Synergistic antitumor activity of gemcitabine combined with triptolide in pancreatic cancer cells

Natural products as inhibitors against pancreatic cancer cell proliferation and invasion: possible mechanisms

Pancreatic cancer is one of the gastrointestinal tumors with the lowest survival rate and the worst prognosis. At the time of diagnosis, the majority of patients have missed the opportunity for radical surgical resection and opt for chemotherapy as their primary treatment choice. And drug resistance emerges during the application of the most widely used chemotherapeutic regimens such as modified FOLFIRINOX regimen, gemcitabine monotherapy or 5-Fluorouracil combination therapy, which further reduces the therapeutic efficacy. Therefore, it is urgent to explore better treatment strategies for pancreatic cancer. In recent years, more and more studies have found that natural products have significant anti-pancreatic cancer properties. In this paper, we reviewed the possible mechanisms by which natural products inhibit the proliferation and invasion of pancreatic cancer cells, including the possible mechanisms of targeting the inhibition of the growth and proliferation regulatory pathways of pancreatic cancer cells, inducing apoptosis and autophagy of pancreatic cancer cells, inhibiting the EMT process of pancreatic cancer cells, and inhibiting the angiogenesis of pancreatic cancer. Meanwhile, natural products have also hindered the progress of their basic and clinical research due to the complexity of their composition and the limitation of biological extraction technology. Further exploration of the specific molecular mechanisms of natural products to inhibit the proliferation and invasion of pancreatic cancer cells, optimization of purification and preparation techniques, and enrichment of basic and clinical trials to verify their efficacy and safety may be the future direction of natural products in the field of anti-pancreatic cancer research.

A comprehensive review on phytochemicals in the treatment and prevention of pancreatic cancer: Focusing on their mechanism of action

Background and Aims

Pancreatic cancer develops in the normal tissues of the pancreas from malignant cells. The chance of recovery is not good, and the chance of survival 5 years following diagnosis is quite low. Pancreatic cancer treatment strategies such as radiotherapy and chemotherapy had relatively low success rates. Therefore, the present study aims to explore new therapies for treating pancreatic cancer.

Methods

The present study searched for information about pancreatic cancer pathophysiology, available treatment options; and their comparative benefits and challenges. Aiming to identify potential alternative therapeutics, this comprehensive review analyzed information from renowned databases such as Scopus, PubMed, and Google Scholar.

Results

In recent years, there has been a rise in interest in the possibility that natural compounds could be used as treatments for cancer. Cannabinoids, curcumin, quercetin, resveratrol, and triptolide are some of the anticancer phytochemicals now used to manage pancreatic cancer. The above compounds are utilized by inhibiting or stimulating biological pathways such as apoptosis, autophagy, cell growth inhibition or reduction, oxidative stress, epithelial-mesenchymal transformation, and increased resistance to chemotherapeutic drugs in the management of pancreatic cancer.

Conclusion

Right now, surgery is the only therapeutic option for patients with pancreatic cancer. However, most people who get sick have been diagnosed too late to benefit from potentially effective surgery. Alternative medications, like natural compounds and herbal medicines, are promising complementary therapies for pancreatic cancer. Therefore, we recommend large-scale standardized clinical research for the investigation of natural compounds to ensure their consistency and comparability in pancreatic cancer treatment.

Natural borneol serves as an adjuvant agent to promote the cellular uptake of piperlongumine for improving its antiglioma efficacy

