Tanshinone IIA increases protein expression levels of PERK, ATF6, IRE1α, CHOP, caspase‑3 and caspase‑12 in pancreatic cancer BxPC‑3 cell‑derived xenograft tumors

Phytochemical-mediated modulation of autophagy and endoplasmic reticulum stress as a cancer therapeutic approach

Autophagy and endoplasmic reticulum (ER) stress are conserved processes that generally promote survival, but can induce cell death when physiological thresholds are crossed. The pro-survival aspects of these processes are exploited by cancer cells for tumor development and progression. Therefore, anticancer drugs targeting autophagy or ER stress to induce cell death and/or block the pro-survival aspects are being investigated extensively. Consistently, several phytochemicals have been reported to exert their anticancer effects by modulating autophagy and/or ER stress. Various phytochemicals (e.g., celastrol, curcumin, emodin, resveratrol, among others) activate the unfolded protein response to induce ER stress-mediated apoptosis through different pathways. Similarly, various phytochemicals induce autophagy through different mechanisms (namely mechanistic target of Rapamycin [mTOR] inhibition). However, phytochemical-induced autophagy can function either as a cytoprotective mechanism or as programmed cell death type II. Interestingly, at times, the same phytochemical (e.g., 6-gingerol, emodin, shikonin, among others) can induce cytoprotective autophagy or programmed cell death type II depending on cellular contexts, such as cancer type. Although there is well-documented mechanistic interplay between autophagy and ER stress, only a one-way modulation was noted with some phytochemicals (carnosol, capsaicin, cryptotanshinone, guangsangon E, kaempferol, and δ-tocotrienol): ER stress-dependent autophagy. Plant extracts are sources of potent phytochemicals and while numerous phytochemicals have been investigated in preclinical and clinical studies, the search for novel phytochemicals with anticancer effects is ongoing from plant extracts used in traditional medicine (e.g., Origanum majorana). Nonetheless, the clinical translation of phytochemicals, a promising avenue for cancer therapeutics, is hindered by several limitations that need to be addressed in future studies.

Study on the Antitumor Mechanism of Tanshinone IIA In Vivo and In Vitro through the Regulation of PERK-ATF4-HSPA5 Pathway-Mediated Ferroptosis

As a traditional Chinese medicine, Salvia miltiorrhiza Bunge was first recorded in the Shennong Materia Medica Classic and is widely used to treat "the accumulation of symptoms and masses". The main active ingredient of Salvia miltiorrhiza Bunge, Tanshinone IIA (TIIA), has shown anti-inflammatory, antitumor, antifibrosis, antibacterial, and antioxidative activities, etc. In this study, the results showed that TIIA could inhibit the proliferation and migration of HepG2 cells and downregulate glutathione (GSH) and Glutathione Peroxidase 4 (GPX4) levels; besides, TIIA induced the production of Reactive Oxygen Species (ROS), and upregulated the total iron content. Based on network pharmacology analysis, the antitumor effect of TIIA was found to be focused on the endoplasmic reticulum (ER)-mediated ferroptosis signaling pathway, with protein kinase R (PKR)-like ER kinase (PERK)-activating transcription factor 4 (ATF4)-heat shock 70 kDa protein 5 (HSPA5) as the main pathway. Herein, TIIA showed typical ferroptosis characteristics, and a ferroptosis inhibitor (ferrostatin-1) was used to verify the effect. The antitumor effects of TIIA, occurring through the inhibition of the PERK-ATF4-HSPA5 pathway, were further observed in vivo as significantly inhibited tumor growth and the improved pathological morphology of tumor tissue in H22-bearing mice. In summary, the antitumor mechanism of TIIA might be related to the downregulation of the activation of PERK-ATF4-HSPA5 pathway-mediated ferroptosis.

