Morusin inhibits cell proliferation and tumor growth by down-regulating c-Myc in human gastric cancer

Network pharmacology and biological verification of morusin's therapeutic mechanisms in inhibiting nasopharyngeal carcinoma growth

Nasopharyngeal carcinoma (NPC) presents a significant therapeutic challenge due to its aggressive nature and limited treatment options. Although morusin, a compound found in traditional Chinese medicines, exhibits significant tumor-inhibiting properties, its specific effects on NPC proliferation remain unclear. This study aims to elucidate the inhibitory effects of morusin on NPC survival and proliferation while exploring the underlying mechanisms through the utilization of network pharmacology, molecular docking, and experimental validation in vitro and in vivo. Network pharmacology analysis identified 117 potential targets of morusin against NPC, with 8 hub targets including AKT1, BCL2, CASP3, CTNNB1, ESR1, HSP90AA1, MMP9, STAT3, and the IL-17 signaling pathway. Further investigation of public data indicated that the expression levels of BLC2, CASP3, CTNNB1, HSP90AA1, and STAT3 in NPC tissue were significantly elevated compared to normal nasopharyngeal tissue. Docking studies exposed robust binding activity between morusin and key gene molecules. Additionally, biological assays demonstrated that morusin effectively inhibits NPC growth both in vivo and in vitro. Through a comprehensive investigation, this study identified the pharmacological mechanisms essential for morusin-induced inhibition of NPC growth by targeting multiple molecular targets and signaling pathways. These findings show the potential to contribute to the development of novel clinical agents for treating NPC.

Morusin-Cu(II)-indocyanine green nanoassembly ignites mitochondrial dysfunction for chemo-photothermal tumor therapy

Nanoscale drug delivery systems derived from natural bioactive materials accelerate the innovation and evolution of cancer treatment modalities. Morusin (Mor) is a prenylated flavonoid compound with high cancer chemoprevention activity, however, the poor water solubility, low active pharmaceutical ingredient (API) loading content, and instability compromise its bioavailability and therapeutic effectiveness. Herein, a full-API carrier-free nanoparticle is developed based on the self-assembly of indocyanine green (ICG), copper ions (Cu2+) and Mor, termed as IMCNs, via coordination-driven and π-π stacking for synergistic tumor therapy. The IMCNs exhibits a desirable loading content of Mor (58.7 %) and pH/glutathione (GSH)-responsive motif. Moreover, the photothermal stability and photo-heat conversion efficiency (42.8 %) of IMCNs are improved after coordination with Cu2+ and help to achieve photothermal therapy. Afterward, the released Cu2+ depletes intracellular overexpressed GSH and mediates Fenton-like reactions, and further synergizes with ICG at high temperatures to expand oxidative damage. Furthermore, the released Mor elicits cytoplasmic vacuolation, expedites mitochondrial dysfunction, and exerts chemo-photothermal therapy after being combined with ICG to suppress the migration of residual live tumor cells. In vivo experiments demonstrate that IMCNs under laser irradiation could excellently inhibit tumor growth (89.6 %) through the multi-modal therapeutic performance of self-enhanced chemotherapy/coordinated-drugs/ photothermal therapy (PTT), presenting a great potential for cancer therapy.

Morusin suppresses the stemness characteristics of gastric cancer cells induced by hypoxic microenvironment through inhibition of HIF-1α accumulation

Gastric cancer (GC) is a common, life-threatening malignancy that contributes to the global burden of cancer-related mortality, as conventional therapeutic modalities show limited effects on GC. Hence, it is critical to develop novel agents for GC therapy. Morusin, a typical prenylated flavonoid, possesses antitumor effects against various cancers. The present study aimed to demonstrate the inhibitory effect and mechanism of morusin on the stemness characteristics of human GC in vitro under hypoxia and to explore the potential molecular mechanisms. The effects of morusin on cell proliferation and cancer stem cell-like properties of the human GC cell lines SNU-1 and AGS were assessed by MTT assay, colony formation test, qRT-PCR, flow cytometry analysis, and sphere formation test under hypoxia or normoxia condition through in vitro assays. The potential molecular mechanisms underlying the effects of morusin on the stem-cell-like properties of human GC cells in vitro were investigated by qRT-PCR, western blotting assay, and immunofluorescence assay by evaluating the nuclear translocation and expression level of hypoxia-inducible factor-1α (HIF-1α). The results showed that morusin exerted growth inhibitory effects on SNU-1 and AGS cells under hypoxia in vitro. Moreover, the proportions of CD44+/CD24- cells and the sphere formation ability of SNU-1 and AGS reduced in a dose-dependent manner following morusin treatment. The expression levels of stem cell-related genes, namely Nanog, OCT4, SOX2, and HIF-1α, gradually decreased, and the nuclear translocation of the HIF-1α protein was apparently attenuated. HIF-1α overexpression partially reversed the abovementioned effects of morusin. Taken together, morusin could restrain stemness characteristics of GC cells by inhibiting HIF-1α accumulation and nuclear translocation and could serve as a promising compound for GC treatment.

Gastrointestinal Cancer Therapeutics via Triggering Unfolded Protein Response and Endoplasmic Reticulum Stress by 2-Arylbenzofuran

Gastrointestinal cancers are a major global health challenge, with high mortality rates. This study investigated the anti-cancer activities of 30 monomers extracted from Morus alba L. (mulberry) against gastrointestinal cancers. Toxicological assessments revealed that most of the compounds, particularly immunotoxicity, exhibit some level of toxicity, but it is generally not life-threatening under normal conditions. Among these components, Sanggenol L, Sanggenon C, Kuwanon H, 3'-Geranyl-3-prenyl-5,7,2',4'-tetrahydroxyflavone, Morusinol, Mulberrin, Moracin P, Kuwanon E, and Kuwanon A demonstrate significant anti-cancer properties against various gastrointestinal cancers, including colon, pancreatic, and gastric cancers. The anti-cancer mechanism of these chemical components was explored in gastric cancer cells, revealing that they inhibit cell cycle and DNA replication-related gene expression, leading to the effective suppression of tumor cell growth. Additionally, they induced unfolded protein response (UPR) and endoplasmic reticulum (ER) stress, potentially resulting in DNA damage, autophagy, and cell death. Moracin P, an active monomer characterized as a 2-arylbenzofuran, was found to induce ER stress and promote apoptosis in gastric cancer cells, confirming its potential to inhibit tumor cell growth in vitro and in vivo. These findings highlight the therapeutic potential of Morus alba L. monomers in gastrointestinal cancers, especially focusing on Moracin P as a potent inducer of ER stress and apoptosis.