Piperlongumine (PL) can selectively inhibit the proliferation of various cancer cells by increasing reactive oxygen species (ROS) level to cause a redox imbalance in cancer cells rather than in normal cells. However, the clinical application of PL is limited by its poor cellular uptake. Natural borneol (NB) is extracted from the fresh branches and leaves of Cinnamomum camphora (L.) Presl. with the purity of (+)-borneol no less than 96.0%. NB has been often used as an adjuvant agent to promote the cellular uptake of other drugs. This study aims to investigate the effect of NB on the cellular uptake of PL for improving its antiglioma efficacy and underlying mechanism. NB obviously promoted the cellular uptake of PL with a 1.3-fold increase in the maximum peak concentration and an earlier peak time of 30 min in C6 glioma cells. The cellular uptake of PL was enhanced by NB through down-regulating the expression levels of P-glycoprotein (ABCB1) and breast cancer resistance protein (ABCG2). The combination of NB and PL significantly induced higher levels of ROS, which increased apoptosis and enhanced G2/M cycle arrest of C6 glioma cells, compared to PL alone administration. NB-enhanced antiglioma efficacy of PL without side effects was confirmed in tumor-bearing mice, which was attributed to the improved cellular uptake of PL. The distribution of PL in the tumor tissue of combined group increased 2.39 times than that of PL-treated group. We firstly report NB as an adjuvant agent to improve the antiglioma efficacy of PL in a ROS-dependent manner, which is due to the enhanced cellular uptake of PL by NB though down-regulating the expression levels of ABCB1 and ABCG2. This work provides a new strategy to promote the cellular uptake of PL with great potential for the treatment of glioma.

Effects of Dietary Phytochemicals on DNA Damage in Cancer Cells

With the increasing incidence of cancer worldwide, the prevention and treatment of cancer have garnered considerable scientific attention. Traditional chemotherapeutic drugs are highly toxic and associated with substantial side effects; therefore, there is an urgent need for developing new therapeutic agents. Dietary phytochemicals are important in tumor prevention and treatment because of their low toxicity and side effects at low concentrations; however, their exact mechanisms of action remain obscure. DNA damage is mainly caused by physical or chemical factors in the environment, such as ultraviolet light, alkylating agents and reactive oxygen species that cause changes in the DNA structure of cells. Several phytochemicals have been shown inhibit the occurrence and development of tumors by inducing DNA damage. This article reviews the advances in phytochemical research; particularly regarding the mechanisms related to DNA damage and provide a theoretical basis for future chemoprophylaxis research.

The therapeutic potential of natural products for treating pancreatic cancer

Pancreatic cancer is one of the most malignant tumors of the digestive tract, with the poor prognosis and low 5-year survival rate less than 10%. Although surgical resection and chemotherapy as gemcitabine (first-line treatment) has been applied to the pancreatic cancer patients, the overall survival rates of pancreatic cancer are quite low due to drug resistance. Therefore, it is of urgent need to develop alternative strategies for its treatment. In this review, we summarized the major herbal drugs and metabolites, including curcumin, triptolide, Panax Notoginseng Saponins and their metabolites etc. These compounds with antioxidant, anti-angiogenic and anti-metastatic activities can inhibit the progression and metastasis of pancreatic cancer. Expecting to provide comprehensive information of potential natural products, our review provides valuable information and strategies for pancreatic cancer treatment.

Opportunities and challenges for co-delivery nanomedicines based on combination of phytochemicals with chemotherapeutic drugs in cancer treatment

The therapeutic limitations such as insufficient efficacy, drug resistance, metastasis, and undesirable side effects are frequently caused by the long duration monotherapy based on chemotherapeutic drugs. multiple combinational anticancer strategies such as nucleic acids combined with chemotherapeutic agents, chemotherapeutic combinations, chemotherapy and tumor immunotherapy combinations have been embraced, holding great promise to counter these limitations, while still taking including some potential risks. Nowadays, an increasing number of research has manifested the anticancer effects of phytochemicals mediated by modulating cancer cellular events directly as well as the tumor microenvironment. Specifically, these natural compounds exhibited suppression of cancer cell proliferation, apoptosis, migration and invasion of cancer cells, P-glycoprotein inhibition, decreasing vascularization and activation of tumor immunosuppression. Due to the low toxicity and multiple modulation pathways of these phytochemicals, the combination of chemotherapeutic agents with natural compounds acts as a novel approach to cancer therapy to increase the efficiency of cancer treatments as well as reduce the adverse consequences. In order to achieve the maximized combination advantages of small-molecule chemotherapeutic drugs and natural compounds, a variety of functional nano-scaled drug delivery systems, such as liposomes, host-guest supramolecules, supramolecules, dendrimers, micelles and inorganic systems have been developed for dual/multiple drug co-delivery. These co-delivery nanomedicines can improve pharmacokinetic behavior, tumor accumulation capacity, and achieve tumor site-targeting delivery. In that way, the improved antitumor effects through multiple-target therapy and reduced side effects by decreasing dose can be implemented. Here, we present the synergistic anticancer outcomes and the related mechanisms of the combination of phytochemicals with small-molecule anticancer drugs. We also focus on illustrating the design concept, and action mechanisms of nanosystems with co-delivery of drugs to synergistically improve anticancer efficacy. In addition, the challenges and prospects of how these insights can be translated into clinical benefits are discussed.

