Pristimerin overcomes adriamycin resistance in breast cancer cells through suppressing Akt signaling

Pristimerin Exerts Pharmacological Effects Through Multiple Signaling Pathways: A Comprehensive Review

Pristimerin, a natural triterpenoid isolated from the plants of southern snake vine and Maidenwood in the family Weseraceae, is anti-inflammatory, insecticidal, antibacterial, and antiviral substance and has been used for its cardioprotective and antitumor effects and in osteoporosis treatment. These qualities explain Pristimerin's therapeutic effects on different types of tumors and other diseases. More and more studies have shown that pristimerin acts in a wide range of biological activities and has shown great potential in various fields of modern and Chinese medicine. While Pristimerin's wide range of pharmacological effects have been widely studied by others, our comprehensive review suggests that its mechanism of action may be through affecting fundamental cellular events, including blocking the cell cycle, inducing apoptosis and autophagy, and inhibiting cell migration and invasion, or through activating or inhibiting certain key molecules in several cell signaling pathways, including nuclear factor κB (NF-κB), phosphatidylinositol 3-kinase/protein kinase B/mammalian-targeted macromycin (PI3K/Akt/mTOR), mitogen-activated protein kinases (MAPKs), extracellular signal-regulated protein kinase 1/2 (ERK1/2), Jun amino-terminal kinase (JNK1/2/3), reactive oxygen species (ROS), wingless/integrin1 (Wnt)/β-catenin, and other signaling pathways. This paper reviews the research progress of Pristimerin's pharmacological mechanism of action in recent years to provide a theoretical basis for the molecular targeting therapy and further development and utilization of Pristimerin. It also provides insights into improved treatments and therapies for clinical patients and the need to explore pristimerin as a potential facet of treatment.

Anticancer Potential and Molecular Targets of Pristimerin in Human Malignancies

The growing global burden of malignant tumors with increasing incidence and mortality rates underscores the urgent need for more effective and less toxic therapeutic options. Herbal compounds are being increasingly studied for their potential to meet these needs due to their reduced side effects and significant efficacy. Pristimerin (PS), a triterpenoid from the quinone formamide class derived from the Celastraceae and Hippocrateaceae families, has emerged as a potent anticancer agent. It exhibits broad-spectrum anti-tumor activity across various cancers such as breast, pancreatic, prostate, glioblastoma, colorectal, cervical, and lung cancers. PS modulates several key cellular processes, including apoptosis, autophagy, cell migration and invasion, angiogenesis, and resistance to chemotherapy, targeting crucial signaling pathways such as those involving NF-κB, p53, and STAT3, among others. The main objective of this review is to provide a comprehensive synthesis of the current literature on PS, emphasizing its mechanisms of action and molecular targets with the utmost clarity. It discusses the comparative advantages of PS over current cancer therapies and explores the implications for future research and clinical applications. By delineating the specific pathways and targets affected by PS, this review seeks to offer valuable insights and directions for future research in this field. The information gathered in this review could pave the way for the successful development of PS into a clinically applicable anticancer therapy.

Cellular and Molecular Mechanisms of Pristimerin in Cancer Therapy: Recent Advances

Seeking an efficient and safe approach to eliminate tumors is a common goal of medical fields. Over these years, traditional Chinese medicine has attracted growing attention in cancer treatment due to its long history. Pristimerin is a naturally occurring quinone methide triterpenoid used in traditional Chinese medicine to treat various cancers. Recent studies have identified alterations in cellular events and molecular signaling targets of cancer cells under pristimerin treatment. Pristimerin induces cell cycle arrest, apoptosis, and autophagy to exhibit anti-proliferation effects against tumors. Pristimerin also inhibits the invasion, migration, and metastasis of tumor cells via affecting cell adhesion, cytoskeleton, epithelial-mesenchymal transition, cancer stem cells, and angiogenesis. Molecular factors and pathways are associated with the anti-cancer activities of pristimerin. Furthermore, pristimerin reverses multidrug resistance of cancer cells and exerts synergizing effects with other chemotherapeutic drugs. This review aims to discuss the anti-cancer potentials of pristimerin, emphasizing multi-targeted biological and molecular regulations in cancers. Further investigations and clinical trials are warranted to understand the advantages and disadvantages of pristimerin treatment much better.

