141: RET/PTC1 in vitro models unveil a novel tumor suppressor miRNA in papillary thyroid carcinoma

2014 ◽  
Vol 50 ◽  
pp. S31
Author(s):  
E. Minna ◽  
P. Romeo ◽  
L. De Cecco ◽  
M. Dugo ◽  
G. Cassinelli ◽  
...  
2021 ◽  
Vol 49 (4) ◽  
pp. 030006052110083
Author(s):  
Zhenya Gao ◽  
Fang Yu ◽  
Huanxia Jia ◽  
Zhuo Ye ◽  
Shijie Yao

Objective To detect the expression of FK506-binding protein 5 (FKBP5) in human papillary thyroid carcinoma (PTC) tissues, and explore its possible role in the progression of PTC. Methods FKBP5 expression levels were assessed in 115 PTC tissues and corresponding normal tissues by immunohistochemistry. We also examined the correlations between FKBP5 expression and clinicopathological factors and survival in 75 patients with PTC. The effects of FKBP5 on the proliferation and apoptosis of PTC cells were detected by colony-formation, MTT, and flow cytometry assays, respectively. We further investigated the effects of FKBP5 on tumor growth in mice. Results We revealed high expression levels of FKBP5 in human PTC tissues compared with normal tissues. Furthermore, high FKBP5 expression was associated with an increased incidence of intraglandular dissemination, and lower overall and progression-free survival. FKBP5 depletion remarkably suppressed the proliferation and induced apoptosis of PTC cells in vitro. FKBP5 further contributed to the growth of PTC tumors in mice. Conclusions The results of this study demonstrated the potential involvement of FKBP5 in the progression of PTC, and confirmed FKBP5 as a novel therapeutic target for PTC treatment.


2008 ◽  
Vol 52 (7) ◽  
pp. 1194-1200 ◽  
Author(s):  
Graciela A. de Cross ◽  
Horacio Suarez ◽  
Fabián Pitoia ◽  
Daniel Moncet ◽  
María Vanegas ◽  
...  

A 29 yrs-old patient was referred to our hospital due to generalized convulsions. She had hyperthyroidism treated with methimazole. Her MRI showed 4 metastatic lesions in the brain. She had a goiter with a "cold" nodule and a palpable ipsilateral lymph node. The FNAB disclosed a papillary thyroid carcinoma. Under 5 mg of MMI treatment, she had a subclinical hyperthyroidism and TRAb were 47.8% (n.v. < 10%). The CT scan also showed lung metastasis. She underwent a total thyroidectomy with a modified neck dissection and she received an accumulated radioiodine dose of 700 mCi during the following two years. She died from the consequences of multiple metastatic lesions. Studies were performed in DNA extracted from paraffin-embedded tissue from the tumor, the metastatic lymph node and the non-tumoral thyroid. The genetic analysis of tumoral DNA revealed point mutations in two different genes: the wild type CAA at codon 61 of N-RAS mutated to CAT, replacing glycine by histidine (G61H) and the normal GCC sequence at codon 623 of the TSHR gene was replaced by TCC, changing the alanine by serine (A623S). In the non-tumoral tissue no mutations were found. In vitro studies showed a constitutive activation of the TSHR. It is very probable that this activating mutation of the TSHR is unable to reach the end point of the PKA cascade in the tumoral tissue. One possibility that could explain this is the presence of a cross-signaling mechanism generating a deviation of the TSH receptor cascade to the more proliferative one involving the MAPKinase, giving perhaps a more aggressive behavior of this papillary thyroid cancer.


2007 ◽  
Vol 21 (12) ◽  
pp. 3039-3049 ◽  
Author(s):  
Dong Wook Kim ◽  
Hyo Kyun Chung ◽  
Ki Cheol Park ◽  
Jung Hwan Hwang ◽  
Young Suk Jo ◽  
...  