Minnelide synergizes with conventional chemotherapy by targeting both cancer and associated stroma components in pancreatic cancer

Addition of nab-paclitaxel to gemcitabine offers a survival benefit of only 6 weeks over gemcitabine alone at a cost of increased toxicity in PDAC. The goal of the present study is to evaluate the efficacy of Minnelide, a water-soluble prodrug of triptolide, in combination with the standard of care regimen for chemotherapy with the added advantage of reducing the doses of these drugs to minimize toxicity. Pancreatic cancer cell lines were implanted subcutaneously or orthotopically in athymic nude or C57BL/6J mice. Subsequently, animals were randomized and received saline or minnelide or full dose chemotherapy or low dose chemotherapy or minnelide in combination with low dose chemotherapy. Our results show that a combination of low doses of Minnelide with Gemcitabine + nab-paclitaxel significantly inhibited tumor progression and increased the survival of tumor-bearing mice in comparison with conventional chemotherapy alone. Moreover, combination therapy significantly reduced cancer-related morbidity by decreasing ascites and metastasis and effectively targeted both cancer and the associated stroma. In vitro studies with a combination of low doses of triptolide and paclitaxel significantly decreased the cell viability, increased apoptosis and led to significantly increased M-phase cell cycle arrest in various pancreatic cancer cell lines as compared to either drug alone. Our results show that Minnelide synergizes with conventional chemotherapy leading to a significant reduction in the doses of these toxic drugs, all the while achieving better efficacy in the treatment of PDAC. This combination effectively targeted both the cancer and the associated stromal components of pancreatic cancer.

Toxicological damages on copper exposure to IgM+ B cells of Nile tilapia (Oreochromis niloticus) and mitigation of its adverse effects by β-glucan administration

Present investigation was carried out to study toxicological damages of copper exposure and mitigation of its adverse effects with β-glucan administration in IgM⁺ B cells which processes multiple roles similar to macrophages in Nile tilapia (Oreochromis niloticus). IgM⁺ B cells were pretreated with β-glucan (25 μg/mL) for 24 h before exposed to cupric oxide nanoparticles (CuO NPs) or cupric chloride (Cu ions) at the doses of 0, 5, 10, and 20 μg/mL for 24 h, respectively. Our results demonstrated that β-glucan increased reduced glutathione (GSH) to against oxidative damage from CuO NPs and Cu ions exposure in IgM⁺ B cells. The apoptosis process through mitochondrial signaling pathway was depressed in IgM⁺ B cells since the mitochondrial membrane potential (ΔΨm) was protected from copper exposure by β-glucan treatment. Furthermore, the inhibition on phagocytic abilities of IgM⁺ B cells caused by copper exposure could be enhanced with β-glucan treatment via evaluation of microspheres and bioparticles uptake and LPS-induced NO production. Importantly, β-glucan might participate in immunomodulation in IgM⁺ B cells through B cell antigen receptor (BCR) to suppress toxicological effect derived from copper exposure. Taken together, this study provides more information on the toxicological damages in IgM⁺ B cells upon copper exposure and explains the molecular mechanism to reverse adverse effects caused by copper exposure with β-glucan administration.

β-glucan mitigation on toxicological effects in monocytes/macrophages of Nile tilapia (Oreochromis niloticus) following copper exposure

