Modulation of CXCR4, CXCL12, and Tumor Cell Invasion Potential In Vitro by Phytochemicals

Genistein in focus: pharmacological effects and immune pathway modulation in cancer

Cancer is a significant global health concern, responsible for mortality and morbidity of individuals. It is characterized by uncontrolled cellular growth, tumor formation, and potential metastasis. The immune system is pivotal in recognizing and eliminating cancerous cells, with immune cells such as T cells, B cells, natural killer cells (NK), and dendritic cells playing critical roles. Dysregulation of immune responses can contribute to cancer progression. Phytochemicals, bioactive compounds derived from plants, have gained attention for their potential roles in cancer prevention and therapy due to their antioxidant, anti-inflammatory, and immunomodulatory properties. Genistein, an isoflavone found in soy products, is of particular interest. In this study, genistein's mechanisms of action at the molecular and cellular levels in cancer were demonstrated, highlighting its impact on T and B lymphocytes, NK cells and dendritic cells. Genistein's ability to influence cytokine production, reducing levels of inflammatory cytokines such as TNF-α, IL-6, and IL-1β, is emphasized. Genistein modulates inflammatory response pathways like Toll-like receptors (TLRs), NF-κB, chemokines, and MAPK, inhibiting tumor growth, promoting apoptosis, and reducing metastasis. It shows promise in overcoming chemoresistance, particularly in ovarian and neuroblastoma cancers, by inhibiting autophagy. Genistein also affects T-cell execution markers, including granzyme B, TNF-α, and FAS ligand in cancer by influencing key proteins involved in immune response and apoptosis. Clinical trials have investigated genistein's therapeutic potential, revealing its promise in enhancing the efficacy of traditional cancer treatments while mitigating associated toxicities. Genistein helps overcome chemoresistance in various cancers by inhibiting autophagy and promoting apoptosis. It also enhances immunotherapy by boosting immune responses and modifying antigens, but careful dosing is needed when combined with anti-PD-1 treatments to avoid reducing effectiveness.

Nutrients Lowering Obesity-Linked Chemokines Blamable for Metastasis

Food intake is an essential contributor to both health and disease. Nutrients contribute to a beneficial metabolic equilibrium at the cellular level, preventing or delaying disease onset. Dietary intake contributes to obesity, and obesity supports further cancer and metastasis. Metastasis, a multifactorial and multistep process, is supported by the systemic inflammation of obesity. Spreading of the cancer cells requires the presence of a plethora of recruiter and regulator molecules. Molecules such as chemokines are provided at high levels by obesity-associated fat depots. Chemokine up-regulation in adipose tissue of obese individuals has been associated with different types of cancers such as breast, prostate, colon, liver, and stomach. Chemokines support all metastasis steps from invasion/migration to intravasation, circulation, extravasation, and ending with colonization. The obesity pool of chemokines supporting these processes includes CCL2, CCL3, CCL4, CCL5, CCL7, CCL8, CCL11, CCL18, CCL19, CCL20, CXCL1, CXCL5, CXCL 8, CXCL10, and CXCL12. Keeping obesity under control can be beneficial in reducing the levels of pro-inflammatory chemokines and the risk of poor cancer outcome. Nutrients can help, support, and boost cancer treatment effects or jeopardize the treatment. Constituents with anti-inflammatory and anti-obesity properties such as polyphenols, organosulfur components, fatty acids, curcumin, and vitamin E have a proven beneficial effect in lowering obesity and its contribution to metastasis.

Rottlerin and genistein inhibit neuroblastoma cell proliferation and invasion through EF2K suppression and related protein pathways