Morusin Inhibits RANKL-induced Osteoclastogenesis and Ovariectomized Osteoporosis

BACKGROUND

Postmenopausal osteoporosis (PMOP) is a classic type of osteoporosis that has gradually become a significant health problem worldwide. There is an urgent need for a safe alternative therapeutic agent considering the poor therapeutic strategies currently available for this disease. The roots and bark of the Morus australis tree (Moraceae) are used to make a traditional Chinese medicine known as "Morusin", and accumulating evidence has demonstrated its multiple activities, such as anti-inflammatory and anti-tumor effects.

OBJECTIVE

In this study, we aim to explore the effect of Morusin on mouse osteoclasts and its mechanism.

METHODS

In this study, we explored the inhibitory effects of Morusin on murine osteoclasts in vitro and its mechanism, and the protective effect of Morusin on an ovariectomy (OVX)-induced osteoporosis model in vivo.

RESULTS

The results showed that Morusin prevented OVX-induced bone loss and dramatically decreased RANKL-induced osteoclastogenesis. Morusin interfered with RANKL-activated NF- κB, MAPK, and PI3K/AKT signaling pathways. The expression of three master factors that control osteoclast differentiation, c-Fos, NFATc1, and c-Jun, was reduced by Morusin treatment. Collectively, in vitro results indicated that Morusin has a protective effect on OVX-induced bone loss in a mouse model.

CONCLUSION

Our data provide encouraging evidence that Morusin may be an effective treatment for PMOP.

PRMT1 promotes the proliferation and metastasis of gastric cancer cells by recruiting MLXIP for the transcriptional activation of the β-catenin pathway

Protein arginine methyltransferase 1 (PRMT1), a type I PRMT, is overexpressed in gastric cancer (GC) cells. To elucidate the function of PRMT1 in GC, PRMT1 expression in HGC-27 and MKN-45 cells was knocked down by short hairpin RNA (shRNA) or inhibited by PRMT1 inhibitors (AMI-1 or DCLX069), which resulted in inhibition of GC cell proliferation, migration, invasion, and tumorigenesis in vitro and in vivo. MLX-interacting protein (MLXIP) and Kinectin 1 (KTN1) were identified as PRMT1-binding proteins. PRMT1 recruited MLXIP to the promoter of β-catenin, which induced β-catenin transcription and activated the β-catenin signaling pathway, promoting GC cell migration and metastasis. Furthermore, KTN1 inhibited the K48-linked ubiquitination of PRMT1 by decreasing the interaction between TRIM48 and PRMT1. Collectively, our findings reveal a mechanism by which PRMT1 promotes cell proliferation and metastasis mediated by the β-catenin signaling pathway.

Apoptotic and anti-Warburg effect of Morusin via ROS mediated inhibition of FOXM1/c-Myc signaling in prostate cancer cells

Though Morusin is known to induce apoptotic, antiprolifertaive, and autophagic effects through several signaling pathways, the underlying molecular mechanisms of Morusin still remain unclear until now. To elucidate antitumor mechanism of Morusin, cytotoxicity assay, cell cycle analysis, Western blotting, TUNEL assay, RNA interference, immunofluorescense, immunoprecipitation, reactive oxygen species (ROS) measurement, and inhibitor study were applied in this study. Morusin enhanced cytotoxicity, increased the number of TUNEL positive cells, sub-G1 population and induced the cleavages of PARP and caspase3, attenuated the expression of HK2, PKM2, LDH, c-Myc, and Forkhead Box M1 (FOXM1) along with the reduction of glucose, lactate, and ATP in DU145 and PC3 cells. Furthermore, Morusin disrupted the binding of c-Myc and FOXM1 in PC-3 cells, which was supported by String and cBioportal database. Notably, Morusin induced c-Myc degradation mediated by FBW7 and suppressed c-Myc stability in PC3 cells exposed to MG132 and cycloheximide. Also, Morusin generated ROS, while NAC disrupted the capacity of Morusin to reduce the expression of FOXM1, c-Myc, pro-PARP, and pro-caspase3 in PC-3 cells. Taken together, these findings provide scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis plays a critical role in Morusin induced apoptotic and anti-Warburg effect in prostate cancer cells. Our findings support scientific evidence that ROS mediated inhibition of FOXM1/c-Myc signaling axis is critically involved in apoptotic and anti-Warburg effect of Morusin in prostate cancer cells.

Morusin shows potent antitumor activity for melanoma through apoptosis induction and proliferation inhibition

BACKGROUND

The discovery of new anti-melanoma drugs with low side effect is urgently required in the clinic. Recent studies showed that morusin, a flavonoid compound isolated from the root bark of Morus Alba, has the potential to treat multiple types of cancers, including breast cancer, gastric cancer, and prostate cancer. However, the anti-cancer effect of morusin on melanoma cells has not been investigated.

METHODS

We analyzed the effects of morusin on the proliferation, cell cycle, apoptosis, cell migration and invasion ability of melanoma cells A375 and MV3, and further explored the effects of morusin on tumor formation of melanoma cell. Finally, the effects of morusin on the proliferation, cycle, apoptosis, migration and invasion of A375 cells after knockdown of p53 were detected.

RESULTS

Morusin effectively inhibits the proliferation of melanoma cells and induces cell cycle arrest in the G2/M phase. Consistently, CyclinB1 and CDK1 that involved in the G2/M phase transition were down-regulated upon morusin treatment, which may be caused by the up-regulation of p53 and p21. In addition, morusin induces cell apoptosis and inhibits migration of melanoma cells, which correlated with the changes in the expression of the associated molecules including PARP, Caspase3, E-Cadherin and Vimentin. Moreover, morusin inhibits tumor growth in vivo with little side effect on the tumor-burden mice. Finally, p53 knockdown partially reversed morusin-mediated cell proliferation inhibition, cell cycle arrest, apoptosis, and metastasis.

CONCLUSION

Collectively, our study expanded the spectrum of the anti-cancer activity of morusin and guaranteed the clinical use of the drug for melanoma treatment.

Morusinol extracted from Morus alba induces cell cycle arrest and apoptosis via inhibition of DNA damage response in melanoma by CHK1 degradation through the ubiquitin-proteasome pathway

BACKGROUD

Flavonoids have a variety of biological activities, such as anti-inflammation, anti-tumor, anti-thrombosis and so on. Morusinol, as a novel isoprene flavonoid extracted from Morus alba root barks, has the effects of anti-arterial thrombosis and anti-inflammatory in previous studies. However, the anti-cancer mechanism of morusinol remains unclear.

PURPOSE

In present study, we mainly studied the anti-tumor effect of morusinol and its mode of action in melanoma.

