The CXCR4/CXCL12 chemokine axis can chemotactically accumulate inflammatory cells to local tissues and regulate the release of inflammatory factors. Developing novel CXCR4 modulators may provide a desirable strategy to control the development of inflammation. A series of novel hybrids were designed by integrating the key pharmacophores of three CXCR4 modulators. The majority of compounds displayed potent CXCR4 binding affinity. Compound 7a exhibited 1000-fold greater affinity than AMD3100 and significantly inhibited invasion of CXCR4-positive tumor cells. Additionally, compound 7a blocked mice ear inflammation by 67% and suppressed the accumulation of inflammatory cells in an in vivo mouse ear edema evaluation. Western blot analyses revealed that 7a inhibited the CXCR4/CXCL12-mediated phosphorylation of Akt and p44 in a dose-dependent manner. Moreover, compound 7a had no observable cytotoxicity and displayed a favorable plasma stability in our preliminary pharmacokinetic study. These results confirmed that this is a feasible method to develop CXCR4 modulators for the regulation and reduction of inflammation.
CXCR4 plays a crucial role in the inflammatory disease process, providing an attractive means for drug targeting. A series of novel amide-sulfamide derivatives were designed, synthesized and comprehensively evaluated. This new scaffold exhibited much more potent CXCR4 inhibitory activity, with more than 70% of the compounds showed notably better binding affinity than the reference drug AMD3100 in the binding assay. Additionally, in the Matrigel invasion assay, most of our compounds significantly blocked the tumor cell invasion, demonstrating superior efficacy compared to AMD3100. Furthermore, compound IIj blocked mice ear inflammation by 75% and attenuated ear edema and damage substantially in an in vivo model of inflammation. Western blot analyses revealed that CXCR4 modulator IIj significantly blocked CXCR4/CXCL12-mediated phosphorylation of Akt. Moreover, compound IIj had no observable cytotoxicity and displayed a favourable plasma stability in our preliminary pharmacokinetic study. The preliminary structure-activity relationships were also summarized. In short, this novel amide-sulfamide scaffold exhibited potent CXCR4 inhibitory activity both in vitro and in vivo. These results also confirmed that developing modulators targeting CXCR4 provides an exciting avenue for treatment of inflammation.
Histone deacetylases regulate a wide variety of cellular functions and have been implicated in redifferentiation of various tumors. Histone deacetylase inhibitors (HDACi) are potential pharmacologic agents to improve outcomes for patients with gliomas. We assessed the therapeutic efficacy of belinostat (PXD-101), an HDACi with blood-brain barrier permeability. Belinostat was first tested in an orthotopic rat glioma model to assess in vivo tumoricidal effect. Our results showed that belinostat was effective in reducing tumor volume in the orthotopic rat glioma model in a dose-dependent manner. We also tested the antidepression activity of belinostat in 2 animal models of depression and found it to be effective. Furthermore, we confirmed that myo-inositol levels improved by belinostat treatment in vitro. In a human pilot study, it was observed that belinostat in combination with chemoradiation may delay initial recurrence of disease. Excitingly, belinostat significantly improved depressive symptoms in patients with glioblastoma compared with control subjects. Finally, spectroscopic magnetic resonance imaging of 2 patient cases from this pilot study are presented to indicate how spectroscopic magnetic resonance imaging can be used to monitor metabolite response and assess treatment effect on whole brain. This study highlights the potential of belinostat to be a synergistic therapeutic agent in the treatment of gliomas.
Multidrug resistance-associated protein (MRP-1/ABCC1) transports a wide range of therapeutic agents and may play a critical role in the development of multidrug resistance (MDR) in tumor cells. However, the regulation of MRP-1 remains controversial. To explore whether miRNAs are involved in the regulation of MRP-1 expression and modulate the sensitivity of tumor cells to chemotherapeutic agents, we analyzed miRNA expression levels in VP-16-resistant MDR cell line, MCF-7/VP, in comparison with its parent cell line, MCF-7, using a miRNA microarray. MCF-7/VP overexpressed MRP-1 mRNA and protein not MDR-1 and BCRP. miR-326 was downregulated in MCF-7/VP compared to MCF-7. Additionally, miR-326 was downregulated in a panel of advanced breast cancer tissues and consistent reversely with expression levels of MRP-1. Furthermore, the elevated levels of miR-326 in the mimics-transfected VP-16-resistant cell line, MCF-7/VP, downregulated MRP-1 expression and sensitized these cells to VP-16 and doxorubicin. These findings demonstrate for the first time the involvement of miRNAs in multidrug resistance mediated by MRP-1 and suggest that miR-326 may be an efficient agent for preventing and reversing MDR in tumor cells.
