Effects of BCL6 B on proliferation and migration of human colorectal car-cinoma LoVo cells and its potential mechanism / 中国病理生理杂志

AIM:To detect the endogenous expression of B-cell leukemia/lymphoma 6 member B (BCL6B) in FHC and LoVo cells, and to investigate the effects of BCL6B on proliferation and migration of LoVo cells for further explo-ring the underlying mechanism .METHODS:The endogenous expression of BCL 6B in the FHC and LoVo cells was detec-ted by RT-PCR and Western blot .The methods of MTT assay , colony formation assay , wound healing assay and Transwell chamber experiment were employed to examine the biological functions of BCL 6B in the LoVo cells.The mRNA and protein levels of BCL6B, cyclin D1 and matrix metalloproteinase-9 ( MMP-9) were determined by RT-PCR and Western blot , re-spectively.The level of phosphorylated protein kinase B (p-AKT) was detected by Western blot.RESULTS:BCL6B ex-pression was notably repressed in the LoVo cells as compared with the FHC cells , which were significantly increased by transfection with pcDNA3.1-BCL6B.The abilities of proliferation and migration of the LoVo cells at 72 h were inhibited by 28.33%(P<0.01) and 36.11%(P<0.05) in BCL6B group.The mRNA levels of cyclin D1 and MMP-9 in the cells of BCL6B group were decreased by 39.90%(P<0.01) and 77.36% (P <0.05), and the protein levels of cyclin D1, MMP-9 and p-AKT were reduced by 44.00%(P<0.05), 47.06%(P<0.01) and 32.88% (P<0.05), respectively. CONCLUSION:BCL6B inhibits proliferation and migration of the LoVo cells , and the PI3K/AKT signaling pathway is in-volved in this process .

High-intensity focused ultrasound inhibits tumor metastasis in a melanoma-bearing mouse model / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of high-intensity focused ultrasound (HIFU) on tumor metastasis in mouse model bearing melanoma xenograft.</p><p><b>METHODS</b>Mice bearing murine melanoma B16-F10 cell xenograft were randomized for sham-HIFU or HIFU exposure when the tumors grew to a maximum diameter of 7-10 mm, and the tumor size was measured every 3 days. The cumulative survival rate of the mice and tumor metastasis rate were calculated, and the circulating melanoma cells were detected using qRT-PCR. At 14 days after HIFU treatment, B16-F10 cells were retransplanted via the tail vein and the pulmonary metastatic nodules were counted.</p><p><b>RESULTS</b>The median survival time of the mice was 19.00 days (95% CI 17.14-20.86 days) in the sham group and 26.00 days (95%CI 24.76-27.25 days) in HIFU group. The cumulative survival rate in the HIFU group was significantly higher than that in sham-HIFU group (P<0.01), and the tumor size was significantly smaller in HIFU group at 20, 23, and 26 days after HIFU treatment (P<0.05). Compared with the sham-HIFU group, HIFU group had significantly lower levels of MAGE-A3, MART1 and PAX3 at 7 days after HIFU (P<0.05) with still lower MAGE-A3 level at 14 days (P<0.05). HIFU group showed a significantly smaller number of pulmonary metastatic nodules following tumor cell retransplantation than in sham-HIFU group (P<0.01) with a metastasis inhibition rate of 42.4%.</p><p><b>CONCLUSION</b>HIFU treatment can inhibit tumor metastasis in melanoma-bearing mice possibly by reducing tumor cell detachment from the primary tumor site and suppressing colonization of the circulating melanoma cells.</p>

[Time varied stress effects on the proliferation of myoblast in rats].

OBJECTIVE: To investigate the effects of time varied stress on the proliferation of myoblast in rats and provide the basic experimental data for the remodeling of tissue in functional orthopaedics. METHODS: Based on the pulsatile mechanical system founded, this study loaded different strain (2.5, 5.0, 10.0 kPa) to the myoblast of lateral pterygoid muscle. The proliferation of myoblast was detected by 3H-TDR. RESULTS: After 6 hours under time varied strain, the significant proliferation of myoblast (P < 0.05) was observed, and the 5.0 kPa group expressed the best proliferation. After 12 hours under time varied strain, all groups expressed a better proliferation. Meanwhile, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain. CONCLUSION: The frequency of time varied strain had also the important influence on the proliferation, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain. In the certain period of time and certain magnitude of time varied strain, the proliferation of myoblasts rised.

Time varied stress effects on the proliferation of myoblast in rats / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of time varied stress on the proliferation of myoblast in rats and provide the basic experimental data for the remodeling of tissue in functional orthopaedics.</p><p><b>METHODS</b>Based on the pulsatile mechanical system founded, this study loaded different strain (2.5, 5.0, 10.0 kPa) to the myoblast of lateral pterygoid muscle. The proliferation of myoblast was detected by 3H-TDR.</p><p><b>RESULTS</b>After 6 hours under time varied strain, the significant proliferation of myoblast (P < 0.05) was observed, and the 5.0 kPa group expressed the best proliferation. After 12 hours under time varied strain, all groups expressed a better proliferation. Meanwhile, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain.</p><p><b>CONCLUSION</b>The frequency of time varied strain had also the important influence on the proliferation, the lower frequency (0.40 Hz) had the bigger effect on the proliferation more than in the higher frequency (1.25 Hz) under the same time varied strain. In the certain period of time and certain magnitude of time varied strain, the proliferation of myoblasts rised.</p>

Lipoxin A4 inhibits TNF-alpha-induced production of interleukins and proliferation of rat mesangial cells.

