These results suggested that NTX-induced P-gp reversal, G0/G1 arrest, and apoptosis in drug-resistant UBC were mediated by inhibition of STAT3 signaling. Our findings repurpose NTX as a novel STAT3 inhibitor to induce P-gp reversal, G0/G1 arrest, and apoptosis in drug-resistant UBC.

Associations of individual and joint expressions of ERCC6 and ERCC8 with clinicopathological parameters and prognosis of gastric cancer

Background

Excision repair cross-complementing group 6 and 8 (ERCC6 and ERCC8) have been implicated in ailments such as genetic diseases and cancers. However, the relationship between individual and joint expressions of ERCC6/ERCC8 and clinicopathological parameters as well as prognosis of gastric cancer (GC) still remains unclear.

Methods

In this study, protein expressions of ERCC6, ERCC8 and ERCC6-ERCC8 were detected by immunohistochemistry (IHC) in 109 paired GC and para-cancerous normal tissue samples. The mRNA expression was detected in 36 pairs of tissue samples. IHC results and RNA-seq data extracted from The Cancer Genome Atlas (TCGA) were used to explore the clinical value of ERCC6 and ERCC8 expression in GC. We further conducted protein-protein interaction analysis, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis, and gene-gene interaction analysis to explore the function and regulation networks of ERCC6 and ERCC8 in GC.

Results

Individual and joint ERCC6/ERCC8 expression were significantly higher in adjacent normal mucosa compared with GC tissues. ERCC6 mRNA expression showed no difference in GC and paired tissues, while ERCC8 mRNA was significantly decreased in GC tissues. Protein expression of ERCC6, ERCC8, double negative ERCC6-ERCC8 and double positive ERCC6-ERCC8 and overexpressed ERCC6 mRNA were related to better clinicopathologic parameters, while overexpressed ERCC8 mRNA suggested worse parameters. Univariate survival analysis indicated that the OS was longer when ERCC6 protein expression and ERCC8 mRNA expression increased, and double negative ERCC6-ERCC8 expression was associated with a short OS. Bioinformatics analyses showed ERCC6 and ERCC8 were associated with nucleotide excision repair (NER) pathway, and six and ten gene sets were figured out to be related with ERCC6 and ERCC8, respectively. KEGG pathway showed that ERCC6/ERCC8 related gene sets were mainly involved in the regulation of PI3K/AKT/mTOR pathway. Direct physical interactions were found between ERCC6 and ERCC8.

Conclusions

Individual and joint expressions of ERCC6/ERCC8 were associated with clinical features of GC. Protein expression of ERCC6, ERCC6-ERCC8, and mRNA expression of ERCC8 were related to prognosis of GC. ERCC6 and ERCC8 primarily function in the NER pathway, and may regulate GC progression through the regulation of PI3K/AKT/mTOR pathway.

Synthesis and Evaluation of Chiral Rhodanine Derivatives Bearing Quinoxalinyl Imidazole Moiety as ALK5 Inhibitors

BACKGROUND

TGF-β signaling pathway inhibition is considered an effective way to prevent the development of several diseases. In the design and synthesis of TGF-β inhibitors, a rhodanine compound containing a quinoxalinyl imidazole moiety was found to have strong antimicrobial activity.

OBJECTIVE

The purpose of this work was to investigate the antimicrobial activity of other chiral rhodanine TGF-β inhibitors synthesized.

METHODS

Two series of 3-substituted-5-((5-(6-methylpyridin-2-yl)-4-(quinoxalinyl-6-yl)- 1H-imidazol-2-yl)methylene)-2-thioxothiazolin-4-ones (12a-h and 13a-e) were synthesized and evaluated for their ALK5 inhibitory and antimicrobial activity. The structures were confirmed by their 1H NMR, 13C NMR, and HRMS spectra. All the synthesized compounds were screened against Gram-positive strains, Gram-negative strains, and fungi.

RESULTS

Among the synthesized compounds, compound 12h showed the highest activity (IC50 = 0.416 μM) against ALK5 kinase. Compound 12h exhibited a good selectivity index of > 24 against p38α MAP kinase and was 6.0-fold more selective than the clinical candidate, compound 2 (LY-2157299). Nearly all the compounds displayed high selectivity toward both Gram-positive and Gram-negative bacteria. They also showed similar or 2.0-fold greater antifungal activity (minimum inhibitory concentration [MIC] = 0.5 µg/mL) compared with the positive control compounds Gatifloxacin (MIC = 0.5 µg/mL) and fluconazole (MIC = 1 µg/mL).

CONCLUSION

The findings suggest that the synthesized rhodanine compounds have good ALK5 inhibitory activity and can be used for further research and development as potential antifungal drugs.