The protective effect of β-glucan against toxicological effects caused by copper oxide nanoparticles (Cu NPs) and copper ions (Cu ions) were studied in monocytes/macrophages (MO/MФ) of Nile tilapia (Oreochromis niloticus). Our results demonstrated that CuO NPs and Cu ions exposure aroused strong oxidative lesion in MO/MФ by detection of cellular reactive oxygen species (ROS) and reduced glutathione (GSH), as well as identification of several antioxidant-related cytokines. Meanwhile, the serious pro-inflammatory responses were accompanied during the processes of oxidative lesion by TNFα, IL-1β, and IL-6 genes validation. Copper induced MO/MФ underwent apoptosis through mitochondrial signaling pathway by mitochondrial membrane potential (ΔΨm) detection and Bax, Bcl-2, Cyt-c, Apaf-1, Caspase 9, Caspase 3 genes validation. Furthermore, the phagocytic abilities were inhibition in MO/MФ by evaluation of microspheres (0.5 and 1.0 μm beads) and bioparticles (S. agalactiae and A. hydrophila) uptake and LPS-induced NO production. However, β-glucan might participate in immunomodulation through C-type lectin receptor (CLR) and complement receptor 3 (CR3) to suppress pro-inflammatory responses, thereby revered all the copper induced aforementioned adverse effects in MO/MΦ. Taken together, our results provide insights on the mechanisms through β-glucan administration to mitigate toxicological effects of CuO NPs and Cu ions exposure to the MO/MΦ, which will benefit aspects related to fish farming and aquaculture production.

One-shot dual gene editing for drug-resistant pancreatic cancer therapy

It is challenging to diagnose patients with pancreatic ductal adenocarcinoma (PDAC) early on, and their treatment is often complex. Gemcitabine (GEM) is the first-line treatment for PDAC, but its efficacy is limited in most patients due to the GEM resistance from KRAS and P53 gene mutations. We describe the correction of a double gene mutation and therapeutic effect for the GEM resistant PDAC. Bio-available nanoliposomes (NL) possessing Cas9-ribonucleoproteins and adenine-base editors were developed to conduct KRAS and P53 mutation gene editing directly. NLs were conjugated with EGFR antibodies to tumor-specific delivery, and the anti-cancer effect was verified in vitro and in vivo Model. Our GEM-combinatorial therapeutic strategies using double gene editing systems with one-shot may be a potent therapy for PDAC, overcoming chemoresistance.

In vitro assessment of a synergistic combination of gemcitabine and zebularine in pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with an extremely poor prognosis. Gemcitabine (Gem) is still the mainstay drug for the treatment of PDAC. However, rapid inactivation by cytidine deaminase (CDA) present in pancreatic cancer cells severely limits anticancer efficacy of Gem. In this study, we investigated the effect of a CDA inhibitor - Zebularine (Zeb) on anticancer activity of Gem in pancreatic cancer cell lines MiaPaCa-2, BxPC-3, and Panc-1. Zeb treatment synergistically increased Gem-induced cytotoxicity in all three pancreatic cancer cell lines. The strongest synergistic activity was found at 1:10 M ratio of Gem/Zeb (combination index 0.04-0.4). Additionally, Gem + Zeb treated cells showed marked decreased in the expressions of anti-apoptotic protein including Bcl-2 and survivin while significantly increased the cleaved caspase-3, and loss of mitochondrial membrane potential was observed. Multicellular 3D spheroids of MiaPaCa-2 cells treated with combination showed significant reduction (25-60%) in spheroid size, weight compared to single drug and control group. Live/dead cell imaging showed that Gem + Zeb treated spheroids exhibited a highly distorted surface with significantly higher number of dead cells (red). The results of the present study confirm that this synergistic combination is worthy of future investigations as a potential approach for the treatment of PDAC.

Role of folate-conjugated glycol-chitosan nanoparticles in modulating the activated macrophages to ameliorate inflammatory arthritis: in vitro and in vivo activities