Pristimerin Suppresses Trophoblast Cell Epithelial-Mesenchymal Transition via miR-542-5p/EGFR Axis

Background

Ectopic pregnancy (EP) is an ectopic embryo implantation occurred outside the uterine cavity. Nowadays, more attention have garnered in fast and effective treatment with less side effects. Pristimerin is known as the clinical application for anti-cancer, and the effect on EP therapy is still unclear.

Materials and Methods

Trophoblast cell line HTR-8/SVneo was used; then, we performed cell counting kit-8 assay, wound healing assay, flow cytometry and real-time polymerase chain reaction analysis (RT-PCR) to detect the cell viability, migration ability, apoptosis and epithelial–mesenchymal transition (EMT) under pristimerin treatment. In addition, public bioinformatic database was used to discover the connection between molecular and genes. Finally, we used miRNA transfection and RT-PCR techniques to determine the underlying molecular mechanism.

Results

We revealed that pristimerin inhibited trophoblast cells proliferation, migration and EMT, while induced trophoblast cell apoptosis. Furthermore, expression of miR-542-5p, AGO2 and EGFR was suppressed in HTR-8/SVneo cells post pristimerin treatment, and miR-542-5p silence showed the same effect. Combing pristimerin treatment and miR-542-5p silence showed a synergistic action.

Conclusion

Pristimerin could be an effective treatment to block embryo implantation by miR-542-5p and EGFR down-regulation.

Pristimerin Suppressed Breast Cancer Progression via miR-542-5p/DUB3 Axis

BACKGROUND

Breast cancer is one of the most common and malignant tumors in the world. Nowadays more attention has been garnered in pristimerin anti-cancer effects. Here, we illustrate the function and regulatory mechanism of pristimerin in breast cancer therapy.

MATERIALS AND METHODS

Breast cancer cell lines MCF-7, MDA-MB-231, and 4T1 were used. Cell Counting Kit-8 (CCK-8) assay was performed to evaluate proliferation viability of breast cancer cells under pristimerin treatment. Wound healing assay was used to examine the migration ability, cell cycle, and cell apoptosis detection were tested by flow cytometry. Bioinformatic analysis was used to find the underlying molecular and gene connected with pristimerin and breast cancer survival. Finally, we used transfection and real-time polymerase chain reaction analysis to confirm the mechanism.

RESULTS

We observed that pristimerin inhibited breast cancer cell viability, migration, and cell cycle, meanwhile induced cell apoptosis. In addition, under pristimerin treatment, miR-542-5p was up-regulated while DUB3 was down-regulated. Furthermore, bioinformatics analysis showed higher expression of DUB3 in breast cancer compared with normal tissue, also with poor prognosis. Overexpression miR-542-5p in breast cancer cells leads to a decrease in DUB3 level. The effect was obviously post pristimerin treatment and miR-542-5p overexpression.

CONCLUSION

Pristimerin inhibited breast cancer progression through DUB3 expression via a canonical miRNA-mediated mechanism.

Terpenoids, Cannabimimetic Ligands, beyond the Cannabis Plant

Medicinal use of Cannabis sativa L. has an extensive history and it was essential in the discovery of phytocannabinoids, including the Cannabis major psychoactive compound-Δ9-tetrahydrocannabinol (Δ9-THC)-as well as the G-protein-coupled cannabinoid receptors (CBR), named cannabinoid receptor type-1 (CB1R) and cannabinoid receptor type-2 (CB2R), both part of the now known endocannabinoid system (ECS). Cannabinoids is a vast term that defines several compounds that have been characterized in three categories: (i) endogenous, (ii) synthetic, and (iii) phytocannabinoids, and are able to modulate the CBR and ECS. Particularly, phytocannabinoids are natural terpenoids or phenolic compounds derived from Cannabis sativa. However, these terpenoids and phenolic compounds can also be derived from other plants (non-cannabinoids) and still induce cannabinoid-like properties. Cannabimimetic ligands, beyond the Cannabis plant, can act as CBR agonists or antagonists, or ECS enzyme inhibitors, besides being able of playing a role in immune-mediated inflammatory and infectious diseases, neuroinflammatory, neurological, and neurodegenerative diseases, as well as in cancer, and autoimmunity by itself. In this review, we summarize and critically highlight past, present, and future progress on the understanding of the role of cannabinoid-like molecules, mainly terpenes, as prospective therapeutics for different pathological conditions.

