Saikosaponin-d, a calcium mobilizing agent, sensitizes chemoresistant ovarian cancer cells to cisplatin-induced apoptosis by facilitating mitochondrial fission and G2/M arrest

Advances in the anti-tumor mechanisms of saikosaponin D

Saikosaponin D, a saponin compound, is extracted from Bupleurum and is a principal active component of the plant. It boasts a variety of pharmacologic effects including anti-inflammatory, antioxidant, immunomodulatory, metabolic, and anti-tumor properties, drawing significant attention in anti-tumor research in recent years. Research indicates that saikosaponin D inhibits the proliferation of numerous tumor cells, curbing the progression of cancers such as liver, pancreatic, lung, glioma, ovarian, thyroid, stomach, and breast cancer. Its anti-tumor mechanisms largely involve inhibiting tumor cell proliferation, promoting tumor cell apoptosis, thwarting tumor-cell invasion, and modulating tumor cell autophagy. Moreover, saikosaponin D enhances the sensitivity to anti-tumor drugs and augments body immunity. Given its multi-faceted anti-tumor roles, saikosaponin D offers promising potential in anti-tumor therapy. This paper reviews recent studies on its anti-tumor effects, aiming to furnish new theoretical insights for clinical cancer treatments.

Molecular mechanism of Saikosaponin-d in the treatment of gastric cancer based on network pharmacology and in vitro experimental verification

The study aimed to utilize network pharmacology combined with cell experiments to research the mechanism of action of Saikosaponin-d in the treatment of gastric cancer. Drug target genes were obtained from the PubChem database and the Swiss Target Prediction database. Additionally, target genes for gastric cancer were obtained from the GEO database and the Gene Cards database. The core targets were then identified and further analyzed through gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and GESA enrichment. The clinical relevance of the core targets was assessed using the GEPIA and HPA databases. Molecular docking of drug monomers and core target proteins was performed using Auto Duck Tools and Pymol software. Finally, in vitro cellular experiments including cell viability, apoptosis, cell scratch, transwell invasion, transwell migration, qRT-PCR, and Western blot were conducted to verify these findings of network pharmacology. The network pharmacology analysis predicted that the drug monomers interacted with 54 disease targets. Based on clinical relevance analysis, six core targets were selected: VEGFA, IL2, CASP3, BCL2L1, MMP2, and MMP1. Molecular docking results showed binding activity between the Saikosaponin-d monomer and these core targets. Saikosaponin-d could inhibit gastric cancer cell proliferation, induce apoptosis, and inhibit cell migration and invasion.

Calcium signals and potential therapy targets in ovarian cancer (Review)

Ovarian cancer (OC) is a deadly disease. The poor prognosis and high lethality of OC are attributed to its high degrees of aggressiveness, resistance to chemotherapy and recurrence rates. Calcium ion (Ca2+) signaling has received attention in recent years, as it appears to form an essential part of various aspects of cancer pathophysiology and is a potential therapeutic target for OC treatment. Disruption of normal Ca2+ signaling pathways can induce changes in cell cycle progression, apoptosis, proliferation and migration and invasion, leading to the development of the malignant phenotype of tumors. In the present review, the main roles of ion channel/receptor/pump‑triggered Ca2+ signaling pathways located at the plasma membrane and organelle Ca2+ transport in OC are summarized. In addition, the potential of Ca2+ signaling as a novel target for the development of effective treatment strategies for OC was discussed. Furthering the understanding into the role of Ca2+ signaling in OC is expected to facilitated the identification of novel therapeutic targets and improved clinical outcomes for patients.

Saikosaponin d modulates the polarization of tumor-associated macrophages by deactivating the PI3K/AKT/mTOR pathway in murine models of pancreatic cancer

The tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) poses a major obstacle to traditional and immunomodulatory cancer therapies and is closely associated with macrophage polarization. Saikosaponin d (SSd), a major active component of triterpene saponins derived from Bupleurum falcatum, has anti-inflammatory and antitumor activities. However, whether SSd can regulate immune cells during the development of the TME in PDAC remains unknown. In the present study, we aimed to analyze the role of SSd in regulating immune cells in the PDAC TME, especially the polarization of macrophages, and examine the related mechanisms. An orthotopic PDAC cancer model was used to investigate the antitumor activities and the regulation of immune cells in vivo. In vitro, bone marrow mononuclear (BM-MNC) cells and RAW 264.7 cells were used to induce the M2 macrophage phenotype and examine the effects and molecular mechanism of SSd on M2 macrophage polarization. The results revealed that SSd could directly inhibit the apoptosis and invasion of pancreatic cancer cells, modulate the immunosuppressive microenvironment and reactivate the local immune response, especially by decreasing the shift toward M2 macrophage polarization by downregulating phosphorylated STAT6 levels and the PI3K/AKT/mTOR signaling pathway. Furthermore, 740-Y-P (PI3K activator) was used to verify that SSd inhibited M2 polarization in RAW264.7 cells via the PI3K/AKT/mTOR signaling pathway. In conclusion, this study provided experimental evidence of the antitumor effect of SSd, especially in the regulation of M2 macrophage polarization, and demonstrated that SSd may be a promising therapeutic agent in PDAC.

Saikosaponin-D induces the pyroptosis of lung cancer by increasing ROS and activating the NF-κB/NLRP3/caspase-1/GSDMD pathway

Saikosaponin-D (SSD), an active ingredient in Bupleurum chinense, exerts anticancer effects in various cancers by inhibiting cancer proliferation and inducing apoptosis. However, whether SSD can induce other forms of cell death is unknown. The current study aims to demonstrate that SSD can induce pyroptosis in non-small-cell lung cancer. In this study, HCC827 and A549 non-small-cell lung cancer cells were treated with different concentrations of SSD for 1.5 h. HE and TUNEL staining were used to verify cell damage caused by SSD. Immunofluorescence and western blotting were performed to verify the effect of SSD on the NF-κB/NLRP3/caspase-1/gasdermin D (GSDMD) pathway. Changes in inflammatory factors were detected by ELISAs. Finally, the reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) was introduced to verify that SSD induces pyroptosis through the ROS/NF-κB pathway. The results of the HE and TUNEL staining showed that SSD resulted in balloon-like swelling of NSCLC cells accompanied by increased DNA damage. Immunofluorescence and western blot assays confirmed that SSD treatment activated the NLRP3/caspase-1/GSDMD pathway, stimulated an increase in ROS levels and activated NF-κB in lung cancer cells. The ROS scavenger N-acetylcysteine significantly attenuated SSD-induced NF-κB/NLRP3/caspase-1/GSDMD pathway activation and inhibited the release of the inflammatory cytokines IL-1β and IL-18. In conclusion, SSD induced lung cancer cell pyroptosis by inducing ROS accumulation and activating the NF-κB/NLRP3/caspase-1/GSDMD pathway. These experiments lay the foundation for the application of SSD in the treatment of non-small-cell lung cancer and regulation of the lung cancer immune microenvironment.

