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2022 ◽  
Author(s):  
Zun-Qiang Zhou ◽  
Jiao Guan ◽  
Shi-Geng Chen ◽  
Jian-Hua Sun ◽  
Zheng-Yun Zhang

Abstract Background: We hypothesized that Sirtuin 1 (SIRT1) might attenuate the Warburg effect in tumor cells by modulating hypoxia-induced factor-1 alpha (HIF-1α) expression. This study aimed to explore the role and the underlying mechanism of SIRT1 in protecting the mitochondrial functions in hepatocellular carcinoma (HCC) cells. Methods: Quantitative real-time PCR and western blot analysis were conducted to determine gene expression in HCC cells. Co-immunoprecipitation (co-IP), chromatin immunoprecipitation (ChIP), and luciferase reporter assays were performed to examine DNA-protein interactions. Colony formation and MTT assays were carried out to explore the role of SIRT1 in HCC cell proliferation in vitro. PLC5 and Huh7 tumor xenografts were generated in mice to investigate the role of SIRT1–HIF-1α signaling in HCC development in vivo. Results: In different HCC cell lines, overexpression of SIRT1 promoted oxidative phosphorylation-associated gene expressions, ATP production, cell proliferation, and apoptotic protein expression while attenuating VEGF expression. In mice, overexpression of SIRT1 resulted in significant reductions in the weights of PLC5 and Huh7 tumor xenografts. Knockdown of SIRT1 exhibited opposite effects. Mechanistically, overexpression of SIRT1 promoted HIF-1α deacetylation, VHL-mediated HIF-1α degradation, and AMPK expression. Furthermore, SIRT1 interfered with the HIF-1α–c-Myc interaction to stimulate the transcription of a mitochondrial biogenesis enhancer mitochondrial transcription factor A (TFAM). Overexpression of HIF-1α completely reversed the effects of SIRT1.Conclusions: SIRT1 protects the mitochondria of HCC cells via suppressing HIF-1α expression, suggesting that SIRT1 may exert antitumor activity in HCC by reducing the Warburg effect.


Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 6030
Author(s):  
Felicia Krämer ◽  
Benedikt Gröner ◽  
Chris Hoffmann ◽  
Austin Craig ◽  
Melanie Brugger ◽  
...  

Purpose: The preclinical evaluation of 3-l- and 3-d-[18F]FPhe in comparison to [18F]FET, an established tracer for tumor imaging. Methods: In vitro studies were conducted with MCF-7, PC-3, and U87 MG human tumor cell lines. In vivo µPET studies were conducted in healthy rats with/without the inhibition of peripheral aromatic l-amino acid decarboxylase by benserazide pretreatment (n = 3 each), in mice bearing subcutaneous MCF-7 or PC-3 tumor xenografts (n = 10), and in rats bearing orthotopic U87 MG tumor xenografts (n = 14). Tracer accumulation was quantified by SUVmax, SUVmean and tumor-to-brain ratios (TBrR). Results: The uptake of 3-l-[18F]FPhe in MCF-7 and PC-3 cells was significantly higher relative to [18F]FET. The uptake of all three tracers was significantly reduced by the suppression of amino acid transport systems L or ASC. 3-l-[18F]FPhe but not 3-d-[18F]FPhe exhibited protein incorporation. In benserazide-treated healthy rats, brain uptake after 42–120 min was significantly higher for 3-d-[18F]FPhe vs. 3-l-[18F]FPhe. [18F]FET showed significantly higher uptake into subcutaneous MCF-7 tumors (52–60 min p.i.), while early uptake into orthotopic U87 MG tumors was significantly higher for 3-l-[18F]FPhe (SUVmax: 3-l-[18F]FPhe, 107.6 ± 11.3; 3-d-[18F]FPhe, 86.0 ± 4.3; [18F]FET, 90.2 ± 7.7). Increased tumoral expression of LAT1 and ASCT2 was confirmed immunohistologically. Conclusion: Both novel tracers enable accurate tumor delineation with an imaging quality comparable to [18F]FET.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Chuang Li ◽  
Lijuan Zhu ◽  
Lijun Fu ◽  
Mingli Han ◽  
Ya Li ◽  
...  

