scholarly journals CXCR4 intracellular protein promotes drug resistance and tumorigenic potential by inversely regulating the expression of Death Receptor 5

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Mushtaq A. Nengroo ◽  
Shrankhla Maheshwari ◽  
Akhilesh Singh ◽  
Ayushi Verma ◽  
Rakesh K. Arya ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Drug Resistance ◽  
Transcriptional Repression ◽  
Clinical Success ◽  
Death Receptor 5 ◽  
Loss Of Function ◽  
Intracellular Protein ◽  
The Impact

AbstractChemokine receptor CXCR4 overexpression in solid tumors has been strongly associated with poor prognosis and adverse clinical outcome. However, blockade of CXCL12-CXCR4 signaling axis by inhibitors like Nox-A12, FDA approved CXCR4 inhibitor drug AMD3100 have shown limited clinical success in cancer treatment. Therefore, exclusive contribution of CXCR4-CXCL12 signaling in pro-tumorigenic function is questionable. In our pursuit to understand the impact of chemokine signaling in carcinogenesis, we reveal that instead of CXCR4-CXCL12 signaling, presence of CXCR4 intracellular protein augments paclitaxel resistance and pro-tumorigenic functions. In search of pro-apoptotic mechanisms for CXCR4 mediated drug resistance; we discover that DR5 is a new selective target of CXCR4 in breast and colon cancer. Further, we detect that CXCR4 directs the differential recruitment of transcription factors p53 and YY1 to the promoter of DR5 in course of its transcriptional repression. Remarkably, inhibiting CXCR4-ligand-mediated signals completely fails to block the above phenotype. Overexpression of different mutant versions of CXCR4 lacking signal transduction capabilities also result in marked downregulation of DR5 expression in colon cancer indeed confirms the reverse relationship between DR5 and intracellular CXCR4 protein expression. Irrespective of CXCR4 surface expression, by utilizing stable gain and loss of function approaches, we observe that intracellular CXCR4 protein selectively resists and sensitizes colon cancer cells against paclitaxel therapy in vitro and in vivo. Finally, performing TCGA data mining and using human breast cancer patient samples, we demonstrate that expression of CXCR4 and DR5 are inversely regulated. Together, our data suggest that targeting CXCR4 intracellular protein may be critical to dampen the pro-tumorigenic functions of CXCR4.

scholarly journals Review HCV Antiviral Resistance: The Impact of in vitro Studies on the Development of Antiviral Agents Targeting the Viral NS5B Polymerase

2005 ◽  
Vol 16 (4) ◽  
pp. 225-245 ◽  
Author(s):  
Licia Tomei ◽  
Sergio Altamura ◽  
Giacomo Paonessa ◽  
Raffaele De Francesco ◽  
Giovanni Migliaccio
Keyword(s):  
Drug Resistance ◽  
Clinical Success ◽  
Antiviral Agents ◽  
High Genetic Diversity ◽  
Drug Resistance Profile ◽  
Hcv Ns5b ◽  
Effective Drugs ◽  
The Impact

The high prevalence of the disease caused by hepatitis C virus (HCV) and the limited efficacy of interferon-based therapies have stimulated the search for safer and more effective drugs. The development of inhibitors of the HCV NS5B RNA polymerase represents a promising strategy for identifying novel anti-HCV therapeutics. However, the high genetic diversity, mutation rate and turnover of HCV are expected to favour the emergence of drug resistance, limiting the clinical usefulness of polymerase inhibitors. Thus, the characterization of the drug-resistance profile of these antiviral agents is considered crucial for identifying the inhibitors with a higher probability of clinical success. In the absence of an efficient in vitro infection system, HCV sub-genomic replicons have been used to study viral resistance to both nucleoside and non-nucleoside NS5B inhibitors. While these studies suggest that drug-resistant viruses are likely to evolve in vivo, they provide a wealth of information that should help in the identification of inhibitors with improved and distinct resistance profiles that might be used for combination therapy.

scholarly journals Liver X Receptor Nuclear Receptors Are Transcriptional Regulators of Dendritic Cell Chemotaxis

2018 ◽  
Vol 38 (10) ◽  
Author(s):  
Susana Beceiro ◽  
Attila Pap ◽  
Zsolt Czimmerer ◽  
Tamer Sallam ◽  
Jose A. Guillén ◽  
...  
Keyword(s):  
Nuclear Receptors ◽  
Low Density Lipoprotein ◽  
Myeloid Cells ◽  
Density Lipoprotein ◽  
Loss Of Function ◽  
Transcriptional Responses ◽  
Cd38 Expression ◽  
The Impact

