The flavonoid p-hydroxycinnamic acid mediates anticancer effects on MDA-MB-231 human breast cancer cells in vitro: Implications for suppression of bone metastases

Plant molecules reinforce bone repair: Novel insights into phenol-modified bone tissue engineering scaffolds for the treatment of bone defects

Bone defects have become a major cause of disability and death. To overcome the limitations of natural bone implants, including donor shortages and immune rejection risks, bone tissue engineering (BTE) scaffolds have emerged as a promising therapy for bone defects. Despite possessing good biocompatibility, these metal, ceramic and polymer-based scaffolds are still challenged by the harsh conditions in bone defect sites. ROS accumulation, bacterial infection, excessive inflammation, compromised blood supply deficiency and tumor recurrence negatively impact bone tissue cells (BTCs) and hinder the osteointegration of BTE scaffolds. Phenolic compounds, derived from plants and fruits, have gained growing application in treating inflammatory, infectious and aging-related diseases due to their antioxidant ability conferred by phenolic hydroxyl groups. The prevalent interactions between phenols and functional groups also facilitate their utilization in fabricating scaffolds. Consequently, phenols are increasingly incorporated into BTE scaffolds to boost therapeutic efficacy in bone defect. This review demonstrated the effects of phenols on BTCs and bone defect microenvironment, summarized the intrinsic mechanisms, presented the advances in phenol-modified BTE scaffolds and analyzed their potential risks in practical applications. Overall, phenol-modified BTE scaffolds hold great potential for repairing bone defects, offering novel patterns for BTE scaffold construction and advancing traumatological medicine.

Stromal Co-Cultivation for Modeling Breast Cancer Dormancy in the Bone Marrow

Cancers metastasize to the bone marrow before primary tumors can be detected. Bone marrow micrometastases are resistant to therapy, and while they are able to remain dormant for decades, they recur steadily and result in incurable metastatic disease. The bone marrow microenvironment maintains the dormancy and chemoresistance of micrometastases through interactions with multiple cell types and through structural and soluble factors. Modeling dormancy in vitro can identify the mechanisms of these interactions. Modeling also identifies mechanisms able to disrupt these interactions or define novel interactions that promote the reawakening of dormant cells. The in vitro modeling of the interactions of cancer cells with various bone marrow elements can generate hypotheses on the mechanisms that control dormancy, treatment resistance and reawakening in vivo. These hypotheses can guide in vivo murine experiments that have high probabilities of succeeding in order to verify in vitro findings while minimizing the use of animals in experiments. This review outlines the existing data on predominant stromal cell types and their use in 2D co-cultures with cancer cells.

Modulation of TLR/NF-κB/NLRP Signaling by Bioactive Phytocompounds: A Promising Strategy to Augment Cancer Chemotherapy and Immunotherapy

Background

Tumors often progress to a more aggressive phenotype to resist drugs. Multiple dysregulated pathways are behind this tumor behavior which is known as cancer chemoresistance. Thus, there is an emerging need to discover pivotal signaling pathways involved in the resistance to chemotherapeutic agents and cancer immunotherapy. Reports indicate the critical role of the toll-like receptor (TLR)/nuclear factor-κB (NF-κB)/Nod-like receptor pyrin domain-containing (NLRP) pathway in cancer initiation, progression, and development. Therefore, targeting TLR/NF-κB/NLRP signaling is a promising strategy to augment cancer chemotherapy and immunotherapy and to combat chemoresistance. Considering the potential of phytochemicals in the regulation of multiple dysregulated pathways during cancer initiation, promotion, and progression, such compounds could be suitable candidates against cancer chemoresistance.

Objectives

This is the first comprehensive and systematic review regarding the role of phytochemicals in the mitigation of chemoresistance by regulating the TLR/NF-κB/NLRP signaling pathway in chemotherapy and immunotherapy.

Methods

A comprehensive and systematic review was designed based on Web of Science, PubMed, Scopus, and Cochrane electronic databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to include papers on TLR/NF-κB/NLRP and chemotherapy/immunotherapy/chemoresistance by phytochemicals.