Cisplatin in Ovarian Cancer Treatment-Known Limitations in Therapy Force New Solutions

Cisplatin is one of the most commonly used anticancer drugs worldwide. It is mainly used in the treatment of ovarian cancer, but also used in testicular, bladder and lung cancers. The significant advantage of this drug is the multidirectional mechanism of its anticancer action, with the most important direction being damaging the DNA of cancer cells. Unfortunately, cisplatin displays a number of serious disadvantages, including toxicity to the most important organs, such as kidneys, heart, liver and inner ear. Moreover, a significant problem among patients with ovarian cancer, treated with cisplatin, is the development of numerous resistance mechanisms during therapy, including changes in the processes of cellular drug import and export, changes in the DNA damage repair mechanisms, as well as numerous changes in the processes of apoptosis and autophagy. Due to all of the mentioned problems, strategies to increase the effectiveness of cisplatin in the treatment of ovarian cancer are intensively sought. The most important strategy includes the development of less toxic cisplatin analogs. Another important direction is combination therapy, involving the simultaneous use of cisplatin with different anticancer drugs, substances derived from plants, temperature or radiotherapy. Many years of observations accompanying the presence of cisplatin in the therapy made it possible to provide a series of verifiable, statistically significant data, but also to show how, over time, with the new information and scientific discoveries, it is possible to describe and understand the therapeutic problems observed in practice, such as the acquisition of drug resistance by tumor cells or induction of changes in the tumor microenvironment. According to the authors, confronting what we knew so far with what new trends offer has a profound meaning. This paper presents information on the history of cisplatin and describes the molecular mechanisms of its action and the development of resistance by cancer cells. In addition, our goal was to highlight a number of therapeutic strategies to increase the effectiveness of cisplatin in the treatment of ovarian cancer, as well as to identify methods to eliminate problems associated with the use of cisplatin.

Targeting ER Stress with Saikosaponin A to Overcome Resistance under Radiation in Gastric Cancer Cells

Saikosaponin A is a triterpene saponin and a potentially bioactive compound derived from Bupleurum falcatum L. However, the molecular mechanisms and effects of saikosaponin A in gastric cancer remain unknown. In the present study, I evaluated the effects of saikosaponin A on cell death and endoplasmic reticulum stress via calcium and reactive oxygen species release. Targeting reactive oxygen species with diphenyleneiodonium and N-acetylcysteine inhibited cell death and protein kinase RNA-like ER kinase signaling pathway by down-regulating Nox4 and inducing glucose-regulated protein 78 exosomes. Furthermore, saikosaponin A caused a synergistic inhibitory effect of the epithelial mesenchymal transition phenomenon, indicating the reversible phenotype modulation by epithelial cells under radiation exposure in radiation-resistant gastric cancer cells. These results suggest that saikosaponin A-mediated calcium and reactive oxygen species-induced endoplasmic reticulum stress overcome radio-resistance and induce cell death under radiation in gastric cancer cells. Therefore, saikosaponin A in combination with radiation may be a potential strategy for gastric cancer therapy.

Ovarian Cancer: A Landscape of Mitochondria with Emphasis on Mitochondrial Dynamics

Ovarian cancer (OC) represents the main cause of death from gynecological malignancies in western countries. Altered cellular and mitochondrial metabolism are considered hallmarks in cancer disease. Several mitochondrial aspects have been found altered in OC, such as the oxidative phosphorylation system, oxidative stress and mitochondrial dynamics. Mitochondrial dynamics includes cristae remodeling, fusion, and fission processes forming a dynamic mitochondrial network. Alteration of mitochondrial dynamics is associated with metabolic change in tumour development and, in particular, the mitochondrial shaping proteins appear also to be responsible for the chemosensitivity and/or chemoresistance in OC. In this review a focus on the mitochondrial dynamics in OC cells is presented.

Chemotherapeutic Potential of Saikosaponin D: Experimental Evidence

Saikosaponin D (SSD), an active compound derived from the traditional plant Radix bupleuri, showcases potential in disease management owing to its antioxidant, antipyretic, and anti-inflammatory properties. The toxicological effects of SSD mainly include hepatotoxicity, neurotoxicity, hemolysis, and cardiotoxicity. SSD exhibits antitumor effects on multiple targets and has been witnessed in diverse cancer types by articulating various cell signaling pathways. As a result, carcinogenic processes such as proliferation, invasion, metastasis, and angiogenesis are inhibited, whereas apoptosis, autophagy, and differentiation are induced in several cancer cells. Since it reduces side effects and strengthens anti-cancerous benefits, SSD has been shown to have an additive or synergistic impact with chemo-preventive medicines. Regardless of its efficacy and benefits, the considerations of SSD in cancer prevention are absolutely under-researched due to its penurious bioavailability. Diverse studies have overcome the impediments of inadequate bioavailability using nanotechnology-based methods such as nanoparticle encapsulation, liposomes, and several other formulations. In this review, we emphasize the association of SSD in cancer therapeutics and the discussion of the mechanisms of action with the significance of experimental evidence.

Saikosaponin D improves chemosensitivity of glioblastoma by reducing the its stemness maintenance

Objective

Chemotherapy is one of the important adjuvant methods for the treatment of glioblastoma (GBM), and chemotherapy resistance is a clinical problem that neurooncologists need to solve urgently. It is reported that Saikosaponin D (SSD), an active component of Bupleurum chinense, had various of antitumor activities and could also enhance the chemosensitivity of liver cancer and other tumors. However, it is not clear whether it has an effect on the chemosensitivity of glioma and its specific mechanism.

Methods

The CCK8 assay, Wound healing assay and Matrigel invasion assay were used to detect the effect of SSD on the phenotype of GBM cells. We detected the effect of SSD on the chemosensitivity of GSM by Flow cytometry, LDH content and MTT assay. Then, we used cell plate cloning, semi-quantitative PCR and western blotting experiments to detect the effect of SSD on the stem potential of GBM cells. Finally, the effect of SSD on the chemosensitivity of GBM and its potential mechanism were verified by nude mouse experiments in vivo.

Results

firstly, we found that SSD could partially inhibit the malignant phenotype of LN-229 cells, including inhibiting migration, invasion and apoptosis, and increasing the apoptosis rate and lactate dehydrogenase (LDH) release of LN-229 cells under the treatment of temozolomide (TMZ), that is to say, increasing the chemotherapy effect of TMZ on the cells. In addition, we unexpectedly found that SSD could partially inhibit the colony forming ability of LN-229 cells, which directly related to the stemness maintenance potential of cancer stem cells. Subsequently, our results showed that SSD could inhibit the gene and protein expression of stemness factors (OCT4, SOX2, c-Myc and Klf4) in LN-229 cells. Finally, we verified that SSD could improve the chemotherapy effect of TMZ by inhibiting the stem potential of glioblastoma in vivo nude mice.