Effect of Danshen for improving clinical outcomes in patients with bladder cancer: a retrospective, population-based study

Introduction: Traditional Chinese Medicine (TCM) has a broad application in healthcare, with Danshen being a notable herb used in Eastern medicine for cancer treatment. This study aims to explore the relationship between Danshen use and cardiovascular risks among bladder cancer patients. Methods: Patients were selected based on a confirmed diagnosis of bladder cancer with specific inclusion and exclusion criteria to control for certain comorbidities and treatments. Utilizing Taiwan's National Health Insurance data from 2003 to 2013, this retrospective, population-based study identified three groups: 525 patients treated with Danshen, 6,419 patients not treated with TCM, and 4,356 patients treated with TCM but not with Danshen. The Cox proportional hazard model was employed to estimate the risks of Major Adverse Cardiovascular Events (MACE) and mortality while accounting for various confounders. Results: The overall incidence of MACEs was significantly lower in the Danshen group (5%) compared to the TCM (8.1%) and non-TCM (9.9%) groups (p < 0.001). The Cox model revealed that bladder cancer patients treated with Danshen had the lowest risk of MACE (adjusted hazard ratio, 0.56; 95% confidence interval, 0.38-0.84) and all-cause mortality (adjusted hazard ratio, 0.60; 95% confidence interval, 0.44-0.82). Discussion: The findings suggest that Danshen reduces the risk of MACE and all-cause mortality in bladder cancer patients, highlighting its potential benefits. This underpins the necessity for further research to substantiate the cardiovascular benefits of Danshen in bladder cancer patients and potentially broaden its application in oncology healthcare.

The mechanisms of tanshinone in the treatment of tumors

Tanshinone is a lipophilic compound that is present in traditional Chinese medicine and is derived from the roots of Salvia miltiorrhiza (Danshen). It has been proven to be highly effective in combating tumors in various parts of the body, including liver carcinoma, gastric cancer, ovarian cancer, cervix carcinoma, breast cancer, colon cancer, and prostate cancer. Tanshinone can efficiently prevent the reproduction of cancerous cells, induce cell death, and inhibit the spread of cancerous cells, which are mainly involved in the PI3K/Akt signaling pathway, NF-κB pathway, Bcl-2 family, Caspase cascades, MicroRNA, MAPK signaling pathway, p21, STAT3 pathway, miR30b-P53-PTPN11/SHP2 axis, β-catenin, and Skp2. However, the properties and mechanisms of tanshinone's anti-tumor effects remain unclear currently. Thus, this study aims to review the research progress on tumor prevention and mechanisms of tanshinone to gain new perspectives for further development and clinical application of tanshinone.

Tanshinone IIA targeting cell signaling pathways: a plausible paradigm for cancer therapy

Natural compounds originating from plants offer a wide range of pharmacological potential and have traditionally been used to treat a wide range of diseases including cancer. Tanshinone IIA (Tan IIA), a bioactive molecule found in the roots of the Traditional Chinese Medicine (TCM) herb Salvia miltiorrhiza, has been shown to have remarkable anticancer properties through several mechanisms, such as inhibition of tumor cell growth and proliferation, metastasis, invasion, and angiogenesis, as well as induction of apoptosis and autophagy. It has demonstrated excellent anticancer efficacy against cell lines from breast, cervical, colorectal, gastric, lung, and prostate cancer by modulating multiple signaling pathways including PI3K/Akt, JAK/STAT, IGF-1R, and Bcl-2-Caspase pathways. This review focuses on the role of Tan IIA in the treatment of various cancers, as well as the underlying molecular mechanisms.

Tanshinone IIA inhibits endometrial carcinoma growth through the MAPK/ERK/TRIB3 pathway

Endometrial carcinoma is the most common gynecological tumor in developed countries. Tanshinone IIA is a traditional herbal medicine which is to treat cardiovascular disease and has been shown to have various biological effects, such as anti-inflammatory, antioxidative and antitumor activities. However, there has been no study about the effect of tanshinone IIA on endometrial carcinoma. Thus, the aim of this study was to determine the antitumor activity of tanshinone IIA against endometrial carcinoma and investigate the associated molecular mechanism. We demonstrated that tanshinone IIA induced cell apoptosis and inhibited migration. We further demonstrated that tanshinone IIA activated the intrinsic (mitochondrial) apoptotic pathway. Mechanistically, tanshinone IIA induced apoptosis by upregulating TRIB3 expression and inhibiting the MAPK/ERK signaling pathway. In addition, knockdown of TRIB3 with an shRNA lentivirus accelerated proliferation and attenuated inhibition mediated by tanshinone IIA. Finally, we further demonstrated that tanshinone IIA inhibited tumor growth by inducing TRIB3 expression in vivo. In conclusion, these findings suggest that tanshinone IIA has a significant antitumor effect by inducing apoptosis and may be used as a drug for the treatment of endometrial carcinoma.

