Comparison of adjuvant chemotherapy and radiotherapy in patients with cervical adenocarcinoma of the uterus after radical hysterectomy: SGSG/TGCU Intergroup surveillance.

PURPOSE: The authors conducted this retrospective study to evaluate the efficacy of radiotherapy (RT) for high-risk patients with adenocarcinoma (AC) compared with chemotherapy (CT) after radical hysterectomy. MATERIALS AND METHODS: There were 263 patients with AC and 58 with adenosquamous cell carcinoma (ASCC). Of these 321 patients, 151 received adjuvant treatment. Of these 151 patients, 69 received radiotherapy (RT) alone, including concurrent chemoradiotherapy (CCRT) with weekly cisdiamminedichloroplatinum (CDDP), 64 patients received CT alone, and 18 patients received concomitant RT and CT (RT + CT). RESULTS: The five-year overall survival (OS) was 70.9% for patients receiving RT, 79.2% for CT, and 66.2% for RT + CT. Adjuvant treatment did not affect the incidence or the pattern of recurrence. The incidence of lymph node involvement was 9.0% in Stage Ib1, 23.9% in Stage Ib2, 30.8% in Stage IIa, and 41.2% in Stage IIb. CONCLUSIONS: Adjuvant CT may be effective for high-risk patients with cervical adenocarcinoma.

Expression of hypoxia-inducible factor 1alpha gene affects the outcome in patients with ovarian cancer.

We conducted study to determine whether and how the expression of the hypoxia-inducible factor 1alpha (HIF-1alpha) gene relates to outcome in patients with epithelial ovarian cancer. A total of 66 patients with epithelial ovarian cancer, who underwent primary surgery followed by platinum-based chemotherapy, were entered into this study. We confirmed the expression of HIF-1alpha and the vascular endothelial growth factor (VEGF) by immunohistochemistry. To determine the quantity of HIF-1alpha and VEGF expression, messenger RNA of each gene was measured by real-time reverse transcription-polymerase chain reaction. The cutoff values were determined by the receiver-operating characteristic curve according to survival. The protein expressions of HIF-1alpha and VEGF were strongly observed in the cancer cells. The cutoff value of HIF-1alpha and VEGF gene expression was 6.0 and 3.0, respectively. The expression of HIF-1alpha did not relate to clinical stage, but tumor with low VEGF expression was observed more frequently in stage I patients. The response rate to chemotherapy did not differ between high and low expression of both genes. The overall survival for patients with high expression of HIF-1alpha was significantly lower, but disease-free survival did not differ between high and low expression of HIF-1alpha, whereas both overall and disease-free survival for patients with high expression of VEGF were significantly lower. Multivariate analysis revealed that FIGO stage and HIF-1alpha expression were independent prognostic factors but that VEGF was not. The present study suggested that the expression level of HIF-1alpha could be an independent prognostic factor in epithelial ovarian cancer.

Low response rate of second-line chemotherapy for recurrent or refractory clear cell carcinoma of the ovary: a retrospective Japan Clear Cell Carcinoma Study.

Clear cell carcinoma (CCC) of the ovary has been recognized to show resistance to anticancer agents in the first-line chemotherapy. Our aim was to evaluate the effect of second-line chemotherapy in a retrospective study. A total of 75 patients diagnosed with CCC and treated between 1992 and 2002 in collaborating hospitals were reviewed. Criteria for the patients' enrollment were 1) diagnosis of pure-type CCC at the initial operation, 2) treatment after one systemic postoperative chemotherapy, 3) measurable recurrent or refractory tumor, 4) at least two cycles of second-line chemotherapy and assessable for the response, and 5) adequate clinical information. Regimens of first-line chemotherapy were conventional platinum-based therapy in 33 cases, paclitaxel plus platinum in 24 cases, irinotecan plus platinum in 9 cases, and irinotecan plus mitomycin C in 7 cases. Treatment-free periods were more than 6 months in 24 cases (group A) and less than 6 months in 51 cases (group B). In group A, response was observed in two cases (8%): one with conventional platinum therapy and another with irinotecan plus platinum. In group B, three cases (6%) responded: two with platinum plus etoposide and one case with irinotecan plus platinum. Median overall survival was 16 months in group A and 7 months in group B (P = 0.04). These findings suggest recurrent or resistant CCC is extremely chemoresistant, and there is only small benefit of long treatment-free period in CCC patients. Another strategy including molecular-targeting therapy is warranted for the treatment of recurrent or refractory CCC.