METHODS

The anti-cancer effect of morusinol on melanoma were evaluated by using the MTT, EdU, plate clone formation and soft agar assay. Flow cytometry was used for detecting cell cycle and apoptosis. The ɣ-H2AX immunofluorescence and the alkaline comet assay were used to detect DNA damage and the Western blotting analysis was used to investigate the expressions of DNA-damage related proteins. Ubiquitination and turnover of CHK1 were also detected by using the immunoprecipitation assay. The cell line-derived xenograft (CDX) mouse models were used in vivo to evaluate the effect of morusinol on tumorigenicity.

RESULTS

We demonstrated that morusinol not only had the ability to inhibit cell proliferation, but also induced cell cycle arrest at G0/G1 phase, caspase-dependent apoptosis and DNA damage in human melanoma cells. In addition, morusinol effectively inhibited the growth of melanoma xenografts in vivo. More strikingly, CHK1, which played an important role in maintaining the integrity of cell cycle, genomic stability and cell viability, was down-regulated in a dose- and time-dependent manner after morusinol treatment. Further research showed that CHK1 was degraded by the ubiquitin-proteasome pathway. Whereafter, morusinol-induced cell cycle arrest, apoptosis and DNA damage were partially salvaged by overexpressing CHK1 in melanoma cell lines. Herein, further experiments demonstrated that morusinol increased the sensitivity of dacarbazine (DTIC) to chemotherapy for melanoma in vitro and in vivo.

CONCLUSION

Morusinol induces CHK1 degradation through the ubiquitin-proteasome pathway, thereby inducing cell cycle arrest, apoptosis and DNA damage response in melanoma. Our study firstly provided a theoretical basis for morusinol to be a candidate drug for clinical treatment of cancer, such as melanoma, alone or combinated with dacarbazine.

Exploring the therapeutic and anti-tumor properties of morusin: a review of recent advances

Morusin is a natural product that has been isolated from the bark of Morus alba, a species of mulberry tree. It belongs to the flavonoid family of chemicals, which is abundantly present in the plant world and is recognized for its wide range of biological activities. Morusin has a number of biological characteristics, including anti-inflammatory, anti-microbial, neuro-protective, and antioxidant capabilities. Morusin has exhibited anti-tumor properties in many different forms of cancer, including breast, prostate, gastric, hepatocarcinoma, glioblastoma, and pancreatic cancer. Potential of morusin as an alternative treatment method for resistant malignancies needs to be explored in animal models in order to move toward clinical trials. In the recent years several novel findings regarding the therapeutic potential of morusin have been made. This aim of this review is to provide an overview of the present understanding of morusin's beneficial effects on human health as well as provide a comprehensive and up-to-date discussion of morusin's anti-cancer properties with a special focus on in vitro and in vivo studies. This review will aid future research on the creation of polyphenolic medicines in the prenylflavone family, for the management and treatment of cancers.

The Silkworm Carboxypeptidase Inhibitor Prevents Gastric Cancer Cells' Proliferation through the EGF/EGFR Signaling Pathway

Gastric cancer is a common malignant tumor originating from the gastric mucosa epithelium. Studies have shown that bioactive substances such as antimicrobial peptides and cantharidin contained in a variety of insects can exert anti-cancer functions; when compared with chemotherapy drugs, these bioactive substances have less toxicity and reduced side effects. Here, we report the first Bombyx mori carboxypeptidase inhibitor that is specifically and highly expressed in silk glands, which can significantly prevent the proliferation of gastric cancer cells by inhibiting the MAPK/ERK pathway initiated by EGF/EGFR through the promotion of expression of the proto-oncogene c-Myc, thereby affecting the expression of related cyclins. Through molecular docking and virtual screening of silkworm carboxypeptidase inhibitors and epidermal growth factor receptors, we identified a polypeptide that overlapped with existing small-molecule inhibitors of the receptor. In the present work, we explore the medicinal potential and application of silkworm carboxypeptidase inhibitors to promote the development of anti-tumor drugs from insect-derived substances.

TRIM50 Inhibits Proliferation and Metastasis of Gastric Cancer via Promoting β-Catenin Degradation

Background

Gastric cancer (GC) is a common malignancy with a poor prognosis. Tripartite motif-containing 50 (TRIM50) belongs to the TRIM family and is reported to be related to numerous cancers. This study aimed to investigate the function of TRIM50 in GC.

Methods

Three microarray datasets (GSE13911, GSE79973, and GSE19826) containing GC and adjacent nontumor tissues were used for bioinformatics analysis to screen GC-related genes and assess the associations between GC development and TRIM50 expression. Then, TRIM50 expression in GC cells was detected at mRNA and protein levels. After TRIM50 was knockdown or overexpressed, the effect of TRIM50 on the proliferation and metastasis of GC cells was analyzed using Cell Counting Kit-8 (CCK-8), flow cytometry, scratch, and Transwell assays. The interaction between TRIM50 and β-catenin was analyzed. The expression of cell cycle-, migration-, invasion-, and Wnt/β-catenin signaling pathway-related proteins was detected by Western blot. Furthermore, we measured the role of TRIM50 overexpression on tumor growth as well as the Wnt/β-catenin signaling pathway in vivo. In addition, XAV939 (a WNT/β-catenin signaling pathway inhibitor) was used to clarify the mechanism of TRIM50 on GC.

Results

Bioinformatics revealed that TRIM50 expression was decreased in GC samples and associated with GC development. In vitro study revealed that TRIM50 overexpression impeded the GC cell proliferation and metastasis, while TRIM50 knockdown presented the opposite results. In addition, TRIM50 interacted with β-catenin to induce the degradation of β-catenin. In in vivo assay, TRIM50 overexpression inhibited tumor growth and blocked the Wnt/β-catenin signaling pathway. In addition, TRIM50 knockdown-promoted cell proliferation and metastasis in GC cells were inverted by XAV939.

Conclusion

TRIM50 overexpression may inhibit cell proliferation and metastasis in GC via β-catenin degradation, indicating that TRIM50 could be a target for the treatment of GC.