Abstract Background Circular RNAs (circRNAs) have become a hot topic in the area of tumor biology due to its closed structure and the post-transcriptional regulatory effect. This study aims to clarify the roles of circRNA nuclear receptor-interacting protein 1 (NRIP1; circNRIP1) and the possible mechanisms in papillary thyroid carcinoma (PTC). Methods The real-time PCR was used to detect the expression level of CircRNA NRIP1 in PTC specimens and cell lines. The effects of CircRNA NRIP1 and miR-195-5p on the PTC cell functions were detected by MTT, transwell, and flow cytometry assays. Dual-luciferase reporter assays and pull down assays were used to verify the association between circRNA NRIP1 and miR-195-5p. The murine xenograft models were constructed to detect the roles of CircRNA NRIP1 and miR-195-5p. Western blot was applied to detect the effects of CircRNA NRIP1 and miR-195-5p on the P38 MAPK and JAK/STAT singling pathways. Results CircRNA NRIP1 was over-expressed in PTC tissues and cells and the high levels of CircRNA NRIP1 were correlated with advanced PTC stage. Depletion of CircRNA NRIP1 inhibited PTC cell proliferation, invasion, while accelerated apoptosis. miR-195-5p upregulation repressed proliferation and invasion capabilities, and accelerated apoptosis of PTC cell lines and restraining the growth of tumor xenografts, while the functions were reversed following CircRNA NRIP1 overexpression in PTC cells and tumor xenografts. Besides, the protein levels of p-p38, p-JAK2 and p-STAT1 were remarkably down-regulated in miR-195-5p overexpressed PTC cells and tumor xenografts, whereas CircRNA NRIP1 up-regulation overturned the impacts. Conclusions In conclusion, CircRNA NRIP1 promoted PTC progression by accelerating PTC cells proliferation, invasion and tumor growth, while impeding apoptosis by way of sponging miR-195-5p and regulating the P38 MAPK and JAK/STAT pathways.


2021 ◽  
Author(s):  
Tao-Yan Lin ◽  
Jun-Shuang Jia ◽  
Wei-Ren Luo ◽  
Sheng-Jun Xiao ◽  
Xiao-Lin Lin ◽  
...  

Abstract In recent years, the development of adjunctive therapeutic hyperthermia for cancer therapy has received considerable attention. However, the mechanisms underlying hyperthermia resistance are still poorly understood. In this study, we investigated the roles of cold-inducible RNA binding protein (Cirbp) in regulating hyperthermia resistance and underlying mechanisms in nasopharyngeal carcinoma (NPC). Our results firstly revealed that hyperthermia significantly attenuated the stemness property of NPC cells, while combination treatment of hyperthermia and oridonin dramatically increased the killing effect on NPC cells and cancer stem cell (CSC)-like population. Moreover, hyperthermia substantially improved the sensitivity of radiation-resistant NPC cells and CSC-like cells to radiotherapy. Hyperthermia noticeably suppressed Cirbp expression in NPC cells and xenograft tumor tissues. Furthermore, Cirbp inhibition remarkably boosted anti-tumor-killing activity of hyperthermia against NPC cells and CSC-like cells, whereas ectopic expression of Cirbp compromised tumor-killing effect of hyperthermia on these cells, indicating that Cirbp overexpression induces hyperthermia resistance. ThermomiR-377–3p improved the sensitivity of NPC cells and cancer stem-like cells to hyperthermia in vitro by directly suppressing Cirbp expression. More importantly, our results displayed the significantly boosted sensitization of tumor xenografts to hyperthermia by Cirbp silencing in vivo, but ectopic expression of Cirbp nearly completely counteracted hyperthermia-mediated tumor cell-killing effect against tumor xenografts in vivo. Mechanistically, Cirbp silencing-induced inhibition of DNA damage repair by inactivating ATM-Chk2 and ATR-Chk1 pathways, decrease in stemness and increase in cell death contributed to hyperthermic sensitization; conversely, Cirbp overexpression-induced promotion of DNA damage repair, increase in stemness and decrease in cell apoptosis contributed to hyperthermia resistance. Taken together, these findings reveal a previously unrecognized role for Cirbp in positively regulating hyperthermia resistance and suggest that thermomiR-377–3p and its target gene Cirbp represent promising targets for therapeutic hyperthermia.


