Combined Parthenolide and Balsalazide Have Enhanced Antitumor Efficacy Through Blockade of NF-κB Activation

Combination Anticancer Therapies Using Selected Phytochemicals

Cancer is still one of the most widespread diseases globally, it is considered a vital health challenge worldwide and one of the main barriers to long life expectancy. Due to the potential toxicity and lack of selectivity of conventional chemotherapeutic agents, discovering alternative treatments is a top priority. Plant-derived natural products have high potential in cancer treatment due to their multiple mechanisms of action, diversity in structure, availability in nature, and relatively low toxicity. In this review, the anticancer mechanisms of the most common phytochemicals were analyzed. Furthermore, a detailed discussion of the anticancer effect of combinations consisting of natural product or natural products with chemotherapeutic drugs was provided. This review should provide a strong platform for researchers and clinicians to improve basic and clinical research in the development of alternative anticancer medicines.

Sesquiterpene Lactones and Cancer: New Insight into Antitumor and Anti-inflammatory Effects of Parthenolide-Derived Dimethylaminomicheliolide and Micheliolide

Applied science nowadays works on the isolation and application of biological macromolecules (BMM). These BMM are isolates from plants using different techniques and used as anticancer, antimicrobial, and anti-inflammatory drugs. Parthenolide (PLT) is one of the most important biological macromolecules and a naturally occurring sesquiterpene lactone that is isolated from a plant species Tanacetum parthenium (T. parthenium). The anti-cancer and anti-inflammatory effects of PTL isolated from T. parthenium were previously reported and summarized in detail. These biological activities make it a vital candidate for further researches and drugs development. As per the previously obtained findings, the sesquiterpene is very much known for some biological activities; therefore, the anti-cancer and anti-inflammatory activities of the sesquiterpene were critically reviewed. During the research process, PTL was found to be unstable in both acidic and basic conditions with low solubility, so structurally related compounds micheliolide (MCL) and Dimethylaminomicheliolide (DMAMCL) (a prodrug of MCL) were developed. In this article, we briefly review the therapeutic effects of PTL and its derivative DMAPT on inflammatory diseases and tumors, focusing on the current application of PTL in targeted therapy and combination therapy, together with anti-inflammatory and anti-tumor functions of MCL and DMAMCL. The uniqueness of this biological macromolecule is not to harm the normal cell but target the cancerous cells. Therefore, the current literature review might be helpful and useful for prospects based on the effects of MCL and DMAMCL on cancer.

Lipocalin 2 potentially contributes to tumorigenesis from colitis via IL-6/STAT3/NF-kB signaling pathway

Lipocalin 2 (LCN2), a member of the lipocalin superfamily, plays an important role in oncogenesis and progression in various types of cancer. However, the role of LCN2 in inflammation-associated cancer remains unknown. Here, we explored the functional role and mechanisms of LCN2 in tumorigenesis using murine colitis-associated cancer (CAC) models and human colorectal cancer (CRC) cells. Using murine CAC models, we found that LCN2 was preferentially expressed in colonic tissues from CAC models compared to tissues from normal mice. In vitro results demonstrated that the levels of LCN2 mRNA and protein were markedly up-regulated by Interleukin-6 (IL-6) in human CRC cells. Interestingly, we found LCN2 up-regulation by IL-6 is diminished by NF-kB and STAT3 inhibition using specific inhibitors and siRNA. Reporter assay results determined that IL-6 induces LCN2 gene promoter activity under control of NF-kB/STAT3 activation. IL-6-induced LCN2 regulated cell survival and susceptibility of developmental factors to the NF-kB/STAT3 pathway. Taken together, our results highlight the unknown role of LCN2 in CAC progression and suggest that increased LCN2 may serve as an indicator of CRC development in the setting of chronic inflammation.

Parthenolide and Its Soluble Analogues: Multitasking Compounds with Antitumor Properties

Due to its chemical properties and multiple molecular effects on different tumor cell types, the sesquiterpene lactone parthenolide (PN) can be considered an effective drug with significant potential in cancer therapy. PN has been shown to induce either classic apoptosis or alternative caspase-independent forms of cell death in many tumor models. The therapeutical potential of PN has been increased by chemical design and synthesis of more soluble analogues including dimethylaminoparthenolide (DMAPT). This review focuses on the molecular mechanisms of both PN and analogues action in tumor models, highlighting their effects on gene expression, signal transduction and execution of different types of cell death. Recent findings indicate that these compounds not only inhibit prosurvival transcriptional factors such as NF-κB and STATs but can also determine the activation of specific death pathways, increasing intracellular reactive oxygen species (ROS) production and modifications of Bcl-2 family members. An intriguing property of these compounds is its specific targeting of cancer stem cells. The unusual actions of PN and its analogues make these agents good candidates for molecular targeted cancer therapy.