Tanshinone IIA (TSIIA) represses the progression of non-small cell lung cancer by the circ_0020123/miR-1299/HMGB3 pathway

Tanshinone IIA (TSIIA), a multi-pharmaceutical compound, has been demonstrated to have anti-tumor properties. This study explores the potential regulatory mechanism of TSIIA on non-small cell lung cancer (NSCLC) progression. The cytotoxicity of TSIIA was evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) and LDH (lactate dehydrogenase) assays. Expression levels of circ_0020123 (hsa_circ_0020123) and microRNA-1299 (miR-1299) were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, migration, invasion, and apoptosis were analyzed by MTT, colony formation, transwell, wound-healing, or flow cytometry assays. The relationship between miR-1299 and circ_0020123 or HMGB3 (high mobility group box 3) was verified by the dual-luciferase reporter and/or RNA immunoprecipitation (RIP) assays. Protein level of HMGB3 was measured by western blotting. The relationship between TSIIA and circ_0020123 was confirmed by xenograft assay. TSIIA reduced xenograft tumor growth in vivo and repressed proliferation, migration, invasion, and facilitated apoptosis of NSCLC cells in vitro. TSIIA reduced circ_0020123 and HMGB3 expression, whereas elevated miR-1299 expression in NSCLC cells. Circ_0020123 knockdown enhanced the repressive influence of TSIIA treatment on the malignancy of NSCLC cells in vitro and in vivo. Circ_0020123 sponged miR-1299 to regulate HMGB3 expression under TSIIA treatment. MiR-1299 inhibitor reversed circ_0020123 knockdown-mediated influence on malignant behaviors of NSCLC cells under TSIIA treatment. HMGB3 elevation offset the suppressive impact of miR-1299 mimic on the malignancy of NSCLC cells under TSIIA treatment. TSIIA curbed NSCLC progression by the circ_0020123/miR-1299/HMGB3 axis, manifesting that the TSIIA/circ_0020123/miR-1299/HMG regulatory network might be a potential treatment strategy for NSCLC.

Advances on Natural Abietane, Labdane and Clerodane Diterpenes as Anti-Cancer Agents: Sources and Mechanisms of Action

Extensive research over the past decades has identified numerous phytochemicals that could represent an important source of anti-cancer compounds. There is an immediate need for less toxic and more effective preventive and therapeutic strategies for the treatment of cancer. Natural compounds are considered suitable candidates for the development of new anti-cancer drugs due to their pleiotropic actions on target events with multiple manners. This comprehensive review highlighted the most relevant findings achieved in the screening of phytochemicals for anticancer drug development, particularly focused on a promising class of phytochemicals such as diterpenes with abietane, clerodane, and labdane skeleton. The chemical structure of these compounds, their main natural sources, and mechanisms of action were critically discussed.

Apoptosis Induction Associated with Enhanced ER Stress Response and Up-Regulation of c-Jun/p38 MAPK Proteins in Human Cervical Cancer Cells by Colocasia esculenta var. aquatilis Hassk Extract

Colocasia esculenta var. Aquatilis Hassk, elephant ear (CF-EE) has been widely used as traditional food and medicine. It also shows other therapeutic properties, such as antimicrobial and anti-cancer activity. In this study, we aim to investigate the effect of CF-EE extract on apoptosis induction associated with ER stress in cervical cancer HeLa cells. Cell viability was determined by MTT assay. Assessments of nuclear morphological changes, mitochondrial membrane potential, and intracellular reactive oxygen species (ROS) production were conducted by hoeshst33342, JC-1, and DCFH-DA fluorescence staining, respectively. Sub-G1 DNA content was analyzed by flow cytometry, and protein expression was determined by Western blotting. The results demonstrate that CF-EE extract suppressed HeLa cell growth and induced nuclear condensation and apoptotic bodies. There was also a loss of mitochondrial membrane potential and increased apoptosis marker protein expression, including Bax, cleaved-caspase-7, and cleaved-PARP. In addition, the results show that CF-EE extract induced ROS, increased ER stress proteins (GRP78 and CHOP), enhanced p38 and c-Jun phosphorylation, and inhibited Akt expression in HeLa cells. In summary, CF-EE extract induced apoptotic cell death-associated ROS-induced ER stress and the MAPK/AKT signaling pathway. Therefore, CF-EE extract has anticancer therapeutic potential for cervical cancer treatment in the future.