Galectin-3 may contribute to Cisplatin resistance in clear cell carcinoma of the ovary.

Our previous findings suggested that lower cell proliferation of clear cell carcinoma (CCC) of the ovary may contribute to its resistance to chemotherapy. We conducted the present study to find the gene that regulates cell proliferation of CCC and to elucidate whether it contributes to cisplatin (CDDP) resistance. Complementary DNA microarray analysis revealed that the gene expression level of galectin-3 of CCC cell lines (KK, RMG-I, HAC-2) was over threefold higher than that of ovarian serous adenocarcinoma (SAC) cell lines (HRA, KF). S-phase fraction increased after knocking down galectin-3 using small interfering RNA in RMG-I, KK, and HAC-2 cells. The protein expression of p27 decreased after knocking down galectin-3. CDDP-induced apoptosis was increased after knocking down galectin-3, and this cytotoxic effect was canceled by roscovitine. Immunohistochemical staining showed that galectin-3 expression in tumors of 20 CCC was significantly more frequent than that of 20 SAC (70.0% vs 15.0%, P = 0.0004). The present study showed that the expression of galectin-3 in CCC might contribute to its lower cell proliferation and lead to CDDP resistance.

Genetic diagnosis for chemosensitivity with drug-resistance genes in epithelial ovarian cancer.

We conducted the present study to investigate whether and how chemosensitivity can be determined by means of genetic diagnosis using drug-resistance genes in patients with epithelial ovarian cancer. A total of 75 patients who had epithelial ovarian cancer with measurable lesions were entered into this study. Thirty-three patients received first-line chemotherapy, consisting of paclitaxel and carboplatin (TJ). Forty-two patients received second-line chemotherapy, 22 received EP therapy consisting of etoposide and cisplatin (CDDP), and 20 received irinotecan (CPT-11) and CDDP (CPT-11/CDDP) therapy. Tumor samples were obtained before chemotherapy. MessengerRNA expressions of the multidrug-resistance (MDR)-1 gene, MDR-associated protein-1 (MRP-1), topoisomerase (topo) I, and topo IIalpha were measured by real-time reverse transcription-polymerase chain reaction. The cutoff values of each gene were determined by the receiver operating characteristic curve. MDR-1 expression was significantly higher in patients who did not respond to TJ therapy. The expression of topo IIalpha was significantly higher in patients who did respond to EP therapy. The expression of topo I was significantly higher in patients who did respond to CPT-11/CDDP. MRP-1 expression did not differ between responders and nonresponders in all regimens. The cutoff value was 80 for MDR-1, 90 for topo IIalpha, and 200 for topo I. Next, to evaluate genetic diagnosis, 31 patients were newly added. The accuracy of this genetic diagnosis for chemosensitivity was 85.7% for TJ, 77.8% for EP, and 100.0% for CPT-11/CDDP therapy. The present study suggests that genetic diagnosis may be useful to determine chemosensitivity in patients with epithelial ovarian cancer.

Phase I trial of paclitaxel, doxorubicin, and carboplatin (TAC) for the treatment of endometrial cancer.

