[The clinical significance of Delphian lymph node metastasis in papillary thyroid cancer]

Objective: To evaluate the clinical significance of Delphian lymph node (DLN) metastasis in papillary thyroid cancer (PTC). Method: A total of 505 cases with PTC confirmed pathologically in our hospital between January 2015 and December 2015 were retrospectively reviewed. 208 patients with DLN assessed separately by histopathologic examination who underwent primary surgery for PTC were included for the following analysis. Results: In 208 patients, the detection rate of DLN was 63.0% and the metastasis rate of DLN was 21.4%. DLN metastasis was correlated with PTC multifocality (P=0.038), tumor size over 1cm (P=0.001), BRAF^V600E mutation (P=0.017) and central neck node metastasis (P<0.001). Tumor size over 1cm (95%CI 1.308-9.909, OR=3.600, P=0.013) and the number of node with central neck metastasis (95%CI 1.313-2.163, OR=1.685, P<0.001) were independent risk factors for DLN metastasis. The presence of DLN metastasis was associated with an 8.8-fold higher frequency of central neck node metastasis compared to cases without DLN metastasis. Among patients with DLN metastases, central lymph node metastasis was more common in the cases with lateral neck node metastases compared to those without lateral neck node metastases (6.5±3.0 vs 1.5±0.7, P=0.009), and 5 of the 6 patients also presented with PTC multifocality and BRAF^V600E mutation. Conclusion: DLN metastasis implies a higher possibility of central neck lymph node metastasis. DLN should be assessed during operation to provide information for neck dissection, post-operative administration and follow-up strategy.

Co-transfection of GK and mhPINS genes into HepG2 cells confers glucose-stimulated insulin secretion

BACKGROUND

The purpose of this study was to construct an 'artificial beta cell' that can exhibit physiologic glucose-stimulated insulin secretion for the treatment of type 1 diabetes.

METHODS

Retroviral vector containing the glucokinase (GK) gene and mutated human proinsulin (mhPINS) gene was constructed. HepG2 cells were first infected with recombinant retrovirus carrying the GK and mhPINS genes, then selectively cultured with G418 to obtain the positive clones. GK and mhPINS gene transcription and expression were identified by radioimmunity, Western blot and RT-PCR techniques. Finally, the dose-response effect of glucose on insulin secretion from those HepG2 cells that expressed both GK and mhPINS genes was tested with HepG2 cells that only expressed the mhPINS gene as a control.

RESULTS

HepG2 cells with transferred GK and mhPINS genes were selectively cultured with G418 and the positive clones were obtained in 3 weeks. Four clones with GK and mhPINS gene expression were selected from 20 positive clones by radioimmunity and Western blot. We picked up one clone with a strong GK and mhPINS gene expression and named it clone Beta. In clone Beta, differences in insulin secretion at 0.5 and 0.75 mmol/L glucose concentrations were not significant (P>0.05) and differences in insulin secretion at 2.0, 3.0, 4.0, 5.0 and 6.0 mmol/L glucose concentrations were not significant (P>0.05), while there were significant differences in insulin secretion at other glucose concentrations(P<0.05). The artificial beta cell, clone Beta, obtained a glucose-stimulated insulin secretion with maximal insulin secretion at 1.75-2.00 mmol/L glucose concentrations.

DISCUSSION

An artificial beta cell that exhibits glucose-stimulated insulin secretion can be constructed successfully.