Application of Nanoparticles in the Treatment of Lung Cancer With Emphasis on Receptors

Lung cancer is one of the malignant tumors that has seen the most rapid growth in terms of morbidity and mortality in recent years, posing the biggest threat to people’s health and lives. In recent years, the nano-drug loading system has made significant progress in the detection, diagnosis, and treatment of lung cancer. Nanomaterials are used to specifically target tumor tissue to minimize therapeutic adverse effects and increase bioavailability. It is achieved primarily through two mechanisms: passive targeting, which entails the use of enhanced penetration and retention (EPR) effect, and active targeting, which entails the loading recognition ligands for tumor marker molecules onto nanomaterials. However, it has been demonstrated that the EPR effect is effective in rodents but not in humans. Taking this into consideration, researchers paid significant attention to the active targeting nano-drug loading system. Additionally, it has been demonstrated to have a higher affinity and specificity for tumor cells. In this review, it describes the development of research into active targeted nano-drug delivery systems for lung cancer treatment from the receptors’ or targets’ perspective. We anticipate that this study will help biomedical researchers use nanoparticles (NPs) to treat lung cancer by providing more and novel drug delivery strategies or solid ligands.

Roles of Inflammasomes in Epstein-Barr Virus-Associated Nasopharyngeal Cancer

Epstein-Barr virus (EBV) infection is recognised as one of the causative agents in most nasopharyngeal carcinoma (NPC) cases. Expression of EBV viral antigens can induce host's antiviral immune response by activating the inflammasomes to produce pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and IL-18. These cytokines are known to be detrimental to a wide range of virus-infected cells, in which they can activate an inflammatory cell death program, called pyroptosis. However, aberrant inflammasome activation and production of its downstream cytokines lead to chronic inflammation that may contribute to various diseases, including NPC. In this review, we summarise the roles of inflammasomes during viral infection, how EBV evades inflammasome-mediated immune response, and progress into tumourigenesis. The contrasting roles of inflammasomes in cancer, as well as the current therapeutic approaches used in targeting inflammasomes, are also discussed in this review. While the inflammasomes appear to have dual roles in carcinogenesis, there are still many questions that remain unanswered. In particular, the exact molecular mechanism responsible for the regulation of the inflammasomes during carcinogenesis of EBV-associated NPC has not been explored thoroughly. Furthermore, the current practical application of inflammasome inhibitors is limited to specific tumour types, hence, further studies are warranted to discover the potential of targeting the inflammasomes for the treatment of NPC.

Parthenolide as Cooperating Agent for Anti-Cancer Treatment of Various Malignancies

Primary and acquired resistance of cancer to therapy is often associated with activation of nuclear factor kappa B (NF-κB). Parthenolide (PN) has been shown to inhibit NF-κB signaling and other pro-survival signaling pathways, induce apoptosis and reduce a subpopulation of cancer stem-like cells in several cancers. Multimodal therapies that include PN or its derivatives seem to be promising approaches enhancing sensitivity of cancer cells to therapy and diminishing development of resistance. A number of studies have demonstrated that several drugs with various targets and mechanisms of action can cooperate with PN to eliminate cancer cells or inhibit their proliferation. This review summarizes the current state of knowledge on PN activity and its potential utility as complementary therapy against different cancers.

Synergy between parthenolide and arsenic trioxide in adult T-cell leukemia/lymphoma cells in vitro

OBJECTIVES

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive lymphoid malignancy with low survival rate and distinct geographical distribution. In search for novel chemotherapeutics against ATLL, we investigated the combinatorial effects of parthenolide, a sesquiterpene lactone with valuable pharmaceutical activities, and arsenic trioxide (ATO) in vitro.

MATERIALS AND METHODS

MT2 cells, an ATLL cell line, were treated with increasing concentrations of parthenolide (1.25, 2.5, and 5 μg/ml) and ATO (2, 4, 8, and 16 µM) to determine their IC50. Then, cells were treated with a combination of sub-IC50 concentrations of parthenolide (1 μg/ml) and ATO (2 µM) for 72 hr. Cell viability and cell cycle changes were assessed by Alamar blue and PI staining, respectively. To understand the mechanisms responsible for observed effects, expression of CD44, NF-κB (REL-A), BMI-1, and C-MYC were investigated by real-time PCR.

