[Mechanism of the Notch1 signaling pathway regulating osteogenic factor influences lumbar disc calcification].

OBJECTIVE: To explore the mechanism of the Notch1 signaling pathway in regulating osteogenic factors and influencing lumbar disc calcification. METHODS: Primary annulus fibroblasts from SD rats were isolated and subcultured in vitro. The calcification-inducing factors bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (b-FGF) were added to separate groups to induce calcification, which were referred to as the BMP-2 group and the b-FGF group, respectively. A control group was also set up, which was cultured in normal medium. Subsequently, cell morphology and fluorescence identification, alizarin red staining, ELISA, and quantitative real-time polymerase chain reaction (QRT-PCR) were performed to determine the effect of calcification induction. Cell grouping was performed again, including the control group, the calcification group (adding the inducer BMP-2), the calcification + LPS group(adding the inducer BMP-2 and the Notch1 pathway activator LPS), and the calcification + DAPT group (adding the inducer BMP-2 and the Notch1 pathway inhibitor DAPT). Alizarin red staining and flow cytometry were used to detect cell apoptosis, ELISA was used to detect the content of osteogenic factors, and Western blot was used to detect the expression of BMP-2, b-FGF, and Notch1 proteins. RESULTS: The induction factor screening results showed that the number of mineralized nodules in fibroannulus cells in BMP-2 group and b-FGF group was significantly increased, and the increase was greater in the BMP-2 group Meanwhile, ELISA and Western blot results showed that BMP-2, b-FGF and mRNA expression levels of BMP-2, b-FGF and Notch1 in the induced group were significantly increased (P<0.01). The results of the mechanism of Notch1 signaling pathway affecting lumbar disc calcification showed that compared to calcified group, the number of fibroannulus cell mineralization nodules, apoptosis rate, BMP-2, b-FGF content, the expression levels of BMP-2, b-FGF, and Notch1 proteins were further increased significantly However, the number of mineralization nodules, apoptosis rate, BMP-2 and b-FGF levels, BMP-2, b-FGF and Notch1 protein expression levels were decreased in the calcified +DAPT group (P<0.05 or P<0.01). CONCLUSION: Notch1 signaling pathway promotes lumbar disc calcification through positive regulation of osteogenic factors.

[Clinical efficacy of posterior percutaneous endoscopic cervical discectomy for single level cervical spondylopathy with intraspinal ossification].

OBJECTIVE: To evaluate the effectiveness and security of posterior percutaneous endoscopic cervical discectomy (PPECD) in the treatment of single level cervical spondylopathy with intraspinal ossification. METHODS: Twenty three patients with single level cervical spondylopathy with intraspinal ossification were treated by posterior percutaneous endoscopic cervical discectomy between August 2017 and July 2019. There were 16 males and 7 females, aged from 29 to 74 years old with an average of (50±13) years.The disease duration were 3 to 120 months with a median of 6 months. There were 9 cases of cervical spondylotic radiculopathy, 6 cases of cervical spondylotic myelopathy, and 8 cases of mixed cervical spondylopathy. According to the characteristics of ossification, 17 cases were osteophytes on the posterior edge of the vertebral body;3 cases were protrusion ossification;3 cases were posterior longitudinal ligament ossification. According to the position of ossification in spinal canal, 14 cases were medial and lateral type, 5 cases were central type, and 4 cases were mixed type. Posterior percutaneous cervical endoscopic cervical discectomy in patients performed by the same surgeon. Japanese Orthopaedic Association (JOA) score and visual analogue scale(VAS) were compared separately before and after operation. At 3 months after operation, clinical effect was assessed according to modified Macnab standard. RESULTS: All operations were successful. The operative time was 30 to 155 (69.1±27.2) min. The bedridden time was 2 to 3(3.0±0.9) h, length of postoperative hospitalization was 2 to 7(4.1± 1.5) d. Three dimensional CT reconstruction of the cervical spine at 3 days after operation showed that ossified tissue of 13 cases were completely removed, and 10 cases were left after operation, and the residual was located at the posterior edge and/or center of the upper vertebral body. VAS score at discharge from hospital was significantly lower than that before operation (t=9.35, P<0.001), and 21 cases had a score of 0 to 3. Postoperative JOA score was significantly higher (t=7.29, P<0.001). At 3 months after operation, according to modified Macnab standard to evaluate clinical effect, 18 cases got exellent results, 4 good and 1 fair, with an excellent and good rate of 95.6%(22/23). CONCLUSION: For an experienced surgeon, percutaneous posterior cervical endoscopic discectomy is safe and reliable in treating single level cervical spondylopathy with intraspinal ossification, and can obtain good clinical results.

