Dissecting the spatial heterogeneity of single circulating tumor cells reveals immune evasion through MAX regulated CCL5 overexpression in hepatocellular carcinoma.

2019 ◽  
Vol 37 (4_suppl) ◽  
pp. 246-246
Author(s):  
Yun-Fan Sun ◽  
Xin-Rong Yang ◽  
Fan Jia

246 Background: The transcriptional heterogeneity and immune evasion mechanisms of CTCs during systemic circulation are not well defined. Methods: Blood was drawn from 4 different vascular sites, including hepatic vein (HV), peripheral artery (PA), peripheral vein (PV) and portal vein (PoV) of 10 localized HCC patients. Single CTCs were isolated by negative enrichment and robotic micromanipulator, followed by single-cell RNA-sequencing (sc-RNAseq). After filtering, 113 CTCs with qualified data remained were subjected to further bioinformatics analysis. The scRNA-seq results were further validated in three independent cohorts of HCC patients. Results: Our scRNA-seq data revealed remarkable intra- and inter-vascular heterogeneity among CTCs from four vascular sites. We determined CTC transcriptional dynamics during transportation through consecutive vascular compartments and revealed their adaptation mechanisms under biomechanical stress during circulation. We further classified CTCs from different vascular sites into two subsets, namely dormant CTCs and activated CTCs. Dormant CTCs were associated with a non-cycling state and upregulation of EMT/angiogenic signatures and showed stronger prognostic ability for early recurrence than activated CTCs did. Furthermore, we discovered an immune escape mechanism by which CTCs recruited regulatory T cells (Tregs) via expression of CCL5, consequently promoting the formation of an immunosuppressive microenvironment favorable for their survival in the bloodstream and seeding in secondary organs. We proved that MAX, activated through the p38 pathway, was the key transcriptional factor regulating CCL5 overexpression, which was validated by ChIP, luciferase reporter gene and in vitro/vivo knockdown assays. And we further determined that Tregs-derived TGF-β1 can heighten MAX expression, thus amplifying the CCL5 expression. Conclusions: Collectively, our results reveal a previously unappreciated spatial heterogeneity of CTCs and a CTC immune-escape mechanism, which may aid in designing new anti-metastasis therapeutic strategies in HCC.

2021 ◽  
Vol 11 ◽  
Author(s):  
Moein Dehbashi ◽  
Zohreh Hojati ◽  
Majid Motovali-bashi ◽  
Mohamad Reza Ganjalikhany ◽  
William C. Cho ◽  
...  

For many years, high-affinity subunit of IL-2 receptor (CD25) has been considered as a promising therapeutic target for different pathologic conditions like allograft rejection, autoimmunity, and cancers. Although CD25 is transiently expressed by newly-activated T cells, it is the hallmark of regulatory T (Treg) cells which are the most important immunosuppressive elements in tumor microenvironment. Thus, Tregs can be considered as a potential target for chimeric antigen receptor (CAR)-based therapeutic approaches. On the other hand, due to some profound adverse effects pertaining to the use of CAR T cells, CAR NK cells have caught researchers’ attention as a safer choice. Based on these, the aim of this study was to design and develop a CAR NK cell against CD25 as the most prominent biomarker of Tregs with the prospect of overcoming immune escape mechanism in solid and liquid cancers. In the current study, an anti-CD25 CAR was designed and evaluated by comprehensive in silico analyses. Then, using lentiviral transduction system, NK-92 cell line was engineered to express this anti-CD25 CAR construct. In vitro functional analyses of anti-CD25 CAR for its reactivity against CD25 antigen as well as for cytotoxicity and cytokine production assays against CD25 bearing Jurkat cell line were done. In silico analyses demonstrated that the anti-CD25 CAR transcript and scFv protein structures were stable and had proper interaction with the target. Also, in vitro analyses showed that the anti-CD25 CAR-engineered NK-92 cells were able to specifically detect and lyse target cells with an appropriate cytokine production and cytotoxic activity. To conclude, the results showed that this novel CAR NK cell is functional and warrant further investigations.