ABSTRACTThe liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues. LXRs exert additional biological functions as negative regulators of inflammation, particularly in macrophages. However, the transcriptional responses controlled by LXRs in other myeloid cells, such as dendritic cells (DCs), are still poorly understood. Here we used gain- and loss-of-function models to characterize the impact of LXR deficiency on DC activation programs. Our results identified an LXR-dependent pathway that is important for DC chemotaxis. LXR-deficient mature DCs are defective in stimulus-induced migrationin vitroandin vivo. Mechanistically, we show that LXRs facilitate DC chemotactic signaling by regulating the expression of CD38, an ectoenzyme important for leukocyte trafficking. Pharmacological or genetic inactivation of CD38 activity abolished the LXR-dependent induction of DC chemotaxis. Using the low-density lipoprotein receptor-deficient (LDLR−/−) LDLR−/−mouse model of atherosclerosis, we also demonstrated that hematopoietic CD38 expression is important for the accumulation of lipid-laden myeloid cells in lesions, suggesting that CD38 is a key factor in leukocyte migration during atherogenesis. Collectively, our results demonstrate that LXRs are required for the efficient emigration of DCs in response to chemotactic signals during inflammation.

scholarly journals P-selectin glycoprotein ligand regulates the interaction of multiple myeloma cells with the bone marrow microenvironment

Blood ◽  
2012 ◽  
Vol 119 (6) ◽  
pp. 1468-1478 ◽  
Author(s):  
Abdel Kareem Azab ◽  
Phong Quang ◽  
Feda Azab ◽  
Costas Pitsillides ◽  
Brian Thompson ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Resistance ◽  
Stromal Cells ◽  
Critical Role ◽  
Loss Of Function ◽  
Downstream Signaling ◽  
Target Organs ◽  
Regulation Of Growth

Abstract Interactions between multiple myeloma (MM) cells and the BM microenvironment play a critical role in the pathogenesis of MM and in the development of drug resistance by MM cells. Selectins are involved in extravasation and homing of leukocytes to target organs. In the present study, we focused on adhesion dynamics that involve P-selectin glycoprotein ligand-1 (PSGL-1) on MM cells and its interaction with selectins in the BM microenvironment. We show that PSGL-1 is highly expressed on MM cells and regulates the adhesion and homing of MM cells to cells in the BM microenvironment in vitro and in vivo. This interaction involves both endothelial cells and BM stromal cells. Using loss-of-function studies and the small-molecule pan-selectin inhibitor GMI-1070, we show that PSGL-1 regulates the activation of integrins and downstream signaling. We also document that this interaction regulates MM-cell proliferation in coculture with BM microenvironmental cells and the development of drug resistance. Furthermore, inhibiting this interaction with GMI-1070 enhances the sensitization of MM cells to bortezomib in vitro and in vivo. These data highlight the critical contribution of PSGL-1 to the regulation of growth, dissemination, and drug resistance in MM in the context of the BM microenvironment.

scholarly journals Andean Berry (Vaccinium meridionale Swartz) Juice in Combination With Aspirin Modulated Apoptotic Signaling in Colon Cancer In Vitro and In Vivo

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 261-261
Author(s):  
Sandra Arango-Varela ◽  
Ivan Luzardo ◽  
Maria Maldonado-Celis
Keyword(s):  
Colorectal Cancer ◽  
Colon Cancer ◽  
In Silico ◽  
Aberrant Crypt Foci ◽  
Apoptotic Signaling ◽  
Polyphenolic Composition ◽  
Apoptotic Effects ◽  
The Impact