Morusin Enhances Temozolomide Efficiency in GBM by Inducing Cytoplasmic Vacuolization and Endoplasmic Reticulum Stress

Glioblastoma multiforme (GBM) is an aggressive brain tumor with high risks of recurrence and mortality. Chemoradiotherapy resistance has been considered a major factor contributing to the extremely poor prognosis of GBM patients. Therefore, there is an urgent need to develop highly effective therapeutic agents. Here, we demonstrate the anti-tumor effect of morusin, a typical prenylated flavonoid, in GBM through in vivo and in vitro models. Morusin showed selective cytotoxicity toward GBM cell lines without harming normal human astrocytes when the concentration was less than 20 µM. Morusin treatment significantly induced apoptosis of GBM cells, accompanied by the activation of endoplasmic reticulum (ER) stress, and the appearance of cytoplasmic vacuolation and autophagosomes in cells. Then, we found the ER stress activation and cytotoxicity of morusin were rescued by ER stress inhibitor 4-PBA. Furthermore, morusin arrested cell cycle at the G1 phase and inhibited cell proliferation of GBM cells through the Akt-mTOR-p70S6K pathway. Dysregulation of ERs and cell cycle in morusin exposed GBM cells were confirmed by RNA-seq analysis. Finally, we demonstrated the combination of morusin and TMZ remarkably enhanced ER stress and displayed a synergistic effect in GBM cells, and suppressed tumor progression in an orthotopic xenograft model. In conclusion, these findings reveal the toxicity of morusin to GBM cells and its ability to enhance drug sensitivity to TMZ, suggesting the potential application value of morusin in the development of therapeutic strategies for human GBM.

Nup54-induced CARM1 nuclear importation promotes gastric cancer cell proliferation and tumorigenesis through transcriptional activation and methylation of Notch2

Gastric cancer (GC) has the fifth highest incidence globally, but its molecular mechanisms are not well understood. Here, we report that coactivator-associated arginine methyltransferase 1 (CARM1) is specifically highly expressed in gastric cancer and that its overexpression correlates with poor prognosis in patients with gastric cancer. Nucleoporin 54 (Nup54) was identified as a CARM1-interacting protein that promoted CARM1 nuclear importation. In the nucleus, CARM1 cooperates with transcriptional factor EB (TFEB) to activate Notch2 transcription by inducing H3R17me2 of the Notch2 promoter but not H3R26me2. Additionally, the Notch2 intracellular domain (N2ICD) was identified as a CARM1 substrate. Methylation of N2ICD at R1786, R1838, and R2047 by CARM1 enhanced the binding between N2ICD and mastermind-like protein 1 (MAML1) and increased gastric cancer cell proliferation in vitro and tumor formation in vivo. Our findings reveal a molecular mechanism linking CARM1-mediated transcriptional activation of the Notch2 signaling pathway to Notch2 methylation in gastric cancer progression.

A review of alpha-glucosidase inhibitors from plants as potential candidates for the treatment of type-2 diabetes

Diabetes mellitus is a multifactorial global health disorder that is rising at an alarming rate. Cardiovascular diseases, kidney damage and neuropathy are the main cause of high mortality rates among individuals with diabetes. One effective therapeutic approach for controlling hyperglycemia associated with type-2 diabetes is to target alpha-amylase and alpha-glucosidase, enzymes that catalyzes starch hydrolysis in the intestine. At present, approved inhibitors for these enzymes are restricted to acarbose, miglitol and voglibose. Although these inhibitors retard glucose absorption, undesirable gastrointestinal side effects impede their application. Therefore, research efforts continue to seek novel inhibitors with improved efficacy and minimal side effects. Natural products of plant origin have been a valuable source of therapeutic agents with lesser toxicity and side effects. The anti-diabetic potential through alpha-glucosidase inhibition of plant-derived molecules are summarized in this review. Eight molecules (Taxumariene F, Akebonoic acid, Morusin, Rhaponticin, Procyanidin A2, Alaternin, Mulberrofuran K and Psoralidin) were selected as promising drug candidates and their pharmacokinetic properties and toxicity were discussed where available.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s11101-021-09773-1.

Caffeine Induces G0/G1 Cell Cycle Arrest and Inhibits Migration through Integrin αv, β3, and FAK/Akt/c-Myc Signaling Pathway

Lung cancer is recognized as a major cause of mortality worldwide owing to its metastatic activity. Given the lack of solid information regarding the possible effects of caffeine, one of the most consumed natural psychoactive substances, on molecular signaling pathways implicated in the aggressive behavior of lung cancer, our study aimed to evaluate the effect and mechanism of caffeine on metastasis-related mechanisms. The results revealed that caffeine treatment at concentrations of 0-500 µM caused no direct cytotoxic effects on NCI-H23 cells. Treatment of cells with caffeine showed good potential to inhibit cell proliferation at 48 h and induced significant cell cycle arrest at the G0/G1 phase. Concerning metastasis, caffeine was shown to reduce filopodia formation, inhibit migration and invasion capability, and reduce the ability of cancer cells to survive and grow in an anchorage-independent manner. Moreover, caffeine could attenuate the formation of 3D tumor spheroids in cancer stem cell (CSC)-enriched populations. With regard to mechanisms, we found that caffeine significantly altered the integrin pattern of the treated cells and caused the downregulation of metastasis-associated integrins, namely, integrins αv and β3. Subsequently, the downstream signals, including protein signaling and transcription factors, namely, phosphorylated focal adhesion kinase (p-FAK), phosphorylated protein kinase B (p-Akt), cell division cycle 42 (Cdc42), and c-Myc, were significantly decreased in caffeine-exposed cells. Taken together, our novel data on caffeine-inhibiting mechanism in relation to metastasis in lung cancer could provide insights into the impact of caffeine intake on human diseases and conditions.

The Pro-Health Benefits of Morusin Administration-An Update Review

Prenylflavonoids are widespread in nature. Plants are valuable sources of natural polyphenolic compounds with isoprenyl groups, which include flavones, flavanones, chalcones and aurones. They can be found in flowers, bark and stems. One of the most important compounds found in the bark of white mulberry (Morus alba) is morusin, a prenylated flavone with interesting pro-health properties. The research carried out so far revealed that morusin has antioxidant, antitumor, anti-inflammatory and anti-allergic activity. Moreover, its neuroprotective and antihyperglycemic properties have also been confirmed. Morusin suppresses the growth of different types of tumors, including breast cancer, glioblastoma, pancreatic cancer, hepatocarcinoma, prostate cancer, and gastric cancer. It also inhibits the inflammatory response by suppressing COX activity and iNOS expression. Moreover, an antimicrobial effect against Gram-positive bacteria was observed after treatment with morusin. The objective of this review is to summarize the current knowledge about the positive effects of morusin on human health in order to facilitate future study on the development of plant polyphenolic drugs and nutraceutics in the group of prenylflavones.