Salviolone from Salvia miltiorrhiza Roots Impairs Cell Cycle Progression, Colony Formation, and Metalloproteinase-2 Activity in A375 Melanoma Cells: Involvement of P21(Cip1/Waf1) Expression and STAT3 Phosphorylation

Melanoma is a highly malignant solid tumor characterized by an elevated growth and propagation rate. Since, often, melanoma treatment cannot prevent recurrences and the appearance of metastasis, new anti-melanoma agents need to be discovered. Salvia miltiorrhiza roots are a source of diterpenoid derivatives, natural compounds with several biological activities, including antiproliferative and anticancer effects. Seven diterpenoid derivatives were purified from S. miltiorrhiza roots and identified by NMR and MS analysis. Tanshinone IIA and cryptotanshinone were detected as the main components of S. miltiorrhiza root ethanol extract. Although their antitumor activity is already known, they have been confirmed to induce a reduction in A375 and MeWo melanoma cell growth. Likewise, salviolone has been shown to impair the viability of melanoma cells without affecting the growth of normal melanocytes. The underlying anticancer activity of salviolone has been investigated and compared to that of cryptotanshinone in A375 cells, showing an increased P21 protein expression in a P53-dependent manner. In that way, salviolone, even more than cryptotanshinone, displays a multitarget effect on cell-cycle-related proteins. Besides, it modulates the phosphorylation level of the signal transducer and activator of transcription (STAT)3. Unexpectedly, salviolone and cryptotanshinone induce sustained activation of the extracellular signal-regulated kinases (ERK)1/2 and the protein kinase B (Akt). However, the blockage of ERK1/2 or Akt activities suggests that kinase activation does not hinder their ability to inhibit A375 cell growth. Finally, salviolone and cryptotanshinone inhibit to a comparable extent some crucial malignancy features of A375 melanoma cells, such as colony formation in soft agar and metalloproteinase-2 activity. In conclusion, it has been shown for the first time that salviolone, harboring a different molecular structure than tanshinone IIA and cryptotanshinone, exhibits a pleiotropic effect against melanoma by hampering cell cycle progression, STAT3 signaling, and malignant phenotype of A375 melanoma cells.

A pharmacognostic approach for mitigating pancreatic cancer: emphasis on herbal extracts and phytoconstituents

Background

Pancreatic cancer is studied as one of the most lethal cancers with currently no control of its lethality, mainly due to its late diagnosis and lack of foolproof treatment processes. Despite continuous efforts being made in looking for therapies to deal with cancer, it keeps on being a labyrinth for the researchers. Efforts like discovering new treatment options, repurposing existing drugs, are continuously made to deal with this cancer.

Main body

With the urge to get answers and the fact that nature has all roots of therapeutics, efforts are made in the direction of finding those answers for providing ministrations for pancreatic cancer from plant products. Plant products are used as treatment options either directly in the form of extracts or an alternative to them is individual phytochemicals that are either isolated from the plants or are commercially synthesized for various purposes. In this review, we put forward such pharmacognostic initiatives made in combating pancreatic cancer, focusing mainly on plant extracts and various phytochemicals; along with the mechanisms which they triggered to fulfill the need for cytotoxicity to pancreatic cancer cells (in vitro and in vivo).

Conclusion

This study will thus provide insights into new combination therapy that can be used and also give a clue on which plant product and phytoconstituent can be used in dealing with pancreatic cancer.