[Analysis of clinical efficacy of C3 expanded half lamina excision combined with unilateral open-door laminoplasty for multiple segmental cervical spinal cord compression syndrome].

OBJECTIVE: To explore the clinical efficacy of C3 expanded half lamina excision combined with unilateral open door laminoplasty for multiple segmental cervical spinal cord compression syndrome. METHODS: The clinical data of 58 patients with multiple segmental cervical spinal cord compression syndrome underwent surgical treatment between September 2014 and May 2018 were retrospectively analyzed. There were 34 males and 24 females with a mean age of 64.4 years old (ranged from 46 to 78 years old). Among them, 28 cases received the surgery of C3 expanded half lamina excision combined with C4-C7 unilateral open-door laminoplasty (improvedgroup), and 30 cases received a single C3-C7 unilateral open-door laminoplasty (traditional group). Operation time, intraoperative blood loss, complications including C5 nerve root palsy and axial symptoms were compared between two groups. To evaluate the situation of the imaging indicators by measuring the space available for the spinal cord through cross sectional MRI of cervical spine at the narrowest segment of C3 (including intervertebral disc levels of C3, 4). Pre- and post-operative Japanese Orthopedic Association(JOA) score, Neck Disability Index(NDI) score, and improvement rate of neurological function, were recorded and analyzed between the two groups. RESULTS: All the patients were followed up for 12 to 18 months with an average of(14.5±1.8) months for improved group and (14.5±1.9) months for traditional group, and no significant difference was found between the two groups (P>0.05). There was no significant difference in intraoperative blood loss and C5 nerve root palsy between the two groups (P>0.05). The operation time (119±10) min vs (126±12) min and axial symptoms 7.1%(2/28) vs 26.6%(8/30) was significant difference between the two groups (P<0.05). Preoperative and postoperative space available for the spinal cord of C3 was (93.61±9.02) mm3 and (153.50±12.76) mm3 respectively, which was obtained obvious improvement in all patients(P<0.05). At the final follow up, JOA scores of improved group and traditional group were 14.36±1.70 and 14.03±1.82 respectively, and NDI scores were 10.36±2.55 and 12.47±3.46 respectively, there was significant difference between two groups (P<0.05). However, there was no significant difference between two groups for the improvement rate (68.36±0.12)%VS (65.01±0.12)%of neurological function(P>0.05). CONCLUSION: C3 expanded half lamina excision combined with unilateral open-door laminoplasty is an effective method to treat multiple segmental cervical spinal cord compression syndrome, for it can not only fully relieved spinal cord compression, but also achievedgood effect in preventing complications such as axial symptoms by reducing stripping of muscles from C2 spinous process.

Morphine and ketamine inhibit immune function of gastric cancer patients by increasing percentage of CD4(+)CD25(+)Foxp3(+) regulatory T cells in vitro.

BACKGROUND: There is conflicting evidence regarding effects of anesthetic and analgesic drugs on immune function of cancer patients. This study was designed to observe changes of T cell subpopulations in the gastric cancer (GC) patients and to assess effects of morphine and ketamine on the CD4(+) T cells, CD8(+) T cells, and regulatory T cells (Tregs) populations obtained from the GC patients in vitro. METHODS: The peripheral blood samples from 20 GC patients and 20 healthy volunteers were obtained. The peripheral blood mononuclear cells were isolated and incubated in a solution containing phorbol-myristate-acetate and ionomycin (2 µL/mL) in the presence or absence of morphine (50 ng/mL) or different-concentration ketamine (25, 50, and 100 µM). The CD4(+) T cells, CD8(+) T cells, and Tregs were determined using the flow cytometric assay. RESULTS: The percentages of CD8(+) T cells were significantly decreased, but the ratio of CD4(+)/CD8(+) T cells and Tregs populations was significantly increased in the GC control group compared with the normal control group (P < 0.05). The ratio of CD4(+)/CD8(+) T cells was significantly increased in the groups M and K3 compared with the control group (P < 0.05) but was significantly decreased in the group K1 compared with the group K3. The percentage of Tregs was significantly increased in the groups M, K1, K2, and K3 compared with the control group. With the increased concentrations, ketamine increased the number of Tregs. CONCLUSIONS: GC shifts the balance of CD4(+)/CD8(+) T cells toward CD4(+) T cells and increases the Tregs populations by inducing immune responses. Morphine increases the ratio of CD4(+)/CD8(+) T cells and Tregs populations. Ketamine affects the ratio of CD4(+)/CD8(+) T cells and Tregs populations in a dose-dependent model.