Pristimerin inhibits the proliferation of HT1080 fibrosarcoma cells by inducing apoptosis

Fibrosarcoma is a soft tissue sarcoma that is classified as a rare cancer. Therefore, no standard anti-tumor drug therapy has been established for fibrosarcoma. Although pristimerin (PM) has been reported to exert an anti-tumor effect on various types of cancer, no studies have examined the therapeutic effect of PM on soft tissue sarcoma. The purpose of the current study was to investigate the anti-tumor effect of PM on human fibrosarcoma cells (HT1080). The present study examined the cell viability, IC50 values and ability to induce apoptosis of PM in HT1080 and normal human dermal fibroblast (aHDF) cells. The effect of PM on the following signaling pathways associated with cell proliferation was also evaluated: AKT and mitogen-activated protein kinase (MAPK). Using mice subcutaneously transplanted with fibrosarcoma cells, the effect of PM treatment was investigated on tumor growth inhibition, body weight and liver and renal function. The results revealed that PM administration reduced cell viability and induced apoptosis in a dose-dependent matter. In HT1080 cells, the IC50 value of PM was 0.16 µM at 24 h and 0.13 µM at 48 h. PM treatment also decreased the levels of phosphorylated AKT, mTOR, NF-κB and phosphorylated ERK in a dose-dependent manner. In the PM injection group, the increase in tumor volume was significantly reduced and the effect on weight loss and liver and renal function were revealed to be insignificant. PM exerted little effect on normal human dermal fibroblasts and was highly effective against human fibrosarcoma cells. The results indicated that PM may be used as a potential therapeutic agent against fibrosarcoma.

Zhankuic Acids A, B and C from Taiwanofungus Camphoratus Act as Cytotoxicity Enhancers by Regulating P-Glycoprotein in Multi-Drug Resistant Cancer Cells

Since P-glycoprotein (P-gp)-related multidrug resistance (MDR) remains the most important unsolved problem in cancer treatment, scientists are attempting to find potential structures from natural resources. The aim of the present study was to elucidate whether the triterpenoids from Taiwanofungus camphoratus could reverse cancer MDR by influencing P-gp efflux pump. Substrates efflux assay and P-gp ATPase activity assay were conducted to reveal the molecular mechanisms of P-gp inhibition, while SRB assay, cell cycle analyses and apoptosis analyses were performed to confirm the cancer MDR modulating effects. The results indicated that Zhankuic acids A, B and C (ZA-A, ZA-B and ZA-C) impacted P-gp efflux function in competitive, noncompetitive and competitive manners, respectively. Furthermore, these triterpenoids all demonstrated inhibitory patterns on both basal P-gp ATPase activity and verapamil-stimulated ATPase activity. In terms of MDR reversal effects, ZA-A sensitized the P-gp over-expressing cell line (ABCB1/Flp-In^TM-293) and MDR cancer cell line (KB/VIN) toward clinically used chemotherapeutic drugs, including doxorubicin, paclitaxel and vincristine, exhibiting the best cytotoxicity enhancing ability among investigated triterpenoids. The present study demonstrated that ZA-A, ZA-B and ZA-C, popular triterpenoids from T. camphoratus, effectively modulated the drug efflux transporter P-gp and reversed the cancer MDR issue.

Anti-Cancer Effects of Pristimerin and the Mechanisms: A Critical Review

As a quinonemethide triterpenoid extracted from species of the Celastraceae and Hippocrateaceae, pristimerin has been shown potent anti-cancer effects. Specifically, it was found that pristimerin can affect many tumor-related processes, such as apoptosis, autophagy, migration and invasion, vasculogenesis, and drug resistance. Various molecular targets or signaling pathways are also involved, such as cyclins, reactive oxygen species (ROS), microRNA, nuclear factor kappa B (NF-κB), mitogen-activated protein kinase (MAPK), and PI3K/AKT/mammalian target of rapamycin (mTOR) pathways. In this review, we will focus on the research about pristimerin-induced anti-cancer activities to achieve a deeper understanding of the targets and mechanisms, which offer evidences suggesting that pristimerin can be a potent anti-cancer drug.