Graphical abstract

Recent Research Progress (2015-2021) and Perspectives on the Pharmacological Effects and Mechanisms of Tanshinone IIA

Tanshinone IIA (Tan IIA) is an important characteristic component and active ingredient in Salvia miltiorrhiza, and its various aspects of research are constantly being updated to explore its potential application. In this paper, we review the recent progress on pharmacological activities and the therapeutic mechanisms of Tan IIA according to literature during the years 2015-2021. Tan IIA shows multiple pharmacological effects, including anticarcinogenic, cardiovascular, nervous, respiratory, urinary, digestive, and motor systems activities. Tan IIA modulates multi-targets referring to Nrf2, AMPK, GSK-3β, EGFR, CD36, HO-1, NOX4, Beclin-1, TLR4, TNF-α, STAT3, Caspase-3, and bcl-2 proteins and multi-pathways including NF-κB, SIRT1/PGC1α, MAPK, SREBP-2/Pcsk9, Wnt, PI3K/Akt/mTOR pathways, TGF-β/Smad and Hippo/YAP pathways, etc., which directly or indirectly influence disease course. Further, with the reported targets, the potential effects and possible mechanisms of Tan IIA against diseases were predicted by bioinformatic analysis. This paper provides new insights into the therapeutic effects and mechanisms of Tan IIA against diseases.

The Role of miRNAs during Endoplasmic Reticulum Stress Induced Apoptosis in Digestive Cancer

Digestive cancer is one of the leading causes of cancer mortality in the world. Despite a number of studies being conducted, the exact mechanism for treating digestive cancer has not yet been fully understood. To survive, digestive cancer cells are subjected to various internal and external adverse factors, such as hypoxia, nutritional deficiencies or drug toxicity, resulting in accumulation of misfolded and unfolded protein in endoplasmic reticulum (ER) lumen further leading to ER stress and the unfolded protein response (UPR). During the last years, studies on the relationship between ER stress and microRNAs (miRNAs) has burst on the scene. miRNAs are non-coding RNAs with a length of 21~22nucleotides involved in post-transcriptional regulation of gene expression, which could be regarded as oncomiRs (tumor inducers) and tumor suppressors regulating cancer cell proliferation, invasion, and apoptosis by differently affecting the expression of genes related to cancer cell signaling. Therefore, investigating the interaction between ER stress and miRNAs is crucial for developing effective cancer treatment and prevention strategies. In this review, we mainly discuss miRNAs focusing on its regulation, role in ER stress induced apoptosis in Digestive cancer, expound the underlying mechanism, thus provides a theoretical foundation for finding new therapeutic targets of digestive cancer.

Dihydroisotanshinone I as a Treatment Option for Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinomas (HNSCCs) are the most common cancers of the head and neck, and their prevalence is rapidly increasing. HNSCCs present a clinical challenge because of their high recurrence rate, therapeutic resistance to radiation and chemotherapy drugs, and adverse effects. Hence, traditional Chinese herbal treatment may be advantageous to therapeutic strategies for HNSCCs. Danshen (Salvia miltiorrhiza), a well-known Chinese herb, has been extensively applied in treatments for various diseases, including cancer, because of its high degree of safety and low rate of adverse effects despite its unclear mechanism. Thus, we aimed to explore the possible anticancer effects and mechanisms of dihydroisotanshinone I (DT), a compound in danshen (extract from danshen), on HNSCCs. Three HNSCCs cell lines were used for in vitro studies, and a Detroit 562 xenograft mouse model was chosen for in vivo studies. Our in vitro results showed that DT could initiate apoptosis, resulting in cell death, and the p38 signaling partially regulated DT-initiated cell apoptosis in the Detroit 562 model. In the xenograft mouse model, DT reduced tumor size with no obvious adverse effect of hepatotoxicity. The present study suggests that DT is a promising novel candidate for anti-HNSCCs therapy.