Twist may be associated with invasion and metastasis of hypoxic NSCLC cells.

Hypoxia promotes tumor invasion and metastasis via multiple mechanisms, including epithelial-mesenchymal transition (EMT). Twist, an EMT regulator, has been disclosed to associate with invasion and metastasis as well as poor prognosis of many malignancies. However, it remains undefined whether Twist is involved in invasion and metastasis of hypoxic non-small cell lung cancer (NSCLC). In this study, protein levels of Twist, hypoxia-inducible factor-1α (HIF-1α), and EMT markers (E-cadherin and vimentin) were examined by immunohistochemistry in 76 lung cancer tissues from NSCLC patients. Expression of Twist and its correlation with HIF-1α, E-cadherin, and vimentin were analyzed. Small interfering RNA (siRNA) against Twist was used to knockdown Twist expression in hypoxic NSCLC cells, A549 and NCI-H460. Cellular invasion and protein levels of Twist, E-cadherin, and vimentin were evaluated by matrigel invasion assay and Western blot, respectively. Our results showed that in clinical samples, there was a significant association between Twist expression and differentiation degree, lymph node metastasis, and TNM stage. Correlation analysis demonstrated that expression of Twist was negatively correlated with E-cadherin expression, but positively associated with HIF-1α and vimentin expression. In cultured NSCLC cells, Twist messenger RNA (mRNA) and protein levels were upregulated under hypoxia, while knockdown of Twist suppressed potentiated invasion and expression of mesenchymal marker vimentin induced by hypoxia. Protein level of increased epithelial marker E-cadherin was shown along with Twist downregulation. These findings suggest that Twist promoting hypoxic invasion and metastasis of NSCLC may be associated with altered expression of EMT markers. Inhibition of Twist may be of therapeutic significance.

Knockdown of Med19 suppresses proliferation and enhances chemo-sensitivity to cisplatin in non-small cell lung cancer cells.

Mediator 19 (Med19) is a component of the mediator complex which is a coactivator for DNA-binding factors that activate transcription via RNA polymerase II. Accumulating evidence has shown that Med19 plays important roles in cancer cell proliferation and tumorigenesis. The involvement of Med19 in sensitivity to the chemotherapeutic agent cisplatin was here investigated. We employed RNA interference to reduce Med19 expression in human non-small cell lung cancer (NSCLC) cell lines and analyzed their phenotypic changes. The results showed that after Med19 siRNA transfection, expression of Med19 mRNA and protein was dramatically reduced (p<0.05). Meanwhile, impaired growth potential, arrested cell cycle at G0/G1 phase and enhanced sensitivity to cisplatin were exhibited. Apoptosis and caspase-3 activity were increased when cells were exposed to Med19 siRNA and/or cisplatin. The present findings suggest that Med19 facilitates tumorigenic properties of NSCLC cells and knockdown of Med19 may be a rational therapeutic tool for lung cancer cisplatin sensitization.

[Unilateral pedicle screw fixation and intervertebral fusion for the treatment of far lateral lumbar disc herniation].

OBJECTIVE: To explore the feasibility and clinical efficacy of unilateral pedicle screw fixation with transforaminal lumbar interbody fusion (TLIF) for the treatment of far lateral lumbar disc herniation. METHODS: From January 2007 to January 2011, 18 patients with far lateral lumbar disc herniation underwent a unilateral TLIF procedure in conjunction with posterior unilateral pedicle screw fixation. There were 13 males and 5 females,ranging in age from 42 to 73 years (means 58.5 years). All cases had single segment involved 5 cases in L3, 4, 10 cases in L4,5,3 cases in LSS. The visual analog scale (VAS) of low back pain and leg pain and Oswestry Disability Index scores were observed in postoperative and followed-up period, and compared with preoperative. RESULTS: The operation of 18 patients was successful,there were no severe complication. The average operative time was 105 min (85 to 125 min), the average amount of blood loss was 145 ml (90 to 340 ml). During the followed-up, the visual analog scale and Oswestry disability index scores were significant improved compared with preoperative (P < 0.05). All patients were followed up from 12 to 48 months with an average of 23 months, there was no implant break and displacement in postoperative X-ray. CONCLUSION: The surgical procedure of unilateral pedicle screw fixation with transforaminal lumbar interbody fusion had the advantage including less invasion, quickly recovery, short operative time, and saving fixation cost, it may provide an alternative treatment for patients with far lateral lumbar disc herniation.