2021 ◽  
Author(s):  
Mahan Si ◽  
Yujia Song ◽  
Xiaohui Wang ◽  
Dong Wang ◽  
Xiaohui Liu ◽  
...  

Abstract Background: CXCR7 is an atypical chemokine receptor that transmits biased signal independent of G-protein activation. However, whether CXCL12/CXCR7 biased signal activation plays an essential role in colorectal cancer (CRC) progression and metastasis remains obscure. Methods: The functional role of CXCL12/CXCR7 biased signal in CRC was investigated by RNA-sequencing, Transwell assay and in vivo tumor xenografts. YAP1 nuclear translocation and molecular mechanisms were determined by cell transfection, luciferase activity assay, immunofluorescence, coimmunoprecipitation and immunohistochemistry and RT-qPCR analysis.Results: In this study, CXCR7 CXCL12/overexpression promotes Epithelial-to-mesenchymal transition (EMT) and upregulates the expression of stem marker doublecortin-like kinase 1 (DCLK1) in CRC cells with concurrent repression of miR-124-3p and miR-188-5p. Further luciferase assay prove that these miRNAs could regulate EMT by direct targeting vimentin and DCLK1. More importantly, CXCL12/CXCR7/β-arrestin1-mediated biased signal induces YAP1 nuclear translocation, which functions as a transcriptional repressor by interacting with Yin Yang 1 (YY1) and recruiting YY1 to the promoter of miR-124-3p and miR-188-5p. Pharmacological inhibitor of YAP1 recapitulates the anti-tumorigenesis and anti-metastasis effects of YAP1 depletion upon CXCR7 activation in tumor xenografts. Clinically, the expression of CXCR7 was positively correlated with nuclear YAP1 levels and EMT markers. Conclusions: Our findings revealed the novel role of YAP1 nuclear translocation in promoting EMT of CRC by repressing miR-124-3p and miR-188-5p through CXCL12/CXCR7/β-arrestin1 biased signal activation. These findings highlight the potential of targeting YAP1 nuclear translocation in hampering CXCL12/CXCR7 biased signal-induced metastasis of CRC.


2021 ◽  
Vol 4 (9) ◽  
pp. 2100139
Author(s):  
Nabila Laroui ◽  
Nicolas Cubedo ◽  
Mireille Rossel ◽  
Nadir Bettache

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Arman Romiani ◽  
Johan Spetz ◽  
Emman Shubbar ◽  
Dan E. Lind ◽  
Bengt Hallberg ◽  
...  