Conclusion

this research can provide a certain theoretical basis for the application of SSD in the chemotherapy resistance of GBM and its mechanism of action, and provide a new hope for the clinical treatment of glioblastoma.

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SSD could inhibit the malignant phenotype of LN-229 cells, increase the chemotherapy effect of TMZ on the cells.

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SSD could inhibit the colony forming ability of LN-229 cells, and also inhibit their gene and protein expression of stemness factors.

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We verified that SSD could improve the chemotherapy effect of TMZ by inhibiting the stem potential of glioblastoma.

Prohibitin 1 interacts with p53 in the regulation of mitochondrial dynamics and chemoresistance in gynecologic cancers

Background

Mitochondrial dynamics (e.g. fission/fusion) play an important role in controlling chemoresistance in representative gynecologic malignancies, ovarian and cervical cancer. Processing the long form of Optic atrophy (L-Opa)1 is a distinctive character of mitochondrial fragmentation, associated with chemosensitivity. Here, we examined the role of prohibitin (Phb)1 in increasing L-Opa1 processing via the regulating mitochondrial protease, Oma1 and its direct interaction with p-p53 (ser15) and pro-apoptotic Bcl-2 antagonist/killer (Bak) 1 in the signaling axis and if this phenomenon is associated with prognosis of patients.

Methods

We compared Cisplatin (CDDP)-induced response of mitochondrial dynamics, molecular interaction among p-p53 (ser15)-Phb1-Bak, and chemoresponsiveness in paired chemosensitive and chemoresistant gynecologic cancer cells (ovarian and cervical cancer cell lines) using western blot, immunoprecipitation, sea horse, and immunofluorescence. Translational strategy with proximity ligation assessment in phb1-p-p53 (ser15) in human ovarian tumor sections further confirmed in vitro finding, associated with clinical outcome.

Results

We report that: (1) Knock-down of Phb1 prevents Cisplatin (cis-diamine-dichloroplatinum; CDDP) -induced changes in mitochondrial fragmentation and Oma1 mediated cleavage, and Opa1 processing; (2) In response to CDDP, Phb1 facilitates the p-p53 (ser15)-Phb1-Bak interaction in mitochondria in chemosensitive gynecologic cancer cells but not in chemoresistant cells; (3) Akt overexpression results in suppressed p-p53(Ser15)-Phb1 interaction and dysregulated mitochondrial dynamics, and (4) Consistent with in vitro findings, proximity ligation assessment (PLA) in human ovarian tumor sections demonstrated that p-p53(ser15)-Phb1-Bak interaction in mitochondria is associated with better chemoresponsiveness and clinical outcome of patients. Determining the molecular mechanisms by which Phb1 facilitates mitochondrial fragmentation and interacts with p53 may advance the current understanding of chemoresistance and pathogenesis of gynecologic cancer.

Conclusion

Determining the key molecular mechanisms by which Phb1 facilitates the formation of p-p53 (ser15)-Bak-Phb1 and its involvement in the regulation of mitochondrial dynamics and apoptosis may ultimately contribute to the current understanding of molecular and cellular basis of chemoresistance in this gynecologic cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-022-00999-x.

Saikosaponin D: review on the antitumour effects, toxicity and pharmacokinetics

CONTEXT

Bupleuri Radix, the dried root of Bupleurum chinense DC and Bupleurum scorzonerifolium Willd (Apiaceae), is an important medicinal herb widely used to treat cancers for hundreds of years in Asian countries. As the most antitumour component but also the main toxic component in Bupleuri Radix, saikosaponin D (SSD) has attracted extensive attention. However, no summary studies have been reported on the antitumour effects, toxicity and pharmacokinetics of this potential natural anticancer substance.

OBJECTIVE

To analyse and summarise the existing findings regarding to the antitumour effects, toxicity and pharmacokinetics of SSD.

MATERIALS AND METHODS

We collected relevant information published before April 2021 by conducting a search of literature available in various online databases including PubMed, Science Direct, CNKI, Wanfang database and the Chinese Biological Medicine Database. Bupleurum, Bupleuri Radix, saikosaponin, saikosaponin D, tumour, toxicity, and pharmacokinetics were used as the keywords.

RESULTS

The antitumour effects of SSD were multi-targeted and can be realised through various mechanisms, including inhibition of proliferation, invasion, metastasis and angiogenesis, as well as induction of cell apoptosis, autophagy, and differentiation. The toxicological effects of SSD mainly included hepatotoxicity, neurotoxicity, haemolysis and cardiotoxicity. Pharmacokinetic studies demonstrated that SSD had the potential to alter the pharmacokinetics of some drugs for its influence on CYPs and P-gp, and the oral bioavailability and actual pharmacodynamic substances in vivo of SSD are still controversial.

CONCLUSIONS

SSD is a potentially effective and relatively safe natural antitumour substance, but more research is needed, especially in vivo antitumour effects and pharmacokinetics of the compound.

δ-Tocotrienol sensitizes and re-sensitizes ovarian cancer cells to cisplatin via induction of G1 phase cell cycle arrest and ROS/MAPK-mediated apoptosis

OBJECTIVES

Among gynaecologic malignancies, ovarian cancer (OC) represents the leading cause of death for women worldwide. Current OC treatment involves cytoreductive surgery followed by platinum-based chemotherapy, which is associated with severe side effects and development of drug resistance. Therefore, new therapeutic strategies are urgently needed. Herein, we evaluated the anti-tumour effects of Vitamin E-derived δ-tocotrienol (δ-TT) in two human OC cell lines, IGROV-1 and SKOV-3 cells.

MATERIALS AND METHODS

MTT and Trypan blue exclusion assays were used to assess δ-TT cytotoxicity, alone or in combination with other molecules. δ-TT effects on cell cycle, apoptosis, ROS generation and MAPK phosphorylation were investigated by flow cytometry, Western blot and immunofluorescence analyses. The synergism between δ-TT and chemotherapy was evaluated by isobologram analysis.

RESULTS

We demonstrated that δ-TT could induce cell cycle block at G1-S phase and mitochondrial apoptosis in OC cell lines. In particular, we found that the proapoptotic activity of δ-TT correlated with mitochondrial ROS production and subsequent JNK and p38 activation. Finally, we observed that the compound was able to synergize with cisplatin, not only enhancing its cytotoxicity in IGROV-1 and SKOV-3 cells but also re-sensitizing IGROV-1/Pt1 cell line to its anti-tumour effects.

CONCLUSIONS

δ-TT triggers G1 phase cell cycle arrest and ROS/MAPK-mediated apoptosis in OC cells and sensitizes them to platinum treatment, thus representing an interesting option for novel chemopreventive/therapeutic strategies for OC.