Lysyl oxidase may play a critical role in hypoxia-induced NSCLC cells invasion and migration.

Lysyl oxidase (LOX), a copper-dependent amine oxidase known to function both intracellularly and extracellularly, is implicated in promoting tumor progression and hypoxic metastasis in certain malignancies. Nonsmall cell lung cancer (NSCLC) is a highly aggressive cancer with poor prognosis worldwide. However, the role and molecular mechanism by which LOX involving in hypoxic NSCLC invasion and migration are poorly understood. This study explores the effect of LOX on invasion and migration of NSCLC cells under hypoxic conditions. Small interfering RNA (siRNA) targeting LOX was used to silence LOX expression of hypoxic NSCLC cells, SPCA1 and A549. Cellular invasive and migratory potentials were determined by matrigel invasion and migration assays. Expression of LOX, Src, Src activation (Tyr418 phosphorylation of Src), and Snail were evaluated by real-time PCR and western blot, respectively. The results showed that LOX mRNA and protein expression were upregulated under hypoxic conditions in NSCLC cells. Knockdown of LOX led to inhibition of hypoxia-induced invasion and migration. Phosphorylated Src (Tyr418) and Snail proteins were decreased along with LOX downregulation. Our data provide molecular evidences that LOX is mechanistically linked to increased invasion and migration of hypoxic NSCLC cells, and may serve as an antimetastasis target of human NSCLC.

Silencing of osteopontin promotes the radiosensitivity of breast cancer cells by reducing the expression of hypoxia inducible factor 1 and vascular endothelial growth factor.

BACKGROUND: Osteopontin (OPN) is a secreted phosphoglycoprotein (SSP) that is overexpressed in a variety of tumors and was regarded as a molecular marker of tumors. In this study, we intended to demonstrate the role of OPN in human breast cancer cell line MDA-MB-231. METHODS: Recombinant plasmid expressing small interfering RNA (siRNA) specific to OPN mRNA was transfected into MDA-MB-231 cells to generate the stable transfected cell line MDA-MB-343, and the empty plasmid tansfected cells (MDA-MB-neg) or wildtype MDA-MB-231 cells were used as control cells respectively. Expression of OPN, hypoxia inducible factor-1 (HIF-1) and vascular endothelial growth factor (VEGF) proteins was analyzed by Western blotting analysis. The radiosensitivity of cells was determined by detecting cell apoptosis, cell proliferation and cell senescence. RESULTS: HIF-1 and VEGF proteins in MDA-MB-343 cells were significantly downregulated upon the efficient knockdown of OPN expression under either hypoxia or normoxia environment. Moreover, expression of OPN protein was upregualted upon hypoxic culture. Stable OPN-silencing also decreased cell invasion, increased cell apoptosis and cell senescence, as well as reduced clonogenic survival, resulting in increase radiation tolerance. CONCLUSIONS: Suppression of OPN gene expression can enhance radiosensitivity and affect cell apoptosis in breast cancer cells. OPN seems to be an attractive target for the improvement of radiotherapy.

Effect of HMGB1 silencing on cell proliferation, invasion and apoptosis of MGC-803 gastric cancer cells.