Activated macrophages are the primary targets in rheumatoid arthritis (RA) management. So, we report efficacious, dual-functional Methotrexate (MTX) loaded folate-conjugated pH-responsive glycol-chitosan nanoparticles (MFGCN) prepared by nano-precipitation and zero-order cross-linking reaction for targeting inflamed arthritic tissue. Physical characterization by DLS, SEM and TEM indicated a spherical, smooth morphology with a diameter ~ 300 nm. ¹H NMR and FTIR indicated folic acid conjugation to GC by zero-order cross-linkers. In vitro release kinetics in PBS showed pH-responsive and sustained release behaviour of MFGCN. Enhanced cellular uptake and cytotoxicity of MFGCN in LPS(+)RAW and activated peritoneal macrophages (Mϕ) were observed when compared to LPS(-)RAW cells. MFGCN-induced mitochondrial membrane potential (MMP) perturbations indicated apoptosis. Oxidative stress was evident by significant increase in ROS and RNS, 4 h post incubation with MFGCN. Negligible hemolysis by FGCN and MFGCN on rat RBC's indicated biocompatibility. In vivo biodistribution of MFGCN in adjuvant-induced arthritis (AIA) rats indicated RA targetability. Prolonged blood circulation coupled with higher concentrations of ^99mTc-MFGCN at the arthritic site was observed post 24 h of injection. The gamma scintigraphic image confirmed accumulation of radiolabelled MFGCN in arthritic paw when compared to the non-inflamed paw, confirming the selective uptake of ^99mTc-MFGCN by folate-overexpressing macrophages in the arthritic synovium thereby proving its targeted efficacy and theranostic potential. In AIA rats, MFGCN lowers arthritic signs, improves antioxidant response and decreases pro-inflammatory cytokines, suggesting its potential in targeting activated macrophages of synovium. Graphical abstract.

Pancreatic Cancer (PDAC): Introduction of Evidence-Based Complementary Measures into Integrative Clinical Management

The most common form of pancreatic cancer is pancreatic ductal adenocarcinoma (PDAC), which comprises some 85% of all cases. Currently, this is the fourth highest cause of cancer mortality worldwide and its incidence is rising steeply. Commonly applied clinical therapies offer limited chance of a lasting cure and the five-year survival rate is one of the lowest of the commonly occurring cancers. This review cultivates the hypothesis that the best management of PDAC would be possible by integrating 'western' clinical medicine with evidence-based complementary measures. Protecting the liver, where PDAC frequently first spreads, is also given some consideration. Overall, the complementary measures are divided into three groups: dietary factors, nutraceutical agents and lifestyle. In turn, dietary factors are considered as general conditioners, multi-factorial foodstuffs and specific compounds. The general conditioners are alkalinity, low-glycemic index and low-cholesterol. The multi-factorial foodstuffs comprise red meat, fish, fruit/vegetables, dairy, honey and coffee. The available evidence for the beneficial effects of the specific dietary and nutraceutical agents was considered at four levels (in order of prominence): clinical trials, meta-analyses, in vivo tests and in vitro studies. Thus, 9 specific agents were identified (6 dietary and 3 nutraceutical) as acceptable for integration with gemcitabine chemotherapy, the first-line treatment for pancreatic cancer. The specific dietary agents were the following: Vitamins A, C, D and E, genistein and curcumin. As nutraceutical compounds, propolis, triptolide and cannabidiol were accepted. The 9 complementary agents were sub-grouped into two with reference to the main 'hallmarks of cancer'. Lifestyle factors covered obesity, diabetes, smoking, alcohol and exercise. An integrative treatment regimen was devised for the management of PDAC patients. This involved combining first-line gemcitabine chemotherapy with the two sub-groups of complementary agents alternately in weekly cycles. The review concludes that integrated management currently offers the best patient outcome. Opportunities to be investigated in the future include emerging modalities, precision medicine, the nerve input to tumors and, importantly, clinical trials.

Diltiazem potentiates the cytotoxicity of gemcitabine and 5-fluorouracil in PANC-1 human pancreatic cancer cells through inhibition of P-glycoprotein

AIM

Pancreatic cancer (PC) is one of the most aggressive tumors with dismal survival and a high death rate due to chemotherapeutic failure. P-glycoprotein (P-gp) plays a pivotal role in PC response to gemcitabine and 5-fluorouracil (5-FU). Diltiazem, a calcium channel blocker, is a P-gp inhibitor. In the current study, we investigated the hypothesis that targeting of P-gp by diltiazem can enhance the cytotoxicity of gemcitabine and 5-FU against human pancreatic cancer cells.

MAIN METHODS

The cytotoxic effect of diltiazem, gemcitabine, and 5-FU in single and combined forms against PANC-1 and AsPC-1 cells were assayed by MTT. Flow cytometric analysis was used for the determination of cell cycle, apoptosis, and stemness markers in PC cells. Besides, immunoblotting was used for assessment of Bax, caspase 3, cyclin D1, and P-gp expressions.