Nuclear HKII-P-p53 (Ser15) Interaction is a Prognostic Biomarker for Chemoresponsiveness and Glycolytic Regulation in Epithelial Ovarian Cancer

Simple Summary

Hexokinase II (HKII) is a key glycolysis enzyme associated with tumorigenesis, but its molecular mechanism and pathophysiological role in chemoresistant ovarian cancer remain elusive. In this study, we delineate the novel mechanism showing that activated phosphorylated-p53 (P-p53 Ser15) is required for the regulation of HKII intracellular trafficking and metabolic regulation in chemosensitive ovarian cancer, but not in chemoresistant ovarian cancer harboring p53 mutation. We have observed that increased nuclear HKII-P-p53 (Ser15) interaction is likely associated with chemosensitivity and better survival outcomes in epithelial ovarian cell lines, human primary epithelial ovarian cancer cells, and tumor sections. Nuclear HKII-P-p53 (Ser15) interaction may function as a promising prognostic biomarker, enabling prediction of patients with poor prognosis for deciding better clinical strategies.

Abstract

In epithelial ovarian cancer (EOC), carboplatin/cisplatin-induced chemoresistance is a major hurdle to successful treatment. Aerobic glycolysis is a common characteristic of cancer. However, the role of glycolytic metabolism in chemoresistance and its impact on clinical outcomes in EOC are not clear. Here, we show a functional interaction between the key glycolytic enzyme hexokinase II (HKII) and activated P-p53 (Ser15) in the regulation of bioenergetics and chemosensitivity. Using translational approaches with proximity ligation assessment in cancer cells and human EOC tumor sections, we showed that nuclear HKII-P-p53 (Ser15) interaction is increased after chemotherapy, and functions as a determinant of chemoresponsiveness as a prognostic biomarker. We also demonstrated that p53 is required for the intracellular nuclear HKII trafficking in the control of glycolysis in EOC, associated with chemosensitivity. Mechanistically, cisplatin-induced P-p53 (Ser15) recruits HKII and apoptosis-inducing factor (AIF) in chemosensitive EOC cells, enabling their translocation from the mitochondria to the nucleus, eliciting AIF-induced apoptosis. Conversely, in p53-defective chemoresistant EOC cells, HKII and AIF are strongly bound in the mitochondria and, therefore, apoptosis is suppressed. Collectively, our findings implicate nuclear HKII-P-p53(Ser15) interaction in chemosensitivity and could provide an effective clinical strategy as a promising biomarker during platinum-based therapy.

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

Mitochondrial functional and structural impairment is involved in the antitumor activity of δ-tocotrienol in prostate cancer cells

The therapeutic options for castration-resistant prostate cancer (CRPC) are still limited. Natural bioactive compounds were shown to possess pro-death properties in different tumors. We previously reported that δ-tocotrienol (δ-TT) induces apoptosis, paraptosis and autophagy in CRPC cells. Here, we investigated whether δ-TT might exert its activity by impairing mitochondrial functions. We demonstrated that, in PC3 and DU145 cells, δ-TT impairs mitochondrial respiration and structural dynamics. In both cell lines, δ-TT triggers mitochondrial Ca²⁺ and ROS overload. In PC3 cells, both Ca²⁺ and ROS mediate the δ-TT-related anticancer activities (decrease of cell viability, apoptosis, paraptosis, autophagy and mitophagy). As expected, in autophagy-defective DU145 cells, Ca²⁺ overload was involved in δ-TT-induced pro-death effects but not in autophagy and mitophagy. In this cell line, we also demonstrated that ROS overload is not involved in the anticancer activities of δ-TT, supporting a low susceptibility of these cells to ROS-related oxidative stress. Taken together, these data demonstrate that, in CRPC cells, δ-TT triggers cell death by inducing mitochondrial functional and structural impairments, providing novel mechanistic insights in its antitumor activity.

Differential effects of cisplatin on cybrid cells with varying mitochondrial DNA haplogroups

Background

Drug therapy yields different results depending on its recipient population. Cisplatin, a commonly used chemotherapeutic agent, causes different levels of resistance and side effects for different patients, but the mechanism(s) are presently unknown. It has been assumed that this variation is a consequence of differences in nuclear (n) DNA, epigenetics, or some external factor(s). There is accumulating evidence that an individual's mitochondrial (mt) DNA may play a role in their response to medications. Variations within mtDNA can be observed, and an individual's mtDNA can be categorized into haplogroups that are defined by accumulations of single nucleotide polymorphisms (SNPs) representing different ethnic populations.

Methods

The present study was conducted on transmitochondrial cytoplasmic hybrids (cybrids) that possess different maternal-origin haplogroup mtDNA from African (L), Hispanic [A+B], or Asian (D) backgrounds. Cybrids were created by fusing Rho0 ARPE-19 cells (lacking mtDNA) with platelets, which contain numerous mitochondria but no nuclei. These cybrid cells were cultured to passage five, treated with cisplatin, incubated for 48 h, then analyzed for cell metabolic activity (tetrazolium dye (MTT) assay), mitochondrial membrane potential (JC-1 assay), cytotoxicity (lactate dehydrogenase (LDH) assay), and gene expression levels for ALK, BRCA1, EGFR, and ERBB2/HER2.

Results

Results indicated that untreated cybrids with varying mtDNA haplogroups had similar relative metabolic activity before cisplatin treatment. When treated with cisplatin, (1) the decline in metabolic activity was greatest in L (27.4%, p < 0.012) < D (24.86%, p = 0.0001) and [A+B] cybrids (24.67%, p = 0.0285) compared to untreated cybrids; (2) mitochondrial membrane potential remained unchanged in all cybrids (3) LDH production varied between cybrids (L >[A+B], p = 0.0270). (4) The expression levels decreased for ALK in L (p < 0.0001) and [A+B] (p = 0.0001) cybrids but not in D cybrids (p = 0.285); and decreased for EGFR in [A+B] cybrids (p = 0.0246) compared to untreated cybrids.

Conclusion

Our findings suggest that an individual's mtDNA background may be associated with variations in their response to cisplatin treatment, thereby affecting the efficiency and the severity of side effects from the treatment.

Saikosaponin D Inhibits Proliferation and Promotes Apoptosis Through Activation of MKK4-JNK Signaling Pathway in Pancreatic Cancer Cells

Introduction

Pancreatic cancer remains one of the most lethal malignancies and has few treatment options. Saikosaponin D (SSD), a major bioactive triterpene saponin isolated from Bupleurum chinense, has been reported to exert cytotoxicity properties toward many cancer cells. However, the effects of SSD on pancreatic cancer have been little scrutinized.

Methods

Here, we investigated the effect of SSD on the proliferation and apoptosis of human pancreatic cancer BxPC3 and PANC1 cells and the mouse pancreatic cancer cell line Pan02. Cell viability was determined by MTT assays and cell apoptosis analyzed by DAPI staining and flow cytometry. Expression levels of apoptosis-regulating markers and activity of the MKK4–JNK signaling pathway were determined by Western blotting. The inhibitor SP600125 was applied to confirm the role of the JNK pathway in SSD efficiency.