2020 ◽  
Vol 20 (6) ◽  
pp. 715-723
Author(s):  
Natarajan Nandakumar ◽  
Pushparathinam Gopinath ◽  
Jacob Gopas ◽  
Kannoth M. Muraleedharan

Background: The authors investigated the NF-κB inhibitory role of three Benzisothiazolone (BIT) derivatives (1, 2 and 3) in Hodgkin’s Lymphoma cells (L428) which constitutively express activated NF-κB. All three compounds showed dose-dependent NF-κB inhibition (78.3, 70.7 and 34.6%) in the luciferase reporter gene assay and were found cytotoxic at IC50 values of 3.3μg/ml, 4.35μg/ml and 13.8μg/ml, respectively by the XTT assay. BIT 1and BIT 2 (but not BIT 3) suppressed both NF-κB subunits p50 and p65 in cytoplasmic and nuclear extracts in a concentration-dependent manner. Furthermore, BIT 1 showed a moderate synergistic effect with the standard chemotherapy drugs etoposide and doxorubicin, whereas BIT 2 and 3 showed a moderate additive effect to antagonistic effect. Cisplatin exhibited an antagonist effect on all the compounds tested under various concentrations, except in the case of 1.56μg/ml of BIT 3 with 0.156μg/ml of cisplatin. The compounds also inhibited the migration of adherent human lung adenocarcinoma cells (A549) in vitro. We conclude that especially BIT 1 and BIT 2 have in vitro anti-inflammatory and anti-cancer activities, which can be further investigated for future potential therapeutic use. Methods: Inspired by the electrophilic sulfur in Nuphar alkaloids, monomeric and dimeric benzisothiazolones were synthesized from dithiodibenzoic acid and their NF-κB inhibitory role was explored. NF-κB inhibition and cytotoxicity of the synthesized derivatives were studied using luciferase reporter gene assay and XTTassay. Immunocytochemistry studies were performed using L428 cells. Cell migration assay was conducted using the A549 cell line. L428 cells were used to conduct combination studies and the results were plotted using CompuSyn software. Results: Benzisothiazolone derivatives exhibited cytotoxicity in Hodgkin’s Lymphoma cells through NF-κB inhibition. Potent compounds showed suppression of both NF-κB subunits p50 and p65 in a concentrationdependent manner, both in cytoplasmic and nuclear extracts. Combination studies suggest that benzisothiazolone derivatives possess a synergistic effect with etoposide and doxorubicin. Furthermore, the compounds also inhibited the migration of A549 cells. Conclusion: Benzisothiazolones bearing one or two electrophilic sulfur atoms as part of the heterocyclic framework exhibited cytotoxicity in Hodgkin’s Lymphoma cells through NF-κB inhibition. In addition, these derivatives also exhibited a synergistic effect with etoposide and doxorubicin along with the ability to inhibit the migration of A549 cells. Our study suggests that BIT-based new chemical entities could lead to potential anticancer agents.


Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 11-26
Author(s):  
Maike Busch ◽  
Natalia Miroschnikov ◽  
Jaroslaw Thomas Dankert ◽  
Marc Wiesehöfer ◽  
Klaus Metz ◽  
...  

BACKGROUND: Retinoblastoma (RB) is the most common childhood eye cancer. Chemotherapeutic drugs such as etoposide used in RB treatment often cause massive side effects and acquired drug resistances. Dysregulated genes and miRNAs have a large impact on cancer progression and development of chemotherapy resistances. OBJECTIVE: This study was designed to investigate the involvement of retinoic acid receptor alpha (RARα) in RB progression and chemoresistance as well as the impact of miR-138, a potential RARα regulating miRNA. METHODS: RARα and miR-138 expression in etoposide resistant RB cell lines and chemotherapy treated patient tumors compared to non-treated tumors was revealed by Real-Time PCR. Overexpression approaches were performed to analyze the effects of RARα on RB cell viability, apoptosis, proliferation and tumorigenesis. Besides, we addressed the effect of miR-138 overexpression on RB cell chemotherapy resistance. RESULTS: A binding between miR-138 and RARα was shown by dual luciferase reporter gene assay. The study presented revealed that RARα is downregulated in etoposide resistant RB cells, while miR-138 is endogenously upregulated. Opposing RARα and miR-138 expression levels were detectable in chemotherapy pre-treated compared to non-treated RB tumor specimen. Overexpression of RARα increases apoptosis levels and reduces tumor cell growth of aggressive etoposide resistant RB cells in vitro and in vivo. Overexpression of miR-138 in chemo-sensitive RB cell lines partly enhances cell viability after etoposide treatment. CONCLUSIONS: Our findings show that RARα acts as a tumor suppressor in retinoblastoma and is downregulated upon etoposide resistance in RB cells. Thus, RARα may contribute to the development and progression of RB chemo-resistance.


