The diarylheptanoid hirsutenone sensitizes chemoresistant ovarian cancer cells to cisplatin via modulation of apoptosis-inducing factor and X-linked inhibitor of apoptosis

The innate effects of plant secondary metabolites in preclusion of gynecologic cancers: Inflammatory response and therapeutic action

Gynecologic cancers can make up the bulk of cancers in both humans and animals. The stage of diagnosis and the type of tumor, its origin, and its spread are a few of the factors that influence how effectively a treatment modality works. Currently, radiotherapy, chemotherapy, and surgery are the major treatment options recommended for the eradication of malignancies. The use of several anti-carcinogenic drugs increases the chance of harmful side effects, and patients might not react to the treatments as expected. The significance of the relationship between inflammation and cancer has been underscored by recent research. As a result, it has been shown that a variety of phytochemicals with beneficial bioactive effects on inflammatory pathways have the potential to act as anti-carcinogenic medications for the treatment of gynecologic cancer. The current paper reviews the significance of inflammatory pathways in gynecologic malignancies and discusses the role of plants-derived secondary metabolites that are useful in the treatment of cancer.

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.

Roles of Medicinal Plants and Constituents in Gynecological Cancer Therapy: Current Literature and Future Directions

Gynecologic cancers, including cervical, primary peritoneal, ovarian, uterine/endometrial, vaginal and vulvar cancers and gestational trophoblastic disease, are characterized by abnormal cell proliferation in female reproductive cells. Due to the variable pathology of these cancers and the lack of appropriate screening tests in developing countries, cancer diagnosis can be reported in advanced stages in most women and this situation adversely affects prognosis and clinical outcomes of illness. For this reason, many researchers in the field of gynecological oncology have carried out many studies. The treatment of various gynecological problems, which cause physical, biological and psychosocial conditions such as fear, shame, blame and anger, has been important throughout the history. Treatment with herbs has become popular nowadays due to the serious side effects of the synthetic drugs used in treatment and the medical and economical problems caused by them. Many scientists have identified various active drug substances through in vivo and in vitro biological activity studies on medicinal plants from the past to the present. While the intrinsic complexity of natural product-based drug discoveries requires highly integrated interdisciplinary approaches, scientific and technological advances and research trends clearly show that natural products will be among the most important new drug sources in the future. In this review, an overview of the studies conducted for the discovery of multitargeted drug molecules in the rational treatment of gynecological cancers is presented.

Akt+ IKKα/β+ Rab5+ Signalosome Mediate the Endosomal Recruitment of Sec61 and Contribute to Cross-Presentation in Bone Marrow Precursor Cells

Cross-presentation in dendritic cells (DC) requires the endosomal relocations of internalized antigens and the endoplasmic reticulum protein Sec61. Despite the fact that endotoxin-containing pathogen and endotoxin-free antigen have different effects on protein kinase B (Akt) and I-kappa B Kinase α/β (IKKα/β) activation, the exact roles of Akt phosphorylation, IKKα or IKKβ activation in endotoxin-containing pathogen-derived cross-presentation are poorly understood. In this study, endotoxin-free ovalbumin supplemented with endotoxin was used as a model pathogen. We investigated the effects of endotoxin-containing pathogen and endotoxin-free antigen on Akt phosphorylation, IKKα/β activation, and explored the mechanisms that the endotoxin-containing pathogen orchestrating the endosomal recruitment of Sec61 of the cross-presentation in bone marrow precursor cells (BMPC). We demonstrated that endotoxin-containing pathogen and endotoxin-free antigen efficiently induced the phosphorylation of Akt-IKKα/β and Akt-IKKα, respectively. Endotoxin-containing pathogen derived Akt+ IKKα/β+ Rab5+ signalosome, together with augmented the recruitment of Sec61 toward endosome, lead to the increased cross-presentation in BMPC. Importantly, the endosomal recruitment of Sec61 was partly mediated by the formation of Akt+ IKKα/β+ signalosome. Thus, these data suggest that Akt+ IKKα/β+ Rab5+ signalosome contribute to endotoxin-containing pathogen-induced the endosomal recruitment of Sec61 and the superior efficacy of cross-presentation in BMPC.

1,7-Bis(4-hydroxyphenyl)-4-hepten-3-one from Betula platyphylla induces apoptosis by suppressing autophagy flux and activating the p38 pathway in lung cancer cells

Betula platyphylla (BP) is frequently administered in the treatment of various human diseases, including cancers. This study was undertaken to investigate the pharmacological function of the active components in BP and the underlying mechanism of its chemotherapeutic effects in human lung cancer cells. We observed that BP extracts and 1,7-bis(4-hydroxyphenyl)-4-hepten-3-one (BE1), one of the components of BP, effectively decreased the cell viability of several lung cancer cell lines. BE1-treated cells exhibited apoptosis induction and cell cycle arrest at the G2/M phase. Further examination demonstrated that BE1 treatment resulted in suppression of autophagy, as evidenced by increased protein expression levels of both LC3 II and p62/SQSTM1. Interestingly, the pharmacological induction of autophagy with rapamycin remarkably reduced the BE1-induced apoptosis, indicating that apoptosis induced by BE1 was associated with autophagy inhibition. Our data also demonstrated that BE1 exposure activated the p38 pathway resulting in regulation of the pro-apoptotic activity. Taken together, we believe that BE1 is a potential anticancer agent for human lung cancer, which exerts its effect by enhancing apoptosis via regulating autophagy and the p38 pathway.