Results

SSD significantly inhibited the proliferation of BxPC3, PANC1, and Pan02 cells in a concentration- and time-dependent manner. Flow-cytometry analysis indicated obvious apoptosis induction after SSD exposure. Furthermore, SSD significantly triggered cleavage of caspase 3 and caspase 9 proteins and increased the expression of FoxO3a. In addition, activity of the MKK4–JNK pathway was dramatically increased after treatment with SSD in BxPC3 cells. SSD obviously stimulated phosphorylation of JNK, cJun, and SEK1/MKK4 proteins within 30 minutes. The addition of SP600125 blocked the activation of SSD on the MKK4–JNK regulatory pathway and reversed the effects of SSD on proliferation inhibition and apoptosis induction in BxPC3 cells.

Conclusion

These results revealed that SSD was capable of suppressing tumor growth and promoting apoptosis of pancreatic cancer cells via targeting the MKK4–JNK signaling pathway, indicating the possibility of further developing SSD as a potential therapeutic candidate for pancreatic cancer.

Saikosaponin D inhibits proliferation and induces apoptosis of non-small cell lung cancer cells by inhibiting the STAT3 pathway

OBJECTIVE

To study the effects of saikosaponin D (SSD) on proliferation and apoptosis in human non-small cell lung cancer cell lines, and to explore underlying mechanisms.

METHODS

Following treatment with saikosaponin D, A549 and H1299 cells were assessed for anti-proliferation effects using cell cycle kit-8 assays, changes in nuclear morphology using 4',6-diamidino-2-phenylindole (DAPI) staining, and cell apoptosis using annexin V/propidium iodide double staining. Proliferation- and apoptosis-related proteins were detected by immunoblotting.

RESULTS

Saikosaponin D had dose-dependent inhibitory effects on A549 cells (IC₅₀, 3.57 µM) and H1299 cells (IC₅₀, 8.46 µM). DAPI staining revealed decreased cell numbers, and most H1299 cells became round after treatment with 20 µM saikosaponin D. As saikosaponin D concentration increased, the proportions of cells in G0/G1 phase, and cells undergoing apoptosis, increased. Levels of phosphorylated p44/42 and signal transducer and activator of transcription (STAT)3 were significantly downregulated in both cell lines, while total STAT3 levels were not significantly affected. The cleaved form of caspase 3 was significantly upregulated.

CONCLUSIONS

Saikosaponin D inhibits proliferation, inducing cell cycle arrest and apoptosis, in lung cancer cells in a dose-dependent manner, possibly through inhibition of STAT3 phosphorylation and activation of caspase 3.

Saikosaponin D: A potential therapeutic drug for osteoarthritis

Osteoarthritis is a degenerative joint disease. Currently, no effective therapeutic exists for osteoarthritis in the clinic setting. Inflammatory response and autophagy are key players in the occurrence and prognosis of osteoarthritis. In recent years, the regulation of inflammation and autophagy signal pathway has been touted as a potential treatment course for osteoarthritis. Saikosaponin D has anti-inflammatory and induces autophagy effects via inhibiting the nuclear transcription factor-κB, mTOR signaling pathways. Here in the report, we analyze and summarize recent evidences pertaining to the relationship between Saikosaponin and osteoarthritis. Published studies were scoured for in research databases, such as PubMed and Scopus with the keywords Saikosaponin and osteoarthritis. Phosphatidylinositol 3-kinase (PI3k)/Akt/mTOR signaling pathway is an important autophagy modulator, and can regulate chondrocytic autophagy, inflammation, and apoptosis. Saikosaponin D alleviates inflammation and regulates autophagy by inhibiting the PI3k/Akt/mTOR signaling pathway. Saikosaponin D could be a potential therapeutic drug for osteoarthritis.

Prognostic impact of Dynamin related protein 1 (Drp1) in epithelial ovarian cancer

BACKGROUND

The mitochondrial fission protein, Dynamin related protein 1 (Drp1), and its upstream protein calcium/calmodulin-dependent protein kinase I (CaMKI) play a critical role in chemoresistance in ovarian cancer (OVCA). Thus, we examined the expression of Drp1, CaMKI and their phosphorylated forms and their prognostic impact in epithelial OVCA patients.

METHODS

Expression analysis was performed by immunohistochemistry (IHC) of paraffin-embedded tumor samples from 49 patients with epithelial OVCA. Staining intensity and the percentage of positively stained tumor cells were used to calculate an immunoreactive score (IRS) of 0-12. The expression scores calculated were correlated with clinicopathological parameters and patient survival.

RESULTS

High immunoreactivity of phospho-Drp1Ser637 was significantly correlated with high-grade serous carcinoma (HGSC) (p = 0.034), residual postoperative tumor of > 1 cm (p = 0.006), and non-responders to adjuvant chemotherapy (p = 0.007), whereas high expression of CaMKI was significantly correlated with stage III/IV [International Federation of Gynecologists and Obstetricians (FIGO)] (p = 0.011) and platinum-resistant recurrence (p = 0.030). ROC curve analysis showed that Drp1, phospho-Drp1Ser637 and CaMKI could significantly detect tumor progression with 0.710, 0.779, and 0.686 of area under the curve (AUC), respectively. The Kaplan-Meier survival curve showed that patients with high Drp1, phospho-Drp1Ser637 and CaMKI levels had significantly poorer progression free survival (PFS) (p = 0.003, p < 0.001 and p = 0.017, respectively). Using multivariate analyses, phospho-Drp1Ser637 was significantly associated with PFS [p = 0.043, hazard ratio (HR) 3.151, 95% confidence interval (CI) 1.039-9.561].

CONCLUSIONS

Drp1 and CaMKI are novel potential candidates for the detection and prognosis of epithelial OVCA and as such further studies should be performed to exploit their therapeutic significance.

Saikosaponin D inhibits autophagosome‑lysosome fusion and induces autophagy‑independent apoptosis in MDA‑MB‑231 breast cancer cells

The present study aimed to explore the effect of Saikosaponin D (SSD) and its underlying mechanism on apoptosis and autophagy in human breast cancer MDA‑MB‑231 cells. MTT assay, flow cytometry, western blotting and confocal fluorescence microscopy detection were employed. SSD, a kind of triterpenoid saponins extracted from Radix bupleuri, has been demonstrated to have the effects of anti‑inflammatory, antioxidative and anticancer effects and can regulate autophagy. The present study revealed that SSD induced apoptosis through the activation of the p38 mitogen‑activated protein kinase (MAPK) signaling pathway in human breast cancer MDA‑MB‑231 cells. The administration of SSD promoted the phosphorylation/activation of p38 MAPK in MDA‑MB‑231 cells, whereas pretreatment with SB203580, an effective p38 MAPK inhibitor, attenuated SSD‑mediated apoptosis, the cleavage of PARP and the activation of caspase‑3. In addition, SSD blocked autophagic degradation by inhibiting autolysosome formation, resulting in the accumulation of autophagosomes. Mechanistically, the results of the present study revealed that SSD inhibited the formation of autophagosomes by inhibiting autophagosome‑lysosome fusion, rather than by damaging lysosome function. Furthermore, blocking autophagy degradation was not associated with SSD‑mediated apoptosis. The genetic knockdown of autophagy‑related protein 5 markedly reduced SSD‑mediated LC3B‑II accumulation; however, it did not affect the SSD‑mediated phosphorylation/activation of p38, cleavage of PARP, activation of caspase‑3 or apoptosis. In conclusion, the findings of the present study suggest that SSD may induce apoptosis and block autophagic degradation, which provides further evidence of the association between the inhibition of autophagic degradation and cell death.