KEY FINDINGS

Diltiazem co-treatment, either with gemcitabine or 5-FU, synergistically reduced cell viability, induced apoptosis, and caused cell cycle arrest. In addition, diltiazem co-treatment decreased the expressions of stem cell markers CD24 and CD44, increased the expressions of Bax and cleaved caspase 3, enhanced DNA fragmentation, and attenuated cyclin D1 and P-gp expressions as compared to cells treated with either gemcitabine or 5-FU alone.

SIGNIFICANCE

Our findings suggest that diltiazem may be potential neoadjuvant therapy to enhance the response of PC to gemcitabine or 5-FU treatment.

Traditional Chinese medicine may be further explored as candidate drugs for pancreatic cancer: A review

Pancreatic cancer is a disease with a high mortality rate. Although survival rates for different types of cancers have improved in recent years, the five-year survival rate of pancreatic cancer stands at 8%. Moreover, the current first-line therapy, gemcitabine, results in low remission rates and is associated with drug resistance problems. Alternative treatments for pancreatic cancer such as surgery, chemotherapy and radiation therapy provide marginal remission and survival rates. This calls for the search of more effective drugs or treatments. Traditional Chinese medicine contains numerous bioactive ingredients some of which show activity against pancreatic cancer. In this review, we summarize the mechanisms of five types of traditional Chinese medicine monomers. In so-doing, we provide new potential drug candidates for the treatment of pancreatic cancer.

Biophysical and pharmacological characterization of a full-length synthetic analog of the antitumor polypeptide crotamine

Crotamine is a polypeptide isolated from the venom of a South American rattlesnake. Among the properties and biological activities of crotamine, the most extraordinary is its ability to enter cells with unique selective affinity and cytotoxic activity against actively proliferating cells, such as tumor cells. This peptide is also a cargo carrier, and anticipating commercial application of this native polypeptide as a potential theranostic compound against cancer, we performed here a side-by-side characterization of a chemically synthesized full-length crotamine compared with its native counterpart. The structural, biophysical, and pharmacological properties were evaluated. Comparative NMR studies showed structural conservation of synthetic crotamine. Moreover, similarly to native crotamine, the synthetic polypeptide was also capable of inhibiting tumor growth in vivo, increasing the survival of mice bearing subcutaneous tumor. We also confirmed the ability of synthetic crotamine to transfect and transport DNA into eukaryotic cells, in addition to the importance of proteoglycans on cell surface for its internalization. This work opens new opportunities for future evaluation of chimeric and/or point-mutated analogs of this snake polypeptide, aiming for improving crotamine properties and applications, as well as possibly diminishing its potential toxic effects. KEY MESSAGES: • Synthetic crotamine showed ex vivo and in vivo activities similar to native peptide. • Synthetic crotamine structure conservation was demonstrated by NMR analysis. • Synthetic crotamine is able to transfect and transport DNA into eukaryotic cells. • Synthetic crotamine shows tumor growth inhibition in vivo. • Synthetic crotamine increases survival of mice bearing tumor.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

Triptolide enhances the sensitivity of pancreatic cancer PANC-1 cells to gemcitabine by inhibiting TLR4/NF-κB signaling

BACKGROUND

This study aimed to investigate roles of Toll-like receptor 4 (TLR4)/nuclear factor (NF)-κB signaling in triptolide (TPL)-induced sensitivity of pancreatic cancer cells to gemcitabine (GEM).

METHODS

In vitro, pancreatic cancer PANC-1 cells were treated with lipopolysaccharide (LPS) to activate TLR4, TLR4-siRNA, GEM alone, or GEM plus TPL. In vivo, nude mice bearing PANC-1 cell xenografts were treated with GEM, TPL, or both. Cell proliferation was detected by MTT assay and Ki-67 staining. Apoptosis was assessed by flow cytometry and TUNEL assay. A double luciferase reporter gene was used to detect NF-κB activity.

