The Antiresection Activity of the X Protein Encoded by Hepatitis Virus B.

Chronic infection of hepatitis B virus (HBV) is associated with an increased incidence of hepatocellular carcinoma (HCC). HBV encodes an oncoprotein, hepatitis B x protein (HBx), that is crucial for viral replication and interferes with multiple cellular activities including gene expression, histone modifications, and genomic stability. To date, it remains unclear how disruption of these activities contributes to hepatocarcinogenesis. Here, we report that HBV exhibits antiresection activity by disrupting DNA end resection, thus impairing the initial steps of homologous recombination (HR). This antiresection activity occurs in primary human hepatocytes undergoing a natural viral infection-replication cycle as well as in cells with integrated HBV genomes. Among the seven HBV-encoded proteins, we identified HBx as the sole viral factor that inhibits resection. By disrupting an evolutionarily conserved Cullin4A-damage-specific DNA binding protein 1-RING type of E3 ligase, CRL4WDR70 , through its H-box, we show that HBx inhibits H2B monoubiquitylation at lysine 120 at double-strand breaks, thus reducing the efficiency of long-range resection. We further show that directly impairing H2B monoubiquitylation elicited tumorigenesis upon engraftment of deficient cells in athymic mice, confirming that the impairment of CRL4WDR70 function by HBx is sufficient to promote carcinogenesis. Finally, we demonstrate that lack of H2B monoubiquitylation is manifest in human HBV-associated HCC when compared with HBV-free HCC, implying corresponding defects of epigenetic regulation and end resection. Conclusion: The antiresection activity of HBx induces an HR defect and genomic instability and contributes to tumorigenesis of host hepatocytes.

The role of granulocyte macrophage colony stimulating factor in hospitalized children with Mycoplasma pneumoniae pneumonia.

BACKGROUND: Inappropriate inflammatory response in children with M. pneumoniae infection might be associated with disease severity. The role of Granulocyte macrophage colony stimulating factor (GM-CSF) in hospitalized children with Mycoplasma pneumoniae pneumonia (MPP) has not been fully discussed. METHODS: Clinical and laboratory data of a total 40 children with MPP were collected. GM-CSF and myeloperoxidase (MPO) were detected by ELISAs. Meanwhile, normal human bronchial epithelium was infected by M. pneumoniae and neutrophils were stimulated by GM-CSF to explore GM-CSF and MPO release in supernatant, respectively. RESULTS: Compared to control group, a significant increased percentage of neutrophils and decreased percentage of macrophages in bronchoalveolar lavage fluid of children with MPP was observed (P < 0.05). Children with MPP had significantly higher levels of GM-CSF (P = 0.0047) and MPO (P = 0.0002) in BALF compared to the controls. Level of GM-CSF in BALF was associated with duration of fever (r = 0.42, P = 0.007) and strongly correlated with level of MPO (r = 0.075, P = 0.0005). Levels of GM-CSF and MPO significantly decreased (both P < 0.05) after treatment. In vitro, M. pneumoniae induced GM-CSF expression in a time-dependent manner during a 72-h period (P < 0.05) and MPO secretion significantly increased by recombinant human GM-CSF stimulation at 24h (P < 0.05). CONCLUSION: GM-CSF could be induced by M. pneumoniae infection in vivo and vitro. Childen with high level GM-CSF had longer duration of fever. GM-CSF probably plays a vital role in neutrophil inflammation in M. pneumoniae infection.

Safety and Efficacy of Neoadjuvant Chemotherapy Followed by Radical Surgery Versus Radical Surgery Alone in Locally Advanced Cervical Cancer Patients.