Abstract Objectives This research aimed to assess the impact of Andean Berry (Vaccinium meridionale Swartz) juice (ABJ) in combination with Aspirin in the apoptotic signaling in colon cancer in vitro and in vivo. We hypothesized that ABJ + Aspirin would produce the most effective anti-proliferative and pro-apoptotic effects in vitro and in vivo. Methods The polyphenolic composition of ABJ was carried out by HPLC-DAD. ABJ (0–30% v/v), Aspirin (0–20 mM), and their mixture were evaluated for their pro-apoptotic effects in human SW480 colorectal cancer cells, followed by human apoptosis proteomic and bioinformatic analysis and in silico docking potential between ABJ components and selected pro-apoptotic targets. For the in vivo assays, colorectal cancer was induced with two injections (separated 1 week each) of azoxymethane (AOM: 15 mg/kg body weight, BW), and treatments were evaluated for its chemopreventive and chemoprotective effects. Hence, 30 male and female Balb/c mice were randomly divided in 5 groups: negative control (basal diet, BD); and four AOM-induced groups: positive control (BD), Aspirin (25 mg/kg BW + BD), ABJ (30% v/v in drinking water ABJ + BD), and ABJ + Aspirin (30% v/v ABJ + 25 mg/kg BW Aspirin + BD). Macroscopic and histopathological parameters were evaluated in vivo. Results The mixture displayed the highest antiproliferative effects (+46%), arrested cell cycle at the G2/M phase, decreased cloning efficiency, but reduced Caspase 3/7 activity, suggesting an alternative apoptotic pathway, compared to untreated SW480 cells. Several pro-apoptotic (cytochrome C, TNFRSF1A, Bax, and Bad) and anti-apoptotic (Hsp70/Hsp32) proteins were decreased. ABJ flavonoids (rutin and kaempferol) exhibited the highest in silico affinity with proteins like TRAILR2 or Catalase. Both chemopreventive and chemoprotective approaches showed similar body/liver weight outcomes, but the mixture displayed the strongest aberrant crypt foci reduction in vivo. The chemopreventive approach was more effective in protecting the colon from AOM. Conclusions Results suggested the potential of ABJ to reduce Aspirin use in the alleviation of colorectal cancer markers in vitro and in vivo, modulating alternate pro-apoptotic signaling. Funding Sources The funding provided by COLCIENCIAS and DGAPA-CTIC-UNAM is appreciated.

Effect of the ADAPT strategy on dormant CD133+ colon cancer stem cells (CSC) and molecular complete remission measured by peripheral blood mononuclear (PBMC) CD133 mRNA.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e14153-e14153
Author(s):  
Edward H. Lin ◽  
Yu Xiazhen ◽  
Xi C He ◽  
Xifeng Wu ◽  
Yang Xie ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Median Survival ◽  
Treatment Protocol ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear ◽  
Colon Cells ◽  
Ca Ix ◽  
The Impact

e14153 Background: The median survival for patients with unresectable metastatic colorectal cancer (CRC) is ~2 years with modern chemotherapy which yields only 5-10% complete responses (CR) including metastasectomy. Recurrences after CR are very common thanks to presence of dormant CSC that are best targeted by our proposed two-step ADAPT strategy: activate from dormancy and potentiate targeting. We examine this strategy in various CRC models and reviewed the impact on stemess including CD133 mRNA, a circulating CSC marker that predict colon cancer relapse. Methods: Different CRC models (in vitro and in vivo) were interrogated similar to clinical ADAPT treatment protocol using capecitabine (or 5FU) plus celecoxib. We also conducted IRB approved retrospective review of unresectable metastatic CRC patients treated ADAPT therapy and in those who also had PBMC CD133 mRNA measured. Results: Contrary to 5FU, which eliminates proliferating CRC cells via apoptosis but also stimulates stemness, celecoxib preferentially deplete CD133+ colon cells and exert potent stemness inhibition via rapid tumor necrosis by perturbing hypoxia and energy metabolism via CA-IX. Following response to first-line chemotherapy, ADAPT strategy plus radiation improved CR or near CR rate to 49/126 (40%) in unresectable CRC patients whose median survival had reached 92.7 months (95% CI, 53.5 months - not reached). Paradoxically, none surgical CR patients (n= 16) enjoyed 100% 5-year relapse free survival compared to 42% of surgical patients (p = 0.04). The PBMC CD133 mRNA in five long-term CR patients were 0.0024, 0.29, 0.5, 0.56, 2.96 respectively, all below previously reported cutoff value of 4.79 for recurrence and far below CD133 mRNA levels (28, 375, 3997, 15662, 83240) in none CR patients. Conclusions: ADAPT plus radiation preferentially targets colon CSC via hypoxia/CA-IX and improves clinical CR rate and molecular CR as measured by PBMC CD133 mRNA. We are actively interrogating the effects of ADAPT strategies in a phase II study funded by Gateway in CRC patients and in genetic CRC animal models.