The CXCR4/CXCL12 axis plays prominent roles in tumor metastasis and inflammation. CXCR4 has been shown to be involved in a variety of inflammation-related diseases. Therefore, CXCR4 is a promising potential target to develop novel anti-inflammatory agents. Taking our previously discovered CXCR4 modulator RB-108 as the lead compound, a series of derivatives were synthesized structurally modifying and optimizing the amide and sulfamide side chains. The derivatives successfully maintained potent CXCR4 binding affinity. Furthermore, compounds IIb, IIc, IIIg, IIIj, and IIIm were all efficacious in inhibiting the invasion of CXCR4-positive cells, displaying a much more potent effect than the lead compound RB-108. Notably, compound IIIm significantly decreased carrageenan-induced swollen volume and paw thickness in a mouse paw edema model. More importantly, IIIm exhibited satisfying PK profiles with a half-life of 4.77 h in an SD rat model. In summary, we have developed compound IIIm as a new candidate for further investigation based on the lead compound RB-108.
Background: Metastasis, the spread and growth of tumor cells to distant organ sites, represents the most devastating attribute and plays a major role in the morbidity and mortality of cancer. Inflammation is crucial for malignant tumor transformation and survival. Thus, blocking inflammation is expected to serve as an effective cancer treatment. Among anti-inflammation therapies, chemokine modulation is now beginning to emerge from the pipeline. CXC chemokine receptor-4 (CXCR4) and its ligand stromal cell-derived factor-1 (CXCL12) interaction and the resulting cell signaling cascade have emerged as highly relevant targets since they play pleiotropic roles in metastatic progression. The unique function of CXCR4 is to promote the homing of tumor cells to their microenvironment at the distant organ sites.
Methodology/Principal Findings: We describe the actions of N,N'-(1,4-phenylenebis(methylene))dipyrimidin-2-amine (designated MSX-122), a novel small molecule and partial CXCR4 antagonist with properties quite unlike that of any other reported CXCR4 antagonists, which was prepared in a single chemical step using a reductive amination reaction. Its specificity toward CXCR4 was tested in a binding affinity assay and a ligand competition assay using 18F-labeled MSX-122. The potency of the compound was determined in two functional assays, Matrigel invasion assay and cAMP modulation. The therapeutic potential of MSX-122 was evaluated in three different murine models for inflammation including an experimental colitis, carrageenan induced paw edema, and bleomycin induced lung fibrosis and three different animal models for metastasis including breast cancer micrometastasis in lung, head and neck cancer metastasis in lung, and uveal melanoma micrometastasis in liver in which CXCR4 was reported to play crucial roles.
Conclusions/Significance: We developed a novel small molecule, MSX-122, that is a partial CXCR4 antagonist without mobilizing stem cells, which can be safer for long-term blockade of metastasis than other reported CXCR4 antagonists.
Nuclear factor kappa B (NF-κB) is a key signaling molecule in the elaboration of the inflammatory response. Data indicate that curcumin, a natural ingredient of the curry spice turmeric, acts as a NF-κB inhibitor and exhibits both anti-inflammatory and anti-cancer properties. Curcumin analogues with enhanced activity on the NF-κB and other inflammatory signaling pathways have been developed including the synthetic monoketone compound termed 3,5-Bis(2-fluorobenzylidene)-4-piperidone (EF24). 3,5-Bis(2-pyridinylmethylidene)-4-piperidone (EF31) is a structurally-related curcumin analogue whose potency for NF-κB inhibition has yet to be determined. To examine the activity of EF31 compared to EF24 and curcumin, mouse RAW264.7 macrophages were treated with EF31, EF24, curcumin (1–100µM) or vehicle (DMSO 1%) for 1 hour. NF-κB pathway activity was assessed following treatment with lipopolysaccharide (LPS) (1µg/mL). EF31 (IC50 ~5µM) exhibited significantly more potent inhibition of LPS-induced NF-κB DNA binding compared to both EF24 (IC50~35µM) and curcumin (IC50 >50µM). In addition, EF31 exhibited significantly greater inhibition of NF-κB nuclear translocation as well as the induction of downstream inflammatory mediators including pro-inflammatory cytokine mRNA and protein (tumor necrosis factor-α, interleukin-1β, and interleukin-6). Regarding the mechanism of these effects on NF-κB activity, EF31 (IC50~1.92µM) exhibited significantly greater inhibition of IκB kinase β compared to EF24 (IC50~131µM). Finally, EF31 demonstrated potent toxicity in NF-κB-dependent cancer cell lines while having minimal and reversible toxicity in RAW264.7 macrophages. These data indicate that EF31 is a more potent inhibitor of NF-κB activity than either EF24 or curcumin while exhibiting both anti-inflammatory and anticancer activities. Thus, EF31 represents a promising curcumin analogue for further therapeutic development.