OBJECTIVES: This study aimed to evaluate the safety and efficacy of neoadjuvant chemotherapy (NACT) followed by radical surgery (RS) among patients with locally advanced cervical cancer (LACC). METHODS: Eight hundred patients with LACC received either NACT followed by RS (NACT-RS) or RS alone. The primary outcome measures assessed the efficacy and adverse effects of NACT. Secondary outcome measures compared the preoperative clinical stage to the postoperative pathologic stage in NACT-RS and RS patients, assessed intraoperative and postoperative complications, including the adverse effects of postoperative radiotherapy and radiochemotherapy, and estimated the 5-year progression-free survival and 5-year overall survival. RESULTS: The clinical response to NACT was 89.54%. Patients in the NACT-RS group had lower preoperative hemoglobin levels (115.20 vs 122.04 g/L, P < 0.001), a longer operative time (mean, 233.66 vs 224.37 minutes, P = 0.008), more intraoperative bleeding (750.34 vs 684.41 mL, P = 0.011), a shorter duration of catheter use (mean, 29.84 vs 32.14 days, P = 0.036), and a lower incidence of postoperative complications (7.30% vs 13.62%, P = 0.002) and postoperative radiotherapeutic and radiochemotherapeutic adverse effects (3.16% vs 4.63%, P < 0.001) compared to patients in the RS group. The 5-year progression-free survival and 5-year overall survival were 80.30% and 81.10% in the NACT-RS group and 81.00% and 78.50% in the RS group (P > 0.05). Pathological poor differentiation, nonsquamous cell carcinoma, parametrial invasion, positive pelvic lymph node, and lymphovascular invasion (P < 0.05) were independent risk factors for recurrence. CONCLUSIONS: Neoadjuvant chemotherapy may reduce RS-associated complications and postoperative radiotherapeutic and radiochemotherapeutic adverse effects in Chinese patients with LACC.

[HPV E7 Function in DNA Damage Response of Cervical Intraepithelial Neoplasia.]

OBJECTIVES: To determine the function of human papillomavirus (HPV) E7 in DNA damage response of cervical intraepithelial neoplasia (CIN) 3 cells. METHODS: Samples of CIN 3 and child foreskin tissues were collected,with pathologically confirmed HPV positive and negative,respectively.Collagenase A was used for digesting tissues prior to primary culture.The HPV negative cells were infected with lentivirus E7 and pLV.Proteins(53BP1,NBS1,BRCA1 and RPA32) responsive to DNA double break damages were detected by indirect immunofluorescent staining after 0-8 h treatment with X-ray (2 or 5 Gy). RESULTS: After treatment with 2 or 5 Gy X-ray,53BP1,NBS1,BRCA1 and RPA32 foci in HPV+ cells increased compared with HPV- cells (P<0.05).Less 53BP1,RPA32,BRCA1 and NBS1 foci positive cells (foci>5) were found in E7 infected cells than in pLV infected cells(P<0.05).Both of them reached the peak at 6 h (2 Gy) or 4 h (5 Gy). CONCLUSIONS: We have successfully established a model to detect the function of HPV E7 in DNA damage response using primary culture of CIN fibroblasts.With the progression of CIN,HPV E7 can inhibit DNA double break repair.

[Employing DNA Damage Response Inhibitors to Enhance Chemosensitivity of Ovarian Carcinoma Cells].

OBJECTIVE: To assess the sensitisation effects of DDR inhibitors combined with conventional chemotherapeutics agents (cisplatin et al) in a drug-resistant ovarian cancer cell line(OVCAR-8). METHODS: Inhibitors of DDR regulators with cisplatin were applied to challenge OVCAR-8, and evaluated the DNA damage response (DDR) and cytotoxic effects of different combination of chemicals. Inhibition of proliferation to OVCAR-8 of different drugs was evaluated by MTT assay. The activation of phosphorylation of histone family 2A variant (yH2AX) and p53 binding protein 1 (53BP1) in OVCAR-8 were evaluated by immunofluorescence to observe their ability of recruitment and forming foci at DNA damage site. RESULTS: We observed that combined treatment of ataxia-telangiectasia mutated (ATM)/ATM and Rad 3-related (ATR) inhibitor and cisplatin can suppress the activation of damage repair mechanisms and weakened the proliferative activity of OVCAR-8 cells (P<0. 01) ; ATR pathway was suppressed and the signal of γH2AX weakened and cell survival rate significantly reduced when combination therapy of HU and Wortmannin (P < 0.05); poly ADP-ribose polymerase (PARP) inhibitor could not enhance chemosensitivity in OVCAR-8 cells when combined with cisplatin (P > 0.05). CONCLUSION: We substantiated that appropriate inhibitors of DNA damage response may have a potential to improve the anti-tumor effect of conventional chemotherapy drugs and prevent drug resistances.