RESULTS

Assessment of cell viability indicated that parthenolide significantly increased the toxicity of ATO, as confirmed by accumulation of MT2 cells in the sub G1 phase of the cell cycle. Moreover, molecular analysis revealed significant down-regulation of CD44, NF-κB (REL-A), BMI-1, and C-MYC upon combinatorial administration of parthenolide and ATO in comparison with relevant controls.

CONCLUSION

Taken together, present results showed that parthenolide significantly enhanced the toxicity of ATO in MT2 cells. Therefore, the future possible clinical impact of our study could be combinatorial use of parthenolide and ATO as a novel and more effective approach for ATLL.

Targeting NF-κB pathway for treating ulcerative colitis: comprehensive regulatory characteristics of Chinese medicines

Nuclear factor-kappa B (NF-κB) is a kind of multi-functional nuclear transcription factor involved in regulating gene transcription to influence pathological evolution of inflammatory and immune diseases. Numerous literature evidence that NF-κB pathway plays an essential role in pathogenic development of ulcerative colitis (UC). UC is a chronic non-specific inflammatory bowel disease, and until now, therapeutic agents for UC including aminosalicylates, corticosteroids and immune inhibitors still cannot exert satisfied effects on patients. In recent years, Chinese medicines suggest the advantages of alleviating symptoms and signs, decreasing side-effects and recurrence, whose one of mechanisms is related to regulation of NF-κB pathway. In this review, we categorize Chinese medicines according to their traditional therapeutic functions, and summarize the characteristics of Chinese medicines targeting NF-κB pathway in UC treatment. It indicates that 85 kinds of Chinese medicines’ compounds and formulae can directly act on NF-κBp65; while 58 Chinese medicines’ ingredients and formulae indirectly suppress NF-κBp65 by regulation of its upstream or other related pathways. Moreover, by the analysis of Chinese medicines’ category based on their traditional functions, we conclude the category of dampness-drying and detoxificating medicine targeting NF-κB pathway accounts for primary status for amelioration of UC. Simultaneously, this review also contributes to the choices of Chinese medicine category and provides curative potential of Chinese medicines for clinical UC treatment.

Discovery of new inhibitors against both NF-κB and osteoclastogenesis from in-house library with α, β-unsaturated-enone fragment

The α,β-unsaturated-enone contained natural products have been reported showing NF-κB inhibition effect. It is well known that NF-κB inhibitors can also be used to inhibit osteoclastogenesis. In a continual discovery new agents for anti-osteoclastogenesis, 8 different type compounds with α,β-unsaturated-enone fragments from our in-house library were evaluated for NF-κB inhibition and anti-osteoclastogenesis. Experimental results indicated five compounds exhibited inhibition of NF-κB signal pathway. Among them, one compound ((E)-2-(4-fluorobenzylidene)-3,4-dihydronaphthalen-1(2H)-one, 6a) simultaneously inhibits both osteoclastogenesis and NF-κB signal pathway. Furthermore, 12 compounds with similar scaffold with 6a were tested for anti-osteoclastogenesis. As a result, 9 compounds inhibited both NF-κB and osteoclastogenesis. Among them, compound 6b is the most potent inhibitor against NF-κB (IC₅₀ = 2.09 μM) and osteoclast differentiation (IC₅₀ = 0.86 μM). Further studies show that compound 6b blocks the phosphorylation of both p65 and IκBα, and suppresses NF-κB targeted gene expression without interfering MAPKs and PI3K/Akt signal transduction pathways. This study demonstrates that we can identify promising synthesized compounds with new scaffolds as therapeutic solutions against osteoclastogenesis inspired by the privileged fragment derived from natural leads.

Inhibition of NF-κB-Dependent Signaling Enhances Sensitivity and Overcomes Resistance to BET Inhibition in Uveal Melanoma

Bromodomain and extraterminal protein inhibitors (BETi) are epigenetic therapies aimed to target dysregulated gene expression in cancer cells. Despite early successes of BETi in a range of malignancies, the development of drug resistance may limit their clinical application. Here, we evaluated the mechanisms of BETi resistance in uveal melanoma, a disease with little treatment options, using two approaches: a high-throughput combinatorial drug screen with the clinical BET inhibitor PLX51107 and RNA sequencing of BETi-resistant cells. NF-κB inhibitors synergistically sensitized uveal melanoma cells to PLX51107 treatment. Furthermore, genes involved in NF-κB signaling were upregulated in BETi-resistant cells, and the transcription factor CEBPD contributed to the mechanism of resistance. These findings suggest that inhibitors of NF-κB signaling may improve the efficacy of BET inhibition in patients with advanced uveal melanoma. SIGNIFICANCE: These findings provide evidence that inhibitors of NF-κB signaling synergize with BET inhibition in in vitro and in vivo models, suggesting a clinical utility of these targeted therapies in patients with uveal melanoma.