2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Zhiyuan Lu ◽  
Dawei Wang ◽  
Xuming Wang ◽  
Jilong Zou ◽  
Jiabing Sun ◽  
...  

Abstract Background More and more studies have confirmed that miRNAs play an important role in maintaining bone remodeling and bone metabolism. This study investigated the expression level of miR-206 in the serum of osteoporosis (OP) patients and explored the effect and mechanism of miR-206 on the occurrence and development of osteoporosis. Methods 120 postmenopausal women were recruited, including 63 cases with OP and 57 women without OP. The levels of miR-206 were determined by qRT-PCR technology. Spearman correlation coefficient was used to evaluate the correlation of miR-206 with bone mineral density (BMD). An ROC curve was used to evaluate the diagnostic value of miR-206 in osteoporosis. The effects of miR-206 on cell proliferation and cell apoptosis of hFOBs were measured by CCK-8 assay and flow cytometry, respectively. Luciferase reporter gene assay was used to confirm the interaction of miR-206 and the 3′UTR of HDAC4. Results Serum miR-206 had low expression level in osteoporosis patient group compared with control group. The expression level of serum miR-206 had diagnostic value for osteoporosis, and the serum miR-206 levels were positively correlated with BMD. The down-regulated miR-206 could inhibit cell proliferation and promote cell apoptosis. Luciferase analysis indicated that HDAC4 was the target gene of miR-206. Conclusions MiR-206 could be used as a new potential diagnostic biomarker for osteoporosis, and in in vitro cell experiments, miR-206 may regulate osteoblast cell proliferation and apoptosis by targeting HDAC4.


2021 ◽  
Vol 20 ◽  
pp. 153303382098011
Author(s):  
Junjun Shu ◽  
Ling Xiao ◽  
Sanhua Yan ◽  
Boqun Fan ◽  
Xia Zou ◽  
...  

Objective: Ovarian cancer (OC) ranks one of the most prevalent fatal tumors of female genital organs. Aberrant promoter methylation triggers changes of microRNA (miR)-375 in OC. Our study aimed to evaluate the mechanism of methylated miR-375 promoter region in OC cell malignancy and to seek the possible treatment for OC. Methods: miR-375 promoter methylation level in OC tissues and cells was detected. miR-375 expression in OC tissues and cell lines was compared with that in demethylated cells. Role of miR-375 in OC progression was measured. Dual-luciferase reporter gene assay was utilized to verify the targeting relationship between miR-375 and Yes-associated protein 1 (YAP1). Then, Wnt/β-catenin pathway-related protein expression was tested. Moreover, xenograft transplantation was applied to confirm the in vitro experiments. Results: Highly methylated miR-375 was seen in OC tissues and cell lines, while its expression was decreased as the promoter methylation increased. Demethylation in OC cells brought miR-375 back to normal level, with obviously declined cell invasion, migration and viability and improved apoptosis. Additionally, miR-375 targeted YAP1 to regulate the Wnt/β-catenin pathway protein expression. Overexpressed YAP1 reversed the protein expression, promoted cell invasion, migration and viability while reduced cell apoptosis. Overexpressed miR-375 in vivo inhibited OC progression. Conclusion: Our study demonstrated that demethylated miR-375 inhibited OC growth by targeting YAP1 and downregulating the Wnt/β-catenin pathway. This investigation may offer novel insight for OC treatment.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Kuijie Liu ◽  
Hua Zhao ◽  
Hongliang Yao ◽  
Sanlin Lei ◽  
Zhendong Lei ◽  
...  