[Functional Analysis of DNA Damage Repair Factor WDR70 and Its Mutation in Ovarian Cancer].

OBJECTIVES: To analyze the cellular function of the newly discovered DNA damage repair factor WDR70, and investigate the mutation in ovarian cancer to verify if function loss of the WDR70gene was associated with ovarian cancer. METHODS: The WDR70 gene was silenced by using siRNA technique or overexpressed its wild and mutation type by with lentivirus and plasmid in hunman cells. The subcellular localization and biochemical function of WDR70 was analyzes by indirect immunofluorescence and immunoblotting. The expression level of WDR70 and the mutations of its cDNA was checked with RT-PCR sequencing for 1 normal ovarian tissue and 16 ovarian cancer specimen. RESULTS: We found gene silencing of WDR70 or overexpression of WDR70 mutation type disrupts the phosphorylation level of homologous recombination functional protein RPA32 and the ability of recruitment at DNA damage site of recombinase RAD51, the loss of function of WDR70 also causes the elevation of the chromosome breakage in metaphase. Meanwhile, we also noticed that the existence of multiple mutations in genomic WDR70 in ovarian cancer specimen. CONCLUSIONS: Our results defined that in vitro system, WDR70 is a DNA damage repair gene, silencing of WDR70 or overexpression of WDR70 mutation type disrupts homologous recombination and chromosomal instability; the frequent mutations of WDR70 gene in genome of ovarian cancer specimens could also lead to DNA repair defeat and gene instability. Consequently WDR70 gene could represent an anti-cancer mechanism for ovarian cancer.

[DNA damage response of epithelial ovarian cancer cells (primary culture) to chemo-radiotherapy].

OBJECTIVE: To detect protein dynamic changes of cellular localization and the DNA damage response of epithelial ovarian cancer cells to chemo-radiotherapy. METHODS: 28 specimens of epithelial ovarian cancer were collected, with 6 cases diagnosed as borderline serous cystadenoma, 5 as highly differentiated, 6 as medium differentiated and 11 as poorly differentiated cystadenocarcinoma. Collagenase A was used for digesting tissues before primary culture. We compared the characteristics of cells cultured in different mediums (MCDB/M199 medium, primary culture medium, and DMEM medium) supplemented with multiple growth-promoting factors. The characteristics of cells were examined in terms of the maintenance of normal cell morphology, proliferation potential, and cell fibrosis proteins (53BP1 and gamma-H2AX) responsive to DNA damage [those in the ATM checkpoint pathway determined by indirect immunofluorescent staining after treatment with camptothecin (CPT) and X-ray]. RESULTS: Normal morphology was maintained relatively well in the cells cultured in MCDB/M199 medium and its cell fibrosis was slow compared with the cells cultured in other media. Gradually increased endogenous damage was demonstrated by the expression of 53BP1 and gamma-H2AX foci (P < 0.05) in all of the ovarian primary cells. After treatment with CPT and ionizing radiation, increased levels of DNA double-strand breaks were observed indicating a classic DNA damage response. CONCLUSION: We have successfully established a protocol for the primary culture of epithelial ovarian cancer cells, which provides an important platform for characterizing DNA damage responses of the cells. With the progression of epithelial ovarian cancers, the ATM checkpoint pathway is activated by endogenous DNA lesions. This signaling pathway can be further activated by CPT or X-ray irradiation, hampering the growth of tumor cells and further progression of cancers.

Preoperative prediction of central lymph node metastasis in follicular variant of papillary thyroid carcinoma using clinical and ultrasound features.