Neuroblastoma is one of the most common solid tumors in children younger than 1 year of age, with poor prognosis and survival rates. Therefore, novel molecular targets and therapeutic strategies are needed to prolong patient survival. For this purpose, we investigated the effects of rottlerin and genistein separately and in combination on neuroblastoma cells (SH-SY5Y, Kelly). First, the effects of rottlerin and genistein were investigated on cell proliferation. Different rottlerin (1-50 µM) and genistein (5-150 µM) doses were used as experimental groups compared to the control (DMSO/vehicle). The IC50 dose was found to be 5 µM for rottlerin and 30 µM for genistein (P < 0.0001). Other analyses, such as colony formation assays, annexin V/propidium iodide staining, matrigel invasion assays, and Western blot analysis, were performed with these doses and their combinations. To assess statistical significance, statistical analysis was conducted using the one-way ANOVA with the post hoc Tukey test. Our results showed that IC50 doses of rottlerin and genistein induced a significant reduction in cell proliferation, colony formation, and invasion in neuroblastoma cells (P < 0.0001). The combination of these doses increased the levels of inhibition of cell proliferation and invasion while decreasing the level of apoptosis (P 0.0001). Furthermore, these agents caused G1-cell cycle arrest in these cells. Our western blot data showed that rottlerin and genistein treatments markedly inhibit elongation factor 2 kinase (EF2K) and other pro-tumorigenic, metastatic proteins in neuroblastoma cells. These agents probably showed their anti-proliferative, anti-metastatic, and pro-apoptotic effects through EF2K downregulation. Our results suggested that rottlerin and genistein have inhibitory effects on cancer cell proliferation, invasion, and cell cycle and induce apoptosis in both cell lines. Combined treatment with rottlerin and genistein may be a viable approach and beneficial to neuroblastoma patients as the combined effect significantly suppresses the above-mentioned pathways.

Molecular effects of genistein, as a potential anticancer agent, on CXCR-4 and VEGF pathway in acute lymphoblastic leukemia

BACKGROUND

Vascular endothelial growth factor (VEGF) is one of the angiogenic mediators that can be secreted by leukemic cells and plays an important role in tumor invasion and metastasis. Another important agent contributing to the relapse of ALL is C-X-C chemokine receptor type-4 (CXCR-4), expression of this receptor in cancer cells has been related to metastasis. It has been identified that genistein-a soy-derived isoflavonoid-has anti-angiogenesis functions. We aimed to show the effects of this compound on VEGF and CXCR-4 in Acute lymphoblastic leukemia (ALL) cell models.

METHODS AND RESULTS

The cytotoxicity of Genistein was measured using the MTS colorimetric assay. After being treated with Genistein, the expression of VEGF in mRNA and protein levels was measured in MOLT-4 and Jurkat cells. We also used flow cytometry assay to determine the expression of CXCR-4 in cell surfaces. We found that Genistein decreased cell viability in two cell models while was more effective on MOLT-4 cells. After Genistein-treatment, surface expression levels of CXCR-4 were decreased, while VEGF secretion and mRNA expression levels were increased in MOLT-4 and Jurkat cells.

CONCLUSIONS

The results suggest that Genistein may not be a reliable choice for the treatment of ALL; however, this different identified pattern can be useful for the recognition of VEGF and CXCR-4 modulators and thus for planning new treatments for leukemia and other VEGF related disorders.

Soy Isoflavones and Breast Cancer Cell Lines: Molecular Mechanisms and Future Perspectives

The potential benefit of soy isoflavones in breast cancer chemoprevention, as suggested by epidemiological studies, has aroused the interest of numerous scientists for over twenty years. Although intensive work has been done in this field, the preclinical results continue to be controversial and the molecular mechanisms are far from being fully understood. The antiproliferative effect of soy isoflavones has been commonly linked to the estrogen receptor interaction, but there is growing evidence that other pathways are influenced as well. Among these, the regulation of apoptosis, cell proliferation and survival, inhibition of angiogenesis and metastasis or antioxidant properties have been recently explored using various isoflavone doses and various breast cancer cells. In this review, we offer a comprehensive perspective on the molecular mechanisms of isoflavones observed in in vitro studies, emphasizing each time the dose-effect relationship and estrogen receptor status of the cells. Furthermore, we present future research directions in this field which could provide a better understanding of the inner molecular mechanisms of soy isoflavones in breast cancer.

Diet-based strategies for cancer chemoprevention: the role of combination regimens using dietary bioactive components

Chemopreventive agents that the general population can consume for prolonged periods of time with minimal risk of any side effects are of great interest to all in search of a solution to the pervasive incidence of cancer. Dietary bioactive components have been found to modulate many deregulated molecular pathways associated with the initiation and progression of different types of cancer. Combination regimens with dietary bioactive components are a promising strategy for cancer chemoprevention because they may offer enhanced protective effects against cancer development but cause little or no adverse effects. This article provides an overview of studies examining the combination of dietary bioactive components for the chemoprevention of major types of cancer. A better understanding of existing research on the combination of dietary bioactive components will provide an important basis for the rational design of future combination studies and the successful development of cancer chemoprevention strategies.