Pristimerin inhibits glioma progression by targeting AGO2 and PTPN1 expression via miR-542-5p

Glioblastoma multiform is the most common and malignant primary tumor of the central nervous system in adults, the high recurrence rate and poor prognosis are critical priorities. Pristimerin is a naturally occurring quinone methide triterpenoid isolated from the Celastraceae and Hippocrateaceae families. Its anticancer effects have garnered considerable attention; nonetheless, the mechanisms of action remain unknown. To predict the hub genes of pristimerin, PharmMapper and the Coremine database were used to identify 13 potential protein targets; protein-protein interaction, for which functional enrichment analyses were performed. Compound-target, target-pathway, and compound-target-pathway networks were constructed using Cytoscape. Biological process analysis first revealed that enrichment of these target genes correlated with negative regulation of symbiont growth in the host, and regulation of chronic inflammatory response to antigenic stimulus. Survival analysis in cBioPortal showed that protein tyrosine phosphatase, non-receptor type 1 (PTPN1) and Argonaute 2 (AGO2) might be involved in the carcinogenesis, invasion, or recurrence of diffuse glioma. In addition, we observed that low-dose pristimerin inhibited the viability of glioma cells, while miR-542-5p in vitro; and reduced PTPN1 expression. Notably, high-dose pristimerin induced apoptosis. Furthermore, miR-542-5p silence with siRNA in glioma cells lead to the elevation in AGO2, and decreased PTPN1 level. The effect was obviously post pristimerin treatment and miR-542-5p suppression. In conclusion, pristimerin inhibited glioma progression through AGO2 and PTPN1 expression via a canonical miRNA-mediated mechanism.

Pristimerin enhances the effect of cisplatin by inhibiting the miR‑23a/Akt/GSK3β signaling pathway and suppressing autophagy in lung cancer cells

Lung cancer is a common type of cancer with a high mortality rate in China. Cisplatin (Cis) is one of the most effective broad‑spectrum chemotherapeutic drugs for the treatment of advanced lung cancer. However, Cis resistance remains an obstacle in the treatment of advanced lung cancer. Pristimerin (Pris), a naturally occurring triterpenoid quinone compound, not only possesses anticancer properties, but also enhances chemosensitivity. Therefore, the present study aimed to investigate whether Pris can enhance the chemosensitivity of lung cancer cells to Cis and identify the underlying mechanism. A Cell Counting kit‑8 and flow cytometry were used to determine cell viability, cell cycle progression and apoptosis in A549 and NCI‑H446 cells. Western blotting was used to determine cell apoptosis‑related, cell cycle‑related and autophagy‑related proteins. The results showed that Pris inhibited cell proliferation, and induced G0/G1 arrest and cell apoptosis in A549 and NCI‑H446 cells. The western blotting revealed that Pris effectively synergized with Cis to induce cell apoptosis by inhibiting the microRNA‑23a/Akt/glycogen synthase kinase 3β signaling pathway and suppressing autophagy. In vivo xenograft experiments confirmed that Pris effectively synergized with Cis to suppress tumor growth. Collectively, these results indicate that Pris synergized with Cis and that this may be a potential therapeutic strategy to overcome lung cancer.

Pristimerin induces apoptosis of oral squamous cell carcinoma cells via G1 phase arrest and MAPK/Erk1/2 and Akt signaling inhibition

Pristimerin is an active compound isolated from the traditional Chinese herbs Celastraceae and Hippocrateaceae. It has been reported to exert antitumor effects under experimental and clinical conditions; however, the antitumor effects and underlying mechanisms of pristimerin in oral cancer cells have not yet been identified. In the present study, the anticancer potential of pristimerin was investigated in two oral squamous cell carcinoma (OSCC) cell lines, CAL-27 and SCC-25. Results demonstrated that pristimerin was toxic against the two cell lines, and exhibited inhibitory effects against proliferation. Furthermore, pristimerin exhibited a more potent anti-proliferative activity in CAL-27 and SCC-25 cells than the common chemotherapy drugs cisplatin and 5-fluorouracil. In addition, cell cycle distribution analysis revealed that G₀/G₁ phase arrest was induced following pristimerin treatment in CAL-27 and SCC-25 cells, which was strongly associated with upregulation of p21 and p27, coupled with downregulation of cyclin D1 and cyclin E. Meanwhile, pristimerin induced significant apoptosis of CAL-27 and SCC-25 cells, alongside decreased levels of caspase-3 and specific cleavage of poly (ADP-ribose) polymerase. These effects were associated with inhibition of the mitogen-activated protein kinase/extracellular signal-regulated kinase 1/2 and protein kinase B signaling pathways. With regards to these results, pristimerin may be considered a potent novel active substance for the treatment of OSCC.