Doxorubicin, platinum compounds, and taxanes represent the chemotherapeutic agents with the greatest activity in endometrial cancer. We conducted an optimal-dose determination of combination chemotherapy consisting of paclitaxel (TXL), doxorubicin, and carboplatin (CBDCA) (TAC) in patients with endometrial cancer. Patients with epithelial endometrial cancer requiring adjuvant therapy were enrolled between June 2003 and March 2005. No patients had received prior radiotherapy, and only two patients had previously undergone chemotherapy. Doxorubicin was infused on day 1, and TXL followed by CBDCA was administered on day 2. The starting dose was doxorubicin 35 mg/m(2), TXL 120 mg/m(2), and CBDCA area under the curve (AUC). The dose of each agent was gradually escalated. Patients were scheduled to receive at least four cycles of therapy. If patients experienced grade 4 neutropenia or neutropenic fever with grade 3 neutropenia, they were permitted to be administered granulocyte colony-stimulating factor after the second course. Twenty-seven patients were enrolled. Although four patients out of 27 experienced dose-limiting toxicities, a maximum tolerated dose was not established at the final dose level. Five patients (three for recurrent and two for advanced) had measurable lesions. There were four responders (three for partial response and one for complete response) in our series. The recommended dose of TAC therapy for endometrial cancer was doxorubicin 45 mg/m(2) for day 1, TXL 150 mg/m(2) and CBDCA AUC 5 for day 2.

Clear cell carcinoma of the ovary: a retrospective multicentre experience of 254 patients with complete surgical staging.

A retrospective analysis was performed to evaluate the clinical characteristics and prognostic factors in the patients with clear cell carcinoma (CCC) of the ovary. After central pathological review and scanning of the medical records of nine Japanese institutions between 1992 and 2003, a total of 254 patients with CCC of the ovary were enrolled in the present study. Mean age was 52.4 years (range 23-73 years). Tumours were 13% (33/254) stage Ia, 36% (92/254) stage Ic, 13% (33/254) stage II, 30% (80/254) stage III, and 6% (16/254) stage IV. Five-year progression-free survival and overall survival was 84 and 88% in stage I, 57 and 70% in stage II, 25 and 33% in stage III and 0 and 0% in stage IV, respectively. Retroperitoneal lymph node metastasis was observed in 9% in pT1a tumours, 7% in pT1c tumours, 13% in pT2 tumours, and 58% in pT3 tumours, respectively. There was no survival benefit according to chemotherapeutic differences in the patients who received complete surgical staging procedures and conventional chemotherapy. Peritoneal cytological status was an independent prognostic factor in stage Ic patients (P=0.03) and only residual tumour diameter was an independent prognostic factor in stage III, IV patients (P=0.02). Our results suggest that cytoreductive surgery resulting in no residual tumour only could improve the prognosis of advanced CCC patients.

Outcome of patients with early ovarian cancer undergoing three courses of adjuvant chemotherapy following complete surgical staging.

We conducted the present study to determine the outcome of patients with early ovarian cancer who underwent three courses of adjuvant chemotherapy after complete surgical staging. One hundred consecutive patients with stage I-II epithelial ovarian cancer who had undergone complete surgical staging and received three courses of platinum-based chemotherapy were entered in this study. Twenty-one patients were low risk, defined as stage IA-B, grade 1 and histologic types except for clear cell adenocarcinoma, and remaining 79 were high risk. All patients with stage IA or IB, whatever histologic type and histopathologic grade, were alive without disease. The 5-year survival rate was 89.4% for patients with stage IC and 76.2% for those with stage II. The 5-year survival rate for low- and high-risk patients was 100% and 89.4%, respectively. The survival rate for grade 1 was significantly better than that for grade 2 or 3. Multivariate analysis revealed that histologic grade was an independent prognostic factor in stage IC-II ovarian cancer. The outcome of patients with early ovarian cancer undergoing three courses of chemotherapy after complete surgical staging was favorable even in high-risk patients.

Effect of simple omentoplasty and omentopexy in the prevention of complications after pelvic lymphadenectomy.