Up-regulation of miR-146a contributes to the inhibition of invasion of pancreatic cancer cells

Pancreatic cancer (PC) is an aggressive malignancy with high mortality and is believed to be in part due to its highly invasive and metastatic behavior, which is associated with over-expression of EGFR and activation of NF-κB. Emerging evidence also suggest critical roles of microRNAs (miRNAs) in the regulation of various pathobiological processes including metastasis in PC and in other human malignancies. In the present study, we found lower expression of miR-146a in PC cells compared to normal human pancreatic duct epithelial (HPDE) cells. Interestingly, re-expression of miR-146a inhibited the invasive capacity of Colo357 and Panc-1 PC cells with concomitant down-regulation of EGFR and IRAK-1. Mechanistic studies including miR-146a re-expression, anti-miR-146 transfection, and EGFR knock-down experiment showed that there was a crosstalk between EGFR, MTA-2, IRAK-1, IκBα and NF-κB. Most importantly, we found that the treatment of PC cells with "natural agents" [3,3'-diinodolylmethane (DIM) or isoflavone] led to an increase in the expression of miR-146a and consequently down-regulated the expression of EGFR, MTA-2, IRAK-1 and NF-κB, resulting in the inhibition of invasion of Colo357 and Panc-1 cells. These results provide experimental evidence in support of the role of DIM and isoflavone as potential non-toxic agents as regulators of miRNA, which could be useful for the inhibition of cancer cell invasion and metastasis, and further suggesting that these agents could be important for designing novel targeted strategy for the treatment of PC.

Systemic neutralization of IL-17A significantly reduces breast cancer associated metastasis in arthritic mice by reducing CXCL12/SDF-1 expression in the metastatic niches

Background

IL-17A is a pro-inflammatory cytokine that is normally associated with autoimmune arthritis and other pro-inflammatory conditions. Recently, IL-17A has emerged as a critical factor in enhancing breast cancer (BC)-associated metastases. We generated immune competent arthritic mouse models that develop spontaneous BC-associated bone and lung metastasis. Using these models, we have previously shown that neutralization of IL-17A resulted in significant reduction in metastasis. However, the underlying mechanism/s remains unknown.

Methods

We have utilized two previously published mouse models for this study: 1) the pro-arthritic mouse model (designated SKG) injected with metastatic BC cell line (4T1) in the mammary fat pad, and 2) the PyV MT mice that develop spontaneous mammary gland tumors injected with type II collagen to induce autoimmune arthritis. Mice were treated with anti-IL-17A neutralizing antibody and monitored for metastasis and assessed for pro-inflammatory cytokines and chemokines associated with BC-associated metastasis.

Results

We first corroborate our previous finding that in vivo neutralization of IL-17A significantly reduced metastasis to the bones and lungs in both models. Next, we report that treatment with anti-IL17A antibody significantly reduced the expression of a key chemokine, CXCL12 (also known as stromal derived factor-1 (SDF - 1)) in the bones and lungs of treated mice. CXCL12 is a ligand for CXCR4 (expressed on BC cells) and their interaction is known to be critical for metastasis. Interestingly, levels of CXCR4 in the tumor remained unchanged with treatment. Consequently, protein lysates derived from the bones and lungs of treated mice were significantly less chemotactic for the BC cells than lysates from untreated mice; and addition of exogenous SDF-1 to the lysates from treated mice completely restored BC cell migration. In addition, cytokines such as IL-6 and M-CSF were significantly reduced in the lung and bone lysates following treatment. The data presented suggests that systemic neutralization of IL-17A can block the CXCR4/SDF-1 signaling pathway by reducing the expression of SDF-1 in the metastatic niches and significantly reducing metastasis in both mouse models.

Conclusion

In our model, neutralization of IL-17A regulates SDF-1 expression in the metastatic niches either directly or indirectly via reducing levels of IL-6 and M-CSF.

