Inhibition of Wnt3a/FOXM1/β-Catenin Axis and Activation of GSK3β and Caspases are Critically Involved in Apoptotic Effect of Moracin D in Breast Cancers

Moracin D suppresses cell growth and induces apoptosis via targeting the XIAP/PARP1 axis in pancreatic cancer

BACKGROUND

Pancreatic cancer, a tumor with a high metastasis rate and poor prognosis, is among the deadliest human malignancies. Investigating effective drugs for their treatment is imperative. Moracin D, a natural benzofuran compound isolated from Morus alba L., shows anti-inflammation and anti-breast cancer properties and is effective against Alzheimer's disease. However, the effect and mechanism of Moracin D action in pancreatic cancer remain obscure.

PURPOSE

To investigate the function and molecular mechanism of Moracin D action in repressing the malignant progression of pancreatic cancer.

METHODS

Pancreatic cancer cells were treated with Moracin D, and cell proliferation was evaluated by cell counting kit-8 (CCK-8) and immunofluorescence assays. The clonogenicity of pancreatic cancer cells was assessed based on plate colony formation and soft agar assay. Flow cytometry was used to detect cell apoptosis. The expression of proteins related to the apoptosis pathway was determined by Western blot analysis. Moracin D and XIAP were subjected to docking by auto-dock molecular docking analysis. Ubiquitination levels of XIAP and the interaction of XIAP and PARP1 were assessed by co-immunoprecipitation analysis. Moracin D's effects on tumorigenicity were assessed by a tumor xenograft assay.

RESULTS

Moracin D inhibited cell proliferation, induced cell apoptosis, and regulated the protein expression of molecules involved in caspase-dependent apoptosis pathways. Moracin D suppressed clonogenicity and tumorigenesis of pancreatic cancer cells. Mechanistically, XIAP could interact with PARP1 and stabilize PARP1 by controlling its ubiquitination levels. Moracin D diminished the stability of XIAP and decreased the expression of XIAP by promoting proteasome-dependent XIAP degradation, further blocking the XIAP/PARP1 axis and repressing the progression of pancreatic cancer. Moracin D could dramatically improve the chemosensitivity of gemcitabine in pancreatic cancer cells.

CONCLUSION

Moracin D repressed cell growth and tumorigenesis, induced cell apoptosis, and enhanced the chemosensitivity of gemcitabine through the XIAP/PARP1 axis in pancreatic cancer. Moracin D is a potential therapeutic agent or adjuvant for pancreatic cancer.

Comprehensive overview of different medicinal parts from Morus alba L.: chemical compositions and pharmacological activities

Morus alba L., a common traditional Chinese medicine (TCM) with a centuries-old medicinal history, owned various medicinal parts like Mori folium, Mori ramulus, Mori cortex and Mori fructus. Different medical parts exhibit distinct modern pharmacological effects. Mori folium exhibited analgesic, anti-inflammatory, hypoglycemic action and lipid-regulation effects. Mori ramulus owned anti-bacterial, anti-asthmatic and diuretic activities. Mori cortex showed counteraction action of pain, inflammatory, bacterial, and platelet aggregation. Mori fructus could decompose fat, lower blood lipids and prevent vascular sclerosis. The main chemical components in Morus alba L. covered flavonoids, phenolic compounds, alkaloids, and amino acids. This article comprehensively analyzed the recent literature related to chemical components and pharmacological actions of M. alba L., summarizing 198 of ingredients and described the modern activities of different extracts and the bioactive constituents in the four parts from M. alba L. These results fully demonstrated the medicinal value of M. alba L., provided valuable references for further comprehensive development, and layed the foundation for the utilization of M. alba L.

Morusinol Extracted from Morus alba Inhibits Cell Proliferation and Induces Autophagy via FOXO3a Nuclear Accumulation-Mediated Cholesterol Biosynthesis Obstruction in Colorectal Cancer

The incidence rate of colorectal cancer (CRC) has been increasing significantly in recent years, and it is urgent to develop novel drugs that have more effects for its treatment. It has been reported that many molecules extracted from the root bark of Morus alba L. (also known as Cortex Mori) have antitumor activities. In our study, we identified morusinol as a promising anticancer agent by selecting from 30 molecules extracted from Morus alba L. We found that morusinol treatment suppressed cell proliferation and promoted apoptosis of CRC cells in vitro. Besides this, we observed that morusinol induced cytoprotective autophagy. The GO analysis of differentially expressed genes from RNA-seq data showed that morusinol affected cholesterol metabolism. Then we found that key enzyme genes in the cholesterol biosynthesis pathway as well as the sterol regulatory element binding transcription factor 2 (SREBF2) were significantly downregulated. Furthermore, additional cholesterol treatment reversed the anti-CRC effect of morusinol. Interestingly, we also found that morusinol treatment could promote forkhead box O3 (FOXO3a) nuclear accumulation, which subsequently suppressed SREBF2 transcription. Then SREBF2-controlled cholesterol biosynthesis was blocked, resulting in the suppression of cell proliferation, promotion of apoptosis, and production of autophagy. The experiments in animal models also showed that morusinol significantly impeded tumor growth in mice models. Our results suggested that morusinol may be used as a candidate anticancer drug for the treatment of CRC.