Attenuation of Lipopolysaccharide-Induced Acute Lung Injury by Hispolon in Mice, Through Regulating the TLR4/PI3K/Akt/mTOR and Keap1/Nrf2/HO-1 Pathways, and Suppressing Oxidative Stress-Mediated ER Stress-Induced Apoptosis and Autophagy

The anti-inflammatory effect of hispolon has identified it as one of the most important compounds from Sanghuangporus sanghuang. The research objectives were to study this compound using an animal model by lipopolysaccharide (LPS)-induced acute lung injury. Hispolon treatment reduced the production of the pro-inflammatory mediator NO, TNF-α, IL-1β, and IL-6 induced by LPS challenge in the lung tissues, as well as decreasing their histological alterations and protein content. Total cell number was also reduced in the bronchoalveolar lavage fluid (BALF). Moreover, hispolon inhibited iNOS, COX-2 and IκB-α and phosphorylated IKK and MAPK, while increasing catalase, SOD, GPx, TLR4, AKT, HO-1, Nrf-2, Keap1 and PPARγ expression, after LPS challenge. It also regulated apoptosis, ER stress and the autophagy signal transduction pathway. The results of this study show that hispolon regulates LPS-induced ER stress (increasing CHOP, PERK, IRE1, ATF6 and GRP78 protein expression), apoptosis (decreasing caspase-3 and Bax and increasing Bcl-2 expression) and autophagy (reducing LC3 I/II and Beclin-1 expression). This in vivo experimental study suggests that hispolon suppresses the LPS-induced activation of inflammatory pathways, oxidative injury, ER stress, apoptosis and autophagy and has the potential to be used therapeutically in major anterior segment lung diseases.

Mechanism of inositol-requiring enzyme 1-alpha inhibition in endoplasmic reticulum stress and apoptosis in ovarian cancer cells

IRE1α endonuclease is a key regulator of endoplasmic reticulum (ER) stress that controls cell survival/apoptosis in cancers. Inhibition of IRE1α endonuclease leads to decreased splice XBP1 which decreases cell proliferation and increases cell death in cancer cells. Therefore, this study investigated the effects and mechanism of STF-083010 (an IRE1α inhibitor) on the cell growth/apoptosis of ovarian malignant cells via the XBP1-CHOP-Bim pathway following the induction of ER stress (ERS). ERS in OVCAR3 and SKOV3 cells was measured using Thioflavin T staining. The expression of ER stress response genes was evaluated by QRT-PCR. The levels of XBP1(s), PERK, phospho-PERK, p-PP2A, ATF4, BIP/GRP78, CHOP, and Bim proteins were evaluated using western blotting. Cell viability and apoptosis in STF-083010 and Tunicamycin (Tm) co-treated cells were assessed using BrdU, MTT, Annexin V-FITC/PI staining, and caspases-12 and -3 activity assays. The results showed increased XBP1, CHOP, and ATF-4 mRNA expression levels as well as high protein aggregation in STF-083010 and Tm co-treated cells. The IRE1α inhibitor down-regulated sXBP1 and BIP proteins, while XBP-1, p-PERK, ATF-4, CHOP, and Bim proteins were up-regulated. STF-083010 reduced cell proliferation and induced apoptosis through the activation of caspases-12 and -3 and Bax/Bcl-2 protein expression. In summary, the present data revealed the effects of STF-083010 in ER stress and apoptosis as well as signaling via XBP1/CHOP/Bim mediators. Thus, STF-083010 is proposed as a new target for the control of ERS in ovarian cancer cells.

The Anticancer Properties of Tanshinones and the Pharmacological Effects of Their Active Ingredients

Cancer is a common malignant disease worldwide with an increasing mortality in recent years. Salvia miltiorrhiza, a well-known traditional Chinese medicine, has been used for the treatment of cardiovascular and cerebrovascular diseases for thousands of years. The liposoluble tanshinones in S. miltiorrhiza are important bioactive components and mainly include tanshinone IIA, dihydrodanshinone, tanshinone I, and cryptotanshinone. Previous studies showed that these four tanshinones exhibited distinct inhibitory effects on tumor cells through different molecular mechanisms in vitro and in vivo. The mechanisms mainly include the inhibition of tumor cell growth, metastasis, invasion, and angiogenesis, apoptosis induction, cell autophagy, and antitumor immunity, and so on. In this review, we describe the latest progress on the antitumor functions and mechanisms of these four tanshinones to provide a deeper understanding of the efficacy. In addition, the important role of tumor immunology is also reviewed.