Background: The most common metastatic site of follicular variant of papillary thyroid carcinoma (FVPTC) is the central lymph nodes, which may be associated with the prognosis and survival of patients. In the present study, we establish a combined model based on preoperative clinical and ultrasound (US) features of FVPTC to predict the risk of central lymph node metastasis (CLNM). Methods: From January 2013 to December 2022, 315 patients with FVPTC were enrolled and randomly divided into the training and validation cohorts in a ratio of 7:3. The independent risk factors for CLNM in FVPTC were analysed using univariate and multivariate logistic regression analyses. Then, three different models were established based on clinical and US data. Subsequently, a nomogram was constructed to predict CLNM. Its predictive effect was evaluated via receiver operating characteristic and calibration curve analyses. Results: Backward multivariate regression analysis revealed that age (P=0.001), thyroid peroxidase antibody (TPOAb) (P=0.11), diameter (P=0.047), irregular/lobulated margin (P=0.15), extrathyroidal extension (P=0.001), nodules with macrocalcifications (P=0.009), nodules with microcalcification (P=0.003) and Thyroid Imaging Reporting and Data System (ACR-TI-RADS) category 5 (P=0.33) were independent risk factors for CLNM in FVPTC. The areas under the curve of the matching nomogram in the training (N=221) and validation cohorts (N=94) were 0.841 [95% confidence interval (CI): 0.788-0.895] and 0.735 (95% CI: 0.621-0.872), respectively. Conclusions: Preoperative thyroid US provides useful features for prediction of CLNM. The nomogram constructed based on combining US and clinical features can better predict the risk of CLNM and may facilitate decision-making in clinical settings.

Uterine cervical malignant granular cell tumor.

Malignant granular cell tumor is relatively uncommon, constituting only 1-2% of all granular cell tumors. It is a rare and unusual tumor, especially in non-typical sites, such as the uterine cervix, and grows more rapidly than benign granular cell tumor. It can be treated with surgical excision, but recurrence is possible and prognosis can be poor. A malignant granular cell tumor in the uterine cervix of a 37-year-old woman was incidentally diagnosed. The patient has a history of irregular vaginal bleeding. Uterine cervical biopsy under colposcope revealed a malignant granular cell tumor. After isophosphamide, etoposide, and cisplatin neoadjuvant chemotherapy, surgery was performed on the lesion, which approximately involved half the depth of cervical stroma. Computed tomography examination showed no local recurrence or distant metastasis during the 26-month follow-up period.

[DNA damage response in ovarian clear cell adenocarcinoma].

OBJECTIVE: To study the relationship between ovarian clear cell adenocarcinoma and DNA damage. METHODS: 14 samples were selected from clinical ovarian cases including 3 cases with normal ovarian tissue, 6 cases with poorly differentiated ovarian tumor, 5 cases with ovarian clear cell adenocarcinoma, treated by X-ray irradiation and frozen sections respectively. DNA damage response was analyzed by immunofluorescence and Western blot. RESULTS: Before X-ray irradiation, compared to normal ovarian tissue, a large number of endogenous damage existed in ovarian clear cell adenocarcinoma, and phosphorylation of histone family 2A variant (H2AX) was abnormally enhanced 1 hour after irradiation treatment, however, DNA repair was normal in ovarian clear cell adenocarcinoma. Phosphorylation of H2AX was dispensable for p53 binding protein 1 (53BP1) activation and couldn't be colocalized in clear-type ovarian cancer tissues. CONCLUSION: The abnormal DNA damage activation implies that the network of DNA damage signaling pathway may be defective.

Neoadjuvant chemotherapy followed by radical surgery and reconstruction of the vagina in a patient with stage II primary vaginal squamous carcinoma.

Primary vaginal carcinoma is a rare gynecologic cancer. Radiotherapy is the standard treatment for patients affected by International Federation of Gynecology and Obstetrics stage II vaginal cancer. Neoadjuvant chemotherapy followed by radical surgery has been shown to be a valid therapeutic strategy in patients with cervical cancer; however, there is little information concerning the feasibility of neoadjuvant chemotherapy followed by radical surgery in patients with invasive vaginal carcinoma. We report the first case of stage II vaginal carcinoma with neoadjuvant chemotherapy followed by radical surgery combined with vaginal reconstruction using bilateral pudendal thigh fasciocutaneous flaps. The patient was free of disease with a satisfactory sexual life after 30 months.