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.

The phenolic components extracted from mulberry fruits as bioactive compounds against cancer: A review

In Asia, mulberry has long been used to treat various infectious and internal ailments as a traditional medication. The compounds found in it have the potential to improve human health. Because there is no approved and defined evaluation procedure, it has not been formally or scientifically recognized. As a result of these investigations, a new frontier in traditional Chinese medicine has opened up, with the possibility of modernization, for the interaction between active components of mulberry and their biological activities. These studies have used current biotechnological technologies. For ages, mulberry has been used as an herbal remedy in Asia to cure various diseases and internal disorders. It has a high concentration of bioactive chemicals that benefit human health. The most abundant phenolic components extracted from white mulberry leaves are flavonoids (Kuwanons, Moracinflavans, Moragrols, and Morkotins), phenolic acids, alkaloids, and so forth. Flavonoids, benzofurans, chalcones, and alkaloids have been discovered to have cytotoxic effects on human cancer cell lines. There is growing evidence that mulberry fruits can potentially prevent cancer and other aging-related disorders due to their high concentration of bioactive polyphenolic-rich compounds and macro and micronutrients. Anthocyanins are rapidly absorbed after eating, arriving in the plasmalemma within 15-50 min and entirely removed after 6-8 hr. Due to a lack of an approved and consistent technique for its examination, it has yet to be formally or scientifically recognized. The mulberry plant is commercially grown for silkworm rearing, and less attention is paid to its bioactive molecules, which have a lot of applications in human health. This review paper discusses the phenolic compounds of white mulberry and black mulberry in detail concerning their role in cancer prevention.

Circ-FOXM1 promotes the proliferation, migration and EMT process of osteosarcoma cells through FOXM1-mediated Wnt pathway activation

BACKGROUND

Osteosarcoma (OS) is a malignant bone tumor that commonly occurs in adolescents with a high mortality rate and frequent pulmonary metastasis. Emerging evidence has suggested that circular RNAs (circRNAs) are important regulators in multiple biological activities of carcinomas. Nevertheless, the role of circRNAs derived from forkhead box M1 (FOXM1), a well-accepted modulator of OS progression, has not been discussed in OS.

METHODS

Quantitative real-time polymerase chain reaction (qRT-PCR) was utilized to test circ-FOXM1 (hsa_circ_0025033) expression in OS cell lines. Cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), transwell assays and western blot analysis of epithelial-mesenchymal transition (EMT) markers were conducted to evaluate cell proliferation, apoptosis, migration, and EMT process. Luciferase reporter assay and RNA-binding protein immunoprecipitation (RIP) assay were utilized to detect the interaction of circ-FOXM1 and RNAs.

RESULTS

High expression of circ-FOXM1 was detected in OS cell lines. Functionally, circ-FOXM1 knockdown inhibited the proliferation, migration and EMT process, whereas induced the apoptosis of OS cells. From the aspect of molecular mechanism, circ-FOXM1 was discovered to upregulate FOXM1 expression via sponging miR-320a and miR-320b, therefore activating Wnt signaling pathway. Besides, rescue experiments elucidated that circ-FOXM1 regulated cellular activities of OS cells via FOXM1. Further, in vivo assays supported that loss of circ-FOXM1 restrained OS tumor growth.

CONCLUSION

Circ-FOXM1 facilitated the malignant phenotypes of OS cells through FOXM1-mediated Wnt pathway activation, revealing circ-FOXM1 as a potential biomarker for OS treatment.

Euphorbiasteroid Abrogates EGFR and Wnt/β-Catenin Signaling in Non-Small-Cell Lung Cancer Cells to Impart Anticancer Activity

EGFR and Wnt/β-catenin signaling pathways play a prominent role in tumor progression in various human cancers including non-small-cell lung carcinoma (NSCLC). Transactivation and crosstalk between the EGFR and Wnt/β-catenin pathways may contribute to the aggressiveness of cancers. Targeting these oncogenic pathways with small molecules is an attractive approach to counteract various types of cancers. In this study, we demonstrate the effect of euphorbiasteroid (EPBS) on the EGFR and Wnt/β-catenin pathways in NSCLC cells. EPBS induced preferential cytotoxicity toward A549 (wildtype EGFR-expressing) cells over PC-9 (mutant EGFR-expressing) cells. EPBS suppressed the expression of EGFR, Wnt3a, β-catenin, and FZD-1, and the reduction in β-catenin levels was found to be mediated through the activation of GSK-3β. EPBS reduced the phosphorylation of GSK-3β^S9 with a parallel increase in β-TrCP and phosphorylation of GSK-3β^Y216. Lithium chloride treatment increased the phosphorylation of GSK-3β^S9 and nuclear localization of β-catenin, whereas EPBS reverted these effects. Forced expression or depletion of EGFR in NSCLC cells increased or decreased the levels of Wnt3a, β-catenin, and FZD-1, respectively. Overall, EPBS abrogates EGFR and Wnt/β-catenin pathways to impart its anticancer activity in NSCLC cells.