Cisplatin targets the stromal cell-derived factor-1-CXC chemokine receptor type 4 axis to suppress metastasis and invasion of ovarian cancer-initiating cells

In ovarian cancer, CD44+/CD117+ stem cells, also known as cancer-initiating cells (CICs), are highly proliferative and invasive. Therefore, the CD44+/CD117+ subpopulation is thought to be an important target for novel therapeutic strategies. In this study, we investigated the effects of cisplatin (CDDP) on metastasis and invasion suppression of ovarian CICs by targeting the CXC chemokine receptor-4 (CXCR4) signaling pathway in vitro and in vivo. CD44+/CD117+ ovarian CICs were enriched from human primary ovarian tumor tissues and confirmed by flow cytometry sorting. A 3-(4,5-dimethylthiazol-2-yl)-2.5-dipheny-tetrazolium bromide (MTT) assay revealed significant inhibition of proliferation of ovarian CICs with increasing CDDP drug concentrations. Moreover, colony formation and transwell migration assays indicated that CDDP significantly suppressed the invasive capacity of ovarian CICs in vitro. The expression levels of stromal cell-derived factor (SDF)-1, CXCR4, matrix metalloproteinase (MMP) 2, and MMP9 mRNA and protein levels were significantly reduced in CDDP-treated cells compared to untreated ovarian CICs. Furthermore, xenograft experiments confirmed that CDDP suppressed the growth of xenograft tumors formed by ovarian CICs in vivo. In addition, CXCR4 agonist (diprotin A) treatment of ovarian CICs weakened the effects of CDDP and enhanced SDF-1-CXCR4 axis expression in ovarian CICs. Thus, the SDF-1-CXCR4 axis is an important mediator of proliferation and invasion in CXCR4-overexpressing ovarian cancer-initiating cells (OCICs). Furthermore, CDDP inhibits invasion and metastasis of OCICs by targeting SDF-1-CXCR4 axis expression.

Rapid generation of multiplexed cell cocultures using acoustic droplet ejection followed by aqueous two-phase exclusion patterning

The development of tools for patterning cocultures of cells is a fundamental interest among cell biologists and tissue engineers. Although a variety of systems exist for micropatterning cells, the methods used to generate cell micropatterns are often cumbersome and difficult to adapt for tissue engineering purposes. This study combines acoustic droplet ejection and aqueous two-phase system exclusion patterning to introduce a method for patterning cocultures of cells in multiplexed arrays. This new method uses focused acoustic radiation pressure to eject discrete droplets of uniform size from the surface of a dextran solution containing cells. The size of droplets is controlled by adjusting ultrasound parameters, such as pulse, duration, and amplitude. The ejected dextran droplets are captured on a cell culture substrate that is manipulated by a computer-controlled 3D positioning system according to predesigned patterns. Polyethylene glycol solution containing an additional cell type is then added to the culture dish to produce a two-phase system capable of depositing different types of cells around the initial pattern of cells. We demonstrate that our method can produce patterns of islands or lines with two or more cell types. Further, we demonstrate that patterns can be multiplexed for studies involving combinations of multiple cell types. This method offers a tool to transfer cell-containing samples in a contact-free, nozzle-less manner, avoiding sample cross-contamination. It can be used to pattern cell cocultures without complicated fabrication of culture substrates. These capabilities were used to examine the response of cancer cells to the presence of a ligand (CXCL12) secreted from surrounding cocultured cells.

Mechanisms and therapeutic implications of cell death induction by indole compounds

Indole compounds, obtained from cruciferous vegetables, are well-known for their anti-cancer properties. In particular, indole-3-carbinol (I3C) and its dimeric product, 3,3′-diindolylmethane (DIM), have been widely investigated for their effectiveness against a number of human cancers in vitro as well as in vivo. These compounds are effective inducers of apoptosis and the accumulating evidence documenting their ability to modulate multiple cellular signaling pathways is a testimony to their pleiotropic behavior. Here we attempt to update current understanding on the various mechanisms that are responsible for the apoptosis-inducing effects by these compounds. The significance of apoptosis-induction as a desirable attribute of anti-cancer agents such as indole compounds cannot be overstated. However, an equally intriguing property of these compounds is their ability to sensitize cancer cells to standard chemotherapeutic agents. Such chemosensitizing effects of indole compounds can potentially have major clinical implications because these non-toxic compounds can reduce the toxicity and drug-resistance associated with available chemotherapies. Combinational therapy is increasingly being realized to be better than single agent therapy and, through this review article, we aim to provide a rationale behind combination of natural compounds such as indoles with conventional therapeutics.