RESULTS

The sensitivity of PANC-1 cells to GEM was reduced by LPS but enhanced by TLR4-siRNA. TPL inhibited expression of TLR4/NF-κB signaling components, which was reversed by LPS. The TPL+GEM group showed more apoptosis than the LPS+TPL+GEM group. Moreover, the activity of NF-κB and the expression of TLR4, p-p65 Survivin, CyclinD1 and Bcl-2 in the TPL+GEM group were lower than in the LPS+TPL+GEM group, whereas Bax expression was higher. The volume of transplanted tumors in the TPL+GEM group was lower than that in the TPL or GEM group. Phospho-p65, Survivin, CyclinD1 and Bcl-2 expression in transplanted tumors was lower in TPL+GEM group than in either single drug group. The Ki-67 staining score of the TPL+GEM group was lower and tumor cells apoptosis rate was increased when compared with TPL or GEM alone.

CONCLUSIONS

TPL enhances the sensitivity of pancreatic cancer PANC-1 cells to GEM by inhibiting TLR4/NF-κB signaling.

Inhibition of insulin-like growth factor 1 signaling synergistically enhances the tumor suppressive role of triptolide in triple-negative breast cancer cells

Triptolide (TPL) is an active extract from a Chinese herb, which has been used for centuries in China. TPL exhibits numerous bioactivities and pharmacological effects, including antitumor, anti-inflammatory and immunosuppressive activities. However, previous studies have further revealed a multi-target toxicity of TPL, including reproductive toxicity, hepatotoxicity and renal cytotoxicity. To validate the clinical benefit and reduce the risk of TPL application, studies have investigated the combination of TPL with other reagents to allow lower doses and decrease toxicity. The present study reported that TPL and the insulin-like growth factor-1 receptor (IGF1R) inhibitor AG1024synergistically inhibited cell proliferation and induced apoptosis in triple-negative breast cancer cells. Overexpression of B-cell lymphoma 2 partially reversed the TPL and AG1024-induced increase in apoptosis. A similar synergistic effect was observed with a combination of AG1024 and cisplatin, a DNA damage inducer, in MDA-MB-231 cells. These results suggested that inhibition of IGF1R may sensitize triple-negative breast cancer cells to DNA damage inducers. Using publicly available data from The Cancer Genome Atlas, an amplification and gain of copy number of IGF1R was observed in 38% of triple-negative breast tumors (n=82), 26% of estrogen receptor (ER)-negative tumors (n=174) and 10% of ER-positive tumors (n=594). Similarly, a higher alteration frequency of IGF1R was identified in basal-like breast tumors compared with luminal A/B-like breast tumors. Overexpressed proteins associated with these alterations were revealed to be significantly enriched in multiple oncogenic signaling pathways, key transcription factor networks and DNA repair pathways. In summary, the present study suggested that inhibition of IGFR signaling and induction of DNA damage may exhibit synergistic effects for the treatment of triple-negative and ER-negative breast cancer.

Traditional Chinese medicine-combination therapies utilizing nanotechnology-based targeted delivery systems: a new strategy for antitumor treatment

Cancer is a major public health problem, and is now the world’s leading cause of death. Traditional Chinese medicine (TCM)-combination therapy is a new treatment approach and a vital therapeutic strategy for cancer, as it exhibits promising antitumor potential. Nano-targeted drug-delivery systems have remarkable advantages and allow the development of TCM-combination therapies by systematically controlling drug release and delivering drugs to solid tumors. In this review, the anticancer activity of TCM compounds is introduced. The combined use of TCM for antitumor treatment is analyzed and summarized. These combination therapies, using a single nanocarrier system, namely codelivery, are analyzed, issues that require attention are determined, and future perspectives are identified. We carried out a systematic review of >280 studies published in PubMed since 1985 (no patents involved), in order to provide a few basic considerations in terms of the design principles and management of targeted nanotechnology-based TCM-combination therapies.

Effect of the Natural Product Triptolide on Pancreatic Cancer: A Systematic Review of Preclinical Studies

Objective: Triptolide (TL), a natural product isolated from Tripterygium wilfordii Hook F (TwHF), shows potent anticancer effects in vitro and in vivo. We aimed to summary the biochemical mechanisms through which TL has been shown to induce apoptosis, autophagy and inhibit angiogenesis in pancreatic cancer (PC).

Methods: We undertook a systematic review of preclinical evidence. We searched electronic databases. The potential mechanisms and the underlying signaling pathways have been accumulated as well.