Albanol B from Mulberries Exerts Anti-Cancer Effect through Mitochondria ROS Production in Lung Cancer Cells and Suppresses In Vivo Tumor Growth

Albanol B (ABN-B), an arylbenzofuran derivative isolated from mulberries, has been shown to have anti-Alzheimer’s disease, anti-bacterial and antioxidant activities. The aim of this study was to investigate the anti-cancer effect of this compound against lung cancer cells. The results show that ABN-B inhibited the proliferation of four human lung cancer cell lines (A549, BZR, H1975, and H226) and induced apoptosis, based on the cleavage of caspase-7 and PARP (poly (ADP-ribose) polymerase), as well as the downregulation of Bcl-2. ABN-B also induced cell cycle arrest at G₂/M by down-regulating the expression of CKD1 (cyclin-dependent kinase 1) and cyclin B1, but up-regulating p21 (cyclin-dependent kinase inhibitor 1) expression. Notably, ABN-B increased the production of mitochondrial reactive oxygen species (ROS); however, treatment with mito-TEMPO (a specific mitochondrial antioxidant) blocked ABN-B-induced cell cycle arrest at G₂/M and apoptosis, as well as the up-regulation of p21 and down-regulation of CDK1 and cyclin B1 induced by ABN-B. At the molecular level, ABN-B-induced mitochondrial ROS production increased the phosphorylation levels of AKT (protein kinase B) and ERK1/2 (extracellular signal-regulated kinase 1/2), while the inhibition of these kinases blocked the ABN-B-induced up-regulation of p21 and down-regulation of CDK1 and cyclin B1. Moreover, ABN-B significantly suppressed tumor growth in Ex-3LL (Lewis lung carcinoma) tumor-bearing mice. Taken together, these results suggest that ABN-B can exert an anti-cancer effect by inducing apoptosis and cell cycle arrest at G₂/M through mitochondrial ROS production in lung cancer cells.

Morusin Suppresses Cancer Cell Invasion and MMP-2 Expression through ERK Signaling in Human Nasopharyngeal Carcinoma

The most important cause of treatment failure of nasopharyngeal carcinoma (NPC) patients is metastasis, including regional lymph nodes or distant metastasis, resulting in a poor prognosis and challenges for treatment. In the present study, we investigated the in vitro anti- tumoral properties of morusin on human nasopharyngeal carcinoma HONE-1, NPC-39, and NPC-BM cells. Our study revealed that morusin suppressed the migration and invasion abilities of the three NPC cells. Gelatin zymography assay and Western blotting demonstrated that the enzyme activity and the level of matrix metalloproteinases-2 (MMP-2) protein were downregulated by the treatment of morusin. Mitogen-activated protein kinase proteins were examined to identify the signaling pathway, which showed that phosphorylation of ERK1/2 was inhibited after the treatment of morusin. In summary, our data showed that morusin inhibited the migration and invasion of NPC cells by suppressing the expression of MMP-2 by downregulating the ERK1/2 signaling pathway, suggesting that morusin may be a potential candidate for chemoprevention or adjuvant therapy of NPC.

Morusin induces apoptosis and autophagy via JNK, ERK and PI3K/Akt signaling in human lung carcinoma cells

Due to drug resistance and side effects, the development of novel therapeutics for the treatment of lung cancer is still in an urgent need. Morusin, a naturally occurring prenylated flavonoid isolated from the root bark of Morus alba, has been reported to be a promising candidate for cancer treatment including lung cancer. This study aimed to validate the anti-cancer effects of morusin in human non-small cell lung cancer (NSCLC) cell lines A549 and NCI-H292. The results indicated that morusin had growth inhibitory, pro-apoptotic and pro-autophagic effects on A549 and NCI-H292 cells. The induction of apoptosis was characterized by chromatin condensation and PARP cleavage. Mitochondrial membrane potential (MMP) loss, cytochrome c release, Bax/Bcl-2 dysregulation, and caspase-3 cleavage were also observed, indicating a mitochondria-dependent apoptosis was induced by morusin. A pro-autophagic effect was demonstrated by the increased level of LC3-Ⅱ and decreased level of SQSTM1/p62. Furthermore, morusin inhibited PI3K/Akt signaling and activated JNK, ERK pathways as indicated by the alteration in the ratio of phosphorylation level over total protein expression level. A PI3K/Akt inhibitor (LY294002), a JNK inhibitor (SP600125) and a MEK/ERK inhibitor (U0126) contributed to the determination that these pathways were involved in both apoptosis and autophagy induced by morusin. Moreover, morusin treatment strikingly enhanced intracellular ROS level, an ROS scavenger NAC blocked cell death and changes of Akt, JNK and ERK induced by morusin.

The Beneficial Effects of Morusin, an Isoprene Flavonoid Isolated from the Root Bark of Morus

The root bark of Morus has long been appreciated as an antiphlogistic, diuretic and expectorant drug in Chinese herbal medicine, albeit with barely known targets and mechanisms of action. In the 1970s, the development of analytic chemistry allowed for the discovery of morusin as one of 7 different isoprene flavonoid derivatives in the root bark of Morus. However, the remarkable antioxidant capacity of morusin with the unexpected potential for health benefits over the other flavonoid derivatives has recently sparked scientific interest in the biochemical identification of target proteins and signaling pathways and further clinical relevance. In this review, we discuss recent advances in the understanding of the functional roles of morusin in multiple biological processes such as inflammation, apoptosis, metabolism and autophagy. We also highlight recent in vivo and in vitro evidence on the clinical potential of morusin treatment for multiple human pathologies including inflammatory diseases, neurological disorders, diabetes, cancer and the underlying mechanisms.

Stress Granule Formation Attenuates RACK1-Mediated Apoptotic Cell Death Induced by Morusin

Stress granules are membraneless organelles composed of numerous components including ribonucleoproteins. The stress granules are characterized by a dynamic complex assembly in response to various environmental stressors, which has been implicated in the coordinated regulation of diverse biological pathways, to exert a protective role against stress-induced cell death. Here, we show that stress granule formation is induced by morusin, a novel phytochemical displaying antitumor capacity through barely known mechanisms. Morusin-mediated induction of stress granules requires activation of protein kinase R (PKR) and subsequent eIF2α phosphorylation. Notably, genetic inactivation of stress granule formation mediated by G3BP1 knockout sensitized cancer cells to morusin treatment. This protective function against morusin-mediated cell death can be attributed at least in part to the sequestration of receptors for activated C kinase-1 (RACK1) within the stress granules, which reduces caspase-3 activation. Collectively, our study provides biochemical evidence for the role of stress granules in suppressing the antitumor capacity of morusin, proposing that morusin treatment, together with pharmacological inhibition of stress granules, could be an efficient strategy for targeting cancer.

MYC Participates in Lipopolysaccharide-Induced Sepsis via Promoting Cell Proliferation and Inhibiting Apoptosis

OBJECTIVE

This study aimed to explore the potential mechanism of MYC proto-oncogene, BHLH Transcription Factor (MYC) gene, on sepsis.