Results

Phytochemicals are promising multi-targeting candidates against the TLR/NF-κB/NLRP signaling pathway and interconnected mediators. Employing phenolic compounds, alkaloids, terpenoids, and sulfur compounds could be a promising strategy for managing cancer chemoresistance through the modulation of the TLR/NF-κB/NLRP signaling pathway. Novel delivery systems of phytochemicals in cancer chemotherapy/immunotherapy are also highlighted.

Conclusion

Targeting TLR/NF-κB/NLRP signaling with bioactive phytocompounds reverses chemoresistance and improves the outcome for chemotherapy and immunotherapy in both preclinical and clinical stages.

Mediterranean Diet Food Components as Possible Adjuvant Therapies to Counteract Breast and Prostate Cancer Progression to Bone Metastasis

Bone metastasis is a serious and often lethal complication of particularly frequent carcinomas, such as breast and prostate cancers, which not only reduces survival but also worsens the patients’ quality of life. Therefore, it is important to find new and/or additional therapeutic possibilities that can counteract the colonization of bone tissue. High adherence to the Mediterranean diet (MD) is effective in the prevention of cancer and improves cancer patients’ health, thus, here, we considered its impact on bone metastasis. We highlighted some molecular events relevant for the development of a metastatic phenotype in cancer cells and the alterations of physiological bone remodeling, which occur during skeleton colonization. We then considered those natural compounds present in MD foods with a recognized role to inhibit or reverse the metastatic process both in in vivo and in vitro systems, and we reported the identified mechanisms of action. The knowledge of this bioactivity by the dietary components of the MD, together with its wide access to all people, could help not only to maintain healthy status but also to improve the quality of life of patients with bone metastases.

The phytochemical p-hydroxycinnamic acid suppresses the growth and stimulates the death in human liver cancer HepG2 cells

Hepatocellular carcinoma (HCC) is one of the most prevalent malignant diseases and causes a third of cancer-related death. The prognosis and effective treatment of advanced HCC remains poor in spite of the development of novel therapeutic strategies. In the present study, we investigate anticancer effects of the botanical molecule p-hydroxycinnamic  acid (HCA) in the HepG2 liver cancer model in vitro. Culturing with HCA (10-1000 nM) suppressed colony formation and growth of HepG2 cells. Mechanistically, culturing with HCA decreased levels of Ras, PI3K, Akt, MAPK, NF-κB p65 and β-catenin, which are linked to processes of cell signaling and transcription, and increased levels of retinoblastoma and regucalcin, which are suppressors for carcinogenesis. These alterations may lead to the suppression of cell growth. Furthermore, culturing with HCA (10-1000 nM) stimulated cell death due to increased caspase-3 levels. Interestingly, the effects of HCA on the growth and death of HepG2 cells were inhibited by culturing with CH223191, an antagonist of aryl hydrocarbon receptor (AHR), suggesting that the flavonoid effects are, at least partly, mediated by activation of AHR signaling. Notably, HCA blocked stimulatory effects of Bay K 8644, an agonist of L-type calcium channel, on the growth of HepG2 cells. Thus, our study demonstrates that HCA suppresses the growth and stimulates the death of human liver cancer HepG2 cells in vitro. The botanical molecule HCA may therefore be a useful tool in the treatment of HCC, providing a novel strategy for the therapy of human liver cancers.

Recent advances in chemistry and bioactivity of Sargentodoxa cuneata

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Sargentodoxa comprises only one species, Sargentodoxa cuneata (Oliv.) Rehd et al., widely distributed in the subtropical zone of China. The plant is extensively used in traditional medicine for treating arthritis, joint pains, amenorrhea, acute appendicitis and inflammatory intestinal obstruction. Pharmacological studies show anti-inflammatory, antioxidant, antitumor, antimicrobial, and anti-sepsis activities.

AIM OF THE REVIEW

This review aims to summarize the information about distribution, traditional uses, chemical constituents and pharmacological activities of S. cuneata, as an attempt to provide a scientific basis for its traditional uses and to support its application and development for new drug development.