High-mobility group box 1 (HMGB1) is a multifunctional protein with intranuclear and extracellular functions. Although HMGB1 is overexpressed in approximately 85% of gastric cancers, the role of HMGB1 in gastric cancer biology remains unclear. In this study, we investigate the effect of downregulation of HMGB1 on the biological behavior of gastric cancer cells. MGC-803 gastric cancer cells were transduced with HMGB1-specific RNAi lentiviral vectors. Real-time polymerase chain reaction and Western blot analysis of HMGB1 mRNA and protein, respectively, validated the silencing effects. HMGB1-specific silencing significantly decreased cell proliferation. The impact on proliferation was observed at the cell cycle level--the number of cells in the G0/G1 phase increased, whereas that in S and G2/M phases decreased. Cell cycle changes were accompanied by decreases in cyclin D1 expression. Furthermore, HMGB1 silencing sensitized cells to apoptosis that was induced by oxaliplatin and mediated by the caspase-3 pathway. Finally, silencing of HMGB1 expression significantly reduced cellular metastatic ability and MMP-9 expression in MGC-803 cells. In summary, HMGB1 not only plays an essential role in the proliferation and invasion of MGC-803 cells but also represents a potential target for the therapeutic intervention of gastric cancer.

[Effects of lysyl oxidase down-regulation on invasion, migration and E-cadherin protein expression of hypoxic lung cancer cells].

OBJECTIVE: To observe the effects of lysyl oxidase (LOX) down-regulation on invasion, migration and epithelial-mesenchymal transition phenotype molecule E-cadherin protein expression, induced by hypoxia in lung cancer NCI-H460 cells. METHODS: Small interfering RNA against human LOX gene (LOX siRNA) was used to transfect lung cancer cells under normoxia (19%O2). After a 24 h incubation, the cells were plated for 24 h in hypoxic incubator (0.5%O2). Real-time polymerase chain reaction (PCR) was performed to detect the LOX mRNA expression. The protein levels of LOX and E-cadherin were determined by Western blot. And invasion and migration capacities were detected by transwell chamber. RESULTS: Compared with NCI-H460 cells under normoxia (set to 1), hypoxia increased to the levels of LOX mRNA and protein expression up to 26.04 ± 1.78 and 5.57 ± 1.27 respectively (both P < 0.05). Compared with control siRNA group (set to 1), LOX mRNA and protein expression after LOX siRNA transfection were 0.24 ± 0.03 and 0.29 ± 0.03 respectively, cellular invasive and migratory capacities were 0.57 ± 0.03 and 0.49 ± 0.02 respectively, the protein expression of E-cadherin was 2.17 ± 0.21 (all P < 0.05). CONCLUSION: LOX down-regulation reduces invasion and migration potentials of hypoxic human lung cancer cell and potentiates the protein expression of E-cadherin.

[Clinical study of open vertebroplasty in treating thoracolumbar metastatic tumor].

OBJECTIVE: To explore the clinical application and therapeutic effect of open vertebroplasty for thoracolumbar metastatic tumor. METHODS: From September 2003 to December 2009, 21 patients with thoracolumbar metastatic tumor underwent the surgical procedure of posterior spinal cord decompression and open vertebroplasty combined with short-segmental pedicle screw fixation during the same intervention. There were 14 males and 7 females, ranging in age from 48 to 73 years with the mean of 59.5 years and ranging in course of disease from 1 to 4 months with an average of 2.5 months. The primary focus of the tumor of 19 cases were established, lung carcinoma was in 8 cases, breast cancer in 4 cases, prostate carcinoma in 4 cases, hepatocarcinoma in 2 cases and thyroid carcinoma in 1 case. The primary focus of 2 cases could not be established. The spinal function according to Frankel grade, grade B was in 4 cases, C in 6, D in 5, E in 6. The lumbar-back pain, height of anterior and posterior vertebral body, Cobb angle and spinal function were recorded before and after operation. RESULTS: The operation of all patients was successful, there were no severe complications and aggravation of spinal function. The VAS score of lumbar-back pain decreased from 8.78 +/- 0.45 preoperatively to 2.25 +/- 0.36 postoperatively. Among 16 cases combined with pathological fracture, the height of anterior spinal vertebral body increased from (12.7 +/- 2.1) mm preoperatively to (19.5 +/- 3.9) mm postoperatively; the height of posterior spinal vertebral body increased from (14.1 +/- 1.8) mm preoperatively to (20.3 +/- 2.3) mm postoperatively; Cobb angle decreased from (26.0 +/- 8.9) degrees preoperatively to (6.0 +/- 0.9) degrees postoperatively. There was significant difference above items between before and after operation (P < 0.05). The spinal function according to Frankel grade at final follow up, grade C was in 2 cases, D in 4, E in 15. All patients were followed up from 5 to 28 months with an average of 14 months, there was no loosening and breakage of internal fixity, 15 cases died during follow-up period. CONCLUSION: The surgical intervention can effectively preserve spinal instability and alleviate the spinal cord symptoms, improve the life quality of patients. It may provide an alternative treatment for patients in poor general health and shorter life expectancy.