CircRNA_103762 promotes multidrug resistance in NSCLC by targeting DNA damage inducible transcript 3 (CHOP)

BACKGROUND

CircRNAs have been found to play crucial roles in multiple tumor including non-small cell lung cancer (NSCLC). Here, we researched the correlation between circRNA_103762 and chemotherapy resistance.

METHODS

RT-PCR assay was performed to detect circRNA_103762 and DNA damage inducible transcript 3 (CHOP) expression. CCK8 assay was performed to examine cell proliferation and IC₅₀ of different drug. Migration and invasion assay was used to detect cell migration and invasion.

RESULTS

In our study, circRNA_103762 expression was upregulated in NSCLC tissues and cell. Knockdown of circRNA_103762 can inhibited cell proliferation, migration and invasion in NSCLC. In addition, downregulation of circRNA_103762 promoted CHOP expression and inhibited multidrug resistance (MDR) in NSCLC.

CONCLUSION

Together, we demonstrated that circRNA_103762 is upregulated in NSCLC and functions as an oncogene in NSCLC, and circRNA_103762 enhanced MDR by inhibited CHOP expression in NSCLC cells. These results will help us understand the MDR of NSCLC, providing better effective therapy strategies for patients.

Tanshinone IIA combined with cisplatin synergistically inhibits non-small-cell lung cancer in vitro and in vivo via down-regulating the phosphatidylinositol 3-kinase/Akt signalling pathway

Cisplatin represents one of the first‐line drugs used for non‐small‐cell lung cancer treatment. However, considerable side effects and the emergence of drug resistance are becoming critical limitations to its application. Combinatorial strategies may be able to extend the use of cisplatin. Both Tanshinone IIA and cisplatin inhibit non‐small‐cell lung cancer cell growth in a time‐ and dose‐dependent manner. When Tanshinone IIA was combined with cisplatin at a ratio of 20:1, they were observed to exert a synergistic inhibitory effect on non‐small‐cell lung cancer cells. The combination treatment was shown to impair cell migration and invasion, arrest the cell cycle in the S phases, and induce apoptosis in A549 and PC9 cells in a synergistic manner. KEGG pathway analysis and molecular docking indicated that Tanshinone IIA might mainly influence the phosphatidylinositol 3‐kinase‐Akt signalling pathway. In all treated groups, the expression levels of Bax and cleaved Caspase‐3 were up‐regulated, whereas the expression levels of Bcl‐2, Caspase‐3, p‐Akt, and p‐PI3K proteins were down‐regulated. Among these, the combination of Tan IIA and cisplatin exhibited the most significant difference. Tanshinone IIA may function as a novel option for combination therapy for non‐small‐cell lung cancer treatment.

Gambogic Acid Shows Anti-Proliferative Effects on Non-Small Cell Lung Cancer (NSCLC) Cells by Activating Reactive Oxygen Species (ROS)-Induced Endoplasmic Reticulum (ER) Stress-Mediated Apoptosis

Background

Gambogic acid (AG) is believed to be a potent anti-cancer agent. ER (endoplasmic reticulum) stress-induced cell apoptosis was identified as one of the anti-proliferative mechanisms of several anti-cancer agents. In this study, we investigated the involvement of ER stress-induced apoptosis in the anti-proliferative effect of GA on NSCLC (non-small cell lung cancer) cells.

Material/Methods

GA at 0, 0.5, and 1.0 μmol/l was used to treat A549 cells. We also used the ER stress-specific inhibitor 4-PBA (4-phenylbutyric acid) (1 μmol/l) to co-treat the cells incubated with GA. Cell viability was assessed by MTT (methyl thiazolyl tetrazolium) assay. Cell apoptosis was evaluated by MTT (methyl thiazolyl tetrazolium) assay. Intracellular ROS (reactive oxygen species) production was detected by DCFH-DA (2,7- dichloro-dihydrofluorescein diacetate) florescent staining. Western blotting was used to assess the expression and phosphorylation levels of protein.