METHODOLOGY

Scientific information of S. cuneata was retrieved from the online bibliographic databases, including Web of Science, Google Scholar, PubMed, Springer Link, the Wiley online library, SciFinder, Baidu Scholar, China national knowledge infrastructure (CNKI) and WANFANG DATA (up to March 2020). We also search doctoral dissertations, master dissertations conference papers and published books. The keywords were used: "Sargentodoxa", "Da Xue Teng", "Hong Teng", "Xue Teng", "secondary metabolites", "chemical components", "biological activity", "pharmacology", "traditional uses".

OBSERVATIONS AND RESULTS

S. cuneata is utilized as valuable herbal medicines to treat various diseases in China. Over 110 chemical constituents have been isolated and identified from the stem of S. cuneata, including phenolic acids, phenolic glycosides, lignans, flavones, triterpenoids and other compounds. The extract and compounds of S. cuneata have a wide spectrum of pharmacological activities, including antitumor, anti-inflammatory, antioxidant, antimicrobial, anti-sepsis and anti-arthritis effects, as well as protective activity against cerebrovascular diseases.

CONCLUSION

S. cuneata has a rich legacy for the treatment of many diseases, especially arthritis and sepsis, which is reinforced by current investigations. However, the present studies about bioactive chemical constituents and detail pharmacological mechanisms of S. cuneata were insufficient. Further studies should focus on these aspects in relation to its clinical applications. This review has systematically summarized the traditional uses, phytochemical constituents and pharmacological effects of S. cuneata, providing references for the therapeutic potential of new drug development.

The botanical component p-hydroxycinnamic acid suppresses the growth and bone metastatic activity of human prostate cancer PC-3 cells in vitro

Bone metastatic prostate cancer is one of the most common malignancies in developed countries and the second leading cause of cancer-related death in men. There remains no effective treatment for metastatic prostate cancer. We investigate here the anticancer effects of botanical component p-hydroxycinnamic acid (HCA) on the PC-3 cells in vitro model of bone metastatic human prostate cancer. Culturing with HCA (10-1000 nM) suppressed colony formation and growth of PC-3 cells. Mechanistically, culturing with HCA decreased protein levels of Ras, PI3K, Akt, MAPK, NF-κB p65 and β-catenin related to processes of cell signaling and transcription, and it increased levels of p21, p53, retinoblastoma and regucalcin, which are suppressors in carcinogenesis. These alterations can lead to suppression of cell growth. Furthermore, culturing with HCA increased cell death and caspase-3 levels. The effects of HCA on the growth and death of PC-3 cells were blocked by culturing with CH223191, an antagonist of aryl hydrocarbon receptor (AHR), suggesting that HCA effects are partly involved in AHR signaling. Interestingly, HCA suppressed the stimulatory effects of Bay K 8644, an agonist of L-type calcium channel, on the growth of PC-3 cells. Coculturing of PC-3 cells and preosteoblastic MC-3T3 E1 cells increased osteoblastic mineralization. This increase was not attenuated by treatment of HCA that stimulated mineralization. Notably, osteoclastogenesis from preosteoclastic RAW264.7 cells was enhanced by coculturing with PC-3 cells, and this enhancement was suppressed by treatment with HCA (10-1000 nM). Thus, HCA has anticancer effects on bone metastatic human prostate cancer, potentially providing a novel therapeutic tool.

Targeting PI3K/Akt/mTOR signaling pathway by polyphenols: Implication for cancer therapy

Cancer is one of the biggest challenges facing medicine and its cure is regarded to be the Holy Grail of medicine. Therapy in cancer is consisted as various artificial cytotoxic agents and radiotherapy, and recently immunotherapy. Recently much attention has been directed to the use of natural occurring agents in cancer therapy. One of the main group of agents utilized in this regard is polyphenols which are found abundantly in berries, fruits and vegetables. Polyphenols show to exert direct and indirect effects in progression of cancer, angiogenesis, proliferation and enhancing resistance to treatment. One of the cellular pathways commonly affected by polyphenols is PI3K/Akt/mTOR pathway, which has far ranging effects on multiple key aspects of cellular growth, metabolism and death. In this review article, evidence regarding the biology of polyphenols in cancer via PI3K/Akt/mTOR pathway is discussed and their application on cancer pathophysiology in various types of human malignancies is shown.