[Molecular imaging of epidermal growth factor receptor in glioma-bearing rats].

OBJECTIVE: To investigate the value of 11C-PD153035 as an EGFR imaging agent in C6 tumor-bearing rat. METHODS: The tumor-bearing rats were generated by subcutaneous injection of glioma C6 cells. Positron emission tomography/computer tomography (PET/CT) scans started as soon as intravenous injection of 11C-PD153035 (15-20 MBq/0.3 ml) was completed, images were collected continuously. The region of interest (ROI) was used to study the percentage of radioactivity in major organs and implanted tumors in the rats. The accumulation and blocking study in vitro was completed. RESULTS: There were significant differences in 11C-PD153035 uptake among major organs. The maximum uptake in the organs ranked in the following order: liver > gastrointestinal tract > kidney > lung > brain > muscle. Radioactivity could be also observed in the tumors. The radioactivity ratio (T/NT, target/non-target) peaked (4.15) at 40 - 50 min post injection. The in vitro blocking study showed that 11C-PD153035 uptaken by C6 cells could be blocked by PD153035. CONCLUSION: The results of this study show that 11C-PD153035 can be uptaken by EGFR-expressing tumors. 11C-PD153035 has a potential as a bioprobe to yield useful information for both diagnosis and therapy of tumors. However, the high concentration of 11C-PD153035 in the gastrointestinal tract is unfavorably affecting the tumor detection in these organs.

Further characterization of the epidermal growth factor receptor ligand 11C-PD153035.

BACKGROUND: (11)C-4-N-(3-bromoanilino)-6,7-dimethoxyquinazoline ((11)C-PD153035) has been reported as a tracer for imaging human tumors that overexpress epidermal growth factor receptor (EGFR). However it is still unclear whether (11)C-PD153035 uptake correlates with EGFR expression levels. The objective of this study was to investigate the relationship between (11)C-PD153035 accumulation and EGFR expression levels. METHODS: Synthesis of (11)C-PD153035 was performed in the Tracerlab FXc system. Accumulation of (11)C-PD153035 by MDA-MB-468, A549 and MDA-MB-231 cells was measured in vitro. There were six tumor-bearing mice in each group. (11)C-PD153035 uptake in tumors was determined by positron emission tomography/computed tomography (PET/CT). Tumor/normal muscle tissue (T/NT) analysis in PET images was applied to quantify the PET data. Sixty minutes after PET/CT scanning, the nude mice were sacrificed and the tumors were excised. The (11)C-PD153035 accumulation in different tumors was determined by a gamma counter. RESULTS: Close correlation existed between the uptake and the level of EGFR expression both in vitro and ex vivo (r(2) = 0.72, P < 0.001; r(2) = 0.63, P = 0.003). When the static T/NT analysis method was applied to analyze the PET data, the observed correlation was again excellent (r(2) = 0.70, P = 0.001). CONCLUSIONS: The uptake of PET tracer (11)C-PD153035 closely correlates with the EGFR expression levels in tumor cells. (11)C-PD153035 has the potential to yield useful information for both cancer diagnosis and therapy.

[Prolonged hypoxia induces GST-pi expression and drug resistance in lung adenocarcinoma cell line SPCA1].

OBJECTIVE: To investigate the association of hypoxia with GST-pi expression in lung adenocarcinoma cells SPCA1 and the drug resistance in hypoxic condition. METHODS: RNA and protein in SPCA1 cells treated with hypoxia (0.5% O(2)) for 16 h were isolated. HIF-1alpha and GST-pi mRNA expression was detected by real time RT-PCR, and HIF-1alpha protein was detected by Western blotting analysis. GST-pi protein was finally analyzed on a FACScan flow cytometer using Cellquest software. Sensitivity of Doxorubicin and Mitomycin in hypoxic SPCA1 cells was detected using cell clonogenic assay. RESULTS: HIF-1alpha expression was up-regulated on mRNA and protein levels in hypoxic SPCA1 cells, so as was GST-pi expression. Doxorubicin resistance was increased, but hypoxia had no significant influence on Mitomycin resistance. GST-pi expression had no significant change after HIF-1alpha was down-regulated by RNA interfering. CONCLUSION: Though prolonged hypoxia can induce GST-pi expression and increase drug resistance such as to Doxorubicin, HIF-1alpha expression has no correlation with GST-pi expression.

