Xiaogang Shu

Expression of SATB1 and heparanase in gastric cancer and its relationship to clinicopathologic features

Cheng C, Lu X, Wang G, Zheng L, Shu X, Zhu S, Liu K, Wu K, Tong Q. Expression of SATB1 and heparanase in gastric cancer and its relationship to clinicopathologic features. APMIS 2010; 118: 855–63.

SATB1 is an independent prognostic marker for gastric cancer in a Chinese population

Special AT-rich sequence binding protein 1 (SATB1), a new type of gene regulator, has been reported to express in various human cancers and may associate with the malignant potential. However, there are few data available on SATB1 expression and its relationship to tumor progression in gastric cancer. The current study was designed to examine the SATB1 expression in gastric cancer and to correlate it with clinical outcome. SATB1 expression was studied by qRT-PCR, western blotting and immunohistochemistry, respectively. The correlations between SATB1 expression and clinicopathological factors were statistically analyzed. SATB1 mRNA expression was significantly up-regulated in gastric cancer specimens as compared with that in normal tissues (P<0.001). Overexpression of SATB1 protein was observed in gastric cancer cell lines by western blotting. Fifty-three (44.9%) cases showed positive staining for the SATB1 proteins by immunohistochemistry. The expression of SATB1 mRNA agreed well with the western blotting and immunohistochemical findings (P<0.001). SATB1 expression was positively correlated with age, depth of invasion, lymph node metastasis, distant metastasis and TNM stage. Moreover, Kaplan-Meier analysis revealed that SATB1 overexpression was associated with a significantly worse survival (P<0.001). Further multivariable analysis indicated that SATB1 expression was an independent prognostic indicator for gastric cancer (P=0.023). In summary, overexpression of SATB1 correlated with metastatic potential of human gastric cancer and would be a novel independent prognostic marker for predicting the outcome of gastric cancer.

Voxel-Based Diffusion Tensor Imaging of an APP/PS1 Mouse Model of Alzheimer's Disease

Increasing evidence has demonstrated that white matter (WM) disruptions, due to the injury of the axon and myelin, play an important role in the pathogenesis of Alzheimer’s disease (AD). Diffusion tensor imaging (DTI) is a sensitive modality to evaluate the WM integrity in both AD patients and animal models. In this study, an advanced DTI modality, employing a 7.0-T magnetic resonance imaging system, was used to analyze WM changes across the whole brain of an amyloid precursor protein/presenilin 1 (APP/PS1) mouse model. A voxel-based analysis was used to compare the quantitative DTI parameters automatically in both APP/PS1 mice (n = 9) and wild-type (WT) controls (n = 9). After DTI examination, the ultrastructure analysis was compared with DTI findings. Compared with WT controls, gray matter (GM) areas in APP/PS1 mice such as the cingulate cortex and the striatum showed significant fractional anisotropy (FA) and axial diffusivity (DA) increase, while the thalamus only showed a significant FA increase (p < 0.01). Similarly, a significant mean diffusivity, DA, and radial diffusivity increase was observed in the bilateral neocortex (p < 0.01). The left hippocampus only showed significant FA increase in APP/PS1 mice (p < 0.01). The changes in WM regions were detected in the forceps minor of the corpus callosum, the anterior part of the anterior commissure, and the internal capsule, with a significant FA or DA increase (p < 0.01). Abnormalities derived from diffusion measurements were in-line with the ultrastructure findings, including extensive pathological damage of the neurons, neutrophils, and vessels. In conclusion, voxel-based diffusion tensor imaging can detect diffusion alterations not only in GM but also in WM areas in AD models, reflecting the extensive pathological changes of AD.