Clair WH, St. Clair DK. Redox Paradox: A Novel Approach to Therapeutics-Resistant Cancer

SIGNIFICANCE

Cancer cells that are resistant to radiation and chemotherapy are a major problem limiting the success of cancer therapy. Aggressive cancer cells depend on elevated intracellular levels of reactive oxygen species (ROS) to proliferate, self-renew, and metastasize. As a result, these aggressive cancers maintain high basal levels of ROS compared with normal cells. The prominence of the redox state in cancer cells led us to consider whether increasing the redox state to the condition of oxidative stress could be used as a successful adjuvant therapy for aggressive cancers. Recent Advances: Past attempts using antioxidant compounds to inhibit ROS levels in cancers as redox-based therapy have met with very limited success. However, recent clinical trials using pro-oxidant compounds reveal noteworthy results, which could have a significant impact on the development of strategies for redox-based therapies.

CRITICAL ISSUES

The major objective of this review is to discuss the role of the redox state in aggressive cancers and how to utilize the shift in redox state to improve cancer therapy. We also discuss the paradox of redox state parameters; that is, hydrogen peroxide (H2O2) as the driver molecule for cancer progression as well as a target for cancer treatment.

FUTURE DIRECTIONS

Based on the biological significance of the redox state, we postulate that this system could potentially be used to create a new avenue for targeted therapy, including the potential to incorporate personalized redox therapy for cancer treatment.

The combined administration of parthenolide and ginsenoside CK in long circulation liposomes with targeted tLyp-1 ligand induce mitochondria-mediated lung cancer apoptosis

BACKGROUND

Combinations of natural products with low toxicities using tumor-targeting carriers may improve cancer treatment. The combined parthenolide and ginsenoside compound K (CK) within tLyp-1 liposomes, with the aim of improving the efficacy of lung cancer treatment.

RESULTS

In vitro studies in A549 human pulmonary adenocarcinoma cells demonstrated that parthenolide/CK tLyp-1 liposomes increased reactive oxygen species levels and induced mitochondrial apoptosis. It enters into cells via receptor-mediated uptake and micropinocytosis, followed by endosomal/lysosomal escape. In vivo studies illustrated that it produced a greater antitumor effect than combined administration of these compounds, with minimal toxicity.

CONCLUSION

The findings of this study indicated that combined application of natural products in nanocarriers could offer attractive therapeutic options.

Epoxymicheliolide, a novelguaiane-type sesquiterpene lactone, inhibits NF‑κB/COX‑2 signaling pathways by targeting leucine 281 and leucine 25 in IKKβ in renal cell carcinoma

Parthenolide (PTL) is a sesquiterpene lactone compound obtained from Tanacetum parthenium (feverfew) and inhibits the activation of nuclear factor (NF)-κB. Epoxymicheliolide (EMCL) is a compound which is structurally related to PTL; however, EMCL is more stable under acidic and alkaline conditions. As a biologically active molecule, the detailed mechanism by which EMCL inhibits tumor activity remains to be elucidated. The present study evaluated the effect of EMCL on renal cell carcinoma (RCC) cells and identified the underlying mechanisms. It was found that treatment with EMCL significantly inhibited the proliferation of RCC cells in vitro and increased the induction of apoptosis by activating the mitochondria- and caspase-dependent pathway. Simultaneously, EMCL suppressed cell invasion and metastasis by inhibiting epithelial-mesenchymal transition, as observed in a microfluidic chip assay. Furthermore, using immunofluorescence analysis, an electrophoretic mobility shift assay and a dual-luciferase reporter assay, it was shown that treatment with EMCL significantly suppressed the expression of cyclooxygenase-2 by inhibiting the translocation of NF-κB p50/p65 and the activity of NF-κB. Collectively, the results indicated that EMCL suppressed tumor growth by inhibiting the activation of NF-κB and suggested that EMCL may be a novel anticancer agent in the treatment of RCC.