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In the present study, we examined the effects of nano tantalum (Ta) dental implants on inducing osteoblast proliferation and differentiation. The MG-63 osteoblasts were divided into 3 groups after recovery, passage and storage: i) Osteoblast culturing group (control group); ii) osteoblast and titanium (Ti) implant co-culturing group (Ti group); and iii) osteoblast and Ta implant co-culturing group (Ta group). After 7 days, a scanning electron microscope was used to observe the growth status, number and morphological changes of the cells on the surfaces of the materials. An MTT assay was used to detect cell proliferation after culturing for 1, 3 and 7 days. ELISA assay was used to detect the levels of alkaline phosphatase (ALP) after 1, 3 and 7 days. Western blot analysis was used to detect the expression levels of collagen type I (Col-1) and osteocalcin after 1, 3 and 7 days. There was significant cell spreading on the surfaces of Ti and of Ta after 7 days, flat and with many pseudopodia. Additionally, there were more cell components in the Ta group. Concurrently, cell proliferation in the Ti and Ta groups increased. There was also an increase in the level of ALP and the expression level of Col-1 over time. The indexes of the Ta group were more apparent than those of the Ti group at each time-point, and the differences were statistically significant (p

The Ras/Raf/MEK/ERK signaling has been implicated in uncontrolled cell proliferation and tumor progression in pancreatic cancer. The purpose of this study is to evaluate the antitumor activity of MEK inhibitor U0126 in combination with Hsp90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) in pancreatic cancer cells. Western blotting showed that 17-AAG caused a 2- to 3-fold transient activation of MEK/ERK signaling in pancreatic cancer cells. The activation sustained for 6 h before phospho-ERK (p-ERK) destabilization. The selective MEK inhibitor U0126 completely abolished 17-AAG induced ERK1/2 activation and resulted in more than 80% of phosphor-ERK degradation after only 15 min treatment. Moreover, U0126 had complementary effect on 17-AAG regulated oncogenic and cell cycle related proteins. Although 17-AAG downregulated cyclin D1, cyclin E, CDK4 and CDK6, it led to cyclin A and CDK2 accumulation, which was reversed by the addition of U0126. Anti-proliferation assay showed that combination of U0126 and 17-AAG resulted in synergistic cytotoxic effect. More importantly, 17-AAG alone only exhibited moderate inhibition of cell migration in vitro, while addition of U0126 dramatically enhanced the inhibitory effect by 2- to 5-fold. Taken together, these data demonstrate that MEK inhibitor U0126 potentiates the activity of Hsp90 inhibitor 17-AAG against pancreatic cancer cells. The combination of Hsp90 and MEK inhibition could provide a promising avenue for the treatment of pancreatic cancer.

The small heat shock protein 27 (Hsp27) is a molecular chaperone that is involved in a variety of cellular functions in cancer cells. The purpose of this research is to study Hsp27 in vitro metastatic behaviors of head and neck squamous cell carcinoma cells (HNSCC). The expression of Hsp27 in primary and metastatic cell lines derived from the primary HNSCC and a synchronous lymph node metastasis in the same patient was determined using real-time PCR and western blotting. Proliferation of the primary and metastatic HNSCC cell lines was evaluated using the MTS proliferation assay. Metastatic behavior was assessed using migration and invasion assays. SiRNA knockdown of Hsp27 was performed in the highly migratory metastatic HNSCC cell line. MTS assays showed that the primary (UM-SCC-22A) and metastatic (UM-SCC-22B) HNSCC have similar proliferation rates. However, UM-SCC-22B derived from the metastasis showed 2.3 to 3.6-fold higher migration ability and 2-fold higher invasion ability than UM-SCC-22A. Real-time PCR demonstrated that Hsp27 mRNA is 22.4-fold higher in metastatic UM-SCC-22B than primary UM-SCC-22A. Similarly, Western blotting showed that Hsp27 is rarely detectable in UM-SCC-22A whereas UM-SCC-22B expresses a 25-fold higher level of Hsp27 protein. SiRNA-mediated knock down of Hsp27 in UM-SCC-22B reduced Hsp27 mRNA expression by nearly 6 - fold and protein expression by 23-fold. Furthermore, siRNA knockdown of Hsp27 decreased metastatic behaviors of UM-SCC-22B by 3 to 4-fold in migration and 2-fold in cell invasion reducing cell invasion and migration to levels similar to the primary HNSCC UM-SCC-22A. These data indicate that Hsp27 may regulate metastatic potential of HNSCC cancer cells. Targeting Hsp27 may decrease metastasis in head and neck squamous cell cancer cells.

The small heat shock protein 27 (Hsp27) is a molecular chaperone that is involved in a variety of cellular functions in cancer cells. The purpose of this research is to study the function of Hsp27 in metastasis of head and neck squamous cancer cells. The expression of Hsp27 in primary and metastatic head and neck cancer cells was determined using real-time PCR and western blotting. The siRNA knockdown of Hsp27 was performed in metastatic head and neck cancer cells using in vitro transfection. The proliferation of the primary and metastatic head and neck cancer cells were evaluated using MTS proliferation assay. The metastatic potential was determined using both migration assay and invasion assay in metastatic head and neck cancer cells after siRNA silencing of Hsp27. MTS proliferation showed that both primary (UM-SCC-22A) and metastatic (UM-SCC-22B) head and neck cancer cells have similar proliferation rate from 24-48 hrs. However, the metastatic head and neck cancer cells (UM-SCC-22B) showed more than 2-fold migration ability and more than 3-fold invasion ability than primary head and neck cancer cells (UM-SCC-22A). Real-time PCR demonstrated that Hsp27 mRNA is 22-fold higher in metastatic UM-SCC-22B than primary UM-SCC-22A. Similarly, Western blotting exhibited that primary UM-SCC-22A did not show any detectable levels of Hsp27, while metastatic UM-SCC-22B showed significant high levels (> 40-fold) of Hsp27. siRNA of Hsp27 knocked down expression of Hsp27 by more than 5-fold in mRNA level and 23-fold in protein levels in metastatic head and neck cancer cells UM-SCC-22B. Furthermore, siRNA knockdown of Hsp27 decreased metastasis of UM-SCC-22B by more than 50% in cell invasion assay. These data suggest that Hsp27 may regulate metastatic potential of head and neck squamous cancer cells. Silencing Hsp27 may decrease metastatic potential of head and neck squamous cancer cells. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3392.