miR-375 Regulates the Proliferation, Apoptosis and Colony Formation of Thyroid Cancer Cells via Targeting YAP1

Objective: Yes-associated protein 1 (YAP1) regulates cell proliferation and apoptosis. Abnormal miR-375 level was related to thyroid cancer. Software predicted a relationship between miR-375 and YAP1. Our study investigated whether miR-375 regulates YAP1 expression and affects thyroid cancer cells. Methods: The tumor tissues and adjacent tissues of thyroid cancer patients were collected to measure miR-375 and YAP1 expression. The dual luciferase reporter experiment verified the regulation between miR-375 and YAP1. Thyroid cancer cell line B-CPAP and TPC-1 cells were divided into miR-NC group and miR-375 mimic group followed by analysis of cell proliferation by flow cytometry, caspase-3 activity, and cell clone formation ability by plate cloning assay. Results: Compared with adjacent cancer tissues, miR-375 in thyroid cancer tissues was decreased and YAP1 was increased. miR-375 targets YAP1. Compared with Nthy-ori 3-1 cells, miR-375 in B-CPAP and TPC-1 cells was significantly reduced and YAP1 was increased. Transfection with miR-375 mimic significantly inhibited cell proliferation, increase caspase-3 activity, and reduced the ability of cells to form clones. Conclusion: miR-375 can inhibit YAP1 expression, decrease the proliferation of thyroid cancer cells, induce cell apoptosis, and reduce clone formation.

MiR-221 Regulates Suppressors of Cytokine Signaling 3-Janus Kinase 2/Signal Transducer and Activator of Transcription 3 (SOCS3-JAK2/STAT3) Pathway and Affects Thyroid Cancer Cell Proliferation and Apoptosis

Objective: Suppressors of cytokine signaling 3 (SOCS3) negatively regulates JAK-STAT signaling. Bioinformatics analysis showed a targeted relationship between miR-221 and SOCS3 mRNA 3′-UTR. This study investigated whether miR-221 regulates SOCS3 expression and affects thyroid cancer cells. Methods: Dual-luciferase reporter gene experiments verified the relationship between miR-221 and SOCS3. The tumor tissues and adjacent tissues of patients with thyroid cancer were collected to detect miR-221 and SOCS3 level. Thyroid cancer cell line KTC-1 cells were assigned into miR-NC group and miR-221 inhibitor group followed by analysis of SOCS3, p-JAK2, and p-STAT3 level by Real-time PCR, cell apoptosis and cell proliferation by flow cytometry and cell invasion by Transwell assay. Results: Compared with adjacent tissues, miR-221 level in tumor tissues was increased, and SCOS3 mRNA level was decreased. There was a targeted relationship between miR-221 and SOCS3 mRNA. MiR-221 level in KTC-1 and TPC-1 cells was increased, while SOCS3 mRNA level was decreased. MiR-221 inhibitor can significantly upregulate SOCS3 mRNA and protein in KTC-1 cells, reduce the expression of p-JAK2, p-STAT3 protein, increase cell apoptosis, and reduce cell proliferation and invasion. Conclusion: The increased miR-221 and decreased SOCS3 expression are related to thyroid cancer pathogenesis. MiR-221 can inhibit the expression of SOCS3, affect JAK-STAT signaling activity, and regulate the proliferation and apoptosis of thyroid cancer cells.

AXL/GAS6 Inhibition Induces Apoptosis and Suppresses Cell Proliferation and Migration by Blocking the PI3K/AKT Signaling Pathways in Thyroid Cancer Cells in Vivo

Background: The Gas6/Axl-PI3K/Akt pathway is known as one of the most critical molecular signaling pathways involved in the regulation of key cellular processes. GAS6 has emerged as the perfect target for many malignancy treatments, but its role in thyroid cancer remains less described. This study aimed to evaluate both knockdown and overexpression effects of GAS6 on thyroid cancer cell proliferation, migration, and viability.Methods: Both RT-PCR and western blot analysis were performed to evaluate mRNA and protein expressions of GAS6; cell viability was assessed by MTT assay; then, TUNEL apoptosis, Transwell and migration assays were monitored to determine the effects of GAS6 knockdown or GAS6 overexpression on 850-5C and CAL62 thyroid cancer cells. Results: The mRNAs and protein expressions of GAS6 were the highest in CAL62 cancer cells. AXL/GAS6 knockdown through the application of siGAS6 and XL184, an AXL inhibitor, strongly diminished the proliferation and migration levels of CAL62 by inducing cell apoptosis. Meanwhile, overexpression of GAS6 produced the inversed effects, and the protein levels of PI3K, AKT, and p-AKT were significantly up and downregulated, accordingly. Conclusion: GAS6 inhibition promotes apoptosis and represses the proliferation of thyroid cancer cells by activating PI3K/AKT pathway; thus, provides a novel target for thyroid cancer therapy.

miRNA-144-5p/ITGA3 Suppressed the Tumor-Promoting Behaviors of Thyroid Cancer Cells by Downregulating ITGA3