Phytochemistry, bioactivities and future prospects of mulberry leaves: A review

Mulberry leaves (MLs) have been used traditionally to raise silkworms and as herbs and herbal drinks. In vitro and in vivo studies as well as some clinical trials provide some evidence of health benefits, mostly for ML extracts. ML extracts showed antioxidant, hypoglycemic, anticholesterol (affecting lipid metabolism), antiobesity, anti-inflammatory, anticancer activities, and so on. These might be linked to strong antioxidant activities, inhibition of α-glucosidase and α-amylase, reduction of foam cell formation, inhibition of fat formation, decrease of NF-κB activity, and the promotion or induction of apoptosis. Phenolic constituents, especially flavonoids, phenolic acids and alkaloids, are likely to contribute to the reported effects. The phytochemistry and pharmacology of MLs confer the traditional and current uses as medicine, food, fodder, and cosmetics. This paper reviews the economic value, chemical composition and pharmacology of MLs to provide a reference for the development and utilization of MLs.

Forkhead Box Protein M1 Promotes Nasopharyngeal Carcinoma Cell Tumorigenesis Possibly via the Wnt/β-Catenin Signaling Pathway

BACKGROUND Forkhead box protein M1 (FoxM1) is an important transcription factor involved in the development and progression of various malignancies. However, its role in nasopharyngeal carcinoma (NPC) remains largely unknown. This study aimed to assess the effect of FoxM1 on NPC cell tumorigenesis as well as the underlying mechanism. MATERIAL AND METHODS NPC cell lines CNE-1 and CNE-2 were treated with vehicle and FoxM1 inhibitor thiostrepton or transfected with small interfering RNA. CCK-8 assay, flow cytometric assay, and Hoechst 33258 staining were performed to assess the viability, apoptosis and nuclear morphological impairment, and cell cycle, respectively. The expression of apoptosis-related caspase-3 and caspase-9 was detected by western blot analysis The tumor growth in the mouse xenograft model of NPC treated with thiostrepton or control was assessed. The expression of Wnt/ß-catenin signaling proteins p27, FoxM1, S phase kinase-associated protein 2 (SKP2), and Cyclin D1 were determined both in cells and xenograft tissues by western blot analysis. RESULTS Inhibition of FoxM1 by thiostrepton significantly suppressed NPC cell viability, induced apoptosis, increased cell cycle arrest, impaired nuclear morphology, and reduced NPC cell-derived tumor xenograft growth. Mechanistically, inhibition or knockdown of FoxM1 inactivated the Wnt/ß-catenin signaling pathway, as demonstrated by altered expression of Wnt/ß-catenin signaling-related genes, including p27, SKP2, and cyclin D1, in both NPC cells and xenograft tissues. CONCLUSIONS We identified FoxM1 as a novel regulator of NPC cell tumorigenesis in vitro and in vivo. Targeting FoxM1 could be a promising therapeutic strategy against NPC.

A narrative review of research progress on FoxM1 in breast cancer carcinogenesis and therapeutics

OBJECTIVE

The purpose of this review is to clarify the potential roles of forkhead box transcription factor M1 (FoxM1) in the occurrence and progression of breast cancer, as well as the predictive value of FoxM1 as a prognostic biomarker and potential therapeutic target for breast cancer.

BACKGROUND

Breast cancer, well-known as a molecularly heterogeneous cancer, is still one of the most frequently diagnosed malignant tumors among females worldwide. Tumor recurrence and metastasis are the central causes of high mortality in breast cancer patients. Many factors contribute to the occurrence and progression of breast cancer, including FoxM1. FoxM1, widely regarded as a classic proliferation-related transcription factor, plays pivotal roles in the occurrence, proliferation, invasion, migration, drug resistance, and epithelial-mesenchymal transition (EMT) processes of multiple human tumors including breast cancer.

METHODS

The PubMed database was searched for articles published in English from February 2008 to May 2021 using related keywords such as "forkhead box transcription factor M1", "human breast cancer", "FoxM1", and "human tumor". About 90 research papers and reports written in English were identified, most of which were published after 2015. These papers mainly concentrated on the functions of FoxM1 in the occurrence, development, drug resistance, and treatment of human breast cancer.