Discrepancies between clinical staging and pathological findings of operable cervical carcinoma with stage IB-IIB: a retrospective analysis of 818 patients.

INTRODUCTION AND OBJECTIVES: Cervical cancer is the only gynaecological cancer that is staged clinically. The clinical stage of cervical cancer relies largely on the pelvic examination. The aim of this study is to analyse the discrepancy between clinical stage and pathological results, and to explore the accuracy of pelvic examination. METHODS: We collected retrospective data from 818 patients with cervical carcinoma staged IB-IIB, who were treated with primary surgery from January 1999 to June 2007. Clinical stages of those patients were determined by pelvic examination without anaesthesia. After surgery, all the patients were assigned to pT category according to the pathological findings. Comparisons were made between these two stages. RESULTS: The total concordance between clinical stage and pT category for stage IB-IIB was 53.1%, with an overestimation of 37.3% and an underestimation of 9.7%. The concordance in stage IB1, stage IB2, stage IIA and stage IIB were 85.4%, 77.4%, 35.3% and 20.5%, respectively. The most significant discrepancy was caused by the failure to detect the parametrial invasion accurately in stage IIB. The accuracy of pelvic examination to determine vaginal and parametrial disease was 70.2% and 74.0%, respectively. CONCLUSIONS: There are significant discrepancies between clinical stage and pathological results. Pelvic examination has its limitations in staging determination. Thus for operable cervical cancer, clinical stage alone is not reliable for selecting postoperative therapies and surgical staging system may be considered.

[Clinicopathologic features of 234 cases with borderline ovarian tumors].

OBJECTIVE: To determine the clinicopathologic characteristics and prognostic factors that may be used to predict the poor outcome of patients with borderline ovarian tumors. METHODS: All cases with borderline ovarian tumors treated in the West China Second University Hospital from January 2001 to June 2007 were analyzed retrospectively for clinicopathologic features, treatment parameters and outcome of treatment. Univariate and multivariate analyses were used to assess independent prognostic factors using the logistic regression model. RESULTS: The median age of 234 patients was 40.1 years with a range of 14 to 80 years. There were 101 (43.2%), 94 (40.2%), 19 (8.1%), 12 (5.1%), 8 (3.4%) cases of serous, mucinous, mixed, endometrioid and clear cell tumors, respectively. Out of 234 cases, 182 (77.8%) underwent laparotomy and 45 (19.2%) underwent laparoscopy. Seven women underwent laparoconversion. Fertility sparing surgery was performed on 119 cases (50.9%) and radical surgery was performed on 115 cases (49.1%). Totally 161 (68.8%) patients had stage I, 19 (8.1%) had stage II, 54 (23.1%) had stage III, and none had stage IV disease. Sixty-four women received postoperative chemotherapy. The median follow-up was 40 months with a range of 8 to 78 months. Recurrence was found in 26 cases (11.1%) during follow-up, and no tumor-related death was reported. The logistic regression model showed that surgery procedure (OR = 2.304, P = 0.024), cyst rupture (OR = 2.213, P = 0.038), stage (OR = 4.114, P < 0.01), microinvasion (OR = 2.291, P = 0.046) and peritoneal implants (OR = 2.101, P = 0.016) were the five independent prognostic factors affecting recurrence. CONCLUSIONS: Although patients with borderline ovarian tumors have an excellent prognosis, the risk of recurrence remains in some patients. Emphasis should be put on these patients with high risk factors and preventive strategies should be taken to prevent their progression.

Unexpected uterine sarcomas after hysterectomy and myomectomy for presumed leiomyoma: a retrospective study of 26,643 patients.