MiR-153-5p Enhances the Sensitivity of Triple-Negative Breast Cancer Cells to Paclitaxel by Inducing G2M Phase Arrest

Background

Paclitaxel (PTX) resistance is a main obstacle for the treatment of triple-negative breast cancers (TNBC). Evidences have shown that miR-153-5p could induce the apoptosis of breast cancer cells. Thus, this study aimed to investigate the effect of miR-153-5p on PTX-resistance TNBC cells.

Methods

Cell Counting Kit-8, flow cytometry and wound healing assays were used to detect the viability, apoptosis and migration of MDA-MB-231/PTX cells, respectively. The luciferase reporter assay was used to explore the potential binding targets of miR-153-5p. The expressions of CDK1, cyclin B1 and p-Akt in MDA-MB-231/PTX cells were detected with Western blot. In vivo animal study was performed finally.

Results

In this study, the inhibitory effects of PTX on the proliferation and migration of MDA-MB-231/PTX cells were significantly enhanced following transfection with miR-153-5p. In addition, overexpression of miR-153-5p markedly enhanced the pro-apoptotic effect of PTX on MDA-MB-231/PTX cells. Luciferase reporter assay validated that cyclin-dependent kinase 1 (CDK1) was a potential binding target of miR-153-5p. Moreover, overexpression of miR-153-5p prominently increased PTX-induced cell cycle arrest at G2/M phase in MDA-MB-231/PTX cells via downregulation of CDK1, cyclin B1 and p-Akt. In vivo experiments confirmed that overexpression of miR-153-5p notably enhanced PTX sensitivity in MDA-MB-231/PTX xenograft model.

Conclusion

We found that overexpression of miR-153-5p could reverse PTX resistance in PTX-resistant TNBC cells via inducing G2/M phase arrest, indicating that miR‑153-5p may be a promising agent for patients with PTX-resistant TNBC.

Links between cancer metabolism and cisplatin resistance

Cisplatin is one of the most potent and widely used chemotherapeutic agent in the treatment of several solid tumors, despite the high toxicity and the frequent relapse of patients due to the onset of drug resistance. Resistance to chemotherapeutic agents, either intrinsic or acquired, is currently one of the major problems in oncology. Thus, understanding the biology of chemoresistance is fundamental in order to overcome this challenge and to improve the survival rate of patients. Studies over the last 30 decades have underlined how resistance is a multifactorial phenomenon not yet completely understood. Recently, tumor metabolism has gained a lot of interest in the context of chemoresistance; accumulating evidence suggests that the rearrangements of the principal metabolic pathways within cells, contributes to the sensitivity of tumor to the drug treatment. In this review, the principal metabolic alterations associated with cisplatin resistance are highlighted. Improving the knowledge of the influence of metabolism on cisplatin response is fundamental to identify new possible metabolic targets useful for combinatory treatments, in order to overcome cisplatin resistance.

Mitochondrial Dysfunction at the Center of Cancer Therapy

Significance: Mitochondria undergo constant morphological changes through fusion, fission, and mitophagy. As the key organelle in cells, mitochondria are responsible for numerous essential cellular functions such as metabolism, regulation of calcium (Ca²⁺), generation of reactive oxygen species, and initiation of apoptosis. Unsurprisingly, mitochondrial dysfunctions underlie many pathologies including cancer. Recent Advances: Currently, the gold standard for cancer treatment is chemotherapy, radiation, and surgery. However, the efficacy of these treatments varies across different cancer cells. It has been suggested that mitochondria may be at the center of these diverse responses. In the past decade, significant advances have been made in understanding distinct types of mitochondrial dysfunctions in cancer. Through investigations of underlying mechanisms, more effective treatment options are developed. Critical Issues: We summarize various mitochondria dysfunctions in cancer progression that have led to the development of therapeutic options. Current mitochondrial-targeted therapies and challenges are discussed. Future Directions: To address the "root" of cancer, utilization of mitochondrial-targeted therapy to target cancer stem cells may be valuable. Investigation of other areas such as mitochondrial trafficking may offer new insights into cancer therapy. Moreover, common antibiotics could be explored as mitocans, and synthetic lethality screens can be utilized to overcome the plasticity of cancer cells.

The role of PPM1D in cancer and advances in studies of its inhibitors

A greater understanding of factors causing cancer initiation, progression and evolution is of paramount importance. Among them, the serine/threonine phosphatase PPM1D, also referred to as wild-type p53-induced phosphatase 1 (Wip1) or protein phosphatase 2C delta (PP2Cδ), is emerging as an important oncoprotein due to its negative regulation on a number of crucial cancer suppressor pathways. Initially identified as a p53-regulated gene, PPM1D has been afterwards found amplified and more recently mutated in many human cancers such as breast cancer. The latest progress in this field further reveals that selective inhibition of PPM1D to delay tumor onset or reduce tumor burden represents a promising anti-cancer strategy. Here, we review the advances in the studies of the PPM1D activity and its relevance to various cancers, and recent progress in development of PPM1D inhibitors and discuss their potential application in cancer therapy. Consecutive research on PPM1D and its relationship with cancer is essential, as it ultimately contributes to the etiology and treatment of cancer.

Integrated Chinese Herbal Medicine Therapy Improves the Survival of Patients With Ovarian Cancer

Background: Ovarian cancer is the seventh most commonly diagnosed malignancy worldwide and has the highest mortality rate among all gynecological cancers. Chinese herbal medicine (CHM) is widely applied in Taiwan and has been used in integrated therapies to treat patients with cancer. Methods: Patients with ovarian cancer who were registered in the Taiwan Registry for Catastrophic Illness Patients Database between 1997 and 2012 were considered for this study. A 1:1 individual matching by age was implemented. A total of 101 CHM users and 101 non-CHM users were involved. A Cox proportional hazard regression model was applied to evaluate the hazard ratio of overall mortality. The Kaplan-Meier method and log-rank test were used to calculate the cumulative incidence of the overall survival rate. Association rule mining and network analysis were used to analyze CHM prescription patterns. Results: CHM users showed a significantly lower risk of overall mortality than nonusers (hazard ratio = 0.45, 95% confidence interval = 0.23-0.91; P = .0256; multivariate Cox proportional hazard model). The cumulative incidence of the overall survival probability was higher for CHM users than for non-CHM users (log-rank test, P = .0009). Association rule mining and network analysis suggested that the main CHM cluster was associated with the usage of Bu-Zhong-Yi-Qi-Tang, Chuan-Xiong, and Xi-Xin, followed by the use of Bai-Shao, Da-Huang, and Di-Huang. Conclusions: CHM, as an adjunctive therapy, may reduce the overall mortality in patients with ovarian cancer. A list of herbal medicines that could potentially be used in future studies and clinical trials has also been provided.

