[Effects of a novel spermine oxidase inhibitor SI-4650 on proliferation and EMT of human ovarian cancer SKVO-3 cells].

Objective: To investigate the effects of SI-4650, a novel small molecule inhibitor of spermine oxidase (SMO), on the proliferation and epithelial mesenchymal transformation (EMT) of human ovarian cancer SKVO-3 cells as well as its underlying molecular mechanisms. Methods: SKVO-3 cells treated with 0 µmol/L SI-4650 were used as control group, SKVO-3 cells treated with 30, 60 µmol/L SI-4650 were used as experimental group. The effects of SI-4650 on the activity of SMO, the polyamine contents and the cellular reactive oxygen species (ROS) were detected. Cell proliferation, cell cycle and mitochondrial membrane potential change of SKVO-3 cells were tested. The effects of SI-4650 on apoptosis, migration and invasion were investigated. The effects of SI-4650 on Bax, Bcl-2, Caspase3, E-cadherin, N-cadherin, Vimentin, matrix metalloproteinase 2 ( MMP2) and MMP 9 expression levels in SKVO-3 cells were detected. Results: Comparison between blank control group and experimental groups,SI-4650 could improve the content of SI-4650 in SKVO-3 cells. SI-4650 could inhibit the activity of SMO (P＜0.01), reduce the ROS (P＜0.01)and polyamine content in SKVO-3 cells (P＜0.01). Treatment of SKVO-3 cells with SI-4650 inhibited the proliferation (the inhibition rate was 32.27% and 47.31% in experimental groups), caused S-phase cell cycle arrest (P＜0.01) and induced apoptosis (P＜0.01). The expressions of Bax and c-Caspase3 in SKVO-3 cells were increased (P＜0.01),the content of Bcl-2 was decreased (P＜0.01), and the mitochondrial membrane potential was decreased (P＜0.01), and the number of apoptotic cells was increased(31.41% and 43.51% in experimental groups). At the same time, SI-4650 could change the expression levels of EMT-related factors, increased the expression level of E-cad , decreased the expression levels of N-cad, Vimentin, MMP-2 and MMP-9, and inhibited the migration and invasion of SKVO-3 cells. Conclusion: SI-4650 can effectively inhibit proliferation, invasion and metastasis of human ovarian cancer SKVO-3 cells, and the mechanism may be related to its ability to depress the activity of SMO, interfere polyamine metabolism and induce cell cycle arrest, mitochondrial apoptosis and inhibit EMT. This study reveals potential application of SI-4650 in the treatment of ovarian cancer.

Wavelength-switchable and multi-pulse bound state based on a hybrid mode-locked mechanism.

Relying on the nonlinear multimode interference in multimode fibers and the nonlinear polarization rotation, these two mode-locked techniques are combined in our proposed fiber laser. Stable optical soliton and multi-pulse regimes with a constant frequency of 11.44 MHz have been generated experimentally. Through altering intra-cavity conditions, bound-state pulses with diverse properties are observed. To the best of our knowledge, the obtained bound-state pulse constituted by more than thirty sub-pulses is achieved for the first time. Moreover, the center wavelength of bound-state pulse could be switched in a certain range covering the entire C band.

Evolutions of Q-switched mode-locked square noise-like pulse with different cavity lengths.

A $Q$-switched mode-locked square noise-like pulse (QMLSNLP) is generated in a nonlinear polarization rotation passively mode-locked fiber laser. When the pump power changes from 154 mW to 414 mW, the frequency of the $Q$-switched envelope varies from 21.7 kHz to 38.9 kHz, while the duration of the $Q$-switched envelope decreases from $5.1\,\,{\unicode{x00B5}\rm s}$ to $3.2{\unicode{x00B5}\rm s}$, correspondingly. In the meantime, QMLSNLP keeps the fundamental repetition rate constant, and the pulse duration increases from 3.4 ns to 6.7 ns. By inserting different lengths of single-mode fiber into the ring cavity, the evolutions of QMLSNLP are measured and analyzed. According to the cavity parameters and experimental results, impacts of the cavity length on QMLSNLP are investigated in detail.

[Role of ABCB1 and ABCG2 in the multidrug resistance of hypopharyngeal carcinoma FaDu cell line].

