Effects of LY294002 on the invasiveness of human gastric cancer in vivo in nude mice

AIM: To investigate the effects of class phosphatidy-linositol 3-kinase (PI3K) inhibitor LY294002 on the invasiveness and related mechanisms of implanted tumors of SGC7901 human gastric carcinoma cells in nude mice. METHODS: Nude mice were randomly divided into model control groups and LY294002 treatment groups. On days 5, 10 and 15 after treatment, the inhibitory rate of tumor growth, pathological changes in tumor specimens, expression levels of matrix metalloproteinase (MMP)-2, MMP-9, CD34 [representing microvessel density (MVD)] and vascular endothelial growth factor (VEGF), as well as apoptosis indexes in tumor samples were observed.RESULTS: In this study, we showed that treatingthe tumors with LY294002 could significantly inhibit carcinoma growth by 11.3%, 29.4% and 36.7%, after 5, 10 and 15 d, respectively, compared to the control group. Hematoxylin & eosin staining indicated that the rate of inhibition increased progressively (23.51% ± 3.11%, 43.20% ± 3.27% and 63.28% ± 2.10% at 5, 10 and 15 d, respectively) along with apoptosis. The expression of MMP-2 was also downregulated (from 71.4% ± 1.6% to 47.9% ± 0.7%, 31.9% ± 0.9% and 7.9% ± 0.7%). The same effects were observed in MMP-9 protein expression (from 49.4% ± 1.5% to 36.9% ± 0.4%, 23.5% ± 0.9% and 7.7% ± 0.6%), the mean MVD (from 51.2% ± 3.1% to 41.9% ± 1.5%, 30.9% ± 1.7% and 14.9% ± 0.8%), and the expression of VEGF (from 47.2% ± 3.1% to 25.9% ± 0.5%, 18.6% ± 1.2% and 5.1% ± 0.9%) by immunohistochemical staining.CONCLUSION: The classPI3K inhibitor LY294002could inhibit the invasiveness of gastric cancer cells by downregulating the expression of MMP-2, MMP-9, and VEGF, and reducing MVD.

Intermittent ice-cooling to prevent skin heat injury caused by highintensity focused ultrasound therapy targeting desmoid-type fibromatosis:A case report

Introduction:Desmoid-type fibromatosis(DF)is a fibrous tumor characterized by low-grade malignant and easy invasive growth and high recurrence.High-intensity focused ultrasound(HIFU)therapy has been identified as a novel non-invasive approach for DF treatment;however,the ultrasonic energy generated by HIFU can cause skin heat injury.Case:A 31-year-old female patient with signs and symptoms of DF received treatment in our institution.The patient had undergone HIFU treatment six times from April 27,2018,to August 21,2019.After HIFU therapy for the third time,she had a third-degree skin burn showing as orange peel-like change and spent three months to promote the recovery of the skin lesions.An intermittent ice-cooling strategy was used to avoid skin damage during the fourth HIFU treatment.This patient did not have any apparent skin injury during the last three HIFU therapy and acquired satisfactory anti-tumor therapeutic effect.Conclusions:There are differences in the thermal selectivity of tumor tissues,which leads to different critical thermal injury temperature values that the tissue can tolerate.Ice-cooling can lower skin tissue temperature and reduce the thermal damage caused by HIFU treatment.

Expression of RECK gene in the osteosarcoma cell line and its correlation with MMP-2

Objective:To detect the expression of RECK gene in the highly and low metastatic cell sublines of human osteosarcoma cell HOS and explore its possible roles on the occurrence and metastasis of osteosarcoma.Methods:RT-PCR, gelatin zymography, and matrigel invasion assay were respectively used to evaluate the endogenous expression of RECK mRNA, MMP-2 activation ratio and invasive capacity in the two osteosarcoma cell sublines.Results:The highly metastatic cell group expressed significantly lower mRNA level of RECK than the low metastatic cell group(P < 0.05), but showed higher MMP-2 activation ratio and invasive capacity(P < 0.05 and P < 0.01, respectively).Conclusion:The abnormal low expression of RECK may participate in osteosarcoma invasion and metastasis, and may be a new therapeutic target for osteosarcoma.

Distributed Plume Source Localization Using Hierarchical Sensor Networks

A hierarchical wireless sensor networks(WSN) was proposed to estimate the plume source location.Such WSN can be of tremendous help to emergency personnel trying to protect people from terrorist attacks or responding to an accident.The entire surveillant field is divided into several small sub-regions.In each sub-region,the localization algorithm based on the improved particle filter(IPF) was performed to estimate the location.Some improved methods such as weighted centroid,residual resampling were introduced to the IPF algorithm to increase the localization performance.This distributed estimation method eliminates many drawbacks inherent with the traditional centralized optimization method.Simulation results show that localization algorithm is efficient for estimating the plume source location.