Chaperone-mediated Autophagy Governs Progression of Papillary Thyroid Carcinoma via PPARγ-SDF1/CXCR4 Signaling.

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy. Chaperone-mediated autophagy (CMA), 1 type of autophagy, is thought to promote or suppress cancer development in different cancer types. However, the effect of CMA on PTC development and the underlying mechanisms remain unknown. To determine whether CMA plays implied critical roles in the development of PTC. We investigated the association between CMA and PTC development in PTC tissues and normal thyroid tissues by detecting the key protein of CMA, lysosome-associated membrane protein type 2A (LAMP2A), using quantitative polymerase chain reaction (PCR) and immunohistochemistry, which were further validated in the TGCA dataset. The effect of CMA on PTC development was studied by cell proliferation, migration, and apoptosis assays. The underlying mechanisms of peroxisome proliferator-activated receptor γ (PPARγ)-stromal cell-derived factor 1 (SDF1)/ C-X-C motif chemokine receptor 4 (CXCR4) signaling were clarified by western blotting, quantitative PCR, and rescue experiments. Knockdown and tamoxifen were used to analyze the effect of estrogen receptor (ER) α on CMA. Our study confirmed that CMA, indicated by LAMP2A expression, was significantly increased in PTC tumor tissues and cell lines, and was associated with tumor size and lymph node metastasis of patients. Higher CMA in PTC promoted tumor cell proliferation and migration, thereby promoting tumor growth and metastasis. These effects of CMA on PTC were exerted by decreasing PPARγ protein expression to enhance SDF1 and CXCR4 expression. Furthermore, CMA was found positively regulated by ERα signaling in PTC. Our investigation identified CMA regulated by ERα promoting PTC tumor progression that enhanced tumor cell proliferation and migration by targeting PPARγ-SDF1/CXCR4 signaling, representing a potential target for treatment of PTC.

Zhou H ，Xie X ，Chen Y ，Lin Y ，Cai Z ，Ding L ，Wu Y ，Peng Y ，Tang S ，Xu H ... -  《-》

Long noncoding RNA CASC9 promotes the proliferation and metastasis of papillary thyroid cancer via sponging miR-488-3p.

Cancer susceptibility candidate 9 (CASC9) is a recently identified lncRNA that acted as a tumor promotor in diversified cancer types. However, its role in papillary thyroid cancer (PTC) remains unknown. The expression of CASC9 was measured in 52 human PTC tissues and PTC cell lines as well as their controls. The proliferation, migration, and invasion of PTC cells were determined after knockdown or overexpression of CASC9 to evaluate the effect of CASC9 on PTC cells. Also, the role of PTC tumorigenesis was confirmed in mice xenograft models. Additionally, the underlying mechanisms of CASC9 were further researched. We found that CASC9 expression was augmented in human PTC tissues and cells. Higher CASC9 expression was associated with large tumor size, advanced stage, or lymph node metastasis. Downregulation of CASC9 significantly attenuated the proliferative, migrative, and invasive abilities of PTC cells, and suppressed tumorigenesis in vivo. While overexpression of CASC9 elevated the proliferation, migration, and invasion of PTC cells. miR-488-3p expression was decreased, and ADAM9 level was increased in PTC tissues and cells. CASC9 expression was negatively related to miR-488-3p, but positively associated with ADAM9 expression in PTC tissues. Molecular mechanism analysis revealed that CASC9 functioned via sponging miR-488-3p to regulate ADAM9 expression, followed by activation of EGFR-Akt signaling. In conclusion, lncRNA CASC9 promoted the malignant phenotypes of PTC via modulating miR-488-3p/ADAM9 pathway. This study may provide a novel therapeutic target for the treatment of PTC.

Chen Y ，Li Y ，Gao H 《Cancer Medicine》

CXCR4 promotes migration, invasion, and epithelial-mesenchymal transition of papillary thyroid carcinoma by activating STAT3 signaling pathway.

Hu Y ，Xu Z ，Zhou D ，Hou H ，Liu B ，Long H ，Hu W ，Tang Y ，Wang J ，Wei D ，Zhao Q ... -  《-》

MiR-548c-3p suppressed the progression of papillary thyroid carcinoma via inhibition of the HIF1α-mediated VEGF signaling pathway.

Du Y ，Zhu J ，Chu BF ，Yang YP ，Zhang SL ... -  《-》

Long noncoding RNA SNHG22 increases ZEB1 expression via competitive binding with microRNA-429 to promote the malignant development of papillary thyroid cancer.

Gao H ，Sun X ，Wang H ，Zheng Y ... -  《-》