Vascular Smooth Muscle Cell Apoptosis Promotes Transplant Arteriosclerosis Through Inducing the Production of SDF-1α

Transplant arteriosclerosis is a leading cause of late allograft loss. Medial smooth muscle cell (SMC) apoptosis is considered to be an important event in transplant arteriosclerosis. However, the precise contribution of medial SMC apoptosis to transplant arteriosclerosis and the underlying mechanisms remain unclear. We transferred wild‐type p53 to induce apoptosis of cultured SMCs. We found that apoptosis induces the production of SDF‐1α from apoptotic and neighboring viable cells, resulting in increased SDF‐1α in the culture media. Conditioned media from Ltv‐p53‐transferred SMCs activated PI3K/Akt/mTOR and MAPK/Erk signaling in a SDF‐1α‐dependent manner and thereby promoted mesenchymal stem cell (MSC) migration and proliferation. In a rat aorta transplantation model, lentivirus‐mediated BclxL transfer selectively inhibits medial SMC apoptosis in aortic allografts, resulting in a remarkable decrease of SDF‐1α both in allograft media and in blood plasma, associated with diminished recruitment of CD90+CD105+ double‐positive cells and impaired neointimal formation. Systemic administration of rapamycin or PD98059 also attenuated MSC recruitment and neointimal formation in the aortic allografts. These results suggest that medial SMC apoptosis is critical for the development of transplant arteriosclerosis through inducing SDF‐1α production and that MSC recruitment represents a major component of vascular remodeling, constituting a relevant target and mechanism for therapeutic interventions.

Construction and Characterization of a Novel Fusion Protein MG7-scFv/SEB against Gastric Cancer

Antibody-targeted superantigen has been developed into a new strategy to treat many malignant tumors. In this study, for specific targeting to gastric cancer cell, superantigen SEB (Staphylococcal Enterotoxin B) was genetically fused to the single-chain variable fragment of gastric carcinoma-associated antibody MG7(MG7-scFv) that recognizes the MG7 antigen frequently expressed in gastric cancer cell. The recombinant MG7-scFv/SEB fusion proteins are expressed in E. coli as inclusion bodies, and the purified MG7-scFv/SEB retains high binding affinity with gastric cancer cell SGC-7901 (positive MG7 antigen expression). When incubated with effector cell—peripheral blood mononuclear cells (PBMCs), MG7-scFv/SEB could effectively inhibit the proliferation and induce apoptosis of SGC-7901. After being treated with MG7-scFv/SEB, PBMCs remarkably increased the production of Th1 cytokines (IFN-gamma, IL-2), and slightly increased the production of Th2 cytokines (IL-4, IL-10) in vitro. It was observed that gastric-tumor-bearing rats administrated with MG7-scFv/SEB showed more inflammatory cell infiltration, more significant tumor inhibition, and longer survival time than those of rats treated with SEB or NS (Normal Saline). The data indicated that MG7-scFv/SEB fusion protein could specifically target gastric cancer cell, enhance the activity of T cells and induce tumor cell apoptosis to exert the antitumor effect on gastric cancer.

The origin of neointimal smooth muscle cells in transplant arteriosclerosis from recipient bone-marrow cells in rat aortic allograft.

In order to investigate the origin of neointimal smooth muscle cells in transplant arteriosclerosis in rat aortic allograft, sex-mismatched bone marrow transplantation was performed from male Wistar rats to female Wistar rats. Four weeks after transplantation, the aortic transplant model was established by means of micro-surgery in rats. The recipients were divided into 4 groups: female Wistar-female Wistar aortic isografts, female SD female Wistar aortic allografts, male SD-male Wistar aortic allografts, female SD-chimera Wistar aortic allografts. Eight weeks after transplantation, aortic grafts were removed at autopsy and processed for histological evaluation and immunohistochemistry. The results indicated that excessive accumulation of α-SMA-positive smooth muscle cells resulted in significant neointima formation and vascular lumen stricture in rat aortic allografts. Neointima assay revealed that the neointimal area and NIA/MA ratio of transplanted artery were significantly increased in all of aortic allograft groups as compared with those in aortic isograft group (P<0.01). Neointimal smooth muscle cells were harvested from cryostat sections of aortic allograft by microdissection method. The Sry gene-specific PCR was performed, and the result showed that a distinct DNA band of 225 bp emerged in the male-male aortic allograft group and chimera aortic allograft group respectively, but not in the female-female aortic allograft group. It was suggested that recipient bone-marrow cells, as the origin of neointimal smooth muscle cells, contributed to the pathological neointimal hyperplasia of aortic allograft and transplant arteriosclerosis.