This multicenter collaborative study prospectively evaluated the effect of omentoplasty and omentopexy on the prevention of complications after pelvic lymphadenectomy. Sixty-four consecutive patients (42 cervical and 22 endometrial cancer) were enrolled and examined periodically for 12 months. All patients underwent simple, semiradical, or Okabayashi's radical hysterectomy and complete pelvic lymphadenectomy. The infracolic omentum was longitudinally divided in half and omentoplasty was performed so that bilateral omental flaps would reach the pelvic floor. The omental flaps were inserted into the retroperitoneal space and the edges of the flaps were sutured to the psoas muscle. The omental flap was then covered by the peritoneum. Incidence of lymphocele, lymphedema, and severe complications associated with lymphocele, such as infection or urinary stenosis, was evaluated at intervals for at least one year after surgery. Among the 64 patients, 12 patients received pelvic radiation because of occult lymph node metastasis. Planned omentoplasty was not possible in one patient because her omentum was too small; therefore, only unilateral omentopexy was performed. Asymptomatic lymphoceles only were detected by ultrasonogram in 12 patients (18.8%). Three patients (4.7%) had a symptomatic but pressure-only lymphocele. Hydronephrosis and bladder compression probably due to lymphocele were observed in one patient, respectively (3.1%), but resolved within 6 months. Lymphedema was observed in seven patients (10.9%) and persisted for more than 6 months in two patients (3.1%). We conclude that this simple technique of omentoplasty and omentopexy appeared to be effective in reducing the incidence of complications after pelvic lymphadenectomy.

Chemosensitivity and p53-Bax pathway-mediated apoptosis in patients with uterine cervical cancer.

OBJECTIVES: To determine whether and how apoptosis through the p53-Bax pathway affects sensitivity to chemotherapy in cervical cancer. MATERIALS AND METHODS: Thirty patients with cervical squamous cell carcinoma, who had human papilloma virus (HPV) and underwent neoadjuvant chemotherapy, were entered in the present study. Tumor specimens were obtained before and after chemotherapy. HPV was detected by polymerase chain reaction. The expression of Ki-67, p53, Bax and Bcl-2 proteins was determined by immunohistochemical staining. Apoptotic cells were identified by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick-end labeling method. RESULTS: Of 30 patients, 18 responded to chemotherapy and 12 did not. The apoptotic index in tumors of responders was significantly higher than in non-responders after chemotherapy. The Ki-67 labeling index (LI) in responders was significantly higher than in non-responders before chemotherapy. Patients with tumors >33% of the LI, which was determined by a receiver operating characteristic curve, had a better survival rate. The incidence of p53 protein expression did not differ between responders and non-responders. After chemotherapy, the expression of Bax protein in responders was more frequent and Bcl-2 protein expression was less frequent than in non-responders. CONCLUSIONS: Chemosensitivity in cervical cancer may be associated with apoptosis via the p53-Bax pathway.

Telomerase activity and p53-dependent apoptosis in ovarian cancer cells.

We conducted the present study to determine the relationship between p53-dependent apoptosis and telomerase activity in ovarian cancer cells. A human ovarian adenocarcinoma cell line, SK-OV-3 that had homozygous deletion of the p53 gene was used in this study. Wild-type p53 genes were transducted to SK-OV-3 cells with a recombinant adenovirus that contained a wild-type p53 gene (AxCAp53). IC(50)to cisplatin (CDDP) was 12.9 microM for SK-OV-3 cells and 9.2 microM for p53 gene-transducted SK-OV-3 cells. The apoptotic index for cells with p53 gene transduction was significantly higher than cells without transduction. Additionally, p53 gene transduction significantly enhanced CDDP-induced apoptosis. Bax protein in SK-OV-3 cells did not differ before and after exposure to CDDP. In SK-OV-3 cells with transduction of the p53 gene, the expression of p53 and Bax proteins increased after exposure to CDDP. Expression of Bcl-xL decreased after exposure to CDDP in SK-OV-3 cells with and without transduction. The telomerase activity in SK-OV-3 cells with the p53 gene was significantly lower compared with the cells without the p53 gene. CDDP exposure did not affect telomerase activity and human telomerase reverse transcriptase (hTERT) expression in both cell lines. We suggest that the p53 gene may relate to telomerase activity, but that p53-dependent apoptosis does not affect the activity.

Expression of P-glycoprotein in human placenta: relation to genetic polymorphism of the multidrug resistance (MDR)-1 gene.