OBJECTIVE: To investigate the expression of multidrug resistance gene ABCB1 and ABCG2 in FaDu cells (human hypopharyngeal carcinoma cell line) and the multidrug resistance (MDR) cell lines FaDu/T transformed from FaDu cells by taxol and underlying mechanisms of MDR. METHODS: The multidrug resistance sensitivities of FaDu and FaDu/T to cisplatin (DDP), 5-fluorouracil (5-FU), doxorubicin (Dox), and vincristine (VCR) were examined by methyl-thiazolyl-tetrazolium (MTT) assay. The mRNA and protein expressions of multidrug resistance genes ABCB1 and ABCG2 were analysed with RT-PCR, Western blot and laser confocal microscopy. JNK signal proteins were detected through Western blot. RESULTS: The multidrug resistance of FaDu/T cells to Taxol, DDP, 5-FU, ADM and VCR was more than that of FaDu cells. The expression of ABCB1 in FaDu/T cells was significantly higher than that in FaDu cells (t = 22.42, P < 0.05), but the expression of ABCG2 in FaDu/T cells was significantly lower than that in FaDu cells (t = 10.06, P < 0.05). JNK signal was inhibited in FaDu or FaDu/T cells and the inhibited JNK was reactivated by taxol or anisomycin (an activator for MAPK signal transduction pathways). Anisomycin down-regulated the expression of ABCB1 (F = 33.72, P < 0.05) and up-regulated the expression of ABCG2 (F = 220.16, P < 0.05) in FaDu/T cells, but not in FaDu/T cells pretreated by JNK inhibitor SP600125 (P > 0.05). CONCLUSION: The overexpression of ABCB1 and the down-regulation of ABCG2 in FaDu/T cells were the main features of MDR in hypopharyngeal carcinomas, in which JNK signal transduction pathways could play an important role.

Down-regulation of TWIST decreases migration and invasion of laryngeal carcinoma Hep-2 cells by regulating the E-cadherin, N-cadherin expression.

PURPOSE: The transcription factor TWIST is an important factor in regulation of the epithelial-mesenchymal transition (EMT), which represents the primary stages during the metastasis of tumors. To identify the role of TWIST in the regulation of metastasis in laryngeal carcinoma Hep-2 cells, we investigated whether the alteration of TWIST has an effect on the Hep-2 cells morphology and whether the alteration of TWIST has an effect on the expression of E-cadherin, N-cadherin as well as the ability of cell motion, migration, and invasion. METHODS: Morphological changes of Hep-2 cells that were transfected a mircoRNA against TWIST vector were observed by the reserved microscope. Reverse transcription-polymerase chain reaction was performed in order to examine the mRNA expression of TWIST, E-cadherin, and N-cadherin. Western blotting was performed to examine the protein expression of TWIST, E-cadherin, and N-cadherin. Cell motion ability was examined by Scratch-wound assay. Transwell(™) chamber assays were used to determine cell migration and invasion. RESULTS: Transfecting a mircoRNA down-regulated TWIST expression at mRNA and protein levels. Down-regulation of TWIST expression induced morphological changes, such as the inversion of the EMT. Moreover, down-regulation of TWIST expression up-regulated E-cadherin and down-regulated N-cadherin expressions at mRNA and protein levels, respectively. Furthermore, we confirmed that down-regulation of TWIST expression decreased the motion, invasion, and migration ability of the Hep-2 cells. CONCLUSIONS: Down-regulation of TWIST expression decreases migration and invasion of laryngeal carcinoma Hep-2 cells by regulation of the E-cadherin, N-cadherin expression.

Twist modulates lymphangiogenesis and correlates with lymph node metastasis in supraglottic carcinoma.