The Effects and Mechanisms by which Saikosaponin-D Enhances the Sensitivity of Human Non-small Cell Lung Cancer Cells to Gefitinib

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR)-sensitive mutations benefit from epidermal growth factor receptor tyrosine kinase inhibitors (EGFR- TKIs). However, drug resistance is a major cause of therapeutic failure. This study examined whether saikosaponin-d (SSD) enhances the anti-tumor effect of gefitinib in NSCLC cells. Cell Counting Kit-8 (CCK-8) was used to determine cell viability. Cell apoptosis was examined by flow cytometry. Signal transducer and activator of transcription (STAT3), phosphor-STAT3 (P-STAT3), and B-cell lymphoma 2 (Bcl-2) were detected by Western blot. An HCC827/GR tumor model was established to observe the effect of combination therapy in vivo. The combination of SSD with gefitinib had an enhanced inhibitory effect by reducing cell viability and inducing cells apoptosis in NSCLC cells. Furthermore, SSD decreased and increased the expression of P-STAT3 and Bcl-2, respectively. Down-regulated STAT3 promoted the sensitivity of lung cancer cells to gefitinib. The results of animal experiments also showed that SSD enhanced the anti-tumor effect of gefitinib. These results indicated that the combination of SSD with gefitinib had an increased antitumor effect in NSCLC cells and that the molecular mechanisms were associated with the inhibition of STAT3/Bcl-2 signaling pathway. Our findings suggest a promising approach for the treatment of NSCLC patients with EGFR-TKI resistance.

Higher expression of calcineurin predicts poor prognosis in unique subtype of ovarian cancer

BACKGROUND

The role of calcineurin/NFAT signaling in ovarian cancer has been unknown. NFAT was significantly overexpressed in ovarian cancer tissues and that overexpression of NFAT was significantly associated with metastasis and poor prognosis on clinical tissue level. To investigate whether NFAT upstream protein, calcineurin (CN), affects the prognosis in various histological subtype of ovarian cancer (OC).

METHODS

The association between CN and clinical features was analyzed in 50 OC patients treated from 2007 to 2012. CN expression was examined using immunohistochemistry. We observed the association of CN expression with the prognosis in these patients.

RESULTS

CN expression was significantly increased in later-stage tumor tissue of serous carcinoma compared with those with early-stage. The expression of CN positively correlated with the serum cancer antigen 125 (CA125) level in ovarian clear-cell carcinoma and the serum alpha-fetoprotein (AFP) level in papillary serous cystadenocarcinoma. Particularly, higher CN expression in tumor tissues significantly correlated with reduced overall survival among patients with serous carcinoma. In addition, the serum cancer antigen 72-4 (CA72-4) level, serum carcinoembryonic antigen (CEA) levels, pathological stage, lymph node metastasis, and chemotherapeutic resistance were identified as significant prognostic factors in ovarian clear-cell carcinoma, serous carcinoma, or papillary serous cystadenocarcinoma.

CONCLUSIONS

CN is upregulated in ovarian cancer tissues with later-stage and that the expression of CN, CA72-4, and CEA was remarkably associated with poor prognosis in unique subtype of ovarian cancer. CN levels may be investigated for use as a prognostic biomarker for risk assessment in unique subtype of OC patients.

Mitochondrial Involvement in Cisplatin Resistance

Cisplatin is one of the worldwide anticancer drugs and, despite its toxicity and frequent recurrence of resistance phenomena, it still remains the only therapeutic option for several tumors. Circumventing cisplatin resistance remains, therefore, a major goal for clinical therapy and represents a challenge for scientific research. Recent studies have brought to light the fundamental role of mitochondria in onset, progression, and metastasis of cancer, as well as its importance in the resistance to chemotherapy. The aim of this review is to give an overview of the current knowledge about the implication of mitochondria in cisplatin resistance and on the recent development in this research field. Recent studies have highlighted the role of mitochondrial DNA alterations in onset of resistance phenomena, being related both to redox balance alterations and to signal crosstalk with the nucleus, allowing a rewiring of cell metabolism. Moreover, an important role of the mitochondrial dynamics in the adaptation mechanism of cancer cells to challenging environment has been revealed. Giving bioenergetic plasticity to tumor cells, mitochondria allow cells to evade death pathways in stressful conditions, including chemotherapy. So far, even if the central role of mitochondria is recognized, little is known about the specific mechanisms implicated in the resistance. Nevertheless, mitochondria appear to be promising pharmacological targets for overcoming cisplatin resistance, but further studies are necessary.

DNA damage response and repair in ovarian cancer: Potential targets for therapeutic strategies

Ovarian cancer is among the most lethal gynecologic malignancies with a poor survival prognosis. The current therapeutic strategies involve surgery and chemotherapy. Research is now focused on novel agents especially those targeting DNA damage response (DDR) pathways. Understanding the DDR process in ovarian cancer necessitates having a detailed knowledge on a series of signaling mediators at the cellular and molecular levels. The complexity of the DDR process in ovarian cancer and how this process works in metastatic conditions is comprehensively reviewed. For evaluating the efficacy of therapeutic agents targeting DNA damage in ovarian cancer, we will discuss the components of this system including DDR sensors, DDR transducers, DDR mediators, and DDR effectors. The constituent pathways include DNA repair machinery, cell cycle checkpoints, and apoptotic pathways. We also will assess the potential of active mediators involved in the DDR process such as therapeutic and prognostic candidates that may facilitate future studies.

Localization of malonyl and acetyl on substituted saikosaponins according to the full-scan mass spectra and the fragmentation of sodium-adduct ions in the positive mode

RATIONALE

Discriminating between aglycone-substituted and saccharide-substituted saikosaponins by liquid chromatography/tandem mass spectrometry (LC/MSⁿ ) is a long-standing issue that is still to be resolved. It is necessary to characterize the two types of substituted saikosaponins taking into consideration the potential significant difference in their bioactivity.

METHODS

Taking the substituents malonyl and acetyl as examples, we developed a MS strategy to discriminate between the aglycone-substituted and saccharide-substituted saikosaponins through comparing their Y₀  - nH₂ O (n = 1-2) ions from the protonated molecules in the full-scan mass spectra and their B ions in the MS² spectra of sodium-adduct molecules in the positive mode.

RESULTS

The deprotonated molecules of the aglycone-substituted saikosaponins presented similar fragmentation patterns to those of saccharide-substituted ones in the negative mode, which could not discriminate whether the substitutes were located on the aglycone or the saccharide. In contrast, the Y₀  - nH₂ O (n = 1-2) ions containing or no substituent were observed respectively in the mass fragmentation of the protonated molecules of aglycone-substituted or saccharide-substituted saikosaponins in the positive mode. In addition, the B ions containing or no substituent were observed respectively in the mass fragmentation of the sodium-adduct molecules of the saccharide-substituted or aglycone-substituted saikosaponins in the positive mode. Two aglycone-malonylated saikosaponins were reported for the first time.