MATERIALS AND METHODS

In this experimental study, rat-derived H9C2 cardiomyocyte cells were cultured in vitro, followed by lipopolysaccharide (LPS) treatment with different concentration gradients. The cholecystokinin octapeptide (CCK-8) assay, enzyme-linked immunoassay (ELISA) assay, quantitative reverse transcription polymerase chain reaction (qRT-PCR), cell transfection, Western blot and flow cytometry were used to observe the cellular apoptosis and proliferation of cells in both treated LPS groups and normal control group.

RESULTS

The result of CCK-8 assay showed that silencing MYC inhibited cellular proliferation of sepsis in absence or presence of LPS treatment. ELISA assay showed that the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were decreased in MYC silenced group, but they were increased after LPS treatment. Moreover, Flow cytometry assay showed that MYC silencing contributed to the apoptosis of sepsis cells. Furthermore, the expression of inflammatory factors showed that MYC silencing elevated the expression of inflammation factors.

CONCLUSION

MYC might take part in the process of LPS induced sepsis through suppressing apoptosis and inducing cell proliferation. Moreover, MYC might reduce inflammation during the progression of LPS induced sepsis.

Morusin exerts anti-cancer activity in renal cell carcinoma by disturbing MAPK signaling pathways

Background

Renal cell carcinoma (RCC) has gradually become a severe type of kidney malignant tumor, which warrants an urgent need for highly efficacious therapeutic agents. Morusin, a typical prenylated flavonoid, has been revealed to possess anticarcinogenic effects against several cancers by inhibiting cell proliferation and tumorigenesis.

Methods

Cells proliferation was examined by CCK-8. Migration assays were performed using a 24-well transwell chamber. Apoptotic cells were detected using the Annexin V PE/7-AAD apoptosis detection kit. Cell cycle analysis was carried out by flow cytometry. Western blotting and quantitative real time (qRT) PCR were used to exam the change of target gene in mRNA and protein level. Nude mouse xenograft experiments were performed to identify vivo function of morusin.

Results

Here, we evaluated the effect of morusin against RCC. We treated three RCC cell lines, 769-P, 786-O, and OSRC-2, with morusin to study its effects on cell growth, migration, apoptosis, cell cycle and cancer-related pathways. Additionally, we assessed the effects of morusin on tumor growth using a nude mouse model. Morusin could inhibit cell growth and migration, induce cell apoptosis and downregulate apoptosis-related proteins, and disturb the cell cycle arrest in the G1 phase. Additionally, morusin could suppress RCC tumorigenesis in vivo. Moreover, mitogen-activated protein kinase (MAPK) signal pathways were found to be involved in morusin-induced anti-cancer activity. P-p38 and P-JNK levels were up-regulated by morusin, while the ERK phosphorylation level was down-regulated.

Conclusions

Our results show that morusin could inhibit the growth of RCC cells in vitro and in vivo through MAPK signal pathways. Thus, morusin could be a potential anti-cancer agent for RCC.

GJB4 promotes gastric cancer cell proliferation and migration via Wnt/CTNNB1 pathway

Background

Gap junction beta-4 protein (GJB4), or connexin 30.3, a member of integral membrane proteins, has been shown to involve and may function as a tumor promoter in tumorigenesis. However, the role of GJB4 in gastric cancer (GC) is still unclear.

Materials and methods

We used Progression-free survival Kaplan-Meier analysis and Western blot analysis to detect the expression of GJB4 in GC tissues and cells. In addition, both in vitro and in vivo assays were used to determine the effect of GJB4 on malignant behavior in GC cells.

Results

We found that GJB4 was overexpressed in gastric cancer tissues and cells compared with normal tissues and cells. The high GJB4 expression was significantly associated with poor overall survival of GC patients. Knocking down GJB4 in GC cells significantly suppressed cell proliferation and migration. We found that the effects of GJB4-knockdown on GC cells were associated with downregulation of CTNNB1 and its downstream MYC, MMP7 and CCND1 expression. In addition, we found that the promotive effect of GJB4 overexpression on cell proliferation and migration was negated by XAV-939, which is the inhibitor of Wnt/CTNNB1 pathway. Therefore, we revealed a novel mechanism by which GJB4 could activate the Wnt/CTNNB1 pathway to promote GC cell's proliferation and migration.

Conclusion

This study offer insights into GJB4 function and indicate that GJB4 is a promising biomarker and therapeutic target for gastric cancer patients.

New prognostic markers revealed by RNA-Seq transcriptome analysis after MYC silencing in a metastatic gastric cancer cell line

MYC overexpression is considered a driver event in gastric cancer (GC), and is frequently correlated with poor prognosis and metastasis. In this study, we evaluated the prognostic value of genes upregulated by MYC in patients with GC. Metastatic GC cells (AGP01) characterized by MYC amplification, were transfected with siRNAs targeting MYC. RNA-seq was performed in silenced and non-silenced AGP01 cells. Among the differentially expressed genes, CIAPIN1, MTA2, and UXT were validated using qRT-PCR, western blot, and immunohistochemistry in gastric tissues of 213 patients with GC; and their expressions were correlated with clinicopathological and survival data. High mRNA and protein levels of CIAPIN1, MTA2, and UXT were strongly associated with advanced GC stages (P < 0.0001). However, only CIAPIN1 and UXT gene expressions were able to predict distant metastases in patients with early-stage GC (P < 0.0001), with high sensitivity (> 92%) and specificity (> 90%). Overall survival rate of patients with overexpressed CIAPIN1 or UXT was significantly lower (P < 0.0001). In conclusion, CIAPIN1 and UXT may serve as potential molecular markers for GC prognosis.

Long Noncoding RNA MRPL39 Inhibits Gastric Cancer Proliferation and Progression by Directly Targeting miR-130

BACKGROUND

Gastric cancer (GC) is one of the most prevalent malignant tumors displaying both high incidence and mortality throughout much of the world. Recently, long noncoding RNAs (lncRNAs) have been implicated in the development and progression of GC.

MATERIALS AND METHODS

In the present study, we investigated the biological function and molecular mechanisms of lncRNA MRPL39 in GC.

RESULTS

We found that MRPL39 was significantly downregulated in GC tissues and cell lines and that its expression level was negatively associated with carcinoma size, tumor, lymph node, metastasis (TNM) stage, and lymphatic metastasis. Patients with low MRPL39 expression levels revealed a short overall and disease-free survival period. Over-expression of MRPL39 in the GC cell lines BGC823 and SGC-7901 inhibited cell growth, proliferation, migration, and invasion. MiR-130, a putative target gene of MRPL39, displayed an inverse association with the expression of MRPL39 in GC tissues and cell lines. Moreover, a luciferase assay demonstrated a direct binding between the miR-130 and MRPL39, and the reintroduction of miR-130 abrogated the anti-tumor effect of MRPL39 on GC cells.