To evaluate whether mutations in the human multidrug resistance (MDR)-1 gene correlate with placental P-glycoprotein (PGP) expression, we sequenced the MDR-1 cDNA and measured PGP expression by Western blotting in 100 placentas obtained from Japanese women. Nine single nucleotide polymorphisms (SNPs) were observed with an allelic frequency of 0.005 to 0.420. Of these SNPs, G2677A (allelic frequency = 0.18) and G2677T (0.39) in exon 21 were associated with an amino acid conversion from Ala to Thr and to Ser, respectively. Sixty-one of 65 samples (93.8%), which had a C3435T allele, also had a mutant G2677(A,T) allele, suggesting an association between the two SNPs. Correlations of mutations with expression levels were observed; individuals having the G2677(A,T) and/or T-129C (p < 0.05) allele had less placental PGP. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based genotyping tests were developed for the detection of these SNPs. The PCR, in which genomic DNAs obtained from healthy subjects (n = 48) are used as samples, was successful. The frequency of mutations in placental cDNA was identical with that in genomic DNA. When genotype results were compared between Caucasians and Japanese, ethnic differences in the frequency of polymorphism in the MDR-1 gene were suspected. Although it remains to be determined whether these SNPs influence the pharmacokinetic and dynamic properties of clinically useful drugs that are substrates of PGP, the polymorphism of the MDR-1 gene presented here may provide useful information in in vivo study of these issues.

Correlation between loss of PTEN expression and Akt phosphorylation in endometrial carcinoma.

The tumor suppressor PTEN acts as a lipid phosphatase, regulates the phosphatidylinositol 3-kinase (PI3K)/Akt-signaling pathway, and modulates cell cycle progression and cell survival. Somatic mutations of PTEN have been reported in a variety of cancers, especially in endometrial carcinoma. To clarify whether and how PTEN and the PI3K/Akt pathway relates to endometrial carcinoma, we examined the expression of those pathway-related proteins in patients with endometrial carcinoma. Of 103 endometrial carcinomas, 37 (36%) showed negative immunohistochemical staining of PTEN. Western blotting revealed that the expression of PTEN in PTEN-negative cases was significantly lower compared with that in positive cases. In contrast, phospho-Akt level in negative cases was significantly higher. We found a significant inverse correlation between PTEN and phospho-Akt (r = -0.796). The expression of phospho-Bad was greater in negative cases, suggesting that Bad might be a target for AKT: The present study demonstrates the phosphorylation of Akt accompanied by the loss of PTEN in clinical specimens of endometrial carcinomas.

p53 gene status and chemosensitivity in ovarian cancer.

Recent studies suggest that drug induced apoptosis relates to the sensitivity. p53 gene, which has a pivotal role in inducing apoptosis, frequently mutates in ovarian cancer. Therefore, p53 gene status and chemosensitivity in epithelial ovarian cancer is discussed. Nonresponders to chemotherapy had mutations of the p53 gene more frequently (83% for nonresponders vs. 16% for responders) in patients with epithelial ovarian cancer undergoing platinum-base chemotherapy. Apoptotic index was significantly greater in tumors with wild-type p53 gene than those without the gene. p53 gene transduction markedly enhanced the sensitivity to cisplatin (CDDP) and CDDP-induced apoptosis, but did not affect the sensitivity to paclitaxel (PTX) nor PTX-induced apoptosis in ovarian cancer cells without p53 gene. The combination treatment with a recombinant adenovirus carrying a wild-type p53 gene (AxCAp53) and CDDP significantly suppressed tumor growth of ovarian cancer cells with and without p53 gene, compared with a single treatment of either AxCAp53 or CDDP in ovarian cancer xenograft. Apoptotic index was significantly higher and proliferating cell nuclear antigen labeling index was relatively lower in an ovarian cancer xenograft without p53 gene receiving combination treatment, compared with a single treatment of either CDDP or AxCAp53, suggesting that the transduction of p53 gene induces apoptosis, but does not enhance the DNA repair system. A significant survival advantage was observed in the combination treatment compared with other treatments in carcinoma peritonitis models. In conclusion, p53 gene status contributes the sensitivity to CDDP in ovarian cancer. Additionally, combination treatment of p53 gene transduction and CDDP may be an effective therapeutic modality for ovarian cancer without wild-type p53 gene.

The role of topoisomerase I inhibitor in cisplatin-resistant ovarian cancer.