Abstract Background Neuroblastoma (NB) is one of the most frequently diagnosed tumors in infants. NB is a neuroendocrine tumor type with various characteristics and features, and with diverse outcome. The most malignant NBs have a 5-year survival rate of only 40–50%, indicating the need for novel and improved treatment options. 177Lu-octreotate is routinely administered for treatment of neuroendocrine tumors overexpressing somatostatin receptors (SSTR). The aim of this study was to examine the biodistribution of 177Lu-octreotate in mice bearing aggressive human NB cell lines, in order to evaluate the potential usefulness of 177Lu-octreotate for treatment of NB. Methods BALB/c nude mice bearing CLB-BAR, CLB-GE or IMR-32 tumor xenografts (n = 5–7/group) were i.v. injected with 0.15 MBq, 1.5 MBq or 15 MBq 177Lu-octreotate and sacrificed 1 h, 24 h, 48 h and 168 h after administration. The radioactivity concentration was determined for collected tissue samples, tumor-to-normal-tissue activity concentration ratios (T/N) and mean absorbed dose for each tissue were calculated. Immunohistochemical (IHC) staining for SSTR1–5, and Ki67 were carried out for tumor xenografts from the three cell lines. Results High 177Lu concentration levels and T/N values were observed in all NB tumors, with the highest for CLB-GE tumor xenografts (72%IA/g 24 h p.i.; 1.5 MBq 177Lu-octreotate). The mean absorbed dose to the tumor was 6.8 Gy, 54 Gy and 29 Gy for CLB-BAR, CLB-GE and IMR-32, respectively, p.i. of 15 MBq 177Lu-octreotate. Receptor saturation was clearly observed in CLB-BAR, resulting in higher concentration levels in the tumor when lower activity levels where administered. IHC staining demonstrated highest expression of SSTR2 in CLB-GE, followed by CLB-BAR and IMR-32. Conclusion T/N values for all three human NB tumor xenograft types investigated were high relative to previously investigated neuroendocrine tumor types. The results indicate a clear potential of 177Lu-octreotate as a therapeutic alternative for metastatic NB.


Author(s):  
Sergio Muñoz Vázquez ◽  
Heike Endepols ◽  
Thomas Fischer ◽  
Samir-Ghali Tawadros ◽  
Melanie Hohberg ◽  
...  

Abstract Purpose We present here a Zr-89-labeled inhibitor of prostate-specific membrane antigen (PSMA) as a complement to the already established F-18- or Ga-68-ligands. Procedures The precursor PSMA-DFO (ABX) was used for Zr-89-labeling. This is not an antibody, but a peptide analogue of the precursor for the production of [177Lu]Lu-PSMA-617. The ligand [89Zr]Zr-PSMA-DFO was compared with [68Ga]Ga-PSMA-11 and [18F]F-JK-PSMA-7 in vitro by determination of the Kd value, cellular uptake, internalization in LNCaP cells, biodistribution studies with LNCaP prostate tumor xenografts in mice, and in vivo by small-animal PET imaging in LNCaP tumor mouse models. A first-in-human PET was performed with [89Zr]Zr-PSMA-DFO on a patient presenting with a biochemical recurrence after brachytherapy and an ambiguous intraprostatic finding with [18F]F-JK-PSMA-7 but histologically benign cells in a prostate biopsy 7 months previously. Results [89Zr]Zr-PSMA-DFO was prepared with a radiochemical purity ≥ 99.9% and a very high in vitro stability for up to 7 days at 37 °C. All radiotracers showed similar specific cellular binding and internalization, in vitro and comparable tumor uptake in biodistribution experiments during the first 5 h. The [89Zr]Zr-PSMA-DFO achieved significantly higher tumor/background ratios in LNCaP tumor xenografts (tumor/blood: 309 ± 89, tumor/muscle: 450 ± 38) after 24 h than [68Ga]Ga-PSMA-11 (tumor/blood: 112 ± 57, tumor/muscle: 58 ± 36) or [18F]F-JK-PSMA-7 (tumor/blood: 175 ± 30, tumor/muscle: 114 ± 14) after 4 h (p < 0.01). Small-animal PET imaging demonstrated in vivo that tumor visualization with [89Zr]Zr-PSMA-DFO is comparable to [68Ga]Ga-PSMA-11 or [18F]F-JK-PSMA-7 at early time points (1 h p.i.) and that PET scans up to 48 h p.i. clearly visualized the tumor at late time points. A late [89Zr]Zr-PSMA-DFO PET scan on a patient with biochemical recurrence (BCR) had demonstrated intensive tracer accumulation in the right (SUVmax 13.25, 48 h p.i.) and in the left prostate lobe (SUV max 9.47), a repeat biopsy revealed cancer cells on both sides. Conclusion [89Zr]Zr-PSMA-DFO is a promising PSMA PET tracer for detection of tumor areas with lower PSMA expression and thus warrants further clinical evaluation.


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