Culture and Identification of Monoclonal Neural Stem Cells Derived from Cerebral Cortex

To isolate and culture the purified monoclonal neural stem cells from the cerebral cortex of new born mice, new-born mice cerebral cortex was isolated and dissociated to single-cell suspension by mechanical trituration. The dissociated single cells were cultured in serum-free medium. After the formation of neurospheres, single-cell clone culture was performed by limiting dilution and the proliferated single-cell clones were harvested for subculture. Immunocytochemistry was used to dtect the specific marker of neuroepithelial stem cells (Nestin) of the primary and monoclonal neurospheres. In the differentiated cells we detected the specific antigen of NF-200 and GFAP. Our results showed that the primary neurospheres expressed Nestin antigen positively. By limiting dilution, we cultured the cell lines from single-cell clone and the monoclonal neurospheres expressed Nestin and had capabilities of self-renewal, proliferation and the potentiality of differentiation into neurons and glial cells. It is concluded that monoclonal neural stem cells which have the ability of proliferation and multi-directional differentiation can be isolated and cultured from the cerebral cortex of new-born mice by limiting dilution.

Prognostic and clinical value of Sirt1 expression in gastric cancer: A systematic meta-analysis

SummaryMany studies have reported that the expression of silent information regulator 1 (Sirt1) is associated with the clinical features and prognosis of patients with gastric cancer, but the exact function remains controversial. We conducted this study to illustrate the clinical and prognostic value of Sirt1 in gastric cancer. The related publications before December 2015 were searched in the databases including Pubmed, Cochrane Library, Embase and China National Knowledge Infrastructure (CNKI). The studies were included and excluded according to the inclusion criteria and exclusion criteria. The 3- and 5-year overall survival (OS) and clinical features such as age, T stage, N stage and differentiation were analyzed by software RevMan 5.3. A total of 1650 patients in 7 studies were included according to the inclusion criteria and exclusion criteria. The high expression of Sirt1 was found in 58.4% cases by immunohistochemistry. High expression of Sirt1 was closely linked with the 3-year OS (OR=0.25, 95% CI: 0.16–0.39, P<0.00001, fixed), patient’s age (≥60 years old vs. <60 years old; OR=1.43, 95% CI: 1.06–1.93, P=0.02, fixed), T stage (T3+T4 vs. T1+T2; OR=1.45, 95% CI: 1.08–1.94, P=0.01, fixed), N stage (N1+N2+N3 vs. N0; OR=3.47, 95% CI: 2.39–5.05, P<0.00001, fixed) and tumor differentiation (G1+G2 vs. G3; OR=0.50, 95% CI: 0.35–0.69, P<0.0001, fixed). Nevertheless, it seemed that high expression of Sirt1 was not associated with 5-year OS (OR=0.44, 95% CI: 0.15–1.28, P=0.13, random). It was suggested that the high expression of Sirt1 implies a poor prognosis of gastric cancer patients in a relatively short period (3 years), but not in a long time (≥5 years). The expression of Sirt1 is also linked with patients’ age, T stage, N stage and tumor differentiation.Many studies have reported that the expression of silent information regulator 1 (Sirt1) is associated with the clinical features and prognosis of patients with gastric cancer, but the exact function remains controversial. We conducted this study to illustrate the clinical and prognostic value of Sirt1 in gastric cancer. The related publications before December 2015 were searched in the databases including Pubmed, Cochrane Library, Embase and China National Knowledge Infrastructure (CNKI). The studies were included and excluded according to the inclusion criteria and exclusion criteria. The 3- and 5-year overall survival (OS) and clinical features such as age, T stage, N stage and differentiation were analyzed by software RevMan 5.3. A total of 1650 patients in 7 studies were included according to the inclusion criteria and exclusion criteria. The high expression of Sirt1 was found in 58.4% cases by immunohistochemistry. High expression of Sirt1 was closely linked with the 3-year OS (OR=0.25, 95% CI: 0.16–0.39, P<0.00001, fixed), patient’s age (≥60 years old vs. <60 years old; OR=1.43, 95% CI: 1.06–1.93, P=0.02, fixed), T stage (T3+T4 vs. T1+T2; OR=1.45, 95% CI: 1.08–1.94, P=0.01, fixed), N stage (N1+N2+N3 vs. N0; OR=3.47, 95% CI: 2.39–5.05, P<0.00001, fixed) and tumor differentiation (G1+G2 vs. G3; OR=0.50, 95% CI: 0.35–0.69, P<0.0001, fixed). Nevertheless, it seemed that high expression of Sirt1 was not associated with 5-year OS (OR=0.44, 95% CI: 0.15–1.28, P=0.13, random). It was suggested that the high expression of Sirt1 implies a poor prognosis of gastric cancer patients in a relatively short period (3 years), but not in a long time (≥5 years). The expression of Sirt1 is also linked with patients’ age, T stage, N stage and tumor differentiation.

