Experimental Study on Ultrasonic Assisted Turning of GH4068 Superalloy.

GH4068 superalloy is a new type of nickel-based superalloy in the aerospace field. It is an important alloy material for the manufacture of aircraft tubular components and aero-engine hot-end components. These components need to be machined with good surface quality to meet their use requirements. New hybrid machining processes can improve the quality of surface finish compared to conventional machines. In this paper, ultrasonic assisted turning (UAT) technology was applied to the machining of GH4068 superalloy. The experimental system of UAT was established. Experiments of UAT and conventional turning (CT) of GH4068 superalloy were carried out to study the effects of cutting speed, feed speed, cutting depth and vibration amplitude on cutting force and surface roughness. The surface morphology of the workpiece and chip were observed. The experimental results show that Fx and Fy can be reduced by a maximum of 44% and 63%, respectively, and the surface roughness can be reduced by a maximum of 31% after adding ultrasonic vibration. Compared with CT, the UAT has a better machining quality, a more obvious chip-breaking effect, and a smaller chip bending radius, which guides the high-quality processing of the GH4068 superalloy.

Identification of differentially expressed proteins and clinicopathological significance of HMGB2 in cervical cancer.

To investigate the complexity of proteomics in cervical cancer tissues, we used isobaric tags for relative and absolute quantitation (iTRAQ)-based mass spectrometry analysis on a panel of normal cervical tissues (N), high-grade squamous intraepithelial lesion tissues (HSIL) and cervical cancer tissues (CC). Total 72 differentially expressed proteins were identified both in CC vs N and CC vs HSIL. The expression of HMGB2 was markedly higher in CC than that in HSIL and N. High HMGB2 expression was significantly correlated with primary tumor size, invasion and tumor stage. The up-regulated HMGB2 was discovered to be associated with human cervical cancer. These findings suggest that HMGB2 may be a potentially prognostic biomarker and a target for the therapy of cervical cancer.

SNHG22 overexpression indicates poor prognosis and induces chemotherapy resistance via the miR-2467/Gal-1 signaling pathway in epithelial ovarian carcinoma.

Recently, an increasing number of studies have reported that dysregulation of long noncoding RNAs (lncRNAs) plays an important role in cancer initiation and progression, including in epithelial ovarian carcinoma (EOC). However, little is known about the detailed biological functions of the lncRNA small nucleolar RNA host gene 22 (SNHG22) during the progression of EOC. Here, we found that SNHG22 was significantly increased in EOC tissues and was significantly associated with a low level of differentiation. Forced SNHG22 expression promoted chemotherapy resistance in EOC cells. Knockdown of SNHG22 expression increased the sensitivity of EOC cells to cisplatin and paclitaxel. Importantly, we found that SNHG22 could directly interact with miR-2467 and lead to the release of miR-2467-targeted Gal-1 mRNA. Moreover, SNHG22 overexpression induced EOC cell resistance to chemotherapy agents via PI3K/AKT and ERK cascade activation. In summary, our findings demonstrate that SNHG22 plays a critical role in the chemotherapy resistance of EOC by mediating the miR-2467/Gal-1 regulatory axis.

miRNA-574-3p inhibits metastasis and chemoresistance of epithelial ovarian cancer (EOC) by negatively regulating epidermal growth factor receptor (EGFR).

BACKGROUND: This current study explored the role of miRNA-574-3p and the related molecular mechanisms in epithelial ovarian cancer (EOC). METHODS: Tissues of ovarian cancer patients were applied to explore the correlation between miRNA-574-3p and EOC. The role of miRNA-574-3p in migration, invasion and chemoresistance of EOC cells was evaluated by overexpression and suppression of miRNA-574-3p in SKOV3 and CAOV3 cells. For the sake of exploring how miRNA-574-3p regulated tumor migration, invasion and chemoresistance of EOC cells, we detected several related molecular expressions and activities of signaling pathways. RESULTS: Overexpression of epidermal growth factor receptor (EGFR) was correlated with downregulation of miR-574-3p in EOC tissues. Overexpression of miRNA-574-3p in EOC cells led to inhibition of cell migration as well as invasion, and it significantly promoted the sensitivities of EOC cells to paclitaxel and cisplatin. Molecular experiments showed miR-574-3p inhibited activation of AKT, FAK and c-Src, as well as MMP-9 expression via targeting EGFR. CONCLUSION: Taken together, these data demonstrated that miRNA-574-3p inhibits both tumor metastasis and chemoresistance in EOC via targeting EGFR. Thus, targeting miRNA-574-3p may become a potential molecular method for EOC.