BACKGROUND: Twist is a highly conserved epithelial-mesenchymal transcription factor that has been reported to be a key factor in tumor malignancy, including lymph node metastasis. It represents the major step of dissemination and serves as a chief prognostic indicator of disease progression. However, the mechanism by which Twist regulates lymph node metastasis remains incompletely understood. Studies on the mechanism of metastasis are thus required for determining appropriate therapeutic strategies. METHODS: Immunohistochemistry for lymphatic vessel endothelial receptor 1 (LYVE-1), Ki-67, Twist, vascular endothelial growth factor C (VEGF-C), and vascular endothelial growth factor receptor 3 (VEGFR-3) was performed to detect lymphatic vessel density (LVD), cell proliferation levels and the expressions of Twist, VEGF-C, and VEGFR-3 were determined from 66 primary supraglottic carcinoma tissue samples from 36 patients with lymph node metastasis (pathological N+, pN+) and 30 patients without metastasis (pathological N0, pN0). Western blotting analysis of the proteins in pN+ and pN0 primary tumors was used to characterize the expressions of Twist, VEGF-C, and VEGFR-3 further. RESULTS: The LVD was 22.4 ± 10.3 in pN+ patients and 6.8 ± 4.1 in pN0 ones. For Ki-67, the number of proliferous cells in pN+ patients was greater than that in pN0 ones. Both, however, were associated with their clinical nodal stages. In pN+ patients, Twist, VEGF-C, and VEGFR-3 expressions were 86.11% (31/36), 80.56% (29/36), and 58.33% (21/36), respectively. These values were higher than those found for pN0 patients (i.e., 13/30, 11/30, and 7/30, respectively) (P < 0.05). Among the samples with Twist expression, 88.64% were VEGF-C-positive and 59.09% were VEGFR-3-positive. The pN0 counterparts were 4.55% and 9.09%, respectively (P < 0.05). The expressions of Twist, VEGF-C, and VEGFR-3 in pN+ patients obtained through Western blotting analysis were significantly higher than those in pN0 patients, and the levels of VEGF-C and VEGFR-3 were positively correlated with that of Twist. CONCLUSIONS: Twist expression correlates with lymph node metastasis. The mechanism involved in such a correlation may be related to lymphangiogenesis.

[Nimesulide induced apoptosis and inhibited metastasis of hypopharyngeal carcinoma cells].

OBJECTIVE: To investigate the effects of Nimesulide, a selective Cox-2 inhibitor, on the apoptosis, invasion and migration of hypopharyngeal carcinoma cell line (FaDu). METHODS: Viabilities of FaDu cells treated with various concentrations of Nimesulide were detected by MTT assay. Morphological changes were observed by acridine orange cytochemistry staining. Apoptosis was examined by flow cytometry. The ability of invasion and migration of cells was detected by Transwell chambers. The mRNA and protein expressions of Cox-2, MMP-9 and caspase-3 in response to Nimesulide were examined by RT-PCR and Western blot, respectively. RESULTS: MTT assay showed that the cell surviving rates significantly decreased in time- and concentration-dependent manners (P < 0.05). The typical morphological changes of apoptotic cells were observed. Percent of apoptosis after 6 h Nimesulide treatment was (32.4 ± 6.1)%. The metastatic cells were decreased by Nimesulide to about 20%. Nimesulide decreased the expressions of Cox-2 and MMP-9, whereas increased expression the of Caspase-3. CONCLUSION: Nimesulide could induce the apoptosis and inhibit metastasis of FaDu cells.

[Role of TWIST in the apoptosis of Hep-2 cells induced by paclitaxel].

OBJECTIVE: To explore the relationship between the expression of transcription factor TWIST and apoptosis of Hep-2 cells induced by paclitaxel. METHODS: Morphological changes of Hep-2 cells were observed by reserved microscopy and acridine orange cytochemistry staining. Viability of Hep-2 cells treated with various concentrations of paclitaxel was detected by MTT assay. Apoptosis was examined by flow cytometry. The expressions of transcription factor TWIST at both mRNA and protein level in response to paclitaxel at 24 h, 48 h and 72 h were then examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot, respectively. RESULTS: Typical morphological changes of apoptotic cells, i.e., cellular rounding-up, cytoplasmic contraction, chromatin condensation and, particularly, apoptotic body, the main morphological characteristic of apoptosis, were observed by reserved microscopy and acridine orange cytochemistry staining. The cell surviving rates significantly decreased in a concentration- and time-dependent manner as evidenced by MTT assay (P < 0.05). Percent of apoptosis after 24 h, 48 h or 72 h paclitaxel-treatment was (22.6 +/- 5.3)%, (38.7 +/- 7.9)% and (52.4 +/- 14.3)%, respectively, whereas the percent of control was (9.85 +/- 5.83)%. There existed a statistically significant difference between treatment and control (F = 12.621, P < 0.05). The expression of TWIST at both mRNA and protein levels for 24 h, 48 h or 72 h in the paclitaxel-induced apoptosis of Hep-2 cells were decreased by 16.7%, 46.8%, 76.9% (F = 10.407, P < 0.05) and 16.4%, 33.6%, 69.6% (F = 18.013, P < 0.05) respectively. CONCLUSIONS: TWIST, which is significantly decreased in expression in response to paclitaxel in Hep-2 cells, may play a pivotal role in paclitaxel-induced apoptosis of Hep-2 cells.