Licochalcone A inhibits proliferation and promotes apoptosis of colon cancer cell by targeting programmed cell death-ligand 1 via the NF-κB and Ras/Raf/MEK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Glycyrrhiza glabra L., a traditional medicinal, has a history of thousands of years. It is widely used in clinic and has been listed in Chinese Pharmacopoeia. Licochalcone A is a phenolic chalcone compound and a characteristic chalcone of Glycyrrhiza glabra L. It has many pharmacological activities, such as anti-cancer, anti-inflammatory, anti-viral and anti-angiogenic activities.

AIM OF THE STUDY

In this study, we explored the anti-tumor activity and potential mechanism of licochalcone A in vitro and in vivo.

MATERIALS AND METHODS

In vitro, the mechanism of licochalcone A at inhibiting PD-L1 expression was investigated by molecular docking, western blotting, RT-PCR, flow cytometry, immunofluorescence and immunoprecipitation assays. The co-culture model of T cells and tumor cells was used to detect the activity of cytotoxic T lymphocytes. Colony formation, EdU labelling and apoptosis assays were used to detect changes in cellular proliferation and apoptosis. In vivo, anti-tumor activity of licochalcone A was assessed in a xenograft model of HCT116 cells.

RESULTS

In the present study, we found that licochalcone A suppressed the expression of programmed cell death ligand-1 (PD-L1), which plays a key role in regulating the immune response. In addition, licochalcone A inhibited the expressions of p65 and Ras. Immunoprecipitation experiment showed that licochalcone A suppressed the expression of PD-L1 by blocking the interaction between p65 and Ras. In the co-culture model of T cells and tumor cells, licochalcone A pretreatment enhanced the activity of cytotoxic T lymphocytes and restored the ability to kill tumor cells. In addition, we showed that licochalcone A inhibited cell proliferation and promoted cell apoptosis by targeting PD-L1. In vivo xenograft assay confirmed that licochalcone A inhibited the growth of tumor xenografts.

CONCLUSION

In general, these results reveal the previously unknown properties of licochalcone A and provide new insights into the anticancer mechanism of this compound.

Tenacissoside G synergistically potentiates inhibitory effects of 5-fluorouracil to human colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most malignant tumors worldwide with poor prognosis and low survival rate. Since the clinical efficacy of the commonly used 5-fluorouracil (5-FU) based chemotherapy in CRC patients is limited because of its intolerable adverse effects, there is an urgent need to explore agents that can enhance the anti-cancer activity of 5-FU, reduce adverse effects and prevent resistance.

PURPOSE

This study aims to investigate Tenacissoside G (TG)'s synergistic potentiation with 5-FU in inhibitory activity to colorectal cancer cells.

METHODS

The anti-proliferation effect of TG on 5 colorectal cancer cell lines was assessed by CCK-8 assay. The isobologram analysis and combination index methods were used to detect the synergistic effect of TG and 5-FU by the CompuSyn software using the T.C. Chou Method. The effects of TG/5-FU combination on cell cycle distribution and apoptosis induction were detected by flow cytometry. DNA damage degrees of cells treated with TG, 5-FU and their combination were evaluated by the alkaline comet assay. Protein expression regulated by the TG/5-FU combination was investigated by western blotting. Furthermore, a xenograft mouse model was established to investigate the synergistic anti-tumor effect in vivo.

RESULTS

In this work, we observed a dose-dependent growth inhibitory activity and cell cycle arrest induction of TG, a monomeric substance originated from Marsdenia tenacissima (Roxb.) Wight et Arn, in colorectal cancer cells. It was found that TG potentiated the anticancer effects of 5-FU with a synergism for the first time. And the co-treatment effects were also validated by in vivo experiments. The underlying mechanisms involved in the synergistic effects were probably included: (1) increased activation of caspase cascade; (2) enhancement of DNA damage degree and (3) induction of p53 phosphorylation at Serine 46.

CONCLUSION

TG potentiated 5-FU's inhibitory activity to human colorectal cancer through arresting cell cycle progression and inducing p53-mediated apoptosis, which may present a novel strategy in CRC therapies and contribute to the optimizing clinical application of 5-FU.