We discussed the role of DNA topoisomerase I (topo I) inhibitor, which is now widely used in clinical practice, in cisplatin-resistant ovarian cancer. Our study showed the synergistic actions between cisplatin and 7-ethyl-10-hydroxycamptothecin (SN-38), an active metabolite of 7-ethyl-10-[4-(1-pyperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11), in two cisplatin-resistant cancer cell lines, HeLa/CDDP and KFr cells, but not in each parent cell line, HeLa and KF cells. Furthermore, HeLa/CDDP cells had a collateral sensitivity to SN-38. The levels of topo I protein in the cisplatin-resistant cells did not differ from those of their parent cell lines and were unaffected by exposure to cisplatin. In contrast, topo I enzymatic activity was 2-4 fold higher in the cisplatin-resistant cell lines compared with their respective parent cell lines. A significant correlation between the sensitivity for SN-38 and topo I activity human clear cell carcinoma cell lines, which are known as intrinsically ciasplatin-resistant cancer, was observed. Next, we examined the relationship between topo I activity and sensitivity to second-line chemotherapy consisting of cisplatin and CPT-11. A total of 30 patients with ovarian cancer who had initially undergone chemotherapy consisting of cisplatin, doxorubicin, and cyclophosphamide (CAP) and exhibited measurable lesions were entered in the study. Tumor samples were obtained in the period between the initial and the second-line chemotherapy. Of those 30 patients, 18 responded to second-line chemotherapy and 12 did not. Topo I activity in tumor samples of responder was significantly greater than that of in nonresponders. In 8 cases whose samples could be obtained before and after CAP, topo I activity significantly increased after CAP therapy. Consequently, the combination therapy with cisplatin and CPT-11 may be effective for patients with cisplatin-resistant ovarian cancer. In addition, topo I enzymatic activity may be a predictor of the sensitivity for topo I inhibitor.

Cellular efflux pump and interaction between cisplatin and paclitaxel in ovarian cancer cells.

OBJECTIVE: The aim of this study was to evaluate the combination effect of paclitaxel (PTX) and cisplatin (CDDP) and to determine the mechanisms of interaction between these agents. METHODS AND RESULTS: We used human ovarian adenocarcinoma cell lines, namely a parent cell line (KF), a CDDP-resistant cell line (KFr) and a PTX-resistant cell line (KFTx).The combination effect of PTX and CDDP was synergistic on KF and KFTx and additive on KFr. The incidence of anaphase or telophase, evaluated by immunofluorescence microscopy, decreased with PTX and significantly decreased with PTX and CDDP in KF and KFTx. The concentration of PTX, which was measured by high-performance liquid chromatography, was higher in KF and KFTx cells treated with a combination of PTX and CDDP than those treated with PTX alone. Multidrug resistance gene mRNA appeared in KFTx and its expression decreased after exposure to PTX and CDDP. After exposure to CDDP, the expression of multidrug resistance-associated protein (MRP) and the concentration of glutathione increased in KF, but not in KFr or KFTx. MRP expression slightly increased in KF and KFTx after exposure to PTX. In contrast, its expression decreased in KFr. CONCLUSION: The present study suggests that CDDP enhances PTX accumulation and that the interaction of these agents is synergistic in CDDP-sensitive cells.

Prognosis and clinicopathological characteristics of Ib-IIb adenocarcinoma of the uterine cervix in patients who have had radical hysterectomy.

AIMS: The aim of the present study was to evaluate the outcome of patients with stage lb-IIb cervical adenocarcinoma treated with radical hysterectomy, and to determine the clinicopathological characteristics of those patients. METHODS: A total of 255 patients with cervical carcinoma stage Ib-IIb (57 adenocarcinoma and 198 squamous cell carcinoma) who had undergone radical hysterectomy were included in this study. Patient survival distribution was calculated using the Kaplan-Meier method. RESULTS: The estimated 5-year survival rate for patients with adenocarcinoma was significantly poorer than that for patients with squamous cell carcinoma (77.9% vs 91.7%). The survival rate in stage Ib patients did not differ between two groups (95.8% vs 94.4% respectively). The incidence of lymph node involvement was significantly higher in patients with adenocarcinoma than in those with squamous cell carcinoma (31.6% vs 14.8%). Among patients receiving post-operative radiotherapy, the survival rate for adenocarcinoma (71.1%) was significantly poorer than that for squamous cell carcinoma (90.0%). When patients underwent radical hysterectomy, the survival rate for stage II patients with adenocarcinoma was significantly poorer than that for patients with squamous cell carcinoma. CONCLUSIONS: The higher incidence of lymph node involvement and lower response to post-operative radiotherapy are considered to be factors of poorer prognosis in cervical adenocarcinoma.

