Induction of cell-cycle arrest and apoptosis in human cholangiocarcinoma cells by pristimerin

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.

The role and implication of autophagy in cholangiocarcinoma

Cholangiocarcinoma (CCA) is a malignant tumor that originates from the biliary epithelial cells. It is characterized by a difficult diagnosis and limited treatment options. Autophagy is a cellular survival mechanism that maintains nutrient and energy homeostasis and eliminates intracellular pathogens. It is involved in various physiological and pathological processes, including the development of cancer. However, the role, mechanism, and potential therapeutic targets of autophagy in CCA have not been thoroughly studied. In this review, we introduce the classification, characteristics, process, and related regulatory genes of autophagy. We summarize the regulation of autophagy on the progression of CCA and collect the latest research progress on some autophagy modulators with clinical potential in CCA. In conclusion, combining autophagy modulators with immunotherapy, chemotherapy, and targeted therapy has great potential in the treatment of CCA. This combination may be a potential therapeutic target for CCA in the future.

The multifaceted mechanisms of pristimerin in the treatment of tumors state-of-the-art

As a globally complicated disease, malignant tumor has long been posing a threat to human health with increasingly high morbidity and mortality. Notably, existing treatments for tumors like chemotherapy generally carry intolerable toxicity, necessitating novel agents balancing safety and potency. Among them, the anti-tumor potency of herbs, featuring few adverse effects and promising efficacy, has attracted much attention recently. Pristimerin, a Quinone formamide triterpenoid compound extracted from Celastraceae and Portulacaceae, carries pronounced anti-tumor activity. It applies to various malignant tumors, including breast cancer, bile duct cancer, gastric cancer, pancreatic cancer, prostate cancer, glioblastoma, colorectal cancer, oral squamous cell carcinoma, cervical cancer, and lung cancer. In state-of-the-art understanding, pristimerin, alone or combined, can inhibit tumor cell proliferation, induce tumor cell apoptosis, inhibit tumor migration and invasion, inhibit angiogenesis, induce tumor cell autophagy, regulate the occurrence of inflammation related tumors, enhance chemosensitivity and regulate tumor microenvironment and immune cells. Despite the abundance of pristimerin-based research, systematic reviews on its anti-tumor mechanism remain needed. This study presented the anti-tumor mechanism of pristimerin by literature review, which might serve as a reference for further research and clinical practice.

A link between chemical structure and biological activity in triterpenoids

BACKGROUND

Plants with triterpenoid compounds in nature have various biological activities and are reported in many scientific works of literature. Triterpenoids are compounds that draw the attention of scientists because of their wide source, wide variety, high medicinal value, and anti-tumor properties. However, a lack of approach to understand their chemical structures has limited the fundamental comprehension of these compounds in cancer cell therapy.

OBJECTIVE

To seek anti-cancer activity of the structures of triterpenoid compounds and their derivatives, we summarized a number of plants and their derivatives that are a source of potential novel therapeutic anti-cancer agents.

METHODS

This work focuses on relevant 1036 patents and references that detail the structure of organic compounds and derivatives for the treatment of tumors.

RESULT

Compared to tetracyclic triterpenoid, pentacyclic triterpenoid has contributed more to improve the autophagic signaling pathways of cancer cells.

CONCLUSION

The heterogenous skeleton structure of triterpenoids impaired the programmed cell death signaling pathway in various cancers.

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.

Cancer-Associated Fibroblast-Derived IL-6 Determines Unfavorable Prognosis in Cholangiocarcinoma by Affecting Autophagy-Associated Chemoresponse

Simple Summary

We aimed to validate with clinical and molecular data the hypothesis that CAF infiltration and release of IL-6 predict poor prognosis in CCA patients following dysregulation of autophagy in cancer cells. Stromal IL-6 and cancer-cell-associated autophagy proteins were assayed by Tissue MicroArray immunohistochemistry and their expression correlated with overall survival (OS) in a cohort of 70 CCA patients. We found that patients bearing a CCA with low stromal IL-6 and active autophagy flux in the cancer cells have the best prognosis and this correlates with a more effective response to post-operative chemotherapy. A similar trend was observed in CCA patients from the TCGA database. In vitro experiments with primary CAFs isolated from human CCA showed that IL-6 impairs the autophagy-associated apoptotic response to 5-FU in human CCA cells. Stromal IL-6 inhibition of autophagy in cancer cells was confirmed in an animal model of CCA. Our data support a therapeutic strategy that includes drugs limiting the stromal inflammation and enhancing autophagy to improve the survival of CCA patients.

Abstract

Background: Interleukin-6 (IL-6) released by cancer-associated fibroblasts (CAFs) has been shown to associate with the malignant behavior of cholangiocarcinoma (CCA). Here, we aimed to validate with clinical and molecular data the hypothesis that CAF infiltration and release of IL-6 predict poor prognosis in CCA patients following dysregulation of autophagy in cancer cells. Methods: Stromal IL-6 and cancer-cell-associated autophagy proteins LC3 and p62 were assayed by Tissue MicroArray immunohistochemistry and their expression correlated with overall survival (OS) in a cohort of 70 CCA patients. The 5-FU cytotoxicity and autophagy were determined in CCA cells cultured with CAF-conditioned medium. Results: We show that patients bearing a CCA with low production of stromal IL-6 and active autophagy flux in the cancer cells have the best prognosis and this correlates with a more effective response to post-operative chemotherapy. A similar trend was observed in CCA patients from the TCGA database. In vitro genetic manipulation of IL-6 production by primary CAFs isolated from human CCA showed that IL-6 impairs the autophagy-associated apoptotic response to 5-FU in human CCA cells. Stromal IL-6 inhibition of autophagy in cancer cells was confirmed in an animal model of CCA. Conclusion: Our data support a therapeutic strategy that includes autophagy-enhancing drugs along with adjuvants limiting the stromal inflammation (i.e., the secretion of IL-6) to improve the survival of CCA patients.