Glioblastoma (GBM) is the most common primary brain tumor and is uniformly fatal despite aggressive surgical and adjuvant therapy. Since survival is short, it is critical to determine the value of therapy early on in treatment. Improved early predictive assessment would allow neuro-oncologists to personalize and adjust or change treatment sooner to maximize use of efficacious therapy. During carcinogenesis, tumor suppressor genes can be silenced by aberrant histone deacetylation. This epigenetic modification has become an important target for tumor therapy. Suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza; Merck & Co., Inc.) is an orally active, potent inhibitor of histone deacetylase (HDAC) activity. A major shortcoming of the use of HDAC inhibitors in treating brain tumor patients is the lack of reliable biomarkers to predict and determine response. Histological evaluation may reflect tumor viability following treatment but it is an invasive procedure and impractical for GBM. Another problem is that response to SAHA therapy is associated with tumor redifferentiation and cytostasis rather than tumor size reduction, thus limiting the use of traditional imaging methods. A noninvasive method to assess drug delivery and efficacy is needed. Here, we investigated whether changes in 1H MRS metabolites could render reliable biomarkers for an early response to SAHA treatment in an orthotopic animal model for glioma. Untreated tumors exhibited significantly elevated alanine and lactate levels and reduced inositol, NAA and creatine, typical changes reported in GBM compared to normal brain tissues. The proton MRS-detectable metabolites of SAHA treated tumors were restored toward those of normal-like brain tissues. In addition, reduced inositol and NAA were found to be potential biomarkers for mood alteration and depression, which may also be alleviated with SAHA treatment. Our study suggests that 1H MRS can provide reliable metabolic biomarkers at the earliest stage of SAHA treatment to predict the therapeutic response.
The C-X-C chemokine receptor type 4 (CXCR4) is a potential therapeutic target for HIV infection, metastatic cancer, and inflammatory autoimmune diseases. In this study, we screened the ZINC chemical database for novel CXCR4 modulators through a series of in silico guided processes. After evaluating the screened compounds for their binding affinities to CXCR4 and inhibitory activities against the chemoattractant CXCL12, we identified a hit compound (ZINC 72372983) showing 100 nM affinity and 69% chemotaxis inhibition at the same concentration (100 nM). To increase the potency of our hit compound, we explored the protein-ligand interactions at an atomic level using molecular dynamics simulation which enabled us to design and synthesize a novel compound (Z7R) with nanomolar affinity (IC50 = 1.25 nM) and improved chemotaxis inhibition (78.5%). Z7R displays promising anti-inflammatory activity (50%) in a mouse edema model by blocking CXCR4-expressed leukocytes, being supported by our immunohistochemistry study.
Despite major advances in targeted drug therapy and radiation therapy, surgery remains the most effective treatment for most solid tumors. The single most important predictor of patient survival is a complete surgical resection of the primary tumor, draining lymph nodes, and metastatic lesions. Presently, however, 20%-30% of patients with head and neck cancer who undergo surgery still leave the operating room without complete resection because of missed lesions. Thus, major opportunities exist to develop advanced imaging tracers and intraoperative instrumentation that would allow surgeons to visualize microscopic tumors during surgery. The cell adhesion molecule integrin αvβ3 is specifically expressed by tumor neovasculature and invading tumor cells, but not by quiescent vessels or normal cells. Here we report the combined use of an integrin-targeting near-infrared tracer (RGD-IRDye800CW) and a handheld spectroscopic device, an integrated point spectroscopy with wide-field imaging system, for highly sensitive detection of integrin overexpression on infiltrating cancer cells. By using an orthotopic head and neck cancer animal model, we show that this tracer-device combination allows intraoperative detection of not only invasive tumor margins but also metastatic lymph nodes. Correlated histological analysis further reveals that microscopic clusters of 50-100 tumor cells can be detected intraoperatively with high sensitivity and specificity, raising new possibilities in guiding surgical resection of microscopic tumors and metastatic lymph nodes.