MicroRNAs are a class of small, noncoding RNAs that function as critical regulators of gene expression by targeting mRNAs for translational repression or degradation. In this study, we demonstrate that expression of microRNA-124 (miR-124) is significantly downregulated in colorectal cancer tissues and cell lines, compared to the matched adjacent tissues. We identified and confirmed inhibitor of apoptosis-stimulating protein of p53 (iASPP) as a novel, direct target of miR-124 using target prediction algorithms and luciferase reporter gene assays. Overexpression of miR-124 suppressed iASPP protein expression, upregulated expression of the downstream signaling molecule nuclear factor-kappa B (NF-κB), and attenuated cell viability, proliferation, and colony formation in SW480 and HT-29 colorectal cancer cells in vitro. Forced overexpression ofiASPPpartly rescued the inhibitory effect of miR-124 on SW480 and HT29 cell proliferation. Taken together, these findings shed light on the role and mechanism of action of miR-124, indicate that the miR-124/iASPP axis can regulate the proliferation of colorectal cancer cells, and suggest that miR-124 may serve as a potential therapeutic target for colorectal cancer.


2002 ◽  
Vol 76 (8) ◽  
pp. 3881-3891 ◽  
Author(s):  
Neerja Kaushik ◽  
Amartya Basu ◽  
Paul Palumbo ◽  
Rene L. Myers ◽  
Virendra N. Pandey

ABSTRACT The emergence of drug-resistant variants has posed a significant setback against effective antiviral treatment for human immunodeficiency virus (HIV) infections. The choice of a nonmutable region of the viral genome such as the conserved transactivation response element (TAR element) in the 5′ long terminal repeat (LTR) may potentially be an effective target for drug development. We have earlier demonstrated that a polyamide nucleotide analog (PNA) targeted to the TAR hairpin element, when transfected into cells, can effectively inhibit Tat-mediated transactivation of HIV type 1 (HIV-1) LTR (T. Mayhood et al., Biochemistry 39:11532-11539, 2000). Here we show that this anti-TAR PNA (PNATAR), upon conjugation with a membrane-permeating peptide vector (transportan) retained its affinity for TAR in vitro similar to the unconjugated analog. The conjugate was efficiently internalized into the cells when added to the culture medium. Examination of the functional efficacy of the PNATAR-transportan conjugate in cell culture using luciferase reporter gene constructs resulted in a significant inhibition of Tat-mediated transactivation of HIV-1 LTR. Furthermore, PNATAR-transportan conjugate substantially inhibited HIV-1 production in chronically HIV-1-infected H9 cells. The mechanism of this inhibition appeared to be regulated at the level of transcription. These results demonstrate the efficacy of PNATAR-transportan as a potential anti-HIV agent.


2020 ◽  
Vol Volume 12 ◽  
pp. 7881-7890
Author(s):  
Michael Wessolly ◽  
Susann Stephan-Falkenau ◽  
Anna Streubel ◽  
Robert Werner ◽  
Sabrina Borchert ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Huapan Fang ◽  
Zhaopei Guo ◽  
Jie Chen ◽  
Lin Lin ◽  
Yingying Hu ◽  
...  

AbstractImmunotherapy has become a powerful cancer treatment, but only a small fraction of patients have achieved durable benefits due to the immune escape mechanism. In this study, epigenetic regulation is combined with gene therapy-mediated immune checkpoint blockade to relieve this immune escape mechanism. PPD (i.e., mPEG-b-PLG/PEI-RT3/DNA) is developed to mediate plasmid-encoding shPD-L1 delivery by introducing multiple interactions (i.e., electrostatic, hydrogen bonding, and hydrophobic interactions) and polyproline II (PPII)-helix conformation, which downregulates PD-L1 expression on tumour cells to relieve the immunosuppression of T cells. Zebularine (abbreviated as Zeb), a DNA methyltransferase inhibitor (DNMTi), is used for the epigenetic regulation of the tumour immune microenvironment, thus inducing DC maturation and MHC I molecule expression to enhance antigen presentation. PPD plus Zeb combination therapy initiates a systemic anti-tumour immune response and effectively prevents tumour relapse and metastasis by generating durable immune memory. This strategy provides a scheme for tumour treatment and the inhibition of relapse and metastasis.


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