Objective. To ascertain the mechanism of miRNA-144-5p and ITGA3 in thyroid cancer (TC). Methods. From The Cancer Genome Atlas (TCGA), RNA expression profiles were obtained for the expression analysis of miRNAs and mRNAs in TC. qRT-PCR and western blot were utilized to measure the expression of miRNA-144-5p and ITGA3 at RNA and protein levels, respectively. The association between miRNA-144-5p and ITGA3 was validated by the dual-luciferase assay. CCK-8, scratch healing, transwell, and flow cytometry assays were employed to evaluate tumor-related cell behaviors. Results. Low-expressed miRNA-144-5p and high-expressed ITGA3 were found in TC cells relative to normal cells. miRNA-144-5p expression was positively associated with suppressive effects on proliferative, invasive, and migratory ability of TC cells while negatively associated with cell apoptosis. miRNA-144-5p inhibited ITGA3 expression in TC, and its overexpression remarkably reversed the tumor-promoting effects of overexpressed ITGA3 on the biological functions of TC. Conclusion. It is verified in our study that cell growth of TC is inhibited by the miRNA-144-5p/ITGA3 axis, which represents an underlying target for TC. This research proposed a new insight into the strategy of TC treatment.

ZIP10 is a negative determinant for anti-tumor effect of mannose in thyroid cancer by activating phosphate mannose isomerase

Background Mannose, a natural hexose existing in daily food, has been demonstrated to preferentially inhibit the progression of tumors with low expression of phosphate mannose isomerase (PMI). However, its function in thyroid cancer still remains elusive. Methods MTT, colony formation and flow cytometry assays were performed to determine the response of thyroid cancer cells to mannose. Meanwhile, mouse models of subcutaneous xenograft and primary papillary thyroid cancer were established to determine in vivo anti-tumor activity of mannose. The underlying mechanism of mannose selectively killing thyroid cancer cells was clarified by a series of molecular and biochemical experiments. Results Our data demonstrated that mannose selectively suppressed the growth of thyroid cancer cells, and found that enzyme activity of PMI rather than its protein expression was negatively associated with the response of thyroid cancer cells to mannose. Besides, our data showed that zinc ion (Zn2+) chelator TPEN clearly increased the response of mannose-insensitive cells to mannose by inhibiting enzyme activity of PMI, while Zn2+ supplement could effectively reverse this effect. Further studies found that the expression of zinc transport protein ZIP10, which transport Zn2+ from extracellular area into cells, was negatively related to the response of thyroid cancer cells to mannose. Knocking down ZIP10 in mannose-insensitive cells significantly inhibited in vitro and in vivo growth of these cells by decreasing intracellular Zn2+ concentration and enzyme activity of PMI. Moreover, ectopic expression of ZIP10 in mannose-sensitive cells decrease their cellular response to mannose. Mechanistically, mannose exerted its anti-tumor effect by inhibiting cellular glycolysis; however, this effect was highly dependent on expression status of ZIP10. Conclusion The present study demonstrate that mannose selectively kills thyroid cancer cells dependent on enzyme activity of PMI rather than its expression, and provide a mechanistic rationale for exploring clinical use of mannose in thyroid cancer therapy.

Changes in Exosomal miRNA Composition in Thyroid Cancer Cells after Prolonged Exposure to Real Microgravity in Space

As much as space travel and exploration have been a goal since humankind looked up to the stars, the challenges coming with it are manifold and difficult to overcome. Therefore, researching the changes the human organism undergoes following exposure to weightlessness, on a cellular or a physiological level, is imperative to reach the goal of exploring space and new planets. Building on the results of our CellBox-1 experiment, where thyroid cancer cells were flown to the International Space Station, we are now taking advantage of the newest technological opportunities to gain more insight into the changes in cell–cell communication of these cells. Analyzing the exosomal microRNA composition after several days of microgravity might elucidate some of the proteomic changes we have reported earlier. An array scan of a total of 754 miRNA targets revealed more than 100 differentially expressed miRNAs in our samples, many of which have been implicated in thyroid disease in other studies.

Artesunate inhibits cell proliferation, migration, and invasion of thyroid cancer by regulating the PI3K/AKT/FKHR pathway

This study characterized the effects of artesunate on thyroid cancer and partially identified its related molecular mechanism. We determined the effect of artesunate on the proliferation of thyroid cancer cells using the MTT assay, cell colony formation experiments, and western blotting, and used flow cytometry to detect the apoptosis of cancer cells. Using a wound-healing assay, Transwell chamber experiments, and western blotting, we determined the effect of artesunate on cancer cell migration. By co-cultivating artesunate with the PI3K agonist, 740Y-P, we also partially identified the molecular mechanism. Artesunate significantly inhibited the growth, proliferation, migration, and invasion of thyroid cancer cells, and promoted the apoptosis of cancer cells. Using co-cultivation with a PI3K agonist, we found that the inhibitory effect of artesunate on cancer cells was mainly due to suppressing the PI3K/AKT/FKHR signaling pathway. By inhibiting the PI3K/AKT/FKHR signaling pathway, artesunate induced apoptosis of thyroid cancer cells and inhibited their proliferation and migration.