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.

Identification of Chaetocin as a Potent non-ROS-mediated Anticancer Drug Candidate for Gastric Cancer

Chaetocin, a natural product extracted from Chaetomium species, possesses anticancer effects in several kinds of tumors. However, it remains unclear whether the potential indication for chaetocin could also include human gastric cancer. We found here that chaetocin induced caspase-dependent and -independent apoptosis in human gastric cancer cell lines, which greatly depended on BID-mediated AIF translocation. Despite not increasing the intercellular ROS levels in gastric cancer cells, chaetocin did cause a reduction in mitochondrial membrane potential probably through its regulation on the expression of Bcl-2 and BAX. Chaetocin could also induce autophagy in gastric cancer cells; blocking autophagy by chloroquine enhanced the cytotoxicity of chaetocin. Chaetocin was further found to suppress the growth of gastric cancer xenograft in nude mice. Therefore, our study provides first evidence that chaetocin has an anticancer efficacy against gastric cancer and the combined use of chaetocin with autophagy inhibitors may enhance the therapeutic effect for gastric cancer. As chronic and exorbitant ROS levels instigate drug resistance, chaetocin, which eradicates gastric cancer cells without increasing ROS levels, may initiate a new line of non-ROS-mediated anti-tumor strategy.

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.

The Role of Secondary Metabolites on Gynecologic Cancer Therapy: Some Pathways and Mechanisms

Gynecologic cancers are among the most common cancers in humans and animals. Treatment success depends on several factors including stage at diagnosis, tumor type, origin and metastasis. Currently, surgery, chemotherapy, and radiotherapy are preferred in the treatment of these cancers. However, many anticarcinogenic drugs can cause severe adverse effects and also the expected response to treatment may not be obtained. In recent studies, the importance of the relationship between cancer and inflammation has been emphasized. Therefore, several phytochemicals that exhibit beneficial bioactive effects towards inflammatory pathways were proven to have anticarcinogenic potential for gynecologic cancer therapy. This review summarizes the role of inflammatory pathways in gynecologic cancers and effective secondary metabolites for cancer therapy.

The Genus Alnus, A Comprehensive Outline of Its Chemical Constituents and Biological Activities

The genus Alnus (Betulaceae) is comprised of more than 40 species. Many species of this genus have a long history of use in folk medicines. Phytochemical investigations have revealed the presence of diarylheptanoids, polyphenols, flavonoids, terpenoids, steroids and other compounds. Diarylheptanoids, natural products with a 1,7-diphenylheptane structural skeleton, are the dominant constituents in the genus, whose anticancer effect has been brought into focus. Pure compounds and crude extracts from the genus exhibit a wide spectrum of pharmacological activities both in vitro and in vivo. This paper compiles 273 naturally occurring compounds from the genus Alnus along with their structures and pharmacological activities, as reported in 138 references.

Historical and Clinical Experiences of Gene Therapy for Solid Cancers in China

Based on the theoretical and clinical development of modern medicines, gene therapy has been a promising treatment strategy for cancer and other diseases. The practice of gene therapy is nearly 27 years old, since the first authorized gene transfer study took place at the National Institute of Health in 1989. However, gene therapy was not readily adopted worldwide, until recently. Several gene therapy clinical trials have been carried out in China since 1998, and medical research in China has flourished. In this report, we review the history of gene therapy in China, focusing on treatment protocol, the administration cycle, dosage calculation, and the evaluation of therapeutic effects, in order to provide more information for the additional development of this promising treatment strategy.

Safety and Efficacy in Advanced Solid Tumors of a Targeted Nanocomplex Carrying the p53 Gene Used in Combination with Docetaxel: A Phase 1b Study

Loss of p53 suppressor function, through mutations or inactivation of the p53 pathway, occurs in most human cancers. SGT-53 is a liposomal nanocomplex designed for systemic, tumor-targeting delivery of the wt p53 gene. In this nanodelivery system, an anti-transferrin receptor single-chain antibody fragment serves as the targeting moiety. In an initial phase 1 trial in patients with advanced solid tumors, SGT-53 demonstrated tumor-specific targeting, was shown to be well tolerated, and was associated with an antitumor effect in several patients. Our preclinical studies have also demonstrated enhanced antitumor activity with the combination of SGT-53 and docetaxel. Thus, this dose-escalation trial was undertaken to assess the combination of SGT-53 and docetaxel for safety and potential efficacy in 14 advanced cancer patients. Results reveal that the combination of SGT-53 (maximum dose, 3.6 mg DNA/infusion) and docetaxel (75 mg/m(2)/infusion) was well tolerated. Moreover, clinical activity involving 12 evaluable patients was observed. Three of these patients achieved RECIST-verified partial responses with tumor reductions of -47%, -51%, and -79%. Two others had stable disease with significant shrinkage (-25% and -16%). These results support phase 2 testing of SGT-53 in combination with docetaxel.