[Flow cytometric quantitative analysis of multiple tumor suppressor gene 1 (MTS1) and cyclooxygenase-2 (COX-2) gene expressions in invasive breast cancers and their clinical significance].

OBJECTIVE: The purpose of the present study was to explore the expression and clinical significance of multiple tumor suppressor gene 1 (MTS1) and cyclooxygenase-2 (COX-2) gene in invasive breast cancers. METHODS: Flow cytometry was used to analyze the expression level of MTS1 and COX-2 in cancer tissues and corresponding para-cancer tissues from 66 cases of primary invasive breast cancers. RESULTS: In breast cancer tissues, the expression of MTS1 and COX-2 assessed by relative fluorescence intensity were 0.84 and 10.54, respectively, and were 1.61 and 4.00 in corresponding para-cancer tissues, respectively. There was a significant difference between MTS1 and COX-2 expressions in cancer and corresponding para-cancer tissues (P <0.05). The differences of MTS1 and COX-2 expression of different ages, pathological types, tumor sizes or clinical stages of the breast cancer patients were not significant (P > 0.05). The MTS1 and COX-2 expressions were 1.12 and 5.94, respectively, in lymph node metastasis positive patients, and 0.79 and 13.05, respectively, in lymph node metastasis negative patients. The differences were significant (P <0.05). CONCLUSION: The preliminary research results suggest that MTS1 and COX-2 gene expressions play fairly important role in tumorigenesis and progression of breast cancers. MTS1 and COX-2 protein expressions have correlation with lymph node metastasis. This study provides theoretical basis for use of COX-2 selective inhibitors in prevention and treatment for breast cancer patients.

[Expression of MDR1 and GST-pi in osteosarcoma and soft tissue sarcoma and their correlation with chemotherapy resistance].

OBJECTIVE: To explore the expression of multidrug resistance gene 1 ( MDR1), glutathione-S-transferases-pi (GST-pi) in osteosarcoma and soft tissue sarcoma tissues from 34 patients and their correlation with chemotherapy resistance. METHODS: MDR1 and GST-pi expressions were analyzed by real-time fluorescence quantitative polymerase chain reaction (FQ-PCR) and flow cytometry (FCM) at mRNA and protein levels, respectively. Chemotherapy sensitivity on adriamycin, cisplatinum, fluorouracil, mitomycin C, dacarbazine, vincristine, methotrexate in tumor tissues were detected by MTT assay. RESULTS: The nonsensitive rates on adriamycin, cisplatinum, fluorouracil, mitomycin C, dacarbazine, vincristine, methotrexate in tumor tissues were 41.18%, 17.7%, 47.1%, 50.0%, 76.5%, 61.8% and 52.9%, respectively. The expression of P-glycoprotein (P-gp) and GST-pi in tumor tissues was 1.54 and 2.58 (relative fluorescence intensity). Chi2 analysis showed that there was a positive correlation between P-gp expression and drug resistance on ADM, GST-pi expression and resistance on ADM, DDP and MMC (P < 0.05). There was not seen obvious correlation between expression of MDR1, GST-pi and age, gender, pathological type, tumor size in osteosarcoma and soft tissue sarcoma patients (P > 0.05). The expression of GST-pi was increased in patients receiving preoperative chemotherapy. The rate of postoperative recurrence was higher in patients with higher GST-pi expression level than those with lower GST-pi expression level before operation (P < 0.05). CONCLUSION: Individual differences exist in chemotherapy sensitivity and expression of MDR1 and GST-pi in osteosarcoma and soft tissue sarcomas patients. Chemotherapy can induce up-regulation of GST-pi protein expression. Primary high expression of GST-pi is the main mechanism of resistance of osteosarcoma and soft tissue sarcomas to chemotherapy and is related to poor prognosis.

Regulation of the chemokine receptor CXCR4 and metastasis by hypoxia-inducible factor in non small cell lung cancer cell lines.