BACKGROUND: Studies have shown that lipoxin A(4) (LXA(4)) and its analogues inhibited proliferation of glomerular mesangial cells induced by leukotriene D(4) (LTD(4)) or platelet-derived growth factor (PDGF), reduced the production of proinflammatory cytokines such as interleukin (IL)-1beta and IL-6 in renal tissue of ischemic injury. In the present studies, we examine whether LXA(4) have inhibitory effects on tumor necrosis factor-alpha (TNF-alpha)-induced productions of IL-1beta and IL-6 and proliferation of glomerular mesangial cells of rat, and explore the molecular mechanisms of signal pathway of LXA(4). METHODS: Cultured glomerular mesangial cells were treated with TNF-alpha (10 ng/mL), with or without preincubation with LXA(4) at the different concentrations. Cell proliferation was assessed by [(3)H]-thymidine incorporation. Proteins of IL-1beta and IL-6 in supernatant were analyzed by enzyme-linked immunosorbent assay (ELISA). Expressions of mRNA of IL-1beta and IL-6 were determined by real-time polymerase chain reaction (PCR) and cyclin E by reverse transcription (RT)-PCR. Proteins of cyclin E, threonine phosphorylated Akt(1) at 308 site (Thr(308)) and p27(kip1) were analyzed by Western blotting studies. Activities of signal transducers and activators of transcription-3 (STAT(3)), nuclear factor-kappaB (NF-kappaB) were determined by electrophroretic mobility shift assay (EMSA). Expression of Src homology (SH) 2-containing protein-tyrosine phosphatase (SHP-2) was assessed by immunoprecipitation and immunoblotting. RESULTS: TNF-alpha-stimulated proliferation, release of proteins and expressions of mRNA of IL-1beta and IL-6 in mesangial cells were inhibited by LXA(4) in a dose-dependent manner. The marked increments in mRNA expression and protein synthesis of cyclin E induced by TNF-alpha in parallel with proliferation of mesangial cells were down-regulated by LXA(4). LXA(4) antagonized the phosphorylation of SHP-2 and activity of NF-kappaB induced by TNF-alpha. Pretreatment of the cells with NF-kappaB inhibitor pyrrolidine dithio-carbamate (PDTC) blocked the productions of IL-1beta, IL-6, and activation of NF-kappaB induced by TNF-alpha. Stimulation of mesangial cells with TNF-alpha resulted in enhanced DNA-binding activity of STAT(3). This increment was inhibited by LXA(4) in a dose-dependent manner. Threonine phosphorylated Akt(1) protein at 308 site stimulated by TNF-alpha was reduced by LXA(4.) TNF-alpha-induced decrement in expression of p27(kip1) protein was ameliorated by LXA(4) in a dose-dependent manner. CONCLUSION: TNF-alpha-induced proliferation and increment of cyclin E of rat mesangial cells can be inhibited by LXA(4), and these inhibitory effects might be through the mechanisms of STAT(3) and Akt(1)/p27(kip1) pathway-dependent signal transduction. LXA(4) also antagonized TNF-alpha-stimulated IL-1beta and IL-6 synthesis, and these antagonisms were related to SHP-2 and NF-kappaB pathway-dependent signal transduction.

High dose of lipoxin A4 induces apoptosis in rat renal interstitial fibroblasts.

Studies have implicated that lipoxinA4 (LXA4) inhibited nuclear factor-kappaB (NF-kappaB), Akt/PKB and PI 3-kinase activity and proliferation of glomerular mesangial cells. It is speculated that LXA4 might serve as pro-apoptotic factor. Rat renal interstitial fibroblasts (NRK-49F cells) were exposed to LXA4 in 5% FCS for 24 h. LXA4 at 0.1 and 1 microM induced 9.83% and 33.82% apoptosis of the cells, respectively, upregulated the expression of calpain 10 and Smac, the levels of [Ca2+]i and activity of caspase-3, and downregulated the activity of STAT3 and threonine phosphorylated Akt1. Transfection of calpain 10 or Smac antisense oligodeoxynucleotide into the cells inhibited the LXA4-induced apoptosis, activity of caspase-3. Pretreatment of the cells with calcium inhibitor SK&F96365 inhibited the LXA4-induced apoptosis, levels of [Ca2+]i, expression of calpain 10 and Smac. In conclusion, LXA4 at high concentrations induced apoptosis of renal interstitial fibroblasts via [Ca2+]i-dependent upregulation of calpain 10 and Smac expression.