Synergistic enhancement of cancer therapy using a combination of fusion protein MG7-scFv/SEB and tumor necrosis factor alpha.

The fusion protein MG7-scFv/SEB has shown anti-tumor activity on gastric cancer in vitro and in vivo. Tumor necrosis factor-alpha (TNF-α) is a cytokine exerting anti-tumor effectiveness in various models and modes of applications. In this study, we explored the combination effects of MG7-scFv/SEB and TNF-α in experimental gastric cancer. Both MG7-scFv/SEB and TNF-α could effectively result in a significant inhibition of tumor growth in our experimental models when administered alone. Whats more, MG7-scFv/SEB synergized with TNF-α in further reducing the growth of gastric tumors in gastric-tumor-bearing rats as compared to mono therapy. Additionally, the survival rate of gastric-tumorbearing rats administrated with combined therapy was significantly higher than that of rats treated with MG7-scFv/SEB or TNF-α. These results indicate that combined therapy with MG7-scFv/SEB and TNF-α is a promising strategy for human cancer therapy.

NFIB Promotes Colorectal Cancer Cell Proliferation, EMT and 5-Fluorouracil Resistance

Nuclear factor I/B (NFIB) is a widely studied transcription factor that participates in tumor progression; nevertheless, studies on NFIB in colorectal cancer (CRC) are limited. In our study, Western blot and RT‐PCR analyses showed that NFIB was overexpressed in CRC tissues and cell lines, which was consistent with our bioinformatic analysis results. Furthermore, NFIB expression was closely related to the TNM stage of CRC. NFIB promoted cell proliferation and migration and inhibited cell apoptosis in vitro. Meanwhile, we discovered that NFIB accelerated xenograft tumor growth in vivo. In addition, NFIB weakened the sensitivity of CRC cells to 5‐fluorouracil (5‐FU). NFIB induced epithelial‐mesenchymal transition (EMT) by upregulating snail expression, which was accompanied by decreased E‐cadherin and Zo‐1 expression and increasedd Vimentin expression. Because the Akt pathway plays an important role in CRC progression, we examined whether there was a correlation between NFIB and the Akt pathway in cell proliferation and migration. Our results showed that NFIB promoted cell proliferation and increased 5‐FU resistance by activating the Akt pathway. In summary, our findings suggested that NFIB induced EMT of CRC cells via upregulating snail expression and promoted cell proliferation and 5‐FU resistance by activating the Akt pathway.