CONCLUSIONS

Considering that the abnormal expression of FoxM1 plays a significant role in the proliferation, invasion, metastasis, and chemotherapy drug resistance of breast cancer, and its overexpression is closely correlated with the unfavorable clinicopathological characteristics of breast tumor patients, it is considerably important to comprehend the regulatory mechanism of FoxM1 in breast cancer. This will provide strong evidence for FoxM1 as a potential biomarker for the targeted treatment and prognostic evaluation of breast cancer patients.

Moracin D induces apoptosis in prostate cancer cells via activation of PPAR gamma/PKC delta and inhibition of PKC alpha

Herein, apoptotic mechanism of Moracin D was explored in prostate cancer cells in association with peroxisome proliferator-activated receptor gamma (PPAR-γ)-related signaling involved in lipid metabolism. Moracin D augmented cytotoxicity and sub G1 population in PC3 and DU145 prostate cancer cells, while DU145 cells were more susceptible to Moracin D than PC3 cells. Moracin D attenuated the expression of caspase-3, poly (ADP-ribose) polymerase (PARP), B-cell lymphoma 2 (Bcl-2), and B-cell lymphoma-extra-large (Bcl-xL) in DU145 cells. Consistently, Moracin D significantly augmented the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells in DU145 cells. Interestingly, Moracin D activated PPAR-γ and phospho-protein kinase C delta (p-PKC-δ) and inhibited phospho-protein kinase C alpha (p-PKC-α) in DU145 cells. Furthermore, STRING bioinformatic analysis reveals that PPAR-γ interacts with nuclear factor-κB (NF-κB) that binds to PKC-α/PKC-δ or protein kinase B (AKT) or extracellular signal-regulated kinase (ERK). Indeed, Moracin D decreased phosphorylation of NF-κB, ERK, and AKT in DU145 cells. Conversely, PPAR-γ inhibitor GW9662 reduced the apoptotic ability of Moracin D to activate caspase 3 and PARP in DU145 cells. Taken together, these findings provide a novel insight that activation of PPAR-γ/p-PKC-δ and inhibition of p-PKC-α are critically involved in Moracin D-induced apoptosis in DU145 prostate cancer cells.

FOXM1 and Cancer: Faulty Cellular Signaling Derails Homeostasis

Forkhead box transcription factor, FOXM1 is implicated in several cellular processes such as proliferation, cell cycle progression, cell differentiation, DNA damage repair, tissue homeostasis, angiogenesis, apoptosis, and redox signaling. In addition to being a boon for the normal functioning of a cell, FOXM1 turns out to be a bane by manifesting in several disease scenarios including cancer. It has been given an oncogenic status based on several evidences indicating its role in tumor development and progression. FOXM1 is highly expressed in several cancers and has also been implicated in poor prognosis. A comprehensive understanding of various aspects of this molecule has revealed its role in angiogenesis, invasion, migration, self- renewal and drug resistance. In this review, we attempt to understand various mechanisms underlying FOXM1 gene and protein regulation in cancer including the different signaling pathways, post-transcriptional and post-translational modifications. Identifying crucial molecules associated with these processes can aid in the development of potential pharmacological approaches to curb FOXM1 mediated tumorigenesis.

FBXL19-AS1 promotes cell proliferation and inhibits cell apoptosis via miR-876-5p/FOXM1 axis in breast cancer

As the most common cancer and one of the leading causes of cancer-associated mortality, breast cancer continues to need more key molecules to regulate its progression. F-box and leucine-rich repeat protein 19 antisense RNA 1 (known as FBXL19-AS1) is a long non-coding RNA (lncRNA) which has been reported as an oncogene in several types of human cancers. However, the specific downstream targets of FBXL19-AS1 remain unknown. In this study, we set out to find more reliable downstream molecules of FBXL19-AS1 in breast cancer. FBXL19-AS1 was expressed at a high level in breast cancer cells. Loss-of-function experiments revealed that silencing FBXL19-AS1 could impair cell proliferation and induce cell apoptosis in breast cancer. In addition, the location of FBXL19-AS1 in the cytoplasm was detected by fluorescent in situ hybridization assay, while FBXL19-AS1 regulated the expression of Forkhead box M1 (FOXM1) by directly absorbing miR-876-5p. Through rescue assays, it was observed that FOXM1 overexpression recovered the inhibited tumor growth caused by FBXL19-AS1 downregulation. We affirmed the function of FBXL19-AS1 in breast cancer and described the mechanism of the FBXL19-AS1/miR-876-5p/FOXM1 axis. The current work presents the molecular mechanism which underlies FBXL19-AS1 in breast cancer and suggests a comprehensive, feasible FBXL19-AS1-mediated therapeutic approach for treating breast cancer.