A calcium-sensing receptor polymorphism at E942K promotes the proliferation of gastric cancer cells via Ca and ERK1/2 pathways / 生理学报

The study was designed to investigate the effects and mechanism of a calcium-sensing receptor (CaSR) polymorphism at E942K on the proliferation of gastric cancer cells. Single nucleotide polymorphisms (SNPs) were detected between gastric cancers group and normal controls group by DNA sequence analysis. The cell model was constructed by transfection of E942K mutant plasmid and wild-type (WT) plasmid into SGC-7901 and HEK-293 cells. The effect of E942K mutation on cell proliferation ability was detected by CCK8 and cell clone formation experiments. The effect of E942K mutation on calcium signaling was detected by calcium imaging. Western blot experiments were used to detect changes in phosphorylation levels of key proteins ERK1/2 and β-catenin in downstream signaling pathways after E942K mutation. The results showed that the mutation rate of E942K in gastric cancer group was significantly higher than that in normal control group (P < 0.05). CCK8 and cell clone formation experiments showed that E942K mutation significantly improved the proliferation ability of SGC-7901 gastric cancer cells and HEK-293 cells. E942K mutation enhanced calcium signaling in SGC-7901 and HEK-293 cells. E942K mutation enhanced ERK1/2 phosphorylation without affecting β-catenin phosphorylation. The results suggest that E942K mutation in CaSR may ultimately promote the proliferation of gastric cancer cells by enhancing intracellular calcium signaling and ERK1/2 phosphorylation. These results have potential clinical implications for the diagnosis and targeted therapy of gastric cancer.

Establishment of animal model of temporomandibular joint synovitis and its histological investigation / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To establish a stable animal model of temporomandibular joint (TMJ) synovitis.</p><p><b>METHODS</b>Sixteen 6-week-old male SD rats were classified into four groups, control group, occlusal dimension increase group, masseter resection group, occlusal dimension increase group and masseter resection group. The rats in the occlusal dimension increase group were adhered composite resin to their maxillary molars in order to increase the occlusal vertical dimension when they were 9-week-old. The rats in the masseter resection group were cut off their bilateral masseter muscles when they were 6-week-old. In the occlusal dimension increase group and masseter resection group, rats' bilateral masseter muscles were resected and occlusal vertical dimension was increased. All rats were sacrificed at their 10 weeks old. TMJ samples were prepared for histology to evaluate the animal model.</p><p><b>RESULTS</b>The control group showed non-inflammatory changes. The occlusal dimension increase group and the masseter resection group showed vascular dilation and synovial lining proliferation, but there were no statistically significant differences between the two groups (P > 0.05). Compared to the two disposed groups, the occlusal dimension increase group and masseter resection group showed significant inflammatory changes (P < 0.05), including synovial lining proliferation, vascular dilation and fibrin deposit.</p><p><b>CONCLUSION</b>The animal model of TMJ synovitis created in the present investigation could simulate the real pathological features of synovitis in vivo, and this animal model showed the obvious merits of high stability and reproduction.</p>