Translocated HMGB3 is involved in papillary thyroid cancer progression by activating cytoplasmic TLR3 and transmembrane TREM1

The family of high mobility group box (HMGB) proteins participates in various biological processes including immunity, inflammation, as well as cancer formation and progression. However, its role in thyroid cancer remains to be clarified. We performed quantitative RT-PCR (qRT-PCR), western blot, enzyme-linked immunosorbent, immunohistochemistry, and immunofluorescence assays to evaluate the expression level and subcellular location of HMGB3. The effects of HMGB3 knockdown on malignant biological behaviors of thyroid cancer were determined by cell proliferation assays, cell cycle and apoptosis assays, and transwell chamber migration and invasion assays. Differential expression genes (DEGs) altered by HMGB3 were analyzed using the Ingenuity Pathway Analysis (IPA) and TRRUST v2 database. HMGB3 correlated pathways predicted by bioinformatic analysis were then confirmed using western blot, co-immunoprecipitation, dual-luciferase reporter assay, and flow cytometry. We found that HMGB3 is overexpressed and its downregulation inhibits cell viability, promotes cell apoptosis and cell cycle arrest, and suppresses cell migration and invasion in thyroid cancer. In PTC, both tissue and serum levels of HMGB3 are elevated and are correlated with lymph node metastasis and advanced tumor stage. Mechanistically, we observed the translocation of HMGB3 in PTC, induced at least partially by hypoxia. Cytoplasmic HMGB3 activates nucleic-acid-mediated TLR3/NF-κB signaling and extracellular HMGB3 interacts with the transmembrane TREM1 receptor in PTC. This study demonstrates the oncogenic role of HMGB3 cytoplasmic and extracellular translocation in papillary thyroid cancers; we recommend its future use as a potential circulating biomarker and therapeutic target for PTC.</p

Epithelial cell-derived periostin functions as a tumor suppressor in gastric cancer through stabilizing p53 and E-cadherin proteins via the Rb/E2F1/p14ARF/Mdm2 signaling pathway

<div><p>Periostin is usually considered as an oncogene in diverse human cancers, including breast, prostate, colon, esophagus, and pancreas cancers, whereas it acts as a tumor suppressor in bladder cancer. In gastric cancer, it has been demonstrated that periglandular periostin expression is decreased whereas stromal periostin expression is significantly increased as compared with normal gastric tissues. Moreover, periostin produced by stromal myofibroblasts markedly promotes gastric cancer cell growth. These observations suggest that periostin derived from different types of cells may play distinct biological roles in gastric tumorigenesis. The aim of this study was to explore the biological functions and related molecular mechanisms of epithelial cell-derived periostin in gastric cancer. Our data showed that periglandular periostin was significantly down-regulated in gastric cancer tissues as compared with matched normal gastric mucosa. In addition, its expression in metastatic lymph nodes was significantly lower than that in their primary cancer tissues. Our data also demonstrated that periglandular periostin expression was negatively associated with tumor stage. More importantly, restoration of periostin expression in gastric cancer cells dramatically suppressed cell growth and invasiveness. Elucidation of the mechanisms involved revealed that periostin restoration enhanced Rb phosphorylation and sequentially activated the transcription of E2F1 target gene <i>p14^ARF</i>, leading to Mdm2 inactivation and the stabilization of p53 and E-cadherin proteins. Strikingly, these effects of periostin were abolished upon Rb deletion. Collectively, we have for the first time demonstrated that epithelial cell-derived periostin exerts tumor-suppressor activities in gastric cancer through stabilizing p53 and E-cadherin proteins via the Rb/E2F1/p14^ARF/Mdm2 signaling pathway.</p></div

CT images of goats in control group, ACVC group, ACCF group 24 weeks after the surgery (ACVC and ACVC-HA appears similar).

<p>A, B, C, Lateral views of C2 to C4 for the three groups; D, G, transverse views of C3 and C4 vertebral bodies in control group; E, H, transverse views of C3 and C4 vertebral bodies in ACVC group; F, I, transverse views of C3 and C4 vertebral bodies in ACCF group.</p

Average changes in the stability index ROMs and stability index NZs from ACVC group, ACVC-HA group and ACCF group.

<p>Average changes in the stability index ROMs and stability index NZs from ACVC group, ACVC-HA group and ACCF group.</p

Typical hysteresis curves of C2-C4 level of the four groups after fatigue test in the directions of flexion-extension (A), lateral bending (B), and rotation (C).

<p>Typical hysteresis curves of C2-C4 level of the four groups after fatigue test in the directions of flexion-extension (A), lateral bending (B), and rotation (C).</p

Comparison histological images of ACVC and ACVC-HA.

<p>A and B, 25X- and 100X- magnified images at the level of ACVC vertebral body component; C and D, 25X- and 100X- magnified images at the level of ACVC-HA vertebral body component; E and F, 25X- and 100X- magnified images at the level of fixation screws of ACVC; G and H, 25X- and 100X- magnified images at the level of fixation screws of ACVC-HA; I, Bone implant contact (BIC) of ACVC and ACVC-HA at vertebral body and screw level.</p

Average unidirectional ROM (A), NZ (B), and stiffness (C) of the four different groups at 24 weeks after surgery in all directions before the fatigue test.

<p>Average unidirectional ROM (A), NZ (B), and stiffness (C) of the four different groups at 24 weeks after surgery in all directions before the fatigue test.</p

Typical hysteresis curves of C2-C4 level of the four groups before fatigue test in the directions of flexion-extension (A), lateral bending (B), and rotation (C).

<p>Typical hysteresis curves of C2-C4 level of the four groups before fatigue test in the directions of flexion-extension (A), lateral bending (B), and rotation (C).</p

Ranges of motion profiles of the cervical segments of the four groups before the fatigue test in all directions.

<p>Ranges of motion profiles of the cervical segments of the four groups before the fatigue test in all directions.</p

Ranges of motion, neutral zones, and stiffness profiles of the C2 to C4 segments of the four groups after the fatigue test in all directions.

<p>Ranges of motion, neutral zones, and stiffness profiles of the C2 to C4 segments of the four groups after the fatigue test in all directions.</p