Nav1.7 target modulation and efficacy can be measured in nonhuman primate assays

2021 ◽  
Vol 13 (594) ◽  
pp. eaay1050
Author(s):  
Richard L. Kraus ◽  
Fuqiang Zhao ◽  
Parul S. Pall ◽  
Dan Zhou ◽  
Joshua D. Vardigan ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Clinical Studies ◽  
Clinical Success ◽  
Rhesus Macaques ◽  
Phase 1 ◽  
Analgesic Efficacy ◽  
Loss Of Function ◽  
Noxious Heat

Humans with loss-of-function mutations in the Nav1.7 channel gene (SCN9A) show profound insensitivity to pain, whereas those with gain-of-function mutations can have inherited pain syndromes. Therefore, inhibition of the Nav1.7 channel with a small molecule has been considered a promising approach for the treatment of various human pain conditions. To date, clinical studies conducted using selective Nav1.7 inhibitors have not provided analgesic efficacy sufficient to warrant further investment. Clinical studies to date used multiples of in vitro IC50 values derived from electrophysiological studies to calculate anticipated human doses. To increase the chance of clinical success, we developed rhesus macaque models of action potential propagation, nociception, and olfaction, to measure Nav1.7 target modulation in vivo. The potent and selective Nav1.7 inhibitors SSCI-1 and SSCI-2 dose-dependently blocked C-fiber nociceptor conduction in microneurography studies and inhibited withdrawal responses to noxious heat in rhesus monkeys. Pharmacological Nav1.7 inhibition also reduced odor-induced activation of the olfactory bulb (OB), measured by functional magnetic resonance imaging (fMRI) studies consistent with the anosmia reported in Nav1.7 loss-of-function patients. These data demonstrate that it is possible to measure Nav1.7 target modulation in rhesus macaques and determine the plasma concentration required to produce a predetermined level of inhibition. The calculated plasma concentration for preclinical efficacy could be used to guide human efficacious exposure estimates. Given the translatable nature of the assays used, it is anticipated that they can be also used in phase 1 clinical studies to measure target modulation and aid in the interpretation of phase 1 clinical data.

TRAIL/Apo2L ligand selectively induces apoptosis and overcomes drug resistance in multiple myeloma: therapeutic applications

Blood ◽  
2001 ◽  
Vol 98 (3) ◽  
pp. 795-804 ◽  
Author(s):  
Constantine S. Mitsiades ◽  
Steven P. Treon ◽  
Nicholas Mitsiades ◽  
Yoshihito Shima ◽  
Paul Richardson ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Resistance ◽  
Mononuclear Cells ◽  
Nuclear Translocation ◽  
Death Receptor 5 ◽  
Therapeutic Applications ◽  
Trail Receptors ◽  
Induced Apoptosis

Abstract Multiple myeloma (MM) remains incurable and novel treatments are urgently needed. Preclinical in vitro and in vivo evaluations were performed to assess the potential therapeutic applications of human recombinant tumor necrosis factor (TNF)–related apoptosis-inducing ligand/Apo2 ligand (TRAIL/Apo2L) in MM. TRAIL/Apo2L potently induced apoptosis of MM cells from patients and the majority of MM cell lines, including cells sensitive or resistant to dexamethasone (Dex), doxorubicin (Dox), melphalan, and mitoxantrone. TRAIL/Apo2L also overcame the survival effect of interleukin 6 on MM cells and did not affect the survival of peripheral blood and bone marrow mononuclear cells and purified B cells from healthy donors. The status of the TRAIL receptors (assessed by immunoblotting and flow cytometry) could not predict TRAIL sensitivity of MM cells. The anti-MM activity of TRAIL/Apo2L was confirmed in nu/xid/bg mice xenografted with human MM cells; TRAIL (500 μg intraperitoneally daily for 14 days) was well tolerated and significantly suppressed the growth of plasmacytomas. Dox up-regulated the expression of the TRAIL receptor death receptor 5 (DR5) and synergistically enhanced the effect of TRAIL not only against MM cells sensitive to, but also against those resistant to, Dex- or Dox-induced apoptosis. Nuclear factor (NF)-κB inhibitors, such as SN50 (a cell-permeable inhibitor of the nuclear translocation and transcriptional activity of NF-κB) or the proteasome inhibitor PS-341, enhanced the proapoptotic activity of TRAIL/Apo2L against TRAIL-sensitive MM cells, whereas SN50 reversed the TRAIL resistance of ARH-77 and IM-9 MM cells. Importantly, normal B lymphocytes were not sensitized to TRAIL by either Dox, SN50, or PS-341. These preclinical studies suggest that TRAIL/Apo2L can overcome conventional drug resistance and provide the basis for clinical trials of TRAIL-based treatment regimens to improve outcome in patients with MM.