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 Inhibits Osteoclast Differentiation and Bone Resorption in vitro and Prevents Ovariectomy-Induced Bone Loss in vivo

Introduction

Osteoporosis is a metabolic bone disease characterized by reduced bone quantity and microstructure, typically owing to increased osteoclastogenesis and/or enhanced osteoclastic bone resorption, resulting in uncontrolled bone loss, which primarily affects postmenopausal women. In consideration of the severe side effects of current drugs for osteoporosis, new safe and effective medications are necessary. Pristimerin (Pri), a quinone methide triterpene extracted from Celastraceae and Hippocrateaceae members, exhibits potent antineoplastic and anti-inflammatory effects. However, its effect on osteoclasts remains unknown.

Materials and Methods

We evaluated the anti-osteoclastogenic and anti-resorptive effect of Pri on bone marrow-derived osteoclasts and its underlying mechanism in vitro. In addition, the protective effect of Pri on ovariectomy model was also explored in vivo.

Results

In vitro, Pri inhibited osteoclast differentiation and mature osteoclastic bone resorption in a time- and dose-dependent manner. Further, Pri suppressed the expression of osteoclast-related genes and the activation of key proteins. Pri also inhibited the early activation of ERK, JNK MAPK, and AKT signaling pathways in bone marrow-derived macrophages (BMMs), ultimately inhibiting the induction and activation of the crucial osteoclast transcriptional factor nuclear factor of activated T‐cell cytoplasmic 1 (NFATc1). In vivo, consistent with our in vitro data, Pri clearly prevented ovariectomy-induced bone loss.

Conclusion

Our data showed that Pri inhibits the differentiation and activation of osteoclasts in vitro and in vivo, and could be a promising candidate for treating osteoporosis.

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.

Therapeutic Potential of Autophagy Modulation in Cholangiocarcinoma

Autophagy is a multistep catabolic process through which misfolded, aggregated or mutated proteins and damaged organelles are internalized in membrane vesicles called autophagosomes and ultimately fused to lysosomes for degradation of sequestered components. The multistep nature of the process offers multiple regulation points prone to be deregulated and cause different human diseases but also offers multiple targetable points for designing therapeutic strategies. Cancer cells have evolved to use autophagy as an adaptive mechanism to survive under extremely stressful conditions within the tumor microenvironment, but also to increase invasiveness and resistance to anticancer drugs such as chemotherapy. This review collects clinical evidence of autophagy deregulation during cholangiocarcinogenesis together with preclinical reports evaluating compounds that modulate autophagy to induce cholangiocarcinoma (CCA) cell death. Altogether, experimental data suggest an impairment of autophagy during initial steps of CCA development and increased expression of autophagy markers on established tumors and in invasive phenotypes. Preclinical efficacy of autophagy modulators promoting CCA cell death, reducing invasiveness capacity and resensitizing CCA cells to chemotherapy open novel therapeutic avenues to design more specific and efficient strategies to treat this aggressive cancer.

LINC00319 acts as a microRNA-335-5p sponge to accelerate tumor growth and metastasis in gastric cancer by upregulating ADCY3

Gastric cancer (GC) is one of the most common cancers in the world and remains a heavy burden of health worldwide. Adenylate cyclase 3 (ADCY3) is a widely expressed membrane-associated protein in human tissues and has been identified to be a new molecular target of GC. Long noncoding RNAs have a substantial influence on tumorigenesis and progression of tumors by binding to microRNAs. Therefore, this study is to clarify the mechanism by which LINC00319 sponges micro RNA-335-5p (miR-335-5p) to influence the development of GC. Initially, microarray analysis identified GC-related differentially expressed LINC00319 and ADCY3 for this study. The interaction was confirmed that LINC00319 interacted with miR-335-5p to regulate ADCY3. Next, SGC-7901 cells presenting with the lowest LINC00319 expression and the highest miR-335-5p expression were transfected with LINC00319, miR-335-5p inhibitor, or ADCY3 vector to examine their roles in growth and metastasis of GC cells, which was further ascertained by in vivo experiments. LINC00319 was upregulated and miR-335-5p was downregulated in GC cells. LINC00319 overexpression, miR-335-5p inhibitor, or ADCY3 overexpression was shown to significantly elevate the expression of cyclin-dependent kinase 4 and metastasis associated 1, decrease that of growth arrest-specific 1, and promote tumor growth and metastasis by increasing proliferation and migration and reducing cell apoptosis. Importantly, it was found that overexpressed miR-335-5p exerted its tumor suppressive role in GC through downregulating ADCY3. Collectively, LINC00319 expedited growth and metastasis of GC by upregulating miR-335-5p-mediated ADCY3.NEW & NOTEWORTHY This study is carried out based on in vivo and in vitro studies in mice and gastric cancer (GC) cells with the aim of clarifying the role of LINC00319 on GC growth and metastasis, which associated with micro RNA-335-5p-mediated adenylate cyclase 3. Altogether, we identified LINC00319 to be a potential therapy to treat GC.