Sensitivity to paclitaxel is not related to p53-dependent apoptosis in ovarian cancer cells.

We conducted this study to determine whether the sensitivity of ovarian cancer cells to paclitaxel (PTX) relates to cells undergoing p53-dependent apoptosis. Human ovarian adenocarcinoma cell lines (SK-OV-3, KF and KP cells) were used in this study. In SK-OV-3 and KP cells, which have a homozygous deletion of the TP53 gene, wild-type TP53 gene-transduction markedly enhanced the sensitivity to cisplatin (CDDP), but did not enhance the sensitivity to PTX. In all cells, the apoptotic index was increased by CDDP or PTX. After exposure to CDDP, p53 and Bax protein expression increased and Bcl-xL expression decreased in the KF cells and TP53 gene-transducted SK-OV-3 cells. However, these proteins did not change in KP cells. Therefore, the role of p53 in CDDP-induced apoptosis depends upon the cell type. In contrast, TP53 gene status did not correlate with PTX-induced cytotoxicity in any of the cell lines with differing apoptotic pathways. In conclusion, the sensitivity to PTX may not be related to p53-dependent apoptosis in ovarian cancer cells.

Mechanism of the combination effect of wild-type TP53 gene transfection and cisplatin treatment for ovarian cancer xenografts.

To clarify the effect of a combination treatment consisting of a recombinant adenovirus carrying a wild-type TP53 gene (AxCATP53) and cisplatin (CDDP), we examined p53-dependent apoptosis in ovarian cancer xenografts with and without the wild-type TP53 gene. Severe combined immunodeficiency (SCID) mice were implanted with ovarian cancer cell lines consisting of SK-OV-3 cells without the TP53 gene and KF cells with the TP53 gene. In SK-OV-3 and KF tumours, the inhibitory effect of the combination treatment on tumour growth was significant, compared with a single treatment with CDDP alone or AxCATP53 alone. The apoptotic index increased significantly after combination treatment in the SK-OV-3 tumours. The expression of Bax protein in SK-OV-3 tumours was weak, but strengthened after TP53 gene transfection. In contrast, AxCATP53 transfection did not affect CDDP-induced apoptosis in the KF tumours. Therefore, combination treatment of AxCATP53 and CDDP may be a new strategy for treating ovarian cancer with or without the TP53 gene.

Immature brain injury via peroxynitrite production induced by inducible nitric oxide synthase after hypoxia-ischemia in rats.

OBJECTIVE: To determine whether, and if so how, iNOS expresses and affects brain injury induced by hypoxia-ischemia in an immature brain. MATERIAL AND METHODS: Seven-day-old Wistar rat pups were exposed to right common carotid artery ligation followed by 1.5 hours of hypoxia. The time course of iNOS mRNA expression, enzymatic activity, and protein production in the cerebral cortex were determined. The extent of the infarct area in the cerebral cortex and the production of 3-nitrotyrosine (a biomarker of peroxynitrite) were compared between the control pups and pups treated with S-methyl-isothiourea (a selective iNOS inhibitor). RESULTS: In the cortex ipsilateral to carotid ligation, iNOS mRNA appeared from 6 hours to 24 hours after hypoxia-ischemia and disappeared at 48 hours. The iNOS protein and its activity also increased at 12 hours and reached a maximum level at 48 hours after the insult. The percentage of damage in the cerebral cortex was significantly higher in the control pups than in treated pups (31.9 vs 10.6%). Tri-nitrotyrosine following iNOS expression-positive cells were located predominantly at the infarct and peri-infarct regions. CONCLUSIONS: iNOS expression might be an important determinant of ischemic immature brain injury.