A nonlinear competitive model of the prostate tumor growth under intermittent androgen suppression.

Hormone suppression has been the primary modality of treatment for prostate cancer. However long-term androgen deprivation may induce androgen-independent (AI) recurrence. Intermittent androgen suppression (IAS) is a potential way to delay or avoid the AI relapse. Mathematical models of tumor growth and treatment are simple while they are capable of capturing the essence of complicated interactions. Game theory models have analyzed that tumor cells can enhance their fitness by adopting genetically determined survival strategies. In this paper, we consider the survival strategies as the competitive advantage of tumor cells and propose a new model to mimic the prostate tumor growth in IAS therapy. Then we investigate the competition effect in tumor development by numerical simulations. The results indicate that successfully IAS-controlled states can be achieved even though the net growth rate of AI cells is positive for any androgen level. There is crucial difference between the previous models and the new one in the phase diagram of successful and unsuccessful tumor control by IAS administration, which means that the suggestions from the models for medication can be different. Furthermore we introduce quadratic logistic terms to the competition model to simulate the tumor growth in the environment with a finite carrying capacity considering the nutrients or inhibitors. The simulations show that the tumor growth can reach an equilibrium state or an oscillatory state with the net growth rate of AI cells being androgen independent. Our results suggest that the competition and the restraint of a limited environment can enhance the possibility of relapse prevention.

Systemically transplanted human gingiva-derived mesenchymal stem cells contributing to bone tissue regeneration.

As novel postnatal stem cells, gingiva-derived mesenchymal stem cells (GMSCs) have been considered as an ideal candidate cell resource for tissue engineering and cell-based therapies. GMSCs implanted into sites of injury have been confirmed to promote the injury repair. However, no studies have demonstrated whether systemically transplanted GMSCs can home to the bone injuries and contribute to the new bone formation in vivo. In this study, we transplanted human GMSCs into C57BL/6J mice with defects in mandibular bone via the tail vein to explore the capacity of transplanted GMSCs to promote bone regeneration. Results showed that the transplanted GMSCs were detected in the bone defects and employed in new bone formation. And the newly formed bone area in mice with GMSCs transplantation was significantly higher than that in control mice. Our findings indicate that systemically transplanted GMSCs can not only home to the mandibular defect but also promote bone regeneration.

[Study on the correlation of epidermal growth factor and Sjoigren's syndrome with atrophic glossitis].

PURPOSE: To investigate the correlation between epidermal growth factor (EFG) and atrophic glossitis (AG) in patients with Sjoigren's syndromes (SS) and explore its pathogenesis. METHODS: Ninety-three patients with SS (60 with AG and 33 without AG) and 20 normal were selected. The concentrations of EGF in saliva were analyzed by ELISA. The expressions of EGF receptor (EGFR) in the epithelial cells of the tongue were assayed by immunohistochemistry. The differences among each group were analyzed with SPSS19.0 software package. RESULTS: The saliva EGF concentrations in SS was lower than that in normal control group(P<0.0001),and EGF concentrations in SS with AG was significantly lower than that in SS without AG (P=0.024). EGF levels in saliva gradually decreased in the mild, moderate and severe atrophic glossitis groups, and there were significant differences among each group(P<0.05). EGFR in the epithelial cells of tongue was lower in SS with moderate and severe AG than in the control group(P=0.009, P=0.037), and there was a significant correlation between EGF and the degree of AG (r=-0.673, P<0.01). CONCLUSIONS: Saliva EGF concentrations decrease significantly in patients with SS and it is closely related to the morbidity of atrophic glossitis.

Factors associated with psychological characteristics in patients with hepatic malignancy before interventional procedures.

OBJECTIVE: To investigate the psychological characteristics of hepatic malignancy patients before interventional procedures and assess associations with related factors. METHODS: Two hundred and thirteen patients requiring interventional procedure for hepatic malignancy were asked to complete a survey of health knowledge and psychological symptom on health knowledge questionnaire and SCL-90 before interventional procedure. Logistic regression analysis was employed to determine the association of various demographic, clinical and health knowledge factors with the presence of psychological symptoms in patients. RESULTS: Eight psychological symptom scores, i.e. somatization, obsessive-compulsive tendencies, depression, anxiety, hostility, phobia, paranoid ideations and psychotic states, were significantly higher than the normal range (P< 0.001). Of 213 cases in the study, 49 families (23.00%) concealed the diagnoses of hepatic carcinoma from patients; 135 patients (63.38%) described the prognosis of the disease correctly. It was demonstrated that the correlations between psychological symptoms and related factors, i.e. age, gender, education, interventional procedure times and health knowledge, were statistically significant (P< 0.05). CONCLUSION: Psychological distress is severe in hepatic malignancy patients before interventional procedures. Age, gender, education, interventional procedure times and health knowledge are associated with psychological symptoms which are significant different from the normal range in Chinese.

[Construction and identification of recombinant adenoviruses containing the gene fragments encoding Her2/neu extracellular and transmembrane domains].