CONCLUSIONS

Whether the substituents were located on the aglycone or the saccharide could be determined according to the Y₀  - nH₂ O (n = 1-2) ions from the protonated molecules in the full-scan mass spectra and the B ions in the MS² spectra of sodium-adduct molecules in the positive mode. Our results have updated the mass fragmentation patterns of substituted saikosaponins, which is helpful for the quality control of pharmaceutical preparations containing saikosaponins. More importantly, this MS strategy should be able to be extended to characterize other substituted saponins of bioactive significance in future studies.

Phytochemicals: Current strategy to sensitize cancer cells to cisplatin

Cisplatin-based chemotherapeutic regimens are the most frequently used adjuvant treatments for many types of cancer. However, the development of chemoresistance to cisplatin results in treatment failure. Despite the significant developments in understanding the mechanisms of cisplatin resistance, effective strategies to enhance the chemosensitivity of cisplatin are lacking. Phytochemicals are naturally occurring plant-based compounds that can augment the anti-cancer activity of cisplatin, with minimal side effects. Notably, some novel phytochemicals, such as curcumin, not only increase the efficacy of cisplatin but also decrease toxicity induced by cisplatin. However, the exact mechanisms underlying this process remain unclear. In this review, we discussed the progress made in utilizing phytochemicals to enhance the anti-cancer efficacy of cisplatin. We also presented some ideal phytochemicals as novel agents for counteracting cisplatin-induced organ damage.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

A comprehensive review and perspectives on pharmacology and toxicology of saikosaponins

BACKGROUND

Radix Bupleuri (RB) has been widely used in Chinese Traditional Medicine for over 2000 years and is currently marketed in China as Chai-Hu-Shu-Gan tablets and Xiao-Yao-Wan tablets. Saikosaponins (SSs, especially SSa, SSc and SSd), as the major bioactive compounds in RB, represent anti-inflammatory, anti-tumor, anti-oxidant, anti-viral and hepatoprotective effects.

PURPOSE

To summarize recent findings regarding to the extraction, detection, biosynthesis, metabolism, pharmacological/toxicological effects of SSs.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "Saikosaponin", "Radix Bupleuri", "Bupleurum" and combinations to include published studies of SSs primarily from 2003 to 2018. Several critical previous studies beyond this period were also included.

RESULTS

354 papers were found and 165 papers were reviewed. SSs have drawn great attention for their anti-inflammation, anti-viral and anti-cancer effects and contradictory roles in the regulation of cell apoptosis, oxidative stress and liver fibrosis. Meanwhile, increased risks of overdose-induced acute or accumulation-related chronic hepatotoxicity of SSs and RB have also been reported. However, underlying mechanisms of SSs bioactivities, the metabolism of SSs and bioactivities of SSs metabolites are largely unknown.

CONCLUSION

This comprehensive review of SSs provides novel insights and perspectives on the limitations of current studies and the importance of metabolism study and the dose-pharmacological/toxic relationship of SSs for the future discovery of SSs-based therapeutic strategies and clinical safe practice.

Saikosaponin D inhibits proliferation of human osteosarcoma cells via the p53 signaling pathway

Saikosaponin D (SSd), the major monomeric terpenoid extracted from Radix bupleuri, a traditional Chinese medicinal herb, exerts various pharmacological properties, including antitumor, anti-inflammatory and antiviral. The present study aimed to investigate the role of SSd in human osteosarcoma (OS) cell growth. In the investigation MTS and EdU assays were applied and flow cytometric analyses of cell cycle and apoptosis were performed. Western blotting and reverse transcription-quantitative polymerase chain reaction analyses were used to explore the underlying mechanisms of SSd on cell cycle transition and p53 signaling. Here, it was demonstrated that SSd administration at 80 µmol/l significantly inhibited 143B and MG-63 proliferation. Furthermore, SSd significantly increased the percentage of 143B and MG-63 cells in G₀-G₁ phase and the number of apoptosis cells compared with the control group. Data further demonstrated that SSd treatment upregulated mRNA and protein levels of tumor protein 53 (p53) and its downstream targets, including p21, p27, B-cell lymphoma-2-like protein 4 and cleaved caspase-3, and downregulated mRNA and protein levels of cyclinD1. The results suggested that SSd was a functional tumor suppressor and inhibited OS proliferation via activation of the p53 signaling pathway and may be used in the treatment of osteosarcoma in future.

Tumor metabolism regulating chemosensitivity in ovarian cancer

Elevated metabolism is a key hallmark of multiple cancers, serving to fulfill high anabolic demands. Ovarian cancer (OVCA) is the fifth leading cause of cancer deaths in women with a high mortality rate (45%). Chemoresistance is a major hurdle for OVCA treatment. Although substantial evidence suggests that metabolic reprogramming contributes to anti-apoptosis and the metastasis of multiple cancers, the link between tumor metabolism and chemoresistance in OVCA remains unknown. While clinical trials targeting metabolic reprogramming alone have been met with limited success, the synergistic effect of inhibiting tumor-specific metabolism with traditional chemotherapy warrants further examination, particularly in OVCA. This review summarizes the role of key glycolytic enzymes and other metabolic synthesis pathways in the progression of cancer and chemoresistance in OVCA. Within this context, mitochondrial dynamics (fission, fusion and cristae structure) are addressed regarding their roles in controlling metabolism and apoptosis, closely associated with chemosensitivity. The roles of multiple key oncogenes (Akt, HIF-1α) and tumor suppressors (p53, PTEN) in metabolic regulation are also described. Next, this review summarizes recent research of metabolism and future direction. Finally, we examine clinical drugs and inhibitors to target glycolytic metabolism, as well as the rationale for such strategies as potential therapeutics to overcome chemoresistant OVCA.

Tumour microenvironment on mitochondrial dynamics and chemoresistance in cancer

Mitochondria, evolutionally acquired symbionts of eukaryotic cells, are essential cytoplasmic organelles. They are structurally dynamic organelles that continually go through fission and fusion processes in response to various stimuli. Tumour tissue is composed of not just cancer cells but also various cell types like fibroblasts, mesenchymal stem and immune cells. Mitochondrial dynamics of cancer cells has been shown to be significantly affected by features of tumour microenvironment such as hypoxia, inflammation and energy deprivation. The interactions of cancer cells with tumour microenvironment like hypoxia give rise to the inter- and intratumoural heterogeneity, causing chemoresistance. In this review, we will focus on the chemoresistance by tumoural heterogeneity in relation to mitochondrial dynamics of cancer cells. Recent findings in molecular mechanisms involved in the control of mitochondrial dynamics as well as the impact of mitochondrial dynamics on drug sensitivity in cancer are highlighted in the current review.