OBJECTIVES: We conducted this study to explore the clinical characteristics, prognosis, and prevalence of unexpected uterine sarcoma (UUS) after hysterectomy and myomectomy for presumed leiomyoma. STUDY DESIGN: The records of women who underwent hysterectomy or myomectomy through laparoscopy or laparotomy for preoperatively presumed uterine leiomyomas from January 2009 to December 2016 were reviewed and data were retrospectively analyzed. RESULTS: Eleven patients had morcellation of uterine sarcoma. Eighty-eight patients were diagnosed with uterine sarcomas (total prevalence: 0.33%) including 29 leiomyosarcomas (LMS), 48 endometrial stromal sarcomas (ESS), and 11 adenosarcomas. ESS patients with advanced stage were significantly associated with worse overall survival (p<0.01). CONCLUSION: Only 0.33% of patients who underwent surgery for presumed leiomyoma experienced UUS, and advanced stage seemed to be the single prognostic factor for sarcoma. However, the time interval between initial treatment and secondary definitive surgery was not shown to impact prognosis. In addition, the small number of UUS patients having morcellation (4 LMS and 7 ESS) may be underpowered to detect differences in survival.

[Improve the chemosensitivity of resistant ovarian cancer cell by small RNA interference].

OBJECTIVE: To investigate the effects of siRNA on the drug resistance reversal of ovarian cancer cell. METHODS: The siRNA was transfected into human ovarian cancer cell line OVCAR8/TR by liposome. ATP-bioluminence assay was applied to measure the drug sensitivity to four chemotherapeutic agents before and after transfection. RESULTS: ATP-bioluminence assay showed that OVCAR8/TR cells were resistant to cDDP, ADM and Taxol. After siRNA transfection, OVCAR8/TR cells were sensitive to ADM and Taxol which are tansported by P-gp. The inhibition rate of ADM was improved from 37% to 58%, and that of Taxol was improved from 26% to 78%. However, the resistance of OVCAR8/TR cells to cDDP was not reversed. CONCLUSION: siRNA can effectively improve the drug resistance to chemotherapeutic agents which are transfered by P-gp. The RNA interference can reverse MDR1-mediated drug resistance in ovarian cancer cell.

[The growth inhibitory effect of non-steroid anti-inflammatory drugs on ovarian cancer].

OBJECTIVE: To evaluate the effects of two commonly used non-steroidal anti-inflammatory drugs (NSAIDs) Celecoxib and Aspirin on the SKOV3 cell growth, apoptosis and neoplasm genesis of ovarian cancer in vitro and vivo. METHODS: The proliferation of SKOV3 cells were determined by MTT assay, the apoptosis of cell were measured by flow cytometry (FCM), and the cell morphologic changes were observed under inverted phase contrast microscope. Xenografted nude mice models of human ovarian cancer were established, and then randomly allocated to treatment or control group, which was administered with either Celecoxib at the dosage of 10, 25, 50 mg/kg or distilled water alone (control) orally daily for 56 d. The mice weight, tumor volume and drug side effects were detected. RESULTS: A dose-dependent inhibition of proliferation of SKOV3 cell appeared after Celecoxib or Aspirin administered for 24 h, and Celecoxib had more inhibiting efficiency to cell growth than Aspirin did. The inhibitory concentration 50% (IC50) in this assay for Celecoxib was 5X 10(-5) mol/L,whereas for Aspirin was 7X 10(-3) mol/L. With cell morphology the "vacuole" presented in the cytoplasm. In contrast to the control, the apoptotic rates (47. 1% and 15. 7%) of SKOV3 were increased after treatment with Celecoxib (5 X 10(-5) mol/L) and Aspirin(7 X 10(-3) mol/L). In nude mice, the average volume of tumor from control mice was (3. 283+/- 0. 432) cm(3) as compared with (2. 457+/- 0. 224) cm(3), (2. 198+/- 0. 500) cm(3), (2. 017+/-0. 166) cm' from Celecoxib mice (10, 25, 50 mg/kg), P<0. 05, and the rates of tumor growth inhibited by 3 Celecoxib dosages to SKOV3 cell burden mice were 25. 20%, 33. 00% and 38. 60%, in a dose-and time-dependent manner, and histopathologic examinations of kidney, liver, stomach and bowel showed no abnormality, with implying no untoward side effects. CONCLUSION: Both COX-2 specific inhibitor Celecoxib and non-selective inhibitor Aspirin can potentially inhibit the tumor growth and induce apoptosis of SKOV3 cells, and the effect of Celecoxib is more potential than that of Aspirin.