CONCLUSION

Taken together, these findings indicate that MRPL39 serves as a tumor suppressor by directly targeting miR-130 in GC, which suggests that it might be a novel biomarker in the diagnosis and prognosis of GC.

Anti-Allergic and Anti-Inflammatory Effects of Kuwanon G and Morusin on MC/9 Mast Cells and HaCaT Keratinocytes

Atopic dermatitis (AD) is a prevalent chronic inflammatory skin disease. The use of immunomodulatory corticosteroids in AD treatment causes adverse side effects. Therefore, novel natural anti-inflammatory therapeutics are needed. The aim of the present study was to investigate the anti-allergic and anti-inflammatory activities of kuwanon G and morusin. To investigate the effect of kuwanon G and morusin on skin inflammation, enzyme-linked immunosorbent assays (ELISA) to quantitate secreted (RANTES/CCL5), thymus- and activation-regulated chemokine (TARC/CCL17), and macrophage-derived chemokine (MDC/CCL22) were performed, followed by Western blotting to measure the phosphorylation of signal transducer and activator of transcription 1 (STAT1) and nuclear transcription factor-κB (NF-κB) p65 in tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ)-stimulated HaCaT keratinocytes. In order to evaluate the anti-allergic effects, ELISA to quantify histamine and leukotriene C₄ (LTC₄) production and Western blotting to measure 5-lipoxygenase (5-LO) activation were performed using PMA and A23187-stimulated MC/9 mast cells. Kuwanon G reduced the release of RANTES/CCL5, TARC/CCL17, and MDC/CCL22 via down-regulation of STAT1 and NF-κB p65 signaling in TNF-α and IFN-γ-stimulated HaCaT keratinocytes. Kuwanon G also inhibited histamine production and 5-LO activation in PMA and A23187-stimulated MC/9 mast cells. Morusin inhibited RANTES/CCL5 and TARC/CCL17 secretion via the suppression of STAT1 and NF-κB p65 phosphorylation in TNF-α and IFN-γ-stimulated HaCaT keratinocytes, and the release of histamine and LTC₄ by suppressing 5-LO activation in PMA and A23187-stimulated MC/9 mast cells. Kuwanon G and morusin are potential anti-inflammatory mediators for the treatment of allergic and inflammatory skin diseases such as AD.

Is co-expression of USP22 and HSP90 more effective in predicting prognosis of gastric cancer?

The ubiquitin-specific peptidase 22 (USP22) belongs to the largest subfamily of deubiquitylases and recent studies indicate that overexpression of USP22 may promote gastric cancer progression and predict prognosis. But little is known about the interaction network of USP22 in gastric cancer. In this study, we applied bioinformatics methods and found that USP22 was correlated with the heat shock protein 90 (HSP90) which is now considered to be a biomarker to predict the prognosis of gastric cancer. Then the siRNA transfection and western blotting were used to testify the correlation of USP22 and HSP90 in gastric cancer cells. The immunohistochemistry staining of the microarrays was applied to confirm the correlation of USP22 and HSP90 expression in gastric cancer tissue and further analysis showed that co-expression of USP22 and HSP90 was related to lymph node metastasis and more effective in predicting the prognosis of gastric cancer. In summary, our data demonstrate that correlation exists between USP22 and HSP90 expressions in gastric cancer and co-expression of USP22 and HSP90 may be more effective in predicting prognosis of gastric cancer.

Syntheses and evaluation of new Quinoline derivatives for inhibition of hnRNP K in regulating oncogene c-myc transcription

Aberrant overexpression of heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a key feature in oncogenesis and progression of many human cancers. hnRNP K has been found to be a transcriptional activator to up-regulate c-myc gene transcription, a critical proto-oncogene for regulation of cell growth and differentiation. Therefore, down-regulation of c-myc transcription by inhibiting hnRNP K through disrupting its binding to c-myc gene promoter is a potential approach for cancer therapy. In the present study, we synthesized and screened a series of Quinoline derivatives and evaluated their binding affinity for hnRNP K. Among these derivatives, (E)-1-(4-methoxyphenyl)-3-(4-morpholino-6-nitroquinolin-2-yl)prop-2-en-1-one (compound 25) was determined to be the first-reported hnRNP K binding ligand with its K_D values of 4.6 and 2.6 μM measured with SPR and MST, respectively. Subsequent evaluation showed that the binding of compound 25 to hnRNP K could disrupt its unfolding of c-myc promoter i-motif, resulting in down-regulation of c-myc transcription. Compound 25 showed a selective anti-proliferative effect on human cancer cell lines with IC₅₀ values ranged from 1.36 to 3.59 μM. Compound 25 exhibited good tumor growth inhibition in a Hela xenograft tumor model, which might be related to its binding with hnRNP K. These findings illustrated that inhibition of DNA-binding protein hnRNP K by compound 25 could be a new and selective strategy of regulating oncogene transcription instead of targeting promoter DNA secondary structures such as G-quadruplexes or i-motifs.

PHF19 promotes the proliferation, migration, and chemosensitivity of glioblastoma to doxorubicin through modulation of the SIAH1/β-catenin axis

PHD finger protein 19 (PHF19), a critical component of the polycomb repressive complex 2 (PRC2), is crucial for maintaining the repressive transcriptional activity of several developmental regulatory genes and plays essential roles in various biological processes. Abnormal expression of PHF19 causes dysplasia or serious diseases, including chronic myeloid disorders and tumors. However, the biological functions and molecular mechanisms of PHF19 in glioblastoma (GBM) remain unclear. Here, we demonstrated that PHF19 expression was positively associated with GBM progression, including cell proliferation, migration, invasion, chemosensitivity, and tumorigenesis. Using XAV-939, a Wnt/β-catenin inhibitor, we found that the effects of PHF19 on GBM cells were β-catenin-dependent. We also demonstrated that PHF19 expression was positively correlated with cytoplasmic β-catenin expression. PHF19 stabilized β-catenin by inhibiting the transcription of seven in absentia homolog 1 (SIAH1), an E3 ubiquitin ligase of β-catenin, through direct binding to the SIAH1 promoter region. Taken together, our results revealed the novel PHF19-SIAH1–β-catenin axis as a potential and promising therapeutic target.