Galectin-1 induces metastasis and epithelial-mesenchymal transition (EMT) in human ovarian cancer cells via activation of the MAPK JNK/p38 signalling pathway.

BACKGROUND: It has been reported that Galectin-1 (Gal-1) indicates bad prognosis of patients with ovarian cancer, and Gal-1 overexpression promotes metastasis of ovarian cancer cells. Nevertheless, the underlying mechanisms of the Gal-1-mediated enhancement of metastasis are still unclear. Furthermore, little is known about whether Gal-1 affects epithelial-mesenchymal transition (EMT) in ovarian cancer. METHODS: The human SKOV3-ip and SKOV3 cell lines were transfected with Gal-1 siRNAs and LV-Gal-1 lentivirus, respectively. Cell migration and cell invasion abilities were examined by transwell assays. Protein or mRNA levels of Gal-1, p-JNK1/2, t-JNK1/2, p-p38, t-p38 and EMT markers were detected via immunohistochemistry, qRT-PCR and western blot in SKOV3-ip as well as SKOV3 cells. A xenograft tumour model was used in vivo to ascertain whether upregulation of Gal-1 in ovarian cancer cells can enhance metastasis in vivo. RESULTS: In a total of 107 human ovarian cancer tissues, higher Gal-1 expression strongly associated with higher histological grade, more lymph node metastases and more advanced FIGO stage, while lower E-cadherin expression strongly associated with higher histological grade, more lymph node metastases and more advanced FIGO stage. In vitro assays revealed that Gal-1 promoted migration and invasion of ovarian cancer cells, as well as EMT. Additionally, the results showed that Gal-1 enhanced EMT, migration and invasion by activating the MAPK JNK/p38 signalling pathway. Moreover, in vivo bioluminescence imaging revealed that Gal-1 modulated ovarian cancer metastasis in nude mice. Immunochemistry of xenograft tumour tissues confirmed that Gal-1 may modulate metastasis and EMT via the MAPK JNK/p38 signalling pathway. Additionally, treatment of Gal-1 mice with the MAPK JNK/p38 signalling pathway antagonists SB203580 or SP600125 reduced cancer metastasis. CONCLUSION: Gal-1 enhances metastasis and EMT of ovarian cancer cells via promoting the activation of the MAPK JNK/p38 signalling pathway, suggesting the possibility that Gal-1 is a molecular target to prevent and cure ovarian cancer metastasis.

High-mobility group box 2 promoted proliferation of cervical cancer cells by activating AKT signaling pathway.

Cervical cancer is one of the leading killers for female worldwide. Nevertheless, the less knowledge of molecular mechanism for cervical cancer limited the improvement of treatment effects. High-mobility group box 2 (HMGB2) belongs to the HMGB family, which could play diverse roles in cell proliferation. This work mainly aimed to study the functions of HMGB2 on cervical cancer cells proliferation. HMGB2 was highly expressed in cervical cancer tissue. The results of real-time polymerase chain reaction and Western blot analysis showed that HMGB2 was expressed in all the five cervical cancer cells (HeLa, CaSki, SiHa, C-33A, and C4-1 cells). In addition, HMGB2 overexpression obviously improved cell viability and promoted cell cycle progression, which suggested that HMGB2 could promote proliferation of cervical cancer cells. Moreover, HMGB2 overexpression increased the level of p-AKT and reduced the levels of p21 and p27. However, HMGB2 downregulation had contrary influences on cell proliferation, cell cycle distribution and the levels of p-AKT, p21, and p27. Notably, LY294002, as an inhibitor of AKT signaling pathway, could significantly weaken the effects of HMGB2 overexpression, which indicated that HMGB2 might promote cell proliferation by activating AKT signaling pathway. Therefore, HMGB2 was hopeful to be a candidate as a new biomarker and therapy target for cervical cancer.

SNAIL gene inhibited by hypoxia-inducible factor 1α (HIF-1α) in epithelial ovarian cancer.