Results

GA treatment significantly reduced cell viabilities of NSCLC cells in a concentration-dependent manner. GA treatment increased intracellular ROS level, expression levels of GRP (glucose-regulated protein) 78, CHOP (C/EBP-homologous protein), ATF (activating transcription factor) 6 and caspase 12, as well as the phosphorylation levels of PERK (protein kinase R-like ER kinase) and IRE (inositol-requiring enzyme) 1α. Co-treatment of 4-PBA dramatically impaired the inhibitory effect of GA on cell viability. 4PBA co-treatment also decreased expression levels of GRP78, CHOP, ATF6, and caspase12, as well as the phosphorylation levels of PERK and IRE1α, in GA-treated NSCLC cells, without affecting ROS levels.

Conclusions

GA inhibited NSCLC cell proliferation by inducing ROS-induced ER stress-medicated apoptosis of NSCLC cells.

Tanshinone IIA induces apoptosis of ovarian cancer cells in vitro and in vivo through attenuation of PI3K/AKT/JNK signaling pathways

Ovarian cancer is one of the most common gynecological tumors and is the second most common cause of gynecological cancer-associated mortality worldwide. Tanshinone IIA (Tan-IIA) possesses anticancer activities through inducing the apoptosis of tumor cells. The purpose of the present study was to analyze the ability of Tan-IIA to induce apoptosis of human ovarian cancer cells in vitro and in vivo, and to examine the potential mechanism underlying its activity. Western blot analysis, immunohistochemistry and flow cytometry were used to analyze the therapeutic effects of Tan-IIA on ovarian cancer. It was demonstrated that Tan-IIA significantly inhibited the growth and aggressiveness of human ovarian cancer cells. Tan-IIA significantly increased the apoptosis of human ovarian cancer cells through cleavage activation of caspases-3, caspase-8 and caspases-9. In addition, Tan-IIA treatment decreased the expression of mitochondrial-protective B-cell lymphoma 2-like protein 2 (Bcl-w) and myeloid cell leukemia-1 long (Mcl-1L) in ovarian cancer cells. Tan-IIA also reduced the expression of phosphoinositide 3-kinase (PI3K), AKT and c-Jun N-terminal kinase (JNK) in human ovarian cancer cells. A specific PI3K inhibitor (LY294002) enhanced the Tan-IIA-inhibited expression of AKT and JNK. The overexpression of PI3K negated the Tan-IIA-inhibited expression of AKT and JNK, and eliminated the Tan-IIA-induced apoptosis of human ovarian cancer cells. Additionally, the in vivo assay showed that Tan-IIA treatment inhibited the growth of ovarian cancer through increasing the apoptosis of tumor cells. In conclusion, these findings suggested that the induction of apoptosis by Tan-IIA involves the PI3K/AKT/JNK signaling pathways in ovarian cancer.

New Hope for Pancreatic Ductal Adenocarcinoma Treatment Targeting Endoplasmic Reticulum Stress Response: A Systematic Review

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal types of tumours, and its incidence is rising worldwide. Although survival can be improved by surgical resection when these tumours are detected at an early stage, this cancer is usually asymptomatic, and disease only becomes apparent after metastasis. Several risk factors are associated with this disease, the most relevant being chronic pancreatitis, diabetes, tobacco and alcohol intake, cadmium, arsenic and lead exposure, certain infectious diseases, and the mutational status of some genes associated to a familial component. PDAC incidence has increased in recent decades, and there are few alternatives for chemotherapeutic treatment. Endoplasmic reticulum (ER) stress factors such as GRP78/BiP (78 kDa glucose-regulated protein), ATF6α (activating transcription factor 6 isoform α), IRE1α (inositol-requiring enzyme 1 isoform α), and PERK (protein kinase RNA-like endoplasmic reticulum kinase) activate the transcription of several genes involved in both survival and apoptosis. Some of these factors aid in inducing a non-proliferative state in cancer called dormancy. Modulation of endoplasmic reticulum stress could induce dormancy of tumour cells, thus prolonging patient survival. In this systematic review, we have compiled relevant results concerning those endoplasmic reticulum stress factors involved in PDAC, and we have analysed the mechanism of dormancy associated to endoplasmic reticulum stress and its potential use as a chemotherapeutic target against PDAC.