Inhibition of cancer cell invasion and metastasis by genistein

Genistein is a small, biologically active flavonoid that is found in high amounts in soy. This important compound possesses a wide variety of biological activities, but it is best known for its ability to inhibit cancer progression. In particular, genistein has emerged as an important inhibitor of cancer metastasis. Consumption of genistein in the diet has been linked to decreased rates of metastatic cancer in a number of population-based studies. Extensive investigations have been performed to determine the molecular mechanisms underlying genistein's antimetastatic activity, with results indicating that this small molecule has significant inhibitory activity at nearly every step of the metastatic cascade. Reports have demonstrated that, at high concentrations, genistein can inhibit several proteins involved with primary tumor growth and apoptosis, including the cyclin class of cell cycle regulators and the Akt family of proteins. At lower concentrations that are similar to those achieved through dietary consumption, genistein can inhibit the prometastatic processes of cancer cell detachment, migration, and invasion through a variety of mechanisms, including the transforming growth factor (TGF)-beta signaling pathway. Several in vitro findings have been corroborated in both in vivo animal studies and in early-phase human clinical trials, demonstrating that genistein can both inhibit human cancer metastasis and also modulate markers of metastatic potential in humans, respectively. Herein, we discuss the variety of mechanisms by which genistein regulates individual steps of the metastatic cascade and highlight the potential of this natural product as a promising therapeutic inhibitor of metastasis.

Mammalian Per-Arnt-Sim proteins in environmental adaptation

The Per-Arnt-Sim (PAS) domain is conserved across the kingdoms of life and found in an ever-growing list of proteins. This domain can bind to and sense endogenous or xenobiotic small molecules such as molecular oxygen, cellular metabolites, or polyaromatic hydrocarbons. Members of this family are often found in pathways that regulate responses to environmental change; in mammals these include the hypoxia, circadian, and dioxin response pathways. These pathways function in development and throughout life to regulate cellular, organ, and whole-organism adaptive responses. Remarkably, in the case of the clock, this adaptation includes anticipation of environmental change. In this review, we summarize the roles of PAS domain-containing proteins in mammals. We provide structural evidence that functionally classifies both known and unknown biological roles. Finally, we discuss the role of PAS proteins in anticipation of and adaptation to environmental change.

miR-146a suppresses invasion of pancreatic cancer cells

The aggressive course of pancreatic cancer is believed to reflect its unusually invasive and metastatic nature, which is associated with epidermal growth factor receptor (EGFR) overexpression and NF-kappaB activation. MicroRNAs (miRNA) have been implicated in the regulation of various pathobiological processes in cancer, including metastasis in pancreatic cancer and in other human malignancies. In this study, we report lower expression of miR-146a in pancreatic cancer cells compared with normal human pancreatic duct epithelial cells. Reexpression of miR-146a inhibited the invasive capacity of pancreatic cancer cells with concomitant downregulation of EGFR and the NF-kappaB regulatory kinase interleukin 1 receptor-associated kinase 1 (IRAK-1). Cellular mechanism studies revealed crosstalk between EGFR, IRAK-1, IkappaBalpha, NF-kappaB, and MTA-2, a transcription factor that regulates metastasis. Treatment of pancreatic cancer cells with the natural products 3,3'-diinodolylmethane (DIM) or isoflavone, which increased miR-146a expression, caused a downregulation of EGFR, MTA-2, IRAK-1, and NF-kappaB, resulting in an inhibition of pancreatic cancer cell invasion. Our findings reveal DIM and isoflavone as nontoxic activators of a miRNA that can block pancreatic cancer cell invasion and metastasis, offering starting points to design novel anticancer agents.

Role of chemokine network in the development and progression of ovarian cancer: a potential novel pharmacological target

Ovarian cancer is the most common type of gynecologic malignancy. Despite advances in surgery and chemotherapy, the survival rate is still low since most ovarian cancers relapse and become drug-resistant. Chemokines are small chemoattractant peptides mainly involved in the immune responses. More recently, chemokines were also demonstrated to regulate extra-immunological functions. It was shown that the chemokine network plays crucial functions in the tumorigenesis in several tissues. In particular the imbalanced or aberrant expression of CXCL12 and its receptor CXCR4 strongly affects cancer cell proliferation, recruitment of immunosuppressive cells, neovascularization, and metastasization. In the last years, several molecules able to target CXCR4 or CXCL12 have been developed to interfere with tumor growth, including pharmacological inhibitors, antagonists, and specific antibodies. This chemokine ligand/receptor pair was also proposed to represent an innovative therapeutic target for the treatment of ovarian cancer. Thus, a thorough understanding of ovarian cancer biology, and how chemokines may control these different biological activities might lead to the development of more effective therapies. This paper will focus on the current biology of CXCL12/CXCR4 axis in the context of understanding their potential role in ovarian cancer development.