The aim of this study was to investigate the relationship between HIF-1α and SNAIL gene expression in the epithelial ovarian cancer (EOC) cell line. EOC cells were treated with hypoxia, hypoxia combined with rapamycin, and control. The expression of HIF-1α and E-cad were assessed by reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. The gene expression of SNAIL was studied by RT-PCR and real-time PCR. RNA interference technology was used to determine the relationship between HIF-1α and SNAIL. The present study indicated that the HIF-1α protein was expressed and increased in EOC cell line. SNAIL mRNA was found to increase and E-cad expression decreased with the time of hypoxia prolonged. Hypoxia increased invasion abilities of EOC cell line, but compared with cells exposed to hypoxia, the change of invasive ability of cells with rapamycin had no effect. The expression of HIF-1α protein and SNAIL mRNA could be inhibited gradually by rapamycin. siRNA of HIF-1α could suppress the expression of SNAIL while siRNA of SNAIL had no influence on HIF-1α protein expression. HIF-1α may be the upstream of the SNAIL gene in EOC. Our data suggested that HIF-1α might be an upregulator of the SNAIL gene and HIF-1α-SNAIL-E-cad pathway may play an important role in EOC invasion and metastasis.

Ovarian torsion caused by hyperreactio luteinalis in the third trimester of pregnancy: a case report.

In this case report, a rare case of an adnexal torsion caused by hyperreactio luteinalis (HL) in the third trimester is described, since adnexal torsions are mainly restricted to the first trimester of pregnancy. In an emergency Cesarean section, the patient gave birth to a healthy female baby weighing 3,300 g and we found an enlarged benign multiple luteinized follicular cyst mass in the right adnexum, which led to an adnexal torsion. After detorsion, both ovaries recovered to their normal sizes two months after the intervention.

Exon 4 deletion variant of epidermal growth factor receptor enhances invasiveness and cisplatin resistance in epithelial ovarian cancer.

Recently, de4 EGFR, a variant of epidermal growth factor receptor (EGFR) with exon 4 deletion, was identified in glioblastoma and ovarian cancer. However, its biological function on ovarian cancer is still not clear. In this study, the expression profile of de4 EGFR and its contribution to epithelial ovarian cancer cells proliferation, invasiveness and drug resistance were studied. Our results showed that 48.6% (35/72) of epithelial ovarian cancer tissues had de4 EGFR expression and the expression ratio positively correlated with clinical stages. Compared with EGFR transfectants, de4 EGFR transfectants exhibited significantly higher level of invasiveness in vitro. Mechanistically, de4 EGFR significantly upregulated the extracellular regulated protein kinase, AKT, focal adhesion kinase (FAK) and Src phosphorylation and matrix metalloproteinase-9 expression while downregulated the expression of E-cadherin. Additionally, knockdown of FAK obviously suppressed de4 EGFR-induced invasiveness. Interestingly, de4 EGFR transfectants displayed significantly lower sensitivity to cisplatin than EGFR transfectants, which could be ascribed to the upregulation of Bcl-2 and downregulation of BAD in the de4 EGFR transfectants. Collectively, these results demonstrate that de4 EGFR plays an important role in the invasiveness and cisplatin resistance in epithelial ovarian cancer cells and may provide a new potential therapeutic target for epithelial ovarian cancer.

Aberration of the PI3K/AKT/mTOR signaling in epithelial ovarian cancer and its implication in cisplatin-based chemotherapy.

OBJECTIVE: This study was to investigate the role of the PI3K/AKT/mTOR signaling in epithelial ovarian cancer development and its mechanism in cisplatin-based chemotherapy. STUDY DESIGN: Western blot and RT-PCR were used to determine the expression of PI3K-p85 subunit at protein and mRNA levels in normal and cancerous ovarian epithelium. SKOV3/DDP cells and SKOV3/MCA (multicellular aggregates) were constructed as chemo-resistant models. The role and mechanism of AKT specific inhibitor or shRNA in different models before and after cisplatin treatment were determined by multiple cellular and molecular approaches such as cell growth assay, flow cytometry, and western blot. RESULTS: PI3K-p85 subunit was detected in 33 out of 39 epithelial ovarian cancer specimens at protein level, but not detected in normal ovarian epithelium. A significant over-expression of PI3K-p85 subunit at mRNA level was observed in tumor tissues, and an increasing trend in advanced stage was also observed. Elevated activation of the AKT/mTOR/Survivin signaling was detected in SKOV3/DDP cells and SKOV3/MCA. Down-regulation of AKT by triciribine or shRNA transfection could attenuate cisplatin resistance through mTOR/Survivin signaling. CONCLUSIONS: The PI3K/AKT/mTOR signaling was involved in epithelial ovarian cancer development and cisplatin-based chemotherapy, and down-regulation of AKT could be an effective adjuvant antitumor therapy.