[Research on human ovarian cancer cell MDR1 gene silenced by siRNA].

OBJECTIVE: To evaluate the effects of siRNA on the inhibitions of mRNA and P-gp expression of ovarian cancer cell with high expression of multidrug resistance gene (MDR1). METHODS: The siRNA was transferred into ovarian cancer cell line OVCAR8/TR. The real time RT-PCR and flow cytometry were used respectively to determine the expression of mRNA or P-gp of MDR1. RESULTS: The inhibition of mRNA-84% expression occurred at 48 h after cell transfection, and the inhibition of P-gp-85.23% expression occurred at 72 h after cell transfection. Afterward the inhibitions to mRNA and P-gp expressions gradually returned to the normal levels. The amounts of mRNA and P-gp expression had no difference between negative control and untransfected cells. CONCLUSION: RNA interference presents in the human ovarian cancer cell, siRNA can effectively inhibit the expression of mRNA and P-gp of MDR1. The RNAi may represent a new approach for the treatment of MDR1-mediated drug resistance.

[Reversal of multi-drug resistance in ovarian cancer cell by RNA interference].

OBJECTIVE: To investigate the effects of small interference RNA (siRNA) on the inhibition of MDR1 mRNA and P-gp expression of ovarian cancer cells with high expression of MDR1 gene, and reversal of drug resistance. METHODS: siRNA was synthesized and transfected into human ovarian cancer cell line OVCAR8/TR by liposome. The expression of MDR1 mRNA at different times after transfection was measured by real time RT-PCR and the P-gp expression was detected by flow cytometry. Adenosine triphosphate (ATP)-bioluminence assay was applied to check the drug sensitivity to four different chemotherapeutic agents before and after transfection. RESULTS: The suppression rates of MDR1 mRNA were 26.42%, 84.00%, 78.43%, 45.85% and 0 respectively at 24, 48, 72, 96 and 120 hours after transfection. The P-gp suppression rates were 16.71%, 49.64%, 85.23%, 65.98%, 9.44% respectively at 24, 48, 72, 96 and 120 hours after transfection. The maximal suppression rates of MDR1 mRNA and P-gp occurred at 48 and 72 hours after transfection respectively. ATP-bioluminence assay showed that OVCAR8/TR cells were sensitive to fluorouracil, resistant to cisplatin, doxorubicin (adriamycin) and paclitaxel (taxol). After siRNA treatment, OVCAR8/TR cells were sensitive to paclitaxel and doxorubicin, but the resistance to cisplatin could not be reversed. CONCLUSIONS: RNA interference (RNAi) presents in human ovarian cancer cells. siRNA can effectively inhibit the expression of mRNA and P-gp of the multidrug resistance gene MDR1, and can reverse the drug resistance to chemotherapeutic agents which are transferred by P-gp.

[Effects of nonsteroidal anti-inflammatory drug celecoxib on expression of cyclooxygenase-2 (COX-2) in ovarian carcinoma cell].

OBJECTIVE: To explore the effects of nonsteroidal anti-inflammatory drug Celecoxib on the expression of cyclooxygenase-2 (COX-2) in the SKOV3 cell line and the xenografted nude mice of ovarian carcinoma. METHODS: The expression of COX-2 in the SKOV3 cell was determined by reverse transcription polymerase chain reaction (RT-PCR), flow cytometry (FCM), and Western blot analysis. The expression of COX-2 in tumor cells was measured with Immunocytochemistry. RESULTS: RT-PCR showed that the expression COX-2 mRNA was strongly down-regulated in SKOV3 cells after treatment with Celecoxib or Aspirin. FCM and Western blot analysis showed that the protein product of COX-2 was strongly decreased by Celecoxib or Aspirin. The Celecoxib was more potential effects than Aspirin. The immunocytochemistry result showed that the expression of COX-2 in 10, 25, 50 mg/kg x d of Celecoxib were lower obviously than it in the control group in Xenografted nude mice. CONCLUSION: The anticarcinogenic effects of Celecoxib is probably related to the down-regulation of COX-2, and can be explained to both COX-2-dependent and -independent mechanisms.