Astragalin Inhibits the Proliferation and Migration of Human Colon Cancer HCT116 Cells by Regulating the NF-κB Signaling Pathway

Astragalin is a flavonoid found in a variety of natural plants. It has anti-inflammatory, anti-oxidant effects and has inhibited effects against several malignant tumor cell types. However, its effects on colon cancer and the molecular mechanisms have remained to be elucidated. In this study, we evaluated the inhibitory effect of astragalin on proliferation and migration of human colon cancer HCT116 cells in vitro and in vivo. Furthermore, we elucidated the mechanism of these effects. The results showed that astragalin significantly inhibited the proliferation and diffusion of HCT116 cells by induced apoptosis (by modulation of Bax, Bcl-2, P53, caspase-3, caspase 6, caspase 7, caspase 8, caspase 9 protein express) and cell cycle arrest (by modulation of Cyclin D1, Cyclin E, P21, P27, CDK2, CDK4 protein express). Moreover, astragalin suppressed HCT116 cell migration by inhibiting the expression of matrix metalloproteinases (MMP-2, MMP-9). In addition, astragalin significantly downregulated the expression of key proteins in the NF-κB signaling pathway and inhibited the transcriptional activity of NF-κB P65 stimulated with inflammatory cytokines TNF-α, thereby inhibiting the growth of colon cancer cells in vitro. Our further investigations unveiled astragalin gavage significantly reduced the proliferation of colon cancer xenograft in nude mice, in vivo experiments showed that tumor growth was related to decreased expression of apoptotic proteins in tumor tissues and decreased activity of the NF-κB signaling pathway. In summary, our results indicated that astragalin inhibits the proliferation and growth of colon cancer cells in vivo and in vitro via the NF-κB pathway. Therefore, astragalin maybe become a potential plant-derived antitumor drug for colon cancer.

Oridonin inhibits tumor angiogenesis and induces vessel normalization in experimental colon cancer

Purpose: Tumor blood vessels exhibit morphological and functional aberrancies. Its maturity and functionality are closely associated with colon cancer progression and therapeutic efficacy. The direct evidence proving whether oridonin (ORI) has vascular normalization promoting effect from which combination therapies will benefit is still lacking. Methods: We established a subcutaneous xenograft model of human colon cancer. The animals were divided into the Control and ORI-treated groups. Immunohistochemical analysis and TUNEL staining was applied to evaluate the proliferation, apoptosis and angiogenesis. Western blot analysis was employed to characterize the angiogenesis-related factors and JAK2/STAT3 signaling. Then, vascular normalization and macrophage reprogramming were assessed by immunofluorescence analysis. Results: The results showed that ORI obviously reduced tumor growth, diminished the numbers of Ki67⁺ cells and CD31⁺ microvessel density, while increased the numbers of TUNEL⁺ cells. The expression levels of VEGF and bFGF proteins were dramatically down-regulated while the angiostatin and endostatin levels were increased in the ORI-treated group. Moreover, ORI therapy remarkably promoted the pericyte coverage of tumor vessels from days 5 to 10, with the highest pericyte coverage rate occurred at day 7. In the time window of vascular normalization, hypoxia of the tumor microenvironment was improved by ORI, the expression of HIF-1a was downregulated. Moreover, CD206⁺ macrophage cells were diminished in the ORI-treated group. These anticancer effects of ORI maybe partly mediated by suppressing JAK2/STAT3 signaling pathway. Conclusions: These results highlight the potential effect of ORI on anti-angiogenesis and inducing vessel normalization roles of ORI, and probably provide optimum time point for the ORI therapy in conjunction with the chemoradiotherapy or immunotherapy.

Anthraquinone derivative C10 inhibits proliferation and cell cycle progression in colon cancer cells via the Jak2/Stat3 signaling pathway

Since its discovery, anthraquinone has become very valuable as a lead compound in the development of anti-cancer drugs. Previously, we designed and synthesized a new type of amide anthraquinone derivative (1-nitro-2-acylanthraquinone glycine, C10) with good activity against colon cancer. However, its effect and the underlying mechanism are unclear. In this study, C10 significantly inhibited the proliferation of HCT116 and HT29 colon cancer cells by blocking the cell cycle at the G2/M phase. C10 also plays a role in cell cycle arrest by reducing the protein and gene expression levels of cyclin B1 and its downstream signaling molecule cyclin-dependent kinase (CDK1). In addition, molecular docking studies showed that C10 has high affinity for Jak2, the first target in the cell cycle-related Jak2/Stat3 signaling pathway. Furthermore, C10 downregulated the expression of Jak2/Stat3 signaling pathway-related signaling molecules proteins and genes, and up-regulated the expression of PIAS-3, the upstream signaling molecule of Stat3, thereby down-regulating Stat3 phosphorylation. C10 reversed the expression of Jak2/Stat3 signaling pathway-related molecules activated by IL-6. Overall, our results indicate for the first time that C10 induces cell cycle arrest and inhibits cell proliferation by inhibiting the Jak2/Stat3 signaling pathway. This study provides new insights into the potential role of Jak2/Stat3 in the regulating cell cycle-related signaling pathways that mediate the inhibitory effects of C10 on colon cancer cell proliferation.