OBJECTIVE: To construct eukaryotic expression vectors using recombinant adenovirus containing the gene fragments encoding Her2/neu extracellular first ligand-binding domain (Her2-ECD), full-length extracellular domain (Her2-ECD), and extracellular and transmembrane domain (Her2-TM). METHODS: The cDNAs were amplified by RT-PCR and inserted into shuttle pAdTrack-CMV plasmids. Viral plasmids were obtained from homologous recombination in E. coli BJ5183, and transfected into 293 cells via liposome. Formation of viral plaque and expression of green fluorescent protein were observed by fluorescence microscopy, and the target proteins were detected by Western blotting. RESULTS: The target cDNA fragments were amplified by PCR with expected lengths and the DNA sequences were confirmed against Genbank. Formation of viral plaque, expression of green fluorescent protein and the target proteins were detected in 293 cells transfected by the viral plasmids, which showed elevated expression of Her2/neu protein with the increase of multiplicity of infection (MOI). CONCLUSION: The eukaryotic expression vectors using recombinant adenovirus have been successfully constructed for expression of Her2/neu extracellular and transmembrane domains.

[Changes in immune function of dendritic cells infected by recombinant adenovirus containing Her2/neu gene of extracellular and transmembrane domain proteins].

OBJECTIVE: To observe the functional changes of dendritic cells (DCs) infected in vitro by 3 recombinant adenoviruses encoding Her2/neu extracellular first-receptor domain (Her2-ECDs), full-length extracellular domain (Her2-ECD), and extracellular and transmembrane domain (Her2-TM) proteins (rAdHer2-ECDs, rAdHer2-ECD and rAdHer2-TM, respectively). METHODS: The expressions of the target proteins were detected with Western blotting. The level of both interleukin (IL)-12 in the supernatant of in vitro cultured DCs infected with recombined adenoviruses and interferon gamma (IFN-gamma) in the supernatant of the lymphocyte populations co-cultured with DCs were determined by enzyme-linked immunosorbent assay (ELISA). The capacity of the DCs to stimulate allogeneic T lymphocyte proliferation was assessed by mixed lymphocyte reaction, and the activity of cellular toxic T lymphocytes (CTL) were investigated by MTT assay. RESULTS: Her2-ECDs, ECD and TM proteins were detected in the transfected DCs. Compared with the untransfected DCs, more abundant IL-12 production was detected in the supernatant of the DCs 5 days after transfection, but the IL-12 level showed no significant difference between the DCs infected with the 3 recombinant adenoviruses. IFN-gamma production increased gradually with passage of the time following DC-stimulated lymphocyte proliferation irrespective of infection of the DCs, and only the DCs infected with rAdHer2-TM seemed to result in significant difference in DC-mediated allogeneic T lymphocyte proliferation. The killing of breast cancer cell line with Her2 overexpression was more efficient with infected DCs priming autologous T lymphocyte to generate CTL than with uninfected DCs and those modified by SK-OV-3 cell fragment. CTL activity induced by rAdHer2-TM-infected DCs was the strongest, and breast cancer cell-killing activity was more efficient against cell line with Her2/neu-overexpression. CONCLUSION: The DCs infected with the recombinant adenovirus encoding Her2/neu extracellular and transmembrane domains show enhanced anti-tumor effect and induce Her2/neu-specific CTL activity.

[Effect of XK469 and adriamycin on the growth of H460 cells in vitro and its mechanism].

OBJECTIVE: To investigate the inhibitory effect of XK469 on the in vitro growth of H460 cells and its mechanism. METHODS: The survival curves of H460 cells treated with XK469, XN472 and adriamycin, respectively, were obtained by MTT analysis, and the effect of XK469 and adriamycin on the cell cycle of H460 cells examined by flow cytometry. Western blotting was adopted for detecting the expression of cdc2 and phos-cdc2 induced by XK469 and adriamycin. RESULTS: Different concentrations of XK469 and adriamycin could significantly inhibit the growth of H460 cells, induce their G2/M phase arrest, and increase phos-cdc2 expression; XN472 had a lesser effect on the growth of H460 cells. CONCLUSION: XK469 can increase phos-cdc2 expression and induce G2/M phase cell cycle arrest of H460 cells, resulting in inhibition of H460 cell growth. The inhibitory effect of XK469 on H460 cell growth is attributed to the chlorine in the 7-positon of its structure.

Down-regulation of apoptosis-inducing factor protein by RNA interference inhibits UVA-induced cell death.

Apoptosis-inducing factor (AIF) is a caspase-independent apoptosis effector. UVA-induced Raji cell death was not completely inhibited by pan-caspase inhibitor zVAD.fmk. Moreover, AIF translocated from its normal location, the mitochondrial intermembrane space, into the nucleus, and induced peripheral chromatin condensation during the early stage of UVA-inducing cell death. Enforced expression of AIF can induce Raji cell death in a caspase-independent manner. Down-regulation of AIF protein level by RNA interference (RNAi) can reduce UVA-induced Raji cell death, but the combination of down-regulation of AIF and zVAD.fmk almost completely inhibited UVA-induced Raji cell death. All these suggest that caspase and AIF are two independent pathways and that UVA-induced Raji cell death is dependent on caspase and AIF.