Morusin Functions as a Lipogenesis Inhibitor as Well as a Lipolysis Stimulator in Differentiated 3T3-L1 and Primary Adipocytes

Conflicting results for morusin activity during adipogenic differentiation are reported in 3T3-L1 adipocytes and cancer cells. To elucidate the influence of morusin on fat metabolism, their anti-obesity effects and molecular mechanism were investigated in 3T3-L1 cells and primary adipocytes. Morusin at a dose of less than 20 µM does not induce any significant change in the viability of 3T3-L1 adipocytes. The accumulation of intracellular lipid droplets in 3T3-L1 adipocytes stimulated with 0.5 mM 3-isobutyl-1-methylxanthine, 1 µM dexamethasone, 10 µg/mL insulin in DMEM containing 10% FBS (MDI)-significantly reduces in a dose-dependent manner after morusin treatment. The phosphorylation level of members in the MAP kinase signaling pathway under the insulin receptor downstream also decrease significantly in the MDI + morusin-treated group compared to MDI + vehicle-treated group. Also, the expression of adipogenic transcription factors (PPARγ and C/EBPα) and lipogenic proteins (aP2 and FAS) are significantly attenuated by exposure to the compound in MDI-stimulated 3T3-L1 adipocytes. Furthermore, the decrease in the G0/G1 arrest of cell cycle after culturing in MDI medium was dramatically recovered after co-culturing in MDI + 20 µM morusin. Moreover, morusin treatment induces glycerol release in the primary adipocytes of SD rats and enhances lipolytic protein expression (HSL, ATGL, and perilipin) in differentiated 3T3-L1 adipocytes. Overall, the results of the present study provide strong evidence that morusin inhibits adipogenesis by regulating the insulin receptor signaling, cell cycle and adipogenic protein expression as well as stimulating lipolysis by enhancing glycerol release and lipolytic proteins expression.

Tanshinone IIA inhibits cell proliferation and tumor growth by downregulating STAT3 in human gastric cancer

Gastric cancer is the third leading cause of cancer-associated deaths worldwide. Research into the underlying mechanisms of gastric cancer is essential for the development of novel therapeutic agents to improve the prognoses of patients with gastric cancer. Tanshinone IIA (Tan IIA) is the pure extract of Danshen root (Salvia miltiorrhiza) and has been report to inhibit the proliferation of gastric cancer cells; however, the intrinsic underlying mechanisms remain unclear. The aim of the present study was to investigate whether Tan IIA has a direct anti-cancer effect in gastric cancer cells and determine the underlying mechanisms responsible. The results revealed that Tan IIA effectively inhibits proliferation in three human gastric cancer cell lines (SNU-638, MKN1 and AGS) in a time- and dose-dependent manner. Furthermore, Tan IIA treatment induced an increase in apoptosis, B-cell lymphoma (Bcl-2)-associated protein X expression and cleaved caspase-3 levels, as well as a decrease in Bcl-2 expression. Treatment with Tan IIA inhibited Furthermore, treatment with Tan IIA significantly inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3), which may be responsible for the changes in apoptosis gene expression. However, overexpression of STAT3 significantly ameliorated the Tan IIA-induced suppression of cell growth and apoptosis. A nude mouse xenograft model was constructed and the results revealed that intraperitoneal Tan IIA treatment for 28 days significantly inhibited tumor growth and STAT3 activation. The results of the present study suggest that Tan IIA exerts potent anti-cancer activity in gastric cancer cells and this effect is mediated by the downregulation of STAT3 activation.

Morusin induces paraptosis-like cell death through mitochondrial calcium overload and dysfunction in epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the leading cause of death among all gynecological cancers. Morusin, a prenylated flavonoid extracted from the root bark of Morus australis, has been reported to exhibit anti-tumor activity against various human cancers except EOC. In the present study, we explored the potential anti-cancer activity of morusin against EOC in vitro and in vivo and possible underlying mechanisms for the first time. We first found that morusin effectively inhibited EOC cell proliferation and survival in vitro and suppressed tumor growth in vivo. Then we observed that treatment of EOC cells with morusin resulted in paraptosis-like cell death, a novel mode of non-apoptotic programmed cell death that is characterized by extensive cytoplasmic vacuolation due to dilation of the endoplasmic reticulum (ER) and mitochondria and lack of apoptotic hallmarks. In addition, we discovered that morusin induced obvious increase in mitochondrial Ca²⁺ levels, accumulation of ER stress markers, generation of reactive oxygen species (ROS), and loss of mitochondrial membrane potential (Δψm) in EOC cells. Furthermore, pretreatment with 4, 4'-diisothiocyanostilbene-2, 2'-disulfonic acid (DIDS), a chemical inhibitor of voltage-dependent anion channel (VDAC) on the outer mitochondrial membrane, effectively inhibited mitochondrial Ca²⁺ influx, cytoplasmic vacuolation and cell death induced by morusin in EOC cells. Moreover, DIDS pretreatment also suppressed morusin-induced accumulation of ER stress markers, ROS production and depletion of Δψm. Consistently, tumor xenograft assays showed that co-treatment with DIDS partially reversed the inhibitory effects of morusin on tumor growth in vivo and inhibited the increased levels of ER stress markers induced by morusin in tumor tissues. Collectively, our results suggest that VDAC-mediated Ca²⁺ influx into mitochondria and subsequent mitochondrial Ca²⁺ overload contribute to mitochondrial swelling and dysfunction, leading to morusin-induced paraptosis-like cell death in EOC. This study may provide alternative therapeutic strategies for EOC exhibiting resistance to apoptosis.

Formulation, characterization and evaluation of morusin loaded niosomes for potentiation of anticancer therapy

Morusin, a water-insoluble prenylated flavonoid is known for its numerous medicinal properties. It manifests its anticancer potential by suppression of genes involved in tumor progression. However, poor solubility of the drug results in low bioavailability and rapid degradation thus hindering its clinical utilization. In order to overcome this, we have synthesized a niosome system composed of non-ionic surfactant span 60 and cholesterol using a thin-layer evaporation technique to improve the aqueous-phase solubility of the drug. Highly cytocompatible niosomes of 479 nm average size with smooth and uniform spherical morphology were synthesized in a facile manner. Unlike free morusin, nanomorusin was found to be freely dispersible in aqueous media. Having an extremely high drug entrapment efficiency (97%), controlled and sustained release of morusin resulting in enhanced therapeutic efficacy was observed in cancer cell lines of 4 different lineages. The results demonstrate that the morusin-niosome system is a promising strategy for enhanced anti-cancer activity against multiple cancer types and could be an indispensable tool for future targeted chemotherapeutic strategies.

Highly cytocompatible morusin-loaded niosomes were synthesized showing high drug loading and encapsulation efficiencies with sustained release of the drug. Enhanced therapeutic efficacy was observed against 4 different cancer cell lines.