Abstract The tumor suppressor LKB1 (STK11) is a cytoplasmic/nuclear serine/threonine kinase, defects in which cause Peutz-Jeghers syndrome (PJS) in humans and animals. Recent studies showed that loss of function of LKB1 is associated with sporadic forms of lung, pancreatic, and ovarian cancer. In cancer cells, LKB1 is inactivated by two mechanisms: mutations in its central kinase domain or complete loss of LKB1 expression. Inactivation of LKB1 is associated with progression of PJS and transformation of benign polyps into malignant tumors. This study examines the effect of LKB1 on regulation of STAT3 and expression of transcriptional targets of STAT3. The results show that LKB1 inhibits rearranged in transformation (RET)/papillary thyroid carcinoma (PTC)-dependent activation of signal transducer and activator of transcription 3 (STAT3), which is mediated by phosphorylation of STAT3 tyrosine 705 by RET/PTC. Suppression of STAT3 transactivation by LKB1 requires the kinase domain but not the kinase activity of LKB1. The centrally located kinase domain of LKB1 is an approximately 260-amino-acid region that binds to the linker domain of STAT3. Chromatin immunoprecipitation studies indicate that expression of LKB1 reduces the binding of STAT3 to its target promoters and suppresses STAT3-mediated expression of Cyclin D1, VEGF, and Bcl-xL. Knockdown of LKB1 by specific small interfering RNA led to an increase in STAT3 transactivation activity and promoted cell proliferation in the presence of RET/PTC. Thus, this study suggests that LKB1 suppresses tumor growth by inhibiting RET/PTC-dependent activation of oncogenic STAT3.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yuan-ming Jiang ◽  
Wei Liu ◽  
Ling Jiang ◽  
Hongbin Chang

Background. Circular RNAs (circRNAs) have been reported to play important roles in the development and progression of papillary thyroid carcinoma (PTC). However, the function and molecular mechanism of circRNA low-density lipoprotein receptor (circLDLR) in the tumorigenesis of PTC remain unknown. Results. In this study, circLDLR was found to be markedly upregulated in PTC tissues and cell lines, and knockdown of circLDLR inhibited PTC cell proliferation, migration, and invasion but induced apoptosis in vitro. Moreover, circLDLR acted as a sponge for miR-637, and miR-637 interference reversed the anticancer effects of circLDLR knockdown on PTC cells. LMO4 was verified to be a target of miR-637; LMO4 upregulation abolished miR-637 mediated inhibition of cell growth and metastasis in PTC. Additionally, circLDLR could indirectly modulate LMO4 via acting as a sponge of miR-637 in PTC cells. Besides that, xenograft analysis showed that circLDLR knockdown suppressed tumor growth in vivo via regulating LMO4 and miR-637. Conclusion. Taken together, these results demonstrated that circLDLR promoted PTC tumorigenesis through miR-637/LMO4 axis, which may provide a novel insight into the understanding of PTC tumorigenesis and be useful in developing potential targets for PTC treatment.


2017 ◽  
Vol 58 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Chen-Tian Shen ◽  
Wei-Jun Wei ◽  
Zhong-Ling Qiu ◽  
Hong-Jun Song ◽  
Xin-Yun Zhang ◽  
...  

More aggressive thyroid cancer cells show a higher activity of glycometabolism. Targeting cancer cell metabolism has emerged as a novel approach to prevent or treat malignant tumors. Glucose metabolism regulation effect of metformin in papillary thyroid cancer was investigated in the current study. Human papillary thyroid carcinoma (PTC) cell lines BCPAP and KTC1 were used. Cell viability was detected by CCK8 assay. Glucose uptake and relative gene expression were measured in metformin (0–10 mM for 48 h)-treated cells by 18F-FDG uptake assay and western blotting analysis, respectively. MicroPET/CT imaging was performed to detect 18F-FDG uptake in vivo. After treatment with metformin at 0, 2.5, 5 and 10 mM for 48 h, the ratio of p-AMPK to total AMPK showed significant rising in a dose-dependent manner in both BCPAP and KTC1, whereas p-AKT and p-mTOR expression level were downregulated. 18F-FDG uptake reduced after metformin treatment in a dose-dependent manner, corresponding to the reduced expression level of HK2 and GLUT1 in vitro. Xenograft model of PTC using BCPAP cells was achieved successfully. MicroPET/CT imaging showed that in vivo 18F-FDG uptake decreased after treatment with metformin. Immunohistochemistry staining further confirmed the reduction of HK2 and GLUT1 expression in the tumor tissue of metformin-treated PTC xenograft model. In conclusion, metformin could reduce glucose metabolism of PTC in vitro and in vivo. Metformin, by targeting glycometabolism of cancer cells, could be a promising adjuvant therapy alternative in the treatment modality of advanced thyroid carcinoma.


Thyroid ◽  
2016 ◽  
Vol 26 (12) ◽  
pp. 1733-1743 ◽  
Author(s):  
Shubin Hong ◽  
Shuang Yu ◽  
Jin Li ◽  
Yali Yin ◽  
Yujie Liu ◽  
...  

2010 ◽  
Vol 9 (7) ◽  
pp. 1968-1976 ◽  
Author(s):  
Ying C. Henderson ◽  
Yunyun Chen ◽  
Mitchell J. Frederick ◽  
Stephen Y. Lai ◽  
Gary L. Clayman

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