Hypoxia promotes metastatic potential of tumor cells by largely unknown mechanisms. Hypoxia inducible factor (HIF) is a heterodimeric transcription factor consisting of alpha and beta (ARNT) subunits and plays an important role in tumor microenvironment. CXCR4 is a cell surface receptor that has been shown to mediate the metastasis of various tumors. CXCR4 induction by hypoxia is dependent on both activation of HIF and transcript stabilization. To investigate the mechanisms involved in hypoxia-induced metastasis and hypoxia-mediated chemokine receptor CXCR4 expression, we used lentiviral vector mediated RNA interfering (RNAi) to knock down expression of HIF-1alpha or HIF-2alpha in two NSCLC cell lines to investigate HIF-dependent invasion, migration and adhesion. Here we show that: (1) hypoxia is an important factor in regulating CXCR4 mediated metastasis and the cells exhibited reducing invasion, adhesion and migration in response to CXCL12 after knocking down HIF. (2) HIF-1alpha and HIF-2alpha are essential for hypoxic cellular response to cancer invasion and adhesion through upregulation of CXCR4. HIF-1alpha and HIF-2alpha are playing important roles in tumor metastasis, which may offer for future intervention strategies. We also show that the lentivirus mediated RNAi technology is very effective on knocking down gene expression.

[The clinical significance of P-glycoprotein, lung resistance protein and multidrug resistance related protein expressions in infiltrating breast carcinoma tissues].

OBJECTIVE: Our purpose was to explore clinical significance of three kinds of drug resistance related proteins, including P-glycoprotein (P-gp), lung resistance protein (LRP), multidrug resistance related protein (MRP) expressions in infiltrating breast carcinoma tissues. METHODS: Flow cytometry was used to analyze the expression of drug resistance related proteins in carcinoma tissues and corresponding para-carcinoma tissues from 68 primary infiltrating breast carcinoma patients. RESULTS: The relative fluorescence intensity (RFI) expressed by median (M) of P-gp, LRP and MRP in breast carcinoma tissues were 0.58, 0.51and 0.56 respectively. In corresponding para-carcinoma tissues, their expression level were 0.26, 0.33 and 0.30. Their difference were obvious (P < 0.05). There were not notable differences of drug resistance related protein expressions in different ages, different tumor sizes, different pathological types, different clinical stages, estrogen receptor or progestin receptor negative and positive patients (P > 0.05). The expressions of P-gp and MRP in lymph node metastasis positive patients were 0.61and 0.69, in lymph node metastasis negative patients they were 0.54 and 0.45. There were no notable differences of P-gp and MRP expression in lymph node metastasis negative and positive patients. The expression of LRP (M = 1.49) was higher in lymph node metastasis positive patients than that in negative patients (M = 0.50, P < 0.05). The correlation analysis showed that there was positive correlation between the expression of LRP and MRP in breast carcinoma tissues (P < 0.05). CONCLUSION: The clinical significance of three kinds of drug resistance related protein expressions had differences in infiltrating breast carcinoma tissues. The expression of LRP had related with lymph node metastasis status and had positive correlation with MRP expression. It can become a target in forecasting breast carcinoma prognosis.

[Primary research on arsenic trioxide inhibiting human breast cancer cells growth and its mechanisms].

OBJECTIVE: The study was to research the biological effect and mechanisms of arsenic trioxide (As2O3) on human breast cancer cell line MDA-MB-231. METHODS: The cytotoxicity was observed by MTT assay. Apoptosis was detected with Annexin V-FITC + PI dual parameter. Cell cycle and positive rate of proliferation cell nuclear antigen (PCNA), apoptosis associated protein Fas and bcl-2 and intracellular calcium ions (IECa(2+)) levels were measured by flow cytometry. RESULTS: As2O3 could inhibit the growth of MDA-MB-231 cells dramatically. There was obvious dosage-effect correlation (r = 0.99, P < 0.01), its half inhibitory concentration (IC(50)) was 6.65 micromol/L. Apoptosis was observed in MDA-MB-231 cells treated with As2O3. As2O3 could increase Fas expression and IECa(2+) levels and decrease PCNA expression in MDA-MB-231 cells (P < 0.01). Cell cycle was arrested in S + G(2)/M phase, but bcl-2 protein expression were not affected (P > 0.05). CONCLUSION: As2O3 could inhibit the growth of MDA-MB-231 cells dramatically and induce apoptosis. We proposed that its mechanisms were probably associated with the improved Fas expression and IECa(2+) levels and decreased PCNA expression and cell cycle arrest.