Elevated phosphatidylinositol 3-kinase activation and its clinicopathological significance in cervical cancer.

OBJECTIVE: The objective was to study the role of PI3K signaling in the development of cervical cancer and the antitumor effect of PI3K inhibitors. STUDY DESIGN: PI3K protein and mRNA expression of cervical cancer and non-neoplastic tissues were analyzed by Western blotting and RT-PCR. PI3K/Akt/mTOR pathway components in HeLa cells were assessed by immunocytochemistry and Western blotting. The inhibitive effect of LY294002 on HeLa cells was studied using MTT assay and flow cytometry. RESULTS: PI3K protein expression was detected in 25 out of 31 tumor specimens. Compared with non-neoplastic tissues, significant overexpression was observed in tumor tissues. For PI3K overexpression with all clinicopathological features, a decreasing trend in adenocarcinoma, advanced stage, and grade was observed. PI3K inhibitor LY294002 efficiently inhibited HeLa cell growth with IC50 of 20.77 microM, and induced apoptosis. The apoptotic rate was 36% at 3h after LY294002 treatment. These pharmacological roles of LY294002 might be played through the PI3K/Akt/mTOR signaling pathway. CONCLUSIONS: The PI3K signaling pathway was implicated in the development of cervical cancer. The activation of its signaling molecules might have clinical implications. Novel targeted therapies for the PI3K/Akt/mTOR signaling pathway components could provide a useful adjuvant therapeutic strategy for cervical cancer.

[Expression of phosphatidylinositol-3 kinase in epithelial ovarian carcinoma].

OBJECTIVE: To explore the expression and significance of phosphatidylinositol-3 kinase (PI3K) in ovarian cancer, and the effect of combined PI3K inhibitor (LY294002) therapy with cisplatin on epithelial ovarian carcinoma, and to explore if there is a synergistic effect between the two therapies. METHODS: The expression levels of PI3K p85 subunit proteins and mRNA were evaluated by western blot and RT-PCR in normal ovarian tissue (G1), ovarian benign tumor tissue (G2), ovarian borderline tumor tissue (G3) and ovarian cancer tissue (G4), and the relevant clinical pathological parameters were analyzed. SKOV3 cells were isolated and cultured by enzymolysis method. SKOV3 cells were treated with culture medium only, LY294002 (1, 10, 30, 50, 100 micromol/L), cisplatin (0.33, 1.25, 2.5, 5, 10 micromol/L), LY294002 (50 micromol/L) + cisplatin (10 micromol/L) for 2 days, respectively. The effect of LY294002 and cisplatin on the growth of SKOV3 cells was measured by methyl thiazolyl tetrazolium assay. RESULTS: There was no positive expression of PI3K p85 subunit proteins in G1 and G2, while the expression was 2/6 in G3, and 85% (33/39) in G4. PI3K p85 subunit mRNA expression levels were 0.178 +/- 0.102 in G1, 0.643 +/- 0.112 in G2, 0.847 +/- 0.058 in G3, 1.689 +/- 0.423 in G4; there was a significant difference between G1, G2, G3 and G4 (P<0.01). There was no significant correlation between protein expression and age at surgery or clinico-pathological staging (P>0.05). Significant differences were noted between protein expression levels in G4 (III, IV) and G4 (I, II; P<0.05). There was a significant difference between expression levels in tissues of different differentiation degrees (P<0.05). LY294002 and cisplatin inhibited the growth of SKOV3 cell in a concentration-dependent manner. The inhibitory activity of LY294002 at the concentration of 50 micromol/L was (46.0 +/- 2.0)% after treatment for two days. The inhibitory activity of cisplatin at the concentration of 10 micromol/L was (44.4 +/- 3.2)% after treatment for two days. After treatment for two days, the inhibitory activity of LY294002 50 micromol/L + cisplatin 10 micromol/L was (57.1 +/- 4.1)%. The inhibition effect on SKOV3 cell growth of the combined treatment group was better than the LY294002 or cisplatin treated group (P<0.01). CONCLUSIONS: PI3K p85 subunit is highly expressed and positively correlated with ovarian cancer. Different expression levels exist in tissues of late ovarian cancer, earlier ovarian cancer, borderline tumor, benign ovarian tumor and normal ovarian tissue. The changes in PI3K p85 subunit are correlated with tumor differentiation degree, but not pathologic typing. LY294002 combined with cisplatin can significantly enhance the killing efficiency in ovarian cancer cells.