A promising natural product, pristimerin, results in cytotoxicity against breast cancer stem cells in vitro and xenografts in vivo through apoptosis and an incomplete autopaghy in breast cancer

Several natural products have been suggested as effective agents for the treatment of cancer. Given the important role of CSCs (Cancer Stem Cells) in cancer, which is a trendy hypothesis, it is worth investigating the effects of pristimerin on CSCs as well as on the other malignant cells (MCF-7 and MDA-MB-231) of breast cancer. The anti-growth activity of pristimerin against MCF-7 and MCF-7s (cancer stem cell enriched population) cells was investigated by real time viability monitorization (xCELLigence System^®) and ATP assay, respectively. Mode of cell death was evaluated using electron and fluorescence microscopies, western blotting (autophagy, apoptosis and ER-stress related markers) and flow cytometry (annexin-V staining, caspase 3/7 activity, BCL-2 and PI3K expressions). Pristimerin showed an anti-growth effect on cancer cells and cancer stem cells with IC₅₀ values ranging at 0.38-1.75μM. It inhibited sphere formation at relatively lower doses (<1.56μM). Apoptosis was induced in MCF-7 and MCF-7s cells. In addition, extensive cytoplasmic vacuolation was observed, implying an incompleted autophagy as evidenced by the increase of autophagy-related proteins (p62 and LC3-II) with an unfolded protein response (UPR). Pristimerin inhibited the growth of MCF-7 and MDA-MB-231-originated xenografts in NOD.CB17-Prkdc^scid/J mice. In mice, apoptosis was further confirmed by cleavage of PARP, activation of caspase 3 and/or 7 and TUNEL staining. Taken together, pristimerin shows cytotoxic activity on breast cancer both in vitro and in vivo. It seems to represent a robust promising agent for the treatment of breast cancer. Pristimerin's itself or synthetic novel derivatives should be taken into consideration for novel potent anticancer agent(s).

Antitumor effects of pristimerin on human osteosarcoma cells in vitro and in vivo

There are very few treatments for musculoskeletal tumors, compared to other cancers; thus, novel therapeutic drugs are needed. Pristimerin (PM) is a triterpene compound isolated from plant extracts that reportedly has antitumor effects on various cancers, such as of the breast and prostate. The purpose of this study was to evaluate the antitumor effects of PM on human osteosarcoma cells. Treatment of the human osteosarcoma cell lines, MNNG and 143B, with PM led to a dose-dependent decrease in cell viability. The effects of PM on apoptosis were evaluated with the Annexin V/propidium iodide assay and analysis of caspases 3, 8, and 9 activities. Western blot analysis showed that PM caused a decrease in the expression of Akt, mTOR, and NF-κB. The volumes and weights of human osteosarcoma xenografts decreased significantly with PM treatment. The results of this study revealed that PM can inhibit human osteosarcoma growth in vitro and in vivo, and may be a novel therapeutic agent for the disease.

Pristimerin effectively inhibits the malignant phenotypes of uveal melanoma cells by targeting NF‑κB pathway

Uveal melanoma (UM) is a highly aggressive intraocular malignancy that lacks any effective targeted-therapy. Neither survival nor prognosis has been improved for the past decades in patients with metastatic UM. NF‑κB pathway is reported to be abnormally activated in UM. However, the role of NF‑κB pathway as a potential therapeutical target in UM remains unclear. Here, the effect of pristimerin, a potent inhibitor of NF‑κB pathway, on UM cells in terms of growth, apoptosis, motility, invasion and cancer stem-like cells (CSCs) was evaluated in vitro. We showed that pristimerin suppressed tumor necrosis factor α (TNFα)-induced IκBα phosphorylation, translocation of p65, and expression of NF‑κB-dependent genes. Moreover, pristimerin decreased cell viability and clonogenic ability of UM cells. A synergistic effect was observed in the treatment of pristimerin combined with vinblastine, a frontline therapeutic agent, in UM. Pristimerin led to a significant increase in the Annexin V+ cell population as measured by flow cytometry. We also observed that pristimerin impaired the abilities of migration and invasion in UM cells. Furthermore, pristimerin eliminated the ALDH+ cells and weakened serial re-plating ability of melanosphere. Collectively, pristimerin shows remarkable anticancer activities in UM cells through inactivating NF‑κB pathway, revealing that pristimerin may be a promising therapeutic agent in UM.