scholarly journals The METTL3/MALAT1/PTBP1/USP8/TAK1 axis promotes pyroptosis and M1 polarization of macrophages and contributes to liver fibrosis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Bo Shu ◽  
Ying-Xia Zhou ◽  
Hao Li ◽  
Rui-Zhi Zhang ◽  
Chao He ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Western Blot ◽  
Rna Stability ◽  
Interferon Γ ◽  
In Vivo Model ◽  
Loss Of Function ◽  
M1 Polarization ◽  
The Impact

AbstractPro-inflammatory M1 macrophages, via activating hepatic stellate cells, contribute to liver fibrosis. In this study, we examined the mechanism and the significance of a signaling axis, METTL3/MALAT1/PTBP1/USP8/TAK1, in regulating pyroptosis and M1 polarization of hepatic macrophages. Liver fibrosis model was established in vivo by CCl4 treatment; M1 polarization was induced in vitro by treating macrophages with lipopolysaccharide or interferon γ. Expressions of METTL3, MALAT1, PTBP1, USP8, and TAK1 were measured by RT-PCR and/or Western blot in Kupffer cells (KCs) isolated from in vivo model or in vitro activated macrophages. Macrophage phenotypes including inflammation (RT-qPCR analysis of a panel of proinflammatory cytokines and ELISA on productions of interleukin (IL)−1β and IL-18) and pyroptosis (Western blot of NLRP3, Caspase-1, and GSDMD) were investigated. The impact of METTL3 on m6A methylation of MALAT1 was examined by methylated RNA immunoprecipitation (RIP), the interaction between PTBP1 and MALAT1 or USP8 mRNA by combining RNA pull-down, RIP, and RNA stability assays, and the crosstalk between USP8 and TAK1 by co-immunoprecipitation and protein degradation assays. Functional significance of individual component of METTL3/MALAT1/PTBP1/USP8/TAK1 axis was assessed by combining gain-of-function and loss-of-function approaches. In KCs isolated from in vivo liver fibrosis model or in vitro M1-polarized macrophages, METTL3 was up-regulated, and sequentially, it increased MALAT1 level via m6A methylation, which promoted USP8 mRNA degradation through the interaction with PTBP1. Reduced USP8 expression regulated the ubiquitination and protein stability of TAK1, which promoted pyroptosis and inflammation of macrophages. The signaling cascade METTL3/MALAT1/PTBP1/USP8/TAK1, by essentially stimulating pyroptosis and inflammation of macrophages, aggravates liver fibrosis. Therefore, targeting individual components of this axis may benefit the treatment of liver fibrosis.

scholarly journals CXCR4 intracellular protein regulates drug resistance and tumorigenic potential via modulating the expression of Death Receptor 5

2019 ◽  
Author(s):  
Mushtaq Ahmed Nengroo ◽  
Shrankhla Maheshwari ◽  
Akhilesh Singh ◽  
Anup Kumar Singh ◽  
Rakesh Kumar Arya ◽  
...  
Keyword(s):  
Clinical Success ◽  
Death Receptor ◽  
Surface Expression ◽  
Therapy Resistance ◽  
Death Receptor 5 ◽  
Intracellular Protein ◽  
Human Patient ◽  
Cxcr4 Signaling ◽  
Inhibitor Drug

AbstractCXCR4 overexpression in solid tumors has been strongly associated with poor prognosis and adverse clinical outcome. However, CXCR4 signaling inhibitor drug Plerixafor has shown limited clinical success in cancer treatment. Therefore, CXCR4 signaling may not be the exclusive contributor to its pro-tumorigenic functions. In our continuous effort to understand the chemokine receptor signaling inhibition as cancer therapy, here we unexpectedly discovered that instead of its signaling, intracellular CXCR4 protein augments therapy resistance and pro-tumorigenic functions. Unbiased proteome profiler apoptosis array followed by immunoblot, FACS, real-time PCR and ChIP analyses demonstrate that CXCR4 promotes DR5 downregulation via modulating differential recruitment of transcription factors p53 and YY1 to its promoter. Surprisingly, inhibiting CXCR4 mediated signals failed to block the above phenotype. Irrespective of CXCR4 surface expression, its loss compromised colon tumor growth in vivo. Finally, TCGA data mining and human patient sample data analysis showed CXCR4 and DR5 are inversely regulated in human cancers. Together, we showed evidence for the first time that targeting CXCR4 intracellular protein may be critical to dampen the pro-tumorigenic functions of CXCR4.

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