Results: We screened 116 abstracts for eligibility and included 17 preclinical studies in the analysis. Details of the animals and cell lines were provided in 16 studies (94.1%). Six studies (75.0%) randomly assigned animals to treatment or control groups and only 1 study (12.5%) reported on blinding. The majority of the TL's research field has focused on its pro-apoptotic effects through downregulation of inhibitory pathways and upregulation of apoptotic pathways. The studies have shown that TL is effective both in vitro and in vivo against PC cells.

Conclusion: This study provides a systematic summary of TL's anti-pancreatic cancer profile and the underlying mechanisms of with special emphasis on the apoptosis, autophagy, angiogenesis and related molecular pathways. Improved study quality in terms of treatment allocation methods reporting, randomization and blinding will accelerate needed progress toward trials.

Gambogenic acid synergistically potentiates bortezomib-induced apoptosis in multiple myeloma

Background: Although the introduction of protease inhibitor bortezomib (BTZ) and immunomodulatory agent lenalidomide has led to improved outcomes in patients with multiple myeloma (MM), the disease remains incurable. Gambogenic acid (GNA), a polyprenylated xanthone isolated from the traditional Chinese medicine gamboge, has been reported to have potent antitumor activity and can effectively inhibit the survival and proliferation of cancer. In this study, we hypothesized that GNA could synergistically potentiate BTZ-induced apoptosis of MM cells and that combining BTZ and GNA may provide a more effective approach to treat MM. Hence, we investigate the in vitro and in vivo effects of BTZ and GNA, alone or in combination, against myeloma MM.1S cells.

Methods: Cell counting kit-8 (CCK-8) assay, combination index (CI) isobologram, flow cytometry, western blot, xenograft tumor models, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and immunochemistry were used in this study.

Results: The results showed that BTZ and GNA combination treatment resulted in a strong synergistic action against the MM.1S cell line. Increased G2/M phase cells were triggered by BTZ, GNA and the combined treatment. The combined treatment could induce more markedly apoptosis of MM.1S cells via the activation of PARP cleavage, P53, Caspase-3 cleavage and Bax and inhibition of Bcl-2 expression. An increased antitumor effects of combination therapy of BTZ and GNA on MM.1S xenograft models were observed, and combining BTZ and GNA was found to be superior to a single agent.

Conclusions: Our data support that a synergistic antitumor activity exists between BTZ and GNA, and provide a rationale for successful utilization of dual BTZ and GNA in MM chemotherapy in the future.

Effect of triptolide on expression of Bax/Bcl-2 and cleaved Caspase 3 in HCT116 cells

AIM

To investigate the effect of triptolide (TP) on the expression of Bax/B cell lymphoma/leukmia-2 (Bcl-2) and cleaved Caspase 3 in HCT116 cells and the mechanism of TP induced apoptosis.

METHODS

HCT116 cells were divided into six groups and treated with 5, 10, 20, 30, 40, and 80 nmol/L TP, respectively. HCT116 cells treated with PBS were used control cells. After HCT116 cells were exposed to TP for 24 h, 48 h or 72 h, MTT assay was used for estimating the survival rates of HCT116 cells, flow cytometry (FCM) was applied to test the effects of TP on cell apoptosis, and Western blot was used for testing the expression of Bcl-2, Bax, Caspase 3, and activated Caspase 3.

RESULTS

TP could inhibit the proliferation of HCT116 cells. The survival rates of HCT116 cells decreased with the increase in the concentration and treatment time of TP. The survival rates were 4.25%, 13.6%, 34.4%, 43.8% and 44.5%, respectively, for cells exposed to 5, 10, 20, 30, and 40 nmol/L TP for 48h. The expression of Bcl-2 was decreased with the increase in the concentration of TP. Additionally, the level of Bax was decreased in the cytoplasm but increased in mitochondria, indicating that TP can promote Bax translocation from the cytoplasm to mitochondria. TP reduced the level of Caspase 3 in a concentration dependent manner; however, cleaved Caspase 3 level was increased.

CONCLUSION

TP can induce apoptosis of HCT116 cells by inhibiting the expression of Bcl-2, increasing the expression of Bax, and promoting the activation of Caspase 3.