Hirsutenone Directly Targets PI3K and ERK to Inhibit Adipogenesis in 3T3-L1 Preadipocytes

Adipogenesis is a key driver of the expansion of adipose tissue mass that causes obesity. Hirsutenone (HST) is an active botanical diarylheptanoid present in Alnus species. In this study, we evaluated the effects of HST on adipogenesis, its mechanisms of action and the molecular targets involved. Using Oil Red O staining, we observed that HST dose-dependently suppresses lipid accumulation during adipogenesis in 3T3-L1 preadipocytes, concomitant with a decrease in peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer-binding protein α (C/EBPα) and fatty acid synthase (FAS) protein expression. This inhibitory effect was largely limited to the early stage of adipogenesis, which includes mitotic clonal expansion (MCE), as evidenced by delayed cell cycle entry of preadipocytes from G1 to S phase. Furthermore, the regulation of MCE was accompanied by suppression of phosphatidylinositol 3-kinase (PI3K) and extracellular-regulated kinase (ERK) activity. HST was also shown to bind directly to PI3K and ERK1 in a non-ATP competitive manner. Our results suggest that HST attenuates adipogenesis by directly targeting PI3K and ERK during MCE in 3T3-L1 preadipocytes, underscoring the potential therapeutic application of HST in preventing obesity.

Elevated β-catenin activity contributes to carboplatin resistance in A2780cp ovarian cancer cells

Ovarian cancer is the fifth leading cause of cancer-related mortalities in women. Epithelial ovarian cancer (EOC) represents approximately 90% of all ovarian malignancies. Most EOC patients are diagnosed at advanced stages and current chemotherapy regimens are ineffective against advanced EOC due to the development of chemoresistance. It is important to better understand the molecular mechanisms underlying acquired resistance to effectively manage this disease. In this study, we examined the expression of the Wnt/β-catenin signaling components in the paired cisplatin-sensitive (A2780s) and cisplatin-resistant (A2780cp) EOC cell lines. Our results showed that several negative regulators of Wnt signaling are downregulated, whereas a few Wnt ligands and known Wnt/β-catenin target genes are upregulated in A2780cp cells compared to A2780s cells, suggesting that Wnt/β-catenin signaling is more active in A2780cp cells. Further analysis revealed nuclear localization of β-catenin and higher β-catenin transcriptional activity in A2780cp cells compared to A2780s cells. Finally, we demonstrated that chemical inhibition of β-catenin transcriptional activity by its inhibitor CCT036477 sensitized A2780cp cells to carboplatin, supporting a role for β-catenin in carboplatin resistance in A2780cp cells. In conclusion, our data suggest that increased Wnt/β-catenin signaling activity contributes to carboplatin resistance in A2780cp cells.

Key points of basic theories and clinical practice in rAd-p53 ( Gendicine ™) gene therapy for solid malignant tumors

INTRODUCTION

Wild-type p53 gene is an essential cancer suppressor gene which plays an important role in carcinogenesis and malignant progressions. The p53 gene family participates in almost all the key procedures of cancer biology, such as programmed cell death, angiogenesis, metabolism and epithelial-mesenchymal transition. The mutation or functional defects of the p53 gene family are detected in most of the solid malignant tumors, and the restoration of the p53 gene by adenovirus-mediated gene therapy becomes a promising treatment for cancer patients now.

AREAS COVERED

In the present review, the potential therapeutic effects of recombinant adenovirus p53 rAd-p53 ( Gendicine ™) were reviewed to explore the biological mechanism underlying the adenovirus-mediated p53 gene therapy. Then, the key points of the drug administration were discussed, including the routes of administration, dosage calculation and treatment cycles, based on findings of the preclinical and clinical trials in order to establish a standard treatment for the p53 gene therapy.

EXPERT OPINION

As an important part of the combined therapy for the cancer patients, the adenovirus-mediated p53 gene therapy was blossomed to be a promising treatment strategy. A new evaluation criteria and guideline for the gene therapy is urgently needed for the further clinical practice.

Phytochemicals: a multitargeted approach to gynecologic cancer therapy

Gynecologic cancers constitute the fourth most common cancer type in women. Treatment outcomes are dictated by a multitude of factors, including stage at diagnosis, tissue type, and overall health of the patient. Current therapeutic options include surgery, radiotherapy, and chemotherapy, although significant unmet medical needs remain in regard to side effects and long-term survival. The efficacy of chemotherapy is influenced by cellular events such as the overexpression of oncogenes and downregulation of tumor suppressors, which together determine apoptotic responses. Phytochemicals are a broad class of natural compounds derived from plants, a number of which exhibit useful bioactive effects toward these pathways. High-throughput screening methods, rational modification, and developments in regulatory policies will accelerate the development of novel therapeutics based on these compounds, which will likely improve overall survival and quality of life for patients.